PROCESSO E DISPOSITIVO PARA O FECHAMENTO DE SACOS GRANDES BEM COMO SACO GRANDE COM UMA DOBRA EM ZIGUE-ZAGUE FORMADA EM UMA EXTREMIDADE DO SACO E CONTRAIDA PARA FORMAR UMA FLOR

摘要

After filling, the open end of a thermoplastic sack is closed by gathering it into zig-zag folding (1) which is compressed between apertured jaws (3, 4). Heated needles (7) insertable through the jaw apertures (5) pierce the compressed zig-zag folding and cause the individual folds to be welded to each other adjacent the piercings to secure the closure against springing open after the jaws (3, 4) are removed.