DAC February 2022

34 n ROBOTICS AND AUTOMATED MANUFACTURING February 2022 www.drivesncontrols.com Servos help Grolsch to fit its iconic bottle tops T his year marks the 125th anniversary of the invention of the distinctive swing-top caps that the Dutch brewer Grolsch fits onto its beer bottles. Coinciding with the anniversary, Grolsch has commissioned a new servo-based technology for installing the caps on bottles at its Enschede plant in the Netherlands. Every hour, the new “swing-top transfer unit” provides around 3,800 bottles with their iconic porcelain caps and rubber rings. Bottles without tops are fed in from one side, while the swing tops arrive from the other side. Before the tops are positioned, the bottle is rotated and a sensor detects the location of one the holes in the bottle neck into which the cap’s metal clips fit. The bottles are rotated into the correct position by a servomotor located underneath. After this, the swing-top transfer unit positions the swing top while the bottle is rotated again so that the clips can first be pressed into the hole on one side of the bottle, and then into the hole on the opposite side. The bottles are then transported to the filling line. One of the most important changes in the new design has been to replace two parallel electrically-powered axes that used to carry out horizontal movements by a heavy-duty toothed belt axis with a double recirculating ball bearing guide. This axis – an EGC model from Festo – is actuated by Festo EMMT servomotors which use a single cable for both motor and encoder signals. The motors can generate low holding torques, allowing several axes to be synchronised, even at low speeds. They have digital, absolute displacement encoders. An existing Siemens PLC with Profibus ports has been upgraded to support Profinet using a Festo CPX-E automation system which acts as a central controller for both the servo and stepper motors, and is configured as an EtherCat master and motion controller. This delivers the required speed, accuracy and dynamic response needed for the swing-top transfer unit. The new controllers and Profinet system simplify the gathering of data, helping to optimise the process, find any faults, and to perform predictive maintenance – capabilities that Grolsch plans to exploit in future to boost machine reliability and availability, and to cut costs. The new capping system was designed by Festo in conjunction with the Dutch system integrator, MCA Linear Motion Robotics. “Everything is running according to plan,” reports Grolsch maintenance engineer, Steven Groot Zevert. “Thanks to the great cooperation between system integrator and automation manufacturer the project has been managed quickly and efficiently. I only really needed to let them know my requirements. These were then translated into a new, future-proof design that fits into our own automation system.” n New servomotor-based technology is helping the Dutch brewer Grolsch to fit its iconic swing-top caps onto bottles of lager. Bottle-tops arriving on a conveyor (right) are fitted to bottles in an automated process (below)