The effect of six different infill patterns on the print quality of a dispenser-printed silver ink on Kapton polyimide film is investigated. The results indicate that improved and more complex ...printed electronic structures can be produced due to the improvement in print homogeneity. Dispenser printing is a rapid manufacturing process using direct write technology that can be used to deposit a broad range of inks onto substrates irrespective of their surface geometry. Standard three-dimensional printer infill patterns known as line, rectilinear, concentric, honeycomb, Hilbert curve and Archimedean chords were tested at densities of 30, 50 and 70%. The prints were timed allowing comparison of print speed. After curing, the coverage was checked and the surface roughness (Ra) was measured. The results showed that only the rectilinear infill pattern at 50% density print, and the rectilinear and honeycomb infill patterns at 70% density achieved 100% coverage. The 50% rectilinear print was the fastest of the 100% coverage prints, and the 70% honeycomb print had the lowest surface roughness. The rectilinear pattern at 50% is recommended if there is only one layer to print. The honeycomb pattern is recommended for multilayer prints, where surface roughness is the key.
This paper presents the effect of infill patterns (IPs) on the mechanical response of 3D printed specimens by conducting the low-velocity impact test (LVI) and compression test. The poly-lactic acid ...(PLA, purity 98 wt% >) material has selected and printed using fused deposition modeling (FDM, speed 20 mm/s, layer height 0.2 mm, no of layers 30, extruded at 200 °C) with four different IPs: triangle, grid, quarter cubic, and tri-hexagon. The LVI test on velocity-time, energy-time and force-displacement, and the compression responses have examined and presented in this study. The LVI test was carried out to determine the penetration energy level, energy absorption capacity (toughness), stiffness, and strength of PLA porous parts (60% infill density) for implant/tissue/recyclable product applications. The results have shown that the triangular pattern has produced the highest absorbed energy in LVI test (penetration energy 7.5 J, and stiffness 668.82 N/mm) due to more sheared/contact layers’ perpendicular to impactor (hemispherical insert); while the grid pattern exhibited the highest compressive strength (72 MPa) due to more layers aligned along the compressive loading direction The SEM fracture surface image of Triangular IP has produced effective raster and layer bonding, less number of voids, more amount of circular beach markings, and absence of ratchet lines leading to possess improved mechanical properties.
•Four infill patterns of triangle, grid, quarter cubic, and tri-hexagon were printed by FDM.•Triangular IP exhibited highest penetration limit velocity (0.28 m/s).•Triangular IP produced maximum stiffness (669 N/mm).•Grid IP displayed more compressive strength (72 MPa).•SEM surface topography and fractography were examined.
This study aimed to create an intricate internal structure of 3D printed chocolate by varying the infill construction. Three intricate infill patterns designed were star, Hilbert curve and honeycomb ...with infill percentage of 5%, 30%, 60% and 100%. Cadbury dark chocolate (Choc-1) and Callebaut bittersweet dark chocolate (Choc-2) powders were used by incorporating magnesium stearate (Mg-ST) and plant sterol (PS) powders as food additives. Printing parameters were set up with an extrusion temperature of 32 °C, nozzle size of 0.78 mm and printing speed of 70 mm/s. The results showed that voids in printed samples of all three pattern with 5% infill density ranged from 60.8 ± 2.1% to 72.2 ± 1.8%. Voids in samples with 30% infill density ranged from 20.9 ± 2.1% to 49.2 ± 3.6% while with 60% infill density it ranged from 11.6 ± 2.3% to 19.4 ± 4.2%. Additionally, star and honeycomb infill pattern produced the most stable and tough structure at 60% infill as indicated by a higher normal force (N) to break the printed sample. Moreover, even at 100% infill percentage, 3D printed chocolate were found less hard (ranged from 82.2 ± 2.2 N to 92.2 ± 1.3 N) as compared to cast samples (>110 N) in the snap test. The results obtained in this study provide a useful insight in creating various internal structures of 3D printed dark chocolate with different textural characteristic and physical stability.
