CA2247342A1

CA2247342A1 - Method of forming an insulation product

Info

Publication number: CA2247342A1
Application number: CA002247342A
Authority: CA
Inventors: W. Scott Miller
Original assignee: Individual
Current assignee: Owens Corning
Priority date: 1996-03-20
Filing date: 1997-03-19
Publication date: 1997-09-25
Also published as: CN1214028A; JP2000506944A; EP0888259A4; EP0888259A1; KR20000064721A; WO1997034845A1

Abstract

A method for forming an insulation product includes centrifuging irregular glass fibers (116) using a rotary process, collecting the fibers as a pack (48), continuously withdrawing a portion of the fibers (116) from the pack (48) to generate a continuous yarn of fibers (116), and pneumatically propelling the yarn toward a receptacle, such as an insulation cativy, to form an insulation product. Also, a strand of continuous, irregular textile fibers (116) can be payed out from a wound package and pneumatically propelled toward a receptacle, such as an insulation cavity, to form an insulation product.

Description

METHOD OF FORMING AN INSULATION PRODUCT

RELATED APPLICATION
The present application is a Continl-~tion-in-Part of commonly ~qeign~d, 5 copending U.S. Patent Application Serial No. 08/310,183 filed September 21, 1994 (Alkire et al.), and entitled PROCESSING METHODS AND PRODUCTS FOR
IRREGULARLY SHAPED BICOMPONENT GLASS FIBERS, and the copending application filed February 29, 1996, entitled METHOD OF FORMING AN
IMPREGNATED FIBROUS MATERIAL, both of which are ac~ign~l to the ~ Fn~e of 10 the present application.
TECHNICAL FIELD
The present invention relates to the processing of glass fiber wool and products the.~rlolll, and more particularly, to methods for processing and products made from irregularly shaped gl~s fibers.
BACKGROUND
Conventional glass fibers are useful in a variety of applications including reinforcements, textiles, and acoustical and thermal insulation materials.
Continuous glass fibers are typically produced via bushings for reinforcement and textile applications. Such fibers are typically made of many glass 20 filarnents held together by sizing. The glass fibers are often further processed by combining them into continuous strands, yarns and rovings, or by chopping the glass fibers into preselected lengths defined by the end user. Where chopped, the resulting short, straight fiber se~m~nt~ may be mixed with other m~t~ , wet processed into mats such as are used for .~hin~l~s~ or otherwise treated for use. While bushings have 25 significant operational lifetimes, their Illlou~ u~ is limited relative to rotary fiberizing techniques for producing glass fibers.
Short, straight fibers typical of acoustic and therrnal insulation m~teri~l~
are made by rotary fiberizing techniques and are interconnected by binders. In such techniques, molten glass is delivered from a furnace to an orificed centrifuge, commonly 30 referred to as a spinner. Fibers produced by the spinner are drawn downward by a blower.
A binder, which is required to bond the fibers into a wool product, is sprayed onto the fibers as they are drawn downward. The fibers are then collected and formed into a wool CA 02247342 1998-08-2~, pack. The resl~lting materials suffer from non-unifor~n m~t~ l distribution, the expense of binder, and costs to treat effluent and exhaust air to protect the environment from the impact of organic compounds in the binder.
In addition to in~ tion materials, other wool products are produced from 5 the wool pack by further comple~ g and heat setting the wool into boards or panels.
Alternately, the wool may be blended with other natural and synthetic fibers to form non-woven materials, and thereafter carded or combed to open up the fiber pack for further processing, such as n~e-lling Carding and combing tends to align the fibers. The blended fibers serve both to open the glass fiber matrix and make the glass fibers amenable to 10 n-oerllinp by 'lubricating' the neetlling action.
Conventional glass fibers, whether continuous, chopped, or in wool packs have found their way into a wide variety of products. It is desirable to further improve the characteristics of products including glass fibers, and to find new uses for glass fibers which take advantage of glass fiber properties.
DISCLOSURE OF INV~NTION
In accold~lce with the present invention an irregularly shaped glass fiber is provided which enjoys improved resiliency, and openness in pack structures. Packs, batts or other assemblies, generally referred to herein as portions, include irregularly shaped glass fibers which are ~nt~n~led and require no binder. As set forth in accordance 20 with the present invention, portions of the wool pack having irregularly shaped fibers may be processed directly without intervening steps which are required in conventional glass fiber processing operations. That is, a wool pack of the irregularly shaped glass fibers may be needled without the plC~,ulSOl steps of carding, blending with other fibers, or lubricating, otherwise re~uired with convçntiolt~l straight glass wools. The Op~ eSS and 25 resiliency of the irregularly shaped glass fibers further allows the wool fibers to resist abrasion and neeriling damage by deflection rather than breakage, producing less dust during procee~in~ Nonetheless, the open ~ lule of the irregularly shaped glass fibers improves the ease with which carding and blending operations are ~.ro.. ~.ed, when such t are desired. Further, irregularly shaped glass fibers produced in accordance with the 30 present invention have a more uniform weight distribution, so that non-woven m~te"~l~
produced by nee~lling or other processing exhibit more ullir~.lln properties. As a result, a W O 97/34845 PCT~US97/04455 senes of articles including irregularly shaped fibers may be produced at lower cost, or processed with less effort, with varied and improved pG.îu--llance characteristics.
Accordingly, the present invention provides a method for producing non-woven n-~t.?ri~l from irregularly shaped glass fibers including the steps of providing a J 5 portion of irregularly shaped glass fiber wool, nee~llin~ the irregularly shaped glass fiber wool, and thereby producing a non-woven m~t~ri~l Y~lb~ liy comprised of irregularly shaped glass fibers. Preferably, the method is pe.ro~ ed with irregularly shaped, bi-component glass fibers produced by rotary fiberization, and re.luilc;s no precursor proces~ing such as carding or blending.
The present invention, thus, provides for a non-woven material comprised of an uncarded, needled glass fiber wool including irregularly shaped glass fibers, ~lt;f~.ably bi-component glass fibers unblended with other fibers. Materials including needled, irregularly shaped glass fibers in accoldallce with the present invention demonstrate not only the high te~ .dlu.e, smoke and chemical re~iqt~nre of glass, and 15 dimensional stability, but also a resiliency, high loft, resistance to tear, and soft felt-like feel (i.e. soft "hand"). The choice of neefll~, repetitive nee~llin~, needling from one or both sides, and location of nPe~llin~ can vary these characteristics, making numerous product applications possible.
By way of example and not limitation, product applications of the res-lltin~
20 woven and non-woven materials include use of irregularly shaped glass fiber m~t~ri~l~ in filtration elem~nt~, sorbants, gaskets, p~ckings, shingles, composite structural elements, furniching~, textiles, yarns, and blown-in insulation systems.
Finally, in a further aspect of the present invention, a non-woven m~tt :ri~l is provided including irregularly shaped fibers in a generally continuous wool tow. The 25 generally continuous tow is produced by "unwinding" a fiberglass wool pack collected by a direct forming method. In the direct forming method, irregularly shaped glass fibers are collected such that a generally spiral fiber relationship in the veil of fibers is captured and then generally m~int~ined in the wool pack. This generally continuous wool tow may be further processed in numerous ways to form yarns, textiles, p~cking~, reinforcem~nt~, and 30 blown-in insulation.

