Shrinkproofing of Wool with Neutral Permanganate or Acid Bromate in Concentrated Sodium Chloride Solution

Abstract

Two shrinkproofing processes of possible industrial value are described. Each may be used continuously or as a batch process.

Treatments are with neutral permanganate (4-6% potassium permanganate on weight of wool) or acid bromate (1-2% potassium bromate on weight of wool) in concentrated sodium chloride solutions, the latter resulting in a chlorination which is more easily con trolled to give even treatment than simple acid chlorinations. Batch processes are carried out at 20-40° C. in normal mill equipment, total processing times being 1-2 hr. Each process produces shrinkproofed wool at relatively low cost with no adverse effects of practical significance, although the acid bromate treatment requires a final softening. Permanganate/salt treatment requires no analytical control, causes no problems with fumes, gives even treatments so that there is no difficulty in piece dyeing after shrink- . proofing, and does not yellow or alter the handle of the wool.