CA2075825A1 - Spinning of high molecular weight polyethylene fiber and the resulting spun fiber - Google Patents

Abstract

A method of spinning discontinuous lengths (staple) of a high molecular weight (over 150,000) polyethylene fiber, and the resulting spun fiber, are disclosed. The method comprises blending a sufficient amount of discontinuous lengths of any other fiber (as a carrier) with the high molecular weight polyethylene fiber lengths to permit spinning. The resulting spun yarn preferably comprises about 5 to 95 weight percent discontinuous lengths of the high molecular weight polyethylene fiber which is characterized by a denier per filament of 20 or under and an ultimate elongation of 8 % or under at room temperature, and about 5 to 95 weight percent discontinuous lengths of the other fiber which is characterized by a denier per filament of 20 or under and which is either permanently crimped or has a memory. The carrier fiber or mixtures of carrier fibers may be chosen to achieve specific properties in the spun fiber: e.g., polyester or cotton for hand; pigmented polypropylene for color; aramids and polybenzimidazoles (PBI) for flame resistance; and carbon for chemical absorbance or resistance and for use in composites requiring strength and toughness. The spun fiber has utility in composites, industrial, medical and/or apparel applications.

Description

207~2~

SPINNING OF HIGH MO~ECULA~ WEIGHT POL~E~HYLENE
FIBER AN~ THE RESULTING SPU~ FIBER
BACKGROUN~ OF T~E INVENTION
l. Field of the Invention The present invention relates to the spinning of staple fibers into yarn and to the resulting spun yarn. More particularly, it relates to the spinning of high molecular weight polyethylene staple fiber and to modifications to conventional spinning technology necessary to spin the high molecular weight polyethylene fiber.

2. The Prior Art The spinning of staple (discontinuous lengths) fibers has been practiced for centuries. Natural fibers are of discontinuous lengths and require spinning to for~ :
a continuous yarn. Synthetic continuous fi}ament fibers -~
are converted into staple fiber and spun for a variety of reasons. one such reason is to improve the hand or appearance of the yarn. Another reason is to m~ke a good yarn less expensively since the spinning process permits the use of some fiber which would have been wasted.
With the advent o~ the high molecular weight polyethylene continuous filament fibers which are produced by solution spinning, such as SPEC~RA high strength polyethylene ~iber, it was only a matter of time before an attempt wa~ made to cut the continuous ~ilament fiber into ~tapl- and spin the staple fiber a fiber into yarn. When the attempt was made, it was not possible to card the fiber since the fiber batt was so slippery that it could not be moved by the conventional feed roll to the card. Further~ore, when an attempt was made to overcome the slipperiness problem by crimping the fiber, it was found that the fiber would not hold crimp.
Another reason to attempt crimping was that the high ~ --strength polyethylene ribers would not spring bac~ from being compr-ssed during normal spinninq processing, which is contrary to experience with other fibers. Until this

3 invention that problem was not solved.
The present invention was developed to overcome these problems.

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This invention is a spun yarn, comprising discontinuous lengths of a high molecular weight polyethylene fiber and a sufficient amount of discontinuous lengths of any other fiber to permit spinning a blend of the fiber lengths The preferred molecular weight of the polyethylene is greater than about 300,000, and more preferred is the molecular weight of greater than about 500,000 The preferred other fiber has ~emory By memory is meant ability to return to original shape a~ter distortion For example a straightened, formerly crimped fiber that will return to its original crimped state The preferred other fiber has a denier per filament of no greater than 20, more preferably the other fiber has a denier per filament of no greater than 3 The preferred discontinuous lengths of the polyethylene fiber and the other fiber are no lo~ger than about 14 inches, more preferably the discontinuous lengths of the polyethylene fiber and the other fiber have a l-ngth ranging ~rom about 0 75 to 14 inches Preferably, the poly-thylene fiber forms about 5 to 95% by weight of the spun fiber, more preferably, tho polyethylen- fibQr form~ about 5 to 60% by weight of ths spun fiber Preferably, the polyethylene fiber has an ultimate elongation of less than about 8% at room temperature, more pref-rably about 2 to 4 5% Preferably the polyethylene ~iber has a denier per filament of no greater than about 20, more prQ~erably about l to 15, and most pref~rably, about 1 to lO Even mor- preferably the polyethylene fiber has a denier per filament of about l to 3 ~he preferred other fiber is selected ~rom the group consisting of polye~ter fiber, polyamide fiber, cotton fiber, wool fiber, rayon fiber, polypropylene .. . .

