gratifying to find that the book has been deemed worthy of trans- lation and that ...
THE first edition of this book was issued in 1907 as "a Report to the. Electors of ...
Published by the University of Manchester at THE UNIVERSITY PRESS (H. M. MCKECHNIE, Secretary) 12 LniE GROVE, OXFORD ROAD, MANCHESTER
LONGMANS, GREEN & CO. LONDON : 39 Paternoster Row
NEW YORK : 443-449 Fourth Avenue and Thirtieth Street BOMBAY : 8 Hornby Road CALCUTTA : 303 Bowbazar Street MADRAS : 167 Mount Road
T
H
E
D
Y
E
I
N
G
I
N
BEING A T H I R D EDITION
D
U
S
T
uF
" D Y E I N G I N G E R M A N Y AND A M E R I C A "
S. H . HIC4GIXS, M.Se. IATE GARTSIDE SCHOLAIi ..F THE UMVCr.s:iV ANT 1M.11-. Nr. T.: _\7 MAS .CHESTER COLLnoi: OF TECH>i'MCnv; DVIT.S ^C .MIWNV .:. . _Z. RESEARCH, 1913; TlXIiN U\\'.. ClirXlJT v^:- VV.-.RK:M.^
MANCHESTER : AT THE UNIVERSITY PRESS 12 Lime Grove, Oxford Road L O N G M A N S , G R E E N Es? CO. London, New "York, Bombay, etc.
R
Y
PUBLICATIONS OF THE UNIVERSITY OF MANCHESTER No. CVIII
First Edition 1907 Second Edition. October 1916 Third Edition September 1919 AU Right* Reserved.
PREFACE I HAVE seized the opportunity presented by the need for a new edition of this book to add a new chapter on recent progress -?i the Industry, founded on my articles in Annual Ik^ori? ch ^j-';>a Chemistry issued by the Society of Chemical Industry, 1917-191S. These reports have also been utilised to provide some of ihe information given in the new chapter on Colour Production. Since tiicboolc now deals as substantially with the Industry in Great Britain as it does with the Industry in other countries, it seems logical to change the title which it bore in previous editions, "Dyeing in Germany and America," into the one which is now used. It U gratifying to find that the book has been deemed worthy of translation and that an edition in French will soon make its appearance. S. H. H. MANCHESTER,
Septernbtr 1919.
PREFACE
TO T H E
SECOND E D I T I O N
"DYEING
IN GERMANY AND
OF
AMERICA"
THE first edition of this book was issued in 1907 as "a Report to the Electors of the Gartside Scholarship of the University of Manchester on the Results of a Tour in the United States of America and G-ermany in 1905-1906," and was intended to give a general survey of the dyeing and allied industries of these countries. The very favourable reception awarded to the book has exhausted the supply of copies and necessitated the issue of this new edition. Although no further visit has been paid to either of the countries, I have been able to add considerably to what appeared in the first edition, chiefly as the result of experience gained during the past nine years, firstly as a demonstrator in the Dyehouse of the Manchester College of Technology, and secondly, as a works chemist and manager. Naturally, this experience is most in evidence in those parts of the book dealing with the branches of the industry with which I am the most familiar. I have also taken the liberty of including certain material -which I have published in various journals since the issue of the first edition. It is hoped that this edition will be useful to the student requiring a general knowledge of the industry, to the publicist seeking a comparison between the industrial conditions in this and other countries, to the general reader, and also to the practical dyer, who may find in these pages some things of value and interest to him. In the preparation of this edition I have received much assistance from the many helpful suggestions made by reviewers when the book was first published. I am also indebted to these gentlemen for the rectification of several errors which appeared therein. I wish to place on record my appreciation of the care taken in the publication of the present edition by H. M. McKechnie, Esq., Secretary of the Manchester University Press; also to repeat my thanks to Arthur Jones, Esq., M.A., for the help he gave me with the first edition. S. H. HIGGINS. LUNOAKTY, PERTH, N.B.,
July 1916.
CONTENTS PREFACE .
.
.
.
.
.
PREFACE TO THE SECOND EDITION
.
.
.
.
V
.
.
vi
CHAPTER I GENERAL .
.
.
.
.
.
.
.
I
The art of dyeing—Influence of chemistry—Opposition to progress— Hank-dyeing and washing—Cloth-dyeing. C H A P T E E II COP-DYEING
.
.
.
.
.
.
.
6
Its object—Selection of colours—The difficulties involved—Machines of two classes—Comparison of these machines—Three important machines— Perfection not attained. C H A P T E E III SULPHUR COLOURS AND INDIGO
.
.
.
.
. 1 2
Fastness of sulphur colours—Importance as cotton dyes—Their tendering action on cotton—Use for wool dyeing—Machines used for dyeing sulphur colours—Natural and synthetic indigo—Substitutes for indigo— Sulphur blues and indigo. C H A P T E E IV MERCERISING
.
.
.
.
.
.
.
20
Invention of the process—Hank-mercerising machines—Piece mercerising—Cooling of the lye—Recovery of the caustic soda—Recent scientific work on mercerising. CHAPTER V BLEACHING
.
.
.
.
.
.
. 3 1
Development of the industry—Effect of chemistry—Efficient scouring— Continuous scouring — Open-width scouring — Electrolytic bleaching— Steeping of goods—The waxes of vegetablefibres—Bleachingwithout boiling. C H A P T E E VI GERMAN AND ENGLISH FLANNELETTES
.
.
.
. 4 3
Use of raising—Cotton blankets—German production—Large-scale production—German and English methods compared—External and internal specialisation—Inflammability of flannelettes. CHAPTEE VII THE INDUSTRY IN THE UNITED STATES
.
.
.
American conditions—Scarcity of labour—Large-scale production— Uncertainty of their industry—Lack of specialisation—Effect of the tariff.
. 4 9
viii
THE DYEING INDUSTRY CHAPTEK VIII PAGE
LOWELL, LAWRENCE, AND FALL RIVER, MASS.
.
.
. 5 3
CONDITIONS OF LIFE IN THE INDUSTRY
.
.
. 6 5
Lowell—The town and its industry—Merrimack Manufacturing Company—Hours and conditions—Turning to finer work—Production of machines—Employer and employed—Hamilton Manufacturing Company— Arrangement of works—American worker—Lawrence and its industry— Peniberton Works — Pacific and Arlington Mills—Fall River—Water supply—Fall River Bleachery—The drying of cloth—Baruaby Works— Bridgeport, Conn. — Salts Manufacturing Company — Klatider - Weldon dyeing machines. CHAPTEE IX .
Injurious conditions in dyeing—England, Germany and America compared—The power of the workmen in Germany—The development in America—Wages in the three countries—America's high wages—Short hours—The German workman and the American. CHAPTEE X EFFICIENCY IN THE INDUSTRY
.
.
.
.
. 7 1
Dyeing in Germany—Application of science to the art—The position in America—English workmen in America—Empiricism and science— Arrangement of the works—Using up of wastes—Aids to manufacture— Specialisation in the industry—Dye-works and machine shops—High specialisation in England—British pessimism. CHAPTER XI INSTRUCTION IN DYEING
.
.
.
.
.
.
80
The dyeing industry subject to change—British pessimism regarding education—Appointments for technical students—German technical schools —Education of the German workman — American schools—Suggested reforms. CHAPTEK XII PROGRESS IN THE INDUSTRY DURING THE WAR PERIOD .
.
94
Research work—Bleaching—Dyeing—Re-dyeing—Mercerising—Printing—Finishing. COLOUR PRODUCTION
CHAPTER
XIII
.
..
.
.
.
.127
The German works—Past, present and future—Combination and its possible effects—Our position — Possible remedies—Protection—Patent legislation—Organisation of the industry in Germany. CHAPTER XIV COLOUR PRODUCTION (continued) .
.
.
.
.
.
.148
CHAPTER XV COLOUR PRODUCTION (continued) .
INDEX
.
.
.
.
16$> 188
CHAPTER
I
GENERAL The art of dyeing—Influence of chemistry—Opposition to progress—Hankdyeing and washing—Cloth-dyeing. T H E art of dyeing is v e r y old, as t h e following q u o t a t i o n from Pliny shows : " Garments are p a i n t e d in E g y p t in a wonderful manner, t h e white cloths being first smeared, not with colours, b u t w i t h drugs which absorb colours. These applications do n o t appear on t h e cloths, b u t when the cloths are immersed in a cauldron of h o t dyeing liquor they are t a k e n o u t p a i n t e d t h e m o m e n t afterwards. I t is wonderful t h a t , although t h e dyeing liquor is only of one colour, t h e g a r m e n t is dyed b y i t of several colours, according to t h e different properties of t h e drugs which have been applied to t h e different p a r t s : nor can this dye be washed out. Thus t h e v a t , which would doubtless have confused all t h e colours if t h e cloth h a d been immersed in a p a i n t e d state, produces a diversity of colours out of one, and at t h e same time fixes t h e m i m m o v a b l y . " Thus we have evidence t h a t a t an early period t h e practice of what is now k n o w n as polygenetic colour-dyeing was carried out. Since such knowledge of dyeing existed in these early times it is surprising t h a t i t is only during t h e last few centuries t h a t m a r k e d progress has been m a d e . The discovery of America influenced t h e a r t of dyeing so materially t h a t its real development dates from t h a t event. Mexico furnished cochineal, and, later, t h e b e a u t i ful tropical indigo displaced t o a large e x t e n t t h e ancient woad of England. W e find t h a t t h e law restricted t h e dyeing industry i n all countries : sometimes t h e m e t h o d s of dyeing were strictly defined a n d no others were permitted ; at other times t h e districts i n which dyeing was
2
THE DYEING INDUSTRY
a]io-*\?d were s t a t e d ; a n d in some periods a d u t y w a s ^ a e e d on all dyed cloth. Fox instance, a t one t i m e logwood was n o t allowed t o be used for dyeing blues, a s t h e eo!o-ir> thus produced weie said t o b e fugitive. A n A c t of Parliament of 1552 limited t h e n u m b e r of coloirrs w h i c h illicit be used ; William I I I . a d d e d t o t h e l i s t ; a n d l a t e i legislation allowed t h e free use of d y e - s t u S s . T h e s e obstacles hindered, t o some e x t e n t , t h e progress of t h e dyeing industry, b u t it is only in quite r e c e n t t i m e s t h a t wcz&i advances have been made. The introduction of chemistry i n t o t h e i n d u s t r y h a s indefinitely enlarged its resources b y showing h o w t o produce varieties of colours extending t h r o u g h t h e whole ranee of t h e prismatic spectrum, a n d h a s e n a b l e d t h e d y e r TO lix and render durable m a n y of t h o s e b e a u t i f u l vegetable dyes t h e ephemeral n a t u r e of whose b r i g h t n e s s formerly d e t r a c t e d from their u t i l i t y . Along w i t h t h e s e improvements t h e nature of t h e s u b s t a n c e t o be d y e d has received careful scientific c o n s i d e r a t i o n ; t h e processes have been adapted t o suit t i e fibres b e i n g d y e d , a n d niordants have been introduced b y m e a n s of w h i c t p e c u l i a r shades have been produced, the m o s t diverse fabrics d y e d together and perfect fixity given t o t h e colours. Yet, during its rapid development, t h e d y e i n g i n d u s t r y h a d t o combat m a n y prejudices, t h e greatest of w h i c h "was the reluctance of t h e dyers themselves t o a d o p t t h e n e w methods when introduced. The u t i l i t y of colours d y e d without m o r d a n t s was n o t a t first recognised, a n d i t w a s a long time before t i e substantive c o t t o n colours could get a footing. T h e general adoption of metallic m o r d a n t s was opposed; b u t t h e discovery of alizarine r e d a n d , l a t e r , of alizarine blue brought in t h i s m e t h o d , a n d i t h a s g r a d u ally grown in use u n t i l now i t is one of t h e m o s t i m p o r t a n t methods of dyeing. I t m u s t be r e m e m b e r e d , h o w e v e r , t h a t every i m p r o v e m e n t i n every t r a d e is received "with opposition of some kind, a n d t h e h i s t o r y of d y e i n g shoTvs the industry t o l a v e been n o exception t o t h e r u l e . T h e preliminary difficulties m a y be great, a n d unwillingness t o discard t i e old methods m a y exist, b u t t h e f a c t t h a t the new methods gain acceptance in o t h e r q u a r t e r s s h o w their utility, and ought t o urge ail b e y o n d initial ohstacles.
GENEEAL
S
As to t i e location of t h e dyeing i n d u s t r y , we h a v e i n Germany : 1. North-West Germany, including R h i n e l a n d a n d W e s t phalia, l a this district the principal centres are Crefeld for silk, Miinchen-Gi-ladbach for cotton,, and ElberfeldBarraen for general manufacture, especially dyeing. 2. Middle Germany, containing w h a t is usually called " the Saxony I n d u s t r y " and spread over a large a r e a . The industry in this district is very old. Chemnitz a n d Zwickau are i m p o r t a n t centres. 3. South-West Germany, where t h e i n d u s t r y is connected with t h e Trench a n d Swiss industries. Mulhausen. is the principal town. M u l t a u s e n is a n i m p o r t a n t fine cotton centre, a n d m u c h fine printing is done i n t h i s district for English a n d F r e n c h firms. The w o r t is t o t a l l y different from t h a t of other p a r t s o i Germany. The jMiinchenGladbach industry is largely devoted t o t h e production of cotton blankets. I n Chemnitz t h e dyeing is of a varied nature. The machines used in t h e textile districts m e n tioned are in m a n y cases of British manufacture, or copies of the same, and e Yen i n t h e t r a d e schools British m a c h i n e r y is used. Yet the Germans are now producing a large number of textile a n d dyeing machines, a n d even e x p o r t ing them to Britain. I n America t h e dyeing industry is scattered. I n t h e Philadelphia district t h e dyeing of carpets a n d coarse goods is t h e principal business. I n t h e S o u t h e r n S t a t e s , where "bleaching and dyeing are c o m p a r a t i v e l y n e w industries, there are some fine w o r k s ; "but t h e works of t h e New England States are the most i m p o r t a n t for t h e present review. Nearly everything t h a t is m a n u f a c t u r e d anywhere in the U n i t e d S t a t e s is made in New York S t a t e . I t has a population, of over 7,000,000, a, foreign commerce only exceeded h y four countries, a n d is t h e leading S t a t e of t h e United States in. m a n y i m p o r t a n t industries. Y e t , turning, farther north, we find New E n g l a n d contains twot l i r d s of all t h e cotton, spindles and three-quarters of all t h e looms of t h e U n i t e d States, while Fall R i v e r m a k e s tliree-quarters of t h e print cloth produced in. t h a t c o u n t r y . Dyeing in E u r o p e was first effected in the y a m form, and this method is still l&Tgely used. HmTc-Hyeing l a s
4
THE DYEING INDUSTRY
not changed much of recent times, a n d in dye-houses in all countries men can be seen s t a n d i n g over w o o d e n v a t s changing periodically the wooden sticks, from w h i c h t h e hanks hang into t h e dye liquor. T h e h a n k s a r e lifted, turned, and dropped back again, while t o i m p r o v e t h e evenness of the dyeing t h e positions of t h e sticks are changed regularly so t h a t all experience t h e s a m e concentration of dye-stuff. Machines have been devised t o i m i t a t e t h i s m o v e m e n t , but few of these have been adopted t o a n y large e x t e n t . Such machines are really only s u i t a b l e for d y e i n g large quantities of y a r n t h e same colour. T h e a u t h o r did n o t see any such machines a t work in G e r m a n y , b u t in America the Klauder-Weldon machine for t h i s p u r p o s e w a s often seen (see p . 63). I n t h e United S t a t e s , h o w e v e r , h a n k dyeing is not so i m p o r t a n t as it used t o be. T h e y m a k e so many cloths where the warp is t h e s a m e c o u n t as t h e weft, t h a t both warp a n d weft are receiving t h e same treatment before weaving. Both a r e d y e d t o g e t h e r in the warp-dyeing machine, and t h e n t a k e n , p a r t t o be quilled and p a r t t o be beamed. This is said t o be a cheaper process t h a n separately t r e a t i n g t h e w a r p a n d weft y a r n s in the more usual way. As regards h a n k - d y e i n g m a c h i n e s , it is evident t h a t t h e y c a n never wholly replace h a n k dyeing by hand, for certain colours require special care, and it is useless t o a t t e m p t t o design m a c h i n e s t o m e e t each special operation. After dyeing, t h e hanks m u s t be w a s h e d , t h i s o p e r a t i o n being of importance. Machines h a v e b e e n devised for t h i s purpose. The simplest m e t h o d is t o p a s s t h e h a n k alternately through water a n d between a p a i r of squeezing rollers. The w a s h i n g - m a c h i n e s are again designed t o imitate washing b y h a n d . Thus, i n one m a c h i n e t h e h a n k is lifted out of t h e water, plunged r a p i d l y i n again, a n d a t t h e same time turned. Haubold's—a large machine firm i n C h e m n i t z , S a x o n y —build a machine which is v e r y economical a n d h a s a large production. I t consists of a circular v a t w i t h a p a r t i t i o n fixed radially at one p a r t of t h e r i m of t h e v a t . F r e s h water is conducted in a t one side of t h i s p a r t i t i o n a n d t h e dirty water flows away a t t h e other side, t h a t is, after
GENERAL
5
h a v i n g traversed r o u n d t h e v a t and washed t h e h a n k s w h i c h are suspended from copper rods placed radially on t h e v a t . E a c h of these rods is covered w i t h a s q u a r e porcelain p a r t on which t h e hanks hang. The porcelain p a r t s revolve, t h u s moving the hanks in t h e water, while t h e whole wheel carrying t h e h a n k s moves r o u n d w i t h a j e r k y motion. During t h e revolution of t h e wheel, t h e h a n k s first meet d i r t y water t h e n cleaner w a t e r as t h e y revolve, until finally t h e y meet clean w a t e r a n d are t a k e n o u t . The hanks are well and rapidly washed, a n d as t h e washing is on t h e counter-current system, t h e w a t e r is economically used. The machine is supplied in three sizes, w i t h 12, 18, a n d 27 copper radii, a n d is suitable for all classes of yarn. Hank-dyeing a n d washing are still principally done b y h a n d , a n d a t Chemnitz workmen are seen standing on low bridges crossing t h e river a n d washing h a n k s in t h e r u n n i n g w a t e r . This peculiar sight m a y be witnessed all along t h e w i n d i n g river. I n t h e Barmen district such a p r a c t i c e is p r e v e n t e d b y t h e b a d state of t h e river, for only on a v e r y w e t S u n d a y , and w h e n t h e factories h a v e been closed some h o u r s , c a n t h e W u p p e r be considered w o r t h y of such u s a g e . Cloth-dyeing is done on t h e jigger or on t h e rope form, a n d big works a b r o a d were seen using b o t h m e t h o d s . T h e d y e i n g of m o r d a n t e d cloth was done in t h e rope-dyeing machines, as t h e m o r d a n t i n g assured even dyeing a n d m a d e t h e use of t h e jigger unnecessary. I t was a frequent occurrence t o see a line of rope-dyeing machines a t work in G e r m a n works. These machines require little a t t e n t i o n , b u t because of t h e difficulty of washing i t is almost necessary t o have different machines for different colours before good results c a n be obtained. This r e m a r k also applies t o t h e use of jiggers for dyeing. I n G e r m a n y some of t h e jiggers h a d e x t r a rollers so as t o increase t h e t i m e of i m m e r s i o n of t h e cloth in t h e dye l i q u o r ; b u t since dyeing is really done more in t h e b a t c h t h a n while in t h e liquor, t h e a d v a n t a g e of these rollers is questionable. A t Miilhausen, as a t Chemnitz, t h e river is used directly for washing, and washing-machines are directly b u i l t over b r a n c h e s of it. Most of t h e works congregate a b o u t t h e rivers a n d streams.
