Load shaping of stretch wrapped palletized loads

Abstract

Compressive forces are applied across opposing sides of a palletized load either before, after, or during stretch wrapping to generate a load having a desirable shape profile once wrapped. The compressive forces may be used, for example, in some instances to overcompress a load in one or more lateral directions beyond desired finished dimensions, such that once the load is thereafter allowed to recover or relax, the load assumes the desired finished dimensions.

1 . A method of generating a wrapped load having a first length in a first lateral direction, the method comprising:
 receiving a load that is unwrapped and that has a second length in the first lateral direction that is larger than the first length in the first lateral direction;   applying a compressive force to opposing sides of the load along the first lateral direction to compress the load to a third length in the first lateral direction that is smaller than the first length in the first lateral direction;   wrapping the load with packaging material using a load wrapping apparatus by generating relative rotation between a packaging material dispenser and the load about an axis of rotation; and   allowing the load to recover in the first lateral direction such that the load has the first length in the first lateral direction after the load has been wrapped with packaging material.   
     
     
         2 . The method of  claim 1 , wherein the load is supported by a pallet, and the first length is substantially equal to a length of the pallet in the first lateral direction. 
     
     
         3 . The method of  claim 1 , wherein applying the compressive force is performed prior to wrapping the load. 
     
     
         4 . The method of  claim 1 , wherein applying the compressive force is performed after wrapping the load. 
     
     
         5 . The method of  claim 1 , wherein applying the compressive force is performed while wrapping the load. 
     
     
         6 . The method of  claim 5 , wherein applying the compressive force to the opposing sides of the load includes positioning opposing press members adjacent the opposing sides of the load, wherein wrapping the load is performed while the opposing press members are positioned adjacent the opposing sides of the load such that packaging material is wrapped over at least a portion of the opposing press members, and wherein the method further comprises withdrawing the opposing press members after wrapping the load. 
     
     
         7 . The method of  claim 6 , wherein withdrawing the opposing press members further comprises engaging the load to restrict lifting of the load while withdrawing the opposing press members. 
     
     
         8 . The method of  claim 1 , wherein applying the compressive force is performed while the load is supported by a conveyor. 
     
     
         9 . The method of  claim 1 , wherein the opposing sides includes first and second sides, and applying the compressive force is performed using first and second opposing press members respectively contacting the first and second sides. 
     
     
         10 . The method of  claim 9 , wherein the first and second press members respectively contact the first and second sides substantially across at least about 50 percent of the second length. 
     
     
         11 . The method of  claim 9 , wherein the first and second sides have respective first and second heights, and wherein the first and second press members respectively contact the first and second sides across at least about 50 percent of the first and second heights. 
     
     
         12 . The method of  claim 9 , wherein the first and second press members respectively contact the first and second sides proximate midpoints of the first and second sides. 
     
     
         13 . The method of  claim 9 , wherein the first and second press members respectively include first and second planar surfaces that respectively contact the first and second sides. 
     
     
         14 . The method of  claim 9 , wherein applying the compressive force includes moving the first and second press members a predetermined distance. 
     
     
         15 . The method of  claim 9 , wherein applying the compressive force includes moving the first and second press members to apply a predetermined force to the load. 
     
     
         16 . The method of  claim 9 , further comprising determining at least one of a distance to move the first and second press members and a force to apply with the first and second press members based on the first and second lengths. 
     
     
         17 . The method of  claim 1 , wherein the compressive force is a first compressive force and the opposing sides are a first set of opposing sides of the load, the method further comprising generating the wrapped load to have a first width in a second lateral direction that is substantially perpendicular to the first lateral direction, wherein the load is received with a second width in the second lateral direction that is larger than the first width in the second lateral direction, and wherein generating the wrapped load to have the first width in the second lateral direction includes:
 applying a second compressive force to a second set of opposing sides of the load along the second lateral direction to compress the load to a third width in the second lateral direction that is smaller than the first width in the second lateral direction; and   allowing the load to recover in the second lateral direction such that the load has the first width in the second lateral direction after the load has been wrapped with packaging material.   
     
     
         18 . The method of  claim 17 , wherein applying the first compressive force and applying the second compressive force are performed concurrently. 
     
     
         19 . The method of  claim 17 , wherein applying the first compressive force and applying the second compressive force are performed sequentially. 
     
     
         20 . The method of  claim 17 , wherein the first set of opposing sides includes first and second sides and the second set of opposing sides includes third and fourth sides, wherein applying the first and second compressive forces is performed using first, second, third, and fourth press members respectively contacting the first, second, third, and fourth sides. 
     
     
         21 . The method of  claim 20 , wherein the first, second, third, and fourth press members are supported by a support structure providing movement of the first and second press members substantially along the first lateral direction and movement of the third and fourth press members substantially along the second lateral direction. 
     
     
         22 . The method of  claim 21 , wherein applying the first and second compressive forces is performed using at least one drive operably coupled to the first, second, third, and fourth press members to move the first and second press members along the first lateral direction to apply the first compressive force to the first set of opposing sides and to move the third and fourth press members along the second lateral direction to apply the second compressive force to the second set of opposing sides. 
     
