Vertical bag form-fill-seal packaging method

Abstract

The present invention provides a first transfer unit instead of a stationary chute. The first drive unit drives the first transfer unit and is controlled to maintain a bag ejection interval or bag posture. Thus, variation of the bag-to-bag pitch and bag posture even in a high-speed operation with an improved bag-forming capacity is prevented.

1 . A method of forming a plurality of bags with items filled therein and transferring the bags to an external device, comprising steps of: 
 forming bags from a film while filling the bags with items;    severing each of the bags;    ejecting the severed bags one by one onto a first transfer unit;    carrying the bags diagonally downward with the first transfer unit, a speed at which the first transfer unit carries the bags being controlled to be faster as an ejection interval at which the first transfer unit receives the severed bags becomes shorter;    ejecting the bags from the first transfer unit onto a second transfer unit;    carrying the bags with the second transfer unit in a direction not parallel to the direction in which the first transfer unit carries the bags; and    ejecting the bags from the second transfer unit onto the external device, ejection intervals at which the second transfer unit ejects the bags onto the external device being substantially even.    
   
   
       2 . The method as defined in  claim 1 , wherein 
 during the ejection of the bags from the first transfer unit to the second transfer unit, a posture of the bags is controlled.    
   
   
       3 . The method as defined in  claim 1 , wherein 
 the first transfer unit is a belt.    
   
   
       4 . The method as defined in  claim 3 , wherein 
 the belt is inclined so that the bags move diagonally downward.    
   
   
       5 . The method as defined in  claim 1 , wherein 
 in the carrying of the bags by the first transfer unit, the speed of the first transfer unit is controlled according to control settings stored in a memory storage unit.    
   
   
       6 . The method as defined in  claim 1 , wherein 
 in the ejection of the bags from the first transfer unit, an ejection interval of the first transfer unit is controlled according to control settings stored in a memory storage unit.    
   
   
       7 . The method as defined in  claim 1 , wherein 
 the forming of the bags includes 
 forming the film into a tubular shape,  
 transferring the tubular-shaped film downward,  
 vertically sealing an overlapped part of the tubular-shaped film,  
 transversely sealing the tubular-shaped film to form the bags, and  
 severing and ejecting each of the bags.  
   
   
   
       8 . The method as defined in  claim 7 , wherein 
 the sealing is by heat-sealing.    
   
   
       9 . The method as defined in  claim 1 , wherein 
 in the ejection of the bags onto the first transfer unit, the severed bags are dropped onto the first transfer unit and the bags do not contact the first transfer unit until after the bags are severed.    
   
   
       10 . The method as defined in  claim 1 , wherein 
 in the ejecting of the bags from the first transfer unit, a speed at which the bags are ejected from the first transfer unit onto the second transfer unit is no faster than a speed at which the bags are ejected onto the first transfer unit.    
   
   
       11 . A method of forming a plurality of bags with items filled therein and transferring the bags to an external device, comprising steps of: 
 forming bags from a film while filling the bags with items;    severing each of the bags;    ejecting the severed bags one by one onto a first transfer unit, the first transfer unit including a pair of belts;    carrying the bags downward with the first transfer unit while sandwiching the bags with the pair of belts, a speed at which the first transfer unit carries the bags being controlled to be faster as an ejection interval at which the first transfer unit receives the severed bags becomes shorter;    ejecting the bags from the first transfer unit onto a second transfer unit;    carrying the bags with the second transfer unit in a direction not parallel to the direction in which the first transfer unit carries the bags; and    ejecting the bags from the second transfer unit onto the external device, ejection intervals at which the second transfer unit ejects the bags onto the external device being substantially even.    
   
   
       12 . The method as defined in  claim 11  wherein 
 during the ejection of the bags from the first transfer unit onto the second transfer unit, a posture of the bags is controlled.    
   
   
       13 . The method as defined in  claim 11 , wherein 
 in the carrying of the bags by the first transfer unit, the speed of the first transfer unit is controlled according to control settings stored in a memory storage unit.    
   
   
       14 . The method as defined in  claim 11 , wherein 
 in the ejection of the bags by the first transfer unit, an ejection interval of the first transfer unit is controlled according to control settings stored in a memory storage unit.    
   
   
       15 . The method as defined in  claim 11 , wherein 
 the forming of the bags includes 
 forming the film into a tubular shape,  
 transferring the tubular-shaped film downward,  
 vertically sealing an overlapped part of the tubular-shaped film,  
 transversely sealing the tubular-shaped packaging material to form the bags, and  
 severing and ejecting each of the bags.  
   
   
   
       16 . The method as defined in  claim 15 , wherein 
 the sealing is by heat-sealing.    
   
   
       17 . The method as defined in  claim 11 , wherein 
 in the ejection of the bags onto the first transfer unit, the severed bags are dropped onto the first transfer unit and the bags do not contact the first transfer unit until after the bags are severed.    
   
   
       18 . The method as defined in  claim 11 , wherein 
 in the ejecting of the bags from the first transfer unit, a speed at which the bags are ejected from the first transfer unit onto the second transfer unit is no faster than a speed at which the bags are ejected onto the first transfer unit.    
   
   
       19 . The method as defined in  claim 11 , wherein 
 in the carrying of the bags by the first transfer unit, a part of a transfer passage formed between the pair of belts of the first transfer unit is inclined so that a direction in which the bags are transferred changes as the bags move through the transfer passage.    
   
   
       20 . The method as defined in  claim 11 , wherein 
 a distance between the pair of belts is adjustable according to a type of the bags.