Shrink wrap machine with film cutting mechanism, film cutting assembly, and related methods

Abstract

A machine is disclosed for shrink wrapping a load of a given size, the machine including a supply conveyor for supplying the load to a wrapping zone, and a wrap conveyor disposed in the wrapping zone, the wrap conveyor receiving the load from the supply conveyor. A film supply supplies a film to the wrapping zone. The film supply includes a cutting mechanism having a position selectively fixed within a cutting zone. A wrap guide is disposed in the wrapping zone for guiding film received from the film supply in a wrap path proximate the wrap conveyor so as to place the film on the load. The wrap guide includes a wrapping bar that moves along the wrap path so as to move the film at a speed varying between a maximum speed and a minimum speed. The cutting mechanism cuts the film when the film speed is below the maximum speed. A heat supply shrinks the film so as to shrink wrap the load. Related machines, cutting assemblies, and methods are disclosed.

1 . A machine for shrink wrapping a load of a given size, the machine comprising: 
 a supply conveyor for supplying the load to a wrapping zone;    a wrap conveyor disposed in the wrapping zone, the wrap conveyor receiving the load from the supply conveyor;    a film supply for supplying a film to the wrapping zone, the film supply including a cutting mechanism having a position selectively fixed within a cutting zone;    a wrap guide disposed in the wrapping zone for guiding film received from the film supply in a wrap path proximate the wrap conveyor so as to place the film on the load, the wrap guide including a wrapping bar that moves along the wrap path so as to move the film at a speed varying between a maximum speed and a minimum speed, the cutting mechanism cutting the film when the film speed is below the maximum speed; and    a heat supply for shrinking the film so as to shrink wrap the load.    
   
   
       2 . The machine of  claim 1 , wherein the film supply includes a track extending along the cutting zone, and the cutting mechanism is positionable along the track.  
   
   
       3 . The machine of  claim 1 , wherein the film supply includes a variable speed vacuum belt operative downstream of the cutting mechanism for moving the film to the wrapping bar.  
   
   
       4 . The machine of  claim 3 , further including a servomotor for driving the vacuum belt at a varying speed corresponding to the speed of the wrapping bar.  
   
   
       5 . The machine of  claim 4 , wherein the cutting mechanism is driven by the servomotor.  
   
   
       6 . The machine of  claim 5 , wherein the cutting mechanism is triggered by an electronic clutch.  
   
   
       7 . The machine of  claim 6 , wherein the cutting mechanism rotates substantially synchronized with the film speed.  
   
   
       8 . The machine of  claim 1 , wherein the cutting mechanism includes a cutter triggered when the film is substantially at or proximate the minimum speed.  
   
   
       9 . The machine of  claim 1 , wherein the film supply includes a film supply roll and a plurality of dance bars.  
   
   
       10 . The machine of  claim 1 , wherein the position of the cutting mechanism is dependent on one or more of: the size of the load, a length of the film after cutting, a point in a wrap cycle in which the cutting mechanism cuts the film, and an amount of leading edge of film placed beneath the load during the wrap cycle.  
   
   
       11 . A cut film supplying assembly for a machine for shrink wrapping a load of a given size, the assembly comprising: 
 a wrap conveyor disposed in a wrapping zone;    a film supply for supplying a film to the wrapping zone, the film supply including a cutting mechanism having a position selectively fixed within a cutting zone; and    a wrap guide disposed in the wrapping zone for guiding film received from the film supply in a wrap path proximate the load on the wrap conveyor so as to place the film on the load, the wrap guide including a wrapping bar that moves along the wrap path so as to move the film at a speed varying between a maximum speed and a minimum speed, the cutting mechanism cutting the film when the film speed is below the maximum speed.    
   
   
       12 . The assembly of  claim 11 , wherein the film supply includes a track extending along the cutting zone, and the cutting mechanism is positionable along the track.  
   
   
       13 . The assembly of  claim 11 , wherein the film supply includes a variable speed vacuum belt operative downstream of the cutting mechanism for moving the film to the wrapping bar.  
   
