Influence of extruder speed on tensile strength of PLA material casted through additive manufacturing

Abstract In recent years, additive manufacturing has opened up significant opportunities for fabricating complex and intricate shapes as well as components from a variety of materials. Advances in this technology hold the potential to replace conventional methods or systems that incur high losses in industrial applications. However, to fully realize the commercial potential of additive manufacturing, further research is required, as many findings remain inconclusive. This investigation aims to explore the impact of extruder speed on the tensile strength of components produced through additive manufacturing for Polylactic acid (PLA). PLA a renewable and biodegradable thermoplastic polymer with extensive industrial applications, was used for casting the test samples. Five different extruder speed i.e. 25, 50, 75, 100, and 125 mm/sec are selected to analyze the effect on the tensile strength. The tensile strength of each sample was evaluated using a universal testing machine by applying controlled stress. The data obtained were analyzed to determine the relationship between extruder speed and tensile strength. The study revealed that the extruder speed as 75 mm/s provides the highest tensile strength, reaching 46 MPa. It is observed that at low extruder speed the thermal gradients between extruder material and environment is high lead to improper fusion between two layers. The rise in temperature also creates high material flow, leading to under-extrusion or the formation of void during casting of specimens. Furthermore, at high extruder temperature the inadequate material fusion takes place responsible for the decrement of tensile strength. Therefore, the optimum extruder speed is noticed at 75 mm/sec having maximum tensile strength as 46 MPa.