Title of Invention	CAST-EXTRUDED OR CAST-CAST COMBINED WATER SOLUBLE FILM AND THE METHOD/PROCESS FOR PRODUCING THE SAME
Abstract	(Currently amended) A cast-extruded or a cast-cast combined water soluble film (WSF) comprising of at least one layer of solution cast WSF provided with a detachable liner, combined with one or more of a water soluble film and further provided with a binder coat in between the two WSF layers; wherein the said binder coat comprises a batch solution of water soluble film and the like, and the said binder coat is preferably associated with a acrylic dispersion used as a tie coat between a WSF and the binder coat.

Title of Invention

CAST-EXTRUDED OR CAST-CAST COMBINED WATER SOLUBLE FILM AND THE METHOD/PROCESS FOR PRODUCING THE SAME

Abstract

(Currently amended) A cast-extruded or a cast-cast combined water soluble film (WSF) comprising of at least one layer of solution cast WSF provided with a detachable liner, combined with one or more of a water soluble film and further provided with a binder coat in between the two WSF layers; wherein the said binder coat comprises a batch solution of water soluble film and the like, and the said binder coat is preferably associated with a acrylic dispersion used as a tie coat between a WSF and the binder coat.

Full Text	FORM 2 THE PATENTS ACT, 1970 (39 of 1970) & THE PATENTS RULES, 2003 COMPLETE SPECIFICATION (See section 10 and Rule 13) 1. TITLE OF INVENTION "Cast-extruded or cast-cast combined water soluble film and the method/process for producing the same" 2. Applicant(s) (a) Name: Arrow Coated Products Ltd. (b) Nationality: Indian Company (c) Address: Arrow Coated Products Ltd., 5-D, Laxmi Industrial Estate, New Link Road, Andheri (West), Mumbai- 400053, Maharashtra State, India 3. Preamble to the description The following specification particularly describes the nature of this invention and the manner in which it is to be performed This invention relates to a cast-extruded or a cast-cast combined water soluble film and a method/process for producing the same. More particularly, this invention relates to a combined water soluble film wherein atleast one layer is a solution cast water soluble film on a liner and atleast one layer is a preformed water soluble film, preferably a thermally extruded water soluble film. The said water soluble films may be edible or non edible. The said water-soluble film on a liner is coated with a tie-coat to enable coating of a water-based binder used for combining the water soluble films without dissolving/damaging WSF on liner. The water based binder used for combining the said water soluble! films may be incorporated with active ingredients like flavours, perfumes, detergents, enzymes, softeners, active agents for cleaning laundry, dishes, floorings, walls, furniture; various agrochemicals like pesticides, insecticides, weedicides, fungicides, bio-pesticides; agro nutrients like urea, fertilizers; dyes, pigments, fluff, pulp, super absorbents and active pharma ingredients like vitamins, drugs, medicine. The said combined water soluble film so achieved will be a substantially pinhole free multi-layered water soluble film of desired mechanical strength at low cost. The Background of Invention Water soluble films (WSFs) are commercially well known in the market. These films are usually used for packaging purpose such as liquid detergents, agrochemicals, toilet blocks, laundry bags, fish baits, pigments and dyestuffs, liquid chemicals and for embroidery purpose such as for making lace or can be used as a backing or a topping for embroidery. However, these applications are by no means limiting. These films may be biodegradable. These films are produced by solution cast method or by extrusion method. Solution cast films are cast from a slot, which controls thickness and weight, onto a steel belt or steel drum or a suitable liner etc. Extruded films can be blown (bubble type) or slit-die cast (Extrusion curtain type). In blown film extrusion, the molten polymer from the extruder enters the die and is forced around a mandrel and emerges from a ring shaped die. The extruded film tube is 2 then expanded to a specific diameter by air pressure from the center of the mandrel. As the bubble expands, the film thickness decreases. In slit die extrusion or flat film extrusion, the WSF is produced by extruding molten polymer through a slit-die and then cooling it on chilled rollers or in a water bath. In flat film extrusion, it is important to cool the material within a short distance of the die head so that a clear film is produced and necking (reduction in; width) does not occur.. These films can be co-extruded in multiple layers or can be fed through multiple hoppers and/or screws. Manufacturing process and the blend will determine the quality of the film. All types of extrusion methods are thermally reactive and create pinholes in the resultant films. These pinholes are due to various reasons including improper thermal reactions, changes in polymer's molecular weight, improper gauge variation, uneven relative humidity acceptance, improper polymer melts, etc. Pinholes are detrimental to the final quality of the product being packed and are not acceptable to the industry. The films so formed have less "shrink back" property. Another problem of this method is control of moisture equilibrium within the WSF. This equilibrium is vital to get the right mechanical properties of WSF. But this process is economical to produce. So there was a need for pinhole free or substantially pinhole free water soluble film. Solution cast manufacturing process is a well accepted process to produce water soluble film with considerably less pinholes. In this process the polymers and additives are all dissolved completely in solvents, like, but not limited to, water of varying qualities and varying temperatures, while mixing in a batch mixing reactor. This leaves less possibility of pinholes as the polymers melts/dissolves in near totality. The additives mix properly and completely and thus the resultant film is of better quality. Moisture equilibrium, thickness and solubility can be finely controlled in this process. But this process is expensive, as the solution has to be cast on metal belt or a conveyor or a detachable liner and cured after the solvents dry out. 3 So there has been a need for an economical and substantially pinhole free water soluble film, with optimal mechanical properties. Combining two water soluble films had their own set of problems. One cannot blow a film on top of a solution cast film, as blown films are in a bubble form and solution cast films are in web forms individually wound. One cannot do T Die extrusion of a water soluble film on a solution cast film web as the film shall not come out unstuck from the chilling cylinder, which is inherent part of the T die extrusion process. Similar problems shall be faced during any of the combination of thermally activated extruded film with cast film. Similarly, one cannot cast a wet mix solution, which is usually cast on a conveyor at about 10°C to 95°C, preferably between 30°C to 70°C, more preferably between 35°C to 60°C. Casting such a wet/ liquid solution on a web of blown/extruded film shall dissolve partially or completely the web, prior to the combination web reaching the dryers and prove it to be commercially unviable. Also, while dispersing the active ingredient into the water soluble film, it has been noticed that some active ingredients like perfumes which are mixed in the batch used for forming the water soluble film layer diminishes after some time during storage, thereby affecting the quality. The Indian prior art 443/MUM/2001, relates to process for manufacturing embedded/entrapped water-soluble film (WSF) system and water soluble film (WSF) system manufactured by the said process. This invention describes the process for manufacturing water soluble films (WSFs) for diverse applications, in which a variety of substances such as detergents, enzymes, softeners, perfumes; agrochemicals like pesticides, fungicides, herbicides, weedicides, insecticides; agro nutrients like urea, 4 fertilizers; dyes, pigments, hazardous chemicals, fluff, pulp, super absorbents, active agents for cleaning laundry, dishes, floorings, walls and the like are embedded for delivering them in precise and desired quantities The above patent relates, to a water soluble film embedded/entrapped with active ingredients for precise delivery of active ingredients. It is restricted to embedding active ingredients within WSF and does not describe a process of combining two water soluble films. Another Indian patent, 1158/MUM/2001 discloses novel pin-hole free multi-layered films consisting partially or fully water soluble films layered! with substantially pin-hole free barrier coatings that are partially insoluble or fully water-soluble or dispersible and methods of manufacturing. The patent describes the detachable and/or non detachable substrate based multi-layered films with water soluble! or partially water-soluble films layered with substantially pin-hole free barrier coatings and methods of manufacturing the same. The above patent relates to a pinhole free multi-layered film by barrier coating on a water soluble film along with a liner. However, the patent does not describe a process of combining two water soluble films. Combination of two layers of water soluble films is desirable but difficult due to hydrophilic properties of both the layers. Various trials were taken and experiments conducted for combining the two layers of any types of water soluble films. This resulted in one of the film dissolving just on applying the coating of an adhesive, creating a hole or a void even before the next layer is brought for lamination. Experiments were even done for combining two layers of water soluble films by using adhesives base on hydrocarbon based solvents like, but not limited to xylene, toluene, MEK, MIBK, but the anchorage of these adhesives was not satisfactory. Hence, the main object of the present invention is to provide a cast-extruded or a cast-cast combined water soluble film, wherein the water soluble film on a liner is coated with a time-delay tie-coat to enable coating of a binder used for combining the layers of water 5 soluble films to achieve a substantially pinhole free multi-layered water soluble film of desired mechanical strength at low cost. Another object of this invention is to provide a combined water soluble film in which the properties like smell of the active ingredient such as perfume is retained for a longer period as the perfume is added to the binder and/or the tie-coat and which will remain blocked between the outer layers of the water soluble film and thereby improving the quality of perfumed/flavoured film. Yet another object of this invention is to provide a combined water soluble film, wherein other active ingredients like flavours, perfumes, detergents, enzymes, softeners, active agents for cleaning laundry, dishes, floorings, walls, furniture; various agrochemicals like pesticides, insecticides, weedicides, fungicides, bio-pesticides; agro nutrients like urea, fertilizers; dyes, pigments, fluff, pulp, super absorbents and active pharma ingredients like vitamins, drugs, medicine are added to the binder and/or the tie-coat for different applications. Statement of invention Thus according to one aspect of this invention, there is provided a cast-extruded or a cast-cast combined WSF comprising of atleast one layer of solution cast WSF with a detachable liner, preferably provided with a tie coat, a binder coating provided on the said solution cast WSF with liner, with or without the said tie-coat and atleast one layer of preformed WSF with or without a detachable liner provided over the said binder coat forming a substantially pin hole free combined multi-layered WSF of desired mechanical strength, at low cost. Accordingly this invention provides a combined WSF, wherein the said preformed WSF is preferably a thermally extruded WSF, such as blown (bubble type) or slit die-cast (extrusion curtain type), forming a cast-extruded combined WSF. 6 Accordingly this invention provides a combined WSF, wherein said preformed WSF is a solution cast WSF forming a cast-cast combined WSF. Accordingly this invention provides a combined WSF, wherein said solution cast WSF with liner is preformed. Accordingly this invention provides a combined WSF, wherein said solution cast WSF with liner is formed in situ. Accordingly this invention provides a combined WSF, wherein said tie coat provided on the solution cast WSF with liner is selected from acrylic acid polymers, acrylic ester polymers, soluble acrylic acid copolymers, soluble acrylic ester copolymers, soluble copolymers of acrylic acids and esters, cross linked polyvinyl alcohols, cross linked cellulose derivatives, ethyl cellulose, nitrocellulose, cellulose butyrate, cellulose acetate butyrate, ethylene vinyl polyalcohol, ethylene vinyl acetate, PVDC (polyvinyldene chloride), acrylic emulsion, PVC (polyvinyl chloride) emulsion, PVDC emulsion, PVB (polyvinyl butyral), natural arid synthetic waxes, polyurethanes and modified polyvinyl alcohols. Accordingly this invention provides a combined WSF, wherein said binder provided on the solution cast WSF with liner directly or over the tie coat is a binder selected from any low viscosity, low solid content binder like different types of adhesives such as pressure sensitive adhesives, cast water soluble film solution, polyurethane dispersion or even a liquid flavour. Accordingly this invention provides a combined WSF, wherein the said solution cast WSF with liner forming one layer and the said preformed WSF forming another layer, are formed of non-edible materials selected from Polyvinyl alcohol copolymer ionomers, Polyvinyl alcohol homopolymer, non - ionomeric poly vinyl alcohol polymer, Polymethacrylate., polyvinyl alchohol, polyacrylamide, polymethacrylamide, polyacrylic 7 acid, polymethacrylic acid, biodegradable polyesters such as ecoflex; polylactic acid (PLA), polyhydroxyalkanoic acid (PHA) and polyurethane. Accordingly this invention provides a combined WSF, wherein the said solution cast WSF with liner forming one layer and the said preformed WSF forming another layer, are formed of edible materials selected from polyethyleneglycol, polyvinylpyrrolidone, proteinaceous binders such as gelatin, modified gelatins such as phthaloyl gelatin, polysaccharides such as starch and its derivatives, sorbitol, sucrose derivatives, gum Arabic, pullulan and dextrin and water-soluble cellulose derivatives or combination thereof. The cellulose derivatives used are methyl cellulose, hydroxy propyl cellulose, hydroxy propyl methyl cellulose, hydroxy propyl ethyl cellulose, hydroxy ethyl cellulose and carboxy methyl cellulose. Accordingly this invention provides a combined WSF, wherein the said tie coat and/or the said binder is incorporated with desired amount of one or more, same or different types of active ingredients, as per the requirement. Accordingly this invention provides a combined WSF, wherein the said one or more active agents are selected from flavours, perfumes, detergents, enzymes, softeners, active agents for cleaning laundry, dishes, floorings, walls, furniture; various agrochemicals like pesticides, insecticides, weedicides, fungicides, bio-pesticides; agro nutrients like urea, fertilizers; dyes, pigments, fluff, pulp, super absorbents and active pharma ingredients like vitamins, drugs, medicine. Accordingly this invention provides a combined WSF, wherein the said detachable liner of the solution cast WSF and optionally of preformed WSF is made of paper, film, foil or fabric, treated or untreated, coated or uncoated, preferably the said liner is made of film, more preferably polyester film. The films can thickness ranging from 3 microns to 500 microns, preferably from 10 microns to 300 microns, more preferably from 25 microns to 100 microns. The film liner may be plain, metallised, embossed, gloss, matt, extrusion coated, laminated or release coated depending on the desired characteristics of the end 8 product. Paper liners are also used for production of WSF. Paper liners that accept temperatures needed for the production of WSF and have thickness ranging from 7 GSM (grams per sq meter - the