Claims:WE CLAIM:
1. A heat sealable paper composition, comprising:
a cellulose-based fiber as a base material added in a composition range of at least 70-80% w/w with respect to the total weight of the composition;
a wet strength resin added in a composition range of 0.3-4 % w/w with respect to the total weight of the composition, in combination with a wet end sizing agent or neutral sizing agent in a range of 0.5% to 6% w/w with respect to the total weight of the composition;
a dry strength additive added in a composition range of 1% to 4% w/w with respect to the total weight of the composition, in combination with retention aids added in a combination range of 0.01% to 0.03% w/w with respect to the total weight of the composition; and
a coating chemical comprising Oil & Grease resistant Chemicals added in a composition range of 0.5% to 3% w/w with respect to the total weight of the composition, or Surface sizing Heat Seal Chemicals added in a composition range of 10% to 20% w/w with respect to the total weight of the composition.
2. The heat sealable paper composition as claimed in claim 1, wherein the cellulose-based fiber comprises a combination of 10% to 50% w/w of a softwood and 50% to 90% w/w of a hardwood or 100% w/w of a hardwood.
3. The heat sealable paper composition as claimed in claim 1, wherein the wet strength resin is selected from poly amido amine Epichlorohydrin resins, Poly amide Epichlorohydrin resin or MF Resins.
4. The heat sealable paper composition as claimed in claim 1, wherein the coating chemical is added in combination of a binder.
5. The heat sealable paper composition as claimed in claim 1, wherein the dry strength additive is selected from anionic polyacrylamides or cationic starch.
6. The heat sealable paper composition as claimed in claim 1, wherein the retention aid comprises micro polymer-based retention aids.
7. The heat sealable paper composition as claimed in claim 1, wherein the composition comprises chemical-based binder selected from at least one of Acrylic polymers, Natural/ Synthetic Waxes, starch, polyvinyl alcohol, or sodium alginate.
8. The heat sealable paper composition as claimed in claim 1, wherein the Oil & Grease resistant Chemicals is selected from atleast one of Wax, C6 fluorochemicals, starch, polyvinyl alcohol (PVOH), or sodium alginate.
9. The heat sealable paper composition as claimed in claim 1, wherein the Heat Seal Chemicals is selected from at least one of acrylics, Polyurethanes or Ethylene Copolymers.
10. A method (100) for obtaining the heat sealable paper, the method comprises preparing a heat sealable paper composition by:
Pulping (101), a cellulose-based fiber material in a pulper and refining the cellulose-based fiber in a refiner prior to mixing with a chemical composition, wherein the cellulose-based fiber material is in a composition range of at least 50% w/w with respect to the total weight of the heat sealable paper composition,
Mixing (102), the cellulose-based fiber material with the chemical composition in a mixing chest, wherein the chemical composition comprises a wet strength resin added in a composition range of 0.3% to 6% w/w with respect to the total weight of the heat sealable paper composition, a wet end sizing agent or a neutral sizing agent added in a composition range of 0.5% to 6% w/w with respect to the total weight of the heat sealable paper composition, a dry strength additive added in a composition range of 1% to 4% w/w with respect to the total weight of the heat sealable paper composition, and a retention aid to form a paper slurry;
Dewatering (103), and rolling the paper slurry, wherein the paper slurry is rolled in a press roller to form a wet paper web, wherein the wet paper web is further dewatered by passing the wet paper web under a predetermined pressure through a series of dryers to form a dried paper web;
Coating (104), the dried paper web in a surface sizing equipment, or an offline coating machine, wherein the dried paper web is passed through a pond of coating chemical to form a coated paper web, and wherein the coating chemical coating chemical comprises Oil & Grease resistant Chemicals added in the composition range of 0.5% to 3% w/w with respect to the total weight of the heat sealable paper composition, or Surface coating Heat Seal Chemicals added in a composition range of 10% to 20% w/w with respect to the total weight of the heat sealable paper composition added in a the range of 10% to 20% w/w with respect to the total weight of the heat sealable paper composition; and
Drying (105), the coated paper web using an infra-red hammer or Hot Air tunnel to dry the coated paper web for proper processing of a paper reel of heat sealable paper.
11. The method (100) for obtaining heat sealable paper composition as claimed in claim 11, wherein the wet strength resin added is selected from poly amido amine Epichlorohydrin resins, Poly amide Epichlorohydrin resin or MF Resins.
12. The method (100) for obtaining heat sealable paper composition as claimed in claim 11, wherein the coating chemical is added in combination of a binder.
13. The method (100) for obtaining heat sealable paper composition as claimed in claim 11, wherein the dry strength additive is selected from anionic polyacrylamides or cationic starch.
14. The method (100) for obtaining heat sealable paper composition as claimed in claim 11, wherein the retention aid comprises micro polymer-based retention aids.
15. The method (100) for obtaining heat sealable paper composition as claimed in claim 11, wherein the composition comprises chemical-based water carrier selected from at least one of Acrylic polymers, Natural/ Synthetic Waxes, starch, polyvinyl alcohol, or sodium alginate.
16. The method (100) for obtaining heat sealable paper composition as claimed in claim 11, wherein the offline coating machine is configured to coat the dried paper slurry using Gravure, Air knife, Curtain coater, rod coater, film coater, short-dwell coater, spray coater, and metering film size press.

