Influence of Pre-wetting on the Characteristics of a Sized Yarn

Abstract

The preparation of a warp yarn is a key element of the success of weaving. Under the economic pressure to which the world textile industry is subjected, an increased attention is given to the equipment, to the products and the processes used in the preparation of warp yarns for weaving. The yarn, the sizing equipment and the size must be adapted to each other, so powerful yarns able to resist the weaving requests with lower cost can be obtained. The aim of this work was the study of the mechanical behavior of sized yarns after a pre-wetting operation with hot water and the drying of these yarns on the sizing machine. First, we showed that the heat transfer coefficient was the same, no matter whether the yarn was pre-wetted or not. Pre-wetting did not decrease the production. However, despite containing less size, the yarn hairiness was reduced as compared to sizing without pre-wetting. The initial modulus of sized yarn with pre-wetting was higher than that of classically sized yarn and the sized yarn with this new technology of sizing presented a more important immediate recovery. Moreover, we studied the influence of a preliminary wetting on the structure of the size bridges between fibers by using scanning electron microscopy. Examination of the cross-section of sized yarn showed that if the yarn was pre-wetted, the bridges between fibers could be observed to a higher extent at the periphery of the yarn, which explained the good mechanical behavior.