CA2194392A1

CA2194392A1 - Bicomponent and long fiber product definition for splittable pack

Info

Publication number: CA2194392A1
Application number: CA002194392A
Authority: CA
Inventors: Clarke Ii Berdan
Original assignee: Individual
Current assignee: Owens Corning
Priority date: 1994-07-18
Filing date: 1995-07-13
Publication date: 1996-02-01
Also published as: WO1996002695A1; JPH10503247A; AU3097095A

Abstract

A splittable pack (78) of long fibers (16) is disclosed by shaping and attaching long fiber (16) wool packs (48) in layered relationship. The resulting wool pack (78) is generally separable along a plane (83) defined between the binderless wool packs (48) for ease of installation around impediments.

Description

BICOMPONENT AND LONG FIBER PRODUCT DEFINITION
FOR SPLITTABLE PACK

TECHN~CAL ~-~LD
5This invention relates to wool materials of mineral fibers and, more specifically, to il.~..l,.l;nl~ products of long glass fibers. The invention also pertairLs to the m7mlf~rnlre of ing~ tion products made of long wool fibers.
BACKGROUND ART
S~lll ~l;si. ~-f t~ r glass fibers are useful in a variety of app~ tionc in~ rling 10 acous~c~l or thermal inc~ tiorl m~t~ lc When these small d;~ ~ te glass fibers are prop~ csemhled into a lattice or web, co.. o~ called a wool pack glass fibers which individually lack al, engLh or ~ ss can be formed into a product which is quite strong.
The glass fiber in~ tion which is produced is lightweight, highly cG~ ,s;ble, and resilient.
For purposes ofthis patent speçificatinn in using the terms "glass fibers" and "glass 15 compositionsH, "glass" is; ~ d to include many ofthe glassy mineral materials, such as roclS slag, and basalt, as well as ~ ;Qn~l glasses.
The co .. -.~-n prior art meth~dc for producing glass fiber il c ~ ;on products involve producing glass fibers from a rotary process. A single molten glass composition is forced through the orifices in the outer wall of a cc,..L irugc or spinner, producing primarily 20 straight glass fibers. The fibers are drawn d~wll~ar d by a blower, and cG.l~ ional air knife and lapping techniques are typically used to dis~ ae the veil to provide acceptable, generally uniform fiber distribution. The binder re~ d to bond the fibers into a wool product and provide product i.~lc~il~ is sprayed onto the fibers as they are drawn d~w.l~.~d. The fibers are then collected and formed into a wool pack. The wool pack is further processed into 25 inc~ tion products by heating in an oven, and ~ r~lly shaping and cutting the wool pack. Once shaped, it is also de~u ~le to highly co..lpless wool packs to reduce sl i~,uil.g costs. rnus, it is also desirable for wool packs to exhibit rapid and reliable recovery from col..pression when unra~ d for use.
Once Imracl~d it is de~u ~'e for ease of in~ tion that wool packs in 30 certain product applir~tiom be se~..u ~le lon~7t~ in~lly. For eY~mrle, installers of wool batts used for wall and attic in~ tion often enrollnt~r ;...re.~ I s where wool is to be placed between studs and ra~ers, such as pipes, cor~ c, wires, and other building system wo 96/0269~ 2 1 9 ~ 3 q 2 PCT/US95/08774 C1~.nF.~nj The co~ ellLional practice has been to sep&~le the short fiber batt longihl~inAlly in the field by rending it generally along a plane. The separated portions of the pack are then positinnPd to straddle the ;...pe~ By their nature, coll...lcreial wool packs of short fibers coMected by binder have been r-- ~~~ *1~ to such longih-~inAI separation.Thus, to achieve desirable lattice propc, lies such as generally uniform density, product integrity, and rccu~tl ~ from co".prc~i~;on in wool inclllAting materials of glass fibers, as well as desirable practical fea~ulf s such as lon~hl~inAI sel,&~bility, it has been npcessAry to use fibers that are relatively short.
Long fibers are not used in wool products of glass fibers because of their 10 tendency to excessive ent~AnglPmf~nt and the forrnAtion of ropes and strings. Thus, while long fibers display some fiber-to-fiber en~ng~ even without binder, the no~ ;rollllil~
of the resulfing wool packs has long made them co...--.~ ,ially undesirable. For purposes of this patent speçific~tion~ in using the terms "short fibers" and "long fibers", the term "short fibers" is intf n~ed to include fibers of applc.~;, Alrly 2S.4 mrn (1 inch) and less, and "long 15 fibers" are intf~nded to include fibers longer than appro~ ly 50.8 mrn (2 inches).
Typically, a wool pack of short fibers produced by rotary ~eli~lg terhniques will include some long fibers which, however, will co~ lise less than 10% ofthe wool pack.
Long fibers have di~c~L aero.lyl~h--.c prop~ lies, and conventional lapping te~lm;1ues have failed to e l;. .~ Ate, and rather tend to e ~hA nce, forrnAtion of ropes and 20 strings in veils of long or semi-continllo~ls fibers. Even when undisLu~bed, veils of long fibers tend to forrn ropes and strings as the veil slows in its descent to the collection surface.
Despite movement of the collection surface, long glass fibers (as do undisturbed veils of short fibers) tend to pile up into no....~.;ro,l" packs of fibers, and lI.... AnAgF~ble fiber aç~ml)lAtionc These n.~.. ;l~.~.. packs, cl~cl~.,f,~ in part by roping and string 25 formafion, have long pl~e--~ed S;~;r~ COl~----~,~;~ use of long fibers. The ropes of long fibers produce a co.. c~cially unde~ble appe&~ce and, more importantly, create deviation from the ideal ulli~ll.. lattice and reduce the inclllAting abilities ofthe glass wool.
The ropes, shings, and t".ce;,~;~c f .lA.. glf .. l of ~ong fibers further inhibit the co.~ .elcially de~_ble pn~pcl~ of lonei~ inAl separation, making practical inctAllAtion 30 more ~liffi~llt Short fiber inclllAtion is not without its pr~ nc however. Even short fibers that are s~raight form only â hAI~hA~A d lattice, and some ofthe fibers lie bunched ~ogcll r~.

