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Heat-shrink tunnels

Heat-shrink tunnels

Heat-shrink tunnels

One of the main features of the heat-shrink tunnels supplied by SMI is the modular composition of the final product. This means that by combining the same modules in different configurations, it is possible to create all models of shrink tunnel, from the smallest that is 2 meters long to the biggest that is 6 meters long, with considerable advantages in terms of time for the supply of the complete and assembled tunnel.
SMI offers not only standard tunnels, but also tunnels in UHQ version for cans and tunnels in ECO version, fuelled by methane gas.

The table below shows the standard models of shrink tunnels available depending on the length, the number of lanes and the chain of the conveyor belt:

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SMI shrink tunnels have the following features:
 

  • the electrical cabinet is positioned longitudinally compared to the leading side, thus improving the thermal insulation and the ergonomics of the solution. This makes the access easier and allows the operator to perform the operations of ordinary and extraordinary maintenance in a simple and fast way;

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  • tunnel guards have been fully insulated laterally, so that the conveyor belt return section is not visible in the lower section of the tunnel and cannot be reached by the operator. This feature results in a higher safety level of the operator's wok and a lower heat dissipation in the lower part of the tunnel;

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  • the inner size deflector unit, whose size covers the whole length of the hot section of the tunnel, allows to direct the air flow to the pack side, in case of need; this results in a more uniform shrinking and so in the improvement of the quality of the final pack;

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  • by joining the passage section up, it has been possible to reduce the system pressure drop and improve the air circulation. This has allowed to increase the flow energy that reaches the packs in the hot section of the tunnel, thus making the shrinking more uniform and the quality of the final pack higher;

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  • SEW gear motor is installed as standard equipment on all models; in particular, according to the type of tunnel, orthogonal gear motors from the SPIROPLAN® W range with high performance or worm gear motors from the S range with a quiet running, capable of providing a high efficiency level, are installed;

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  • the number of fans is between 2 and 6 depending on the length of the tunnel (one for each meter of tunnel); this feature is made possible by the shrink tunnel modularity that allows to improve the system efficiency and the quality of the pack;

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  • the iris-shaped shutter unit enables to adjust the suction section of the fan and so the amount of air flow generated; in particular, by adjusting the position of the lever, it is possible to increase or decrease the air flow generated by the fan, with considerable advantages for the quality of the final pack. For 2- and 3-meter long tunnels on single lane the unit is available as optional;

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  • the upper deflector handling unit can be adjusted in height, thus allowing to optimize the height of the conveyor. This enables to obtain better results when very small packs are handled, concentrating the heat on the pack. 2- and 3-meter long tunnels in single lane are not equipped with this unit;

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  • intrachain deflectors have a racks structure, that is with two superimposed sliding panels, that allow to have a better adjustment of the flows. 2- and 3-meter long entry level tunnels on single lane are an exception, as they are equipped with a single deflector for the whole length of the hot section;

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