Producing a succession of individual, e.g. multi-tube, packs

摘要

In a horizontal form-fill-seal machine, twin-tube packs, for example, can be produced by forming in a moving flexible web (11) two corrugations running in the direction of movement of the web; bringing the opposite edge regions of the web (11) towards one another beneath the corrugations and folding the edge regions against one another to form a fin projecting beneath the centreline of the web; gripping the fin between pairs of contra-rotating rollers which drive it in the direction of movement of the web and which crimp the fin to seal it; sealing the web surfaces between the corrugations together to define twin tubes in the web; and cross-sealing and severing the web at intervals spaced along its length. The two thicknesses of material between the currugations are sealed by nipping them between a heated sealing roller and the face or faces of one or a pair of the contra-rotating rollers which are themselves heated to seal the fin as it passes through their nip. The web may be perforated or separated longitudinally between twin tubes.