Rotor Spinning Machine R 40 - Trend-Setting Innovations for ... - Rieter

Rotor Spinning Machine R 40 - Trend-Setting Innovations for Profitable Rotor Spinning

Rotor Spinning Machine R 40 - Basis for Profitable Rotor Spinning Dr. Stephan Weidner-Bohnenberger, Head Product Management Rotor, Rieter Ingolstadt Since ITMA Asia in 2001, the Rieter R 40 rotor spinning machine has set new benchmarks by an optimized combination of the most advanced spinning technology and a most modern machine concept. The official sales release of the R 40 was in 2002. The R 40 impresses the customers by its high productivity and by its fast and reliable automation. In this article, we can only point out some of the benefits of this new machine. Features such as the ease of operation, user friendliness and the simple approach to maintenance can be mentioned, but they must be experienced to create the full impression.

Optimal combination of leading technology and modern machine concept The R 40 is the combination of a new core, the spinning box SC-R, and as a basis, the reliable R 20. Its realization became possible after Rieter took over large sections of the Suessen Group at the beginning of 2001. The target was to combine the most interesting features of the Suessen spinning box, a further development of the 2.5 million spinning boxes delivered worldwide, and the most advanced automation concept of the R 20.

As a result, the R 40 is characterized by: • An optimal yarn quality with the most technologically advanced spinning box.

Fig. 1: Optimal combination of leading technology and modern machine concept

• The spinning box has an optimized geometry to the machine and an exceptionally good spinning stability which enables the achievement of highest production speeds. • Rieter basic machine concept with the biggest can and package dimensions offers an increase in productivity for a given floor space. • The modern Rieter automation concept has been improved to attain high piecing reliability and quality at the highest speed. The result is maximum machine efficiency at very high productivity. • An innovative drive system has been implemented to minimize energy consumption.

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Superior yarn quality with the most advanced spinning box technology Fig. 2: Advantageous yarn quality with the most advanced spin box technology

The new SC-R spinning box is based on the high quality of the previous generations and compared to other spinning boxes available on the market, and includes a number of innovative features, of which the main ones are: • The fixed fibre beard support guarantees constant conditions at the point in the spinning box, where the opening roller combs out the sliver. In the SC-R box this point cannot be influenced by any differences in the shape of the sliver, e.g. given by the pressure inside the spinning can. • The adaptable BYpass allows the extraction of trash and small fibre parts by the opening unit to be influenced. The adaptation of the airflow in the trash extraction chute of the SC-R spinning box results in better spinning conditions. High trash content in the sliver exerts less influence on the yarn quality.

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• The unique possibility to adapt a special opening unit offers further improvements in yarn quality and productivity compared to a standard spinning box. This unit is of special interest for customers, specialising in synthetic fibers. The SC-R spinning box can be equipped with a wide range of spinning elements, such as rotors from 28 to 56 mm diameter, nozzles and opening rollers with different surface structures and coatings. This range is subject to a steady growth due to constant research & development in our laboratories and by further development of materials and coatings. As a remarkable difference to other suppliers, the SC-R box also can be equipped with special channel inserts with a SPEEDpass allowing the increase of the airflow particularly in the opening unit. Additional airflow for example, helps to support the fibre transportation when producing coarse yarn counts at high production speeds.

Best spinning stability for highest production speed

Fig. 3: Best spinning stability for highest production speed

Rotor spinning is a well established spinning process today. The high spinning speeds are in tune with the stability of the spinning box. Extensive investigations have shown, that the distance between rotor groove and takeoff roller is crucial for optimal spinning conditions. The incorporation of the SC-R spinning box in the R 40 machine provides an especially sharp angle between the axle of the nozzle and the direction of the yarn. This increases the false twist effect before the TWISTstop element and thus increases the spinning stability. A higher spinning stability facilitates either the application of higher rotor speeds or the reduction of the yarn twist and therefore the increase of the delivery speed.

Sketch Cross section Sp9inning geometry

With its excellent conditions for spinning stability, the SC-R spinning box permits achievement of the highest productivity per spinning position. Customers familiar with several types of Rieter rotor spinning machines report significantly increased spinning speeds with the same sliver for the same knitting yarn compared to the last version of the R 20. Cross-checks performed at customers, who have installed the latest technology of our competitor’s spinning box showed an 8 % higher production per position with the identical products. This advantage can be used to increase the mill productivity as well as to revise the raw material requirements in order to reduce its cost.

