Process for bleaching webs of fibrous cellulose material with hydrogen peroxide vapor containing water vapor

Claim 1

A BLEACHING PROCESS COMPRISING SEPARATELY AND CONTINUOUSLY APPLYING TO A MOVING DAMP WEB OF A FIBROUS CELLULOSE MATERIAL BLEACHABLE WITH HYDROGEN PEROXIDE (A) A LIQUID, NON-VOLATILE, WATER-SOLUBLE CONDITIONING AGENT EFFECTIVE IN ENCHANCING THE BLEACHING ACTION OF HYDROGEN PEROXIDE UPON SAID MATERIAL, AND (B) HYDROGEN PEROXIDE VAPOR, SAID DAMP WEB CONTAINING FREE WATER EQUAL TO FROM 5 TO 70% OF ITS WEIGTH AND SAID VAPOR BEING APPLIED BY CONTACTING THE MOVING DAMP WEB WITH A MIXTURE OF HYDROGEN PEROXIDE VAPOR AND AT LEAST 45% BY VOLUME WATER VAPOR FOR A TIME OF FROM 0.05 TO 0.2 SECOND UNTIL FROM 0.01 TO 3% HYDROGEN PEROXIDE BASED UPON THE DRY WEIGHT OF SAID FIBROUS MATERIAL IS ABSORBED BY SAID WEB, AND THEREAFTER BLEACHING SAID WEB WITH THE ABSORBED HYDROGEN PEROXIDE IN THE ABSENCE OF ANY FURTHER AMOUNT OF HYDROGEN PEROXIDE.