The role of PVC lubricants is to improve the flowability of the resin and the demolding properties of the products during plastic processing, preventing defects caused by adhesion inside the machine or mold.

PVC lubricants are typically odorless, tasteless, non-toxic, and appear as a pale yellow waxy solid or flakes.

In the plastic industry, PVC lubricants are mainly used, especially as anti-shrink agents for plastic foam products. They serve as internal lubricants in the production of PVC products and can also act as modifiers for alkyd resins and plasticizers for nitrocellulose.

Lubricants in plastic processing enhance the demolding properties of products, preventing defects caused by adhesion inside the machine or mold. They are generally added to the molding plastic or applied to the surface of the mold cavity. Common lubricants include fatty acids and their salts, as well as long-chain fatty hydrocarbons. Depending on the mechanism of action, lubricants can be classified as external lubricants and internal lubricants.

(1) External lubricants: These lubricants have poor compatibility with the resin used for molding, so they are often used on molding processing machinery or molds. They form a lubricating layer between the lubricant and the resin, facilitating the flow of the resin and the demolding of the products, such as paraffin.

(2) Internal lubricants: These lubricants have good compatibility with the resin and are often mixed into the resin to reduce the melt viscosity and improve its flowability. Examples include butyl stearate and lead stearate. Stearate salts are both good lubricants and effective stabilizers.