Gas-assisted injection (injection) moulding, also known as gas injection moulding process, is a new injection moulding process . It is one of the most important developments in the injection moulding industry since the advent of reciprocating screw injection machines.

Gas-assisted injection moulding process is an extension of injection moulding,unlike 2 shot moulding process. It is developed on the basis of injection moulding technology and structural foam injection moulding. it can also be considered as a composite of injection moulding and hollow moulding. In this sense, it can also be called "Hollow injection moulding". The principle is to replace the resin pressure in the cavity with a relatively low-pressure gas during the pressure holding phase of the original injection moulding.

Gas-assisted injection, unlike unscrewing mould mechanism, can be achieved by simply adding an air supply device to the existing injection moulding machine. The gas supply device is composed of an air pump, a high-pressure gas generating device, a gas control device, and a gas nozzle. The gas control device uses a special compressor to continuously supply gas, and is controlled by an electronic control valve to keep the pressure constant. There are usually 3 levels of pressure. A set of gas control device can be equipped with multiple injection moulding machines.To achieve this, whole gas injectino moulding process required closely connections.

The gas generally used is nitrogen. Gas pressure and gas purity are determined by the shape of the moulding material and product. The pressure is generally 5 ~ 32MPa, the highest is 40MPa.

Gas Assist Injection moulding Cases