Mold design and manufacturing are closely related to plastic processing. The success or failure of plastic processing largely depends on the effectiveness of mold design and the quality of mold manufacturing, and plastic mold design is based on the correct design of plastic products.

The structural elements to consider in plastic mold design include:

① The parting surface refers to the contact surface between the concave and convex molds when the mold is closed. The selection of its position and form is influenced by factors such as product shape and appearance, wall thickness, forming method, post processing technology, mold type and structure, demolding method, and forming machine structure.

② Structural components, such as sliding blocks, inclined roofs, straight top blocks, etc. of complex molds. The design of structural components is crucial, as it relates to the lifespan, processing cycle, cost, product quality, etc. of the mold. Therefore, designing a complex core structure of the mold requires a high level of comprehensive ability from the designer, striving for a simpler, more durable, and more economical design solution as much as possible.

③ Mold accuracy, including card avoidance, precise positioning, guide pillars, positioning pins, etc. The positioning system is related to the appearance quality of the product, the quality and service life of the mold. Different positioning methods are selected according to the different mold structures. The positioning accuracy control mainly relies on processing, and the internal mold positioning is mainly considered by the designer to design a more reasonable and easy to adjust positioning method.

② The pouring system refers to the feeding channel from the injection molding machine nozzle to the mold cavity, including the main flow channel, diversion channel, gate, and cold material cavity. Especially, the selection of the gate position should be conducive to the molten plastic filling the mold cavity in a good flow state, and the solid runner and gate cold material attached to the product are easy to be ejected from the mold and removed during mold opening (excluding hot runner molds).

③ Plastic shrinkage rate and various factors that affect the dimensional accuracy of products, such as mold manufacturing and assembly errors, mold wear, etc. In addition, when designing compression and injection molds, consideration should also be given to the matching of the process and structural parameters of the molding machine. Computer aided design technology has been widely used in plastic mold design.