Flame-Retardant, Petrol, Oil, Water, And Acid Repellent Wool
Scouring of wool in alkaline conditions in the presence of a detergent not sub stantive to wool is essential to achieve adequate oil, petrol. water, and acid repellency prior to treatment with fluorocarbons. The effectiveness of this repellent treatment depends not only on the chemical composition and concentration of the fluorocarbon, but also on the chemical Composition and physical parameters of the fabric substrate. At the same concentration of the fluorocarbon evaluated, aramid fibers produced lower repellency than wool, probably because of the more oleophilic and hydrophilic nature of the former. A decrease in the density of wool fabric appears to result in lower petrol repellency. A one-bath exhaustion treatment involving the Zirpro flame retardants and a suitable fluorocarbon imparts adequate flame retardance, oil, petrol, and water repellency to wool, including protection against dangerous chemicals and a simulated petrol bomb test, fast to at least 25 charged dry cleanings. Other flammable liquids evaluated in the simulated bomb test, such as diesel, motor oil, and their mixtures with petrol, were less severe than petrol on Zirpro and fluorocarbon treated wool, presumably because they have a higher surface tension than petrol.