Partnering route helps robots put bricks in their place

A global manufacturer of high quality bricks, Wienerberger produces its standard products using conventional dedicated automation systems. In addition it also produces what it calls ‘special-specials’ – bricks manufactured at its Tamworth site in lower volumes and to special designs.

Having to re-site one of its UK facilities into the Tamworth site, the opportunity was taken to fully automate the ‘special-specials’ process. The existing automation only managed to handle 20% of ‘special-specials’ output the remaining being done by hand.
Wienerberger is not new to robotic automation, already having many installations worldwide; it was therefore decided to use a robot for the specials application. Unlike previous installations, however, where robot systems had been purchased as part of an OEM designed system, Uk Engineering Manager Dennis Brittle, set out to make sure the robot was at the heart of the new system and was utilised fully and efficiently.

Dennis Brittle explains, “Core objectives for the new system were high productivity and efficiency and to achieve this we knew we needed to put the robot’s capabilities to full use. The decision was made for Wienerberger Uk to project manage the entire system working in partnership with FANUC Robotics UK and using a local subcontract machine builder.

“Although only part of an overall project that involved making, drying, firing and setting of the ‘special specials’, the robot handling of bricks at the ‘green’ or unfired stage was critical as previously 80% of bricks had to be manually handled. A decision was made early on to handle bricks one at a time – the robot had time to handle them as single units and also had the ability to locate brick position using vision.”

The system uses a FANUC Robotics M710-iC six axes robot to pick up ‘green’ bricks from an input conveyor and positions them onto a ceramic pallet where they remain until fired. Typical brick handling systems attempt to pick complete layers but for ‘special-specials’ this poses many problems. Special order bricks can have multiple chamfered sides, radiused edges and several faces where damage has to be avoided.

Wienerberger and FANUC Robotics worked together to resolve these issues by handling the bricks separately with a ‘suits-all’ vacuum gripper solution, a vision system and bespoke palletising software. Single or double bricks enter the system on a conveyor and their precise position is identified by a vision system using FANUC Robotics IR-Vision integrated software.

The M710-iC robot is fitted with a single vacuum gripper that orientates itself to information fed by the vision system and picks up the brick. Dennis Brittle continues, “The gripper is a good example of what we expected to buy in to with this project – ‘know how’. FANUC has thousands of these robots installed around Europe so we knew reliability and functionality would be good but we also understand that it’s the application know-how that makes it work.

“The gripper will accommodate over two hundred variants and using it with the vision system makes the system far more reliable and reduces maintenance issues associated with over complicated product orientation systems.”

Palletising patterns for each layer design are defined by the bespoke software developed by FANUC and Wienerberger. The control panel has PC and Human Machine Interfaces (HMI) which allows the shape to be drawn, edited and dimensions to be input. From this information the software defines where the gripper locates the brick, where to place the brick and how to orientate each layer to complete a 950mm x 950mm x 1,000mm pallet.
Maximising the robot’s capability, an innovative approach to sanding each layer – a process to separate brick layers during the firing therefore preventing sticking – has been taken by using the robot to draw the sander across each layer as it is completed. The level of sand dispensed is controlled by the speed, height and tilt of the dispenser as the robot passes it over the bricks.

The ceramic pallet is positioned on a rotary table that removes the pallet to an unloading area and positions a new pallet so that uninterrupted production can continue.

“The system has been in operation now for six months and has one supervisor to control the cell as opposed to six people manually stacking the bricks. Damage to bricks caused by handling has been eliminated and overall the system is much faster and more accurate.
“By our partnering approach we have really benefited from a better understanding of robot capability and in particular by installing a system that really meets our needs. We are very pleased with the outcome of this project, and we look forward to working with Fanuc on future installations in the UK.”