Coating: used for anticorrosion, insulation, decoration and other purposes. A thin plastic layer is coated on the surface of fabric, paper, metal foil or board in the form of liquid or powder.

Anticorrosion is to protect metal objects that are easy to rust by various means, so as to achieve the purpose of prolonging their service life. Physical corrosion protection, chemical corrosion protection and electrochemical corrosion protection are usually adopted.