The injection molding process was invented in 1872. Since then, the injection molding business and the plastic industry has ballooned into a multi billion dollar business venture. In fact, thirty two percent of plastics by weight are processed through injection molding. Injection molding has greatly helped in making the US economy boom because through it, cheap and durable consumer and industrial items essential to almost all industries is made possible.

 

Components of the injection molding machine

 

The injection molding machine converts granular or pelleted raw plastic into final molded parts through the use of a melt, inject, pack and cool cycle for thermoplastics.

 

A basic injection molding machine is typically composed of the following: injection system, hydraulic system, mold system, clamping system and control system. The clamping tonnage and shot size are both used in identifying the dimensions of the injection molding machine for thermoplastics, which is the main factor in the whole process. Other consideration include rate of injection, pressure, design of screw, thickness of the mold and distance between tie bars.

 

Functions of the machine

 

The injection molding machine can be classified into three categories, namely: general purpose machines, precision/tight-tolerance machines and high-speed thin-wall machines. All three types require auxiliary equipment to function. These support equipment includes dryers (resin), material handling equipment, granulators, mold temperature controllers and chillers, part-handling equipment and part-removal robots.