VERFAHREN ZUR HERSTELLUNG EINER PRAEGEWALZE ZUM KONTINUIERLICHEN PRAEGEN DER OBERFLAECHE EINER THERMOPLASTISCHEN FOLIE

摘要

Leather sheets having desired grain pattern are mounted on a roller with edges abutting. Onto the surface of the grain pattern a silicone synthetic resin is applied as a uniformly thick coating with a coating knife as the roller rotates. The resin is hardened into a matrix. It is then peeled off the grain pattern. The grain pattern in the matrix is interrupted where the leather sheets abutted. The matrix is placed with the pattern outward on a roller whose diameter pretty much matches the diameter of the embossing roller to be produced. The surface of a tubular thermoplastic film is embossed by contact with the cylindrical matrix under heat and pressure. The embossed surface of the thermoplastic film is once again overembossed under heat and pressure in the areas along the abutting edges of the natural grain pattern on the roller, so that an endless positive impression without seams in the grain's pattern is produced. Another layer of silicone rubber is applied to the positive impression, which layer is vulcanized into a matrix which is peeled off the positive form and adhered to the circumferential surface of the embossing roller with the negative side out. With this embossing roller a natural leather grain can be embossed on a thermoplastic film without the appearance of discontinuities at the abutting edges.