Nozzle Temperature Research Articles

Problems and Handling Methods of Laser Printers

A laser printer is a common office and personal printing equipment widely welcomed for high-speed, high-quality print output. The high temperature usually causes the printer nozzle temperature to be too high, affecting the printing quality and even damaging the printer. This is because the laser printer works by attaching the toner to the paper through high-temperature sintering, hence the print head’s temperature. Maintaining a suitable temperature environment is crucial for the normal operation and life of the laser printer. In addition, If the position and thickness of the black and white tendons change, it may affect the uneven distribution of the ink when printing, resulting in patches or blur of the printed image. In the printer’s cartridges, the black and white bars are separated, ensuring that the ink in the cartridge is evenly distributed when printing. If the position and thickness of the black and white tendons change, it may affect the uneven distribution of the ink when printing, resulting in patches or blur of the printed image. Therefore, when replacing ink cartridges or resetting or modifying some settings of the printer, be careful to be sure not to damage the printer. This study aims to solve the technical defects of laser printers, improve the level of printing technology, and improve the user experience.

Extraction of volatile organic compounds liberated upon filament extrusion by 3D pen and its comparison with a desktop 3D printer using solid-phase microextraction fiber and Arrow

Desktop 3D printers that operate by the fused deposition modeling (FDM) mechanism are known to release numerous hazardous volatile organic compounds (VOCs) during printing, including some with potential carcinogenic effects. Operating in a similar manner to FDM 3D printers, 3D pens have gained popularity recently from their ability to allow users to effortlessly draw in the air or create various 3D printed shapes while handling the device like a pen. In contrast to numerous modern 3D printers, 3D pens lack their own ventilation systems and are often used in settings with minimum airflow. Their operation makes users more vulnerable to VOC emissions, as the released VOCs are likely to be in the breathing zone. Consequently, monitoring VOCs released during the use of 3D pens is crucial. In this study, VOCs liberated while extruding acrylonitrile butadiene styrene (ABS) filaments from a 3D pen were measured by solid-phase microextraction (SPME) combined with gas chromatography/mass spectrometry (GC/MS). SPME was investigated using the traditional fiber and Arrow geometries with the DVB/Carbon WR/PDMS sorbent while four different brands of ABS filaments—Amazon Basics, Gizmodork, Mynt 3D, and Novamaker—were used with the 3D pen. Heatmap analysis showed differentiation among these brands based on the liberated VOCs. The nozzle temperature and printing speed were found to affect the number and amount of released VOCs. This study goes a step further and presents for the first time a comparison between 3D pen and a desktop 3D printer based on liberated VOCs. Interestingly, the findings reveal that the 3D pen releases a greater number and amount of VOCs compared to the printer. The amounts of liberated VOCs, as indicated by the corresponding chromatographic peak areas, were found to be 1.4 to 62.6 times higher for the 3D pen compared to the 3D printer when using SPME Arrow.

Computational Analysis and Regression Laws for Nozzle Erosion Prediction in Hybrid Rockets

The erosion of the nozzle throat can represent one of the major limitations against the future widespread use of hybrid rocket engines (HREs) in the space industry. In fact, nozzle erosion in HREs can be more severe and harder to predict than in solid rockets due to the higher concentration of oxidizing species in the combustion products and to mixture ratio shifts and/or throttling. Therefore, an accurate understanding of the erosion phenomenon is of fundamental importance for the technological advancement of HREs. This work is focused on the investigation of graphite nozzle erosion in HREs burning high-density polyethylene with two different oxidizers, oxygen and nitrous oxide. First, the results of a computational fluid dynamics parametric analysis are used to derive closed-form regression laws for the rapid estimation of nozzle throat erosion and wall temperature depending on chamber pressure and mixture ratio. Then, a one-dimensional transient heat conduction solver is loosely coupled with the aforementioned regression laws, allowing to reconstruct the transient heating process within the solid. The obtained numerical results are validated against experimental data. Finally, the effect of gas-phase reactions on the heterogeneous reactions occurring at the nozzle surface is highlighted when moving from fuel-rich to oxidizer-rich conditions.

