US3457135A - Method for preparing woven carpets and the carpets produced therefrom - Google Patents

Description

United States Patent 3,457,135 METHOD FOR PREPARING WOVEN CARPETS AND THE CARPETS PRODUCED THEREFROM Edward Peter Campbell Sington, Saffron Walden, England, assignor to Revertex Ltd., London, England, a British corporation No Drawing. Filed Feb. 3, 1966, Ser. No. 524,841 Claims priority, application Great Britain, Feb. 5, 1965, 5,183/65 Int. Cl. D04h 11/00 US. Cl. 161-66 9 Claims ABSTRACT OF THE DISCLOSURE A method for making a carpet having pile yarn interwoven with and adhesively bonded to a woven backing comprising the steps of weaving a backing from backing threads, selected backing threads being wet and impregnated with an aqueous adhesive, and thereafter interweaving pile yarn into the woven backing; the adhesive serving to bond the pile yarn to the woven backing upon drying and during interweaving thereof.

This invention relates to the preparation of pile carpets and the like tufted woven articles having improved porosity, stiffness, tuft-lock and other properties. In particular, this invention relates to a method for making pile carpets such as Wilton and Axminster carpets by adhesively bonding the pile tufts or yarns and selected wet backing threads together during weaving of the carpets and to the improved carpets made thereby.

Heretofore, the manufacturers of carpets have often employed an additional bonding material for the pile tufts in the form of a continuous coating or layer of adhesive such as latex, thermoplastic resin and/or thermosetting resin which has been applied to the back of the already woven carpet. In this manner the continuous layer of adhesive bonds simultaneously to the bi'ghts or hidden ends of the pile tuft yarns and to the woven backing fabric. The coating is usually sprayed or otherwise applied to the back side of the backing fabric as an emulsion, solution, or melt after the carpet has been woven and the pile yarn has been cut; with the surplus adhesive material being scraped off the back of the carpet by a doctor blade or other similar type device and then dried. It will be appreciated that when using this technique, the adhesiv material acts to fill in all of the interstices of the backing fabric and destroys the natural porosity of the carpet.

Furthermore, it is often difiicult, particularly with dense carpet to insure that the adhesive penetrates sufficiently into the backing fabric to anchor the pile tufts of the carpet. Thus, excessive quantities of adhesives, such as rubbery latex and/or special coating techniques are often required to produce the stiffness and tuft-locking necessary for a satisfactory carpet.

In order to overcome many of the difficulties of the prior art, this invention contemplates making a carpet having pile yarn interwoven with and adhesively bonded to a Woven backing by weaving the backing from a plurality of backing threads with selected backing threads being wet and impregnated with an aqueous adhesive and by interweaving pile yarn into said woven backing; the adhesive bonding the pile yarn to the selected backing threads upon drying and during interweaving of the pile yarns whereby the resulting carpet has improved stiffness, tuft-lock and other desirable properties.

More particularly, this invention is directed to a method for weaving carpets which comprises impregnating selected backing threads, preferably, the Weft threads, and

3,457,135 Patented July 22, 1969 in some cases both the weft and warp threads, with a water dispersible adhesive until the threads are substantially saturated therewith, storing the impregnated threads in a wet condition until needed, interweaving the wet selected backing threads, pile yarns and any other backing threads to form a carpet or two backing fabrics interconnected by the pile yarns, with the adhesive concurrently drying during interweaving of the pile yarns to bond the yarns to the selected backing threads.

The backing threads as well as the pile yarns are usually made of a multiplicity of individual fibers or filaments twisted together to form weaveable yarns, threads, or strands. Pile yarns are made of the more expensivetype materials, e.g., wool, the acrylic fibers, nylon, and the like, and are usually loosely twisted; whereas the backing threads are made of carpet rayon, cotton, Kraftcord, jute, and the like, and are usually twisted more tightly together than the pile yarns.

