| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for manufacturing a foamed molding good in appearance quality which prevents the occurrence of an annular mark around a gate. SOLUTION: In the method for manufacturing the foamed molding, injection from a molding machine into a mold is started by a signal from a valve gate for opening/closing a communication opening between a hot runner and a cavity. The cavity is composed of a main cavity 1 for a molding and a sacrifice cavity 2. The valve gates 3 and 4 are formed separately in the communication opening between the cavities 1 and 2 and the hot runner 7. First, the valve gate 4 of the cavity 2 is opened, and the injection of a resin from the molding machine is started. After the packing of the resin in the cavity 2 is started, the valve gate 3 of the cavity 1 is opened, and the resin is packed in the cavity 1 to mold the molding. COPYRIGHT: (C)2003,JPO |
