Casting polypropylene film with controllable friction coefficient and preparation method thereof

Abstract

The invention discloses a casting polypropylene film with a controllable friction coefficient and a preparation method thereof, belonging to the technical field of packaging materials. The casting polypropylene film sequentially comprises a corona layer, a middle layer and a heat-seal layer with a thickness ratio of (20-30) to (50-65) to (15-20). The corona layer is made from homo-polypropylene or polypropylene random copolymer, the middle layer is made from isotactic homo-polypropylene, and the heat-seal layer comprises 90wt%-98wt% of propylene copolymer, 1wt%-3wt% of adhesion resisting agent and 1wt%-7wt% of macromolecule slip agent, namely silicone master batch. The preparation method sequentially comprises the following steps: mixing materials, extruding to form a film, cooling for shaping, measuring thickness, aureoling, trimming, reeling, performing aging treatment, and slitting. The heat-seal layer is uniformly dispersed in main body resin by the macromolecule slip agent, and the slip agent is well compatible with the main body resin due to high molecular weight, and thus a film surface friction coefficient is prevented from being changed by migration of the macromolecule slip agent due to temperature of a storage or usage environment.

Description

technical field [0001] The invention belongs to the technical field of packaging materials, and in particular relates to a cast polypropylene film with a controllable friction coefficient and a preparation method thereof. Background technique [0002] Food and other daily necessities are indispensable to people's daily life. With the continuous acceleration of the pace of life, all kinds of packaged food and daily necessities are filled with supermarkets and shopping malls, which facilitate people's purchase, storage and use. Among them, packaging materials play a crucial role. important role. With the continuous development of the packaging industry, automatic packaging production lines are used more and more widely in the production of food and daily necessities. As the running speed and automation of automatic packaging machines are getting higher and higher, their quality problems are also prominent. Problems such as packaging film breakage, slippage, packaging line int...

AI Technical Summary

Problems solved by technology

[0003] 1) The friction coefficient of the outer layer of the packaging film is low, while the friction coefficient of the inner layer is relatively high, causing the film to slip on the packaging line

[0004] 2) The packaging film is used well at low temperature, but when the temperature is high, the film will not move smoothly during the automatic packaging process

[0005] 3) The friction coefficient of the inner layer of the packaging film is too low, and the content cannot be positioned after being placed on the packaging film. When it slides to the sealing area, the heat sealing strip is pressed on the content, resulting in sealing failure

[0006] 4) The packaging film is used well at low speed, but when the packaging line speed is increased, the film has poor heat sealing and there is a problem of air leakage

The mechanism is that the free isocyanate monomer in the adhesive migrates to the surface of the film and reacts with the amide to form urea. Due to the high melting point of urea, the heat sealing performance of the film after compounding is reduced.

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