wo 96/0269~ 2 1 9 4 3 9 2 PCT/US95/08774 As a result existing glass wool inc~ fing materials continue to have cignifici~nt nonun,rul,.,iLies in the disllil ulion of fibers within the product.
A further problem with short fiber wools is that the binder used is expensive and has several ell~iron~ drawbacks. Many binders include organic c~lllpou,.ds, and 5 effluent from the prod~lction process must be p~ucessed to a.l,elio,~le the negative en~ilOl."~ impact of such co",pou"ds. In a~dition the need fûr curing binder with an oven conc~mes ~d~lition~l energy, ~realing ~d~ition~l en~i,o.u..clllal cleanup costs. A still further problem with short fiber products arises when the product is co...?ressed. While the binder holds firm at fiber-to-fiber intersecfione while the glass fibers themselves fiex if the 10 stress upon the fiber inc,ciases due to excessive colll~,n . . ;on the fiber breaks. Thus, current ine~ tinn products are limited in the amount of co"""~ sion possible while still ~ 1 l;., n;
çqll~te recove~y.
Nonçth~lecc because long fibers are probl~m~tic in nearly all respe. ls, co, . " ,.ercial wool in~ finn products of glass fibers have long used only short straight fibers, 15 despite the various drawbacks of short fibers in lattice non-uniro~"Lly, need for binder, and limited co,l,p-ess;l,ilily. Acco,dingly, the need remains for further irnprovements in wool in~ tion products to improve wool pack propc,lies, reduce cost, and elimin~te en~hu~llllF ll~3l COllCe~l15.
DISCLOSURE OF INVENTION
The present invention saficfi~s that need by providing methods for further defining the shape of wool packs of long glass fibers, which mrthods generally ., .i.;"l i~;n lattice un;fo", ily, el;~ e the need for binder, and result in a wool pack which displays si~nific~nt co",~,~siil,ility and lecov~,y desired for co,,u,,~r.;al products.
In accûr~ance with the present invention, a wûol pack ûf long glass fibers is 25 provided inrlu~ling long fibers of a single glass cG~ Gs;lion, as well as fibers inrlll~ing two glass col..~,Gsilions which produce a non-linear, b - . ~""~onenl fiber. Collç~tion of long fibers into a wool pack is achieved by receiving a veil from a rotary fiberizer on a pair of high-speed rol~ g fo,~u,uno~s drum-like ~ ~. ri ceS sepa,al-l,g the gases in the veil from the fibers by suction through the drum surfaces, and conveying the re~ in~ fibers at high 30 speed through a narrow gap bCh.~.en the drums to forrn a web. The drum surfaces are ûperated at high speeds to have a surface speed in the range of apl),o~"ately 50% to 150%
of the speed of the veil at the drums. The web is then di~llibuled to forrn the wool pack.

wo 96/0269~ 2 1 9 4 3 9 2 PCT/US95/08774 The fibers in the resulting wool pack are generally randornly and uniforrnly distributed.
Alternatively, collection of long fibers into a wool pack may be achieved by receiving a veil produced by a rotary Lbe~er on opposing first for~mino~.s conveyor surfaces, removing the gases IhertL~ l, and conveying the ~e .h;; .g fibers on second conveyor surfaces through a 5 pSlCC51ge, while s~lbsts~nti~lly l..s~ .;ng fiber ori~nt~tirn established by the rotary fiberizer.
The fibers in the resulting wool pack are oriented, inl~ ,ldled in a generally spiral rel~tionchip.
The methodc for producing these wool packs are set forth in greater detail in co-pending applications, co....-.only acc;~rd with the present appliczltiorl U.S. Patent 10 Application Serial No. 08/236,067, filed May 2, 1994, entitled WOOL PACK FORMlNG
PROCESS USING HIGH SPEED ROTATING DRUMS AND LOW FREQUENCY
SOUND DISTRIBUTION, by Aschenl,eck, and U.S. Patent Application Serial No.
08/239,820, filed May 9, 1994, entitled DIRECT FORMING METHOD OF COLLECTING
LONG WOOL FIBERS, by Grant, et al, both ih,coll~ol~led herein by l~;Çe.e.lce.
The wool packs of long fibers produced in accord~ce with either method have a generally uniform distribution of fibers, and roping is generally absent. Such wool packs may be shaped initially by the forming process and p~ ged in plastic to pro~ide product d~finition~ or zllt~rn~tively shaped in acco.-lance with the methods ~icrlos~d in greater detail below.
As used herein, the phrase "wool pack of long fibers" refers to wool packs having a sub~llial plopollion of long fibers, generally 50% or more by number or weight, but may also include wool packs having sollle~.hat smaller pelce~ Pçs (greater than appl..,.;. . .~nF~ly 10%) of long fibers which, ~ r.F ~ cc dk~ ricl . ~le the behavior of wool packs having higher pc~ ..t~gec of long fibers.
Wool packs of long glass fibers provided in the present invention present unique probll .ns related to product defil.;1;oll The long fibers are çntslnglFd to a lesser degree than short fibers, and are produced without binder. While initial wool pack shape is provided as outlined above, and can be retained by paC~ng in film, greater definitiorl in the wool pack for various products is desired. The thicker, binderless mats and wool packs of 30 long fibers in the present invention present problems of product definition not previously fillly addressed by the prior art. The present invention seeks to provide shape to wool packs inr~ in~ long fibers, pa. i~ irregular, bicc,lllpon~.ll fibers, which tend to forrn bunches, wo 96/0269~ 3 q ~PCT/US95/08774 rather than readily adapting to shapes by the conventional application of binder combined with heat setting. As well, while the entanglement of long fibers makes difficult the commercially desirable feahure of longih--1in~l separation of the pack during inct~ tion around ".lpe(l;...... ~l~ the present invention seeks to provide for a lo~h1din~lly separable or 5 "splittable" pack.
The methsdc of the present invention, thus, first provide various alternative ways to produce product definitiQn in such thick, binderless wool packs of long, single component, and particularly, bico...pone.ll, glass fibers. The present methods are loosely grouped as those inrlntling a step which disturbs the fiber matrix, those inrlu~lin~ a step 10 which adds an element to the fiber matrix, and those inrlu~ing a step offusing fibers. It has been found, particularly with regard to long irregularly shaped bico.l.l,onenL fibers, that excessive ent~n~pnlçnt induced in the surface ofthe wool pack has a negative impact on recovery. Further, it has been found that excessive di~lulbal1ce of the fiber matrix beyond the surface, such as by nPe~lling, may cause otherwise ent~nglP,~ irregularly shaped fibers in 15 the wool pack to become str~i~htpnp~7 losing some ofthe desirable volume filling characteristics otherwise valued in the wool pack. Thus, care must be taken to preserve important co...,ne.cial and filnrtion~l characteristics while providing desired product dçfinition The mPthotlc ofthe present invention which disturb the fiber matrix include 20 hydroent~ngkmPnt and air knife ent~nglPmPnt techni~lues which are adapted in accordance with the present invention for use with thicker ~e,glass mats, i.e. those ~yceetlinp~
applo~ ely 76 mm (3 inches) in thir.lrn~cs Needle-pu~rl-ing is further disclosed herein using heated nloe~lles Those m~thorlc of the present invention which add an element to the fiber 25 matrix include the injection of an adhesive string or ~ .,oplastic string along a plurality of locations through the width of the wool pack; surface application of hot melt thermoplastic spray or thel."oplastic fibers with active surface heating; post-productisn ad.litisn of t~lelllloplaalic fibers to the wool pack which is still hot from initial ~IIIIil~, and 5~ h;l~g with fiber segfnPnts These methods are generally less intrusive than the first group, and only 30 more defined portions or cohlmnc within the fiber matrix are disturbed.
The methotlc of the present invention which include fusing of fibers include the use of lasers to provide bor~dillg, at fiber-to-fiber connPcti~nC the fusing of surface areas wo 96/02695 2 1 9 4 3 9 2 PCT/US95/08774 of fibers with heated platens or other groups of fibers with heated needles; and the use of bicolnponent fibers which include as one component a more easily fusible materiaL such as a glass of lower melting tell.l,cl~ re~ or other ll.elllloplastic component. These latter methods for fusing are the least intrusive, involving only portions or coll~mnC ofthe fiber matrix, S without ci~ificAntly disturbing the matrix or introducing additional material into the wool pack.
The l..~hods of the present invention, second, further provide various alternative ways to produce lon itu~in~lly separable or splittAhle packs desired for in~AllAtion Plcp~a~ion of a splittable pack of long fibers is achieved in accoldance with the 10 present invention by layering predclelll,ined first and second weights of long fiber wool packs. Each layer is seqllPntiAlly processed into the desired pack shaped by one ofthe methods just noted. The top layer is ~ttar-hPd to the bottom layer during or after the shaping of the top layer. In ~ition a wool pack separable along more than one plane may be formed by layering a plurality of wool pack layers.
These methorlc and other fc~lules and advantages of the present invention are set forth in greater detail in the &awulgS and detailed description below.
BRIEF DESCRIPTION OF DRAWINGS
Figure 1 is a s~ P...~ic view in side elevation ofthe method ofthe present invention.
Figure 2 is a sch~mAtis detail view in pel~e.,live of one embodiment of the present invention, pc.ru.l..ed at B in Figure 1.
Figure 3 is a sch ~n~;c detail view in pe.~peclive of a device ~eprcsenla~ive ofseveral embodimPntc of the present invention, pelrolll.ed at B in Figure 1.
Figures 4A through 4D are 5Ch~ A~ ;C cross-sectionAl views of fibers in a 25 wool pack hlle,lclated in accorda,~ce with the present invention.
Figure S is a sr,h~ ~-A~;C view in pcl~pe~live of a layering process ~cplcsell~li~re ofthe present invention.
Figure 6 is 5~h. .~i~l;c cross-section~l view of wool packs in a layered structure AttArhPd in accold~1ce with the present invention.
Figure 7 is a sçhPmAtic view in p~ e~ilive of a splinAble wool pack in accordance with the present invention.

