Patent ID: 8201606

Claim:
A device for transverse sealing of a tube of thermoplastic coated packaging material, the tube being formed by sealing of an overlapping joint between mutually opposing inner and outer edge sections of a sheet of packaging material, the device comprising first and second opposing jaws having first and second main sealing surfaces, respectively, between which the tube is arranged to be flat-laid and squeezed to heat the thermoplastic between the first and second main sealing surfaces and obtain a transverse seal along a main sealing line of the tube, and penetration means for penetrating only the outer edge section of the overlapping joint along the main sealing line prior to sealing to allow the first main sealing surface to contact the inner edge section of the overlapping joint, wherein the first jaw comprises the penetration means for penetrating only the outer edge section of the overlapping joint prior to sealing and wherein the penetration means is formed as a tapered part of the first main sealing surface, the tapered part of the first main sealing surface being adjacent to a non-tapered part of the first main sealing surface.