Suitable aqueous or water dispersible adhesive for the present invention include air-drying and air-hardening synthetic and natural adhesives, all of which must be water-soluble or emulsifiable in water. Examples of suitable adhesives include polyvinyl acetate, copolymers of vinyl acetate with other ethylenically unsaturated monomers, e.g., styrene, vinyl chloride and the like, carboxylated polyvinyl acetate resin; e.g., a copolymer of vinyl acetate and an acrylic acid, vinyl esters, polyvinyl alcohol, acrylic resins, bone glue, casein and the like; the carboxylated polyvinyl acetate resins being particularly effective adhesives. Also, in some cases, aqueous emulsions or latices of polymeric materials such as carboxylated styrene butadiene copolymers containing a high proportion of styrene, i.e., above about 70% by weight, other butadiene copolymers and natural rubber latices may be used as adhesives.

As noted above, the backing threads selected to be woven wet are preferably the weft threads. Advantageously, the weft thread can be impregnated either before, during or after the thread is wound into a cop or cone. When the wet cop is prepared before it is needed in the weaving operation, it is stored in the wet state, for example, in a polyethylene bag or in a wet blanket.

A cop of weft thread may be impregnated by immersing it into a solution of adhesive and heating it in an autoclave for about 15 minutes at about 15 p.s.i.g. to insure substantially complete saturation of the cop with the adhesive. After being saturated with the adhesive, the cop is then placed in a bag made of polyethylene or like material to cool so that it may be used as desired for weaving of the carpet.

It will be appreciated that the cop of weft thread may be impregnated by other methods, e.-g., by a percolation technique or the like, just as long as the cop is thoroughly saturated with the aqueous adhesive.

It will be appreciated that the weft threads may also be impregnated with the aqueous adhesive as a single thread or strand just after leaving a cop and prior to the weaving operation by being immersed in a bath of the adhesive. Advantageously, impregnation of the weft is preferably effected while it is wound into a cop. This practice insures that the weft threads are completely saturated with the adhesive prior to weaving, provides a large bulk or mass of thread that facilitates maintaining the thread in a wet state, thereby preventing premature drying or hardening of the adhesive (both in storage and in use), and also avoids any carry-over of an excess of aqueous adhesive that may fall off the thread onto the other yarns or onto the weaving loom itself.

-It will be appreciated that during weaving of the carpet, which may be etfected on a variety of conventional weaving apparatus, the aqueous adhesive is sorbed by the other threads and yarns in contact with the wet threads and is placed at those points in the carpet where additional bonding is needed so that improved stiifness and tuft-lock properties can be obtained using substantially less adhesive material than by applying a layer or coating of adhesive material onto the back side of an already woven carpet. Furthermore, by the time the weft threads have been interwoven with the other threads and yarns in the carpet, the aqueous adhesive is beginning to air-dry and to air-harden, thereby eifecting bonding of the carpet without any additional drying operation.

It will be understood that adhesive bonding of the carpets produced in accordance with this invention can be further accelerated by heating the carpets in an oven at temperatures of about 120 C. or higher for a few minutes, by passing the carpets under a bank of heating lamps, by blowing heated air over them or by other known conventional methods of drying.

The method of this invention and the improved carpets made thereby, are more specifically described in the following examples which are illustrative of the invention:

EXAMPLE 1 A cop of jute yarn was immersed in an aqueous 10% colloidal solution of a carboxylated polyvinyl acetate resin dissolved in sufiicient sodium hydroxide to render the resin water-soluble. The cop was then heated in an autoclave for 15 minutes at 15 p.s.i.g. This treatment resulted in a pick-up of 75 parts of solution per hundred parts of dry jute yarn, i.e., a pick-up of 7.5% of resin based on the dry yarn. The cop was then packed in a polyethylene bag, cooled and stored wet until it was ready for use.

The wet cop was then employed to form the weft of a Wilton carpet produced from wooden pile yarns on a loom with a setting that employed 0.7 pound jute weft (dry) per square yard of carpet. When dry, the resulting carpet contained about 0.84 ounce of dry resin per square yard and had a stiffness which was approximately equal to that obtained by applying suflicient resin to result in a pick-up of 2 /2 to 3 ounces of dry resin per square yard of carpet to the back of a dry woven Wilton carpet by a conventional licker roll technique.

