| 摘要 |
PURPOSE:To manufacture special shape rubber molded product without generating discoloration, by removing an unnecessary thin part by performing extrusion molding of an unvulcanized special shape premolding having unnecessary thin parts on both ends through a crosshead. CONSTITUTION:A colored compound and a synthetic rubber material are supplied within a cylinder 7 and the synthetic rubber material with which the colored compound has been mixed is fed within a head body 2 of a crosshead 1 under a molten state by driving the same by turning a screw 3 while heating the same. The synthetic resin material is extruded continuously through a die hole 6a of a die 6 and thin part molding holes 6a, 6b and an unvulcanized special shape premolding 10 on both ends of which unnecessary thin parts 10a, 10a are molded unitarily is obtained. Extrusion molding of the synthetic rubber material is performed by extruding the same through the die hole 6a by the die 6 while flowing bidirectionally by facing toward the thin part molding holes 6a, 6b on the ends of the special shape premolding 10. Therefore, discoloration is not generated on the unvulcanized special shape premolding 10 along a longitudinal direction of the same, but generated on each end of the unnecessary thin parts 10a, 10a. The unnecessary thin parts 10a, 10a are removed through cutting off and made into a product by performing press molding and vulcanization in the next process. |
