Estudo da influência da velocidade e temperatura de operação em impressão 3D por extrusão de polímeros granulados

Abstract

Additive manufacturing is gaining more space in the universe of large-scale production. Invented as an agile and flexible production process, it emerged as a rapid prototyping alternative for small assemblies with complex geometry. Today, the challenges in this new direction towards large-scale manufacturing are numerous. Larger printing platforms, combined with the use of large extruders controlled by robotic arms are examples of new applications of additive manufacturing. The process also needs to adapt to the new requirements. It can be said that the printing quality combined with good properties are among the most desired by the market. In this way, the main objective of this research was to identify the influence of the variables speed and temperature in the printing method by extrusion of granulated material, in the properties of the extruded polymer and printing quality. For this, samples were collected from an extruder customized for vertical orientation of three different polymers (ABS, PLA and PCL), dimensional measurements of filaments were carried out, as well as measurement of extrusion pressure, weight and volume. Thermal characterization was also carried out using DSC (Differential Scanning Calorimetry), to verify the thermal transition temperatures (Tg and Tm) and the degree of crystallinity (Xc). to verify the glass and melt temperatures (Tg and Tm), and the degree of crystallinity (Xc). After compiling all the results, it is possible to conclude that for the three polymers, the rotation speed of 20 rpm manages can deliver filaments with good properties, without significantly losing the geometric qualities. ABS proved to be better when extruded at 190°C and it was also possible to conclude that at 180°C the ABS may not have melted correctly, and that at 200°C there are signs of degradation of the material. PLA showed its best performance extruded at 170°C and at lower temperatures, its density was lower, which can be explained by the polymer not having melted correctly. For PCL, better characteristics were observed when extruded at a temperature of 70°C, but there was great difficulty in handling, cooling and solidifying the samples due to its low melting temperature, relatively close to room temperature. Finally, it is possible to conclude that PCL is not suitable for large extruders, and for the additive manufacturing process of large-scale parts.