Claims:We claim:
1. A biodegradable packaging material comprising biocomposite,
wherein the biocomposite comprises at least one agricultural residue as reinforcement and at least one natural protein or natural carbohydrate as binder in the weight ratio of reinforcement to binder from 50:50 to 90:10 ;
wherein the packaging material is having tensile strength ranging from 10 to 25 N/mm², young’s modulus ranging from 185 to 383 N/mm², elongation at break ranging from 5.0 to 8.5 % and thermal conductivity ranging from 0.11to 0.22 W/mK
2. The biodegradable packaging material as claimed in claim 1, wherein the packaging material is anti-microbial, water resistant, microwavable and completely biodegradable.
3. The biodegradable packaging material as claimed in claim 1 wherein the agricultural residue is one or more selected from the group consisting of rice straw, wheat straw, coconut coir, banana fibre, sugarcane bagasse, arecanut shell, groundnut shell, oilseed cakes, cotton stalk, and a blend thereof.
4. The biodegradable packaging material as claimed in claim 1 wherein the natural protein or natural carbohydrate is one or more selected from the group consisting of wheat gluten, soyprotein, oil seed proteins, casein, silk, wool, poultry feathers, starch, cellulose, and a blend thereof.
5. The biodegradable packaging material as claimed in claim 1, wherein the material is for food and non-food packaging selected from cooked foods or dishes, ready to eat packaged foods, dairy products, vegetables, fruits, flowers, cereals, grains, textiles, apparels, shoes, books, magazines, electronic items, automotive parts, medical goods and supplies.
5. The biodegradable packaging material as claimed in claim 1 wherein the packaging material is in different sizes and shape, selected from cups, bowls, plates, trays, containers and carton packages.
6. A method of production of the biodegradable packaging material, the method comprising the steps of:
(a) producing biocomposite comprising:
i. preparing a plurality of reinforcement layers comprising one or more agricultural residue in its native form selected from the group consisting of rice straw, wheat straw, coconut coir, banana fibre, sugarcane bagasse, arecanut shell, groundnut shell, oilseed cakes and cotton stalk;
ii. incorporating a binder within the network of reinforcement layers, wherein the binder is added between the reinforcement or sprayed on the reinforcement, wherein the binder is natural protein or natural carbohydrate selected from the group consisting of wheat gluten, soyprotein, oil seed proteins, casein, silk, wool, poultry feathers, starch and cellulose; wherein the weight ratio of the reinforcement to binder is from 50:50 to 90:10;
(b) compressing the biocomposite in a moulding unit at temperature ranging from 70 to 200?C, pressure ranging from 100 to 40000 PSI for 2 to 30 minutes depending upon the type of the agricultural residue and the number of layers of the reinforcement to obtain packaging material of different sizes and shape.
7. The method of production of the biodegradable packaging material as claimed in claim 6, wherein the method further comprises the step of spraying or adding water to the biocomposite in the weight ratio ranging from 0.5:1 to 1.5:1
8. The method of production of the biodegradable packaging material as claimed in claim 6, wherein the packaging material tensile strength ranges from 10 to 25 N/mm², young’s modulus from 185 to 383 N/mm², elongation at break from 5.0 to 8.5 % and thermal conductivity from 0.11 to 0.22 W/mK.
9. The method of production of the biodegradable packaging material as claimed in claim 6, wherein the packaging material is anti-microbial, water resistant, microwavable and completely biodegradable.
10. The method of production of the biodegradable packaging material as claimed in claim 6, wherein the material is for food and non-food packaging including but not limited to cooked foods or dishes, dairy products, vegetables, fruits, flowers, cereals, grains, textiles, apparels, shoes, books, magazines, electronic items, automotive parts, medical goods and supplies.
11. The method of production of the biodegradable packaging material as claimed in claim 6, wherein the packaging material is in different sizes and shape, not limited to cups, bowls, plates, trays, containers and carton packages.
, Description:NON-PULP COMPLETELY BIODEGRADABLE PACKAGING MATERIALS FROM AGRICULTURAL RESIDUES AND PROTEINS
FIELD OF THE INVENTION
[001] The present invention relates to packaging materials, more particularly to biodegradable packaging materials derived from agricultural residues and proteins for commodity and non-commodity products as substitutes for plastics and method of production thereof.