W091/14029 2 0 7 ~ ~ 2 a PCT/USgl/01561 fiber, aramid fiber, lower molecular weight polyethylene fibers, carbon fiber, and mixtures thereof.
It is preferred that the other fiber forms ~-about s to 95% by weight of the spun fiber and is characterized by having memory, a denier per filament of no more tha~ about 20, and discontinuous lengths of no more than about 14 inches. -It is preferred that polyethylene fiber forms about 5 to 95% by weight of the spun fiber and is characterized by an elongation of no more than about 8%
at room temperature, a denier per filament of no more than about 20, and discontinuous lengths of no more than about l4 inches. -It is more preferred that the other fiber is an aramid fiber which forms no more than about 50S by weight lS of the spun fiber.
The preferred aramid other fiber is poly(p-phenylene terephthalamide)~
Use of lower price other fiber can create lower cost yarn blends.
This invention is al50 an article made from the s pun yarn of the spun fiber d-scribed above, preferably the article made from the spun fiber of about 50%
ara~id.
This inventlon i- also a m~thod o~ spinning discontinuous lengths of a high molocular wei~ht polyethylen~ fib~r, comprising bl-nding a sufficient amount of discontinuous lengths of any other fiber to permit spinning of a blond of the fiber lengths.
The preferred and ~ore preferred molecular weights o~ the polyethyl-no are given above, along with the preferred, more preferr~d porcent by weight blends, fiber weight5, other fibor typ~, elongations, etc. -~
Thi~ invontion ~g al~o an apparatus for moving a fiber batt o~ at least about 50 w~ight percent high ~ 35 molecular w-ight poly~thyleno fiber, comprising rotating ar.s, said rotating ~ans having a ~urfaco which rotates ,':.

