Shrink Systems for Labels

Abstract

A shrink system for a labelling system includes a return duct and a make up duct connected to the inlet of a fan. A valve regulates the temperature of air supplied to the inlet by varying the proportion of air flow between the return and make up ducts. The output of the fan is supplied to a nozzle configured to entrain ambient air with the outlet from the nozzle.

1 . A shrink system to supply heated air to an exterior surface of a container, said shrink system comprising a fan to supply air, a heater to heat said air, an air outlet connected to said fan and positioned to cause air supplied by said fan to impinge on said container, a plenum chamber to collect air from said air outlet, a return duct connected between said plenum and said fan to supply air to an inlet of said fan, a make up duct connected to said inlet of said fan and a valve member to control relative proportions of air supplied to said inlet by said return duct and said make up duct, whereby the temperature of air supplied to said fan may be modulated. 
     
     
         2 . A shrink system according to  claim 1  including a control system to adjust said valve member and maintain the temperature of air supplied to said fan at a predetermined value. 
     
     
         3 . A shrink system according to  claim 2  wherein said control system includes a temperature sensor located in said inlet to said fan. 
     
     
         4 . A shrink system according to  claim 1  wherein said heater is located between said fan and said outlet. 
     
     
         5 . A shrink system according to  claim 4  wherein said outlet is a nozzle having convergent walls. 
     
     
         6 . A shrink system according to  claim 5  wherein said walls are configured to induce air flow across said walls and entrain said air flow with air from said nozzle. 
     
     
         7 . A shrink system according to  claim 6  wherein said walls converge with an included angle of 30°. 
     
     
         8 . A shrink system according to  claim 5  including a pair of nozzles, each extending along a path followed by said container and spaced to impinge said container at different locations. 
     
     
         9 . A shrink system according to  claim 5  wherein said plenum chamber is located on an opposite side of a path followed by said container to said outlet. 
     
     
         10 . A shrink system according to  claim 9  wherein said outlet includes a nozzle having convergent walls. 
     
     
         11 . A shrink system according to  claim 10  wherein a pair of nozzles are provided at spaced locations along said path and said plenum is positioned opposite each of said nozzles. 
     
     
         12 . A shrink system to supply heated air to an exterior surface of a container, said shrink system comprising a source of heated air, an air outlet connected to said source to cause air supplied by said source to impinge upon said container, a plenum chamber to collect air from said outlet and return collected air in said plenum chamber to said source, said outlet being configured to entrain a flow of ambient air with air flowing from said outlet to impinge on said container. 
     
     
         13 . A shrink system according to  claim 12  wherein said outlet is a nozzle having convergent walls. 
     
     
         14 . A shrink system according to  claim 13  including a pair of nozzles spaced apart along a path followed by said container. 
     
     
         15 . A shrink system according to  claim 14  wherein said plenum chamber is located on opposite side of said path to said nozzles. 
     
     
         16 . A shrink system according to  claim 15  wherein a pair of nozzles are located at the same location along said path to impinge different locations on said container. 
     
     
         17 . A shrink system according to  claim 13  wherein said nozzle has an elongate outlet extending along a path followed by a container. 
     
     
         18 . A shrink system according to  claim 17  wherein said walls converge at an included angle of 30° toward said outlet. 
     
     
         19 . A shrink system according to  claim 12  wherein said source includes a fan and a heater located between said fan and said outlet. 
     
     
         20 . A shrink system according to  claim 19  wherein said plenum is connected to an inlet of said fan.