Polyethylene film that can be sealed with polyethylene and polypropylene materials
Through the polyethylene film of a specific grade, the three- or five-layer coextrusion molding process of corona layer, intermediate layer and dead sealing layer is used to solve the problem that polyethylene and polypropylene materials cannot be heat sealed well, achieving low-cost and high-efficiency heat sealing effect, and simplifying management and inventory.
Patent Information
- Application Number
- CN202211385451.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-11-07
- Publication Date
- 2025-09-02
- Estimated Expiration
- 2042-11-07
AI Technical Summary
Polyethylene and polypropylene materials are not fully compatible, and conventional materials have no strength after being sealed, which increases corporate inventory and management costs, and the cost of adding elastomers or EVA modification is high and processing is difficult.
The polyethylene film of a specific grade, including corona layer, intermediate layer and dead sealing layer, are all polyethylene materials, and are made through three- or five-layer coextrusion molding process. The suitable dead sealing layer grade is 6056 or 6026, to achieve good heat sealing with polyethylene and polypropylene materials.
It has achieved good heat sealing of polyethylene and polypropylene materials, reduced costs, simplified management, improved yield and efficiency, and reduced enterprise inventory.
Smart Images
Figure CN115816950B_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of films, in particular to a polyethylene film which can be sealed with polyethylene and polypropylene materials. Background Art
[0002] Polyethylene (PE) and polypropylene (PP) are two polyolefin resins with different properties and are not completely compatible. Conventional seals made with these two materials do not provide a good seal and lack strength. In film-based lidding products, polyethylene cups and bowls are typically sealed with polyethylene film, while polypropylene cups and bowls are sealed with polypropylene film. This increases costs, inventory, and management workloads for businesses.
[0003] When polyethylene and polypropylene are sealed together, elastomers or ethylene-vinyl acetate copolymer (EVA) are often added to the polyethylene to modify its properties. However, polyethylene films with elastomers or EVA added are expensive and difficult to process. They also fail to completely seal with polypropylene and are easily peeled off. Summary of the Invention
[0004] Based on this, the present invention provides a polyethylene film that can be sealed with both polyethylene and polypropylene materials. The polyethylene film is a pure polyethylene film, rather than an elastomer or modified polyolefin material. By selecting a specific brand of polyethylene, a polyethylene brand that can be sealed with both polyethylene and polypropylene materials is obtained, thereby achieving the goal that the same material can be sealed with both polyethylene and polypropylene materials. The processing technology is simple, the cost is low, the yield is high, and the efficiency is high. It can be applied to the covering films of polyethylene cups and bowls and polypropylene cups and bowls at the same time, which can simplify the types of covering films, reduce corporate inventory, reduce costs, and simplify management.
[0005] The technical solution adopted in the present invention is:
[0006] A polyethylene film that can be dead-sealed with both polyethylene and polypropylene materials comprises a corona layer, an intermediate layer and a dead-sealing layer arranged in sequence, wherein the corona layer, the intermediate layer and the dead-sealing layer are all made of polyethylene, and the polyethylene grade of the dead-sealing layer is 1881G, PT1450, 6056, 8784 or 6026.
[0007] In the polyethylene film disclosed in the present application that can be sealed with both polyethylene and polypropylene materials, the polyethylene grade of the sealing layer is 6056 or 6026.
[0008] In the polyethylene film disclosed in this application that can be sealed with both polyethylene and polypropylene materials, the heat sealing temperature of the polyethylene film and the polyethylene material is not less than 120°C, and the heat sealing temperature of the polyethylene film and the polypropylene material is not less than 165°C.
[0009] In the polyethylene film disclosed in the present application that can be sealed with both polyethylene and polypropylene materials, the polyethylene grade of the corona layer is 1002AY, 7042N, 2420H or 6230.
[0010] In the polyethylene film disclosed in the present application that can be sealed with both polyethylene and polypropylene materials, the middle layer is ordinary polyethylene or functional polyethylene.
[0011] In the polyethylene film disclosed in the present application that can be sealed with both polyethylene and polypropylene materials, the intermediate layer is a multi-layer structure.
[0012] In the polyethylene film disclosed in the present application that can be sealed with both polyethylene and polypropylene materials, the middle layer is a three-layer structure, including a first layer, a second layer and a third layer arranged in sequence.
[0013] In the polyethylene film disclosed in this application that can be sealed with both polyethylene and polypropylene materials, when the first layer and the third layer are polyethylene modified adhesive layers, the second layer is nylon or ethylene-vinyl alcohol copolymer; when the first layer and the third layer are polyethylene layers, the second layer is functional polyethylene.
[0014] In the polyethylene film disclosed in the present application that can form a dead seal with both polyethylene and polypropylene materials, the corona layer, the middle layer and the dead seal layer are produced by three-layer co-extrusion molding.
