| 摘要 |
PROBLEM TO BE SOLVED: To prevent securely the generation of residual gas in a molding tool and manufacture a rubber molded product of smooth surface in the case of manufacture of the rubber molded product by expanding a molding material formed of a rubber material containing a foaming agent in the molding tool. SOLUTION: A core bar is inserted into a rubber roll material formed by using a rubber material containing a foaming agent and molded in a molding tool 21, and the core bar is embedded in a flowing layer 29 filled with glass beads 28 and heated uniformly by a heater 30 while air is blow in. A central section 22a of the molding tool is formed to be thin, while both ends 22a and 22b are formed to be thick, and heat is transferred first to the central section of a rubber roll material inside and foaming is started thereon prior to the start of foaming on the end sides, and the foaming of the end sides is carried out successively. The rubber roll material is expanded and the central section is fixed by pressure to a molding tool inner peripheral face, and successively fixed by pressure to the end sides, and gas inside is collected on the end faces and pushed out of gas vent holes. Or else, the central section only can be heated preliminarily. |
