NZ243405A - Penetrable fabric backing material comprising silica fabric and impregnated with lubricant - Google Patents

Description

New Zealand Paient Spedficaiion for Paient Number £43405 243405 Priority C..

Cu.icicle C, „ i,."'. ':c:i J: . l\ Cla«?s: //. fi?f,?.iy\i3 j .•.?*?? ;Ph(. n, 22 DEC 1994 ;Publication Data: ;P.O. Jcn-nrA f::: . .Ah*7). 3 ' Wih»iiirtud NEW ZEALAND PATENTS ACT, 1953 No.: Date: COMPLETE SPECIFICATION N.Z. PATENT C -1 JUL 1S92 RLx'diVuD NEW AND IMPROVED BACKING FOR CARPETS AND THE LIKE FELTEX MOD0LAR CARPETS PTY. LTD., an Australian company, of 15th Floor 390 St. Kilda Road, Melbourne, Victoria, Australia hereby declare the invention for which i"7 we pray that a patent may be granted to me/us, and the method by which it is to be performed, to be particularly described in and by the following statement: - (followed by page la) 243405 - 1Q- NEW AND IMPROVED BACKING FOR CARPETS AND THE LIKE This invention relates to a fabric backing suitable for use in manufacturing tufted textile materials such as carpets and in particular carpet tiles. 5 The present invention will be discussed in reference to carpets and carpet tiles. However, the principles are equally applicable to other tufted textile materials such as fabrics used in wall coverings/ seat coverings and the like, as will be 10 appreciated. The invention should not be taken as restricted to its application to carpets and carpet tiles.

A large number of carpet tiles are sold each year. They are generally comprised by a thermoplastic 15 backing into which the carpet yarn such as wool is tufted. Traditional thermoplastic backings include polypropylene or polyester fibres which can be in the form of solid sheets or woven material but generally are comprised of a non-woven random layered web of 20 thermoplastic material partially melted to provide a backing sheet material.

Needles are used to force the yarn through the thermoplastic backing.

It is common then to apply a support layer 25 comprised of fibreglass in the form of a non-woven random layered sheet. The fibreglass sheet is generally coated with a binding material such as a polyvinylchloride resin or the like. The carpet is then cut into tiles.

It has been found that carpet tiles so produced tend to lift at the edges particularly after printing. The edges curl upwards to make the floor unattractive and the tiles unacceptable. It has been practice to apply adhesive to keep the tiles flat to the 35 floor. Similar problems arise with other tufted fabrics.

In the past it has been practice to deform carpet tiles mechanically to stretch the backing layer thereby to keep the tile flat. This is a labour 24 3 4 05 intensive procedure and even so does not prevent sufficiently the tendency of the tile edges to lift.

Over the years many attempts have been made to solve the problems believed to be inherent in the 5 manufacture of tufted fabrics but without success.

The present invention provides a fabric backing for tufted textile materials such as carpet tiles and other carpets that allows for the manufacture of tufted products that have acceptable dimensional 10 stability and flatness such that for example the carpet can be laid onto floors without the need for adhesives.

The invention is based on the realisation that the penetration of the thermoplastic backing material by tufting needles introduces dimensional instability into 15 the backing causing shrinkage to occur during subsequent processing. The invention provides a construction where this effect is minimized or avoided.

The present invention provides a penetrable fabric backing material comprising a woven silica fabric 20 having warp and weft threads, said fabric being impregnated with a lubricant comprising a stabilising amount of polyacrylic or polyacrylate resin, whereby to bind said warp and weft threads to stabilize said woven fabric and allow penetration by needles during a tufting 25 process while said fabric remains sufficiently flexible to allow it to pass around rollers in a manufacturing process.

According to the present invention a carpet construction includes a carpet backing comprised of a 30 woven silica fabric, at least relatively dimensionally stable when penetrated by needles during the tufting process. Preferably the woven silica fabric is a woven fibreglass fabric. The fibreglass fabric may be comprised of a fabric woven with multifilament 35 fibreglass thread. The thread may be between 40 and 80 tex. A 66 tex fibreglass thread has been found particularly satisfactory as has a fabric woven with a double weft and single warp thread. 24 34 05 A single warp and weft woven construction has been found particularly satisfactory, although it should be appreciated that more complex warp and weft thread constructions may be employed. For example, 2x2 and 3 5 x 3 warp and weft constructions have been found to be satisfactory.