24. CRITICAL IMPORTANCE OF NOZZLE TEMPERATURE TO BIOPRINT VASCULAR GRAFTS WITH SHEAR-THINNING HYDROGEL

Abstract Introduction The development of vascular grafts adapted to the nature of the patient and their treatment is constantly evolving. Fine control of the bioprinting manufacturing process is a key issue to obtain proper personalized vascular grafts. The aim is to check the influence of the nozzle temperature during bioprinting a Gelatin/Gellan Gum/Alginate hydrogel vascular grafts. Methods Vascular grafts were printed using a Gelatin/Gellan Gum/Alginate (8:3:0.5 %w/v) hydrogel in an BioX bioprinter with the printhead and bed set up to 65 °C. Two configurations were set: 1) a standard conical tip (nozzle) and 2) the same nozzle thermally insulated with aluminum foil to uniformly distribute the temperature. A temperature control using a 100 kΩ thermistor was performed in four points: chamber, nozzle, printhead, and bed. Four heating/cooling cycles were performed in each control point. Results The grafts printed with the standard nozzle exhibited irregular wall thickness and an uneven surface, attributed to lower temperatures in the conical tip. In contrast, results from the aluminum-covered nozzle indicated temperature distributions of 33.13±0.87, 49.03±3.92, 52.38±3.53, and 64.98±0.10 °C for chamber, nozzle, printhead, and bed, respectively. This improved temperature distribution enhanced the printability of Gelatin/Gellan Gum/Alginate vascular grafts, resulting in a more regular wall thickness and surface profile. Conclusion The optimization of temperature in the nozzle during the printing process is a critical parameter for bioprinting vascular grafts using this shear-thinning Gelatin/Gellan Gum/Alginate hydrogel.

Effect of meta-structure on mechanical properties of polyvinylidene fluoride composite-based 3D printed intramedullary pins

Some studies have outlined the use of 3D-printed polyvinylidene fluoride (PVDF) composite-based solid intramedullary (IM) pins with tunable mechanical (tensile, compressive, flexural, and torsional) properties for orthopedic applications. But hitherto little has been reported on the effect of meta-structure induced in 3D-printed IM pins for canines from the mechanical properties’ viewpoint. This study highlights the design, fabrication, and testing to mimic actual loading conditions in the canine femur bone on novel IM pin with meta-structure employed in different length zones (30%, 40%, and 50% of total gauge length) prepared by fused filament fabrication (FFF) of PVDF composite. The IM pin (of length 150 mm) has square threads (pitch 2 mm) at the distal end (ɸ7 mm, up to 60 mm in length), and V threads (pitch 1.5 mm) at the proximal end (ɸ6 mm, up to 30 mm in length). The IM pin was fabricated at the best setting (of the FFF process) suggested by the multifactor optimization (at nozzle temperature (Nt) 235°C, printing speed (Ps) 60 mm/s, and raster angle (RA) 45°). The result suggests that for the solid IM pins prepared at the optimized settings the observed elongation, peak load (PL), and break load (BL) during tensile and compressive loading were 4.83 mm, 968.40 N, 958.20 N, and 14.19 mm, 412.80 N, 371.52 N respectively. Whereas for 50% meta-structure the observed elongation, PL, and BL during tensile and compressive loading were 14.49 mm, 405.49 N, 90.20 N, and 13.23 mm, 243.20 N, 218.88 N respectively. For both tensile and compression loading (in this case study), better elongation was noticed for the FFF-based IM pin with 50% meta-structure and hence recommended for implantation in the canine femur bone. The results are also supported by scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) based surface characteristics of the fracture sites.

