Effect of mechanical consolidation on adhesion mechanism of hybrid non-woven Alfa fibers reinforced unsaturated polyester composite

Vibrational analysis based on FTIR measurements were performed on hybrid non-woven Alfa fibers reinforced unsaturated polyester composite (HNWAFRUP) and its constituents. The reinforcement was made up of Alfa and wool fibers in the relative volume fractions ratio 4:1. These non-woven fibers sheet were consolidated mechanically by means of the needle punching. This study revealed that the increase of passages numbers in this device allowed the separation of the Alfa fibers and the reduction of the lignin’s component in these fibers which decreased its hydrophilic character. Chemical reactions between wool and Alfa fibers were based mainly on the appearance of new vibrations originating from wool fibers in the reinforcement. Adhesion mechanism between the matrix and the reinforcement was established by chemical bonds formed by secondary bonding. Tensile testing performed on this composite revealed the enhancement of its mechanical properties attributed to a less fiber to fiber contact of wool fibers. Nevertheless, the decrease of its specific Young’s modulus revealed the mechanical consolidation effect on Alfa fibers/matrix adhesion.