RCPP liquid packaging film and production process thereof

Abstract

The invention relates to the technical field of packaging, and discloses an RCPP liquid packaging film, which comprises an outer layer, a middle layer and an inner layer, the middle layer comprises 200 parts by mass of polypropylene, 200 parts by mass of binary polypropylene, 50 parts by mass of a styrene-ethylene-butylene-styrene block copolymer, 50 parts by mass of a polyolefin elastomer and 50 parts by mass of thermoplastic polyolefin, and the inner layer comprises 300 parts by mass of binary co-polypropylene, 100 parts by mass of ternary co-polypropylene, 25 parts by mass of polyethylene, 6 parts by mass of a slipping agent and 8 parts by mass of an anti-blocking agent. The invention can solve the problems that the packaging bag becomes brittle and fractures after long-term low-temperature storage after the food is packaged by the CPP film packaging bag in the prior art, and the low-temperature packaging and storage requirements of the food cannot be effectively met.

Description

Technical Field

[0001] The invention relates to the technical field of packaging, in particular to an RCPP liquid packaging film and a production process thereof. Background Art

[0002] CPP liquid packaging film is a multi-layer composite film used for liquid packaging. "CPP" is the abbreviation of "CastPolypropylene", which refers to cast polypropylene. Therefore, CPP liquid packaging film is a cast polypropylene film with high transparency, excellent heat sealing performance, good barrier properties, excellent mechanical properties, heat resistance, environmental protection and good processing performance, and is widely used in the field of food packaging.

[0003] With the development of science and technology, more and more foods are being produced in a prefabricated manner. Manufacturers package prefabricated foods in packaging bags and sell them. People can eat them by simply heating them up. Prefabricated food packaging needs to ensure the safety, sealing, and non-deterioration of the food. Therefore, such prefabricated foods usually need to be stored at low temperatures after packaging. After people buy them, they heat them together with the packaging bags and pour them out for consumption. This also places higher requirements on high-temperature sterilization retort bags, such as the packaging needs to be cold-resistant, high-temperature-resistant, puncture-resistant, and soft.

[0004] However, conventional CPP films in the prior art are not cold-resistant. For foods that need to be stored at low temperatures, they need to be stored and transported at low temperatures after packaging. After packaging with existing packaging films, it is found that the packaging bags often become brittle and crack after long-term low-temperature storage, which cannot effectively meet the needs of low-temperature packaging and storage of foods. Summary of the invention

[0005] The present invention aims to provide a RCPP liquid packaging film and a production process thereof, so as to solve the problem that the CPP film packaging bag of the prior art becomes brittle and cracked after long-term low-temperature storage of packaged food, and cannot effectively meet the needs of low-temperature packaging and storage of food.

[0006] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: an RCPP liquid packaging film, comprising an outer layer, a middle layer and an inner layer, the outer layer comprising 400 parts by weight of binary polypropylene T10F, the middle layer comprising 200 parts by weight of polypropylene CF330, 200 parts by weight of binary polypropylene T10F, 50 parts by weight of styrene-ethylene-butylene-styrene block copolymer C2000, 50 parts by weight of polyolefin elastomer 6102FL, and 50 parts by weight of thermoplastic polyolefin C200F, and the inner layer comprising 300 parts by weight of binary copolymer polypropylene W0723F, 100 parts of ternary copolymer polypropylene TF1007, 25 parts of polyethylene SP0540, 6 parts of lubricant SAB39N, and 8 parts of opening agent AB05N.

[0007] Preferably, as an improvement, the mass ratio of the inner layer, the outer layer and the middle layer is 1:1:3.

[0008] Preferably, as an improvement, the thickness is 9.5 filaments.

[0009] The technical principle of the RCPP liquid packaging film provided by this solution is mainly to achieve the stability and durability of the packaging film in a low temperature environment through a carefully designed three-layer structure and its raw material ratio. The outer layer uses high-quality binary polypropylene T10F, which has good mechanical properties and thermal stability, provides the strength of the packaging film and certain barrier properties, and can effectively protect the packaging film from external physical damage. The middle layer introduces polypropylene CF330 and binary polypropylene T10F as basic materials, and adds styrene-ethylene-butylene-styrene block copolymer C2000 (SEBS) and polyolefin elastomer 6102FL. This ratio can significantly improve the cold resistance, high temperature resistance and puncture resistance of the packaging film. Among them, the addition of styrene-ethylene-butylene-styrene block copolymer C2000 and polyolefin elastomer 6102FL, these two materials have excellent cold resistance and elasticity, increase the flexibility and elasticity of the film layer, can maintain the flexibility and toughness of the film at low temperatures, prevent the film from becoming brittle and cracking, and make the packaging film not easy to become brittle and crack in a low temperature environment. The addition of thermoplastic polyolefin C200F further enhances the heat sealing and mechanical properties of the middle layer. The inner layer uses binary copolymer polypropylene W0723F and ternary copolymer polypropylene TF1007 as the main components. These two materials have good thermal stability and processing properties. At the same time, polyethylene SP0540 is added to improve the sealing and barrier properties of the inner layer. Slip agent SAB39N and opening agent AB05N are used to improve the surface properties and opening properties of the packaging film.

