Plastic additives, also known as plastic additives, are some compounds that must be added to improve the processing performance of polymer (synthetic resin) or to improve the performance of the resin itself during the molding process. For example, plasticizer added to reduce the molding temperature of PVC resin and make the product soft; Another example is to add foaming agent to prepare foamed plastics with light weight, vibration resistance, heat insulation and sound insulation; The thermal decomposition temperature of some plastics is very close to the molding processing temperature, and it can not be formed without adding heat stabilizer. Therefore, plastic additives play a particularly important role in plastic molding. A large category of additives used for plastic molding and processing products, including plasticizers, heat stabilizers, antioxidants, light stabilizers, flame retardants, foaming agents, antistatic agents, mildew inhibitors, colorants and brighteners (see pigments), fillers, coupling agents, lubricants, release agents, etc. Among them, colorants, brighteners and fillers are not special chemicals for plastics, but are widely used coordination materials.