E FFECT OF P ROCESS P ARAMETERS ON D IMENSIONAL A CCURACY AND T ENSILE S TRENGTH OF FDM P RINTED P ARTS

Fused Deposition Modeling (FDM) is one of the most popular additive manufacturing technologies for various engineering applications. Due to the mechanism of building of products on the principle of adding layer by layer, the mechanical characteristics and quality of the product directly depend on the values of process parameters. Therefore, in this paper, test tubes for mechanical properties testing and model samples for dimensional testing were made using FDM technology. Two different polymeric materials, PLA and PC, were used to make the tubes and models. During the production of test tubes and models, three more influential process parameters varied on three levels: printing temperature, infill density and layer height. The test tubes were printed and tensile tested according to the ISO 527-2 standard. Dimensional measurements were performed on the made samples of models for dimensional tests, and dimensional deviations of the finished product in relation to the designed dimensions of the 3D model were analyzed, deviations from the shape, as well as the presence of surface defects and irregularities. At the end of the paper, recommendations are given which combination of process parameters gives for both analyzed materials better mechanical characteristics and smaller dimensional deviations of the product in the manufacture of FDM technology. PLA material, where it is concluded that the model has the smallest deviation in the direction of dimensions a1 a2 and a3 if printed at a temperature of 200-230 °C, which also belongs to the recommended printing temperature by the material manufacturer. Figure 2b. shows the influence of the printing temperature on the average value of the deviation of external dimensions for PC material, where it is concluded that the model has the smallest deviation in the direction of dimensions a1 , a2 and a3 if printed at a temperature from 255-280 °C, which also belongs to the recommended printing temperature by the material manufacturer, except for the largest dimension a3 where the smallest dimensional deviations in the temperature range from 230 to 255 °C.