Preparation method of co-extruded plastic films different in melting point and special die head

Abstract

A preparation method of co-extruded plastic films different in melting point is characterized in that a die head is layered to form a plurality of sub-die heads, each sub-die head is provided with a heating rod and a temperature control system according to sequentially arrangement of forming films, and different materials are identical in temperature when entering a driving cooling roller and a driven cooling roller by cooling high-melting-point materials. Therefore, the special die head for co-extruded films made from different melting points of materials is designed, and heat insulation layers are arranged among sub-die head layers different in temperature. The overall change of an existing device is small, separated control is conducted on the heating temperatures of the different materials by creatively adopting the design of the sub-die heads, and meanwhile the high-melting-point materials are cooled, so that the different materials are identical in temperature when entering the driving cooling roller and the driven cooling roller for extrusion, the adverse influence of high-temperature materials on low-temperature materials is eliminated, accordingly shape stability is ensured, and product quality is improved.

Description

technical field [0001] The invention belongs to the manufacture of films, and in particular relates to a die head for making co-extruded films. Background technique [0002] All layers of the co-extruded film are extruded together at the same time, and the layers are bonded by hot melt, so they have good tensile properties and good surface brightness, which are in line with many of the adhesive films, food films and advanced packaging films. This standard is now widely used. like figure 1 As shown, it is a schematic diagram of the production and molding of a three-layer co-extruded film. There is a heating rod 12 in the die head 1, and the die head is heated, so that the plastic in the die lip is extruded from the die lip 11 in a molten state, and is actively cooled by the lower part. The roller 5 and the driven rubber roller 2 (the active cooling roller and the driven rubber roller are a pair of squeeze rollers) are compacted and formed, and the co-extruded film 6 is woun...

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to overcome the defect that the shape of low-temperature materials affected by high temperature is unstable and affect product quality in the co-extrusion process of existing materials with different melting points, and to provide a stable and high-quality co-extruded plastic film with different melting points.

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