Stretch wrapping with film severing

Abstract

A load of stretch wrap with a sheet of stretch wrap packaging material by feeding a sheet through a stretch wrap dispenser and stretching and dispensing from the dispenser, and providing relative rotation between the dispenser and the load to wrap the stretched sheet around the load. The portion of the sheet is weakened with a sheet weakening device, and sheet is tensioned to break the sheet at the weakened portion.

What is claimed is:  
     
       1. A process for stretch wrapping a load with a sheet of stretch wrap packaging material comprising: 
       feeding a sheet of stretch wrap packaging material through a stretch wrap dispenser having a prestretch portion, prestretching the sheet of stretch wrap packaging material in the prestretching portion, and dispensing the sheet from the dispenser;  
       providing relative rotation between the dispenser and the load to wrap the stretched sheet of stretch wrap packaging material around the load;  
       weakening a portion of the sheet of stretch wrap packaging material at a predetermined location downstream of the prestretching portion by puncturing the sheet of stretch wrap packaging material at the predetermined location during the relative rotation between the dispenser and the load after prestretching the sheet of stretch wrap packaging material; and  
       tensioning the weakened punctured sheet of stretch wrap packaging material during the relative rotation between the dispenser and the load to break the sheet of stretch wrap packaging material at the weakened punctured portion due to the relative rotation between the dispenser and the load.  
     
     
       2. The process of claim  1 , wherein the tensioning step includes reducing the rate of feeding the sheet through the stretch wrap dispenser. 
     
     
       3. The process of claim  1 , including the step of transporting the weakened portion to a position sufficiently downstream of the stretch wrap dispenser to allow a graspable tail of the sheet to extend downstream of the stretch wrap dispenser after the sheet is broken at the weakened portion. 
     
     
       4. The process of claim  1 , including the step of transporting the weakened portion of the sheet to a position sufficiently downstream of the prestretching portion to allow a graspable tail of the sheet to extend downstream of the prestretching portion after the sheet is broken at the weakened portion. 
     
     
       5. The process of claim  1 , wherein the stretch wrap dispenser includes a final dispensing roller and including the step of transporting the weakened portion of the sheet to a position sufficiently downstream of the final dispensing roller to allow a graspable tail of the sheet to extend downstream of the final dispensing roller after the sheet is broken at the weakened portion. 
     
     
       6. The process of claim  1  wherein the stretch wrap dispenser includes a final dispensing roller and the weakening step includes weakening the film at a predetermined location upstream of the final dispensing roller and including the step of transporting the weakened portion of the sheet to a position sufficiently downstream of the final dispensing roller to allow a graspable tail of the sheet to extend downstream of the final dispensing roller after the sheet is broken at the weakened portion. 
     
     
       7. The process of claim  1 , wherein the weakening step includes puncturing the sheet in a plurality of places across the sheet. 
     
     
       8. The process of claim  1 , wherein the weakening step includes electronically controlling the activation of a sheet weakening tool. 
     
     
       9. The process of claim  1  wherein the weakening step occurs in response to an actuation signal. 
     
     
       10. An apparatus for stretch wrapping a load with a sheet of stretch wrap packaging material comprising: 
       a stretch wrap dispenser for feeding and dispensing a sheet of stretch wrap packaging material from the dispenser, the stretch wrap dispenser having a prestretching portion for prestretching the sheet of stretch wrap packaging material;  
       means for providing relative rotation between the dispenser and the load to wrap the stretched sheet of stretch wrap packaging material around the load;  
       a sheet weakening device for selectively weakening a portion of the sheet of stretch wrap packaging material at a predetermined location downstream of the prestretching portion by puncturing the sheet of stretch wrap packaging material at the predetermined location during the relative rotation between the dispenser and the load after prestretching the sheet of stretch wrap packaging material; and  
       a controller for tensioning the punctured sheet of stretch wrap packaging material during the relative rotation between the dispenser and the load to break the sheet of stretch wrap packaging material at the weakened punctured portion due to the relative rotation between the dispenser and the load.  
     
