Masters Degrees (Forest and Wood Science)

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Browsing Masters Degrees (Forest and Wood Science) by browse.metadata.advisor "Bariska, M."

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    Feasibility study on addition of a colourant to commercially used fire-retardant formulations to enable visual distinguishability between treated and untreated mine support timber
    (Stellenbosch : Stellenbosch University, 1991-12) Du Toit, C. B.; Bariska, M.; Van der Klashorst, G.; Stellenbosch University. Faculty of AgriSciences. Dept. of Forest & Wood Science.
    ENGLISH SUMMARY: The ability to visually distinguish between fire-retardant treated and untreated mining support timber, treated with ammonium sulphate and ammonium phosphate salts, is very difficult. In fact, once treated and allowed to dry for approximately three days, it visually becomes totally non-distinguishable from untreated timber. The project objective is to identify a suitable colourant which can be incorporated into the fire-retardant formulation which will enable visual distinction between fire-retardant treated and untreated mining timber support on a cost effective basis. The following aspects were evaluated: - Compatability and stability within fire-retardant formulations. - Colour effectiveness and fastness. - Effect on combustion. The results showed that: * Three of the chemical colourants proved to be compatible and stable at two ranges of temperatures. Colourants were Acid Green, Bazazol Red 76L and Malachite Green. * Of the colourants evaluated, Malachite Green and Bazazol Red 76L performed most satisfactorily over two exposure trials, i.e. controlled weather-o-meter and natural exposure. * All three colouration chemicals had no effect on the combustibility of timber when included into the fire-retardant formulations. * The inclusion of a colourant into the fire-retardant can be performed in such a manner that fire-retardant treatment economy is hardly affected. * Large scale evaluations need to be performed to verify colour efficiency over time.