Use of hot air jets to seal incipient cracks in packaging films - to suppress crack propagation from residual stress zones near weld junctions

摘要

In process for wrapping a series of articles between two layers of wide thermoplastics film which are then welded along their borders and then between successive packs before being mechanically trimmed, the welded zones are subjected to hot air jets to fuse and seal any incipient splits induced alongside the weld zones, esp. at the corners where the transverse and longitudinal welds intersect. Esp. for use with 'SERIENPACKER' or 'PACKAUTOMATEN' machines.