[0015] In the polyethylene film disclosed in the present application that can be dead-sealed with both polyethylene and polypropylene materials, the corona layer, the first layer, the second layer, the third layer, and the dead-sealing layer are manufactured by a five-layer co-extrusion molding method.
[0016] The beneficial effects of the invention are:
[0017] The present invention provides a polyethylene film that can be sealed with both polyethylene and polypropylene materials. The polyethylene film is a pure polyethylene film, rather than an elastomer or modified polyolefin material. The polyethylene grade of the sealing layer is obtained by selecting a specific polyethylene grade. The polyethylene film has good processing performance, good transparency, and low cost. It has the performance of being sealed with both polyethylene and polypropylene materials, and can achieve the dead sealing of the same material with both polyethylene and polypropylene materials. The processing technology of the polyethylene film is simple, the cost is low, the yield is high, and the efficiency is high. It can also reduce the inventory of existing enterprises and simplify management. The polyethylene film can be widely used in the dead sealing covering films of polyethylene paper cups, polyethylene bottles, polyethylene bowls, polypropylene bottles, polypropylene bottles, and polypropylene bowls. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.
[0019] Figure 1 This is a schematic structural diagram of a polyethylene film that can be sealed with both polyethylene and polypropylene materials according to an embodiment of the present application;
[0020] Figure 2 This is a schematic structural diagram of a polyethylene film that can be sealed with both polyethylene and polypropylene materials according to another embodiment of the present application.
[0021] Reference numerals:
[0022] 1. Corona layer; 2. Middle layer; 3. Dead seal layer; 21. First layer; 22. Second layer; 23. Third layer. DETAILED DESCRIPTION
[0023] In the following, only certain exemplary embodiments are briefly described. As those skilled in the art would realize, the described embodiments may be modified in various different ways without departing from the spirit or scope of the present invention.
[0024] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.
[0025] See also Figures 1 and 2 As shown, the embodiment of the present application provides a polyethylene film that can be sealed with both polyethylene and polypropylene materials. The main purpose is to achieve the performance of being able to seal with both polyethylene and polypropylene materials by selecting a specific brand of polyethylene.
[0026] Polyethylene and polypropylene are two polyolefin resins with different properties, and conventionally, the two materials are not completely compatible. When heat-sealed, the two materials do not form a good seal, and the seal strength is lacking after heat sealing. In film-covered products, polyethylene cups and bowls are typically sealed with polyethylene film, while polypropylene cups and bowls are sealed with polypropylene film. This increases a company's inventory, costs, and management workload. When polyethylene and polypropylene are sealed, elastomers or EVA are typically added to modify the polyethylene material. However, polyethylene films with added elastomers or EVA are expensive and difficult to process. When sealed with polypropylene, they are not completely sealed and are easily peeled off.
[0027] To address the problems of the prior art, the present application provides a polyethylene film that can seal tightly with both polyethylene and polypropylene materials, comprising a corona layer 1, an intermediate layer 2, and a seal layer 3, arranged in sequence. The corona layer 1, intermediate layer 2, and seal layer 3 are all made of polyethylene. The present application utilizes pure polyethylene that is compatible with and seals tightly with both polyethylene and polypropylene materials to produce a heat-sealable polyethylene film that can completely seal tightly with both polyethylene and polypropylene materials. This film can be used as a cover film for polyethylene and polypropylene cups and bowls, simplifying the variety of cover films, reducing corporate inventory, lowering costs, and simplifying management.
[0028] Different polyethylene grades have different properties. To ensure that polyethylene film can heat-seal with both polyethylene and polypropylene materials, the polyethylene grade for the sealing layer 3 is carefully selected. As shown in Table 1, a performance study of different polyethylene grades revealed that polyethylene grades 1881G, PT1450, 6056, 8784, and 6026 can heat-seal with both polyethylene and polypropylene. Polyethylene grade 1820 can heat-seal with polyethylene but not with polypropylene. Among them, polyethylene grade 1881G is difficult to process, polyethylene grade PT1450 is difficult to open, and polyethylene grades 1820 and 8784 lack transparency. Therefore, polyethylene grades 6056 and 6026 are preferred for the sealing layer 3.
[0029] Table 1 Performance study of different polyethylene grades
[0030]
[0031] The polyethylene grade of the polyethylene film dead seal layer 3 is preferably 6056 and 6026, which have good processing performance, can be dead-sealed with polyethylene and polypropylene materials, and have good transparency and low cost.
[0032] When polyethylene and polypropylene are sealed together, elastomers or EVA are usually added to the polyethylene to modify it. However, elastomers and EVA are relatively expensive and difficult to process after modification. The polyethylene film of this application is pure polyethylene film, rather than an elastomer or modified polyolefin material. This allows the same material to be sealed together with polyethylene and polypropylene materials. Its processing is simple, low-cost, high-yield, and efficient. It can also reduce existing companies' inventory and simplify management. It can be widely used as a sealing film for polyethylene paper cups, polyethylene bottles, polyethylene bowls, polypropylene bottles, polypropylene bottles, and polypropylene bowls.
