US 3645949 A
Description (OCR text may contain errors)
Feb. 29, 1972 F. J. cRlMl PROCESS FOR CONSTRUCTING TUFTED CARPETS AND RUGS AND BONDING AGENTS-l USEFUL THEREIN F'led April 4, 1968 f KX ATTORNEY) United States Patent O PROCESS FOR CONSTRUCTIN G TUFIED CARPETS AND RUGS AND BONDING AGENTS USEFUL THEREIN Fred J. Crimi, Somerville, NJ., assignor to Union Carbide Corporation Filed Apr. 4, 1968, Ser. No. 718,870 Int. Cl. C08f 29/12 U.S. Cl. 260-28.5 10 Claims ABSTRACT OF THE DISCLOSURE Tufted carpets and rugs of fibrous strands are constructed by singeing the back of a tufted web, and preheating the back of the tufted web, applying a particulate bonding agent to the preheated web, heating the bonding agent above its fusion temperature and applying a pressure with cooling to force the bonding `agent over the back of the tufted Web and into the fibrous strands.
A novel composition utile as the bonding agent comprises a hydrocarbon polymer of a lower alkene, such as polyethylene, having a melt index less than 150, an ethylene/ mono-unsaturated ester copolymer having a melt index greater than l0() and a wax having a melting point of from 75 to 95 C.
BACKGROUND OF THE INVENTION Although of fairly recent vintage, tufting has become the dominant method of constructing carpets and rugs.
Tufted carpets and rugs are typically manufactured in two operations. A tufted pile is first created by sewing continuous strands comprised of a plurality of fibers into a backing which is usually woven from jute, hemp, kraft cord or cotton, or plastic and may also be at net or a random fiber mat. This backing or scrim holds the tufted pile which is essentially a series of loops in some predisposed pattern. The result, at this stage, is a fairly limp tufted web which is then coated on the back with a bonding agent to permanently bond the tufts to the backing. A secondary scrim may also be added to lend additional hand and dimensional stability to the finished product.
Bonding agents today are typically a latex formulation applied as a wet coating over the back of the tufted web. While this results in acceptable bonding, costly and time consuming drying steps must then be performed before the manufacturing operation is complete. Such steps have, however, been deemed necessary to firmly bond all fibers which comprise the strands to preclude fibers from withdrawing from the carpet or web and forming into unsightly balls or pills The phenomenon of pilling has been observed to be. most prevalent in tufted carpets or rugs constructed of strong filaments such as nylon.
The object of this invention therefore, is to provide an improved process for manufacturing tufted carpets and rugs which eliminates the costly drying steps associated with the use of latex bonding agents and which provides finished carpets and rugs of good pilling resistance.
SUMMARY OF THE INVENTION A new and improved continuous process for producing tufted carpets and rugs has been developed which comprises passing the back of a fibrous tufted web through a singeing zone to remove fiber fuzz from the back of the fibrous tufted web, preheating the back of the tufted web to a temperature below the fusion temperature of the tuft fibers, applying a particulate bonding agent to the preheated back of the tufted web, heating the bonding agent to a temperature above the fusion temperature of the bonding agent, applying a positive pressure to the bonding agent to cause fiow of the bonding argent over the back of the web and penetration of the fibrous tufts and cooling the back of the web to set the bonding agent. As an optional alternative, a secondary scrim may be applied to the heated bonding agent prior to or simultaneous with the application of pressure.
In another aspect of this invention a new and novel resinous bonding agent composition utile in the above process has been found which comp-rises a blend based on the total weight of the bonding agent, from about 70 to about percent by weight of hydrocarbon polymer of a lower alkene having a melt index measured at 44 p.s.i. and 190 C. of less than about 150 dgn/min., from about 10 to about 30 percent by weight of an ethylene/ monounsaturated ester copolymer having a melt index measured at 44 p.s.i. and 190 C. greater than about 100 dgm./min., and from 0 to about 15 percent by weight of a wax having a melting point of from about 75 to about C. For each 100 parts by weight of this resin bonding agent blend there can be added up to about 33 parts by weight of a filler.
IN THE DRAWING The attached drawing is a schematic illustration of the method constructing carpets and rugs according to one aspect of this invention.
