AU2006242781A1

AU2006242781A1 - Packaging materials

Info

Publication number: AU2006242781A1
Application number: AU2006242781A
Authority: AU
Inventors: Shilpan Pravinchandra Patel
Original assignee: Individual
Current assignee: Individual
Priority date: 2005-03-03
Filing date: 2006-03-02
Publication date: 2006-11-09
Also published as: WO2006117801A3; WO2006117801B1; ZA200708451B; WO2006117801A2

Description

WO 2006/117801 PCT/IN2006/000072 PACKAGING MATERIALS Field of invention 5 This invention relates to biodegradable multi-layered composite packaging materials and to methods for manufacturing the same. Background of the Invention Various packaging products are known wherein biodegradable materials such as paper, jute 10 or naturally corrosive and subsequently biodegradable metallic foils are laminated with non biodegradable petro-plastics to achieve properties like high strength, heat sealing and/or to control unwanted fibres, foreign particles or surface impurities to come in contact with the packed goods, particularly edible goods. For example, extrusion coating of polyethylene is done on paper to enable heat sealing during the process of packaging or manufacture of 15 pouches and polyethylene lamination is done to Hessian or Jute fabric to ensure that no fibres or foreign particles get mixed with the packed edible material. A disadvantage of these laminations is they turn the naturally biodegradable materials non degradable. One solution propagated through the industry is to laminate biodegradable substrates such as 20 paper with biodegradable PLA (poly lactic acid) or PHA (polyhydroxy alkanoate) layers by processes such as coextrusion with an adhesive polymer to avoid delamination. But there are certain limitations to the PLA and PHA coatings i.e. the cost is very high, the sealing properties are not that good and also the lamination method with adhesive requires expensive processes which add to the final cost of the multi-layered biodegradable product. 25 It is an object of the present invention to provide a multi-layered biodegradable composite packaging material and method of manufacturing same that overcomes or at least mitigates some or all of the problems and disadvantages of existing packaging materials and methods of manufacture. 30 Summary of invention According to a first aspect, the present invention provides a biodegradable multi-layered composite packaging material comprising of a biodegradable substrate layer and a biodegradable film uniformly well adhered at least on one side of the said substrate without 35 using any adhesive.

