GERMANY – A tandem operation for cross web labellers that enables labellers to be installed very close to each other on a packaging machine has been developed by Multivac Marking & Inspection.
For applications that require the installation of two cross web labellers on one thermoforming packaging machine –such as instances where pack formats with a particularly large number of rows have to be labelled at high speed, or where two different labels, for example a decorative label and a promotional label, have to be applied to the pack - the two cross web labellers share the labelling. With multi-row formats a longitudinal shift unit is usually used to move the label dispenser from row to row.
The fitting of two cross web labellers on a thermoforming packaging machine requires a very large area for installation, since the longitudinal shift unit of each labeller can move in both directions. This can lead to the risk of squashing between the labellers: "For safety reasons there must be a distance of at least the width of one body between the two labellers", noted Klaus Rocholl, Multivac Marking & Inspection’s safety expert.
This space is however not usually available. As an alternative solution, Multivac Marking & Inspection has developed a tandem operation for cross web labellers. With this solution two labellers of the same type are mechanically coupled together.
"Both labellers work with just one longitudinal shift unit. This means that the two labellers can no longer move independently of each other. The danger of any squashing arising is therefore eliminated. Both labellers can be installed on the packaging machine in a very space-saving way", explained Rocholl.
An additional benefit of the tandem operation is also the lower cost, with the elimination of one longitudinal shift unit.
A pneumatic clamp can be released when the cross web labellers in tandem operation need to be set up. This way, it is possible to slide the two labellers apart, which simplifies the label roll change proceduree.
In addition, a spindle adjustment mechanism with position display is used to set up the labeller to a new pack length.