Monitoring of abrasive loading for optimal belt ...

Monitoring of abrasive loading for optimal belt cleaning or replacement Andres L Carrano; Bhavin S Vora; Ferat Sahin; Richard L Lemaster Forest Produc ts Journal; May 2007 ; 57, 5; ABI/INFORM Global pg. 78

Monitoring of abrasive loading for optimal belt cleaning or replacement Andres L. Carrano ' Bhavin S. Vora Ferat Sahin Richard L. Lemaster '

Abstract Surfac e q uali ty is a n im po rta nt c ha rac te ristic co m mo n ly asse sse d in woo d produ ct s . Sa nd ing reli es a ll coa ted a bra sives as too ling for bot h di men sioni ng a nd s ur fac e fini shi ng. bu t th eir pe rform an ce is de pe nda nt o n c hip load ing a nd gr it wea r. Tr ad ition ally, the useful life o f ab rasi ve belt s in sa nd ing o pe ratio ns has bee n ma nu all y assessed . T hi s typ e o f insp ec tio n is h ighl y depen dent up on indi vidua l e xpertise a nd usu a lly lead s 10 eithe r und cnui liza tio n or overutilization o f the a bras ive. w hic h in tum affects the pro duc tio n co sts a nd qu a lity o lt hc prod uct. A c lassifica tio n meth od that c ha rac te rizes the ab ras ive load ing c ur ve with art ific ia l ne ural net wor ks a nd comp ute r v is ion was de ve loped . Co ntro lled ex pe rime nts we re co nd ucted to de ve lop a bras ive belts of known ma c h ini ng exposure. Image proce ss ing wa s co mp le me nted w ith patt ern c lass ifica tion an d recog nit ion a lgor ithms to suppo rt a de ci s io n-maki ng fra me wor k . Th e resu lts show 9 3 pe rce nt a nd 9 5 pe rce nt suc cess rat es in a bras ive im ages class ifica tio n. A lso . c lassi fica tion o f im ages fro m interpolated a nd e xtrap o lat ed limes o f ab rasive usa ge is ac hie ved w ith hig h s uccess rates . T his app ro ac h is p rop osed as a n in pu t to a deci s ion syste m th at wo u ld hel p in ev aluating th e rem ai ning life o f the ab ras ive a nd wo uld tri gge r o ptima l too l rep lace me nts .

S a ndin g ope ra t io ns a re a lmo st uni ver sa l pr acti ce for ac hiev ing fina l di men s ion ing a nd sur face q ual ity a fter most woo d m ac hini ng pro cess es . Sa nd ing invo lves the usc o f coated a b rasive belts a nd tends to be o ne o f the most ex pe ns ive mac h ini ng o pe ra tions in the wood ma nu facturi ng seque nce (P eak a nd M yers 19 8 1). Sa nding belts o r coa ted ab ras ives a re c rus hed parti cles of m ine ral mat e rial g lued to a bac king ma te ria l. us ua lly c loth or pa pe r. T hese s ha rp part ic les ac t like mult ipoi nrs o f co ntac t c utt ing too ls 10 rem ove ma ter ial a nd fin ish the surface by c utting. rubb ing a nd plo wing mech anism s . H igh temper atures a nd pr essur e for ces de velop ed d uring the c utt ing proce ss ca use these pa ni cl es 10 undergo wea r and fractu re. co nseq ue ntly de vel op ing une ven struc tures. The fracturi ng part o f the wear is a self-sha rpe ning process for th e a bra sive bUI ca use s the pa rtic le size 10 dec rease. w ith the corresp onding imp act o n the usefu l life of the too l. A no the r factor ca us ing use fu l life to decrease is be lt loading . Du ring a brasive mac hi n ing. wood c hips a nd e xtra ct ives tend 10 pack be twee n the a bras ive part ic les. thu s lowe rin g the effec tive profi le o f the too l a nd o bstructing c h ip n ow c ha nne ls in the a bra sive be lts . Th is oc c urre nce is sim ila r 10 the "b u iltlip edg e (B U E)"" form ation tha t oc c urs ill met a l c utting a nd is the co nse que nc e of p lastic deformati on a nd ad hes ion d ur ing 78

c hip format ion as we ll as high te mpe ra tures a nd pr essures at the s lid ing inte r face bet ween to o l a nd ma ter ia l (S te wa rt 1978