WO 2006/117801 PCT/IN2006/000072 Combining two biodegradable materials as per the invention can give better properties in strength, smoothness and biodegradability without sacrificing inherent properties of heat sealing and down stream conversion. The end product will be a biodegradable multi-layered 5 composite packaging material, which shall be beneficial to the society. The invention has application to various types of substrates while retaining stretchability of the substrate and elasticity of the biodegradable water soluble/non soluble hydrophilic film and simultaneously enhancing the physical characteristics like tensile, tear, puncture 10 resistance, burst factor, and breaking strength of the resulting biodegradable packaging material. The biodegradable substrate layer is preferably formed of biodegradable fibres, fabric, pulps like cotton, jute, hemp, baggasse, wood pulp. Alternatively, the biodegradable substrate layer 15 may be formed of naturally corrosive and subsequently bio-degradable metallic foils like aluminium foil, brass foil, copper foil, tin foil, steel foil and zinc foil. The biodegradable film may be soluble in water, i.e. a water soluble film (WSF) or non soluble in water but swellable under moisture and biodegradable. The WSF may be cold 20 water soluble, warm water soluble, or hot water soluble. The biodegradable film may. be made of raw materials selected from Polyvinyl alcohol copolymer ionomers, Polyvinyl alcohol homopolymer, non - ionomeric poly vinyl alcohol polymer, Polymethacrylate, polyvinyl alchohol, polyacrylamide, polymethacrylamide, 25 polyacrylic acid, polymethacrylic acid, polyurethane, 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 such as methyl cellulose, hydroxy propyl cellulose, hydroxy propyl methyl cellulose, hydroxy propyl ethyl cellulose, hydroxy ethyl cellulose, 30 carboxy methyl cellulose either alone or combinations thereof. The biodegradable film is alternatively a non soluble or non soluble partially hydrophilic film. A partially hydrophilic film may be made out of non hydrophilic materials, wherein atleast one side may be cast with a water soluble film material and dried, to make the -2- WO 2006/117801 PCT/IN2006/000072 coated/cast side hydrophilic, to enable lamination with a biodegradable substrate with the aid of water and the term non soluble hydrophilic film is to be construed accordingly to include all of these i.e. a non soluble hydrophilic film and a non soluble partially hydrophilic film cast with a water soluble film material atleast on one side to make the coated/cast side 5 hydrophilic. The non soluble partially hydrophilic film is preferably made out of thermoplastic starch materials. 10 The water soluble film material may be 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, polyethyleneglycol, polyvinylpyrrolidone, proteinaceous binders such as gelatin, modified gelatins such as phthaloyl gelatin, 15 polysaccharides such as starch, gum Arabic, pullulan and dextrin and water-soluble cellulose derivatives such as methyl cellulose, hydroxy propyl cellulose, hydroxy propyl methyl cellulose, hydroxy propyl ethyl cellulose, hydroxy ethyl cellulose, carboxy methyl cellulose either alone or combinations thereof. 20 The biodegradable substrate and biodegradable film may be combined by layering, coating, impregnating or laminating resulting into a biodegradable multi-layered composite packaging material with enhanced characteristics like strength and biodegradability. According to a second aspect, the present invention provides a method of manufacturing a 25 biodegradable multi-layered composite packaging material comprising of the following steps: (i) casting a water soluble/non soluble hydrophilic film on a liner at a primary casting head of a casting machine; (ii) semi-drying the cast water soluble/non soluble hydrophilic film and feeding the said semi-dried water soluble/non soluble hydrophilic film to nip rolls; 30 (iii) passing a biodegradable substrate to the nip rolls for combining with the said semi dried water soluble/non soluble hydrophilic film; (iv) passing the substrate and semi-dried water soluble/non soluble hydrophilic film through the nip rolls and storing the laminated substrate with water soluble/non soluble hydrophilic film for an internal ageing period. -3- WO 2006/117801 PCT/IN2006/000072 According to a third aspect, the present invention provides a method of manufacturing a biodegradable multi-layered composite packaging material comprising of the following steps: (i) providing a hydrophilic biodegradable substrate and a preformed water soluble/non 5 soluble hydrophilic film with a liner; (ii) wetting the substrate by passing it through a wetting tray containing water with or without a wetting agent; (iii) removing excess water from the substrate; (iv) applying the preformed water soluble/non soluble hydrophilic film to the wet substrate; 0 (v) storing the laminate of biodegradable substrate with preformed water soluble/non soluble hydrophilic film with or without liner for an internal ageing period. According to a fourth aspect, the present invention provides a method of manufacturing a biodegradable multi-layered composite packaging material comprising of the following steps: 15 (i) casting a water soluble/non soluble hydrophilic film on a non porous biodegradable substrate at a primary casting head; (ii) drying the laminate of non porous biodegradable substrate with cast water soluble/non soluble hydrophilic film. 20 According to a fifth aspect, the present invention provides a method of manufacturing biodegradable multi-layered composite packaging material comprising of the following steps: (i) flat die extruding a desired thickness of water soluble/non soluble hydrophilic film directly onto a biodegradable substrate; (ii) passing the extruded water soluble/non soluble hydrophilic film with biodegradable 25 substrate through a chiller