Dated this 22nd Day of March 2021

Priyank Gupta
Agent for the Applicant
IN/PA-1454
, Description:FORM 2

THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENT RULES, 2003

COMPLETE SPECIFICATION

(See Section 10 and Rule 13)

Title of disclosure:
A HEAT SEALABLE PAPER COMPOSITION

APPLICANT:
PUDUMJEE PAPER PRODUCTS LTD.
An Indian entity having address as
Pudumjee Paper Products Ltd,
Thergaon, Chinchwad, Pune 411033,
Maharashtra, India.

The following specification particularly describes the disclosure and the method in which it is to be performed.

CROSS-REFERENCE TO RELATED APPLICATIONS AND PRIORITY
The present application does not claim priority from any patent application.

TECHNICAL FIELD
The present disclosure is directed to a composition of a packaging paper, particularly to a heat sealable packaging paper compositions for packaging food and allied products.

BACKGROUND
Packaging industry in India has been experiencing major innovations, especially in packaging and branding. Most of the packaging industry is procured by food packaging industry. Further, various packaging used in food packaging industry comprises plastic-based packaging. Food packaging industry is expected to fuel the demand for plastic-based packaging. Further, the plastic packaging ensures food quality, safety and long shelf life. Plastic packaging uses plastic and paper bags, and the said plastic and paper bags coated with poly-compositions to form poly-coated paper bags.
Conventional processes of manufacturing such poly-coated paper bags comprises addition of various chemicals onto a cellulose base material to form a paper composition. Further, the various chemicals may be selected from but not limited to strength additives, retention aids, and polyethylene or polypropylene lamination, sizing agents, and the like. Further, the composition is subjected to various milling processes and drying, further processed to form a paper bag.
However, the plastic and paper bags which are used for packaging food products are mainly laminated by polyethylene or polypropylene. These laminated plastic and paper bags are not easily biodegradable. Further, the plastic bags or poly-coated paper bags are difficult in repulping and are not as easily recyclable as conventional paper or paperboard. Further, the paper bags also provide no thermal or heat insulation, wherein the food packaged in the paper bag may get cooled down easily.
What is needed is a durable and cost-effective heat sealable paper composition for food-based packaging, and at the same time is environmentally friendly which may solve long pressing need.
SUMMARY
This summary is provided to introduce aspects related to development of a heat sealable paper composition for food-based and allied products packaging. This summary is however not intended to disclose essential features of the innovation, nor is it intended to determine, limit or restrict the scope of the innovation.
The present disclosure provides a heat sealable paper composition for food-based and allied products packaging, and the method of formulation thereof. Further, in one aspect of the disclosure, the heat sealable paper composition may comprise a cellulose fibres as a base material, wherein the cellulose fibres may comprise hardwood or softwood, or a combination thereof. Further, variant species of softwood or hardwood may be selected to enable strength property to the final paper sheet.
In one aspect of the disclosure, the heat sealable paper composition may comprise a wet strength resin, wherein the wet strength resin is configured to hold the cellulose fiber and prevents rupture of the paper, especially when the paper is wet. Further, the wet strength resin is selected from but not limited to PAAE (poly amido amine Epichlorohydrin) resins or PAE (Poly amide Epichlorohydrin) resin or MF (melamine formaldehyde) Resins.
In one aspect of the disclosure, the heat sealable paper composition may comprise sizing agents, wherein the sizing agents are configured to reduce water absorption characteristics of the final paper sheet. Further, the sizing agents may be selected from Alkaline sizing agents or ASA (Alkenyl Succinic Anhydride) or Neutral sizing agents.
In one aspect of the disclosure, the heat sealable paper composition may comprise dry strength additives, wherein the dry strength additives may be selected from but not limited to anionic polyacrylamides, cationic starch and Retention aids like micro polymers, and the like.
In one aspect of the disclosure, the heat sealable paper composition may comprise a coating chemical comprising Oil & Grease resistant Chemicals and heat seal chemicals, wherein the coating chemical may be configured to enable greaseproofness to the paper, as well as provide heat sealable property to the paper composition.
In one aspect of the disclosure, the process of obtaining the heat sealable paper composition is illustrated as an aspect of the present disclosure. Further the method comprises pulping a cellulose-based fiber material in a pulper and refining the cellulose-based fiber in a refiner prior to mixing with a chemical composition. Further, the method comprises mixing the cellulose-based fiber material with the chemical composition in a mixing chest. Further, the method comprises dewatering and rolling the paper slurry, wherein the paper slurry is rolled in a press roller to form a wet paper web. Further, the wet paper web is dewatered by passing the wet paper web under a predetermined pressure through a series of dryers to form a dried paper web. Further, the method comprises coating the dried paper web in a surface sizing equipment, or an offline coating machine, wherein the dried paper web is passed through a pond of coating chemical to form a coated paper web. Further, the method comprises drying the coated paper web using an infra-red dryer or Hot Air tunnel to dry the coated paper web for proper processing of a paper reel of heat sealable paper.
Other features and advantages of the present disclosure will be apparent from the following detailed description of the disclosure which illustrates, by way of example, the principles of the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS
The detailed description is given with reference to the accompanying figure. In the figure, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the drawings to refer like features and components.
Figure 1 illustrates an overview of a method for obtaining the heat sealable paper composition, in accordance with an embodiment of the present disclosure.
The figures depict embodiments of the present disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the steps illustrated herein may be employed without departing from the principles of the disclosure described herein.