wo 96/0269~ 2 1 9 4 3 9 2 PCT/USg5/08774 MODES FOR CARRYING OUl THE INVENTION
The method of the present invention may be used to produce splittable wool packs 78 of long glass fibers 16 as re~,l cse.lL~Lively shown in Figures 5 through 7.
Referring to Figures 1 through 7, it may be seen in accordance with the 5 present invention that the method for fo~.~.g a splittable wool pack begins by defining the s_apes of at least two binderless wool packs of long glass fibers (Figures 1 through 4D), and QttQGhin~ the bintlPrlçee wool packs together in layered, s~ble rel~tionehip (Figures 5 through 7). In acco-dallce with the plcÇcllcd meth--ds of producing binderless packs 48 of long fibers 16, noted below, each wool pack 48 will have long glass fibers 16 generatly 10 ul~iro...lly ~ .;h~,(ed therein, and may have long glass fibers 16 which are generally oriented.
Defining the shape of each binderless wool pack 48 of long glass fibers 16 incllldPs interrelating first pluralities of long fibers in generally specific portions of the wool pack 48 by any ofthe various mpthode further dieclosed herein. While the term, "generally specificN is used to describe the portions of the wool pack 48 so interrelated, it is understood lS that those generally specific portions might also be lefe.,ed to as ~ge~edN, "defined", "limited", "distinct", "discrete", or like pollions ofthe wool pack 48. As may be seen in Figures 4A through 4D, those pluralities are in portions 88 (shown in Figure 2) or areas, groups, colllmne 100, diagonals 102, planar secti~ nc 104, or other ~scoc ~I;Ol~c of fibers 16 in spaced rel~tio~ehir which result from the various methods dierlosed Regardless, such 20 ih~c..~ ;onchips ~~.A;.~l~i~- the binderless wool pack 48 in a shape of desired thi~nesc Referring to Figures 5 and 6, al l q~ hin~ the binderless wool packs 48 togetherin layered, separable rel~tit~nchir in~ludes i,~tt;" ela~ing second pluralities 79 of long fibers in a.~jacPnt generally specific p~lliOllS ofthe wool packs 48. ~ cl.... ~ ofthe wool packs 48 includçs positionir~ at the least, a top wool pack layer 82 over a bottom wool pack layer 25 80. Adjacent surfaces of the pack layers 80, 82 generally define the plane 83 along which the binderless wool packs are sepa-_ble T.~1~....e~ e wool pack layers 81 may be further provided to define multiple planes 83 of separation, as shown in Figure 6. The wool packs 48 are pl~;~lably of pred~... ined weights, and when layered may be provided as completPly shaped wool packs, or with at least one of the wool packs, such as the top wool 30 pack, p,. pal. d to be shaped before, after or during ~tt~rhmPnt to the a~jacent layer.
Def~ning the shape ofthe wool packs 48, and ~ ch;l~P the wool packs 48 in layered rel~tio~chir may, thus, be either sequPnti~lly or cimlllt~nPollcly pe.ru....ed.

Shaping Techniques The method of the present invention may be used to define the shape of wool packs 48 of long glass fibers 16 as ,epiese~ltaLi~ely shown in Figures 1 through 4D.
Referring to Figure 1, it may be seen in accordance with the present invention 5 that the method begins by providing a binderless wool pack 48 of long glass fibers 16 in which the long glass fibers are generally uniformly distributed. A rotary fil,eli~,g apparatus 11 is l~ presenLaLiv-ely shown. Stated broadly, d~finin~ the shape of the wool pack 48 of long fibers then inrl-ldes C~:Sull)l e;~alllg the wool pack 48 to a first thiçL npsc~ (as shown at B), and interrelating first pluralities of long fibers 16 in specific portions of the wool pack 48.
10 Thereafter, the pack is released (as il-~l;r~led at C), whereupon the first pluralities of long fibers 16 remain s~ al~nl;~lly inL~ la~ed in tension to ...~;..1~;.. the wool pack 48 in a shape of desired thirL-nPcc The first pluralities of fibers 16 are placed in tension by the tendency of the wool pack 48 to rebound to a less defined bunch or pack having only its initial shape.
When further co"")rcssed to a thinner, second Ih;~L ..~C5, as for sl~;p~ "l (inr~ ted at D), 15 the illkl~ l;onchips e~l~h!i~l~ed between fibers 16 ideally permit the fibers to fiex and the wool pack 48 lecclvt;la to its desired l~ L ~5C when the further co"~rcsa;on is relieved.
Unlike prior art wool packs of short glass fibers interrelated with a generalized applic~tion of binder during ~cl~lg the present invention disrl~ses primarily post-production mPtho~s for u~L~ laL~g specific portions of binderless wool packs 48 of 20 long fibers 16.
In accord~1ce with the method of the present invention the first pluralities of fibers 16 in the wool pack 48 may be either ,.lt~ l,elaLed by ad~litiQn~l ent~lPm~nt or may beiult~-~la~edbyinter~v~ ;on orboth. However,int1ucings~l~s~ a~litio~
entanglement of fibers 16 on the surface ofthe pack while providing good pack shape 25 dPfinition has been found to adversely effect lecuvt;~ ofthe pack a~er co~ leaaion.
Acco,dingl~, it is pre~,.ed that COIu~Jl'eSail~, the wool pack 48 occurs sukal;~ ly vithout relat*e motion b~tlneell the two faces ofthe wool pack 48 and co",~,~sàion surfaces 84 in contact the,t;wilh, thus generally ".~i"~ p the interrel~tionships b~tweell long fibers 16 in contact with the co",~ sion surfaces 84.
As shown in Figure 2, the cGlllplession a~ r~ce~ 84 may be continllouC belts or, alternatively, may be a plurality of smaller c~ntin~Qus belts in parallel or series, or a plurality of rollers o,i~ ed transversely to the direction of movement ofthe wool pack 48 ~1 q4392 or still other CQ~ g~ lions or co-,.billa~ions of such elPmPntc Particularly where the pack is stopped for colllpl'e,~7.,ing and int~ elaling fibers, the co...~ .,a;on surfaces 84 may be provided by plates or other more rigid, non-moving surfaces Regardless, the exact confi~lration and co,nb;~ ion ofthe cG-l-pres.,;on surfaces 84 is not critical to the present 5 invention, so long as the co..-p-ess;on surfaces 84 provide the needed co~ esaion and allow for pe.Çu...l.ng the step of interrelating (through a confi~-ration of gaps, sp~cing ope~ings) without producing u.,~ ted surface e "~gl~ " in the wool pack 48 The first pluralities of long fibers 16 which are interrelated in the wool packs48 in accoldal~ce with the present invention may be randomly distributed or generally 10 oriented, for e ,.~ple in a generally h5~;>~ l or spiral rPI~tionchip. The long fibers 16 may be straight, made of a single glass, or may be irregularly shaped, bico~ponenL fibers Further, the methods disclosed herein can be practiced separately or in co...l,;..alion to interrelate first pluralities of fibers in a wool pack. While the methods of the present invention can also find use with other ll,~;.l..oplastic, polymer and mineral fiber types, their 15 appli~-~tion to b;.~de.1~ ~ long glass fibers is p. .;re.. ~1 In ac~ance with the present invention, several methods are provided which include fusing pluralities of long fibers 16 to provide interrPl~tionchirs, and more p,ecisely, i..le~cQ~ ;onC, 11~ t~
In the first such method, with the wool pack 48 con,~, ~ssed to a desired 20 thic~npcc~ first pluralities of long fibers 16 in specific portions of the wool pack 48 are illle.. elaled by cont~cting at least a portion of one face of the wool pack 48 with a heated surface 86, and inle.,jonl-F~ g a first plurality of long fibers 16 in that portion of the wool pack 48 by heating the fibers to define the shape of the wool pack 48 Referring to Figure 2, the heated surfaces 86 are pre~ applied to a con~inllous wool pack 48, and move with 25 the pack to avoid excessive surface e~ ngl~ F ~1 Alternatively, the heated surfaces 86 may be applied to a st~tion~ry wool batt. The heated surfaces 86 may, for c r'e, be actively heated platens, or may be passively heated by virtue of pl~ ,e .. - .l within an oven Heated surfaces 86 may be applied to a portion of the wool pack 48 along an edge, corner or face thereof, or in a pattern at such loc~ti-.nc to shape the wool pack 48.
30 Figure 2 shows a series of heated surfaces 86 moving with the wool pack 48 on a track structure (not shown) to re~.~se.lla~ ely illt~-coni~e~,l fibers 16 on the faces and edges of a wool pack 48 as inrlic~ted at portions 88. The heated surfaces 86 may be specially d~i~ed wo 96/0269~ 2 1 9 4 3 q 2 PCT/US95/08774 with a targeted power and te~ w ~l~re which determines the number of fibers 16 fused and the depth of peneL-a~ion through the pack. The texture of the fused surface portions 88 can range from soft and pliable to stiff and hard.
Where the long fibers 16 are bicomponent fibers in~lurlin~ two materials 5 having diJre~e.,~ melting points, the heated surface may be heated to a te...pe.~ re below the melting or s~ ..;.,g point of one material and above the melting point of the other, so that inLerco~ e~,l ;r~n of the first plurality of long fibers 16 is provided by melting or so~Pnin s.~b~ lly one of the two materials of the b;cGl..pone..L fibers.
A second method is provided in acco,dance with the present invention in 10 which first pluralities of long fibers 16 in specific portions of the wool pack 48 inward from the faces of a wool pack 48 are il.l.,r~,o~ ed by po~ifiQni~ a heated surface therein. In this mPthod the heated surface is pre~e.~bly a heated needle 90. Wlth the wool pack 48 con~ressed to a desired th~ n~occ~ contact with a first plurality of long fibers 16 is made by inserting the heated needle 90 into the wool pack 48 from at least one face thereof. Such lS insertion defines at least a portion ofthe path oftravel ofthe needle, and inlelconn~;on of a first plurality of fibers 16 is p~ Çullllcd along the path of travel ofthe needle. The path of travel ofthe needle further inrllld~s its path of retraction, as well as any lateral travel relative to the wool pack 48 while inserted therein. The needle thus forms internal inl~ on,~ ;onc b~lween first pluralities of binderless, long fibers 16. As shown in Figures 4A through 4D, 20 the path oftravel may cause those il.Ler~ol~ l;onc to be oriented in colllmnc 100, along ~liagon~l directions 102, or along short planar sectionC 104 if the heated needle 90 moves somewhat relative to the wool pack 48. Needle pen~LI~Lion may be varied in depth and angle, and may be applied from oppos;le sides ofthe wool pack 48, all of which depends on the particular r,.luilelll~ ofthe product being produced. PIcÇ~.~bly a plurality of heated 25 needles 90 are inserted at lesp~iLi~e spaced loc~tinnc throughout the wool pack 48 to provide product definifi~ n Some p~s;;~l~ p~l le llc in this regard are shown in Figures 4A
through 4D; however, there is no intent to lirnit the present invention to the illustrative p~l lr~ shown.
Again, where the long fibers 16 are bico...~,on.,..l fibers of two materials 30 having di~ ;lll melting points, the needle may be heated to a telll~c.~ re below the melting point of one m~teri~l and above the melting point of the other, so that interco~ g a first wo 96/0269~ 2 1 q 4 3 9 2 PCT/US95/08774 plurality of long fibers 16 may be pe.rOI .ned by melting or softening primarily one of the two materials of the bico...pone..l fibers.
Needles for use in accordance with this method are preferably smooth condllctive metal nPedlpc~ to l. .n;...;,e related fiber entAn~lf mPnt induced by its use, or could 5 be textured to intçntionAAlly provide some level of fiber entanglement.
A thir~ method is provided in accordance with the present invention in which first pluralities of long fibers 16 are u.~elcol-l-P~led in specific portions ofthe wool pack 48 inward from its faces by applying laser light energy to heat portions of the fibers in the wool pack 48 Pl ~r~l~bly a bank of laser light sources 92 (shown in Figure 3) are provided to 10 apply laser light energy at le~eclive spaced locations thro~lgho-ut the wool pack 48 The laser source 92 may be any convention~l laser source capable of gener~lu1g heat suffi~ient to initiate fusing bel~een the fibers 16. The ulte~ y (power) and beam width may vary depending on the wool pack 48 density, shape of fibers 16, and the product whose shape is being defined. Variation in the intensity and beam width affects the depth of penetration and 15 the number of fibers 16 inte~onn~p~le~ As well, the glass fibers may include additives to make them opaque or more abso,l)ti~ ofthe particular laser light being applied The laser beam 94 may be applied in a p~ nrli~ r or angular ollf IIAI;On to the wool pack 48 to fuse first pluralities of fibers 16 into c~ mn~ 100 or ~i~onAlly oriented groups, and may enter from any face of the wool pack 48, as illu~ ly shown in Figure 4. This third 20 method may also be used with bico,llpon.,llt fibers, with the beam intensity ta,~eted to affect one fiber component more than another or additives in~luded for enhAnced laser light abso~ ion in one fiber conlponc~ll, and can be applied to provide fusing and interrel~tionchirs b~ Iween fibers of many types in ~dr1i1ion to the glass fibers plerelled herein.
In accold~.ce with the present invention, several rnethods df ,o,,~;nAIed the fourth through sixth mf tho~c are also provided which include a step of adding an f l~mPnt such ac polymer materials, to the fiber matrix to provide interco"nP~;onc between first pluralities of fibers 16. Thus, .ere..h.g again to Figure 1, the fourth method of the present invention inl~ludec~ prior to or concurrent with co.n~. e~:~ulg the wool pack 48, the step of 30 di~ibuLiilg hot melt polymer spray or polymer fibers 96 over a portion of the surface of the wool pack 48 (shown at A), and then heating the wool pack 48 (as shown at B) to melt or soften the fibers and provide an intt~Connf~l;on between first pluralities of binderless glass wo 96/02695 2 1 9 4 3 ~ 2 Pcr~uss5/08774 fibers 16. The polymer chosen for the polymer fibers 96 may be any polymer material which is capable of inlcrcol~nP,c~ , glass fibers when melted or so~Pned which is s~l~ciPntly strong to ".5~ - such inte.co~ P-;';on when in tension when the col.lples~ e force is released, and which is fiexible during col~ ;on of the wool pack 48.
Distribution of hot melt polymer spray or polymer fibers 96 over at least a portion ofthe surface ofthe wool pack 48 will provide illlclcol~l~e~;l;oll of glass fibers 16 wherever those fibers are positionP,d during melting or solkn;ng whether on or near a face ofthe wool pack 48, or inwardly disposed from a face. This method may further bepracticed by distributing polymer fibers 96 sized to lodge s.~b~ lly inward from a face of 10 the wool pack 48. Both longer and shorter polymer fibers 96 may be intel~l,cl~ed to provide illtclco~ Pcl;on through the depth ofthe wool pack 48.
Alternatively, the fourth method may be practiced immptli~tply after formation ofthe wool pack 48, which may emerge from folll~ processes at tclllp~.~LuleS
as high as app~o~ p~ly 93 to 204 degrees Centigrade (~C) (~pro~ y 200 to 400 15 degrees Fahre~lhcil [~F]). Thus, the method may include providing a wool pack 48 having latent heat of produetisn, and di~Llil,.llin~, polyrner fibers 96 over a portion ofthe surface of the wool pack 48. Polymer fibers 96 may be distributed prior to or during the step of COIIIIJI esjing (shown at B). Fibers of di~c(ell~ sizes, may be applied to provide illle..,onl-e~,~;rJns at din'crcllt depths within the wool pack 48. In ad~itio~, the step of heating 20 to further melt or soften the polymer fibers 96 may be either elimin~ted or performed (as inrlic~ted at H) to further melt or soften the polymer fibers 96.
A fifth method is provided which also inrl~lde5 a step adding an element to the wool pack 48 to provide hllclcG~ne~,l;ol C bcL~ccl first pluralities of fibers 16 therein. In the fifth method, the i.llel~ol~l.ecl;on of the binderless long fibers 16 is provided by injecting 25 streams of polymer material into a first plurality of spaced loc~tionc throughout the wool pack 48, and fv, ...; .g a first plurality of coll~mnc 100 inrlu~li~ bintlerless long fibers 16 bonded together by such polymer m~teri~l The polymer material is plercl~bly injected by a plurality of injection needles 98, as illusll~Li~,ely shown in Figure 3. The injection needles 98 may be pocitio~ed above the wool pack 48 or, plcrclably, inserted into the wool pack 48 30 from at least one face thereof. As with the heated needles 90 des~ ed above, insertion of the injection needles 98 defines at least a portion of a path of travel along which a stream of polymer material is injected. Such injection is l,lefe.~bly pclrolllled concurrently with ._ col"pressing the wool pack 48 to a desired thirl~nPss Again, the path of travel may cause the intelconnP~ ;onc thus formed to be oriented in columns 100, along diagonal directions 102, or along short planar sections 104, as shown in Figures 4A through 4D, if the injection needle 98 moves so.l.~,vl.al relative to the wool pack 48. Injection needle 98 penetration 5 may thus be varied in depth and angle, and may be applied from opposite sides of the wool pack 48, all of which depend on the particular requi,eme..ls ofthe product being produced.
A~s well, the injection needle 98 may expel polymer from its tip, or from at least one opening along its length, or both. The injection needles 98 are specially deci~Pd with a targeted yres-~ules and stream width which determines the number of fibers 16 bonded and the depth 10 of pen. L~lion through the pack.
A sixth method is provided which also incl~ldes adding an element to the wool pack 48 to provide inte..iol-l-ecl;onc belw~n first pluralities of fibers 16 therein. The sixth method comprises driving at least one fiber 106 i -l~---lillently into the wool pack 48 of long glass fibers 16 con.;u..~..lly with the step of colllylesa;llg. The thirl~n~Pss ofthe wool pack 15 48 is typically greater than 76.2 mm (3 inches). It is plerellcd in accol-lance with this met_od that a plurality of sepalale fiber se~,..P..lQ 106 be driven into the wool pack 48 at spaced loc~l;onc So driven, the fibers 106 tend to deform, and otherwise interrelate with t_e binderless long fibers 16 so as to be locked into place by such d~Ç~- .l.alion, thereby inte~ L.ng a first plurality of fibers 16. Alternatively, ~ e may be provided by a bank 20 of al;~ P n~e~llPC, in like fashion as heated needles 90 in Figure 3. When the pack is colllplessed to a first thit ~nPcc the stitr-hin~ needles introduce a glass or other material fiber through the pack. This produces coll~mnc 100 of fibers 16, illte.l,_lated by fibers 106 or a contim.ous fiber 108. The number of fibers 106 driven into the wool pack 48, and the spacing thereof, however, is dependent on the amount of shape definition for the particular 25 product. Regardless, the spacing is such that the recovt.y of the overall wool pack 48 is not zdvtlaely effected by concequpnti~l P..l~ produced in the wool pack 48. Moreover, the driven fiber 106 or stitrhçfl co~ o~c fiber 108 results in a rigid column in tension and a flexible column in culllpleaa;on. The th~ead or fiber 106 or 108 is specially dec;~led with a ~n~n~c to resist heat fiow and a sll~l gLh to ...~;"l~in top to bottom con"-, ~n;C~tion in the 30 pack.
Finally, a third group of methods is provided in acco~ ce with the present invention, which include a step which disturbs the fiber matrix of the wool pack 48 to wo 96/02695 2 1 9 4 3 9 2 PCTIUS95/08774 provide inte, col~ne.,lions bc~wcen the first pluralities of fibers 16. These methods include hydroe~ glenlcnt and air entqnglpmpnt methods adapted to the thick wool packs 48 of long fibers 16 pres~,.-Led by the present invention. In particular, the eighth method ill~ell ~,laLes the long fibers 16 by injecting a high velocity, low volume strearn of fiuid S through the wool pack 48 at spaced locqtionc concullelllly with colll~resslng the wool pack 48 to a desired shape. This may be understood by Icrclling to Figure 3, and subs~ g water jets for laser beams 94. The fiuid is prcrel~bly water, but may allelllalively be steam, air, other gases or co..,l,;~l;ons thereo~ The stream offiuid drags individu. l fibers 16 to a new lor-qtion within the wool pack 48 and results in the ent~nglpmpnt of those fibers 16 with 10 others in the area. A~er the wool pack 48 is released, the finished product attains the desired shape as a result ofthe entqngled fibers. The volume offluid used and the ple:~-7l1leS
with which it is injected are dependent on fiber ~iqmetpr~ product density, and product thic~ness.
The shaping of wool packs 48 is further ~liccllc~ed in a commQnly a~ci~nP,fl, 15 copending, related appli~ ~tion U.S. Patent Applic~tion Serial No. 08/279,613, filed July 25, 1994, entitled BICOMPON~NT AND LONG FIBER PRODUCT DEFINITION, by Berdan, filed co~ ,.?o,~nco~lsly heicwi~ll, the (li~clos -re of which is hereby incG~o~ted by r~le"ce.
The various mptho~ls noted above provide desired interrelationships between 20 first pluralities of fibers 16 in wool packs 48 to provide ad~ition~l shape and product definition thereto. Practice of the ~ hotlc will vary depe -~;n~ on the product being produced. Nonethple~s~ the methods share the co..~..on end of addl~sa;,lg the unique problems pl~,s~ ted by binderless wool packs 48 of long fibers 16, and in particular, irregularly shaped, bicollll)onenl fibers.
Layering Techniques Referring now to Figures S through 7, the mPthod5 of the present invention further provide various ~hern~tive ways to produce lon~h~lin~lly separable or splitt~*le packs 78 desired for in~t~ tion. Thus, the step of int~ la~ng the second pluralities 79 of long fibers 16 to attach layered wool packs may be pclr~JIllled by cont~cting those fibers 30 with a heated surface; such as a platen or needle, heating those fibers with laser light energy;
bonding those fibers with polymer material provided, e.g. by intermixture of fibers or injection; or by cQ-. .hi~ ;Qnc of those methods. These mPth(~dc have in common the w096/02695 2 1 q43 ~2 PCT/US95/08774 illLell el~ ;on5hir of second pluralities of fibers by interconn~ction. In accordance with the present invention, it is pl ere,l ed to interrelate the second pluralities of long fibers by heating them witb laser light energy.
As ~licrlr~sed above, the step of intellelalil,g the second pluralities 79 of long 5 fibers 16 to attach layered wool packs may also be pclfùrllled by injecting a high velocity stream of fiuid through generally specific portions of said wool packs at spaced loc~tions hlje~ling a needle into said wool pack at spaced loc~tinnc, driving at least one fiber illtelllL~ ly into said wool pack or co..~ .nl;ons thereo~ These methods have in con....on the result that the second pluralities of fibers are inlell~làled by fiber ent~nElPm~nt As the tecl~n;~ es used for definin~ the shape ofthe wool packs 48 and for ~tt~r~in~ the wool packs 48 in layered rel~tinnchip can be the same, the wool packs 48 may be layered before the top pack layer 82 is defined. Thus, in accordance with the present invention, the step of hll~ lalhlg first pluralities of fibers in a wool pack and the step of i~tellelaLing second pluralities 79 in a~j~cPnt wool packs 48 may be pelfulllled after 15 poCitionir~ the top wool pack layer 82 over the bottom wool pack layer 80. Shaping ofthe top wool pack layer 82 may be cc n~ cted either cim~ neu~ ~cly or sequenti~lly with att~rl.. l ofthe layers 80, 82. For some methods, shaping and ~ chin~ are performed by the same method, but to dilr~ depths in the layered wool pack structure 76. That is, inte"elaLLl~g the first pluralities of fibers may be pc;lfo""ed to a first depth e-l~nd;l~p 20 generally into the top wool pack layer 82 only, while interrelating the second pluralities 79 of fibers may be pwfu""ed generally to a second depth e- If 1~1;~ through the top wool pack layer 82 into the bottom wool pack layer 80. In this regard, with techn;ques such as hot needleinjection,lasabûnding,needleplmrhin~ hydroe~ hgl~ "~.l andal;~ gand sprling the ill~,.l elaLlllg of second pluralities 79 of long fibers 16 may further açco~ ~plicl .
25 siml~lt~neollcly the il~tell~la~ing of first pluralities of long fibers. Other techniques, such as thûse il~ g polymer m~teri~lc from a face ofthe wool pack oppoa;le the plane 83 of separation, may be sl e~;r~ ly l~eted to il~h.l~late only second pluralities 79 of fibers (such as shown in Figure 5) by lirniting the injection of polymer until the needle is placed at the second pluralities of fibers.
It is ~ld~lalood that where intelllledi~.le wool pack layers 81 are provided to define m~lltiple planes 83 of separation, each illte"l,ediale wool pack layer 81 may be wo 96/02695 2 i 9 4 3 9 2 PCT/US95/08774 ~ts~r-hP~ or shaped and ~ttarhed, sequenti~lly to one or more of the lower layers, as just described for the illustrative two-layer structure disc~csed above.
In this regard, however, the second pluralities of fibers may be specifically targeted by each ofthe methodc tlicrlosed by pc.ru...lil g those methods from at least one 5 side face 77 of the layered wool pack structure 76. As shown in Figure 6, when p~-~-..fillg the various mçtho~s from a side face 77, the second pluralities 79 of fibers may be e -~,l&Led along columns 110, tli~gon~lC 112 or planar sectionc 114 or areas positionP,d generally along or crossing belw~l adjacPnt faces of layered wool packs 48. The plane 83 of separation ofthe splitt~ble pack 78 is thereby defined, and the methods applied may be 10 targeted more p.ecisely to second pluralities 79 of fibers 16 without req~irin~ pene~-a~ion through the th ~ L ..~.c~ of a layer. Approach from the side face 77 of the layered structure 76 is adv~nt~geo--c where m--ltipte planes 83 of separation are defined in the splitt~ble pack 78.
Some layering terhn;1ues require at least partial p~ llllallce before the wool packs 48 may be placed in layered rel~tinnchir and joined. Such layering techniques further 15 illustrate that the shaping and layering tçrhniquçs may be entirely di~ele.,L. For exarnple, le~n.ng to Figure 5, regardless of how the wool packs 48 are shaped, the wool packs 48 may be ~tt~rh~d in layered rel~tionchip with hot melt polymer spray or polymer fibers 96 applied, as repre3~.1dli~ely shown. Applir~tinn of the polyrner precedes the layenng step, and polymer is applied to at least one face of at least one of the wool packs 48 being joined.
20 The second pluralities 79 of fibers being joined are thus generally on or near the opposing faces or surfaces of the wool packs 48.
Where hot melt polyrner spray is used, the polymer is pre-heated. Where polymer fibers 96 are used they are melted after app~ ;Qn to the wool pack 48 toillte,com~e~,~ the second pluralities 79 of fibers. Heat to melt the polymer and join the glass 25 fibers may be present as latent heat of prodl~cti- n of the wool pack 48. Alle.lla~vely, heat may be provided to the face of a wool pack 48 prior to or after the appli~ ;on of polymer fibers 96. As re~,rese~ rely shown in Figure 5, prior to applic~tion of fibers heat may be "~ "ir~lly provided to a face by means of a heated roller 89, or radiantly with heat lamps 91. Further, after the appliç~tion of fibers, or after layering of the wool packs 48, heat may 30 be applied by way of heat lamps, or hot gases to melt the polymer fibers and join the wool packs 48 in layered rels.l;ol.~l.;l).

- - -wo 96/0269~ 2 1 9 4 3 9 2 PCT/US95/08774 Plcrc.lcd polymer materials for hot melt polymer spray or polymer fibers 96 include polyethylene, preferably linear low density polyethylene; or polypropylene, ethylene vinyl acetate, or co...l,il.~l;ons thereof; or other suitable polymer materials. Hot melt polymer spray is p,crc,~bly a polymer which is press.-re sensitive, so that when layers of 5 wool packs 48 are COlllpl essed into contact, the second pluralities 79 of fibers will bond and intc.,.,ld~e, joining the layers.
Thus, it is undcl aLood that the techniques used for d~fining the shape of the wool packs 48 used in a splittable pack, and for ~tt~t~hin~ the wool packs 48 in layered rPl~tionchip, can be the same or di~c~ c"l. Regardless, where d~fininp~ the shape of a wool 10 pack 48 is pc,~""ed after the wool packs are in layered rel~tionchir, the step of definîng further preferably inr.l.ldes co",l"~s~ g at least a portion ofthe layered wool pack structure 76 to a first thir~nPcs, and interrelating first pluralities of long fibers 16 in generally specific portions of the wool pack 48 to . . IA; 1~ the wool pack in a shape of desired thir~n~ss It is pfc~e"cd to s lbst~nti~lly simlllt~npQllcly interrelate the second pluralities 79 of long fibers 16 15 in adjac~nt generally specific portions ofthe wool packs 48, as desired to ..,~;.,l~ill them in a layered rel~tionchir, and then release the wool packs 48 from co,np[e~a;on, much as shown aLlali~cly in Figure 1. Altematively, the wool packs 48 may be ,~,leased from co"~pr~ jsion, and the second pluralities 79 of long fibers 16 Ll,ereancr inte"~,ldLcd.
Finally, in acco,dance with the present invention, dçfining the shape of the 20 wool packs can include l~cling two continllo~lc wool packs, and after attachm~nt, cutting the ~ cl~d wool packs into splitt~ble wool packs 78 of defined length as shown in Figure 7.
Alternatively, at least one of the wool packs 48 may be cut into a wool batt having a defined length prior to the layclhlg step indic~ted in Figure 5. Regardless, the m~th')dC ofthe present invention produce a splittable wool pack 78 of long binderless glass fibers, generally 25 sepa,~ble along at least one plane 83.
While certain, ~pre3~,.,t~Li.le ~mhotlim~ntc and details have been shown for ,oses of illua~l ~Lu~g the invention, it will be app~e.lt to those skilled in the art that various changes in the method and system ~!;crlosed herein may be made without dep~l~l,g from the scope of the invention, which is defined in the appended claims.

