| 摘要 |
PURPOSE:To save the amount of steam for heating during expansion molding period as well as shorten the time of heating by reducing the discharge amount of drain by adjusting the opening of the drain valve of the molding machine in molding a thermoplastic resin by one-side heat expansion. CONSTITUTION:For example, a steam valve 10 on the cavity side is opened, a steam valve 11 on the core side is closed, a drain valve 12 on the cavity side is closed, a drain valve 13 on the core side is opened, and a small drain valve 19 is opened to start up one-side heating operation. The air in the cavity side steam chamber 1, an expandible thermoplastic resin 5, e.g., expandible styrene, etc., and the core side steam chamber 3 is replaced by steam and drain discharge in the early period is finished. Afterwards, the core side drain valve 13 is closed, only the samll drain valve 19 is opened, the opening of the drain valve is adjusted to reduce the discharge amount of drain, and one-side heating is further made. The adjustment of the opening of the drain valve is preferably made only after the ending of degassing during the one-side heating period. |
