| 摘要 |
PURPOSE:To minimize eccentricity and offset in thickness of a rubber-like plastic which is coated on a tube, by installing a stationary mixing element for mixing a material between a point of a crosshead and a point holder. CONSTITUTION:In a crosshead type extruder with a crosshead 11 having a tilt of 90 degrees or less, a stationary mixing element 16 such as an impeller is installed between a point 17 of the crosshead 11 and a point holder 12. The mixing element 16 has a through hole at its center which passes a core material 14 such as a core wire or a tube. At the outlet of the hole, the point 17 being free of assembling and disassembling is installed. Then a mixture of foaming material 15 such as polyethylene containing a foaming agent is extruded and coated on the core material 14. EFFECT:A high foaming body with its foaming ratio of 3 or more is extruded and coated smoothly with no offset in thickness. |
