According to the characteristics of gas-assisted injection molding, gas-assisted injection molding can be realized by adding a set of gas supply device to the existing injection machine. According to the use abroad, gas-assisted injection molding can be divided into standard molding method, melt reflow molding method and movable core withdrawal method.
The principle of gas-assisted injection molding is relatively simple. In the process of injection filling, the gas with lower pressure than the injection pressure is injected into the melt, usually several to dozens of megapascals, and the pressure of the gas is used to realize pressure maintaining and feeding. The principle of gas-assisted injection molding. The principle of gas-assisted injection molding is that the gas enters from the inside of the plastic melt. When molding, the accurately measured melt is injected into the mold cavity first, and then the gas is injected into the melt through a special nozzle. The gas diffusion pushes the melt to fill the mold cavity. After mold filling, the pressure of the gas in the melt remains unchanged or rises to maintain pressure and replenish the material. After cooling, the gas in the plastic part can be removed. The pressure forming method of gas on the surface of plastic melt is also called surface gas forming method. This method is a method of injecting high-pressure gas into the special closed part of the bottom surface of the plastic injection molding products in the mold to make the surface of the injection molding products free of shrinkage marks.