     
         23 . The method of  claim 22 , wherein the at least one drive includes at least one screw drive, at least one chain drive, at least one belt drive, at least one electric motor, at least one electric drive, at least one pneumatic drive, or at least one hydraulic actuator. 
     
     
         24 . The method of  claim 20 , wherein the first, second, third, and fourth press members are configured to apply the first and second compressive forces while the load is disposed on a conveyor, wherein the third and fourth press members each comprise at least one door movable between an open position and a closed position, the method further comprising:
 prior to applying the first and second compressive forces, moving the at least one door of the third press member to the open position when conveying the load along the conveyor to position the load between the first and second press members; and   after applying the first and second compressive forces, moving the at least one door of the fourth press member to the open position when conveying the load along the conveyor downstream of the first and second press members.   
     
     
         25 . The method of  claim 20 , further comprising:
 prior to applying the second compressive forces, moving the first, second, third, and fourth press members in a substantially vertical direction to respectively position the first, second, third, and fourth press members adjacent to the first, second, third, and fourth sides; and   after applying the first and second compressive forces, moving the first, second, third, and fourth press members in an opposite substantially vertical direction.   
     
     
         26 . The method of  claim 20 , wherein the first and third sides of the load extend along a first corner of the load, and the first and third press members include a plurality of interleaved fingers extending laterally to constrain the first corner of the load when applying the first and second compressive forces. 
     
     
         27 . The method of  claim 20 , wherein the first and third sides of the load extend along a first corner of the load, and the first and third press members are movably coupled to a floating corner member that extends along the first corner to constrain the first corner of the load when applying the first and second compressive forces. 
     
     
         28 . The method of  claim 1 , wherein wrapping the load is performed after applying the compressive force and using a wrap profile that applies a first containment force to the load based upon compressed dimensions of the load during wrapping such that a second containment force that is higher than the first containment force is applied to the load after recovery of the load after wrapping. 
     
     
         29 . The method of  claim 1 , wherein wrapping the load is performed while applying the compressive force and using a wrap profile that applies a first containment force to the load based upon compressed dimensions of the load during wrapping such that a second containment force that is higher than the first containment force is applied to the load after recovery of the load after wrapping. 
     
     
         30 . The method of  claim 1 , wherein wrapping the load is performed prior to applying the compressive force and using a wrap profile that applies a first containment force to the load based upon uncompressed dimensions of the load during wrapping such that a second containment force that is lower than the first containment force is applied to the load after recovery of the load after applying the compressive force. 
     
     
         31 . A method of generating a wrapped load having a first length in a first lateral direction and a first width in a second lateral direction that is substantially perpendicular to the first lateral direction, the method comprising:
 receiving a load that is unwrapped and that has a second length in the first lateral direction and a second width in the second lateral direction;   applying a first compressive force to a first set of opposing sides of the load along the first lateral direction and a second compressive force to a second set of opposing sides of the load along the second lateral direction to compress the load to a third length in the first lateral direction and a third width in the second lateral direction;   after applying and releasing the first and second compressive forces, wrapping the load with packaging material using a load wrapping apparatus by generating relative rotation between a packaging material dispenser and the load about an axis of rotation; and   allowing the load to recover in the first and second lateral directions after wrapping the load such that the load has the first length in the first lateral direction and the first width in the second lateral direction after the load has been wrapped with packaging material.   
     
     
         32 . A method of generating a wrapped load having a first length in a first lateral direction and a first width in a second lateral direction that is substantially perpendicular to the first lateral direction, the method comprising:
 receiving a load that is unwrapped and that has a second length in the first lateral direction and a second width in the second lateral direction;   applying a first compressive force to a first set of opposing sides of the load along the first lateral direction and a second compressive force to a second set of opposing sides of the load along the second lateral direction to compress the load to a third length in the first lateral direction and a third width in the second lateral direction;   while applying the first and second compressive forces, wrapping the load with packaging material using a load wrapping apparatus by generating relative rotation between a packaging material dispenser and the load about an axis of rotation; and   allowing the load to recover in the first and second lateral directions after wrapping the load such that the load has the first length in the first lateral direction and the first width in the second lateral direction after the load has been wrapped with packaging material.   
     
     
         33 . A method of generating a wrapped load having a first length in a first lateral direction and a first width in a second lateral direction that is substantially perpendicular to the first lateral direction, the method comprising:
 receiving a load that is unwrapped and that has a second length in the first lateral direction and a second width in the second lateral direction;   wrapping the load with packaging material using a load wrapping apparatus by generating relative rotation between a packaging material dispenser and the load about an axis of rotation;   after wrapping the load, applying a first compressive force to a first set of opposing sides of the load along the first lateral direction and a second compressive force to a second set of opposing sides of the load along the second lateral direction to compress the load to a third length in the first lateral direction and a third width in the second lateral direction; and   allowing the load to recover in the first and second lateral directions after wrapping the load and applying the first and second compressive forces such that the load has the first length in the first lateral direction and the first width in the second lateral direction after the load has been wrapped with packaging material.   
     
     
         34 .- 41 . (canceled)