Environment-friendly food packaging bag and preparation method thereof

Abstract

The invention discloses an environment-friendly food packaging bag and a preparation method thereof, and belongs to the technical field of food packaging.The environment-friendly food packaging bag comprises a packaging bag body, the packaging bag body is composed of an inner layer, a middle layer and an outer layer, the middle layer is arranged on the outer side of the inner layer, and the outer layer is arranged on the outer side of the middle layer; the inner layer is prepared from the following main raw materials in parts by weight: 90 parts of polyethylene resin, 5 parts of an antifreeze agent, 3 parts of a flexibilizer and 2 parts of a degradation agent, the antifreeze agent is made of an ethylene-vinyl acetate copolymer, and through a series of designs, the composite structure design of the inner layer, the middle layer and the outer layer is adopted, so that each layer of material can play a specific function, and the service life of the inner layer is prolonged. The inner layer guarantees food safety and has good low-temperature adaptability, the middle layer enhances the strength of the packaging bag and provides better mechanical performance, and the outer layer effectively prevents ultraviolet rays from affecting the packaging bag and food in the packaging bag and keeps the freshness of the food.

Description

Technical Field

[0001] The present invention belongs to the technical field of food packaging, and particularly relates to an environmentally friendly food packaging bag and a preparation method thereof. Background Art

[0002] With the rapid development of the modern food industry, the frozen food market has been continuously expanding. During the storage, transportation, and sales of frozen foods, packaging bags with good performance are required to maintain their freshness, nutritional components, and quality. Traditional frozen food packaging bags often have some deficiencies, such as poor frost resistance, brittle fracture at low temperatures, inability to effectively block ultraviolet rays, and environmental impact. These problems not only affect the food quality but may also cause long-term environmental pollution after the packaging bags are used.

[0003] Most of the existing frozen food packaging bags use a single material and do not fully consider the special requirements of the frozen environment. This makes the packaging bags prone to breakage or performance degradation during long-term low-temperature storage or transportation of frozen foods. In addition, due to the increasing market demand for environmental protection, traditional packaging bags are often difficult to degrade after use, resulting in waste of resources and environmental burden. Therefore, we designed an environmentally friendly food packaging bag and a preparation method thereof to provide another technical solution to the above technical problems. Summary of the Invention

[0004] The purpose of the present invention is to provide an environmentally friendly food packaging bag and a preparation method thereof to solve the problems in the existing technology during use mentioned in the above background art.

[0005] To achieve the above purpose, the present invention provides the following technical solution: An environmentally friendly food packaging bag includes a bag body. The bag body is composed of an inner layer, a middle layer, and an outer layer. The middle layer is arranged outside the inner layer, and the outer layer is arranged outside the middle layer. The inner layer is made of the following main raw materials in parts by weight: 90 parts of polyethylene resin, 5 parts of antifreeze, 3 parts of toughening agent, and 2 parts of degradation agent.

[0006] Preferably, the antifreeze is made of ethylene-vinyl acetate copolymer.

[0007] Preferably, the toughening agent is made of polyolefin elastomer.

[0008] Preferably, the degradation agent is made of an oxidative biodegradable agent.

[0009] Preferably, the middle layer is made of the following main raw materials in parts by weight: 95 parts of polyethylene resin and 5 parts of nano-silica.

[0010] Preferably, the outer layer is made of the following main raw materials in parts by weight: 92 parts of polyethylene resin and 3 parts of ultraviolet absorber.

[0011] Preferably, the thickness of the inner layer is 30 μm, the thickness of the middle layer is 20 μm, and the thickness of the outer layer is 50 μm.

[0012] Preferably, the heat seal strength of the packaging bag body is 15 N / 15 mm, and the tear strength of the packaging bag body is 80 N / mm.

[0013] Preferably, the packaging bag body maintains flexibility at a temperature of -50°C, and the packaging bag body can be degraded within 18 months in the natural environment.

[0014] The processing technology of the environment-friendly food packaging bag is used for the above-mentioned polyethylene frozen food packaging bag, and the steps are as follows:

[0015] S1. Material preparation: Mix polyethylene resin, antifreeze, toughening agent and degradation agent in proportion;

[0016] Mix polyethylene resin and nano-silica in proportion;

[0017] Mix polyethylene resin and ultraviolet absorber in proportion;

[0018] S2. Then add the above groups of materials into a high-speed mixer in turn to ensure that each component is evenly mixed to form a modified polyethylene material;

[0019] S3. Put the three groups of raw materials into a co-extrusion blown film machine in turn, and process each group of modified polyethylene materials into a multi-layer composite film through the co-extrusion blown film machine;

[0020] S4. Cut and heat-seal the multi-layer composite film through a bag-making machine, and the heat-sealing temperature is 160°C;

[0021] S5. Carry out corona treatment on the packaging bag, and the corona treatment power is 8 kW.