     
       11. The apparatus of claim  10 , wherein the controller tensions the sheet by reducing the rate of feeding the sheet through the stretch wrap dispenser. 
     
     
       12. The apparatus of claim  10 , wherein the controller permits the weakened portion of the sheet to be transported to a position sufficiently downstream of the stretch wrap dispenser to allow a graspable tail of the sheet to extend downstream of the stretch wrap dispenser after the sheet is broken at the weakened portion. 
     
     
       13. The apparatus of claim  10 , wherein the controller permits the weakened portion of the sheet to be transported to a position sufficiently downstream of the prestretching portion to allow a graspable tail of the sheet to extend downstream of the prestretching portion after the sheet is broken at the weakened portion. 
     
     
       14. The apparatus of claim  10 , wherein the stretch wrap dispenser includes a final dispensing roller and wherein the controller permits the weakened portion of the sheet to be transported to a position sufficiently downstream of the final dispensing roller to allow a graspable tail of sheet to extend downstream of the final dispensing roller after the sheet is broken at the weakened portion. 
     
     
       15. The apparatus of claim  10 , wherein the stretch wrap dispenser includes a final dispensing roller, the sheet weakening device is located upstream of the final dispensing roller, and the controller permits the weakened portion of the sheet to be transported to a position sufficiently downstream of the final dispensing roller to allow a graspable tail of the sheet to extend downstream of the final dispensing roller after the sheet is broken at the weakened portion. 
     
     
       16. The apparatus of claim  10 , wherein the sheet weakening device includes a plurality of puncturing devices for puncturing the sheet in a plurality of places across the sheet. 
     
     
       17. The apparatus of claim  10 , wherein the controller electronically controls the activation of the sheet weakening device. 
     
     
       18. The apparatus of claim  10 , wherein the controller electronically controls the activation of the sheet weakening device in response to an actuation signal. 
     
     
       19. A process for stretch wrapping a load and having at least one corner with a sheet of stretch wrap packaging material comprising: 
       feeding a sheet of stretch wrap packaging material through a stretch wrap dispenser having a prestretching portion, prestretching the sheet of stretch wrap packaging material in the prestretching portion, and dispensing the sheet from the dispenser;  
       providing relative rotation between the dispenser and the load to wrap the stretched sheet of stretch wrap packaging material around the load;  
       weakening a portion of the sheet of stretch wrap packaging material at a predetermined location downstream of the prestretching portion by puncturing the sheet of stretch wrap packaging material at the predetermined location during the relative rotation between the dispenser and the load after prestretching the sheet of stretch wrap packaging material; and  
       tensioning the weakened punctured sheet of stretch wrap packaging material during the relative rotation between the dispenser and the load to break the sheet of stretch wrap packaging material at the weakened punctured portion thereby creating a tail extending from the load  dispenser.  
     
     
       20. The process of claim  19 , wherein the tensioning step includes reducing the rate of feeding the sheet through the stretch wrap dispenser. 
     
     
       21. The process of claim  19 , including the step of transporting the weakened portion to a position sufficiently downstream of the stretch wrap dispenser to allow a graspable tail of the sheet to extend downstream of the stretch wrap dispenser after the sheet is broken at the weakened portion. 
     
     
       22. An apparatus for stretch wrapping a load having at least one corner with a sheet of stretch wrap packaging material comprising: 
       a stretch wrap dispenser for feeding and dispensing a sheet of stretch wrap packaging material from the dispenser, the stretch wrap dispenser having a prestretching portion for prestretching the sheet of stretch wrap packaging material;  
       means for providing relative rotation between the dispenser and the load to wrap the stretched sheet of stretch wrap packaging material around the load;  
       a sheet weakening device for selectively weakening a portion of the sheet of stretch wrap packaging material at a predetermined location downstream of the prestretching portion by puncturing the sheet of stretch wrap packaging material at the predetermined location during the relative rotation between the dispenser and the load after prestretching the sheet of stretch wrap packaging material; and  
       a controller for tensioning the punctured sheet of stretch wrap packaging material during the relative rotation between the dispenser and the load to break the sheet of stretch wrap packaging material at the weakened punctured portion thereby creating a tail extending from the load  dispenser, thereby minimizing the length of the tail extending from the load.  
     