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ning positions facilitates the placing of cans as big as 18_” (470 mm) in diameter in a spacesaving two rows arrangement under the machine. Additionally a significantly narrower plant layout is possible with R 40 . The combination of extra-wide gauge and substantially narrower machine width makes the R 40 the most productive machine per given floor area. The R 40 winding units can produce very large packages with a diameter of 340 mm. This allows - by far – the heaviest packages on the market. Compared to other machines, the number of cans and packages to be changed and moved is reduced by up to 20%! This saves labour, reduces the number of empty tubes in circulation and reduces interruptions of the spinning process, which influence the machine efficiency. The wax blocks in the yarn waxing device are about 4 times bigger then in competitors machines. This also reduces the frequency and cost of changing the waxing blocks. Fig. 4: Lowest floor space requirement combined with largest cans

Productivity by a modern machine concept For a profitable operation, the combination of those very high productive spinning boxes in a machine has to be accompanied by intelligent machine features. The machine drives of R 40 allow rotor speeds of up to 150’000 rpm and a possible delivery speed of up to 255 m/min. This gives scope for high productive spinning of high quality yarns, also covering increases by future developments of spinning elements. A rotor spinning machine with a large number of rotors and a high productivity, has to handle a large volume of material in a large number of cans and has to handle many yarn packages. Faster production increases the frequency of package changes. So the machine automation has to be able to handle more spinning positions, and more stops. The modern concept of R 40 fulfils these requirements. It allows the biggest possible use of transportation units: The wide gauge of the spin-

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Four robots option to increase efficiency with coarse yarn counts R 40 can be equipped with four robots, effectively doubling the capacity of the machine automation. So the R 40 is able to handle a large workload on a long machine with a fast package build up at coarse yarn counts, high delivery speeds, possibly small package sizes and possibly with a high rate ends-down . With four robots even a coarse yarn Ne 7 (Nm 12) can be produced with a long R 40 machine of 320 rotors at a machine efficiency of 96 %! Furthermore the start-up time of a machine after a standstill period is reduced by half with four robots, increasing the overall efficiency of the plant. This option is backed up with concepts of flexible and easily adaptable working procedure. An intelligent service concept guarantees that the other robots serve all rotor positions of the machine, while one of them is in a service position.

R 40 supports the operator intervention by a selective guidance. This includes programmable signal lights on the machine gearing end and tail end, signals on the robots, sections and spinning boxes. It is completed by big plain text displays with graphical support on the robots and on the touch screen display of the machine control unit. This concept positively influences the machine efficiency while optimizing the required work force.

Highest speed and efficiency with state-of-the-art robotic automation The robot of the R 40 itself has remarkable features making it outstanding in performance and speed. Its advantages are based on the modular AERObotic concept: The robot is equipped with independently acting electro-pneumatic units. Each unit is performing a specialised task. This significantly speeds up and eases the setting of the robot and indicates any service needs. Operation and maintenance are assisted by clear information with graphics in a big plain text display.

Fig. 5: Four robots option to increase efficiency with coarse yarn counts

The robot’s microprocessor controls all the actions. It constantly communicates with the machine control. Therefore, the travelling robot can quickly and directly approach the next working position, centring at the box with a laser beam. A cleaning module cleans the box, rotor and the rotor groove with a concentrated jet of compressed air, on demand assisted by mechanical cleaning. The robot performs all necessary tasks for piecing. It prepares the end of the sliver and the end of the yarn. For starting winding on empty tubes, the robot carries a seed yarn which is afterwards sucked into the filter chamber. The complete cycle time of a combined piecing and doffing operation on the R 40 robot is under 25 seconds. Combined with a very high piecing efficiency, the robot is able to keep up the machine efficiency to the utmost. The starting time of the R 40 after a machine stop is kept to a minimum. 7

Rotor speed Start of piecing 100% 80%

Time of piecing cycle

Fig. 6: Quality of piecing at an utmost level with the unique piecing principle

Quality of piecing at an utmost level with the unique piecing principle

Fast and easy lot change with VARIOdraft

The piecing principle of the Rieter SYNCROtop system is based on the fact that the Robot has full control of all the speeds. The piecing process is performed at a defined and constant rotor speed, which can be set as needed (i.e. usually between 65% and 100% of the normal rotor speed). This allows constant and defined conditions for all other corresponding speeds, such as sliver feed and yarn takeoff, independently from the actual time consumption of the individual steps during the piecing process. Although each step can be optimized to the needs of the specific product, the piecing is performed under equal conditions, permitting the highest possible rotor speeds. All piecings go through the yarn clearer at the spinning position. The piecing is checked for its thickness using a special channel of clearer settings.

