EFFECT OF INJECTION PARAMETERS ON TENSILE AND FLEXURAL PROPERTIES OF GREEN COMPOSITES

Natural fibres are used to develop green composites due to their environmentally friendly nature, ease of availability, low cost, higher strength, as well as good thermal, acoustic, and insulating properties. In this study, jute fibre (JF) and sisal fibre (SF) were considered as reinforcement and a biodegradable polymer, namely polylactic acid (PLA), was selected to fabricate the composites by the injection moulding process. The fibres were chemically treated with sodium hydroxide (NaOH) at a concentration of 2% to improve the characteristics of the fibre. The effect of the injection moulding parameters like injec-tion pressure (bars), injection speed (mm/s), and melting temperature (?) on the tensile and flexural properties of the sisal fibre/ polylactic acid (SF/PLA) and jute fibre/polylactic acid (JF/PLA) composites were investigated. Taguchi's L9 orthogonal array was chosen for the design of experiments, and analysis of variance (ANOVA) was performed to find the significance and con-tribution of the selected parameters. The optimum levels from the main plots of both the tensile and flexural strength of the JF/PLA composite were found to be the injection pressure of 90 bars, injection speed of 60 mm/s, and injection temperature of 165?. Meanwhile, the optimum level of tensile strength for SF/PLA-based composite was recorded as the injection pressure of 70 bars, injection speed of 40 mm/s, and temperature of 165?. For the flexural strength, the optimum level was determined as the injection pressure of 90 bars, injection speed of 60 mm/s, and temperature of 165?.