1. parting surface, that is, the contact surface between female die and male die during mould closing. The choice of its position and form is influenced by the product shape and appearance, wall thickness, moulding method, post-processing technology, Stool Mould type and structure, demoulding method and moulding machine structure.
2. Structural parts, i.e. sliding block, inclined top, straight top block of complex mould, etc. The design of structural parts is very critical, which is related to the life, processing cycle, cost and product quality of stool mould. Therefore, the design of complex mould core structure requires designers to have higher comprehensive ability and pursue simpler, more durable and more economical design as much as possible.
3. Die precision, i.e. avoiding sticking, precise positioning, guide posts, positioning pins, etc. The positioning system is related to the appearance quality of products, the quality and service life of stool moulds. Choose different positioning methods according to different die structures. Positioning accuracy control mainly depends on processing. The positioning of the internal mould is mainly designed by the designer, which is more reasonable and easy to adjust.
4. Gating system, that is, the feeding channel from nozzle to cavity of injection moulding machine, including main channel, branch channel, gate and cold cavity. In particular, the location of the gate should be selected so that the molten plastic can fill the mould cavity in a good flowing state. The solid runner and the cold material attached to the product can be easily ejected from the stool mould, and can be removed when the mould is opened (except the runner mould).
5. Plastic shrinkage and various factors affecting the dimensional accuracy of products, such as mould manufacturing and assembly errors, mould wear and so on. In addition, when designing compression mould and injection mould, the matching machine of moulding process and structural parameters should also be considered. Computer aided design technology has been widely used in stool mould design.