Double stacker system and method

Abstract

A system and method for stacking two bulk bags one on top of the other on a pallet, the method comprising controlling a pallet feeder into providing a pallet; filling a first bag with a first amount of product on the pallet and sealing the first bag; filling a second bag with a second amount of product, and depositing the second bag filled with the second amount of product on top of the first bag on the pallet; and straightening the bags on the pallet; wherein these steps of controlling, filling the first and second bags, and straightening are controlled by a programmable controller, the programmable controller selecting the first amount to be fed to the first bag supported by the pallet and, selecting the second amount to be fed to the second bag.

1 . A system for stacking two bulk bags one on top of the other on a pallet, comprising:
 a pallet feeder;   a first filling station, receiving a pallet from said pallet feeder and a first amount of product to be bagged, said first filling station comprising hooks for securing a first bag with an open mouth above said pallet, and filling the first bag with the first amount of product on top of said pallet;   a second filling station, said second filling station comprising hooks for securing a second bag with an open mouth, said second filling station receiving a second amount of the product to be bagged, filing the second bag with the amount of the product and filing the second bag, receiving the pallet with the first bag filled with the first amount of product and sealed at said first filling station, and depositing said second bag filled with said second amount of product and sealed on top of said first bag;   a bag straightener station, receiving the pallet supporting the second bag on top of the first bag from said second filling station, said bag straightener station straightening the bags on the pallet; and   a programmable controller;   wherein said programmable controller operates said pallet feeder into sending a pallet to said first filling station when said first filling station is empty, selects said first amount to be fed to said first bag supported by the pallet at said first filling station, operates said first filling station to send the pallet supporting the first bag filled with the first amount of product to said second filling station when said second filling station is empty, selects said second amount to be fed to said second bag at said second filling station, operates said first filling station to send the pallet with the first bag filled with the first amount of product and sealed at said first filling station to said second filling station when said second bag is filled, and said second filling station to send the pallet supporting the first bag filled with the first amount of product and the second bag filled with the second amount of product on top of the first bag to said bag straightener station when said bag straightener station is empty.   
     
     
         2 . The system of  claim 1 , comprising a batching supply, said batching supply feeding said first filling station with said first amount of product and said second filling station with said second amount of product. 
     
     
         3 . The system of  claim 1 , wherein said pallet feeder moves a pallet to said first feeding station when instructed by said programmable controller. 
     
     
         4 . The system of  claim 1 , further comprising a compression station, receiving the pallet supporting the first bag filled with the first amount of product and sealed at said first filling station, said compression station compacting said first bag, said programmable controller operating said compression station into sending the pallet supporting the first bag to said second filling station when said second filling station is empty of a pallet. 
     
     
         5 . The system of  claim 1 , wherein said bag straightener station comprises:
 walls; and   a compression plate;   wherein said walls are controlled by said programmable controller into moving from an opened position, to receive the pallet supporting the first and second bags from the second filling station, to an enclosure position around the pallet supporting the first and second bags; and said compression plate is then controlled by said programmable controller to compress the bags in the enclosure formed by said walls.   
     
     
         6 . A method for stacking two bulk bags one on top of the other on a pallet, comprising:
 controlling a pallet feeder into providing a pallet;   filling a first bag with a first amount of product on the pallet and sealing the first bag;   filling a second bag with a second amount of product, and depositing the second bag filled with the second amount of product on top of the first bag on the pallet; and   straightening the bags on the pallet;   wherein said controlling, filling the first and second bags, and straightening are controlled by a programmable controller, the programmable controller selecting the first amount to be fed to the first bag supported by the pallet and, selecting the second amount to be fed to the second bag.   
     
     
         7 . The method of  claim 6 , comprising feeding said filling of the first bag and said filling of the second bag through a batching supply controlled by the programmable controller. 
     
     
         8 . The method of  claim 6 , wherein said straightening the bags on the pallet comprises centering the pallet supporting the second bag on top of the first bag within vertical walls, controlling the walls into moving from an opened position to an enclosure position around the pallet supporting the first and second bags; and activating, by the programmable controller, compression of the bags supported by the pallet in the enclosure formed by the vertical walls by a compression plate. 
     
     
         9 . The method of  claim 6 , comprising selecting, by the programmable controller, the first and second amounts of product to be filed in the first bag and in the second bag respectively, from a batching supply. 
     
     
         10 . The method of  claim 6 , comprising an operator positioning the first bag with an open mouth and activating feeding of the first amount of product within the first bag, and an operator positioning the second bag with an open mouth and activating feeding of the second amount of product within the second bag. 
     
     
         11 . The method of  claim 6 , wherein said filing the first bag comprises shaking the first bag and guiding the first bag into a shape footprint corresponding to the pallet using guiding plates. 
     
     
         12 . The method of  claim 6 , comprising, before said depositing the second bag filled with the second amount of product on top of the first bag filled with the first amount of product, compacting a positioning hole in a top surface of the first bag. 
     
     
         13 . The method of  claim 6 , comprising filling the second bag, lifting up the filled second bag, positioning the filled first bag underneath the filled second bag, and depositing the second bag filled with the second amount of product on top of the first bag on the pallet. 
     
     
         14 . A bag straightener, comprising:
 vertical walls; and   a top compression plate;   wherein said walls are controlled by cylinders into moving from an opened position, to receive a bag, to an enclosure position around the bag; and said compression plate is then actuated by a compaction cylinder operating a compaction shaft supporting the compression plate into compressing the bag in the enclosure formed by said walls.