CHAPTER
II
COP-DYEING Its object—Selection of colours-—The difficulties involved—Machines of two classes Comparison of these machines—Three important machines— Perfection not attained. U N T I L comparatively recently, c o t t o n y a r n h a d t o be dyed i n the h a n k f o r m : t h e c o p p r o d u c e d b y t h e spinningmachine was unwound, t h e y a r n m a d e into t h e h a n k form, dyed, t h e n rewound t o t h e cop form a n d placed in t h e s h u t t l e . During tMs operation of u n w i n d i n g a n d rewinding, cotton was lost owing t o t h e e n t a n g l i n g of t h e t h r e a d s , a n d cop-dyeing arose t o s a v e t h e t r o u b l e m e n t i o n e d a n d t h u s to economise b o t h labour a n d m a t e r i a l . Cop-dyeing originated in t h e Manchester district a b o u t t h i r t y years ago, and has now assumed considerable dimensions in Germany. Many machines are i n use for cop-dyeing, b u t t h e success of t h e operation seems t o d e p e n d n o t so m u c h o n the machinery used as o n t h e p r o p e r selection of t h e dye-stuffs a n d on t h e careful h a n d l i n g of t h e machines. During t h e dyeing operation t h e d y e l i q u o r h a s t o b e forced t h r o u g h t h e cop, a n d in t h i s w a y t h e material of t h e cop acts as a kind of filter for t h e dye-stuff. I t is therefore evident t h a t success i n cop-dyeing can best be a t t a i n e d b y using perfectly soluble colours, w h i c h leave no residue in the d y e - b a t h ; otherwise t h e r e is a t e n d e n c y t o w a r d s uneven dyeing, a n d t o c o n c e n t r a t i o n of t h e d y e stuff: on t h e outside of t h e cop. T h i s is p a r t l y counteracted i n some machines b y periodically reversing t h e direction of flow of t h e dye liquor t h r o u g h t h e c o p . Consideration shows us t h a t m a n y colours, as aniline black, t u r k e y red, etc., c a n n o t b e d y e d w i t h success on 6
COP-DYEING
7
cops ; others, such as indigo, are difficult t o m a n a g e . T h e dyeing w i t h sulphur colours is also difficult because of t h e i r t e n d e n c y t o oxidise on t h e outside of t h e cops, t h u s p r o ducing unevenness. I n using these colours, t h e cops m u s t be k e p t immersed in t h e d y e liquor d u r i n g t h e d y e i n g operation. Those colours which are slowly t a k e n u p b y t h e fibres are tlie best t o use in cop-dyeing, as e v e n p e n e t r a tion is o b t a i n e d ; dyeing w i t h basic colours, w h i c h a c t quickly, is difficult. To overcome t h e difficulties m e n tioned, various precautions are t a k e n , a n d t h e colour firms give every assistance in t h a t direction b y t h e i r carefully p r e p a r e d recipes. Moreover, i n cop-dyeing t h e difficulties are accentuated b y t h e fact t h a t a n y m i s t a k e s a r e n o t revealed t o t h e dyer, who c a n n o t tell if h e is sending b l a c k cops w i t h white cores t o t h e weaver. If t h e l a t t e r is n o t a n observant person, pieces of cloth m a y t h u s be spoiled. T h e machines for cop-dyeing are of t w o classes : (1) those in which t h e cops have solid spindles, a n d (2) t h o s e in which t h e spindles of t h e cops are p e r f o r a t e d . I n t h e first class t h e cops containing t h e solid spindles, which serve t o keep t h e cops from b e c o m i n g d a m a g e d , are p a c k e d together into a s uniform a m a s s as possible b y means of c o t t o n waste a n d other s u c h m a t e r i a l . S t e a m is first sent t h r o u g h t h e mass a n d t h e n t h e d y e liquor. T h e success of t h e operation d e p e n d s o n good p a c k i n g , for, if t h e dye liquor passes along c e r t a i n channels only, t h e dyeing of t h e cops is n o t uniform. One of t h e oldest of these machines a n d t h e simplest is t h e M o m m e r m a c h i n e , in which t h e cops are t i g h t l y p a c k e d i n a s q u a r e b o x w h i c h h a s t w o of its opposite sides perforated. T h e d y e liquor is p u m p e d between t h e s e perforations a n d through, t h e m a s s i n t h e box. B y reversing t h e d i r e c t i o n of t h e d y e liquor more even p e n e t r a t i o n is o b t a i n e d , for, if c e r t a i n channels are produced d u r i n g t h e p a s s a g e of t h e d y e liquor in one direction, i t is n o t likely t h a t channels will b e formed i n t h e same places w h e n t h e p u m p is r e v e r s e d a n d t h e d y e liquor travels in t h e o t h e r direction. I n Cohnen's machine t h e cops c a n be h y d r o - e x t r a c t e d i m mediately after dyeing, b y merely revolving t h e b o x in which, t i e cops are packed. T h e m a c h i n e a c t s in t h e same w a y as t h e one previously described, b u t t h e a r r a n g e m e n t
8
THE DYEING INDUSTRY
for hydro-extracting is very convenient. T h e cops ca t h u s be dyed, washed, and hydro-extracted w i t h o u t takin out of t h e machine. The machine is specially suitable fc dyeing basic colours on cops, for in this case i t is necessar t o hydro-extract after each operation if u n e v e n dyeing i t o be avoided. The Obermaier machine, s u c h as is use for dyeing loose fibres, can also be used for dyeing cop with solid spindles. Interest in t h e solid spindle machines, however, i rapidly decreasing, and attention is being g i v e n t o machine of t h e second class. Some machines can, however, b adapted t o dye b y b o t h systems. For i n s t a n c e , t h author saw a machine m a d e b y Schirp of B a r m e n bein used for dyeing cops with solid spindles, w h e r e a s thi machine is usually employed for dyeing a c c o r d i n g to th other system. The penetration of t h e dye liquor in t h e machine using perforated spindles is more uniform, a n d this facto has decided in their favour. F u r t h e r , t h e p o w e r t o driv t h e dye liquor t h r o u g h t h e cops is m u c h less t h a n in t h first system. I n t h e second system, t h e d y e liquor i forced into t h e perforated spindle on which each cop i placed, through t h e perforations of t h e s p i n d l e , throug] the cop surrounding t h e spindle, and back i n t o t h e dye b a t h . I n this way each cop receives i n d i v i d u a l treatment instead of being p e n e t r a t e d by t h e dye liquox in a mas as in the first system. Formerly there was a difficulty ii transferring t h e cops t o and from t h e m e t a l l i c spindle used in these machines, b u t , later, perforated p a p e r spindle were introduced, which remain inside t h e c o p s during t b operations and keep t h e t h r e a d s in position. T h e metallic spindles of t h e dyeing machines fit inside t h e p a p e r spindles After dyeing, t h e cop along with t h e paper s p i n d l e is take] to the hydro-erfcractor. One case of uneven cop-dyeing, which h a d l e e n causec by t h e paper spindle, came t o t h e author's n o t i c e whil< in Germany. The inside of t h e cop, i m m e d i a t e l y next t< where t h e paper spindle h a d been, was more d e e p l y dyec t h a n the remainder of t h e cop. Investigation s h o w e d thathe alum used in t h e manufacture of t h e p a p e r h a d actec as acid to t h e dye liquor, d r a w n t h e dye-stuff f r o m solution
COP-DYEING
9
a n d c o n c e n t r a t e d it on t h e p a r t of t h e cop i m m e d i a t e l y next to the paper. I n t h e case of t h e perforated spindle m a c h i n e s t h e direction of m o t i o n of t h e d y e liquor is altered from t i m e t o t i m e b y reversing t h e p u m p , i n order again t o ensure uniformity of d y e i n g . A n y i m p u r i t i e s or solid particles of a n y kind in t h e d y e - b a t h , which rise t o t h e t o p of t h e d y e - b a t h , t e n d t o fill u p t h e t o p holes of t h e perforated spindles a n d t o t h u s p r o d u c e u n e v e n dyeing. Modern p e r f o r a t e d spindle m a c h i n e s : (1) Gramiger's. (2) H a u b o l d ' s , (3) Schirp's, a n d (4) P o r n i t z ' s . Gramiger's, o n e of t h e first of t h i s t y p e , h a s been i m p r o v e d in E n g l a n d , a n d is used for d y e i n g indigo o n cops. H a u b o l d ' s m a c h i n e w a s seen a t w o r k b y t h e a u t h o r i n t h e dye-works of H e r r H a a s e , its i n v e n t o r . This w o r k s is s i t u a t e d a t Neukirchen, a few miles over t h e hills from Chemnitz, a n d is principally concerned w i t h t h e dyeing of cops a n d stockings. Chemn i t z h a s a large business i n t h e d y e i n g of stockings. The cop-dyeing m a c h i n e consists of t w o p a r t s , a d y e - b a t h of t u n - d i s h s h a p e a n d a receptacle for t h e d y e liquor. The b o t t o m of t h e d y e - b a t h is perforated, a n d i n these perforat i o n s t h e spindles carrying t h e cops are screwed. The d y e - b a t h is c o n n e c t e d t h r o u g h a p u m p w i t h t h e dye-vessel. T h e p u m p d r a w s t h e liquor from t h e dye-vessel, forces it t h r o u g h t h e cops i n t o t h e d y e - b a t h u n t i l t h e liquor fills t h e d y e - b a t h , a n d t h e n d r a w s s o m e of t h e liquor b a c k a g a i n t h r o u g h t h e cops i n t o t h e dye-vessel. T h e cops a r e k e p t wholly i m m e r s e d i n t h e d y e liquor d u r i n g t h e process, a n d m a n y a l t e r n a t i o n s of t h e p u m p ensure even d y e i n g . T h e passages of t h e d y e liquor, first in one direct i o n and' t h e n in t h e other, t a k e p l a c e a b o u t t w e n t y t i m e s d u r i n g a n h o u r , according t o t h e n a t u r e of t h e dyeing. If four m a c h i n e s are r u n t o g e t h e r , a s w a s t h e case a t t h i s works, one engine suffices for all, b u t w i t h single m a c h i n e s t h e cost of d r i v i n g becomes r e l a t i v e l y higher. The m a c h i n e , which was first b u i l t i n 1892, costs a b o u t £600. I t is suitable for c o t t o n a n d wool cops, a n d t h e p r o d u c t s , t h e a u t h o r found, stood m i n u t e e x a m i n a t i o n . After d y e ing, t h e cops were p u t i n small b a s k e t s a n d a r r a n g e d in a circle inside a h y d r o - e x t r a c t o r . After h y d r o - e x t r a c t i n g t h e y were d r i e d i n a c h a m b e r t h r o u g h which a strong
10
THE DYEING INDUSTRY
current of h o t air was passed. If t h e cops d r y too slowly, there is a tendency for t h e u p p e r side of the cop t o dry first, to extract t h e dye liquor from t h e lower p a r t , and t h u s produce uneven dyeing. The ScHrp machine consists of a s t o u t square box with removable sides. I n t h e middle of t h i s b o x is another box, which might be considered a longitudinal section of t h e larger one. On b o t h faces of t h e smaller b o x . t h e perforated spindles carrying t h e cops are placed, so t h a t t h e spindles project into t h e space of t h e larger box. The smaller box is fitted w i t h t h e cops, wheeled into position, a n d t h e n t h e dye liquor is forced i n t o t h e small box, through the cops into t h e larger box, a n d round again in circulation. As in t h e other cases, t h e direction of t h e dye liquor is reversed from time t o t i m e . I n t h e P o r n i t z machine t h e cop carrier is a perforated cylinder, t h e cops t a k i n g u p the whole of t h e round surface. W h e n t h e cops h a v e been fitted into position, this cylinder is lowered by m e a n s of a chain into t h e dye-bath, which is a cylindrical vessel big enough t o a d m i t t h e cops. B y means of compression a n d suction t h e dye liquor is m a d e t o pass from t h e d y e - b a t h t h r o u g h t h e cops into t h e dye reservoir. F r e s h dye-stuff can be a d d e d to t h e liquor while in t h e reservoir, a n d in t h i s w a y slow a n d even dyeing assured. The suction a n d compression are performed b y m e a n s of a double-acting air-pump. The machine can also be used for dyeing w a r p s ; for this purpose t h e warps are wrapped r o u n d t h e cylinder of t h e machine over t h e perforations, which usually carry the cop spindles. T h e dye reservoir is usually placed undern e a t h the d y e - b a t h so as to save space. I n all these machines t h e cops h a v e first t o be steamed a n d h o t water sent t h r o u g h t h e m before dyeing, in order t o ensure" even penetration. P e n e t r a t i o n is of course assisted b y " boiling o u t " t h e cops on a kier before dyeing, or b y adding t u r k e y r e d oil t o t h e water used for " wetting o u t " t h e cops. At one works cops were seen being d y e d in a foam dyeing-machine. The cops were t i g h t l y packed in t h e t o p of a n u p r i g h t cylinder, while a t t h e b o t t o m of t h e cylinder t h e d y e liquor, containing soap, was m a d e t o
COP-DYEING
11
froth u p by m e a n s of s t e a m . W h e n t h e b u b b l e s burst, t h e air r o u n d t h e fibres is d r i v e n a w a y a n d t h e dye-stuff a t t r a c t e d . T h i s m e t h o d is said t o b e successful in* dyeing certain shades on cheeses. T h e a u t h o r saw n o cop-dyeing m a c h i n e s in t h e U n i t e d S t a t e s ; cop-dyeing is too delicate a process for t h e American class of t r a d e . N e a r l y all t h e cop-dyeing m a c h i n e s i n use i n G e r m a n y are v e r y similar t o each o t h e r , different forms being merely modifications of t h e s a m e principal idea. The production of m a c h i n e s for sale is a s y e t little developed. Mommer of B a r m e n informed t h e a u t h o r t h a t t h e y no longer build t h e i r m a c h i n e , b e c a u s e t h e r e is n o d e m a n d for it. Of recent years t h e d y e i n g of cops h a s n o t b e e n m u c h developed, a n d in spite of careful a t t e n t i o n t o t h e difficulties a t t e n d a n t u p o n t h e o p e r a t i o n , perfect p e n e t r a t i o n h a s not been a t t a i n e d . T h e O b e r m a i e r m a c h i n e is successful for t h e d y e i n g of loose wool, b u t i t h a s n o t been so successful i n t h e dyeing of c o p s . T h e Theis a p p a r a t u s is m u c h used i n W e s t p h a l i a a n d H o l l a n d for t h e bleaching of c o p s ; i t is also said t o b e satisfactory for dyeing. T h e m a c h i n e s used for c o p - d y e i n g d o n o t v a r y m u c h , a n d from t i m e t o t i m e old t y p e s a r e i m p r o v e d .
