There are many ways of developing the heat necessary to shrink a sleeve and electric tunnels are probably the most convenient. However the heat sink effect of glass and cold containers in particular must be taken into consideration when selecting a tunnel.

For most Tamper Evident applications, where the sleeve is 20 to 50mm long, an electric tunnel or a fully recirculating electric tunnel will suffice. In a few installations these are supplemented by an infrared tunnel upstream to take the chill off the container before sleeve application.

Recirculating tunnels have a series of fully adjustable nozzles that are configured to shrink from the bottom of the sleeve upwards as the container passes through. The exact model and style will depend upon the linear speed and the size of the container.
The ShrinkMaster 750 and 1500 may also be used for preheat and final shrinking of Sleeve Labels but a ShrinkMaster Steam 2000 tunnel will be needed for ultimate quality at high speeds. Steam eliminates the need to preheat and gives excellent artwork retention. The ShrinkMaster Steam range is modular in 2M sections and maybe supplied with a complete boiler house to suit.
Usually a ShrinkMaster air dryer system is placed after a Steam tunnel to remove excess moisture before packing.

The full range of models can be seen below......