Solvent solutions

Four MecWash installations at the Goodrich Actuation Systems plant in Wolverhampton are a key element in a move to replace solvent use at the site, with the units replacing 24 solvent degreasing stations. Located in key areas of the manufacturing facility, three of the MecWash Midi units are dedicated to specific activity, with the fourth supporting a wide range of component cleaning options. Because the vast majority of the company's business is focused on aerospace, cleanliness and performance requirements are paramount. PAINT AND PLATE One of the dedicated installations is sited ahead of the painting and plating facility. Responsible for the removal of oil before onward processing, the unit's rotating drum is loaded directly from a static roller conveyor. A series of pre-set programmes rotate and oscillate the drum through spray and flood washing, and then rinsing stages, ensuring that components are fully cleaned and dried. Parts are held either in simple plastic containers with internal separators, purpose-designed fixtures or in mesh baskets. A similar arrangement in the Goodrich heat-treatment area is also now fully functional and this alone has replaced three solvent-based installations. Key objectives need to be met in this location, as Mark Binfield, operations manager (Special Process), Goodrich, explains: "Parts must be totally dry ahead of the heat-treatment process, so the vacuum drying capability of the MecWash Midi is very important. Typical products that go through this machine are gears and rotary actuators manufactured from high strength steel, which can present particular corrosion considerations and are thus coated with a suitable inhibitor. It is the removal of this that is the prime function of the MecWash installation." The third machine, located alongside the Goodrich NDT facility and through which virtually all components manufactured at the site pass, was considered by Goodrich to be the only machine of its type on the market that could deliver suitable cleaning results for this vital operation. "The MecWash Midi here is equipped with both ultrasonics and vacuum drying and can accommodated, both large, fixtured parts and smaller components in baskets," explains Steve Parks, NDT level three at the site. "Cleanliness here is paramount if all potential cracks are to be identified in components, so the performance of the MecWash Midi is crucial to our quality control procedures." While three of the MecWash Midi units focus on specific activities, the fourth installation, which also benefits from ultrasonic cleaning operating in conjunction with the rotating drum, offers Goodrich a versatile cleaning option. Able to accommodate both heavily contaminated refurbished and new build parts – even components up to two metres in length – the unit operating on a 'bus stop' basis, with parts arriving from around the site, as well as often working in conjunction with blasting stations positioned alongside. Again, this one installation has replaced three solvent degreasing stations. All the MecWash units feature AquaSave water recycling technology. OPEN-TOP AQUEOUS SOLUTION Turning to a new product that also has solvent degreasing companies in its sights, and Technowash is offering yet another alternative to those moving away from such degreasing, saying that "manufacturers can now have a safe alternative to open tank vapour solvent degreasing, yet still achieve effective and consistent high integrity precision cleaning". The company's new open-top Vapourwash machine is claimed "the first fully aqueous-based alternative [open-top] vapour degreasing system available on the market". The new Vapourwash machine offers a genuinely 'safe' like-for-like alternative, which has all the benefits of traditional solvent cleaning, yet without any of the hazards, it is claimed. The machine looks like a conventional open-top solvent vapour degreasing, with a similar footprint, and is operated like a conventional solvent vapour degreaser. Technowash says: "Rigorous performance testing has shown that the cleaning standards achieved are consistent, effective and precise, either matching or outperforming traditional solvent vapour degreasers on each occasion – yet all with the use of only water-based detergents." The machine cycle is split into three cleaning stages and a drying stage. Component parts are processed through a heated agitation immersion stage, high powered spray wash stage and a fine heated vapourised mist rinse stage, before finally a hot air drying stage, during which the unit's top closes, ensures parts leave the machine both clean and dry. Technowash technical director Tony Grayson says of his company's latest development: "We knew aqueous vapour degreasing would only be possible if it could match the performance of solvent cleaning. When one of our most sceptical customers conceded that the cleanliness of their parts were actually improved in comparison to the results achieved with their existing vapour solvent degreasing systems – we knew we had developed something significant." A video of the company's unit in operation can be viewed at its website – www.technowash.com. Box item Twice as good MecWash's new MecWash Duo brings a combination of cleaning, rinsing and drying capabilities that is said to offer high performance and excellent value for money, into a highly compact, energy- efficient unit. The Duo features twin wash and rinse tanks, allowing it to deliver both a high volume, flood/immersion wash cycle and a powerful spray rinse stage. With a footprint of just 1,520 by 1,635 by 2,235 mm in height, the MecWash Duo is designed for easy location in a range of operational environments. A single chamber format, which houses 100 jetting nozzles, receives parts and components in plastic or metal baskets, or in purpose-designed fixtures. This then either gently rotates or oscillates, depending upon component design and which of the six pre-loaded programs is selected. Components ranging from those with relatively simple geometry to highly complex parts with multiple holes, recesses and galleries are thoroughly and efficiently cleaned via the washing and rinsing process, which is then followed by a high velocity, heated drying cycle. Article first published in Machinery, May, 2009