W O 97/34845 PCTrUS97/04455 A still further feature of the continuous tow is that the generally continuous tow may be transported between operating stations through tubes blown or drawn by air movement in~ çecl by fans or vacuum.
The production of a genPr~lly continuous tow by "unwinding" a fiberglass 5 wool pack collected by a direct forming method may further be applied in a portable blowing wool system co~ ;sing a wool pack of irregularly shaped glass fibers collected by direct form methods, which may be unwound and cubed on site, and blown into spaces to be in~ ted In another embodiment of the invention, an insulation product is forrned 10 by providing irregular fibers as a pack, continuously withdrawing a portion of the fibers from the pack to generate a continuous yarn of fibers, and propelling the yarn toward a receptacle to form an in~ tion product. The receptacle can be any substrate for receiving the fibers, or anything co~ P a cavity which requires ine~ ti~n. The yarn can be propelled by running it through a pn~ tic nozzle, and can be chopped as it is 15 propelled through the nozzle. The fibers can be produced using a rotary process or can be provided as a strand wound on a package, with the skand produced from a textile bushing. The insulation product formed by this method can be formed in nurnerousapplications, such as in a cavity in a building or in a cavity in an appliance.
BRIEF DESCRIPTION OF DRAWINGS
Figure 1 is a s~ h~m~tic pc~eclivc view of a direct forming method of collecting irregularly shaped glass fibers in accordance with the present invention.
Figure 2 is a schematic perspective view of an irregularly shaped glass fiber in accordance with the present invention.
Figure 3 is a srhtotn~tic side view of various processing steps pc~ro.,~led on 25 a wool pack of irregularly shaped glass fibers in acco~ ce with the present invention.
Figure 4 is a sçht?m~tic perspective view of a filtration element including needled irregularly shaped glass fibers embodied in a ~ -cse~ ive panel configuration.
Figure S is a sçh~m~tic perspective view of a filtration elem~-nt including needled irregularly shaped glass fibers embodied in a representative filter bag 30 configuration.
Figure 6a is a s~ h~ tic p. ~ecl i ~e view of a ~cp.~ s~n~live gasket including a resilient matrix of needled irregularly shaped glass fibers.

