Plastic Classification
DATE：2021/10/29 9:08:49 / READ： / SOURCE：This station
Plastic Classification
There are many types of plastics, there are about 300 kinds, and there are more than 40 kinds of commonly used plastics classification methods and many, generally according to the heating behavior of plastics, they are divided into thermoplastic plastics and thermosetting plastics.1. Thermoplastics
Thermoplastics refer to plastics that can be repeatedly heated and softened to melt and flow within a certain temperature range, and can solidify into a certain shape after cooling.
①Typical varieties. Polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyamide, polycarbonate, polyformaldehyde, etc.
② Features. This type of plastic has good physical and mechanical properties, is easy to form and process, and develops rapidly in variety and output. The disadvantage is that except for a few products, the heat resistance and rigidity are generally poor. There are also some thermoplastics, such as fluoroplastics, polyimides, etc., which have excellent properties such as corrosion resistance, high temperature resistance, high insulation, and low friction coefficient.
2. Thermoset plastic
Thermosetting plastics refer to plastics in which the resin undergoes a chemical reaction during the heating process, changing from a linear polymer to a bulk polymer structure, and then no longer melts when exposed to heat, and is insoluble in organic solvents. If the heating temperature is too high, it can only be carbonized.
①Typical varieties. Phenolic plastics, urea-formaldehyde plastics, unsaturated polyesters, epoxy resins and amino plastics, etc.
②No features. It has high heat resistance, good dimensional stability, and low price, but its mechanical properties are poor and need to be reinforced. For example, reinforced plastics made from glass fiber reinforcement, commonly known as "glass reinforced plastics", have strength comparable to metals.
Plastics are also divided into general-purpose plastics and engineering plastics based on their uses.
①General-purpose plastics are the largest output among plastics, accounting for about 80% of the total output
Above, among them, polyethylene, polypropylene, polyvinyl chloride, polystyrene, phenolic plastics, base plastics, etc. have a large output, and they are characterized by high output, low price and wide application.
②Engineering plastics have considerable strength and rigidity, can work at higher temperatures, and are suitable for structural material applications in engineering. Among them, the output of polyamide, polycarbonate, polyoxymethylene, and ABS is relatively large.
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