During the recent building boom it may have gone unnoticed by many unless you were a ‘would be’ purchaser, that most building sites are now relatively tidy places. They are also virtually smoke free zones and the constant rubbish burning fire in the middle of the site is just a distant memory. This is driven by legislative and environmental controls, the impact of which goes right back to the raw materials manufacturer.

The traditional method for transporting blocks around a site was to lower packs of blocks from a lorry onto a pallet for fork truck access. The pallets are not wanted on site especially now that fires are illegal and putting a return deposit on pallets can be seen as penalising the customer particularly when pallets are not returned.

The solution for getting rid of pallets is to provide voids in the pack for fork truck lifting which obviously has an immediate effect on reducing packaging. For a leading manufacturer producing the configurations for over seventeen different void packs was impossible for its dedicated automated packaging system so robots were considered and several suppliers consulted.

As an existing user of FANUC robots at its tile manufacturing facility it was decided to contract them to design and install a system at the block making plant. To make this important selection of supplier their experience within the aggregate sector and a progressive approach were essential for another major system to be engineered.

It was necessary to bring several new technologies to play in the system and at the same time to engineer simplicity into a complex system. The existing process equipment, which delivers a ‘cake’ of 28 columns of blocks every 150 seconds, dictates the palletising cycle time. To achieve this two independent cells of three robots each were supplied with each cell working from each end of the cake.

Robot one of each cell is a six-axis 200kg payload R2000I200F and picks up a column of blocks and places it onto an accumulating transfer conveyor. Dependent on the block size the system programme instructs the robot to select either a clamping gripper for small blocks or a vacuum plate for larger blocks from the auto tool changer.

The tidiness of the completed pack is a core objective of the system to ensure secure packing and minimisation of pack ‘footprint’ to minimise storage space for vehicles, yards, sites etc . To enable this it was essential for the sides to be flat by aligning the bricks. To do this the accumulation transfer conveyor uses a laser positioning system and a servo driven blade to accurately position the blocks for the pack building robot.

The pack building is carried out on both lines by a four-axis M410/WW 450kg palletising robot in conjunction with a third robot, an R000/B robot for creating the void layer.

Robot two picks aligned blocks from the pack building system and places the first layer directly onto a conveyor while robot three has blocks placed in front of it which it arranges to form a void layer. A protection sheet is placed on top of the void layer by robot three to protect blocks from lifting forks when being handled. The void layer when complete is positioned by robot two, which continues to make up the finished pack picking up two rows at a time with its specially designed grippers.

Then complete packs are conveyed into a ‘fly strapping’ area where to avoid block breakages, a unique clamping system applies pressure to the sides of the pack system before the straps are applied. Strapped packs then continue to a wrapping area and are collated for pick up outside the cell.

Viewing the system in operation provides the best indication of the control complexity managed by the six robot control systems as they operate within each others work space, robots two and three being linked to avoid collision. An operator touch screen monitor provides straightforward status information and allows for routine interventions such as system clean down.

This is a perfect example of robot capabilities where on the one hand they are rugged enough to handle heavy and dusty products, yet function dextrously and in a complex process along side other robots.

When environmental pressures oblige a company to review its supply line a radical change can be the answer as in this case, remove the unwanted packaging, reconfigure products and use robots. As systems partners Micromech Robotics and FANUC can specify, build and install the right equipment that is simple to programme and operate. Perhaps you are not already using a robot and this has tempted you to lay the foundations of your own factory rebuild, if that is so and you would like to find out more about our products and services then contact Stirling Morley on stirling@micromech.co.uk or 01376 333311