High-temperature-resistant packaging bag film for food and composite process thereof

Abstract

The application provides a high-temperature-resistant packaging bag film for food and a composite process thereof, and belongs to the technical field of food packaging bag films, and comprises an outer layer, a middle layer and an inner layer; the outer layer is a high-temperature-resistant PET film layer; the middle layer is a high-temperature-resistant polypropylene film, which comprises a split line, the split line splits the high-temperature-resistant polypropylene film into two parts, and the two parts of the high-temperature-resistant polypropylene film are stacked to form a connecting part at the split line; the connecting part is provided with heat-expandable microspheres; and the inner layer is a high-temperature-resistant antibacterial polyvinyl alcohol film layer. The film has high strength and high-temperature resistance, and is suitable for cooking and heating. The middle layer comprises a split part, so that the packaging bag can be easily torn and opened.

Description

Technical Field

[0001] This invention relates to the field of food packaging bag film technology, specifically to a high-temperature resistant food packaging bag film and its composite process. Background Technology

[0002] With the advancement of technology, a large number of industrially produced foods have entered the market, gaining popularity among consumers due to their convenience. These industrially produced foods are preserved by being wrapped in food packaging films, which need to be torn open before consumption. Some packaging films are heat-resistant and can be directly used for steaming or heating; others have notches or seams to facilitate tearing open the film and removing the food inside. However, heat-resistant packaging films reach relatively high temperatures after heating, which is unbearable for direct human contact, requiring cooling before handling. However, controlling the cooling time is difficult; prolonged cooling affects the taste, while short cooling results in only a limited temperature drop, and waiting can be unpleasant for hungry individuals. Therefore, this invention designs a heat-resistant food packaging film that is easy to tear after heating and its composite process. Summary of the Invention

[0003] The purpose of this invention is to provide a high-temperature resistant food packaging film and its composite process.

[0004] To solve the above-mentioned technical problems, the objective of this invention is achieved as follows:

[0005] A high-temperature resistant packaging bag film for food includes: an outer layer, a middle layer, and an inner layer;

[0006] The outer layer is a high-temperature resistant PET film layer;

[0007] The middle layer of high-temperature resistant polypropylene film includes a dividing line that divides the high-temperature resistant polypropylene film into two parts, and the two parts of the high-temperature resistant polypropylene film are stacked at the dividing line to form a connecting part; the connecting part is provided with heating and expansion microspheres.

[0008] The inner layer is a high-temperature resistant and antibacterial polyvinyl alcohol film layer.

[0009] Based on the above scheme and as a preferred embodiment of the above scheme, the high-temperature resistant PET film layer comprises the following raw materials in parts by weight: 40-55 parts of polyethylene terephthalate, 7-10 parts of polyethylene, 10-20 parts of glass fiber / graphite / silver nanocomposite, 2-5 parts of photothermal stabilizer, 1-3 parts of antioxidant, 1-2 parts of coupling agent, 2-4 parts of plasticizer and 1-3 parts of toughening agent.

[0010] Based on the above scheme and as a preferred embodiment of the above scheme, the high-temperature resistant polypropylene film comprises the following raw materials in parts by weight: 50-60 parts of homopolymer polypropylene, 2-5 parts of anti-sticking agent, 3-6 parts of antioxidant, and 5-10 parts of sericite powder.

[0011] Based on the above scheme and as a preferred embodiment of the above scheme, the heated expansion microspheres include a thermoplastic polymer shell and liquid alkane encapsulated in the thermoplastic polymer shell; the particle size of the heated expansion microspheres is 0.3-0.5 mm, the heating expansion temperature is 100-150℃, and the expansion ratio is 200-300%.

[0012] Based on the above scheme and as a preferred embodiment of the above scheme, the high-temperature resistant antibacterial polyvinyl alcohol film layer comprises the following raw materials in parts by weight: 60-80 parts of polyvinyl alcohol, 20-40 parts of chitosan, 6-15 parts of antibacterial agent, 6-10 parts of silica, 1-3 parts of zeolite, and 100-150 parts of water.

[0013] Based on the above scheme and as a preferred embodiment of the above scheme, the antibacterial agent comprises the following raw materials in parts by weight: 10-30 parts of calcium propionate, 10-20 parts of glyceryl monolaurate, 5-10 parts of polydimethylsiloxane, and 10-15 parts of potassium sorbate.

[0014] A composite process for producing high-temperature resistant food packaging bag films includes the following steps:

[0015] S1, Production of high-temperature resistant PET film layer;

[0016] S2, Production of high-temperature resistant polypropylene film layer;

[0017] S3, production of high-temperature resistant and antibacterial polyvinyl alcohol film layer;

[0018] S4, composite;

[0019] Step S1 includes: first, mixing raw materials to obtain a mixture; second, drying the mixture and then melting and extruding it to obtain a thick film sheet; third, biaxially stretching the thick film sheet to obtain a film.

