Butyl vs WTRR: which reclaimed rubber grade do you need?

Butyl vs WTRR: which reclaimed grade do you need?

The two most commonly specified reclaimed rubber grades are Butyl Reclaim and Whole Tyre Reclaim Rubber (WTRR). They are not interchangeable. Here is how to decide which one to specify, and why.

The key differentiator: air permeability

Butyl rubber’s commercial value comes from one mechanical property: low gas permeability. It holds air better than natural rubber or SBR, which is why it is used in inner tubes and certain sealants. Butyl Reclaim preserves this property because it is made from a single feedstock — used butyl tubes — and no other rubber type is blended in during processing.

The moment you introduce natural rubber or tyre rubber into a butyl reclaim stream, you dilute the gas-barrier property. Buyers who are purchasing Butyl Reclaim for tube compounds or airtight mouldings are buying that specific property, and a blended reclaim will fail in their application.

When to use WTRR

WTRR is appropriate when air impermeability is not a specification requirement and the buyer is looking for cost reduction against virgin rubber in a mechanical compound. Tyre compounders, mat manufacturers, belt manufacturers, and roofing membrane producers all use WTRR. It is the highest-volume grade in the reclaim market globally and in Pakistan specifically.

A practical check: if your compound already uses SBR or NR as the primary polymer and you are looking for a cost-reduction ingredient, WTRR is the right starting point. If your compound requires air-tight performance — inner tube, sealed-chamber moulding, sealant — specify Butyl Reclaim.