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•Mg-ST and PS did not affect the shape fidelity of printed chocolate.•Void fraction of the printed chocolate was affected by increasing the infill percentage.•Higher force (N) is required to break 3D printed samples as infill percentage increase.•3DFP is a powerful tool to control the mechanical properties of 3D printed food.
•Infill density affects tensile strength and Young’s modulus significantly.•Mesh modifiers can enhance tensile properties of Tough PLA samples.•Grid pattern without modifiers shows best fatigue ...life.•Line modifier provides an optimal balance between tensile and fatigue strength.
This research examines the structural performance of Tough Polylactic Acid (PLA) components made through material extrusion, focusing on tensile and fatigue behaviors. Tough PLA, similar to regular PLA, exhibits improved toughness comparable to acrylonitrile butadiene styrene (ABS). As the application of 3D printed parts for functional use expands, understanding the mechanical attributes of materials under both static and dynamic loading conditions is crucial. This study investigates the impact of infill pattern/density and localized reinforcement on the tensile and fatigue strength of Tough PLA samples. Digital image correlation (DIC) and optical micrographs were used to acquire surface-strain data. The findings highlight the influence of localized reinforcement and infill density. Increased infill density is associated with higher tensile strength and Young’s modulus, with specimens at 90 % infill achieving a tensile strength of 28 MPa and Young’s modulus of 0.46 GPa. Incorporating mesh modifiers can enhance tensile properties by up to 20 %. An Analysis of Variance (ANOVA) confirmed the significant effects of these factors on tensile strength. Fatigue test results show a grid pattern without modifiers exhibits the best fatigue life, with specimens enduring up to forty-two thousand cycles at 45 % UTS, while a line modifier balances fatigue strength and tensile properties.
One of the advantage of additive manufacturing technologies is the possibility to produce hollow section products, which are lighter, cheaper, faster to create and still they can have the required ...mechanical properties. Most of the times a 3D printed part's most important feature is the freedom of shape, and by setting the appropriate infill we can ensure the proper resilience as well. In this paper the different infill patterns and volume related percentages are compared by using the commercial Fused Deposition Modelling (FDM) technology. For the investigation non-standardized bending test were made with two loading orientation. From the results, the relation between the mass of the product and manufacturing time can be stated clearly, the pattern and percentage, as well as the decrease of the resilience in case the use of hollow areas in products.
•Print time of infill patterns is affected by the overlapping factor of the pattern.•By increasing the density of the parts, the resistance a bending is increasing linearly.•There is no significant anisotropy between the different infill patterns.•The crack formation can be affected by the structure of the shell.
In this paper, the sliding structure morphology, mechanical and tribological behavior of thermoplastic polyurethanes (TPU) under different conditions were studied. The coefficient of friction of TPU ...stabilizes rapidly at relatively low values and the wear rate increased. High load conditions significantly improved TPU's coefficient of friction and wear rate. However, a high sliding speed was helpful to form a transfer flimsy. Therefore, the coefficient of friction and wear rate of TPU were reduced at higher sliding speeds. The morphology of the wear surface of TPU indicated that the main wear process was viscous wear and wears fatigue under dry and sliding conditions. Using open-source 3D printer is common to use a series of fillers mode and density to reduce time and consumption. Involving the same FDM technique, it is an important to evaluate its strength with this technology. Herein, the effects of more adjustable variables, such as frequencies, infill patterns, density and loads, has been evaluated in detail.
