PVC Coating
PVC, or polyvinyl chloride coating is a widely used alternative to plastisol. It is used as the plastic coating agent in the dip molding and dip coating processes. By itself, PVC resin is a hard, inflexible solid. When mixed with a plasticizer additive, it becomes much more flexible and less rigid. PVC coated products exhibit good chemical and water resistance. Products like wires, chords, wire mesh, frozen food shelving, dishwasher baskets and chain link fences are often coated in polyvinyl chloride. It is available FDA approved for food processing applications, and since it serves as a thermal and electrical insulator, PVC often coats electrical components like jumper cables. The coating comes in a number of different colors, although black and red are standard. The finish is smooth and glossy and serves as an attractive finishing coat to many products.
The
dip molding and
coating processes that uses PVC as the molten plastic coating is simple and takes little time. First, the product (usually made of a metal) or the mandrel (a mold) is thoroughly cleaned and sprayed with phosphate or chromate. This increases the PVC's adhesion to the metal. The PVC plastic is heated to its melting point, and is able to stay in molten form even in room temperature. The part or mold is dipped into the PVC and left in there for a certain amount of time; the longer the part is submerged in the PVC, the thicker the coating will be. After dipping, the part is heat treated one more time. PVC is the third most widely used plastic product and serves as an alternative to plastisol when more flexibility is desired.