The main problems that need to be paid attention to in the design of plastic molds are as following:

Number and arrangement of cavities, when the design of plastic parts is completed and the materials used are selected, it is necessary to consider whether to use single cavity molds or multi-cavities molds.

The number of cavities should be determined: first, batch and delivery cycle of plastic parts. Secondly, quality control requirements. Thirdly, shapes and dimensions of molded plastics and plastic parts. Fourth, cost of plastic parts. Fifth, cavity layout.

The selection of the parting surface, the parting surface should be selected at the maximum contour of the plastic part; determining the favorable retention mode to facilitate the smooth release of the plastic part; ensuring the precision requirements of the part; meetting the appearance requirements of the plastic part; facilitating the mold manufacturing ; Conduciving to improve the exhaust effect; Conduciving to lateral core pulling.

The design of the gating system and the drainage system is generally composed of four parts: the main flow channel, the runner, the gate and the cold material hole. The design of the gating system is reasonable, not only have a great influence for the performance of the plastic part, structure, size, internal and external quality, etc, and also the utilization rate of plastics used in plastic parts. Molding production efficiency and other related, excretion system is mainly to eliminate the air and plastic in the cavity from the heat or solidification of low molecular volatile gases, usually there are four ways: Use the clearance gap exhaust; Open the exhaust groove on the parting surface; Exhaust with the exhaust plug; Mandatory exhaust.