to cool the laminate of biodegradable substrate and extruded water soluble/non soluble hydrophilic film. In the above-described methods the biodegradable substrate may be selected from natural biodegradable substrates made from materials like bio-degradable fibres, fabric, pulps like 30 cotton, jute, hemp, baggasse, wood pulp. Alternatively, the biodegradable substrate may be selected from naturally corrosive and subsequently biodegradable metallic foils like aluminium foil, brass foil, copper foil, tin foil, steel foil and zinc foil, -4- WO 2006/117801 PCT/IN2006/000072 In the above described methods, where the substrates are hydrophilic these may be made from materials such as biodegradable fibres, fabric, pulps like cotton, jute, hemp, baggasse, wood pulp and the like and, where the substrates are non-porous these may be made from non porous paper or naturally corrosive and subsequently biodegradable metallic foils like 5 aluminium foil, brass foil, copper foil, tin foil, steel foil and zinc foil. In the above described methods, the biodegradable water soluble/non soluble hydrophilic film may be made of raw materials selected from Polyvinyl alcohol copolymer ionomers, Polyvinyl alcohol homopolymer, non - ionomeric poly vinyl alcohol polymer, 10 Polymethacrylate, polyvinyl alchohol, polyacrylamide, polymethacrylamide, polyacrylic acid, polymethacrylic acid, polyurethane, 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 such as methyl cellulose, hydroxy propyl cellulose, hydroxy propyl methyl 15 cellulose, hydroxy propyl ethyl cellulose, hydroxy ethyl cellulose, carboxy methyl cellulose either alone or combinations thereof. In the above described methods, The biodegradable film is alternatively a non soluble partially hydrophilic film made out of thermoplastic starch materials, wherein atleast one side 20 is cast with a water soluble film material and dried, to make the cast side hydrophilic, to enable lamination with a biodegradable substrate with the aid of water and the term non soluble hydrophilic film is to be construed accordingly to include all of these i.e. a non soluble hydrophilic film and a non soluble partially hydrophilic film coated/cast with a water soluble material atleast on one side to make the coated/cast side hydrophilic. 25 In the above described methods, the non soluble partially hydrophilic film is made out of thermoplastic starch materials. In the above described methods, the water soluble film material for casting on non soluble 30 partially hydrophilic film may be 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, polyethyleneglycol, polyvinylpyrrolidone, proteinaceous binders such as gelatin, modified gelatins such as phthaloyl gelatin, -5- WO 2006/117801 PCT/IN2006/000072 polysaccharides such as starch, gum Arabic, pullulan and dextrin and wvater-soluble cellulose derivatives such as methyl cellulose, hydroxy propyl cellulose, hydroxy propyl methyl cellulose, hydroxy propyl ethyl cellulose, hydroxy ethyl cellulose, carboxy methyl cellulose either alone or combinations thereof. 5 Exemplary embodiments of the invention will now be described with reference to the accompanying drawings, wherein Fig 1. is a schematic block diagram for method of manufacturing biodegradable multi-layered 0 composites according to an embodiment of this invention, Fig 2. is a schematic block diagram for method of manufacturing biodegradable multi-layered composites according to another embodiment of this invention, 5 Fig 3. is a schematic block diagram for method of manufacturing biodegradable multi-layered composites according to a further embodiment of this invention, Fig 4. is a schematic block diagram for method of manufacturing biodegradable multi-layered composites according to a further embodiment of this invention 0 Referring to fig.1, illustrating the process of laminating a biodegradable substrate to a biodegradable water soluble/non soluble hydrophilic film comprising the following steps: I. Placing a liner (1), for casting of water soluble/non soluble hydrophilic film, on an 15 unwinder (2) of a casting machine. The liner (1) 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 0 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 -6- WO 2006/117801 PCT/IN2006/000072 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 may be used as liner based on the desired end product 5 properties. However, these liners are by no means limiting. II. Placing the biodegradable substrate (3), on another unwinder (4) of the casting machine, wherein the said biodegradable substrate is selected from natural substrates made from bio-degradable fibres, fabric, pulps like cotton, jute, hemp, baggasse, wood pulp and naturally corrosive and subsequently bio-degradable metallic foils like aluminium foil, 0 brass foil, copper foil, tin foil, steel foil and zinc foil. However, these bio-degradable materials are by no means limiting. III. Unwinding of the liner (1) at unwinder (2) for casting of water soluble/non soluble hydrophilic film on it by using known formulation of water soluble/non soluble hydrophilic film in a batch reactor (5), at the primary casting head (6). The temperature 5 of the batch solution ranges from 10 0 C to 95 0 C, preferably from 20 0 C to 85 0 C, more preferably from 25 0 C to 70 0 C. The raw materials used for making the water soluble/non soluble hydrophilic film are selected from Polyvinyl alcohol copolymer ionomers, Polyvinyl alcohol homopolymer, non - ionomeric poly vinyl alcohol polymer, Polymethacrylate, polyvinyl alchohol, 10 polyacrylamide, polymethacrylamide, polyacrylic acid, polymethacrylic acid, polyurethane, polyethyleneglycol, polyvinylpyrrolidone, proteinaceous binders such as gelatin, modified gelatins such as phthaloyl gelatin, polysac.charides such as starch, gum Arabic, pullulan and dextrin and water-soluble cellulose derivatives such as methyl cellulose, hydroxy propyl cellulose, hydroxy