BOPET film capable of being directly heat-sealed

Abstract

The invention relates to a BOPET film capable of being directly heat-sealed, which consists of a surface heat-sealing layer, a sandwich layer and a bottom layer, wherein the surface heat-sealing layer comprises the following components in percentage by weight: 85 percent of copolyester PETG, and 15 percent of silicon masterbatch; the sandwich layer comprises the following components in percentage by weight: 80 percent of PET light material, and 20 percent of PET regenerated granules, or 85 percent of PET light material, and 15 percent of PET regenerated granules; and the bottom layer comprises the following components in percentage by weight: 100 percent of anti-adhesive silicon masterbatch. The surface heat-sealing layer of the film has lower melting point; the heat sealing temperature is 130 DEG C or so after the folding; the heat-sealing temperature of the film is equivalent to those (between 120 and 140 DEG C) of heat-sealing layer materials which are commonly used in soft packaging industry such as CPP, PE and the like; main technical indexes have already reached the level of similar products abroad; and the heat-sealing strength of the film is superior to those of BOPET films with the same specification abroad. In addition, the film is applicable for the mass production by the prior three-runner three-layer coextrusion and bidirectional stretching equipment, and has the outstanding advantages of low investment and steady quality.

Description

technical field [0001] The invention belongs to polyester films, in particular to a directly heat-sealable BOPET film. Background technique [0002] Biaxially oriented polyester film (BOPET) has excellent properties, such as high tensile strength, good stiffness, good hygroscopicity, good dimensional stability, low air permeability, good insulation performance, good optical performance, etc., which makes it in It is widely used in industrial, civil, agricultural and other fields. [0003] At present, the application of PET film is mainly concentrated in the fields of packaging, decoration, adhesive tape, tape substrate, photographic film, electrical insulating material, tracing paper and so on. However, because the PET molecular chain itself is rigid, and the heat setting in the production process makes its crystallinity high, resulting in a relatively high melting point, so the BOPET film itself cannot be heat-sealed and bonded, which greatly limits the direct use of BOPET...

AI Technical Summary

Problems solved by technology

Domestic attention to heat-sealable BOPET film began in 2004. So far, a small number of units have been able to produce similar products that have been produced abroad. The heat-sealing performance of the product itself is basically the same, but the technology of each domestic unit has not been disclosed.

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