standard for measuring weight of paper) to 500 GSM, preferably from 20 GSM to 300 GSM, more preferably from 60 GSM to 180 GSM can be used. The paper liner may be plain, embossed, gloss, matt, extrusion coated laminated or release coated depending on the desired characteristics Of the end product. Fabrics made of cotton or synthetic yarns, solution coated, plain, embossed, gloss, matt, extrusion coated or laminated. Accordingly this invention provides a combined WSF, wherein the said WSF is cold water soluble, warm water soluble, hot water soluble, edible or non edible, depending upon the raw materials used according to the requirement of various applications. Accordingly this invention provides a method/process for producing a cast-extruded or cast-cast combined WSF comprising of the following steps: a. placing a preformed WSF with detachable liner on an unwinder of a coating machine, forming one layer of the combined WSF, b. placing another preformed WSF with or without a detachable liner on another unwinder of the coating machine, forming another layer of the combined WSF, c. unwinding said preformed WSF with liner and passing through a coating head of a coating machine for applying a tie coat on one surface, opposite to liner, of said WSF, d. drying and curing the tie coated WSF by passing it through a coating head of the coating machine, the temperature of the drying section ranging from 50°C to 200°C, preferably from 60°C to 175°C, more preferably from 75°C to 150°C, e. applying a binder coat over the said tie coat of the WSF with liner by passing it through another coating section of the coating machine, f. passing the WSF with liner having tie coat followed by binder coat through an air blower section of the coating machine for semi-drying the binder, the temperature of the blower section ranging from 10°C to 100°C, preferably from 30°C to 70°C, more preferably from 30°C to 50°C, 9 g. unwinding the said other preformed WSF and guiding it to combine with the first WSF of the step (f) by passing through a nip roll of the coating machine, forming a laminated double layered combined WSF, h. rewinding the laminate of combined WSF of step (g) on a rewinder and storing for internal ageing, i. detaching the liner and slitting/cutting the combined WSF laminate, as per requirement. Accordingly this invention provides a method/process producing a cast-extruded or cast-cast combined WSF, comprising of the following steps: a. placing a liner for casting WSF on it, on an unwinder of a casting-cum-coating machine, b. placing a preformed WSF with or without a detachable liner on another unwinder of a casting-cum-coating machine, c. unwinding the liner and casting WSF on it by using known edible or non-edible formulations of WSF in a batch reactor and metering the cast WSF at the primary casting head of a casting-cum-coating machine, the temperature of the batch solution in the reactor ranging from 10°C to 95°C, preferably from 13°C to 90°C and more preferably from 15°C to 85°C, d. drying the cast WSF of step (c) at a primary drying section, forming one/first layer of the combined WSF, the temperature in the drying section ranging form 50°C to 200°C, preferably from 60°C to 175°C and more preferably from 75°C to 150°C, e. applying a tie-coat on one side of the WSF with the liner passing through a coating head, f. drying and curing the tie-coated WSF by passing it through the drying section of the casting-cum-coating machine, the temperature in the drying section ranging from 50°C to 200°C, preferably from 60°C to 175°C, more preferably from 75°C to 150°C, g. applying a binder coat over the said tie coat of the WSF with liner by passing it through another coating section of the coating machine, h. passing the WSF with liner having tie coat followed by binder coat through an air blower section of the coating machine for semi-drying the binder, the temperature of 10 the blower section ranging from 10°C to 100°C, preferably from 30°C to 70°C, more preferably from 30°C to 50°C, i. unwinding the said other WSF and guiding it to combine with the first WSF of the step (h) by passing through a nip roll of the coating machine, forming a laminated double layered combined WSF, j. rewinding the laminate of combined WSF of step (i) on a rewinder and storing for internal ageing, k. detaching the liner and slitting/cutting the combined WSF laminate, as per requirement. Accordingly this invention provides a method/process, wherein the cast WSF on a detachable liner after drying at primary drying section is applied with a binder coat directly, without coating it with the tie-coat. Accordingly this invention provides a method/process, wherein the said tie-coat is preferably applied by using a gravure cylinder of varying cell sizes and depths; or by using flexo plates of varying cell sizes and depths, or by combination of flexo plates with gravure cylinder, for transferring net solid contents of the tie-coat from the cells of the cylinder and that maximum water/solvent is scrapped before hand by cam shaft moving doctoring blade. Accordingly this invention provides a method/proces$, wherein the said tie coat is selected from acrylic acid polymers, acrylic ester polymers, soluble acrylic acid copolymers, soluble acrylic ester copolymers, soluble copolymers of acrylic acids and esters, cross linked polyvinyl alcohols, cross linked cellulose derivatives, ethyl cellulose, nitrocellulose, cellulose butyrate, cellulose acetate butyrate, ethylene vinyl polyalcohol, ethylene vinyl acetate, PVDC (polyvinyldene chloride), acrylic emulsion, PVC (polyvinyl chloride) emulsion, PVDC emulsion, PVB (polyvinyl butyral), natural arid synthetic waxes, polyurethanes and modified polyvinyl alcohols. 11 Accordingly this invention provides a method/process, wherein the said binder coat is applied by using a wire bound mayer bar. Accordingly this invention provides a method/process, wherein the said liner is made of paper, film, foil or fabric, treated or untreated, coated or uncoated, preferably the said liner is made of film, more preferably polyester film. The films can thickness ranging from 3 microns to 500 microns, preferably from 10 microns to 300 microns, more preferably from 25 microns to 100 microns. The film liner may be plain, metallised, embossed, gloss, matt, extrusion coated, laminated or release coated depending on the desired characteristics of the end product. Paper liners are also used for production of WSF. Paper liners that accept temperatures needed for the production of WSF and have thickness ranging from 7 GSM (grams per sq meter - the standard for measuring weight of paper) to 500 GSM, preferably from 20 GSM to 300 GSM, more preferably from 60 GSM to 180 GSM can be used. The paper liner may be plain, embossed, gloss, matt, extrusion coated laminated or release coated depending on the desired characteristics of the end product. Fabrics made of cotton or synthetic yarns, solution coated, plain, embossed, gloss, matt, extrusion coated or laminated. Accordingly this invention provides a method/process, wherein the said binder is selected from any low viscosity, low solid content binder like different types of adhesives such as pressure sensitive adhesives, cast water soluble film solution, polyurethane dispersion or even a liquid flavour. Accordingly this invention provides a method/process wherein the said edible WSF formulation is formed of edible materials selected from polyethyleneglycol, polyvinylpyrrolidone, proteinaceous binders such as gelatin, modified gelatins such as phthaloyl gelatin, polysaccharides such as starch and its derivatives, sorbitol, sucrose derivatives, gum Arabic, pullulan and dextrin and water-soluble cellulose derivatives or combination thereof. The cellulose derivatives used are methyl cellulose, hydroxy propyl cellulose, hydroxy propyl methyl cellulose, hydroxy propyl ethyl cellulose, hydroxy ethyl cellulose and carboxy methyl cellulose. 12 Accordingly this invention provides a method/process, wherein the said non-edible WSF formulation is formed of non-edible materials selected from Polyvinyl alcohol copolymer ionomers, Polyvinyl alcohol homopolymer, non - ionomeric poly vinyl alcohol polymer, Polymethacrylate., polyvinyl alchohol, polyacrylamide, polymethacrylamide, polyacrylic acid, polymethacrylic acid biodegradable polyesters such as ecoflex; polylactic acid (PLA), polyhydroxyalkanoic acid (PHA) and polyurethane. Accordingly this invention provides a method/process, wherein one or more of same or different types of active ingredients are incorporated in.the said tie-coat and/or the said binder. Accordingly this invention provides a method/process, wherein the said active ingredients are selected from flavours, perfumes, detergents, enzymes, softeners, active agents for cleaning laundry, dishes, floorings, walls, furniture; various agrochemicals like pesticides, insecticides, weedicides, fungicides, bio-pesticides; agro nutrients like urea, fertilizers; dyes, pigments, fluff, pulp, super absorbents and active pharma ingredients like vitamins, drugs, medicine. Accordingly this invention provides a method/process, wherein the raw materials of the WSF, the tie-coat and/or the binder are selected such that the combined WSF is soluble in cold water, warm water or hot water, as per requirement. Accordingly this invention provides a method/process, wherein the WSF with liner is moved at high speed, preferably from 15 to 100 meter/min., more preferably from 25 to 70 meter/min. for preventing the WSF from dissolving when the binder is applied on it directly, without the tie-coat. Accordingly this invention provides a method/process, wherein the air blower section temperature is kept high ranging from 20°C to 100°C, preferably from 30°C to 70°C, more preferably from 50°C to 60°C for instantly semi-drying the said binder coated directly without the tie-coat, for preventing the WSF from dissolving. 13 Accordingly this invention provides a method/process for producing cast-cast or cast-extruded combined WSF, comprising of the following steps: a. placing/loading a preformed WSF with a detachable liner on a flat die extruder, b. extruding desired thickness of WSF directly onto the said preformed cast WSF with liner through the extruder, c. passing the combined WSF laminate of step (b) through chilling cylinders, keeping the said liner in contact with the chilling cylinder, d. rewinding the combined WSF laminate of step (c) on a rewinder and storing for internal ageing period, e. detaching the liner and slitting/cutting the combined WSF laminate as per requirement. Accordingly this invention provides a method/process, wherein the said liner is a hydrophobic, thermally active detachable liner. Accordingly this invention provides a method/process, wherein the said combined WSF laminate is stored for an internal ageing period ranging from 1 hour to 720 hours, preferably from 10 hours to 360 hours and more preferably from 24 hours to 100 hours. Accordingly this invention provides a method/process, wherein the said double layered combined WSF with liner is unwound and applied with a tie-coat in a coating head, dried and cured in the drying section, applied with a binder coat over the said tie-coat in another coating section, passed through air blower section for semi drying the binder coat and combined with a third layer of WSF with or without detachable liner by passing through nip roll and rewound on another rewinder forming three layered combined WSF. Accordingly this invention provides a method/process, wherein the said double layered combined WSF with liner is unwound and applied with a binder coat directly, without the tie-coat, in a coating section, passed through air blower section for semi drying the binder 14 coat and combined with a third layer of WSF with or without detachable liner by passing through nip roll and rewound on another rewinder forming three layered combined WSF. Accordingly this invention provides a method/process, wherein the said double layered combined WSF with liner is unwound and passed through the flat die extruder for extruding desired thickness of WSF directly on it and passed through the chilling cylinder and rewound on the rewinder forming three layered combined WSF. Accordingly this invention provides a method/process, wherein the said process is repeated to form any desired numbers of multi-layered combined WSF of this invention. Accordingly this invention provides a method/process, wherein one or more of the same or different types of active ingredients are incorporated in the binder and/or the tie-coat and/or in the flat die extruder while extruding the desired thickness of WSF directly on the preformed WSF with liner. Accordingly this invention provides a method/process for producing cast-extruded or cast-cast combined WSF substantially as herein described and illustrated in figs. 1 to 5 of the accompanying drawings. The invention will now be described with reference to accompanying drawings, wherein Fig.l shows a schematic line diagram illustrating an offline process of combining two layers of water soluble films using a tie-coat and a binder according to an embodiment of this invention. Fig. 2 shows a schematic line diagram illustrating an online process of combining two layers of water soluble films using a tie-coat and a binder, according to another embodiment of this invention. 15 Fig. 3 shows a schematic line diagram illustrating a process of combining two layers of water soluble films, using a binder according to a further embodiment of the invention. Fig. 4 shows a schematic line diagram illustrating a process of combining two layers of water soluble films by flat-die extruding of a water soluble film onto a water soluble film along with a detachable liner. Fig. 5 shows a diagram illustrating a three layered combined water soluble film produced according to an embodiment of this invention. Referring to fig.l, illustrating the offline process of producing a cast-blown or a cast-cast combined water soluble film comprising the following steps: I. Placing a web of preformed WSF (1) with detachable liner, forming one layer of the combined WSF, on an unwinder (2) of a coating machine, wherein the said WSF (1) is a solution cast film. II. Placing a web of preformed WSF (3) with or without detachable liner, forming another layer of the combined WSF, on another unwinder (4) of the coating machine, wherein the said WSF (3) is a solution cast film or a thermally extruded film. III. Unwinding the preformed WSF (1) along with detachable liner at unwinder (2). IV. Applying a tie-coat on the preformed WSF (1) by passing the WSF along with the liner through the coating head (5) of the coating machine. The tie-coat is preferably applied preferably, by using a gravure cylinder of varying cell sizes and depths; or by using flexo plates of varying cell sizes and depths, or by combination of flexo plates with gravure cylinder, for transferring net solid contents of the tie-coat from the cells of the cylinder and that maximum water/solvent is scrapped before hand by cam shaft moving doctoring blade. These processes reduces the possibility of the pre-formed water soluble film from dissolving when the binder or subsequent WSF casting is done for the end purpose of affixing another water soluble film. 16 The tie-coat being selected from acrylic acid polymers, acrylic ester polymers, soluble acrylic acid copolymers, soluble acrylic ester copolymers, soluble copolymers of acrylic acids and esters, cross linked polyvinyl alcohols, cross linked cellulose derivatives, ethyl cellulose, nitrocellulose, cellulose butyrate, cellulose acetate butyrate, ethylene vinyl polyalcohol, ethylene vinyl acetate, PVDC (polyvinyldene chloride), acrylic emulsion, PVC (polyvinyl chloride) emulsion, PVDC emulsion, PVB (polyvinyl butyral), natural arid synthetic waxes, polyurethanes and modified polyvinyl alcohols. However, these tie-coats are by no means limiting. These tie-coats will not allow the WSF to dissolve and will act as a barrier between the WSF and the binder to be applied at a later stage. Optionally, the tie-coat is incorporated with one or more active ingredients such as flavours, perfumes, detergents, enzymes, softeners, active agents for cleaning laundry, dishes, floorings, walls, furniture; various agrochemicals like pesticides, insecticides, weedicides, fungicides, bio-pesticides; agro nutrients like urea, fertilizers; dyes, pigments, fluff, pulp, super absorbents and active pharma ingredients like vitamins, drugs, medicine. However, these active ingredients are by no means limiting. V. Drying and curing of WSF (1) coated with tie-coat, at the drying section (6). The temperature in the dryers ranges from 50°C to 200°C, preferably from 60°C to 175°C, more preferably from 75°C to 150°C. VI. Passing the WSF (1) coated with tie-coat through another coating section (7) for applying/coating a binder on the tie-coat coated side of WSF. The binder is coated using a wire wound mayer bar. The said binder being selected from any low viscosity, low solid content binder like different types of adhesives such as pressure sensitive adhesives, cast water soluble film solution, polyurethane dispersion or even a liquid flavour. However, these binders are by no means limiting. Optionally, the binder is incorporated with one or more of the active ingredients as per requirement. 