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Emerald Group Publishing Limited
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Bottle recycling firm also recycles industrial robots
Article Type: Mini features From: Industrial Robot: An International Journal, Volume 36, Issue 6
Recycling is now on most people's agenda, as a way of saving energy and conserving the environment, although recycling industrial robots is rather unusual. But leading UK robotics integrator, Barr & Paatz of Totnes, Devon, recently supplied two pre-owned SCARA type robots to an SME customer for performing conveyor loading and unloading duties. This high-technology recycling initiative underlines the inherent flexibility and reusability of robots and confirms that these well-engineered machines will continue to give many years of reliable service (Figure 2).
The customer in question, Trading Green of Wadebridge, Cornwall, is usually associated with a more familiar form of recycling: it transforms used beer and wine bottles into an award-winning range of “Green Glass” goblets, flutes and tumblers, which are widely sold in gift shops, museums and leisure attractions. Part of a largely craft process, which has been designed to be as energy efficient as possible, the two robots help perform routine and potentially hazardous grinding and annealing functions, freeing up operators to focus on quality control and removing, excuse the pun, a production bottleneck. So much, so that productivity has increased by 45 per cent, through automation of these two key tasks.
Glenn Slade, Founder of Trading Green and the innovative Green Glass brand, first came across the idea of recycling old glass bottles into attractive glassware, when working on environmental projects in Africa. He wanted to earn a living “doing something that felt good” and where his children would enjoy life, so he set up the Green Glass operation in a garden shed by the sea, in Cornwall.
Word spread and soon Green Glass products were listed in hundreds of gift shops, including such notable attractions as the Natural History Museum, Kew Gardens and the Eden Project. Output increased to 250,000 units a year, production outgrew the garden shed and, whilst still largely a manual operation, certain processes became repetitive, tedious and potentially hazardous.
Glenn approached robot specialist Barr & Paatz, with a tentative enquiry and a “shoestring” budget, and was offered a pre-owned Bosch Rexroth turboscara SR8, a four-axis machine with an 800 mm reach, 5 kg maximum payload capacity and repetitive precision of ±0.025 mm. Now manufactured and marketed by Stäubli, the turboscara has all the performance characteristics suitable for loading/unloading duties, including very high speed, high rigidity, outstanding reliability, user-friendly programming under Windows, and an absolute encoder system, so the end-of-arm tooling “knows” its position in the work envelope, without reference points.
Barr & Paatz designed and built a prototype CAD system, to prove the principles and produce the initial software, then taught Glenn and his colleagues how to program and operate the machine, and provided back-up technical support. The first robot's function is to present the cut edges of bottles to a grinding machine, to ensure a perfect fit between the neck and the base, for bonding.
“They took to robotics very easily, especially having designed and built a lot of their existing machinery themselves. We prototyped the first system and provided template programs, then gave them technical training back at our site, but they actually installed the machine,” says Barr & Paatz, MD, Stirling Paatz. “After that, they've done everything themselves and installed, then programmed the second robot completely unaided. Actually, with the right training and guidance, other firms could do the same, because modern robotics is far more intuitive and user-friendly than many people think.”
The second robot, another pre-owned turboscara SR8, took over a repetitive task that exposed workers, using insulated gloves and tongs, to intense levels of heat, to which they could be subject for only short periods of time. After the bottoms of the beer and wine bottles are cut-off, leaving a raw edge, the robot places product continuously onto a flame polishing device, which produces a smooth, melted edge suitable for drinking. Once the bottles have cooled, the robot flips them over and places the product in rows on a conveyor belt leading to an annealing oven, for strengthening and destressing the glass; this application takes advantage of the turboscara's renowned belt tracking capabilities, which enable the robot to keep pace with the varying flow of bottles. The end-of-arm tooling was made in-house by Trading Green, combining a proprietary pneumatic gripper mechanism with what Glenn describes as “Wallace and Gromit style” custom-made jaws.
“Given our green ethos, we try to keep the manufacturing process as simple and eco-friendly as possible, doing much of the work by hand, but there are certain functions that were potentially hazardous, especially as output increased. So we applied our recycling principles to robotics and integrated secondhand machines into the manufacturing process, while the guys who previously undertook those tasks now focus on operating the robots and quality control, to the benefit of our end-customers,” says Glenn Slade.
“Since we never know exactly what type of bottle we shall be dealing with next,” he continues, “robotics has another tremendous benefit, because setting-up times have been drastically reduced. Whereas with linear systems, we'd need to change things physically each time, the robots just have to be reprogrammed for different bottle sizes and heights and we're off.”
“Robots are often viewed as something exclusive to large manufacturers and many smaller firms are resistant to the technology,” he concludes. “But there are nearby small firms with processes like pouring molten wax or metal that could be performed more safely and accurately by robots.”
For further information, please contact: Barr & Paatz, Ford Road, Totnes Industrial Estate, Totnes TQ9 5LQ; Tel.: 01803 869 833; E-mail: email@example.com
Press contact: David Gent Creative, Tel.: 01706 220388; E-mail: firstname.lastname@example.org