DETAILED DESCRIPTION
The foregoing detailed description of embodiments is better understood when read in conjunction with the appended drawings. For the purpose of illustrating the disclosure, there are shown in the present document example constructions of the disclosure; however, the disclosure is not limited to the specific design disclosed in the document and the drawings.
The detailed description is provided with reference to the accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the drawings to refer like features and components.
The present disclosure is directed to formulation of a heat sealable paper composition and a process of obtaining heat sealable paper. Heat Sealable Papers may be used in various packaging industries, or more preferably, in packaging of food products, and the like. The production process of the heat sealable paper is based on addition technique for a base cellulose fibres using additives like Wet strength Resins, Sizing agents, Dry strength additives, retention aids, coating chemicals, and a combination thereof.
In one embodiment, the disclosure relates to formulation of the heat sealable paper composition, wherein the formulation comprises a cellulose-based fiber as a base material. Further, the cellulose-based fiber may comprise a wood pulp, preferably a softwood or a hardwood pulp. Further, the hardwood may be added individually or in a combination with a softwood. Further, the hardwood may be added in a composition range of at least 50% of the total weight of the composition. Further, the hardwood may be added in combination with a softwood, wherein the softwood may be added in a composition range of 10-50% of the total weight of the composition, and the hardwood may be added in a composition range of at least 50-90% of the total weight of the composition. Further, the cellulose-based fiber as a base material enables the finished paper to enable strength property to the final paper sheet.
In one embodiment of the formulation of the heat sealable paper composition, a wet strength resin may be added, wherein the wet strength resin is configured to hold the cellulose fiber and prevents rupture of the paper, especially when the paper is wet. Further, the wet strength resin is selected from but not limited to PAAE (poly amido amine Epichlorohydrin) resins or PAE (Poly amide Epichlorohydrin) resin or MF (melamine formaldehyde) Resins. Further, the wet strength resin may be added in a composition range of 0.3-6% w/w with respect to the total weight of the composition.
In one embodiment of the formulation of the heat sealable paper composition, a sizing agent may be added to improve adsorption and wear characteristics of the final paper sheet. Further, the sizing agent may comprise a wet end sizing agent or neutral sizing agent. Further, the sizing agent may be added after addition of a wet strength resin in a range of 0.5% to 6% w/w with respect to the total weight of the composition. Further, the sizing agents may be selected from Alkaline sizing agents or ASA (Alkenyl Succinic Anhydride) or Neutral sizing agents.
In one embodiment of the formulation of the heat sealable paper composition, a dry strength additive may be added to impart stiffness, wax pick, and other surface properties to the finished paper. Further, the dry strength additives may be selected from but not limited to anionic polyacrylamides, cationic starch and Retention aids like micro polymers, and the like. Further, the dry strength additive may be added in a composition range of 1% to 4% w/w with respect to the total weight of the composition.