propyl methyl cellulose, hydroxy propyl 25 ethyl cellulose, hydroxy ethyl cellulose, carboxy methyl cellulose either alone or combinations thereof. However, these raw materials are by no means limiting. The water soluble films can be cold water soluble, warm water soluble, hot water soluble or non soluble depending upon the formulation. IV. Metering of the cast water soluble/non soluble hydrophilic film at the primary casting 30 head (6). V. Passing water soluble/non soluble hydrophilic film from the above step IV through an air blower section (7) with or without applying heat, for semi-drying. The temperature in the blower section ranges from 10 0 C to 140 0 C, preferably from 30 0 C to 100 0 C, more -7- WO 2006/117801 PCT/IN2006/000072 preferably from 40 0 C to 90 0 C. The temperature in the blower section will be dependent upon the web speed. VI. Unwinding the biodegradable substrate (3) from the unwinder (4) and guiding it through the guide rolls (8) to combine with the semi-dried water soluble/non soluble hydrophilic 5 film from the step V by passing through the nip roll (9). VII. Rewinding the laminate on a rewinder (10) 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. 10 Now referring to fig.2, illustrating the process of laminating a biodegradable substrate to a water soluble/non soluble hydrophilic film comprising the following steps: I. Unwinding the hydrophilic biodegradable substrate (11) from the unwinder (12). The 15 said hydrophilic biodegradable substrate is selected from natural substrates made from bio-degradable fibres, fabric, pulps like cotton, jute, hemp, baggasse, wood pulp or the like. II. Passing the hydrophilic biodegradable substrate through a wetting process by dipping in the wetting tray (15) consisting water with or without a wetting agent. 20 The wetting agent is selected from anionic based surfactants (based on sulfonate anions or carboxylate anions), fatty acid salts, sodium dodecyl sulfate (SDS) or sodium laureth sulfate, ammonium lauryl sulfate and other alkyl sulfate salts; cationic based surfactants such as cetyl pyridinium chloride; ampholytic surfactants like dodecyl betaine, dodecyl dimethylamine oxide; nonionic surfactants like alkyl polyethylene oxide, alkyl 25 polyglucosides and fatty alcohols. However, these wetting agents mentioned here are by no means limiting. The amount of wetting agent in the water ranges from 0.5% to 10% by wt, preferably from 1% to 5% by wt, more preferably from 2% to 3% by wt. III. Passing the wet dipped hydrophilic biodegradable substrate in between two squeeze rollers (16) so as to squeeze the excess water with or without a wetting agent, back into 30 the wetting tray (15). The pressure between two squeeze rolls responsible for control of the moisture in the hydrophylic substrate can be between 1 Psi to 25 Psi, preferably 3 Psi to 20 Psi, more preferably between 4 Psi to 9 Psi. The pressure can be adjusted as per the liquid pickup by the substrate. -8- WO 2006/117801 PCT/IN2006/000072 IV. Unwinding the preformed water soluble/non soluble hydrophilic film (13) with or without the liner from the unwinder (14). The water soluble/non soluble hydrophilic film is made from raw materials as described above. Here, a non soluble partially hydrophilic film cast with water soluble film material(s) atleast on one side can also be used. The 5 non soluble partially hydrophilic film is made out of thermoplastic starch materials. The water soluble film material(s) 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, polyethyleneglycol, polyvinylpyrrolidone, 10 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 such as methyl cellulose, hydroxy propyl cellulose, hydroxy propyl methyl cellulose, hydroxy propyl ethyl cellulose, hydroxy ethyl cellulose, carboxy methyl cellulose either alone or combinations thereof. However, theses are by no means 15 limiting. The water soluble film material is cast on a non soluble partially hydrophilic film by passing it through the casting head and dried at a temperature ranging from 60 0 C to 200 0 C, preferably from 80 0 C to 175 0 C, more preferably from 100 0 C to 150 0 C. This cast non soluble partially hydrophilic film is rewound and stored for further using it as a 29 preformed non soluble hydrophilic for the purpose of this invention. For the purpose of this invention non soluble partially hydrophilic film may be used without a liner. V. Passing the preformed water soluble/non soluble hydrophilic film and the wet hydrophilic biodegradable substrate through the respective affixing guide rollers (19 & 17). 25 VI. Affixing of the preformed water soluble/non soluble hydrophilic film with the wet hydrophilic biodegradable substrate at the affixing rollers (18 & 20). VII. Optionally drying the laminate from step VI by passing through a set of dryers (21). The temperature in the dryers ranges froml0 0 C to 100 0 C, preferably from 30 0 C to 70 0 C, more preferably from 30 0 C to 50 0 C. 30 VIII.Rewinding the laminate with or without the liner at the rewinder (22). The liner can be stripped immediately or after aging period of around 1 to around 720 hours. IX. Slitting/cutting the laminate as per requirement. -9- WO 2006/117801 PCT/IN2006/000072 Now referring to fig.3, illustrating the process of casting a water soluble/non soluble hydrophilic film formulation on a biodegradable substrate comprising the following steps: I. Placing a non-porous biodegradable substrate (23) such as naturally corrosive and subsequently bio-degradable metallic foils like aluminium foil, brass foil, copper foil, tin 5 foil, steel foil and zinc foil; non porous paper and the like on an unwinder (24) of a casting machine. II. Unwinding the biodegradable substrate (23) at unwinder (24) for casting of water soluble/non soluble hydrophilic film by using known formulation of water soluble/non soluble hydrophilic film in a batch reactor (5), at the primary casting