| abstract |
A perforated sheet, particularly for sanitary articles, made of a liquid-tight material and comprising a multiplicity of pits (6) each having a base (4) lying in the plane of the outer surface, an apex and an inner wall sloping upwards from the base (4) to the apex. The outline of the base (4) includes at least one point of discontinuity (27, 28, 29, 30) so that, as it extends around the edge of each pit, the inner wall has a non-uniform slope with angles of slope, relative to a line perpendicular to the plane of the outer sheet surface, that vary between positive and negative values, and are negative at least at the point of discontinuity. The outline of the base is preferably defined by a number of partially overlapping curved geometrical shapes, particularly circles and ellipses, and the point of discontinuity corresponds to where these shapes meet. A composite planar material comprising said sheet coated at least on its outer surface with thermoplastic fibres bonded to one another and to the sheet is also disclosed. |