KOBE, Japan—Sumitomo Rubber Industries Ltd. (SRI) has developed a design technique that results in deeper black coloring in rubber, which helps improve the visibility of lettering, logos and patterns imprinted on tire sidewalls.
The new technique, dubbed "Nano Black," involves the use of extremely fine ridges to the sidewall surface that inhibit the reflection of light, thereby producing a deeper shade of black than conventional hues and enhancing the contrast between areas that use the technique and those where it isn't used.
SRI said using the new technique will allow it to improve the visibility of brand logos, trade names and other markings on tire sidewalls while at the same time giving tires a "more luxurious overall design aesthetic."
The company, which controls the Dunlop brand in markets throughout Asia and Africa but which goes to market in North America and Europe with the Falken brand, said the change is part of ongoing efforts "to make more appealing products that more customers will be happy to choose."
The new technique, which is applied in the mold-making process, is based on the principle that the more times that light strikes a light-absorbing surface, the more light ultimately is absorbed, resulting in deeper, darker shades of black.
Nano Black incorporates a novel design that takes full advantage of this principle by adding fine ridges to the surface of a tire sidewall in order to maximize the light-absorbing surface area per unit of sidewall area.