| 摘要 |
PURPOSE: To obtain a product having a buoyancy, a cold resistance and a moisture resistance by mixing a low density polyethylene, a foaming agent and a surfactant, and processing it at a series of different temperatures. CONSTITUTION: A mixture is prepared by mixing a low density polyethylene with an azodicarvone amide as a foaming agent, a zinc oxide as a surfactant, a ZnC as a release agent and a fluorocarbon as a gas foaming agent. The mixture is melted at 170 deg.C at a first stage of a heating tunnel. A melted lump is moved to a second stage held at 200 deg.C. Then, when the lump is cooled to 150 deg.C at a third stage, foam is cured and contracted. A fluorocarbon is introduced, the lump is foamed, lowered to 100 deg.C to a state adapted to cutting. The lump is extruded into an atmosphere at about 25 deg.C, and a sheet having a thickness of about 1 mm is formed via rollers. It is then left to stand for 24 hours at 25 deg.C. Thin garments having a light weight can be provided with the polyethylene product. |