Shape Morphing of 4D-Printed Polylactic Acid Structures under Thermal Stimuli: An Experimental and Finite Element Analysis

This study explores the shape-morphing behavior of 4D-printed structures made from Polylactic Acid (PLA), a prominent bio-sourced shape-memory polymer. Focusing on the response of these structures to thermal stimuli, this research investigates how various printing parameters influence their morphing capabilities. The experimental approach integrates design and slicing, printing using fused deposition modeling (FDM), and a post-printing activation phase in a controlled laboratory environment. This process aims to replicate the external stimuli that induce shape morphing, highlighting the dynamic potential of 4D printing. Utilizing Taguchi’s Design of Experiments (DoE), this study examines the effects of printing speed, layer height, layer width, nozzle temperature, bed temperature, and activation temperature on the morphing behavior. The analysis includes precise measurements of deformation parameters, providing a comprehensive understanding of the morphing process. Regression models demonstrate strong correlations with observed data, suggesting their effectiveness in predicting responses based on control parameters. Additionally, finite element analysis (FEA) modeling successfully predicts the performance of these structures, validating its application as a design tool in 4D printing. This research contributes to the understanding of 4D printing dynamics and offers insights for optimizing printing processes to harness the full potential of shape-morphing materials. It sets a foundation for future research, particularly in exploring the relationship between printing parameters and the functional capabilities of 4D-printed structures.

Semi-crystalline materials for pharmaceutical fused filament fabrication: Dissolution and porosity

A better understanding of crystallization kinetics and the effect on drug product quality characteristics is needed to exploit the use of semi-crystalline polymers in pharmaceutical fused filament fabrication. Filaments were prepared from polycaprolactone or polyethylene oxide loaded with a crystallization inhibitor or inducer, which was either 10% (w/w) ibuprofen or theophylline. A design-of-experiments approach was conducted to investigate the effect of nozzle temperature, bed temperature and print speed on the printed tablets’ microstructure and dissolution kinetics. Helium pycnometry derived porosity proved an ideal technique to capture significant distortions in the tablets’ microstructure. On the other hand, terahertz time domain spectroscopy (THz-TDS) analysis proved valuable to investigate additional enclosed pores of the tablets’ microstructure. The surface roughness was analyzed using optical coherence tomography, showing the importance of extensional viscosity for printed drug products. Drug release occurred via erosion for tablets consisting of polyethylene oxide, which partly reduced the effect of the inner microstructure on the drug release kinetics. An initial burst release effect was noted for polycaprolactone tablets, after which drug release continued via diffusion. Both the pore and crystalline microstructure were deemed essential to steer drug release. In conclusion, this research provided guidelines for material and process choice when a specific microstructure has to be constructed from semi-crystalline materials. In addition, non-destructive tests for the characterization of printed products were evaluated.

Direct Pellet Three-Dimensional Printing of Polybutylene Adipate-co-Terephthalate for a Greener Future.

The widespread use of conventional plastics in various industries has resulted in increased oil consumption and environmental pollution. To address these issues, a combination of plastic recycling and the use of biodegradable plastics is essential. Among biodegradable polymers, poly butylene adipate-co-terephthalate (PBAT) has attracted significant attention due to its favorable mechanical properties and biodegradability. In this study, we investigated the potential of using PBAT for direct pellet printing, eliminating the need for filament conversion. To determine the optimal printing temperature, three sets of tensile specimens were 3D-printed at varying nozzle temperatures, and their mechanical properties and microstructure were analyzed. Additionally, dynamic mechanical thermal analysis (DMTA) was conducted to evaluate the thermal behavior of the printed PBAT. Furthermore, we designed and printed two structures with different infill percentages (40% and 60%) to assess their compressive strength and energy absorption properties. DMTA revealed that PBAT's glass-rubber transition temperature is approximately -25 °C. Our findings demonstrate that increasing the nozzle temperature enhances the mechanical properties of PBAT. Notably, the highest nozzle temperature of 200 °C yielded remarkable results, with an elongation of 1379% and a tensile strength of 7.5 MPa. Moreover, specimens with a 60% infill density exhibited superior compressive strength (1338 KPa) and energy absorption compared with those with 40% infill density (1306 KPa). The SEM images showed that with an increase in the nozzle temperature, the quality of the print was greatly improved, and it was difficult to find microholes or even a layered structure for the sample printed at 200 °C.

