Preparation and application of open-cell foamed polyolefin

Abstract

The invention relates to a preparation method of open-cell foamed polyolefin. The preparation method comprises the following steps of: mixing the polyolefin with nucleating agent master batch prepared by same olefin type polyolefin granules, a nucleating agent, a foaming-assisting anti-shrinking agent and an antioxidant, putting the obtained mixture into a single-screw or double-screw extruder with the length-diameter ratio of 20-50 for heating, plasticizing and melting, injecting high-pressure gas, fully melting, mixing and extruding out the high-pressure gas and the polyolefin, releasing, expanding, foaming when extruding the obtained mixture out of a mold at an outlet mold of the extruder so as to prepare open-cell foaming products with various shapes. The open-cell foamed products are used as adsorption substrates and adsorption carriers, and can also be used as sound-insulating, sound-absorbing, and heat-insulating materials. According to the strength and visco-elasticity of the polyolefin melt, the invention selects an appropriate position to inject the high-pressure gas, and adjusts the structure of the screw, gas pressure and gas quantity, and the heating temperature so as to lead the polyolefin to be fully foamed and cells to be opened thereon when the materials are extruded out of the outlet mold of the extruder, therefore, the gas among the cells is mutually communicated, thus having relatively high adsorption capacity, overcoming the shortage of difficult cell-opening in the existing polyolefin foaming technology and causing the polyolefin application to be more diversified and practical.

Description

technical field [0001] The invention relates to the preparation and practical application of open-cell foamed polyolefin plastics, in particular to the preparation method and application field of polyolefin open-cell foamed pellets, plates, pipes and foams of various shapes. Background technique [0002] The production technology of closed-cell polyolefin foam is relatively mature, and its application range is quite extensive. However, because the pores of closed-cell foamed polyolefin are not connected in series, the adsorption performance is very poor, so its application is limited. Although there is a great demand for open-cell foamed polyolefin, its open-cell foam technology has certain difficulties in foaming process and formula design, especially in the foaming process, to achieve a high foam body. The opening rate of the foam, screw structure, mold shape, processing temperature, injected gas volume, and gas injection pressure all have a very important influence on th...

AI Technical Summary

Problems solved by technology

However, because the pores of closed-cell foamed polyolefin are not connected in series, the adsorption performance is very poor, so its application is limited.

Although there is a great demand for open-cell foamed polyolefin, its open-cell foam technology has certain difficulties in foaming process and formula design, especially in the foaming process, to achieve a high foam body. The opening ratio of the foam, screw structure, mold shape, processing temperature, injection gas volume, and gas injection pressure all have a very important influence on the opening ratio of the foam, which is technically difficult.