One of the interesting developments in engineering plastics this year, particularly for injection molded electronics applications such as housings, is a new environmentally friending flame retardant system that is nonmigratory, and often offers property enhancements to the host polymer, usually PBT-type polysters or ABS/polycarbonate.
Its name is in Nofia (as in “no fire” with a heavy Boston accident).
It’s a polymer, unlike most other FR systems which are not miscible with the host polymer, and can be a drag on mechanical properties or clarity. It is a polyphosphonate made in very much the same way that polycarbonate is manufactured, but without the bisphenol A (BPA) baggage, according to a discussion I had late last week with Marc Lebel, the CEO of FRX Polymers, which is commercializing the technology.
Loadings can be as low as 5 percent because of the effectiveness of Nofia, which has a limiting oxygen index of 65 percent. The next best plastic is PVC at 44 percent. Loadings go as high as 25 percent.
“We start with a foundation of flame retardance and nonmigration, and then we always try to add some other benefit,” Label said. “(in terms of mechanical properties), we compare ourselves to the competitive flame-retarded compound not to the neat polymer.” In other words, which FR does the least damage to the host material’s physical properties?
“The first requirement is always to achieve the FR, and then in some cases we can dramatically improve impact, tensile strength and in some cases heat distortion” of the final compound. “I’m not saying across the board that always happens. There’s always something we can bring in addition to FR and nonmigration.”
Nofia is cost competitive with its competitors based in part on a spefic gravity advantage, according to Lebel. The product is marketed on cost per cubic centimeter to accentuate its density advantages.