The mechanical and tribological behaviors of the parts manufactured with 3D printing methods differ with variations in the manufacturing parameters. This paper aims to investigate the effect of the layer thickness and layer orientation parameters on the hardness, friction coefficient and wear properties of PLA samples printed by Fused Deposition Modelling (FDM) method. Samples were printed with three different layer thicknesses in two different build orientations. The hardness of the samples was tested by D-type shore hardness durometer and a pin-on-disc setup was used to measure the friction coefficient and wear rate of the samples. The analysis of the experimental results showed the distinctive effect of the layer orientation and layer thickness which further discussed in the paper.

Purpose This paper aims to analyze experimentally and numerically the effect of the nozzle temperature and feed rates on the dimensions of the fused deposition modeling (FDM) polymer parts. Design/methodology/approach In total, 30 strips per sample were printed with the same width as the nozzle diameter. The strips were printed with one vertical movement of the nozzle head. The width of the strips was measured with a caliper at five locations. A linear regression model was created based on the experimental data to understand the correlation between the strip width deviation and the parameters of interest. Numerical simulations were performed to predict the swell of the polymer exiting the nozzle using finite element method combined with level set method. The experimental results were then used to validate the models. Findings The average accuracy of polylactic acid (PLA) samples was better than that of acrylonitrile butadiene styrene (ABS) samples. The average strip width had a tendency to increase with increasing temperature for PLA samples, whereas ABS samples showed mixed behavior. The strip width decreased with increasing feed rate for most cases. The measurement positions had a major effect on strip width when compared to nozzle temperature and feed rate. The numerical model predictions were in good agreement with the experimental data. A few discrepancies were observed at high feed rates and nozzle temperatures. Originality/value This study will contribute to gaps in knowledge regarding the effect of processing conditions on dimensional accuracy of FDM-printed parts. The developed numerical model can be efficiently used to predict the dimensional accuracy of FDM-printed parts.