[0010] The advantages of this solution include:

[0011] Significantly improved cold resistance: By adding styrene-ethylene-butylene-styrene block copolymer C2000 and polyolefin elastomer 6102FL to the middle layer, these two materials can still maintain good flexibility and elasticity at low temperatures, thereby significantly improving the cold resistance of the packaging film. Even during long-term low-temperature storage and transportation, the packaging film is not easy to become brittle and crack, effectively ensuring the safety and integrity of food.

[0012] Enhanced tensile properties and flexibility: The addition of SEBS and polyolefin elastomer 6102FL not only improves the cold resistance of the packaging film, but also enhances its tensile properties and flexibility. This makes the packaging film easier to operate and less prone to damage during processing and use, and improves the reliability and durability of the packaging.

[0013] Good heat-sealing and barrier properties: The selection and ratio of the inner and outer layer raw materials ensure that the packaging film has good heat-sealing and barrier properties, which can effectively prevent food from being contaminated and oxidized during the packaging process and extend the shelf life of food.

[0014] Environmentally friendly and easy to process: All raw materials are environmentally friendly materials, meeting food safety and environmental protection requirements. At the same time, these materials have good processing properties, making the production process of packaging film more efficient and stable.

[0015] Precise thickness control: By precisely controlling the extrusion ratio of each layer of raw materials and the temperature, speed and other parameters during the casting process, the total thickness of the packaging film is precisely controlled. The total thickness of the RCPP liquid packaging film of the present invention is 9-10 filaments, which not only ensures the strength and stability of the packaging, but also avoids unnecessary material waste.

[0016] The present invention also provides a RCPP liquid packaging film production process, which is used to produce the RCPP liquid packaging film as described above, comprising:

[0017] S1. Weighing raw materials: weigh the raw materials for the outer layer, which include 400 parts of binary polypropylene T10F; weigh the raw materials for the middle layer, which include 200 parts of polypropylene CF330, 200 parts of binary polypropylene T10F, 50 parts of styrene-ethylene-butylene-styrene block copolymer C2000, 50 parts of polyolefin elastomer 6102FL, and 50 parts of thermoplastic polyolefin C200F; weigh the raw materials for the inner layer, which include 300 parts of binary copolymer polypropylene W0723F, 100 parts of ternary copolymer polypropylene TF1007, 25 parts of polyethylene SP0540, 6 parts of lubricant SAB39N, and 8 parts of anti-blocking agent AB05N; after weighing the raw materials for each layer, stir the raw materials for each layer evenly and feed them into the three barrels of the extruder respectively;

[0018] S2, the raw materials of the three barrels are co-extruded with the same die head, and after co-extrusion, they enter the casting station for cooling and shaping; the temperature in the three barrels is divided into a feeding section, a melting section and a heat preservation section, the starting temperature of the feeding section is lower than 185°C, the end temperature is 220-230°C, the temperature of the melting section and the heat preservation section are both controlled at 230°C-240°C, the die head temperature is 220-230°C, and the roller surface temperature of the casting roller in the casting is 20-40°C;

[0019] S3. Corona discharge is performed on the outer layer of the cast RCPP liquid packaging film.

[0020] Preferably, as an improvement, when the raw material is extruded, the thickness ratio of the outer layer, the middle layer and the inner layer is 1:3:1; and S4 is also included to measure the total thickness of the RCPP liquid packaging film after cast molding, and the total thickness of the RCPP liquid packaging film is required to be 9-10 filaments.

[0021] Preferably, as an improvement, the power of the corona treatment in step S3 is 12KW-15KW, and the width of the die head is 3.6 meters.

[0022] Raw material weighing and mixing in this solution: accurately weigh the raw materials required for each layer to ensure the accuracy of the formula, and then mix the raw materials of each layer evenly to ensure the uniform distribution of each layer during co-extrusion, which is crucial to the performance of the final product.

[0023] Co-extrusion process: Using the same die head to co-extrude the raw materials in three barrels, this process can ensure that each layer of material is closely combined during the extrusion process to form a uniform multi-layer structure. During the co-extrusion process, temperature control of different sections is crucial for the melting and flow of the raw materials to ensure uniform extrusion of the materials and uniformity of the final product.

[0024] Casting cooling and shaping: The co-extruded film enters the casting station for cooling and shaping. The temperature control of the casting roller surface has an important influence on the forming and performance of the film. Appropriate roller surface temperature helps the film to cool and shape quickly, while reducing the thermal degradation of the material.