CHAPTER
III
SULPHUR COLOURS AND INDIGO Fastness of sulphur colours—Importance as cotton dyes—Their tendering action on cotton—Use for wool dyeing—Machines used for dyeing sulphur colours—Natural and synthetic indigo—Substitutes for indigo—Sulphur blues and indigo. T H E first sulphur dye-stuff was Cachou de Laval. Vidal black was afterwards produced b y Vidal, a n d was t h e first real member of this i m p o r t a n t class of dye-stuffs, for it was b y imitating Vidal's m e t h o d of production t h a t other sulphur colours were produced. These dye-stuffs were a t one time known as " t h e colours of t h e f u t u r e / ' and nowadays t h e y are recognised as v e r y i m p o r t a n t cotton dyes. Their brilliancy, deepness of shade, fastness, and cheapness have created quite a revolution in t h e dyeing industry. Cassella's sulphur blues are well-known colours, a n d t h e Hoechst thiogen violets are bright, clear shades. The l a t t e r firm claim t h a t their t h i o g e n p u r p u r was t h e first red sulphur dye-stuff t o be p u t on t h e m a r k e t . I t has been stated, however, t h a t other firms h a d previously h a d products of a similar n a t u r e which t h e y did n o t d e e m w o r t h y of being placed on t h e i r lists. Of recent years a large n u m b e r of sulphur colours h a v e been placed on t h e market, a n d among these t h e b r a n d s of sulphur blacks have been of special importance. All t h e colour firms h a v e b r o u g h t out sulphur blacks of great p u r i t y a n d concentration. Their b e a u t y of shade is beyond dispute, and only in fastness t o bleaching powder solution do t h e y fail t o compare w i t h aniline black. The fact t h a t sulphur colours are a p t t o cause t h e tendering of t h e c o t t o n fibre on which t h e y are dyed, has 12
SULPHUR COLOURS AND INDIGO
13
p r e v e n t e d t h e m from b e c o m i n g of still g r e a t e r i m p o r t a n c e i n t h e dyeing i n d u s t r y . T h e t e n d e r i n g does n o t t a k e p l a c e for some t i m e after t h e d y e i n g , b u t i n s o m e cases c o t t o n goods, w h i c h h a d b e e n d y e d a y e a r previously, h a d become q u i t e r o t t e n . T h e cause of t h e t e n d e r i n g seems t o be d u e t o t h e d e v e l o p m e n t of sulphuric acid b v t h e o x i d a t i o n of t h e s u l p h u r c o n t a i n e d in t h e dye-stuffs. A f t e r - t r e a t m e n t w i t h c o p p e r salts accelerates t h i s action a n d should n o t b e p e r f o r m e d . C h r o m i n g is r e c o m m e n d e d , b u t m a n y d y e r s object t o t h i s e x t r a t r e a t m e n t , s a y i n g i t is costly a n d t h e s h a d e is a l t e r e d t h e r e b y . T h e r e is n o d o u b t , however, t h a t c h r o m i n g , or t r e a t m e n t w i t h some o t h e r oxidising a g e n t , as h y d r o g e n p e r o x i d e , b r i n g s a b o u t t h e full o x i d a t i o n of t h e r e d u c e d s u l p h u r dye-stuff, a n d t h u s p r o d u c e s t h e fullest s h a d e i m m e d i a t e l y . T o overc o m e t h e t e n d e r i n g c a u s e d b y t h e s e dye-stuffs small a m o u n t s of c e r t a i n chemicals, w h i c h n e u t r a l i s e t h e sulp h u r i c acid as i t is p r o d u c e d , a r e s o m e t i m e s left in t h e c l o t h . F o r i n s t a n c e , s o d i u m a c e t a t e is e m p l o y e d for t h i s p u r p o s e , a n d also several p a t e n t s u b s t a n c e s . S u l p h u r colours are r e d u c e d b y s o d i u m sulphide solut i o n , a n d t h e solution t h u s p r o d u c e d used for i m p r e g n a t i n g t h e m a t e r i a l t o be d y e d . T h e colour is developed b y t h e g r a d u a l o x i d a t i o n of t h e r e d u c e d solution in t h e air, a n d i n m o s t cases a change of colour of t h e m a t e r i a l d u r i n g t h e o x i d a t i o n is n o t i c e a b l e . A s r e g a r d s t h e t e m p e r a t u r e a t which d y e i n g t a k e s p l a c e , t h i s varies for different b r a n d s . M a n y s u l p h u r b l a c k s d y e best j u s t b e l o w boiling p o i n t , b u t 60° C. is s o m e t i m e s h i g h e n o u g h . A low t e m p e r a t u r e is preferable in m a n y cases, since slow o x i d a t i o n results a n d t h e dyeings a r e m o r e uniform. A slightly faster r e s u l t is o b t a i n e d a t h i g h t e m p e r a t u r e s , b u t a t l o w t e m p e r a t u r e t h e c o t t o n is b e t t e r preserved. F o r l i g h t shades 30° C. is often h i g h e n o u g h , while s o m e of t h e indigo b r a n d s m a y be d y e d cold w i t h a d v a n t a g e . T h e a m o u n t of s o d i u m sulphide t o b e a d d e d t o t h e b a t h is also of i m p o r t a n c e , as a q u a n t i t y w h i c h is sufficient t o r e d u c e t h e dye-stuff is n o t a l w a y s e n o u g h t o fix t h e dye-stuff o n t h e fibre. Since ^ o d i i ^ ^ ^ l ^ h i d e solution a t t a c k s t h e wool fitoe^sul£^^ nTthe~ d y e i n g o F f a b r i c s o o n t a i a i n g wool. B y using o t h e r
14
THE DYEING INDUSTKY
reducing agents however, such as hydrosulphites, sulphites, etc., in place of t h e sodium sulphide, this objection has been somewhat overcome. B u t it has been found t h a t on using these reducing agents t h e results are n o t exactly t h e same as those produced b y sodium sulphide. For dyeing cloth w i t h sulphur colours t h e ordinary jigger is m u c h used, b u t t h e a u t h o r also saw jiggers a t work in which t h e cloth was k e p t wholly immersed in t h e dye liquor during t h e dyeing operation. E x p o s u r e t o t h e air during dyeing is said t o cause bronzy precipitates on t h e cloth. The addition of a little glue t o t h e d y e - b a t h is said t o p r e v e n t these b r o n z y patches, a n d t h u s t o assist t h e dyeing on t h e jigger. I n dyeing h a n k s with these colours, exposure t o air during t h e dyeing operation is also avoided. The Klauder-Weldon machine is used for this operation (see p . 63) in t h e U n i t e d S t a t e s . The a u t h o r found t h a t slop p a d d i n g was t a k i n g t h e place of dyeing for some classes of colours. E v e r y dyer knows t h e difficulty of dyeing evenly, a n d in cases of m o r d a n t i n g a n d developing dye-stuffs on t h e fibre t h e difficulties are increased. Tannic acid divides itself fairly evenly over t h e fibres, so t h a t impregnation in this case is easily accomplished; b u t in dealing with some of t h e chromium m o r d a n t s a n d other compounds, difficulties arise. Moreover, t a n n i c acid c a n be fixed in t h e wet s t a t e , whereas some agents m u s t b e dried evenly on t h e cloth before proceeding t o t h e other operations. Difficulties of this kind h a v e led t o t h e introduction of p a d d i n g . T h u s , in G e r m a n y a n d America, m o r d a n t s were often padded, a n d t h e n t h e dyeing done in t h e s t r a n d dyeing machines. I n p a d d i n g , t h e cloth passes t h r o u g h t h e liquor t o be padded, a n d is t h e n squeezed evenly b y a p a i r of rollers. One of these rollers is usually of brass a n d t h e other rubber covered. P a d d i n g w i t h sulphur colours is difficult, because t o ensure a uniform result t h e dye-stuff should be completely dissolved in t h e p a d d i n g liquor. I n Germany t h e a u t h o r found glucose was used as a reducing agent in preparing sulphur colours for p a d d i n g . T h e brass roller of t h e p a d d i n g mangle was replaced b y a n iron one, since brass a n d copper p a r t s are a t t a c k e d b y sulphur colour solutions.
S U L P H U R COLOURS AKD INDIGO
15
_ P r i n t i n g w i t h s u l p h u r colours is n o w p e r f o r m e d b y u s i n g special r e d u c i n g a g e n t s for p r e p a r i n g t h e p r i n t i n g p a s t e s . Cassella's first u s e d c a u s t i c s o d a a n d glycerine. S u l p h u r colours a r e m u c h u s e d i n t h e U n i t e d States. F o r i n s t a n c e , o n e r e p r e s e n t a t i v e of a G e r m a n colour works t o l d t h e a u t h o r t h a t h e h a d sold a million p o u n d s of colour i n a v e r y s h o r t t i m e . S u l p h u r b l a c k s were i n g r e a t d e m a n d . T h e i n t r o d u c t i o n of t h e s e colours h a s led t o changes in t h e m a c h i n e r y i n u s e ; c o p p e r p a r t s h a v e b e e n replaced. S o m e firms i n t h e U n i t e d S t a t e s c l a i m t o h a v e t h e best m a c h i n e r y for d y e i n g s u l p h u r c o l o u r s , b u t w h e t h e r t h i s is t h e case or n o t c a n n o t b e d e t e r m i n e d because t h e s e firms r e s o l u t e l y refuse t o p l a c e t h e i r m a c h i n e s o n view. R e p r e s e n t a t i v e s of t h e colour m a k e r s w e r e n o t allowed t o see t h e m a c h i n e s , a n d t h e s e g e n t l e m e n f o u n d t h e m s e l v e s in t h e p e c u l i a r p o s i t i o n of giving i n s t r u c t i o n s a n d seeing t h e firm's s e r v a n t s oscillating b e t w e e n t h e m s e l v e s a n d t h e dye-house. S u l p h u r dye-stuffs h a v e n o w a d a y s b e c o m e so i m p o r t a n t t h a t t h e y h a v e challenged t h e p o s i t i o n of some of t h e older f a s t colours. As p r e v i o u s l y m e n t i o n e d , s u l p h u r blacks are u s e d i n p l a c e of aniline black, a n d w e also find t h a t some s u l p h u r b l u e s h a v e r e p l a c e d t h e u s e of indigo t o some extent. I n d i g o , o n e of t h e oldest a n d still t h e m o s t i m p o r t a n t dye-stuff, h a s a h i s t o r y full of i n t e r e s t . N o t o n l y has t h e n a t u r a l a r t i c l e h a d t o o v e r c o m e t h e o p p o s i t i o n of subs t i t u t e s ; t h i s o p p o s i t i o n i t c o u n t e r a c t e d v e r y well, u n t i l t h e p r o d u c t i o n of s y n t h e t i c i n d i g o c a u s e d t h e n a t u r a l article t o b e c o m e of less a n d less i m p o r t a n c e . I n d e e d , i t is only t h e p r e s e n t w a r w h i c h h a s c a u s e d a r e n e w e d i n t e r e s t in t h i s colour. I n 1880 t h e c h e m i c a l c o n s t i t u t i o n of indigo w a s d e c l a r e d , a n e v e n t w h i c h l e d l a t e r t o t h e p r o d u c t i o n of s y n t h e t i c i n d i g o on. a c o m m e r c i a l scale. A large i n d u s t r y h a s a r i s e n t h e r e f r o m , as t h e following figures s h o w : from 1896 t o 1904 G e r m a n y ' s e x p o r t of s y n t h e t i c indigo inc r e a s e d i n v a l u e f r o m 6'4 t o 2 5 million m a r k s , a n d t h e l a t e s t r e t u r n s p u b l i s h e d (for t h e y e a r 1913) s h o w t h e s e t o h a v e i n c r e a s e d t o 40 million m a r k s . As a r e s u l t , during t h e y e a r s 1899 t o 1903 t h e price of indigo fell 50 per cent. I n 1900, D r . B r u n c k of t h e B a d i s c h e Anilin u n d Soda
16
THE DYEING INDUSTRY
F a b r i k s t a t e d t h a t t h e q u a n t i t y of indigo produced annually in their factory would require t h e cultivation of more t h a n a quarter of a million acres of land in t h e home of t h e indigo p l a n t . I t h a s been prophesied t h a t n a t u r a l indigo will be as d e a d as m a d d e r in a few years' time, y e t we find it has t o some e x t e n t held its position in the E a s t , and various Commissions h a v e tried t o improve t h e cultivation in order t o increase t h e production. B u t there is obviously a limit t o which t h e production can be improved, for p l a n t life does n o t a d m i t of the t h o r o u g h comprehension t h a t operations in a colour works do, a n d the producers of synthetic indigo h a v e the price of indigo a n d production very m u c h in their own h a n d s . The crippling of t h e synthetic indigo industry b y t h e war has been t u r n e d t o account b y t h e British and Indian press as an occasion t o revive interest in t h e restoration of t h e n a t u r a l production. The m o v e m e n t t o break t h e German synthetic indigo monopoly was started in London three years ago, b u t despite all efforts t h e vegetable dye failed t o m a k e h e a d w a y . Many dyers a n d consumers would h a v e lent t h e i r support t o t h e restoration of t h e natural industry, b u t the crop season was t o o far advanced t o secure a n increased o u t p u t in t h e near future. I n fact, t h e area u n d e r cultivation in I n d i a in 1914 was 20 per cent less t h a n t h e previous year. I n 1895-96 exports reached their m a x i m u m a t 187,337 c w t . ; in 1902-3, a period following t h e establishment of t h e synthetic industry in E u r o p e , t h e exports fell t o 65,337 c w t . ; while in. 1912-13 t h e y only reached 11,857 cwt. The United Kingdom h a s been m o s t faithful among t h e principal consuming countries t o r e t a i n t h e n a t u r a l dye, although t h e country's r e q u i r e m e n t s h a v e been steadily curtailed. Among t h e strongest merits of t h e artificial dye were its more uniform c h a r a c t e r a n d t h e easier methods of using it. Moreover, t h e percentage of indigotin in t h e n a t u r a l article was found difficult t o determine. Wool takes more readily t o t h e n a t u r a l dye, b u t while t h e artificial article does n o t yield quite so bright a n effect, its colour is cons t a n t . T o encourage t h e development of the n a t u r a l industry t w o proposals h a v e been m a d e : (1) t o subsidise t h e industry i n I n d i a , a n d (2) t o restore t h e obligatory
S U L P H U R COLOURS A N D I N D I G O
17
n a t u r a l indigo clause i n all G o v e r n m e n t c o n t r a c t s . This clause is said t o have been deleted u n d e r pressure of t h e G e r m a n monopoly, combined w i t h r e p r e s e n t a t i o n s on the p a r t of English dyers. The British G o v e r n m e n t b o u g h t u p t h e I n d i a n crop a t t h e beginning of t h e war. The a u t h o r thinks t h a t any a t t e m p t t o p e r m a n e n t l y bolster u p t h e n a t u r a l indigo i n d u s t r y will n o t m e e t w i t h success. The only w a y of fighting t h e G e r m a n s in t h i s i n d u s t r y will b e by t a k i n g u p t h e production of s y n t h e t i c indigo. J a p a n a n d China h a v e also renewed t h e i r interest in t h e n a t u r a l article. L a t t e r l y these countries h a d depended almost entirely on G e r m a n s y n t h e t i c indigo. N a t u r a l indigo production is one of t h e oldest industries of b o t h China and J a p a n . Their own needs being g r e a t , t h e y do n o t expect t o be able t o export a n y of t h e n a t u r a l article. Besides t h e competition of t h e s y n t h e t i c article, indigo has h a d other rivals t o face. T h e i n t r o d u c t i o n of t h e direct cotton colours h a d little m o r e t h a n a n initial effect on t h e consumption of indigo, because t h e direct blues of this class of dye-stufis were n o t f o u n d t o be n e a r l y so fast as indigo. I t is t r u e t h a t some direct blues are faster t o light t h a n indigo, a n d t h a t some d a r k shades h a v e t h e coppery appearance of t h a t dye-stuff, b u t none h a v e been found really fast t o washing. A t t e m p t s h a v e b e e n m a d e to increase t h e fastness of these dye-stufis. T h e fastness t o l i g h t was improved b y a n after t r e a t m e n t w i t h coppers u l p h a t e solution, a n d i n some cases t h e fastness t o washing was improved b y t r e a t i n g t h e d y e d m a t e r i a l w i t h a w e a k solution of potassium b i c h r o m a t e ; b u t still t h e fastness t o chlorine was i n few cases good. This fault was also evident in t h e case of indigo-blue dye-stufis belonging t o t h e basic class. Metaphenylene b l u e , I n d a m i n e blue, J a n u s blue, Indoine blue, a n d D i p h e n e blue h a d certain good features, b u t were found w a n t i n g w h e n s u b m i t t e d t o t h e action of weak bleaching-powder solution. Napht h i n d o n e blue resembles indigo v e r y m u c h i n aspect, reflex, a n d i n being exceedingly fast t o light, washing, a n d acids, b u t again t h e fastness t o chlorine is n o t good. I n order t o increase t h e fastness of t h e direct c o t t o n dye-stuffs, diazotising a n d developing o n t h e fibre was introduced, a n d in t h i s way m a n y good imitations of indigo were produced.
18
THE DYEING INDUSTRY
Diamine blacks a n d blues, N a p h t h y l a m i n e black, a n d certain Benzo blues diazotised a n d developed with b e t a n a p h t h o l a n d other developers h a v e been much used for producing indigo shades, b u t again t h e fastness to chlorine was n o t found as good as t h a t of indigo. Alizarine blues a n d t h e alizarine cyanines h a v e also substituted indigo i n m a n y cases. As regards t h e newer v a t blues, there is n o d o u b t t h a t these colours are used for purposes for which indigo was formerly u s e d ; b u t t h e high price of t h e s e colours restricts their application. Moreover, these d y e stuffs are found t o " bleed " i n t o white cloth (and more so t h a n indigo itself) w h e n boiled in caustic-soda solutions. This defect is particularly noticeable when the caustic-soda solution contains m a t t e r which h a s a reducing action. B u t of all t h e colours which h a v e been used as substitutes for indigo from t i m e t o t i m e , sulphur colours are t h e most i m p o r t a n t . Sulphur blues, which are exceedingly fast t o light a n d washing, are now supplied b y t h e different colour firms ; in some cases t h e fastness t o chlorine is fairly good, b u t this defect is their g r e a t disadvantage. The first sulphur blue was introduced b y t h e Society of Chemical I n d u s t r y , Basle, a n d was soon followed by Cassella's Immedial blue C ; t h e p a t e n t s for t h e two colours were owned conjointly b y t h e t w o firms. Other sulphur blues were soon p u t on t h e m a r k e t b y t h e other colour firms. I n America, sulphur blues are m u c h used for warp-dyeing a n d for piece-goods. I t is found, however, t h a t these colours are n o t usually v e r y fast t o alkaline boiling. I n spite of t h e contentions of t h e makers of sulphur blues, there is n o d o u b t t h a t for producing indigo-blue shades indigo itself is t h e cheapest and t h e fastest d y e stuff t o use. A t one t i m e t h e firm of F . Bayer supplied p a t t e r n s of cloth d y e d w i t h (1) indigo and (2) sulphur indigo blue, saying, " Please t e s t t h e comparative fastness t o washing a n d boiling." B u t t h e fastness of incligo depends largely on t h e m e t h o d of dyeing, for if a s t r o n g v a t be used a n d few " dips " given, t h e result is n o t so good as in t h e case of t h e e m p l o y m e n t of a weaker v a t a n d giving more " d i p s . " This r e m a r k also applies t o Cassella's s t a t e m e n t in their b o o k on cotton-dyeing, t h a t indigo loses in d e p t h of shade every t i m e the material is
S U L P H U E COLOUES A N D I N D I G O
19
washed, w h e r e a s s o m e sulphur colours do n o t . If pieces of cotton d y e d w i t h indigo a n d w i t h s u l p h u r b l u e are exposed t o t h e l i g h t , i t is found t h a t t h e former f a d e s m o r e rapidly t h a n t h e l a t t e r ; i n fact, some s u l p h u r colours improve i n s h a d e a f t e r a s h o r t e x p o s u r e t o t h e a i r . On further e x p o s u r e , however, t h e c o n d i t i o n s are r e v e r s e d , a n d this d i s t i n c t i o n is a p p a r e n t after a few d a y s i n s u m m e r or a few w e e k s i n w i n t e r . Moreover, i t is n o t i c e d t h a t , although t h e i n d i g o becomes l i g h t e r i n colour, i t r e m a i n s the original t o n e , whereas t h e s u l p h u r b l u e , w h e t h e r i t b e after t r e a t e d o r n o t , fades t o a g r e y i s h s h a d e . Sulphur colours, u n l i k e i n d i g o , are n o t definite chemical c o m p o u n d s whose c o n s t i t u t i o n s a r e k n o w n t o c h e m i s t s ; a n d a s m o s t of t h e m a r e p r o b a b l y m i x t u r e s , i t c a n n o t b e e x p e c t e d t h a t , as t h e y a r e g r a d u a l l y decomposed b y s u n l i g h t , t h e r e s i d u a l unaffected c o l o u r will be t h e s a m e b l u e s u b s t a n c e a s c o m posed t h e original dye-stuff. I n o r d e r t o e m p h a s i s e t h e marked difference b e t w e e n indigo a n d s u l p h u r b l u e s u n d e r t h e action of l i g h t , t h e B a y e r p a t t e r n s m e n t i o n e d a b o v e were exposed. A f t e r fourteen d a y s b o t h were still good in shade, b u t a f t e r forty d a y s t h e r e w a s a c o n s i d e r a b l e distinction i n f a v o u r of t h e indigo ; t h e indigo h a d r e mained a l i g h t b l u e , whereas t h e s u l p h u r colour h a d b e c o m e a dirty r e d - g r e y s h a d e . T h e s u p p o r t e r s of s u l p h u r colours assert t h a t t h e t e s t s m e n t i o n e d a r e t o o s e a r c h i n g a n d t h a t the fastness is g o o d e n o u g h ; b u t s u c h s t a t e m e n t s d o n o t satisfy t h e d y e r , since for blouses, s h i r t s , a n d o t h e r articles, colours a r e r e q u i r e d which fade i n a n agreeable m a n n e r . Indigo alone d o e s t h i s , a n d m a n y G e r m a n d y e - w o r k s h a v e found t h i s o u t t o t h e i r cost, a r e t u r n t o t h e i n d i g o v a t being t h e c o n s e q u e n c e . Vat dye-stuffs, which h a v e b e e n p r o d u c e d i n large variety of r e c e n t y e a r s , are e x t r e m e l y fast a n d m u c h u s e d for woven g o o d s . Thioindigo r e d w a s p u t on t h e m a r k e t b y Kalle & Co. i n 1905, a n d since t h a t t i m e t h e C i b a a n d Algol colours h a v e p r o v i d e d m a n y o t h e r s h a d e s . These colours, a l o n g w i t h t h e I n d a n t h r e n e series, a r e d y e d like indigo a n d a r e v e r y fast, b u t b e c a u s e of t h e i r e x p e n s e are not usually u s e d for h e a v y s h a d e s .