BACKGROUND OF THE INVENTION
[002] Considerable efforts are done worldwide to develop biodegradable products as substitutes for plastic based materials, those used for packaging in current use. One of the most common approaches to develop biodegradable products is to use natural fibers such as jute or coir along with synthetic polymers such as polypropylene, polyethylene as binders. In some other instance, completely biodegradable products have been developed using biobased fibrous materials as reinforcement and biodegradable synthetic polymers as binders. However, using biobased materials and synthetic polymers results only in partially biodegradable products. Similarly, biodegradable synthetic polymers are expensive and also do not meet the desired functional properties. Hence, there are limited or no completely biodegradable products available in the market.
[003] Attempts to develop biodegradable products using fibers, agricultural residues or biomass essentially requires physical and/or chemical processes where the raw materials are made into pulp or particles or modified from their native form. Such modifications are inevitable since current processing methods cannot accommodate natural materials in fibrous form. Hence, biodegradable products currently available in the market are mostly made using the pulping method. Further, Pulping or other common modifications methods require chemicals and also pollute the environment. In addition, they increase the cost of the products and damage the inherent properties and uniqueness of the raw materials. So far, there are no biobased products that are developed using agricultural residues or biomass in their native form and without either subjecting them to chemical or physical processing. Some of the reports on developing biobased materials are discussed below:
[004] German patent DE60313679T2/USUS6878199B2 describes the development of a fully biodegradable material made using pre-gelatinized starch suspension, "the pregel", containing about 2-15% potato starch and 75-95% water which is mixed with wood fibers or wood flour with a length ratio or aspect ratio between about 1: 2 and 1: 8. The starch wood mixture is made into a moldable form and heated to form a biodegradable material. This invention used wood fibers in specific aspect ratio and also requires the use of an aqueous suspension.
[005] US8382888B2 discloses the development of biodegradable containers made from pre-gelatinized starch and short fibers (less than 0.5 mm) and long fibers ( more than 4 mm) and optionally other constituents including mold releasing agents, wax emulsion and a protein or natural polymeric component. The mixture could be made into suitable containers for food or non-food use.
[006] Starch based biodegradable containers were developed (KR100636367B1) by including reactants that crosslink the starch or between starch and subsidiary materials, including fillers, foaming aids, coagulants, A biodegradable container composition comprising at least one component selected from a softening agent, a plasticizer, a binder, and a physical reinforcing agent, a releasing agent, a humectant, and a hydrophobic imparting agent. The described composition was molded into the desired shape and size and further laminated with a biodegradable film.
[007] Biodegradable chum containers were described in US patent 6848210B1 where the biodegradable material was made from polyethylene oxide resins, methyl cellulose, hydroxylpropyl cellulose, polysaccharides. The containers made using these materials were the chum which was supposed to leave the container after 7 days in water.
[008] US20200063373A1 relates to the development of contoured materials formed from fiber slurry made of cellulose fibers and a cellulose ester. The pulp for developing the products having fiber slurry properties of (i) Williams Slowness of less than 400 seconds; and (ii) Canadian Standard Freeness of at least 100 ml. The said materials may be made into molded articles Including cups, lids, boxes or pouches, storage containers, trays, plates, food trays, cutlery, coffee cups, coffee cup lid, packaging, bowls, clam shells, bottle caps, straws, covers, and inserts.
[009] WO2009137382A1 describes the development of thermoformed biobased material using renewable polymer and/or natural fiber comprises a polyhydroxyalkanoate polymer, a polycaprolactone polymer, a starch-based polymer, a cellulose-based polymer, or combination thereof the natural fiber are cellulose fibers and powders, rice fiber husk fiber, wheat barn fiber, straw fiber, corn cob fiber, wood fibers, and bamboo fibers. The materials are co-extruded to form the composite product.
[0010] Weber, C. J., V. Haugaard, R. Festersen, and G. Bertelsen.in "Production and applications of biobased packaging materials for the food industry." Food Additives & Contaminants 19, no. S1 (2002): 172-177 list the types of biopolymers available for food packaging. In their review, they report the necessity for biodegradable packaging but indicate that other than poly(lactic acid), there are very limited choices of biobased packaging.
[0011] Bio-nanocomposites have been developed for packaging applications. In such composites, the biopolymers are generally made into nanoparticles or nanofibers and combined with a synthetic polymer or natural binder. Later, the composites are moulded or extruded into desired shape and size (Sorrentino, 2007).
[0012] A biobased packaging catalog has been developed by Wagnengen University, Netherlands. The catalog has a comprehensive of all the biodegradable packaging available in the market. As seen from the report, there are two types of biodegradable packaging available. First, those made from synthetic biopolymers mostly PLA and the other type is those made using biobased cellulosic materials but after pulping.
