Robotic palletising system delivers production benefits for Australian manufacturer.

Incorporating a robotic palletising system into its new production line ensures that occupational health and safety issues are never a problem.

As a world-class company with a history of strong growth and a string of leading brands behind it this leading Australian manufacturer was clear on three points when it came to the automation of its new production line at its manufacturing facility in Sydney: eliminate occupational health and safety issues; reduce labour costs; and increase production capacity. Integral to the automation of the production line and its three new packing machines would be the installation of a palletising system that could deliver on those three key points: a challenge in any industry involving palletising, where manual systems are notoriously labour intensive, time consuming and plagued with the occupational health and safety issues associated with heavy lifting.

Robotic palletising at work

The system principle delivered by Machinery Automation & Robotics (MAR) is simple: automate carton handling; automate pallet handling; automate stretchwrapping; install a single robot system to perform the process; design a user-friendly touch screen; and the entire palletising system can be controlled by a single operator.

At system start up the operator loads a stack of up to ten empty pallets into each of the Chep and Export pallet stack frames. These pallets – of which 20 can be accommodated at any one time – are then automatically conveyed to the pallet pick-up position. Using the PanelView touch screen the operator determines the criteria by which the system will function. After ensuring that no personnel are within the cell the operator closes the switch-protected safety gate and uses the PanelView touch screen to start the robot system.

The robot system, which provides continuous operation during the palletising process, comprises a robot which distributes the empty pallet stacks to the loading stations. If required at this stage, the robot picks and places a pallet layer sheet onto the appropriate empty pallet. As cartons are received at the infeed conveyor sensors count the required quantity to commence pallet layering. When the correct number of cartons is reached, a stop plate prevents additional cartons from entering the final pick-off point. Moving to the carton infeed conveyor the robot grips the set of cartons and raises them from the conveyor. Following system confirmation that the cartons are securely gripped the robot transfers the cartons to the loading station and continues the palletising process until a pallet load is complete.

Each fully loaded pallet is removed from the loading station to the 90-degree conveyor transfer, from where it travels along the main trunk line before exiting the cell through the muted safety light curtain. The pallet then enters the stretchwrapper where, if preselected by the operator at the PanelView touch screen, it is wrapped prior to exiting the system for the pallet pick-off point.

Design of the robot palletising system provides the flexibility of manual stretchwrapper infeed in addition to the fully automated process. The pallet conveyor section between the robot cell exit and the stretchwrapper entry points allows pallet placement by a forklift operator for automatic stretchwrapping. The break in the light curtain created by the forklift operator entering the area powers down the section, enabling the pallet to be placed on the conveyor. The driver simply presses the reset button as he clears the light curtain to activate the conveyor section.

All completed pallets exit the stretchwrapper, whether preselected for wrapping or not, and are ready for removal by the forklift operator. In a similar process to the manual stretchwrapper infeed system the conveyor is powered down by a break in the light curtain, the pallet is loaded and the forklift driver exits the area and reactivates the conveyor section with a simple push of a button.

Control at your fingertips

Operation of the entire robotic palletising system and conveyors is controlled from the colour PanelView 700 Human Machine Interface (HMI) touch screen located inside the robot enclosure. The ten-page PanelView program is easy to navigate and includes primary control for system start/stop function and a graphical display to assist the operator. In addition the program provides a dedicated page for each of the following: manual control of conveyors; manual control of the gripper; shift production data; error reporting; robot control in service position; and robot control in the elevated home position, maximising access around the cell during maintenance and cleaning operations.

The PanelView touch screen program also incorporates a number of selection options enabling the operator to determine: carton tuning to allow for changes in card production and case packing tolerances; the products to be palletised; the number of carton layers per pallet; the pallet station to which the product is to be transferred; the type of pallet – Chep or Export – to be used at each station; whether a pallet sheet is to be used at each station; and, finally, whether a completed pallet is to be stretchwrapped.

 Safety first

The automated system upgrade enabled two specific features to be incorporated into the design of the system cell: firstly, that no part of the robot or gripper make contact with the perimeter fence or the four surrounding walls; and secondly that the area within the cell be maximised to ensure free access around the robot and conveyors for cleaning, maintenance and general operation.

 Adding up the benefits

Automation delivered a range of benefits including:

  • The manufacture, supply, installation and commissioning of a complete robotic palletising system
  • Elimination of all manual handling during palletising operations, resulting in significant labour-cost savings and adherence to occupational health and safety standards
  • High-speed palletising, processing up to three cartons per cycle and completing a minimum of eight cycles per minute
  • Incorporation of four separate carton infeed conveyors and four pallet-loading stations within a single cell
  • Flexible palletising – both Chep and Export pallets can be processed simultaneously within the cell
  • Incorporation of a fully automatic stretchwrapper system
  • A user-friendly, customised PanelView Plus 700 HMI
  • An increase in production capacity due to the fully automatic upstream packing systems

Technology at work

  • The control system features an Allen Bradley MicroLogix PLC mounted within the robot enclosure
  • The operator workstation features a cabinet-mounted Allen Bradley colour PanelView 700 HMI touch screen located within the enclosure
  • The four-axis industrial robot system comprises a KUKA KR180PA featuring a 180kg payload capacity and 3200mm reach
  • The robotic gripper system is fully customised
  • The system accommodates varying empty pallet dimensions of 1165x1165x145mm (Chep) and 1100x1100x130mm (Export)
  • The system has the capacity to simultaneously transfer three 16kg cartons and up to 50kg mass in empty Chep or Export pallets
  • Incorporated light curtain safety systems ensure enhanced personnel safety at all times
  • Automatic stretchwrapper located at the pallet conveyor outfeed
  • A total of four 2500mm carton infeed conveyors supply cartons to the four pallet-loading stations