CA2079225A1 - Making rounded clusters of fibers - Google Patents

Abstract

Ball-shaped and other rounded fiber clusters that have a density that may be controlled, as desired, with good uniformity of size and density, may be obtained from staple fiber that has been crimped mechanically, as well as from spirally-crimped polyester staple fiber, by an improved process and apparatus at a high through put.

Description

WO91/1~ ~ -1- PCT/US91/02268 2~792?~

TITLE
Making Rounded Clu6ters of Flber6 FIELD OF INVENTION
Thi6 invention relate~ to ~mprovement~ ~n making rounded clu6ters fro~ ~taple f~be~, ~nd ~ore partlcularly to a proces6 ~nd ~pp~ratus for m~king 6uch cluster~, and the re6ulting rounded ~e.g. ball-llke) clu~ter6, especially from re6ilient crimped flber of denier 4 to 15 (about 4 to 17 dtex) 6uch a6 i6 u6eful for filling purpo6es.
~AC~GROUND
Staple fiber ha6 long been u6ed a6 filllng material, for support and/or in6ulating purpose6.
Polye6ter flberfill has b~en a p~rticularly de6irable f~ber for such purposes, bec~u~e of its bulk, reslllence, re61stance to att~ck by m~ldew and other deslrable features. Conventionally, flberfill u6ed to be proce6sed in the form of ba..~, af'~r :he flber6 were parallellzed on a card (or garnett), becau6e thls wa6 an economlcally attr~ctlve and u~eful way of handllng flberflll.
Recently, however, Marcus ha6 dl6clo~0d ln U.S. Patent No6. 4,61~,531 and 4,7B3,364 how 6plrally-crlmped fiberfill can be formed lnto fiberball6 that make a partlcularly desirable fllllng mater~al, belng lofty, ~oft and refluffable ~n a way that 16 1milar to down filllng. Marcus has also dl~closed ln U.~. Patent No.~4,794,03B how flberbalis can be made 6imilarly from blends of fiberfill wlth blnder fiber, whlch can then be activated to make useful bonded 35 ; ~upp it ~truc.u~e~, 2.j. 'o; cu;~'_..'r.g ~..d matL c~ e~.
arcu6 has disclo6ed a useful batch process and apparatu6 th-t take6 advantage of the spirally-crlmped ~ .

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W091/~ 2- PCT/US91/02268 2 ~ 2 ~
nature of his feed materlal for mak~ng such flberball6, which are belng produced commercially and h~ve proved useful and lnteresting ball-llke flber ~tructure~, becau6e of their lofty nature, becau6e they are ea6~1y trAn6ported by air-conveylng dur~ng proce66ing, and becau6e of the lnterest~ng and advant~geous propertie6 of the product6, which may be proce66ed into ~everal lntere6ting v~riant6. We generally refer to the6e ctrùcture6 herein a6 fiber clu6ter6.
An ob~cct of the present lnventlon 1B to provlde a proce~6 and apparatu~ that can be op~rated to provlde 6uch ball-like clu6ter6 of fiber6 continuou61y at high throughput6. Another ob~ect 16 to provlde a proce66 and apparatus that doe6 not nece6sar~1y require - :
a ~pecial feed flber, but can be operated ~ati6factorlly alco wlth regular polye6ter 6t~ple flber, or lndeed other fibrous materlal6, to form flber clu6ters of ruch dens~tles and unlformlty ~6 ~y be requlred. ~ further ~`
ob~ect 16 to provlde a proce66 and apparatu6 that may be used to form clu6ter6 from fiber6 of coar6er denier, even abovo iO.
A6 will be noted herelnafter, we have made 60veral modlflcation6 to a type of cardlng mschine in order to achieve our re6ult6.
8UMM~RY or TB~ INV~NTION
Aocordlng to one aspect o the pre~ent inventlon, there i~ provided a proce6s for preparing rounded clu~ter~ of flber6, compri6ing feeding a uniform layer of 6taple fiber onto the perlpheral 6urface of a rotatlng main cylinder covered with card clothing, whereby the flber ic advanced around the perlpheral surface by ~ald clothing and i~ brought lnto contact with a plurallty of frictlonal 6urface6, whereby 6ald fiDer i~ f~m~B into c;-~6te-8 .ha. are rOlleu into rounded configuration~ on the peripheral 6urface, charact~r~zed in that there i6 provided at leagt one ~, . . . . ~ , . . . , .;. . ; . ,~. . ,,. . . :

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Wos1/t64~ -3~ PCT/US91/02268 arcuate doff~ng 6creen, radlally-6paced from 6~1d clothing, 6aid dofflng screen being provided with opening6 of 6ufficient size for the clu6ter~ to p366 through 6aid openings, and to be doffed by emerging through 6ald openi ngs .
U6e of a ~creen to doff clu~ter6 18 a 61gnlflcant dlfference from exl6ting cardin~ machine~, whlch have generally u6ed a roll to doff carded flber We have doffed clu6ter6 very éffeetlvely u~lng an arcuate rlbbed 6creen that 16 provlded wlth tran6ver6e rib6 with ba6e6 that are epaced radlally from the clothng on the main cylinder, and wlth openlng6 that are the tran6ver6e spaee6 between the6e r'b6 It will be under6tood herein that ~tran6ver6e mean6 transver6e to the machine dlrectlon, l e the directlon of rotatlon of the maln cyllnder, eo the ~tràn~ver6e~
rlb6 of 6uch dofflng 6creen are parallel to the axl6 of the main cyllnder Aeeordlng to another aspeet of our lnventlon, therefore, there 16 provlded a clu6ter-formlng maehlne that 1B an lmprovement ln a staple flber cardlng machine eomprl6ing a rotatable maln eyllnier havlng lt6 peripheral 6urfaee eovered with eard elothlng and adapted to rotate ln elo~e proximlty wlth a plurallty of eooperatlng frletlonal ~urfaee~, mean6 to fe-d ~taple f'ber in ~ unform layer onto ~aid man eylinder, and doffing mean6, the lmprovement eharaeterlzed ln that 6aid frletional ~urfaees eooperate wlth the eard elothlng on the peripheral ~urfaee of the maln eyllnder ln 6ueh a way that flber elu6ters aré formed by the eooperation between the eard elothing and 6aid frletional 6urfaee6, and the dofflng mean6 eomprl6es a doffing 6creen provlded wlth openlng~ of ~ufflelent slze --ror tne rioer elu6ter~ to emerge ~x~ffip;e~ o "eooperating frlet'onal surfaee~ are de6erlbed herein, and lnelude ~ationary element~ with frietion~l . ~ , ' ~.