CHAPTEE
IV
MERCERISING Invention of the process—Hank-niercerising machines—Piece mercerising— Cooling of the lye—Recovery of the caustic soda—Recent scientific work on mercerising. MERCERISING is a process of t r e a t i n g c o t t o n with conc e n t r a t e d caustic-soda solution in order t o give i t a silky lustre a n d feel. T h e effect is n o t merely produced b y the action of t h e caustic soda on t h e cotton, b u t either (1) t h e cotton m u s t be k e p t stretched during t h e action or (2) it m u s t be s t r e t c h e d t o t h e original dimensions after the action. The soda causes t h e c o t t o n t o become t r a n s p a r e n t , t o swell, a n d t o shrink c o n s i d e r a b l y ; b y resisting the shrinkage t h e lustre is produced, and, b y washing t h e soda o u t of t h e cloth while t h e cloth is stretched, t h e cloth does n o t afterwards shrink w h e n t h e stretching force is removed. Mercer in 1844 noticed t h a t caustic-soda solution caused cotton fibres t o become t r a n s p a r e n t , t o swell, a n d t o s h r i n k ; h e made use of his observation i n t h e production of " c r i m p e d " cloth b y printing caustic soda on cotton cloth. Lowe in 1889 discovered t h a t cotton in t h e stretched s t a t e became more lustrous w h e n t r e a t e d with caustic soda a n d washed while still stretched. He p a t e n t e d t h i s m e t h o d of lustring, b u t allowed his p a t e n t t o lapse. I n 1895 T h o m a s & P r e v o s t r e p a t e n t e d Lowe's idea, b u t t h e p a t e n t was d i s p u t e d a n d became void. Experience h a s shown t h a t for all classes of mercerising, caustic soda of s t r e n g t h n o t less t h a n 55° Tw. should be used, t h a t is, in t h e mercerising m a n g l e , a n d the caustic soda should be k e p t as cool as possible during its action on t h e c o t t o n . Numerous p a t e n t s h a v e been t a k e n o u t 20
MERCERISING
21
for a d d i n g different s u b s t a n c e s t o t h e caustic soda t o increase t h e shrinkage p r o d u c e d in t h e c o t t o n , b u t all t h e s e h a v e p r o v e d worse t h a n useless. P r o g r e s s in t h e a r t of mercerising h a s t u r n e d t o t h e m e c h a n i c a l r a t h e r t h a n t h e chemical side. I n all mercerising machines t h e q u e s t i o n is t h e opposing of t h e force w h i c h t e n d s t o m a k e t h e c o t t o n shrink, for if shrinkage t a k e s place t h e l u s t r e suffers. Cotton c a n b e mercerised as (1) loose, (2) h a n k , (3) w a r p , a n d (4) piece. T h e mercerising of loose c o t t o n does n o t seem t o h a v e y e t a d v a n c e d from t h e e x p e r i m e n t a l s t a g e . Different m e a n s h a v e been suggested for g r i p p i n g t h e fibres a n d t h u s p r e v e n t i n g t h e m from s h r i n k i n g , b u t t h i s h a s b e e n found a difficult m a t t e r . F o r y a r n mercerising t h e r e a r e m a n y m a c h i n e s . T h e principal G-erman machines w h i c h t h e a u t h o r s a w a t w o r k were : (1) Kleinewefer's, (2) H a u b o l d ' s , a n d (3) B e m b e r g ' s . T h e Kleinewefer mercerising e s t a b l i s h m e n t is said t o b e t h e largest of its k i n d in t h e w o r l d . T h e i r h a n k - m e r c e r i s i n g m a c h i n e w o r k s on t h e centrifugal principle. T h e h a n k s are p u t over a p e r f o r a t e d d r u m a n d enclosed b y a n o t h e r d r u m . This d r u m is c o n n e c t e d b y a shaft t o a n e x a c t l y similar d r u m a t t h e o t h e r side of t h e m a c h i n e . T h r e e h u n d r e d kilos of h a n k s a r e p l a c e d over e a c h perfora t e d d r u m , t h e o u t e r d r u m s a r e fixed over t h e h a n k s , caustic soda is a d m i t t e d t o t h e i n n e r p e r f o r a t e d d r u m s , and then these drums carrying t h e h a n k s are made t o revolve b y m e a n s of t h e shaft. Centrifugal force causes t h e caustic soda t o pass t h r o u g h t h e perforations of t h e inner drums, through the hanks a n d into the other drums. F r o m these i t passes b a c k t o t h e s t o r a g e cisterns. T h e i n n e r d r u m s , being s t o u t l y b u i l t , resist t h e shrinkage of t h e h a n k s , a n d i n t h i s w a y l u s t r e is p r o d u c e d . T h e p i p e is t h e n disconnected from t h e caustic-soda cisterns, a n d w a t e r is let i n t o t h e i n n e r d r u m s t o w a s h (again b y centrifugal action) t h e h a n k s . T h e h a n k s after b e i n g t a k e n o u t of t h e d r u m s are furtheT w a s h e d i n v a t s b y h a n d . T h e caustic soda after being u s e d i n t h e m a c h i n e s , of w h i c h t h e r e are m a n y in t h e s a m e r o o m , p a s s e s i n t o a t r o u g h in t h e middle of t h e r o o m a n d thence t o a resexvoix, w h e r e i t is k e p t u p t o s t r e n g t h - T h e w a s h - w a t e r is u s e d for
22
THE DYEING
INDUSTRY
dissolving t h e solid caustic soda used for making up t h e solution in t h e reservoir. The t i m e allowed for the action of t h e caustic s o d a on tlxe c o t t o n was iive minutes, a n d t h e lustre p r o d u c e d w a s seen t o be v e r y good. I t is imp o r t a n t t o note t h a t t h e economy of t h e caustic soda was also said t o be good. Most of t h e i r mercerising was clone in t h e grey s t a t e . Messrs. Kleinewefer informed t h e a u t h o r t h a t t h e y were not allowed t o sell their machine in England, as t h e i r p a t e n t r i g h t s were bought by an English association of m a n u f a c t u r e r s . The H a u b o l d h a n k mereeriser is very much used in Germany. I t consists of two sets of heavy stretching rollers arranged in p a i r s , one over t h e other, and over each pair t h e h a n k s are placed. The distance, between each pair is regulated so as t o give t h e hanks a slight stretch, and t h e n t h e rollers are caused to revolve. I n this way t h e h a n k s are made t o move round and round. The lower Toller is t h e n placed in a t r o u g h containing t.he caustic-soda solution, so that- t h e h a n k s pass in and o u t of this solution m a n y times. Shrinkage is prevented by t h e heavy rollers. After the h a n k s are thoroughly impregnated by t h e caustic solution, the. cau.stic-.soda trough is removed, and t h e h a n k s washed by jets of cold w a t e r while still stretched over t h e rollers. T o economise t h e caustic lye, t h e u p p e r roller is provided with a squeezing roller which, pressing against the h a n k s , causes as much caustic lye as possible, t o flow back i n t o the, trough. T h e machine is m a d e very strong in o r d e r t o withstand t h e great shrinking force exerted by t h e h a n k s when treated with t h e caustic s o d a . A t t h e back of t h e machine there is a similar set of rollers which hav«» t h e name position a n d are continuations of those a t the, front. The, machines are made generally with twelve pairs of rollers, and h a v e a capacity of from 500 t o 1800 p o u n d s of y a r n . Bemberg'n h a v e supplied their h a n k mercerixer t o Germany, F r a n c e , a n d I t a l y . I t i.s m u c h like H a u b o i d ' s in principle, t h e h a n k s being scratched over heavy revolving r o l l e r s ; b u t t h e r e are four t a n k * o r trough;*, e a c h containing t w o p a i r s of rollers. Them* tank* are joined together b y pipes, a n o t h e r net of pipes connecting t h e m with t h e supply of c a u s t i c soda-
MERCERISING
23
I n a v e r y efficient A m e r i c a n h a n k merceriser t h e principle is t h e same as t h a t of the. l i a u b o l d , b u t in t h i s case t h e rollers move along longitudinal p a t h s , t h e u p p e r and lower rollers describing endless p a t h s while c a r r y i n g the hanks. T h e h a n k s are p u t on t h e rollers a t one end of t h e machine, s p u r t e d with caustic, s o d a while passing through t h e machine, a n d washed t o w a r d s t h e end of l-lie passage while still s t r e t c h e d . At t h e farther end of t h e machine t h e h a n k s are r e m o v e d , so t h a t t h e o p e r a t i o n is a continuous one. The m a c h i n e is t h e s a m e a t t h e back as a t t h e front, a n d its removable, glass sides .show w h a t is t a k i n g place within. T h e d r i v i n g is very powerful. This machine is v e r y suitable for large p r o d u c t i o n and is used b y one of t h e associations of m a n u f a c t u r e r s in this country. I n t h e Cohnen machine, t h e h a n k s a r e a r r a n g e d radially on a revolving frame, in a s o m e w h a t similar manner t o t h e m e t h o d applied in the, Klauder-VVVldon machine. I t was t h o u g h t t h a t t h e lustre would be increased b y a l t e r n a t e l y s t r e t c h i n g a n d releasing the. h a n k s while s a t u r a t e d w i t h t h e caustic-soda solution, b u t it wus found t h a t no b e t t e r lustre resulted. W i t h all these h a n k mercerising machines it is found t h a t .some h a n k s have, been less affected by t h e process t h a n o t h e r s , a n d in this case t h e h a n k s w i t h t h e poor lustre are t r e a t e d aguin in t h e machine. W i t h high perfection in mercerising m a c h i n e s , inventive skill h a s t u r n e d t o t h e s a v i n g of t h e c a u s t i c sodu. The h a n k s are well squeezed b y a u x i l i a r y rollers a n d t h e n washed on t h e c o u n t e r - c u r r e n t principle,. T h e washwaters are sometimes used in t h e blo-ach-hou.se, a n d in other cases t h e y are e v a p o r a t e d a n d t h e c a u s t i c .soda used again. Sometimes t h e first w a s h - w a t e r s are re-eaunticiHed and e v a p o r a t e d a n d t h e weaker w a s h - w a t e m used for boiling purposes. H o t water arid direct s t e a m are Hometimes employed t o r e m o v e the. l a s t t r a c e s of c a u s t i c MKIH from t h e material, b u t it is said t h a t b y .such a p r o c e d u r e special effects are produced. T h e swelling of t h e iibrtw in said t o be less t h a n w h e n cold w a t e r alone in used for w a s h i n g ; c o n s e q u e n t l y t h e t h r e a d s o c c u p y less apace, a n d t h e material h a s a h a r s h e r feel. The mercerising of c o t t o n w a r p s is performed on t h e
24
THE DYEING
INDUSTRY
w a r p s l a s l e r or w a r p - d y e i n g m a c h i n e , tension b e i n g produced b y allowing t h e rollers t o t r a v e l a t different speeds. _ . . . . . j mm MacMn.es for piece mercerising m a y be divided i n t o t w o classes : (1) t h o s e in which p e n e t r a t i o n is carried o u t on one machine, t h e cloth, m a d e i n t o a b a t c h a n d s t r e t c h e d on another m a c h i n e ; and (2) t h o s e in which p e n e t r a t i o n is carried o u t on o n e machine, a n d t h e cloth stretched o n t i e same m a c h i n e . A t one time m a n y machines worked b y m e t h o d (1), b u t nowadays m o s t mercerising is d o n e b y t h e second m e t h o d . M a n y different w a y s h a r e been t r i e d for gripping t h e cloth a n d p r e v e n t i n g i t from shrinking u n d e r t h e action of t h e caustic s o d a , b u t in m o s t cases i t has been found t h a t t h e s t e n t e r h a s t o be finally u s e d i n order t o bring t h e cloth, o u t t o t h e desired w i d t h . I t h a s , therefore, become evident t h a t t h e stenter is. t i e best machine t o u s e to keep t i e c l o t l s t r e t c h e d while u n d e r t h e action of t h e caustic soda. Cloth has t o be t u r n e d o u t b y t h e merceriser a t t h e original w i d t h or a t some definite w i d t h , a n d t h i s necessity l a s led t o t h e a l m o s t universal a d o p t i o n of t h e stenter for p i e c e mercerising. At one -works i n t i e U n i t e d S t a t e s t i e a u t h o r found c o t t o n pieces "being ran i n t h e r o p e form t h r o u g h s t r o n g caustic-soda solution, t l e n washed a n d bleached in t i e u s u a l m a n n e r . As a final operation t h e goods were stentered, a n d in t h i s way a fair gloss w a s obtained, although t h e w i d t h w a s n o t fully recovered. One m a n a t t e n d e d t o six m a n g l e s i n w l i c h t h e cloth, w a s s a t u r a t e d with t h e caustic l y e , so t h a t t h e labour cost "was n o t high. T i e m o s t n o t e w o r t h y machines n o t using t h e s t e n t e r for stretching p u r p o s e s are S c h w a b e ' s a n d Jeanm&ire's. I n t h e former, t h e c l o t l is p a s s e d t h r o u g h caustic-soda solution c o n t a i n e d i n a t r o u g h , t h e n between a pair of squeezing rollers, a n d finally o n t o a series of large a n d small r u b b e i - c o v e r e d cylinders. These cylinders are so arranged t l a t t i e clofch is continuously i n contact with one of t h e i r n u m b e r , e a c h cylinder t i g h t l y pressing against t h o s e adjacent. T h e c l o t h l a s t h u s little chance of s l r i n k i n g , and t h e s u c t i o n of t h e cloth a g a i n s t t h e m b b e x acts
MERCEEISING
25
the same direction. T h e cloth is washed while, .si.ilI etched b y passing t h r o u g h t r o u g h s c o n t a i n i n g w a t e r , :hat t h e washing is simpler t h a n on t h e s t e n t e r . T h i s shine gives a good lustre, a n d t h e s h r i n k a g e is said to Dnly half a n inch i n a 27-inch cloth. T h e r e is no d a n g e r selvedge d a m a g e s as on t h e s t e n t e r , a n d no d a n g e r oi ducing a r a g g y cloth b y o v e r s t r e t c h i n g . Sehwalx^s 3hine h a s t u r n e d o u t high-class goods for m a n y y e a r s , . has sometimes been worked n i g h t a n d d a y . Judging n its s t r u c t u r e a n d t h e n u m b e r of rollers its initial 5 m u s t h a v e b e e n h e a v y . The, m a c h i n e s of Keob . Hasslacher are similar in a c t i o n t o t h e one jiwf. bribed. When using t h e s t e n t e r for mercerising, t h e g r e a t .nkage force, resulting from t h e action of ilie* can: tic a on t h e cloth, necessitates caution, when fine cloths treated. I n Schwabe's m a c h i n e , when*, the tension is ributed over t h e whole of t h e cloth, t h e r e is no d a n g e r rearing, b u t on t h e s t e n t e r t h e cloth, is liable t o give r a t a n y w e a k p a r t . I n the, m a c h i n e for which J e a n re took o u t his first p a t e n t , t h e cloth w a s held by ITS, his device being similar in t h i s p a r t i c u l a r t o wabe's machine ; b u t afterwards pins were, used t o hold cloth. T h e a u t h o r saw a J e a n r n a i r e m a c h i n e a t work 1 t h e firm of Koechlin F r e r e s of Miiihausen. Its o u t of fine cloth was five miles p e r d a y . T h e d o t h puweH mgh t h e caustic lye on t o t h e r o u n d surfaces of c y l i n d e r s >se surfaces are covered with a large n u m b e r of pin:., se pins hold t h e cloth and p r e v e n t it/ from .shrinking, ee cylinders are used for this p u r p o s e , t h e d o t h paasing r each. These m a c h i n e s are a t work in G e r m a n y a n d erica, a n d are v e r y s u i t a b l e for t h e mercerising of fine hs. A n e w F r e n c h m a c h i n e s t r e t c h e s t h e c l o t h b y ,ns of a series of c u r b e d b a r e x p a n d e r s T h e ringing l w a t e r t a k e s place directly t h e d o t h leaves tin* irnjnating mangle. T h e e x p a n d e r s are placed b o t h a b o v e below t h e cloth, a n d t h e w a s h i n g is o n t h e c o u n t e r *ent principle. T h e cloth is squeezed in panning from wash-box t o a n o t h e r . The piece mercerising, done a t Bemberg'H of B a r m e n , a t one t i m e s u c h a r e p u t a t i o n t h a t English rnanu-
26
THE DYEING INDUSTRY
facturers were anxious t o ascertain their methods of production. They use the method of " batching " after impregnating with t h e caustic lye. A tight b a t c h is made which after standing some time is t a k e n t o a stenter close by, passed through a n d at t h e same t i m e washed, t r e a t e d with acid, a n d again washed. The machines are m a d e in various sizes, a n d with 6 H . P . t h e y claim t o mercerise 16,000 yards of cloth in ten hours. There was a large plant attached for cooling t h e caustic soda, b u t at t h e time of t h e author's visit it was not in use. I n fact, icecooling plants, which were at one t i m e used, are now seldom seen. Impregnating troughs, however, are made with a double jacket, so t h a t if necessary t h e lye in t h e trough can be cooled b y passing cold water t h r o u g h t h e jacket. I n order t o produce uniform mercerising i t is necessary t o keep t h e caustic soda at a fairly even temperature and not above 65° F . I t is impossible t o obtain a good regular lustre on cloth which has not been thoroughly " boiled o u t " before mercerising. During t h e short time t h e material is in t h e cold caustic lye, unboiled cloth does n o t soak u p t h e lye very well, and uneven mercerising results. This defect is usually shown u p if the cloth is afterwards dyed or bleached, for the properly mercerised p a r t s t a k e u p more dye-stuff and are more affected b y the bleaching liquor t h a n t h e parts which have n o t been thoroughly impregnated by t h e caustic-soda solution. B a d mercerising can be corrected to some extent b y remercerising as previously mentioned in the case of yarn mercerising. When one has experience of mercerising a certain class of goods on t h e stenter, one continually alters t h e machine until the best results are achieved, and it is only after m a n y trials t h a t perfect results are obtained. I n this connection, it is interesting t o recall the observation of Hiibner a n d Pope t h a t t h e greatest shrinkage takes place w i t h caustic soda a t 45° Tw. If lye of 55° Tw. be used, t h e n on washing, t h a t is a t t h e first spirt pipe, sudden shrinkage takes place, or a t least t h e tension is so great t h a t careful w a t c h must be kept. The author came across a machine in t h e United States which h a d been altered after repeated trials made by the managers. After impregnation in t h e ordinary
MERCERISING
27
