Positioning round labels exactly in the centre of round can lids at high speeds is a challenging task. A special labelling system with a self-adjusting camera system from Herma GmbH, Filderstadt, ensures the extremely precise positioning of lid labels for tobacco products from the globally renowned company Swedish Match.
The Swedish company specialises in the manufacture of tobacco products and matches. An important part of the product portfolio is Snus, a favourite in Norway and Sweden moist tobacco powder for oral use. It is packed in small portion bags in tins for sale. With the Inline labelling of these doses and especially in the Precise positioning of the round labels on the round can lids, Swedish Match sets high standards.
If the edge trimming of the labels is not always completely correct, placement is a particular challenge. And Swedish Match was not prepared to compromise on this point. That is why the Labelling specialist HERMA has developed a particularly precise solution for this task, which is specially tailored to the requirements of Swedish Match.
Fast and highly accurate
„We wanted to take over the labelling of the can lids ourselves, instead of leaving this task to our suppliers, in order to save more time. Flexibilityt in our processes,“ recalls Mattias Wermé, Manager Process Development at Swedish Match. „Once we had selected the right plastic containers for our various production lines, the requirements for the labelling systems became clear. The particular challenges we faced included the required labelling speed and precision. HERMA was already known to us as a supplier and demonstrated in a test how our requirements could best be met.“
The choice fell on Obenauf labelling machines, Type 452E S was developed by HERMA as a Customised design specially designed for this application. Swedish Match now successfully operates 13 of these systems in its production facilities in Sweden: seven at the Gothenburg site and six at the Kungälv site.
They are customised to the available space in the production line and are equipped with different housings depending on their respective location. In most cases, they label the lids attached to the cans; in a few cases, they label the very flat lids alone: here, a special light barrier and adapted side belts ensure that the lids are labelled correctly. very flat objects correctly and labelled.
The tins are either round, 20 millimetres high and have a diameter of 66 millimetres. Or they are 24 millimetres high and have a diameter of 70 millimetres. One of the lid formats has a raised rim of around two millimetres. This should also be taken into account when labelling. In total, a Labelling speed of 175 products per minute achieved.
Reliable operation with minimal input
The HERMA 452E S labelling machine has many sophisticated features, including a special Self-adjusting camera system, which checks the presence and position of the labels. This keeps the labelling tolerance to a very low level of ± 0.7 millimetres.
Even if the edge trim of the labels is not 100 per cent correct, as is occasionally the case, this can be compensated for along two axes by positioning the cans. This is achieved by adjusting the lateral conveyor belts using a Festo linear unit and through a Change the start delay. For this purpose, the products are labelled after the label has been applied. Cognex vision system which detects the position of the label. Missing, incorrectly positioned or incorrect labels are registered and faulty products are conveyed to an ejection chute using a blast of compressed air.
A Control sensor prevents them from leaving the system. The label position data collected is used to adjust the following products. One Height adjustment with servo drive automatically adjusts the height of the labeller to the product format. Alternatively, operators can also make settings on the HMI. Overall, however, only minimal operator input is required, resulting in long running times.
A sensor monitors the product outlet for jams and, if necessary, stops the infeed conveyor until the fault has been rectified. In addition, a servo motor automatically moves the labeller up and down, thus enabling Simple label roll change. A new type of Vacuum waste system is used to remove and dispose of backing paper, any waste is shredded immediately.
Good timing
„Thanks to HERMA, it was possible to realise this project within a tight time frame to realise,“ summarises Wermé. „We also had to comply with new packaging guidelines for tobacco products sold in Norway: As of 1 July 2018 ‚Plain packaging‘ mandatory. In order to comply with these regulations, we had to rearrange the installation and commissioning of some labelling machines. HERMA also provided us with active support here.“
Christoph Ziegler, from labelling machine sales at HERMA, adds: „The decisive factor here was not only the cooperation with Swedish Match, but also the good collaboration between our sites. The machines were built in Haverhill (UK), and there was always a close dialogue with our headquarters in Filderstadt.“
Wermé summarises his experience to date with the new labelling systems from HERMA as „consistently positive - we have fully achieved our goals“.
Martin Kühl, Head of the HERMA Labelling Machines division, adds: „This application is an example of how a special machine can solve even highly complex requirements in several production lines in slightly modified versions.“
HERMA GmbH at FachPack 2019: Hall 3A, Stand 236
