| 摘要 |
<p>PURPOSE:To mold a locking part having an undercut portion without thickness of the undercut portion being especially thinner than other portions by molding a locking part body first and then molding an undercut recess of the locking part at a protrusion protruding from a side rim of the body. CONSTITUTION:A parison is placed between separate metal molds 6, 7 to perform preliminary blowing to mold a depressed part 9a of a locking part 1. Then while the parison can be still, plasticized, respective slide molds 10a, 10b are advanced to make each protrusion 12 protrude from sides of an inner mold 9 and perform final blowing. Thus undercut recesses 4a, 4b are molded at a rim of the depressed part. Thus thickness of the undercut parts may not be especially thinner than other parts, as well as by sliding the slid mold in a depth direction of the recess, molding of the locking part having the undercut parts can be easily done.</p> |