In one embodiment of the formulation of the heat sealable paper composition, a wet end sizing agent may be added, wherein the wet end sizing agent may be configured to influence dewatering and retention of fibres in the paper sheet. Further, the wet end sizing agent may be selected from Alkaline sizing agents (AKD / Alkene Ketene Dimer), ASA (Alkenyl Succinic Anhydride) or Neutral sizing agents. Further, the AKD / Alkene Ketene Dimer may be added in a range of 0.5%-6 % w/w of the total weight of the composition. Further, the ASA may be added in a range of 0.08-0.3% w/w of the total weight of the composition, and Neutral sizing agent may be added in the range of 0.5-6% w/w of the total weight of the composition.
In one embodiment of the formulation of the heat sealable paper composition, a coating chemical comprising Oil & Grease resistant Chemicals, wherein the Oil & Grease resistant Chemicals are configured to provide greaseproof property to the final paper. Further, the coating chemical may also comprise heat seal chemicals to impart the important feature of heat sealability which enables to pack dry & semi-liquid food products. Further, the paper may be immersed, or is sprayed thereon by the coating chemical, during or post-production. Further, the coating chemical may comprise Oil & Grease resistant Chemicals like Wax, C6 fluorochemicals, starch, polyvinyl alcohol (PVOH), sodium alginate. Further, the oil and grease resistance material may be added in a range of 0.5-3% w/w of the total weight of the composition. Further, the coating chemical may also comprise Surface sizing Heat Seal Chemicals like acrylics, Ethylene Copolymers, Polyurethane etc. Further, the Surface coating Heat Seal chemicals may be added in a range of 10-20% w/w of the total weight of the composition.
In one embodiment, the coating chemical may be mixed with a binder, wherein the binder may be selected from Oxidised starch, Poly Vinyl Alcohol, Carboxy Methyl Cellulose ,Na-Alginate, Poly Ethylene Glycol etc . Further, the binders may be configured to bind the coating chemicals on to the surface of the paper composition, to enhance the oil and grease resistance, and heat sealability of the paper composition.
The following examples of the various embodiments may reveal a deeper understanding of the various properties of the heat sealable paper composition:
Example 1:
Procedure: A pulp slurry in an amount of 80% w/w with respect to the total weight of the composition combination of Hardwood & Softwood with a consistency about 4- 5%, is subjected to pulping and refining, followed by dewatering under atmospheric temperature & pressure. Further, a wet strength resin comprising poly amido amine Epichlorohydrin resins is added in an amount of 4 % w/w with respect to the total weight of the composition. Further, a wet end sizing agent is added in an amount of 3 % w/w with respect to the total weight of the composition. Further, a dry strength additive such as anionic polyacrylamides is added in an amount of 1 % w/w with respect to the total weight of the composition. Further a micro polymer-based retention aid may be added in amount of 0.02 % w/w with respect to the total weight of the composition. Further, the dried slurry is passed through a pond of coating chemical. Further, the coating chemical comprising Acrylic polymers may be added in 2% w/w with respect to the total weight of the composition. Further, a Heat Seal Chemicals comprising Ethylene Copolymers may be added in 10% w/w with respect to the total weight of the composition.