[0025] Corona treatment: The outer layer of RCPP liquid packaging film is corona treated to increase the roughness and polarity of the film surface and enhance its adhesion with ink or adhesive, which is very important for the printing and subsequent processing of the packaging film.

[0026] The advantages of this solution include:

[0027] Accurate raw material ratio: Through precise raw material weighing and mixing, the material ratio of each layer of RCPP liquid packaging film is ensured to be accurate, thus ensuring the consistency and repeatability of the product.

[0028] Uniform multi-layer structure: The co-extrusion process ensures the uniform distribution and close combination of the outer layer, middle layer and inner layer materials, forming a uniform multi-layer structure and improving the overall performance of the packaging film.

[0029] Optimized temperature control: Precise control of the temperature of different sections during the extrusion process ensures uniform melting and flow of raw materials, avoiding uneven extrusion of materials and product defects.

[0030] Rapid cooling and shaping: The temperature control of the casting roller surface helps to quickly cool and shape the film material, improve production efficiency, and ensure the dimensional stability and physical properties of the product.

[0031] Improve surface adhesion: Corona treatment increases the surface roughness and polarity of the outer layer of RCPP liquid packaging film, enhances the adhesion with ink or adhesive, and is beneficial to improving the printing quality and appearance of the packaging.

[0032] Precise thickness control: By measuring the total thickness of the RCPP liquid packaging film after casting, the thickness uniformity of the product is ensured, which is crucial to ensure the strength and protection performance of the packaging film.

[0033] Efficient production process: Through optimized production processes, such as the power of corona treatment and the adaptation of die width, production efficiency and product quality are improved, while production costs are reduced. DETAILED DESCRIPTION

[0034] The following is further described in detail through specific implementation methods:

[0035] Example 1, an RCPP liquid packaging film, comprising an outer layer, a middle layer and an inner layer, the outer layer comprising 400 parts by weight of binary polypropylene (in this embodiment, a Lanzhou Petrochemical T10F product is used), the middle layer comprising 200 parts by weight of polypropylene (in this embodiment, a Hanwha Total Petrochemical CF330 product is used), 200 parts of binary polypropylene (in this embodiment, a Lanzhou Petrochemical T10F product is used), 50 parts of styrene-ethylene-butylene-styrene block copolymer (in this embodiment, a Kraton C2000 product is used), 50 parts of polyolefin elastomer The outer layer comprises 300 parts by weight of binary copolymer polypropylene (in this embodiment, ExxonMobil 6102FL product is used), 50 parts of thermoplastic polyolefin (in this embodiment, LyondellBasell C200F product is used), and the inner layer comprises 300 parts by weight of binary copolymer polypropylene (in this embodiment, Dushanzi W0723F product is used), 100 parts of ternary copolymer polypropylene (in this embodiment, Dushanzi TF1007 product is used), 25 parts of polyethylene (in this embodiment, Priman SP0540 product is used), 6 parts of lubricant SAB39N, and 8 parts of anti-blocking agent AB05N.

[0036] The mass ratio of the inner layer, outer layer and middle layer is 1:1:3, and the finished product thickness is 9.5 silk.

[0037] Embodiment 2, a RCPP liquid packaging film production process, used to produce the RCPP liquid packaging film as described above, comprising:

[0038] S1. Weighing of raw materials: weigh the raw materials for the outer layer, which include 400 parts of binary polypropylene T10F; weigh the raw materials for the middle layer, which include 200 parts of polypropylene CF330, 200 parts of binary polypropylene T10F, 50 parts of styrene-ethylene-butylene-styrene block copolymer C2000, 50 parts of polyolefin elastomer 6102FL, and 50 parts of thermoplastic polyolefin C200F; weigh the raw materials for the inner layer, which include 300 parts of binary copolymer polypropylene W0723F, 100 parts of ternary copolymer polypropylene TF1007, 25 parts of polyethylene SP0540, 6 parts of lubricant SAB39N, and 8 parts of anti-blocking agent AB05N; after weighing the raw materials for each layer, stir the raw materials for each layer evenly and feed them into the three barrels of the extruder respectively;

[0039] S2, the raw materials of the three barrels are co-extruded through the same die head, and after co-extrusion, they enter the casting station for cooling and shaping; the temperature in the three barrels is divided into a feeding section, a melting section and a heat preservation section in turn, the starting temperature of the feeding section is lower than 185°C, the end temperature is 220-230°C, the temperature of the melting section and the heat preservation section are both controlled at 230°C-240°C, the die head temperature is 220-230°C, and the roller surface temperature of the casting roller in the casting is 20-40°C; when the raw materials are extruded, the thickness ratio of the outer layer, the middle layer and the inner layer is 1:3:1;

[0040] S3. The outer layer of the cast RCPP liquid packaging film is subjected to corona treatment. The power of the corona treatment is 12KW-15KW, and the width of the die head is 3.6 meters.