17 VII. Passing through an air blower section (8) of the coating machine with or without applying heat, for semi-drying the binder. The temperature in the blower section ranges from 10°C to 100°C, preferably from 30°C to 70°C, more preferably from 30°C to 50°C. VIII. Unwinding the pre-formed WSF (3) from the unwinder (4) and guiding it through the guide rolls (9) to combine with the WSF (1) from step VII by passing through the nip roll (10). IX. Rewinding the laminate of combined WSF on a rewinder (11) and store for internal ageing period ranging from 1 hour to 720 hours, preferably 10 hours to 360 hours, more preferably from 24 hours to 100 hours. X. Detaching the liner and slitting/cutting the combined WSF as per requirement. Now, referring to fig.2, illustrating the online process of producing a cast-blown or a cast-cast combined water soluble film comprising the following steps: I. Placing a liner (12), for casting of WSF, on an unwinder (13) of a casting-cum-coating machine. The liner (12) is optionally treated or untreated and coated or uncoated. The liner can be of paper, film, foil or fabric, preferably of film, more preferably of polyester film. The film thickness ranges from 3 microns to 500 microns, preferably from 10 microns to 300 microns, more preferably from 25 microns to 100 microns. The film liner may be plain, metallised, embossed, gloss, matt, extrusion coated, laminated or release coated depending on the desired characteristics of the end product. Paper liner is also used for production of WSF. Paper liner that accept temperatures needed for the production of WSF and have thickness ranging from 7 GSM (grams per sq meter - the standard for measuring weight of paper) to 500 GSM, preferably from; 20 GSM to 300 GSM, more preferably from 60 GSM to 180 GSM can be used. The paper liner may be plain, embossed, gloss, matt, extrusion coated laminated! or release coated depending on the desired characteristics of the end product. Fabrics made of cotton or synthetic yarns, solution coated, plain, embossed, gloss, matt, extrusion coated or laminated 18 may be used as liner based on the desired end product properties. However, these liners are by no means limiting. II. Placing the preformed WSF (3) with or without a detachable liner, forming another layer of the combined WSF, on another unwinder (4) of the coating machine. wherein the said WSF (3) is a solution cast film or a thermally extruded film. HI. Unwinding of the liner (12) at unwinder (13) for the formation of WSF. IV. Casting of WSF by using known formulation of WSF in a batch reactor (14), on the liner (12), at the primary casting head (15). The temperature of the batch solution ranges from 10°C to 95°C, preferably from 20°C to 85°C, more preferably from 25°C to 70°C. The non-edible raw materials used for making the WSF are selected from Polyvinyl alcohol copolymer ionomers, Polyvinyl alcohol homopolymer, non - ionomeric poly vinyl alcohol polymer, Polymethacrylate., polyvinyl alchohol, polyacrylamide. polymethacrylamide, polyacrylic acid, polymethacrylic acid, polyurethane and edible raw materials are selected from polyethyleneglycol, polyvinylpyrrolidone, proteinaceous binders such as gelatin, modified gelatins such as phthaloyl gelatin, polysaccharides such as starch, gum Arabic, pullulan and dextrin and water-soluble cellulose derivatives or combination thereof. The cellulose derivatives used are methyl cellulose, hydroxy propyl cellulose, hydroxy propyl methyl cellulose, hydroxy propyl ethyl cellulose, hydroxy ethyl cellulose, carboxy methyl cellulose. However, these are by no means limiting. V. Metering of the cast WSF at the primary casting head (15). VI. Drying of the WSF of the above step V at primary drying section (16) to form the first layer of WSF (1) with the liner. The temperature in the dryers ranges form 50°C to 200°C, preferably from 60°C to 175°C, more preferably from 75°C to 150°C. VII. Applying/Coating a tie-coat on the formed WSF (1) by passing the WSF along with the liner through a coating head (5). The tie-coat is preferably applied preferably, by using a gravure cylinder of varying cell sizes and depths; or by using flexo plates of varying cell sizes and depths, or by combination of flexo plates with gravure cylinder, for transferring net solid contents of the tie-coat from the cells of the cylinder and that maximum water/solvent is 19 scrapped before hand by cam shaft moving doctoring blade. These processes reduces the possibility of the pre-formed water soluble film from dissolving when the binder or subsequent WSF casting is done for the end purpose of affixing another water soluble film. The tie-coat is preferably applied by using a gravure cylinder of varying cell sizes and depths, by transferring the net solid contents of the active polymers of the tie coat from the cells of the cylinder, and the water/solvent liquid is scraped before hand by the cam shaft moving doctoring blade. This process reduces the possibility of the pre-formed water soluble film from dissolving when the tie coat or subsequent WSF casting is done for the end purpose of lamination to another water soluble film. The tie-coat being selected from acrylic acid polymers, acrylic ester polymers, soluble acrylic acid copolymers, soluble acrylic ester copolymers, soluble copolymers of acrylic acids and esters, cross linked polyvinyl alcohols, cross linked cellulose derivatives, ethyl cellulose, nitrocellulose, cellulose butyrate, cellulose acetate butyrate, ethylene vinyl polyalcohol, ethylene vinyl acetate, PVDC (polyvinyldene chloride), acrylic emulsion, PVC (polyvinyl chloride)emulsion, PVDC emulsion, PVB (polyvinyl butyral), natural arid synthetic waxes, polyurethanes and modified polyvinyl alcohols. However, these tie-coats are by no means limiting. These tie-coats will not allow the WSF to dissolve and will act as a barrier between the WSF and the binder to be applied at a later stage. Optionally, the tie-coat is incorporated with one or; more active ingredients such as flavours, perfumes, detergents, en2ymes, softeners, active agents for cleaning laundry, dishes, floorings, walls, furniture; various agrochemicals like pesticides, insecticides, weedicides, fungicides, bio-pesticides; agro nutrients like urea, fertilizers; dyes, pigments, fluff, pulp, super absorbents and active pharma ingredients like vitamins, drugs, medicine. However, these active ingredients are by no means limiting. VIII.Drying and curing of WSF (1) coated with tie-coat at the drying section (6). The temperature in the dryers ranges from 50°C to 200°C, preferably from 60°C to 175°C, more preferably from 75°C to 150°C. 20 IX. Passing the WSF (1) coated with tie-coat through another coating section (7) for applying/coating of the binder on the tie-coat coated side of WSF. The binder is coated using a wire wound mayer bar. The said binder being selected from any low viscosity, low solid content binder like different types of adhesives such as pressure sensitive adhesives, cast water soluble film solution, polyurethane dispersion or even a liquid flavour. However, these binders are by no means limiting. Optionally, the binder is incorporated with one or more of the active ingredients as described earlier. X. Passing through an air blower section (8) with or without applying heat, for semi- drying the binder. The temperature in the blower section ranges from 10°C to 100°C, preferably from 30°C to 70°C, more preferably from 30°C to 50°C. XI. Unwinding the pre-formed WSF (3) from the unwinder (4) and guiding it through the guide rolls (9) to combine with the WSF (1) from the step X by passing through the nip roll (10). XII. Rewinding the laminate of combined WSF on a rewinder (11) and store for internal ageing period ranging from 1 hour to 720 hours, preferably 10 hours to 360 hours, more preferably from 24 hours to 100 hours. XIII. Detaching the liner and slitting/cutting as per requirement. Referring to fig 3, illustrating the process of producing a cast-blown or a cast-cast combined water soluble film using only the binder directly on the water soluble film along with a liner without applying any tie-coat comprising the following steps: I. Placing the preformed WSF (1) with a detachable liner, forming one layer of the combined WSF, on an unwinder (2) of a coating machine, wherein the said WSF (1) is a solution cast film. II. Placing the preformed WSF (3) with or without a detachable liner, forming another layer of the combined WSF, on another unwinder (4) of the coating machine. wherein the said WSF (3) is a solution cast film or a thermally extruded film. III. Unwinding the preformed WSF (1) along with a detachable liner at unwinder (2) 21 IV. Passing the WSF (1) through the coating section (7) for coating of the binder on the WSF. The said binder being selected from any low viscosity, low solid content binder like different types of adhesives such as pressure sensitive adhesives, cast water soluble film solution, polyurethane dispersion or even a liquid flavour. However, these binders are by no means limiting. Optionally, the binder is incorporated with one or more of the active ingredients as described earlier. V. Passing through an air blower section (8) with or without applying heat, for semi-drying the binder. The temperature in the blower section ranges from 20°C to 100°C, preferably from 40°C to 80°C, more preferably from 50°C to 60°C. VI. Unwinding the pre-formed WSF (3) from the unwinder (4) and guiding it through the guide rolls (9) to combine with the WSF (1) from step V by passing through the nip roll (10). VII. Rewinding the laminate of combined WSF on a rewinder (11) and storing for internal ageing period ranging from 1 hour to 720 hours, preferably 10 hours to 360 hours, more preferably from 24 hours to 100 hours. VIII.Detaching the liner and slitting/cutting as per requirement. As this process has a detachable liner as a pre-requisite, speed of WSF (1) is kept high, preferably from 15 to 100 metres/min, more preferably from 25 to 70 metres/min, the binder will not be able to dissolve the WSF and will enable combining two films even without using a tie-coat. The property of a specified binder of thixotropic nature shall determine this process of speed, which shall not be treated as a limiting factor for this invenrion. Further, the liner provided with the WSF (1) gives the desired strength for withstanding the binder coating for the required time enabling the combining of two layers of WSF without a tie-coat. 22 Further, the temperature of the air blower section being kept at 20 C to 100 C, preferably from 40°C to 80°C, more preferably from 50°C to 60°C (higher then the temperature used for the process using tie-coat), the binder will dry instantly and will not dissolve the WSF and will enable combining two films even without using a tie-coat. Fig. 3 of the accompanying drawing though illustrates an offline process, is equally applicable in an online process. Referring to fig 4, illustrating the process of producing a cast-blown combined water soluble film by directly extruding a water soluble film through a flat die extruder onto a water soluble film along with a liner comprising the follovving steps: I. Load a roll of preformed WSF (1) along with a detachable liner on a flat die extruder. II. Extruding the desired thickness of WSF directly through the extruder (17) onto the preformed cast WSF. III. Passing the construction from step II through chilling cylinders) (18), keeping the hydrophobic, but thermally active detachable liner in contact with the chilling cylinder. IV. Rewinding the laminate at rewinder (20) by passing through the guide roll (19) and store for internal ageing period ranging from 1 hour to 720 hours, preferably 10 hours to 360 hours, more preferably from 24 hours to 100 hours. V. Detaching the liner and slitting/cutting as per requirement. To make a three layered combined WSF, the double layered combined WSF on liner, produced as per any of the above processes, is again unwound along with the liner and passed through a tie-coat coating head and dried. The tie-coat coated double layered WSF is then coated with a binder and semi-dried by passing through the air blowing section. A third layer of preformed WSF is passed through the affixing nip roll and laminated with the double layered WSF forming thee layered combined WSF. 23 Fig. 5 represents a three layered combined WSF, wherein a WSF with liner (21) is coated with a tie-coat (22) and further coated with a binder (23) to laminate another WSF (24). This will form a double layered WSF. The WSF (24) of the double layered WSF is again coated with a tie coat (25) and further coated with a binder (26) to laminate the third layer of WSF (27) to form a three layered film. The tie-coats (22) and (25) and the binders (23) and (26) coated on the respective water soluble films can be of same type or different type. In the same way, by repeating the above process, any number of layers can be laminated to form a combined multi-layered WSF. While making a multi-layered WSF, different or same kind of active ingredients in desired amount can be incorporated in the binder and/or tie-coat so as to have a multi-layered WSF to carry several or same types of active ingredients, for diverse uses. The water soluble films mentioned in the above processes may be cold water soluble, hot water soluble, warm water soluble, edible or non edible depending upon the end application. 24 We Claim: 1. (Currently amended) A cast-extruded or a cast-cast combined water soluble film (WSF) comprising of at least one layer of solution cast WSF provided with a detachable liner, combined with one or more of a water soluble film and further provided with a binder coat in between the two WSF layers; wherein the said binder coat comprises a batch solution of water soluble film and the like, and the said binder coat is preferably associated with a acrylic dispersion used as a tie coat between a WSF and the binder coat. 2. The combined WSF as claimed in claim 1, wherein the said preformed WSF is preferably a thermally extruded WSF, such as blown (bubble type) or slit die-cast (extrusion curtain type), forming a cast-extruded combined WSF. 3. The combined WSF as claimed in claim 1, wherein said preformed WSF is a solution cast WSF forming a cast-cast combined WSF. 4. The combined WSF as claimed in claim 1, wherein said solution cast WSF with liner is preformed. 5. The combined WSF as claimed in claim 1, wherein said solution cast WSF with liner is formed in situ. 6. The combined WSF as claimed in claim 1, wherein said tie coat provided on the solution cast WSF with liner is selected from acrylic acid polymers, acrylic ester polymers, soluble acrylic acid copolymers, soluble acrylic ester copolymers, soluble copolymers of acrylic acids and esters, cross linked polyvinyl alcohols, cross linked cellulose derivatives, ethyl cellulose, nitrocellulose, cellulose butyrate, cellulose acetate butyrate, ethylene vinyl polyalcohol, ethylene vinyl acetate, PVDC (polyvinyldene chloride), acrylic emulsion, PVC (polyvinyl chloride) emulsion, PVDC emulsion, PVB (polyvinyl butyral), natural arid synthetic waxes, polyurethanes and modified polyvinyl alcohols. 