Butter is delivered to the SÃ¼dwestbutter creamery in bulk and packed in 25kg cartons on pallets. Individual cartons then 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, but it is now handled completely automatically by a gantry robot. 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.
For this particular application, Parker constructed the gantry robot from special materials in order to meet the high demands for cleanliness, productivity, and short cycle times. The robot’s movements are actuated by fully digital drives and transmitted by low-friction toothed belts, which provide a highly reliable, low-maintenance solution, even after years of continuous multi-shift operation.
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 contaminating dust.
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.
The Electromechanical Division at Parker Hannifin produces a wide range of materials handling robots for the food industry. In this particular case, the gantry robot is controlled by a programmable logic controller although the automation system could be controlled equally well by networking the robots with custom industrial computers and industry-standard PCs.
To ensure safe and reliable system operation, even during unsupervised shifts, the pallet stacks, gripper unit and orientation station are all equipped with photoelectric sensors, to provide monitoring of the movement of butter packages at all times.