Convertible form, fill and seal packaging machine and method

Abstract

A convertible, vertical form, fill and seal packaging machine and method for making a variety of types and styles of bags and seals is disclosed. The machine produces durable, substantially air-tight bags at high speed and provides for the production of different size and make of bags and different amounts and types of product in the bags. The machine includes a film drive and pinch roll pair, a pair of film pull belts, and a pair of zipper drive rollers for pulling plastic film and zipper strip through the machine. The machine is convertible from one for producing reclosable edge fin seal bags to another for producing nonreclosable midline seal pillow type bags. Conversion from one to another is facilitated by having the pinch seal assembly mounted on a base plate which is releasably secured to a drawer-like device. This allows the pinch seal assembly to be pulled out of the machine, indexed 90.degree., and pushed back into the machine. The film pull belts are part of a self-contained pull belt unit which can be adjusted or removed from the machine, inverted and placed back into the machine. Different formers, fill tubes, and/or vertical sealing units are used to produce different types and styles of bags. The production of different size bags is facilitated by having the film drive roll, pull belts, and zipper drive rollers simultaneously driven in bag length increments by a common drive source. Also, to accommodate the production of different size bags, the machine includes a programmable control system, an optical mark sensor, and an adjustable film path length.