25 7. The combined WSF as claimed in claim 1, wherein said binder provided on the solution cast WSF with liner directly or over the tie coat is a binder selected from any low viscosity, low solid content binder like different types of adhesives such as pressure sensitive adhesives, cast water soluble film solution, polyurethane dispersion or even a liquid flavour. 8. The combined WSF as claimed in claim 1, wherein the said solution cast WSF with liner forming one layer and the said preformed WSF forming another layer, are formed of non-edible materials selected from Polyvinyl alcohol copolymer ionomers, Polyvinyl alcohol homopolymer, non - ionomeric poly vinyl alcohol polymer, Polymethacrylate., polyvinyl alchohol, polyacrylamide, polymethacrylamide, polyacrylic acid, polymethacrylic acid, biodegradable polyesters such as ecoflex; polylactic acid (PLA), polyhydroxyalkanoic acid (PHA) and polyurethane. 9. The combined WSF as claimed in claim 1, wherein the said solution cast WSF with liner forming one layer and the said preformed WSF forming another layer, are formed of edible materials selected from polyethyleneglycol, polyvinylpyrrolidone, proteinaceous binders such as gelatin, modified gelatins such as phthaloyl gelatin, polysaccharides such as starch and its derivatives, sorbitol, sucrose derivatives, gum Arabic, pullulan and dextrin and water-soluble cellulose derivatives or combination thereof. The cellulose derivatives used are methyl cellulose, hydroxy propyl cellulose, hydroxy propyl methyl cellulose, hydroxy propyl ethyl cellulose, hydroxy ethyl cellulose and carboxy methyl cellulose. 10. (Currently amended) The combined WSF as claimed in claim 1, wherein the said tie coat and/or the said binder is incorporated with desired amount of one or more, same or different types of active ingredients, as per the requirement 11. (Currently amended) The combined WSF as claimed in claim 1, wherein the said one or more active ingredients are selected from flavours, perfumes, detergents, enzymes, softeners, active agents for cleaning laundry, dishes, floorings, walls, furniture; various agrochemicals like pesticides, insecticides, weedicides, fungicides, bio-pesticides; agro nutrients like urea, fertilizers; dyes, pigments, fluff, pulp, super absorbents and active pharma ingredients like vitamins, drugs, medicine. 12. The combined WSF as claimed in claim 1, wherein the said detachable liner of the solution cast WSF and optionally of preformed WSF is made of paper, film, foil or fabric, treated or untreated, coated or uncoated, preferably the said liner is made of film, more preferably polyester film. The films can thickness ranging from 3 microns to 500 microns, preferably from 10 microns to 300 microns, more preferably from 25 microns to 100 microns. The film liner may be plain, metallised, embossed, gloss, matt, extrusion coated, laminated or release coated depending on the desired characteristics of the end product. Paper liners are also used for production of WSF. Paper liners that accept temperatures needed for the production of WSF and have thickness ranging from 7 GSM (grams per sq meter - the standard for measuring weight of paper) to 500 GSM, preferably from 20 GSM to 300 GSM, more preferably from 60 GSM to 180 GSM can be used. The paper liner may be plain, embossed, gloss, matt, extrusion coated laminated or release coated depending on the desired characteristics of the end product. Fabrics made of cotton or synthetic yarns, solution coated, plain, embossed, gloss, matt, extrusion coated or laminated. 13. The combined WSF as claimed in claim 1, wherein the said WSF is cold water soluble, warm water soluble, hot water soluble, edible or non edible, depending upon the raw materials used according to the requirement of various applications. 14. A method/process for producing a cast-extruded or cast-cast combined WSF as claimed in claim 1, comprising of the following steps: a) placing a preformed WSF with detachable liner on an unwinder of a coating machine, forming one layer of the combined WSF, 27 b) placing another preformed WSF with or without a detachable liner on another unwinder of the coating machine, forming another layer of the combined WSF, c) unwinding said preformed WSF with liner and passing through a coating head of a coating machine for applying a tie coat on one surface, opposite to liner, of said WSF, d) drying and curing the tie coated WSF by passing it through a coating head of the coating machine, the temperature of the drying section ranging from 50 C to 200°C, preferably from 60°C to 175°C, more preferably from 75°C to 150°C, e) applying a binder coat over the said tie coat of the WSF with liner by passing it through another coating section of the coating machine, f) passing the WSF with liner having tie coat followed by binder coat through an air blower section of the coating machine for semi-drying the binder, the temperature of the blower section ranging from 10°C to 100°C, preferably from 30°C to 70°C, more preferably from 30°C to 50°C, g) unwinding the said other preformed WSF and guiding it to combine with the first WSF of the step (f) by passing through a nip roll of the coating machine, forming a laminated double layered combined WSF, h) rewinding the laminate of combined WSF of step (g) on a re winder and storing for internal ageing, i) detaching the liner and slitting/cutting the combined WSF laminate, as per requirement. 15. The process as claimed in claim 14, wherein the said preformed WSF with liner is unwound and applied with the binder coat directly, without coating it with the tie coat. 16. A method/process for producing a cast-extruded or cast-cast combined WSF as claimed in claim 1, comprising of the following steps: a) placing a liner for casting WSF on it, on an unwinder of a casting-cum-coating machine, b) placing a preformed WSF with or without a detachable liner on another unwinder of a casting-cum-coating machine, c) unwinding the liner and casting WSF on it by using known edible or non-edible formulations of WSF in a batch reactor and metering the cast WSF at the primary casting head of a casting-cum-coating machine, the temperature of the batch solution in the reactor ranging from 10°C to 95°C, preferably from 13°C to 90°C and more preferably from 15°C to 85°C, d) drying the cast WSF of step (c) at a primary drying section, forming one/first layer of the combined WSF, the temperature in the drying section ranging form 50°C to 200°C, preferably from 60°C to 175°C and more preferably from 75°C to l50°C, e) applying a tie-coat on one side of the WSF with the liner passing through a coating head, f) drying and curing the tie-coated WSF by passing it through the drying section of the casting-cum-coating machine, the temperature in the drying section ranging from 50°C to 200°C, preferably from 60°C to 175°C, more preferably from75°C to l50°C, g) applying a binder coat over the said tie coat of the WSF with liner by passing it through another coating section of the coating machine, h) passing the WSF with liner having tie coat followed by binder coat through an air blower section of the coating machine for semi-drying the binder, the temperature of the blower section ranging from 10°C to 100°C, preferably from 30°C to 70°C, more preferably from 30°C to 50°C, i) unwinding the said other WSF and guiding it to combine with the first WSF of the step (h) by passing through a nip roll of the coating machine, forming a laminated double layered combined WSF, j) rewinding the laminate of combined WSF of step (i) on a rewinder and storing for internal ageing, k) detaching the liner and slitting/cutting the combined WSF laminate, as per requirement. 17. (currently amended) The process as claimed in claim 14 or l6, wherein the cast WSF on a detachable liner after drying at primary drying section is applied with a binder coat directly, without coating it with the tie-coat. 18. The process as claimed in claim 14 or 16, wherein the said tie-coat is preferably applied by using a gravure cylinder of varying cell sizes and depths; or by using flexo plates of varying cell sizes and depths, or by combination of flexo plates with gravure cylinder, for transferring net solid contents of the tie-coat from the cells of the cylinder and that maximum water/solvent is scrapped before hand by cam shaft moving doctoring blade. 19. The process as claimed in claim 14 or 16, wherein the said tie coat is selected from acrylic acid polymers, acrylic ester polymers, soluble acrylic acid copolymers, soluble acrylic ester copolymers, soluble copolymers of acrylic acids and esters, cross linked polyvinyl alcohols, cross linked cellulose derivatives, ethyl cellulose, nitrocellulose, cellulose butyrate, cellulose acetate butyrate, ethylene vinyl polyalcohol, ethylene vinyl acetate, PVDC (polyvinyldene chloride), acrylic emulsion, PVC (polyvinyl chloride) emulsion, PVDC emulsion, PVB (polyvinyl butyral), natural arid synthetic waxes, polyurethanes and modified polyvinyl alcohols. 20. The process as claimed in claim 14, 15, 16 or 17, wherein the said binder coat is applied by using a wire bound mayer bar. 21. The process as claimed in claim 14 or 16, wherein the said liner is made of paper, film, foil or fabric, treated or untreated, coated or uncoated, preferably the said liner is made of film, more preferably polyester film. The films can thickness ranging from 3 microns to 500 microns, preferably from 10 microns to 300 microns, more preferably from 25 microns to 100 microns. The film liner may be plain, metallised, embossed, gloss, matt, extrusion coated, laminated or release coated depending on the desired characteristics of the end product. Paper liners are also used for production of WSF. Paper liners that accept temperatures needed for the production of WSF and have thickness ranging from 7 GSM (grams per sq meter - the standard for measuring weight of paper) to 500 GSM, preferably from 20 GSM to 300 GSM, more preferably from 60 GSM to 180 GSM can be used. The paper liner may be plain, embossed, gloss, matt, extrusion coated laminated or release coated depending on the desired characteristics of the end product. Fabrics made of cotton or synthetic yarns, solution coated, plain, embossed, gloss, matt, extrusion coated or laminated. 22.The process as claimed in claim 14 or 16, wherein the said binder is selected from any low viscosity, low solid content binder like different types of adhesives such as pressure sensitive adhesives, cast water soluble film solution, polyurethane dispersion or even a liquid flavour. 23.The process as claimed in claim 14 or 16, wherein the said edible WSF formulation is formed of edible materials selected from polyethyleneglycol, polyvinylpyrrolidone, proteinaceous binders such as gelatin, modified gelatins such as phthaloyl gelatin, polysaccharides such as starch and its derivatives, sorbitol, sucrose derivatives, gum Arabic, pullulan and dextrin and water-soluble cellulose derivatives or combination thereof. The cellulose derivatives used are methyl cellulose, hydroxy propyl cellulose, hydroxy propyl methyl cellulose, hydroxy propyl ethyl cellulose, hydroxy ethyl cellulose and carboxy methyl cellulose. 24.The process as claimed in claim 14 or 16, wherein the said non-edible WSF formulation is formed of non-edible materials selected from Polyvinyl alcohol copolymer ionomers, Polyvinyl alcohol homopolymer, non - ionomeric poly vinyl alcohol polymer, Polymethacrylate., polyvinyl alchohol, polyacrylamide, pplymethacrylamide, polyacrylic acid, polymethacrylic acid biodegradable polyesters such as ecoflex; polylactic acid (PLA), polyhydroxyalkanoic acid (PHA) and polyurethane. 25. The process as claimed in claim 14 or 16, wherein one or more of same or different types of active ingredients are incorporated in the said tie-coat and/or the said binder. 26.The process as claimed in claim 25, wherein the said active ingredients are selected from flavours, perfumes, detergents, enzymes, softeners, active agents for cleaning laundry, dishes, floorings, walls, furniture; various agrochemicals like pesticides, insecticides, weedicides, fungicides, bio-pesticides; agro nutrients like urea, fertilizers; dyes, pigments, fluff, pulp, super absorbents and active pharma ingredients like vitamins, drugs, medicine. 27.The process as claimed in claim 14 or 16, wherein the raw materials of the WSF, the tie-coat and/or the binder are selected such that the combined WSF is soluble in cold water, warm water or hot water, as per requirement. 28.The process as claimed in claim 15 or 17, wherein the WSF with liner is moved at high speed, preferably from 15 to 100 meter/min., more preferably from 25 to 70 meter/min. for preventing the WSF from dissolving when the binder is applied on it directly, without the tie-coat. 29.The process as claimed in claim 15 or 17, wherein the air blower section temperature is kept high ranging from 20°C to 100°C, preferably from 30°C to 70°C, more preferably from 50°C to 60°C for instantly semi-drying the said binder coated directly without the tie-coat, for preventing the WSF from dissolving. 30. A method/process of producing cast-cast or cast-extruded combined WSF, comprising of the following steps: i. placing/loading a preformed WSF with a detachable liner on a flat die extruder, ii. extruding desired thickness of WSF directly onto the said preformed cast WSF with liner through the extruder, iii. passing the combined WSF laminate of step (b) through chilling cylinders, keeping the said liner in contact with the chilling cylinder, iv. rewinding the combined WSF laminate of step (c) on a rewinder and storing for internal ageing period, v. detaching the liner and slitting/cutting the combined WSF laminate as per requirement. 31. The process as claimed in claim 30, wherein the said preformed WSF with detachable liner is cast/solution cast WSF. 32. The process as claimed in claim 30, wherein the said liner is a hydrophobic, thermally active detachable liner. 33. The process as claimed in claim 14, 15,16, 17 or 30, wherein the said combined WSF laminate is stored for an internal ageing period ranging from 1 hour to 720 hours, preferably from 10 hours to 360 hours and more preferably from 24 hours to 100 hours. 34.The process as claimed in claim 14, 15, 16, 17 or 30, wherein the said double layered combined WSF with liner is unwound and applied with a tie-coat in a coating head, dried and cured in the drying section, applied with a binder coat over the said tie-coat in another coating section, passed through air blower section for semi drying the binder coat and combined with a third layer of WSF with or without detachable liner by passing through nip roll and rewound on another rewinder forming three layered combined WSF. 35. The process as claimed in claim 14, 15, 16, 17 or 30, wherein the said double layered combined WSF with liner is unwound and applied with a binder coat directly, without the tie-coat, in a coating section, passed through air blower section for semi drying the binder coat and combined with a third layer of WSF with or without detachable liner by passing through nip roll and rewound on another rewinder forming three layered combined WSF. 36.The process as claimed in claim 14, 15, 16, 17 or 30, wherein the said double layered combined WSF with liner is unwound and passed through the flat die extruder for extruding desired thickness of WSF directly on it and passed through the chilling cylinder and rewound on the rewinder forming three layered combined WSF. 37. The process as claimed in claim 34, 35 or 36, wherein the said process is repeated to form any desired numbers of multi-layered combined WSF of this invention. 38. The method/process as claimed in claim 34, 35, 36 or 37, wherein one or more of the same or different types of active ingredients are incorporated in the binder and/or the tie-coat and/or in the flat die extruder while extruding the desired thickness of WSF directly on the preformed WSF with liner. 39. The process as claimed in claim 34, 35, 36 or 37, wherein the said combined WSF laminate is stored for an internal ageing period ranging from 1 hour to 720 hours, preferably from 10 hours to 360 hours and more preferably from 24 hours to 100 hours. 40. A method/process for producing cast-extruded or cast-cast combined WSF substantially as herein described Arrow Coated Products Ltd. Dated this 12th day of January, 2006