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WO91/14029 20 7 5 ~ 2 ~ PCT/US91/01561 --into contact with said fiber batt, said surface being modified across at least a portion thereof to increase the friction between the surface and the fiber batt so that the batt moves when contacted by the rotating surface It is preferred that the surface be modlfied by having an adhesive across said portion, a double-backed tape across said portion, or fabric capable of increasing friction or engaging the fiber (such as a Velcro tape or Emory cloth) attached to said portion The surrace also can be modified by roughening to a surface of roughness of similar to 800 grit sandpaper or more coarse 3RIEF DESCRIPTION OF ~HE DRAWINGS
In the accompanying drawings, FIGURE 1 is a schematic overview of the prior art cotton carding process for sliver production;
FIGURE 2 is a detail of the card from FIGURE l;
FIGURE 3 is a detail of the feed to the card, with emphasis on fesd to the lickerin;
FIGU~E 4 is a detail of the modified feed roll 23;
FIGURE 5 has various viows o~ trumpet 21 FIGURE 5A is an isometric view of a prior art trumpet shown in section in FIGURE 5B and FIGURE 5C is a sQction o~ a modi~i-d trump-t, showing th~ enlarged exit opening FIGURE 5D i5 an end view ~TAILED DESCRIPTION OF THE ~NVENTION
In the accompanying drawings, like numbers r-fer to like apparatus The process which is depicted and which was used in the examplQs which follow was the cotton system of spinning yarn For more detail on this system, reference may be had to Textile Processing Vol by John ~ Marvin, (l973) - South Caro~ina State Dept of Education o~ce of Vocational Education and Textiles ~lber to Fabric by M D Pott-r and B P Corbman (1975) -~cGraw-~ill IAC., ee C~pt 3 pp 35 to 71 ~ ' '' ." ' WO91/14029 ~ 7 ~ PCT/US91/01561 With reference to FIGU~E l, discontinuous fiber lengths, here staple, are placed by an operator into the backs of a plurality of hoppers ll. Inside each hopper ll, the individual mass of fibers is broken into smaller tufts by spiked conveying aprons (not shown) which then 5 feed the tufts onto conveyor belt 12 to mix with tufts of fibers from other hoppers ll. Conveyor belt 12 then feeds the mixture of fibers into a blending unit 13 where they are further broken into smaller elements and further mixed. From unit 13 the fibers are transported through pipe 15 via Whitin Axi-Flo Unit 14 which is a pneumatic system, to pneumatic distributor 16. Distributor 16 further opens and fluffs the fibrous mass and then meters the fiber into the CMC Evenfeed Unit 17 which begins to form the fibèr batt 35 from fiber 24 (referred to as a fiber lap in the art). With reference to Fig. l, Fig. 2, Fig. 3 and FIGURE 5 fiber batt 35 is fed via feed plate 37 in association with feed roll 23 to lickerin 22 which ; -has a plurality of wires 50 (card cloth) which rotate against bat. 35 to pull and align discrete fi~ers from 20 batt 35 and transf-r them to the card cloth 50 covering ;
the card cylinder 33 where they are further oriented and worked (brushed/combed) by the carding plates or flats 25. Doffer 30 is also cov-red with a card cloth, removes the accumulating ~heet o~ orlented ~ibers from card 18 and carrie~ the sheet o~ Sibers to a removal point where it can be r-moved by a co~b 28. The sheet of fi~ers is then fed through a trumpet 21 which forces the sheet to nec~ down for passage through a circular aperture 54.
From aperture 54, the sliver 20 (necked down fiber sheet) is piddled into a take-up can l9 where it is loosely coiled.
The modification to feed roll 23 is shown in Fig. 4; double-sided adhesive tape 52 was spiralled around roll 23, as shown. Without use of an adhesive such as the tape, or another surface modification the feed roll does not function properly when high strength, WO91/14029 2 ~ 7 ~ g 2 ~ PCT/US91/01561 high molecular weight polyethylene staple fiber i9 being processed, especially when blends over about 50~ high molecular weight polyethylene are being processed.
Without modification, the batt of fibers just slips and backs up, forms clumps and therefore the machine must be stopped because the fiber can not be carded.
Figs. 2,3,4 and 5 provide more detail regarding the prior art process showing feed roll 23 and surrounding members in greater detail.
Fig. 2 shows feed plate 37, card cylinder 33 screen 38, having wire 50 protruding, lickerin screen 40, backplate 34, spiral brush 31 for flats 25, front plate 29. Calender rolls 27 ~onvey the sliver 20 from trumpet 21 to sliver can 19 on holder 26. Clearer 43, clears feed roll 23. Lap guide 45 guides the lap to feed roll 23. Mote knives 48 cut away motes which may accum~late from the lap.
Fig. 5 shows trumpet 21 in various aspects.
Figure 5A is an isometric view and Fig. 5B is a cross section showing outl-t opening 54 while 5D shows end view oS trumpet 21 having outer perimeter 55 and outlet 54.
Fig. 5C show the enlarged outlet opening 57, necessary for production of the spun fiber of this invention. For further reference to the general discussion which follows, ref~r to Textile Proc-~ing Vol.I, supra.
As pr-viously indicated, when an attempt was made to spin staple high molecular weight polyethylene fiber alone with the system depicted in the drawing figures, feed roll 23 could not move batt 35 forward to the lic~erin. Two modifications were made. The fiber was blended with other fiber, to ~e discussed in more detail below, and the feed roll 23 wa~ modified as shown in FIGURE 4 with a spiral of double-backed masking tape on its surface that rotates into contact with batt 35 to p~rm~t it to move batt 35 ~orward. Anything that can be put on the feed roll 23 to enchance the frictional characterist$cs between its surface and batt 35 is i . _ 'i ' ~ . . ! .:, ' .. . .

