Title of Invention	NEW POLYMER SHEET,METHOD THEREOF AND METHOD OF BACKING CARPET OR SUCH THICK FABRIC MATERIAL WITH THE SAME.
Abstract	A NEW POLYMER SHEET AND METHOD OF BACKING A CARPET OR SUCH THICK MATERIAL WITH THE SAID POLYMER SHEET WHEREIN THE POLYMER SHEET COMPRISES ETHYL VINYL ACETATE (EVA) OR POLYMER CHOLRIDE (PVC)OR BLEND OF EVA AND PVC TOGETHER WITH A FILER MATERIAL. THE POLYMER SHEET IS BACKED ON THE CARPET OR SUCH THICK MATERIAL BY HOT PRESSING THE POLYMER SHEET IN A HEATING CHAMBER ON A HEATING PLATE.

Full Text

The present invention relates to a new polymer sheet, method thereof and a method of backing carpet or such thick fabric materials with the said polymer sheet. More particularly the invention relates to a new polymer sheet and to a method for improved backing of carpet or such thick fabric materials with the new polymer sheet thereby improving the durability and aesthetic aspect of the carpet. According to the prior practice, backing of carpet or such thick fabric materials is done by bonding multiple backing textile fabrics with chemical coating such as latext which is a rubber compound comprising ingredients like adhesive, fillers( which includes zinc oxide, chalk powder, sulpher powder, titanium dioxide, sodium hexametaphospate, etc.), preservative( zinc, pentaclorophenol or such compounds) and other chemicals. However the formulation of latex and its manual application for bonding multiple backing textile fabrics is hazardous, toxic and the process is time consuming and drudgery. The tufts of carpet or such type of thick fabric project upward on the face of fabric and provide comfort to foot and or aesthetic look. Such tufts are formed over a yarn or group of yarns of a warp beam or over a yarn or group of yarn of a Primary fabric of desired material and construction. Commonly used materials are cotton yarn/silk yarn/blended yarn and fabrics of cotton & jute. The tufts formed over yarn or fabric results formation of a thick fabric known as Carpet. Such carpets/thick fabrics, irrespective of manufacturing method, are used for purposes like floor covering, wall hanging, upholsteries, furnishings, etc., after the backing process which in many cases like tufting, involves secondary backing followed by third backing using different type of fabrics and chemicals as per the requirement to enhance the tuft withdrawl force cum durability and also enhances the aesthetic appeal of the carpet. Presently used technique for backing involves using of two series of backing fabrics (net fabric and dosuti/Matt or Hessian) which are fixed by chemicals, such as Latex, for both the backing surfaces, followed by stretching and drying of the backing surfaces. All the operations are either carried out mechanically or manually (fully or partially). The feed back reveals that the receipe and or operation as mentioned above does not meet the requirement in many cases. The backing techniques in practice are not user friendly. The drawbacks of the presently used methods are: (i) Chemicals used for the backing, requires in heavy quantity and poses problem for material handling. (ii) Use of such chemicals in higher does is hazardous either from the process and or product point of view. (iii) Most chemical formulation demands addition of preservative/pesticide which is another problem with respect to eco-norms. (iv) Poor availability of net fabric and problem in handling. One aspect of the present invention is to produce a new polymer sheet which is used for backing carpet or such thick fabric materials. Another aspect of the present invention is a method for backing carpet or such thick fabric material with the said new polymer sheet. According to the present invention there is provided: New polymer sheet comprising Ethyl Vinyl Acetate(EVA) or Polyvinyl Chloride(PVC) or blend of Ethyl Vinyl Acetate and Polyvinyl Chloride and filler materials. The invention is now described in details with reference to the accompanying drawings. Fig. 1 shows a heating chamber for heating the new polymer sheet and backing the carpet or such thick fabric with said sheet. The new polymer sheet is prepared, from Ethyl vinyl Acetate (EVA) or Polyvinyl Chloride (PVC) Or blends of both EVA and PVC are mixed with filler materials to form the new polymer sheet. The filler material used is one or more of the materials selected from chalk powder, zinc powder or talc. The filler material content in the polymer sheet is 18 ± 12 % of the final composition. The content of EVA or PVC or blend of both in the polymer sheet is 70 to 80 % of the final composition. The EVA or PVC granuales or blends of both are mixed with filler materials in a homogeniser at a temperature between 70 deg. C to 120 deg. C until the mixture is mixed homogeniously and forms a viscous pasty material. This pasty material is extruded and hot pressed and subsequently cooled in atmosphere or by a blower to form the new polmer sheet. The new polymer sheet so formed have the following physical characteristics : Specific Gravity : 1.3 ± 0.2 Ash content(in %) for EVA : 23 ± 4 PVC : 0.03 ± 0.01 Acetone Extract(in %) for EVA : 23 ± 4 PVC : 35 ± 10 Melting Point : 75 ± 10 deg.C The carpet 1 or such thick fabric material is layed upside down on a platform 5, such that the top