[0013] Biodegradable packaging materials available in the market are either made using synthetic biopolymers, by pulping of natural fibrous materials or after extensive chemical/physical modifications. This makes the packaging expensive and also adds to pollution of the environment. Unlike the prior arts discussed above, the present invention is directed towards the need to develop bio-based packaging materials using agricultural residues in their original form without the need of any chemicals or pulping process along with natural binders. This means that the products of the present invention are 100% biodegradable and developed without affecting the inherent properties of the agricultural residues. Using the agricultural residues in their native form also enabled the inventors of the instant application to adopt broader conversion technologies. The process of the present invention is simple and can be adopted in rural areas where raw materials are available in abundance.
OBJECT OF THE INVENTION
[0014] The main object of the present invention is to develop 100% biodegradable packaging materials that are environmentally friendly and safe.
[0015] It is another object of the present invention to develop biodegradable packaging materials derived from renewable resources and be used as an alternative to the plastic packaging materials in current use.
[0016] It is yet another object of the present invention to develop biodegradable packaging materials using agricultural byproducts and biomass that are available in large quantities at low cost and eliminate the need for burning or burying the crop residues.
[0017] It is still another object of the present invention to develop biodegradable packaging materials using agricultural residues in their native form along with natural binders.
[0018] It is another object of the present invention to develop a method or process for preparation of the biodegradable packaging material using agricultural residues without the need for any physical or chemical modifications of the residues.
[0019] It is a further object of the present invention to provide packaging materials that exhibits the above properties and which can be produced economically on a commercial scale.
[0020] Other objects of the inventions will be apparent from the description of the invention herein below.
SUMMARY OF THE INVENTION
[0021] According to a first aspect of the present invention there is provided a biodegradable packaging material comprising biocomposite, wherein the biocomposite comprises at least one agricultural residue as reinforcement and at least one natural protein or natural carbohydrate as binder.
[0022] In another aspect of the present invention, the weight ratio of reinforcement to binder ranges from 50:50 to 90:10.
[0023] In certain aspects of the present invention, the agricultural residue is one or more selected from the group consisting of but not limited to rice straw, wheat straw, coconut coir, banana fibre, sugarcane bagasse, arecanut shell, groundnut shell, oilseed cakes, cotton stalk, and a blend thereof.
[0024] In certain aspects of the present invention, the natural protein or natural carbohydrate is one or more selected from the group consisting of but not limited to wheat gluten, soyprotein, oil seed proteins, casein, silk, wool, poultry feathers, starch, cellulose, and a blend thereof.
[0025] In an aspect of the present invention, the packaging material tensile strength ranges from 10 to 25 N/mm², Young’s modulus from 185 to 383 N/mm², elongation at break from 5.0 to 8.5 % and thermal conductivity from 0.11 to 0.22 W/mK
[0026] In an aspect of the present invention, the packaging material is anti-microbial, water resistant, microwavable and completely biodegradable.
[0027] In certain aspects of the present invention, the packaging material is for food and non-food packaging including but not limited to cooked foods or dishes, ready to eat packaged foods, dairy products, vegetables, fruits, flowers, cereals, grains, textiles, apparels, shoes, books, magazines, electronic items, automotive parts, medical goods and supplies.
[0028] In certain aspects of the present invention, the packaging material is in different sizes and shape, not limited to cups, bowls, plates, trays, containers and carton packages.
[0029] In an aspect of the present invention, the packaging material is disposed as fertilizer or animal feed or is composted without causing any harm to the environment.
[0030] In an aspect of the present invention, a label or impression or logo is created on the packaging material of the present invention during or after the production of the material.
[0031] In an aspect of the present invention, additional coatings, paints, layers are added to the packaging material of the present invention for aesthetic, functional or other applications.
[0032] A method of production of the biodegradable packaging material is also disclosed in the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS
[0033] For a better understanding of the invention, few embodiments are described below with reference to the accompanying figures, purely by way of example and non-limiting in which:
Fig 1 shows the different sizes and shapes of the biodegradable packaging material of the present invention;
Fig 2 illustrates the production of box from coir of (a) placing the coir and binder in the compression unit (b) the coir and binder being compressed (c) formation of product after compression moulding (d) final product of box;
Fig 3 shows the packaging material of box from rice straw in accordance with an aspect of the present invention;
Fig 4 illustrates the compressability of the packaging material of the present invention;
Fig 5 illustrates the microwave capability of the packaging material of the present invention;
Fig 6 illustrates the water resistance of the packaging material of the present invention;
Fig 7 illustrates the biodegradability of the packaging material of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0034] For the better understanding of the objects, technology and advantages of the present invention, the instant invention will be further explained in detail with respect to embodiments and accompanying figures as given above. It should be understood that the specific embodiments described herein are only to be used for explaining the present invention but not used to limit the present invention
[0035] Ubiquitous use and indiscriminate use of plastics is one of the major health, environmental and economic concerns across the globe. Packaging is the largest application of plastic (synthetic polymers), particularly, for single-use or use and throw packaging. Hence, considerable efforts are being done to reduce and even eliminate the use of plastic packaging. Current alternatives to plastic packaging are either very inexpensive, not readily available, do not meet required standards or use extensive chemicals and environmentally unfriendly processes.