W 097/3484~ PCT~US97/04455 Figure 6b is a ~çl~ ;c perspective view of a ,~lcse"~~ e shingle including a matrix of irregular glass fibers needled to provide dir~lcn~ thicknessec Figure 7 is a srhem~tic perspective view of a representative structural element having an inner core of irregularly shaped glass fibers.
Figure 8a is a schematic perspective view of representative teX ~
process applied to a mat of irregular glass fibers in accordance with the present invention.
Figure 8b is a schem~tic cross sectional view of a te~ 7e~ mat of irregularly shaped glass fibers Figure 9 is a s~.hçn-~tic p~.~pe-;live view of a generally continuous tow of 10 irregularly shaped wool fibers being produced from a wool pack collected by direct forming methods.
Figure 10 is a sçhem~tic perspective view of a method for making yarn from a generally continuous tow of irregularly shaped wool fibers.
Figure 11 is a sch~m~tic perspective view of a generally continuous tow 15 and a distribution system therefor in accordance with the present invention.
Figure 12 is a srhem~tic perspective view of a portable blown in insulation system in accorda,~ce with the present invention.
Figure 13 is a srhrm~tic p~ e1live view illustrating the method for introducing a continuous yarn of fibers into a wall cavity of a building.
Figure 14 is a s~hem~tic view in elevation of drawing irregular fibers from a bushing and col}ecting them as a strand in a wound package.
Figure 15 is a srllPm~tic view in p~.a~e~ e of a process for continuously withdrawing a strand from the package and directing it into the cavity of a muffler.
BEST MODE FOR CARRYrNG OUT THE lNVENTION
The methods of the present invention may be used to process wool packs of irregularly shaped long glass fibers into further products and materials as ,~,.csc;"l~lively shown in Figures 1 through 12.
Referring to Figure 1, irregularly shaped glass fibers 116 are provided which enJoy hl~p~oved resiliency, and openness in pack structures 48. Packs, batts or 30 other assemblies, generally referred to herein as portions 148, include irregularly shaped glass fibers 116 which are ent~nglerl, and require no binder. The fiber structure and methods of m~nllf~r.tllring wool packs 48 are set forth in commonly ~ign~d U.S. Patent CA 02247342 1998-08-2~