Optimisation of processing parameters for wear properties of polylactic acid biopolymer parts in FDM process

ABSTRACT Currently, additive manufacturing (AM) technology has been expanding in advanced engineering and biomedical applications. The fused deposition modelling (FDMTM) method, also known as fused filament fabrication (FFF), is one of the most extensively used AM methods owing to its simple operation, reliability and potential to manufacture intricate components. The mechanical and wear properties of these components depend mainly on the proper selection of processing parameters. This study aims to determine the optimum parameters for low wear rate, less frictional force and good surface roughness. To achieve this aim, a hybrid approach based on user preference ranking is adopted to evaluate the effect of the four processing parameters including nozzle temperature, fill density, layer thickness and printing speed, on the wear behaviour, frictional force and surface roughness. The study procedure includes Taguchi L27 experiment design, finding the weight ratios, calculating utility index (UI) values and optimising UI values using Taguchi methodology for maximum utilisation. The results found that at 220°C of nozzle temperature, 100% fill density, 0.24 mm layer thickness and a printing speed of 60 mm/s are optimal parameters for the maximum utility index value. From the results, the percentage of contribution of fill density, nozzle temperature, layer thickness and printing speed were observed as 69.071%, 15.974%, 5.431% and 2.306%, respectively.

Effects of 3D-printing processing parameters on FFF parts’ porosity: outlook and trends

ABSTRACT The filament material extrusion (ME) process manufactures functional components for a wide range of personalized applications in medicine, fashion and remanufacturing cases, or customized batch production for aviation and automotive industries. Therefore, structural and welding parameters affect porosity during 3D printing and are of paramount interest concerning the parts’ mechanical response to static and dynamic loadings. This work aims to arrange the literature’s experimental findings of crucial processing parameters’ effects on the fused filament fabrication (FFF) part’s porosity and structural strength. Therefore, the materials and structure parameters, including the filament material properties, deposited strand geometry, infill rate, infill pattern design type and orientation, and part orientation, as well as welding parameters such as material flow, nozzle temperature, bed temperature, printing feed, and environmental conditions, are critically reviewed and study in profoundness regarding porosity and mechanical loading of 3D printed parts. Experimental studies are critically examined, emphasizing the effects of parameters and interactions between them.

Tailoring the crystalline structures and mechanical properties of polyamide 1012 specimens by material extrusion-based additive manufacturing

In this work, the evolution of the crystalline structures of MEAM-printed polyamide1012 (PA1012) parts with the nozzle temperatures (Tn) and thermal annealing temperatures (Ta) was investigated. It is found that Tn plays an important role in determining the crystalline structure of PA1012 parts. The freshly-printed PA1012 parts crystalize as γ crystals at Tn lower than 230 °C. With Tn increasing to above 230 °C, a small amount of α phase coexists with γ phase in the PA1012 parts. Also, the thermal annealing treatment can tailor the crystalline structure of the MEAM-printed PA1012 parts. Specifically, the crystalline structure exhibits a transformation from γ phase to α crystal, after annealing the PA1012 parts at a Ta higher than 90 °C for 10 min. Due to the presence of a high content of γ phase, the Brill transition occurs at a low temperature for the MEAM-printed PA1012 parts, implying a close relationship between the H-bond sheet structures and the formation of γ phase. Moreover, the crystalline structure exerts a significant influence on the mechanical properties of the PA1012 parts. The samples with only γ phase exhibit much higher tensile strength and Young's modulus, but much lower ductility, compared to those containing only α crystal. Hence, this work provides effective pathways for regulating crystalline structures as well as mechanical properties of MEAM-printed long-chain polyamide materials.