It has been found that a thread density of between 7 and 5 threads per centimeter, that is between about 17.5 and 12.5 threads per inch both warp and weft provides a suitable thread density. It has been found that if the thread density is too high there is an increased possibility of needle damage and yarn breakage but that if the thread density is too low there may be insufficient strength in the backing material. 15 It has also been found that a woven weight of between 80 and 150 grams per square metre is satisfactory and in one example a woven weight of about 110 grams per square metre has proven particularly satisfactory.

More than one layer of woven fibreglass material may be employed as the carpet backing as will be appreciated by those skilled in the art. Additional layers provide additional strength where this may be needed although it will be appreciated that a single 25 layer of woven fibreglass material is satisfactory in most applications.

The backing of the present invention is impregnated with a stabilising amount of an acrylic material. Any suitable polymeric or mixture of 30 polymeric materials may be used provided it will stabilize the fibreglass material while remaining sufficiently flexible for the material to pass around rollers during manufacture and penatrable to allow tufting needs to pass through it. Commercially 35 available "acrylic" mixes are suitable for this purpose and are sufficiently stable at processing temperatures. It is important to note that impregnation occurs and a coating layer is not produced as would result if 24 3 405 non-solubilised materials such as polyvinylchloride were used.

The acrylic mix may include one or more acrylic polymers or copolymers of acrylic acid, and 5 acrylic acid esters such as butyl acrylate, ethyl acrylate or methyl methacrylate for example. The polymers preferably have a molecular weight of between 50,000 and 250,000 and a viscosity in the range of from 50 to 1000 CPS. A surfactant may be included to provide 10 increased penetration of the material into the material of the fabric. A filler such as calcium carbonate may be included if desired.

The polymeric material is preferably in solution or emulsified. An aqueous emulsion has been 15 found to be particularly suitable in providing impregnation or penetration of fibreglass filaments.

A suitable material available commercially is PRIMAL TR 407 manufactured by Rohm & Haas sold as a 45% solids aqueous emulsion.

The stabilising polymeric material may be applied by passing the woven fibreglass material through a bath containing the stabilising polymeric mixture to obtain a satisfactory impregnation. However other application methods have been found to be satisfactory. 25 It has been found that the carpet backing of the present invention remains sufficiently flexible for the tufting needles to penetrate the backing without ripping the fibres. The material is able to pass around rollers and be separable when cut into carpet strips or 30 tile shapes. It is also thermally stable at processing temperatures employed in the carpet tile manufacturing processes.

The impregnated backing of the present invention provides a suitable backing for carpet 35 manufacture. Using the standard tufting machine a continuous width of backing may be tufted with carpet yarn which may be comprised by wool or synthetic material or a combination of wool and synthetic m^e^ial ■ i #0 2 1 JUWj993 n J z 4 3 4 0 5 for example. The tufting needles easily penetrate the backing of the present invention. A 1.9 metre wide tufting machine has been used with success.

The tufted backing may then have applied to it 5 a binding coating layer which may be comprised for example by a polyvinylchloride layer or other binding layer which binds the tufted yarn to the backing material. Suitable binding layers include polyvinylchloride preferably in the form of a 10 plastisol. With the backing of the present invention it is possible to use a polyvinylchloride mixture of lower quality, than was previously employed. This is possible because greater tension may be applied to the carpet thereby to increase the penetration of the binding layer. !5 A support layer may be applied. The support layer may include a fibreglass material such as a non-woven random layered fibreglass sheet bound with an acrylic resin as is known in the art. A further coating of a binding layer may be applied thereto to complete 20 the carpet construction.

Thus, in a preferred method of construction the backing of the present invention is tufted in a tufting machine to form a carpet strip. In a treatment machine a binding layer is applied to a support backing, 25 a support layer is applied to the binding layer as it passes therethrough, a further binding layer is applied to the support layer and then the carpet strip applied thereto with the backing adjacent the binding layer. The laminated strip then passed to an oven for curing. 30 Subsequently, the carpet strip may be cut into carpet strips or tile shapes as desired and printed by dyeing processes as is known in the art.

