2.2 Sample preparation
Although PLA pellets and BC particle are hydrophobic. they are sensitive to moisture [41-45]. Therefore, BC particles and PLA pellets were mixed and dried in a chamber of a Mini hot air Moretto dryer at 70C for 24 h in order to minimise excessive moisture content
prior to the extrusion. Subsequently, different mixtures of particles and PLA pellets were blended by Axon Pacific Pty Ltd single screw extruder. The BC/PLA mixtures contained BC particles ranging from 2.5 to
10 wt% with the interval of 2.5 wt% each.The extruder was run at 80 rpm and 190 C in the extrude zone and 180 C in blending zone. After cooling, the extruded mixtures were chopped into pellets. These pellets were dried in the dryer at 70 C for 2 h prior to injection moulding. The injection moulding was carried out with four temperature zones. The nozzle temperature was 183 C and all other zones were kept at 180 C. The mould was set to 50 C. The pressure was maintained at 1 bar.