`' , , ~ ! . ~ . ` ~ ` i . . ' WO91/14029 20 7 ~J~ 2 i~3 PCT/US91/01561 acceptable, and it may ~e coextensive with the roll surface or distributed over a portion thereof as long as the batt 18 can be moved by it For example, veic~o -type tape, Emery cloth, a roughened surface, adhesive, double-backed tape or the like can be used Another problem was encountered at trumpet 21 Due to the inability of the fiber to hold crimp, it does not spring back after deformation After the neck down of trumpet 21 aperture 28, the sliver 20 is like a rod and dif~icult to piddle Therefore, trumpet 21 was bored out su~ficiently to increase the size of the sliver 20 and to reduce or limit the compression of the sliver to the extent that it could be piddled (see FIGURE 5C~
Cans of the attenuated sliver are collected and transferred to a draw frame, in the accompanying examples lS a Saco Lowell four over five draw frame, where several individual slivers are blended and further attenuated/drawn The cans of att-nuat-d, blended sl$ver are then transferred to a roving fram for further attenuation and ~1 a very low l~v-l of twist is ins~rted The sliver is now ready for spinning and i- tak-n-up on a bobbin which is th~ fe~d~r packag- for th- spinning frame Th~ bobblnJ ~r- hung on a spinning frame, pr-~rably a ring plnning ~ram-, wh-r~ the slivers are again indivitually ~tt-nuat~d and spun into yarn by twi ting Tha spun yarn i- th-n tak-n up for packaqing or furth-r procossing U S Patent 4,457,985, heroby incorporated by reforenc-, g-n~rally di cu~ high ~olecular weight -~
polyethylen- In th- cas- of polyothyl-ne, suitable fiber~ are tho~- of ~ol-cular woight of at least about lS0,000, pr-f-rably at l-ast about 300,000, ~ore proforably at l~a~t about S00,000, most pr-ferably in ~xce~J o~ about on~ million Such xt-nd-d chain poly~thylono (ECPE) f~bers ~ay b- grown in olution as d~scribQd in U S Pat-nt 4,137,394 or U S Patant ''' '. ' '.: .'` ''' ''''` ~ ' ;' ' ' ' ' ~ " ' i ~
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4,356,l38, here~y incorporated by reference, or may be a filament spun from a solution to form a gel structure, as described in German Off. 3,004,699 and GB 2,05l,667, and especially described in U.S. Patent 4,551,296, also hereby incorporated by reference As used herein, the term polyethylene shall mean a predominantly linear polyethylene materiai that may contain minor amounts of chain branching or comonomers not exceeding 5 modifying units per lO0 main chain carbon atoms, and that may also contain admixed therewith not more than about 50 weight percent of one or more polymeric additives such as alkene-l-polymers, in particular low density polyethylene, polypropylene or polybutylene, copolymers containing mono-olefins as primarv monomers, oxidized polyolefins, graft polyolefin copolymers and polyoxymethylenes, or low molecular weight additives such as lubricants, colorants, fillers and the like which are commonly incorporated by reference. Depending upon the formation technique, the draw ratio and temperatures, and other conditions, a variety of properties can be imparted to these filaments. The tenacity of the filaments should be at least a~out 8 g/d, pr-ferably in the range of from about 8 to 45 g/d, most preferably in the range of a~out ~-25 to 35 g/d/. Similarly, the tensile modulus of the filaments, as measur~d by an Instron tensile testing machine, 1s at least about 160 g/d, preferably in the rang~ of about 150 to 3300 g/d, most preferably in the range of about l,200 to 2,500 g/d. These highest values for tensile modulus and tenacity are generally o~tainable only by emp}oying solution grown or solution spun, gel 3 o f ~lament proc~sse~.
The polyethylene fiber should preferably have an ultimate elongation by Instron tensile test of no greater than 8%, preferably in range of 2 to 4.5%, at room temperature, i.e., about 25- C. T~e denier per ;
3 5 filament i5 prefarably no greater than 20, more preferably l to 15, most pr~ferably l to lO, even more preferably l to ~ WO91/14029 2 0 7 ~3 ~ 2 .j PCT/US91/01561 _g_ 3 The smaller denler per filament fibers are desirable to use in spinnlng blends for apparel applications The larger denier per filament fibers are better to use in spinnfng blends for cordage, ropes, or heavy fabric applications The amount of polyethylene fiber in the blend ranges from about 5 to 95% by weight, preferably about 20 to 80 % by weight as the primary fiber and about 5 to 40%
by weight as the support fiber The carrier fiber may be any other fiber i e , anything except the high molecular weight polyethylene fiber just described Exemplary fibers may be found listed in allowed U S Patent Application S N 62,998 filed July 13, 1987, hereby incorporated by reference A
partial listing would include the ara~ids, cottons, carbon, polyester, polyamides, wool, rayon, polypropylene, lower molecular w-ight polyQthylenes, etc ~he carrier fib-r prof-rably should ha~e the following charact-ristics it should preferably be a fiber which has memory or is pormanently crimped; it ' should pro~rably have a denier per filament of no greater than 20, more pr-ferably 0 5 to 3 for apparel applications and pr-f-rably 3 to 20 for ropos, cordage, and h-avy fabric application~
~h- minimum amount o~ carrier ~iber n-eded is about 5% by w-ight of th- ~pun fib-r, and up to 95% by w-ight is acc-ptAblo Tho pr~ferred a~ount will range ~ro~ about 20 to 50% by w-ight mO ~oount will be a ~unction of th- d-nior or the polyothylen- ~iber, e g on would n--~ about 30% by w~ight carrior fiber to spin a 20 denier per filam-nt polyothylon- fib-r, and would n~d l-g8 to ~pin a low r deni-r p-r filament polyQthylon- fib-r ~oth th- carri-r ~ib-r and th- poly-thyl-ne fiber ar- form-d from di~continuou~ l-ngths of no greater than about 14 inches, preferably no longer than 2 25 inche~ in ~he cotton 9ystam (moro pr~erably 0 7S to 2 inch~

