Most births are painful. Trivex, the new lens material developed by PPG Industries, has been hit by initial production capacity and yield problems that have prevented one of its first licensees, Hoya, from introducing it on the European market this fall, as previously planned. Hoya, which calls the material Phoenix or PNX, has cast it sofar only in Japan and at its 14 laboratories in the USA. Its European launch, which was due to be announced at the latest Silmo fair in Pairs, has been postponed to the beginning of 2002.

Besides Intercast, which uses Trivex for plano sunglass lenses, the only other licensee for the moment is Younger, which calls it Trilogy, but PPG has already started to make contact with other lens casters. The general idea is to make the new material broadly available from a wider variety of sources from mid-2002 onwards.

Pricing is a sensitive issue. Trivex is inherently a bit more expensive than polycarbonate because of the raw materials are more expensive, and it's preferable to polycarbonate in terms of lightness, thinness, stress resistance and of its Abbé value of 42-43. The impact resistance of Trivex is similar, but the refraction index is on average lower at 1.53.

Like C39, Trivex has been developed by PPG from military applications. The decision to launch it first in the USA was probably due to the strong market share already enjoyed there by polycarbonate, which now represents about one-fourth of the total North American lens market in terms of units, following plastic's lead with 55 percent and way above glass with 8 percent and high-index lenses with 13 percent. Globally, polycarbonate has a market share of about 4 percent only.

Trivex is meant to compete directly with polycarbonate, whose Abbe value of 29 causes a much higher degree of chromatic dispersion. Its density of 1.11 is lower than poly's 1.22 and the lowest in the market. Unlike poly, Trivex can be tinted, and its surfacing properties are far better. It's three times more resistant to scratches, although not quite as C39.