Pre-Colored Stainless Steel Improves Product Design, Productivity

 Sandvik Materials Technology has rolled out a pre-coated metal strip steel intended to boost productivity and reduce environmental constraints associated with plating and coating in the consumer electronics, small appliance, packaging, automotive and interior design industries.

 

Decorex can be cold formed and bent to close radii without affecting the color quality due to improved adhesion between the base material and the coating, says Jeremy Gaspard, marketing specialist at Sandvik.

The product also leaves no fingerprint marks, making it especially attractive to the consumer electronics and automotive markets.

“Our diverse stainless steels can be coated with several layers of metals like nickel, tin, silver or similar, which increases product performance through high surface conductivity, corrosion protection and wear resistance,” Gaspard says.

Color is added to stainless strip steel in a vacuum process. Metal oxides of various types and in different combinations are integrated with the metal surface of the strip, resulting in a color layer thickness of less than one micron.

Gaspard says that incoming strip steel is cleaned and inspected by laser cameras before being put through the vacuum vessel where the coating takes place. Once the coloring is completed, Decorex is coated with a water-based layer finish used as a sealant to give durability and provide a barrier to fingerprints and other types of oils and fluids.

After coating, the Sandvik Decorex product undergoes several surface controls and testing, Gaspard says.

Sandvik won a Materialica Design + Technology Award at the Materialica Trade Fair in Munich, Germany, for its development of Decorex. The annual awards, which have been held since 2003, highlight the importance of materials for industrial design-oriented applications, as well as encourage a dialogue between designers and manufacturers.

“It is harder, more elastic and more flexible than aluminum,” competition judge Peter Naumann says. “It is scratch-proof and weldable, and can be cut, etched and engraved with a laser. It allows for the experimental design of cameras, mobile phones and interior design objects.”

Dan Dannberg, Sandvik Decorex global product manager, says the award signified the many design attributes of Decorex.

“We are extremely proud that Sandvik Decorex fired the imagination of the independent judges,” Dannberg says. “We are honored that such a highly regarded and auspicious organization recognized the innovation and engineering achievements of the product, which is also extremely environmentally friendly and completely recyclable.”

Sandvik Decorex coiled strip is delivered color-coated with excellent adhesion between the base material and the surface layer, Gaspard says.

“Our advanced technology system uses a roll-to-roll process where single or multiple layer coatings can be applied to one or both sides of the strip,” he says. “Most bending and forming processes do not affect the color.”

While the Decorex cost may be higher than post-operation color coating methods of paintings and other coatings, Gaspard says Decorex removes manufacturing steps that shortens production time, with less material tied up in production and stock.

“The color stability of this innovative material improves production yields and green practices, as it doesn’t require any wet operations during the coloration process,” he says.

Sandvik says Decorex’s dry color coating process produces no hazardous waste water or air pollution. The process is completely free from volatile organic compounds, heavy metals, or other ecologically harmful substances.

“We use approximately 70% recycled material when producing our 304 grades. For other grades, we use up to 85% recycled material,” he says.

Sandvik also says the use of stainless steel has a favorable impact on the overall energy consumption. For example, they claim that when producing the raw material, three times more energy is used for a batch of aluminum of the same weight, and that stainless steel only requires about 20% of the energy used to produce aluminum.

Currently available in thicknesses up to 0.8mm and in widths up to 370mm, Decorex is manufactured using stainless strip (Sandvik 6LR10) AISI 304 as base material and is offered in two hardness conditions, while other stainless steel grades are available upon request for specific application.

For draw forming, Sandvik offers annealed material delivered at 650 +/- Mpa (94.3 ksi), and for general stamping applications offers half hard material delivered at 950 +/- Mpa (137.8 ksi). The surface finishes are scratch resistant and meet the pencil hardness tests ( ISO 15184 or ASTM D3363).

Some of the colors offered are ebony, mocha, admiral blue, emerald, tangerine, amber, coral, lavender, olive, classic, titanium, sapphire and pacific. Gaspard said new colors are being developed.

Sandvik Materials Technology is one of the world’s largest manufacturers of specialized steel products. It is part of the Sandvik Group, a Swedish entity headquartered in Sandviken, Sweden, currently employing more than 47,000 people worldwide. n

To contact Sandvik Surface Technology, please call 269-519-3817, or visit smt.sandvik.com/surftech.