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WO 91/14029 2 ~ 7 3 ~, 21 ~l PCr/l~S91/01561 i The particular blends of carrier fibers will depend on desired properties of the spun fiber. It is contemplated that a blend of polyester and/or cotton with the polyethylene will enhance hand; polypropylene can be blended for pigmentation: aramids, specifically Kevlar and Nomex can be includes for flame resistance;
polybenzimidazoles (PBI), avilable commercially from Hoechst-Celanese, can be included for flame resistance and enchanced comfort due to higher moisture regain;
carbon for use in fiber for composites requiring strength and toughness. Activated carbon fiber could be used for chemical absorption protection.
EXAMPLES
EXAMPLE 1 ~including comparative) Using the apparatus of Fig. 1, a two-inch SPECTRA 900 ~iber available from Allied-Signal Inc. is run on the apparatus, unsuccessfully. The fiber slips on the feed rolls, clumps up in the feed mechanism and the machine must be stopped. A second trial was attempted with a ~iber blend of 70% of the SPECTRA lO dpf fiber ;~
~bove and 30~ 1.2 denier per filament (dpf) Kodel polyester 1.5 inch staple. The mixture of 70% Spectra lO
dp~ two inch staple and 30% 1.2 dpf Kodel 1.5 inch polyeater staple was prepared and loaded into the card ~eeder. Di~ficulty in carding the fiber mixture was encountered a~t-r about 30 minut-~ b~cau~e the polyester ~ber roll-d on itself and ~orm-d small balls of fiber.
The scr-en inside the Even Feed unit could not move the bat of Spectra fiber and the balls of polyester fiber to the card main cyl~nder. The fiber bat was probably too slipp~rty to be moved by the feeder mechanism. The trial was terminated and the card feeder was cleaned.
Th- ~econd trial was conducted u~ing a blend by w~ight of 60% Spectra 900 lO dp~ 2.0 inch staple fiber and 40% Xevlar 1.5 dp~ 1.5 inch staple fiber. A len~th o~ double-bac~ed adhe~ive tapo wa~ spirally wrapped around feed roll 23 as in Fig. 4. The difrerence in the two -" ~

