CA1212610A - Method for making hot melt adhesive bonded pile fabrics - Google Patents

Abstract

Abstract Of The Disclosure A method for making hot melt adhesive bonded pile fabric which comprises positioning a pile forming yarn in pile forming fashion adjacent to one side of a liquid-permeable base layer, applying a hot melt adhesive heated to at least its softening point to the base layer on the opposite side of the base layer from the side adjacent to the pile forming yarn, forcing said hot melt ad-hesive through the support layer into bond forming contact with the pile forming yarn, and allowing the adhesive to cool to a temperature below its softening temperature to thereby bond the pile forming yarn to the base layer.

Description

~212610 ~ I

APPARATUS FOR MAKING HOT MEI,T
ADHES IVE BONDED P I LE FABRI CS

The present invention relates to pile fabrics. More par- ¦
ticularly the present invention relates to a method of manufactur-ing hot melt adhesive bonded pile fabrics.
Pile fabrics such as carpeting may be manufactured in several ways such as by weaving, tufting, needling or bonding.
In each method the pile must be secured to a base or support layer in one way or another. The present invention is particular-ly concerned in one aspect with a method of manufacture wherein the pile is bonded by means of a hot melt adhesive to a base layer. Such fabrics will herein be referred to variously as hot melt adhesive bonded pile fabrics, or hot melt adhesive bonded carpets.
A number of t~chniques are knQwn for the manufacture of bonded ~ile fabrics which involve the coating of a preformed base layer with a layer of an adhesive and thereafter pressing pile-forming lengths of a yarn into the adhesive to adhere pile-forming lengths to the base laver.
The ~rior commercial techniaues for making bonded fabrics have relied very extensively on the use of PVC plastisol formu-lations because of the processing disadvantages thought to be associated with the use of other adhesive formulations such as hot melt systems. According to such techni~ues a ~olvvinyl chloride plastisol was applied to the base layer prior to position-ing the pile-forming yarn relative to the base layer. Then the ile yarn may be posi-ioned into contact wit the base layer and the plas-tisol may then be fused or cured, t~pically by hea-tiny.
When attempts were made to substitute other adhesives, such as hot melt adhesives for the PVC plastisol in -this process diffi-culties were encountered. Thus, for instance, with regard to hot melt adhesives, it has generally been thought that the apparatus employed for positioning the yarn may become coated with the ad-hesive requiring fre~uent shut downs of the apparatus for cleaning which is, of course, commercially unattractive~
Thus, while PVC plastisol has been the bonding agent of choice in the preparation of pile fabrics it is ~uite expensive, and it may tend to give off noxious gases when the product is sub-jected to combustion conditions~ Also, while polyvinyl chloride (PVC) plastisol compositions generally may provide good "tuft lock" characteristics, that is its use results in a firm bond of the pile forming yarn to the base layer, PVC plastisols generallv may not penetrate to the desired extent into the yarn bundles to effect complete adhesion of all pile yarn ibers of the pile yarn bundle to the pile fabric structure which may result in "fuzzing"
of the end product, especially in carpeting end uses.
Another disadvantage typically associated with the prior art techni~ues for making non-tufted pile fabrics, that is fabrics where the pile yarn is not tufted through the backinq but simply adhered to the backing, is that the adhesive is normally applied to -the base layer on the side of the base layer ~acing the pile yarns, and the base layer is normally of a construction such that the adhesive will not flow through it but will substantially remair on that surface with perhaps some penetration into the base layer.
Then, if it is desired to apply a backing layer, e.g., a hard back, o the back side ot the pile fabrlc as may be desired in the making of carpet tiles the backing layer must be either adhered directly to the backing layer or an additional ~rocess step of applying adhesive to the back side of the suppor~ layer may be necessary. In either event, there is created mlmerous distinct layers in the finished product, namely pile layer, adhesive layerS
base layer, another adhesive layer and a hard back layer. Such constructions may inherently have processing disadvantages and be costly to construct. These layers may also be subject to undesired separation during use.
The method of the present invention provides bonded pile fabrics wherein the bonding of the pile-fon~ng yarn to the base ayer may be accomplished by means of a hot melt adhesive which is a rela~ively inexpensive and hence commercially attractive ad-hesive system, which maY advantageously flow into the individual yarn ~undles to effect more complete adhesion of all the ~ibers of the pile farming yarn to the pile fabric product. In acoordance with the method herein the hot melt a~lesive is applied to the base layer conveniently and in a manner which does not interefere with the machinery employed for positioning the pile yarn. This step in the method may accomplish an additional function, namely that of bonding the individual pile-forming yarns to themselves typi cally at or near the portion of the yarns nearest the base layer, thereby providing improved performance characteristics to the pile fabric product. In addition according to the invention, the ad-hesive may be applied to the base layer, which is a li~uid-permeabl layer, from the back of the base layer and it snay be forced throuyh ¦he base laye o tha~ a ne step adhesive la r application may 12~26~

