CA1314368C - Polyester fiberfill - Google Patents

Abstract

ABSTRACT
New polyester fiberfill of round cross-section, but containing multiple peripheral voids around an axial void, and preferably seven such voids in a hexagonal packing arrangement, and processes for preparation and use, and articles filled with such new fiberfill.

Description

1 3 1 ~363 TI TLE
NEW PC)LYESTER FIBERFILL
A~ rl~LD
Thi~ inventlon concern~ n~w polyester fiborill cont~ining ~ultiple cont$nuvlls voidc ~l~nq tho length of the fil~ment~, ~nd proc~Ge6 ~or lt~ pr~p~ra1;~0n ~nd lt~
uce, ~nd arti~le6 ~illcd w~th ~uch new ~lber~E111.
~CXGROUND OF THE INVENTION
Polye~ter 1berflll ~60D~ti-nos r~err~d to ~
polye~ter iber~ terl~l ~ h~6 become well accept~d a~ a rea onably ~nexpen6iv~ f~ g ~nd/or ~n~ulat~rlg m~teri~l fc,r pillow8, cu~hi~rl~ ~nd oth~r ~urn~h~ng ~ateri~ ncluding bedding ~21t~rl~ nd ~n ~pp~rel, and is ~anugactured and used ~n large qu~n~t~e~
3.5 commerc~ally~ Orig~nally, ~, w~th other p~lyeæte~ f~ber6, 601id ~ib~E o~ round cro~s-~ectiQn ~ere u~d, be~ng the t expen~lve fib~rE to ~ake, and ~u~h ~ol~d round poly~6ter flberfill 1~ ~tili ~d ~o~mercl~lly. ~ome twenty year6 ago, however, hcllow polyeeter f~berfill wa~
cuggested and u~ed, a8 disclo~ed, e.g. by Toll$ver $n U.S.
: Paten~ No. 3,772,137 And by ~lanz~toff ln G~ P~ten~
No. 1,168,759. ~oll~ver ~how~ a ~i~gle hollo~ cor~ or eentral ~ontinuou~ l~ngitudlnal ~1d. The pref~rrod 6hape ~f the void was non-round ~n c~o~ ectlon, ~ut ~old~
appr~xlfflately clrcular ~n cro~s-8ectlon w~r~ o di~lo6ed, and large quantitl~ o~ hollow polyester ~ ~lberf~ll hav~ng ~ingl~ c~n~r~ d6 ~f ~ircular and of :~ non-round cro~ ec~ion ha~e ~e~n ~anu~ctured ~nd u~ed ~cau~e o~ their greater llghtne~ (lower ~ ty), ~n 3~ ~ontra~t to ~olid $b~r~ and bec~use o~ tbe ~provemen~ in ln~ulatlr3g pow~r, ~nd for other ae~thetic rea~on~. ~ore r2c~!ntly, there haz ~e~n pr~vided an i~proved hollow polye~ter ~ibier~l, ch~r~ct~riz~d ~y ~our equi~ized, ~qui6pac~d, non-rDlund void6 ~round ~ ~olid axi~l core, 1:he ~ ment cro~,6-~ection h~ving ~
quadrilat~ral per~ph~ral eontour de~ined by four flattened ~-4335 ~, .~ .

