What are Internal and External Lubricants for PVC Applications?

Internal and External Lubricants are two types of lubricants used in PVC applications. They serve the process of reducing friction. However, both of these category of lubricants act differently and have distinct functions. There are certain lubricants such as Stearic Acid that act as both external and internal lubricants.

Unlike internal lubricants that enhance the polymer melt’s flow properties, external lubricants tend to migrate to the PVC’s surface, forming a lubricating layer between the melt and the processing equipment.