ABSTRACT
Comparison of some mechanical properties of injection and extrusion moulded pineapple leaf powder (PALP) filled high density polyethylene (HDPE) was studied. PALP and HDPE composites were prepared using injection and extrusion moulding techniques respectively. The weight percentages (wt.%) of filler contents investigated were varied as 0, 2, 4, 6, 8, 10 wt.%. It was observed from the results of the mechanical properties carried out on the composites that the tensile strength, tensile modulus, abrasion resistance, and hardness of the composites increased with increases in filler content for all the filler contents investigated both for the injection, and extrusion moulded composites while the elongation at break (EB) for HDPE/PALP composites was found to decrease with increases in filler content for all the filler contents investigated both for the injection, and extrusion moulded composites. The results also showed that the extrusion moulded HDPE/PALP composites exhibited better tensile strength, tensile modulus, hardness, abrasion resistance and flexural strength than the injection moulded HDPE/PALP composites for all the filler contents investigated while the elongation at break (EB) of the extrusion moulded HDPE/PALP composites exhibited lower elongation at break (EB) values than the injection moulded composites for all the filler contents investigated. From the present study, it has been proved that PALP can be used as reinforcing filler in polymer composites and that the use of extrusion moulding technique produced HDPE/PALP composites of slightly better mechanical properties than those produced using injection moulding technique. This has shown that the quality of moulded products depends on the selection of correct processing techniques. Therefore, in processing bio- composites, suitable processing techniques must be carefully selected in order to obtain optimum composite properties.