131~368 6ides ~nd ~our rounded corner~, in conjunction with a s~w~toothed type of crimp c~nfiguration and ~ clickening agent, to provide hi~h bulk and hagh bulk durability with improved ~ftnes ~ore like th~t of natural down ~illing, as disclo~ed in EPA2 67,684.
Surpri6ingly, however, de~pit~ the l~prove~ents thot hav~ been available ~or 6everal y~ar~ ~ro~ the v~riou~ exi~tln~ configuration~ that h~ve been ~ugge6ted ~nd u~ed commerci~lly for polye~ter ~bcr~ll h~vlng lQ continuou~ longitudin~l voidsp the new ~nproved polyester ~iberfill, ~ccording to the pre~ent invention/ provide~
adv~ntage6 in contr~6t with ~ach of the Ispec~fic prior configuration~, con~idered ~eparately, ~s will be evident.
SUMMARY OF THE IN~ NTIt)N
AccDrding to the ~nvent~on, there i~ provided polye6ter flberfill of denier p~r fila~ent ~bout 5 t~
~bout 2D, ~nd o~ ee~entially sound per~pheral cro~6-~ection, with ~ le~st 7 continuous void~ of e6~enti~11y circular cros6-~ection nlong th~ length of ~he ~ila~en~s, one ~uch void being located essentially centrally, while the remaining ~oids are of es~entiHlly the saD~e ~ize as e~ch ~ther and ~re eE;~entially equa}ly ~p~eed ~round the central void ar~d ~r~m the centr~l v oid ~nd fro~n the periphery of 'che ~ila~nent. ~ccording to one e~bodi~entt all void~ ~re pr~erably o~ es~entially the ~ ze and #~senti~lly equally ~ipaced ~ro~ adjacent void~ nd 60 constitute eJ~ctly 7 $n nu~ber, in ~ hex~gonal p~cking arrange~erlt with a centrAl vc~id and 6 outer vcid~ ~t the points of ~ hexagon, ~ w~ll be part~oularly $11~!s~rated and di~u~6ed hereinafter.
~t i6 al~o contempl~ted, however, th~t the centr~l vo~d may be somewhat larger in ~ro . ~-~e~tion th~n the outer voi~, which l~tter ~re sub~'canti~lly equisized ~nd equispaced from eaeh other, ~nd ~r~ o equ~lly ~p~ed from lthe periphery o t!h~ cen~r~l vsld, ISo a6 to pr~vide the ~dvan1:aqe~ of a larger central void; a~cording :

