Influence of wetting phenomenon on the characteristics of a sized yarn

The aim of this work is to study the effect of the addition of a wetting agent to a size solution and to the water used for the pre-wetting to know if it is possible to reduce size content of the yarn with mechanical properties allowing a good ‘weavability’. The effect on the physical and mechanical characteristics of adding the wetting agent was examined. In the tensile test, as a result of adding the wetting agent to a size solution, an increase in the Young modulus of the yarn sized classically was induced, and a decrease with a pre-wetting technique. Concerning the bending rigidity, the same conclusion as for the tensile strength has been demonstrated by using the Kawabata unit. These deteriorations have been explained by using scanning electron microscopy. Indeed, the micrographs seem to show that the fibers of yarns sized with the pre-wetting technique are coated with the size film and not bridged to themselves with the size which explained the decrease of the mechanical properties. However this coating is not recommended in the sizing process.