   
       14 . The assembly of  claim 13 , further including a servomotor for driving the vacuum belt at a varying speed corresponding to the speed of the wrapping bar.  
   
   
       15 . The assembly of  claim 14 , wherein the cutting mechanism is driven by the servomotor.  
   
   
       16 . The assembly of  claim 15 , wherein the cutting mechanism is triggered by an electronic clutch.  
   
   
       17 . The assembly of  claim 16 , wherein the cutting mechanism rotates substantially synchronized with the film speed.  
   
   
       18 . The assembly of  claim 11 , wherein the cutting mechanism includes a cutter triggered when the film is substantially at or proximate the minimum speed.  
   
   
       19 . The assembly of  claim 11 , wherein the film supply includes a film supply roll and a plurality of dance bars.  
   
   
       20 . The assembly of  claim 11 , wherein the position of the cutting mechanism is dependent on one or more of: the size of the load, a length of the film after cutting, a point in a wrap cycle in which the cutting mechanism cuts the film, and an amount of leading edge of film placed beneath the load during the wrap cycle.  
   
   
       21 . A machine for shrink wrapping a load of a given size, the machine comprising: 
 a supply conveyor for supplying the load to a wrapping zone;    a wrap conveyor disposed in the wrapping zone, the wrap conveyor receiving the load from the supply conveyor;    a film supply for supplying a film to the wrapping zone;    a wrap guide disposed in the wrapping zone for guiding film received from the film supply in a wrap path proximate the wrap conveyor so as to place the film on the load, the wrap guide moving the film along the wrap path at a speed varying between a maximum speed and a minimum speed;    selectively fixable cutting means for cutting the film when the film speed is below the maximum speed; and    a heat supply for shrinking the film so as to shrink wrap the load.    
   
   
       22 . The machine of  claim 21 , wherein the film supply includes a track extending along the cutting zone, and the cutting mechanism is positionable along the track.  
   
   
       23 . The machine of  claim 21 , wherein the film supply includes a variable speed vacuum belt operative downstream of the cutting mechanism for moving the film to the wrapping bar.  
   
   
       24 . The machine of  claim 23 , further including a servomotor for driving the vacuum belt at a varying speed corresponding to the speed of the wrapping bar.  
   
   
       25 . The machine of  claim 24 , wherein the cutting mechanism is driven by the servomotor.  
   
   
       26 . The machine of  claim 25 , wherein the cutting mechanism is triggered by an electronic clutch.  
   
   
       27 . The machine of  claim 26 , wherein the cutting mechanism rotates substantially synchronized with the film speed.  
   
   
       28 . The machine of  claim 21 , wherein the cutting mechanism includes a cutter triggered when the film is substantially at or proximate the minimum speed.  
   
   
       29 . The machine of  claim 21 , wherein the film supply includes a film supply roll and a plurality of dance bars.  
   
   
       30 . The machine of  claim 21 , wherein the position of the cutting mechanism is dependent on one or more of: the size of the load, a length of the film after cutting, a point in a wrap cycle in which the cutting mechanism cuts the film, and an amount of leading edge of film placed beneath the load during the wrap cycle.  
   
   
       31 . A cut film supplying assembly for a machine for shrink wrapping a load of a given size, the assembly comprising: 
 a wrap conveyor disposed in a wrapping zone, the wrap conveyor receiving the load from the supply conveyor;    a film supply for supplying a film to the wrapping zone; and    a wrap guide disposed in the wrapping zone for guiding film received from the film supply in a wrap path proximate the load on the wrap conveyor so as to place the film on the load, the wrap guide moving the film along the wrap path at a speed varying between a maximum speed and a minimum speed; and    selectively fixable cutting means for cutting the film when the film speed is below the maximum speed.    
   
   
       32 . The assembly of  claim 31 , wherein the film supply includes a track extending along the cutting zone, and the cutting mechanism is positionable along the track.  
   
   
       33 . The assembly of  claim 31 , wherein the film supply includes a variable speed vacuum belt operative downstream of the cutting mechanism for moving the film to the wrapping bar.  
   
