What are the plastic materials?

Classification of plastic raw materials

According to the molecular structure of synthetic resin, plastic raw materials are mainly divided into thermoplastics and thermosetting plastics. For thermoplastics, it refers to plastics that are still plastic after repeated heating: there are mainly common raw materials such as PE/PP/PVC/PS/ABS/PMMA/POM/PC/PA. Thermosetting plastics mainly refer to plastics that are hardened by heating synthetic resins, such as some phenolic plastics and amino plastics, which are not commonly used.

From the perspective of application, there are mainly general plastics such as PE/PP/PVC/PS and engineering plastics such as ABS/POM/PC/PA. In addition, there are some special plastics, such as high temperature, humidity and corrosion resistance, which are modified for special purposes.

Material utilization and color processing

1. Most plastic raw materials can be recycled, but because the recycled plastic (nozzle material) is more brittle than ordinary raw materials, it can only be used with new materials (raw materials), and the maximum proportion cannot exceed 25%, according to customer requirements. Various types of plastic materials should not be confused in production, because their melting points and injection pressures are different.

2. Because plastic products need color matching, plastic raw materials can be divided into: granular materials, toner materials, color seed materials, and recently added liquid for coloring in plastic raw materials. Granulation raw materials are mixed with pigments, and each plastic material is colored, so the color of the product is stable and uniform. Toner materials and color seed materials are used together with color seeds or mixed raw materials, with low cost and no need to store a large amount of color raw materials. However, the color is unstable.

classify

According to thermal properties and processability

Thermoplasticity: it softens when heated, and can be repeatedly heated and molded.

Such as polyvinyl chloride plastic, polypropylene plastic

Thermosetting plastics: after heating and curing, it cannot be heated and melted to form.

Such as phenolic plastics, urea-formaldehyde plastics

Divide by purpose

General purpose plastics: large output

Such as polyethylene, polypropylene, polyvinyl chloride

engineering plastics

Such as polycarbonate, polysulfone, polyphenylene ether, polyamide and polyoxymethylene.

special plastics

Such as medical plastics, conductive plastics, high-temperature resistant plastics, etc.