Alkaline hydrogen peroxide bleaching method

Abstract

A process for scouring, desizing and bleaching cotton greige goods comprises the steps of immersing the goods for a time sufficient to achieve commercial brightness in an aqueous solution have a temperature in the range from 100.degree. to 212.degree. F and consisting of from 0.3 to 70% by volume hydrogen peroxide, water and sufficient hydroxide to adjust the solution to a pH in the alkaline range, the solution being substantially free of heavy metal ions and maintained out of contact with all metals while the goods are immersed therein and cycling a portion of the solution through a filtration means to remove solid impurities therefrom while maintaining the volume, composition and pH of the solution in contact with the goods substantially the same. Preferably, the process is conducted as a simultaneous scouring, desizing and bleaching process in a temperature range 160.degree. to 212.degree. F in a solution including 1 to 50% by volume hydrogen peroxide, the goods being immersed in the solution for less than about 31/2 minutes. In another embodiment, the goods are immersed in an alkaline scour solution for from 5 seconds to 31/2 minutes prior to bleaching in the hydrogen peroxide solution, the alkaline scour solution having a temperature in the range 160.degree. - 212.degree. F and a pH from 10 to 14. Still another embodiment of the invention includes the alkaline scour plus an acid scour, in any sequence, prior to bleaching in the hydrogen peroxide solution.

Dependencies are inferred from the claim text.