Table 1A:
Ingredient % w/w of the total composition
Pulp 80 (Combination of Hardwood & Softwood)
Wet strength resin 4
Wet End sizing agent 3
Dry strength additive 1
Retention aids 0.02
Oil and grease resistant chemical 2
Heat seal chemicals 10

At the end of coating, the paper web is then dried using IR Chambers or Hot air Tunnel to dry the coating and enable proper building of reel. The resulting heat sealable has the following properties contained in Table 1B:
Table 1B:
Parameters Value
Tensile strength when dry 7500 m (MD)
5500 m (CD)
Tensile strength when wet 25-30%
Thickness of the coating film 5-6 micron
Water Absorbency (Coated Side) 7-10 gsm
Grammage of Coated paper 43 to 63 gsm

Now, referring to Table 1B, which illustrates the properties of a final heat sealable paper prepared from the composition disclosed in Table 1A. Further, the final heat sealable paper discloses a dry tensile strength of 7500 m in machine direction (MD) and 5500 m in cross direction (CD). Further, the wet tensile strength is in the range between 25-30% of dry tensile strength. Further, the thickness of the coating film is in the range between 5-6 micron. Further, the water absorbency on the coated side is in the range between 7-10 gsm. Further, the grammage of paper composition lies in the range between 43 to 63 gsm.

Example 2:
Procedure: A pulp slurry in an amount of 75% w/w with respect to the total weight of the composition combination of Hardwood & Softwood with a consistency about 4- 5%, is subjected to pulping and refining, followed by dewatering under atmospheric temperature & pressure. Further, a wet strength resin comprising Melamine-Formaldehyde (MF) Resin resins is added in an amount of 3 % w/w with respect to the total weight of the composition. Further, a wet end sizing agent is added in an amount of 3 % w/w with respect to the total weight of the composition. Further, a dry strength additive comprising cationic starch is added in an amount of 2 % w/w with respect to the total weight of the composition. Further a micro polymer-based retention aid may be added in amount of 0.02 % with respect to the total weight of the composition. Further, the dried slurry is passed through a pond of coating chemical. Further, the coating chemical comprising Natural/ Synthetic Waxes may be added in 2% w/w with respect to the total weight of the composition. Further, a Heat Seal Chemicals comprising acrylics may be added in 15% w/w with respect to the total weight of the composition.
Table 2A:
Ingredient Weight % of the total composition
Pulp 75 (Combination of Hardwood & Softwood)
Wet strength resin 3
Wet End sizing agent 3
Dry strength additive 2
Retention aids 0.02
Oil and grease resistant chemical 2
Heat seal chemicals 15

At the end of coating, the paper web is then dried using IR Chambers or Hot air Tunnel to dry the coating and enable proper building of reel. The resulting heat sealable has the following properties contained in Table 2B:
Table 2B:
Parameters Value
Tensile strength when dry 7100 m (MD)
5200 m (CD)
Tensile strength when wet 25-30%
Thickness of the coating film 5-6 micron
Water Absorbency (Coated Side) 7-10 gsm
Grammage of coated paper 43 to 63 gsm

