1. Control of material temperature and mold temperature. Different brands of plastics must have different temperature requirements. Poor fluidity of plastic materials and the use of two or more mixtures will happen differently. It is usually easy to control plastic materials within the optimal flow value range, but the control of mold temperature is more complicated. Different shapes, sizes and wall thickness ratios of molded parts have different effects on cooling. The mold temperature controls the cooling time to a great extent, so try to keep the mold at an allowable low temperature to shorten the injection cycle and improve the production efficiency. If the mold temperature changes, the shrinkage rate will also change, the mold temperature will remain stable, and the dimensional accuracy will also be stable, thus preventing the deformation, poor gloss, cooling spots and other defects of the molded parts, and making the physical properties of plastics in the best state. Of course, there is still a debugging process, especially the molded parts with multiple cavities are more complicated.

2. Adjustment and control of pressure and exhaust:

Proper injection pressure and matching of clamping force should be determined when debugging the mold. The air in the gap between the mold cavity and the core and the gas generated by plastic must be exhausted from the exhaust slot. If the exhaust is not smooth, there will be insufficient filling, weld marks or burns. These three forming defects sometimes appear in the same place. When there is a thick wall around the thin wall part of the molded part, When the mold temperature is too low, there will be insufficient filling, and when the mold temperature is too high, there will be burn. Usually, there will be weld marks at the burn site at the same time, and the vent groove will often be ignored and generally in a small state. Therefore, as long as there is no burr, the depth of the vent shoulder should be as deep as possible, and a larger vent groove should be opened at the back of the shoulder so that the gas passing through the shoulder can be quickly discharged from the mold. If necessary, the vent groove should be opened on the ejector pin. The reason is the same.

3. Supplementary shaping control of injection molded parts:

Some plastic parts will be deformed and warped under different conditions due to different shapes and sizes with the change of temperature and pressure loss after demoulding. At this time, some auxiliary fixtures can be used to adjust, and remedial measures can be taken promptly after the molded parts are taken out of the mold, and good correction and adjustment effects can be achieved after they are naturally cooled and set. If strict management is ensured in the whole injection process, the size of injection molded parts will be controlled very ideally.