In this study, the effect of 3D printing process parameters, specifically line width and layer thickness, on the tensile properties of continuous carbon fiber-reinforced PLA composites fabricated via the Fused Filament Fabrication (FFF) method was investigated. The incorporation of continuous carbon fibers into the PLA matrix aims to enhance the mechanical performance of the printed composites, overcoming the inherent limitations of polymer-based additive manufacturing. The Taguchi method was employed to optimize the process parameters, enabling a systematic evaluation of their influence on tensile strength. An L9 orthogonal array was used to design the experiments, and the Signal-to-Noise (S/N) ratio was analyzed to determine the optimal parameter combination. The results demonstrate that line width and layer thickness significantly affect the tensile performance of printed composites, with narrower line widths (1.0 mm) and thinner layers (0.2 mm) yielding the highest tensile strength (291.3 MPa). Statistical analysis using Analysis of Variance (ANOVA) revealed that line width contributes 58.65% to the overall mechanical performance, making it the most influential factor, followed by layer thickness (33.55%). Microstructural analyses further confirmed that optimized printing parameters improve fiber alignment, enhance interlayer bonding, and minimize void formation. These findings highlight the crucial role of process optimization in maximizing the mechanical properties of FFF-printed continuous carbon fiber reinforced polymer (CFRP) composites, offering insights into achieving high-performance and lightweight structural components.

In this study, an aluminum heating block with two inlets (for the Polylactic acid (PLA) filament and the continuous aramid fiber) was produced and placed onto an extruder, and continuous-aramid-fiber-reinforced PLA composites were fabricated by using the nozzle impregnation method. Layer height values of 0.4 mm, 0.6 mm, and 0.8 mm and hatch spacing values of 0.6 mm, 0.8 mm, and 1.0 mm were used for the investigation of the processing parameters on the properties of composites by differentiating the reinforcement volume fraction. Additionally, atmospheric plasma treatment was used for the surface modification of the reinforcement fiber. The properties of composites reinforced by using surface-modified fibers were also investigated in order to reveal the efficacy of the atmospheric plasma treatment on the properties of composites. The effect of the atmospheric plasma treatment on the fiber properties was investigated by using scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS). Continuous-aramid-fiber-reinforced PLA composites were characterized mechanically by fiber pull-out, tensile, and flexural testing. The fracture surfaces of composites were analyzed by using SEM. The combination of a reduced layer height and a narrower hatch spacing yielded the best mechanical performance, with a tensile strength of 410.25 MPa achieved at a 0.6 mm layer height and a 0.4 mm hatch spacing. This combination minimizes void formation, enhances fiber alignment, and strengthens interlayer adhesion, leading to superior mechanical properties. The FTIR and XPS results showed that atmospheric plasma modification can enhance the interfacial bonding strength by improving the surface morphology and increasing the content of polar groups on the fiber surface. By combining optimized manufacturing conditions with the atmospheric plasma treatment, the mechanical performance of continuous-aramid-fiber-reinforced PLA composites was enhanced.

The mechanical performance of Fused Deposition Modeling (FDM)-produced polymer composites is highly dependent on processing parameters; however, most studies focus on unreinforced polymers, leaving a gap in understanding how these parameters influence continuous wire-reinforced composites. This study addresses this gap by investigating the effect of hatch spacing and layer thickness on the tensile properties of steel wire-reinforced PLA composites. The Taguchi method was employed to systematically optimize mechanical performance, using an L9 orthogonal array to evaluate tensile strength across different process conditions. The results showed that layer thickness was the most influential factor, contributing to 75.861% of the total variance (F = 60.90, p = 0.001), followed by hatch spacing (21.647%, F = 17.37, p = 0.010). The highest tensile strength of 231.61 MPa was obtained at a hatch spacing of 0.4 mm and a layer thickness of 0.2 mm, confirming the importance of optimizing these parameters to improve interfacial bonding and minimize defects. Signal-to-Noise (S/N) ratio analysis further validated these optimal conditions, with the highest S/N ratio of 47.29 observed under the same settings. This study provides a structured approach to optimizing process parameters for metal-reinforced polymer composites, contributing to the development of stronger, more reliable FDM-produced composite materials.

This paper aims to provide a comparison between properties of CuSn10 bronze alloy produced by two methods: FDM (fused deposition modelling) and casting. Wear behavior, mechanical performance and microstructure of CuSn10 alloy produced by FDM and casting methods were determined and compared. 3D printed parts were sintered at 875 °C for 5 h and casting was done at 1200 °C. The amount of porosity was determined by the metallographic cross-sectional examination. Vicker’s hardness, wear and tensile properties of samples were determined. As a result, the porosity value of the CuSn10 alloy produced by the FDM technique was determined as 5.07 ± 0.53%. Tensile strength values were 233.75 ± 18.48 MPa and 349.04 ± 5.10 MPa for CuSn10 alloys produced by FDM and casting methods respectively. While adhesive wear occurs in both production methods, it was observed that the FDM method reduced the wear resistance.

This study investigates the effect of line-width values on the properties of 3D (three dimensional) printed PLA (polylactic acid) parts. 3D printing of parts was carried out by using low-cost cartesian type FFF (fused filament fabrication) desktop 3D printer. Brass nozzle with a diameter of 0.6 mm was used to print PLA parts. Parts having line-width values of 0.6 mm to 1.2 mm were printed and the effect of line-width values on the mechanical properties and printing time was investigated. Mechanical properties of 3D printed parts were determined by using tensile testing device (Zwick/Roell, Z250). Microstructures of 3D printed samples were investigated by using optical microscope (Leica, DM 2500). Printing time for each part was recorded during 3D printing process. Surface profiles of parts were investigated by using surface roughness tester (Mitutoyo SJ-210). Microstructural investigations showed that the voids were formed between adjacent deposited lines and the void content decreased from 5.89% to 5.13% with increasing line-width value up to 1.0 mm. Surface roughness parameter of Ra increased from 5.11±0.21 µm to 9.29±1.12 µm with increasing line-width. Tensile strength of 3D printed specimens showed a slight decrease with increasing line-width due to the presence of voids between adjacent u-turn sections. The tensile strength values were determined as 58.52±1.93 MPa and 46.54±1.18 MPa for specimens printed with line-width values of 0.6 mm and 1.2 mm respectively. SEM images of tensile fracture surface demonstrated that the main failure mechanism of the printed specimens was the rupture of deposited lines instead of fracture of inter-line bonding.

Continuous nettle fiber-reinforced PLA composites were fabricated using a custom-designed fused deposition modeling (FDM) 3D printer equipped with an in-nozzle fiber impregnation system. The influence of hatch spacing and layer thickness on fiber volume fraction, tensile strength, and fracture surface morphology was systematically examined. Fiber content increased from 7.94 vol.% to 12.21 vol.% when hatch spacing was reduced from 1.0 mm to 0.6 mm at a constant 0.4 mm layer thickness, and from 12.21 vol.% to 24.43 vol.% when layer thickness was decreased from 0.4 mm to 0.2 mm at a fixed 0.6 mm hatch spacing. When compared to neat PLA, tensile strength was improved by 18.69% for the configuration of 1_04 and 75.83% for the configuration of 06_02. SEM analysis revealed orderly fiber deposition in all samples, with 3D-printing-induced voids and fiber pull-out observed on fracture surfaces. Reduced hatch spacing and layer thickness resulted in denser fiber packing, consistent with mechanical performance trends. The results highlight the strong influence of printing parameters on the microstructural and mechanical behavior of continuous natural fiber composites produced by FDM.