[0036] Agricultural residues, particularly crop residues are inevitably generated and are available in large quantities at no or low cost. Most of these residues are either burnt or buried leading to loss of valuable raw materials and also causes environmental pollution. Hence, it is necessary to find applications for these raw materials in transforming into a useful product. Also, disposing these residues is an economic loss to the farmers and reduces the income from crops/farming.
[0037] The present invention provides, in an aspect, a biodegradable packaging material comprising biocomposite derived from agricultural residues and natural binders.
[0038] In an embodiment, the biocomposite comprises at least one agricultural residue as reinforcement.
[0039] In certain embodiments, the agricultural residues is one or more selected from the group consisting of but not limited to rice straw, wheat straw, coconut coir, banana fibre, sugarcane bagasse, arecanut shell, groundnut shell, oilseed cakes and cotton stalk.
[0040] In an embodiment, the natural binder in the biocomposite is protein or carbohydrate.
[0041] In certain embodiments, the protein or carbohydrate is one or more selected from the group consisting of but not limited to wheat gluten, soyprotein, oil seed proteins, casein, silk, wool, poultry feathers, starch and cellulose
[0042] In an embodiment, the weight ratio of reinforcement to binder ranges from 50:50 to 90:10.
[0043] In an embodiment, the packaging material is in different sizes and shape, not limited to cups, bowls, plates, trays, containers and carton packages.
[0044] In an embodiment, the packaging material is for food and non-food items.
[0045] In an embodiment, the packaging material holds food items in dry, damp or wet conditions.
[0046] In an embodiment, the food items includes but not limited to cooked foods or dishes, ready to eat packaged foods, dairy products, vegetables, fruits, flowers, cereals and grains.
[0047] In an embodiment, the non-food items includes but not limited to textiles, apparels, shoes, books, magazines, electronic items, automotive parts, medical goods and supplies.
[0048] In an embodiment, as the packaging material of the present invention is intended for food and non-food applications, they are subjected to physical and biological tests. These tests are necessary to understand the shelf-life, reusability, applications of the packaging material among others.
[0049] In an embodiment, the tensile strength of the packaging material indicates the ability of the material to bear load and resistance external forces.
[0050] In an embodiment, the tensile strength of the packaging material of the present invention ranges from about 10 to 25 N/mm².
[0051] In an embodiment, the Young’s modulus of the packaging material indicates the durability of the product.
[0052] In an embodiment, the Young’s modulus of the packaging material of the present invention ranges from about 185 to 383 N/mm².
[0053] In an embodiment, the elongation at break of the packaging material indicates the extensibility of the product.
[0054] In an embodiment, the elongation at break of the packaging material of the present invention ranges from about 5.0 to 8.5 %
[0055] In an embodiment, the thermal conductivity for food containers is important since it is expected that there should be minimal heat loss and the food remains hot for more time.
[0056] In an embodiment, the thermal conductivity of the packaging material of the present invention ranges from about 0.11 to 0.22 W/mK.
[0057] After large number of experimentations, the inventors of the present invention found that the packaging material of the present invention is anti-microbial, water resistant, microwavable and completely biodegradable. Due to its antimicrobial activity, non-toxicity and biodegradability, it exhibits a great potential for using as packaging material.
[0058] In an embodiment, the biodegradable packaging material of the present invention do not contain any chemicals or synthetic polymers.
[0059] In an embodiment, the biodegradable packaging material of the present invention does not contain any pulp.
[0060] In an embodiment, the biodegradable packaging material is naturally compostable and biodegradable.
[0061] In an embodiment, the biodegradable packaging material is disposed as fertilizer or animal feed or is composted without causing any harm to the environment.
[0062] In an embodiment, a label or impression or logo is created on the packaging material of the present invention during or after the production of the material.
[0063] In an embodiment, additional coatings, paints, layers are added to the packaging material of the present invention for aesthetic, functional or other applications.
[0064] The present invention provides, in another aspect, a method of production of the biodegradable packaging material of the present invention.