The tuft-lock of the carpet made by the present method was also improved over that of the conventional carpet to an extent which could not be obtained by applying resin by the licker roller technique unless considerably more than 2 /2 to 3 ounces per square yard of dry resin were applied.

EXAMPLE 2 Following the procedure outlined in Example 1, a carpet is made by using a cop of jute yarn impregnated with a 10% aqueous solution of 99% hydrolyzed polyvinyl alcohol resin having a viscosity of 5 centipoises at a concentration of 4% in water and at a temperature of 25 C.

Testing of the resulting carpet shows that it also has improved stiffness and tuft-lock over a carpet produced by the conventional licker roll technique.

'EXAMPLE 3 A prevulcanized ammoniated natural rubber latex was impregnated onto jute yarn immediately prior to weaving the yarn into an Axminster carpet to give an application of dry rubber equivalent to (a) 3.9 ounces per square yard of carpet and (b) 10.4 ounces per square yard. No special drying was required. The force required to remove a single tuft from the carpet was found to be 1.13 pounds in (a) and 6.11 pounds in (b).

Similarly, evaporated ammoniated natural rubber latex was impregnated onto jute yarn at an applied dry rubber weight of (c) 5.4 ounces per square yard and (d) 10.6 ounces per square yard. The force required to remove a single tuft from the carpet was 1.6 pounds (c) and 5.51 pounds in (d).

Thus, it will be seen from the above examples that the method of this invention produces carpets having improved stiffness and tuft-lock and that the amount of adhesive material loaded into the wet saturated backing threads substantially affects the tuft-lock obtained.

While the novel aspects of the invention have been exemplified and described and are pointed out in the appended claims, it is to be understood that various modifications and alterations in the method for making improved woven carpets may be made by those skilled in the art without departing from the spirit and scope of the invention.

What is claimed is:

1. A carpet having pile yam interwoven with and adhesively bonded to a woven backing which comprises a backing woven from a plurality of backing threads with selected backing threads being wet and impregnated with an aqueous adhesive and pile yarn interwoven into said woven backing, said pile yarn being bonded to the woven backing by said adhesive upon drying and during interweaving with said backing whereby said carpet exhibits improved stiffness and tuft-lock.

2. A method for making a carpet having pile yarn interwoven with and adhesively bonded to a woven backing, which comprises weaving said backing from a plurality of backing threads, selected backing threads being wet and impregnated with an aqueous adhesive, and interweaving pile yarn into said woven backing, said adhesive bonding said pile yarn to the woven backing upon drying and during interweaving thereof where-by improved stiifness and tuft-lock is imparted to the resulting carpet.

3. The method of claim 2 in which said selected backing threads are the weft threads of the carpet.

4. The method of claim 2 in which said aqueous adhesive is selected from the group consisting of watersoluble and water-emulsifiable adhesive materials.

5. The method of claim 2 in which said aqueous adhesive is impregnated onto a selected backing thread when the thread is wound into a cop.

- 6. The method of claim 5 in which the cop is impregnated with the aqueous adhesive by immersing it into solution of adhesive and heating it in an autoclave for about 15 minutes at about 15 p.s.i.g. to insure substantially complete saturation 'of the cop with the adhesive.

7. The method of claim 2 in which a selected backing thread is impregnated with the aqueous adhesive just after unwinding from a cop and before weaving of the backing.

8. The method of claim 2 in which a selected backing thread is saturated with an aqueous adhesive and stored wet before being used to weave the backing material.

9. The method of claim 2 in which said resulting carpet is further dried to accelerate bonding of said adhesive material by the application of heat.

References Cited UNITED STATES PATENTS 2,809,909 10/ 1957 Chatanay l5672 X 3,285,797 11/1966 Harrison et al. 15672 X 3,390,036 6/1968' Wright et a1 156-93 3,390,037 6/ 1968 Christie 156-448 HAROLD ANSHER, Primary Examiner US. Cl. X.R.