PVC lubricants play a vital role in PVC processing, contributing to improved performance and quality. They can be classified into two main categories: PVC internal lubricants and PVC external lubricants.

External Lubricants

PVC external lubricants serve the purpose of creating a lubricating thin layer at the interface between the plastic melt and metal. These lubricants have limited compatibility with polymers, making them prone to migration from the melt to the exterior. As a result, they effectively reduce friction and enhance the overall processing of PVC.

Internal Lubricants

PVC internal lubricants are characterized by their strong compatibility with polymers. They work by reducing the cohesion between polymer molecules within the polymer matrix. This reduction in internal friction heat generation enhances the melt fluidity of the plastic melt, further improving the processing of PVC.

Dual Role Lubricants

Most lubricants exhibit a dual role, functioning as both internal and external lubricants. Take stearic acid, for instance. When processing conditions involve low temperatures or a substantial amount of lubricant, the external lubricating properties take precedence. Conversely, under high-temperature conditions and with an optimal amount, the lubricant's compatibility with PVC makes internal lubrication the primary function.

The Role of Wax

Wax is an important PVC lubricant, and it includes oxidized polyethylene wax, polyethylene wax, and FT wax.Polyethylene wax itself is a type of polyolefin synthetic wax. Oxidized polyethylene wax is prepared from polyethylene wax after special oxidation process.FT wax (Fischer Tropsch) is a methylene polymer synthesized from hydrocarbon-based synthetic gas or natural gas. Together with G60, G74, G70, and G78, these waxes serve as essential internal and external lubricants in the production of PVC products.