Full Text

FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See section 10 and Rule 13)
1. TITLE OF INVENTION
"Cast-extruded or cast-cast combined water soluble film and the method/process for producing the same"
2. Applicant(s)
(a) Name: Arrow Coated Products Ltd.
(b) Nationality: Indian Company
(c) Address: Arrow Coated Products Ltd.,
5-D, Laxmi Industrial Estate, New Link Road, Andheri (West), Mumbai- 400053, Maharashtra State, India
3. Preamble to the description
The following specification particularly describes the nature of this
invention and the manner in which it is to be performed

This invention relates to a cast-extruded or a cast-cast combined water soluble film and a method/process for producing the same.
More particularly, this invention relates to a combined water soluble film wherein atleast one layer is a solution cast water soluble film on a liner and atleast one layer is a preformed water soluble film, preferably a thermally extruded water soluble film. The said water soluble films may be edible or non edible. The said water-soluble film on a liner is coated with a tie-coat to enable coating of a water-based binder used for combining the water soluble films without dissolving/damaging WSF on liner. The water based binder used for combining the said water soluble! films may be incorporated with active ingredients like flavours, perfumes, detergents, enzymes, softeners, active agents for cleaning laundry, dishes, floorings, walls, furniture; various agrochemicals like pesticides, insecticides, weedicides, fungicides, bio-pesticides; agro nutrients like urea, fertilizers; dyes, pigments, fluff, pulp, super absorbents and active pharma ingredients like vitamins, drugs, medicine. The said combined water soluble film so achieved will be a substantially pinhole free multi-layered water soluble film of desired mechanical strength at low cost.
The Background of Invention
Water soluble films (WSFs) are commercially well known in the market. These films are usually used for packaging purpose such as liquid detergents, agrochemicals, toilet blocks, laundry bags, fish baits, pigments and dyestuffs, liquid chemicals and for embroidery purpose such as for making lace or can be used as a backing or a topping for embroidery. However, these applications are by no means limiting. These films may be biodegradable.
These films are produced by solution cast method or by extrusion method. Solution cast films are cast from a slot, which controls thickness and weight, onto a steel belt or steel drum or a suitable liner etc.
Extruded films can be blown (bubble type) or slit-die cast (Extrusion curtain type).
In blown film extrusion, the molten polymer from the extruder enters the die and is
forced around a mandrel and emerges from a ring shaped die. The extruded film tube is
2

then expanded to a specific diameter by air pressure from the center of the mandrel. As
the bubble expands, the film thickness decreases.
In slit die extrusion or flat film extrusion, the WSF is produced by extruding molten
polymer through a slit-die and then cooling it on chilled rollers or in a water bath. In flat
film extrusion, it is important to cool the material within a short distance of the die head
so that a clear film is produced and necking (reduction in; width) does not occur..
These films can be co-extruded in multiple layers or can be fed through multiple hoppers
and/or screws. Manufacturing process and the blend will determine the quality of the
film.
All types of extrusion methods are thermally reactive and create pinholes in the resultant
films. These pinholes are due to various reasons including improper thermal reactions,
changes in polymer's molecular weight, improper gauge variation, uneven relative
humidity acceptance, improper polymer melts, etc. Pinholes are detrimental to the final
quality of the product being packed and are not acceptable to the industry. The films so
formed have less "shrink back" property.
Another problem of this method is control of moisture equilibrium within the WSF. This
equilibrium is vital to get the right mechanical properties of WSF.
But this process is economical to produce. So there was a need for pinhole free or
substantially pinhole free water soluble film.
Solution cast manufacturing process is a well accepted process to produce water soluble film with considerably less pinholes. In this process the polymers and additives are all dissolved completely in solvents, like, but not limited to, water of varying qualities and varying temperatures, while mixing in a batch mixing reactor. This leaves less possibility of pinholes as the polymers melts/dissolves in near totality. The additives mix properly and completely and thus the resultant film is of better quality. Moisture equilibrium, thickness and solubility can be finely controlled in this process.
But this process is expensive, as the solution has to be cast on metal belt or a conveyor or a detachable liner and cured after the solvents dry out.
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So there has been a need for an economical and substantially pinhole free water soluble film, with optimal mechanical properties.
Combining two water soluble films had their own set of problems. One cannot blow a film on top of a solution cast film, as blown films are in a bubble form and solution cast films are in web forms individually wound.
One cannot do T Die extrusion of a water soluble film on a solution cast film web as the film shall not come out unstuck from the chilling cylinder, which is inherent part of the T die extrusion process.
Similar problems shall be faced during any of the combination of thermally activated extruded film with cast film.
Similarly, one cannot cast a wet mix solution, which is usually cast on a conveyor at about 10°C to 95°C, preferably between 30°C to 70°C, more preferably between 35°C to 60°C. Casting such a wet/ liquid solution on a web of blown/extruded film shall dissolve partially or completely the web, prior to the combination web reaching the dryers and prove it to be commercially unviable.
Also, while dispersing the active ingredient into the water soluble film, it has been noticed that some active ingredients like perfumes which are mixed in the batch used for forming the water soluble film layer diminishes after some time during storage, thereby affecting the quality.
The Indian prior art 443/MUM/2001, relates to process for manufacturing embedded/entrapped water-soluble film (WSF) system and water soluble film (WSF) system manufactured by the said process. This invention describes the process for manufacturing water soluble films (WSFs) for diverse applications, in which a variety of substances such as detergents, enzymes, softeners, perfumes; agrochemicals like pesticides, fungicides, herbicides, weedicides, insecticides; agro nutrients like urea,
4

fertilizers; dyes, pigments, hazardous chemicals, fluff, pulp, super absorbents, active
agents for cleaning laundry, dishes, floorings, walls and the like are embedded for
delivering them in precise and desired quantities
The above patent relates, to a water soluble film embedded/entrapped with active
ingredients for precise delivery of active ingredients. It is restricted to embedding active
ingredients within WSF and does not describe a process of combining two water soluble
films.
Another Indian patent, 1158/MUM/2001 discloses novel pin-hole free multi-layered films consisting partially or fully water soluble films layered! with substantially pin-hole free barrier coatings that are partially insoluble or fully water-soluble or dispersible and methods of manufacturing. The patent describes the detachable and/or non detachable substrate based multi-layered films with water soluble! or partially water-soluble films layered with substantially pin-hole free barrier coatings and methods of manufacturing the same.
The above patent relates to a pinhole free multi-layered film by barrier coating on a water soluble film along with a liner. However, the patent does not describe a process of combining two water soluble films.
Combination of two layers of water soluble films is desirable but difficult due to hydrophilic properties of both the layers. Various trials were taken and experiments conducted for combining the two layers of any types of water soluble films. This resulted in one of the film dissolving just on applying the coating of an adhesive, creating a hole or a void even before the next layer is brought for lamination. Experiments were even done for combining two layers of water soluble films by using adhesives base on hydrocarbon based solvents like, but not limited to xylene, toluene, MEK, MIBK, but the anchorage of these adhesives was not satisfactory.
Hence, the main object of the present invention is to provide a cast-extruded or a cast-cast combined water soluble film, wherein the water soluble film on a liner is coated with a time-delay tie-coat to enable coating of a binder used for combining the layers of water
5

soluble films to achieve a substantially pinhole free multi-layered water soluble film of desired mechanical strength at low cost.
Another object of this invention is to provide a combined water soluble film in which the properties like smell of the active ingredient such as perfume is retained for a longer period as the perfume is added to the binder and/or the tie-coat and which will remain blocked between the outer layers of the water soluble film and thereby improving the quality of perfumed/flavoured film.
Yet another object of this invention is to provide a combined water soluble film, wherein other active ingredients like flavours, perfumes, detergents, enzymes, softeners, active agents for cleaning laundry, dishes, floorings, walls, furniture; various agrochemicals like pesticides, insecticides, weedicides, fungicides, bio-pesticides; agro nutrients like urea, fertilizers; dyes, pigments, fluff, pulp, super absorbents and active pharma ingredients like vitamins, drugs, medicine are added to the binder and/or the tie-coat for different applications.
Statement of invention
Thus according to one aspect of this invention, there is provided a cast-extruded or a cast-cast combined WSF comprising of atleast one layer of solution cast WSF with a detachable liner, preferably provided with a tie coat, a binder coating provided on the said solution cast WSF with liner, with or without the said tie-coat and atleast one layer of preformed WSF with or without a detachable liner provided over the said binder coat forming a substantially pin hole free combined multi-layered WSF of desired mechanical strength, at low cost.
Accordingly this invention provides a combined WSF, wherein the said preformed WSF is preferably a thermally extruded WSF, such as blown (bubble type) or slit die-cast (extrusion curtain type), forming a cast-extruded combined WSF.
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Accordingly this invention provides a combined WSF, wherein said preformed WSF is a solution cast WSF forming a cast-cast combined WSF.
Accordingly this invention provides a combined WSF, wherein said solution cast WSF with liner is preformed.
Accordingly this invention provides a combined WSF, wherein said solution cast WSF with liner is formed in situ.
Accordingly this invention provides a combined WSF, wherein said tie coat provided on the solution cast WSF with liner is selected from acrylic acid polymers, acrylic ester polymers, soluble acrylic acid copolymers, soluble acrylic ester copolymers, soluble copolymers of acrylic acids and esters, cross linked polyvinyl alcohols, cross linked cellulose derivatives, ethyl cellulose, nitrocellulose, cellulose butyrate, cellulose acetate butyrate, ethylene vinyl polyalcohol, ethylene vinyl acetate, PVDC (polyvinyldene chloride), acrylic emulsion, PVC (polyvinyl chloride) emulsion, PVDC emulsion, PVB (polyvinyl butyral), natural arid synthetic waxes, polyurethanes and modified polyvinyl alcohols.
Accordingly this invention provides a combined WSF, wherein said binder provided on the solution cast WSF with liner directly or over the tie coat is a binder selected from any low viscosity, low solid content binder like different types of adhesives such as pressure sensitive adhesives, cast water soluble film solution, polyurethane dispersion or even a liquid flavour.
Accordingly this invention provides a combined WSF, wherein the said solution cast WSF with liner forming one layer and the said preformed WSF forming another layer, are formed of non-edible materials selected from Polyvinyl alcohol copolymer ionomers, Polyvinyl alcohol homopolymer, non - ionomeric poly vinyl alcohol polymer, Polymethacrylate., polyvinyl alchohol, polyacrylamide, polymethacrylamide, polyacrylic
7

acid, polymethacrylic acid, biodegradable polyesters such as ecoflex; polylactic acid (PLA), polyhydroxyalkanoic acid (PHA) and polyurethane.
Accordingly this invention provides a combined WSF, wherein the said solution cast WSF with liner forming one layer and the said preformed WSF forming another layer, are formed of edible materials selected from polyethyleneglycol, polyvinylpyrrolidone, proteinaceous binders such as gelatin, modified gelatins such as phthaloyl gelatin, polysaccharides such as starch and its derivatives, sorbitol, sucrose derivatives, gum Arabic, pullulan and dextrin and water-soluble cellulose derivatives or combination thereof. The cellulose derivatives used are methyl cellulose, hydroxy propyl cellulose, hydroxy propyl methyl cellulose, hydroxy propyl ethyl cellulose, hydroxy ethyl cellulose and carboxy methyl cellulose.
Accordingly this invention provides a combined WSF, wherein the said tie coat and/or the said binder is incorporated with desired amount of one or more, same or different types of active ingredients, as per the requirement.
Accordingly this invention provides a combined WSF, wherein the said one or more active agents are selected from flavours, perfumes, detergents, enzymes, softeners, active agents for cleaning laundry, dishes, floorings, walls, furniture; various agrochemicals like pesticides, insecticides, weedicides, fungicides, bio-pesticides; agro nutrients like urea, fertilizers; dyes, pigments, fluff, pulp, super absorbents and active pharma ingredients like vitamins, drugs, medicine.
Accordingly this invention provides a combined WSF, wherein the said detachable liner of the solution cast WSF and optionally of preformed WSF is made of paper, film, foil or fabric, treated or untreated, coated or uncoated, preferably the said liner is made of film, more preferably polyester film. The films can thickness ranging from 3 microns to 500 microns, preferably from 10 microns to 300 microns, more preferably from 25 microns to 100 microns. The film liner may be plain, metallised, embossed, gloss, matt, extrusion coated, laminated or release coated depending on the desired characteristics of the end
8

