High-strength ultrathin heavy-packaged thermal contraction film and preparation method thereof

Abstract

The invention discloses a high-strength ultrathin heavy-packaged thermal contraction film and a preparation method thereof and belongs to the technical field of package films. The thickness of the thermal contraction film disclosed by the invention is 25 to 40mu m; the thermal contraction film is formed by three layers of co-extruded adhered films of an outer layer, a middle layer and an inner layer; a thickness ratio of the outer layer to the middle layer to the inner layer is 1 to (3 to 5) to 1; the outer layer is prepared from high-density polyethylene, metallocene polyethylene (1), linear low-density polyethylene, hydroxyl modified vinisol and amorphous copolyester; the middle layer is prepared from linear low-density polyethylene, high-density polyethylene, metallocene polyethylene (2), hydroxyl modified vinisol and amorphous copolyester; the inner layer is prepared from high-density polyethylene, linear low-density polyethylene, metallocene polyethylene (1), and amorphous copolyester. The thickness of the thermal contraction film disclosed by the invention is ultrathin, materials are saved by 55.6% to 72.2%, and the thermal contraction film has excellent low temperature contraction performance, high strength, simple technology and suitability for large-scale industrial production.

Description

technical field [0001] A high-strength ultra-thin heavy-duty packaging heat-shrinkable film and a preparation method thereof belong to the technical field of polymer materials, further belong to the field of new polymer functional film materials, and specifically belong to the technical field of packaging films. Background technique [0002] With the scarcity of natural resources, the existing wooden packaging, paper packaging and metal packaging materials urgently need new low-cost, environmentally friendly packaging materials to replace. Heat-shrinkable film is a thermoplastic film that is stretched and oriented during processing and shrunk by heat during use. During processing, the energy stretched longitudinally or transversely in the high elastic state of the heat-shrinkable film is stored in the film through quenching. When the film is heated again, it will return to the relaxed molecular structure state, thereby changing the shape before stretching. It has a memory e...

AI Technical Summary

Problems solved by technology

[0003] The current ordinary heat shrinkable film is thicker, and its strength and mechanical properties need to be improved. It is generally only suitable for the outer packaging of small and light items. The method of adding a variety of composite functional additives limits the scope of use of the heat shrinkable film, which is prone to the risk of dissolution and degradation pollution, and has relatively large use defects.

In addition, in order to obtain better printing performance, ordinary heat shrinkable films often need to undergo corona treatment or add surface modification additives. This method complicates the process and increases production costs.

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