DESCRIPTION This invention relates to an improved process for constructing tufted carpets and rugs and to a new and novel bonding agent composition useful in such process.
With reference first to the attached drawing, the mproved process generally comprises passing the back of a tilted web through a singeing zone to remove fibrous fuzz, preheating the back of the Web to a temperature below fusion temperature of the fibers, applying a particulate bonding agent to the preheated back of the web, heating the bonding agent to a temperature above its fusion point, applying a positive pressure to the bonding agent to cause flow over the back of the Web and penetration of the fibrous strands which comprise the tufts and cooling the back of the web to set the bonding agent. As an alternative, a second backing may be applied before setting the bonding agent to lend additional hand to the finished rug or carpet.
As mentioned above, the first step in constructing tufted carpets and rugs and which generally precedes the practice of this invention is the insertion of continuous strands of compacted fiber or fiber bundles into a backing or scrim before applying a bonding agent to the back of the web to lock the tufts in place. It has been found, that such fibrous strands contain substantial amounts of fiber fuzz lwhich impedes the fiow of a molten bonding agent into the strands. It has been found according to the present invention that if this fiber fuzz is singed off by the application of a flame or hot air stream that fiber bundle penetration will be substantially increased, other factors being constant.
With particular reference to the drawing, singeing may be accomplished by passing the tufted web through in a pair of idler rolls to maintain tension and then through the singeing zone where fiber fuzz is removed by the action of the impinged flame or blast of hot gas. Radiant heat has been tried and found ineffective as it tended to fuse the surface of the fibrous strand thus further impeding penetration.
In the second step of the novel process of this invention, the singed tufted web is passed through a pre-heating zone where the back of the tufted web is heated until it is warm to the touch or to a temperature of about 40 to about 70 C., but below the fusion temperature of the fibers. The importance of this step will be more clearly set forth below.
The heating units useful in this pre-heating step include amongst others, radiant heat devices and the like, and should be sized to provide at least about one third of heat output of the main heating unit. The residence time of the web in this zone will, of course depend upon the heat output. It has been generally found that a bank of radiant heaters having an output of about 8 kilowatts positioned about inches above the back of the 12 inch Wide tufted web moving at a rate of five feet per minute has been found effective for pre-heating nylon filament tufts. As will lbe understood however, these requirements are flexible and that residence time will vary depending on the nature of the synthetic fiber, the output of the heat source and its position relative to the tufted web as well as rate at which web is passed through the pre-heating zone.
The heated web is then passed through the zone wherein a particulate bonding agent composition which is preferably a powder is applied to the heated back of the tufted web by a variety of means including the vibrating plate and hopper arrangement shown in the drawing. While other mechanical devices for applying the particulate bonding agent may be used, they should act to evenly distribute the particulate bonding agent over the pre-heated web to an average weight of about 5 ounces to about 35 ounces per square yard of tufted web to obtain good tuft lock and 10G percent liber penetration and allow for the addition of a secondary backing.
The pre-heated web and applied bonding agent are then passed through a heating zone wherein the bond ing agent is raised to a temperature above its fusion point and preferably above its melting point where such bonding agent will generally pool into beads on the back of the tufted web and begin to penetrate the fibrous strand. For good operating compatibility with the pre-heating zone heat output, this main heating zone should generally be from about 2 to about 5 times the heat output of the pre-heating zone.
It is in this connection that the pre-heating serves an important role. First, pre-heating provides a warm deposition surface rather than 'a heat sink to promote completed thermal uidization of the bonding agent and to preclude resistance to bonding agent heating at the webbonding agent interface. Secondly, it promotes fiber liexibility to increase bonding agent flow into the fibrous tuft. Pre-heating has been found to effectively reduce residence time in the main heat unit by as much as 50 percent all other factors being constant.
After leaving the main heating unit, the tufted web and now uid bonding agent are passed through a pressure zone which is shown in the drawing as a pair of nip rolls. In this zone there is applied a pressure which is slightly less than that required to crush the tufts but sufficient to force fiuid bonding agent uniformly over the back of the tufted web and into the fibrous tufts thereby bonding the tufts to the backing and the fibers of each tuft together.
