Abstract: A process is described for the production of biaxially stretched and embossed polyvinyl chloride film, in which a polyvinyl chloride film is first stretched biaxially at specific stretching ratios and, immediately after being stretched, is embossed under specific conditions. The film produced by this process is employed with particular advantage as base film for adhesive tapes.

Abstract: A wall covering system of plastics elements consisting of strips of sheeting or panels the lateral edges of which are folded by an angle of more than 90.degree. and profiles having a dovetail cross section for holding and fastening the strips, wherein the profiles are fixed on structural shapes, fastened to the wall and likewise having a dovetail cross section, by means of spacers of V-shaped cross section with chamfered end sections, which spacers are fitted into the structural shapes in a manner to enable them to slide in longitudinal direction.

Abstract: Extruder with blow head comprising a cylindrical body containing at least one rotating screw in coaxial position, a feeding device for the thermoplastic material near one end of the cylinder and a blow head comprising a housing and a mandrel at the other end of the cylinder forming a slit tapering in the direction of flow of the plasticized material and through which said material issues, the screw and the blow head being arranged in one plane, and directly behind the blow head a cooling device for cooling the extruded tube, whereinA. the screw and the mandrel are rigidly connected with each other without any distortion being possible,B. the lip of the housing of the blow head protrudes from 0.1 to 10 mm over the lip of the mandrel,C. the diameter of the slit formed by the housing and the mandrel is in the range of from 1 to 20 mm in the most narrow area, andD.