Gas assisted plastic model

The gas auxiliary device is composed of a standard nitrogen generator, a control unit and a nitrogen recovery unit. A nitrogen generator provides the nitrogen required for injection. There are two types of inlet nozzles for inlet nozzles. One is the mainstream nozzle, that is, one nozzle of plastic melt and gas. After the injection of plastic melt is finished, the nozzle is switched to the gas passage to realize gas injection; the other is gas. The special nozzle for the passage is divided into two types: embedded and flat.

At present, several injection molding machine manufacturers in Europe can produce gas-assisted molding units. Among them, Germany BATTENFELD has mature technology and has a separate system called AIRMOULD.

The required injection pressure is small. Since the flow rate of the plastic melt is proportional to the value of the pressure gradient and the fluidity of the melt, the inlet pressure should be increased to maintain a certain value when the flow length of the melt increases and the flow rate is required to be constant. Gradient, which is why the inlet pressure is increasing in normal injection molding. In gas-assisted molding, when the gas pushes the melt forward, the gas is required to penetrate the melt, and the distance from the gas front to the melt front is shortened, that is, the effective flow length is shortened, so the gas required to maintain a certain pressure gradient is maintained. The frontal pressure is reduced.

As the required injection pressure is reduced, the required clamping force is also reduced, which greatly reduces the requirements on the tonnage of the injection molding machine and the wall thickness of the mold.