~3~368 to this embodi~ent, the outer voids are preferably cymmetri~ally arranged and constitute ~n even number, e~peei~lly B, ~king a t~tal of 9 void~ with the central void.
~he pre~erred ~otal v~id c~ntent will gen~rally be ~bout B to ~bout 25% (by ~r~a, ~a~ur~d on th~ cros6-~ect$on of the polye~ter f~la~ent~, on ~verag~).
A~ i~ known in the art, and di~scu6~ed herein~fter, the provi~ion of cri~p in p~lye~ter fiberfill 1~ extremely ~portant in prov~dinq bulk, or loft, an~
with regard to it~ durability, and the ~ri~p frequency i6 pre~erably about 4 to about 12 crimp~ per ~nch, corre~ponding approxlmately to ab~ut l.S to about S cri~ps per ~m.
lS rhe f~berf~ll is pr~ferably 61ickened w~th durable ~l~ckener~
According to the invent~on, th~re are al~o provided proces6ec for preparing 6uch new polyester fiberfill and precur60r ~ilament~, a~ descrlbed hereinhfter ~nd filled furni~hing and app~rel article~
that are filled with 6uch new p~lyecter fiberfill, ; ~ncludiny ~uch ~rticle~ ~illed with ~uch n~w polye~ter fiberfill ~lone or blended with other filllng ~aterial6.
~RIEF DESCRIPTION OF TH~ DRAW ~G~
Figure 1 i~ a photo~icrograph of cro~ e~tion~
~ of typical poly~ster ~iberf~ ment~ ~cording to one ; embodi~ent o~ the precent ~nvent~on.
; Figure 2 i~ ~n enl~rg~d v~ew of ~ ~pi~neret : orifice ~uitable or ~elt 8pinn~ng polye~ter fiberfill filament6 ~ ~hown $n Figur~ 1.
Figure 3 i~ a repr~entation of a cro~6-~ection of another embodi~nt c th~ inventi~n.
DETAI~D DESCRIPTION OF THE INVENTlON
__ - ~ believe tha~ the e~ential el~ment~ o~ the lnve~tion ar~ the number and arranq~m~n~ of the ~ultiple ~ont~nuou~ void~ along the length o~ ~he ~oun~ ~1~m~nt~, : . -3-1 3 1 ~368 ~nd contribute to improve~ent~ ~er those that have been ~uggested or used for polyester ~iberfill hitherto. One can ~peculate th~t so~e, at lea~t, o the advant~ge~ c~n be explained, ln retrospect, by 2n~10gy with ~nd S co~parison with prior ~rt configur~ti~n6/cro~c-~oct~on~, but thi6 co~binatlon ~f element6 i~ believ~d new, ~n~f~r as poly~t~'r fiberfill is conc~rned. I b~ ve the ~ound periphery i~ of i~port~n~e. I beli~ve th~t the loc~tion o~ a void ~entr~lly, i.e. ~x$~11y, i~ i~portant; polyester fiberfill ~ccording to the invention has thi~ ~eature in c~mmon with the e~rlier 6ugy~ti~n by ~oll$ver; polye~ter fiber~ill of ~y lnvention i~, however, d.isting~i~hed from T~lliver's con~iguration by the provicion of ~u~tiple e~sentially p~rall~l v~ld~, w~ere~6 T~ er provided ~nly a cingle void. In contra~t, ~PA2 67,684 provided ~ultiple essenti~lly parallel v~id~ (4 $n nu~ber), and thereby deriYed ~ertain i~prove~ent~ in co~p~ri~on with the p~lye~ter flberfill of ~olliver, containin~ Dnly ~ ~ingle axially-located void; the polye~ter ~iberfill ~f EP~2 67,684 i6 di~tin~ui6hed in 6everal re~pect~, namely being of e~entially quadrilater~l peripheræl cro~-section, h~ving a 601id axi~l o~re ~nd only 4 continuou~
parallel void~ that are them~elve~ non-round and only ~n the corner~, vr lobes, of the qu~drilater~ 5 will be noted hereinafter, the polye~ter f~berfall of ny ~nv~ntion ~ke po~sible ~n ~provement in cri~p conf~gurat~on that i~ belie~ed ~ore diff~cult, ~nd p~ibly even l~pr~ctical to ach~ev~ w~th thi~ prior ~rt polye~ter ~iber~
~lthough ~y ~nv~ntion ~ not l~lted by ~ny theory of cperat~on, or any ~pecul~ted rationallzation, in view o~ the ~any ~ao~orc involved ~nd 8 6~ill i~per~ect und~r6tanding of tbe re~60n~ for the improvements, one ~ay 6peculate that the ~ultiple void~ with one central void of the eonfi~uration of the pre~ent ~nvention provid~ better ~r~h r~ tance, ~n the 6en~e ~f per~itting ~ hig~r 6tiffn~6~ ~or the ~a~e void content, ~nd one ~n ~urther 1 3 ~ ~368 ~pecul~te that, after crimping, the cri~p configuration providec more r~unded eorner~, as opp~6ed to a ~n~re caw-t~othed or 6h~rp