Now, referring to Table 2B, which illustrates the properties of a final heat sealable paper prepared from the composition disclosed in Table 2A. Further, the final heat sealable paper discloses a dry tensile strength of 7100 m in machine direction (MD) and 5200 m in cross direction (CD). Further, the wet tensile strength is in the range between 25-30% of dry tensile strength. Further, the thickness of the coating film is in the range between 5-6 micron. Further, the water absorbency on the coated side is in the range between 7-10 gsm. Further, the grammage of paper composition lies in the range between 43 to 63 gsm.

Example 3:
Procedure: A pulp slurry in an amount of 78% w/w with respect to the total weight of the composition combination of Hardwood & Softwood with a consistency about 4- 5%, is subjected to pulping and refining, followed by dewatering under atmospheric temperature & pressure. Further, a wet strength resin comprising poly amido amine Epichlorohydrin resins is added in an amount of 3 % w/w with respect to the total weight of the composition. Further, a wet end sizing agent is added in an amount of 2 % w/w with respect to the total weight of the composition. Further, a dry strength additive such as anionic polyacrylamides is added in an amount of 2 % w/w with respect to the total weight of the composition. Further a micro polymer-based retention aid may be added in amount of 0.02 % w/w with respect to the total weight of the composition. Further, the dried slurry is passed through a pond of coating chemical. Further, the coating chemical comprising Acrylic polymers may be added in 2% w/w with respect to the total weight of the composition. Further, a Heat Seal Chemicals comprising Ethylene Copolymers may be added in 13% w/w with respect to the total weight of the composition.
Table 3A:
Ingredient % w/w of the total composition
Pulp 78 (Combination of Hardwood & Softwood)
Wet strength resin 3
Wet End sizing agent 2
Dry strength additive 2
Retention aids 0.02
Oil and grease resistant chemical 2
Heat seal chemicals 13

At the end of coating, the paper web is then dried using IR Chambers or Hot air Tunnel to dry the coating and enable proper building of reel. The resulting heat sealable has the following properties contained in Table 3B:
Table 3B:
Parameters Value
Tensile strength when dry 7300 m (MD)
5400 m (CD)
Tensile strength when wet 25-30%
Thickness of the film 5-6 micron
Water Absorbency (Coated Side) 7-10 gsm
Grammage of coated paper 43 to 63 gsm

Now, referring to Table 3B, which illustrates the properties of a final heat sealable paper prepared from the composition disclosed in Table 3A. Further, the final heat sealable paper discloses a dry tensile strength of 7300 m in machine direction (MD) and 5400 m in cross direction (CD). Further, the wet tensile strength is in the range between 25-30% of dry tensile strength. Further, the thickness of the coating film is in the range between 5-6 micron. Further, the water absorbency on the coated side is in the range between 7-10 gsm. Further, the grammage of paper composition lies in the range between 43 to 63 gsm.

Example 4:
Procedure: A pulp slurry in an amount of 70% w/w with respect to the total weight of the composition combination of Hardwood & Softwood with a consistency about 4- 5%, is subjected to pulping and refining, followed by dewatering under atmospheric temperature & pressure. Further, a wet strength resin comprising Poly amide Epichlorohydrin resin is added in an amount of 3 % w/w with respect to the total weight of the composition. Further, a wet end sizing agent is added in an amount of 2 % w/w with respect to the total weight of the composition. Further, a dry strength additive such as anionic polyacrylamides is added in an amount of 3% w/w with respect to the total weight of the composition. Further a micro polymer-based retention aid may be added in amount of 0.02 % w/w with respect to the total weight of the composition. Further, the dried slurry is passed through a pond of coating chemical. Further, the coating chemical comprising Acrylic polymers may be added in 2% w/w with respect to the total weight of the composition. Further, a Heat Seal Chemicals comprising Acrylic /Ethylene Copolymers/ Polyurethane Chemistry may be added in 20% w/w with respect to the total weight of the composition.
Table 4A:
Ingredient % w/w of the total composition
Pulp 70 (Combination of Hardwood & Softwood)
Wet strength resin 3
Wet End sizing agent 2
Dry strength additive 3
Retention aids 0.02
Oil and grease resistant chemical 2
Heat seal chemicals 20