As shown, the nip roll above the web is preferably cooled to simultaneously set the bonding agent so that the finished carpet or rug can be immediately passed through any desired series of idler and tension rolls to the finished roll for storage.
As an alternative to the above process, a secondary backing or "sci-im may be applied to the web while the bonding agent is fluid to produce a rug or carpet having a double backing and improved hand Where a double backing is used, a greater amount of bonding agent may be required since it must also serve the function of bonding the secondary backing of the web.
As another alternative, the finished tufted carpet or rug may have applied thereto a foamed latex or the like to provide inherent cushioning.
The novel resinous bonding agent composition of this invention generally comprises a lower alkene polymer, an ethylene copolymer and desirably a minor amount of a wax having a melting point of from about to about C.
The hydrocarbon polymer of the lower alkenes useful as a component of the bonding agent composition principally contain carbon and hydrogen and includes homopolymers and copolymers of alkenes containing from 2 to 6 carbon atoms. The lower alkene polymer should have a melt index measured at 44 p.s.i. and 190 C. below about 150 dgm./min. and preferably from about 50 to about 100 dgnL/rm'n. The desired lower alkene polymers are those of low crystallinity and low stiffness modulus, and include amongst others polyethylene, ethylene copolymers, ethylene-butene copolymers and the like. The preferred lower alkene polymers are ethylene homopolymers having a density of from about 0.910 to 0.935.
The ethylene/ mono-unsaturated ester copolymers used in the practice in the bonding agent compositions of this invention are prepared by polymerizing ethylene with one or more mono-unsaturated esters copolymerizable therewith. Copolymerizable mono-unsaturated esters include the vinyl esters such as vinyl acetate, vinyl formate, vinyl propionate, vinyl butyrate and the like as Well as alkyl esters of unsaturated acids such as methylacrylate, ethyl acrylate, isopropyl a-crylate, butyl acrylate, 2-ethyl hexyl acrylate, loi-cyclo-heptyl acrylate, 2-methylamino ethyl methacrylate, 2-diethylamino ethyl acrylate and the like. These copolymers preferably contain a predominant amount of polymerized ethylene and more preferably greater than 60 percent by weight polymerized ethylene.
The ethylene/mono-unsaturated ester copolymers used in the practice of this invention, preferably have a melt index measured at 44 p.s.i. and 190 C. greater than 100 dgm./min. and more preferably a melt index between about and 400 dgm./ min. Lower melt index copolymers may be used, however, where the lower alkene polymer has a high melt index.
The wax component having a melting point of from about 75 to about 95 C. may be a naturally occurring or a synthetic wax and is preferably a microcrystalline wax.
The function and relationship of the components of the bonding agent of this invention are of considerable importance.
The lower alkene polymer acts as the base of the bonding agent composition and is present in an amount of from about 70 to about 90 percent by weight based on the total weight of the resinous bonding agent composition, preferably from about 75 to about 85 percent by weight.
-As a component of the bonding agent composition, the ethylene copolymer appears to serve important wetting and adhesive functions. The bonding agent must bind substantially all the fibers of a strand together at the back of the tufted web to assure a low incidence of pilling.
The presence of the high melt index ethylene copolymers in the bonding agent composition of this invention appear to promote fiber wetting and thereby enhance complete fiber bundle penetration. The copolymers also enjoy an adhesive function as an aliinity intermediary between the relatively non-polar lower alkene polymer base and more polar continuous filaments such as nylon, polyesters, acrylics, modacrylics and the like.
The wax component of the bonding agent composition of this invention appears to act as a penetrant or lubricant to promote How of the bonding agent composition into the fibrous bundle. While essentially required for low melt index hydrocarbon polymer of a lower alkene and typically considered advantageous for all blends the use of wax can be avoided where the fibrous strand has a low crosssectional fiber density and where both the hydrocarbon polymer of a lower alkene and the ethylene copolymer have proportionally high melt indices. It has been found, however, that when present the wax must fit into the proscribed melting range to provide utile tufted carpets and rugs, since it has been found that waxes of a lower melting point appear to cause excess penetration and introduce boardiness and rbrittleness to the rug or carpet due to strike-through of the backing and waxes of higher melting point fail to improve the penetrability and cause brittleness inthe end product.