[0020] Step S2 includes: first, mixing raw materials to obtain a mixture; second, feeding the mixture into an extruder for melt extrusion to obtain a cast sheet; third, stretching the cast sheet to obtain a film; fourth, drying the film and then cutting it; fifth, coating the edges of the cut film with an adhesive mixed with heat-expanding microspheres; sixth, covering another film onto the film coated with the adhesive and drying it to solidify the adhesive.

[0021] Step S3 includes: First, mixing and stirring the raw materials to obtain a mixed solution; Second, sending the mixed solution from the first step into a filter for coarse filtration; Third, sending the solution obtained in the second step into a degassing device for degassing; Fourth, sending the degassed solution into a filter for fine filtration; Fifth, sending the finely filtered solution into a casting mold and then onto a forming roller for casting and flattening, and preliminarily drying to form a film; Sixth, peeling the initial film off the forming roller and then drying it; Seventh, calendering; Eighth, shaping.

[0022] Step S4 includes: first, feeding the three films separately to the adhesive coating mechanism by feeding rollers to coat them with adhesive; second, combining the three films and applying pressure to bond them together.

[0023] The beneficial effects of this invention are as follows: This invention is composed of an outer layer, a middle layer, and an inner layer. The film has high strength and high temperature resistance, making it suitable for steaming and heating. The middle layer includes a dividing point, separating it into two parts for easy tearing. During packaging, this dividing point is positioned at the opening of the food packaging bag. Upon heating, the microspheres at the dividing point expand, increasing their volume and reducing the adhesion between the two middle layers, allowing for easy tearing of the packaging bag by hand, reducing waiting time, while also ensuring the strength of the packaging bag. Compared to traditional easy-tear aluminum foil composite films, it has higher extensibility and plasticity, better conforms to food, and provides better coverage. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of the present invention.

[0025] In the diagram: 1. Outer layer; 2. Middle layer; 3. Inner layer; 21. Connecting part. Detailed Implementation

[0026] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0027] like Figure 1 As shown, a high-temperature resistant food packaging bag film includes: an outer layer 1, a middle layer 2, and an inner layer 3;

[0028] The outer layer 1 is a high-temperature resistant PET film layer. Preferably, the high-temperature resistant PET film layer comprises the following raw materials in parts by weight: 40-55 parts of polyethylene terephthalate, 7-10 parts of polyethylene, 10-20 parts of glass fiber / graphite / silver nanocomposite, 2-5 parts of photothermal stabilizer, 1-3 parts of antioxidant, 1-2 parts of coupling agent, 2-4 parts of plasticizer, and 1-3 parts of toughening agent.

[0029] The middle layer 2 high-temperature resistant polypropylene film includes a dividing line that divides the high-temperature resistant polypropylene film into two parts, and the two parts of the high-temperature resistant polypropylene film are stacked at the dividing line to form a connecting part 21; the connecting part 21 is provided with heating expansion microspheres.

[0030] Preferably, the high-temperature resistant polypropylene film comprises the following raw materials in parts by weight: 50-60 parts homopolymer polypropylene, 2-5 parts anti-sticking agent, 3-6 parts antioxidant, and 5-10 parts sericite powder. The heat-expanding microspheres comprise a thermoplastic polymer shell and liquid alkane encapsulated within the thermoplastic polymer shell; the particle size of the heat-expanding microspheres is 0.3-0.5 mm, the heating expansion temperature is 100-150°C, and the expansion ratio is 200-300%.

[0031] The inner layer 3 is a high-temperature resistant and antibacterial polyvinyl alcohol (PVA) film layer. The high-temperature resistant and antibacterial PVA film layer comprises the following raw materials in parts by weight: 60-80 parts PVA, 20-40 parts chitosan, 6-15 parts antibacterial agent, 6-10 parts silica, 1-3 parts zeolite, and 100-150 parts water. The antibacterial agent comprises the following raw materials in parts by weight: 10-30 parts calcium propionate, 10-20 parts glyceryl monolaurate, 5-10 parts polydimethylsiloxane, and 10-15 parts potassium sorbate.

[0032] A composite process for producing high-temperature resistant food packaging bag films includes the following steps:

[0033] S1, Production of high-temperature resistant PET film layer;

[0034] S2, Production of high-temperature resistant polypropylene film layer;

[0035] S3, production of high-temperature resistant and antibacterial polyvinyl alcohol film layer;

[0036] S4, composite;

[0037] Step S1 includes: first, mixing raw materials to obtain a mixture; second, drying the mixture and then melting and extruding it to obtain a thick film sheet; third, biaxially stretching the thick film sheet to obtain a film.