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2 ~ 7 9 ~ 4 PCT/US91/02268 surf~ce6, 6uch ~6 plate~ and ~egment6 thit may b~ smooth or covered with card clothing, and 6creen6, and al60 movable elements, including worker and 6tripper r~lls, 6uch a6 are used on roller-top cards, and belt-drlven flat element6, ~uch a6 ~re u6ed on revolvlng fl~t cards.
An ~mportant advantage accordlng to the lnventlon 16 that dofflng and tran6portatlon of the emerglng cluster6 may be ~6616ted by ~uctlon and/or blowing. ror in6tance, the rounded clu6ter6 ~ay be blown directly into tlckings and formed lnto plllow6 or other filled article6. Alternatively, thc clu6ter6 may be packed and later proce66ed a6 de61red.
Ac~ordlng to another a6pect of our lnventlon, there i6 provided an improved proce66 for preparing rounded cluster6 of fibers, compr~sing feeding a unlform layer of 6taple fibcr onto the peripheral ~urface of a rotating main cylinder covered with card clothing, provlding a plurality of e66entially arcuate frlctional 6urface6 that are 6paced r~dially from ~ald clothing, wherein the radlal 6paclng and frictional characteri~tic6 of 6a~d frictlonal surface6 and of 6aid clothlng ~nd the rate of feed of said 6taple flber are controlled so that ~aid clothing becomes loaded wlth a co~pre~clble layer of flber6, whereby lofty rounded clu6tor6 of fiber6 ~re formed ln the pcripheral 6pace between ~aid clothing and said frictional 6urface6, and doffing ~aid clu~ters. A6 will be de6crlbed herein, the fact th~t the card clothing 16 loaded wlth flber 16 another 6ignlficant dlfference from operiting a conventional carding machine of thl6 type. It i6 very 6urpr~6ing that rounded clu6ter6 are formed ln the peripheral space when the6e (arcuate) frlctional ~urface6 ~re 60 ~paced and the proce6s i6 60 operated, ~-a6 de6cr~bed hereln.
The 6taple flber that 16 fed to the maln cyllnder may be in variou6 form~, e.g. a cros~-lapped .~ .

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WO91/1~ ~ _5_ PCT/US91/02268 2~79~7 -~
batt, or may be bale stock that has previousiy been baled, but i8 fed to the main cylinder ifter havlng been opened.
Preferably, especially for making pillow~, filled articles of apparel, or like article6 where such aesthetic6 are important, the 6taple fiber fed to the main cylinder may have been 61ickened.
For lower density and better ln6ulatlon, 6taple fiber of hollow cro66-6ection i6 preferred.
If de6ired, for making bonded ~upport artlcle6, the 6taple fiber fed to the maln cyllnder may be a blend of polye6ter fiberflll or other hlgh meltlng flber blended wlth lower melting blnder fiber.
The denier of the feed flber may be a6 hlgh a6 15 dpf ~about 17 dtex), ~nd wlll gcnerally be bt le~st 4 dpf ~about 4 dtex~ for u6e a6 filling m~terlal, e6pecially for support purpo6e6, but wlll be 6elected ~ccordlng to the desired end u6e. For in6tance, u6eful blend6 for apparel ln6ulatlon have been made from flber of denier a6 low a6 1-2 dpf (about 1-2 dtex).
By u6e of our lnvention, a6 de~cribed ~ -herelnafter, we have found it po66ible to proce66 ~taple fiber that ha~ been mechanically crlmped, and to produce desir~ble lofty flberball6 of uniform average density.
According to another a6pect of our invention, therefore, ther2 16 provided a ma6~ of lofty rounded 6taple flber clu6ter6 of average dimen6ion about 1 to about-15 mm, ~nd of average denaity 1~66 than about 1 pound per cubic foot (about 16 Kg/cu m), con61stlng ec6entially of randomly-entwined, mechanically-crimped synthetic 6taple fiber of cut length about 10 to about 60 mm. The6e~ ~lofty cluster are randomly-brranged and entw~ned ~6 i Marcusi riber ciu6~ers prcpared rrom cpirally-crim ed feed fiber; they are qulte dirtinct from the h~rd neps or nub~ that have been u~ed in .;,'', . "
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Wo91/1~ ~ 2 ~ r~ J ;~ -6- PCT/US91/U2268 novelty yarn6, and that are fimall knotted or t~ngled clumps of 6ynthetlc fiber6 or indeed of n~tural fiber6, ~uch as cotton. Ac lndicated, preferred form~ of our mechanically-crlmped 6ynthetlc f~ber may be cllckened polye~ter 6taple flber, ~nd/or ~ blend wlth ~ lower meltlng binder fiber, th~t may, if desired, be ~ ~
Ghe~th/core blcomponent wlth ~ 6he~th of lower ~elting -binder material, and a core of polye~ter or like high meltlng fi~er-forming material.
~RIEF DESCRIPTION or DRA~ING~
rigure 1 i6 a cchematic 61de-vlew ln elevatlon of a preferred app~r~tu6 according to the pre~ent invention.
Figure 2 16 a ~ketched repre6ent~tlon of how ~
6ectlon cut through cArd clothlng lo~ded with flber that ha6 been removed from a main cyl~nder, mlght 6how the topography of the surf~ce, D5 will be de6cribed hereafter.
rlgure 3 i6 a 6ketched repre6entitlon of how cardinq teeth grlp the flber6.
- Flgure 4 lc a 6chem~tlc v~ew ln pirs2e~tlv^ oS
a portlon of a preferred rlbbed 6creen accordlng to the pre~ent ~nvention. ~ -Figure 5 i6 a ~ketched repre6entatlon of an 25 end-view of a portion of the maln cylinder and doffing 6creen with the clu~ter6 emerg~ng.
D~TAIL~D D~SCRIPTION OF T~E INV~NTION
A preferred apparatu6 according to the invention will be de~cribed wlth reference to the accompanying dr~wing6. A6 indlcated, in 60me re6pect6, ~ome of the feature6 of thi~ apparatu~ re6emble a card ~or cardlng mach~ne) from which, for convenience, ~ucb element6 ~nd feature6 have been adapted.
S~, :ef~r~r.c~ ~8 ~de to th~ ~rt cn. c~rdln.g, including a Manu~l of Textile Technology, in the -~hort-Staple Splnning ~erle6, Volume 2, entltled "A