When present, the amount of wax also appears to be important. While wax concentrations of from about 2 to about percent by weight based on the total weight of the resin bonding agent are universally useful and wax concentrations up to about l5 percent by weight are utilitarian, concentrations above this upper limit tend to show excessive penetration and strike-through of the backing causing the rug or carpet to become stiff or boardy.
The bonding agent compositions of this invention may be readily prepared by conventional methods such as hot compounding techniques and can be applied to the Aback of a tufted web as a particulate dry powder, a melt or in a solvent solution. Application as a particulate dry powder is particularly preferred when the resin bonding agent composition is used in conjunction with the aforementioned process of this invention.
The bonding agents of this invention display a good tolerance for fillers. Fillers may be added in an amount up to about 33 parts by weight for each 100 parts by weight bonding agent and include amongst others, barium sulfate and calcium carbonate based `fillers with barium sulfate based fillers preferred. The fillers should have a particle size below about 60 microns and preferably below about 40 microns.
In addition to fillers, dyes, pigments, preservatives, opaciers, extenders and the like may be incorporated to the bonding agent compositions of this in-vention.
While the bonding agents of ythis invention show particular utility in constructing tufted rugs and carpets from fibrous strands of continuous lament synthetic fibers, it will be appreciated lthat the bonding agents may also be used in construction of tufted rugs and carpets from all natural and synthetic libers including amongst others wool, rayon, cotton, nylon, the acrylics, modacrylics, the polyolefins and the like. In addition, the bonding agents may be used to provide additional backing and body to conventional woven and nonwoven rugs and carpets.
While the novel bonding agent composition of this invention is particulary utile in the practice of the process of this invention, it must be appreciated that other bonding agents may also be used so long as the steps of singeing and pre-heating are incorporated to achieve the good fiber bundle penetration and reduction is bonding agent composition heating time.
Methods used for determining the properties of resins evaluated in the following examples were:
Resin A-a polyethylene homopolymer having a melt index of between 18 and 25 and a density between about 0.916 and 0.920.
Resin B-a polyethylene homopolymer having a melt index ybetween 50 and 100 and a density between about 0.916 and 0.920.
Resin C-an ethylene-acrylic acid copolymer containing about 12% by weight combined acrylic acid and having a melt index of about 90.
Resin D-an ethylene-ethyl acrylate copolymer containing about 15% by weight combined ethyl acrylate and having a melt index of about 20.
Resin E-an ethylene-vinyl acetate copolymer containing about 18% by weight combined vinyl acetate and having a melt index of about 110.
Resin F-an ethylene-vinyl acetate copolymer containing about 28% by weight combined vinyl acetate and having a melt index between about 250 and 350.
Mixtures of the resins employed in the studies were obtained by dry blending in a high speed stirrer.
The mixtures were applied in powder form to the back of a nylon 4 x 4" tufted web sample until an even coating having a weight of l2 ounces per square yard of tufted backing was obtained. The powdered resin mixtures were then exposed to a heat zone of 10 infrared lamps having a power of 375 watts per lamp at a distance of six inches from the back of the tufted web back for a period of three minutes. The sample was then removed from the heat zone, and the iiuid bonding agent candidate smoothed over the back with a hand roll, the coated carpet sample was then allowed to cool for 24 hours and tested for the degree of fibrous strand penetration, and in some instances tuft lock.
Fibrous strand penetration was determined by cutting a section of the bonded portion of the tufted carpet in the tuft direction and observing the cut section under a microscope having a magnification of The degree of penetration of the adhesive coating resin mixture into the ber bundles was objectively determined and expressed as percentage penetration.
The test for tuft lock was made by selecting loops of the bonded tufts for testing and then cutting the tufted loops in the tuft direction. A weight scale was then inserted into the test loop and pulled until the loop lbroke away from the backing and the pounds of force required to break the test loop measured. The average of ve separate tests for each resin coating mixture was taken and reported as tuft lock in pounds.
The results of testing samples of nylon tufted carpets for fiber -bundle penetration and tuft lock after being treated Density ASTM D-1505 with various bonding agent mixtures are set forth in Table Melt index ASTM D-1238 I below wherein the amount of lower alkene polymer and ethylene copolymer resin present in the bonding agent are expressed as percent by weight.