Exploring impact, spreading, and bonding dynamics in molten metal deposition for novel drop-on-demand printing

This study delves into the dynamics of molten metal deposition (MMD)-based drop-on-demand (DoD) printing, focusing on the interaction between aluminum droplets and substrates. Nozzle-to-substrate distances below 20 mm prevent droplet pinch-off, while distances exceeding 40 mm result in no droplet-substrate adhesion. Operating within the substrate temperature range of 350–550 °C is crucial, avoiding delamination, and shrinkage pits at lower temperatures, and substrate deformation and heightened oxidation at higher temperatures. Droplet adhesion is impeded at nozzle temperatures below 700 °C. Impact-driven and inviscid, DoD-MMD exhibits spreading outpacing overall solidification, particularly at higher temperatures. Surface tension forces dominate, influencing droplet spreading and leading to underdamped interfacial oscillations. Weak droplet-substrate adherence, facilitated by Van der Waals forces, allows easy droplet detachment, beneficial for successive drop-on-drop deposition. Unique to DoD-MMD, ridges along the droplet periphery act as solidification paths, influenced by thermal contraction and surface tension. The spherical pancake shape of the droplet, characterized by a solidification angle >90°, is elucidated through Weber and Freezing numbers. The final deposited droplet width to initial diameter ratio increases with the droplet temperature and deposition height. In contrast to other metal DoD studies, the spreading factor decreases with a rise in substrate temperature, attributed to intensified oxidation at higher substrate temperatures.

Optimizing surface roughness in soft pneumatic gripper fabricated via FDM: experimental investigation using Taguchi method

Purpose In this study, experimental studies were carried out using different process parameters of the soft pneumatic gripper (SPG) fabricated by the fused deposition modeling method. In the experimental studies, the surface quality of the gripper was examined by determining four different levels and factors. The experiment was designed to estimate the surface roughness of the SPG.Design/methodology/approach The methodology consists of an experimental phase in which the SPG is fabricated and the surface roughness is measured. Thermoplastic polyurethane (TPU) flex filament material was used in the fabrication of SPG. The control factors used in the Taguchi L16 vertical array experimental design and their level values were determined. Analysis of variance (ANOVA) was performed to observe the effect of printing parameters on the surface quality. Finally, regression analysis was applied to mathematically model the surface roughness values obtained from the experimental measurements.Findings Based on the Taguchi signal-to-noise ratio and ANOVA, layer height is the most influential parameter for surface roughness. The best surface quality value was obtained with a surface roughness value of 18.752 µm using the combination of 100 µm layer height, 2 mm wall thickness, 200 °C nozzle temperature and 120 mm/s printing speed. The developed model predicted the surface roughness of SPG with 95% confidence intervals.Originality/value It is essential to examine the surface quality of parts fabricated in additive manufacturing using different variables. In the literature, surface roughness has been examined using different factors and levels. However, the surface roughness of a soft gripper fabricated with TPU material has not been examined previously. The surface quality of parts fabricated using flexible materials is very important.

Optimizing the printing parameters for dimensional accuracy of distal femur bone by using Taguchi’s method

BackgroundFused deposition modelling (FDM) is a popular additive manufacturing technique with capability of producing complex and integrate shapes. One of the critical aspects of FDM is the dimensional accuracy of 3D (three-dimension) printed model, especially in medical science applications, as proper fit and function with human body can prevent patient’s discomfort, complication or even harm.ObjectiveIn this research work, the optimisation of print parameters: layer height, nozzle temperature, printing speed, infill pattern and infill density for improving the dimensional accuracy of distal femur bone, an irregular and complex shaped geometry is carried out using Taguchi’s method and to study its influence using ANOVA (analysis of variance).Methodology3D CAD (computer-aided design) model of the distal femur bone is generated from a CT (computerized tomography) scan using 3D slicer and its associated errors are corrected using Ansys SpaceClaim. The model is prepared for printing using Ultimaker Cura as per L16 orthogonal array experimental layout where TEA (trans epicondylar axis), which is the distance between the most prominent point of the lateral and medial epicondyle, is set at 45° from X-axis in XY plane, i.e. diagonally on the plane of printing bed. It is then printed with PLA (polylactic acid) filament. Length along TEA is compared accordingly with 3D CAD model. Taguchi’s method of ‘smaller the better’ is applied for reducing deviation. Further, ANOVA analysis is done on the data set and a linear regression model is also developed.ResultThrough Taguchi’s method, the optimum parameters were found to be triangle for infill pattern, 200 °C for nozzle temperature, 30 mm/s for nozzle speed, 0.1 mm for layer height and 40% for infill density. ANOVA analysis shows that all parameters contribute significantly with layer height being the most influential parameter, followed by infill pattern, nozzle speed, nozzle temperature and infill density. Mathematical model through multiple linear regression method was developed with determination of coefficient value of 96.91% and standard residual value is within the acceptable range of ± 2 indicating that there is no outliner in the data.

