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The mechanical properties of components manufactured by fused filament fabrication lack sufficient levels for industrial applications. The need for post-processing is, therefore, necessary to enhance the interlayer strength and mechanical characteristics. In the present study, experimental analysis of the effects of annealing on polycarbonate acrylonitrile butadiene styrene manufactured by fused filament fabrication is explored. Annealing temperatures are selected in the range from 90 to 210[degrees]C based on differential scanning calorimetry analysis. The ultimate tensile strength improved by 20.39% from 32.39 to 38.99 MPa after the heat treatment at 180[degrees]C for 1-h duration. Flexural strength showed a remarkable enhancement of 53.21% after annealing at 180[degrees]C for 2 h. The interlayer diffusion and bonding are boosted following heat treatment and microstructural imaging proved the same although the surface had flakes due to the high heat exposure. X-ray diffraction testing of annealed models demonstrated a maximum crystallinity index of 32.56% when compared with nonannealed samples with 6.58%. The addition of polycarbonate to acrylonitrile butadiene styrene improves the stiffness and impact loading capacity with high heat resistance. The heat treatment process is capable of magnifying the mechanical characteristics of the end functional components, thereby opening up the scope for more engineering applications. KEYWORDS crystallinity, flexural strength, fused filament fabrication, heat treatment, tensile strength, orcid.org/00000001-9725-6640 1 | INTRODUCTION Fused filament fabrication (FFF) is an extrusion-based layer-by-layer 3D printing methodology producing consumer-specific components. The possibility to integrate any complex customizations to the target 3D item [...]

The technological development of the 3D printing industry has been tremendous starting from stereolithography in the 1980 s. Low throughput and surface quality had been the major obstacles to this technology, which offers very limited constraints to the geometrical shapes. In this work, we designed a low-cost volumetric 3D printer that, unlike traditional 3D printers, polymerizes the whole geometry within the revolving resin container. Optimized projections needed for the polymerization of target objects were developed in MATLAB R2020b using the concepts of tomographic reconstruction. The rotation of the resin container and the projections rate were matched to develop the target geometries after the oxygen depletion. Commercially available low viscous Anycubic plant-based resins were used as the printing material. 3D objects of centimeter scale could be manufactured in 30 seconds with extremely low surface roughness in the sub-micron range. The dimensional deviation of final components from the CAD model was found to be within 5%. The overprinting on existing solid structures was successfully experimented with and thus opens the way for future developments. Commercialization of volumetric 3D printers would result in mass production of complex customer-specific functional components which in turn boosts the manufacturing sector significantly. KEYWORDS 3D printing, photopolymerization, tomography, volumetric additive manufacturing, 1 | INTRODUCTION The popularity of additive manufacturing technologies is attaining more reach due to their capability to fabricate complex customer-specific components. Ever since its inception in the 1980 s [...]

The shift from rapid prototyping to rapid manufacturing using 3D printing is prominent after the development of volumetric 3D printing, multi-material printing, and functional materials development. Fused filament fabrication (FFF) is a fast-growing additive manufacturing technology with widespread end-user applications. The key constraints to its growth are the lower surface and mechanical properties compared to conventional manufacturing paradigms. The goal of this review is to look at the numerous pre-processing and post-processing parameters for the property enhancement of FFF. Preprocessing methods included optimization of process parameters (infill percentage, pattern, layer height, nozzle and platform temperature, raster angle and width, build orientation, and air gap) and adaptive slicing techniques. Mechanical (hot air jetting, barrel finishing, sand blasting, laser polishing, etc.), chemical (vapor smoothing, dipping, plating, and painting), and thermal (thermal annealing and normalizing) post-processing techniques were successful in improving the mechanical strength and surface finish of fused filament fabricated parts. This paper outlines the various methodologies a FFF user could incorporate for enhancing the final finished product's properties. The potential future prospects for the development of the 3D printing sector are also examined. KEYWORDS adaptive slicing, additive manufacturing, fused filament fabrication, mechanical strength, post-processing, process parameters, surface finish, 1 | INTRODUCTION The technology advancements and new functional materials had helped in the transition of layer-by-layer additive manufacturing from mere rapid prototyping to rapid manufacturing and further. [1] The [...]

The requirement for post-processing methods in 3D printing has increased due to its major limitations such as poor mechanical and surface properties. Thermal annealing, a heat-treatment procedure, has proven to be an excellent approach for increasing the mechanical strength of additive manufactured thermoplastics. The optimized thermal annealing parameters for maximum tensile strength are identified. The Adaptive Neuro-fuzzy Inference System (ANFIS) methodology is employed in this study to forecast the tensile strength of thermal annealed fused filament fabricated polylactic acid (PLA), carbon fiber filled polylactic acid (PLA-CF), and polycarbonate acrylonitrile butadiene styrene (PC-ABS). The root mean square error (RMSE) of the predicted tensile strength of PLA, PLA-CF, and PC-ABS are obtained as 1.012, 0.5, and 0.835 respectively. The coefficient of determination for the predicted model of thermoplastics PLA, PLA-CF, and PC-ABS is determined as 0.98, 0.99, and 0.89 respectively. The ANFIS model developed is successful in determining the tensile strength of annealed 3D printed thermoplastics at various annealing conditions of temperature and duration. Further, the study investigates the effect of heat treatment on the compressive, impact, and flexural properties of PLA prints. [ABSTRACT FROM AUTHOR]

The mechanical properties of fused filament-fabricated specimens are the primary considerations of researchers. Process parameters have a significant impact on the mechanical strength of 3D-printed parts. In this work, the effect of process variables such as infill volume, pattern, layer height, nozzle temperature, and print speed on tensile and compressive strength of polylactic acid samples are investigated. The maximum tensile strength of 27.87 MPa was obtained at 90% infill density for gyroid pattern of a layer thickness of 0.1 mm at a nozzle temperature of 220°C and print speed of 30 mm/s. The maximum compressive strength of 38.21 MPa was achieved at 90% infill density for the triangle pattern of a layer thickness of 0.1 mm at a nozzle temperature of 220°C and print speed of 30 mm/s. Thermal annealing as a post processing method to enhance the mechanical properties is also explored. The effect of annealing temperatures 65°C, 95°C and 125°C and time 30, 60 and 120 minutes on mechanical strength were studied. Ultimate tensile strength showed an improvement of 25.26% to achieve 34.91 MPa whereas compressive strength increased by 21.87% to give 46.57 MPa strength. [ABSTRACT FROM AUTHOR]