26—THE RÔLE OF WATER IN THE SETTING OF WOOL: A STUDY OF SETTING AT TEMPERATURES ABOVE 100°C: PART I: DEGREE OF SET

Permanent setting of wool fabrics can be achieved by setting in steam autoclaves at temperatures above 100°C. An account is given in this paper of experiments performed on a laboratory scale and on full-scale equipment in which fabrics were set in rolls. One of the main problems in this kind of process is to ensure an even setting throughout the roll. Temperature and moisture regain are rate-determining factors in steam-setting, so a study was made of the temperature and moisture-regain changes in the different parts of the roll during heating up and subsequent steaming. The degree of set also depends on the steaming time and acidity of the cloth, but these factors are more easily controlled.

The investigation shows that the steam-setting of wool-containing fabrics imparts a very high degree of permanent set and that reproducible and even setting may be achieved, provided that all treatment variables are kept under close control. Of all the parameters studied, the moisture regain seems to be the most important.