Effect of Deposited Calcium Hydrogen Phosphate Dihydrate on the Flame Retardancy Imparted to Cotton Fabric

Abstract

The influence of calcium hydrogen phosphate dihydrate on the flammability of cotton fabric (serge construction, 220 g/m²) is investigated. The samples were impregnated with suitable concentrations of aqueous solutions of calcium hydrogen phosphate dihydrate by means of squeeze rolIs and dried in an oven at 110°C for 30 min. Then the samples were cooled in a desiccator, weighed and kept under ordinary conditions before the accomplishment of the vertical flame test. The optimum add-on value to impart flame and glow retardancy was about 23.0 g of calcium hydrogen phosphate dihydrate per 100 g fabric. The results obtained comply with chemical theory, coating theory and condensed phase retardation theory.