Method and Apparatus for Producing Perforated Strings of Separable Packages

Abstract

A vertical form, fill and seal machine includes a pair of reciprocating jaws, located below the product delivery conduit of the machine. The jaws are spaced apart to permit the film tube coming off the product delivery conduit to pass between the jaws after the film tube separates from the product delivery conduit. One of the reciprocating jaws has a toothed blade with a leading edge of the toothed blade extending beyond a leading edge of the one jaw. When the pair of jaws closes, teeth of the blade cut a transversely extending series of perforations adjacent to a transverse seal. Accordingly, the machine outputs a continuous string of connected sealed packages having a transversely extending perforation between adjacent packages is formed.

1 . An continuous vertical form, fill and seal machine for making a continuous string of separable connected packages, the machine comprising:
 a vertically-oriented product delivery conduit;   a film dispensing roller configured to mount thereon a roll of package-forming film;   a film tensioner oriented and configured to receive, tension and guide package-forming film dispensed from the dispensing roller;   a package-former located and configured to receive tensioned package-film from the film tensioner and guide the package-film around an outer surface of the product delivery conduit;   a heat seal bar adjacent the product delivery conduit to seal together longitudinal opposed ends of the package-film to form a film tube as the package-film traverses down the outer surface of the product delivery conduit; and   a pair of reciprocating jaws located below the product delivery conduit and spaced apart to permit the film tube to pass between the jaws after the film tube separates from the product delivery conduit, one jaw of the reciprocating jaws having a toothed blade, a leading edge of the toothed blade extending beyond a leading edge of the one jaw;   wherein, when the pair of jaws closes, teeth of the blade cut a transversely extending series of perforations adjacent to a transverse seal, whereby a continuous string of connected sealed packages having a transversely extending perforation between adjacent packages is formed.   
     
     
         2 . The machine of  claim 1 , wherein the toothed blade extends between a pair of sealing surfaces of one of the reciprocating jaws. 
     
     
         3 . The machine of  claim 1 , wherein the toothed blade comprises a series of teeth spaced equidistant from each other. 
     
     
         4 . The machine of  claim 3 , wherein each tooth of the blade comprises wedges along laterally opposed sides of the tooth, the wedges each terminating in a cutting edge along a perimeter of the tooth, the laterally opposed wedges converging in a sharp point at a leading edge of the tooth. 
     
     
         5 . The machine of  claim 4 , wherein each tooth of the blade has wedges only on one side of the blade. 
     
     
         6 . The machine of  claim 1 , wherein the toothed blade comprises a series of pairs of teeth, each pair of teeth spaced equidistant from each other. 
     
     
         7 . The machine of  claim 6 , wherein each tooth of the pair of teeth comprises wedges along laterally opposed sides of the tooth, the wedges each terminating in a cutting edge along a perimeter of the tooth, the laterally opposed wedges converging in a sharp point at a leading edge of the tooth. 
     
     
         8 . The machine of  claim 7 , wherein each tooth of the blade has wedges only on one side of the blade. 
     
     
         9 . The machine of  claim 2 , wherein the toothed blade comprises a series of teeth spaced equidistant from each other. 
     
     
         10 . The machine of  claim 9 , wherein each tooth of the blade comprises wedges along laterally opposed sides of the tooth, the wedges each terminating in a cutting edge along a perimeter of the tooth, the laterally opposed wedges converging in a sharp point at a leading edge of the tooth. 
     
     
         11 . The machine of  claim 10 , wherein each tooth of the blade has wedges only on one side of the blade. 
     
     
         12 . The machine of  claim 2 , wherein the toothed blade comprises a series of pairs of teeth, each pair of teeth spaced equidistant from each other. 
     
     
         13 . The machine of  claim 12 , wherein each tooth of the pair of teeth comprises wedges along laterally opposed sides of the tooth, the wedges each terminating in a cutting edge along a perimeter of the tooth, the laterally opposed wedges converging in a sharp point at a leading edge of the tooth. 
     
     
         14 . The machine of  claim 13 , wherein each tooth of the blade has wedges only on one side of the blade. 
     
     
         15 . The machine of  claim 1 , wherein motion of the sealing and perforating jaws is restricted to only reciprocating motion, and the blade is fixedly mounted to one of the pair of jaws. 
     
     
         16 . The machine of  claim 2 , wherein motion of the sealing and perforating jaws is restricted to only reciprocating motion, and the blade is fixedly mounted to one of the pair of jaws. 
     
     
         17 . The machine of  claim 3 , wherein motion of the sealing and perforating jaws is restricted to only reciprocating motion, and the blade is fixedly mounted to one of the pair of jaws. 
     
     
         18 . The machine of  claim 6 , wherein motion of the sealing and perforating jaws is restricted to only reciprocating motion, and the blade is fixedly mounted to one of the pair of jaws. 
     
     
         19 . The machine of  claim 1 , wherein the toothed blade is planar, each tooth of the blade is coplanar with the blade, each tooth has wedges only on a first surface, the wedges each extending laterally along opposite sides of the tooth, each wedge terminating in a cutting edge along a perimeter of the tooth, the wedges converging in a sharp point at a leading edge of the tooth, the tooth symmetrical about an axis extending through the sharp point. 
     
     
         20 . The machine of  claim 2 , wherein the toothed blade is planar, each tooth of the blade is coplanar with the blade, each tooth has wedges only on a first surface, the wedges each extending laterally along opposite sides of the tooth, each wedge terminating in a cutting edge along a perimeter of the tooth, the wedges converging in a sharp point at a leading edge of the tooth, the tooth symmetrical about an axis extending through the sharp point. 
     
     
         21 . A method of making a continuous string of separable connected packages on a vertical form, fill and seal machine, the method comprising:
 continuously dispensing packaging-film from a roll of packaging film;   tensioning and guiding the dispensed packaging-film;   enveloping a product delivery conduit with tensioned and guided packaging-film;   sealing together longitudinal opposed ends of the package-film to form a film tube;   moving the film tube down and feeding product into the film tube from the product delivery conduit; and   sealing and the film tube with a pair of transverse seals having a transverse tear line comprising perforations located between the transverse seals;   whereby continuous operation of the vertical form, fill and seal machine provides a continuous string of connected sealed packages having a transversely extending perforation between adjacent packages.   
     
     
         22 . The method of  claim 21 , wherein the step of sealing comprises reciprocating a pair of jaws comprising a pair of heat sealing elements and a toothed blade to seal the film tube by forming a pair of spaced apart transverse seals and substantially simultaneously creating a perforated tear line between the transverse seals with the teeth of the blade.