Pouch machine for making variably-sized pouches

Abstract

A pouch machine continuously forms a series of multi-pitch, multi-product pouches in a continuous web of pouch material by folding the web and then forming spaced side seals to define a pouch closed on three sides with an initially unsealed mouth on top. The pouch is opened to its maximum volume prior to filling by pressurizing the pouch. Pressurization is achieved by introducing a curtain of compressed air under a plate and passing the mouths of the pouches adjacent the plate and thus through the air curtain. First and second plates engage the front and back panels of the pouches to assure correct pressurization of the pouches.

1 . In a pouch machine of the type which forms a series of pouches in a continuously moving web of pouch material, the pouches being defined by front and back panels with side seals and a closed bottom, the tops of the front and back panels prior to filling being open to define a mouth, the improvement comprising first and second plates mounted for engagement with the front and back panels, respectively, prior to filling of the pouches, the plates defining at least a portion of a pressure chamber which is in communication with the mouth of the pouches, and a source of pressurized gas supplied to said chamber for opening the pouches to their maximum volume prior to filling by generating an internal pouch pressure high enough to separate substantially all unsealed portions of the front and back panels from one another.  
     
     
         2 . The pouch machine of    claim 1    wherein the pouch is unbalanced and the first and second plates are vertically spaced from one another.  
     
     
         3 . The pouch machine of    claim 2    wherein the first plate overlies the second plate and the source of pressurized gas introduces gas between the plates.  
     
     
         4 . The pouch machine of    claim 1    wherein at least one of the plates engages the uppermost edge of the panel with which it is engageable.  
     
     
         5 . The pouch machine of    claim 1    wherein the first and second plates are horizontally separated to define a gap between them and the pouch, when engaging the plates, spans said gap.  
     
     
         6 . A filler wheel for a rotary pouch machine of the type which forms a series of pouches in a web of pouch material, the pouches being defined by front and back panels joined by side seals and a closed bottom, successive pouches having different widths, the tops of the pouches prior to filling being open to define a mouth, the filler wheel comprising: 
 a vacuum transfer wheel mounted for rotation and having a plurality of lands on its periphery for receiving and temporarily fixing thereto the side seals of the web of pouches fed into the transfer wheel at an entry point, the lands being unequally-spaced to match the different widths of the pouches;    air delivery means for creating a zone of pressurized air in the path of the pouch mouths downstream of the entry point; and    first and second plates engageable with the upper portions of the front and back panels, respectively, in the zone of pressurized air to direct the air into the pouches.    
     
     
         7 . The filler wheel of    claim 6    wherein the plates are mounted adjacent the vacuum transfer wheel.  
     
     
         8 . In a pouch machine of the type which forms a series of pouches in a web of pouch material, the pouches being defined by front and back panels joined by side seals and a closed bottom, the tops of the pouches prior to filling being open to define a mouth, an improved method of opening the pouches to their maximum volume prior to filling, comprising the steps of: 
 temporarily restricting air flow adjacent both the front and back panels of the pouch by engaging both panels with first and second plates; and    subjecting the fill extent of the mouth of a pouch at one time to a zone of compressed air thereby pressurizing the pouch to an internal pressure high enough to separate substantially all unsealed portions of the front and back panels from one another.    
     
     
         9 . In a pouch machine of the type which forms a series of pouches in a web of pouch material, the pouches being defined by front and back panels joined by side seals and a closed bottom, the tops of the pouches prior to filling being open to define a mouth, an improved method of opening the pouches to their maximum volume prior to filling, comprising the steps of temporarily restricting air flow adjacent both the front and back panels of the pouch by engaging both panels with first and second plates in the vicinity of the mouth of a pouch and then pressurizing the pouch to an internal pressure high enough to separate substantially all unsealed portions of the front and back panels from one another.