e~rnered erlmp ~onfiguration ~uch a~ ~ay re~ult from cr~mping prior conf~gu~at~on~ ~Eor polye6t~r fiberfill having ~i~ilar void eontent, ~nd thi~ ~in a~60ci~tion with the round peripheral ~ro~ ;ect~on) IQay acc~unt for better ~ri~tional prope~t$eli ~nd ~r gre~ter dur~bility during u~e. Thi~ coult!!i 3be el;pecl~lly true for the c~nfiguration $hown ln F~gure 1, lnvolving ~xactly 7 void6, that ~re equ~zed and equi~p~ed fro~ d~ent void6, in other w~rd6 ln a hex~gonAl pack~ng arr~nge~nt, sinee I believe th~ tc provide ~n Opt~ Ua ~tru~ture in thi~ reg~rd, be~nq ~y~lunetr~c~al, and pre6entillg arl opti~ur~
~trength:weaght (in the ~e~e c~f lightne~ el~t~on~hip~
However, for ~ome appl~cat~ons, lt ~ay prove pre~er~ble to in~r~se the cize of the centr~l void t~n relati~n to the outer void~), and thereby derive ~o~ 9f the adv~nt~ge~ of the large ~entr~l vo$d ~u~ge~ted by Tolliver, ~n a~ociDtl~n with a ~ult~-void 6tructure; in th~6 r~g~rd, I
believ~ that h cy~metr~c~l arrang~ent provide~
advantæge~; $n othcr word~, e.q., ~s ~hDwn in Figure 3, 8 ~quispaced outer void6 21 arr~nged ~round ~nd oqually paced ~rom a larger central void 22, ~aking ~ total of 9 e~entially parallel vo~d6 in a ~ila~ent of e6~entially round peripher~l cro~-$ection 23, ~ay provide ~ert~in adv~nt~ges, ~t b~ing under6tood that other orrangement~ of ~ultiple void~ around ~ central v~ld ~re pos~lbl~, but will qeneral}y provide le~s ~ymmetry th~n hexag~nal-packing ~rrangement.
In pr~n~lple, the technology ~nr ~elt-6pinning holl~w fil~m~nt~ from polye~ter and o~her synth~ic polymer6 ha6 lon~ been known ~nd di6closed ln tbe art.
. Bohringer ~nd F. ~oll~nd pre~enteB ~ paper ent~tled "Development and ~val~ation of Profiled ~ynthetic Fiber6 3~ ~ith ~nd ~i~hou~ Hollow Cor~, Fa~e~fsr~ehung ~nd ~ext~ltechnik g, ~o. 10 ~Octob~r, 1~5~) page~ ~05-416, and ~ 3 1 ~36~
referred to ~everal other public~tions therein. Although thi~ publlcat~on s~a~ prl~ar~ly ~ddr~6~ed to provldirlg nylon filament~, for use in making textile fabrics, e.g.
by knitting, a~ ~ppo~ed to polye~ter ~iberflll for u6e ~15 filling m~teri~l, the came el;~en~ial con~ider~tlon~ ~pply in~of~r ~ preparation o llollow ~ilament6 ~re ~nc~rned.
Neverthele6s, al~chough ~evsr21 ~ulti-hole fila~@nt6 ~re ~hown, wi~h 6pinner~t de~ign~ for obtain~ng ~uoh ~ulti-hole filaments, thi~ public~t~on (in ~o~!non with ~veral oth@r~) did not di~clo~e ~ny wny to aak~ a coni~igurat~on ~ccording ~o the pre~ent ~r~vent~on ~ith ~ c~n'crAl void having ~ tot~l of ~t least 7 void6~ ~n an es~entially round fila~nent. Con ~derable di~ iculty and exten~ive experilDentation was nece~ary ~o acco~pl~h 'chi~ t~slt, ~nd ~'c w~ doubted by ~ome that the ta&~ oould be ~chie~d in practice because, ~.9., o~ the ~inene6~ o~ the ~ilament6 ~nd v~id~ and the well-known pheno~enon o~ p~st-orifice bulg~ng and be~au~e o~ ~he dif~culty ~nown ~6 aknee~ng~.
" Neverthele6~, thl6 t~sk wa~ ~chieved ~s described hereina~ter u~in~ a ~pinneret orifice de~ign ~ ~hown in F$gure 2, in which ~ix ori~i~e~ re arranged (in the ~urf~ce 12 of the ~pinner~t~ ~o that polymer will be extruded through eaeh orifice and then c~le6~e to fozm a round ~ilament with 7 void6 e~sentially equi-~zed and ~5 equi-~p~ced ~6 ~hown ln Figure l. Alth~ugh, $n retrospect, thi~ de~ign doe~ follow the generDl prineiple~
~ that have al~eady been outlin~d ~n ~he ~rt, a~ ~ention~d, :~ conGider~bl~ e~for~ and experi~ent~tion w~ nece~ary before it wa~ pos~ibl~ to ach~eve round ffl~lti-hole polye~ter fil~ment~ with ~ central void according t~ ~y ~nvention~
Apart f~om th~ form3tion o~ tbe polye~ter fil~ent~ having th~ particul~r con~iguration accordiny to my inventlon, ~he v~riou~ 6~ep~ in the ~anu~ac~ure of the l1~ment~, including preparation of the poly~er, ~nd the proce~sing of th~ filament~, their ~onver6ion ~nto ~taple 131~36~

