Cementing palletising safety standards

Jeff Fordham* looks at how robotic systems is helping make materials handling applications safer.

A LEADING Australian manufacturer of sealing products wanted to incorporate a robotic palletising system into its new production line to ensure that occupational health and safety issues would never be a problem.

As a world-class company with a history of strong growth and a string of leading brands behind it, this manufacturer was clear on three points fundamental to the automation of its new production line at its manufacturing facility in Padstow, Sydney.

To be successful, the automated system must eliminate OHS issues, reduce labour costs and increase production capacity.

Integral to the automation of the company’s production line and its three new packing machines was the installation of a palletising system that could deliver on those three key points.

This is a challenge in any industry involving palletising, where manual systems are notoriously labour intensive, time consuming and plagued with the OHS issues associated with heavy lifting.

Automated solutions

Machinery Automation & Robotics (MAR) designed a system for the sealing product manufacturer based on the following simple principles: automate carton handling; automate pallet handling; automate stretchwrapping processes; install a single robot system to perform the process; design a user-friendly touchscreen and; ensure the entire palletising system can be controlled by a single operator.

From the robot and conveyor systems operations, to the stretchwrapper infeed function and pallet removal sequence, the automated robotic palletising process is initiated and controlled by one person.

At system start up, the operator loads a stack of up to ten empty pallets into each of the pallet stack frames. The pallets – of which 20 can be accommodated at any one time – are then automatically conveyed to the pallet pick-up position.

A simple function selection made on the touch screen controller ensures that any incomplete pallets are automatically removed from the cell at this stage. After ensuring that no personnel are within the cell the operator closes the switch-protected safety gate and starts the robot system.

The robot system, which provides continuous operation during the pallet stacking process, comprises a robot which distributes the empty pallet stacks to the loading stations.

If required, the robot picks and places a pallet layer card 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 and none remain on the infeed conveyor, 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° 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, it is wrapped prior to exiting the system for the pallet pick-off point. 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 and then the driver simply presses the reset button as he clears the light curtain to activate the conveyor section and reset the timer.

Safety at your fingertips

Operation of the entire robotic palletising system and conveyors is controlled from the colour Human Machine Interface (HMI) touchscreen located inside the robot enclosure.

It is through this that the operator can determine: 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 to be used at each station; whether a pallet card is to be used at each station and; whether a completed pallet is to be stretchwrapped

The integration of an automated system upgrade provides the perfect opportunity for any manufacturing company to ensure that personnel safety precautions are first rate.

With this in mind MAR incorporated two specific features into the design of the system cell.

Primarily, no part of the robot or gripper can make contact with the perimeter fence or the four surrounding walls. In addition, the area within the cell has been maximised to ensure free access around the robot and conveyors is available for cleaning, maintenance and general operation.

The robotics company’s fully automated palletising solution delivered a range of benefits including incorporation of four separate carton infeed conveyors and four pallet-loading stations within a single cell.

This provides high speed palletising, processing up to three cartons per cycle and completing a minimum of eight cycles per minute.