Kaolin in plastics provides smooth surface, dimensional stability and resistance to chemical attack. It also acts as a rheological modifier and functional filler. Kaolin also conceals conceals fibre reinforcement patterns and reduces shrinkage and cracks during polymer compounding and shape forming. One of the major application of kaolin is in PVC cables where it is used to improve electrical properties.
Kaolin adds strength, abrasion resistance and rigidity to rubber. Kaolin finds extensive use in high value thermoplastic elastomers for a variety of applications and in rubber insulation on high voltage power lines. Kaolin also applied in films where they impart anti-blocking or infrared absorption characteristics. Fine kaolin is one of the major additives used in the manufacture of automotive parts based on engineering thermoplastics.