[0065] In an embodiment, the method of production of the biodegradable packaging material comprises (a) producing biocomposite and (b) compressing the biocomposite in a moulding unit.
[0066] In an embodiment, the method of producing biocomposite comprises:
i. preparing a plurality of reinforcement layers comprising one or more agricultural residue in its native form selected from the group consisting of rice straw, wheat straw, coconut coir, banana fibre, sugarcane bagasse, arecanut shell, groundnut shell, oilseed cakes and cotton stalk;
ii. incorporating a binder within the network of reinforcement layers, wherein the binder is added between the reinforcement or sprayed on the reinforcement, wherein the binder is natural protein or natural carbohydrate selected from the group consisting of wheat gluten, soyprotein, oil seed proteins, casein, silk, wool, poultry feathers, starch and cellulose; wherein the weight ratio of the reinforcement to binder is from 50:50 to 90:10.
[0067] In an embodiment, the method of compressing the biocomposite in a moulding unit comprises: compressing the biocomposite in a moulding unit at temperature ranging from 70 to 200?C, pressure ranging from 100 to 40000 PSI for 2 to 30 minutes depending upon the type of the agricultural residue and the number of layers of the reinforcement to obtain packaging material of different sizes and shape.
[0068] In an embodiment, the method further comprises the step of spraying or adding water to the biocomposite wherein the weight ratio of water to biocomposite ranges from 0.5:1 to 1.5: 1
[0069] In an embodiment, the packaging material is produced using any suitable technology including but not limited to compression, injection molding or solution casting or a combination of these methods.
[0070] The above description of the invention, together with the below accompanying examples should not be construed as limiting the invention because those skilled in the art to which this invention pertains will be able to devise other forms thereof within the ambit of the appended claims.
EXAMPLES
Example 1: Method of Production of Biocomposite
[0071] The method of the present invention is related to the utilization and conversion of agricultural residues such as rice straw, wheat straw, coconut coir, banana fibre, sugarcane bagasse, arecanut shell, groundnut shell, oilseed cakes and cotton stalk into value added bioproducts for various applications. The uniqueness of this method is that the raw materials are used in their original form without any physical or chemical modifications. The method essentially involves producing a plurality of reinforcement layers comprising one or more agricultural residue in its native form selected from the group consisting of rice straw, wheat straw, coconut coir, banana fibre, sugarcane bagasse, arecanut shell, groundnut shell, oilseed cakes and cotton stalk and incorporating a binder within the network of reinforcement layers, wherein the binder is added between the reinforcement or sprayed on the reinforcement, wherein the binder is natural protein or natural carbohydrate selected from the group consisting of wheat gluten, soyprotein, oil seed proteins, casein, silk, wool, poultry feathers, starch and cellulose to obtain the biodegradable biocomposite.

Example 2: Method of Production of Packaging materials
[0072] The biodegradable biocomposite is compressed in a moulding unit at temperature ranging from 70 to 200?C, pressure ranging from 100 to 40000 PSI for 2 to 30 minutes depending upon the type of the agricultural residue and the number of layers of the reinforcement to obtain packaging material of different sizes and shape. A label or impression or logo is created on the packaging material during or after the production of the material. Also, additional coatings, paints, layers are added to the packaging material for aesthetic, functional or other applications (Fig 1).
[0073] The source and geographical origin of the raw materials used in the present invention are as follows:
Table 1: Source and Biological origin of the raw materials used in the present invention
Raw Material Source Biological origin
Sugarcane bagasse Local sugarcane processors who make juice and dispose the bagasse as waste Growing regions nearby to Bangalore such as Mandya.
Coconut coir Commercial vendors who sell coir Karnataka/ Tamilnadu
Cotton stalks Farms/farmers where the stalk is left as residue Nanjangud area in Karnataka, Guntur and surrounding regions
Rice and ragi straw Farmers nearby Bengaluru Region around Bengaluru
Ground nut shells Processors of ground nuts, shells sold commercially Karnataka, Andhra pradesh
Oil seed cakes Commercial sellers of oil cakes Karnataka, Andhra, Telangana and Tamil nadu
Wheat gluten Commercial vendors (manufacturers) Karnataka
Soyprotein Commercial vendors (manufacturers) Karnataka
Sheepwool Farmers, commercial vendors Karnataka
Starch Commercial vendors Across India
Poultry feathers Poultry industries and chicken processors, retail and wholesale shops Across India

Example 2a: Packaging material of box from coconut coir
[0074] Coir is purchased from commercial vendors and the coir is used as reinforcement material. Before using, the coir is carded to align the fibers and obtain mats. The binder wheat gluten is sprayed onto the mats. Additional layers of mats and adequate binder is added. The overall reinforcement to binder ratio is maintained at 85:15 and the total weight of the biocomposite is 250 gram. Water equivalent to 100 gram is sprayed onto the biocomposite. After spraying the water, the biocomposite is placed on a compression moulding unit that has a box mold fitted onto it. The compression unit is preheated to 130?C and compression is done for 10 minutes at pressure of 1000 PSI. After compression, the unit was released and the box formed is collected. Excess fibers are trimmed and the box is stored. Fig 2 illustrates the production of box from coir of (a) placing the coir and binder in the compression unit (b) the coir and binder being compressed (c) formation of product after compression moulding (d) final product of box.