     
       23. The apparatus of claim  22 , wherein the controller tensions the sheet by reducing the rate of feeding the sheet through the stretch wrap dispenser. 
     
     
       24. The apparatus of claim  22 , wherein the controller permits the weakened portion of the sheet to be transported to a position sufficiently downstream of the stretch wrap dispenser to allow a graspable tail of the sheet to extend downstream of the stretch wrap dispenser after the sheet is broken at the weakened portion. 
     
     
       25. A rotary stretch wrapping process for stretch wrapping a load with a sheet of stretch wrap packaging material comprising: 
       
         feeding a sheet of stretch wrap packaging material through a stretch wrap dispenser and dispensing the sheet from the dispenser;  
       
       
         providing relative rotation between the dispenser and the load to wrap the stretched sheet of stretch wrap packaging material around the load;  
       
       
         prestretching the sheet of stretch wrap packaging material in a prestretching portion of the dispenser;  
       
       
         weakening a portion of the sheet of stretch wrap packaging material at a predetermined location downstream of the prestretching portion by puncturing the sheet of stretch wrap packaging material during the relative rotation between the dispenser and the load; and  
       
       
         tensioning the weakened sheet of stretch wrap packaging material to break the sheet of stretch wrap packaging material at the weakened portion. 
       
     
     
       26. A rotary stretch wrapping process for stretch wrapping a load with a sheet of stretch wrap packaging material comprising: 
       
         feeding a sheet of stretch wrap packaging material through a stretch wrap dispenser and dispensing the sheet from the dispenser;  
       
       
         providing relative rotation between the dispenser and the load to wrap the stretched sheet of stretch wrap packaging material around the load;  
       
       
         prestretching the sheet of stretch wrap packaging material in a prestretch portion of the dispenser;  
       
       
         weakening a portion of the sheet of stretch wrap packaging material at a predetermined location downstream of the prestretching portion by puncturing the sheet of stretch wrap packaging material during the relative rotation between the dispenser and the load; and  
       
       
         tensioning the weakened sheet of stretch wrap packaging material during relative movement between the dispenser and the load to break the sheet of stretch wrap packaging material at the weakened portion due to the relative movement. 
       
     
     
       27. A rotary stretch wrapping process for stretch wrapping a load with a sheet of stretch wrap packaging material comprising: 
       
         initiating the wrapping of each load by feeding a sheet of stretch wrap packaging material through a stretch wrap dispenser, attaching a leading end of the sheet of stretch wrap packaging material to the load to be wrapped or a support near the load to be wrapped, and dispensing the sheet from the dispenser;  
       
       
         providing relative rotation between the dispenser and the load to wrap the stretched sheet of stretch wrap packaging material around the load;  
       
       
         prestretching the sheet of stretch wrap packaging material in a prestretching portion of the dispenser;  
       
       
         weakening a portion of the sheet of stretch wrap packaging material at a predetermined location downstream of the prestretching portion by puncturing the sheet of stretch wrap packaging material during the relative rotation; and  
       
       
         tensioning the weakened sheet of stretch wrap packaging material between the dispenser and the load to break the sheet of stretch wrap packaging material at the weakened portion. 
       
