Continuous mfr. of combination film tubing for bags - in which wrapped films with longitudinally overlapping edges are ultrasonically welded

摘要

Endless tubing for bags is produced continuously, using at least 1 thermoplastic layer which is first wrapped with its longitudinal edges overlapping and then bonded together while moving forwards. The overlapping process is performed between a support tool and a sonotrode, the latter producing a continuous ultra-sonic weld. Process of closing off inte bags is simplified. Closures provide good protection against moisture and are gas-tight.