Production Machining

SEP 2018

Production Machining - Your access to the precision machining industrial buyer.

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By Barbara Kanegsberg and Ed Kanegsberg Ph.D. Erasing Particles with Ultrasonics R emoving particles from machined and fabricated parts is a must for productivity and profitability. Particles interfere with coating adhesion and appearance, and can also decrease product quality and performance. An exercise conducted by participants at the recent Product Quality Cleaning Workshop sponsored by Gardner Business Media (Production Machining's parent company) illustrates simple, effective methods to test how well cleaning processes can remove particles from high-value products. e exercise used a graphite removal test to indicate ultra- sonics functionality and showed that ultrasonic cleaning can erase particles from surfaces. Participants marked the frosted end of a glass slide with a pencil, then submerged the marked slide in an aqueous cleaning agent in the bath of an ultrasonics tank heated to 40°C. Immersion alone did not have any immediate, visible effect. However, the mark— particles of graphite—disappeared within seconds after the ultrasonics cleaner was activated. An aluminum foil test is most commonly used to detect ultrasonic functionality, especially at lower frequencies, but it is generally a visual, qualitative indicator that the ultra- sonics work. We know of no standard test method for the foil test. Typically, for 40-kHz tanks, an "orange peel" erosion pattern is visible on regular weight, commercial aluminum foil after 30 seconds of exposure. While the graphite removal test is probably less well-known than the aluminum foil test, a number of participants in the workshop latched on to this idea. Why would using ultra- sonics essentially as a pencil eraser produce such interest among rather sophisticated participants? One reason is simply that particles on product surfaces are a persistent pain in the posterior. Another is that, at frequencies above 100 kHz, the foil test ceases to be a reliable indicator of ultrasonic activity, but the graphite removal test still works well. Particles sprinkled on a clean surface can sometimes be dusted or rinsed off, especially if the surface is otherwise clean and if the action is taken immediately. But will this happen reliably, and will all particles be removed? Nope. In manufacturing, particles have an unfortunate desire to cling to surfaces. Small particles are more difficult to COMING CLEAN COMING CLEAN 52 PRODUCTION MACHINING :: SEPTEMBER 2018 Cleaning Technologies Group has been the single-source provider of industrial parts washers and custom ultrasonic cleaning solutions to the world's metalworking industries for over 100 years. At IMTS, in our new East Building, Level 2 location, you'll find a new generation of fast, highly automated and extremely efficient parts cleaning technologies from our world-renowned Ransohoff and Blackstone-Ney Ultrasonics divisions. Schedule your visit: WE'RE MAKING A SPLASH AT IMTS East Building, Level 2 Booth #121513 | 800.766.6606

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