| 摘要 |
PROBLEM TO BE SOLVED: To increase the strength of a jointed part by a method wherein a molten resin is injected and filled upon secondary molding process so that an angle between the injecting and filling direction of the molten resin, injected against an abutted part, and a tangential line at the injecting and filling point of the abutted part becomes smaller than a specific angle. SOLUTION: A molten resin for secondary molding is injected out of an injection machine. The molten resin arrives at a second runner for secondary molding through the spool 2 of a fixed board 1, the second through hole 10 of a valve body 7 for a spool switching device 5, a recessed groove 11, a side opening 12, the second runner 4, a spool 33 for secondary molding and the like. Subsequently, the molten resin is injected out of a gate against a jointing space unit. The injection angle of this time is specified so that an angle between an injecting direction line J and a tangential line of the jointing space unit at an injection point becomes smaller than 90 deg.. According to this secondary molding, primary and secondary semi-blow moldings are integrated. According to this method, a blow molding, whose jointing strength is high, can be obtained. |
