| 摘要 |
PURPOSE:To produce high precision, thick wall optical products without shrinkage and internal stress from highly viscous resin such as acrylic resin by cooling rapidly a metallic mold by means of a low temperature medium after injecting resin into the metallic mold that has been kept at high temperature by means of a high temperature heat medium. CONSTITUTION:A high temperature heat medium is supplied to a metallic mold 1 from a heating device 2 via an electromagnetic change-over valve 4A and an electromagnetic proportional flow rate valve 8 to keep the metallic mold at high temperature, and at the same time the high temperature heat medium is recovered to the heating device 2 through an electromagnetic change-over valve 4C. Next, highly viscous resin (for instance, acrylic, polycarbonate) is injected into the metallic mold 1 that is at high temperature, and at the same time the circuit of the high temperature heat medium is closed, and a cooling heat medium is supplied from a cooling device B into the metallic mold 1 through the electromagnetic change-over valve 8 to cool rapidly the metallic mold 1. The flow rate of the heat media is controlled by an electromagnetic change- over valve 8. Because the metallic mold 1 is kept warm for injection, the fluidity of resin is good, and because the resin is cooled rapidly, optical characteristics of the products are excellent. |
