Covering panel

Covering panel with a width B comprising a single-piece extruded support plate with a thickness T, made of synthetic plastic material and containing recycled plastic resin, with a flat top surface, a bottom face and with pairs of opposite sides that are provided with complementary profile edges in the form of a male profile edge on one side and a female profile edge on an opposite side of said pair, of which a said male profile edge of said panel can be connected in a clamping or anchoring manner to a female edge of an equal adjacent covering panel, whereby a number of strip-shaped recesses are present in said bottom faces, which recesses run according to the direction of extrusion and that alternate with a number of support strips and wherein the upper wall of said recesses is less even than the top surface of the support plate.

Covering panel comprising a single-piece extruded support plate made of synthetic plastic material, with a flat top surface, a bottom face and with pairs of opposite sides that are fitted with complementary profile edges in the form of a male profile edge on one side and a female profile edge on an opposite side of said pair, where said male profile edge of this panel can be connected in a clamping manner to a female edge of an equal adjacent covering panel along direction D that runs perpendicular to said top surface, of which the support plates have a maximum thickness T of seven mm, and which have strip- shaped recesses pointing downwards to the bottom face that follow the direction of extrusion and that alternate with a number of support strips of which at least a part has width S along the bottom face that complies with 1.5T<S<10T, whereby the part is substantially evenly spread over the width B of the panel and with 0.4T<C<0.7T in which C is the average depth of said recesses.

A process for the extrusion of a synthetic plastic plate with an even top surface and with a bottom face which has a profile of protruding strips, with slanted upright edges following the direction of extrusion that alternates with parallel-running intermediate strip-shaped recesses, comprising advancing the extruded plate emerging from an extrusion nozzle through a calibration section with controlled cooling that is fitted with partial vacuum equipment, at least against said top surface and whereby the passage space for the plate, to be calibrated in the calibration section, gradually narrows downstream from an input slot to an output slot with a height between top surface and bottom face at the spot of said protruding strips of the plate on the output slot that is equal to the thickness T of the plate, while the passage space at the spot of said intermediate recesses narrows much less or even not at all from its input slot to its output slot, so that in that area the height between the top surface and the bottom of the output slot is larger than T-C, due to the presence of compensation chambers.