It is a dimple geomembrane, produced by extruding plastic sheet into dimple shape.On top of it, there is filtration geotextile. Shenghong composite drainage board is a dimple geomembrane,which produced by extruding plastic sheet into dimple shape. These dimples, in spatial structure with centain heigth, can resist long-term high pressure without deformation. On the top of the dimples, there is ...