WATER AND/OR OIL TIGHT PACKING ROOFING THAT CONSISTS SUBSTANTIALLY OF BASE LAYER, EXPANSIVE CLAY LAYER AND COVER LAYER

摘要

A waterproof and/or oilproof needled sealing mat composed of nonwovens and swellable clay is made available, in which a clay layer is located between the support and covering layer. The clay layer is, together with the support and covering layer, a special feature combination. The support layer can also consist of a nonwoven in combination with a woven fabric, knitted fabric and/or a plastic film. The sealing mat, even in the swollen state of the clay, is a stable fibre composite which, to a high extent, can divert shearing forces which act on the covering layer into the support layer, without the swollen bentonite becoming the sliding surface.