   
       34 . The assembly of  claim 33 , further including a servomotor for driving the vacuum belt at a varying speed corresponding to the speed of the wrapping bar.  
   
   
       35 . The assembly of  claim 34 , wherein the cutting mechanism is driven by the servomotor.  
   
   
       36 . The assembly of  claim 35 , wherein the cutting mechanism is triggered by an electronic clutch.  
   
   
       37 . The assembly of  claim 36 , wherein the cutting mechanism rotates substantially synchronized with the film speed.  
   
   
       38 . The assembly of  claim 31 , wherein the cutting mechanism includes a cutter triggered when the film is substantially at or proximate the minimum speed.  
   
   
       39 . The assembly of  claim 31 , wherein the film supply includes a film supply roll and a plurality of dance bars.  
   
   
       40 . The assembly of  claim 31 , wherein the position of the cutting mechanism is dependent on one or more of: the size of the load, a length of the film after cutting, a point in a wrap cycle in which the cutting mechanism cuts the film, and an amount of leading edge of film placed beneath the load during the wrap cycle.  
   
   
       41 . A machine for shrink wrapping a load of a given size, the machine comprising: 
 a supply conveyor for supplying the load to a wrapping zone;    a wrap conveyor disposed in the wrapping zone, the wrap conveyor receiving the load from the supply conveyor;    a film supply for supplying a film to the wrapping zone, the film supply including a cutting mechanism having a position selectively fixed within a cutting zone;    a wrap guide disposed in the wrapping zone for guiding film received from the film supply in a wrap path proximate the wrap conveyor so as to place the film on the load, the wrap guide including at least one wrapping bar that moves along the wrap path so as to move the film at a speed varying between a maximum speed and a minimum speed, the cutting mechanism cutting the film when the film speed is substantially at or proximate the minimum speed; and    a heat supply for shrinking the film so as to shrink wrap the load.    
   
   
       42 . The machine of  claim 41 , wherein the film supply includes a track extending along the cutting zone, and the cutting mechanism is positionable along the track.  
   
   
       43 . The machine of  claim 41 , wherein the film supply includes a variable speed vacuum belt operative downstream of the cutting mechanism for moving the film to the wrapping bar.  
   
   
       44 . The machine of  claim 43 , further including a servomotor for driving the vacuum belt at a varying speed corresponding to the speed of the wrapping bar.  
   
   
       45 . The machine of  claim 44 , wherein the cutting mechanism is driven by the servomotor.  
   
   
       46 . The machine of  claim 45 , wherein the cutting mechanism is triggered by an electronic clutch.  
   
   
       47 . The machine of  claim 46 , wherein the cutting mechanism rotates substantially synchronized with the film speed.  
   
   
       48 . The machine of  claim 41 , wherein the cutting mechanism includes a cutter triggered when the film is substantially at or proximate the minimum speed.  
   
   
       49 . The machine of  claim 41 , wherein the film supply includes a film supply roll and a plurality of dance bars.  
   
   
       50 . The machine of  claim 41 , wherein the position of the cutting mechanism is dependent on one or more of: the size of the load, a length of the film after cutting, a point in a wrap cycle in which the cutting mechanism cuts the film, and an amount of leading edge of film placed beneath the load during the wrap cycle.  
   
   
       51 . A cut film supplying assembly for a machine for shrink wrapping a load of a given size, the assembly comprising: 
 a wrap conveyor disposed in a wrapping zone;    a film supply for supplying a film to the wrapping zone, the film supply including a cutting mechanism having a position selectively fixed within a cutting zone; and    a wrap guide disposed in the wrapping zone for guiding film received from the film supply in a wrap path proximate the load on the wrap conveyor so as to place the film on the load, the wrap guide including at least one wrapping bar that moves along the wrap path so as to move the film at a speed varying between a maximum speed and a minimum speed, the cutting mechanism cutting the film when the film speed is substantially at or proximate the minimum speed.    
   
