Continuous extrusion production line for PET foamed sheet

Abstract

The invention discloses a continuous extrusion production line for a PET foamed sheet. The production line comprises an automatic feeding mechanism, a solid additive side feeding system, a multi-pathphysical foaming agent filling system, a drying-free system, a multi-stage melt pressurization system, a melt homogenizing system and distributed outputting and converged forming molds. Materials aresubjected to double-step mixing extrusion by a double-screw extruder and a single-screw extruder and are connected with a melt cooling system. A foamed sheet produced by the combined system enters a cooling forming system, and the cooling forming system comprises a multi-roller cooling flattening system, a cooling carrier roller system, an auxiliary traction system, a side edge shaping and transverse cutting system, a multi-stage cooling overturning frame and a double-face shaping system with grinding and planing functions. The production line has the technical effects that PET raw materials can directly enter an extrusion system without drying treatment, the viscosity of the materials is not reduced, the vacuum degree is adjustable, the melt cooling rate is easy to control, different types of physical foaming agents can be adopted, the addition amount is accurately controlled, and the foamed sheets with different densities are produced.

Description

Technical field[0001]The invention relates to the field of foamed board production, in particular to a continuous extrusion production line for PET foamed board.Background technique[0002]PET sheet has excellent air tightness, durability and chemical resistance; good transparency, will not produce any toxic gas when burned, has high environmental protection, and meets the US Food and Drug Administration (FDA) and Japan's Ministry of Health and Welfare Food Sanitation The legal standard has become the safest material for food; it can be used for various processing, display or display, vacuum forming and other purposes. As a packaging material, PET has the following advantages: good mechanical properties, high tensile strength and impact strength, good folding resistance; good barrier properties, resistance to oil, fat, dilute acid, dilute alkali, and most solvents; Excellent resistance to high and low temperature performance, can be used for a long time in the temperature range of -40...

AI Technical Summary

Problems solved by technology

[0003] However, in the existing PET sheet production line, the PET sheet is usually cut and packed after extrusion molding, so that the cooling time of the PET sheet is too short, and the contact area with the air is concentrated on the upper surface of the PET sheet. Therefore, the cooling effect is poor, which will lead to a decrease in the final molding quality of the PET sheet

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