Abstract:
A pouch production apparatus includes a pouch forming apparatus operable to form pouches from an elongate web of material and zipper tape and an extrusion apparatus responsive to operation of the pouch forming apparatus and operable to extrude zipper tape. A pneumatic transport apparatus is operable to transport the zipper tape from the extrusion apparatus to the pouch forming apparatus during operation of the pouch forming apparatus. A method of producing a pouch using such apparatus is also disclosed.

Description:
TECHNICAL FIELD  
       [0001]     The present invention relates to a production apparatus and method, and more particularly to an apparatus and method for producing pouches.  
       BACKGROUND ART  
       [0002]     Thermoplastic storage bags or pouches or bags are widely used to store and/or keep items fresh. A thermoplastic storage pouch may be of the reclosable type in the sense that such a bag includes a section of zipper tape joined to an upper edge of thermoplastic film forming the walls of the pouch wherein the zipper tape includes first and second mating sections. The mating sections can be separated from one another to permit articles to be inserted into or withdrawn from the pouch and further may be closed or occluded to seal the pouch. The opening and closing of the sections may be accomplished with or without the aid of a slider that may be mounted on the zipper tape.  
         [0003]     In the past, thermoplastic bags of the foregoing type have been manufactured by separately extruding zipper tape and plastic film and storing the zipper tape and plastic film on separate rolls. Thereafter, the rolls are loaded into a pouch production machine and are unwound from the rolls during production. Such a manufacturing methodology requires bulky and expensive handling apparatus for manipulating the rolls of material. In addition, expense is further increased due to the need for spools or reels upon which the material may be stored.  
         [0004]     Many production techniques have been developed for the production of thermoplastic zipper tape. Specifically, it is well known to extrude zipper tape directly into a water bath and to draw the hardened zipper tape sections from the water bath. See, for example, Chantry et al. U.S. Pat. No. 5,223,187.  
         [0005]     Transport devices have been developed for transporting articles between locations. For example, pneumatic tube systems have been developed for transporting a shuttle containing one or more documents or other articles. In addition, pneumatic systems have been used to pick up waste thermoplastic product and deliver same to a receptacle for recycling.  
       SUMMARY OF THE INVENTION  
       [0006]     According to one aspect of the present invention, a pouch production apparatus includes pouch forming apparatus operable to form pouches from an elongate web of material and zipper tape and an extrusion apparatus responsive to operation of the pouch forming apparatus and operable to extrude zipper tape. A pneumatic transport apparatus is operable to transport the zipper tape from the extrusion apparatus to the pouch forming apparatus during operation of the pouch forming apparatus.  
         [0007]     According to a further aspect of the present invention, a zipper tape transfer system includes an air tube having a first end adapted to receive the zipper tape and a blower for blowing air through the air tube. A venturi is disposed in the air tube adjacent the first end thereof for accelerating air through the air tube.  
         [0008]     In accordance with yet another aspect of the present invention, a method of producing storage pouches includes the steps of supplying an elongate web of pouch body material to pouch forming apparatus, providing a length of zipper tape and using pneumatic transport apparatus to transport the length of zipper tape to the pouch forming apparatus. The pouch forming apparatus is operated to produce storage pouches from the elongate web of pouch body material and the length of zipper tape According to still another aspect of the present invention, a method of transferring zipper tape material includes the steps of guiding a zipper tape through a first end of an air tube, accelerating the zipper tape through the pipe with a blower and a venturi and drawing the zipper tape out a second end of the pipe.  
         [0009]     Other aspects and advantages of the present invention will become apparent upon consideration of the following detailed description and the attached drawings, in which like elements are assigned like reference numerals.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]      FIG. 1  is a block diagram of a pouch production apparatus incorporating the present invention;  
         [0011]      FIG. 2  is a block diagram of a portion of the pouch production apparatus of  FIG. 1  according to a first embodiment of the present invention;  
         [0012]      FIG. 3  is a block diagram of a portion of the pouch production apparatus of  FIG. 1  according to a second embodiment of the present invention;  
         [0013]      FIG. 4  is a combined block diagram and diagrammatic view of a portion of the apparatus of  FIG. 2 ;  
         [0014]      FIG. 5  is a diagrammatic view of the zipper tape transport apparatus of  FIGS. 2 and 3 ; and  
         [0015]      FIG. 6  is a diagrammatic view of the venturi of  FIG. 5 . 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0016]     Referring first to  FIG. 1 , a production system  10  includes a pouch production apparatus  12  that receives zipper tape from a first supply apparatus  14  and pouch body material from a second supply apparatus  16 . In the preferred embodiment, the zipper tape and the pouch body material are both made of thermoplastic polymer material and the pouch body material comprises an elongate web of such thermoplastic material that is stored on a spool or reel or produced in-line using film extrusion technology known in the art. The pouch production apparatus  12  is operable to manufacture a plurality of thermoplastic storage pouches or bags  18  from the zipper tape and the pouch body material.  