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Wo91/164~ -7~ PCT/US91/02268 2~79~ ~
Practlc~l Gu~de to Opening and Caedlng", by W. ~leln, The Textile Instltute, 19~7, and to a 6umm~ry of available types, in an article by s. Wolf, in Intern~tional Textile sulletin 2/B5, page~ 9, 12, 16, 19 ~nd 20, referred to on pAge 35 of ~leln~ Manu~l, both the M~nual and the artlcle belng hereby lnco~porated hereln, by reference.
The ta6k6 of a card are 116ted in the former Opening to ~nd~vldual flber~-~llmln~tlon of lmpuritle6- -Ellmln~tion of du6t-Dlsentangllng of nep6-Ellmin~tion of 6hort fiber6-Flber blending- -Flber orlentatlon- and Sllver formation.
Such are lndeed the ta6k6 of mo6t card6. In '-' other word6, cuch ta6k~ ~of most card~) do not lnclude formlng ball-llke flber clu6ter6. However, card6 have been u6ed by ~ome to entangle fiber~ l..t~ bodlcs variou61y referred to by terms 6uch ~6 nep6, nub6, and '' other termlnology. Thl6 technology has been regarded ~6 proprletary, ~o the llterature on proces~e6 that may ''' have been u6ed for thl6 purpose 1~ 6parse. 8telnruek, however, dl~closed ~n apparatu6 for maklng nubs in U.S.
P~tent No. 2,923,9BO.'"'8telnruck lndlc~ted that, prevlou81y~ a6 many a6 10 machlne6 ln a row had been used to reduce the flber 6tock to the de61red small hard '' nub6. Stelnruck 6aid hi~ machlne could be operated to form nub~ of the 6ize and hardne66 de61red by perhap6 ~6 $ew a6 2 machine6 ln 6equence. Even thl6 need for a 6eguence o 2 m~chlne6 ~, however unde~lrable, and 60 we have prov~ded a macnine tnat c~n m~ke u~ eBl rc~
clu6ter6 on a 61ngle machlne. 8telnruck wanted hard nep6 or nub6. In contra6t, we want to make re6111ent WO 91/16484 -8- PCI'/US91/02268 2 0 r~ sj lofty ball-llke 6tructures of controlled and uniform den61ty. Another difference from prior art nep lor nub) formation i6 that the6e ha've generally been ~ade from fiber6 of low dpf (denler or dtex per fllament of les than 3) ~uch a6 cotton and other low denier fibers that knot ea6ily and can form hard neps that are useful in novelty yarn6. When a filling i6 u6ed for 6upport purpo~e6, 6uch low dpf fiber i6 generally not a6 de6irable a~ higher denier6 of 4 (about 4 dtex) and above ~even up to 15 denier, about 17 dtex) that are generally preferred, beeau6e of their r~6111ence. This property, however, lncrea6e6 the dlfflculty of maklng clu6ter6 tbat will not later unravel. It 6hould be ~;
under6tood that our proce66 and machine may al60 be operated with low denler feed flber that i6 ea61er to form into clu6ter6. In other word6, although hlgher denler 6ynthetic flber6 are generally preferred as filling materlal, lower denler 6ynthetlc and natural flber6 may al60 be'formed lnto flber clu~ter~ by our proces6 and machine. ~' A6 e~phO~lzed by 8telnruck, hi~ ob~ectlve of formlng nub6 i6 almo6t the rever6e of the primary functlon of operatlng an ordinary card (to lay individual fiber6 a6 much a6 po66ible in parallel line6 and to remove any neps or nub6). Indeed, a book wa6 '' publl~hed by Wlra, entltled "Nep Formation ln Carding", by P.P. Townend, to advi6e how to avoid the ma~or ~; -problem of nep formation in the carding of ~taple fiber6. Steinruck wanted to convert his fibrou6 ma66 into nub6 which Steinruck would later incorporate lnto '' web6 or ~liver6 on a card in a sub6eguént operation.
Steinruck u6ed a (modified) roller-top card, and it i6 believed that other exi6ting proce6~es for making nep6, ~v6, ecc., hove gBille~a~ UDed ~Gllêr~tOp ;:ard~. I;l contra6t, for a preferred machine according to the pre6ent invention, we have modlfied a card wlth carding ~ : .. ~ . : .. .: ; : : , . . :: ............ :

wo g~ 9- 2 ~ 7 ~ ;~3 2 ~ Pcr U 68 plates (60mewhat a6 6hown in Flgure 101 on page 45 of th~ MOnu~l by Rleln, or in Flgure 22 on pay~ 20 of the artlcle by Wolf, both referred to here~n~bove). our o~ectlve i6 also the rever6e of the prlmary functlon of operatlng an ordinary card.
our preferred machine i6 lllu6trated in F~gure 1 (which does not 6how the card clothlng) and consi~t6 e66entially of a main cylinder 10, of diameter 50 lnche~ (about 1.3 m), that i6 covered wlth card clothing, and that 1~ ~hown drlven ln a clockwl~e dlrectlon ~t a rate that largely determlne6 throughput, bolng generally 6cme hundred6 of revolution6 per minute ~rpm), preceded by a roll 11 that 16 referred to a6 a licker-in (~leln refer6 to thi6 a6 a "t~ker-ln"), of diameter 9 inche6 ~sbout 23 cm), that i~ al60 covered with clothlng (but of much lower polnt den61ty), and that 16 chown driven ln a counter-clockwlOe dlrect~on, l.e., oppozlte to that of maln cylinder 10, wlth an undcrlylng ba6ket llA, and lt6elf preccded ~y a feed roll 12, that 16 ~hown drlven al60 ln ~
c~unter-clockwi6e dlrectlon (llke licker-ln 11), ~nd that cooper~tc6 with a fced plate 13 ln feedlng opened ~-flbcr from a 60urce of 6upply (not 6hown) at a unlform r~te evenly ~cros6 the width of licker-in 11. Tho perlphery of maln cyllnder 10 18 6urrounded by a ~crle6 of Otatlonary cooperatlng frlctlonal 6urface elemcnts, lndlcated generally by 14, and more speclflcally (6erl~11y from llcker-in 11) a6 15, 16, 17, 1~ and 19, all of which havc arcuate frictlonal ~urface6 that are 6paced-radlally from the (teeth of the card clothlng on) main cyllnder.l0 to allow proce661ng llnto cluOter6) fiber fed from licker-in 11 within the peripheral ~pace ~round main cyllnder 10, and def~ned on tbe outslde PC-~2'2--i ' ~_h zp~ca by the ~roU'~o ~-C~-~n,~l 6urface6 of the6e 6tatlonary element6 14. The radial ; : ~p~clng ly toe ~diu-ted, ~nd thl~ c~n oe an l-portant :
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~, -wo 9l/l~ 2 ~ r~ O- PCT/VS91/02268 me~n~ for controlllng the proces6 ~nd the product6 produced. ~ :
A6 lndicated, opened fiber ls unlformly fed between feed plate 13 and feed roll 12, whlch latter i8 .:
provided wlth teeth (or other means) to adv~nce the f~ber toward6 l~cker-in 11, more or les~ a6 ~hown ~n F~gure ~4, on page 39 of ~lein'6 Manual. The clothlng on llcker-ln 11 forward~ the new flber ~fed fro~ feed roll 12 and feed plate 13) pa6t underlylng ba~ket ll~ to the clothlng on maln cyllnder lO. Both ~t6 of clothlng -are tr~velling ln the ~me dlrectlon, but that on maln cyllnder 10 i6 ~ovlng at a much higher 6peed. Thu6, the new fibee i6 picked up by the teeth on main ~ylinder lO
and enter~ the 6pace between the arcuate frictlonal surfaces of 6tatlonary element6 14 and maln cyllnder 10 (covered wlth card clothlng). Durlng 6tart-up, new flber (fed from llcker-ln 11) wlll loid onto the card clothlng on maln cyllnder lO, and ~o ~ome mlnute6 are llkely to pa66 before any product i6 dellvèred in the form of ball-llke cluster6. Al60, a6 will be evldent, a certain amount of cmplr~cl6m m~y be needad ~o ad~u~t the feed rate of any partlcular feed flber to the 6urface ~paed of the maln cylinder, clothed wlth approprlate card clothlng, and currounded by approprlately ~paced 6tatlonary element6 14, ln order to obt~in a ~ati~factory dellvery of the de61red clu6ter6, and 6teady ~tate operatlon. Once the proc~680r reache6 6teady 6tate operation, ~.e. once the amount o flber (in the }orm of rounded ball-llke clu6ter~) dellvered by maln cyllnder 10 i6 the 6ame a6 the amount fed to the proce~60r, the card clothlng on the ~aln cyllnder wlll have become loaded w~th flber that ha6 worked lt6 way down the teoth, 60 the now fiber can only be collected ~t lor near ~ tha ou.a. ax' -am' t' a~ o' tbe t~ath cf thi card clothing. However, 6urpri6ingly, thl6 fiber ~6 not loaded unlformly ln denslty or 6patlally (when the , '' :, .

