WATER NON-PERMEABLE AND/OR OIL PERMEABLE SEALING MAT MADE UP SUBSTANTIALLY OF BASE LAYER, SWELLING CLAY LAYER AND COVER LAYER

摘要

PURPOSE: To provide a sealing mat for controlling environmental pollution at the time of construction of a hydraulic power industry basin and a lagoon and useful as a soil sealant for a dangerous/harmful substance or waste or a water and/or oil permeable barrier suitable for holding animal waste, for example, discharged from a pasture. CONSTITUTION: A sealing mat is constituted by the needle punching of three layers consisting of a substrate layer, a swellable clay intermediate layer and a cover layer and the substrate layer and the cover layer are composed of a material selected from a group consisting of a nonwoven fiber material, a fabric, a sewn fabric and a plastic sheet but at least one of both layers comprises the nonwoven fiber material and the area wt. and swelling capacity of the clay layer satisfy conditions prescribed by a drawing and the area wt. and effective aperture size of the nonwoven fiber material also satisfy specific conditions necessarily.