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CN-120245573-B - High-permeability polyethylene blown film for industrial packaging and preparation method thereof

CN120245573BCN 120245573 BCN120245573 BCN 120245573BCN-120245573-B

Abstract

The invention discloses a high-permeability polyethylene blown film for industrial packaging and a preparation method thereof, belonging to the technical field of packaging films and being characterized in that a film body consists of an outer layer, an intermediate layer and an inner layer from outside to inside in sequence; the outer layer is made of 6-9 parts by mass of metallocene linear low-density polyethylene, 1.5-2.5 parts by mass of first low-density polyethylene and 0.3-0.7 part by mass of PPA, the middle layer is made of 8-11 parts by mass of matte linear low-density polyethylene, and the inner layer is made of 5.5-8.5 parts by mass of metallocene linear low-density polyethylene, 1.5-2.5 parts by mass of first low-density polyethylene, 0.3-0.7 part by mass of PPA and 0.3-0.7 part by mass of opening slipping agent. The film maintains higher mechanical property through the proportion of raw materials, can greatly improve the stability of film bubbles, can prepare the packaging film with uniform thickness and stable width, can improve the plasticization of the raw materials, improve the flow rate of melt, reduce the generation of crystal points and eliminate water ripple generated by melt fracture on the surface of the film, thereby improving the transparency of the film body.

Inventors

  • YANG YU
  • CUI CHEN
  • YANG SHENGDONG

Assignees

  • 山东旭喜新材料科技有限公司

Dates

Publication Date
20260512
Application Date
20250605

Claims (10)

  1. 1. The high-permeability polyethylene blown film for industrial packaging comprises a film body, wherein the film body sequentially comprises an outer layer, an intermediate layer and an inner layer from outside to inside, and is characterized in that: The outer layer is prepared from the following raw materials in parts by mass: 6-9 parts of metallocene linear low-density polyethylene 1.5-2.5 Parts of first low-density polyethylene PPA 0.3-0.7 parts The middle layer is prepared from the following raw materials in parts by mass: 8-11 parts of matte low-density polyethylene The surface glossiness of the matte low-density polyethylene is 12-15%, and the haze is 70-75%; the inner layer is prepared from the following raw materials in parts by mass: 5.5-8.5 parts of metallocene linear low density polyethylene 1.5-2.5 Parts of first low-density polyethylene PPA 0.3-0.7 parts 0.3 To 0.7 part of an opening slipping agent The opening slipping agent is prepared from the following raw materials in percentage by mass: Erucic acid amide 3-7% 12-18% Of microcrystalline glass 76-84% Of second low-density polyethylene The brand of the metallocene linear low-density polyethylene is SP1520, the brand of the first low-density polyethylene is 105BR, the brand of the PPA is PEA-3S, and the PAA is a processing aid.
  2. 2. A high-permeability polyethylene blown film for industrial packaging according to claim 1, wherein: The outer layer is prepared from the following raw materials in parts by mass: Metallocene linear low density polyethylene 7.5 parts First Low Density polyethylene 2 parts PPA 0.5 parts The middle layer is prepared from the following raw materials in parts by mass: 9.5 parts of matte low density polyethylene The inner layer is prepared from the following raw materials in parts by mass: Metallocene linear low density polyethylene 7 parts First Low Density polyethylene 2 parts PPA 0.5 parts 0.5 Part of open smooth agent The opening slipping agent is prepared from the following raw materials in percentage by mass: Erucamide 5% Microcrystalline glass 15% The second low density polyethylene 80%.
  3. 3. A high-permeability polyethylene blown film for industrial packaging according to claim 2, wherein the matte linear low density polyethylene is identified as FB2230.
  4. 4. A high-permeability polyethylene blown film for industrial packaging according to any one of claims 1 to 3, wherein the film body has a thickness of 50 to 100. Mu.m.
  5. 5. The high-permeability polyethylene blown film for industrial packaging according to claim 4, wherein the thickness ratio of the outer layer, the intermediate layer and the inner layer is 2:1:2.
  6. 6. The preparation method of the high-permeability polyethylene blown film for industrial packaging is characterized by comprising the following steps of: (1) Preparing a first special material, namely mixing 6-9 parts by mass of metallocene linear low-density polyethylene, 1.5-2.5 parts by mass of first low-density polyethylene and 0.3-0.7 part by mass of PPA to prepare a first mixture; (2) Preparing a second special material, namely mixing 5.5-8.5 parts by mass of metallocene linear low-density polyethylene, 1.5-2.5 parts by mass of first low-density polyethylene, 0.3-0.7 part by mass of PPA and 0.3-0.7 part by mass of open slipping agent to prepare a second mixture; The open-end slipping agent is prepared from 3-7% by weight of erucamide, 12-18% by weight of microcrystalline glass and 76-84% by weight of second low-density polyethylene; (3) The co-extrusion film blowing is that the first mixture prepared in the step (1), the matte linear low-density polyethylene and the second mixture prepared in the step (2) are subjected to multi-layer co-extrusion blowing to form an outer layer, an intermediate layer and an inner layer which are sequentially arranged from outside to inside of the packaging film; The brand of the metallocene linear low-density polyethylene is SP1520, the brand of the first low-density polyethylene is 105BR, the surface glossiness of the matte linear low-density polyethylene is 12-15%, the haze is 70-75%, the brand of PPA is PEA-3S, and PAA is a processing aid.
  7. 7. The method for producing a high-permeability polyethylene blown film for industrial packaging according to claim 6, wherein in the step (1), the first mixture is formed by mixing 7.5 parts by mass of a metallocene linear low-density polyethylene, 2 parts by mass of the first low-density polyethylene and 0.5 part by mass of PPA; In the step (2), the second mixture is formed by mixing 7 parts by mass of metallocene linear low-density polyethylene, 2 parts by mass of first low-density polyethylene, 0.5 part by mass of PPA and 0.5 part by mass of an open slipping agent, wherein the mass percentage of erucamide in the open slipping agent is 5%, the mass percentage of glass ceramics in the open slipping agent is 15%, and the mass percentage of second low-density polyethylene in the open slipping agent is 80%.
  8. 8. The method for producing a high-permeability polyethylene blown film for industrial packaging according to claim 6 or 7, wherein said first low-density polyethylene has the same brand as the second low-density polyethylene.
  9. 9. The method of producing a high-permeability polyethylene blown film for industrial packaging according to claim 8, wherein the first mixture of step (1) and the second mixture of step (2) are granulated and then fed to step (3).
  10. 10. The method of producing a high-permeability polyethylene blown film for industrial packaging according to claim 9, wherein in the step (3), the extrusion temperature of the outer layer and the inner layer is 165 to 175℃and the extrusion temperature of the intermediate layer is 160 to 170 ℃.

