Can EPDM use regrind?

[samsangsam]

Just notice that our rubber part use EPDM material, the drawing call out 25% regrind allow, as understand that regrind is not an option for EPDM, is it true?

 

[Pud]

I have always understood EPDM to be a Thermoplastic Elastomer Vulcanisate - in that it is cross-linked during processing? If so, regrind use will not be possible. (Unless it's put in as a filler - I guess all things are possible).

H

www.tynevalleyplastics.co.uk

It's ok to soar like an eagle, but weasels don't get sucked into jet engines.

 

[Compositepro]

Prevulcanized rubbers are sold as ingredients for rubber formulation, so yes it can be done. The properties will not be the same as virgin rubber. It is the the same as using reground thermoplastics, but may be okay for some applications.

 

[stancom]

Let's be clear about 'regrind'. I regard it as ground vulcanized rubber from scrap or recycled products, notably tyres. It could be made from EPDM and this would probably make it the most appropriate type for adding to virgin EPDM. However, regrind also comes from natural and other synthetic rubbers and their blends. Some can be added to EPDM in relatively small dosages but there will be an incompatibility problem arising from different rates of cure. NR and SBR regrinds can still undergo further vulcanization and since they cure faster than EPDM there could be a depletion in the amount of sulphur and accelerators available for the EPDM.

I'm sure Pud meant to say 'thermoset' rather than 'thermoplastic'

 

[Pud]

I'm sure Pud meant to say 'thermoset' rather than 'thermoplastic'

Indeed he did, stancom. Yet another senior moment.... Although a google would suggest I was almost correct in my error! TPV


www.tynevalleyplastics.co.uk

It's ok to soar like an eagle, but weasels don't get sucked into jet engines.

 

[dgallup]

Whenever I talking about the permissible use of regrind material in a molding operation, it is the sprues and runners or scrap parts from the identical material as the virgin material. Thee is no cross contamination from other sources. Certainly not things like tires that could contain hundreds of different compounds. That is recycled material and completely different than reground material. I only allow regrind for thermoplastics, not thermosets.

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