in manufacturing methods, including minimal losses from scrap (since scrap pieces can be melted and recycled), and minimal finishing requirements. Injection moulding machine are usually different from metal die casting, in that molten metals can simply be poured, and plastic resins must be injected with force It is most common used method for mass production of plastic articles. In pneumatically operated plastic injection machine two pneumatic cylinders are usually used: One for injection of plastic, and the other for automatic opening of the die. The finished product has a very high temperature, so automatic die opening mechanism is required. The advantage of this machine is to increase the productivity as compared to manual machine, space required is less as compared to other machine, there is no problem of oil leakage and fire hazards and the cost is very less as compared to hydraulic machine. In manual machine there is a problem of automatic removal of product. This problem is solved in pneumatic machine by using pneumatic cylinder.