Shrink wrap apparatus

Abstract

A tunnel for shrink wrapping at least one product includes a housing having an interior space with a top, a bottom, an entrance and an exit. A conveyor belt passes through the interior space from the entrance to the exit. The conveyor belt is substantially unobstructed on upper and lower sides and includes an opened configuration allowing substantial air flow therethrough at relatively low velocity. Heaters and air movers are located above and below the conveyor belt to uniformly heat products contained in shrink film and moving along the conveyor belt. The shrink tunnel further includes an adjustable riser member to allow a transverse section of the conveyor belt to be selectively adjusted in height from outside the housing.

What is claimed is:  
     
         1 . A tunnel for shrink wrapping at least one product, comprising: 
 a housing having an interior space with a top, a bottom, an entrance and an exit;    a conveyor belt passing through the interior space from the entrance to the exit, the conveyor belt having an open mesh structure and being substantially unobstructed on upper and lower sides thereof in its travel from the entrance to the exit;    a first heater thermally coupled to the interior space; and    a first air mover operatively coupled with the interior space and configured to move air uniformly within the interior space.    
     
     
         2 . The tunnel of  claim 1 , wherein the conveyor belt provides at least 80% open area.  
     
     
         3 . The tunnel of  claim 1 , wherein the interior space has a total interior height with a midpoint between the top and the bottom, and the conveyor passes through the interior space at a height which is closer to the midpoint then to the top or bottom.  
     
     
         4 . The tunnel of  claim 3 , further comprising a second heater thermally coupled to the interior space; and 
 a second air mover operatively coupled with the interior space and configured to move air uniformly within the interior space;    wherein the first heater and first air mover are positioned closely adjacent the top and the second heater and second air mover are positioned closely adjacent the bottom.    
     
     
         5 . The tunnel of  claim 1 , wherein the first air mover further comprises a plurality of blades extending radially from an axis of rotation thereof, the blades having at least substantially no pitch so as to gently move air within the interior space when rotating about the axis of rotation.  
     
     
         6 . The tunnel of  claim 1 , wherein the conveyor belt is a free tension belt.