Assessing quality in extrusion based additive manufacturing technologies

Quality is a magic word that has fascinated the people since the early days of civilization and today, quality is the only mantra to survive. Quality is the only relevant attribute associated with product and processes that makes any technology in-demand. The quality of the parts produced by Additive Manufacturing (AM) Technologies depends on many factors, like print speed, nozzle temperature etc. The aim of this work is the identification of influence factors that affect the performance measures of extrusion based Additive Manufacturing (AM) technologies, namely, Fused Deposition Modelling (FDM). These processes can be characterized by a set of influence factors, like print speed, infill density, temperature; layer thickness and build orientation are responsible for quality of the product. In this work, Grey relational Analysis (GRA) is employed. GRA is a method which enables determination of the relational degree of every factor in the system. The method can be used for systems that are not completely described and with relatively few available data. Reliable technique of optimization GRA is clubbed with another established technique; called Interrelation ship Diagram (ID), to identify and optimize the influence factors, that yields highest performance characteristics. Manufacturing Combinations are evaluated against performance measures. In the earlier research, the authors have applied same tool, GRA clubbed with 7QC tools, to evaluate extrinsic and intrinsic qualities of the parts produced by FDM, In this research, the entire focus is paid to the intrinsic properties of the parts produced by FDM. This research will have a greater impact on the quality of the parts produced by the FDM.

Assessing layer deviations and correction for robotic polymer 3D printing applications

Additive manufacturing (AM), often referred to as 3D printing, is a manufacturing technique that involves the creation of complex objects layer-by-layer while providing design flexibility. The broad spectrum of additive manufacturing applications in aerospace, medicine, automotive industries, etc., using high-value materials necessitates a precise final product with minimal wastage. However, the print's dependence on optimizing parameters such as nozzle diameter, printing speed, extrusion speed, nozzle temperature and other multifaceted factors can contribute to deviations from the intended design. This paper introduces a closed-loop in-situ assessment of layer height deviations using point cloud data to ensure real-time printed part modification. The printing is done using a direct-fed pellet screw extruder mounted on top of 6 degrees of freedom robotic arm. A structured light 3D scanner is used to obtain point cloud data. A Robot Operating System (ROS) based digital toolchain is employed to have seamless communication between all nodes of the AM system. The layer-by-layer printing is observed using an in-house CAM solution, which examines the point cloud data and compares it to the original CAD model. The deviations are analyzed, and the path of the next layer is re-planned to adjust for the digression in the previous layer. This control loop ensures that the final product meets the desired quality standards at minimum cost and efficient time and increases the opportunity for rapid prototyping and iterative design improvements.

Defect Detection and Closed-loop Feedback Using Machine Learning for Fused Filament Fabrication

The objective of this study was to develop a closed-loop system for a commercial fused filament fabrication printer based on visual machine learning inspection of common defects. Convolutional neural network was used to identify levels of common defects: stringing, over/under-extrusion, and weak infill. Transfer learning was used to adapt a pre-trained model to fit this problem, as it involves incrementally fine-tuning the model parameters to new data. The observation model achieved an accuracy of 92.86% on validation data set and 90.0% on the testing data set. By modifying the input G-code, the custom program could adjust the feed-rate, nozzle temperature, material extrusion amount, and fan speed to correct for identified extrusion defects.

Magnetism of single-doped paramagnetic tin clusters studied using temperature-dependent Stern-Gerlach experiments with enhanced sensitivity: impact of the diamagnetic ligand field and paramagnetic dopant.