mangle, t h e cloth passed on t o t h e stentex in the usual way. After a short passage, a n d when still far from stretched t o its full width, t h e cloth was sprayed with t h e strong caustic lye used in the mangle. This arrangement was apparently to dispense with t h e use of two impregnating mangles, a n d t h e idea was t o give t h e cloth another t r e a t m e n t with t h e caustic soda after t h e first dose h a d h a d time t o penetrate t h e cloth. After this t r e a t m e n t t h e stenter gradually widened, and w h e n t h e cloth was a t its full width there was a break in t h e stenter. The cloth t h e n passed between two squeezing rollers, a n d again on to t h e stenter, where it was washed. The manager s t a t e d t h a t this arrangement was t h e best t h e y h a d used, a n d t h e y h a d tried m a n y others. The cloth was certainly a long t i m e in contact with the caustic lye, so t h a t p e n e t r a tion was evidently good. The a u t h o r t h i n k s , however, t h a t t w o mangles, as often used, would h a v e h a d a similar effect. Some works in the United States claim t o have mercerising machines which are b e t t e r t h a n those generally known. Unfortunately these are n o t placed on view. I t m a y be t h a t t h e y have some special devices for overcoming mechanical difficulties, b u t t h e merits of t h e s e machines are probably exaggerated. A t one American works t h e author was shown everything b u t a new mercerising machine and a machine for dyeing sulphur colours. Both these were regarded as being of special importance, b u t t h e partial mobility of labour has probably revealed their " secrets " b y now. I n the Gruschwitz machine for piece mercerising, t h e space t a k e n u p b y t h e stenter is**srf ~ ^ 1 b y arranging g g p a r t of it over t h e lye mang]3. i M y ^^S ^ Jft o f t hhe s t e n t e r passes wholly t h r o u g h w a r m water t o wasn o u t t h e caustic soda. The space required for t h e horizontal stenter is reduced in t h e Weisbach machine b y adopting a vertical arrangement, t h e cloth being stretched on a circular c h a i n stenter t h e two side-wheels of which have axles which are not parallel. The cloth after impregnation enters t h e clips where t h e y are nearest together, a n d as t h e wheels revolve t h e cloth is carried r o u n d a n d stretched. T h e r e t u r n s for Crefeld a n d district, a t t h e t i m e of t h e a u t h o r ' s
28
THE DYEING INDUSTEY
visit, showed t h a t the business of mercerising was n o t increasing and t h a t t h e y were losing some of their m a r k e t s . The export t o t h e United States h a d fallen ofl, as t h e Americans are now mercerising their own yarns, often buying t h e m from England. At t h e same time, S o u t h America and E a s t Asia h a d b y increased d e m a n d partially made u p t h e deficiency. Competition from all quarters is lowering t h e profits in this branch of the t r a d e . On t h e scientific side of t h e subject, work has been done b y Hiibner in contradiction of t h e early work of J . H . Gladstone on t h e action of caustic soda on c o t t o n . Gladstone maintained t h a t cotton combined with caustic soda, when immersed in a strong solution of t h a t substance, t o form definite compounds called " soda celluloses," while in weak solutions t h e caustic soda h a d no such action. Since t h a t time t h e t e r m " soda cellulose " h a s h a d a recognised m e a n i n g ; b u t further work has t e n d e d t o show t h a t such compounds do not exist, a n d practical experience also points in t h e same direction. I t has been shown t h a t cotton absorbs caustic soda from all strengths of solution of t h a t substance in water, a n d t h a t t h e r e is no dividing line as suggested b y Gladstone. Great interest was t a k e n in t h e statement, which e m a n a t e d from Germany, t h a t cotton takes u p considerably more caustic soda from a soda lye which has been saturated w i t h c o m m o n salt t h a n from a lye of t h e same concentration containing no salt. I t was stated t h a t 100 grms. of cotton w h e n immersed in a soda lye containing 12 p e r cent sodium hydroxide absorbed 8*4 grms. of t h e hydroxide, whereas from a 12 per cent solution which h a d been s a t u r a t e d with salt, as much a s § " | f e ^ ^ i r w , were t a k e n u p . I t was t h u s t h o u g h t t h a t s a f e s a ^ ' d supplant some of t h e caustic soda used in mercerising, and t h u s economise this expensive chemical. These statements V e r e tested b o t h on t h e large a n d small scale, wiien it was found t h a t t h e effect of a d d i n g common salt t o a 12 per cent soda lye was t o decrease its mercerising power instead of increasing it. W h e n t h e lye was saturated with salt, t h e mercerised cotton p r o d u c e d h a d n o t t h e same lustre or t h e same a t t r a c t i o n for substantive cotton dye-stuffs as cotton mercerised u n d e r t h e ordinary conditions. Moreover, on allowing t h e c o t t o n
MERCEEISING
29
to shrink while i n t h e lye, it w a s noticed t h a t t h e shrinkage p r o d u c e d was n o t so g r e a t w h e n t h e lye was s a t u r a t e d with salt. L a r g e - s c a l e mercerising showed t h a t t h e addition of s a l t t o t h e lye h a d n o p r a c t i c a l v a l u e . I t is k n o w n t h a t mercerised c o t t o n absorbs more subs t a n t i v e dye-stuff a n d m o r e m o i s t u r e from t h e air t h a n ordinary c o t t o n does. T h e p r e s e n t a u t h o r further showed (Journ. Soc. Chem. Ind*, 1909, xxviii. 188) t h a t t h e moisture absorbed from t h e air b y mercerised c o t t o n increased as t h e s t r e n g t h of t h e lye u s e d i n mercerising increased, a n d was a p p r o x i m a t e l y p r o p o r t i o n e d t o t h e a m o u n t of s u b s t a n t i v e c o t t o n dye-stuff a n d of iodine t a k e n u p from solutions of t h e s e substances b y t h e samples of c o t t o n mercerised w i t h different s t r e n g t h s of caustic soda. As r e g a r d s t h e t e s t i n g of c o t t o n for mercerisation, t w o m e t h o d s were described b y J . H t i b n e r (Journ. Soc. Chem. Ind., 1908, xxvii. 105) while t h e p r e s e n t a u t h o r was his assistant a n d d e m o n s t r a t o r i n t h e D e p a r t m e n t of D y e i n g , Manchester Municipal School of Technology. Of t h e s e m e t h o d s t h e a u t h o r h a s found t h e following v e r y serviceable in p r a c t i c e . T h e p a t t e r n t o b e t e s t e d is first freed from finishing m a t e r i a l a n d t h e n immersed, for a b o u t one m i n u t e , i n a solution of 20 g r m s . of iodine in s a t u r a t e d p o t a s s i u m iodide solution. I t is t h e n t a k e n o u t a n d washed in a t e s t - t u b e w i t h cold w a t e r . Mercerised c o t t o n retains t h e iodine for a long t i m e d u r i n g t h e washing, a n d remains of a blue-black colour, w h e r e a s o r d i n a r y c o t t o n is soon w a s h e d w h i t e . T h e a u t h o r uses t h e iodine solution over a n d over again, merely p o u r i n g i t b a c k i n t o t h e b o t t l e after use, so t h a t t h e m e t h o d is a quick one. I n c o m p a r ing degrees of mercerisatic \, b y t h i s t e s t , i t is necessary t o h a v e t h e samples i n a p p r o x i m a t e l y t h e s a m e physical s t a t e before t e s t i n g . F o r instance, care h a s t o be exercised in c o m p a r i n g t w o p a t t e r n s one of w h i c h h a s b e e n calendared m a n y t i m e s a n d t h e o t h e r n o t calendared a t all, for t h e form of t h e fibre h a s some effect on t h e a b s o r p t i o n of t h e iodine, a n d also o n t h e s u r r e n d e r of t h e iodine t o t h e wash-water. After some experience, however, t h e t e s t is a v a l u a b l e one t o u s e as a guidance. C o t t o n cloth is sometimes given t h e o p e n - w i d t h bleach, t h e boiling being c o n d u c t e d withCcaustic soda T of a b o u t 5° T w . a n d after
30
T H E DYEING INDUSTRY
schreinering t h e goods are sent out as mercerised cloth. The a b o v e t e s t serves to d e t e c t such goods. I t also shows a n y u n e v e n action d u e t o b a d penetration and, w h e n carefully performed, gives some indication of t h e s t r e n g t h of t h e caustic soda used for t h e mercerising.
CHAPTER
V
BLEACHING Development of fclie industry—Effect of chemistry—Efficient scouring— Continuous scouring—Open-width scouring—Electrolytic "bleaching— Steeping of goods—The waxes of vegetablefibres—Bleachingwithout boiling. BLEACHING is now a very different process from w h a t i t was In t h e eighteenth century. A t t h a t time a period of several months was required t o "bleach a piece of cloth, a n d in some cases cloth w a s sent from this c o u n t r y t o Holland t o b e "bleached on t h e grassy plains of t h a t c o u n t r y . F o r instance, our linen manufactures were sent i n t h e spring t o Holland, where t h e y were steeped i n p o t a s h lye, washed, steeped i n b u t t e r m i l k , laid on t h e grass for several m o n t h s , and finally r e t u r n e d in t h e a u t u m n . Afterwards a very similar process became established in this c o u n t r y , a n d t h e goods were no longer sent t o Holland. The i n t r o d u c t i o n of sulphuric acid to replace butter-milk reduced t h e period of bleacMng considerably, and t h e g r a d u a l a d o p t i o n of chlorine compounds eliminated t h e long process of " g r a s s i n g " for m o s t classes of goods. T h e discovery of t h e "bleaching properties of chlorine gas led t o Berthollet in 17S0 practically applying this gas t o t h e "bleaching of textiles. The m e t h o d was introduced i n t o E n g l a n d a n d Scotlaad, b u t it was n o t until Tennant used slaked lime for absorbing t h e chlorine, a n d t h u s m a n u factured bleaching powder, t h a t chlorine compounds became extensively used £OT bleaching. B y t h e introduction of chemicals t h e l e n g t h of t i m e occupied in t h e bleaching process for c o t t o n goods was reduced from seveial m o n t h s t o a few d a y s , 31
32
THE DYEING INDUSTKY
T h e i n d u s t r i a l s y s t e m of bleaching h a s really developed from t h e domestic system, t h a t is in imitation of t h e actions of t h e housewife in boiling t h e clothes w i t h alkali, washing t h e m well with water, a n d spreading t h e m in t h e s u n t o d r y a n d bleach. Moreover, m o d e r n bleaching m a c h i n e r y h a s gradually been evolved from t h e domestic articles. F o r instance, t h e copper has produced t h e kier, a n d t h e domestic dolly t u b , after itself being used in largescale operations for a considerable time, was replaced b y t h e wash-mills $nd, later, b y m o d e r n washing-machines. J u s t as t h e i n t r o d u c t i o n of chemicals shortened t h e period required for bleaching, so h a s t h e introduction of improved m a c h i n e r y caused a similar c u r t a i l m e n t ; b u t it is r e m a r k able t h a t , a l t h o u g h t h e t i m e required for t h e different operations has b e e n v e r y m u c h reduced, t h e old process of bleaching h a s undergone little change. Details h a v e received a t t e n t i o n and some i m p r o v e m e n t s h a v e been m a d e , y e t t h e operations of liming, grey souring, ash boiling, chemicking, scalding, chemicking, souring, a n d washing r e m a i n substantially t h e same. A t t e m p t s h a v e been m a d e t o curtail t h e long scouring operations, b u t these h a v e seldom been successful. L a t t e r l y chemistry h a s been applied t o t h e process itself, b u t it is r e m a r k a b l e t h a t science h a s caused little change in t h e old process. T h e i n t r o d u c t i o n of t h e caustic soda and resin boil h a s certainly replaced lime boiling for some classes of goods, b u t still t h e p r o d u c t i o n of m a r k e t whites is m o s t often performed b y t h e series of operations j u s t described. M a n y good bleachers are i g n o r a n t of t h e science of chemistry, a n d as this science h a s affected t h e m v e r y little t h e y are a p t t o belittle i t a n d appeal t o their empiricism. O n t h e other h a n d , chemists are a p t t o ridicule empirical m e t h o d s . B u t i t m u s t be remembered t h a t a knowledge of chemistry c a n n o t replace experience in t h e bleaching i n d u s t r y ; t h e r e are m a n y observations in practice which t h e chemist c a n n o t explain, a n d he m u s t proceed cautiously while p a y i n g d u e regard t o t h e teaching of experience, i n s t e a d of u n d e r r a t i n g t h e value of t h a t experience. Textile fibres are complex bodies which are n o t t h o r o u g h l y u n d e r s t o o d b y chemists. E v e n p u r e cellulose, t h e basis of vegetable fibres, m a y be considered
BLEACHING
33
as one of t h e enigmas of t h e chemical world, in spite OY t h e large a m o u n t of work which has been performed on that substance. Nowadays, if a n y t h i n g goes wron^ in t h e b l e a c h - h o u s e resulting in " t e n d e r " goods, t h e ° c r v is " o x y c e l l u l o s e . " The chemist knows t h a t oxygen and cellulose h a v e been present during t h e tendering action, a n d he i n v e n t s a word t o explain t h e phenomenon, or r a t h e r t o s c r e e n his own ignorance. The same m a y be said of t h e u s e of t h e t e r m " hydroeellulose." The employm e n t of s u c h t e r m s is an indication t h a t chemists know little c o n c e r n i n g t h e n a t u r e of cellulose. P r o g r e s s i n bleaching has recently been principally on t h e m e c h a n i c a l side. Proper scouring is essential t o good bleaching, a n d this is probably t h e m o s t difficult of" the operations o f t h e craft. All bleachers know t h e difficulty of o b t a i n i n g a really effective and thorough circulation of t h e lye t h r o u g h t h e mass of t h e fabric in t h e kier. E v e n in t h e b e s t c o n s t r u c t e d closed kiers t h e liquor endeavours t o force i t s e l f along t h e walls of t h e vessel, where the cloth is l e s s t i g h t l y compressed a n d consequently offers less r e s i s t a n c e . The remainder of t h e mass is not so well t r e a t e d , a n d t h e result is t h a t t h e bleach is lacking in uniformity. I t is obvious t h a t those p a r t s lying in t h e d i r e c t p a t h of t h e circulating lye will be bleached first, while t h o s e lying v e r y remote will s t a n d a poor chance. If, t h e r e f o r e , t h e boiling of t h e charge be interrupted after a h a l f or one quarter t h e normal time for t h e operat i o n , i n s t e a d of t h e whole q u a n t i t y of cloth being in a uniformly c l e a n s e d condition, some p a r t s will be perfectly cleansed, o t h e r s less so, a n d finally, there will be p a r t s w h i c h a r e only superficially attacked b y t h e lye. F o r this r e a s o n i t is necessary n o t oiily t o employ a higher t e m p e r a t u r e in order t o o b t a i n uniform bleaching, b u t also t o p r o l o n g t h e time of boiling for several hours, whereas f o r t h e complete transformation of t h e impurities of t h e c o t t o n only a s h o r t t i m e is really required. V a r i o u s kiers h a v e been introduced t o ensure evenness i n t h e t r e a t m e n t , a n d some of these h a v e m e t with success. One t y p e l i a s a perforated pipe down t h e middle and a p e r f o r a t e d cylinder lining t h e kier and a t a s h o r t distance from its w a l l . Between t h e perforations of t h e inner and D
34
THE DYEING INDUSTRY
o u t e r cylinders t h e lye circulates instead of being injected t h r o u g h t h e u s u a l non-perforated puffer pipe a n d showered over t h e t o p of t h e cloth. Kiers of this t y p e t h e a u t h o r saw u n d e r construction a t t h e machine works of H a u b o l d , Chemnitz a n d Gebauer, Berlin. I n t h e W a l s h - J a c k s o n kier circulation is p r o d u c e d b y means of a powerful centrifugal p u m p . T h e lye passes from t h e b o t t o m of t h e kier into t h e p u m p , a n d t h e n t o a cylinder containing a coil supplied with high-pressure s t e a m ; t h e lye is t h u s h e a t e d while in t h e cylinder a n d is t h e n forced b y t h e p u m p b a c k into t h e kier. I n all boiling operations t h e principal danger, as before stated, is t h a t of u n e v e n penetration, for in a kier containing t w o t o n s of cloth, t h e lye h a s t o t r a v e l t h r o u g h m a n y layers of fabric. This consideration h a s led t o t h e introduction of scouring a n d bleaching in t h e open w i d t h . I n t h i s s y s t e m t h e cloth is never m a d e into t h e s t r a n d or rope form, b u t is t r e a t e d t h e whole t i m e a t full w i d t h . I t c a n be readily u n d e r s t o o d t h a t this system gives uniform results a n d t h e d a m a g e t o t h e cloth is less, since t h e r e is less chance of t h e cloth rubbing against objects in t h e way during t h e t r e a t m e n t . The J a c k s o n - H u n t kier for o p e n - w i d t h bleaching consists of a cylinder w i t h a horizontal axis and open a t one end. T h e cloth in t h e form of a large " b a t c h " is placed on a special a p p a r a t u s a n d wheeled into t h e kier. The m e c h a n i s m is so arranged t h a t t h e b a t c h can be u n wound, passed over a perforated d r u m , a n d r e w o u n d into a n o t h e r b a t c h . The cloth is, in fact, wound b a c k w a r d s a n d forwards i n t h i s w a y over t h e perforated d r u m during t h e scouring operation, ap.d while passing over t h e perforated d r u m it is subjected t o t h e action of a s p r a y of caustic-soda solution, which is p u m p e d from t h e b o t t o m of t h e kier a n d t h u s t h r o u g h t h e cloth. There is a specially arranged driving geaT t o reverse t h e direction of winding of t h e cloth w h e n each b a t c h has been u n w o u n d . The contents of t h e kier are supplied with s t e a m a t a pressure of 60 lb. p e r s q u a r e inch during t h e operation, a n d i t can be readily u n d e r s t o o d t h a t t h e caustic soda, at t h e t e m p e r a t u r e indicated b y such a pressure, produces a t h o r o u g h a n d v e r y uniform scouring of t h e cloth. Before placing
BLEACHING
35