head (6). The 10 temperature of the batch solution ranges from 10 0 C to 95 0 C, preferably from 20 0 C to 85 0 C, more preferably from 25 0 C to 70 0 C. The raw materials used for making the water soluble/non soluble hydrophilic film are selected from Polyvinyl alcohol copolymer ionomers, Polyvinyl alcohol homopolymer, non - ionomeric poly vinyl alcohol polymer, Polymethacrylate, polyvinyl alchohol, 15 polyacrylamide, polymethacrylamide, polyacrylic acid, polymethacrylic acid, polyurethane, 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 such as methyl cellulose, hydroxy propyl cellulose, hydroxy propyl methyl cellulose, hydroxy propyl 20 ethyl cellulose, hydroxy ethyl cellulose, carboxy methyl cellulose either alone or combinations thereof. However, these raw materials are by no means limiting. The water soluble films can be cold water soluble, warm water soluble, hot water soluble or non soluble depending upon the formulation. III. Metering of the water soluble/non soluble hydrophilic film cast on a biodegradable 25 substrate at the primary casting head (6). IV. Passing through a dryer section (25), for drying the water soluble/non soluble hydrophilic film from the above step V. The temperature in the drying section ranges from 60 0 C to 200 0 C, preferably from 80 0 C to 175 0 C, more preferably from 100 0 C to 150 0 C. 30 V. Rewinding the laminate with or without the liner at the rewinder (22). VI. Slitting/cutting the laminate as per requirement. Now referring to fig.4, illustrating the process of flat-die extrusion of water soluble/non soluble hydrophilic film on a biodegradable substrate comprising the following steps: - 10- WO 2006/117801 PCT/IN2006/000072 I. Load a roll of biodegradable substrate (23) on a flat-die extruder. II. Extruding the desired thickness of water soluble/non soluble hydrophilic film directly through the extruder (27) onto the biodegradable substrate (23). 5 III. Passing the construction from step II through chilling cylinder(s) (28). IV. Rewinding the laminate at rewinder (30) by passing through the guide roll (29). Examples: A water soluble/non soluble hydrophilic film was laminated with a biodegradable substrate 10 such as crepe paper, the strength of the laminate increased as compared to the biodegradable substrate. In this example of a crepe paper (110 GSM with 40% crepe) laminated to water soluble/non soluble hydrophilic film of 25 GSM. The data comparison of the tensile strength test between crepe paper and crepe paper + water soluble/non soluble hydrophilic film laminate, done on a Universal Testing Machine (UTM) (from International Equipments), is as 15 below: Mech. Tensile Strength Peak Load rps. Units Kg/cm 2 Kg Resultant Values MD: 95.42 MD: 2.5784 0 of crepe paper TD: 53.33 TD: 2.00 Resultant Values MD: 115.28 MD: 5.764 of crepe paper + TD: 54.79 TD : 2.7395 WSF laminate 25 This invention also creates a range of options to use combinations of lower GSM of paper by tailoring the percentage of creping for specified end use applications. The various embodiments of the invention therefore provides for the use of combining biodegradable materials taking advantage of the best characteristics of the combining materials resulting in novel "high-performance multi-layered biodegradable composite materials". 30 In a non-limiting example as in case of crepe paper one can use a 50-gsm paper and with 40 % crepe stretch with layering/lamination/coating/impregnating of 25 GSM of water soluble/non soluble hydrophilic film to result in a "multi-layered biodegradable composite material" that is equivalent to a material of about 110 GSM of Kraft paper. Such new "multi - 11 - WO 2006/117801 PCT/IN2006/000072 layered biodegradable composite materials" would result in the use of less weight of the packaging material saving in freight, give higher yield of packaging material per kilo of raw material used, etc. 5 In another example, a laminate as shown in fig. 5 was produced consisting layers of paper (31), water soluble/non soluble hydrophilic film (32), aluminium foil (33) and another water soluble/non soluble hydrophilic film (34) laminated together as per the methods mentioned above. This laminate can be used for packaging various liquids such as milk, juices, etc, with non soluble biodegradable film in contact with the liquid. 10 In yet another example, jute or hessian fabric is layered/laminated/coated/impregnated with a water soluble/non soluble hydrophilic film so that cement or other fine powdered material will not go waste due to seepage. This laminate can also be used for packing various food products such as sugar so that the fibres or unwanted particles will not get mixed with the 15 edible material. The laminate will have an added advantage of better heat sealing, which was not possible if only jute or hessian fabric was used to make bags. The multi-layered biodegradable composite materials thus produced are most suited for a variety of applications including, but not limited to, a wide range of packaging materials like 20 grocery sacks, box inter-liner, retail pouches, shopping bags etc. Biodegradability Test: Following laminated materials were placed in the mature compost for time scale of 6 months as specified under EN 13432 standard. 25 1. PE + crepe paper laminate 2. PE + Aluminium foil laminate 3. water soluble film + Crepe paper laminate 4. non soluble hydrophilic film + Aluminium foil laminate After 6 months it was observed that the water soluble film + Crepe paper laminate had almost 30 disintegrated completely. After thoroughly observing the non soluble hydrophilic film + Aluminium foil laminate, it was observed that the non soluble hydrophilic film had disintegrated thoroughly while the aluminium foil had started corroding. The PE + crepe paper laminate and PE + Aluminium foil laminate did not disintegrate thoroughly as some parts of the laminates could be seen in the compost. -12-