TABLE I Example 1 2 3 5 6 7 s 9 10 11 12 13 14 15 16 Percent of resin in bonding agent mixture Resin A 100 90 80 70 90 s0 70 90 80 70 B 100 9o so 7o e0 su C 1o 20 30 Examples 1-16 Since tufted carpets and rugs constructed from strong, continuous nylon filaments exhibit a great tendency to pill, nylon tufted webs were used in evaluating several synthetic resin compositions to determine which would show good iiber bundle penetration and therefore introduce effective pilling resistance to the tufted web. The
From this information, several factors become evident. It was clear that a broad mixture of resins was not the solution to the problem of obtaining good ber bundle penetration.
When considering the ethylene copolymers, the nature of the comonomer appeared important. While the medium combinable resins selected for the study were as follows: polarity copolymers such as ethylene-ethyl acrylate and Example 40 To establish the effect of singeing the back of a tufted web to remove fiber fuzz prior to application of the bonding agent, a hot air gun, a gas burner and infrared lamps were first evaluated as possible singeing means. In a prebonding agent deposition test it was shown that while the hot air gun and Bunsen burner singed olf liber fuzz without deleteriously fusing the fiber bundle, the infrared lamps were found to fuse a portion of the fiber bundle before ber fuzz was effectively signed olf.
To remove liber fuzz with a hot air gun, the gun was set at the hot setting and positioned over the back surface of the tufted roll at height of about 2 inches and held there for a period of about 10 seconds. The temperature at the nozzle of the hot air gun when set at hot was about 230 C.
At this time exposure it was found that fiber fuzz was almost completely removed with only a negligible amount of fusion of the nylon fiber bundle. When the gun was applied for 15 seconds under the same conditions, it was found that, in addition to singeing off the liber fuzz, a substantial portion of the nylon fibers were fused.
The degree to which fiber bundle penetration could be increased by removing ber fuzz from the back of nylon tufted carpet samples was studied using the l second hot air gun treatment described hereinabove, prior to preheating the carpet and applying the bonding agent. The penetrations obtained for a variety of compositions were compared to the fiber bundle penetration obtained when no fiber fuzz were removed. It was found that fiber bundle penetration increased in an amount of between about l-35% depending upon the composition employed. The results of these tests are set forth in Table III.
5% wax 1 1 A microcrystalline wax having a melting point ot SBZ-83 C.
In lieu of the hot air gun, a Bunsen burner was employed to singe off ber fuzz by playing the ame on the back of the carpet for a period of between about -20 seconds at a distance of between about 3-5 inches. Results were comparable to that obtained when the hot air gun was used.
Example 41 Using apparatus corresponding to that shown in the Drawing, studies were made to determine the effect of pre-heating on liber bundle penetration.
For each study, a standard consisting of a powdered bonding agent comprising 80 percent by weight of resin A and percent by weight resin D was applied to 4" x 4" sections of a nylon tufted carpet until a coating weight of 12 ounces per square yard was obtained. Prior to application of the bonding agent, the carpet sections were pre-heated by a unit consisting of a bank of 10 infrared lamps each having a power of 375 watts which were used to heat carpet surface until it was warm to the touch; namely at a te perature of between about 40-60 C. After the bondi g agent was applied, the coated carpet sections were again heated under l0 infrared lamps of the same power until the bonding agent melted and penetrated the web. The fiber bundle penetrations obtained as well as the effect of pre-heat on time required t0 cause fiber penetration are set forth in Table IV.
TABLE IV Time required Percent fiber to achieve fiber bundle strand penetrapenet-ration tion, seconds Pre-heat time,
Examples 42 In order to provide added body to carpets, various commercially available filler materials were added to the bonding agent of the present invention. Among the filler materials tested were a barium sulfate-based filler consisting of about 98 percent by weight of powdered barium sulfate and having a particle -size of between about 3-40 microns and a specific gravity of about 4.4, a barium sulfate-based filler consisting of about 94 percent by weight of powdered barium sulfate and having a particle size of .between about 55-75 microns and a specific gravity of about 4.3, and a calcium carbonate-based filler consisting of about 98 percent by weight of powdered calcium carbonate and having a particle size of between about 0.3-14 micron-s and a specific gravity of about 2.71. These llers were incorporated into the -bonding agent compositions of the present invention in amounts ranging from between about 5425 percent by weight based upon the total weight of the composition. At these ller concentrations, good results were obtained with both of the ybarium sulfate-based fillers, the lbarium sulfate-based filler ha-ving the smaller particle size exhibiting slightly better characteristics than the one having the larger particle size. Use of the calcium carbonatebased filler, while operable, required an increase in time to fuse the adhesive coating composition and resulted in tufted carpets exhibiting unsatisfactory brittleness.
