A kind of preparation method of formamide-free ixpe foam

Abstract

The invention relates to a preparation method of a formamide-free IXPE (irradiation crosslinked polyethylene) foam. The foam comprises a main material of low-density polyethylene and auxiliary materials including ethylene-vinyl acetate copolymer and an azodicarbonamide foaming agent, and is prepared through the following steps of: raw material preparation, mixing granulation, extrusion molding, radiation crosslinking and gas-fired horizontal furnace foaming, wherein during heating and foaming, a certain amount of sodium bicarbonate, zinc oxide or zinc stearate, a main antioxidant and an auxiliary antioxidant are added. A product prepared by the preparation method is more environmentally-friendly, can meet requirements of European Union, can be used for reducing the residual quantity of the foaming agent, improving the melt strength of the polyethylene foam in a foaming furnace body and reducing rupturing and crushing phenomena, and is more excellent in temperature resistance and aging resistance and lower in energy consumption.

Description

technical field [0001] The invention belongs to the technical field of materials, and in particular relates to a preparation method of formamide-free electron radiation cross-linked polyethylene foam. Background technique [0002] Electron radiation cross-linked polyethylene foam (IXPE) material is made of low-density polyethylene (LDPE) as the main raw material, foaming agent azodicarbonamide (AC) and other chemical raw materials, which are mixed, granulated, extruded It is a high-temperature foamed high-molecular foam material that is processed, radiated cross-linked, and foamed. It has a smooth surface, closed cells, fine and uniform, non-absorbent, environmentally friendly, and has good mechanical properties and superior insulation. Thermal and sound insulation properties, easy secondary processing, and flexible foam plastics that can give it good flame retardancy are widely used in automotive interiors, sports and leisure, travel products, children's toys, medical care ...

AI Technical Summary

Problems solved by technology

[0004] Yet this electronic radiation cross-linked polyethylene foam formula and preparation method, can produce formamide and dimethylformamide because of conventional AC foaming agent in the decomposition process; Because AC foaming agent is azodicarbonamide, conventional The AC foaming agent is incompletely decomposed and will remain in the foam product; the IXPE sheet adopts pneumatic heat transfer in the foaming furnace, the temperature is high and the energy consumption is high; the foaming temperature of the IXPE sheet in the foaming furnace is high, resulting in The thermal stability of the product is reduced; IXPE sheets are prone to breakage during the foaming process due to high temperature and poor mechanical properties in the foaming furnace, resulting in large losses and many waste products