     
     
       28. A rotary stretch wrapping process for stretch wrapping a load with a sheet of stretch wrap packaging material comprising: 
       
         feeding a sheet of stretch wrap packaging material through a stretch wrap dispenser and dispensing the sheet from the dispenser;  
       
       
         providing relative rotation between the dispenser and the load to wrap the stretched sheet of stretch wrap packaging material around the load;  
       
       
         prestretching the sheet of stretch wrap packaging material in a prestretching portion of the dispenser;  
       
       
         weakening a portion of the sheet of stretch wrap packaging material at a predetermined location downstream of the prestretching portion by puncturing the sheet of stretch wrap packaging material during the relative rotation; and  
       
       
         transporting the weakened portion of the sheet of stretch wrap material downstream of the predetermined location; and  
       
       
         tensioning the weakened sheet of stretch wrap packaging material to break the sheet of stretch wrap packaging material at the weakened portion. 
       
     
     
       29. A rotary stretch wrapping process for stretch wrapping a load with a sheet of stretch wrap packaging material comprising: 
       
         feeding a sheet of stretch wrap packaging material through a stretch wrap dispenser and dispensing the sheet from the dispenser;  
       
       
         providing relative rotation between the dispenser and the load to wrap the stretched sheet of stretch wrap packaging material around the load;  
       
       
         prestretching the sheet of stretch wrap packaging material in a prestretching portion of the dispenser;  
       
       
         weakening a portion of the sheet of stretch wrap packaging material at a predetermined location downstream of the prestretching portion by puncturing the sheet of stretch wrap packaging material during the relative rotation between the dispenser and the load; and  
       
       
         tensioning the weakened sheet of stretch wrap packaging material during relative movement between the dispenser and the load to break the sheet of stretch wrap packaging material at the weakened portion due to the relative movement. 
       
     
     
       30. A rotary stretch wrapping process for stretch wrapping a load with a sheet of stretch wrap packaging material comprising: 
       
         feeding a sheet of stretch wrap packaging material through a stretch wrap dispenser and dispensing the sheet from the dispenser;  
       
       
         providing relative rotation between the dispenser and the load to wrap the stretched sheet of stretch wrap packaging material around the load;  
       
       
         prestretching the sheet of stretch wrap packaging material in a prestretching portion of the dispenser;  
       
       
         weakening a portion of the sheet of stretch wrap packaging material at a predetermined location downstream of the prestretching portion by puncturing the sheet of stretch wrap packaging material during the relative rotation and after wrapping the stretched sheet of stretch wrap packaging material around the load;  
       
       
         transporting the weakened portion of the sheet of stretch wrap material downstream of the predetermined location; and  
       
       
         tensioning the weakened sheet of stretch wrap packaging material to break the sheet of stretch wrap packaging material at the weakened portion. 
       
     
     
       31. A rotary stretch wrapping apparatus for stretch wrapping a load with a sheet of stretch wrap packaging material comprising: 
       
         a stretch wrap dispenser for feeding and dispensing a sheet of stretch wrap packaging material from the dispenser;  
       
       
         means for providing relative rotation between the dispenser and the load to wrap the stretched sheet of stretch wrap packaging material around the load;  
       
       
         a prestretch portion of the dispenser for prestretching the sheet of stretch wrap packaging material;  
       
       
         a sheet weakening device for selectively weakening a portion of the sheet of stretch wrap packaging material at a predetermined location downstream of the prestretching portion by puncturing the sheet of stretch wrap packaging material during the relative rotation; and  
       
       
         a controller for permitting tensioning of the sheet of stretch wrap packaging material to break the sheet of stretch wrap packaging material at the weakened portion. 
       
     
     
       32. A rotary stretch wrapping apparatus for stretch wrapping a load with a sheet of stretch wrap packaging material comprising: 
       
         a stretch wrap dispenser for feeding and dispensing a sheet of stretch wrap packaging material from the dispenser;  
       
       
         means for providing relative rotation between the dispenser and the load to wrap the stretched sheet of stretch wrap packaging material around the load;  
       
       
         a prestretch portion of the dispenser for prestretching the sheet of stretch wrap packaging material;  
       
       
         a sheet weakening device for selectively weakening a portion of the sheet of stretch wrap packaging material at a predetermined location downstream of the prestretching portion by puncturing the sheet of stretch wrap packaging material during the relative rotation; and  
       
       
         a controller for permitting tensioning of the sheet of stretch wrap packaging material so that the sheet of stretch wrap packaging material can be broken at the weakened portion during relative movement between the dispenser and the load. 
       
