Industry Focus

Rubber

Reinforcing & Extending Fillers for Rubber Compounds

Overview

The rubber industry uses mineral fillers extensively to reinforce compound properties, reduce cost, and improve processing characteristics. Raviraj Minerals supplies talc, calcium carbonate, dolomite, and kaolin for use in natural rubber (NR), styrene-butadiene rubber (SBR), EPDM, and nitrile rubber compounds across tyre, industrial, and consumer rubber applications.

Talc Powder

Talc is used in rubber compounding both as a reinforcing extender and as a processing aid. Its plate-like morphology provides good mechanical reinforcement, improving tear strength and modulus without significantly increasing hardness. As a dusting agent, talc is applied to the surface of uncured rubber to prevent self-adhesion during storage and handling.

Improves tear strength and modulus in natural and synthetic rubber
Used as a dusting agent to prevent rubber sheet self-adhesion
Reduces compound cost as an active extender
Improves surface finish of molded rubber articles
Compatible with NR, SBR, EPDM, and NBR rubber systems

Calcium Carbonate

Calcium carbonate is the most widely used extender filler in rubber. At moderate loadings, coated CaCO₃ grades from Raviraj Minerals integrate smoothly into rubber matrices, improving processability, reducing compound Mooney viscosity, and enhancing the surface quality of finished rubber goods.

Reduces compound cost while maintaining mechanical performance
Coated grades improve dispersion and reduce Mooney viscosity
Improves surface smoothness of rubber articles
Used in conveyor belts, hoses, gaskets, and moulded rubber goods
Available in both uncoated and stearic-acid treated grades

Kaolin / China Clay

Hard kaolin is used in rubber as a semi-reinforcing filler that provides good electrical resistance and chemical inertness. It is used in wire and cable insulation compounds where high volume resistivity and acid resistance are required.