Claims

1. A degradable multi-layered composite packaging material comprising of a substrate layer and a biodegradable film adhered at least on one side of the said , substrate without using 5 any adhesive; wherein, a. the said substrate is a degradable material that is a metal foil or a sheet made out of a biodegradable material selected from the group comprisitig biodegradable fibres, fabric, pulps like cotton, jute, hemp, baggasse, wood pulp ancd the like; and b. the said biodegradable film is a water soluble. / non-soliable totally or partially 10 hydrophilic film,

2. The packaging material according to claim 1, wherein the said metal foil comprises an aluminium foil, brass foil, copper foil, tin foil, steel foil, zinc foiliand the like. 15

3. The packaging material according to claim 1, wherein the water soluble/non soluble totally or partially hydrophilic film is made of one or more of:a raw material including Polyvinyl alcohol copolymer lonomers, Polyvinyl alcohol homopolymer, non - ionomeric poly vinyl alcohol polymer, Polymethaorylate, polyvinyl alphohol, polyacrylamide, polymethacrylamide, polyacrylic acid, polymethacrylic acid, polyurethane, 20 polyethyleneglycol, polyvinylpyrrolidone, proteinaceous birders such as gelatin, modified gelatins such as phthaloyl gelatin, polysaccharides sud.h as starch, gum Arabic, pullulan and dextrin and water-soluble cellulose derivatives such as methyl cellulose, hydroxy propyl cellulose, hydroxy propyl methyl cellulose. hydroxy propyl ethyl cellulose, hydroxy ethyl cellulose, carboxy methyl cellulose either alone or combinations 25 thereof and the like.

4. The packaging material according to claim 3, wherein the said water soluble/non soluble totally or partially hydrophilic film is cold water soluble, warm: water soluble, hot water soluble or non soluble in water but swellable under moisture ind biodegradable; where 30 cold water soluble film dissolves in water between temperature range of around laC to 35 0 C, warm water soluble film dissolves in water between teriperature range of around 35 0 C to 50 0 C and hot water soluble film dissolves in water having temperature above 50 0 C. AMENDED SHEET (ARTICLE 19) WO 2006/117801 PCT/IN2006/000072 20

5. The packaging material according to claim I or claim 3 or claim 4, wherein the biodegradable film is a partially hydrophilic filth, non soluble in Water, which may be cast with water soluble film materials at least on one side of the film. 5

6. The packaging material according to claim 5, wherein the said non soluble partially hydrophilic film is made of thermoplastic starch materials.

7. The packaging material according to claim 6, wherein the water soluble film material for casting on the non soluble partially hydrophilic film comprises one or more of a raw 10 material includingPolyvinyl alcohol copolymer lonome-s, Polyvinyl alcohol homopolymer, non .- ionomeric poly vinyl alcohol polymer, Pollymethacrylate, polyvinyl alcohol, polyacryhlumnide, polymethacrylamide, polyacrylic acM, polymethaerylic acid, polyurethane, polyethyleneglycol, polyvinylpyrrolidone, protei-aceous binders such as gelatin, modified gelatins such as phthaloyl gelatin, polysacchalides such as starch, gum 15 arabic, pullulan and dextrin and water-soluble cellulose derivatives such as methyl cellulose, hydroxy propyl cellulose, hydroxy propyl methyl c-llulose, hydroxy propyl ethyl cellulose, hydroxy ethyl cellulose, carboxy methyl eillulose either alone or combinations thereof and the like. 20

8. The packaging material according to claim 1, wherein the ,-aid substrate and water soluble/non soluble hydrophilic film are combined by layering,coating, impregnating or laminating.

9. A method of manufacturing a multi-layered composite packaging material, comprising at 25 least one of the material that is a biodegradable film and one or more of the other being a film of a material that is biodegradable or degradable by cof;:Tosion, the said method comprising of the following steps: a. casting a water soluble/non soluble hydrophilic film on a liner at a primary casting head of a casting machine; 30 b. semi-drying the said east film and feeding the said semi-dried film to nip rolls; c. unwinding a web of a material that is biodegradable or degradable by corrosion as a substrate to the said nip rolls for combining with the said semi-dried cast film; d. passing the said substrate combined with cast film througlt nip rolls and storing the combined substrate and east film for an internal ageing period. AMENDED SHEET (ARTICLE 19) WO 2006/117801 PCT/IN2006/000072 21

10. The method according to claim 9, wherein the said cast film is semi-dried with or without applying heat in a blower section having temperature ranging from 10 0 C to 140 0 C, preferably from 300C to 1 00C and more preferably from 40 0 C toh;900C. 5

11. A method of manufacturing multi-layered composite packaging material comprising at least one hydrophilic biodegradable substrate and one or more of a biodegradable totally or partially hydrophilic film, the said method comprising following steps: a. providing a hydrophilic biodegradable substrate and a preformed water soluble/non soluble hydrophilic film with a liner; 10 b. wetting the substrate by passing it through a wetting tray containing water with or without a wetting agent; c. removing excess water, the said water being with or withou wetting agent, from the substrate; d. affixing the water soluble/non soluble hydrophilic film withlthe said wet substrate by 15 passing through nip rolls; e. storing the laminate of biodegradable substrate with preformed water soluble/non soluble hydrophilic film for an internal ageing period.

