- Thermoplastic plastics: refers to plastics that can be repeatedly softened and flowed when heated, and can be solidified and formed when cooled. Thermoplastic plastics have the advantages of good processing performance, high recyclability, and low cost, but they also have disadvantages such as poor heat resistance, easy deformation, and easy aging. Commonly used thermoplastic plastics include polyethylene (PE), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), polyamide (PA), polycarbonate (PC), polyethylene terephthalate (PET), etc.

- Thermosetting plastics: refers to plastics that can undergo irreversible chemical cross-linking reactions when heated, but will not soften or flow when cooled. Thermosetting plastics have advantages such as good heat resistance, dimensional stability, and high strength, but also have disadvantages such as poor processing performance, non-recyclability, and high cost. Commonly used thermosetting plastics include phenolic resin (PF), urea-formaldehyde resin (UF), epoxy resin (EP), unsaturated polyester resin (UP), etc.

- Elastomers: refers to plastics with high elasticity and reversible deformation at room temperature. Elastomers have advantages such as good softness, good resilience, and good low temperature resistance, but also have disadvantages such as poor oil resistance and poor high temperature resistance. Commonly used elastomers include natural rubber (NR), styrene-butadiene rubber (SBR), chloroprene rubber (CR), silicone rubber (SI), amino rubber (NBR), etc.

- Engineering plastics: refers to plastics with excellent comprehensive properties that can replace metals or other traditional materials and are used under harsh conditions such as high temperature, high pressure, and high strength. Engineering plastics have advantages such as light weight, high strength, corrosion resistance, and good insulation, but they also have disadvantages such as high cost and difficulty in processing. Commonly used engineering plastics include polyimide (PI), polyphenylene sulfide (PPS), polyetheretherketone (PEEK)