| 摘要 |
Polymer films (10, 18) are welded by dielectric welding between opposed electrodes (12, 20) to form a seam or flange of a sachet, and are simultaneously cut out. One electrode (20) is connected to a solid-state source (26) of radio frequency signals by an active matching network (36), at least one of the electrodes is coated with a hard insulating layer (15) at least 50 µm thick, and the electrodes are shaped so as to define a knife edge (30) extending along the welding zone, projecting between 30% and 150% of the thickness of a film. This enables enclosures such as sachets of detergent to be formed and cut out in a single operation. |
