Plastics material classification

Normally there is 3 types material for different use.

1. General-purpose thermoplastics: 

General plastic material includes various major plastics such as ABS, PC, PP, PVC PS, and PE. 

These can be further subdivided into multiple varieties, for example, PP includes homopolymers and copolymers; PVC includes rigid plasticized varieties; PS is divided into general-purpose and toughened grades, referred to as TPS or HIPS; PE includes LDPE, LLDPE, HDPE. Although about 70% of the plastics currently used belong to this class, their importance should not be overestimated. The main reason for the widespread of these plastics is that the raw materials required for production are relatively cheap and can be easily converted into useful plastic products. It is also known that the properties of these can be improved to compete with more special and expensive plastics. UPVC is one such example, as it has inherent flame retardant properties, it has been developed into grades, making it competitive with engineering thermoplastics in some uses. 

2. Engineering thermoplastics:

 Engineering plastics (EP) are a group of polymers that some of the following properties: high strength, rigidity, toughness, wear resistance, chemical resistance, and high-temperature resistance. Information on engineering plastics generally focuses onamides (PA), acetals, polycarbonates (PC), thermoplastic polyesters, and modified polyphenylene oxide PPO (or modified polyylene ether PPE). Because more than 90% of the engineering plastics currently used worldwide belong to one of the above categories, (and these five types of plastics account for about 8% of the total plastics used globally.) Other engineering plastics such as sulphones and modified polyamides only account for a small proportion of usage (about 1 to 2%), because they are mostly used to replace metal parts, hence they are especially expensive. As for the EP that is used in quantities, although it has a lower heat resistance (below 150 C) and particularly poor creep resistance at high temperatures, it has a wide range of uses

3. Thermoplastic elastomers: 

Thermoplastic elastomers (TPE), also known as "thermoplastic rubbers" (TPR), relatively new plastics, but their usage and value continue to increase as new markets are continuously being developed, and they can replace other plastics or gerneral rubber in some cases.  some of the properties of traditional or vulcanized rubber, as well as the easy and quick processing performance of thermoplastic plastics, and can be reprocessed, are available in a variety of colors. TPE is made from special polymers (such as SBS, PEEL) or a blend of rubber and plastic ( as PVC/NBR and PP/EPDM).