both provide a mea~s for bonding the pile yarn to the base layer and also provide a means by which a backing layer may be integrally affixed to the base layer. The resulting product may be less com-plicated and costly to manufacture and may have fewer separate and distinct layers in the final product where undesired separation may occur.
The pile fabrics made by the present invention are hot melt !¦adhesive bonded fabrics which are comprised of a li~uid-permeable ¦Ibase layer, a pile forming yarn adjacent to but not tufted through I the base layer, in pile for~ing, preferably folded, fashion; the pile forming yarn having been bonded to ~he base layer by means of a hot melt adhesive applied to the back of said base layer and forced through said base layer into contact with said pile forming l yarn. Pile forming configurations may include the so-called I-tuft configuration, e.g. r a non-folded configuration, U-tuft configurations, and loop pile configurations, among others. Wi~h regard to the phrase "folded, ~ile forminy fashion," which refers to a preferred embodiment, it should be understood that what is intended is a configuration of the pile yarns where the yarns are ~rovided with at least one fold at the portion of the yarn generall~
most nearly adjacent to the base layer, e.g., a cut pile con-figuration. Another "folded" configuration which is contemplated lis a loo~ pile configuration where the pile yarns remain uncut in ¦the form of substantially continuous folded yarns in the final product. A variety of pile configurations both nonfolded and folded are illustrated in the attached drawing. According to the most preferred embodiment the pile yarns are cut to form a folded, cut pile product.
According to the method of the present in-3D ~ention a pile forming yarn is positioned in pila forming fashion Ij 12~ 0 adjacent to one side of a liquid-permeable base layer. Thereafter~
a hot melt adhesive, heated to at least its softening point is applied to the base layer on the opposite side of the base layer from the side adjacent to the pile forming yarn. According to the next step of the method a hot melt adhesive may be forced, either simultaneously with its application or in a separate step, through the base layer into bond forming contact with the pile forming yarn, and the adhesive is then allowed to cool, either passively or by active cooling to a temperature helow its softening tempera-ture to thereby bond the pile forming yarn to the base layer. The apparatus includes a means for applyiny the adhesive and forcing it through the base layer~ It is to be understood that the ~; apparatus is not limited to means for applying only a hot melt adhesive but may include other bonding compositions commonly used in the making of bonded fabrics such as, for instance, polyvinyl ~ chloride plastisol formula~ions, etc.
i ~ccording to a preferred embodiment of the present inventior a method is provided wherein two continuous, liquid- !
permeable base layers are positioned in a passage where they lie in substantial parallel rela~ionship to one another at a prede-termined distance from one another; at least one continuous pile forming yarn is driven by folder blades alternatively against the opposing surfaces of said base layers when they are at or near the entrance to the above mentioned passage in such a way as to ~5 position the pile forming yarn relative to the base layers and to old it zig-zag; thereafter applying to the back of said base layers a hot melt adhesive; ~orcing said hot melt adhesive through said base layers so that said hot melt adhesive contacts said pile forming yarn; and cooling said hot melt adhesive to a tempera-ture ~elow its softening point to thereby bond said pile forming 1 ~o ~ ~