5,431,992 and commonly ~eeign~fl and copending U.S. Patent Application Serial Nos.
08l240,428, filed May 10, 1994; 08/236,061, filed May 2, 1994; and 08/236,067 filed May 2, 1994, all of which are incorporated by leÇe.~ nce herein in their entirety.
l~efelTing to Figure 1, the plef~ d process for producing a wool pack 48 5 ~or portion 148) is shown in which long, irregularly shaped glass fibers 116 are collected upon opposing first conveyor surfaces 22. Referred to also as a direct form collection, the preferred process is best disclosed in greater detail in U.S. Patent Application Serial No.
08/240,428, previously incorporated by reference. This method has the benefit ofcollecting the irregularly shaped fibers 116 with a generally spiral orientation in the wool 10 pack 48. The irregularly shaped long glass fiber 116 is ~ es~l.~Lively shown in Figure 2 along with its two-dimensional projection shadow 118, which illu~llates the irregular shape or rotation along its length.
Referring now to Figure 3, in accordance with the present invention, the wool portions 148 including irregularly shaped glass fibers 116 may be processed directly 15 without intervening steps which accompany conventional glass fiber proce~ing operations. That is, a wool portion 148 of the irregularly shaped glass fibers 116 may be needled, as generally indicated at 130, without the precursor steps of carding, blending with other fibers, or lubricating, otherwise required with conventional straight glass wools. The openness and resiliency of fibers 116 further allow them to resist abrasion 20 and nee-lling damage by deflection rather than breakage, producing less dust during proc.o~in~ Nonetheless, the open structure ofthe irregularly shaped glass fibers 116 improves the ease with which carding and/or blending operations, generally indicated at 132 and 134 le;,~e~;lively, are performed, when such are desired. Such processes are preferably p~,.ro~.l-ed before neerlling~ but could also follow n-oe~ling 130.
Further, irregularly shaped glass fibers 116 produced in accordance with the present invention have a more uniform weight distribution, so that non-wovenm~t~ri~l~ produced by nPe~lling or other processing exhibit more uniform p.~,p~,Lies. As a result, a series of articles inclu-1ing irregularly shaped glass fibers 116 are illustratively disclosed herein in Figures 3-12 which may be produced at lower cost, or processed with 30 less effort, with varied and improved product p~ .rol-llance characteristics.Accordingly, the present invention provides a method for producing non-woven material 150 from irregularly shaped glass fibers 116 including the steps of W O 97/34845 PCT~US97/04455 providing a portion 148 of irregularly shaped glass fiber wool, neerlling the irregularly shaped glass fiber wool, thereby producing a non-woven m~teri~l 150 substantially compri~ed of irregularly shaped glass fibers 1 16. Preferably, the method is performed with irregularly shaped, bi-component glass fibers produced by rotary fiberization, and 5 re~uires no precursor procec~ing such as carding or blen~iing.
~ he present invention, thus, provides for a non-woven material 150 co~ ised of an uncarded, needled glass fiber wool including irregularly shaped glass fibers 1 16, preferably bi-component glass fibers unblended with other fibers. Non-woven m~teri~lc 150 including needled, irregularly shaped glass fibers in accordance with the 10 present invention demonstrate not only the high tt:m~cldlule and çhemic~l resi~t~nre of glass, but resiliency, high loft, resi~t~nee to tear, and a soft felt-like feel (i.e. soft "hand").
The choice of needles, penetrations per square centimeter of m~teri~l~ line speed, vertical displacement of the Tl~eAIes, repetitive neeAling and neerlling from one or both sides, as scl-l~ ely indicated in phantom at 130, can vary these characteristics, making 15 numerous product applications possible.
As may be understood, elimin~ti-~n of carding 132 and/or blending steps 134 makes possible lower cost production of non-woven m~t~ri~l which, further, exhibits beneficial characteristics of the irregular glass fibers 1 16 of the present invention in a resilient felt-like material. Due to the nature of the fiberizing and collection techniques 20 incolpol~l~d by reference above, the neeAIing 130 or other processes can proceed directly upon the wool pack 48 after production. Simply stated, a non-woven fabric material 150 may be produced in sheets 152 by a cutting or st~mping process, indicated enlali~rely at 136, as shown in Figure 3.
Further proces~ing in the way of applying a coating, ~Lu~ , or filler is 25 representatively indicated at 138, and may include, as necess~y for a particular coating, s~hlr~nt or filler, or other surface tre~tment to include multiple steps such as he~ting, drying, or rinsing.
Referring to Figures 4-7, illustrative product applications are shown.
Figures 4 and 5 illustrate ~ltern~tive filtration element~ 160, 162 using the non-woven, 30 felt-like m~fçri~t 150 of needled irregularly shaped glass fibers 116. The filtration element is illustratively configured as a panel 160 or a bag 162. Due to the fiber çh~r~r~Pristics, filtration elements 160, 162 will exhibit generally uniform filtr~ti~n CA 02247342 1998-08-2~
W O 97t34845 PCT~US97/04455 characteristics throughout, and are capable of application in high lelllpeldlulc;
environm~nt~. In addition, surface tre~tment~ may be added (e.g. at 138) to provide increased surface area, or reaction sites for application-specific chemical species. In addition, sheets 152 of the non-woven m~t~ri~l 150 may also serve as a sorbant m~t~r,~l 5 without further proce~sing, or include a surface treatment to enh~n~e sorbant properties of the wool portion, or form part of a composite sorbant m~teri~l One particular application of interest in this regard is its use as a sorbant for water-borne oil spills.
With or without neerlling, the irregularly shaped glass fibers 116 in acc~idance with the present invention may be keated (a~s in~lic~t~d generally at 138) with 10 a sorbant or combined with a filler which penetrates into the fiber matrix to produce additional composite products. Referring now to Figure 6a, a .c~.c stl.laLive gasket 166 is made of a needled unwoven material 150 (as shown) or ~Itern~tively of an un-needled wool portion 148 in combination with a saLul~t 164 such as a closed cell foam. In accordance with the present invention, the resiliency and Op~ of the irregularly15 shaped fibers 116 in the needled wool material 150 provides to the combination needed recovery not present in the foam saturant, while the foarn saturant 164 provides a sealing capability lacking in the more open fiber structure of the needled material 150. Similarly, in a reinforcPmPnt~ application, needled felts or un-needled wool portions may be used to reinforce a filler material. Needled, unwoven wool material 150 including the irregularly 20 shaped fibers 1 16 of the present invention may be used, for example, with an asphalt filler 151 for a high loft roofing product. In this regard, neerlling may be varied across the width of the m~t~ ri~l SO that when cut to forrn sepal~Le ~hingles 168, areas have different thiçknesses, as shown in Figure 6b. Alternatively, needled or un-needled wool portions 148 may be used, for example, with a polyester or other polymer fillers to provide 25 reinforcement for a sllhst~nti~lly rigid composite structural element. As ~ep.~sel.L~Lively shown in Figure 7, needled wool materials 150 including the irregularly shaped fibers 116 may form the core of an extruded or pultruded structural element 153.
In addition to neerlling, carding and blending processes 130, 132, 134, the irregularly shaped fiber 1 16 of the present invention may be processed by chopping into 30 fiber segments for use, as indicated at 140 in Figure 3. Such chopping follows rotary fiberization or even may follow needling, to prepare the irregularly shaped fibers 1 16 for use as a reinforcement. In some applications, the fibers 1 16 may ~ltern~tively be carded W O 97134845 PCTrUS97/044S~