Example 43 Various commercially available surfactants were also employed to determine if the properties of tuft lock, pill resistance and ber bundle penetration could be irnproved. The surfactants tested included an anionic surfactant comprising a solution of 25 percent by weight sodium heptadecyl sulfate in water, a nonionic surfactant consisting of the reaction product of a nonylphenol and ethylene oxide, and a cationic surfactant comprising a suspension of oleic imidazoline (91% active) and unreacted linear amides. These surfactants -were blended into the bonding agent compositions in amounts ranging from between about 0.2-0.5 percent by weight based on the total weight of the adhesive coating composition. Tests were conducted under similar control conditions as de scribed hereinabove with regard to the fillers wherein tufted carpets were first pre-heated and then not preheated, the fuzzy bers were rst removed by singeing and then `were not removed, and llers were first incorporated in the coating composition and then Were 1 1 omitted. The results obtained revealed that the anionic surfactant employed improved pilling resistance while exhibiting no deleterious etect on tuft lock or brous strand penetration. The nonionic surfactant had no affect on the properties tested While use of the cationic surfactant resulted in poorer pilling resistance.
Example 44 The combined effect of singeing and pre-heating were 12 (c) from to about l5 percent by weight of a wax having a melting point of from about 75 to 95 C. 2. A bonding agent as claimed in claim 1 in Which the ethylene hydrocarbon polymer has a melt index measured at 190 C. and 44 p.s.i. of from about 50 to about 100 dgrnjmin` 3. A bonding agent as claimed in claim 12 in which the hydrocarbon polymer is polyethylene.
4. A bonding agent as claimed in claim 1 in which evaluated on a Continuons Web Coating Unit Which Sub* 1() the ethylene/monounsaturated ester copolymer is selected stantially conformed to the unit schematically shown in from the group Consisting of ethylene/vinyl acetato and the attached drawing. This unit was provided with an ethylene/ethyl acrylato copolymers Containing a major open gas flame singeing zone, a 14.4 kw. radiant pre-heatproportion by Weight polymorzed ethylene. ing zone and a 43.2 kw. radiant heating zone each heat- 5, A bonding agent as Claimed in claim 1 in which the ing Zone operated at UP to 55% of eaPaeitY- The appara' 15 ethylene/ monounsaturated ester copolymer has a melt tllS Was Used in Coating a i2 ineil Wide nyion tufted Web index measured at 190 C. and 44 p.s.i. of from about at a rate of 5 feet per minute. 100 to about 400 dgmJmin.
Three bonding agent Systems Were Studied- 6. A bonding agent composition as claimed in claim 1 Bonding Agent I constituted a blend 0f 72.7 percent in which 3, filler is present in an amount up t0 33 parts -by Weight Resin B, 18.2 percent by weight lResin E and by weight per 10() parts by weight resin 9-1 Peleent by Weight of Iniefoefystaiiine WaX having a 7. A bonding agent as claimed in claim 6 in which the melting point of 188 F. ller is barium sulfate or calcium carbonate.