         [0017]     Referring next to  FIG. 2 , according to a first embodiment, the zipper tape supply apparatus  14  may comprise an extruder system  20  that is operable to extrude male and female zipper tape profiles. The zipper tape profiles are supplied to a zipper tape transport apparatus  22  that delivers the profiles to the pouch production apparatus  12 .  
         [0018]     The embodiment of  FIG. 2  is referred to as an in-line production system in that the zipper tape is produced and immediately used to form pouches by the pouch production apparatus  12  without the intermediate step of storing the zipper tape, for example, on a spool or reel. If desired, the extruder system  20  may be responsive to the production rate of the pouch production apparatus  12  whereby the extrusion rate of the zipper tape is precisely matched to the line speed of the pouch production apparatus  12 . Alternatively, if desired, the extrusion rate of the extruder system  20  may be somewhat variable and an accumulator may be interposed between the system  20  and the transfer apparatus  22  or between the transfer apparatus  22  and the pouch production apparatus  12  so that any mismatch between the extrusion rate and the line speed of the production apparatus  12  can be accommodated.  
         [0019]     The extruder system  20  may include any conventional extrusion die and associated apparatus as desired. For example, as seen in  FIG. 4 , a conventional extrusion die  40  simultaneously extrudes the male and female profiles into a conventional water bath-cooling tank  42 . Thereafter, the male and female profiles are drawn around one or more rollers  44 ,  46  and are delivered to a dewatering apparatus  48 . The dewatering apparatus  48  removes any water carried by the male and female profiles. The profiles are then preferably delivered separately to a first end  52  of an air tube  54 . Alternatively, the profiles maybe be joined together by nip rolls  50 A,  50 B and delivered to the first end  52  of an air tube  54  as zipper tape.  
         [0020]     According to an alternative embodiment of the present invention as seen in  FIG. 3 , the male and female zipper tape profiles are stored on a spool or reel  24  and are unwound and provided by the zipper tape transport apparatus  22  to the pouch production apparatus  12 .  
         [0021]     As seen in  FIG. 5 , the air tube  54  includes a venturi  56 . A source of pressurized air comprising a blower  58  is coupled by a conduit  60  to the venturi  56  with a valve  61  disposed therebetween. The valve  61  is wide open when the production system  10  starts up so that maximum airflow from the blower  58  is utilized to transport the profiles  55  through the air tube  54 . As the blower  58  continues to produce airflow in the venturi  56 , the high velocity airflow increases the heat within the venturi  56 . To avoid overheating of the venturi  56 , after the profiles  55  exit the air tube  54  and enter the pouch production apparatus  12  through nip rolls  64   a,    64   b,  the valve  61  is manually turned down to decrease the airflow from the blower  58 .  
         [0022]     As seen in  FIG. 6 , the conduit  60  is interconnected with the venturi  56  between an inlet nozzle  66  of the venturi  56  and a body  68  of the venturi  56 . The profiles  55  flow through the venturi inlet nozzle  66  and continue through the venturi body  68  until they exit the venturi  56  into the tube  54 . By rotating the venturi inlet nozzle  66  clockwise or counterclockwise, a gap  70  formed between the venturi inlet nozzle  66  and the venturi body  68  increases or decreases until full optimization of the venturi  56  is achieved.  
         [0023]     The venturi  56  accelerates the air flow through the air tube  54 . When the joined or separated male and female profiles are delivered to the end  52 , the profiles are sucked through the air tube  54  and travel outwardly through a second end  62  to a further pair of nip rolls  64   a,    64   b.  The nip rolls  64   a,    64   b  are driven to deliver the mated male and female profiles to downstream processing apparatus, such as the pouch production apparatus  12 .  
         [0024]     Preferably, the air tube is made of aluminum or stainless steel and is preferably round in cross section. Further, it has been found that mated zipper profiles can be delivered over distances of 75 feet or even greater distances can be traversed through the addition of one or more further venturis and/or blowers and/or by increasing the flow rate of the air delivered by the blower(s).  
       INDUSTRIAL APPLICABILITY  
       [0025]     According to one aspect of the present invention in-line extrusion of zipper tape and transport of such zipper tape to pouch production apparatus are accomplished as the production apparatus is operating to produce pouches. Accordingly, according to this aspect of the present invention, there is no need to store zipper tape on a spool or reel. Further, one or more sources of zipper tape, such as the extruder system  20  or the spool  24 , may supply zipper tape through a transport apparatus  22  to more than one pouch production apparatus. In such a case, zipper tape may be extruded and/or unwound from a spool or reel at a single location in a manufacturing facility and may be delivered by transport apparatus as described herein to plural locations in the production facility at which the pouch production machines are disposed.  
         [0026]     Numerous modifications to the present invention will be apparent to those skilled in the art in view of the foregoing description. Accordingly, this description is to be construed as illustrative only and is presented for the purpose of enabling those skilled in the art to make and use the invention and to teach the best mode of carrying out same. The exclusive rights to all modifications which come within the scope of the appended claims are reserved.