product. Paper liners are also used for production of WSF. Paper liners that accept temperatures needed for the production of WSF and have thickness ranging from 7 GSM (grams per sq meter - the standard for measuring weight of paper) to 500 GSM, preferably from 20 GSM to 300 GSM, more preferably from 60 GSM to 180 GSM can be used. The paper liner may be plain, embossed, gloss, matt, extrusion coated laminated or release coated depending on the desired characteristics Of the end product. Fabrics made of cotton or synthetic yarns, solution coated, plain, embossed, gloss, matt, extrusion coated or laminated.
Accordingly this invention provides a combined WSF, wherein the said WSF is cold water soluble, warm water soluble, hot water soluble, edible or non edible, depending upon the raw materials used according to the requirement of various applications.
Accordingly this invention provides a method/process for producing a cast-extruded or cast-cast combined WSF comprising of the following steps:
a. placing a preformed WSF with detachable liner on an unwinder of a coating
machine, forming one layer of the combined WSF,
b. placing another preformed WSF with or without a detachable liner on another
unwinder of the coating machine, forming another layer of the combined WSF,
c. unwinding said preformed WSF with liner and passing through a coating head of a
coating machine for applying a tie coat on one surface, opposite to liner, of said
WSF,
d. drying and curing the tie coated WSF by passing it through a coating head of the
coating machine, the temperature of the drying section ranging from 50°C to 200°C,
preferably from 60°C to 175°C, more preferably from 75°C to 150°C,
e. applying a binder coat over the said tie coat of the WSF with liner by passing it
through another coating section of the coating machine,
f. passing the WSF with liner having tie coat followed by binder coat through an air
blower section of the coating machine for semi-drying the binder, the temperature of
the blower section ranging from 10°C to 100°C, preferably from 30°C to 70°C, more
preferably from 30°C to 50°C,
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g. unwinding the said other preformed WSF and guiding it to combine with the first
WSF of the step (f) by passing through a nip roll of the coating machine, forming a
laminated double layered combined WSF, h. rewinding the laminate of combined WSF of step (g) on a rewinder and storing for
internal ageing, i. detaching the liner and slitting/cutting the combined WSF laminate, as per
requirement.
Accordingly this invention provides a method/process producing a cast-extruded or cast-cast combined WSF, comprising of the following steps:
a. placing a liner for casting WSF on it, on an unwinder of a casting-cum-coating
machine,
b. placing a preformed WSF with or without a detachable liner on another unwinder of
a casting-cum-coating machine,
c. unwinding the liner and casting WSF on it by using known edible or non-edible
formulations of WSF in a batch reactor and metering the cast WSF at the primary
casting head of a casting-cum-coating machine, the temperature of the batch solution
in the reactor ranging from 10°C to 95°C, preferably from 13°C to 90°C and more
preferably from 15°C to 85°C,
d. drying the cast WSF of step (c) at a primary drying section, forming one/first layer
of the combined WSF, the temperature in the drying section ranging form 50°C to
200°C, preferably from 60°C to 175°C and more preferably from 75°C to 150°C,
e. applying a tie-coat on one side of the WSF with the liner passing through a coating
head,
f. drying and curing the tie-coated WSF by passing it through the drying section of the
casting-cum-coating machine, the temperature in the drying section ranging from
50°C to 200°C, preferably from 60°C to 175°C, more preferably from 75°C to 150°C,
g. applying a binder coat over the said tie coat of the WSF with liner by passing it
through another coating section of the coating machine,
h. passing the WSF with liner having tie coat followed by binder coat through an air blower section of the coating machine for semi-drying the binder, the temperature of
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the blower section ranging from 10°C to 100°C, preferably from 30°C to 70°C, more
preferably from 30°C to 50°C, i. unwinding the said other WSF and guiding it to combine with the first WSF of the
step (h) by passing through a nip roll of the coating machine, forming a laminated
double layered combined WSF, j. rewinding the laminate of combined WSF of step (i) on a rewinder and storing for
internal ageing, k. detaching the liner and slitting/cutting the combined WSF laminate, as per
requirement.
Accordingly this invention provides a method/process, wherein the cast WSF on a detachable liner after drying at primary drying section is applied with a binder coat directly, without coating it with the tie-coat.
Accordingly this invention provides a method/process, wherein the said tie-coat is preferably applied by using a gravure cylinder of varying cell sizes and depths; or by using flexo plates of varying cell sizes and depths, or by combination of flexo plates with gravure cylinder, for transferring net solid contents of the tie-coat from the cells of the cylinder and that maximum water/solvent is scrapped before hand by cam shaft moving doctoring blade.
Accordingly this invention provides a method/proces$, wherein the said tie coat is selected from acrylic acid polymers, acrylic ester polymers, soluble acrylic acid copolymers, soluble acrylic ester copolymers, soluble copolymers of acrylic acids and esters, cross linked polyvinyl alcohols, cross linked cellulose derivatives, ethyl cellulose, nitrocellulose, cellulose butyrate, cellulose acetate butyrate, ethylene vinyl polyalcohol, ethylene vinyl acetate, PVDC (polyvinyldene chloride), acrylic emulsion, PVC (polyvinyl chloride) emulsion, PVDC emulsion, PVB (polyvinyl butyral), natural arid synthetic waxes, polyurethanes and modified polyvinyl alcohols.
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Accordingly this invention provides a method/process, wherein the said binder coat is applied by using a wire bound mayer bar.
Accordingly this invention provides a method/process, wherein the said liner is made of paper, film, foil or fabric, treated or untreated, coated or uncoated, preferably the said liner is made of film, more preferably polyester film. The films can thickness ranging from 3 microns to 500 microns, preferably from 10 microns to 300 microns, more preferably from 25 microns to 100 microns. The film liner may be plain, metallised, embossed, gloss, matt, extrusion coated, laminated or release coated depending on the desired characteristics of the end product. Paper liners are also used for production of WSF. Paper liners that accept temperatures needed for the production of WSF and have thickness ranging from 7 GSM (grams per sq meter - the standard for measuring weight of paper) to 500 GSM, preferably from 20 GSM to 300 GSM, more preferably from 60 GSM to 180 GSM can be used. The paper liner may be plain, embossed, gloss, matt, extrusion coated laminated or release coated depending on the desired characteristics of the end product. Fabrics made of cotton or synthetic yarns, solution coated, plain, embossed, gloss, matt, extrusion coated or laminated.
Accordingly this invention provides a method/process, wherein the said binder is selected from any low viscosity, low solid content binder like different types of adhesives such as pressure sensitive adhesives, cast water soluble film solution, polyurethane dispersion or even a liquid flavour.
Accordingly this invention provides a method/process wherein the said edible WSF formulation is formed of edible materials selected from polyethyleneglycol, polyvinylpyrrolidone, proteinaceous binders such as gelatin, modified gelatins such as phthaloyl gelatin, polysaccharides such as starch and its derivatives, sorbitol, sucrose derivatives, gum Arabic, pullulan and dextrin and water-soluble cellulose derivatives or combination thereof. The cellulose derivatives used are methyl cellulose, hydroxy propyl cellulose, hydroxy propyl methyl cellulose, hydroxy propyl ethyl cellulose, hydroxy ethyl cellulose and carboxy methyl cellulose.
12

Accordingly this invention provides a method/process, wherein the said non-edible WSF formulation is formed of non-edible materials selected from Polyvinyl alcohol copolymer ionomers, Polyvinyl alcohol homopolymer, non - ionomeric poly vinyl alcohol polymer, Polymethacrylate., polyvinyl alchohol, polyacrylamide, polymethacrylamide, polyacrylic acid, polymethacrylic acid biodegradable polyesters such as ecoflex; polylactic acid (PLA), polyhydroxyalkanoic acid (PHA) and polyurethane.
Accordingly this invention provides a method/process, wherein one or more of same or different types of active ingredients are incorporated in.the said tie-coat and/or the said binder.
Accordingly this invention provides a method/process, wherein the said active ingredients are selected from flavours, perfumes, detergents, enzymes, softeners, active agents for cleaning laundry, dishes, floorings, walls, furniture; various agrochemicals like pesticides, insecticides, weedicides, fungicides, bio-pesticides; agro nutrients like urea, fertilizers; dyes, pigments, fluff, pulp, super absorbents and active pharma ingredients like vitamins, drugs, medicine.
Accordingly this invention provides a method/process, wherein the raw materials of the WSF, the tie-coat and/or the binder are selected such that the combined WSF is soluble in cold water, warm water or hot water, as per requirement.
Accordingly this invention provides a method/process, wherein the WSF with liner is moved at high speed, preferably from 15 to 100 meter/min., more preferably from 25 to 70 meter/min. for preventing the WSF from dissolving when the binder is applied on it directly, without the tie-coat.
Accordingly this invention provides a method/process, wherein the air blower section temperature is kept high ranging from 20°C to 100°C, preferably from 30°C to 70°C, more preferably from 50°C to 60°C for instantly semi-drying the said binder coated directly without the tie-coat, for preventing the WSF from dissolving.
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Accordingly this invention provides a method/process for producing cast-cast or cast-extruded combined WSF, comprising of the following steps:
a. placing/loading a preformed WSF with a detachable liner on a flat die extruder,
b. extruding desired thickness of WSF directly onto the said preformed cast WSF with
liner through the extruder,
c. passing the combined WSF laminate of step (b) through chilling cylinders, keeping
the said liner in contact with the chilling cylinder,
d. rewinding the combined WSF laminate of step (c) on a rewinder and storing for
internal ageing period,
e. detaching the liner and slitting/cutting the combined WSF laminate as per
requirement.
Accordingly this invention provides a method/process, wherein the said liner is a hydrophobic, thermally active detachable liner.
Accordingly this invention provides a method/process, wherein the said combined WSF laminate is stored for an internal ageing period ranging from 1 hour to 720 hours, preferably from 10 hours to 360 hours and more preferably from 24 hours to 100 hours.
Accordingly this invention provides a method/process, wherein the said double layered combined WSF with liner is unwound and applied with a tie-coat in a coating head, dried and cured in the drying section, applied with a binder coat over the said tie-coat in another coating section, passed through air blower section for semi drying the binder coat and combined with a third layer of WSF with or without detachable liner by passing through nip roll and rewound on another rewinder forming three layered combined WSF.
Accordingly this invention provides a method/process, wherein the said double layered combined WSF with liner is unwound and applied with a binder coat directly, without the tie-coat, in a coating section, passed through air blower section for semi drying the binder
14

coat and combined with a third layer of WSF with or without detachable liner by passing through nip roll and rewound on another rewinder forming three layered combined WSF. Accordingly this invention provides a method/process, wherein the said double layered combined WSF with liner is unwound and passed through the flat die extruder for extruding desired thickness of WSF directly on it and passed through the chilling cylinder and rewound on the rewinder forming three layered combined WSF.
Accordingly this invention provides a method/process, wherein the said process is repeated to form any desired numbers of multi-layered combined WSF of this invention.
Accordingly this invention provides a method/process, wherein one or more of the same or different types of active ingredients are incorporated in the binder and/or the tie-coat and/or in the flat die extruder while extruding the desired thickness of WSF directly on the preformed WSF with liner.
Accordingly this invention provides a method/process for producing cast-extruded or cast-cast combined WSF substantially as herein described and illustrated in figs. 1 to 5 of the accompanying drawings.
The invention will now be described with reference to accompanying drawings, wherein
Fig.l shows a schematic line diagram illustrating an offline process of combining two layers of water soluble films using a tie-coat and a binder according to an embodiment of this invention.
Fig. 2 shows a schematic line diagram illustrating an online process of combining two layers of water soluble films using a tie-coat and a binder, according to another embodiment of this invention.
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Fig. 3 shows a schematic line diagram illustrating a process of combining two layers of water soluble films, using a binder according to a further embodiment of the invention.
Fig. 4 shows a schematic line diagram illustrating a process of combining two layers of water soluble films by flat-die extruding of a water soluble film onto a water soluble film along with a detachable liner.
Fig. 5 shows a diagram illustrating a three layered combined water soluble film produced according to an embodiment of this invention.
Referring to fig.l, illustrating the offline process of producing a cast-blown or a cast-cast combined water soluble film comprising the following steps:
I. Placing a web of preformed WSF (1) with detachable liner, forming one layer of the combined WSF, on an unwinder (2) of a coating machine, wherein the said WSF (1) is a solution cast film.
II. Placing a web of preformed WSF (3) with or without detachable liner, forming another layer of the combined WSF, on another unwinder (4) of the coating machine, wherein the said WSF (3) is a solution cast film or a thermally extruded film.
III. Unwinding the preformed WSF (1) along with detachable liner at unwinder (2).
IV. Applying a tie-coat on the preformed WSF (1) by passing the WSF along with the liner through the coating head (5) of the coating machine.
The tie-coat is preferably applied preferably, by using a gravure cylinder of varying cell sizes and depths; or by using flexo plates of varying cell sizes and depths, or by combination of flexo plates with gravure cylinder, for transferring net solid contents of the tie-coat from the cells of the cylinder and that maximum water/solvent is scrapped before hand by cam shaft moving doctoring blade. These processes reduces the possibility of the pre-formed water soluble film from dissolving when the binder or subsequent WSF casting is done for the end purpose of affixing another water soluble film.
16

The tie-coat being selected from acrylic acid polymers, acrylic ester polymers, soluble acrylic acid copolymers, soluble acrylic ester copolymers, soluble copolymers of acrylic acids and esters, cross linked polyvinyl alcohols, cross linked cellulose derivatives, ethyl cellulose, nitrocellulose, cellulose butyrate, cellulose acetate butyrate, ethylene vinyl polyalcohol, ethylene vinyl acetate, PVDC (polyvinyldene chloride), acrylic emulsion, PVC (polyvinyl chloride) emulsion, PVDC emulsion, PVB (polyvinyl butyral), natural arid synthetic waxes, polyurethanes and modified polyvinyl alcohols. However, these tie-coats are by no means limiting.
These tie-coats will not allow the WSF to dissolve and will act as a barrier between the WSF and the binder to be applied at a later stage. Optionally, the tie-coat is incorporated with one or more active ingredients such as flavours, perfumes, detergents, enzymes, softeners, active agents for cleaning laundry, dishes, floorings, walls, furniture; various agrochemicals like pesticides, insecticides, weedicides, fungicides, bio-pesticides; agro nutrients like urea, fertilizers; dyes, pigments, fluff, pulp, super absorbents and active pharma ingredients like vitamins, drugs, medicine. However, these active ingredients are by no means limiting.
V. Drying and curing of WSF (1) coated with tie-coat, at the drying section (6). The temperature in the dryers ranges from 50°C to 200°C, preferably from 60°C to 175°C, more preferably from 75°C to 150°C.
VI. Passing the WSF (1) coated with tie-coat through another coating section (7) for applying/coating a binder on the tie-coat coated side of WSF. The binder is coated using a wire wound mayer bar.
The said binder being selected from any low viscosity, low solid content binder like different types of adhesives such as pressure sensitive adhesives, cast water soluble film solution, polyurethane dispersion or even a liquid flavour. However, these binders are by no means limiting. Optionally, the binder is incorporated with one or more of the active ingredients as per requirement.
17

VII. Passing through an air blower section (8) of the coating machine with or without applying heat, for semi-drying the binder. The temperature in the blower section ranges from 10°C to 100°C, preferably from 30°C to 70°C, more preferably from 30°C to 50°C.
VIII. Unwinding the pre-formed WSF (3) from the unwinder (4) and guiding it through the guide rolls (9) to combine with the WSF (1) from step VII by passing through the nip roll (10).