[0022] Compared with the prior art, the beneficial effects of the present invention are:

[0023] 1. Through a series of designs, the present invention adopts the composite structure design of the inner layer, the middle layer and the outer layer, so that each layer of material can play its specific function. The inner layer ensures food safety and has good low-temperature adaptability. The middle layer enhances the strength of the packaging bag and provides better mechanical properties. The outer layer effectively prevents the influence of ultraviolet rays on the packaging bag and the food in the bag, and keeps the freshness of the food;

[0024] 2. By adding antifreeze and toughening agents, the packaging bag of the present invention can still maintain flexibility in a low-temperature environment of -50°C, avoiding brittle cracking or damage caused by low temperature, improving the reliability during the storage and transportation of frozen foods. After use, the packaging bag can be degraded in the natural environment, reducing the environmental pollution caused by plastic packaging bags, meeting modern environmental protection requirements, and enhancing the sustainability of packaging materials.

[0025] 3. The present invention significantly improves the tear resistance and impact resistance of the packaging bag, reduces the risk of damage during transportation and storage, effectively blocks the penetration of ultraviolet rays, prevents the packaging bag and food from being damaged by ultraviolet rays, maintains the nutrition and quality of the food, extends the shelf life of frozen foods, and the corona treatment process further improves the adhesion of the packaging bag, providing ideal surface conditions for printing and other treatments. Specific Embodiments

[0026] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0027] An environmentally friendly food packaging bag includes a bagging main body. The packaging bag main body is composed of an inner layer, a middle layer, and an outer layer. The middle layer is arranged on the outer side of the inner layer, and the outer layer is arranged on the outer side of the middle layer. The inner layer is made of the following main raw materials in parts by weight: 90 parts of polyethylene resin, 5 parts of antifreeze, 3 parts of toughening agent, and 2 parts of degradation agent.

[0028] The accurately proportioned antifreeze, toughening agent, and degradation agent endow the packaging bag with excellent low-temperature antifreeze performance, while improving the flexibility of the packaging bag, avoiding brittle cracking in the frozen environment. The addition of the degradation agent enables the packaging bag to decompose in the environment after use, reducing environmental pollution and meeting environmental protection requirements.

[0029] The material of the antifreeze is ethylene-vinyl acetate copolymer. Ethylene-vinyl acetate copolymer has good low-temperature flexibility and can effectively prevent the packaging bag from cracking or brittle fracture at low temperatures.

[0030] The material of the toughening agent is polyolefin elastomer. Polyolefin elastomer provides better toughening performance and improves the tear resistance of the packaging bag.

[0031] The material of the degradation agent is oxidative biodegradant. Oxidative biodegradant can accelerate the degradation process of the packaging bag in the natural environment, contributing to reducing environmental pollution.

[0032] The middle layer is made of the following main raw materials in parts by weight: 95 parts of polyethylene resin and 5 parts of nano-silica. The nano-silica increases the tear resistance and impact resistance of the bag, and also improves the overall rigidity and heat resistance of the bag, making the packaging bag safer and more reliable during transportation and storage;

[0033] The outer layer is made of the following main raw materials in parts by weight: 92 parts of polyethylene resin and 3 parts of ultraviolet absorber. Adding the ultraviolet absorber effectively blocks the penetration of ultraviolet rays, preventing the quality of frozen food from being damaged by ultraviolet rays. The ultraviolet absorber can protect the packaging bag and the food inside, avoiding component changes or nutrient loss caused by light, so as to keep the food fresh and maintain its taste;

[0034] The thickness of the inner layer is 30μm, the thickness of the middle layer is 20μm, and the thickness of the outer layer is 50μm. The reasonable thickness distribution enables each layer of material to play its best role. The inner layer is thinner, ensuring good flexibility and heat sealability. The middle layer provides sufficient tear resistance and support. The outer layer is thicker, ensuring the anti-ultraviolet effect and protection function. The overall thickness configuration can control the material cost while meeting the functionality requirements;

[0035] The heat seal strength of the packaging bag body is 15N / 15mm, and the tear strength of the packaging bag body is 80N / mm. The requirements for heat seal strength and tear resistance ensure the reliability of the packaging bag in actual use. The higher heat seal strength ensures the sealing performance of the packaging bag, preventing food leakage. The higher tear resistance ensures that the packaging bag is not easily damaged during transportation, handling and storage, thus improving the service life of the packaging bag and food safety;

[0036] The packaging bag body remains flexible at a temperature of -50°C, and the packaging bag body can be degraded within 18 months in the natural environment. It can ensure that the packaging bag still remains flexible in a low-temperature environment and is not easily brittle. The requirement for degradation performance enables the packaging bag to be degraded in a short time in the natural environment, helping to reduce the environmental burden and meeting the requirements of modern environmental protection;

[0037] Here, a preparation method of an environmentally friendly food packaging bag is disclosed:

[0038] S1. Material preparation: Mix polyethylene resin, antifreeze, toughening agent and degradation agent in proportion;

[0039] Mix polyethylene resin and nano-silica in proportion;

[0040] Mix polyethylene resin and ultraviolet absorber in proportion;

[0041] S2. Then add the above groups of materials into a high-speed mixer in turn and stir at a speed of 800r / min for 15 minutes to ensure that each component is evenly mixed to form a modified polyethylene material;