     
     
       33. A rotary stretch wrapping apparatus for stretch wrapping a load with a sheet of stretch wrap packaging material comprising: 
       
         a stretch wrap dispenser for feeding and dispensing a sheet of stretch wrap packaging material from the dispenser;  
       
       
         means for providing relative rotation between the dispenser and the load to wrap the sheet of stretch wrap packaging material around the load;  
       
       
         a prestretch portion of the dispenser for prestretching the sheet of stretch wrap packaging material;  
       
       
         a sheet weakening device for selectively weakening a portion of the sheet of stretch wrap packaging material at a predetermined location downstream of the prestretching portion by puncturing the sheet of stretch wrap packaging material during the relative rotation; and  
       
       
         a controller for operating the rotary stretch wrapping apparatus in a semi-automatic mode to initiate wrapping subsequent to attaching a leading end of the sheet of stretch wrap packaging material to the load or a support near the load prior to wrapping each load, and for permitting tensioning of the sheet of stretch wrap packaging material between the dispenser and the load to break the sheet of stretch wrap packaging material at the weakened portion. 
       
     
     
       34. A rotary stretch wrapping apparatus for stretch wrapping a load with a sheet of stretch wrap packaging material comprising: 
       
         a stretch wrap dispenser for feeding and dispensing a sheet of stretch wrap packaging material from the dispenser;  
       
       
         means for providing relative rotation between the dispenser and the load to wrap the stretched sheet of stretch wrap packaging material around the load;  
       
       
         a prestretch portion of the dispenser for prestretching the sheet of stretch wrap packaging material;  
       
       
         a sheet weakening device for selectively weakening a portion of the sheet of stretch wrap packaging material at a predetermined location downstream of the prestretching portion by puncturing the sheet of stretch wrap packaging material during the relative rotation; and  
       
       
         a controller for permitting tensioning of the weakened sheet of stretch wrap packaging material between the dispenser and the load to break the sheet of stretch wrap packaging material at the weakened portion thereby creating a graspable tail of packaging material extending from the dispenser. 
       
     
     
       35. A rotary stretch wrapping apparatus for stretch wrapping a load having at least one corner with a sheet of stretch wrap packaging material comprising: 
       
         a stretch wrap dispenser for feeding and dispensing a sheet of stretch wrap packaging material from the dispenser;  
       
       
         means for providing relative rotation between the dispenser and the load to wrap the stretched sheet of stretch wrap packaging material around the load;  
       
       
         a prestretch portion of the dispenser for prestretching the sheet of stretch wrap packaging material;  
       
       
         a sheet weakening device for selectively weakening a portion of the sheet of stretch wrap packaging material at a predetermined location downstream of the prestretching portion by puncturing the sheet of stretch wrap packaging material during the relative rotation; and  
       
       
         a controller for permitting tensioning of the weakened portion of stretch wrap packaging material downstream of the predetermined location and for permitting tensioning of the weakened sheet of stretch wrap packaging material to break the sheet of stretch wrap packaging material at the weakened portion. 
       
     
     
       36. A rotary stretch wrapping apparatus for stretch wrapping a load having at least one corner with a sheet of stretch wrap packaging material comprising: 
       
         a stretch wrap dispenser for feeding and dispensing a sheet of stretch wrap packaging material from the dispenser;  
       
       
         means for providing relative rotation between the dispenser and the load to wrap the stretched sheet of stretch wrap packaging material around the load;  
       
       
         a prestretch portion of the dispenser for prestretching the sheet of stretch wrap packaging material;  
       
       
         a sheet weakening device for selectively weakening a portion of the sheet of stretch wrap packaging material at a predetermined location downstream of the prestretching portion by puncturing the sheet of stretch wrap packaging material during the relative rotation and after wrapping the stretched sheet of stretch wrap packaging material around the load; and  
       
       
         a controller for permitting transporting of the weakened portion of stretch wrap packaging material downstream of the predetermined location and for permitting tensioning of the weakened sheet of stretch wrap packaging material to break the sheet of stretch wrap packaging material at the weakened portion. 
       
