The trade show attendee moves absentmindedly toward our booth at SUR/FIN, clearly in a state of sensory overload. He stares at the signs, looking slightly bemused at the concept of critical cleaning. What should we do? Say hello? Offer him a dark chocolate? Even better, eat the chocolate ourselves?
Cleaning is CriticalOur visitor stops, focuses and smiles. Realization dawns. He asserts that, of course, you have to clean properly in order to achieve good plating. We then begin to discuss cleaning requirements, cleaning challenges, etc. Such interchanges occurred over and over. In the past, cleaning was lumped with a number of steps like pickling, electropolishing, and heat treatment under the general concept of “surface prep.” Cleaning was, at best, acknowledged as an afterthought, as a necessary evil; as a sort of appendage to plating. This has changed. Cleaning is now recognized as an important, value-added step in the manufacturing process. One reason, perhaps, is that surface finishing has evolved to include not only traditional plating, but also deposition and application of a wide range of engineered coatings.
We have a love/hate relationship with trade shows. Manning our own booth (“personning” a booth sounds awkward) is intimidating. The prospect of smiling for hours on end is daunting. Our selection of comfortable rather than stylish shoes probably helps avoid scowling, limping, or giggling. We love having a booth, because it provides an unparalleled opportunity to discuss aspirations, goals, and problems with a range of manufacturers. Attendees may think of questions hours after a presentation, so it was helpful for them to have a place to find us. Having a booth means we get to discuss problems informally, to exchange information. The line between information exchange and teaching becomes blurred. When we teach, we inevitably learn.
BasicsThere were many requests to write about the basics of cleaning. These requests came from people in engineering, production, marketing, sales, and distribution. OK, here are a few basics: A typical, complete cleaning process is likely to require washing, rinsing, and drying steps. There is a temptation to take cleaning for granted, and newer employees have to be educated about cleaning. If you have a good cleaning process, make sure the process is in writing. If it is not in writing, write it down. If it is in writing, make sure that your employees are following the directions that are called out in the process and that they buy in to the cleaning process. This includes educating older employees, newer employees, and middle management. Economic considerations may make it tempting to rush through the cleaning process or to cut corners in process monitoring or bath changeout. A successful change in the cleaning process cannot be accomplished based on hope, opinion (of any expert, including us), expected economy, expected efficiency, or “leanness.” The decision to shorten or even eliminate any of the steps in the cleaning the process has to be backed up by testing and evaluation of the process with typical and challenging soils and soil loading.
Vibratory Cleaning?An attendee asked whether or not a vibratory process was a cleaning process. The answer is: it depends. Using media, either wet or dry, has traditionally been considered polishing rather than cleaning. Vibratory processes may be considered at least part of a cleaning process. Factors in successful cleaning include chemistry, temperature, physical force, and time. Even dry processes using vibratory media supply force, and the force can be successful in dislodging soil from the part. However, there are important provisos. For successful cleaning, the soil must be removed from the vicinity of the part. Soils may include things like metal fines. If the vibratory media breaks down, the particles can recontaminate the part. Think of those particles as akin to cleaning agent residue; a rinse step may be needed. If a rinse step is needed, a drying step may also be required.
Green?The specifics of and motivations for planned cleaning process changes was varied. Some attendees expressed interest in CO2 and plasma cleaning. “Greening” of the process was not the major factor, at least among most of the people with whom we spoke. A primary reason was the need to have a particle- and film-free surface prior to depositing a coating. Some ‘chemical free’ cleaning processes can be effective at removing small amounts of contamination, as well as modifying the surface so that subsequently applied coatings adhere strongly. There were a number of expected, and not totally unjustified comments about regulation by agencies concerned with worker safety and/or with environmental impacts. The end result, many asserted, was the elimination of all effective cleaning chemistries. At the booth and during the conference itself, there were verbal comments about using the vote to achieve less environmental regulation. Given the size and complexity of government, perhaps it would be more productive to proactively investigate more effective cleaning processes and, at the same time, look to the “greenness” of the proposed process change. Of course, regulatory status does not necessarily mesh with greenness. A process that is promoted as green but is inefficient or marginally effective is not going to be either economically or ecologically viable.
Complex AssembliesIn a recent ‘on the surface’ column, we discussed the decrease in cleanliness of as-received parts [1]. That topic resonated with quite a few SUR/FIN attendees. Many manufacturers indicated that need to do more cleaning of as-received parts, and they are having difficulty getting a handle on managing consistency of the supply chain.
To get the parts and components you need, use suppliers who are educated in cleaning and surface quality.. Science writer Frank Blanchard asserts, “Communication precedes education.” (2). Communication of surface quality requirements between suppliers and final assemblers ought to be a two-way street. So is communication within a company. Without understanding and buy-in of the cleaning process, a series of orders, standards, and directives are likely to be circumvented.
That’s another reason we value trade shows: communication happens. When communication happens, education happens! Attendees often come to conferences to solve problems. As part of those discussions, we all become more educated.
Sparkle and SubstanceIt is not enough for exhibitors to have flashy signs and a fishbowl to collect cards for a tablet give-away; they have to interact and respond to manufacturing requirements. In some instances, those staffing the booth do not want to be there or, even worse, have no clue about the requirements of their products or services. In fact, at another event awhile back, one booth person — perhaps most kindly described as naïve —discounted the need for cleaning for his medical devices. He commented that while the sterile devices were dirty, it was not a problem because they would be implanted and no one would see them! While the physical appearance, the “beauty” of a product surface can be important to customer acceptance, understanding, defining, and controlling acceptable levels of residue is even more important to successful manufacturing.
In contrast, in exploring booths at the SUR/FIN conference, there was an encouraging level of technical expertise. This may be a reflection of increasing sophistication among manufacturers as well as of the increasing need to justify time spent at conferences. In either case, having marketing managers, distributors, and sales reps immediately recognize the need for cleaning can only be seen as a positive sign for manufacturing. Booth babes of both genders have changed for the better.
References
- B. Kanegsberg and E. Kanegsberg, “On the Surface: Clean ‘As-Received?’”Metal Finishing Magazine, Vol. 111, #3, May-June 2013.
- F. Blanchard, “A Field Guide for Science Writers,” Blum, Knudson and Henig, editors, Oxford University Press, 2006.
ABOUT THE AUTHORS Barbara Kanegsberg and Ed Kanegsberg (the Cleaning Lady and the Rocket Scientist) are experienced consultants and educators in critical and precision cleaning, surface preparation, and contamination control. Their diverse projects include medical device manufacturing, microelectronics, optics, and aerospace. Contact: info@bfksolutions.com