Effect of the carding process and fibre length on the properties of pineapple leaf fibre and reinforced polypropylene composites

In this work, a greener approach, the carding process, was used to remove extraneous materials from the surface of pineapple leaf fibre (PALF) instead of using conventional chemical treatments. PALF was cut into three lengths and processed using a carding machine for different numbers of passages. Carded PALF and polypropylene (PP) fibres were then blended uniformly at 50% weight percentage through the carding process. The mixed fibres were further processed by a gill-drawing machine to produce oriented PALF-PP silvers, which were consolidated in a compression moulding machine to fabricate the unidirectional composites. The experimental results indicated that the increase in the number of carding passages and PALF cut-length increased the surface fibrillation, roughness and crystallinity, and reduced the water contact angle (i.e., increased hydrophilicity) of carded PALF. The thermal insulation performance of the composites improved in cases of shorter PALF length after five carding passages and coarser PP fibres, but at the same time, the water absorbency also increased, indicating reduced water resistance of such composites.