The design points of the injection plastic molding

- 2021-10-29-

1. Parting surface(injection plastic molding), that is, the contact surface between the female die and the male die when the die is closed. The selection of its position and form is affected by product shape and appearance, wall thickness, forming method, post-processing technology, mold type and structure, demoulding method and molding machine structure.

2. Structural parts(injection plastic molding), i.e. sliding block, inclined top, straight top block, etc. of complex die. The design of structural parts is very key, which is related to the service life, processing cycle, cost and product quality of the die. Therefore, the design of complex die core structure requires higher comprehensive ability of the designer, and pursues a simpler, more durable and more economical design scheme as far as possible.

3. Die accuracy, i.e. card avoidance, fine positioning, guide post, positioning pin, etc. The positioning system is related to the appearance quality of products, mold quality and service life. Different positioning modes are selected according to different mold structures. The positioning accuracy control mainly depends on processing. The internal mold positioning is mainly considered by the designer to design a more reasonable and easy to adjust positioning mode.

4.The gating system, that is, the feeding channel from the nozzle of the injection molding machine to the mold cavity, includes the main flow channel, shunt channel, gate and cold material cavity. In particular, the selection of gate position shall be conducive to the filling of the mold cavity with molten plastic under good flow state, and the solid runner and gate cold material attached to the product shall be easy to be ejected from the mold and removed during mold opening (except hot runner mold).

5. Plastic shrinkage and various factors affecting the dimensional accuracy of products, such as mold manufacturing and assembly error, mold wear and so on. In addition, the matching of process and structural parameters of the molding machine should also be considered when designing the compression mold and injection mold. Computer aided design technology has been widely used in plastic mold design.