An IRB 2600 robot unloads and stacks through the unmanned night shift A manufacturer of precision plastic bearing cages has substantially improved productivity by using an ABB IRB 2600 robot to unload and stack products throughout the unmanned night shift. ABB’s six-axis robot has helped SynthoTec to address the limitations of a previously-installed Cartesian-based robot system that prevented it from achieving its full production capacity. SynthoTec specialises in manufacturing precision moulded bearing cages and other products made from engineering grade polymers, with much of its production going to the automotive industry. With moulding machines that produce parts with masses ranging from one gram to 120g, much of SynthoTec’s machine unloading, parts handling and stacking is performed by robots. One particular moulding machine produces six bearing cages with a cycle time of just over 18 seconds. A robot unloads six bearing cages simultaneously and stacks them onto pallets. The company’s previously-installed Cartesian robot was unable to make full use of the total storage space available for stacking the pallets. With a servo-driven, six-axis ‘wrist’ that moved up-down, in-out and back-forth, it could only reach certain parts of the loading area, which limited the total number of pallets that could be stacked. This was a particular problem during the night-shift, when there was no-one on hand to move the stacks around to make more room. To help it find ways to expand its production output, SynthoTec called in robotic systems integrator Geku Automation to investigate the unloader applications and design a more productive solution. SynthoTec has been working for many years with Geku Automation, which specialises in robots and handling systems, including gripper systems and conveyors, for customers in industries from aerospace to agricultural manufacturing. Geku assessed the need for the application using ABB’s RobotStudio offline programming and simulation tool that allows 3D modelling of robot applications. This enabled SynthoTec to test in advance how the robot would work with the pallet server to carry out the necessary unloading and stacking tasks. Low scrap rates The robot chosen was the ABB IRB 2600, a six-axis unit that offers a high payload capacity of up to 20kg and a working range optimised for material handling, machine tending and arc welding. It also offers the best accuracy and acceleration in its class, securing high output and low scrap rates for improved productivity. The unit for SynthoTec is mounted on the floor between the moulding machine and the pallet server. With its six-axis movement, it can readily access the pallets and stack them throughout the night shift with none of the limitations of the company’s previous system. The old system could have two empty pallets with one being stacked, while the new system increases capacity to three empty pallets and one being stacked. Nigel Richardson, joint managing director of Geku, says: “The ABB six-axis IR2600 has several advantages over the Cartesian based robot previously employed. One is that its rotary bearings are much more reliable than the linear bearings employed on the Cartesian robot.” The six-axis system now operates for 20,000 hours before needing a service, a six-fold improvement over the Cartesian system. Another advantage of the ABB IRB 2600 is its ability to be mounted in a variety of configurations, including floor, tilted, wall, inverted or shelf mounted – which help to reduce floor space and increase access to the equipment being served. Edward Mason, engineering director of SynthoTec, says: “The new robot is part of a continuing programme of developing our moulding and part handling applications. The ABB robot helps to us achieve an 18.5 second cycle time; maximises production capacity, and also adds new value, such as automatic waste recovery compared with the previous manned system. “As well as improving our productivity, giving us an improvement in Overall Equipment Effectiveness of 5%, the new robot also needs less maintenance. We also received excellent programming and engineering support from both ABB and Geku.” SynthoTec has ordered a second ABB robot from Geku for another very similar application.