Improved heat sealing method and apparatus in continuous self-standing upright bag forming/filling machine

摘要

Improved apparatus in a continuous self standing upright bag (12) forming/filling comprises heat sealing stations (4a,4b) each have a hot plate and an abutment (3) for heat sealing therebetween a laminate paper previously folded into a sectionally w-shaped form with long front and back layers and short intermediate layers.;The hot plate (2) is provided thereon with both end side heat sealing projections (2a) and bottom side heat sealing projection (2b), said end side heat sealing projections being made thicker than the bottom side heat sealing projection by a value corresponding to difference of thickness of the total thickness of the four layered lower portion of the preformed laminate paper from that of two layered upper portion thereof, and there are further provided on the same hot plate such spot heat sealing projections (2c,2d) that are thicker than the end side heat sealing projections at the intermediate joining portion between the end side heat sealing projections and the bottom side heat sealing projection, so that end side heat sealing and bottom side heat sealing as well as spot heat sealing on the intermediate joining portions can be carried out simultaneously.