Analysis of manufacturing and material parameters in 3D-printed polylactic acid (PLA) parts filled with glass powder: mechanical, economic, and environmental assessment

Abstract

This study investigates the influence of the addition of glass powder, nozzle size, and infill density on the mechanical properties of 3D-printed polylactic acid (PLA) pieces. To do so, a factorial design of experiments was accomplished. The specimens were tested under tensile and bending conditions. Regression equations were extracted from the maximal strength, strain at maximal strength and modulus, and an analysis of the significance of the terms was carried out. All the factors influence the output variables, independently and in combination. As for the environmental impact, a cradle-to-gate life cycle analysis (LCA) of the printing material with different glass powder additions, including the manufacturing process and transportation of the raw materials, was performed. Additionally, a cost assessment of each alternative was calculated for each case. Since the concurrence of mechanical, environmental, and cost performance is needed to enter a new product in the industry, a multicriteria decision-making analysis was performed to select the best combination. The criteria considered were the material and printing costs and the environmental impact, all normalized with maximal strength. Two different alternatives were found to be the best solution depending on the strength selected. Both of them were printed using a 1.2-mm nozzle with 100% infill and different glass percentages.