The R 40 is equipped with an intelligent combination of frequency converter driven motors. This enables the fastest possible lot changes. Draft, winding tension and twist can be individually set on the touch screen of the machine display, without gear changes. This is known as VARIOdraft and is already used on the R 20. Additionally the R 40 is equipped with an inverter drive for rotor speed. The setting of all speeds can be carried out independently in small increments during machine operation without stopping of the machine.

This results in very uniform piecings and because the piecing was done at a high rotor speed, it has a high resistance.

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This is a big advantage for fast lot changes: After changing the spinning elements the speeds need only be set at the machine panel. Usually a few packages are tested in the laboratory after check of the yarn count. The fine-tuning of draft is then done on the touch-screen. The full production can be started right away without stopping the machine and without a time-consuming search for the correct gears in the tool shop. The combination of these features on the R 40 results in a machine efficiency increase of 1% or more. Each 1% increase in machine efficiency results in additional yarn production without any production cost! With an Ne 7 (Nm 12) this may signify more than 23’000 kg of additional yarn per machine per year.

Low production cost with efficient energy saving An important target when designing the new R 40 was the minimized energy consumption. The Rieter machine concept of low energy consumption had to be improved further. The focus was set on the two main areas of consumption: the rotor drive and the main suction systems. The rotor drive system is by far the biggest energy consumer in a rotor-spinning machine. Its energy consumption depends on the pressure of the tangential belt to the rotor shafts, which is needed to ensure rotor speed increase. With the R 40, this pressure was generally reduced, because the robot is able to increase the belt pressure at an individual spinning box for fast speeding up the rotor. Therefore, allowing the power consumption for the rotor drive to be reduced. The second biggest consumption source is the main fan. It has been redesigned for the R 40. The new fan has a bigger volume. Thanks to its high efficiency it allows a lower power installation than for other machines. A new intelligent

concept is used to keep constant spinning conditions with minimum energy consumption, even if the filter mat becomes loaded. An electronic sensor for the negative pressure starts automatic cycles to remove the filter mat as soon as a certain decrease of negative pressure occurs. Only if the decrease cannot be neutralized sufficiently, the manual removal of the filter mat is requested by a signal to the operator. Compared to conventional systems, the interval of operator interventions is reduced by up to three times. Alternatively, the removal of the filter mat is possible by a fully automatic vacuum waste removal system. Admitting small deviations in the negative pressure which do not influence spinning, with the R 40 system there is no need to implement additional power consumption to overcome the resistance of the growing filter mat.

A new rotor spinning mill with 10 R 40: a showcase for high productivity

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Best mill experience by customers In the short period since its market introduction there there have been sold over 190 machines of the R 40. The main customers of R 40 are in Europe and Asia. Shortly after installation the customers became acquainted with the advantages and stated: • R 40 offers excellent yarn quality with the SCR spinning box with, significantly increased production speeds. The possibilities to handle sliver with high trash contents was greatly improved with the advantage of the BYpass settings. • The spinning geometry with the SC-R box offers a better spinning stability, facilitating higher yarn strength or alternatively allowing implementation of lower yarn twist. • Big can and package dimensions, which are only possible on the R 40, are crucial for the reduction of the working load for material flow. This fact gains even more importance than before with such long and productive machines.

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• Fast lot changes and a fast start-up of the R 40 after a machine stop are possible with the VARIOdraft inverter drive system. • The very fast robot of the R 40 and its high efficiency for piecing allows a long machine to reach full working efficiency within only about 75 minutes. With four robots per machine, this time is nearly halved. This speed is really adding flexibility to a spinning mill. • The measures to minimize power consumption in the R 40 are effective, as could be proven by a direct comparison under equal running conditions.

Rieter Machine Works Ltd. Klosterstrasse 20 CH-8406 Winterthur T +41 (0)52 208 71 71 F +41 (0)52 208 83 20 Rieter Ingolstadt Spinnereimaschinenbau AG Friedrich-Ebert-Strasse 84 DE-85055 Ingolstadt T +49 (0)841 9536 01 F +49 (0)841 9536 850 Rieter CZ a.s. Csl. armady 1181 CZ-56215 Ústí nad Orlicí T +420 465 557 232 F +420 465 524 237 http://www.rieter.com E-mail: [email protected] The data and illustrations in this brochure refer to the date of printing. Rieter reserves the right to make any necessary changes at any time and without special notice. Rieter systems and Rieter innovations are protected by patents in most industrialized countries. 1747e–AEAE–6–Printed in Switzerland