IX. Rewinding the laminate of combined WSF on a rewinder (11) and store for internal ageing period ranging from 1 hour to 720 hours, preferably 10 hours to 360 hours, more preferably from 24 hours to 100 hours.
X. Detaching the liner and slitting/cutting the combined WSF as per requirement.
Now, referring to fig.2, illustrating the online process of producing a cast-blown or a cast-cast combined water soluble film comprising the following steps:
I. Placing a liner (12), for casting of WSF, on an unwinder (13) of a casting-cum-coating machine. The liner (12) is optionally treated or untreated and coated or uncoated. The liner can be of paper, film, foil or fabric, preferably of film, more preferably of polyester film. The film thickness ranges from 3 microns to 500 microns, preferably from 10 microns to 300 microns, more preferably from 25 microns to 100 microns. The film liner may be plain, metallised, embossed, gloss, matt, extrusion coated, laminated or release coated depending on the desired characteristics of the end product. Paper liner is also used for production of WSF. Paper liner that accept temperatures needed for the production of WSF and have thickness ranging from 7 GSM (grams per sq meter - the standard for measuring weight of paper) to 500 GSM, preferably from; 20 GSM to 300 GSM, more preferably from 60 GSM to 180 GSM can be used. The paper liner may be plain, embossed, gloss, matt, extrusion coated laminated! or release coated depending on the desired characteristics of the end product. Fabrics made of cotton or synthetic yarns, solution coated, plain, embossed, gloss, matt, extrusion coated or laminated
18

may be used as liner based on the desired end product properties. However, these
liners are by no means limiting. II. Placing the preformed WSF (3) with or without a detachable liner, forming another
layer of the combined WSF, on another unwinder (4) of the coating machine.
wherein the said WSF (3) is a solution cast film or a thermally extruded film. HI. Unwinding of the liner (12) at unwinder (13) for the formation of WSF.
IV. Casting of WSF by using known formulation of WSF in a batch reactor (14), on the
liner (12), at the primary casting head (15). The temperature of the batch solution
ranges from 10°C to 95°C, preferably from 20°C to 85°C, more preferably from
25°C to 70°C.
The non-edible raw materials used for making the WSF are selected from Polyvinyl alcohol copolymer ionomers, Polyvinyl alcohol homopolymer, non - ionomeric poly vinyl alcohol polymer, Polymethacrylate., polyvinyl alchohol, polyacrylamide. polymethacrylamide, polyacrylic acid, polymethacrylic acid, polyurethane and edible raw materials are selected from polyethyleneglycol, polyvinylpyrrolidone, proteinaceous binders such as gelatin, modified gelatins such as phthaloyl gelatin, polysaccharides such as starch, gum Arabic, pullulan and dextrin and water-soluble cellulose derivatives or combination thereof. The cellulose derivatives used are methyl cellulose, hydroxy propyl cellulose, hydroxy propyl methyl cellulose, hydroxy propyl ethyl cellulose, hydroxy ethyl cellulose, carboxy methyl cellulose. However, these are by no means limiting.
V. Metering of the cast WSF at the primary casting head (15).
VI. Drying of the WSF of the above step V at primary drying section (16) to form the first layer of WSF (1) with the liner. The temperature in the dryers ranges form 50°C to 200°C, preferably from 60°C to 175°C, more preferably from 75°C to 150°C.
VII. Applying/Coating a tie-coat on the formed WSF (1) by passing the WSF along with the liner through a coating head (5).
The tie-coat is preferably applied preferably, by using a gravure cylinder of varying cell sizes and depths; or by using flexo plates of varying cell sizes and depths, or by combination of flexo plates with gravure cylinder, for transferring net solid contents of the tie-coat from the cells of the cylinder and that maximum water/solvent is
19

scrapped before hand by cam shaft moving doctoring blade. These processes reduces the possibility of the pre-formed water soluble film from dissolving when the binder or subsequent WSF casting is done for the end purpose of affixing another water soluble film. The tie-coat is preferably applied by using a gravure cylinder of varying cell sizes and depths, by transferring the net solid contents of the active polymers of the tie coat from the cells of the cylinder, and the water/solvent liquid is scraped before hand by the cam shaft moving doctoring blade. This process reduces the possibility of the pre-formed water soluble film from dissolving when the tie coat or subsequent WSF casting is done for the end purpose of lamination to another water soluble film.
The tie-coat being selected from acrylic acid polymers, acrylic ester polymers, soluble acrylic acid copolymers, soluble acrylic ester copolymers, soluble copolymers of acrylic acids and esters, cross linked polyvinyl alcohols, cross linked cellulose derivatives, ethyl cellulose, nitrocellulose, cellulose butyrate, cellulose acetate butyrate, ethylene vinyl polyalcohol, ethylene vinyl acetate, PVDC (polyvinyldene chloride), acrylic emulsion, PVC (polyvinyl chloride)emulsion, PVDC emulsion, PVB (polyvinyl butyral), natural arid synthetic waxes, polyurethanes and modified polyvinyl alcohols. However, these tie-coats are by no means limiting.
These tie-coats will not allow the WSF to dissolve and will act as a barrier between the WSF and the binder to be applied at a later stage. Optionally, the tie-coat is incorporated with one or; more active ingredients such as flavours, perfumes, detergents, en2ymes, softeners, active agents for cleaning laundry, dishes, floorings, walls, furniture; various agrochemicals like pesticides, insecticides, weedicides, fungicides, bio-pesticides; agro nutrients like urea, fertilizers; dyes, pigments, fluff, pulp, super absorbents and active pharma ingredients like vitamins, drugs, medicine. However, these active ingredients are by no means limiting. VIII.Drying and curing of WSF (1) coated with tie-coat at the drying section (6). The temperature in the dryers ranges from 50°C to 200°C, preferably from 60°C to 175°C, more preferably from 75°C to 150°C.
20

IX. Passing the WSF (1) coated with tie-coat through another coating section (7) for
applying/coating of the binder on the tie-coat coated side of WSF. The binder is
coated using a wire wound mayer bar.
The said binder being selected from any low viscosity, low solid content binder like different types of adhesives such as pressure sensitive adhesives, cast water soluble film solution, polyurethane dispersion or even a liquid flavour. However, these binders are by no means limiting. Optionally, the binder is incorporated with one or more of the active ingredients as described earlier.
X. Passing through an air blower section (8) with or without applying heat, for semi-
drying the binder. The temperature in the blower section ranges from 10°C to 100°C,
preferably from 30°C to 70°C, more preferably from 30°C to 50°C.
XI. Unwinding the pre-formed WSF (3) from the unwinder (4) and guiding it through the guide rolls (9) to combine with the WSF (1) from the step X by passing through the nip roll (10).
XII. Rewinding the laminate of combined WSF on a rewinder (11) and store for internal ageing period ranging from 1 hour to 720 hours, preferably 10 hours to 360 hours, more preferably from 24 hours to 100 hours.
XIII. Detaching the liner and slitting/cutting as per requirement.
Referring to fig 3, illustrating the process of producing a cast-blown or a cast-cast combined water soluble film using only the binder directly on the water soluble film along with a liner without applying any tie-coat comprising the following steps:
I. Placing the preformed WSF (1) with a detachable liner, forming one layer of the combined WSF, on an unwinder (2) of a coating machine, wherein the said WSF (1) is a solution cast film.
II. Placing the preformed WSF (3) with or without a detachable liner, forming another layer of the combined WSF, on another unwinder (4) of the coating machine.

wherein the said WSF (3) is a solution cast film or a

thermally extruded film.

III. Unwinding the preformed WSF (1) along with a detachable liner at unwinder (2)
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IV. Passing the WSF (1) through the coating section (7) for coating of the binder on the
WSF.
The said binder being selected from any low viscosity, low solid content binder like different types of adhesives such as pressure sensitive adhesives, cast water soluble film solution, polyurethane dispersion or even a liquid flavour. However, these binders are by no means limiting. Optionally, the binder is incorporated with one or more of the active ingredients as described earlier.
V. Passing through an air blower section (8) with or without applying heat, for semi-drying the binder. The temperature in the blower section ranges from 20°C to 100°C, preferably from 40°C to 80°C, more preferably from 50°C to 60°C.
VI. Unwinding the pre-formed WSF (3) from the unwinder (4) and guiding it through the guide rolls (9) to combine with the WSF (1) from step V by passing through the nip roll (10).
VII. Rewinding the laminate of combined WSF on a rewinder (11) and storing for internal ageing period ranging from 1 hour to 720 hours, preferably 10 hours to 360 hours, more preferably from 24 hours to 100 hours.
VIII.Detaching the liner and slitting/cutting as per requirement.
As this process has a detachable liner as a pre-requisite, speed of WSF (1) is kept high, preferably from 15 to 100 metres/min, more preferably from 25 to 70 metres/min, the binder will not be able to dissolve the WSF and will enable combining two films even without using a tie-coat. The property of a specified binder of thixotropic nature shall determine this process of speed, which shall not be treated as a limiting factor for this invenrion.
Further, the liner provided with the WSF (1) gives the desired strength for withstanding the binder coating for the required time enabling the combining of two layers of WSF without a tie-coat.
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Further, the temperature of the air blower section being kept at 20 C to 100 C, preferably from 40°C to 80°C, more preferably from 50°C to 60°C (higher then the temperature used for the process using tie-coat), the binder will dry instantly and will not dissolve the WSF and will enable combining two films even without using a tie-coat.
Fig. 3 of the accompanying drawing though illustrates an offline process, is equally applicable in an online process.
Referring to fig 4, illustrating the process of producing a cast-blown combined water soluble film by directly extruding a water soluble film through a flat die extruder onto a water soluble film along with a liner comprising the follovving steps:
I. Load a roll of preformed WSF (1) along with a detachable liner on a flat die extruder.
II. Extruding the desired thickness of WSF directly through the extruder (17) onto the preformed cast WSF.
III. Passing the construction from step II through chilling cylinders) (18), keeping the hydrophobic, but thermally active detachable liner in contact with the chilling cylinder.
IV. Rewinding the laminate at rewinder (20) by passing through the guide roll (19) and store for internal ageing period ranging from 1 hour to 720 hours, preferably 10 hours to 360 hours, more preferably from 24 hours to 100 hours.
V. Detaching the liner and slitting/cutting as per requirement.
To make a three layered combined WSF, the double layered combined WSF on liner, produced as per any of the above processes, is again unwound along with the liner and passed through a tie-coat coating head and dried. The tie-coat coated double layered WSF is then coated with a binder and semi-dried by passing through the air blowing section. A third layer of preformed WSF is passed through the affixing nip roll and laminated with the double layered WSF forming thee layered combined WSF.
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Fig. 5 represents a three layered combined WSF, wherein a WSF with liner (21) is coated with a tie-coat (22) and further coated with a binder (23) to laminate another WSF (24). This will form a double layered WSF. The WSF (24) of the double layered WSF is again coated with a tie coat (25) and further coated with a binder (26) to laminate the third layer of WSF (27) to form a three layered film. The tie-coats (22) and (25) and the binders (23) and (26) coated on the respective water soluble films can be of same type or different type.
In the same way, by repeating the above process, any number of layers can be laminated to form a combined multi-layered WSF.
While making a multi-layered WSF, different or same kind of active ingredients in desired amount can be incorporated in the binder and/or tie-coat so as to have a multi-layered WSF to carry several or same types of active ingredients, for diverse uses.
The water soluble films mentioned in the above processes may be cold water soluble, hot water soluble, warm water soluble, edible or non edible depending upon the end application.
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We Claim:
1. (Currently amended) A cast-extruded or a cast-cast combined water soluble film (WSF) comprising of at least one layer of solution cast WSF provided with a detachable liner, combined with one or more of a water soluble film and further provided with a binder coat in between the two WSF layers; wherein the said binder coat comprises a batch solution of water soluble film and the like, and the said binder coat is preferably associated with a acrylic dispersion used as a tie coat between a WSF and the binder coat.
2. The combined WSF as claimed in claim 1, wherein the said preformed WSF is preferably a thermally extruded WSF, such as blown (bubble type) or slit die-cast (extrusion curtain type), forming a cast-extruded combined WSF.
3. The combined WSF as claimed in claim 1, wherein said preformed WSF is a solution cast WSF forming a cast-cast combined WSF.
4. The combined WSF as claimed in claim 1, wherein said solution cast WSF with liner is preformed.
5. The combined WSF as claimed in claim 1, wherein said solution cast WSF with liner is formed in situ.
6. The combined WSF as claimed in claim 1, wherein said tie coat provided on the solution cast WSF with liner is selected from acrylic acid polymers, acrylic ester polymers, soluble acrylic acid copolymers, soluble acrylic ester copolymers, soluble copolymers of acrylic acids and esters, cross linked polyvinyl alcohols, cross linked cellulose derivatives, ethyl cellulose, nitrocellulose, cellulose butyrate, cellulose acetate butyrate, ethylene vinyl polyalcohol, ethylene vinyl acetate, PVDC (polyvinyldene chloride), acrylic emulsion, PVC (polyvinyl chloride) emulsion, PVDC emulsion, PVB (polyvinyl butyral), natural arid synthetic waxes, polyurethanes and modified polyvinyl alcohols.
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7. The combined WSF as claimed in claim 1, wherein said binder provided on the solution cast WSF with liner directly or over the tie coat is a binder selected from any low viscosity, low solid content binder like different types of adhesives such as pressure sensitive adhesives, cast water soluble film solution, polyurethane dispersion or even a liquid flavour.
8. The combined WSF as claimed in claim 1, wherein the said solution cast WSF with liner forming one layer and the said preformed WSF forming another layer, are formed of non-edible materials selected from Polyvinyl alcohol copolymer ionomers, Polyvinyl alcohol homopolymer, non - ionomeric poly vinyl alcohol polymer, Polymethacrylate., polyvinyl alchohol, polyacrylamide, polymethacrylamide, polyacrylic acid, polymethacrylic acid, biodegradable polyesters such as ecoflex; polylactic acid (PLA), polyhydroxyalkanoic acid (PHA) and polyurethane.
9. The combined WSF as claimed in claim 1, wherein the said solution cast WSF with liner forming one layer and the said preformed WSF forming another layer, are formed of edible materials selected from polyethyleneglycol, polyvinylpyrrolidone, proteinaceous binders such as gelatin, modified gelatins such as phthaloyl gelatin, polysaccharides such as starch and its derivatives, sorbitol, sucrose derivatives, gum Arabic, pullulan and dextrin and water-soluble cellulose derivatives or combination thereof. The cellulose derivatives used are methyl cellulose, hydroxy propyl cellulose, hydroxy propyl methyl cellulose, hydroxy propyl ethyl cellulose, hydroxy ethyl cellulose and carboxy methyl cellulose.