or combed to break down the pack structure. Regardless, as in wet lay techniques known for straight fibers, the irregularly shaped fibers 116 may then be wetted, deposited, and dried to form a mat 154 of irregularly shaped fibers 116, as l~prt;s~ /ely shown in Figure 8a. Such a mat 154 could be used as a precursor for shingles 168, as well as an 5 underlying matrix for furni~hin~ such as wall coverings, floorings, and ceiling tiles which are fire, smoke or ~h~mic~l resi~t~nt As shown in Figures 8a and 8b, the resiliency and opel~ne~s of the irregularly shaped glass fiber 116 makes possible texturing the mat structure to provide a variety of looks previously unavailable with conventional fiber substrates.
As shown in Figure 8a, a conveyor l 44, such as a forarninous or split conveyor, may be used to carTy the mat over a t~ g station where air jets 146a, brushes 146b, vacuum 146c or other te~Lu~ g means causes irregular fibers 116 in the mat surface to release and create a textured line 158. Subsequent application of a coating, saturant or filler (~ c,s~ ely shown in Figure 3) such as used for ceiling tiles, wall 15 coverings, floorings, ~hinpl~s or g~ket~, will produce atextured product. A
representative cross section of the teY.Iul;~t;d mat 156 is shown in Figure 8b.
Finally, in a further aspect of the present invention, a non-woven m~t~
150 including irregularly shaped fibers 116 is provided in a generally continuous wool tow 170. The generally continuous tow 170 is produced by "unwinding" a fiberglass 20 wool paclc 48 collected by a direct forming rnethod, such as that described in U.S. Patent Application Serial No. 08/240,428, incorporated by reference herein. In the direct forming method, irregularly shaped glass fibers 116 are collected such that a generally spiral fiber relationship in the veil of fibers is captured and their spiral orientation is generally ~ rl in the wool pack 48. As the direct forming method may also be 25 used to collect long straight fibers from a rotary fiberizer, the "unwinding" ~licc~ etl herein is understood to be capable of pelrc -l-lallce on batts of such m~teri~l, albeit with added difficulty in ~ g the continuous tow due to the reduced fiber çnt~nglçmç-lt Nonetheless, the generally continuous wool tow 170 may be further processed in nurnerous ways, and rolled onto a core 176.
The tow 170 may be needled without further processing to create a non-woven fabric strip, or further processed by carding or blending; by cutting, chopping, or WO 97/34845 PCTrUS97/04455 stS-mI-ing; or by addition of a co~tin~, saturant or filler in like fashion as set forth in Figure 3 and discussed above.
Moreover, the generally continuous wool tow 170 of irregularly shaped fibers 1 16 may be fed one or more times through an air driven venturi tube 180, shown in 5 Figure 10. Suchaventuritube 180hasair~ets 182providinganaxiallyalignedairflow,and acts as an air amplifier. Venturi tubes 180 are commercially available, such as Model No. 218 Vortex tube from ITW Vortec Corp., Cincinnati, Ohio. The venturi tube 180 may be used to simply assist in unwinding the tow from a wool pack 48. However, when modified in accordance with the present invention, the venturi tube further includes a 10 plurality of tangentially targeted air jets 184 inclllc.ing a spiraling vortex of air. Given the axial air flow component and the spiraling vortex, the venturi tube 180 induces a longitudinal twist in the tow 170 driven therethrough, resulting in a yarn 172. Yarns of varying openness can be made from wool fibers, straight or preferably irregularly shaped, depending on the degree of twist imparted to the tow 170. Alternately, the yarn 172 may 15 be formed by meçh~nical means, however, air means are pre~ll~d for reduced impact on the entanglement of irregularly shaped fibers and the integrity of the tow 170.
In addition, with continued reference to Figure 10, the yarn 172 thus formed may be further combined (in~ tl~l generally at 186) with other yarns of like or different fibers by m~ch~nical twisting means, or by a subsequent pass through the venturi 20 tube 180, to yield combined yarn properties for specific applications. The yarns of irregularly shaped glass fibers, alone or in combination with other fibers, may then be used as carriers or l~i{lfo~ ents, or in additional textile operations including production of woven textiles.
p~eferrin~ now to Figure 11, in accordance with the present invention, a 25 still further feature of the continU~ us tow 170 is that the generally continuous tow 170 may be transported b~ O~. -a~ g stations in a m~nllf~rturing facility throughL~ OlL tubes 188. The tow may be blown or drawn by air movement in~ ce~1 by fans or vacuum or venturi tubes. Thus, from the fiberizing station, wool packs 48 of irregularly '' shaped fibers 1 16 collected by direct forming methods as disclosed herein may be 30 "ullw~J~uld" into a tow 170 and Lldllsl~olled for further processing at remote stations without manual intervention, conventional conveyors or other mer.hz~nit~ l transport.

