Injection parameters affecting the mechanical and morphological characteristics of polylactic acid/flax green composites: An experimental investigationUntersuchung des Einflusses der Einspritzparameter auf die mechanischen und morphologischen Eigenschaften von Verbundwerkstoffen aus Polymilchsäure und Flachsgrün

This research aims to study the effect of injection parameters on the mechanical properties of the developed green composites. Natural flax fibre and biodegradable polymer, polylactic acid was chosen to develop the green composites. The flax fibre was chemically treated using sodium hydroxide to fabricate the green composite by injection moulding. The injection parameters namely (i) injection pressure (bar), (ii) injection speed (mm/s), and (iii) injection temperature (degrees C) was considered to investigate their effect on the mechanical properties of developed polylactic acid/flax green composites. The mechanical properties, such as (a) tensile strength (TS), (b) tensile modulus (TM), (c) percentage elongation under tensile loading (PET), (d) flexural strength (FS), (e) flexural modulus (FM), (f) percentage elongation under flexural loading (PEF), (g) compressive strength (CS), and (h) shear strength (SS) was evaluated under different injection conditions. Furthermore, the morphology of the mechanically tested specimens was investigated using a scanning electron microscope. Grey relational analysis was performed to find the optimal injection condition. The optimum injection condition depicting superior mechanical properties was found at injection parameters combination of 90 bar (injection pressure), 60 mm/s (injection speed), and 165 degrees C (injection temperature). Fully green composite was developed by direct injection molding to investigate the effect of injection (injection pressure, injection speed, temperature) parameters on the mechanical properties. Multi-objective optimization using grey relational analysis of the mechanical properties and morphological characterization of the developed composites was carried out.image