Rising into the Manhattan sky like a bronze beacon is a sculpture known as Vessel. The design, inspired by the Spanish Steps in Rome, is the central feature of the public square in the newly renovated Hudson Yards.
The interactive landmark soars a massive 16 stories high, has 154 interconnecting flights of stairs, 80 landings, and 2,465 steps. But what makes this structure unique is not necessarily its vast dimensions. It is its use of copper-colored PVD (physical vapor deposition) stainless steel.
Chinese-headquartered Double Stone Steel fabricated the current PVD product for the Vessel. But, the company is partnered with Kloeckner Metals Corp., headquartered in Roswell, Ga., to produce, market and sell the PVD-coated stainless products in the United States.
The Vessel’s design plan involves adding colorful structures to draw the eye upward and toward the aesthetic elements of the location, offering residents and businesses onsite a colorful theme to enjoy each day unlike anything the area has seen. It is already a popular attraction, and is expected to draw visitors by the hundreds and perhaps thousands on a daily basis upon the site’s entire completion.
A licensing agreement with Double Stone Steel allows Kloeckner Metals to use the proprietary technology in the U.S, enabling the firm to manufacture PVD for the project. The two companies have formed a union that ultimately yields an entirely new way for United States commercial businesses to design and color the face of their buildings and structures.
For commercial architects, the technology is opening doors to specifying colorful buildings and structures with decorative and branding requirements. Specification often involves architectural elements and metalwork being color-matched to nearly any existing or intended finish.
The Kloeckner Metals partnership with Double Stone Steel has led to domestic applications in larger and more advanced scopes.
“With the agreement, we became the first domestic producer of PVD to the scale we can produce it,” says Jamie Pfleger, director of PVD for Kloeckner Metals. “There are a lot of smaller PVD machines domestically. Companies use these machines for jewelry, smartphones and in the medical industry. But no other domestic company can color sheets or fabricated parts to the dimensions we can.”
The U.S. company produces up to 60-inch by 144-inch sheets of PVD-coated stainless steel. In contrast, even companies in Asia, the traditional source for larger PVD applications, produce 48-inch by 96-inch sheets or 48-inch by 120-inch sheets.
Pfleger predicts sheet size and domestic availability, especially with the trade issues with China, will boost interest in PVD in the U.S. “PVD has always been imported,” she says. “Domestically, companies have shied away from it for large-scale projects. They did not want to depend on 20- to 30-week lead times for shipments.”
What is PVD coating?
The PVD (physical vapor deposition) process generates a metallic vapor from titanium or chromium through a heating and sputtering action. A vacuum chamber deposits the metallic vapor onto a substrate where it condenses and applies a colored finish. Kloeckner’s PVD process, which takes 30 minutes to 1 ½ hours depending on the hue, adds color to stainless steel.
“The color is determined by the target (sacrificial element), the gas (argon, nitrogen or oxygen) used in the chamber, and the temperature,” Pfleger says. Hues come in a broad spectrum of colors, from black and gold to cobalt and emerald green. Customized hues are available if customers desire a trademark color.
Kloeckner can apply PVD to a variety of surfaces, including mirror, coil and mesh products as well as textured materials. Though the substrate picks up a brilliant color, the finish maintains the integrity and look of stainless.
“Because the finish bonds to the substrate’s surface at the micron level, you can fabricate it, laser cut it and bend it without crazing the edges,” she says. “However, you can’t do a lot of welding on it, which is why some clients buy colored sheets from us for say, panels in an elevator, then send us fabricated handrails to apply color to.”
Kloeckner Metals installed four PVD lines at its Cincinnati location. The massive undertaking took over a year. “The electrical, the power, the water, and the layout all had to be considered,” Pfleger says. “We’d never done this before. We’re a steel service center, so we deal in tons, flat roll, heavy carbon and stainless aluminum but not in processing, vacuum chambers and fabricated parts.”
The innovative company relies on its Chinese partner for technical advice. Technicians from Double Stone Steel work alongside their operators to help them master the process.
“There is an art to this. You don’t dial in a recipe to get a specific color; you adjust as you go,” she says. “The atmosphere within your chambers changes throughout the day. As the atmosphere changes, you must adjust the gas, temperature and the time to maintain color consistency.”
The labor-intensive PVD process also required new equipment. Besides vacuum chambers, the company added a Bilco Sheet Washer and ultrasonic tanks to wash and rinse the product. “You cannot have any dirt on the product or you will have an adhesion problem,” Pfleger explains.
The company also installed a magnetron sputtering system—the largest of its size in the world—to apply black and blue colors and anti-fingerprint coatings. Applying blue or black finish requires special attention, Pfleger explains, because the colors can be unstable.
Perks of PVD
Kloeckner Metals applies Double Stone’s PVD Titanium Ion Coating, which improves the performance of stainless steel by enhancing corrosion, scratch and wear resistance. In fact, the finish is harder than stainless steel. It resists saltwater corrosion too, making it suitable for marine environments.
The company also uses the vapor process to bond anti-fingerprint coating to PVD surfaces. In contrast, most companies spray on resin-based, anti-fingerprint coatings. But resins wear quickly, dull the finish of stainless steel, and cannot adhere to smooth surfaces like mirrors.
“Our anti-fingerprint finish bonds well to smooth surfaces and is translucent,” Pfleger says. “It also provides an anti-graffiti finish. You cannot spray paint it or write on it with a Sharpie. The finish is generating interest for high traffic areas, such as escalators, elevators and walls in lobbies.”
The anti-fingerprint finish also repels water. This works well on building exteriors and with restaurant industry equipment. “In food service, it’s very easy to wipe the water off and it doesn’t stain stainless,” she says. “People are looking at this product for hospital doors, kick plates, anything they have to clean often.”
A Brightly Colored Future
“PVD products open up new areas of business for us. No. 1 is in the architectural market,” says Pfleger. Other markets include aftermarket parts for heavy-duty trucks, restaurant equipment, medical supplies and art installations.
Pfleger reports Kloeckner Metals sees less competition for PVD domestically than it does for its carbon steel products. “There are other ways to colorize stainless steel, but they are very caustic and acidic,” she says. “And, the companies that use these techniques, rarely do structural shapes, like handrails, nuts and bolts. This opens many doors for us and our architect and design-build customers.”
Currently, Kloeckner Metals runs one PVD shift per day, so there is room for growth, according to Pfleger.
“We are early in this process, but our PVD sales from the beginning of the year until now have increased up to 500% a month. We tripled last year’s sales. If we can do that again next year, we will be extremely satisfied by what we have achieved in a very short time,” she says.
Short-term, the goal is to increase business until the Cincinnati chambers run 24 hours a day, seven days a week. After this ramp up, Pfleger predicts Kloeckner Metals will add chambers to other North American facilities.
It makes sense, she adds, remarking that two architectural clients expressed sincere excitement about having a U.S supplier for PVD products. “Both made the same comment: ‘You don’t have enough (chambers).’ They know how big this can be,” she says. “But we were very intentional about adding PVD capabilities. This year was our year for the final install, to get equipment operating well, and to put best practices in place. We are ready to focus on building our client base.” Learn more: architects.kloecknermetals.com.