An injection moulding machine consists of a feed, a backflow valve, an injection nozzle, and injector unit and a double cylinder. The raw material of plastic pellets or granules is fed into the machine via a material tank. The individual particles of plastic rub up against each other, which creates a significant amount of heat. Eventually, the heat created starts to melt the plastic granules, and a plastic “paste” develops. Pressure is then used to blast the molten plastic through the injection nozzle and into the mould. After the plastic has cooled (which takes just a few seconds), the shell of the mould is split in half by the backflowvalve. The finished plastic part is released by the ejector unit and drops into a container ready for checking and retrieval.
Injection moulding machine in use
This process of manufacturing plastic parts and components is now very accurate, but it results in a large amount of waste. An advanced injection moulding machine collects this waste efficiently through product and injection channels are kept separate. The moulds used in an injection moulding machine can operate with either a cold runner system or a hot runner system. The cold runner system involves a simple channel that is carved into the mould. The hot runner system is usually more costly, and it involves the use of cartridge heaters to keep the plastic hot in the runners. Although more expensive to operate, this system reduces waste, as the remaining plastic in a hot runner can be injected into the next part.