Example 2b: Packaging material of cup from coconut coir
[0075] To convert coir into cups, the fibers about 50 grams and binder (wheat gluten or soyprotein or sheepwool keratin) about 5 grams are mixed together in water (50gram) to form a slurry. The slurry is allowed to dry until 50% of the water is evaporated. Later, the obtained biocomposite is compressed molded at 120 ?C for 15 minutes at pressure of 2000 PSI. The mold is released and the cups formed are collected. In this instance, the cups require additional water for consolidation. Also, the binder is in a slurry which ensures deeper penetration and binding. The amount of binder and fibers depends on the thickness of the cup desired.
Example 2c: Packaging material of box from banana fibre
[0076] Banana fibers contain less lignin and are also considerably finer and whiter than coir. Hence, the same processing conditions used for coir is not applicable to banana fibers. To process banana fibers, the fibers are first cut into lengths of about 2 to 3 cm. Later, the fibers are spread on the sheet. Since banana fibers are finer and it is necessary to achieve uniform distribution of the binder, the binder, in this case wheat gluten or soyproteins are first dispersed in water. The dispersed binder is sprayed onto the fibers until the weight of the binder on the fibers is about 20%. After spraying, the biocomposite is placed in the mold having a box shape and compressed. The compression is done at 130?C for 10 minutes at pressure of 1500 PSI.
Example 2d: Packaging material of box lid from banana fibre
[0077] The boxes developed by the present invention also contain a cap or lid. This lid has to produced separately and using different conditions. Banana fibers were carded to form a mat since the fibers in the lid are required to align and provide adequate strength. The carded fibers are placed on a table and the binder (wheat gluten) in the form of a slurry is sprayed. For the lids, the ratio of fibers to binder is maintained at 90:10. After evaporating the water, the biocomposite is compressed at 130 ?C for 10 minutes at pressure of 1200 PSI to form the lid.
Example 2e: Packaging material of box from arecanut shells
[0078] Areca shell are disposed as waste but are highly fibrous. However, the fibers in the areca shells are considerably shorter and hence difficult to be processed into any bioproducts. Areca shells are mechanically opened to obtain the fibers. The fibers are spread on a jute cloth to ensure they retain a sheet form. The jute mat with the fibers is dipped into wheat gluten solution for 10 minutes. Later, the mat and fibers are dried in an oven at 70?C. After drying, the areca fibers adhere together by the binder. Water is sprayed on to the adhered areca fiber sheet. The biocomposite is then placed in a mold and compressed into boxes by heating at 120?C for 10 minutes at pressure of 2500 PSI.
Example 2f: Packaging material of box from cotton stalks
[0079] Cotton stalks are residues generated in large quantities, often weighing up to 10 times the amount of cotton fiber harvested. Cotton stalks are currently disposed as waste and are either burnt or buried. However, cotton stalks are highly fibrous and the fibers obtained are carded to form a mat. Wheat gluten about 15% of the weight of the fibers is sprayed over the fibers. The biocomposite is placed in mold and compressed at 120 ?C for 10 minutes at pressure of 3000 PSI to form a box.
Example 2g: Packaging material of box from sugarcane bagasse.
[0080] Biodegradable boxes have been developed by pulping bagasse. Pulping is a chemically intensive process and also releases toxic effluents. We propose to use bagasse for developing bioproducts without the need for pulping. In the present invention, bagasse is cut into pieces with length of about 1 to 3cm. The cut bagasse is soaked in a 10% wheat gluten suspension in water for 24 hours. After 24 hours, the bagasse is taken out and squeezed between rollers to remove excess water. The binder wheat gluten is penetrated through the bagasse. The wet bagasse with the binder is compressed molded at 130?C for 15 minutes at a pressure of 500 PSI. Later, the boxes formed are collected. It is ensured that the amount of binder on the bagasse is at least 10%.
