Flexible elastomeric foams
The industry widely uses flexible elastomeric foams (FEF’s) for thermal and acoustic insulation in air-conditioning and heating installations. Such materials are more or less solely based upon two different rubbers:
- nitrile butadiene rubber (NBR), often blended with polyvinyl chloride (PVC)
- or ethylene propylene diene rubber (EPDM).
NBR and NBR/PVC based FEF’s are the most widespread polymers for standard FEF’s while companies use EPDM mainly for applications requiring higher temperature resistance, e.g. solar applications.
PVC resins are blended with NBR to provide increased resistance to ozone and abrasion. Also, PVC has the effect of increasing the level of fire retardancy, and you can further improve this by the addition of flame retardant fillers.