Insulating flexible ventilation duct for mine workings - has woven synthetic core pref. PVC foam and metal foil on outer facing foil

摘要

An insulating duct for the ventilation systems of tunnels and mines comprises a core material consisting of woven, synthetic fibres coated on one or both faces, a layer of foam on one or both sides of this core, and a covering foil having a vapour-deposited metal foil on its outer face. The foam is pref. of PVC, and the metal foil is pref. aluminium. This material provides a high level of thermal insulation, thus preventing the incoming air from becoming heated, and also adequate strength accompanied by flexibility.