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.