Synthetic resins are used in almost all plastics. Resin is the most important component of plastic, plays the role of adhesive, can be plastic other ingredients into a whole. Although adding various additives can change the properties of plastics, resin is the fundamental factor determining the type, performance and use of plastics. 
The types of resins commonly used in plastic decorating materials are:
Polyethylene (PE), polyvinyl chloride (PVC), polystyrene (PS), phenolic (PF), urea-formaldehyde (UF), epoxy (EP), polyester (PR), polyurethane (PU), poly (methyl methacrylate) (PUMA), silicone (SI) and so on.
According to the change of the heating, the synthetic resin can be divided into two kinds: thermoplastic resin and thermosetting resin.
It has the properties of softening, cooling and hardening, and does not react to chemical reactions, which can keep this performance no matter how many times the heating and cooling are repeated. The molecular structure of thermoplastic resins is linear. It includes all polymeric resins and partially condensed resins. Thermoplastic resins are: polyethylene, polyvinyl chloride, polystyrene, polyamide, POM, polycarbonate, polyphenylene ether, polysulfone, rubber and so on.
After the resin is heated, the chemical change is gradually hardened, and then the heat is not softened or dissolved. The molecular structure of thermosetting resins, which includes most of the condensed resins, has the advantages of high heat resistance and hard deformation.