GB1524569A - Scouring desizing and bleaching of cotton greige goods - Google Patents

Abstract

1524569 Scouring, desizing and bleaching J KATZ 3 Oct 1975 53835/77 Divided out of 1524568 Heading DIP A process for scouring, desizing and bleaching cotton greige goods comprises the steps of: (a) immersing said goods for a time not more than 30 minutes to achieve commercially acceptable whiteness in an aqueous solution having a temperature in the range from 100 to 212 degrees F and consisting of from 0.3 to 70% by volume hydrogen peroxide, water and sufficient hydroxide to adjust said solution to a pH in the range from 10-14, said solution being substantially free of heavy metal ions and maintained out of contact with all metals while said goods are immersed therein; (b) cycling at least a portion of said solution through a filtration means to remove solid impurities therefrom or through purification means to remove contaminants therefrom while maintaining the volume, composition and pH of said solution in contact with said goods substantially the same; (c) rinsing said goods with water to wash said aqueous solution therefrom; and (d) drying said goods. The recycling may be effected continuously or intermittently through a mechanical filter such as a fibre e.g. plastic screen or a microporous membrane. Chemical purification may also be used. Scouring, desizing and bleaching may be simultaneous and carried out in one or a plurality of glass-lined or hard polypropylene tanks through which the goods may be advanced e.g. as a web. The hydrogen peroxide solution may contain additives such as fluorescent brighteners and bluing agents or these may be contained in a separate tank. Each bath may be preceded by a water-dip at elevated temperature. The temperature of the various baths may be maintained by steam heat exchangers. Optionally steamheated squeeze-rolls may be provided to prevent solution carry over between baths. Temperature, pH and concentration parameters are optimised for the many treatments disclosed.