Injection molding machine has induction heating at mold surface, to raise its surface layer temperature directly before injection of molten plastics

摘要

Injection molding machine, to mold workpieces of thermoplastic materials, has a cooling channel at the mold to take a coolant flow preferably of water. The molten plastics is injected into the mold, which has a surface layer of an induction heating material where the injected plastics strike it. The layer, which can be heated by induction, covers the whole mold surface, or is at discrete zones. An electrical inductor raises the mold surface temperature, so that a thin surface layer is heated directly before the arrival of the molten plastics to a level close to or at the plastics melting point. The inductor is an alternating current coil in a serpentine, circular or spiral structure.