-fiber, and the handling of the fiberfill and its use as filling material in the preparation of articles such as pillows and other filled articles, such as cushions, or formation into quilts, including quilted articles, including garments, may be ca-rried out according to known 5 procedures, as described in the prior art referred to herein and elsewhere. As explained, poly(ethylene terephthalate) is generally preferred as the polyester polymer, on account of its commercial availability and cost, and a relative viscosity will be selected appropriately in conjunction with processing conditions, to provide the desired configuration that is the essence of the present invention. A chain-brancher may be used, as described, e.g. in copending Application Serial No. 014,246 filed February 11, 1987, by Broaddus et al. ~/
As indicated, it has long been known and commercially practiced to "slicken"
polyester fiberfill by use, e.g., of polysiloxane slickening agents, as taught for example by Hoffman U.S. Patent No. 3,271,189, Mead et al. in U.S. Patent No. 3,454,422, Ryan U.S.
Patent No. 3,488,217, Salamon et al., U.S. Patent No. 4,146,674, and Takemoto Oil & Fat Co., Ltd., Japanese Published Patent Application 58-214,585 (1983). Polysiloxane and/or other slickening agents are used to improve the aesthetics of polyester fiberfill, and use of such slickener is preferred for some purposes according to the present invention. Non-silicone slickeners, as disclosed in copending Canadian application No. 549,793, filed by Marcus on 1987 October 20, may prove advantageous for some purposes. Slickeners are preferably "cured", e.g. by heating, onto the filaments, so as to improve their durability, for most purposes.
In this regard, reference may be made to the ~ollowing Example, which further illustrates my invention.
EXAMPLE
Filaments are spun from poly(ethylene terephthalate) of relative viscosity of 20.4 (as measured 1 31 ~368 at 25C fDr 80 ~9 of polymer in 10 ~1 of hex~luoroi~opropanol containing lQ0 ppm of ~ulfuric ~cid) ~t ~ p~lymer temperature of 291-297C at 900 ypm (B23 mpm) through a ~pinneret with 28a capillarie~ with a throughput per capillary of 0.306 lbs./hr. (0.139 ~yO/hr.), u~ng orifice~ as ~hown in Figure 2. The ~ nt~ grouped together to for~ a rope (of 914,000 rel~xed dr~wn deni~r).
The rope i~ dr~wn ~n a conventional ~anner, uclng a draw ratio of 3.46X ~n a hot, wet spray dr~w ~one ~aint~lned ~t 90~C. The drawn filament~ ~re cri~ped ~n a conv~ntional ~tuffer box cri~per o~ a cantile~er type ~3.5 ~n., 8.9 cm.
~ize~ and the cri~ped rope 1~ relaxed in an oven ~t 180CC.
61ickening fini~h cont~ining ~ polyamino~iloxane is applied to the fila~onts to give about 0.32% ~ilicone ~llds) by weisht on the ~ber, ~nd th~n ~ convent~sn~l anti~tatic ~verl~y flnl~h o~ a~out 0.07~ by wei~ht. The fiber~ are cut in ~ convent~on~l ~anner to ~ length of 3.0 in. ~75 ~). The fibers are found to have Bn ~veraqe total void content cf about 12.3% and a deni~r per ~ilament of about 9. The ~iber6 have a cros6 ~ectlon ~
shown in rigure 1, containing seven ~ontinuou~ void~ which are parallel, nnd sub~tantially egual ~n 6ize, ~ix being ~ubstantially equ~-~pa~ed ~round the ~venth which form~
the eenter of th~ fiber. The perlphery o~ the ~iber :: 25 round ~nd ~mooth.
A ~ampl~ (C) of ~imilar denier ~s ~ade ~i~ilarly, ~xcept that it contain~ our p~rall~l continuou~ void~ with ~ ~olid ~xi~l core, ~nd wlth ~n average total Yoid content of 17~7~, ~nd ~6 cri~ped to ~bout the ca~e crimp frequency ~nd bulk (xt 0.2 psi) the 7-hole f~ber, for compar~tive purpo~e~.
Variou~ pro~ertie~ o~ the 7-h~l~ ex~mple (1) ~nd o~ ~h0 4-hole compari60n ~C) are mea~ured, and are 6et out ~n the ~abl~. It will be no~ed ~b~t the F-F ~rict~on (~oe~flc~nt of ~lber-~o-f~ber ~ri~t~on) i~ low~r, and that the bulk at 0.001 p51 ~ 60mewhat bettçr, ~hich ~re both advantage~u~ and ~urpri~

