Short shelf life on epdm rubber that contain a lot of clay

[Solrubber]

Hello

We have developped a rubber epdm carbon black with a high percentage of clay comparativly with other rubber that contain only carbon black. This kind of rubber doesn't have a long shelf life as an ucured rubber. The scorch time doesn't change much but the viscosity goes up so fast that we have to cure it in few days. Does anyone have a idea of a kind of product that epdm rubber with high ratio of clay need to keep it stable in the uncured form? Does it need some kind of bounding molecule betwin epdm and clay?

Thank you

 

[btrueblood]

Is it possible that the oil fraction is being absorbed by the clay? Could you keep the clay out of the mix, and only mill it in just before molding/curing?

 

[Solrubber]

We have adjust the amount of oil to the compound so that we can conserve the same duro. Could the clay absorb more of it over a longer period? Unfortunetly, we cannot keep the clay out of the batch and remixt it just before using it in the extruder, but that would have been a good solution.