Influence of Wear on the Sizing Layer and Desizing of Single Carbon Fibre-to-Fibre Friction

Carbon fibres are sized for use in the reinforcement of composite materials. The purposes for sizing include improving yarn cohesion, which is necessary for the weaving process, and increasing the adhesion between the fibres and the matrix. Nevertheless, during weaving, some fibrillation can occur, and that has detrimental effects on the weaving productivity and on the composite's properties. The purposes of this research were: (a) to determine whether abrasive wear between sliding fibres would modify the sizing and (b) to study the influence of sizing on the friction between fibres. The same type of carbon fibre was subjected to different desizing processes. The coefficient of friction between single fibres was obtained before and after desizing. The effects of sizing and sliding distance on frictional behaviour were investigated, and are related to the observed the wear of sizing layer. In fact, it increased with sliding distance and induced a decrease in the coefficient of friction. Moreover, an efficient desizing process induced a decrease of the coefficient of friction.