Bonding Agent II constituted a blend of 76.3 percent 8, A resinous bonding agent comprising, based on the weight Resin B, 19.0 percent lby weight Resin F and 1.9 t0ta1weight 0f the resins from percent by weight of a microcrystalline wax having a (a) about 75 to about 85 percent by Weight of an ethylmelting point of 86-87 C. ene homopolymer having a melt index of from about Bonding Agent Ill constituted a blend of 100 parts by 50 to about 100 dgm./min. measured at 190 C. Weight Bonding Agent H and 25 parts by weight 0f No. and 44 p.s.i. 1 Bleached Barytes. (b) about 15 to about 25 percent by weight of an ethyl- The operating conditions employed and results obene/monounsaturated ester copolymer selected from tained are listed in Table V. the group consisting of ethylene/vinyl acetate and TABLE v Bonding agent 1 1 1 r 1I Il 1I I1 IH III III In Mmierigiiifji No Yes Yes No No Yes Yes No No Yes Yes No Main heating, percent capacit 35 35 35 35 35 35 35 45 45 45 45 Inaboveweb 6.5 6.5 6.5 6.6 4.0 4.0 4.o 4.6 6 6 6 s Nip roll pressure, p.s. 40 40 40 30 30 30 30 g5 25 25 25 Secondary backing No No Yes Yes No I lo Yes Yes No No Yes Yes een at ai at at ai et es es at as friiircteiiiciaiigsgll111111111 21421 24.0 14.1 16.8 23.9 21.9 19,3 16.7 23.7 23.5 16.6 14.9
Although the bond agent compositions universally gave about 100% brous strand penetration, adding the singe- 4 ing step actually improved overall pilling resistance. The reduction in tuft lock when a secondary backing was used was attributed to allocation of part of the available bonding agent to bond the scrirn to the web. Note, however, that the presence of a secondary scrim did not affect iibrous strand penetration.
When independently evaluated using subjective but industry accepted pilling rating tests, tufted nylon carpet and rug samples produced using the method and compositions of the invention were rated from good to excellent. A carpet or rug having a good rating is considered to be merchantable.
What is claimed is:
1. A resinous bonding agent which comprises, based on the total weight of the resin from (a) about 70 to about 90 percent by weight of an ethylene hydrocarbon polymer having a melt index measured at 44 p.s.i. and 190 C. of less than about 150 dgm./min. which polymer is composed of lowerallrene,
(b) about 10 to about 30 percent by Weight of an ethylene/monounsaturated ester copolymer having a melt index measured at 44 p.s.i. and 190 C. greater than about 100 dgrrL/min., which copolymer contains greater than by Weight polymerized ethylene,
ethylene/ ethyl acrylate copolymers having a melt index of from about 100 to about 400 dgm./min. measured at 190 C. and 44 p.s.i.
(c) about 0 to about 10 percent by weight of a microcrystalline wax having a melting point of from about to about 95 C.
9. A resinous bonding agent as claimed in claim 8 in which a ller is present in an amount up to 33 parts by Weight per parts by weight resinous bonding agent.
10. A resinous bonding agent as claimed in claim 9 in which the iiller is barium sulfate or calcium carbonate.
References Cited UNITED STATES PATENTS 3,201,498 8/1965 Brunson 260--897 B 3,218,373 11/ 1965 Salyer 260-897 B 3,275,494 9/ 1966 Brunson 260-897 B 3,318,977 5/ 1967 Battersby 260-897 B 3,399,250 8/ 1968 Kirk 260-897 B 3,485,784 12/ 1969 Waples 260-28.5 AV 3,489,824 1/1970 Anspon 260-89-7 B MORRIS LIEBMAN, Primary Examiner P. R. MICHL, Assistant Examiner U.S. Cl. X. R.
117-1388 A; 161-66; 260-28.5 AV, 4l R, 897 B Patent No. 3,645 ,949 Dated Feblllaly 29, 1972 Inventods) Fred J. Crim 1t is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:
Column Z, line 33, "tilted" should read ftufted line 35, insert the after "be1ow"; line 48, "fiber",
second occurrence, should read fibers Column 4, line 13,
after "ene" inSert propylene Column 8, line 11, under "Example .35, relativeto'- "Tuft lock, 1b's.", "21.1." should read 21.2 Co1umn'9, line 10, "signed" should read snged A Column 10, line 28, "Examples" should read Example Column ll, line 23, insert by after "percent". Column l2, v line 7, in claim 3, "claim lZ"lshou1d read 'claim 2 I Signed and sealed this 7th day of January 1975.
cCOY FI. GIBSON JE. C. MARSHALL, .DANN L ttesting Officer Commissioner of Patents F ORM PO-1050 (ID-69) USCOMM-DC 60376-P89 us. GOVERNMENT PRINTING orFxcE: 869. 930