Heat Tunnel for Film-Shrinking

Abstract

A heat tunnel for applying heated air to articles enclosed in shrink-wrap film includes at least one air supply unit; a conveyor; and a heat shroud spaced from the conveyor. The air supply unit includes a source of heated air, a fan, a heated air plenum, air ducts, and a return air plenum. Multiple air supply units can be provided along the conveyor to create a heat tunnel of desired length.

1 - 22 . (canceled)  
   
   
       23 : Method for shrink wrapping comprising: 
 providing a group of articles wrapped with a tube of film having a lap seam extending under the group of articles between first and second open ends and beyond the group of articles;    moving the tube wrapped group of articles in a movement direction perpendicular to the lap seam and through a film shrinking area extending along the movement direction; and    providing heated air within the film shrinking area to shrink the tube of film onto the group of articles to form a package, with providing the heated air comprising flowing air into the film shrinking area through a duct having an opening extending continuously along the movement direction while the tube of film is being shrunk to form the package.    
   
   
       24 : Apparatus for applying heat to at least a first group of articles wrapped with a tube of film comprising, in combination: 
 a heated air plenum having a top surface, an upstream end and a downstream end, with heated air being introduced into the heated air plenum flowing in a movement direction between the upstream and downstream ends, with the group of articles wrapped with a tube of film moving in the movement direction along the top surface, with the heated air passing from the heated air plenum past the top surface into a film shrinking area extending in the movement direction; and    a duct having an opening extending continuously along the movement direction between the upstream end and the downstream end in the film shrinking area.    
   
   
       25 : Method for shrink wrapping comprising: 
 providing a group of articles wrapped with a tube of film having a lap seam extending under the group of articles between first and second open ends and beyond the group of articles;    moving the tube wrapped group of articles in a movement direction perpendicular to the lap seam and through a film shrinking area extending along the movement direction; and    providing heated air within the film shrinking area to shrink the tube of film onto the group of articles to form a package, with providing the heated air comprising passing heated air through a heated air plenum into the film shrinking area, with providing the heated air including introducing heated air into the heated air plenum for movement between a downstream end spaced from an upstream end in the movement direction, with introducing the heated air into the heated air plenum comprising rotating a fan having elongated blades extending perpendicular to the movement direction and spaced from and parallel to a rotation axis.    
   
   
       26 : Apparatus for applying heat to at least a first group of articles wrapped with a tube of film comprising, in combination: 
 a heated air plenum having a top surface, an upstream end and a downstream end, with heated air being introduced into the heated air plenum flowing in a movement direction between the upstream and downstream ends, with the group of articles wrapped with a tube of film moving in the movement direction along the top surface, with the heated air passing from the heated air plenum past the top surface into a film shrinking area extending in the movement direction; and    a fan having elongated blades extending perpendicular to the movement direction and spaced from and parallel to a rotation axis and the top surface, with the fan introducing the heated air into the heated air plenum.