Mold design and manufacturing are closely related to plastic processing. The success or failure of plastic processing, to a large extent, depends on the mold design effect and mold manufacturing quality, and the plastic mold design is based on the correct plastic product design.
The structural elements to be considered in the design of plastic mould are as follows:
① The parting surface is the contact surface between the punch and the die when the die is closed. The selection of its location and form is affected by the shape and appearance of the product, wall thickness, molding method, post-processing technology, mold type and structure, demoulding method and molding machine structure.
② Structural parts, such as slide block, slant top and straight top block of complex die. The design of structural parts is very important, which is related to the service life, processing cycle, cost and product quality of the mold. Therefore, the design of complex core structure of mold requires high comprehensive ability of the designer, and pursues a simpler, more durable and more economical design scheme as far as possible.
③ The precision of the mould is to avoid jamming, fine positioning, guide pillar, positioning pin, etc. The positioning system is related to the product appearance quality, mold quality and life. According to the mold structure, different positioning methods are selected. 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.
② The gating system is the feeding channel from the nozzle to the cavity of the injection molding machine, including the main channel, the diversion channel, the gate and the cold cavity. In particular, the selection of gate location should be conducive to the molten plastic filling the 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 (except for hot runner mold).
③ The shrinkage of plastics and the factors that affect the dimensional accuracy of products, such as mold manufacturing and assembly errors, mold wear and so on. In addition, the matching of process and structure parameters of molding machine should also be considered in the design of compression mold and injection mold. Computer aided design technology has been widely used in plastic mold design.