yarn to said base layers. This step in the method may accomplish an additional function, namely that of bonding the individual pile forming yarns to themselves ty~ically at or near the portion of the yarns nearest the base layer, thereby providing improved per- ¦
formance characteristics to the pile fabric product. Thereafter, the base layers may be separated from one another to form two continuous, hot melt adhesive bonded products. Typically such separation may be accomplished by means of a stationary or moving knife blade positioned between the base lavers which cuts the pile yarns along the entire width of the joined base layers to provide the hot melt adhesive bonded products.
The yarn used in forming the pile mav be made of any type of fiber known to be useful for fusion bonded fabrics such as carpets, for example nylon, acrylics, polyester, wool, cotton and rayon.
The hot melt adhesive compositions which may be emplo~ed according to the present invention include a wide range of hot melt adhesives which have been available for many ~ears. Typicall~
such compositions mav have a melt viscositv of less than about 200,000 cps, preferably less than about 100,000 cps a~ 30~F.
Examples include, for instance, blends of ethylene/vinyl ester co-polymer, petroleum wax and a thermoplastic resin as disclosed in U. S. Patent Number 3,551,2310 Other suitable blends which ~ay be used include ethylene/vinyl ester copolymer, low molecular weight, low density polyethylene, micro-crystalline wax, aliphatic thermoplastic hydrocarbon resin, di-cyclopentadiene alkylation polymer, antioxidant and filler as disclosed in U. S. Patent Number 3,684,600.
Other suitable hot melt adhesives of the ethylene/
vinyl ester tvpe which may be used are disclosed in U. S. Patent , ,`
- :~L2~
~ , ¦Numbers 3,583,936, 3,676,280, 3,684,600, 3,745,054, 3,723,371, 3,911,185, 3,914,489 and 4,012,547.
Other hot melt adhesive formulations which may be employed include those of the atactic polypropylene type. In general such com-positions may contain a predominant amoun~, e.g., from about 10 parts to about 100 parts or more, preferably from about 60 parts to 100 parts, by weight atactic polypropylene; from 0 to about 70 parts of another compatible thermoplastic material such as hvdro-carbon resins, waxes, polyethylene, especially linear, low density polyethylene; isotactic polypropylene, polyisobutylene and poly-butene~l. Fillers in widely varying amounts may be added to such compositions as will be readily apparent to those skilled in the art.
Other compatible thermoplastic materials which may be em-ployed in the adhesive formulation include ethylene/ethyl acrylate polyacetals, polyes~ers, polystyrene, polyacrylonitrile, polyacry-lic ester, polymethacrylic ester, polyvinyl chloride, polyvinyli-dene chloride, polyvinyl acetate, polyvinyl acetal, polyvinyl ether, polytetrafluoroethylene, polyamide, coumarone/indene resins~
natural resins, hydrocarbon resin, bitumen and others.
The amount of hot melt adhesive applied may vary widely, based upon the particular pile yarn employed, base layer and pro-perties desired in the pile fabric product. In general the amount employed may be from about 2 to about 200 ounces, preferably about 4 to about 80 ounces per square yard. Tuft binds for carpet yarns that may be achieved according to the invention may be from about

2 to about 20 pounds.
Suitable liquid-permeable base layers which may be employed n the product and process of the nvention include woven fabrics, i nitted $abrics, non-woven scrims, felted materials, or even flexible, foraminous materials.
Where it is desired to provide the ho~ melt adhesive bonded pile fabrics as floor covering products, especially carpet tile~, it may be desirable to apply any of a wide variety of suitable, resilient backing layers to the fabric. Such carpet tiles are also considered to be within the scope of the present invention. The backing layer may be formed, for example, from a suitable thermoplastic ~aterial such as blends containing ethylene/vinyl acetate copolymers, atactic polypropvlene, bi~umen, hydrocarbon resins, waxes, synthetic and natural rubbers.
The backing may be bonded to the base layer by means of the same adhesive applied to the base layer to bond the pile fibers.
Thus, the resulting product may have fewer separate layers subject to separation than known carpet tiles. This is, rather than having pile layer, adhesive layer, base layer, another adhesive la~er and backing layer, the pr~sent car~et tile may typically have a pile layer, a single, integral, hot melt adhesive layer int ~a which the base layex may be disposed or suspended, and a back~ng layer bonded to the comnosite by means of the hot melt adhesive.
ThP backing layer may be provided with at least one stiffening and stabilizing membrane, such as woven or nonwoven glass fibers.
After the backing has been applied the consolidated material may then be severed by suitable cutting means into a carpet tile bv an~ of a variety of techniques which are well-known to those skilled in the art.

1` ~,~,26~.

