Method and machine for forming gripping elements in bags filled with bulk material

Abstract

Machine comprising at least one station (F) for forming the bag ( 1 ) from a tubular element ( 101 ), at least one station (R) for filling the bag with the material ( 2 ) supplied from a supplying apparatus ( 200 ) and at least one station (S) for sealing the mouth ( 1 a ) of the bag, a first and second die-cutting apparatus ( 500 ) being envisaged for forming at least one first opening ( 6 b ) in the zone of the bottom ( 1 b ) and at least one second opening ( 6 a ) in the zone of the mouth ( 1 a ) of the bag ( 1 ).

1 . Method for forming means for gripping bags to be filled with bulk products, wherein it comprises the following steps: 
 supplying a tubular element to a die-cutting apparatus;    forming at least one opening in a predefined area;    supplying the tubular element to a station for forming a bag;    providing at least two welding lines along the bottom zone lb of the bag and on opposite sides in the longitudinal direction X-X with respect to said opening;    transporting the bag to the filling station and filling the bag;    feeding the bag to a station or closing said bag;    providing at least two welding lines, substantially parallel to the transverse direction Y-Y and at a suitable relative distance in the longitudinal direction X-X of the bag;    forming at least one opening in the zone comprised between the two welds of the mouth of the bag.    
   
   
       2 . Method according to  claim 1 , wherein the tubular element is supplied by means of unwinding thereof from a reel.  
   
   
       3 . Method according to  claim 1 , wherein the tubular element is centred in position during the step involving die-cutting thereof.  
   
   
       4 . Method according to  claim 1 , wherein said at least one opening is a hole.  
   
   
       5 . Method according to  claim 1 , wherein said at least one opening is an eyelet extending in the transverse direction.  
   
   
       6 . Method according to  claim 1 , wherein the opening along the side where the mouth of the bag is situated is formed during a step separate from that for performing welds for closing the said bag.  
   
   
       7 . Method according to  claim 1 , wherein the die-cutting is performed in the hot state.  
   
   
       8 . Method according to  claim 7 , wherein the die-cutting step comprises a step involving taking-in the edge of the opening.  
   
   
       9 . Method according to  claim 7 , wherein said step of taking-in the edge of the opening is performed by means of eccentric rotation of the die-cutting apparatus around the centre of the opening.  
   
   
       10 . Method according to  claim 1 , wherein it comprises an additional step involving application of a strip of material to the tubular element upstream of the first operation involving die-cutting of the bottom of the bag.  
   
   
       11 . Method according to  claim 10 , wherein said strip of material is applied symmetrically with respect to the line for cutting the bottom during forming of the bag.  
   
   
       12 . Method according to  claim 1 , wherein said strip of material is a label.  
   
   
       13 . Machine comprising at least one station for forming the bag from a tubular element, at least one station for filling the bag with the material supplied from a supplying apparatus and at least one station for sealing the mouth of the bag, wherein it comprises a first and a second die-cutting apparatus for forming at least one first opening in the zone of the bottom and at least one second opening in the zone of the mouth of the bag.  
   
   
       14 . Machine according to  claim 13 , wherein said die-cutting apparatus is arranged upstream of the forming station.  
   
   
       15 . Machine according to  claim 13 , wherein said first die-cutting apparatus comprises means for positioning the tubular element in the longitudinal direction (X-X).  
   
   
       16 . Machine according to  claim 15 , wherein said means for positioning the tubular element consist of at least one pair of fixed rollers and a movable roller for adjusting centring of the tubular element with respect to the apparatus for first die-cutting of the tubular element.  
   
   
       17 . Machine according to  claim 13 , wherein said first die-cutting apparatus performs first successive openings at a predefined interaxial distance.  
   
   
       18 . Machine according to  claim 17 , wherein said interaxial distance of the first openings in the longitudinal direction is predetermined depending on the length of the bag in the same longitudinal direction.  
   
   
       19 . Machine according to  claim 13 , wherein said first die-cutting apparatus is controlled by means for controlling and implementing the automatic machine cycle.  
   
   
       20 . Machine according to  claim 13 , wherein means for welding the bottom of the bag are arranged in the forming station.  
   
   
       21 . Machine according to  claim 20 , wherein said means for welding the bottom are able to form two welding lines extending in a direction substantially parallel to the transverse direction (Y-Y) of the bag and spaced from each other in the longitudinal direction (X-X) by a suitable amount able to contain the opening for gripping the bag.  
   
   
       22 . Machine according to  claim 13 , wherein means for sealing the mouth of the bag are arranged in the sealing station  
   
   
       23 . Machine according to  claim 22 , wherein said means for welding the mouth of the bag are able to form two welding lines extending in a direction substantially parallel to the transverse direction (Y-Y) of the bag and spaced from each other in the longitudinal direction (X-X) by a suitable amount able to contain a second opening for gripping the bag.  
   
   
       24 . Machine according to  claim 13 , wherein said second die-cutting apparatus is arranged downstream of the sealing station.  
   
   
       25 . Machine according to  claim 13 , wherein said second die-cutting apparatus is able to form openings in a strip of bag situated between the two seals of the mouth of the said bag.  
   
   
       26 . Machine according to  claim 13 , wherein said second die-cutting apparatus is controlled by means for controlling and implementing the automatic machine cycle.  
   
   
       27 . Machine according to  claim 13 , wherein said die-cutting apparatus is of the hot type.  
   
   
       28 . Machine according to  claim 13 , wherein said die-cutting apparatus is associated with means able to impart an eccentric rotation of the apparatus about the centre of the opening.  
   
   
       29 . Machine according to  claim 13 , wherein it comprises an apparatus (E) for applying a layer of material to the tubular element.  
   
   
       30 . Machine according to  claim 29 , wherein it comprises an apparatus (E) for applying a layer of material which is arranged upstream of the apparatus for first die-cutting the bottom of the bag.  
   
   
       31 . Machine according to  claim 30 , wherein said apparatus for applying a layer of material is a labeling machine.  
   
   
       32 . Bag filled with bulk material, wherein it comprises at least one first opening arranged on the bottom of the bag and at least one second opening arranged in the zone where the mouth of the said bag is situated, each gripping opening being delimited in the longitudinal direction (X-X) of the bag by at least two welding lines extending in a transverse direction (Y-Y) of the bag and suitably spaced from each other in the longitudinal direction (X-X) of the said bag.  
   
   
       33 . (canceled)  
   
   
       34 . (canceled)  
   
   
       35 . Bag according to  claim 32 , wherein said at least one first and second openings consist of a hole.  
   
   
       36 . Bag according to  claim 32 , wherein said at least one first and second openings consist of an eyelet extending in the transverse direction (Y-Y).