Three-layer co-extrusion plastic film

Abstract

The invention relates to a three-layer co-extrusion plastic film, consisting of three layers comprising an inner layer, a middle layer and an outer layer, wherein the inner layer consists of a mixture of an ethylene-propylene-butadiene ternary polypropylene random copolymer and poly (octene-ethylene), wherein the content of poly (octene-ethylene) is 80-92%, the middle layer consists of a mixture of an ethylene-propylene binary polypropylene random copolymer and the poly (octene-ethylene), wherein the content of the poly (octene-ethylene) is 60-70%, and the outer layer consists of a mixture of homo-polypropylene and poly (octene-ethylene) (POE), wherein the content of the poly (octene-ethylene) is 85-90%. The three-layer co-extrusion plastic film provided by the invention has the following characteristics of wide heat seal temperature range, high welding strength, excellent anti-falling property, no crystal spot, high transparence, excellent steam and oxygen barrier property, excellent flexibility, no yellowing and embrittlement problems after being sterilized at a high temperature, excellent compatibility with liquid medicine, high heat seal strength, and the like, thereby being an environment-friendly high-property film for infusion bags.

Description

technical field [0001] The invention relates to a polymer material, in particular to a three-layer co-extruded plastic film used in the pharmaceutical industry for making large transfusion soft bags. It is a three-layer co-extruded film formed by down-blowing and water-cooling. Background technique [0002] With the development of medical and health services, the requirements for infusion medical devices are getting higher and higher, which is reflected in the safety of infusion containers, the compatibility of liquid medicine, and the convenience of transportation and use. Infusion containers have mainly experienced the development process from glass bottles to plastic bottles and then to plastic soft bags. Due to the disadvantages of inconvenient transportation and easy bursting or ejection of bottle stoppers during high temperature sterilization, soft bags have become the development of infusion containers. trend. The infusion soft bag should meet the requirements of th...

AI Technical Summary

Problems solved by technology

However, with the development of medical technology, the requirements for infusion membranes are getting higher and higher, especially for high-temperature steam sterilization of large infusions. Even imported membranes are difficult to achieve high temperature resistance.

At present, the three-layer films of domestic and foreign manufacturers used for large infusion bags all have shortcomings such as shrinkage, hardening, brittleness, whitening, and poor transparency after high-temperature sterilization, or have poor fusion with the mouth tube of the infusion set. Poor, poor high temperature resistance, local adhesion phenomenon occurs during heat sealing

Polypropylene is a semi-crystalline polymer. As the temperature increases, the crystallinity of polypropylene increases, and the structure tends to be regular, resulting in poor transparency and a corresponding decrease in softness.

Although most co-extruded film materials are modified by blending polypropylene and other materials to improve the transparency and flexibility of the material, since the plastic processing process is carried out under high temperature conditions, if the two-phase If the difference between melt strength and melt index is large, phase separation will easily occur, resulting in excessive or excessive crystal points.

Especially for film materials after high-temperature sterilization in the later period, the performance of the material often decreases rapidly, and phenomena such as yellowing, brittleness, and hardness appear.

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