The resulting carpet tile product is suitable for use as a floor covering in home and/or commercial use in an office en-vironmen~ where substantial high stress conditions (e.g., wheeled traffic) are applied across the tiles. The tiles typically have a dense pile and may not re~uire adhesives for installation. The individual modules may be replaced or rotated as necessary or de-sired. The carpet tiles may also have excellent dimensional sta-bility with substantially no curling, slipping, bucklin~, stretchi] ~g or shrinking. In addition -the carpet tiles may have low smoke emission and low "fuzzing" characteristics.
The invention may be further understood bv reference to the drawings and accompanying description thereof. It is to be under-stood, however, that various changes may be made without departing from the scope or spirit of the invention which is to be limited only by the scope of the appended claims. Referring now to the drawings:
Figure 1 is an elevation view oE the apparatus; and Figures 2 through 4 illustrate various embodiments for forcin~ the adhesive through the base layer.
~o Figures 5 through 8 illustrate various pile forming con-figurations which may be employed in the hot melt adhesive bonded pile fabrics of the present invention. Figures 9 and 10 illustratl , conventional tufted pile fabric configurations showing the pile yarns tufted through a base layer. Figure 11 illustrates a con-ventional I-tuft bonded fabric configuration showing a relatively impermeable base layer.
Referring now to Figure 1 r carpet yarn 10 is supplied from a yarn source (not shown) over and around guide rolls 12 and 14 d dow~ to the vertical guides 16 ~ase layer 17 ls supplied 121:11ilU

from rolls 18 into position between the guides 16. As the yarn 10 enters between the vertical guides 16 the ~olding blades 20 and 22 alternately displace the yarn in a zig-zag fashion into one or the other of the base layer sheets 17 as the carpet backing is being drawn downwardly. Pivotally mounted bladelets 24 and 26 may assist in the folding of the yarn. Folding blades 20 and 22 are mounted, respectively, to connecting rods 28 and 30. Connecting rod 28 is pivotally connected to vivot shafts 32 and 34 and con-necting rod 30 is pivotally connected to pivot shafts 36 and 38 through suitable links (not shown). The shafts 32 and 38 are oscillated by an oscillating crank arm mechanism (not shown).
It should be noted that the blade 20 is out of phase with the blade 22 so that when the blade 22 is being pivoted inwardly as shown in Figure 1 the blade 20 is being pivoted outwardly and vice versa to provide a zig-zag configuration of the yarn between the carpet base layers 17 which are liquid~permeable, that is permeable to the adhesive to be applied.
After the yarn has been positioned in zig-zag configuration between the carpet base layers 17, hot melt adhesive 80 maintained in troughs 82is applied to applicator rolls 34 by passing through gaps 86 between the side walls 88 of the troughs 32 and the appli-cator rolls 84. The hot melt adhesive may be maintained in the liquid phase by heating means not shown. The amount of adhesive applied to the applicator rollx may be adjusted as desired by moving troughs 82 upwardly or downwardly as indicated. Applicator rolls 84 are caused to move preferably in the directions indicated by drive means not shown whereby adhesive is applied to the carpet base layers 17 and simultaneously forced through the base layers into contact with yarn 10. The rolls maY also be forced to move in the opposite direction to the directions indicated if so ,deslred.

~1~6~0` 1 After the hot melt adhesive has been applied to -the carpet base layer and forced through it into contact with the car~et yarn, it may be converted into the solid phase by cooling means 90 to form a bond between the carpet yarn 10 and the carpet base layers 17. Cooling means 90 may be supplied with air blowers 9~, cooling coils 94 over which air is forced and thereby cooled prior to exiting the cooling means through exit ducts 96 into contact with the carpet base layers to thereby cool the hot melt adhesive causi g it to revert to the solid phase. The yarn 10 may then be severed, generally in the middle of the base layers 17 by cutting blade 98 to provide, simultaneously, ~wo sheets of carpet.
Figure 2 is an enlarged view of the hot melt adhesive appli cator means embodiment 7~ shown in Figure 1. Numbers in Figure 2 corresponding to numbers used in preceding drawings refer to cor-responding parts of the apparatus. The gaps 86 by means of which the amount of ho-t melt adhesive to be applied may be adjusted as desired are more clearly illustrated. Also shown in ~igure 2 are pre-heating plates 101 which may be provided to pre-heat the base layers prior to application of hot melt adhesive and to facilitate ~o such application.
Figure 3 illustrates an alternative embodiment wherein the hot melt adhesive is maintained in a reservoir sided on one side by base layers 17 and on the other side by doctor blades 104. The adhesive 80 is allowed to contact the carpet backings and is forced therethrough by the tips 106 of doctor blades 104.
Figure 4 illustrates yet another embodiment of the inventio where the hot melt adhesive is maintained in tanks 108. Appli-cation of the adhesive to the base layers 17 is accomplished by drawing the adhesive out of the tanks 80 through pumps 110 into 12~

