In order to design an advanced plastic mold, first of all, we need to have a high level of design ideas, and we must also study the product technology, the characteristics and uses of plastic materials, the selection of mold steel, processing methods, mold structure design, molding scheme and injection machine model.
It is very necessary to study the process of mold design from the perspective of mold design and injection molding. The purpose is to reduce the trouble of mold manufacturing and molding caused by poor mold process.
Plastic properties
Plastic is a kind of material with polymer synthetic resin as the main component, which has plasticity and fluidity under certain temperature and pressure, can be molded into a certain shape, and keep the shape unchanged under certain conditions. Commonly used plastics are divided into thermosetting plastics and thermoplastic plastics. The characteristic of thermosetting plastics is that they can be solidified into insoluble materials under heating or other conditions. The characteristic of thermoplastics is that they can be heated and softened or cooled and solidified repeatedly in a specific temperature range.
Plastics have the advantages of light weight, good strength, corrosion resistance, good insulation, easy coloring, products can be processed into any shape, high production efficiency and low price.
The extensive application of plastic products is inseparable from its own characteristics. The following introduces the composition characteristics of plastics.
(1) Molecular structure of plastics
The main component of plastics is resin, which includes natural resin and synthetic resin.
(2) Composition of plastics
- Resin: Its main function is to bond other components of plastics and determine the main properties of plastics, such as mechanical, physical, electrical and chemical properties. The proportion of resin in plastics is generally 40% ～ 65%.
- Fillers: Also known as additives, the correct choice of fillers can improve the performance of plastics and expand its scope of use.
- Plasticizer: Some resins have little plasticity and poor softness. In order to reduce the melt viscosity and melt temperature of the resin, improve its molding and processing properties, and improve the flexibility, elasticity and other necessary properties of plastics, non-volatile organic compounds with high boiling point which are compatible with the resin are usually added. Such substances are called plasticizers.
- Colorant: Also known as pigment, mainly plays the role of beauty and decoration, including the coating part.
- Stabilizers: The substances that can delay the deterioration of plastics are called stabilizers, light stabilizers, heat stabilizers and antioxidants.
- Lubricants: Improve the fluidity of plastic melt, reduce or avoid friction and adhesion to equipment or mold, and improve the surface finish of plastic parts.