. , . ., . ,. , . , .. , ,; .. ;,, , . ,! .~ . ... , ., ., . , . ', ' . ' ~, WO9~ 029 2 ~ 7 ~ ~ 2 3 PCT/US91/01561 fibers dpf caused some problems with how well the mixture blended and carded. The problems were not serious.
However, to optimize the process it may be desirable to have fibers which have similar dpf.
A total of S0 pounds of Spectra/Kevlar fiber blend was made. To control static electricity Stay Guard antistatic spray was purchased fro~ a local grocery store. The anti static spray was added to the fiber in the opener as the fiber was being opened and blended.
There were no static electricity problems.
The ~ain problem encountered during carding was the loading of the card main cylinder by the Spectra fiber. This problem may be solved by using a fiber with `
a smaller dpf or development of a special fiber finish.
There was also a large amount of Spectra fiber removed by the card flats. The card flats rotate against the main cylinder to help clean it. This problem may disappear if the cylinder loading problem can be solved.
The carded sliv-r was divided into six ends which were fed into a Saco Lowell 4 over 5 draw frame.
The draw ~rame was running black coated rubber rolls.
The black rolls seemed to ~inimize the tendency cf the sliver to wrap. $he draw frame further blended the carded sliver and reduced the sliver weight by about 50%.
The roving was produc-d on a Saco Lowell roving ~ram-. No probl-ms w~re encount-r~d during the rovinq formation.
The roving was convert-d to spun yarn on a ring spinning frame. ~he speeds and conditions were varied to produce a y~rn which had a spaciSic cotton count. The ~irst yarn count atte~pted was a 20's.
The spinning of the 20' 5 yarn was very difficult because the yarn kept breaking. A calculation showed that because of the Siber dia~eters, the formation of a 20's count yarn waa on the ~dge of being a physical impo~ibility. (Theoretically, at least 88 fibers are required in the cross section of a spun yarn. Because o~
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wo gl/14029 ~ ~ 7 ~ 3 PCT/US91/01561 the dpf of the Spectra fiber, it is impossible to have enough fiber in the spun yarn cross section and the yar~
still be small enough to be a 20's ) ~ he two spun yarns produced were a 10's and a s~5 cotton count Both of these yarns spun easily some optimization will be necessary to achieve the best balance of physical properties in the finished yarn E~ L~ 2 Example 1 was repeated loading the following fibers 70% o~ 3 dpf SPECTRA ~ 2" staple 30% of 1 2 dp~ Kodel polyester 1 5" staple Four spun yarns were successfuly produced -10 cotton count single, 10 cotton count two-ply, 20 cotton count single, 20 cotton count two-ply ~The SPECrRA fiber had a lower intrinsic viscosity of between about 6 and a, estimat-d ~olecular weight about 700, 000.
EXAMP~E 3 (Comparativ-) An attempt to ~pin 100% SPECTRA fiber on the unmodifiet apparatus of Exampl- 1 wa~ unsucc-ss~ul, as was anoth~r attempt on a worst-d ~pinning syst-m SPECTRA / AR~M~LZ~ Laoey~ YARN G~OVE
Th- articl- mad- fron th bl-nd of Sp ctra and X-vlar flb-r from Exampl- #l xhlblt-d good ~lame r-~i~tanc- and ln~ulat~ng prop-rtl-- Wh-n th- fabric (ln this ca~- a knitt-d glov-) wa~ xpos-d to a ~lame from a clg~r-tt- light-r th- ~xpo--d polyQthylene ~ibers on th- rabric ~urfac- m-lt-d b~ck into th- f~brie even with th- ar~id fib ~urr~c- Th- fabric did not ignite or burn which is ~urpri~lng b-cau~- Sp-ctra fib~r is a polyol-f~n which will burn it it b-co~-- hot nough The in~id- o~ ~h- glov- rain-d cool Th Sp-ctra fibers di~ not ~-m to m~lt on th- id- Or th- tabric opposite the ~a~- Wh-n ~n att-mpt to int-ntion~ily ignlt~ the 3~ rabrio mad- from th~i bl~nd or Sp-ctra and aramid ~l~ers wa~ ~ad~ the fabric axhibit-d a ~-lf xtingui~hing WO91t14029 ~ 7 ~ ~ 2 a PCT/US91/01561 behavior and did not readily support combustion.
(surprising because olefin fibers are known to burn).
The Spectra fiber should improve the abrasion resistance of the aramid fiber (in the case of the glove and allow the item to have a longer service life. The fabric made from the blend of fibers had a good hand and the frictional characteristics of the fabric surface were improved over an all Spectra fabric because the aramid ~ -fiber reduced the slickness of the surface. This improved frictional property would be desirable in a glove because of the necessity of keeping a good grip on objects being handled.

