Journal articles on the topic 'Printing velocity'
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1
Edwards, D. A., M. E. Mackay, Z. R. Swain, C. R. Banbury, and D. D. Phan. "Maximal 3D printing extrusion rates." IMA Journal of Applied Mathematics 84, no. 5 (October 2019): 1022–43. http://dx.doi.org/10.1093/imamat/hxz024.
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Abstract Many applications of 3D printing are enhanced by increased printing speed. In the hot end of a 3D printer, the polymer feed stock flows in a heated cylinder at a set temperature. Since the polymer must be hot enough to reach a pliant state before extrusion, this establishes a maximum velocity beyond which the polymer is too rigid to be extruded. A mathematical model is presented for this system, and both amorphous and crystalline polymer systems are examined. The former is a heat transfer problem; the latter is a Stefan problem. Several different conditions for establishing the maximum velocity are considered; using the average polymer temperature in the hot end matches well with experimental data.
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Chen, Xinxing, Aidan P. O’Mahony, and Tracie Barber. "The assessment of average cell number inside in-flight 3D printed droplets in microvalve-based bioprinting." Journal of Applied Physics 131, no. 22 (June 14, 2022): 224701. http://dx.doi.org/10.1063/5.0096468.
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3D cell bioprinting is an innovative and time-saving additive manufacturing technology; it precisely generates complex cell-laden constructs to overcome the limitations of 2D cell culture and conventional tissue engineering scaffold technology. Many efforts have been made to evaluate the bioprinter performance by considering printed cell number and the consistency of printed cell number. In this paper, a modified droplet imaging system is used to study the printing performance for a micro-valve-based 3D bioprinter using fluorescence MCF-7 cells. The effects of droplet dispensing physics (dosing energy [Formula: see text]), ink properties (Z number—the inverse of the Ohnesorge number and particle sedimentation velocity), and input cell concentration are considered. The droplet imaging system demonstrates a strong capability and accuracy in analyzing bioprinting performance for printed cell density less than 300 cells/droplet. The average printed cell number is positively correlated with the increasing input cell concentration, dosing energy, and printing time. Printing ink, with Z number ranging from 4 to 7.41 and cell sedimentation velocity at [Formula: see text] m/s, can provide the estimated printed cell number and consistent cell printing results within 2 min printing time. Printing inks with higher Z number or cell sedimentation velocity should be ejected under dosing energy below 2.1 La and printed right after filling the reservoir to achieve reliable and stable printing results.
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Zhao, Xiaoyang, and Jin Huang. "Ink Droplet Position Compensation Based on Extended State Observer." International Journal of Automation Technology 5, no. 5 (September 5, 2011): 629–33. http://dx.doi.org/10.20965/ijat.2011.p0629.
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The parabolic droplet trajectory in inkjet printing causes errors between actual position and expected positioning, deteriorating printing quality in highspeed printing. To improve printing quality and increase printing speed, an accurate firing time estimation method is proposed to compensate the droplet position error. A speed estimator based on the extended state observer is designed to estimate carriage speed on-line, based on which, the exact firing time for droplet position compensation is calculated. Simulation result shows the effectiveness of carriage velocity estimation, and experimental results show that the printing quality is markedly improved.
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Zhao, Li, Zhaoliang Jiang, Cheng Zhang, and Wenping Liu. "Influence of 3D printing stress wave on residual stress." EPL (Europhysics Letters) 135, no. 6 (September 1, 2021): 64002. http://dx.doi.org/10.1209/0295-5075/135/64002.
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Abstract As a popular rapid manufacturing technology, three-dimensional printing (3D printing) has been widely adopted in medical, automotive, aerospace, construction and other industrial fields. The stereo lithography apparatus (SLA) is an effective 3D printing method for ceramic printing. However, shrinkage from monomer to polymer and laser stress wave cause residual stress in the formed parts during SLA. Serious quality defects including cracks, warpage and deformation caused by residual stress have remained to be a problem. Basically, the laser stress wave plays an important role in the generation of 3D printing residual stress. In this work, to investigate the propagation mechanism of the laser stress wave, the finite element method was adopted to simulate the SLA process of zirconia. The influence of 3D printing factors on the residual stress was obtained, and we found that the wave velocity of the stress wave obtained by the simulation model was highly consistent with the theoretical wave velocity. Meanwhile, the attenuation formula of the stress wave in the 3D printing process was obtained by fitting to investigate its attenuation law. Based on the above results, the attenuation law of the 3D printing stress wave has a direct influence on the development and variation trend of its residual stress.
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Hamad, Aamir, Adam Archacki, and Ahsan Mian. "Characteristics of nanosilver ink (UTDAg) microdroplets and lines on polyimide during inkjet printing at high stage velocity." Materials Advances 1, no. 1 (2020): 99–107. http://dx.doi.org/10.1039/d0ma00048e.