In this work, the magnetic properties of tetrel clusters SnNTM, which are singly doped with transition metals (TM), are investigated. On the one hand, the number of tetrel atoms (N = 11, 12, 14 and 17 with TM = Mn) is varied; on the other hand, different transition metals (N = 14, TM = Cr, Mn, Fe) are studied. Magnetic deflection experiments under cryogenic conditions show that the variation of the number of tetrel atoms strongly changes the magnetic properties of the Mn-doped clusters. It is observed that Sn12Mn, Sn11Mn and Sn14Mn partially show super-atomic behaviour, while spin relaxation occurs in Sn17Mn. Magnetic deflection experiments at higher nozzle temperatures were carried out for the first time enhanced by a second parallel-aligned Stern-Gerlach magnet to achieve larger deflections. The resulting temperature-dependent one-sided deflections are quantitatively analysed using Curie's law and show that Sn17Mn possesses the highest magnetic moment of these clusters, followed by Sn12Mn and Sn11Mn. Sn14Mn shows the lowest magnetic moment. The replacement of Mn by Cr in Sn14Mn leads to a diamagnetic singlet, i.e., the magnetic moment of Cr in Sn14Cr is completely quenched. The replacement of Mn by Fe in turn leads to a paramagnetic species, whereby Sn14Fe is most likely present as a triplet. On this basis, the geometrical and electronic structures are analysed using quantum chemical calculations, indicating an arachno-type structure for Sn14Cr, Sn14Mn and Sn14Fe, which has already been predicted in the literature for Si14Cr. This is experimentally confirmed by deflection of molecular beams with an electric field under cryogenic conditions, suggesting that the arachno-type geometry is crucial for the overall stability of the transition-metal-doped tetrel clusters Sn14TM with TM = Cr, Mn, Fe.

Pengaruh Sudut Part Build Orientation Z-Direction Terhadap Kuat Tarik Spesimen Uji Standar Astm D638 Type IV Menggunakan Filamen Pla+

This study will try to investigate variations in the angle of the Z-direction build part by using a 3D Printer with Fused Deposition Modeling (FDM) technology made from PLA + Sugoi. This study uses a 0.4mm nozzle with a Bowden type extruder. This study uses a PLA+ filament from the Sugoi brand with a nozzle of 0.4 mm, diameter filament 1,75 mm, 3D Printer with Fused Deposition Modeling (FDM) technology used is Creality Ender 3 V2 with process parameter settings in slicing software using a layer thickness of 0.30 mm, Top solid Layer 5, Bottom Solid Layer 5, Fill density 100%, cooling speed 100%, and flowrate 100%, nozzle temperature 205°C, and bed temperature 60°C. Variation in angle Part build Z-direction is proven to have a significant difference in Tensile strength with a difference of 10° resulting in a difference in Tensile strength of 15 MPa, where the highest tensile strength is 67.50 MPa with part build Z-direction at an angle of 80°, and the lowest tensile strength of 52.50 MPa with a Z-direction part build angle at an angle of 70°.

Effect of autoclaving on the dimensional stability and surface characteristics of 3D printed PVDF composite-based implants

In the past decade, a lot of work has been reported on the use of polyvinylidene fluoride (PVDF) based thermoplastic composites as energy storage devices, and implant materials. But hitherto little has been reported on the dimensional stability and surface characteristics of 3D-printed PVDF composites after autoclaving for implant applications. In this study, the effect of autoclaving on surface characteristics (Shore-D hardness, surface roughness (Ra), morphological characteristics), and dimensional stability of 3D printed PVDF-hydroxyapatite (HAp)- chitosan (CS) composite has been reported for implant applications. The signal-to-noise (S/N) ratio approach was used to ascertain the best setting of process parameters for 3D printing by fused filament fabrication (FFF) process. This study suggests that the best setting for the FFF process, for the 3D printing of PVDF composite (90%PVDF-8%HAp-2%CS) are the nozzle temperature (NT) of 225°C, raster angle (RA) 0°, and printing speed (PS) 40 mm/s, resulting in Shore-D hardness 48.5 HD (before autoclaving) and 55.0 HD (after autoclaving), dimensional deviation 0.01 mm (after autoclaving). The results are supported by scanning electron microscopy (SEM) and Fourier transmission infrared (FTIR) spectroscopy analysis.