A Critical Study of Wool Carbonizing 1

Abstract

A critical study was made of the sulfuric acid carbonizing process. Three main fac tors governed the strength loss of the wool: (1) the acid content of the wool as it en tered the dryer; (2) the moisture content of the acid-containing wool as it entered the dryer; and (3) the temperature of the air used in drying the extracted, acid-containing wool prior to baking. Increase in any one of these factors beyond a certain level, while the others were maintained constant, caused a loss in tensile strength of the wool ; these three factors were all interrelated in their effects on the strength of the wool. Studies are presented which indicate the critical limits for each factor in raw wool carbonizing. Conditions were found which cumpletely charred the burrs in the wool without causing any measurable strength loss. The rates of absorption of acid by the wool and by the burrs were found to be very different. This was used to advantage in depositing the amount of acid on the burr contaminants required for satisfactory carbonization, while applying a minimum amount of acid in the wool. Wetting agents in the acid hath also had beneficial effects. Practical implications of the data for commercial processing are discussed.