[0042] S3. Put the three groups of raw materials into the co-extrusion blown film machine in sequence. The temperature of the inner layer is 180 °C, the temperature of the middle layer is 175 °C, and the temperature of the outer layer is 179 °C. The extrusion speed is 25 m / min. And the thickness of the inner layer is controlled at 30 μm, the thickness of the middle layer is controlled at 20 μm, and the thickness of the outer layer is controlled at 50 μm. Process each group of modified polyethylene materials into a multi-layer composite film through the co-extrusion blown film machine. Controlling the temperature range of the co-extrusion blown film process ensures that the plastic materials can be extruded evenly, avoids overheating or overcooling of the film, and guarantees the quality and strength of the film layer;

[0043] S4. Cut and heat-seal the multi-layer composite film through a bag-making machine. The heat-sealing temperature is 160 °C. Precise heat-sealing temperature control makes the seal of the packaging bag firm and has good airtightness;

[0044] S5. Carry out corona treatment on the packaging bag. The corona treatment power is 8 kW. The power of the corona treatment ensures an increase in the adhesion force on the surface of the packaging bag, providing a good foundation for printing and other post-processing.

[0045] Adopting the composite structure design of the inner layer, middle layer and outer layer enables each layer of material to play its specific function. The inner layer ensures food safety and has good low-temperature adaptability. The middle layer enhances the strength of the packaging bag and provides better mechanical properties. The outer layer effectively prevents the influence of ultraviolet rays on the packaging bag and the food inside, and keeps the food fresh;

[0046] By adding antifreeze and toughening agents, the packaging bag can still maintain flexibility in a low-temperature environment of -50 °C, avoiding problems such as embrittlement or breakage caused by low temperature, improving the reliability during the storage and transportation of frozen food. The packaging bag can be degraded in the natural environment after use, reducing the pollution of plastic packaging bags to the environment, meeting modern environmental protection requirements, and enhancing the sustainability of packaging materials;

[0047] Significantly improves the tear resistance and impact resistance of the packaging bag, reduces the risk of damage to the packaging bag during transportation and storage, effectively blocks the penetration of ultraviolet rays, prevents the packaging bag and food from being damaged by ultraviolet rays, keeps the nutrition and quality of the food, extends the shelf life of frozen food, and the corona treatment process further improves the adhesion force of the packaging bag, providing an ideal surface condition for printing and other processing.

[0048] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An environmentally friendly food packaging bag, characterized in that: The main body of the packaging bag, which is composed of an inner layer, a middle layer and an outer layer. The middle layer is arranged on the outer side of the inner layer, and the outer layer is arranged on the outer side of the middle layer. The inner layer is made of the following main raw materials by weight: 90 parts of polyethylene resin, 5 parts of antifreeze, 3 parts of toughening agent, and 2 parts of degradation agent.

2. The environmentally friendly food packaging bag according to claim 1, characterized in that: The antifreeze is made of ethylene-vinyl acetate copolymer.

3. The environmentally friendly food packaging bag according to claim 1, wherein: The toughening agent is made of polyolefin elastomer.

4. The environmentally friendly food packaging bag according to claim 1, characterized in that: The degradation agent is made of an oxidative biodegradable agent.

5. The environmentally friendly food packaging bag according to claim 1, wherein: The middle layer is made of the following main raw materials by weight: 95 parts of polyethylene resin and 5 parts of nano-silica.

6. The environmentally friendly food packaging bag according to claim 1, characterized in that: The outer layer is made of the following main raw materials by weight: 92 parts of polyethylene resin and 3 parts of ultraviolet absorber.

7. The environmentally friendly food packaging bag according to claim 1, wherein: The thickness of the inner layer is 30μm, the thickness of the middle layer is 20μm, and the thickness of the outer layer is 50μm.

8. The environmentally friendly food packaging bag according to claim 1, wherein: The heat-sealing strength of the main body of the packaging bag is 15N / 15mm, and the tear strength of the main body of the packaging bag is 80N / mm.

9. The environmentally friendly food packaging bag according to claim 1, wherein: The main body of the packaging bag remains flexible at a temperature of -50°C, and the main body of the packaging bag can be degraded within 18 months in the natural environment.

10. A preparation method of an environment-friendly food packaging bag, which is used for the environment-friendly food packaging bag described in any one of claims 1-9, and is characterized in that, The steps are as follows: S1. Material preparation: Mix polyethylene resin, antifreeze, toughening agent and degradation agent in proportion; Mix polyethylene resin and nano-silica in proportion; Mix polyethylene resin and ultraviolet absorber in proportion; S2. Then sequentially add the above groups of materials into a high-speed mixer to ensure that each component is evenly mixed to form a modified polyethylene material; S3. Put the three groups of raw materials into a co-extrusion blown film machine in sequence, and process each group of modified polyethylene materials into a multi-layer composite film through the co-extrusion blown film machine; S4. Cut and heat-seal the multi-layer composite film through a bag-making machine, and the heat-sealing temperature is 160°C; S5. Carry out corona treatment on the packaging bag, and the corona treatment power is 8kW.