[0038] Step S2 includes: first, mixing raw materials to obtain a mixture; second, feeding the mixture into an extruder for melt extrusion to obtain a cast sheet; third, stretching the cast sheet to obtain a film; fourth, drying the film and then cutting it; fifth, coating the edges of the cut film with an adhesive mixed with heat-expanding microspheres; sixth, covering another film onto the film coated with the adhesive and drying it to solidify the adhesive.

[0039] Step S3 includes: First, mixing and stirring the raw materials to obtain a mixed solution; Second, sending the mixed solution from the first step into a filter for coarse filtration; Third, sending the solution obtained in the second step into a degassing device for degassing; Fourth, sending the degassed solution into a filter for fine filtration; Fifth, sending the finely filtered solution into a casting mold and then onto a forming roller for casting and flattening, and preliminarily drying to form a film; Sixth, peeling the initial film off the forming roller and then drying it; Seventh, calendering; Eighth, shaping.

[0040] Step S4 includes: first, feeding the three films separately to the adhesive coating mechanism by feeding rollers to coat them with adhesive; second, combining the three films and applying pressure to bond them together.

[0041] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A food retort packaging bag film, characterized by, The application relates to a high-temperature-resistant and bacteriostatic composite film. The outer layer (1), the middle layer (2) and the inner layer (3); The outer layer (1) is a high-temperature-resistant PET film layer; The middle layer (2) is a high-temperature-resistant polypropylene film, which comprises a split line, the split line divides the high-temperature-resistant polypropylene film into two parts, and the two parts of the high-temperature-resistant polypropylene film are laminated to form a connecting part (21) at the split line; the connecting part (21) is provided with heated expanded microspheres; The inner layer (3) is a high-temperature-resistant and bacteriostatic polyvinyl alcohol film layer; The high-temperature-resistant PET film layer comprises the following raw materials in parts by weight: polyethylene terephthalate 40-55 parts, polyethylene 7-10 parts, glass fiber / graphite / silver nano composite 10-20 parts, photothermal stabilizer 2-5 parts, antioxidant 1-3 parts, coupling agent 1-2 parts, plasticizer 2-4 parts and toughening agent 1-3 parts; The heated expanded microspheres comprise a thermoplastic polymer shell and a liquid alkane enclosed by the thermoplastic polymer shell; the particle size of the heated expanded microspheres is 0.3-0.5 mm, the heating expansion temperature is 100-150 DEG C, and the expansion ratio is 200-300%; The high-temperature-resistant and bacteriostatic polyvinyl alcohol film layer comprises the following raw materials in parts by weight: polyvinyl alcohol 60-80 parts, chitosan 20-40 parts, bacteriostatic agent 6-15 parts, silicon dioxide 6-10 parts, zeolite 1-3 parts and water 100-150 parts; The bacteriostatic agent comprises the following raw materials in parts by weight: calcium propionate 10-30 parts, lauric acid monoglyceride 10-20 parts, polydimethylsiloxane 5-10 parts and potassium sorbate 10-15 parts.

2. The food retort packaging film according to claim 1, wherein, The high-temperature-resistant polypropylene film comprises the following raw materials in parts by weight: homopolymer polypropylene 50-60 parts, anti-sticking agent 2-5 parts, antioxidant 3-6 parts and sericite powder 5-10 parts.

3. A production lamination process of a food retort pouch film according to any one of claims 1-2, characterized by, The application further discloses a production method of the high-temperature-resistant and bacteriostatic composite film. The application further discloses a production method of the high-temperature-resistant and bacteriostatic composite film. The application further discloses a production method of the high-temperature-resistant and bacteriostatic composite film. The application further discloses a production method of the high-temperature-resistant and bacteriostatic composite film. The step S1 comprises the following steps: first, mixing raw materials to obtain a mixture; second, drying the mixture and then melt-extruding a thick film; and third, bidirectionally stretching the thick film to obtain a film. The step S2 comprises the following steps: first, mixing raw materials to obtain a mixture; second, feeding the mixture into an extruder to melt-extrude a cast sheet; third, stretching the cast sheet to obtain a film; fourth, drying the film and then cutting the film; fifth, coating an adhesive mixed with heated expanded microspheres on the edges of the cut film; and sixth, covering another film on the film coated with the adhesive and drying the film to solidify the adhesive. The step S3 comprises the following steps: first, mixing and stirring raw materials to obtain a mixed solution; second, feeding the mixed solution into a filter to perform coarse filtration; third, feeding the solution obtained in the second step into a defoaming device to perform defoaming; fourth, feeding the defoamed solution into a filter to perform fine filtration; fifth, feeding the fine-filtered solution into a flow die and then into a forming roller to flow and spread, and then preliminarily drying the solution to form a film; sixth, peeling the film from the forming roller and then drying the film; seventh, calendering; and eighth, shaping. ​ The step S4 includes: a first step of feeding the three films respectively by feeding rollers to a binder coating mechanism to coat the binder; and a second step of compounding the three films and pressing to adhere them together.

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