Equipped to handle all sorts
August 1st 2009

CKF Systems of Gloucester recently won a £1.2 million contract to design and install a new automated robot palletising system at Cadbury, Sheffield. It was installed and commissioned over a 12 week period with the planned loss of only 12 hours production

The original system was based on eight conveyor lines feeding a central palletising area where the wide range of cases were manually stacked onto pallets, employing 24 personnel over a three-shift operation.

Specific challenges in designing the new operation included a confined floor space with restricted headroom, a wide range of case sizes, high flow rates, an increase in pallet stacking heights and large number of stacking patterns.

The new arrangement incorporates three robot palletising cells each comprising an ABB IRB660 robot complete with vacuum gripper, utilising the latest pickmaster operating software. Each cell also included a dedicated pallet conveyor for each product line, each comprising of an empty pallet buffer position; a load station adjacent to the robot to receive, locate and hold an empty pallet against defined datum's for placement of the stacking patterns; and a discharge section to receive and hold a loaded pallet from the load station ready for transfer to the end-of-line stretch wrapping station.

Individual empty pallets are transferred from one of three dedicated magazines – designed to handle Chep UK, Chep USA or Euro pallets – onto a common shuttle for transportation to each robot palletising cell.

A similar shuttle arrangement is across the outfeeds from the three robot cells to receive individual loaded pallets and deliver them to the central stretch wrapping station.

Cases are fed from each of the nine existing production lines on a series of dedicated conveyors including a spiral elevator and high level driven roller sections.

The interface between the case feed conveyors and robot cell includes localised buffer/collator sections to create defined batch counts of cases in the correct orientation for presentation to the robot gripper. Each batch is then collected from the feed section and stacked on the associated pallet.

The infeed to the stretch wrapper includes a buffer section and turn-table to ensure correct presentation to the high speed stretch wrapper. Loaded pallets dispensed from the wrapper are transferred on to a dedicated conveyor for removal and transportation to dispatch.

The palletising system was fully enclosed within a 2.5 metre high guard structure; subdivided into six zones complete with localised fencing, light guards and interlocked access gates providing safe access into each zone via a key exchange system - without shutting down the full system.

The electrical control system comprises of four panels. The master panel, housing a Siemens plc, controls the pallet magazines, transfer shuttles and transfer conveyors to the wrapper system; and the three localised panels, with remote I/O, control the conveyors within each robot cell and associated feed conveyor systems. The integral control panel, and plc, in the stretch wrapper incorporates the controls for the local pallet conveyors within the associated guard zone.

Environmental benefits are derived through the ability of the system to create increased pallet stack heights of 1.7m, thereby reducing the number of delivery vehicles required (typically 650 vehicles per year) and improved utilisation of the warehouse space.

"We are very impressed with CKF Systems' execution to this project," comments Dave Hough, Cadbury project manager. "They have been professional throughout and provided a very effective system to meet our specific demands." Operationally, the system was installed and commissioned over a twelve week period with the planned loss of only twelve hours production. Since being implemented the department has gone through an unprecedented twenty-two week period of peak volume and delivered service levels above 99.5 per cent, incurring zero accidents or incidents.

"Without a doubt, this has changed the face of Sheffield's packing hall," says Michelle Fitton, manufacturing manager, Gums & Liquorice, "It has made us more cost effective, further improved our high standards of safety, and enabled a cross functional team to work more collaboratively than ever before. Not to forget playing our part in improving the environment by reducing the number of vehicle moves each year." "This project has demonstrated the ability of CKF to undertake major conveyor and palletising systems," says Kevin Staines, sales director for CKF Systems.

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