[0041] S4, measuring the total thickness of the RCPP liquid packaging film after tape casting, requiring the total thickness of the RCPP liquid packaging film to be 9-10 filaments.

[0042] The present invention adds styrene-ethylene-butylene-styrene block copolymer C2000 and polyolefin elastomer 6102FL to the middle layer, and these two materials can still maintain good flexibility and elasticity at low temperatures, thereby significantly improving the cold resistance of the packaging film. Even during long-term low-temperature storage and transportation, the packaging film is not easy to become brittle and crack, effectively ensuring the safety and integrity of food. The addition of SEBS and polyolefin elastomer 6102FL not only improves the cold resistance of the packaging film, but also enhances its tensile properties and flexibility. This makes the packaging film easier to operate during processing and use, less likely to break, and improves the reliability and durability of the packaging.

[0043] The selection and ratio of the inner and outer layer raw materials ensure that the packaging film has good heat sealing and barrier properties, which can effectively prevent food from being contaminated and oxidized during the packaging process and extend the shelf life of food.

[0044] All raw materials are environmentally friendly materials, in line with food safety and environmental protection requirements. At the same time, these materials have good processing properties, making the production process of packaging film more efficient and stable.

[0045] The above is only an embodiment of the present invention, and the common knowledge such as the known specific technical solutions and / or characteristics in the solution is not described in detail here. It should be pointed out that for those skilled in the art, without departing from the technical solution of the present invention, several modifications and improvements can be made, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A RCPP liquid packaging film, characterized in that: It includes an outer layer, a middle layer and an inner layer. The outer layer includes 400 parts by weight of binary polypropylene T10F, the middle layer includes 200 parts by weight of polypropylene CF330, 200 parts by weight of binary polypropylene T10F, 50 parts by weight of styrene-ethylene-butylene-styrene block copolymer C2000, 50 parts by weight of polyolefin elastomer 6102FL, and 50 parts by weight of thermoplastic polyolefin C200F, and the inner layer includes 300 parts by weight of binary copolymer polypropylene W0723F, 100 parts of ternary copolymer polypropylene TF1007, 25 parts of polyethylene SP0540, 6 parts of lubricant SAB39N, and 8 parts of opening agent AB05N.

2. The RCPP liquid packaging film according to claim 1, characterized in that: The mass ratio of the inner layer, outer layer and middle layer is 1:1:

3.

3. The RCPP liquid packaging film according to claim 2, characterized in that: The thickness is 9.5 silk.

4. A RCPP liquid packaging film production process, used to produce a RCPP liquid packaging film as claimed in any one of claims 1 to 3, characterized in that: include S1. Weighing of raw materials: weigh the raw materials for the outer layer, which include 400 parts of binary polypropylene T10F; weigh the raw materials for the middle layer, which include 200 parts of polypropylene CF330, 200 parts of binary polypropylene T10F, 50 parts of styrene-ethylene-butylene-styrene block copolymer C2000, 50 parts of polyolefin elastomer 6102FL, and 50 parts of thermoplastic polyolefin C200F; weigh the raw materials for the inner layer, which include 300 parts of binary copolymer polypropylene W0723F, 100 parts of ternary copolymer polypropylene TF1007, 25 parts of polyethylene SP0540, 6 parts of lubricant SAB39N, and 8 parts of anti-blocking agent AB05N; after weighing the raw materials for each layer, stir the raw materials for each layer evenly and feed them into the three barrels of the extruder respectively; S2, the raw materials of the three barrels are co-extruded with the same die head, and after co-extrusion, they enter the casting station for cooling and shaping; the temperature in the three barrels is divided into a feeding section, a melting section and a heat preservation section, the starting temperature of the feeding section is lower than 185°C, the end temperature is 220-230°C, the temperature of the melting section and the heat preservation section are both controlled at 230°C-240°C, the die head temperature is 220-230°C, and the roller surface temperature of the casting roller in the casting is 20-40°C; S3. Corona discharge is performed on the outer layer of the cast RCPP liquid packaging film.

5. The RCPP liquid packaging film and its production process according to claim 4, characterized in that: When the raw materials are extruded, the thickness ratio of the outer layer, the middle layer and the inner layer is 1:3:1; it also includes S4, measuring the total thickness of the RCPP liquid packaging film after cast molding, and the total thickness of the RCPP liquid packaging film is required to be 9-10 filaments.

6. The RCPP liquid packaging film and its production process according to claim 5, characterized in that: The power of the corona treatment in step S3 is 12KW-15KW, and the width of the die head is 3.6 meters.