Bring home the butter

A purpose-built gantry robot is providing clean and reliable de-palletising functions for German creamery without supervision.

A PLC controlled handling system at the Südwestbutter creamery in Karlsruhe, Germany utilises a robot to carry out all butter de-palletising tasks, eliminating the need for arduous physical labour and significantly speeding throughput. The system has been designed by the Electromechanical Division of Parker Hannifin.

Butter is delivered in bulk, packed in 25kg cartons on pallets. The individual cartons need to be removed from the pallets and placed in the proper position for dispensing, prior to the butter being divided and re-packaged in 250g portions ready for resale. Until recently, this strenuous and repetitive task was performed manually.

The robot operates without need of supervision, and accommodates all the work steps involved in de-stacking and readying the cartons of butter. After removing the cartons from the palettes in accordance with a programmed operational sequence, it places them onto a turning-tilting station. The cartons are then brought into the correct position for automatic unpacking and portioning. The gantry robot also transports palette separators and empty palettes, and stacks them onto a second palette, ready for return to the supplier.

In order to meet the high demands for cleanliness, productivity, and short cycle times, Parker constructed the gantry robot from special materials. The robot’s movements are actuated by digital drives and transmitted by low-friction toothed belts, which provide a highly reliable, low-maintenance solution. The carrier beam profiles are manufactured from aluminium, ensuring that they will not oxidise in damp and harsh environments, and the wear-resistant plastic rollers that are used to provide movement and transmit forces are located within the carrier profiles, to prevent generation of any contamination.

Since the system employs plastic rollers, toothed belts and belt drives – none of which requires lubrication – any possible food contamination by mineral oil-based lubricants is precluded. In fact, it is worth pointing out that gantry robots built to these types of rigorous specifications require little modification to meet the considerably higher levels of cleanliness required for operation in the type of clean-rooms employed by semiconductor manufacturers.