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Permeability barrier

Permeability barrier Imerys minerals improve the barrier properties of rubber compounds

Due to the platy shape of their particles, Imerys high aspect ratio talcs and kaolins reduce the gas and vapor permeability of rubber materials leading to improved barrier properties.

High aspect ratio minerals have highly lamellar particles which create an impermeable barrier, reducing air and liquid permeability in the rubber compound due to an increase in the mean-free path of diffusion.

High aspect ratio minerals improve air permeability in butyl, natural and polyisoprene rubber compounds.

Platy minerals form a more effective barrier against gas diffusion

Image Barrier property diffusion path
The platier the mineral, the lower the permeability

Generally speaking, the more lamellar the mineral, the lower the permeability.

Imerys platy minerals are particularly suitable for improve permeability in tire inner liners, medical stoppers, membranes and hoses.

We recommend:

  • High aspect ratio talc, Mistron HAR® talc for critical applications such as tire inner liners, where they provide downgauging opportunities.
  • Cost-effective Polwhite grades which can be used at a significant loading to improve permeability in tire inner liners at standard inner liner gauge.
  • Mistron® talc and silane-treated Mistrobond®  talc to improve barrier properties in medical stoppers, gaskets and membrane applications.



We offer a full range of bespoke formulation and technical and process support services to help you match the right mineral grade to your application requirement.

Please contact us, we will be only too happy to help

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