Plastic is a synthetic polymer compound, also known as leading polymer or macromolecule, is also commonly known as plastic or resin, can freely change the shape style. Is the use of monomer raw materials to synthesis or condensation polymerization of materials, by synthetic resin and filler, plasticizer, stabilizer, lubricant, pigment and other additives, its main component is synthetic resin. Resin was originally named after lipids secreted by animals and plants, such as rosin, shellac, etc. at present, resin refers to polymers that have not been mixed with various additives. The basic properties of plastics mainly depend on the nature of resin, but additives also play an important role. Some plastics are basically composed of synthetic resins, with no or little additives, such as plexiglass, polystyrene, etc. The so-called plastic, in fact, it is a kind of synthetic resin, the shape of which is similar to the pine resin in natural resin, but it is called plastic because it is synthesized by chemical force.