Patent ID: 6890290
Filing Date: 2005-05-10
Classification: B29C,B29L,B31B,B65B,B65D

Abstract:
1. A bag forming and sealing apparatus for forming a bag of predetermined length from a web of material, and said bag forming and sealing apparatus comprising: a web forming section having a plurality of components arranged to fold the web into a continuous tubular web, said tubular web defining an interior and a longitudinal opening leading into said interior, said tubular web having an outer wall and overlapping flaps that straddle said longitudinal opening and extend into its said interior; a web sealing section having web advancing apparatus to engage and advance said tubular web in a machine direction during an advance cycle and stop said tubular web during a stop cycle; a longitudinal sealer movable between release and seal positions during said stop cycle, said longitudinal sealer having a floating sealer with a contoured heating element positioned between first and second platens, said floating sealer being biased away from said platens when in said release position to permit advancement of said tubular web during said advance cycle, said outer wall of said tubular web extending between said first platen and said floating sealer, and said overlapping flaps extending between said second platen and said floating sealer, said heating element pressing directly against one of said overlapping flaps when in said seal position, sufficient heat, pressure and time forming a contoured longitudinal seal between said flaps during said stop cycle, said longitudinal seal spanning less than the bag length to define a valve opening between said flaps; and, a cross-sealer with at least one heating element to form spaced cross-seals across said tubular web, said tubular web being cut at predetermined spaced locations to form individual bags of the predetermined length.