| 摘要 |
A welding unit(11) produces a long welding joint between tow film strips(23a,23b) and has a cutter head(17) for cutting of the welded film strips. A fixed blade(19) on the cutting head is heated and has a cutting edge(21). Blade(19) heating, which is continuous, is produced by a heating system(15) for the welding unit(11). Heat is transferred to the blade(19) via a heat bridge(18). The heat bridge extends to and contacts the blade and is preferably part of the cutting head(17) or a blade holder. The blade and cutting edge(21) pass right through the film strips(23a,23b) with the cutting edge at an angle, preferably 10-50degrees, more preferably 15-35degrees, to a the film strip plane(24). The cutter head is a few centimeters behind the welding wheels in the direction of film movement. Blades have an anti-adhesion coating. The welding unit comprises a pair of welding wheels, one(12) above and the other(13) below the film strip plane(24) so that they compress film strips between them. |