12. A method according to claim 11, wherein the said wetting agent comprises one or more of 20 a surfactant including anionic based surfactants (based on sulfonate anions or carboxylate anions), fatty acid salts, sodium dodecyl sulfate (SDS) or'. sodium lauryl sulfate, ammonium lauryl sulfate and other alkyl sulfate salts; cationic based surfactants such as cetyl pyridinium chloride; ampholytic surfactants like dc.decyl betaine, dodecyl dimethylamine oxide; nonionic surfactants like alkyl polyethylene oxide, alkyl 25 polyglucosides and fatty alcohols either alone or combinations tIereof and the like.

13. A method according to claim 12, wherein the.amount of wetting agent in water ranges from 0.5% to 10% by wt, preferably from 1% to 5% by wt, mere preferably from 2% to 3% by wt. 30

14. A method according to claim 12, wherein the excess water is§ removed by passing the substrate through squeeze rollers kept under pressure to corfrol the moisture in the substrate, the pressure between the squeeze rollers ranging fronmiPsi to 25 psi, preferably 3 psi to 20 psi, morn: preferably between 4 psi to 9 psi. AMENDED SHEET (ARTICLE 19) WO 2006/117801 PCT/IN2006/000072 22

15. The method according to claim 12, wherein the. laminate of wetesubstrate and preformed water soluble/non soluble hydrophilic film is dried before storing for internal ageing by passing through a dryer section, the temperature in the dryer section ranging from I 0OC to 100 0 C,-preferably from 30 0 C to 70 0 C, more preferably from 3 0 C - to 50 0 C. 5

16. A method of manufacturing of multi-layered composite packagigjg material comprising at least one biodegradable hydrophilic film and one or moe of the other being biodegradable non porous substrate, the said method comprising of the following steps: a. casting a water soluble/non soluble hydrophilic film on a non porous biodegradable 10 substrate; b. drying the laminate of step (i) by passing it through a set of dryers, the temperature in the dryers ranging from 60oC to 200 0 C, preferably frott 80 0 C to 175'C, more preferably from 1 00 0 C to 150 0 C. 15

17. A method according to claim 9 or 16, wherein the water solubl,/non soluble hydrophilic film is cast from a batch solution in a batch reactor having a t-mperature ranging from 10C to 95 0 C, preferably from 20 0 C to 85 0 C, more preferably from 25 0 C to 70 0 C.

18. A method of manufacturing of multi-layered composite packaging comprising at least one 20 material that is biodegradable and one or more of the othei being biodegradable or degradable by corrosion, the said method comprising following -teps: a. extruding a desired thickness of water soluble/non solubli hydrophilic film onto a biodegradable substrate; b. passing the extruded water soluble/non soluble hydrophilic: film with biodegradable 25 substrate through a chiller.

19. A method according to claim 9 or 11, wherein the said interna ageing period is ranging from I hour to 720 hours, preferably 10 hours to 360 hours, imore preferably from 24 hours to 100 hours. 30

20. The method according to claim 9, or 11 or 16 wherein the said i!ner is of paper, film,.foil or fabric. AMENDED SHEET (ARTICLE 19) WO 2006/117801 PCT/IN2006/000072 23

21. The method according to claim 9, or 11, or 16 or 18, wherein the said biodegradable substrate is made from materials selected from the group co uprising bio-degradable fibres, fabric, pulps like cotton, jute, hemp, baggasse, wood pulp' 5

22. The method according to claim 9, or 16 or or 18, wherein the said biodegradable substrate is made from naturally corrosive metallic foils selected froma the group comprising aluminium foil, brass foil, copper foil, tin foil, steel foil and zinc:foil.

23. The method according to claim 9, or 16 or 18, wherein the said isubstrate is selected from 10 non porous substrates including non porous paper and naturally corrosive and subsequently bio-degradable metallic foils selected from the group of aluminium foil, brass foil, copper foil, tin foil, steel foil and zinc foil.

24. The method according to claim 9, or 11, or 16 or 18, wherein the said water soluble/non 15 soluble hydrophilic film is made of raw materials selected from Polyvinyl alcohol copolymer ionomcrs, Polyvinyl alcohol homopolymer, non-- ionomeric poly vinyl alcohol polymer, Polymethacrylate, polyvinyl alchohol, polyacrylamide, polymethacrylamide, polyacrylic acid, polymetbacryli.: acid, polyurethane, polyethyleneglycol, polyvinylpyrrolidone, proteinaceous binders such as gelatin, 20 modified gelatins such as phthaloyl gelatin, polysaccharides sdibh as starch, gum Arabic, pullulan and dextrin and water-soluble cellulose derivatives such as methyl cellulose, hydroxy propyl cellulose, hydroxy propyl methyl cellulose, hydroxy propyl ethyl cellulose, hydroxy ethyl cellulose, carboxy methyl cellulose either alone or combinations thereof. 25

25. The method according to claim 9, or 11, or 16 or 18, wherein the biodegradable film is a non soluble partially hydrophilic film which may be cast withowater soluble materials at least on one side of the film. 30

26. The method according to claim 25, wherein the said non soluble partially hydrophilic film is made of thermoplastic starch materials.