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w09t/164~ ~, i3 ~ 2 ? PCT/US91/02268 proce6~0r i6 run with a correct feed r~te of flber and ma~n cyllnder 6peed~5 in other words, there are relatively high locations loaded with m ie fiber and contra6tingly lower locations loaded with le66 fiber acro6s the w~dth of the main cyllnder and in the direction of rotatlon.
Thi6 loading of fiber on the main cylinder, ~ccording to th~s preferred a6pect of our lnventlon, 16 an lmportant diference from a cardlng opcratlon (u61ng thi6 type of machlne, before modlfication). Durlng 6uch carding, lt ig de61rable to doff all the flber 60 that only a very th~n l~yer of flber i6 fed ~nd 60 that all ~6 doffed. In other word6, durlng 6uch cardlng, it i6 lmportant to avoid load~ng the cyl~nder.
Such loading according to our inventlon i6 represented ln ~ cketch ln rlgure 2, ~howlng how a typical 6ection might look lf cut through the c~rd clothlng and fiber on ~ loaded main cyllnder ~not 6hown in rigure 2) in a 61mpllfied and idealized vlew. The upper portion 21 6how6 fiber while the lower portlon 22 indlcate6 tne ioc~tion of the card clothlng ( BO~e of whlch *ould be grlpping fiber). Figure 3 16 a 6ketched repregentatlon of how fiber6 24 are qripped by card~ng teeth 25 of a type that we have u~d. Afi ~ome of the fiber ~hown ln the upper portlon 21 of ~lgure 2 1B
relea~ed ln clu8ter6 23, and 1~ no longer grlpped by the card clothlng, 6uch clu6ter~ pa66 through the 6pace between the card clothlng (loaded wlth flbcr) and ~tatlonary frlctional 6urface element6 14, and are belleved to follow tortuous path~, and 80 to be rolled and become rounded clu6ter6. A6 the clu~ter6 progre~6 ~round ~in cyllnd~r lO, they reach the 6pace between the ~urface of maln cylinder 10 and ~ doffing 6creen, wnicb i6 one or tne statiol~dry e~ehlent~ 14, ~peclfically ~ -element 17, whlch i6 a rlbbed 6creen.
We have u6ed n6 6uch n ribbed doffing screen . .

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W091/1~ ~ -12- PCT/US91/02268 17, a 6creèn suc~ as ha6 previously been used underneath commercial card6 (probably shown under the maln cyllnder in F19. 101 on page 45 of Klein'6 Manual) for the different purpose of removing waste. we prefer, however, to doff our fiber clu6ter6 through 6creen~ wlth larger 6p~cing6 between the rib6. One type of preferred ~creen i6 de6crlbed now with reference to Figure 4. The rlb6 31 of 6uch 6creen run tran6ver~ely (~.e. parallel to the axi6 of main cylinder 10) and are 6haped convenlently with tri~ngular cro66-6ectlon6, wlth 6mooth ba6es that are 6paced radially from the 6urface of main cylinder 10, and are 6eparated al60 tran6ver6ely along thelr length8 fro~ each nelghborlng rlb, 60 the rounded fiber clu6ter6 m~y contlnue to roll ln the arcuate 6pace between ~in cylinder 10 and the frlctional 6urface6 that ar~ the ba6es o the rlbs of the rcreon, but may also emerge between the rib6, becau6e of centrifugal force. Thl6 16 repre6ented in Flg. 5, which 6how6 clu6ter6 23 emerglng between rlbs 31, after belng relè~6ed from the loaded flber 21 ln the perlpheral ap~ce between the rlbc 31 and maln cyllnder 10. .~ny 1006e flber or lncompletely-formed clu6ter 18 1eE6 llkely to omerge from the proce660r through the tran6verse ~pace6, and 6uch flber ma~6e6 a~ do not emerge may ro}l back down the slde6 of the rlb6 to reenter the arcuate 6pace around maln cyllnder 10. Az the flbér cluster6 emerge, they may be collccted, e.g.
under low 6uction, and delivered, e.g. for packlng and shlpplng, or for further proce66ing, by an alr conveylng ~y6tem. An lmportant ~dv~ntage of flberflll ln the form of round clu6ter6 which do not readlly entangle, 16 the abllity to tran6port them ea6ily by blowing.
As will readily be under6tood, a-dofflng ~c;ce.. ~ d.~an.~7eouz~l be ueed to d^r~ ~luetere ~adn on other type6 of machine6, different from the preferred type accord~ng to our lnvention.

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W091/164~ -13~ 9~2;~ PCT/US91/02268 The next element 18 may al60 be a 6~reen that act6 a8 a furthec doffing screen, and performs a 6imilar function. ~he last ele~ent 19 may al50 be ~ 6creen, referred to as a back bottom screen; this element is preferably, however, a plate to provide a frictional surface w~thout doffing. Element 19 may be connected to licker-ln ba6ket llA, as 6hown ln rig. 1, to avoid 106 of flber from the machine at thi6 point.
Although five frictional surface element~ 14 are 6hown in rlg. 1, it wlll be under~tood that the invention iB not limited to only five 6uch elementc, and moee or les6 may be u6ed, if de6~red. Indeed a larger number were used i6 Example 3.
We have found the following a6pect6 affect the process of our ~nvention and the re~ulting product~.
With regard to the card clothing on the main cylinder, lncrea~lng point den6ity~generally reduces the potential to form a compre6sible fiber loading on the main cyllnder, whlch lead6 to making clu6ter6 that are more den6e, le66 rounded and le66 acceptable for end u6e6 llke plllow6 ~nd bedding. Conver~ely, a ~ e- polnt den61ty generally allow6 for more flber loadlng of the ma~n cyllnder, and generate6 a topogr~phy that ic more conducive to fiber clu~ter mak~ng. A more aggre66ive tooth angle 16 preferred wlth fiber~ havlng higher degree6 of ~llckne~6. Even a very aggre~slve tooth angle may not be 6ufflcient when the point den61ty get6 extreme, e.g. more than 800 pp6i (point6 per sq in, and eguivalent to about 124 polnt6 per 6q cm), a6 thl6 will ~ventually make loadlng practlcally lmpos61ble and zo clu6ter formation wlll al60 not be po6slble. Les6 aggre~6ive teeth will not hold highly sllckened fiber6, and thi6 will reduce the potential to form an a~ceptable o'uzt_z. ~i~h s-3i-s~ick -r.d dry f~r5~ a less aggre66ive tooth i6 required to ~1) prevent overloading ~ `
the ma~n cyllnder and ~2) allow a 6table load and .: -' .,; .
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W091/t~ ~ ~ -14- PCT/US91/02268 topography due to higher fiber-flber 6 fiber-metal frlction to achieve good fiberball ~clu6ter) form~tlon.
The 6peed of the main cylinder 6hould be matched to the fiber feed rate. If the 6peed i5 not high en~ugh, then the main cyl~nder, ~s well ~6 the llcker-ln, can overload, and overlo~ding le~d6 to unacceptable cluster formation, and may even damage the machine. Once the main cylinder ha6 reached a 6ufficient 6peed to sati6fy the flber feed rate, 6table loading and good clu6ter formation wlll occur. Increa61ng the 6peed wlthout increa6ing flber feed will u6ually re6ult in ~maller, den6er clu6ters. The fiber feed rate 6hould be tuned to the spaclng6 between ths frictional 6urface6 and the ma~n cylinder, and to the 6peed of the maln cyllnder.
If the clearance6 are too tight, then thl6 can overload the maln cyllnder, or ~ake very tlght, den~e non-round clu6ter6. A6 the clearan~e 15 lncreased, then the ball6 may become more halry, i.e. have more free end6. Higher fced rate6 can be accommodated with approprlate --clearance6 and speed to glve good clu~ter6. The ClO~rallCe6 ~pacln;6: b~.ween the ~aln cyllnder and the frlctlonal ~urface element6 6hould not be too tlght, or this wlll cau6e very den6e loading of clothing and lead to clu6ter form6 that may be unacceptable. ~he 6p~clng6 need to be ad~usted to achleve a ~table load~ng ~topography) and can be u~ed to help change the average ball dlameter. These ~paclng6 may be ad~u~ted by conventlonal mean6, 6uch a6 610t~ ln the rlm6 of the element6 14, with bolt6 on the msin cyllnder ~nd nut6 tD
tlghten and flx the ele~ent6 at the de6ired 6paclng, a6 6hown ln Flg. 4.
A6 wlth conventlonal card6, the varlou6 ~le~ent6 14 6urrounding the circumference of the main cylir.ueL may .hau-~e'ic~ 'a BU;;_U..~ by :e~ov~ble 6ections of coverlng plate6 to retaln any 1006e fiber that would otherwl6e e6cape, but the6e are not 6hown ln ... . : - : .

WO 91/16484 -15- ~ ~ j rJ rl 2 2 ~ PCI`/US91/02268 the lnterests of clarlty and 61mpllc~ty.
The lnveintlon 18 further de6crlbed wlth reference to the followlng Example6, ln which ~11 p~rt6 and percentages are by weight, unless otherwlse lndicated. For test procedure~ and in other respect~, reference may be made to the Marcufi U.S. Patent Nos.
4,61~,531, 4,783,36i and 4,794,03~, and 4,~18,599, whlch are all hereby ~pecifically incorporated herein, by reference. Different feed fibers may require different proce~ and/or mach~ne features for approprlate clu6ter-formatlon to be performed, 60 different feed fibers have been processed. Some of the different feed fiber6 are exemplified below, and others may be proce66ed, by 6ultable adjustment of the var~ous proce66 lS and apparatus feature6 mentioned. In the flr~t Example, wè proce6sed 61~ckened 6plrally-crimped fiber, becau6e the 3-d~menslonal cr~mp of zuch f~berg 1~ preferred for ea6e of ball ormation, and 61~ekened f~berfill 16 al60 generally preferred for ae6thetlc6.
~hAMPLE 1 A tow of a6ymmetrically jet-quenched, dr~wn, sllckencd, poly(ethylene terephthalate~ f~lament6 of 4.5 den (5 dtex) wa~ prepared conventionally, wlthout mechanically crimping, us~ng a draw ratio of about 2.8X, applying a poly6110xane sllckener ln amount ~bout 0.3~
Sl OWF, and relaxlng at a temperature of about 175DC ln cope form. The rope was then cut lnto 32 mm (about 1.25 ;~
lncheE) fitaple, and relaxed aga~n at about 175C. The crlmp developed by thi~ procez6 1~ 3-dimensional in nature and is a non-chemical approach to achleving a ~piral-type of crimp. The staple w~s for~ed into a bale, compres~ed to i density of approximately 12 lb/cu. ~ -t (about 192 Kg/cu m).
.hai ;taple ~z~ oper.Pd uslng a Y.azte;clea opener (available from John D. Holling6worth On Wheels, Greenville, SC) and then manually charged to the hopper .

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' . ,. '.' "`, . ` ". ",, "' .' '~ '' ,.`. ~ `'. ' " " ' ~ '`' ' ' "' W09t/164~ -16- PCT/US91/02268 2~.r?25 6ectlon of ~ CMC Evenfeed (~vailable from Rando M~chine Company, Macedon, NY), whlch pre~ented a unlform amount of opened feed fiber acros6 the width of the proees60r.
The processor was a6 6hown in Figure 1, belng a 40 inch (1 meter) wide card (available from John D.
Holling6worth on Wheel6, Greenv~lle, SC) modlfied 60 ~6 to have the following e66entl~1 elements:
~1) Feed roll 12 (2.25 inch diameter, i.e. almost 6 cm) with feed plate 13 who6e function 16 to ~et~r flber to llcker-ln 11. reed roll speed was controlled independently with a 6eparate DC motor and drlve. Fiber throughput6 were determined by weighing product delivered by the proce660r over a prescribed tlme perlod. Feed roll 12 rotate6 in a counter-clockwi6e dlrection a6 6hown.
(2) Licker-ln roll 11 (9 lnch diameter, ~bout 23 cm) who~e function i6 to remove flber dellvered from the 6pace between feed roll 11 and feed plate 12 and pre6ent it to main cylinder 10. For thl6 Example, the llcker-ln roll 6peed wa6 ratioed to the main cylinder, i.e. both used the 6ame mechanlca~ drlve. (~hl6 16 not lleCeCBary, a6 independent 6peed control of the llcker-in ha6 been evaluated acro66 a wide range of 100-950 rpm and found to have llttle effect on ball formatlon, or even on thel~ unlformlty and/or den~ity). Tho licker-ln clothlng wa6 ~tantard 24 pp6i ~about 4 pt6/sq cm) wlre ~avallable from John D. Holling6worth On Wheel6, Greenville, SC). ~icker-in roll 11 rotate~ in the 6ame direction a6 feed roll 12, but at a hlgher ~urface 6peed.

(3) A 50 lnch (about 1.3 meter6) diameter main cylinder 10 clothed with a low point den6ity (132 : ~ -pp6i, ~bout 20 pt6/sg cm), moderately aggre66ivc tooth aDgl~ (about 25 po6it'-va/ c'~Lhi,.s ;~va~'aL'2 'ro~ uv~.,.
D. Holling6worth On Wheel~, Greenville, SC). Thi6 i6 a preferred clothing for u6e with fiber6 coated wlth , , ::: . , . . ; :
:.:: ~ . , : . : . . .

Wogl/164~ -17- PCT/US91/02268 2~7,922a poly6iloxane ~llckeners. Thl6 clothlng allowed hlghly 61ickened fibers to load the main cylinder under the conditions of operation here~n in 6uch a fashion a6 to form an equilibrium 3-dimensional 6urface topography of fiber~ embedded in the clothing voids, but 6till expo6ed enough of the wiring points to draw fiber6 away from the licker-in roll and not allow the licker-in to overload.
Main cyllnder 10 rotate6 in the opposite direction to licker-in 11 and feed roll 12.

(4) A ~et of 6tationary frictional 6urface element6 14 mounted on the perlphery of main cylinder 10. ror thi6 Example, the entire periphery wa8 covered with rlbbed 6creens (available from Ell~ott Metal Works, Greenville, SC). The fir6t 6creen 15 ~referred to ~ometime6 ~s the upper back 6~reen) was po6itioned where a ctandard backplate would normally be po61tloned in a carding machine. Screen 15 had a rib 6pacing of a qua.ter of an inch (about 6mm) and contained 34 trlangular 6haped rib6, the ba6e of the trlangle being located clo6e6t to, but ~paced from, main cyl~nder 10 and being nomlnally ~ ee eighth6 of an lnch ~about lOmm) in width. The next (top) 6creen 16 had 11 rectangular-based rlb6, wlth one nnd a half lnche~
~about 4 cm) rlb wldth and guarter lnch (about 6mm) 6pacing. ~oth 6creen6 15 ~nd 16 were Otandard screen6 that we u6ed a6 proce66~ng screen6, becauOe of the narrow ~paclng between thelr r~b6. The next (upper front) 6creen 17 wa6 a doffing 6creen that wa6 cu6tom-made with 23 triangular rlb6, of wldth three eighth~ ~nch (about lOmm), 6p~ced half an inch (about 13 mm) apart. The othee (bottom front and bottom back) 6creen6 18 ~nd 19 were proces~ing 6creen6, 6imilar to upper back ~creen 15.
The cv~f lyu~utl v~ Oc .' e ocre~8 o~ th~
periphery of the main cyllnder was 6uch that 6taple fiber6 were forced to unlte and begin rolllng ln the WO91/1~ ~ -18- PCT/US9I/02268 perlph~ Rl ~pa~;i around the maln cylinder when lt reached equillbr~u~ load~ng tl.e. A 6teady ~t~te conditlon), whlch occurred within le6s than about 10 minutes. Spacing of all ~creens from the ma~n cylinder wa6 6et at 0.080 ~nch (about 2mm) for thi~ Example.
The6e 6paclng6 are adju6table within limit6, ~nd ~y be varled to control cluster den61ty ~nd 61ze.
~6 lndicated, r~bbed screen6 are not the only statlonary element6 wlth frictlonal 6urface6 which can be u6ed to achiove a good clu6ter product. We have 6ucce66fully u6ed elements with 6mooth ~olid 6urfaces ln pl~ce of the upper back, top and lower back 6creen6, a6 ~hown in Fi~re 1. Solid clothed element6 can ~160 be u~ed when mounted wlth the cloth~ng reversied, ~o thot the teeth polnt ln the dire~tion oppo~lte to that used ln carding, and w~th a wlde range of po~nt den6itle~;
(thege are more expen6ive to make than 6mooth plate6).
Although the frictional element6 14 th~t we have u6ed have been 6t~itlon~ry, ~pproprlate to the des~gn of the type of card we h~ve modifled, 60me card6 w~th movable fr~ct~cnal element6 may al80 be mod~f$ed for u6e acccrding to our lnvention, for ~n6tance wlth roller6 or belt-driven flat element6.
Control of product removal 16 acco~pll6hed by u~lng one or more rlbbed doff~ng screen6 (with adeguately wlde rib-to-r~b 6pacing) accordlng to our inventlon. The~e have been located it the upper and lower front screen locatlon6 on main cylinder 10, corre6ponding to where a card 16 generally doffed. Thl6 dofflng locatlon 16 conventlonal but 16 not e66entlal, and an advantage may be obtalned w~th other ioffing locationc, depending on the design and layout of the operation. Wider doffing 6paclngs have been more useful wh~n doffing w~t~ a lowee ~creen~ ~uch a~ a6 centrlfugal force i6 assi6ted by grav~ty underneath maln cylinder 10. On the upper front Idoffing) 6creen 17, . : , , . . ~ :: .
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Wo g~ 9- 2 ~ ?, -~ PcT/US91/02268 6pacings wider than about half an inch ~about 13 mm) have resulted in problems in getting the clu6ter6 propelled away from the proximity of the main cylinder.
we have also noted that free fiber may emerge w~th the desired clu6ters if there ~8 a "wlndow" of w~dth ~ m~ch a~ three inche6 ~8 cm). This may not be des~rable, ln general, when the ob~ect 16 to make clu6ter~
efficiently. For bonded product6 however, a8 indlcated by Marcus, it may be de6ired to provide a mlxture of rounded fiberball6 and loose binder fiber, in wh~ch case free fiber may provide an advantage.
Several varlat~on6 may prove effective and de6irable. For in6tance, a 6creen and rib design 6imilar to ~ venetian blind concept, u6ing ad~u6table openings, and de6igns prov~ding a Coanda effect may be u6ed to a6si6t eentrifugal force in removing the ~ - -clu6ters from the main cylinder.
rOr ~xample 1, the-speed of main cylinder 10 wa6 ~et and controlled at 250 rpm, and the 6peed of licker-in 11 was ad~ugted to provide ~ normali~ed fiber feed rate of about 00-90 pph/meter (of the ord~r of 40 ~g/hr/m) card wldth. The 6peed of llcker-ln 11 wa~
ratioed to the maln cylinder, and wa6 measured at 180 rpm. Spacing of the peripheral frictlonal element6 14 from the main cylinder (clothing) was 6et at 0.080 inch ~about 2 mm). U~ing the~e 6etting~, 6atisfactory clustors were produced having free fall bulk densitie6 that were satisfactorily uniform, and me~ured between 0.55 ~nd 0.70 lbs/cuft (about 9 to about 11 ~g/cu m).
The6e clu~ters of our invention ~INV) were te6ted, ~nd compared with refluffable commercial cluster6 (ART) made from 6imilar fiber u~ing the prior art air-tumbling process described in U.S. Patent No.
3~ 4,51~,531, me~suri~g their cohns;~n !in NewtQns! and their bulk ~measured as heights, in cm, of the 1Oo6e clu~terr., rather than for pillow6) under load6 of 0.01 WO 91/16484 . r -20- PCl`tUS91/02268 2a~
p6i and of 0.2 p6i, (corre6pondlng to ~bout 7 and about 140 Kg/6q m~ e66entially ag de6cr~bed in U.S. Patent No.
4,61a,531. The clu6ters compared well w~th 6uch prior clu6ters in the6e test6, a6 can be seen from the result6 ln Table 1.
T~LE 1 Cohe610n Heiqhts (cm) (Newtons) ~t 0.01 p8i at 0.2 psi INV 2.6 22.8 7.6 ~RT 3.3 22.3 6.2 E~AMPLE 2 Four different feed flber6 were fed in opened cond~tion to the proce660r a6 de6crlbed in Example 1 above, under e6sentlally the ~ame conditlon6, to demon6trate that ball-like clu6ter6 can be made from varlou6 type6 of mechanically-crlmped flber. ~11 four dlfferont feed iber6 were 6pun from poly~ethylene terephthalate) polymer supply on a 6ingle po6ition of a multi-porltion eommercial opinning machine. Sufflclent endo of each type were creeled together to m~ke a ~ult~ble erimper denier on a low eapacity technical draw mach~ne, were oubsequently drawn, mochanically crimped, ;~
polyoiloxane-61ickened ~approximately 0.3 ~ 8i OWF), relaxod at 175'C to 6et the crimp 6tructure and cure the olickener, and then eut to 1.125 ~neh ~bout 3 cm) ~taple hav~ng the follovlng propertie6: . -35: ~

