| 摘要 |
PURPOSE:To prevent the lowering of the degree of crosslinking of a plastic material on extrusion molding and the generation of micro-voids due to oxygen in air by sealing an N2 gas to a supply section for the plastic material in an extruder. CONSTITUTION:A supply section (a hopper 2 and a screw section in an extruder 1) for a plastic material in the extruder 1 is formed into an airtight structure. Air in the supply section is replaced with N2 gas before staring of extrusion, and the state in which the N2 gas is sealed is brought. Air is not mixed into the molten plastic material, and the extruding crosslinking molding of an insulator in an electric wire-cable, crosslinking efficiency of which is hardly lowered and in which there are few micro-voids, or these connecting sections is attained. |