With the increasing application of additive manufacturing (AM) in the industry, more attention has been paid to the performance of the additively manufactured part. How to maximize the structural ...efficiency of a part to achieve the desired performance has become the focus and challenge of design for additive manufacturing (DFAM). To give full play to the complex-geometry, multi-material, multi-scale, and multi-function manufacturing capabilities of AM, new approaches in DFAM have to be explored. The relationship between stress and growth in biology indicates that naturally evolved perfect structures are all optimal responses to their applied force. This work discusses a novel method to DFAM at the macroscale, mesoscale and microscale from a force-flow perspective, aiming to achieve an organic integration of force-flow based design with AM-driven manufacturing. Firstly, the characteristics of force-flow and its embodiment in nature and engineering are analyzed. Then, an overview of topology optimization, lattice/cellular structure design and infill pattern design are respectively provided in the combination of force-flow and AM. Finally, the future development directions of DFAM based on force-flow are proposed according to the limitations of current research.
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•A multi-scale design method for additive manufacturing is discussed from a force-flow perspective.•The visualization forms, characteristics and the application of force-flow are elucidated.•Force-flow based topology optimization, mesoscopic structure design and infill pattern design are respectively reviewed.•Future research directions are indicated to make AM and force flow highly compatible.
The study herein combines the use of fused filament fabrication (FFF) with finite element analysis (FEA) to enhance the understanding of certain manufacturing parameters (i.e. material, infill ...density, infill pattern, and outer vertical shell) in the design process of a lumbar fusion cage. Three FFF materials with distinct mechanical properties namely polycarbonate (PC), acrylonitrile butadiene styrene (ABS), and polylactic acid (PLA) were tested. Three infill densities (i.e. 25%, 50%, 75%) were investigated along with two different infill patterns (i.e. rectangular and honeycomb). Compressive modulus and compressive yield strength values obtained from standard mechanical analysis were used as input for FEA to assess numerically the mechanical performance of a lumbar fusion cage under physiological static loading. The findings suggest that both infill density and infill pattern influence the quality of the finished part in terms of both printing accuracy and mechanical response. FEA results indicate that both PC and ABS can be safely adopted to fabricate a porous lumbar cage with a 50% honeycomb infill density and a honeycomb infill pattern. This paper demonstrates that 3D printing assisted FEA can be used to predict the performance of a lumbar cage design with varying manufacturing parameters and potentially reduce product design and development time.
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•Porous structures printed by FFF with varying material, infill density, and infill pattern have been studied.•Compressive results were used as input for FEA to optimise the manufacturing process of a lumbar fusion cage.•Differences in dimensional accuracy, volume fraction, and compressive properties were found between patterns.•FEA allowed the selection of optimal materials and cage structure capable to withstand the maximum expected static loads.
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The aim of this study was to investigate the impact of infill patterns on the drug release of 3D-printed tablets and the possibility of tailoring drug release through the use of ...excipients. Furthermore, the influence of wall thickness was evaluated. Amlodipine was used as a model drug, polyvinyl alcohol (PVA) as a polymer and excipients including sodium starch glycolate (SSG) and hydroxypropyl methyl cellulose (HPMC) HME 4 M were used. Four different formulations were prepared. Firstly, the substances were mixed and then extruded by hot melt extrusion to form filaments. The obtained filaments were used to print amlodipine tablets by fused deposition modeling (FDM) 3D-printing technique. Each formulation was printed in four different infill patterns: zigzag, cubic, tri-hexagon and concentric, while infill density remained constant (20%). The mechanical properties of the obtained filaments were also evaluated using three-point bend test. Amlodipine tablets were printed with varying wall thickness (1 mm, 2 mm and 3 mm) and varying infill patterns. With regard to the infill patterns, higher drug release was achieved with zigzag infill pattern. The simultaneous effect of excipients and infill patterns on amlodipine release has been described and modeled through self - organizing maps (SOMs), which visualize the effect of these variables. Self-organizing maps confirmed the fastest drug release when the zigzag pattern and SSG were used, but also showed that the presence of HPMC HME 4 M was not decisive for drug release rate. As for the wall thickness, higher drug release was achieved with decreasing wall thickness. The results indicated that proper selection of excipients and/or adjusting the infill pattern and wall thickness are ways of tailoring drug release in FDM 3D printing. This study draws the attention to the importance of adjusting the settings of the printer and the usage of excipients to produce release-tailored medications.
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