A multilayer coextruded cpp film structure resistant to high temperature retort

Abstract

The utility model relates to CPP film technical field, concretely is a kind of multilayer co-extrusion CPP film of high-temperature cooking resistance, including CPP film body, the CPP film body is sequentially composed of outer heat sealing layer, outer barrier layer, support layer, inner barrier layer and inner heat sealing layer from outside to inside, the outer heat sealing layer provides printing surface for CPP film, the outer barrier layer is used to isolate water vapor from outside, the support layer provides mechanical support for CPP film, the inner barrier layer is used to isolate water vapor from inside, the inner heat sealing layer is used to contact food;The outer heat sealing layer is made of BOPA biaxially oriented nylon film, and the thickness is 2-5 μm, for printing product information.The utility model is provided with symmetrical outer barrier layer and inner barrier layer on the both sides of support layer, prevent the moisture and gas of inside and outside from contacting support layer, guarantee the mechanical strength of support layer, mutually cooperate between each layer, maintain the integrity of CPP film, make it high-temperature cooking resistance.

Description

Technical Field

[0001] This utility model relates to the field of CPP film technology, and in particular to a multilayer co-extruded CPP film that is resistant to high-temperature cooking. Background Technology

[0002] CPP film, or cast polypropylene film, is a non-stretched, non-oriented planar extruded film produced through melt casting and rapid cooling. Materials for each layer can be selected individually to meet specific requirements, giving the film different functions and applications. High-temperature retortible multilayer co-extruded CPP films are typically made from copolymerized polypropylene or blended modified polypropylene granules.

[0003] In multilayer co-extruded films, the layers are joined together in a molten state using a precision die and then cooled to form the final product. Different extruders heat and melt plastic particles with different formulations (such as PP and adhesive resin) into melts, and these molten streams are precisely fed into a multilayer co-extrusion die. Inside the die, they are stacked parallel to each other according to a predetermined layered structure. These molten film layers are extruded as a single unit at the die exit and rapidly cooled and shaped by cooling rollers. In the molten state, the polymer molecular chains at the contact surfaces of each layer intertwine through diffusion and entanglement, forming a strong, unified whole during cooling. This is a bulk bonding process, with strength far exceeding that of later adhesive bonding.

[0004] Multilayer co-extruded CPP film is commonly used for packaging various cooked meat products such as roast chicken, roast duck, braised beef, braised food, and roast ribs. These foods usually require high-temperature sterilization to extend their shelf life. However, traditional multilayer co-extruded CPP film is prone to deformation under high-temperature cooking at temperatures above 121°C, leading to packaging breakage. Summary of the Invention

[0005] The main objective of this invention is to provide a high-temperature resistant, multi-layer co-extruded CPP film to solve the problems raised in related technologies.

[0006] To achieve the above objectives, according to one aspect of the present invention, a high-temperature resistant, multilayer co-extruded CPP film is provided, comprising a CPP film body, wherein the CPP film body is composed of an outer heat-sealing layer, an outer barrier layer, a support layer, an inner barrier layer, and an inner heat-sealing layer from the outside to the inside. The outer heat-sealing layer provides a printing surface for the CPP film, the outer barrier layer is used to isolate water vapor from the outside, the support layer provides mechanical support for the CPP film, the inner barrier layer is used to isolate water vapor from the inside, and the inner heat-sealing layer is used to contact food.

[0007] Furthermore, the external heat-sealing layer is made of BOPA biaxially oriented nylon film with a thickness of 2-5 μm, and is used for printing product information.

[0008] Furthermore, the outer barrier layer and the inner barrier layer are made of the same material, both of which are made of highly barrier polypropylene-based nanocomposite material with a thickness of 10-15 μm, used to isolate the support layer from moisture and gas on the inner and outer sides.

[0009] Furthermore, the support layer is made of block copolymer PP with a thickness of 20-30 μm.

[0010] Furthermore, the inner heat seal layer is made of ethylene-propylene copolymer polypropylene with a thickness of 5-10 μm.

[0011] Compared with the prior art, the present invention has the following beneficial effects: This invention prevents moisture and gas from contacting the support layer by setting symmetrical outer and inner barrier layers on both sides of the support layer, ensuring the mechanical strength of the support layer. The layers cooperate with each other to maintain the integrity of the CPP film and make it resistant to high-temperature cooking. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the overall design of this utility model.

[0013] Figure 2 This is a cross-sectional view of the present invention.

[0014] Figure 3 This is a partially enlarged schematic diagram of the present invention.

