Mechanical properties for rubber

Our minerals are excellent reinforcement agents improving the mechanical properties of rubber compounds.

Improving mechanical properties of finished rubber items 

Imerys minerals improve the mechanical properties of finished rubber items in most rubber applications. They can be used in association with most elastomers commonly used by the rubber industry.

Imerys kaolins, talcs, wollastonites and diatomaceous earths, particularly the finest grades with the highest surface areas, are highly effective mechanical reinforcement agents in rubber.

Our minerals improve:

  • Tensile strength
  • Elongation
  • Modulus
  • Compression set
  • Cut and tear resistance
  • Abrasion resistance
  • Crack growth and fatigue resistance
  • Thermal and weather aging


Imerys calcined clays such as those from our Polestar™ and Glomax™ ranges are particularly effective for improving the compression set in gaskets and seals.

Imerys Suprex™, Windsor, Aiken, and Hexafil™ hydrous clays are excellent solutions for boosting the mechanical performance of rubber hoses for automotive and domestic appliance applications.


Microlamellar ImerFlex® talc, which has a higher surface area at the same fineness as conventional lamellar talc, improves elastomer chain wetting, providing better reinforcement levels than conventional lamellar talcs. 

Used as a partial substitution for carbon black, ImerFlex talc improves mechanical properties such as elongation at break and cut and tear resistance of peroxide cured compounds, even at high temperatures.


Fine grade wollastonites such as our Wollastocoat® range with their acicular shape provide excellent reinforcement properties and reduced costs in fluoroelastomer (FKM) seals, gaskets, plugs, o-rings and molded applications.

Diatomaceous earth

Natural diatomaceous earths such as our Celtix™ grades are a good choice for replacing precipitated silica to improve compression set in EPDM.

*Talc products are not available in the USA and Canada. Contact us for an alternative range.