Paint robots for advanced painting plant
Paint robots for advanced painting plant
Keywords: Paintbox Ltd, Paints, Robots
An advanced painting plant equipped with three ABB IRB 5002 paint robots is processing 63,000 mobile phone cases a day for Banbury- based company Paintbox Ltd.
Paintbox has developed the system – regarded as one of the most modern in Europe specifically for painting a wide variety of thin wall injection mouldings, and is presently producing several million mobile phone cases a year for some of the world's leading telecommunication equipment manufacturers.
The paint plant - comprising the three ABB robots with Integrated Process System and RobView control system, spray booths, flash-offs, oven, conveyor,incinerator, paint kitchen and paint mixing/distribution equipment – was commissioned in December 1999 and has improved output 10-fold since superseding a hand spraying process.
A Paintbox spokesperson said: “it's not just the speed of the robots that is important, we also rely on their astonishing accuracy and repeatability to achieve a consistent, high quality paint finish. Indeed, the robots can spray a base coat which is just 10 to 20 microns (10 to 20 thousandths of a millimetre) in thickness, followed by a clear lacquer coat 20 to 30 microns thick – held within tolerances of five per cent.”
The IRB 5002 is an advanced paint robot that can be configured with a variety of arm and mounting options (floor, wall or suspended mounting) as well as a wide range of integrated paint equipment allowing it to be "tailor-made" to suit customers' needs.
The robot uses an accurate spray gun triggering system, built-in spray gun delay compensation, conveyor tracking, patented hollow wrist design with integrated paint and air hoses, and fully balanced manipulator throughout the whole working envelope, to contribute to the achievement of high quality, low cost manufacturing.
Additionally, ABB's Integrated Process System actively controls atomising airflow, fan width and paint flow that together are said to produce considerable paint savings.
Paintbox's highly successful operation is currently running a "double-day"shift and may soon extend to "round-the-clock" operation. The production line is also likely to be expanded with the addition of two more IRB 5002 paint robots.
In a second ABB project Plastic injection moulding experts Rosti (Scotland),based in Larkhall near Glasgow, installed its first ABB paint robots in 1994 to evaluate their merits against hand spraying methods. Two IRB 510 robots –for which a purpose-built extension to the plant was built – were acquired as a measure to improve both productivity and quality on conductive surface finishes, which, at the time, were difficult to apply by hand spraying methods.
The installation was said to be an outstanding success, doubling productivity and improving quality to such an extent that seven years on, ABB paint robots are the standard by which Rosti measures all its automated paint processes.
The Rosti plant at Larkhall offers a total moulding process capability to its customers, as well as additional processes such as RFI/EMI Shielding, high volume cosmetic painting, printing, and assembly.
Technical team leader for the Paintshop and Assembly Areas, Scott Simpson,was one of the first to be trained in programming and operating the original robots: "In 1994, robot-equipped paintshops were quite 'state-of-the-art' and it was a bold move by the company in investing in this technology.”
“With the new robots installed, however, we rapidly upped productivity and quality, which in turn made us more competitive, and this in itself brought in more work. As our workload increased, this led to the purchase of a third IRB 510 paint robot to keep pace with demand.”
The success of the original unit led to the building of a new paint plant five years ago, for the application of special surface finishes to new products. Rosti invested in new IRB 5002 paint robots that incorporated ABB's Integrated Process System (IPS), enabling rapid selection of different spray gun control parameters (Plates 2 and 3).
Plate 2One of the three IRB 5002 robots (background) incorporated into the Paintbox plant
Plate 3ABB paint robot in operation at Rosti (Scotland)
Rosti's engineers were able to modify the robots in other ways to make them even more efficient. “We were using a two-part paint mix for certain components,” says Scott Simpson. “When the two elements were put together the paint was only viable for use within two to three hours or it would'go-off'. There was, unfortunately, the odd occasion when large quantities of paint were pre- mixed; then unforeseen production hold-ups would mean that it couldn't be used, thereby creating a lot of waste.”
“To alleviate this problem, we modified the robots by installing two gear-type metering pumps, separate lines for paint and, hardener, and a mixing chamber within the body. The only waste now is residual paint left in the line between the mixing chamber and the spray gun mounting – a matter of a few metres. Using this method we have made savings of between 10–15 per cent in paint usage, in addition to the savings made over traditional hand spraying.”
Scott adds, “There is no overspray with the ABB paint robots, as with hand spraying, and on special coatings the IRB 5002 has to hold some very tight tolerances, usually two microns, which it does unfailingly.”
'The robots are also almost maintenance-free and work virtually non-stop for three or four years before any replacement parts are needed. They are also extremely robust. We have had incidents when the fixture conveyor (not part of the robot) has failed to move in co-ordination with the robot, and the two have collided. Although the fixturing was badly damaged every time, the robot required little more than a lick of paint.”
“With the productivity, quality and paint saving gains we have achieved, coupled to an easy-to-learn programming language, robustness and reliability, I cannot praise ABB paint robots highly enough.”
Details available from: ABB, Tel. +44 (0) 1908 350300; Fax. +44 (0) 1908 350301; E-mail: david.marshall@gb.abb.com