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Claims (12)

WE CLAIM

1. A spun yarn, comprising discontinuous lengths of a high molecular weight polyethylene fiber and a sufficient amount of discontinuous lengths of any other fiber to permit spinning a blend of the fiber lengths wherein the molecular weight of the polyethylene is greater than about 300,000

2. The yarn of claim 1 wherein the other fiber has a denier per filament of no greater than about 20.

3. The yarn of claim 1 wherein the discontinuous lengths of the polyethylene fiber and the other fiber are no longer than about 14 inches

4. The yarn of claim 1 wherein the other fiber is selected from the group consisting of polyester fiber, polyamide fiber, cotton fiber, wool fiber, rayon fiber, polypropylene fiber, aramid fiber, lower molecular weight polyethylene fibers, carbon fiber, and mixtures thereof.

5. The yarn of claim 2 wherein the other fiber is an aramid fiber which forms no more than about 50% by weight of the spun fiber.

6. The yarn of claim 2 wherein the other fiber is poly(p-phenylene terephthalamide).

7. An article made from the spun yarn of claim 3.

8. An article made from the spun yarn of claim 1.

9. A method of spinning discontinuous lengths of a high molecular weight polyethylene fiber, comprising blending a sufficient amount of discontinuous lengths of any other fiber to permit spinning of a blend of the fiber lengths wherein the molecular weight of the polyethylene is greater than about 300,000 and the polyethylene fiber forms about 5 to 95% by weight of the blend.

10. The method of claim 9 wherein the other fiber is selected from the group consisting of polyester fiber, polyamide fiber, cotton fiber, wool fiber, rayon fiber, polypropylene fiber, aramid fiber, lower molecular weight polyethylene fibers, carbon fiber, and mixtures thereof.

11. Apparatus for moving a fiber batt of at least about 50 weight percent high molecular weight polyethylene fiber, comprising rotating means, said rotating means having a surface which rotates into contact with said fiber batt, said surface being modified across at least a portion thereof to increase the friction between the surface and the fiber batt so that the batt moves when contacted by the rotating surface.

12. The apparatus of claim 11 wherein the fiber batt is processed further on a card having trumpet to form the batt into a sliver, said trumpet being modified by having an enlarged exit opening.