On process capability comparison of hybrid and multi blend PLA matrix composite: Magnetic and surface properties view point

Abstract

The poly lactic acid (PLA) matrix composites have wide self-assembly non-structural engineering applications. Some studies have reported the use of hybrid blend and multi blend PLA matrix for possible 3D printing. This work is an extension of studies reported on optimization of magnetic and surface properties for hybrid blend (PLA-50 wt%, poly vinyl chloride (PVC)-25 wt%, wood powder-5% and Fe3O4-20 wt%) and multi blend (PLA-80 wt% and Fe3O4-20 wt%) in self assembly applications. The hybrid and multi blended feedstock filaments for 3D printing has been prepared by using established conditions of twin screw extrusion (TSE) as per reported literature (i.e. barrel temperature of 170 °C, screw speed 45 rpm and extrusion load of 5 kg). For industrial applications of any process it must be statistically controlled for batch/mass production. Therefore in the present work an effort has been made for comparative process capability analysis based upon magnetic properties (obtained by vibration sample magnetometer, surface porosity (obtained by photomicrographs) and surface hardness (obtained by Shore D hardness) after preparing multi-blend and hybrid blend of PLA matrix composite as feed stock filament. The results of the study suggests that process of multi blend and hybrid blend of PLA matrix is under statistical control as the values of process capability indices (Cp and Cpk) for magnetic as well as surface properties are ≥1. Further X-chart and R-chart also signifies that both multi blend and hybrid blend PLA matrix composite predicts almost similar range of Cp and Cpk. Hence either multi blend or hybrid blend feed stock filament of PLA matrix composite may be used in batch/mass production for non-structural engineering applications.