Three robotic packing cells developed by Motoman Robotics and supplied as turnkey systems to Wrexham-based Calypso Soft Drinks have enabled significant improvements in efficiency. In one case, introduction of an SV-3 robot for placement of 85ml cuplet drinks into outer boxes has allowed line speed to be increased by 25 per cent. In another, the cell has succeeded in automating the palletisation of 56 different product and pack size combinations onto shipping pallets.

Calypso decided to automate the palletising function on four lines producing Tetra packed drinks. This is quite a complex task as the system has to be capable of coping with trays comprising either 24 or 27 packs with further variation occasioned by the use of 200 ml and 250 ml packs in addition to differences in the flavour of the actual product. In all there are 56 pack variations that demand three different pallet stacking patterns.

The aims of the robot packing project were well defined from the start. One cell would be required to place the six 200ml packs and cuplets into cartons as they came off the filling line. Flexibility was needed to pack 200 ml six-packs at a density of four packs per box, or individual cuplets at a density of five layers of 20 per box. Specified packing time was four seconds per box for the six-packs. An additional requirement for the cuplets was the insertion of a cardboard separator between each of five layers; around 20 seconds/box is allowed on this product.

A second cell on the same line was required to stack the cartons from the cup line onto pallets, with a maximum case weight of 12 kg for the cuplet boxes.

In selecting Motoman Robotics as supplier/project partner, Calypso was drawn to the company’s systems experience and the quality and performance of the product. The electric operation of the basic robot was also seen to be an advantage on the basis of the need to combine speed with precise positioning accuracy in both the box-filling and pallet stacking applications. Likewise the six-axis robot format provided comprehensive positioning flexibility which proved essential in the box filling role.

As installed, the latter system comprises a pair of Motoman SV-3 robots for box filling.  One of these is equipped with a handling device comprising vacuum suction cups for the pick and place function, while the second is dedicated to inserting a separator card.

The palletising robot on the same line operates equally well. Again, vacuum-suction is used to grip the cartons which are palletised two at a time. Once a pallet load is completed, the pallet is moved away from the load area on a powered roller conveyor. The robot then picks an empty pallet from an integrated pallet stacker using hook-type lifters built into the box handling attachment. The new pallet is placed onto the load area.

Alongside this installation is the palletising cell for the Tetrapak line. This is the most complicated of the three Motoman-supplied systems as the robot needs to service up to three process lines simultaneously. It does this using an ingenious marshalling system, which is operated by the incoming trays, each of which has a product-specific barcode.

Factory engineering manager Mr Edwards related, “When the robot cells initially arrived on the shop floor I found it difficult to see how we were going to benefit. However, once I had completed the Motoman training course and began to gain some programming experience as we developed the application, it began to make a lot of sense. It is actually quite easy to teach the robot what to do and it is also very satisfying.”

Mr Ball, the company engineering manager, concluded, “We now have a system in which people have complete confidence and which is fully accepted by the workforce. It has also allowed us to redeploy a number of people to tasks where they add value to the end product.”

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