1~

W O 97/34845 PCTrUS97/04455 Preferably the transport pipes 188 are built as overhead systems requiring a minimum of plant floor space.
The production of a generally continuous tow 170 by "unwinding" a fiberglass wool pack 48 collected by a direct forming method may further be applied in 5 providing a portable blowing wool a~dl~ls 190 comprising a wool pack 48 of irregularly shaped glass fibers 1 16 collected by direct form methods. In accordance with the present invention, a highly co~ essed wool pack 48 is nnr~ ,1 on site and the tow 170 drawn therefrom by means of a standard venturi tube 192. The tow 170 is the.earL~I
passed through a cubing ~ m~?nt 194 which cuts the tow 170 into cubes or pieces, which 10 are then preferably blown by colllplessed air into spaces to be inc~ ted The cubing element 194 preferably includes two hollow cutting cylinders 196. The cubes are preferably 1.2 to 2.S cm in any of the width, length or height directions. Once cut, the cubes drop into the center of the cylinders 196 from where they are blown by co,,,plcssed air from an air COlllplesSOr (not shown), or ~l~....A1;vely, by a fan or blower, through the 15 duct 198. This portable system allows an installer to take advantage of the high colllp,essibility of the irregularly shaped fiber 1 16, reduce capital costs of trucks and hoses, and p~,lr~ a cleaner on-site procedure.
As shown in Fig. 13, yarn 170 can be continuously withdrawn from a wool pack 48 and fed into a roving gun 200 which propels the yarn toward the wall cavity 202 20 of a building structure 204. Any device, such as a pn.oum~tic nozle, suitable for propelling the yarn toward the building structure can be used. A convenient propelling device is a roving gun, which is well known in the lay-up molding industry. Roving guns are usually pnellm~ti~lly driven, and typically include a rotary cutter mech~ni~m to chop the yarn or strand while dispensing it. Various sizes of roving guns are available, and the 25 C,~Lill~ size will depend on the rate of propulsion desired and the weight, strength and thickness of the yarn or strand. The roving gun is provided with pleS~ i air supplied via air supply line 206, connected to a source of pressurized air, not shown. For some applications the roving gun will have a built-in chopper, not shown, to chop the yarn into discrete lengths as the yarn passes through the roving gun. The preferred yarn for use 30 with the invention is bicomponent, irregular glass fibers made from a dual glass composition. The ple~.lcd method for m~nuf~-turing the pack of irregular fibers is using a rotary process, as described above.

