Process and device for the positioning of printed images on package troughs

Abstract

The present invention relates to a process and device for the cyclic positioning of images over package troughs, said images being printed on a covering film.

1 . A process for the cyclic precise positioning of printed images ( 3 ) over package troughs ( 4 ), said images ( 3 ) being printed on a covering film ( 1 ) at a certain distance apart to retain an unprinted strip ( 2 ), using a device ( 10 ) which consists of a first and a second photoelectric cell ( 5 ,  6 ) and a film brake ( 7 ) arranged between the photoelectric cells ( 5 ,  6 ), the covering film ( 1 ) being sealed after positioning on the package trough ( 4 ) and the package ( 8 ) thus obtained and hence the covering film ( 1 ) being fed onward afterwards by a defined distance, wherein 
 at each stoppage of the film, preferably during sealing, it is ascertained whether the second photoelectric cell ( 6 ) detects a strip ( 2 ) and upon detecting a strip the first photoelectric cell ( 5 ) is activated,    during the onward feed of the covering film ( 1 ), the first photoelectric cell ( 5 ) triggers the film brake ( 7 ) as soon as it has detected a strip ( 2 ) between two passing images ( 3 ), so that the onward feed of the covering film ( 1 ) is stopped at the position of the film brake ( 7 ) and the covering film ( 1 ) is stretched as a result of the ongoing forward feed of the package ( 8 ) last sealed.    
     
     
         2 . The process according to    claim 1   , characterized in that the first photoelectric cell ( 5 ) is displaced along the x axis in order to change the time of strip ( 2 ) detection.  
     
     
         3 . The process according to    claim 1    or    2   , characterized in that a printing mark ( 9 ), which is used for the positioning of the images ( 3 ), is printed on the strip ( 2 ).  
     
     
         4 . A device ( 10 ) for the cyclic precise positioning of printed images ( 3 ) over package troughs ( 4 ), said images ( 3 ) being printed on a covering film ( 1 ), using a first and a second photoelectric cell ( 5 ,  6 ) and a film brake ( 7 ) arranged between the photoelectric cells ( 5 ,  6 ).  
     
     
         5 . The device according to    claim 4   , characterized in that the second photoelectric cell ( 6 ) detects the position of the strip ( 2 ) and/or printing mark ( 9 ) at each stoppage of the covering film ( 1 ) and, depending on this, optionally activates the first photoelectric cell ( 5 ) which in turn, if activated, triggers the film brake ( 7 ) as soon as it has detected a strip ( 2 ) and/or printing mark ( 9 ) between two passing images ( 3 ).  
     
     
         6 . The device according to    claim 4    or    5   , characterized in that the second photoelectric cell ( 6 ) is preferably arranged immediately upstream of the sealing device ( 11 ).  
     
     
         7 . The device according to any of    claims 4    to    6   , characterized in that the first photoelectric cell ( 5 ) is pivotable about the z axis in order to change the time of detection of a strip ( 2 ) and/or printing mark ( 9 ).  
     
     
         8 . The device according to any of    claims 4    to    7   , characterized in that detection hysteresis of at least the second photoelectric cell ( 6 ) is <0.4 mm, preferably <0.25 mm and especially preferably <0.15 mm.  
     
     
         9 . The device according to any of    claims 4    to    8   , characterized in that the device is controlled by an SPC.  
     
     
         10 . A film brake having three rolls ( 12  to  14 ) and two braking means ( 15 ,  16 ) which cooperate with the rolls ( 12 ,  14 ), the rolls ( 12 ,  14 ) having a different direction of rotation than the roll ( 13 ).  
     
     
         11 . The film brake according to    claim 10   , characterized in that the roll ( 13 ) has a displaceable bearing.  
     
     
         12 . The film brake according to    claim 10    or    11   , characterized in that the braking means ( 15 ,  16 ) are driven pneumatically or electrically.  
     
     
         13 . The film brake according to any of    claims 10    to    12   , characterized in that the film brake is activated by the first photoelectric cell ( 5 ).