Three-layer co-extrusion blown film die for producing tpu film

Abstract

A three-layer co-extrusion blown film die for producing TPU film, comprising four layers of concentric sleeves nested inside and outside, the four layers of concentric sleeves are from outside to inside an outer layer concentric sleeve, a secondary outer layer concentric sleeve, a secondary inner layer concentric sleeve and an inner layer concentric sleeve, each concentric sleeve is in the shape of a ring, a radial gap is left between the outer layer concentric sleeve and the secondary outer layer concentric sleeve to form an outer annular flow channel for the flow of outer layer TPU material, a radial gap is left between the secondary outer layer concentric sleeve and the secondary inner layer concentric sleeve to form a middle annular flow channel for the flow of PE material, and a radial gap is left between the secondary inner layer concentric sleeve and the inner layer concentric sleeve to form an inner annular flow channel for the flow of inner layer TPU material; a plurality of vertically extending first vertical grooves are formed on the inner circumferential surface of the upper part of the secondary outer layer concentric sleeve, and a plurality of vertically extending second vertical grooves are formed on the outer circumferential surface of the upper part of the secondary inner layer concentric sleeve. The TPU film layer produced by the die is easy to peel off from the PE film layer.

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