One, gas-assisted molding requires a control system to control the nitrogen gas from the gas source to the mold. To complete the filling of the plastic. 2. Gas discharge: All the gas needed in the whole process must be discharged before the mold is opened. Nitrogen can come from nitrogen cylinders or storage tanks. Next, I will introduce its equipment and molding process. However, the cost of filling and transportation of the cylinders is relatively high. The system is generally composed of 4 parts: Pressure generator: The pressure generator is the central device of gas supply, which is connected to the injection machine through the high-pressure hose and the high-pressure gas continuously produced by the compressor. If the pressure gas is not discharged in time, the plastic part will swell or even burst. Gas injection: Gas injection can be injected through the injection molding machine nozzle, or it can be injected from other single or multiple places in the mold. The nozzle of the injection molding machine is generally equipped with a check valve to prevent gas from entering the barrel or molten glue back to the barrel. The independent system can be used independently, and can be plug and play with any kind of injection molding machine.. Resin filling mold: part or all of the mold is filled with melt, and the fully filled mold must have an overflow device. Gas pressure keeping: Due to the joint action of melt and gas, after the mold is filled, nitrogen stays in the gas flow channel of the plastic part. This system is usually a relatively independent unit, which is located very close to the injection molding machine. Gas pressure control: This pressure control system can be controlled by the injection molding machine control system or by an external independent system. Therefore, the pressure control can be used as a fixed control part of an injection molding machine or as a mobile control part in multiple machines. When a large amount of nitrogen is required, the general Gas-assisted molding adds a set of independent nitrogen generator, which can not be restricted by external supply, and can produce nitrogen at low cost. It has enough pressure to compact the plastic part and eliminate the sink marks on the surface of the plastic part. The key components of the control system get signals from the injection molding machine and can provide necessary energy, water and compressed gas. Nitrogen generator: The gas used in general gas-assisted molding is nitrogen with a purity of about 98%.In the previous article, I introduced the advantages and disadvantages of gas-assisted injection molding. Gas-assisted injection molding process: gas filling: gas is injected into the hot melt according to requirements, the gas flows rapidly in the high temperature and low pressure area, and the pressure gas is used to replace the hot melt material at the thick section of the plastic part. Inject from the air passage on the mold requires a gas injection assembly. The system control device is connected to the high speed injection molding process injection molding machine, but they both operate independently