     
     
       37. A rotary stretch wrapping process for stretch wrapping a load with a sheet of stretch wrap packaging material comprising: 
       
         feeding a sheet of stretch wrap packaging material through a stretch wrap dispenser having a prestretch portion, prestretching the sheet of stretch wrap packaging material in the prestretch portion, and dispensing the sheet from the dispenser;  
       
       
         providing relative rotation between the dispenser and the load to wrap the stretched sheet of stretch wrap packaging material around the load;  
       
       
         weakening a portion of the sheet of stretch wrap packaging material at a predetermined location downstream of the prestretching portion by puncturing the sheet of stretch wrap packaging material at the predetermined location during the relative rotation between the dispenser and the load and after prestretching the sheet of stretch wrap packaging material; and  
       
       
         tensioning the weakened punctured sheet of stretch wrap packaging material to break the sheet of stretch wrap packaging material at the weakened punctured portion. 
       
     
     
       38. A rotary stretch wrapping process for stretch wrapping a load with a sheet of stretch wrap packaging material comprising: 
       
         feeding a sheet of stretch wrap packaging material through a stretch wrap dispenser having a prestretch portion, prestretching the sheet of stretch wrap packaging material in the prestretch portion, and dispensing the sheet from the dispenser;  
       
       
         providing relative rotation between the dispenser and the load to wrap the stretched sheet of stretch wrap packaging material around the load;  
       
       
         weakening a portion of the sheet of stretch wrap packaging material at a predetermined location downstream of the prestretching portion by puncturing the sheet of stretch wrap packaging material at the predetermined location during the relative rotation between the dispenser and the load; and  
       
       
         tensioning the weakened punctured sheet of stretch wrap packaging material to break the sheet of stretch wrap packaging material at the weakened punctured portion. 
       
     
     
       39. A rotary stretch wrapping apparatus for stretch wrapping a load with a sheet of stretch wrap packaging material comprising: 
       
         a stretch wrap dispenser for feeding and dispensing a sheet of stretch wrap packaging material from the dispenser, the stretch wrap dispenser having a prestretching portion for prestretching the sheet of stretch wrap packaging material;  
       
       
         means for providing relative rotation between the dispenser and the load to wrap the stretched sheet of stretch wrap packaging material around the load;  
       
       
         a sheet weakening device for selectively weakening a portion of the sheet of stretch wrap packaging material at a predetermined location downstream of the prestretching portion by puncturing the sheet of stretch wrap packaging material at the predetermined location during the relative rotation between the dispenser and the load after prestretching the sheet of stretch wrap packaging material; and  
       
       
         a controller for permitting tensioning of the sheet of stretch wrap packaging material to break the sheet of stretch wrap packaging material can be broken at the weakened punctured portion. 
       
     
     
       40. A rotary stretch wrapping apparatus for stretch wrapping a load with a sheet of stretch wrap packaging material comprising: 
       
         a stretch wrap dispenser for feeding the dispensing a sheet of stretch wrap packaging material from the dispenser, the stretch wrap dispenser having a prestretching portion for prestretching the sheet of stretch wrap packaging material;  
       
       
         means for providing relative rotation between the dispenser and the load to wrap the stretched sheet of stretch wrap packaging material around the load;  
       
       
         a sheet weakening device for selectively weakening a portion of the sheet of stretch wrap packaging material at a predetermined location downstream of the prestretching portion by puncturing the sheet of stretch wrap packaging material at the predetermined location during the relative rotation between the dispenser and the load; and  
       
       
         a controller for permitting tensioning of the sheet of stretch wrap packaging material to break the sheet of stretch wrap packaging material can be broken at the weakened punctured portion.