Injection Molding

Injection molding :

This method is to melt resin and put it in a mold to be shaped.
This is to heat and soften material and insert it into cavity of closed mold, and then harden the material to make shaped product. It’s to use for mass production of complicated shaped products, and this is one of the major methods along with extrusion molding.

The material for injection molding is mainly thermoplastic resin, however almost all materials such as heat cementation resin, rubber, and forming mold material are also used. Variety of molders and structure of molder are being developed in consideration of raw materials, form of products, productivity.

Indicates the stage when molder is closed and emission is completed, and when material is hardened and product is completed after molder is open. A mold is generally cooled off with water and automatically released by structure. Molding has a cycle of ①shape, ②emission, ③adding pressure, and it includes preventing countercurrent in cavity and releasing by refrigeration.

Inline screw type molder is a standard type, and screw retreats by softening of material and screw moves forward for ejection. This type of molder is used to mold for heat hardening resin. Comparing to heat hardening resin, it has a difference in process that lower the temperature of the heating cylinder after heating up the molder to harden resin to prevent resin becoming hardened, andaccordingly heating method of cylinder or shape of screw could be different from each other.