FANUC robots reduce part stacking time

Marley Eternit has installed two FANUC robot systems at its Burton-on-Trent tile manufacturing plant.

Comprising six robots in total, the systems were needed to replace older dedicated machinery and to accommodate additional capacity transferred from another facility.

Steve Herriott, head of engineering, Marley Eternit, says: 'Using robots we knew we could save over three minutes on each product changeover, and as we have eight profiles and up to 40 changeovers per shift the robot approach would increase capacity.

'FANUC Robotics was chosen as the supplier and robot system integrator on the basis of experience in our sector and its understanding of the aggressive nature of the product on equipment.

The four-robot system has one line feeding into it and two identical cells of two robots each to handle the throughput.

Each cell has a six-axis R2000 robot that handles two stacks of tiles simultaneously and places them onto a larger vertical stack for handling by a six-axis M900 with a 600kg capacity.

Tiles entering the system are diverted to either of the two cells and are stacked in two piles for the R2000 to pick up.

The height of each stack is measured by a straightforward through-beam sensor, as the sizes of tiles and stack height can vary typically by +/-15mm.

This information is stored by the robot, which is able to adjust its positioning when placing them down to avoid collision and damage.

The FANUC Robotics R2000 robot places the tiles in the vertical position, which provides considerable advantage as the gripper of the M900 is able to support the stack weight from underneath and use the closing of the gripper to align the sides of the stack instead of applying a potentially damaging gripping pressure.

This process had not been possible on Marley Eternit's previous tile pick-up systems, as only four-axis heavy-duty robots had been available.

With its 2.8m reach, the M900 robot is fully utilised in the cell - before palletising the tiles it positions them vertically, while clamping them neatly in its gripper, into the strapping machine.

A single strap holds them securely and allows them to be stacked neatly onto the pallet.

This process has had a significant effect in eliminating breakages and ensuring pallets remain consistent during transportation.

Compared to automotive-type installations, the dimensional accuracy of aggregate components is a major issue that Marley Eternit has to address, and grippers were designed and supplied by FANUC to allow trials to be carried out prior to installation.

The sensor system was also tested rigorously by FANUC to prove its accuracy and integration with the R2000 robot.

The system is now operating two shifts per day, seven days per week at a capacity of 150 tiles per minute.

This was achieved after a three-month installation and commissioning period that included operator training at FANUC's Coventry training school.

Although packing smaller tiles, the second system comprises a single cell with two robots.

Output from the cell is 120 tiles per minute.

Back to top