At the end of coating, the paper web is then dried using IR Chambers or Hot air Tunnel to dry the coating and enable proper building of reel. The resulting heat sealable has the following properties contained in Table 4B:
Table 4B:
Parameters Value
Tensile strength when dry 7800 m (MD)
5700 m (CD)
Tensile strength when wet 25-30%
Thickness of the film 5-6 micron
Water Absorbency (Coated Side) 7-10 gsm
Grammage of coated paper 43 to 63 gsm

Now, referring to Table 4B, which illustrates the properties of a final heat sealable paper prepared from the composition disclosed in Table 4A. Further, the final heat sealable paper discloses a dry tensile strength of 7800 m in machine direction (MD) and 5700 m in cross direction (CD). Further, the wet tensile strength is in the range between 25-30% of dry tensile strength. Further, the thickness of the coating film is in the range between 5-6 micron. Further, the water absorbency on the coated side is in the range between 7-10 gsm. Further, the grammage of paper composition lies in the range between 43 to 63 gsm.

In one embodiment, refer to Figure 1, which illustrates an overview 100 of the method for obtaining the heat sealable paper composition, in accordance with an embodiment of the present disclosure. Further, the method comprises:
Pulping (101), a cellulose-based fiber material in a pulper and refining the cellulose-based fiber in a refiner prior to mixing with a chemical composition. Further, the cellulose-based fiber material is in a composition range of at least 70-80% w/w with respect to the total weight of the heat sealable paper composition.
Mixing (102) the cellulose-based fiber material with the chemical composition in a mixing chest. Further, the chemical composition comprises a wet strength resin added in a composition range of 2 % to 4% w/w with respect to the total weight of the heat sealable paper, a wet end sizing agent or a neutral sizing agent added in a composition range of 2 % to 3 % w/w with respect to the total weight of the heat sealable paper composition, a dry strength additive added in a composition range of 1% to 3% w/w with respect to the total weight of the heat sealable paper composition in a combination with a retention aid to form a paper slurry.
Dewatering and rolling (103) the paper slurry in a press roller to form a wet paper web, wherein the wet paper web is further dewatered by passing the wet paper web under a predetermined pressure through a series of dryers to form a dried paper web.
Coating (104) the dried paper web in a surface coating equipment, or an offline coating machine by passing the dried paper web through a pond of coating chemical to form a coated paper web. Further, the offline coating machine is configured to coat the dried paper slurry using Gravure, Air knife, Curtain coater, rod coater, film coater, short-dwell coater, spray coater, and metering film size press. Further, the coating chemical comprises Oil & Grease resistant Chemicals added in the composition range of 2 % to 3% w/w with respect to the total weight of the heat sealable paper composition, or Surface coating Heat Seal Chemicals added in a composition range of 10% to 20% w/w with respect to the total weight of the heat sealable paper composition, and
Drying (105) the coated paper web using an infra-red dryer or Hot Air tunnel to dry the coated paper web for proper processing of a paper reel of heat sealable paper.
Further, the above embodiments of the disclosure may provide the following advantages over the conventional paper compositions used in packaging industry:
• The Heat sealable Paper composition developed as mentioned in the above disclosure eliminates the use of plastic films.
• The Heat sealable Paper composition also enables storing of dry & semi liquid products due to high wet strength property.
• These Heat sealable Paper compositions are 100% biodegradable & home compostable.
• The Heat Sealable Paper composition enables Superior Dry & wet strength, water & Oil Resistance and heat sealable properties to the finished paper.
The foregoing description shall be interpreted as illustrative and not in any limiting sense. A person of ordinary skill in the art would understand that certain modifications could come within the scope of this disclosure.