Imagine curing the coatings on your gears with the flip of a light switch, and being able to handle and examine the end results only a few moments later. Think of the time savings, and also the increased throughput you’d be able to achieve. Sound like the stuff of dreams? Well, thanks to the efforts of Sally Ramsey — co-founder of Ecology Coatings, and its chief chemist — that technology is available today and already in use in a variety of applications, including within the automotive industry.
“This is an emerging technology, but it’s one that gear manufacturers should know about and keep an eye on,” Ramsey says. “And while tooling up can seem a little expensive on paper, you begin saving money immediately, with energy savings of about 80 percent. Plus there are virtually no emissions, so that’s why it’s considered a green technology.” (Figure 1)
It was while working for a metal finishing shop in California that Ramsey first began looking into emissions-saving techniques. “UV technology looked very promising, so we wrote a grant proposal, which we were awarded, and that’s when we discovered that there weren’t any decent coatings for metals available,” she says. “People would send us their stuff to test, and when we’d put it in a salt-spray booth it would be rusting and peeling off half an hour later.”
A chemist by training and trade, Ramsey began experimenting with different formulations, specifically in the area of “nano-engineered, liquid 100-percent solids, ultraviolet-curable industrial coatings.” Although there were a few “starting formulations” that had been developed in Europe, she didn’t find them to be particularly effective. “For the most part they were way too thick, and they’d tell me to dilute them with solvents, but then we’d lose the whole point of the exercise,” she says. “So I started working in my lab, and I’d take the different formulations out on the floor to be tested, which was convenient.”
This work led to the founding of Ecology Coatings in 1990 — the CEO is Richard Stromback, and it is located in Akron, Ohio — and to the development of LiquidN Steel, which exhibits high abrasion and corrosion resistance and a “4H+” pencil hardness, among other attributes. Additional formulations introduced since that time include LiquidN Brass, Polycarbonate, Composites, Paper, and others for medical and electronics applications.
The success of these efforts is made apparent by the company’s licensing agreement with DuPont, which is the source for materials used in all aspects of the automotive industry. “We are the direct contact for companies interested in entering into licensing contracts for other applications, however,” Ramsey says, “and we’re also available to connect customers with the right people to set their lighting system in place. And that’s very important, because if you don’t use the right equipment, it’s just not going to work.” (Figure 2)
As is always the case when adopting a new manufacturing process of any kind, the tooling is the most expensive aspect of the system. “There are many kinds of lamps, but the ones that work best with our coatings are fusion lamps, usually featuring a combination of two frequency ranges,” Ramsey explains, “and those tend to cost around $12,000 apiece, depending on their length.”
The number of lamps required has to do with the size of the parts to be cured. For smaller parts, two lamps will usually suffice, while larger parts will require more. The reason for this has to do with “line of sight” access to all of the part’s surfaces — the light beams must be able to reach them all in order for complete curing to be achieved. That’s why Ramsey is quick to add that this technique might not be appropriate for more-complex gears or parts, “although reflectors can be set up to help the UV rays reach all of the nooks and crannies,” she says. Conventional conveyor belts can be used, or the parts being introduced into the curing chamber can be fed manually. In addition, positioning systems can be designed that rotate the part to be cured, ensuring even exposure to the light.
Another cost to be aware of is that of the coatings, themselves, because 100-percent solids UV curables tend to be more expensive than conventional formulations since no solvents — the cheapest part — are used. Still, overspray is completely reclaimable, and once filtered can be reapplied to the next batch of parts entering the spray booth. (Figure 3)
The primary benefits of Ecology Coatings’ products have to do with the fact that the materials are so safe — they are not corrosives or heavy metals, and they are nonflammable — and that very little emissions are produced. That in itself leads to savings in the time spent keeping and filing associated records, and also the cost of hazardous-waste disposal, since there are none. Additional savings include the aforementioned energy costs, which can be reduced by as much as 80 percent, and that the system’s physical footprint is so small — amounting to another 80 percent gained in shop-floor space. Also, the per-part curing rate is slashed from as much as 20 minutes in an oven to a few seconds using UV lighting, which can allow for a reduction in shifts required to man the operation.
As for post-curing properties, Ramsey says the nano-particles offer improved “space-filling” attributes — actually filling in the spaces between larger particles, thereby providing a better barrier to water, solvents, etc. — which also leads to excellent abrasion resistance. “Toyota ran some tests on parts for dampers that go in their Camrys,” she says, “and except for some powders, ours were the only ones that could stand up to their long-term abrasion resistance tests.”
Although hardness has much to do with the underlying substrate, Ecology Coatings has achieved seven and eight H-pencil hardness in some cases, and it is constantly working to improve its existing products, and to formulate new coatings for additional applications.
“Our products are continually evolving, and I really see this as a beginning rather than a mature technology at this point,” Ramsey says. “We’re probably where powder was a few years back, when it needed to grow and advance a little before people were comfortable with it. But we’ve achieved remarkable results in recent years, so it’s definitely something for gear manufacturers to be aware of, especially if they’re interested in lowering their energy costs and raising their environmental profile.” (Figures 4 and 5)