10. (Currently amended) The combined WSF as claimed in claim 1, wherein the said tie coat and/or the said binder is incorporated with desired amount of one or more, same or different types of active ingredients, as per the requirement
11. (Currently amended) The combined WSF as claimed in claim 1, wherein the said one or more active ingredients are selected from flavours, perfumes, detergents, enzymes,

softeners, active agents for cleaning laundry, dishes, floorings, walls, furniture; various agrochemicals like pesticides, insecticides, weedicides, fungicides, bio-pesticides; agro nutrients like urea, fertilizers; dyes, pigments, fluff, pulp, super absorbents and active pharma ingredients like vitamins, drugs, medicine.
12. The combined WSF as claimed in claim 1, wherein the said detachable liner of the solution cast WSF and optionally of preformed WSF is made of paper, film, foil or fabric, treated or untreated, coated or uncoated, preferably the said liner is made of film, more preferably polyester film. The films can thickness ranging from 3 microns to 500 microns, preferably from 10 microns to 300 microns, more preferably from 25 microns to 100 microns. The film liner may be plain, metallised, embossed, gloss, matt, extrusion coated, laminated or release coated depending on the desired characteristics of the end product. Paper liners are also used for production of WSF. Paper liners that accept temperatures needed for the production of WSF and have thickness ranging from 7 GSM (grams per sq meter - the standard for measuring weight of paper) to 500 GSM, preferably from 20 GSM to 300 GSM, more preferably from 60 GSM to 180 GSM can be used. The paper liner may be plain, embossed, gloss, matt, extrusion coated laminated or release coated depending on the desired characteristics of the end product. Fabrics made of cotton or synthetic yarns, solution coated, plain, embossed, gloss, matt, extrusion coated or laminated.
13. The combined WSF as claimed in claim 1, wherein the said WSF is cold water soluble, warm water soluble, hot water soluble, edible or non edible, depending upon the raw materials used according to the requirement of various applications.
14. A method/process for producing a cast-extruded or cast-cast combined WSF as claimed in claim 1, comprising of the following steps:
a) placing a preformed WSF with detachable liner on an unwinder of a coating machine, forming one layer of the combined WSF,
27
b) placing another preformed WSF with or without a detachable liner on another unwinder of the coating machine, forming another layer of the combined WSF,
c) unwinding said preformed WSF with liner and passing through a coating head of a coating machine for applying a tie coat on one surface, opposite to liner, of said WSF,
d) drying and curing the tie coated WSF by passing it through a coating head of the coating machine, the temperature of the drying section ranging from 50 C to 200°C, preferably from 60°C to 175°C, more preferably from 75°C to 150°C,
e) applying a binder coat over the said tie coat of the WSF with liner by passing it through another coating section of the coating machine,
f) passing the WSF with liner having tie coat followed by binder coat through an air blower section of the coating machine for semi-drying the binder, the temperature of the blower section ranging from 10°C to 100°C, preferably from 30°C to 70°C, more preferably from 30°C to 50°C,
g) unwinding the said other preformed WSF and guiding it to combine with the first WSF of the step (f) by passing through a nip roll of the coating machine, forming a laminated double layered combined WSF,
h) rewinding the laminate of combined WSF of step (g) on a re winder and
storing for internal ageing, i) detaching the liner and slitting/cutting the combined WSF laminate, as per
requirement.
15. The process as claimed in claim 14, wherein the said preformed WSF with liner is unwound and applied with the binder coat directly, without coating it with the tie coat.
16. A method/process for producing a cast-extruded or cast-cast combined WSF as claimed in claim 1, comprising of the following steps:
a) placing a liner for casting WSF on it, on an unwinder of a casting-cum-coating machine,
b) placing a preformed WSF with or without a detachable liner on another unwinder of a casting-cum-coating machine,
c) unwinding the liner and casting WSF on it by using known edible or non-edible formulations of WSF in a batch reactor and metering the cast WSF at the primary casting head of a casting-cum-coating machine, the temperature of the batch solution in the reactor ranging from 10°C to 95°C, preferably from 13°C to 90°C and more preferably from 15°C to 85°C,
d) drying the cast WSF of step (c) at a primary drying section, forming one/first layer of the combined WSF, the temperature in the drying section ranging form 50°C to 200°C, preferably from 60°C to 175°C and more preferably from 75°C to l50°C,
e) applying a tie-coat on one side of the WSF with the liner passing through a coating head,
f) drying and curing the tie-coated WSF by passing it through the drying section of the casting-cum-coating machine, the temperature in the drying section ranging from 50°C to 200°C, preferably from 60°C to 175°C, more preferably from75°C to l50°C,
g) applying a binder coat over the said tie coat of the WSF with liner by passing it through another coating section of the coating machine,
h) passing the WSF with liner having tie coat followed by binder coat through an air blower section of the coating machine for semi-drying the binder, the temperature of the blower section ranging from 10°C to 100°C, preferably from 30°C to 70°C, more preferably from 30°C to 50°C,
i) unwinding the said other WSF and guiding it to combine with the first WSF of the step (h) by passing through a nip roll of the coating machine, forming a laminated double layered combined WSF,
j) rewinding the laminate of combined WSF of step (i) on a rewinder and storing for internal ageing,

k) detaching the liner and slitting/cutting the combined WSF laminate, as per requirement.
17. (currently amended) The process as claimed in claim 14 or l6, wherein the cast WSF on a detachable liner after drying at primary drying section is applied with a binder coat directly, without coating it with the tie-coat.
18. The process as claimed in claim 14 or 16, wherein the said tie-coat is preferably applied by using a gravure cylinder of varying cell sizes and depths; or by using flexo plates of varying cell sizes and depths, or by combination of flexo plates with gravure cylinder, for transferring net solid contents of the tie-coat from the cells of the cylinder and that maximum water/solvent is scrapped before hand by cam shaft moving doctoring blade.
19. The process as claimed in claim 14 or 16, wherein the said tie coat is selected from acrylic acid polymers, acrylic ester polymers, soluble acrylic acid copolymers, soluble acrylic ester copolymers, soluble copolymers of acrylic acids and esters, cross linked polyvinyl alcohols, cross linked cellulose derivatives, ethyl cellulose, nitrocellulose, cellulose butyrate, cellulose acetate butyrate, ethylene vinyl polyalcohol, ethylene vinyl acetate, PVDC (polyvinyldene chloride), acrylic emulsion, PVC (polyvinyl chloride) emulsion, PVDC emulsion, PVB (polyvinyl butyral), natural arid synthetic waxes, polyurethanes and modified polyvinyl alcohols.
20. The process as claimed in claim 14, 15, 16 or 17, wherein the said binder coat is applied by using a wire bound mayer bar.
21. The process as claimed in claim 14 or 16, wherein the said liner is made of paper,
film, foil or fabric, treated or untreated, coated or uncoated, preferably the said liner is
made of film, more preferably polyester film. The films can thickness ranging from 3
microns to 500 microns, preferably from 10 microns to 300 microns, more preferably
from 25 microns to 100 microns. The film liner may be plain, metallised, embossed,

gloss, matt, extrusion coated, laminated or release coated depending on the desired characteristics of the end product. Paper liners are also used for production of WSF. Paper liners that accept temperatures needed for the production of WSF and have thickness ranging from 7 GSM (grams per sq meter - the standard for measuring weight of paper) to 500 GSM, preferably from 20 GSM to 300 GSM, more preferably from 60 GSM to 180 GSM can be used. The paper liner may be plain, embossed, gloss, matt, extrusion coated laminated or release coated depending on the desired characteristics of the end product. Fabrics made of cotton or synthetic yarns, solution coated, plain, embossed, gloss, matt, extrusion coated or laminated.
22.The process as claimed in claim 14 or 16, wherein the said binder is selected from any low viscosity, low solid content binder like different types of adhesives such as pressure sensitive adhesives, cast water soluble film solution, polyurethane dispersion or even a liquid flavour.
23.The process as claimed in claim 14 or 16, wherein the said edible WSF formulation is formed of edible materials selected from polyethyleneglycol, polyvinylpyrrolidone, proteinaceous binders such as gelatin, modified gelatins such as phthaloyl gelatin, polysaccharides such as starch and its derivatives, sorbitol, sucrose derivatives, gum Arabic, pullulan and dextrin and water-soluble cellulose derivatives or combination thereof. The cellulose derivatives used are methyl cellulose, hydroxy propyl cellulose, hydroxy propyl methyl cellulose, hydroxy propyl ethyl cellulose, hydroxy ethyl cellulose and carboxy methyl cellulose.
24.The process as claimed in claim 14 or 16, wherein the said non-edible WSF formulation is formed of non-edible materials selected from Polyvinyl alcohol copolymer ionomers, Polyvinyl alcohol homopolymer, non - ionomeric poly vinyl alcohol polymer, Polymethacrylate., polyvinyl alchohol, polyacrylamide, pplymethacrylamide, polyacrylic acid, polymethacrylic acid biodegradable polyesters such as ecoflex; polylactic acid (PLA), polyhydroxyalkanoic acid (PHA) and polyurethane.

25. The process as claimed in claim 14 or 16, wherein one or more of same or different types of active ingredients are incorporated in the said tie-coat and/or the said binder.
26.The process as claimed in claim 25, wherein the said active ingredients are selected from flavours, perfumes, detergents, enzymes, softeners, active agents for cleaning laundry, dishes, floorings, walls, furniture; various agrochemicals like pesticides, insecticides, weedicides, fungicides, bio-pesticides; agro nutrients like urea, fertilizers; dyes, pigments, fluff, pulp, super absorbents and active pharma ingredients like vitamins, drugs, medicine.
27.The process as claimed in claim 14 or 16, wherein the raw materials of the WSF, the tie-coat and/or the binder are selected such that the combined WSF is soluble in cold water, warm water or hot water, as per requirement.
28.The process as claimed in claim 15 or 17, wherein the WSF with liner is moved at high speed, preferably from 15 to 100 meter/min., more preferably from 25 to 70 meter/min. for preventing the WSF from dissolving when the binder is applied on it directly, without the tie-coat.
29.The process as claimed in claim 15 or 17, wherein the air blower section temperature is kept high ranging from 20°C to 100°C, preferably from 30°C to 70°C, more preferably from 50°C to 60°C for instantly semi-drying the said binder coated directly without the tie-coat, for preventing the WSF from dissolving.
30. A method/process of producing cast-cast or cast-extruded combined WSF, comprising of the following steps:
i. placing/loading a preformed WSF with a detachable liner on a flat die extruder, ii. extruding desired thickness of WSF directly onto the said preformed cast WSF
with liner through the extruder, iii. passing the combined WSF laminate of step (b) through chilling cylinders, keeping the said liner in contact with the chilling cylinder,

iv. rewinding the combined WSF laminate of step (c) on a rewinder and storing for
internal ageing period, v. detaching the liner and slitting/cutting the combined WSF laminate as per
requirement.
31. The process as claimed in claim 30, wherein the said preformed WSF with detachable liner is cast/solution cast WSF.
32. The process as claimed in claim 30, wherein the said liner is a hydrophobic, thermally active detachable liner.
33. The process as claimed in claim 14, 15,16, 17 or 30, wherein the said combined WSF laminate is stored for an internal ageing period ranging from 1 hour to 720 hours, preferably from 10 hours to 360 hours and more preferably from 24 hours to 100 hours.
34.The process as claimed in claim 14, 15, 16, 17 or 30, wherein the said double layered combined WSF with liner is unwound and applied with a tie-coat in a coating head, dried and cured in the drying section, applied with a binder coat over the said tie-coat in another coating section, passed through air blower section for semi drying the binder coat and combined with a third layer of WSF with or without detachable liner by passing through nip roll and rewound on another rewinder forming three layered combined WSF.
35. The process as claimed in claim 14, 15, 16, 17 or 30, wherein the said double layered combined WSF with liner is unwound and applied with a binder coat directly, without the tie-coat, in a coating section, passed through air blower section for semi drying the binder coat and combined with a third layer of WSF with or without detachable liner by passing through nip roll and rewound on another rewinder forming three layered combined WSF. 36.The process as claimed in claim 14, 15, 16, 17 or 30, wherein the said double layered combined WSF with liner is unwound and passed through the flat die extruder for extruding desired thickness of WSF directly on it and passed through the chilling cylinder and rewound on the rewinder forming three layered combined WSF.

37. The process as claimed in claim 34, 35 or 36, wherein the said process is repeated to form any desired numbers of multi-layered combined WSF of this invention.
38. The method/process as claimed in claim 34, 35, 36 or 37, wherein one or more of the same or different types of active ingredients are incorporated in the binder and/or the tie-coat and/or in the flat die extruder while extruding the desired thickness of WSF directly on the preformed WSF with liner.
39. The process as claimed in claim 34, 35, 36 or 37, wherein the said combined WSF
laminate is stored for an internal ageing period ranging from 1 hour to 720 hours,
preferably from 10 hours to 360 hours and more preferably from 24 hours to 100 hours.
40. A method/process for producing cast-extruded or cast-cast combined WSF
substantially as herein described

Arrow Coated Products Ltd.
Dated this 12th day of January, 2006

CAST-EXTRUDED OR CAST-CAST COMBINED WATER SOLUBLE FILM AND THE METHOD/PROCESS FOR PRODUCING THE SAME

Documents:

Inventors:

PCT Conventions: