Patent Publication Number: US-6655110-B2

Title: Apparatus to aid in forming a package

Description:
TECHNICAL FIELD 
     The present invention relates to methods and apparatus to aid in the forming of packaging. 
     BACKGROUND OF THE INVENTION 
     There is known packaging apparatus in which plastic film is removed from a roll and delivered to a former. The former forms the plastic film into a tubular configuration. The tubular bag material then passes to a packaging assembly in which the longitudinal edges of the film are sealingly joined and product delivered to internally of the tubular bag material. The tubular bag material is then transversely sealed and cut to form discreet packages. 
     Such packaging machines are described in U.S. Pat. Nos. 4,663,917, 6,185,200 and 4,910,943. 
     There is a requirement for bags to be of a square or generally rectangular configuration with corner flanges. Traditional continuous motion vertical form fill and seal packaging machines are not adapted to produce such packages. 
     OBJECT OF THE INVENTION 
     It is the object of the present invention to overcome or substantially ameliorate the above disadvantage. 
     SUMMARY OF THE INVENTION 
     There is disclosed herein a machine to aid in forming at least one longitudinal flange on tubular bag material into which there is delivered product so that when the tubular bag material is transversely sealed and cut discreet bags of the product are formed, said machine including an assembly having: 
     a base providing a slot along which a fold of the tubular bag material passes in a predetermined direction, the base having apertures facing said slot so as to enable the delivery of a hot gas to said slot to heat said fold; 
     ducts to deliver the hot gas to said apertures; and 
     a pressure device to apply pressure to the fold so that longitudinally extending portions of the bag forming the fold adhere to form said flange. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A preferred form of the present invention will now be described by way of example with reference to the accompanying drawing with schematically depicts a device to aid in forming longitudinally extending flanges on tubular bag material. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In the accompanying drawing there is schematically depicted a machine  10  to aid in forming at least one flange  11  on tubular bag material  12 . The tubular bag material  12  of this embodiment is of a rectangular transverse cross section and is delivered from a former to the machine  10  so that there are four longitudinally extending corner folds  13 . Each fold  13  includes longitudinally extending bag portions  14 . The bag portions  14  adhere to each other to form the longitudinally extending flanges  11 . 
     In forming a bag, product is delivered to the interior  15  of the tubular bag material  12 , and the bag material  12  transversely cut and transversely sealed to form discreet bags of the product. 
     The machine  10  includes an assembly  28  having a base  16  which is generally hollow so as to provide a chamber  17  into which air under pressure is delivered by one or more ducts  18 . Attached to and extending inwardly of the base  16  is a heating element  19  which is electrically heated by means of being attached to a supply of electricity via wires  20 . The element  19  heats air passing through the chamber  17 . 
     The base  16  includes an apertured member  21  which provides a longitudinally extending slot  22  along which the tubular bag material  12  passes in the direction of the arrow  26 . Typically, the tubular bag material  12  would be engaged by rollers or belts that pull the tubular bag material  12  through an associated packaging machine. 
     The member  22  has parallel side walls  23  defining the slot  22 , which walls  23  each have a plurality of apertures  24  which by ducts are in communication with the chamber  17  so as to receive hot air therefrom. As the hot air is under pressure, jets of hot air issuing from the apertures  24 . The hot air impinges upon the fold  13  so that the bag material  14  forming the folds  13  is heated. 
     Downstream of the slot  23  is a pressure device  25  that applies pressure to the fold  13  so that the bag material  14  of each fold adheres to form the flanges  11 . In this embodiment the pressure device is a pair of cooperating rollers  27  between which the associated fold  13  passes. Typically, the rollers  27  would be adjustably mounted so that the pressure applied to the associated fold  13  may be adjusted to suit the particular bag material and heating conditions. 
     In the above-described preferred embodiment only one assembly  28  of the machine  10  is described. In this respect it should be appreciated that a machine  10  would require an assembly  28  for each of the folds  13 . Accordingly, in the above-described preferred embodiment four assemblies  28  would be required. However, in forming packages of other configuration, the number of assemblies  28  will change. For example, two assemblies  28  may be used to form a package with a “stand up base” or satchel.