PURPOSE: To prevent raw materials from leaking without making use of external parts, by a method wherein after integral foaming of liquid raw materials by casting them through a raw material casting port to be formed by placing a skin end, which is bent inside of a baggy skin in an opening part of the bottom of the skin, between two clip plates made of resin, whose parts of the raw materials casting ports are bent outward, a curved part of the one side clip plate is inverted and the raw material casting port is clogged up by clipping the skin end.
CONSTITUTION: A crevicelike opening part 22 in the bottom of a baggy skin 24 is bent inward without sewing up skin ends 22a, 22b, which are confronted with earch other. Then an insert 28 is inserted through the opening part 22 along with fitting stays 28b, 28b. Continuously, two clip plates 30, 32 made of resin are inserted and they are fitted in each other by confronting them with the outsides of the skin ends 22a, 22b. The central parts of them are made into curved parts 34, 36 which are bent and projected outward. With this construction, parts corresponding to the curved parts 34, 36 are sealed except for a raw material casting port 46 of them, liquid foaming raw materials are case within the baggy skin 24 through a casting funnel and foamed integrally. After foaming and curing, the casting funnel is pulled out, inverted to the other curved part 34 side with elasticity by applying stress to the curved part 36, both the skin ends 22a, 22b are clipped and the raw material casting port 46 is closed.
KOBAYASHI SHINYA