Thermally Purified Carbon Additive (TPC18) for Low Iron / Ultra Clear Glass
Low Iron / Ultra Clear Glass delivers maximum clarity and color neutrality clear to the edge, without the green tint of a standard float glass. Low Iron offers more light transmission vs regular soda-lime glass. Low Iron glass is widely used in applications in which low coloration and/or high optical transmission is desired.
Ultra-low Iron content retains clarity even when manufactured in heavier thicknesses, unlike conventional clear glass, which becomes progressively greener and darker as thickness increases.
Fig. 01
Standard clear glass with green tint vs. Low Iron glass without green tint

Take Control of Color Using TPC18, a Thermally Purified Carbon Additive
Superior Graphite has recently developed TPC18, a Thermally Purified Carbon product specifically for Low Iron or Ultra Clear Glass application, virtually free of color imparting heavy elements like Iron (Fe <75 ppm). The high-temperature purification treatment of the carbon allows for the highest purity, low gas content, and superior consistency. TPC18 has a very specific morphology and pore structure, coming from Superior Graphite’s proprietary high-temperature treatment, greatly enhancing the dissolution speed of carbon in the melt.
TPC18 Main Features:
- Ultra-High Purity Carbon (>99.7%)
- Exceptionally low level of impurities, Fe (<75 ppm ), Cr (<10 ppm), Cu (<10 ppm)
- Highly consistent product quality
- Guaranteed low gas content, O2, N2, and H2
- Extremely low Sulfur content (<0.03%)
- High speed dissolution due to very high surface area and porosity
- Made in the USA