   
       52 . The assembly of  claim 51 , wherein the film supply includes a track extending along the cutting zone, and the cutting mechanism is positionable along the track.  
   
   
       53 . The assembly of  claim 51 , wherein the film supply includes a variable speed vacuum belt operative downstream of the cutting mechanism for moving the film to the wrapping bar.  
   
   
       54 . The assembly of  claim 53 , further including a servomotor for driving the vacuum belt at a varying speed corresponding to the speed of the wrapping bar.  
   
   
       55 . The assembly of  claim 54 , wherein the cutting mechanism is driven by the servomotor.  
   
   
       56 . The assembly of  claim 55 , wherein the cutting mechanism is triggered by an electronic clutch.  
   
   
       57 . The assembly of  claim 56 , wherein the cutting mechanism rotates substantially synchronized with the film speed.  
   
   
       58 . The assembly of  claim 51 , wherein the cutting mechanism includes a cutter triggered when the film is substantially at or proximate the minimum speed.  
   
   
       59 . The assembly of  claim 51 , wherein the film supply includes a film supply roll and a plurality of dance bars.  
   
   
       60 . The assembly of  claim 51 , wherein the position of the cutting mechanism is dependent on one or more of: the size of the load, a length of the film after cutting, a point in a wrap cycle in which the cutting mechanism cuts the film, and an amount of leading edge of film placed beneath the load during the wrap cycle.  
   
   
       61 . A method for selectively shrink wrapping a first load of a first size and a second load of a second size, the method comprising the steps of: 
 (a) fixing a cutting mechanism in a first position in a cutting zone, the first position dependent upon the size of the first load;    (b) supplying the first load of the first size to a wrapping conveyor;    (c) supplying a film for wrapping the first load;    (d) driving a wrap guide in a wrap path proximate the wrap conveyor so as to place the film on the first load, the wrap guide including a wrapping bar that moves along the wrap path so as to move the film at a speed varying between a maximum speed and a minimum speed;    (e) cutting the film with the cutting mechanism when the film speed is below the maximum speed;    (f) heating the film so as to shrink wrap the first load;    (g) fixing the cutting mechanism in a second position within the cutting zone, the second position dependent upon the size of the second load; and    (h) repeating steps (b) to (f) with the second load.    
   
   
       62 . The method of  claim 61 , wherein step (e) includes cutting the film when it is substantially at or proximate the minimum speed.  
   
   
       63 . The method of  claim 61 , wherein steps (a) and (g) include moving the cutting mechanism along a track and fixing the cutting mechanism at the respective first or second position along the track.  
   
   
       64 . The method of  claim 63 , wherein the first and second positions are determined based on one or more of: the size of the load, a length of the film after cutting, a point in a wrap cycle in which the cutting mechanism cuts the film, and an amount of leading edge of film placed beneath the load during the wrap cycle.  
   
   
       65 . A method for shrink wrapping a load having a size, the method comprising the steps of: 
 (a) selecting a cutting position from a range of cutting positions within a cutting zone dependent on the size of the load;    (b) fixing a cutting mechanism in the cutting position;    (c) supplying the load to a wrapping conveyor;    (d) supplying a film for wrapping the load;    (e) driving a wrap guide in a wrap path proximate the wrap conveyor so as to place the film on the load, the wrap guide including a wrapping bar that moves along the wrap path so as to move the film at a speed varying between a maximum speed and a minimum speed;    (f) cutting the film with the cutting mechanism when the film speed is below the maximum speed; and    (g) heating the film so as to shrink wrap the first load.    
   
   
       66 . The method of  claim 65 , wherein step (f) includes cutting the film when it is substantially at or proximate the minimum speed.  
   
   
       67 . The method of  claim 65 , wherein step (a) includes moving the cutting mechanism along a track and fixing the cutting mechanism at the selected cutting position along the track.  
   
   
       68 . The method of  claim 67 , wherein the selected cutting position is determined based on one or more of: the size of the load, a length of the film after cutting, a point in a wrap cycle in which the cutting mechanism cuts the film, and an amount of leading edge of film placed beneath the load during the wrap cycle.