surface of the carpet rests on the platform and back surface is on the top. On the back surface of the carpet , the new polymer sheet 2 is layed. On top of the polymer sheet, if necessary , textile backing(TB) 3 is also layed in a single or multiple layer depending upon the requirement for forming the backing sheet. The platform alongwith carpet, new polymer sheet and textile backing is inserted into the heating chamber 6. The heat plate 4 of the heat chamber, is heated by an electrical heating coil( 240 V, 500W ) until the temperature of the heat plate rises to 130 to 280 deg. C. The heated heat plate is brought in contact with the polymer sheet until it initiates melting of the polymer sheet. The temperature of the plate is monitored by a digital thermocouple. The heated heat plate, which xs in contact with polymer sheet, presses the polymer sheet by a pneumatic system or a counter load system at an average pressure of 2 to 8 kg/sq.cm for a period of open time 30-120 sec. for backing the carpet or such thick fabric material with the new polymer sheet. The composite material of new polymer sheet and carpet or such thick fabric material is passed through a pair of rollers, which may be manually driven or self driven, to ensure uniform bondage of the new polymer sheet and textile backing tnaterxal on to the carpet or such thick fabric material and also ensuring that the bonded carpet is properly selvedged. The carpet backed with the new polymer sheet is removed from the heat chamber and kept in open air and allowed to be cooled for atleast an hour. The carpet or such thick fabric material is finally backed with the new polymer sheet. It is evident that the steps of the method of backing the carpet may be modified in order to obtain the same result without departing from the scope of the invention. I CLAIM 1. New polymer sheet comprising Ethyl Vinyl Acetate(EVA) or Polyvinyl Chloride(PVC) or blend of Ethyl Vinyl Acetate and Polyvinyl Chloride and filler materials. 2. New polymer sheet as claimed in claim 1 wherein filler materials is one or more selected from chalk powder, zinc oxide or talc. 3. New polymer sheet as claimed in claim 1 wherein Ethyl vinyl acetate is 70 to 80 weight% of the final composition of polymer sheet. 4. New polymer sheet as claimed in claim 1 wherein polyvinyl chloride is 70 to 80 weight% of the final composition of polymer sheet. 5. New polymer sheet as claimed in claim 1 wherein the filler materials content is 18 ± 12 weight% of the final composition. 6. Method of preparing the new polymer sheet as claimed in claim 1 comprising the steps of mixing the granules of EVA and/or granules of PVC together with the filler materials in a homogeniser at a temperature between 70 to 120 deg. C to form a viscous liquid which is subsequently extruded, hot pressed and cooled in atmosphere. 7. A method of backing carpet or such thick fabric material with the new polymer sheet as claimed in claim 1, comprises the steps of: (a) laying the carpet or such thick fabric material, upside down, on a platform of a heating chamber, (b) laying the new polymer sheet on the back side of the carpet or such thick fabric material, (c) inserting the platform along with the carpet and polymer sheet inside the heating chamber, (d) pressing the new polymer sheet with the heard plate at an average pressure of 2 to 8 kg/sq.cm for a period of 30 tol20 Sec. until the new polymer sheet initiates melting and bonded to the backside of the carpet. (e) passing the composite material of new polymer sheet and carpet or such thick fabric material through a pair of rollers for uniform bondage. (f) cooling the composite material of new polymer sheet and carpet or such thick fabric material. 8. A method of backing carpet as claimed in claim 6 wherein the plate is heated to 130 to 280 deg. C by an electrical heating coil. 9. A method of backing carpet as claimed in claim 6 wherein the pressure on the polymer sheet is applied by pneumatic system. 10. A method of backing carpet as claimed in claim 6 wherein the composite material is cooled in the open air or by a blower for at least one hour. 11. A method of backing carpet as claimed in claim 6 wherein at least a layer of textile backing is layed over the new polymer sheet for backing carpet or such thick fabric material. 12. New polymer sheet substantially as herein before described. Dated this 10th day of June 2004. A new polymer sheet and method of backing a carpet or such thick material with the said polymer sheet wherein the polymer sheet comprises Ethyl Vinyl Acetate(EVA) or Polyvenyl Cholride(PVC) or blend of EVA and PVC together with a filler material. The polymer sheet is backed on the carpet or such thick material by hot pressing the polymer sheet in a heating chamber on a heating plate.

Documents:

00311-kol-2004-abstract.pdf

00311-kol-2004-claims.pdf

00311-kol-2004-correspondence.pdf

00311-kol-2004-description (complete).pdf

00311-kol-2004-drawings.pdf

00311-kol-2004-form 1.pdf

00311-kol-2004-form 2.pdf

00311-kol-2004-form 26.pdf

00311-kol-2004-form 3.pdf

00311-kol-2004-form 5.pdf

00311-kol-2004-letter patent.pdf

00311-kol-2004-reply f.e.r.pdf

311-KOL-2004-CORRESPONDENCE 1.1.pdf

311-KOL-2004-FORM 27-1.1.pdf

311-KOL-2004-FORM 27.pdf

311-KOL-2004-FORM-27.pdf