| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem that releasing of a sprue from a sprue bush becomes impossible due to insufficient filling in an undercut part of the sprue when molding of a disc board is started similarly to normal molding so that the sprue is retained in the bush, and when the retained sprue is removed, there is a riskiness of damaging the mold, much working time is required and starting-up of molding is hindered. SOLUTION: A method for molding the disc board comprises the steps of taking out the sprue integrally with the disc board without forming a central opening of the disc in a mold while a prescribed molding cycle at a mold starting time of the board. |