[0033] In one embodiment, see Figure 1 As shown, the polyethylene film has a three-layer structure, wherein the corona layer 1, the middle layer 2 and the dead seal layer 3 are produced by three-layer co-extrusion molding.
[0034] The polyethylene of the corona layer 1 is made of polyethylene without additives, and its specific brands are: 1002AY, 7042N, 2420H, 6230, etc.
[0035] The middle layer 2 is ordinary polyethylene or functional polyethylene, which is used to reduce costs, provide special properties, reduce screw load, provide barrier properties, increase strength, improve tearing properties and the like.
[0036] The dead seal layer 3 is a functional layer, which can be dead sealed with polyethylene and polypropylene materials by selecting a specific grade of polyethylene.
[0037] In another embodiment, the middle layer 2 is a multi-layer structure, which may be two layers, three layers or four layers. Figure 2 As shown, the middle layer 2 is a three-layer structure, including a first layer 21, a second layer 22 and a third layer 23 arranged in sequence.
[0038] The polyethylene film has a five-layer structure, wherein the corona layer 1, the first layer 21, the second layer 22, the third layer 23 and the dead seal layer 3 are produced by co-extrusion molding of the five layers.
[0039] The polyethylene of the corona layer 1 is made of polyethylene without additives, and its specific brands are: 1002AY, 7042N, 2420H, 6230, etc.
[0040] In a specific embodiment, the first layer 21, the second layer 22 and the third layer 23 are all functional polyethylene, which is used to reduce costs, reduce screw load, improve strength, increase stiffness, reduce tearing, etc.
[0041] In another specific embodiment, the first layer 21 and the third layer 23 are both polyethylene modified adhesive layers for bonding high-performance polymers. The second layer 22 is a functional material for improving barrier properties, such as nylon or ethylene-vinyl alcohol copolymer.
[0042] In one embodiment, the heat-sealing temperature of the polyethylene film and the polyethylene material is not less than 120°C, and the heat-sealing temperature of the polyethylene film and the polypropylene material is not less than 165°C. The polyethylene film can achieve a dead seal when heat-sealed with the polyethylene material at a temperature above 120°C. The polyethylene film can achieve a dead seal when heat-sealed with the polypropylene material at a temperature above 165°C.
[0043] The embodiment of the present application provides a polyethylene film that can be sealed with both polyethylene and polypropylene materials. The polyethylene film is a pure polyethylene film, rather than an elastomer or modified polyolefin material. The polyethylene grade of the sealing layer 3 is obtained by selecting a specific grade of polyethylene. The polyethylene grade has good processing performance, good transparency, and low cost. It has the performance of being sealed with both polyethylene and polypropylene materials, and can achieve that the same material can be sealed with both polyethylene and polypropylene materials. The processing technology of the polyethylene film is simple, the cost is low, the yield is high, and the efficiency is high. It can also reduce the inventory of existing enterprises and simplify management. It can be widely used in the sealing covering films of polyethylene paper cups, polyethylene bottles, polyethylene bowls, polypropylene bottles, polypropylene bottles, and polypropylene bowls.
[0044] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.
Claims
1. A polyethylene film heat-sealable with polyethylene and polypropylene materials, comprising a corona layer, an intermediate layer and a heat-seal layer arranged in sequence, characterized in that: The corona layer, the middle layer and the heat-sealing layer are all made of polyethylene, and the polyethylene grade of the heat-sealing layer is 6056 or 6026; The heat-sealing temperature between the polyethylene film and the polyethylene material is not less than 120°C, and the heat-sealing temperature between the polyethylene film and the polypropylene material is not less than 165°C.
2. The polyethylene film heat-sealable with polyethylene and polypropylene materials according to claim 1, characterized in that: The polyethylene grade of the corona layer is 1002AY, 7042N, 2420H or 6230.
3. The polyethylene film heat-sealable with polyethylene and polypropylene materials according to claim 1, characterized in that: The middle layer is a multi-layer structure.
4. The polyethylene film heat-sealable with polyethylene and polypropylene materials according to claim 3, characterized in that: The middle layer is a three-layer structure, including a first layer, a second layer and a third layer arranged in sequence.
5. The polyethylene film heat-sealable with polyethylene and polypropylene materials according to claim 1, characterized in that: The corona layer, the middle layer and the heat-sealing layer are prepared by three-layer co-extrusion molding.
6. The polyethylene film heat-sealable with polyethylene and polypropylene materials according to claim 4, characterized in that: The corona layer, the first layer, the second layer, the third layer and the heat-sealing layer are prepared by a five-layer co-extrusion molding method.