| 摘要 |
A hot air generator with a slit-type nozzle(23) blows air between two films or strips to be welded. In front of the nozzle or immediately behind it there is an abrading roller(41) with a tapering conical profile. The walls of the slit nozzle(27) converge in the direction of strips to be welded and are parallel to the outer profile of the conical abrading roller(41). The abrading roller is mounted on a holder(45) at the side of the nozzle and/or the roller and holder are mounted on the nozzle. Viewed from above the front edge(42) of the roller is either parallel to the nozzle outlet shape or is slightly angled away from the latter. The roller comprises a row of adjacent cylindrical segments(43) on a transverse supporting bar(48) attached to the holder. Roller surfaces are roughened or are formed of disc-shaped abrading plates perpendicular to the nozzle. Rollers have an eccentric holding bore to allow them to adapt individually to uneven surfaces. An Independent claim is included for a process for welding films or strips using the claimed equipment in which the surface of both films to be joined are roughened before or during welding by hot air. |