i t i n t h e kier t h e cloth is passed through a special .-an^a*-i n g machine. This machine consists of a large perforated d r u m placed in a t a n k of caustic soda solution. "Tne oloih p a s s e s over this drum, and t h e soda is forced into it Lv m e a n s of steam which is blown against its surface. The c l o t h is t h e n wound into t h e tight batch for placing in t h e Mer. Gebauer's of Berlin also build a machine ol this kind, i a which t h e cloth is s a t u r a t e d with caustic soda and w o u n d backwards and forwards under steam pressure. T h e Tagliani-Rigamonti p a t e n t continuous kier was i n v e n t e d b y two Milan chemists, and t h e p a t e n t rights were s e c u r e d b y Bemberg's of Barmen, at whose works t h e a u t h o r saw it in operation. Steam of low pressure is a d m i t t e d t o t h e chamber of the machine, which stands o v e r t h e scouring solution, and at one side of the machine a n d outside t h e chamber a head of lye is t h u s created. w i n c h produces a kind of seal for t h e apparatus. The c l o t h passes t h r o u g h this seal, t h a t is, through the head of l y e between t h e pressure chamber and t h e wall of t h e v e s s e l containing t h e lye, and is plaited down between two e n d l e s s chains, which travel continuously over rollers. B e t w e e n these chains t h e cloth is carried along, being a t o n e time immersed in t h e scouring solution, and at another s t e a m e d b y exposure t o t h e pressure steam in t h e chamber. T l i e complete operations consist of (1) immersion in h o t s o d a lye, (2) steaming, (3) reimmersion in t h e lye, (4) r e s t r a i n i n g , and finally, t h e cloth passes through t h e soda l y e in t h e seal a n d o u t of t h e apparatus. The working of t h e chains mentioned suggests complications, b u t devices h a v e been introduced t o ensure against mishaps. The a p p a r a t u s takes u p little space, and for its size has a large c a p a c i t y - T h e scouring liquor is k e p t thoroughly circul a t e d b y means of a p u m p , being drawn from the b o t t o m o f t h e kier a n d showered over t h e cloth, while it is passing t h r o u g h t h e kier. I t is claimed t h a t t h e apparatus can t a k e u p from 2000 t o 8000 y a r d s of cloth, a n d as t h e cloth, a c c o r d i n g t o its n a t u r e , remains in the kier from one t o o n e a n d a half hours, the machine can scour from 20,000 t o 50,000 y a r d s of cloth in t e n hours. I t is also claimed t h a t t h e kier is more economical t h a n the ordinary boiling
36
THE DYEING INDUSTRY
process. The machine t h e a u t h o r saw a n d a few in I t a l y are t h e only ones known t o be in use. I n t h e Welter (Miilhausen) continuous kier t h e inlet and outlet of t h e steam chamber are hydraulic t r a p s , t h e former containing the scouring lye, while t h e other acts as a washing-box. I t has, however, a small capacity for its size, even though the capacity has been doubled b y r u n n i n g two pieces of cloth in together, t h a t is, one u p o n t h e other. Moreover, the apparatus being large, it is necessary to keep the steam pressure low, a n d this is a g r e a t disadvantage. The question of bleaching in t h e w i d t h is as i m p o r t a n t as ever, b u t t h e cost is higher t h a n for t h e ordinary process of bleaching. The apparatus of Welter, Tagliani a n d Muntadas (Paris) give good results, the high cost being their principal disadvantage. The Jackson kier is excellent for heavy goods, b u t here again t h e cost of t h e a p p a r a t u s is high. I n considering t h e merits of these kiers i t m u s t be remembered, however, t h a t t h e J a c k s o n a p p a r a t u s is different from t h e others in t h e sense t h a t it does n o t work on t h e continuous principle, a n d t h a t , unlike t h e other kiers, a high steam-pressure is used. The J a c k s o n Mer undoubtedly produces a perfect scouring of t h e cloth. The Edmeston is another continuous kier. I t w a s t h e first of its kind. I t consists of one large t a n k open a t t h e top, into which another t a n k is placed open a t t h e bottom. Steam is a d m i t t e d i n t o t h e inner t a n k a n d causes a head of lye in t h e space between this t a n k a n d t h e outer one, t h e outer t a n k containing t h e scouring lye. The cloth is passed t h r o u g h this seal of lye b e t w e e n t h e two tanks, into t h e lye of t h e inner t a n k , a n d t h e n , b y means of rollers, i t passes alternately into t h e s t e a m of t h e inner t a n k a n d into t h e lye. Finally, it passes o u t through the other seal of lye. The Tagliani kier is a similar machine, except t h a t it has one seal i n s t e a d of two, and t h e cloth is passed along b y means of c h a i n s instead of by means of rollers* The alternate s t e a m i n g and lye boiling in t h e E d m e s t o n kier is very effective i n bringing about t h e scouring^of t h e cloth. The cloth p a s s e s a t a rate of from 30 t o 50 yards per minute, according t o the nature of t h e cloth. The pressure of t h e s t e a m is of
BLEACHING
37
course low, b u t high, pressures and temperatures ar^ n o : essential for good scouring. I n fact, high pre-st;r-> are used in practice in order t o overcome the main defects of closed kiers, viz. want of movement. Nevertheless it is obvious t h a t a kier of this kind is not suitable for all classes of cloth, but for some purposes the scoiirks produced is quite sufficient. Of new methods of bleaching which have been introduced from time t o time, t h a t of Pick and E r b a n has received a t t e n t i o n . They work the material in a 2-percent solution of turkey-red oil containing chlor-soda, and find this m e t h o d successful for cops and spools. Turkeyred oil a n d castor-oil soaps have also been added t o t h e scouring lyes t o produce more uniform scouring. Other bleaching agents besides bleaehing-powder solution h a v e been tried from time to time, b u t few have n:et with success, a n d bleaching powder still remains the only decolorising agent used t o a n y great extent. Hydrogen peroxide gives an excellent bleach on cotton, but its cost is prohibitive. Sodium peroxide is used for special work. Sodium hypochlorite, made from bleaching-powdex solution b y adding soda ash a n d running off the clear solution, is a commercial article a n d is used in some works. I t has t h e a d v a n t a g e over bleaching powder of being perfectly soluble, so t h a t there is no danger of suspended undissolved particles i n t h e solution. The present author maintains, however, t h a t this danger does not exist in the case of bleaching-powder solution, if this solution be properly prepared, a n d if t h e steeping system of " chemicking r? be used. Bleaching powder is made in large quantities nowadays from chlorine gas, which is made from common salt solution b y electrolytic decomposition: chlorine gas is given off a n d caustic soda solution is left behind. B u t if t h e chlorine gas be not allowed t o escape, b u t is mixed with t h e caustic soda, a solution of sodium hypochlorite containing m u c h common salt is produced. Special electrolysers h a v e been devised t o produce hypochlorite solution in this w a y . I n one of these t h e electrodes aTe placed in a shallow trough, t h e space between t h e m being t a k e n u p b y a series of glass plates covered with platinum-iridium
38
T H E DYEING INDUSTRY
wire a n d s t a n d i n g vertically a n d parallel in t h e t r o u g h . The salt passes i n t o t h e trough from a cooled coil, a n d b y t h e a c t i o n of t h e c u r r e n t it is electrolysed t o give a solut i o n c o n t a i n i n g 3 t o 5 grms. of active chlorine per litre. A n o t h e r electrolyser uses carbon electrodes instead of t h e expensive p l a t i n u m ones, and produces a hypochlorite solution containing as m u c h as 15 grms. of active chlorine per litre. T h e a u t h o r was at one time m u c h impressed w i t h t h e idea of m a k i n g bleaching solution b y t h e electrolysis of c o m m o n s a l t solution, a n d even t h e failure of a bleaching c o m p a n y using this m e t h o d did n o t shake his confidence. L a t e r , however, he h a d a n o p p o r t u n i t y of testing t h e s y s t e m o n a large scale. A n electrolyser of t h e best t y p e w a s o b t a i n e d and worked for m a n y m o n t h s , so as t o give i t a fair trial. The result has been t h a t t h e electrolyser is now idle, several experiments h a v i n g p r o v e d unsuccessful. F r o m time t o t i m e there was trouble in working it, a n d t h e a t t e n t i o n required was far greater t h a n in t h e case of dissolving bleaching powder. I t has often been s t a t e d t h a t electrolytic bleaching liquor is not alkaline, b u t t h e a u t h o r found t h a t in all cases it was. B y t h e decomposition of t h e salt, ions of sodium a n d chlorine are p r o d u c e d : t h e s o d i u m ions r e a c t with t h e w a t e r t o produce caustic soda a n d hydrogen, which escapes, a n d t h e chlorine reacting w i t h this caustic soda produces t h e h y p o chlorite. This is t h e simplest explanation of t h e electrolysis ; a n d chemical equations show t h a t if all t h e chlorine unites w i t h all t h e caustic soda produced t h e solution remains n e u t r a l , as i t originally was. This complete union, however, d e p e n d s on perfect circulation in t h e electrolyser. B u t in a n y case t h e caustic soda c a n n o t g e t out of t h e electrolyser, and, as in practice it is found t h a t some chlorine escapes, t h e result is t h a t t h e caustic soda p r e d o m i n a t e s , t h a t is, t h e solution is alkaline. Donizelli s t a t e d t h a t electrolytic liquor often contained so m u c h caustic soda t h a t certain stains were produced on some cloths, b u t i n s u c h a case as t h i s t h e circulation i n t h e a p p a r a t u s w h i c h p r o d u c e d t h e electrolytic liquor m u s t h a v e b e e n v e r y deficient. Roscoe a n d L u n t , on m a k i n g hypochlorite solution b y t h e electrolysis of s e a - w a t e r , found, on slightly electrolysing it and allowing i t t o s t a n d ,
BLEACHING
39
t h e liquor decomposed xapidly. T H s decomposition was obviously caused b y t k e weak solution oxidising t h e impurities of the s e a - w a t e r , fox stronger solutions did n o t decompose so rapidly, n o r did weak solutions m a d e b y t h e dilution of stronger ones with distilled water. Ou t h e large scale t h e a u t h o r used bleaching-powder solution of 17° Tw. ? a n d such a strong solution contained a relatively small a m o u n t of lime. I t was found t h a t t h e bleaching properties of such a solution were identically t h e same as those of t i e solution prepared "by t h e electrolyser. Moreover, on using sodium hypochlorite (obtained from "bleaching-powdex solution b y adding soda-ash solution, t h e "bleaching powdex being in slight excess) it w a s found t h a t t h i s solution h a d t h e same efficiency as t h e bleaching-powder solution from which it was m a d e , a n d also t h e same as t h a t of t h e electrolytic liquor. A large n u m b e r of bleaching tests proved this (Journ. Soc. Chem. Ind., 1911, xxx. 185), a n d also their rates of decomposition i n air were found t o be t h e same. Among t h e a d v a n t a g e s claimed for electrolytic bleaching liquor axe (1) t h e bleached material is s t r o n g e r ; (2) t h e white produced is more perm a n e n t ; (3) there is a saving of acid i n t h e subsequent souring o p e r a t i o n ; and (4) t h e r e is less loss in weight. As regards these contentions, t h e author has shown [Journ-. Soc. Chem. Ind., 1911, xxx. 1295) t h a t , no m a t t e r w h a t agent b e used for decolorising, t h e cloth m u s t be well scoured, a n d t h a t i t is in the boiling operations a n d n o t in the bleaching pxopeT t h a t t h e principal drop in weight takes place. The tests of t h e author (Joum. Soc. Chem. Ind., 1911, x x x . 185) showed t h a t t h e cloth was not stronger or heavier when bleached b y electrolytic liquor t h a n when bleaching-powder solution was used. As regards cost of production, it was shown (bo. cvt.) t h a t with salt a t 23s. a t o n t h e cost of t h e salt alone was as high as t h e t o t a l cost of t h e bleaching powder, which t h e electxolysex seeks to displace. Similarly w i t h current at f d . a unit, t h e cost of t i e electricity was equal t o t h e t o t a l cost of t h e bleaching powder. B u t m t h cheap salt a n d cheap current, it might p a y t o produce bleaching liquor b y the electrolytic m e t h o d . Electrolytic liquor is very suitable for bleaching
40
T H E DYEING INDUSTRY
wood p u l p , r a w cotton, cops a n d artificial silk, b u t for o r d i n a r y m a c h i n e chemicking, t h e trouble is t h a t no electrolyser p r o d u c e s liquor strong enough for this p u r p o s e (Higgins, Journ. Soc. Dyers and Col, 1912, 254). A n o t h e r i t e m of interest t o bleachers is t h e effect which n e u t r a l salts have in retarding t h e action of t h e lyes d u r i n g boiling. I t has also been recently shown t h a t dextrose r e t a r d s t h e saponifying action of caustic soda. These facts p o i n t t o the advantage of giving t h e " rotten, steep " before boiling, in order t o remove a n y mineral a n d other m a t t e r used in t h e sizing of t h e cloth {Journ. Soc. Dyers and Col, 1912, 254). The work of K n e c h t (Journ. Text In$t.91911, ii. 22-29) on t h e c o n s t i t u e n t s of raw cotton is of great interest t o bleachers. I n t h e first place he showed t h a t cotton y a r n , from which t h e w a x h a d been e x t r a c t e d was stronger t h a n t h e u n e x t r a c t e d y a r n . Since lye boiling t a k e s away m u c h of this w a x , i t is probably on this account t h a t lye boiling is often found to increase t h e tensile s t r e n g t h of c o t t o n goods. T h e present a u t h o r further showed (Journ. ^oc.(77^3m./ncZ.,1914,xxxiii.902)the efficacy of t h e lime boil, followed b y a soda-ash boil, in eliminating t h e waxes from textile fibres. T h e lime boil is n o t a mere survival of the d a y s of empiricism ; it is t h e best t r e a t m e n t for t h e bleaching of certain classes of goods. I t was noticed, on plunging lime-boiled a n d soured cloth into h o t s o d a - a s h solution, t h a t a large a m o u n t of m a t t e r was separated from the cloth, a n d its w a x contents were considerably r e d u c e d ; t h i s fact is p r o b a b l y due t o unsaponifiable a n d saponifiable (now p r e s e n t as f a t t y acid after t h e lime boil a n d sour) c o n s t i t u e n t s of t h e w a x existing together, t h e alkali producing a soap w i t h t h e latter and at t h e same t i m e removing some of t h e unsaponifiable m a t t e r , b y disturbing it and producing a n emulsion. The soap is produced quickly as t h e f a t t y acid is free (unlike t h e w a x i n t h e case of clotli n o t previously lime boiled), and a concentration of the soap in t h e neighbourhood of t h e unsaponifiable w a x is produced. I n s u p p o r t of this explanation, it is interesting t o recall a n e x p e r i m e n t b y Shorter (Journ. Soc. Dyers and Col., 1915, 3), i n which he showed t h a t on adding a
BLEACHING
41
solution^ of a n alkali t o a mixture of a mineral oil and a f a t t y acid, t h e emulsification was practically spontaneous. H e explained this observation as being due to (1) t h e r a p i d i t y of t h e formation of the soap layer, and (2) t h e plasticity of t h e layer. W e have these conditions reproduced in t h e case of t h e lime-boiled and soured cloth p l u n g e d into t h e alkali solution. H e r e t h e wax of the cloth consists of a fatty acid and a n unsaponifiable wax, which for this purpose is similar t o t h e mineral oil. Many m e t h o d s of bleaching without boiling have from time t o t i m e b e e n proposed, b u t t h e present a u t h o r (loc. cit) gives experiments in support of t h e contention t h a t only b y t h o r o u g h scouring can good bleaching be p r o d u c e d / I n fact, if t h e boiling operations be curtailed, t h e n t h e impurities of t h e cloth, which are usually eliminated during t h e scouring, have t o be decomposed b y oxidising agents* a n d figures show t h a t this is a m u c h more expensive m e t h o d of removal. At one American work cotton goods, principally crash and towels, were found to t u r n yellow a n d become " tender " in stock, a n d a n explanation of t h e t r o u b l e was found after a consideration of the method of bleaching. The pieces in t h e d r y state were steeped in bleaching-powder solution of 5° Tw. for one hour, allowed t o d r a i n for a short time, and t h e n washed twice through a n ordinary roller w a s h i n g - m a c h i n e . They were t h e n m a n g l e d and dried. As t o t h e actual cause of t h e " tenderi n g " of these goods opinions m a y differ—chloramines m a y be suggested b y some chemists as t h e cause,—but certain it is t h a t t h e trouble arose because t h e goods h a d n o t been scoured before t h e application of t h e bleachingpowder solution. R e c e n t l y a n u m b e r of substances have been introduced for use in t h e scouring lyes, in order t o remove t h e w a x y m a t t e r s of t h e cloth. I n some cases carbon tetrachloride, n a p h t h a , a n d other volatile organic solvents are mixed w i t h t u r k e y - r e d oil, so as t o form a n emulsion which does n o t readily separate into its constituents. These preparations a c t very well in extracting t h e w a x y m a t t e r s from t h e cloth, b u t their high cost does n o t admit of extensive a d o p t i o n . As a result of some tests performed b y t h e a u t h o r on t h e effect of hypochlorite solutions on these
42
THE DYEING INDUSTRY
waxes, it was found t h a t t h e y were partially decomposed and chlorine substitution products were formed, which yielded more readily t o saponification t h a n t h e original waxes. This observation explained t h e fact t h a t on scalding after " c h e m i c k i n g / ' a large a m o u n t of m a t t e r is r e m o v e d from t h e cloth.
