Development of Durable Shrink-resist Coating of Wool with Sol-gel Polymer Processing

Knitted wool fabric was pre-treated with the serine type protease, Esperase 8.0L (EC3.4.21.62), and sodium sulphite followed by an immersion treatment with a sol-gel hybrid polymer. To enhance the durability of the sol-gel treatment on wool, one of two different alkoxysilane containing coupling epoxy or mercapto groups were added to the sol-gel hybrid. The combination of protease treatment with an immersion sol-gel treatment achieved wool fabric that was lightweight with a soft handle and had combined shrink-resistance and hydrophobic properties without fibre discoloration. The addition of an alkoxysilane with a mercapto coupling group within the sol-gel hybrid gave better performance than using an alkoxysilane with an epoxy coupling group in terms of polymer uptake, fabric shrink resistance, whiteness and durability to washing.