Description

High-permeability polyethylene blown film for industrial packaging and preparation method thereof Technical Field The invention belongs to the technical field of preparation of packaging films, and particularly relates to a high-permeability polyethylene blown film for industrial packaging and a preparation method thereof. Background Polyethylene films are important as materials for packaging products, and are favored in the packaging industry for foods, medicines, various industrial products, and the like. Because the weight of the industrial product is far more than that of foods and medicines and even is thousands of times higher, the polyethylene packaging film of the industrial product is required to have higher mechanical property requirements, so that the polyethylene industrial packaging film adopts metallocene linear low-density polyethylene with larger molecular weight as a main raw material, the transparency of the packaging film is reduced while the use requirement is met, and the transparency of the packaging film can only be 85 percent. With the increasing convenience of life and work habits of people, higher requirements are put on the transparency of the polyethylene packaging film in order to observe the condition of the packaged objects through the packaging film, and then the requirements and the high mechanical properties form irreconcilable contradictions. For this reason, the invention patent with publication number CN102476491a discloses a method and process for manufacturing a high transparent composite plastic film, wherein an anti-reflection layer is respectively arranged outside a polyamide polyethylene mixed layer (PA/PE), and the anti-reflection layer is made of polypropylene (PP), biaxially oriented polypropylene (BOPP), low Density Polyethylene (LDPE), high Density Polyethylene (HDPE), linear Low Density Polyethylene (LLDPE) or polyvinyl chloride (PVC). The film can strengthen the transmitted light by utilizing the principle that the film interference can greatly weaken the reflected light intensity, thereby improving the transparency of the film, but can only form the film by biaxial stretching, thereby not only reducing the production efficiency, but also weakening the mechanical property of the film, so that the requirement of high mechanical property cannot be met. Disclosure of Invention The invention aims to solve the technical problem of providing a high-permeability polyethylene blown film for industrial packaging and a preparation method thereof, which can greatly reduce the haze of the packaging film and improve the transparency of the packaging film on the premise of meeting the mechanical properties required by industrial packaging. In order to solve the technical problems, the technical scheme of the invention is to design a high-permeability polyethylene blown film for industrial packaging, which comprises a film body, wherein the film body sequentially comprises an outer layer, a middle layer and an inner layer from outside to inside, and is characterized in that: The outer layer is prepared from the following raw materials in parts by mass: 6-9 parts of metallocene linear low-density polyethylene 1.5-2.5 Parts of first low-density polyethylene PPA 0.3-0.7 parts The middle layer is prepared from the following raw materials in parts by mass: 8-11 parts of matte low-density polyethylene The surface glossiness of the matte low-density polyethylene is 12-15%, and the haze is 70-75%; the inner layer is prepared from the following raw materials in parts by mass: 5.5-8.5 parts of metallocene linear low density polyethylene 1.5-2.5 Parts of first low-density polyethylene PPA 0.3-0.7 parts 0.3 To 0.7 part of an opening slipping agent The opening slipping agent is prepared from the following raw materials in percentage by mass: Erucic acid amide 3-7% 12-18% Of microcrystalline glass 76-84% Of second low-density polyethylene The brand of the metallocene polyethylene is SP1520, and the brand of the first low density polyethylene is 105BR. Preferably, the outer layer is prepared from the following raw materials in parts by mass: Metallocene linear low density polyethylene 7.5 parts First Low Density polyethylene 2 parts PPA 0.5 parts The middle layer is prepared from the following raw materials in parts by mass: 9.5 parts of matte low density polyethylene The inner layer is prepared from the following raw materials in parts by mass: Metallocene linear low density polyethylene 7 parts First Low Density polyethylene 2 parts PPA 0.5 parts 0.5 Part of open smooth agent The opening slipping agent is prepared from the following raw materials in percentage by mass: Erucamide 5% Microcrystalline glass 15% The second low density polyethylene 80%. Preferably, the matte low density polyethylene is identified as FB2230. Preferably, the thickness of the film body is 50-100 μm. Preferably, the thickness ratio of the outer layer, the middle layer and the inner layer is 2:1:2. The invention