Analysis of Fibre Length, Dispersion, and Orientation During Injection Moulding of Short Natural Fibre-Reinforced Biocomposites

Fibre dispersion, orientation, and length are the key factors that influence the properties of biocomposites. The current experimental study investigates the different injection parameters affecting the fibre length, dispersion, and orientation during injection moulding of a biocomposite based on bamboo fibre (BF) and polylactic acid (PLA). BF/PLA biocomposite was developed considering 4 mm fibre length and 10% fibre loading. Taguchi’s L9 orthogonal array was chosen to investigate the effect of injection parameters on fibre length, dispersion, and orientation. The injection parameters considered for the experimentation were injection pressure (70, 90, and 110 bars), injection speed (40, 50, and 60 mm/s), and injection temperature (165, 175, and 185 ºC). The effect of injection parameters on fibre dispersion and orientation was examined using a toolmaker’s microscope. The top layer of the fabricated biocomposite specimen was removed by the mechanical process to investigate the dispersion and orientation of the short fibre into the matrix. Whereas composite specimens were dipped into acetone solution to separate the matrix and fibre to study the variation in the fibre length during injection moulding. The tensile and flexural behaviour of BF/PLA biocomposite was also experimentally evaluated. ANOVA was carried out to verify the significance of injection moulding parameters on the mechanical properties of BF/PLA biocomposite.