CHAPTER
VI
GERMAN AND ENGLISH FLANNELETTES Use of raising—Cotton blankets—German production—Large-scale production —German and English methods compared — External and internal specialisation—Inflammability of flannelettes. COTTON, unlike wool, does not grow on t i e back of an animal, a n d therefore cannot have the value of wool as a clothing material. Wool is a b a d conductor of heat, whereas cotton is a fairly good conductor. B u t air is also a b a d conductor of heat, so t h a t in a " raised " fabric where a m i x t u r e of cotton a n d air is presented to t h e body t h e h e a t conducted away is less t h a n when unraised cotton cloth is used. I n short, raising greatly improves cotton as a clothing material. Very soon after arriving i n G e r m a n y one encounters cotton blankets. These are made in beautiful designs, b y raising heavy cotton cloths, a n d are found on most German beds. The demand for t h e m is therefore great, and a special industry has arisen t o supply t h e m . Miinchen-Gladbach, t h e centre of this industry, is a severely industrial Ehineland town, which resembles our cotton city only in so far as it is principally engaged in a n industry which deals with t h e cotton fibre. I n and about this t o w n are 400 textile factories employing 42,000 operatives, a n d also 111 engineering works w i t h 4000 hands. Since there are only 62,000 people engaged in industry in this district, and as no other industry employs more t h a n 2500 hands, it is manifest t h a t textiles are t h e chief concern of the people of this town. The author visited factories engaged in t h e production of cotton blankets, and found t h e m distinguished for their economic working. Water-softening plants were often used because
44
T H E DYEING INDUSTRY
of t h e h a r d n e s s of t h e water of t h e district, a n d were of p r i v e d economy. I n t h e preparing-room of one works, I n d i a n c o t t o n a n d cotton-waste from D a r w e n a n d other L a n c a s h i r e t o w n s were seen being t r e a t e d , i n t h e first place, b y m a c h i n e r y of a Manchester maker. Mule-spinning was u s e d i n t h e p r e p a r a t i o n of t h e weft-yarns, a n d only slight t w i s t w a s given, because of t h e subsequent use t o which t h e y a r n was p u t . T h e cotton used for m a k i n g t h e weft-yarns w a s d y e d i n t h e loose state, for if d y e d in t h e cop t h e soft feel so essential for blanket-making is lost. The chief considerat i o n is t h e p r e p a r a t i o n of a good soft oozy weft, and no pains were spared in t h e manufacture. A f-inch staple is used a n d s p u n b y t h e condenser system. As m a n y as six machines are used in t h e preparing, so as t o produce a uniform y a r n a n d in t h i s w a y a uniform n a p when t h e cloth passes t o t h e raising m a c h i n e . The consequence is t h a t , on examining a G e r m a n cloth, little u n e v e n n e s s i n t h e y a r n is apparent, whereas t h e irregular n a t u r e of some English cloths places t h e finishers a t a disadvantage in a t t e m p t i n g t o produce a good raised article. At t h e Gladbach works mentioned above w a r p - y a r n s were bought from other manufacturers in Gladbach a n d R h e y d t , and m a n y coloured y a r n s from which grandrelle y a r n s were m a d e were o b t a i n e d from Saxony. I n t h e weaving-sheds t h e J a c q u a r d looms were seen p r o d u c i n g a v a r i e t y of p a t t e r n s on a coarse, apparently h a r d , cloth. I n t h e raising operation, t h e machines have t o be carefully w a t c h e d in order t o produce a cloth of the r i g h t " f e e l " a n d weight. A t t h e t i m e of t h e a u t h o r ' s visit, operatives for this class of work were difficult t o get, a n d a l t h o u g h t h e i n d u s t r y was in a flourishing s t a t e there w a s a scarcity of skilled workers. Belgians, a n d workers of o t h e r nationaUties, a t one t i m e paid p r e m i u m s in order t o l e a r n t h e business of such a works as described. The cloth, before t h e a c t u a l raising, is s u b m i t t e d t o a felting o p e r a t i o n i n a special machine, so as t o m a k e t h e cloth m o r e solid a n d t o improve t h e feel; a brushing and s t e a m i n g m a c M n e is also used t o improve t h e finish. B y t h e s e processes q u i t e a different article is produced t h a n b y merely passing t h e cloth t h r o u g h t h e raising machine. T h e superior finish of t h e Gladbach goods h a s been attrib u t e d t o t h e good quality of t h e cotton u s e d ; b u t as this
G E R M A N AND ENGLISH FLANNELETTES
io
is a m i x t u r e of E g y p t i a n and Sea Island waste vdth special short staple I n d i a n cotton, success seems to be due to more careful preparation of t h e weft-yarns. A uniform yarn is^ produced from c l e a p material a n d a uniform nap is obtained on t h e raised c l o t l . T h e nap obtained being short a n d uniform, t h e p a t t e r n is clear and the danger o: firing is small. I n England t h e cheaper flannelettes are raised quickly, a long fihrous n a p heing produced. T.iueisimply covers t h e interstices between t h e t l r e a d s and causes a flame t o ran quickly over t h e surface of the fabric. The ^ o r k s described above h a d little t r a d e with England, t h e h o m e m a r k e t being particularly catered for. "Some shipping was done, and t h a t t h r o u g l H a m b u r g . I t vras noticed t h a t a Manchester firm of colour printers l a d been enterprising enough to supply their calendars to \roiks in this district. T i e specialised factories t h a t h a v e arisen in MiinclenG l a d l a c h were originally intended for t i e supply of t h e large h o m e d e m a n d . Large-scale production., however, led t o economic working, a n d after t h e home market h a d been supplied a t t e n t i o n was t u r n e d to t h e building u p of an e x p o r t trade, which soon assumed large proportions. Before t h e o u t b r e a k of war, t r a d e -with England w a s increasing, a n d exports were being made t o other E u r o p e a n countries, as well as to South Africa, British India, Dutch. E a s t Indies, Siam, China, Australia, S o u t l a n d Central America, Mexico, Canada, a n d t h e U n i t e d States. I n m o s t cases a large h o m e consumption leads t o specialisation a n d t o export. Sometimes t h e export t r a d e is v e i y profitable a n d temporarily raises the price at home, b u t i n t h e long xun t h e o u t p u t increases, further economies are introduced, and t h e home price is in consequence reduced. A splendid "blanket can "be bought for four shillings at Munchen-Gladfcack. I n comparing English a n d German flannelettes t h e s t a t e m e n t w a s m a d e t o t h e a u t h o r t h a t , with t i e improved i n a c l i i i e i y used by t h e G e r m a n firms, i t w a s possible to obtain a finish which could n o t b e produced in England. I t was also stated t h a t during t i e last ten years the Germ a n machine had been protected by p a t e n t s in England, wheieas n o s u c l protection existed in CTermany; t l i a t
46
T H E DYEING INDUSTRY
high prices h a d "been charged for t h e English machines and few i m p r o v e m e n t s m a d e ; t h a t German m a k e r s h a v e been d e b a r r e d from exporting their machines t o this country, a n d as a consequence t h e English flannelette t r a d e has r e m a i n e d s t a g n a n t . These statements, m a d e b y different persons, are certainly not a t r u e representation of t h e situation, for t w o of the m o s t p r o m i n e n t of G e r m a n makers of raising machines have been shipping their machines t o t h i s c o u n t r y for m a n y years. I t is t r u e t h a t these firms h a d a d i s p u t e a t one time over certain p a t e n t rights in t h i s country, b u t when this m a t t e r was settled b o t h firms exported t h e i r machines t o us. German textile engineers h a v e a h a b i t of sending their sons t o this c o u n t r y t o receive some e d u c a t i o n a n d incidentally to exploit their m a c h i n e s ; in t h i s w a y a son of one of t h e machine-makers mentioned booked m a n y orders in this country in 1906. I n c o m p a r i n g t h e flannelette t r a d e in E n g l a n d and G e r m a n y i t m u s t be remembered, a t t h e outset, t h a t t h e i n d u s t r y h a s developed in different ways in t h e two countries. T h e German producers of flannelettes spin, weave, a n d raise their own material, b u t i n E n g l a n d t h e m a n u f a c t u r e is principally in t h e h a n d s of t h r e e specialised businesses,—spinners, weavers, a n d finishers. Moreover, in G e r m a n y t h e spinning a n d weaving operations are specially a d a p t e d t o ensure good raising, whereas in E n g l a n d t h e different agents for flannelettes on receiving orders for these goods often also receive stipulations as t o whose y a r n or cloth is t o be supplied, a n d whose finish is t o b e given t o t h e cloth. Certain English manufacturers produce cloths of world-wide r e p u t a t i o n ; customers will h a v e t h e s e cloths a n d no others. Similarly, certain works h a v e a r e p u t a t i o n for their finishes, a n d these productions are likewise i n demand. I t is therefore manifest t h a t t h e a g e n t h a s seldom a free h a n d in t h e m a t t e r , a n d cons e q u e n t l y t h e spinning a n d weaving of t h e cloth used for producing English flannelettes are n o t specially a d a p t e d t o suit t h e raising operation, as t h e y are in t h e specialised G e r m a n factories devoted t o this class of work. Moreover, were a n English firm t o a d o p t t h e G e r m a n m e t h o d a n d u n d e r t a k e all branches of t h e manufacture, t h e y would h a v e difficulty in finding customers unless t h e agents
G E R M A N AND
ENGLISH
FLAXNELETTEs
received no stipulation as t o t i e m a k e of the d o t h t h e finish t o be used for t h e production. Bu t i e organisation of t i e English industry has d i s k d v a : : r ^ such as those mentioned, it m u s t be a d m i t t e d t h a t certain a d v a n t a g e s accrue from t h i s development. Tlie faer :.*• t l a t specialisation i n this i n d u s t r y has become I n t e n u l instead of external i n this country. Specialised nriishins: w o r t s devoted t o raising liave arisen, a n d it is "because of fckis development t h a t t h e English finishers liave Leen able t o keep m a n y branches of t i e flannelette t r a d e entirely in their own l a n d s . Clotks of all kinds pass t h r o u g h t h e h a n d s of t h e English finishers, a n d consequently a* large a m o u n t of machinery is required, since different cloths require different t r e a t m e n t i n t h e raising operation. These machines h a v e "been constantly improved. T h e Germans t r e a t fewer classes of goods, a n d therefore do not require such a v a r i e t y of machinery. The upright English-made mac-line h a s been adopted for certain classes of goods in this country, a n d i t is said t o give a closer a n d less inflammable nap t h a n the usual machines. The 36-roller machine, which was first m a d e in Germany, is now m u c h used in E n g l a n d : a 38-rolIer m a c h i n e lias "been m a d e in F r a n c e . R e t u r n i n g t o a comparison of t h e English, a n d G-erman i n d u s t r y we find t h a t some Lancashire works haye adopted t h e G e r m a n m e t h o d of p u t t i n g t h e cotton t h r o u g h all t i e processes from t i e raw c o t t o n t o t h e finished cloth, b u t t h i s is n o t general. Internal specialisation l a s become t h e practice of t h e English textile industry, because of t h e growth a n d v a r i e t y of t h a t industry. Manufacturers prefer t o send their goods t o outside finishers t h a n t o p u t d o w n machines which they themselves could only r u n intermittently, whereas t h e specialised finishers, b y keeping their machines constantly running, secure t h e m o s t economic production. I n s u m m a r y , we find tlie w o r t s at Miinchen-Gladbact using our machinery a n d o u r cotton-waste t o produce an article which is in great d e m a n d all ever t h e world. They p r o d u c e this article cheaply, because of t h e large scale^ of production, a n d because t h e y have specialised production for one class of article. I n England we also specialise
48
THE DYEING INDUSTRY
in t h e production of flannelettes, b u t our specialisation has developed internally instead of externally. W e h a v e specialised in t h e production of a variety of flannelettes which no other country can excel. B u t it is because of t h e very nature of the development of our industry t h a t we find it difficult to compete w i t h t h e Germans in t h e one class of article which t h e y m a k e well. There is no doubt, however, t h a t we could produce cotton blankets as well as t h e Germans, b u t we would h a v e to do it in t h e same way, namely, b y producing a good low condenser-weft (about 8?s) and following up t h e manufacture carefully as t h e y do. I n t h e past, however, t h e Germans were not our only competitors, for Dutch, Italian, a n d Spanish flannelettes have been sold in this country. As regards t h e inflammability of flannelette, it m u s t be remembered t h a t i t is only t h e low cloths with long irregular naps which are very d a n g e r o u s ; goods which are well raised and have a regular surface are very little more inflammable t h a n t h e unfinished article. Soaking the cloth in certain chemicals decreases t h e inflammability, and this process has been gradually improved, b u t unfortunately those people who have n o t t h e sense t o exercise care when their children are wearing flannelette articles, have also not t h e sense t o p a y a little more for t h e material which has been treated t o m a k e it non-inflammable. Hence t h e complaints of coroners. Moreover, t h e cost of t h e extra t r e a t m e n t required t o m a k e low flannelettes fire-proof, brings t h e price of t h e t r e a t e d material very near to t h a t of well-raised goods which, as before stated, are not dangerous t o wear.
CHAPTER
VII
THE INDUSTRY IN" THE UNITED STATES American conditions—Scarcity of la/bour—large-scale production—"Uncertainty of their industry—Lack of specialisation—Effect of the tariff. W E h e a r so m u c k nowadays a b o u t American progressiveness a n d a b o u t m a n u f a c t u r e r s " s c r a p p i n g 5 ' old machinery to m a k e w a y for new, t h a t any information concerning industrial conditions in. America is welcome. The author's experience is t h a t America l a s not much, t o teach us as regards t h e dyeing industry. Some machines were seen which are worthy of m e n t i o n ; a few of these have "been devised because of t h e scarcity of labour, since some of t h e mills of isTew England could not, a t t h e t i m e of t h e a u t h o r ' s visit, be r u n a t fclieir full capacity, because hands could n o t b e obtained. Moreover, t h e enormous influx of foreigners does n o t supply all demands, fOT t h e poorest classes of l a b o u r are difficult t o obtain, and in t h e summer m o n t h s colour strainers a n d mixers are missing from t h e print-works because of t i e objectionable smells of acetie acid a n d other chemicals. I n the manufacturing t o w n of Passaic, N e w Jersey, which has a population of 35,000* every race of people is said t o be represented, a n d costumes of all nationalities are seen in the streets, while i n t h e N e w E n g l a n d cotton mills t h e Irish work-people are being gradually displaced b y Hungarians, Greeks, a n d French Canadians. The American cotton and woollen industries, and particularly t h e dyeing branches of these industries, are so different from ouis t h a t often different conditions a n d m a c h i n e r y are necessary. T h e American home demand is so large t h a t t h e manufacturers a i e n o t so particular a s 49 E
50
THE DYEING INDUSTRY
we a r e as t o t h e material t h e y t u r n out. American people all desire t o be well dressed, a n d as different seasons of t h e y e a r d e m a n d entirely different clothes, a huge d e m a n d arises. T h e calico-printing done is essentially t h a t of t h e million, a n d t h e very best stuff is either i m p o r t e d or m a d e b y a few concerns. F o r instance, t h e h e a d of one of t h e largest firms in N e w E n g l a n d s a i d : " H e r e w e p r i n t or d y e a whole lot, p u t it on a train, a n d send i t in the direction of California; i t soon sells. I n America there is a h u g e m a r k e t , whereas in E n g l a n d y o u h a v e different designs for different m a r k e t s . Y e t t h e English business is surer. A manufacturer knows how m u c h t h e grey takes for bleaching, how m u c h for mercerising, dyeing, printing, or finishing, a n d if h e w a n t s a t u r k e y - r e d he knows how m u c h h e has t o p a y t h e dyer. R e c k o n i n g in t h i s way he can arrive a t t h e cost of placing t h e goods in his customer's hands, and b e assured of his profit. B u t in our case, where we perform t h e whole of t h e operations from spinning t o finishing, we h a v e t o wait u n t i l some period of t h e year when t h e a u d i t tell us our fate. I n America we aim a t t u r n i n g out t h e stuff cheaply and q u i c k l y / ' Most mills u n d e r t a k e t h e whole of t h e operations from t h e r a w material t o t h e finished article, nor does t h e i n d u s t r y show m u c h sign of modification in this respect. I n s t e a d of specialising internally we find t h e mills extending their scale of operations. F o r example, t h e Gera Mills, Passaic, N e w Jersey, h a v e begun t o spin their own y a r n s for t h e m a k i n g of woollen piece-goods for which t h e y have already a reputation. I n New E n g l a n d some specialised works are arising, owing t o t h e r a t h e r highly developed state of t h e i n d u s t r y i n this p a r t , a n d managers are hoping for a t i m e w h e n goods will be d y e d on commission, as is done i n this country. Specialised bleach-works a n d dye-works h a v e been installed a t Fall River, Lawrence, a n d other places, a n d English conditions h a v e ensued a t N e w Bedford in t h e separation of t h e spinning a n d weaving branches of t h e i n d u s t r y . Moreover, t h e e x t e n t a n d homogeneity of t h e American m a r k e t h a s led t o t h e production of large quantities of t h e same material, a n d h a s t h u s b r o u g h t a b o u t t h e economies incident t o large-scale production, a n d a t t h e
T H E I N D U S T R Y IN T H E U N I T E D STATES
51
s a m e t i m e m a d e t h e i r i n d u s t r y of a p a r t i c u l a r a n d u n i q u e c h a r a c t e r . A m e r i c a is too occupied w i t h t h e developm e n t of h e r o w n m a r k e t for textiles t o give m u c h a t t e n t i o n t o t h e e x p o r t t r a d e ; b u t t h i s d e v e l o p m e n t is b o u n d t o t a k e place, a n d a l r e a d y s o m e of t h e N e w E n g l a n d p r i n t w o r k s ship some v e r y fine p r i n t s . W i t h t h e change a n d increase i n t h e v a r i e t y of h u m a n t a s t e s e v e r y b o d y lias s o u g h t t h e b e s t m a t e r i a l , a n d t h i s c i r c u m s t a n c e h a s led t o t h e c r e a t i o n of a large class of good i m i t a t i o n s i n order t o m e e t all p u r c h a s e r s . I t is said t h a t i n t h i s class of w o r k w e a r e b e h i n d h a n d , a n d p o i n t i n g t o t h e foreigner we a r e u r g e d t o a d a p t ourselves t o t h e c h a n g e of circums t a n c e s . T h i s s u p p o s e d b a c k w a r d n e s s i n t h e a r t of i m i t a t i o n h a s n o t , however, a l w a y s been one of o u r failings, for, t o t h e former possession of this t r a i t in o u r characters, A m e r i c a owes m u c h of t h e f a m e of h e r c o t t o n goods i n E a s t e r n m a r k e t s . I n t h e "sixties we used t o send c o t t o n goods t o China, which c o n t a i n e d m o r e filling t h a n t h e y d i d c o t t o n , a n d i n some cases t h e y were k n o w n e v e n t o crack. China clay a n d o t h e r fillings were e m p l o y e d t o c a t e r for a p p e a r a n c e s a n d also t o s a v e c o t t o n , a n d so m u c h filling w a s d e m a n d e d t h a t t h e finishers complained t h a t t h e t r e a t m e n t w a s r u i n i n g t h e i r m a c h i n e r y . Moreover, m i l d e w w a s a frequent occurrence in t h e s e goods, as a t t h a t t i m e a n antiseptic w a s n o t used i n t h e finishing m i x i n g s . After t h e Civil W a r , A m e r i c a n m a n u f a c t u r e r s s e n t o u t goods w h i c h c o n t a i n e d v e r y little finishing material, a n d v e r y soon A m e r i c a n drills a n d sheetings b e c a m e of w o r l d - w i d e fame. N o w a d a y s we send similar goods a n d n o t h e a v i l y filled cloths t o c o m p e t e i n t h e s a m e markets. T h e h i g h A m e r i c a n tariff h a s in m a n y cases caused foreign m a n u f a c t u r e r s t o establish b r a n c h e s i n t h e U n i t e d S t a t e s , a n d often t h e m a c h i n e r y a n d h a n d s t o o p e r a t e i t h a v e b e e n i m p o r t e d . B u t after a t i m e some of t h e s e b r a n c h e s h a v e b e c o m e Americanised a n d changed i n c h a r a c t e r . T h e G e r a woollen mills is a b r a n c h of t h e firm a t Gera, G e r m a n y , t h e employees, machines, a n d m e t h o d s h a v i n g b e e n b r o u g h t over from t h e p a r e n t works. T i t u s S a l t ' s of Saltaire h a v e a b r a n c h i n B r i d g e p o r t / Conn., which is in a f u r t h e r s t a t e of d e v e l o p m e n t , h a v i n g b e c o m e
52
THE DYEING INDUSTRY
an A m e r i c a n concern. Originally i t h a d English, employees, b u t n o w only t h e principals are English b y birth. Linen t h r e a d mills h a v e also been established, which import t h e i r m a t e r i a l from t h e p a r e n t works a n d t h u s escape the tariff.
