Unitika: glass fiber to withstand incinerator filter heat

Unitika Ltd. reported on 19 September 2006 that it has developed a type of glass fiber that can withstand temperatures above 400C, higher than the typical 270C or so. The company said it plans to sell…

Unitika Ltd. reported on 19 September 2006 that it has developed a type of glass fiber that can withstand temperatures above 400C, higher than the typical 270C or so. The company said it plans to sell the new fiber to makers of filters for incinerators. Strong demand is foreseen because the present trend is to clean incinerator exhaust gases at temperatures above 400C rather than letting them cool first, since toxic dioxins can re-form when the temperature drops near 200C. Unitika said it increased the amount of silicon oxide in the mix relative to the other ingredients, which include calcium oxide and aluminium oxide, to boost heat resistance. The filters made from the new glass fiber exhibit better performance when exposed to acidic and alkaline gases because silicon oxide is also strongly resistant to acids and bases. The new glass fiber retains more than 60% of its original strength compared to conventional glass fibers, which lose 75% of their strength when exposed to such gases. Filters are fitted to the dust collectors at incinerators to remove nitrogen oxide compounds and sulphur oxide compounds that are generated during the incineration of industrial waste.