Engineering a Green Future
Coating metals like steel and iron usually involves a process known by the disturbing title of “acid pickling.” Speaking to me from Denham Springs, Louisiana where CAP’s 50,000-square-foot state-of-the-art facility opened only three years ago, Company President Eddie Daigle is quick to point out the drawbacks of the old-school procedure. “Acid picking involves a lot of fumes and corrosion, even though there are now so called fumeless pickling; nonetheless the system is a very nasty process that’s not good for the people who do it.”
Fortunately for the industry workers and the environment generally electrolytic plasma technology (EPT) is in its third generation since its birth in 1929. As Eddie informed me with an unmistakable awe for the progenitors in his industry, “I was working in Russia on another project and discovered this technology and was intrigued by it. Once home, I began to work with people here in the U.S. to develop the technology as well as continuing to work with the two Russian scientists that expanded it. The technology itself was invented in 1929 in the UK, and between then and 1995, fifteen patents were filed on this process. But the developers all made the same mistake until the Russians pushed the electrical envelope farther, and they realized they could create low discharge plasma in an aqueous solution.”
Electronic plasma technology both cleans and coats metals, thereby providing an effective surface engineering tool that doesn’t harm the environment or the technicians who administer it. In EPT, DC voltage is applied to electrodes in an aqueous electrolyte (which is a mineral capable of conducting electricity) solution, which in turn creates plasma on the surface of the material being coated. Unique surface properties occur through the thermal, electrical, chemical and mechanical effects of EPT.
“You have to look at the electrical current because as you apply current to the workpiece (material being coated), it begins to heat up, and the oxygen and hydrogen in the water surrounding it disassociate, and you begin to get electric arcing at some point,” Eddie explained.
“In the early years, nobody pushed through the electrical arcing phase in the curve until the Russians dared. They found that by increasing the voltage, the current actually stopped rising and then even started coming down, and eventually low discharge plasma forms.”
Many other applications for CAP Technologies’ coatings have emerged since the company began at the dawn of this century. “We’ve created nickel coating on aluminum that could be drawn, which is almost impossible with conventional processes. We’ve created silver coating on stainless steel as well as high carbon steel. We’ve modified titanium. We’ve done hydroxy acetate coatings on titanium and stainless steel for medical applications. Those are some of the more exotic applications. Now we’re getting industry interested.”
Due to its use of only benign electrolytes and electricity, CAP technologies exclude the acids normally used along with the need for handling, storing and disposing of them. Conceived in 2001, on the campus of Louisiana State University, CAP only began the slow transformation from the laboratory to a commercial model in 2011.
“One of the challenges we face is that this is a new technology, and people have been stuck in the ways of the past, doing things the same for a long time, so we offer comparative analytical testing to build confidence. It’s one of those show me things. They’ve got to feel it and touch it before they’ll accept it. We have our own in-house laboratory where we do our own analytical testing, and then we do outside testing and compare the two, so we allow the customer to have a spectrum of analytical results not just coming from us but independent laboratories as well.”
Acid pickling, aside from being toxic to the workers and the environment, creates significant waste and costs associated with managing it. “Acid pickling removes the oxide mill scale, but to get the material one hundred percent clean, inhibitors have to be added to the acid bath to stop the acid from eating the raw steel. It’s very difficult to control, and if you try and get to one hundred percent clean, you’re going to lose some steel, and weight is money.”
“In the CAP process, the actual inner layer of the three – there are three – the inner layer is not removed, but is reconstituted into what’s called alpha iron or pure iron, which does not corrode. You don’t get a solid layer of pure iron though. I wouldn’t say it would prevent corrosion but inhibit it. The example being a coil of acid pickled steel has to be neutralized with fresh water, and then if they don’t put some type of external coating on, it will rust. With CAP, the steel can last days, weeks, months before any corrosion develops depending on the atmosphere. The other important aspect is that this is an in-line process, so material goes directly from cleaning into coating, which is an advantage because you are getting both in one step.”
Of course sometimes adopting CAP technologies involves large investment in new equipment but the cost savings emerge instantly. “Being green always helps; it’s not the guiding factor. If someone needs to purchase material, price is the number one factor, but being green does help. When you tell people it’s green technology, they like it and as acid pickling is replaced, the environmental aspect will be a significant differentiator for our products. We really do provide a better situation for their employees.”
Price and the environment are two competitive advantages for CAP Technologies, but the longevity of its coatings is remarkable as well. “It’s green. It’s cheaper. Our coating is three to five times longer-lasting. The coatings themselves are unique. With wire, if you get a thirty to thirty-five percent reduction in drawing, the coating starts to break off. This coating that we apply with the plasma can go to a 98 percent reduction without any loss.”
Despite the science and engineering invested in electrolytic plasma technologies, operating the lines where the coatings are applied is surprisingly easy. “The technology is unique, so we have to work with the operators, but three of our line operators only have a high school education, so they don’t need to learn how the plasma works. They just need to know how to control the plasma in the operation.”
The United States needs investment in infrastructure to the tune of hundreds of billions of dollars directed towards improving public drinking and wastewater operations, dams, levees, airports, railroads and mass transit systems. “We were awarded a grant from the Federal Highway Administration to develop a long life coating that could be used on PC strand and PT strand and we made it.”
(PC strand or prestressed concrete strand is a high-carbon steel wire that reinforces prestressed concrete structures. PT strand or post-tension cables are in a plastic tube and are tensioned after the concrete is poured to allow for thinner slabs and longer runs between supporting structure.)
“After that, we met with them, and they told us they had no more funds to go forward with the project unfortunately. But we do have the coating, and it’s patented and trademarked, and we will continue developing it.”
“We’ve applied silver to stainless steel and high carbon steel that was tested for fourteen months and proved to be one hundred percent effective against e-coli. In fact, we have a company now that is working with the FDA to test food conveyers. We’ve also done nickel coating on aluminum for the aircraft industry. For the first ten years, this was strictly a research company, and we’ve kept that aspect moving forward. However, most importantly, the procedures are emerging from the lab.”
On August 11, flooding began through Southeast Louisiana that damaged 146,000 homes and has left thirty percent of the school-aged population still without a place to learn. But in times of trial and tribulation, real friends emerge and the relationships are tested. “The suppliers and the vendors work with us. A prime example is the flood. A few of our vendors called and said ‘don’t worry about paying your invoices; we’ll wait until you get back on your feet. Don’t be concerned about it at all.’ Which was very comforting for us, because when you’re buying steel, there’s a lot of money involved. A lot of our vendors have actually worked very hard with us to help us back on our feet.”
CAP Technologies has built relationships with the people in the industry and with the planet itself while saving its clients millions in the long run by replacing toxic and obsolete industrial practices. “Especially being aqueous plasma, there’s a lot of gas plasma operations that are very different, because you have to work in a vacuum. This is atmospheric; it’s totally green, and we use benign electrolytes, other than the actual metals themselves. It’s a closed system; nothing escapes other than some water vapor which is, for the most part, condensed and returned.”
The future is here for those willing to try something new and practical that allows producers to let go of toxic practices that have been superseded by science and applied by an industry that needs CAP Engineering.