The quality of injection molded products involves product design, plastic materials, mold design and processing quality, selection of injection molding machines and process adjustment.
For normal production molds, it is necessary to ensure and improve the quality of the product, only the adjustment of the injection process; that is, the temperature, pressure flow rate, time and position adjustment.
Process adjustments must be fully integrated. If the size of the product changes greatly, it can be considered from the plastic raw material, whether it is crystalline plastic or amorphous plastic, the molecular weight of the plastic, and so on. It is a crystalline plastic and a macromolecular plastic. The crystallinity and molecular orientation of the product should be considered. The shape of the product changes with the flow during molding, which causes the change and size of the stress in the product, resulting in shrinkage of the product.
Solve the small size change of the product, improve the material temperature, reduce the mold temperature, control the injection volume, reduce the injection pressure, increase the injection speed, instantly fill the mold cavity, reduce the pressure holding time, and extend the cooling time. To ensure the product density when the product is shot. It is achieved to reduce the internal stress of the product, thereby reducing the shrinkage of the product.
In short, the injection process adjustment can not be started from a certain point, must start from the injection process principle. Comprehensive and balanced consideration of issues, can be adjusted from multiple aspects one by one or multiple issues at a time. However, the adjustment method and adjustment principle should be determined by the quality and process conditions of the products produced at that time.
