The mold design for bottle cap should be based on the shape, precision, size, process requirements and production batch. The mold design should consider the following aspects:
A cavity number and arrangement: As a packaging container for mass production, it is advisable to adopt multiple cavities of one mold. Considering the clamping force and injection amount of the existing injection molding machine, as well as the precision and economic factors of the bottle cap, it is determined to be 1 mold and 10 cavities, and the arrangement mode of the cavities is "one shape".
B Gating system design: According to the structure of the plastic parts, the mold is designed into three plates and USES a point gate. The gate is set in the central position of the top of the plastic parts. The point gate can significantly improve the melt shear rate and greatly reduce the melt viscosity, which is conducive to mold filling, especially effective for the PE melt sensitive to shear rate. And plastic as a packaging container, the appearance of high quality requirements, small point gate residual traces, to ensure the surface quality of plastic parts, stripping at the gate automatically break, easy to realize the automation of the product production process, improve production efficiency, increase economic benefits. Unbalanced casting system is adopted to compact the mold cavity and reduce the mold size. In order to make each mold cavity fill evenly at the same time, the method is adopted to manually modify the gate size of each mold cavity to achieve balance. Use cold hole to store forward cold material.
C cooling system design: The mold temperature regulation system of cap mold directly affects the product quality and production efficiency. In order to improve the cooling efficiency of the cavity, a cooling loop is adopted. The inlet of one loop is located near the outlet of the other loop. According to the mold shape and mold structure restrictions, the diameter of the fixed mold cooling channel is 12mm, which is connected with the mold external hose to form circular cooling. The diameter of the moving model core is relatively small, and the steel pipe is used for cooling. The soft copper core rod with good thermal conductivity is pressed into the center of the core, and one end of the core rod is extended into the cooling water hole for cooling.