Injection molding machine basic functions:
The injection and molding is achieved by injection molding machine and mold. Although in various types of injection molding machine, no matter which type, it have two functions:
1 heating plastic and make it melt
2 used high pressure on the melt plastic and make it injection the mold cavity
According to the type of plastication, the injection molding machine can divide into following two types:
Plunger Injection molding machines
Screw Injection molding machines
The plunger injection molding machine push the melt plastic forward in the charging barrel through movement of plunger in there, and the spreader through the nozzle injects it into the mould cavity. The plastic in the charging barrel plastication is mainly depended on the heat provided by the external heater of the charging barrel. The poor thermal conductivity of plastic lead to the charging barrel internal and external unbalanced plastication, so the plunger injection molding machine unsuitable for the molding of low fluidity plastic parts, heat sensitivity is strong and amount of injection.
Between the screw injection molding machine and the plunger injection molding machine differentiates from is mainly due to the horizontally-pushed plunger is replaced by a rotary screw it do all the melt, plastication and injection the material in the charging barrel. The screw not only can rotate in the charging barrel but also can moved forward and backward, thus can complete send material compacting, plasticating and transmitting pressure. At present the screw injection molding machine is the highest production quantity and it also the most widely used.