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WO 91/16484 -21- 2 ~ 7 9 ? ?, r~j PCr/US91/02268 Item Cro66-Section DPF Crimp6/ln~erimp6/cm) -8calloped oval 6.7 6.7 (2.6) T Trilobal (MR about 2.0) 6.1 6.5 ~2.5) RH Round (one hole) 6.1 5.2 (2.0) - ;
RS Round ~6011d) 6.2 5.4 (2.1) A6 ln Example 1, the cohe6$0n and bulk of the clu~tor6 wete ~ea~ured ~nd comp~red w~th co~merci~l clucter6 ~ART). The6e mea6urement6 ~glven in Table 2B) lndlcate that thelr cohe610n and bulk under load varled ~lgnificantly, depending on the fiber u6ed, and it6 crimp and configuration, and their cohesion value6 were not a6 good a6 for the ~p~ral cr~mp flber~ of Example 1.
Some aspeet6 of the cluster products from there dlfferent fiber~ could pos6iaiy be ~mproved by varylng the proce6~1ng condition6.

It_mCohe610n Heiqht6 ~cm) (Newton6)at 0.01 p~i at 0.2 p~

~0 5.~ 22.2 7.0 T 9.0 24.B 9.2 RH 5.1 23.7 9.0 RS 4.6 23.1 7.1 ART 3.3 22.3 6.2 E~A~PL~ 3 - -- The feed fiber for thi~ ~xample wa6 6pun from poly~ethylene terephthalate), of 5.5 dpf ~about 6 dtex), mechanically crimped ~about 7 cpi, about 3/cm), 9;3il~zly p~ ; lo~.ane-~lickened (about 0.3 ~ Ei Q~F~;
7-hole flber ~total void content about 12%), cut to 1.25 Inch (about 3cm) ~taple. Thi6 fiber wa6 opened on a : .
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Ma6t~rQ~eànR opener, as in Example6 1 and 2, prlor to feedlng to a flberball making apparatu~.
For this Example, the configuratlon of the frictional 6urfaces 14 was 60me~hat different from that u6ed in Example 1 (and as shown ln Figure 1) but the apparatu6 wa6 otherwise as described hereinbefore The frictional surfaoes 14 were, in order 6tarting from licker-in 11 as follows, with 6pacing6 mea6ured from the card clothlng on the main cylinder, it being under6tood that the plateD were all 6mooth or with their card ..
clothing rever6ed from the normal carding d~rection, ~o a6 not to be oppo6ed to the agqres6ive clothing on main cyllnder 10.
TA~LE 3 ~paclng No. ~lement lnche6 (mm) : .
ctandard backplate l9.5 inch - 6mooth) 0.08 2 20 l5A cardlng ~egment ~6 lnch - 72 pp6i rever6ed) 0.01 0.25 ~ :
16A Cardma6terR plate (15 lnch - rmooth;0.08 2 16B Elliott ~creen (a6 top 6creen in Example 1~ 0.08 2 16C carding 6egment t7 inch - 378 pp6~ reversed) 0.01 0.25 17 doffing 6creen (a6 ln Example 1) O.OB 2 25 lB bottom front ~creen (a6 in Example 1) 0.08 2 19 bottom b~ck screen (a6 in Example 1) 0.08 2 Maln cylinder lO wa6 driven àt 270 rpm, and licker-in 11 at obOut 195 rpm, with a feed rate of fiber to provide about 80-90 pph of clu6ter6. The~e clu6ter6 were well rounded, were ea6ily tran6por~ed by air, and remained di6crete even after repeatedly being compre~sed by h~nd, although they had Dignlficantly ~ore free endD
35 than .he C1UDterD from Examyle '. The p:oduct ~ bl_~n into commercial pillow tick6 of regular 6ize, uslng 22 oz (625 g) f~lling weight6 equivalent to commerclal ..
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' ~ ': , ' "' ~ ' . .: ' - . , . ' . " ' ' ' ' WO91/16484 -23- 2 ~ 7 J ~ '7J ~i PCr/US91/02268 , plllow6 (filled w~th clu6ters), 60 that they could be r~ted vi6ually, both when newly-filled and after three 6tandardized 6tomp and laundry cycle6, and were found only 61ightly le6s lofty and refluffable than 6uch commercial clu6ter filling.
Although much empha6i6 ha6 been given to the desirabllity of making round ball-llke fiber cluster6, 6uch a6 have proved very de6irable for fllling purpo~e6, our proce66 and machlne may be operated to make rounded clu6tcr6 or other 6hape6, e.g. elllp601ds, -- -if thl6 i6 de6ired, by u6ing a higher point den6ity for the card clothing, and ad~u6ting the clearance6. Al60 hard, more compact fiber clu6ter6 may be produced by our proce66 and machine if 6uch are de6ired, a6 our invention provide6 for flexibility of operation.