CA 02247342 1998-08-2~

W097/34845 PCTrUS97/04455 The insulation installer can direct the chopped yarn, in the form of loosefil insulation 208, in a manner known in the art to insulate the cavities 202 of the building structure 204. Typical building structures include wall studs 210 over which a plastic vapor barrier 212 is ~ h~l The loosefil insulation 208 is directed through smallS openings, not shown, in the plastic vapor barrier, or over the top of the plastic vapor barrier, as shown. The loosefil insulation accum~ t~s as an insulation body or product 214 in the wall cavity. In addition to in~ul~ting cavities in bl~il(1ing~, the method of the invention can be used with an open molding technique to insulate many other kinds of u~es, such as vehicles, industrial eq--ipm~nt and appliances.
There are several advantages in using the method of the invention for producing insulation products. In contrast to the bulky and cumbersome conventionally used eql~ipm~nt for installing blowing wool or loosefil insulation in buildings, the paying out of yarn and propelling it with a roving gun or a similar applicator device allows easy freedom of movement for the installer, a quicker setup and knockdown time for the 15 e4ll;p,.,~l~t and more precise control in directing the loosefil insulation. Also, other m~t~ri~l~ can be applied to the fibrous material as it is dispensed. Examples include antistatic m~teri~l, fire retardants, and lubricants.
In an ~ltern~t~ embodiment, as shown in Fig. 14, irregular glass fibers are drawn as fil~ment~ 220 from bushing 222. The fil~ment~ 220 can be contacted by size 20 applicator 224 which applies a coating on the fil~ment~ for protection from abrasion and for enh~n~e~l compatibility with a resin matrix to be reinforced. The fil~ment~ are gathered into a strand 226 and wound as a package 228 on rotating collet 230 of winder 232.
The irregular fibers are preferably dual glass fibers produced from two 25 different glasses 234 and 236, having different coefficients of thermal conductivity. Each ofthe bushing tips 238 is conn~ct~-l to both bodies of glass 234 and glass 236 so that a dual glass fiber is formed. The d;fferences in coefficients of thermal expansion will provide an inherent curliness in the fibers. Additionally, a turbulence generator, such as a ~
fan 240, can be used to provide enough turbulence to impart random forces on the fibers 30 as they are being formed, thereby producing irregular dual glass fibers.
Once the strands of irregular fibers are formed into a package, they can be payed out as shown in Fig. 15. The strand can be propelled by any suitable means such as CA 02247342 1998-08-2~

