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How heat affects EPDM vs Silicone
May 15, 2018

As shown in the diagram, silicone and EPDM vary when exposed to varying degrees of heat.

Our Laboratory team performed a series of heat age tests on a standard piece of silicone sponge alongside a standard piece of EPDM sponge, both were 6mm thick.

Six 58mm circles were cut from the original pieces and then placed in the oven at different temperatures. The results were then recorded as follows:

EPDM Results

At 100°C, the EPDM sample had shrunk by 17% to 48mm. A surprising result considering that the datasheet indicated the temperature limit was 130°C.

At 125°C the shrinkage continued but this time it was more severe, showing a 52% decrease from its original size to 28mm.

Finally at 150°C the EPDM had decreased but only by a further 1mm, concluding that 125°C is where the material saw severe deformity.

Silicone Results

The silicone samples showed no shrinkage after being subjected to the same temperatures as the EPDM. All silicone samples stayed at 58mm when taken out of the oven, showing the stability of silicone at high heat.