27. The method according to claim 25, wherein the water soluble i.oaterials for casting on the non soluble partially hydrophilic film is made of one or more of a raw material including AMENDED SHEET (ARTICLE 19) WO 2006/117801 PCT/IN2006/000072 24 Polyvinyl alcohol copolymer lonomers, Polyvinyl alcohol homopolymer, non - ionomeric poly vinyl alcohol polymer, Polymethacrylate, polyvinyl althobol, polyacrylamide, polymethacrylamide, polyacrylic acid, polymethacrylic: acid, polyurethane, polyethyleneglycol, polyvinylpyrrolidone, proteinaceous birders such as gelatin, 5 modified gelatins such as phthaloyl gelatin, polysaccharides suhib as starch, gum arabic, pullulan and dextrin and water-soluble cellulose derivatives sjch as methyl cellulose, hydroxy propyl cellulose, hydroxy propyl methyl cellulose- hydroxy propyl ethyl cellulose, hydroxy ethyl cellulose, carboxy methyl cellulose either alone.or combinations thereof and the like. 10

28. The method according to claim 9, or 11, or 16 or 18, further including the step of slitting/cutting the laminate prior to or after the internal ageing priod 15 AMENDED SHEET (ARTICLE 19) WO 2006/117801 PCT/IN2006/000072 25 STATEMENT UNDER ARTICLE 19 (1) The applicant humbly presents his informal response to the reasoned statement given under title Re Item V in the Written Opinion of the Hoilorable ISR Authority. In the light of the cited documents in Re Item V and comment on independent claim 1, to clarify the intended invention as noted above, it was found useful to combine or rearrange the elements of "as filed" claim nos. :1 to 4. It was also felt that other claims, including method claims need modified wording on account of one or more reasons including change in the serial numberi!of earlier claims. This has resulted in change in total number of claims and some modification in each claim. Hence, without implying any admission of any kind gto the assessment of the hon. Authorized officer in the ISR, we prefer to cancel all "as filed" claims numbered from claim no. 1 to 32 and replace them with anew set of "amended claims" under Article 19 numbered from claim no, 1 to 28. Invention in this application lies, amongst other elements claimed in the specification, in "amended claim no. 1" which discloses a degradable multi-layer composite packaging material which comprises at least one layer being that of a biodegradable fully or partially hydrophilic film and at least one layer that is either a degradable metallic film or a sheet of biodegragable material. D1, D3, D4, D5, D6 and D7 disclose a composite in which film of the composite is hydrophobic. D8 discloses a method for manufacture-..of a foil from water soluble proteins, and does not speak of a composite in combination with D2. D9 discloses an extrusion die and nothing of the I subject matter of PCT/IN2006/000072. Thus, none of the cited documents disclose such a composite. Hence, the "amended claim no. 1" satisfies requirements of Article 32(1) and 32(2) PCT. Similarly, none of the independent amended method claimilnos. 9, 11, 16 and 18 are disclosed in any of the cited documents. (a) D2 docurn!ent discloses that the laminates can be formed by co-extrusion or by combining separately formed film layers by pressing together at 1200 C under elaborate step of pressing and then WO 2006/117801 PCT/IN2006/000072 26 conditioning at 60% RH and 200 C. This process is fundar:,Ientally different than above mentioned claims and do not just differ in normal process steps as drying, chilling or storing steps that are not mentioned in D2. (by Mention of steps of drying of cellulose pulp in DI and mention of chilling on hill rolls in D9 do not take away inventive step of claim nos. 9, 11, 16 and 18 because claims have to be construed as a whole taking into account ALL =imitations in totality simultaneously and not individually independent of other associated limitations in the same claim. Thus, amended claim nos. 9, 11, 16 and 118 have inventive step too and satisfies criteria of Rule 65(1)(2)PCT. Since all independent amended claims do not infringe thi cited documents or any of the prior art, none of the dependent amended claims too infringe any of the cited documents. By implication, the subject matter o- this application now meets the criteria of Article 33 (1) PCT and Article 33 (2) PCT. There is no necessity of any amendment in the drawings. There may be a need to amend description in view of comments in ISR and amendments in the claims. If a demand is made for International Preliminary Examination, applicant wishes that these amendments be taken into account.