W O 97/34845 PCT~US97/04455 a pneumatic nozle 242. The air nozzle is supplied with air via air line 244 for a source of pressurized air, not shown, to drive the strand through the nozzle. The nozzle can be provided with a chopper, not shown, to cut the strand into discrete lengths. The nozzle can be arranged to direct the strand into an al)pLo~, iate receptacle, such as the cavity 246 S of a muffler 248. This application of irregular fibers provides acoustic insulation.
~ItPrn~tively, the nozzle can be arranged to propel the strand into other types of receptacles, including transportation vehicles, such as airplanes and automobiles, and also including appliances such as kitchen ranges and dishwashers. Additionally, the irregular fibers can be propelled into receptacles for forming industrial insulation products, such as 10 automobile h(~(1liner and pipe insulation products. Further, the insulation product may be primarily ~tl uulwdl in nature, with the insulation quality being of secondary i~llpOl l~ce, such as in a window lineal or a compressed fiber building stud.
In a particular embodiment of the invention, the irregular fibers of the yarn (formed by pulling a yarn from a wool pack) or of the strand (pulled from a textile 15 bushing) can be treated with a coating or finish desi~necl to reduce the blllkin~?s.~ ofthe yarn or strand during the p~c~gin~ and l~al~ul~alion stages. The finish can be applied to the irregular fibers in a rotary process with a liquid spray, not shown, or applied to the yarn in a post forming operation by running the yarn through a coating bath. In a textile process the finish can be applied to the strand by the applicator 224. The nozzle or roving 20 gun can be provided with a mech~ni~m for impinging upon or breaking the finish on the . irregular fibers, thereby degrading the finish. This degrading of the finish will release control of the finish over the irregular fibers, thereby enabling the yarn or strand to increase in bl~lkin~
Having described the invention in detail and by reference to the preferred 25 embofliment~ thereof, it will be appalellt that modifications and variations are possible without departing from the scope of the invention which is defined in the appended claims.
INDUSTRIAL APPLI~ABILITY
The invention can be useful producing insulation products such as 30 insulation for wall cavities in buildings and insulation in appliances such as kitchen ranges and automobile mufflers.

Claims

1. A method for forming an insulation product comprising providing irregular fibers as a pack, continuously withdrawing a portion of the fibers from the pack to generate a continuous yarn of fibers, and propelling the yarn toward a receptacle to form an insulation product.

2. The method of claim 1 in which the yarn is propelled by running it through a pneumatic nozzle.

3. The method of claim 2 comprising chopping the yarn as it is propelled through the nozzle.

4. The method of claim 1 in which the pack of irregular fibers is provided by centrifuging fibers using a rotary process and collecting the fibers as a pack.

5. The method of claim 1 in which the receptacle is a cavity in a building, and the yarn is propelled into the cavity.

6. The method of claim 1 in which the receptacle is a cavity in an appliance, and the yarn is propelled into the cavity.

7. The method of claim l in which the irregular fibers in the pack have a finish applied to them to reduce the bulkiness of the pack, and in which the propelling step degrades the effect of the finish, thereby increasing the bulkiness of the irregular fibers.

8. The method of claim 1 in which the pack of irregular fibers is provided by centrifuging fibers using a rotary process and collecting the fibers as a pack, and in which the yarn is propelled by running it through a pneumatic nozzle and the yarn is chopped as it is propelled through the nozzle, where the receptacle is a cavity in a building, and the yarn is propelled into the cavity.

9. A method for forming an insulation product comprising centrifuging irregular glass fibers using a rotary process, collecting the fibers as a pack, continuously withdrawing a portion of the fibers from the pack to generate a continuous yarn of fibers, and propelling the yarn toward a receptacle to form an insulation product.

10. The method of claim 9 in which the yarn is propelled by running it through a pneumatic nozzle and chopping the yarn as it is propelled through the nozzle.

11. The method of claim 10 in which the receptacle is a cavity in a building, and the yarn is propelled into the cavity.

12. The method of claim 10 in which the receptacle is a cavity in an appliance, and the yarn is propelled into the cavity.

13. A method for forming an insulation product comprising providing irregular fibers as a wound package, continuously withdrawing a strand from the package, and propelling the strand toward a receptacle to form an insulation product.

14. The method of claim 13 in which the strand is propelled by running it through a pneumatic nozzle.

15. The method of claim 14 comprising chopping the strand as it is propelled through the nozzle.

16. The method of claim 13 in which the wound package of irregular fibers is provided by drawing the fibers from a bushing, and collecting the strand as a wound package.

17. The method of claim 13 in which the receptacle is a cavity in a building, and the strand is propelled into the cavity.

18. The method of claim 13 in which the receptacle is a cavity in an appliance, and the strand is propelled into the cavity.

19. The method of claim 13 in which the irregular fibers in the pack have a finish applied to them to reduce the bulkiness of the pack, and in which the propelling step degrades the effect of the finish, thereby increasing the bulkiness of the irregular fibers.

20. The method of claim 13 in which the wound package of irregular fibers is provided by drawing irregular glass fibers from a bushing containing molten glass, and collecting the strand as a wound package, and in which the strand is propelled by running it through a pneumatic nozzle, and chopped as it is propelled through the nozzle.