manifolds 112. The adhesive is -then forced from -the openings 114 ln manifolds 112 under sufficient pressure to force the adhesive through the carpet base layers 17 into contact with carpet yarn l 10.
¦ Figure 5 illustrates an embodiment oE the present invention showing an I-tuft configuration of the pile yarns, base layer 17 in the form of a relatively open-weave, adhesive permeable fabric.
Hot melt adhesive 80 is shown as a continuous layer into which the base layer 17 has become embedded at the base -thereof. A backing layer 150 made of a thermioplastic material is shown as having been bonded to the pile fabric by means of the same hot melt adhesive 80 used to bond the pile formirlg varns. Figures 6, 7 and 8 illustrate some folded configurations of the pile forming yarns which may be preferred. Identifying numbers refer to the same structural components as in Figure 5. Figure 6 shows a folded, cut pile configuration. Figure 7 shows a loop pile conEiguration.
Figure 8 shows another folded pile configuration where the folded portion of the yarn is on the surface giving the appearance of a loop pile, although the loops are not joined to one another at their base. This configuration provides in essence a loop pile product while simultaneously offering the advantages of, for instance, yarn savings of the so-called I-tuft configuration.
Figure 9 illustrates a conventional cut pile tufted carpet tile having pile yarn 10 tufted through a conventional, polvpropv-lene backing 152, adhesive layer 153, and backing layer 154.
Figure 11 differs from Figure 10 only in the illustration of a loop pile tufted configuration rather than a cut pile configuratior i.
Figure 11 illustrates conventional, multilayered I-tuft bonded roduct showing the configuration of oile yarns 10, adheslve layer l~

155, adhesiv impermeable base layer 156 in the Eor~ of tightl~
woven jute, another adhesive layer 157 by means of which backing layer 15~ may be adhered to the base layer.
The invention may be further understood by reference to the following examples which are not to be construed as undulv limiting the invention.
EXA~LE 1 Using a machine similar to that shown in Figure 1, a n~lon carpet yarn was folded between layers of a woven rayon fabric.
By means of an electrically heated plate mounted on one side only, directly below the vertical guide 16, the yarn loops in contact with the fabric at this side only were lightly fused to the fabric.
By omitting the hot-melt adhesive application and the cutting by the blade, a loop-pile fabric was produced on removal of the other non-adhering rayon fabric.
A hot-melt adhesive composition was formulated using atactic polypropylene, hydrocarbon resin and wax, and a molten film of this adhesive cast on a hot-plate at about 350~F. A portion of ~he loop-pile fabric made as described above was contacted on the loop-pile face with a piece of non-woven glass scrim. This asse~bly was then placed with the glass in contact with the hot-melt adhesive, rolled to force the adhesive through the glass and into the loop pile yarns, and cooled. Then the glass side of the sandwich was laminated under heat and pressure to a 60 mils thick sheet of Keldax~, ~a trademark of DuPont for a filled hot-melt composition based on a copolymer of ethylene and vinyl acetate).
A blade was then used to cut the yarn sandwich between the rayon fabric and the glass, thus producing two cut-pile carpets.

Single yarns were then pulled from the carpet bonded by the hot-melt adhesive to the glass. The average force required was found to be 4.6 pounds.

Used a machine similar to that of Figure 1 with a heater plate as described in Example 1. There was a rayon fabric on the same side as the heater plate, an open leno-woven glass scrim fabric on the non-heated side, and a nylon carpet yarn folded into the aap. The glass side of the sandwich was contacted with a heated applicator (identified as Number 84 in Figure 1), above which was mounted a trough 88 containinq the following formulated hot-melt adhesive at about 300F:
Elvax~ 350 (DuPont ~thylene/vinyl 30 parts acetate copolymer melt index - 19) 5hellmax*400 (Shell micro crystalline 45 parts wax, melting Point 177F) Piccopale*100 (Hercules hydrocarbon 25 parts resin, softening point: 212F) By varying the speed of the application roll relative to the yarn sandwich, and the gap between the trough and the applicator roll, various levels of adhesive were applied to the yarn loops through the woven glass scrim. After cooling and cutting of the yarns to make two cut-pile carpets, the tuft bind was measured on the glass backed carpet portion. Values varied from 4 pounds tuft bind with 15 ounces/sauare yard of adhesive to 6 pounds with 50 ounces/sauar yard of adhesive.

A hot-melt adhesive was formulated as follows:

*Trademark ~Z~
- l Elvax*350 30 parts U~ 653-04 (U.S. Industries ethYlene/ 10 parts vinyl acetate copolymer, melt index: 375) Shellma~ 500 (Shell micro crystalline 35 parts wax, melting point 171F) Piccopale~ 100 25 parts Using the procedure of Example 2, this adhesive was applied to the glass side of the yarn sandwich giving tuft bind ranging from 7 to 10 pounds with an adhesive pick-up of 32 to 48 ounces/square yard.

With the following hot-melt adhesive formulation:

Elvax*260 ~DuPont ethylene/vinyl 35 parts acetate copolymer melt index: 6) Shellma~ 400 40 parts Piccopale*100 25 parts and using the procedure of Example 2, obtained a tuft-bind of 5 pounds w.ith as low as 8 ounces/square yard of adhesive. With 36 ounces of adhesive, the tuft-bind was 9 pounds.

Used the same procedure as for Example 2, except that the heated applicator roll/trough to apply the hot-melt adhesive was replaced by a doctor ~lade applicator on the glass side as depicted in Figure 3. The adhesive was:

Elva~ 660 (DuPont ethylene~vi~yl acetate 20 ~arts copolymer melt index: 2.5) D-82~(Hercules experimental hot~melt 80 parts adhesive) With an adhesive pick uv in the range of 5-20 ounces/square yard following from the relatively high viscosity of this adhesive, the tuft-bind averaged 4 pounds.

*Trad~ark ll 12126~

¦ Used ~he method of Example 5, but with a lower viscosit~
adhesive prepared thus:
Atactic polypropylene 83 parts 5 . Dowle~ (Dow linear low density 17 parts polyethylene, melt index: 20) A 3 pound tuft-bind was obtained with adhesive pick ups in the ¦range l4- ~nwes/~u~rc y-~d.

~Trademark

Claims (4)

WHAT IS CLAIMED IS:

1. A method for making hot melt adhesive bonded pile fabric which comprises positioning a pile forming yarn in pile forming fashion adjacent to one side of a liquid permeable base layer, applying a hot melt adhesive heated to at least its soften-ing point to the base layer on the opposite side of the base layer from the side adjacent to the pile forming yarn, forcing said hot melt adhesive through the support layer into bond forming contact with the pile forming yarn, and allowing the adhesive to cool to a temperature below its softening temperature to thereby bond the pile forming yarn to the base layer.

2. A method for making a hot melt adhesive bonded pile fabric which comprises: positioning two continuous, liquid-per-meable base layers in a passage where they lie in substantial parallel relationship to one another at a predetermined distance from one another; driving at least one continuous pile forming yarn by folder blades alternatively against the opposing surfaces of said base layers when they are at or near the entrace to the above mentioned passage in such a way as to position the pile forming yarn relative to the base layers and to fold it zig-zag;
thereafter applying to the back of said base layers a hot melt adhesive; forcing said hot melt adhesive through said base layers so that said hot melt adhesive contacts said pile forming yarns;
and cooling said hot melt adhesive to a temperature below its softening point to thereby bond said pile forming yarn to said base layers.

3. The method according to Claim 2 which comprises the further step of separating said base layers from one another to form two continuous hot melt adhesive bonded products.

4. A method for making a hot melt adhesive bonded pile fabric which comprises: positioning two continuous, liquid-permeable base layers in a passage where they lie in substantial parallel relationship to one another at a predetermined distance from one another; driving at least one continuous pile forming yarn by folder blades alternatively against the opposing surfaces of said base layers when they are at or near the entrance to the above mentioned passage in such a way as to position the pile forming yarn relative to the base layers and to fold it zig-zag without tufting said pile-forming yarns through said base layers, thereafter applying to the back of said base layers a hot melt adhesive; forcing said hot melt adhesive through said base layers so that said hot melt adhesive contacts said pile forming yarn; cooling said hot melt adhesive to a temperature below its softening point to thereby bond said pile forming yarn to said base layers; and cutting said pile forming yarns to form two continuous hot melt adhesive bonded products.