Plastic material forming base or final covering of landfill preventing sliding relative to considerably-sloping landfill or ground, includes new pattern of raised ridges intersecting at prominent studs

摘要

Either or both sides are structured. Projecting ridges (2) are distributed over the surface in association with studs (3), which project still further. An Independent claim is included for the pressing roller forming the material which has corresponding dimensions and negative form. Preferred features: Ridges intersect at studs. Studs are a result of the intersection. Ridges form polygons with four to twelve sides, or rhombi. The structure is on both sides. Total area of ridges per square meter on front or rear is 25-50 dm<2>, especially 35-45 dm<2>. Angles of intersection are 110 deg -170 deg , preferably 120 deg -150 deg . Further detailed structure quantification is included. Studs can have various shapes, e.g. pyramids, and may lean. They can be e.g. rounded or pointed, and are further dimensioned. Dimensioned water drainage channels are included in the surface(s) of the sheet. The structure is produced by pressing.