28--THE EFFECT OF STEAMING ON THE LONGITUDINAL STABILITY OF WOOL YARN.

An account is given of an investigation of the effectiveness of steaming on the longitudinal stabilization of wool yarn. Specially prepared worsted yarns were used to study the effects of initial regain and of time and temperature of steaming. Of the several different mechanisms proposed for the longitudinal stabilization of yarn by steaming, only permanent setting is demonstrated directly, and the effects of temperature, initial regain, and time of treatment are established. Two threshold values were observed below which no permanent setting took place—an Initial-regain threshold of 7-8 % and a temperature threshold of about 88 °C. It is considered possible that the threshold temperature is a function of the particular release treatment used and that it would increase with increasing severity of the conditions of release. The contribution of permanent setting to the over-all longitudinal stabilization was apparently small, but this may have been a result of using a rather severe release treatment. [ABSTRACT FROM AUTHOR]