| 摘要 |
PURPOSE:To improve the rigidity of a foam insulator in the lengthy direction and the perpendicular direction by suppressing the growth of bubbles in the lengthy direction of an insulated electric wire and growing them in the outer periphery direction of the insulated electric wire. CONSTITUTION:In an extruding device, an extruding machine 1 of plastic not containing a foaming agent and an extruding machine 2 of plastic containing the foaming agent are connected by a cross head 3, the cross head 3 is mainly constituted of a cartridge 4, a nipple 5, a die 6, an out die 7, and a die holder 8. A non-foam plastic layer is continuously provided in the lengthy direction with it, the dropping force of a foam plastic layer is mitigated, the foam growth in the lengthy direction is suppressed. In this case, the non-foam plastic layer is provided not to cover the whole outer periphery of the foam plastic layer, thus the foam growth in the outer periphery direction is not suppressed. The rigidity in the lengthy direction and the perpendicular direction can be improved. |