CHAPTER
VIII
LOWELL, LAWHENCE, AND PALL RIVER, MASS. Lowell—The town and its industry—Merrimack Manufacturing Company— Hours and conditions—Turning to finer work—Production of machines— Employer and employed—Hamilton Manufacturing Company—Arrangement of works—American worker—Lawrence and its industry—Pemberton. Works—Pacific and Arlington Mills—Fall River—Water supply— Fall River Bleachery—The drying of cloth—Barnaby Works—Bridgeport, Conn.—Salts Manufacturing Company—Klauder-Weldon dyeing machines. T H E t o w n of Lowell is b r i g h t e r t h a n m o s t English m a n u facturing t o w n s ; i t is nicely s i t u a t e d i n t h e c o u n t r y , and a b o u n d s i n a m u s e m e n t s of t h e best k i n d . T h e r e is also a splendid l i b r a r y a n d a technical i n s t i t u t e . T h e p o p u l a t i o n is 100,000, a n d t h e r e a r e forty mills engaged in different b r a n c h e s of t h e textile i n d u s t r y . Bleaching, dyeing, a n d finishing are usually performed b y t h e big works themselves, b u t t h e r e is one specialised bleachery. Lowell is well served b y t w o railroads. T h e M e r r i m a c k Manufacturing C o m p a n y h a v e t h e largest mill i n Lowell. T h e y m a n u f a c t u r e plain a n d fancy c o t t o n goods, linens, towels, a n d corduroys. T h e capital of t h e c o m p a n y is $4,400,000, a n d 140,000 spindles, 7200 looms, a n d 21 p r i n t i n g - m a c h i n e s a r e used in t h e works. T h e m a n a g e r of t h e p r i n t i n g d e p a r t m e n t c a m e from Manchester, E n g l a n d , a n d t h u s was able t o c o m p a r e English a n d American conditions in t h e d y e i n g a n d p r i n t i n g i n d u s t r y . T h e firm willingly allowed visitors to go over t h e i r works. T h e r e w a s a c o m b i n a t i o n of m a n u f a c t u r e r s allowing s e r v a n t s of t h e different w o r k s t o visit other w o r k s i n t h e combination, a n d t h i s a r r a n g e m e n t w a s found t o b e t o t h e m u t u a l benefit of t h e w o r k s 53
54
THE DYEING INDUSTRY
themselves. A m a n might get a n idea from visiting a neighbouring works, a n d he m i g h t use t h i s idea a d v a n tageously, without in a n y w a y hindering t h e works from which he obtained t h e idea. This combination was really a pool of knowledge, a n d t h e m a n a g e r of t h e Merrimack W o r k s t h o u g h t it was t h e best w a y of conducting i n d u s t r y , since it was useless t o a t t e m p t t o keep secrets. B u t all t h e works do n o t grant t h e same concession t o strangers, as regards looking over their p l a n t , a n d some firms are becoming very strict a n d exclusive. F o r instance, t h e r e are two print-works in N o r t h A d a m s , Mass., where rivalry is so bitter t h a t t h e operatives from one works are n o t allowed t o discuss business m a t t e r s with t h e operatives from t h e other. This behaviour, however, w a s n o t approved b y other employers i n t h e i n d u s t r y . I n t h e Merrimack W o r k s n o secrets are allowed. All t h e mixings used in t h e different d e p a r t m e n t s are k n o w n t o t h e principals, since t h e y consider t h a t t h e y know more a b o u t t h e dyeing, printing, a n d finishing of their own cloth than, say, a foreman newly introduced from a b r o a d . Some time ago t h e y h a d a case of a n indigo-dyer who refused to give full particulars of his mixings a n d m e t h o d s . This m a n h a d t o be discharged. I t is essential t h a t t h e managers of a works should h a v e full information regarding all t h e separate processes of t h e w o r k s so as t o t r a c e b a c k a n y faults which might occur, a n d also t o see t h a t as little waste as possible takes place. A t t h e Merrimack W o r k s a book in each d e p a r t m e n t records w h a t is going on therein. T h e colour-mixing is of course a n i m p o r t a n t p a r t of t h e industry, and n o dyer is allowed t o m i x his own colour. Moreover, t h e dyer is n o t allowed t o t a k e a n y p a r t i n t h e buying of t h e dye-stuffs, a n d on receiving his dye-stuffs he is often ignorant as t o t h e firms which h a v e supplied t h e m . The manager said h e h a d never m e t a dyer who could mix colour; t h e y usually a d d e d t h e dye-stuff t o t h e b a t h in pinches instead' of t a k i n g t h e greatest precautions t o ensure perfect solution. I n t h e colour-mixing room t h e r e w a s a strong smell of acetic acid, and, as s t a t e d before (p. 49), i t is because of this unpleasantness t h a t t h e m a n a g e m e n t h a v e t h e g r e a t e s t difficulty in t h e summer m o n t h s of getting m e n t o w o r k
LOWELL
55
in t h i s d e p a r t m e n t . I n fact, t h e scarcity of labour does n o t only a p p l y t o such low-grade labour, b u t is evident in all b r a n c h e s of t h e i n d u s t r y . F o r instance, p a r t of t h e weaving-shed a t t h e Merrimack W o r k s was s h u t down a t t h e t i m e of t h e a u t h o r ' s visit because of t h e lack of operatives, a n d a n A m e r i c a n professor t o l d t h e a u t h o r t h a t , for t h e s a m e reason, h e could n o t get a fence p u t r o u n d p a r t of his garden. Y e t in all t h e open spaces of N e w E n g l a n d m a n u f a c t u r i n g t o w n s , a n d p a r t i c u l a r l y in Lawrence, m e n are seen lounging a b o u t a n d a p p a r e n t l y escaping t h e work. A t t h e Merrimack W o r k s t h e w o r k i n g h o u r s a r e 10£ a d a y , a n d a stoppage is m a d e a t n o o n on S a t u r d a y s . T h e m a n a g e r said t h a t t h e m o s t successful w o r k s were those which employed t h e highest-paid h a n d s , h a d t h e works scientifically m a n a g e d , a n d used t h e latest m a c h i n ery. T h e A r n o l d W o r k s a t N o r t h A d a m s , Mass., is t h e best p r i n t - w o r k s in t h e country, a n d their fine p r i n t s c o m m a n d a foreign m a r k e t . T h e y a r e a n old-established works, which h a v e specialised in fine p r i n t s , a n d h a v e been v e r y successful. Their success, h e said, was d u e t o specialisation, t h e e m p l o y m e n t of t h e b e s t h a n d s i n t h e c o u n t r y , good m a n a g e m e n t , a n d t h e u s e of t h e l a t e s t m a c h i n e r y . Only t h e firm w i t h t h e l a t e s t m a c h i n e r y could survive i n t h e long r u n , a n d if a firm m a k e s big profits, these should n o t b e all paid a w a y in dividends, b u t a p o r t i o n p u t t o reserve, i n order t o ensure even g r e a t e r profits in t h e future. T h e b e s t i n v e s t m e n t is t h e " s c r a p p i n g " of inefficient m a c h i n e r y t o m a k e w a y for l a t e r i n v e n t i o n s . T h e m a n a g e r t h e n spoke of t h e a d v a n t a g e s of specialisation, a n d t h i s d e v e l o p m e n t h e regarded as t h e t r u e road t o success. Schoenhof, i n his Economy of High Wages, s t a t e s : " A n E n g l i s h paper-mill b o a s t s of m a k i n g one h u n d r e d a n d s i x t y varieties, whereas a n A m e r i c a n mill confines itself t o one, a n d whereas a Salford mill weaves m a n y k i n d s of cloth t h e y (Americans) t r e a t of few." T h e r e is t h u s a certain k i n d of specialisation in A m e r i c a ; b u t t h e m a n a g e r of t h e M e r r i m a c k referred t o t h e English k i n d of specialisation, namely, t h a t i n which a works d e v o t e s itself t o one class of operations only. A t t h e Merrimack W o r k s t h e y recognise t h a t t h e y a r e t r e a t i n g t o o m a n y k i n d s of cloth. T h e y h a v e a r e p u t a t i o n
56
THE DYEING INDUSTRY
for their coarse goods, having m a d e these since 1823, b u t they have found t h a t treating these goods and their fine goods with t h e same machinery did n o t p a y . T h e y are consequently going in more and more for t h e finer goods. This trade was t h e more profitable, a n d t h e price of cotton had not so much influence as it h a d on t h e cost of production of the coarser goods. A t one time the Southern growers combined, and would only supply a certain a m o u n t of cotton. The manufacture of their coarse cloths was thereby severely affected, a n d t h e y h a d t o s h u t down p a r t of their mills. I t is thus seen t h a t American i n d u s t r y is affected as ours is by speculators i n cotton. Moreover, wMle at Chemnitz t h e author found t h e Germans m u c h interested in t h e presidential election i n t h e United States, as they considered this event decided t o a large e x t e n t t h e stability of t h e cotton market. As regards his own department, t h e manager a t t h e Merrimack said, t h a t if t h e y took other people's cloth and printed it a t so m u c h per piece t h e y m i g h t be more prosperous and more certain of some profit. A t present t h e y were making a n effort t o t u r n out finer counts, a n d t h u s t o lead to fine prints. Although E n g l a n d h a s m a n y more spindles t h a n America, yet t h e l a t t e r country consumes more cotton, a state of affairs due t o t h e fact t h a t English yarn has grown finer and finer. Long training and heredit a r y skill, among other things, accounted for this a d v a n tage of t h e English, a n d he t h o u g h t t i m e would bring England and other countries nearer together, certainly E n g l a n d and America closer, and, he hoped, Bolton a n d Lowell. At this works there is a mercerising-machine (described on p . 26), and also a machine for giving a slight mercerised finish (p. 24). These machines were built in their own shop, where t h e y employ m a n y m e n a n d make m o s t of their own machinery. This system of a t t a c h i n g machineshops t o t h e works was also found in Germany, and serves to show how m u c h more specialised t h e textile industry has become in England. Those exploiting industries in new countries can speak of t h e annoyance caused b y t h e lack of machine a n d other subsidiary industries, and, in order t o ensure success, these subsidiary industries h a v e t o be built u p along with t h e p r i m a i y ones. B u t specialised
LOWELL
57
m a c h i n e - s l o p s are a o w arising i n all districts of t h e United S t a t e s , a n d gradually t i e conditions are coniin^- t o resemble t h o s e existing in this country. They l a v e a B i r d (English) soaper and also m a n.V y c o p i e s of t h i s machine, a M a t t e r a n d P l a t t ager. and some o f t h e same firm's printing maclinexy. T h e y a r e gradually I n t r o d u c i n g t h e i r own machines in place of t i e imported a r t i c l e s . Beetling w a s done at one time, b u t was found t o o expensive a finishing process for t i e class of goods s o l d in t l e i r markets. Some of their stentering raaeMnes 'were enclosed in glass a n d wood frames. These enclosures confine the heat, t u t a t t h e same time t h e y d o n o t allow t h e moisture to escape freely from t i e cloth which is drying o n t i e stenter. B u t a n i m p o r t a n t point is t h a t t h e y prot e c t t i e operatives from t h e t e a t , and t h u s ensure t l e i i x e g n l a r a t t e n d a n c e . In other stenter d r y i n g machines s t e a m - p i p e s ^ e r e placed directly undex t h e travelling cloth, a n d t i e moisture driven o S t h e cloth was allowed to escape freely. The pipes were enclosed in order t o confine tleix h e a t , b u t t h e cloth w a s freely exposed. T i e l o t - a i r diving a r r a n g e m e n t was also in operation, b u t t h e second system m e n t i o n e d , namely enclosed steam-pipes and exposed cloth, "was found t o "be t i e l e s t . F e w jiggers were used i n t h e dyeing department, most of t h e dyeing being done b y padding. A large a m o u n t of p a r a - n i t a n i l i n e l e d and naphthylamine claret l a d been d o n e by t l e m , b u t t l e r e was little demand for these goods a t t h e t i m e of t i e author's visit. Turkey r e d Tvras too e x p e n s i v e for t i e ijtneriean market. I n t i e p a s t t h e Meiximack Company have h a d much t r o u b l e w i t l t h e i r operatives, "but manufacturers have c o m b i n e d a n d t a k e n a firm stand o n some occasions. T i e m a n a g e r said t h a t if they once yielded, t h e y would have l i t t l e peace afterwards. B y agreement they s l u t down all t h e mills immediately one radii's hands strike, and t h u s a l l Lowell is idle. Then t h e operatives soon, surrender, a n d resume o n t h e old conditions. There was a strike of e n g r a v e r s a t one time, a n d t h e Merrrmaek Company, i n s t e a d of submitting, sent all their rollers t o England t o b e engraved. This action cost t h e m §300,000, h u t they g a i n e d i n t h e long run.
tf 5
THE DYEING INDUSTRY
Beierring to engraving, lie said t h e y were forced t o keep a large n u m b e r of rollers i n stock, b u t , owing to t h e high price of copper, t h e y took risks a n d t u r n e d rollers down even when there was a possible chance of a r e p e a t order. English firms, having more designs, h a v e t o keep a bigger stock of rollers. The M e r r i m a c k C o m p a n y , like other similar firms, makes its own p a t t e r n - c a r d s a n d does its own m a k i n g - u p and packing, b a t t h e y h a v e outside selling agents. At one time t h e operatives were m o s t l y English and Irish, b u t now t h e y a r e of m a n y nationalities, Greeks a n d Armenians predominating. The operatives are encouraged t o work u p t o t h e i r utmost capacity. A t one time, if a w o r k m a n r e t u r n e d more t h a n t h e usual a m o u n t of work, t h e foreman u s e d t o stop t i e excess; b u t this procedure h a s been stopped, a n d the men are allowed t o t u r n out as much, w o r k a s t h e y can. The machines are r u n a t a high speed, because it would not p a y t o r u n t h e m slower. T h u s , i n t h e p r i n t i n g d e p a r t ment the machines never stop r u n n i n g from 6 A.M:. t o 5.30 P.M. ; t h e printer stays b y t h e m a c h i n e all d a y , n o t even leading it for meals, which are t a k e n a t irregular intervals. The American workmen r u n their m a c h i n e s a t t h e greatest capacity, and endeavour t o get t h r o u g h as m u c h work as possible; whereas in England, so t i e m a n a g e r said, t h e Trade Unions restrict o u t p u t a n d l i n d e x development. H e said t i e m e n were too m u d . i n league in E n g l a n d , while in America t h e slightest united m o v e m e n t is detected, and, whenever possible, prevented. Yet it is difficult t o strike a h a p p y m e d i u m between t h e cause of labour and t i a t of industrial development. I t must b e remembered t h a t other c o u n t r i e s are developing towards our position as regards t i e power of labour, a n d in the near future i t will b e found i n America t h a t t u r n i n g a whole t o w n idle from t i m e t o t i m e "will n o t solve all t k e employers' troubles. F r o m t i m e t o t i m e we h a v e h a d instances i n this c o u n t r y of t h e t e n d e n c y of l a b o u r to hinder t h e introduction of new machinery. This policy is of course a "bad one for all concerned, for if we a r e t o k e e p our industrial position t h e efficacy of n e w machinery m u s t be recognised. Tlte development a n d progress of our industries during t i e last h u n d r e d y e a i s i a v e been t r u l y
LOWELL
^
maryellous, surpassing b y far the progress ira-le ^ ^ ^ previous history of tlie v o i l d , but the rarrld ^ v ^ . - - 7 " t i e U n i t e d States a n d of Germany in rec-n: : : : ^ L.> perhaps "been even more phenomenal. These auvar.r