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Claims (30)

1. Lofty rounded staple fiber clusters of average dimension about 1 to about 15 mm, and of average density less than about 1 pound per cubic foot, consisting essentially of randomly-entwined, mechanically-crimped synthetic staple fiber of cut length about 10 to about 60 mm.

2. Clusters according to Claim 1, wherein the staple fiber is slickened polyester staple fiber.

3. Clusters according to Claim 1, wherein the denier per filament of the staple fiber 16 about 4 to 15.

4. Clusters according to Claim 1, wherein the staple fiber is hollow.

5. Clusters according to any one of Claims 1 to 4, consisting essentially of a blend of the synthetic fiber blended with a lower melting binder fiber.

6. Clusters according to Claim 5, wherein the binder fiber is a sheath/core bicomponent with a sheath of lower melting binder material, and a core of polyester or like high melting fiber-forming material.

7. A process for preparing rounded clusters of fibers, comprising feeding a uniform layer of staple fiber onto the peripheral surface of a rotating main cylinder covered with card clothing, whereby the fiber is advanced around the peripheral surface by said clothing and is brought into contact with a plurality of frictional surfaces, whereby said fiber is formed into clusters that are rolled into rounded configurations on the peripheral surface, characterized in that there is provided at least one arcuate doffing screen, radially-spaced from said clothing, said doffing screen being provided with openings of sufficient size for the clusters to pass through said openings, and to be doffed by emerging through said openings.

8. A process according to Claim 7, wherein said doffing screen is provided with transverse ribs with bases that are spaced radially from said clothing, and that said openings are transverse spaces between said ribs.

9. A process for preparing rounded clusters of fibers, comprising feeding a uniform layer of staple fiber onto the peripheral surface of a rotating main cylinder covered with card clothing, providing a plurality of essentially arcuate frictional surfaces that are spaced radially from said clothing, wherein the radial spacing and frictional characteristics of said frictional surfaces and of said clothing and the rate of feed of said staple fiber are controlled so that said clothing becomes loaded with a compressible layer of fibers, whereby lofty rounded clusters of fibers are formed in the peripheral space between said clothing and said frictional surfaces, and doffing said clusters.

10. A process according to Claim 9, wherein a doffing screen is provided with openings of sufficient size for the clusters to pass through said openings and be doffed thereby.

11. A process according to Claim 10, wherein said doffing screen is provided with transverse ribs with bases that are spaced radially from said clothing, and that said openings are transverse spaces between said ribs.

12. A process according to Claim 8 or 11, wherein said ribs are of triangular cross-section with bases that are spaced radially from said clothing.

13. A process according to any one of Claims 7 to 11, wherein the fiber is advanced around the peripheral surface through a succession of zones between the cylinder clothing and a plurality of arcuate plates spaced radially from the card clothing.

14. A process according to any one of Claims 7 to 11, wherein the fiber is advanced around the peripheral surface through a succession of zones between the cylinder clothing and a plurality of transversely-ribbed arcuate screens with spaces between the transverse ribs.

15. A process according to any one of Claims 7 to 11, wherein at least some of said frictional surfaces comprise card clothing whose tooth orientation is not opposed to the direction of rotation of the main cylinder.

16. A process according to any one of Claims 7 to 11, wherein doffing and transportation of the emerging clusters is assisted by suction and/or blowing.

17. A process according to Claim 16, wherein the rounded clusters are blown into tickings and formed into pillows or other filled articles.

18. A process according to any one of Claims 7 to 11, wherein the staple fiber is fed to the main cylinder in the form of a cross-lapped batt.

19. A process according to any one of Claims 7 to 11, wherein the staple fiber fed to the main cylinder has previously been baled, but is fed to the main cylinder after having been opened.

20. A process according to any one of Claims 7 to 11, wherein the staple fiber fed to the main cylinder has been mechanically crimped.

21. A process according to any one of Claims 7 to 11, wherein the staple fiber fed to the main cylinder is of hollow cross-section.

22. A process according to any one of Claims 7 to 11, wherein the staple fiber fed to the main cylinder has been slickened.

23. A process according to any one of Claims 7 to 11, wherein the staple fiber fed to the main cylinder is a blend of polyester fiberfill or other high melting fiber blended with lower melting binder fiber.

24. In a staple fiber carding machine comprising a rotatable main cylinder having its peripheral surface covered with card clothing and adapted to rotate in close proximity with a plurality of cooperating frictional surfaces, means to feed staple fiber in a uniform layer onto said main cylinder, and doffing means, the improvement characterized in that said frictional surfaces cooperate with the card clothing on the peripheral surface of the main cylinder in such a way that fiber clusters are formed by the cooperation between the card clothing and said frictional surfaces, and the doffing means comprises a doffing screen provided with openings of sufficient size for the fiber clusters to emerge.

25. A machine according to Claim 24, wherein said cooperating frictional surfaces are arcuate plates spaced radially from the card clothing.

26. A machine according to Claim 24, wherein at least some of said cooperating frictional surfaces comprise card clothing whose tooth orientation is not opposed to the direction of rotation of the main cylinder.

27. A machine according to Claim 25, wherein at least some of said cooperating frictional surfaces comprise card clothing whose tooth orientation is not opposed to the direction of rotation of the main cylinder.

28. A machine according to Claim 24, wherein said cooperating frictional surfaces are transversely-ribbed arcuate screens with spaces between the transverse ribs, that are spaced radially from the card clothing.

29. A machine according to any one of Claims 24-27, wherein said doffing screen is provided with transverse ribs with bases that are spaced radially from said clothing, and that said openings are transverse spaces between said transverse ribs.

30. A machine according to Claim 29, wherein said ribs are of triangular cross-section with bases that are spaced radially from said clothing.