Measurements of Tensile Strength and Elongation of 3D Printed Polylactide Solids Produced with Different Temperatures of Extruder Using Coordinate Measuring Technique and Finite Element Method

In order to determine the largest and smallest deformations during 3D printing, measurements were made for pure polylactide (PLA) using a coordinate measuring technique using a measuring arm. The additive manufacturing process was carried out using four nozzle temperatures: 190℃, 200℃, 210℃ and 220℃. The model was properly selected to check the cylindricity, angles of inclination and dimensional deviations from the nominal value of the cuboid. FEM analysis was used to confirm the obtained results. The cylindricity and shape tolerances were shown to be the best at 190℃. The smallest deviations from the angle of 90 ° have solids made at 200 ℃ and 220 ℃. In the case of dimensional tolerances of the centers of the holes relative to each other, the best deviations were obtained for the temperature of 190 ℃ and 220 ℃. The highest stress values during uniaxial stretching using FEM analysis were obtained for samples made with nozzle temperatures of 200°C and 210°C, which are about 31 MPa. For the temperature of 190°C and 220°C, the deviations are the closest to the reference model and are equal to about 30 MPa. In the case of the FEM analysis for single-point bending, the element made at 190°C had a maximum deformation of 0.203 mm, which was the same for the reference model. The largest deviation is noticeable for the printing temperature of 200°C and is 0.211 mm.