The polymer is formed by a number of small, simple, small molecules (monomer), which are formed by covalent bonds.
(1) classification of the properties of the resin during the heating and cooling
PET plastic raw materials
PET plastic raw materials
Thermoset plastics thermoset plastics): refers to is heating, the molecular structure are combined into a reticular pattern, but a combination of reticular polymer, even heating does not soften, showing the so-called non reversible change], is the occurrence of molecular structure changes (Chemistry) - induced.
Second, thermal plastic plastic thermo plastics): refers to the heated melting can flow to the mold cooling after molding, heat will melt the plastic can be used heating and cooling, to produce a reversible change of [] (liquid vs. solid), is what is called a physical change.
In accordance with the application of the main points of the general plastic such as PE/PP/PVC/PS, engineering plastics such as ABS/POM/PC/PA and other commonly used. In addition, there are a number of special plastic such as high temperature and high humidity and corrosion resistance and some other special use and modified for the production of plastic.
(2) classification by use of plastic
A. general plastics plastics such as uses a wide range of plastics because of its high output, accounting for about of the total output of plastic three out of four points, the price is low, widely used to make little of daily necessities, such as the shell of the TV set, telephone casings, plastic bowl, plastic barrels, and other. And people's relationship is very close, become an important pillar of the plastic industry. Commonly used in general plastic has PE, PVC, PS, PP, PF, UF, MF, etc..
B. engineering plastics, GE Plastics, although the price is low, but its mechanical properties, heat resistance and corrosion resistance are difficult to meet some engineering and equipment used as structural materials need. Therefore, engineering plastics came into being, it has high mechanical strength, rigidity, can replace some steel or nonferrous materials, manufacturing complex mechanical parts or engineering mechanical parts, a lot of use effect is more than the original material, commonly used engineering plastics with PA, ABS, PSF, PTFE plastic raw materials, POM plastic raw materials, PC.
C. special plastic raw material of this kind of plastic raw material has unique function. It can be used for special occasions, such as the guide magnetic plastics, plasma plastics, pearlescent plastic, photo plastics, medical plastic and so on.