Compared with other materials, plastic and other materials have the following characteristics: 1 light weight plastic is light material, the relative density is between 2.2 and 0.90. It is clear that the plastic can float to the surface of the water, especially the foam plastic, because there are micro holes, texture is lighter, the relative density of only 0.01. This feature makes it available for the production of products to reduce the weight of the product. 2 excellent chemical stability of the vast majority of plastic on acid, alkali and other chemical substances have good corrosion resistance. Especially, commonly known as plastic king of PTFE (F4) and its chemical stability even better than gold, put boil ten hours in the "aqua" will not degenerate. Because F4 has excellent chemical stability, it is an ideal corrosion resistant material. Such as F4 can be used as a material for conveying corrosive and viscous liquid pipelines. 3 excellent electrical insulating properties of ordinary plastic is a poor conductor of electricity, the surface resistance, a large volume resistance, with a digital representation of up to 1018 a 109 ohm. The breakdown voltage, dielectric loss tangent value is very small. Therefore, the plastic in the electronic industry and machinery industry has a wide range of applications. Plastic insulated control cable. 4 poor conductor of heat, with noise attenuation, the role of shock in general, plastic heat is relatively low, equivalent to steel 1/225 - 1/75, foam plastic. Containing gas, the heat insulation, sound insulation, better shock resistance. Such as polyvinyl chloride (PVC) thermal conductivity is only 1/357 of steel, aluminum 1/1250. In the heat insulating ability, single glass window than single glass windows 40%, double glass high 50%. The plastic form and hollow glass combined, in the residential, office buildings, wards, hotels in the winter to save heating, air conditioning costs in the summer, the benefits are very obvious. 5. Mechanical strength distribution wider and higher than the strength of some plastic as hard as stone, steel, some soft such as paper, leather; from the plastic hardness, tensile strength, extension rate and impact strength and mechanical properties, wide distribution, great choice. Because of the small proportion of plastic, high strength, and thus has a high ratio of strength. Compared with other materials, plastic also has obvious shortcomings, such as easy to burn, the stiffness is not as high as metal, poor aging resistance, heat resistance and so on.