Sheet or hollow cylinder shaped insulating piece

摘要

The present invention includes an insulating piece formed from a rubber based elastomeric foam having a density of 30 to 120 g/dm<3 >or between 40 to 80 g/dm<3>. The foam may be acrylonitrile-butadiene rubber (NBR), ethylene propylene diene monomer (EPDM) rubber, styrene butadiene rubber (SBR), or butyl rubber (IIR). Additionally, separate air channels are provided which extend in the longitudinal direction outside the projections in a uniform distribution over the cross-sectional area of the insulating piece.