In one example of the present invention a 66 tex multifilament glass fibre was woven in a one by one 35 warp and weft construction to produce a woven fibreglass material having a thread density of between 5 and 7 threads per centimetre in the warp and weft direction and a woven weight of about 109 grams per square metre.

Claims (16)

£4 34 0 - 6 - It was cut into a strip having a width of 1.9 metre. The fibreglass fabric was dipped through an impregnation bath containing a PRIMAL TR 407 being a 45% solids aqueous emulsion. The impregnated fibreglass backing 5 was then cured and formed into a backing roll. The backing roll was then mounted onto a standard tufting machine. It was found that the backing material was particularly suitable for use in the standard tufting machine and a tufted carpet strip 10 produced. In the manner hereinbefore outlined a binding layer and support layer structure was produced in which the binding layer comprised polyvinylchloride and plastisol. The viscosity was 5000 cps (Brookfield). 15 The support layer comprised a non-woven fibreglass material. The laminated structure was cured in a curing oven. After cooling the carpet strip was cut into carpet tiles and printed using standard dyeing 20 procedures. The carpet tiles so produced were placed onto a floor following standard procedures. It was found there was no tendency for the edges to raise and the carpet tile structure gave the appearance of a non-tiled 25 carpet structure. It was found that at the edges of the carpet tile there was no fraying and ends or threads of fibreglass material were not evident. Thus, in accordance with the present invention it is possible to produce a tufted carpet tile structure 30 which is dimensionally stable and which can be placed onto floors using standard procedures without risk of raising of carpet tile edges and fraying. It will be appreciated that many variations and modifications may be made to the above described 35 construction, and choices of materials may be varied, without departing from the ambit of the present invention. 243405 WHAT /x CLAIMS i LA!M IS 7

1. A penetrable fabric backing material comprising a woven silica fabric having warp and weft threads, said fabric being impregnated with a lubricant 5 comprising a stabilising amount of polyacrylic or polyacrylate resin, whereby to bind said warp and weft threads to stabilize said woven fabric to allow penetration by needles during a tufting process while said fabric remains sufficiently flexible to allow it to 10 pass around rollers in a manufacturing process.

2. A fabric as claimed in claim 1, wherein said fabric is a woven fibreglass fabric.

3. A fabric as claimed in claim 2, wherein said fabric is comprised of woven fibreglass thread of 15 between 40 and 80 tex.

4. A fabric as claimed in claim 3, wherein said fabric is of a single warp and single weft construction.

5. A fabric as claimed in any one of claims 2 to 4, wherein said fabric has a thread density of between 5 20 and 7 threads per centimetre, warp and weft and a woven weight of between 80 and 150 grams per square metre.

6. A fabric as claimed in any preceding claim, wherein an aqueous emulsion of resin is employed.

7. A fabric as claimed in any preceding claim, 25 wherein said resin is one or more polymer or copolymer of acrylic acid, an acrylic acid ester or methacrylic acid ester.

8. A fabric as claimed in claim 7, wherein said polymer or copolymer has a molecular weight of between 30 50,000 and 250,000 and a viscosity in the range of from 50 to 100 cps.

9. A tufted textile material for carpet manufacture including a fabric backing as claimed in any preceding claim, tufted with yarn using tufting needles, a support layer 35 and a binding layer therebetween.

10. A textile material as claimed in wherein said support layer is a fibreglass. 24 3 4 0 5 10 - 8 -

11. A textile material as claimed in claim 9 or claim 10 wherein said binding layer is a polyvinylchloride binding layer.

12. A carpet comprised of a tufted textile material as claimed in any one of claims 9 to 11 in the form of a carpet strip.

13. A carpet comprised of a tufted textile material as claimed in any one of claims 9 to 11 in the form of a carpet tile.

14. A penetrable fabric backing material when constructed, arranged and operable substantially as herein described with reference to any example thereof.

15. A tufted textile material when constructed, arranged and operable substantially as herein described with reference to any example thereof.

16. A carpet when constructed, arranged and operable substantially as herein described with reference to any example thereof. DATED THIS DAY OFTOUUca 19c=~^ A.J. PARK & SON ^ PER AGcNTS FOR THE APPLICANTS