_~_ 1 31 ~3~8 ~ th the 7-hole fiber~ cc~rding tD the invention ~nd the ~-hole co~p~ri~on are processed into 2Q oz. r~lled b~tting pillow~. Shey h~ve 6i~nila~ height~, ~s ~hown in the l~able, but the 7-h~le 2iber pillow 5 6ubjectively ~e~lr s~fter snd mor~ de~irable, both when fre~hly made ~nd a~ter l~b~ratory-~to~pirlg. ~he 7-hole ~iber ~ee~ to give a ~low2r recovery froll3 eo~pr~lon, that i6 very de~irable.

TABI,~

Crimp ~R~ ~ulk (~n) F-F ~ w Height ~in) ~te~ Per ~nch . 0~1 p~i . 2 p~i Fri~tion 1- 7-hole 4.B 6.25 0.43 0.203 9.15 a.o7 C- 4-hole 4 . 5 5 . 38 0 . 450 . 219 9 . 09 8 . 22 _g_

Claims (10)

1. Polyester fiberfill of denier per filament about 5 to about 20, and of essentially round peripheral cross-section, with at least 7 continuous voids of essentially circular cross-section along the length of the filaments, one such void being located essentially centrally, while the remaining voids are of essentially the same size as each other and are essentially equally spaced around the central void and from the central void and from the periphery of the filament.

2. Polyester fiberfill according to Claim 1, wherein there are 7 such voids all of essentially the same size and essentially equally spaced from adjacent voids.

3. Polyester fiberfill according to Claim 2, wherein the fiberfill is slickened with a durable slickener.

4. Polyester fiberfill according to any one of Claims 1 to 3, wherein the total void content is about 8 to about 25%.

5. Polyester fiberfill according to any one of Claims 1 to 3, wherein the fiberfill is crimped with a frequency of about 4 to about 12 crimps/inch.

6. An improved process for preparing polyester fiberfill, wherein the improvement is characterized by melt-spinning polyester into filaments of essentially round peripheral cross-section, with at least 7 continuous voids of essentially circular cross-section along the length of the filaments, one such void being located essentially centrally, while the remaining voids are of essentially the same size as each other and are essentially equally spaced around the central void and are essentially equally spaced from the central void.

7. A process for preparing slickened polyester fiberfill, comprising the steps of melt-spinning poly(ethylene terephthalate) into filament of essentially round peripheral cross-section, with at least 7 continuous voids of essentially circular cross-section along the length of the filaments, one such void being located essentially centrally, while the remaining voids are of essentially the same size as each other and are essentially equally spaced around the central void and are essentially equally spaced from the central void, processing such filaments in the form of a tow by drawing, applying a slickener, crimping and relaxing, and converting the filaments into staple fiber.

8. A process according to Claim 6 or 7, wherein the filaments contain 7 such voids of essentially circular cross-section along the length of the filaments, one such void being located essentially centrally, while the remaining voids are of essentially the same size as each other and are essentially equally spaced around the central void and are essentially equally spaced from the central void.

9. A batt consisting essentially of polyester fiberfill according to any one of Claims 1 to 3.

10. A filled furnishing or apparel article that is filled with polyester fiberfill according to any one of Claims 1 to 3.