NEW AND IMPROVED BACKING FOR CARPETS AND THE LIKE

Abstract: A fabric backing which may be used in manufacturing tufted carpets, which is comprised of woven silica fibres impregnated with a stabilising amount of acrylic resin which can be penetrated by needles during tufting and retain its dimensional stability.

Description: 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. 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 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 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 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 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 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 intensive procedure and even so does not preven sufficiently the tendency of the tile edges to lift. Over the years many attempts have been made t solve the problems believed to be inherent in th manufacture of tufted fabrics but without success. The present invention provides a fabri backing for tufted textile materials such as carpe tiles and other carpets that allows for the manufactur of tufted products that have acceptable dimensiona stability and flatness such that for example the carpe can be laid onto floors without the need for adhesives. The invention is based on the realisation tha the penetration of the thermoplastic backing material b tufting needles introduces dimensional instability into 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 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 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 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 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. 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, 2 2 and 3 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. 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 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 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 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 non-solubilised materials such as polyvinylchloride we used. The acrylic mix may include one or mor acrylic polymers or copolymers of acrylic acid, an acrylic acid ester such as butyl acrylate, ethy acrylate or methyl methacrylate for example. Th polymers preferably have a molecular weight of betwee 50,000 and 250,000 and a viscosity in the range of fro 50 to 1000 CPS. A surfactant may be included to provid increased penetration of the material into the materia of the fabric. A filler such as calcium carbonate ma be included if desired. The polymeric material is preferably i solution or emulsified. An aqueous emulsion has bee found to be particularly suitable in providin impregnation or penetration of fibreglass filaments. A suitable material available commercially i PRIMAL TR 407 manufactured by Rohm & Haas sold as a 45 solids aqueous emulsion. The stabilising polymeric material may b applied by passing the woven fibreglass material throug a bath containing the stabilising polymeric mixture t obtain a satisfactory impregnation. However other application methods have been found to be satisfactory. 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 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 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 material 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 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 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. 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 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, 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. 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 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. It was cut into a strip having a width of 1.9 metr The fibreglass fabric was dipped through an impregnati bath containing a PRIMAL TR 407 being a 45% soli aqueous emulsion. The impregnated fibreglass backi was then cured and formed into a backing roll. The backing roll was then mounted onto standard tufting machine. It was found that the backi material was particularly suitable for use in t standard tufting machine and a tufted carpet stri produced. In the manner hereinbefore outlined a bindin layer and support layer structure was produced in whic the binding layer comprised polyvinylchloride an plastisol." The viscosity was 5000 cps (Brookfield) . The support layer comprised a non-wove fibreglass material. The laminated structure was cured in a curin oven. After cooling the carpet strip was cut int carpet tiles and printed using standard dyein procedures . The carpet tiles so produced were placed ont a floor following standard procedures. It was foun there was no tendency for the edges to raise and th carpet tile structure gave the appearance of a non-tile carpet structure. It was found that at the edges of th carpet tile there was no fraying and ends or threads o fibreglass material were not evident. Thus, in accordance with the present inventio it is possible to produce a tufted carpet tile structur which is dimensionally stable and which can be place 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 construction, and choices of materials may be varied, without departing from the ambit of the present invention.

Claims: CLAIMS: 1. A penetrable fabric backing material comprising a woven silica fabric 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 to allow penetration by needles during a tufting process while said fabric remains sufficiently flexible to allow it to 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 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 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, 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 50,000 and 250,000 and a viscosity in the range of from 50 to 100 cps. 9. A tufted textile material including including a fabric backing as claimed in any preceding claim, - ' tufted with yarn using tufting needles, a support layer and a binding layer therebetween. 10. A textile material as claimed in claim 9, wherein said support layer is a web of non-woven fibreglass. 11. A textile material as claimed in claim 9 o claim 10 wherein said binding layer is polyvinylchloride binding layer. 12. A carpet comprised of a tufted textil material as claimed in any one of claims 9 to 11 in th form of a carpet strip. 13. A carpet comprised of a tufted textil material as claimed in any one of claims 9 to 11 in th form of a carpet tile.

Inventors: BLOOD ROY HAROLD, DEVLIN PATRICK, MURRAY PETER JOHN, BLOOD, ROY, HAROLD, DEVLIN, PATRICK, MURRAY, PETER, JOHN
Applicants: FELTEX MODULAR CARPETS PTY LTD, FELTEX MODULAR CARPETS PTY. LTD.
Application year: 1992
Main classification: D06M15
IPC codes: D03D15, D05C17, D06M15, D06M101, D06N7