14--REVERSIBLE AND IRREVERSIBLE DIMENSIONAL CHANGES IN WOOL FABRICS.

An account is given of experiments made with an apparatus constructed for recording, simultaneously and continuously, weight and length changes during the drying and steaming of fabrics. Hot air at a temperature of 100 or 115°C was used in the drying experiments. Steaming was done under the same conditions. The maximum level to which the moisture regain could be increased with steam varied with the fabric construction. Below this maximum level, absorption and desorption experiments with relaxed fabrics gave reproducible and identical hygral-expansion curves. Moisture-regain changes below saturation caused by steaming and drying did not completely release the strain in fabrics cohesively set. The difference resulting from the use of saturated and superheated steam was negligible. The lower the temperature during cohesive setting, the less resistant was the set towards moisture-regain changes. [ABSTRACT FROM AUTHOR]