Claims

A method for producing a splittable wool pack of long glass fibers comprising:
defining the shapes of at least two binderless wool packs of long glass fibers;
attaching said at least two binderless wool packs together in layered, separable relationship.
2. The method of claim 1 wherein said step of defining the shapes of at least two binderless wool packs of long glass fibers includes, for each wool pack the step of interrelating first pluralities of long fibers in generally specific portions of said wool pack which maintain said wool pack in a shape of desired thickness.
3. The method of claim 1 wherein said step of attaching said at least two binderless wool packs together in layered separable relationship includes the step of interrelating second pluralities of long fibers in adjacent generally specific portions of said wool packs to maintain said wool packs in layered relationship.
4. The method of claim 3 wherein the step of interrelating said second pluralities of long fibers is performed by heating said second pluralities with laser light energy, and interconnecting said second pluralities of long fibers.
5. The method of claim 3 wherein the step of interrelating said second pluralities of long fibers is a method step performed from the group consisting of: contacting said second pluralities of fibers with a heated surface, heating said second pluralities of fibers with laser light energy, bonding said second pluralities of fibers with polymer material, or combinations thereof.
6. The method of claim 3 wherein the step of interrelating said second pluralities of long fibers is a method step performed from the group consisting of: injecting a high velocity stream of fluid through generally specific portions of said wool packs at spaced locations, injecting a needle into said wool pack at spaced locations, driving at least one fiber intermittently into said wool pack, or combinations thereof.
7. The method of claim 3 wherein said step of interrelating said second pluralities of long fibers comprises fusing said second pluralities of fibers.
8. The method of claim 3 wherein the step of interrelating said second pluralities of long fibers comprises bonding with polymer material limited portions of said binderless wool packs comprising said second pluralities of fibers.
9. The method of claim 1 wherein said step of attaching includes:
providing said at least two binderless wool packs in separated relationship;
applying a polymer material to second pluralities of long fibers in specific portions of at least one said wool packs generally near a surface thereof;
positioning said at least two binderless wool packs in layered relationship, wherein said surface of said at least one wool pack is in contact with an opposing surface of an adjacent wool pack, and interrelating said second pluralities of long fibers by bonding with said polymer material.
10. The method of claim 9 wherein said step of applying a polymer material is a method step performed from the group consisting of: sprinkling, spraying, or distributing polymer material.
11. The method of claim 1 wherein the step of attaching includes positioning at least a top wool pack over a bottom wool pack.
12. The method of claim 11 wherein said steps of positioning further include defining at least one plane along which said at least two binderless wool packs are generally separable.
13. The method of claim 11 wherein:
said step of defining the shapes of at least two binderless wool packs of long glass fibers includes, for each wool pack the step of interrelating first pluralities of long fibers in generally specific portions of said wool pack which maintain said wool pack in a shape of desired thickness; and said step of attaching said at least two binderless wool packs together in layered, separable relationship includes the step of interrelating second pluralities of long fibers in adjacent generally specific portions of said wool packs to maintain said wool packs in layered relationship.
14. The method of claim 11 wherein said step of interrelating first pluralities and said step of interrelating second pluralities are performed to different depths, wherein said step of interrelating first pluralities is performed to a depth extending generally into the top wool pack only and the step of interrelating second pluralities is performed generally to a depth extending through the top wool pack into the bottom wool pack.
15. The method of claim 11 wherein said step of interrelating first pluralities and said step of interrelating second pluralities are performed by different techniques.
16. The method of claim 11 wherein:
said step of attaching includes positioning at least one intermediate wool pack between said top wool pack and said bottom wool pack; and said steps of defining and attaching generally define at least two planes along which said wool packs are generally separable.
17. The method of claim 1 wherein said step of attaching is performed sequentially after said step of defining.
18. The method of claim 1 wherein said step of attaching is performed substantially simultaneously with the step of defining at least one of said wool packs.
19. The method of claim 18 wherein said step of defining further includes the steps of:
compressing at least a portion of said at least two wool packs to a first thickness; and interrelating first pluralities of long fibers in generally specific portions of said wool pack to maintain said wool pack in a shape of desired thickness;
substantially simultaneously interrelating second pluralities of long fibers in adjacent generally specific portions of said wool packs to maintain said wool packs in a layered relationship;
releasing said at least two wool packs from compression;
whereby said first pluralities of long fibers remain substantially interrelated in tension in at least one wool pack to maintain said pack in a shape of desired thickness, and said second pluralities of long fibers maintain said wool packs in a separable, layered relationship.
20. The method of claim 19 wherein performing said step of interrelating said first pluralities of long fibers further interrelates said second pluralities of long fibers.
21. The method of claim 1 wherein the step of defining comprises cutting at least one wool pack into a wool batt having a defined length.
22. The method of claim 1 further including, after the step of attaching, the step of cutting said wool packs into at least one wool batt having a defined length.
23. A splittable wool pack of long glass fibers comprising at least two binderless wool packs of long glass fibers attached in layered relationship, generally separable along at least one plane.
24. The splittable wool pack of claim 23 wherein said at least two binderless wool packs are maintained in a shape of desired thickness by the interrelation of first pluralities of long fibers in spaced, generally specific portions of said wool pack.
25. The splittable wool pack of claim 23 wherein said binderless wool packs are attached in layered relationship at second pluralities of long fibers in adjacent, generally specific portions of said wool packs.
26. The splittable wool pack of claim 23 wherein at least one of said binderless wool packs includes long glass fibers generally uniformly distributed therein.
27. The splittable wool pack of claim 23 wherein said long glass fibers in at least one of said binderless wool packs include generally oriented fibers.