Author: MULAN –Plastic Molding Manufacturer
Gas-assisted molding means that during the injection molding process, part of the plasticized melt is injected into the cavity of the injection mold, and then air with a certain pressure (usually nitrogen) is input into the cavity of the injection mold through the set air pipe hole inside the melt body. Gas-assisted molding is a rapidly developing new plastic molding technology. What are the advantages of gas-assisted molding and ordinary injection molding? 1. The production cycle of gas-assisted molding is short.
Due to the small amount of molten material used for product molding, the injection time and product cooling time are shortened a lot. 2. The clamping force is small. Gas-assisted molding mainly uses air pressure to inflate the molten material, so that the clamping force can be greatly reduced when the injection molding machine is processing, and the mold manufacturing cost is reduced.
3. Adjust the pressure of air blowing to get products with different wall thickness. The molten material is inflated, and the air pressure is evenly distributed, which can well form plastic products with complex shapes, which ensures the quality of the products and reduces the stress concentration. 4. The gas injection time and gas injection pressure should be strictly controlled according to the characteristics of the material used for product molding, the complexity of the cavity structure, and the temperature conditions of the melt and the mold.
If the aerosol is poured too early and the outer layer is not cooled, the air pressure will easily cause the inflated melt to infiltrate. If the aerosol is poured too late, it will be cooled and solidified, and it will not be easy to inflate the melt. The blowing of pressure gas should be high first and then low. Greater air pressure can force the blown melt against the inner wall of the cavity.
After the movement is completed, the air pressure can be reduced to avoid internal stress. When controlling the mold temperature, the cooling rate of the molten material should be conducive to gas inflation forming. 5. For gas-assisted molding, add a set of gas supply device and inflation nozzle.
There are strict requirements on the gas injection conditions. 6. The surface of the gas-assisted molding product should be decorated with patterns to cover up the defects of the surface of the product.