[0015] Figure label: 1. CPP film body; 11. Outer heat-sealing layer; 12. Outer barrier layer; 13. Support layer; 14. Inner barrier layer; 15. Inner heat-sealing layer. Detailed Implementation

[0016] To further illustrate the technical means and effects adopted by this utility model in order to achieve the intended utility model purpose, the following detailed description of the specific implementation methods, structure, features and effects of this utility model is provided in conjunction with the accompanying drawings and preferred embodiments.

[0017] This embodiment provides a high-temperature resistant, multilayer co-extruded CPP film, such as... Figure 1-3 As shown, the CPP film body 1 is composed of an outer heat-sealing layer 11, an outer barrier layer 12, a support layer 13, an inner barrier layer 14, and an inner heat-sealing layer 15, from the outside to the inside. The outer heat-sealing layer 11 provides a printing surface for the CPP film, the outer barrier layer 12 is used to isolate water vapor from the outside, the support layer 13 provides mechanical support for the CPP film, the inner barrier layer 14 is used to isolate water vapor from the inside, and the inner heat-sealing layer 15 is used to contact food.

[0018] The outer heat-sealing layer 11 is made of BOPA biaxially oriented nylon film with a thickness of 2-5 μm. It has resistance to boiling, puncture, and printability, and is used for printing product information. As the outer printing substrate of the composite structure, the outer heat-sealing layer 11 made of BOPA biaxially oriented nylon film can withstand high-temperature boiling at 121-135℃ and has good chemical stability.

[0019] The outer barrier layer 12 and the inner barrier layer 14 are made of the same material, both being high-barrier polypropylene-based nanocomposite materials with a thickness of 10-15 μm. This material has excellent water vapor barrier properties and is used to isolate the support layer 13 from moisture and gas on both the inner and outer sides. The symmetrically arranged outer barrier layer 12 and inner barrier layer 14 are located on both sides of the support layer 13, respectively, preventing moisture and gas from contacting the support layer 13, ensuring the mechanical strength of the support layer 13, thereby maintaining the integrity of the CPP film and making it resistant to high-temperature cooking.

[0020] The support layer 13 is made of block copolymer PP and has a thickness of 20-30 μm. The support layer 13 made of block copolymer PP has excellent mechanical strength, rigidity and stability, which can maintain the integrity of the CPP film, and has a melting point of about 150-160℃, making it resistant to high-temperature cooking.

[0021] The inner heat seal layer 15 is made of ethylene-propylene copolymer polypropylene with a thickness of 5-10μm. It has certain rigidity and toughness, is resistant to acids and alkalis, has no odor, and is suitable for contact with food.

[0022] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Although the present utility model has been disclosed above with reference to a preferred embodiment, it is not intended to limit the present utility model. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present utility model. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present utility model without departing from the scope of the present utility model shall still fall within the scope of the present utility model.

Claims

1. A high-temperature resistant, multilayer co-extruded CPP film, comprising a CPP film body (1), characterized in that, The CPP film body (1) is composed of an outer heat-sealing layer (11), an outer barrier layer (12), a support layer (13), an inner barrier layer (14), and an inner heat-sealing layer (15) from the outside to the inside. The outer heat-sealing layer (11) provides a printing surface for the CPP film. The outer barrier layer (12) is used to isolate water vapor from the outside. The support layer (13) provides mechanical support for the CPP film. The inner barrier layer (14) is used to isolate water vapor from the inside. The inner heat-sealing layer (15) is used to contact food.

2. The high-temperature resistant, retortable multilayer co-extruded CPP film according to claim 1, characterized in that, The external heat seal layer (11) is made of BOPA biaxially oriented nylon film with a thickness of 2-5 μm and is used for printing product information.

3. The high-temperature resistant, retortable multilayer co-extruded CPP film according to claim 1, characterized in that, The outer barrier layer (12) and the inner barrier layer (14) are made of the same material, both of which are made of polypropylene-based nanocomposite material with high barrier properties and a thickness of 10-15 μm. They are used to isolate the support layer (13) from the moisture and gas on the inner and outer sides.

4. The high-temperature resistant, retortable multilayer co-extruded CPP film according to claim 1, characterized in that, The support layer (13) is made of block copolymer PP with a thickness of 20-30 μm.

5. The high-temperature resistant, retortable multilayer co-extruded CPP film according to claim 1, characterized in that, The inner heat seal layer (15) is made of ethylene-propylene copolymer polypropylene with a thickness of 5-10 μm.

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