Example 2h: Packaging material of box from rice straw
[0081] Rice straw is combined with the protein-sheepwool keratin and water equivalent to 5 times the weight of the straw and proteins is added into a cooker. The mixture is steamed for 15 minutes without using any chemicals. After cooling down, the water is drained and the straw-protein mixture is dried. The obtained biocomposite is compressed molded into boxes by heating at 130? C for 5 minutes at a pressure of 1000 PSI (Fig 3).
Example 2i: Plant containers from blends of banana fibers and coir
[0082] Since plant containers or pots intended for germination and plant growth need longer duration, strength and stability against environmental degradation, a blend of coir and banana fibers is considered. The two fibers in 50:50 ratio are combined and carded together to form a uniform mat. The binder in this instance is a blend of wheat gluten and wheat flour in 50:50 ratio and is sprayed on the mats. Total weight is 600 grams and the fiber and binder ratio is 80:20. Water of about 200 gram is sprayed across the bicomposite. The biocomposite is then placed inside a mold and compression is done at 140 ? C for 20 minutes at a pressure of 2200 PSI. The mold is released and the plant container formed is collected.
Example 3: Performance Evaluation of the Packaging material
[0083] The packaging materials of the present invention are intended for food and non-food applications and hence are subject to various physical, chemical and biological tests. Physical and biological (mainly resistance to microbial attack) are the most important tests. Tensile tests are done to determine the flexural and tensile resistance of the samples. Tensile tests are done according to ASTM standard 642 or ASTM standard D4169. Tensile strength of the boxes indicate the ability of the material to bear load and resistance to external forces. Flexural or compression strength indicates the ability of the boxes/bioproducts to bend and buckle under different forces. Similarly, elongation at break indicates the extensibility of the product and Young’s modulus indicates the durability of the bioproducts. These properties are necessary to understand the applications, shelf-life, re-useability among others.
Example 3a: Tensile strength, Young’s modulus and Elongation at break of the packaging
material
[0084] Biobased packaging materials intended for food and non-food applications are developed from rice straw, banana fibers and coir using wheat gluten as the binder. The boxes did not contain any other ingredient and are hence 100% chemical free and 100% biodegradable. These boxes are tested for their tensile properties in comparison to a plastic box currently used for food packaging applications (Table 2). Boxes made from banana fibers and gluten has similar strength and elongation as the plastic boxes. Boxes made from coir are weaker compared to banana fibers or rice straw. However, the density and or the proportion of the coir in the product can be changed to obtain coir based boxes with similar strength and stability as the banana fiber or plastic boxes. The ratio of the fibers and binders or the total weight of the box (weight/unit area) could be changed to obtain higher weight for the coir and banana fiber boxes. Thermal conductivity is a measure of the ability of the material to hold, transfer or dissipate heat. This property is particularly important for food containers since it is expected that there should be minimal heat loss and the food remains hot. The inventors studied the thermal conductivity of the boxes of the present invention using the JIS 1412-2 standard in an EKO Thermal Conductometer. A minimum of 3 samples of 200mm x 200mm x 10mm each are tested in every ratio for the thermal conductivity. Briefly, the test sample is stacked in between a heating plate and cooling plate that maintains a steady temperature difference allowing heat to flow across the sample at a constant rate. Thermal conductivity is calculated based on the resistivity to the heat flow.
Table 2: Tensile strength, Young’s modulus, Elongation at break and Thermal Conductivity of the packaging material
S.No Name Tensile strength
(N/mm²) Young’s modulus
(N/mm²) Elongation at break(%) Thermal conductivity W/mK
1 Plastic Box
25.9 ± 0.94 593.41 ± 1.42 9.16 ± 0.56 0.3-0.33
2 Rice straw + Gluten
17.3 ± 0.91 186.71 ± 1.26 7.15 ± 1.24 0.209±0.007
3 Banana + Gluten
24.9 ± 0.42 378.19 ± 0.68 6.77 ± 0.74 0.152±0.05
4 Coir + Gluten
11.3 ± 1.02 381.45 ± 1.74 6.71 ± 1.46 0.139±0.021

Example 3b: Compressability of the packaging material
[0085] The biodegradable boxes of the present invention are subject to compression tests in a Universal Testing Machine (MTS Corporation, USA) with a 500 N load cell and the testing is done at a crosshead speed of 5mm/min (Fig 4).
Example 3c: Microwave capability of the packaging material
[0086] Since the packaging materials of the present invention are intended for food applications, the inventors studied the ability of the boxes to be microwaved and changes to the food being microwaved is observed. As seen from the figure 5, rice at 37 ?C could be microwaved up to 74 ?C without any change to the texture, smell, taste of rice. No damage is observed to the box.
Example 3d: Water resistance of the packaging material
[0087] The packaging boxes are tested for their ability to retain water or be stable at high humidity and temperatures. As seen from the figure 6, the boxes of the present invention can retain water and other aqueous solutions such as syrups used in sweets, fruit juices, supplements used during consuming rice etc. To determine the water resistance of the boxes, tap water was poured into the boxes and any leakage of water from the boxes is observed for 24 hour and found there is no leakage of water. This test confirms that the packaging materials of the present invention could be used for packaging typical Indian food such as idly-sambar, sweets containing syrups, curd etc.
Example 3e: Biodegradability of the packaging materials
[0088] The biodegradable packaging materials of the present invention is buried in normal soil to check their biodegradation. As seen from the figure7 the packaging materials (containers) degraded substantially within 30 days of burial indicating excellent degradability.
Example 3f: Analysis of microbial growth in the food material stored in various package materials
[0089] Antimicrobial resistance is necessary to ensure that the food packaged in the containers does not get spoilt. Even for non-food items, it has be ensured that the packaging does not support the growth of microorganisms. Hence, the antimicrobial properties are evaluated for the packaging materials of the present invention. Test carried out for enumeration of microbial load with time at room temperature and the results are shown below in Table 3.
Table 3: Analysis of microbial growth in the food material stored in various package materials
Sample Food Number of colonies observed
0 Day Day 1 Day 2 Day 4 Day 8
Commercial plastic box Sweets 0 2 4 15 numerous
Dry fruits 0 0 0 0 3
Chapatis with pickle 0 2 3 13 numerous
Coir box Sweets 0 0 0 2 25
Dry fruits 0 0 0 0 0
Chapatis with pickle 0 0 0 0 5
Banana fiber box Sweets 0 0 1 2 28
Dry fruits 0 0 0 0 0
Chapatis with pickle 0 0 0 2 6

Example 4: Packaging material from blends of proteins and carbohydrates as binders
[0090] The primary binder used in the present invention is a natural, biodegradable and renewable plant based protein i.e wheat gluten. However, proteins are expensive compared to carbohydrates such as cellulose and starch. Hence, the inventors attempted to blend proteins and starch in order to reduce the cost of the packaging material. Different ratios of proteins and starch are blended together and compressed molded into boxes. The strength and stability of the protein-starch based boxes is examined. The results (Table 4) show that adding starch into the proteins did not affect the strength of the samples. Hence, the method of the present invention can use both proteins and starch or other polysaccharides as binders to ensure that the cost is competitive to the plastic based materials in current use.
[0091] Coir fibers are separated, carded and laid in the form a sheet. Wheat gluten and starch are combined in 50/50 w/w ratio. The blend powder is sprayed on the coir sheet ensuring that the weight of the powder is about 20% based on the weight of the coir. After adding the powder, water equivalent to the weight of the coir and binder (gluten+starch) is sprayed on to the sheet. Later, the sheet is placed in a compression mold and compressed at 2500 PSI for 15 minutes at 130?C. The sheet and binder are compression molded to form a box suitable for food packaging application.
Table 4: Characteristic of the Packaging material with blend of proteins and carbohydrates as binders
Type of Packaging material and biocomposite blend Peak Load, N Compressive Strength, MPa Young’s Modulus
MPa
Biodegradable Boxes

25Starch/75protein
2311±209 13.6±1.9 336±17
50Starch/50protein
3241±414 19.1±2.4 256±21
75Starch/25protein
2725±216 16.1±2.1 346±19
100% Protein
2851±443 16.8 ± 2.6 284±45
Biodegradable cups

100% Protein
3048±299 11.8±5.2 404±44
25Starch/75protein
2914±107 10.6±2.2 354±56
50Starch/50protein
2765±318 17.1±1.4 395±27
75Starch/25protein
2525±199 17.7±3.1 376±29

[0092] A main advantage of the present invention is that the packaging material is produced by the method where there is no physical or chemical modification of the raw materials of agricultural residues.
[0093] Another advantage of the present invention is that the packaging material of the present invention is without any chemicals or synthetic polymer.
[0094] Yet another advantage of the present invention is that the packaging material of the present invention is 100% biodegradable and hence does not cause any harm to the environment.
[0095] Still another advantage of the present invention is that the method of production of the biodegradable packaging material of the present invention is easily scalable and adaptable in rural areas.
[0096] While the present disclosure has been described with respect to the specific embodiments, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the disclosure as defined in the following claims.