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Dvoryankin, O. A., and N. I. Baurova. "Application of 3D-printing technologies for production of master-model in engineering industry." Technology of Metals, no. 9 (September 2021): 17–21. http://dx.doi.org/10.31044/1684-2499-2021-0-9-17-21.
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Analysis of 3D-printing methods used in the molding production to manufacture master-models has been carried out. The technology was selected, which allowed one to make high-precision parts, combining the molding and the 3D-printing. Factors effecting on the quality of 3D-models printed by this technology were analyzed. Experimental studied for determination of the printing parameter influence (layer thickness, filling percentage, printing velocity) on ultimate strength of specimens made of ABS-plastic were carried out.
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Pittayachaval, Paphakorn, and Thanakharn Baothong. "An Effect of Screw Extrusion Parameters on a Pottery Model Formed by a Clay Printing Machine." Materials Science Forum 1046 (September 22, 2021): 29–38. http://dx.doi.org/10.4028/www.scientific.net/msf.1046.29.
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This paper presents a study of the screw extrusion parameters that affect on the appearance of clay filament for a clay printing machine. Traditionally, pottery models are formed by using paster mold or hand throwing, which require experienced and proficient workers to form the complex pottery models. Therefore, the clay printing machine has been developed to improve manual pottery fabrication to automatic construction. This machine has been modified based on the additive manufacturing (AM). To assess a capability material deposition of the clay printing machine, nozzle diameter, screw extruder velocity, and screw pitch were investigated as the printing parameters to evaluate a quality of clay filament. Analysis of variance (ANOVA) is used to analyze main effect parameters. The experimental results showed that the 6 mm nozzle diameter, 19 mm/s screw extruder velocity and 24 mm screw pitch were the suitable printing parameters for providing an appropriate appearance of clay filament. A mathematical model was formulated to propose the relationship between response and main effects with their interactions.
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Rastogi, Prasansha, Cornelis H. Venner, and Claas Willem Visser. "Deposition Offset of Printed Foam Strands in Direct Bubble Writing." Polymers 14, no. 14 (July 16, 2022): 2895. http://dx.doi.org/10.3390/polym14142895.
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Direct Bubble Writing is a recent technique to print shape-stable 3-dimensional foams from streams of liquid bubbles. These bubbles are ejected from a core-shell nozzle, deposited on the build platform placed at a distance of approximately 10 cm below the nozzle, and photo-polymerized in situ. The bubbles are ejected diagonally, with a vertical velocity component equal to the ejection velocity and a horizontal velocity component equal to the motion of the printhead. Owing to the horizontal velocity component, a discrepancy exists between the nozzle trajectory and the location of the printed strand. This discrepancy can be substantial, as for high printhead velocities (500 mm/s) an offset of 8 mm (in radius) was measured. Here, we model and measure the deviation in bubble deposition location as a function of printhead velocity. The model is experimentally validated by the printing of foam patterns including a straight line, a circle, and sharp corners. The deposition offset is compensated by tuning the print path, enabling the printing of a circular path to the design specifications and printing of sharp corners with improved accuracy. These results are an essential step towards the Direct Bubble Writing of 3-dimensional polymer foam parts with high dimensional accuracy.
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Xu, Lei, and Hui Ming Huang. "A Performance Evaluation of Printing RFID Tags." Advanced Materials Research 314-316 (August 2011): 1321–24. http://dx.doi.org/10.4028/www.scientific.net/amr.314-316.1321.
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Printing RFID tag is a potential substitute for etching RFID tag as it has advantages in metal waste and substrate selection due to its addictive process. An evaluation of printing tags is conducted on their performance and reliability. It is observed that low printing tag antenna resistance results from slow printing velocity, low printing pressure, high curing temperature as well as long curing time. Printing tags have an equidistant read range with etching tags in the case of low printing antenna resistance when chips are bound to printing tag antennae. Furthermore, printing tags are comparable to etching tags in the sensitivity to environmental temperature and humidity under alternative and constant temperature-humidity tests. It is also demonstrated a weaker ability for printing tags to withstand the mechanical stress than etching tags under the bend test. Experimental results show that printing tags have better performance when their antenna resistances are low.
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Li, Jie, Hong Bin Li, Jing Chuan Dong, Tai Yong Wang, and Hai Tao Zhang. "The Investigation of the Effect Caused by Deposition Velocity on Bonding Degree within the Structure of FDM." Key Engineering Materials 764 (February 2018): 142–55. http://dx.doi.org/10.4028/www.scientific.net/kem.764.142.
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In this paper, the effect of deposition velocity on bonding degree is studied in the aspects of experiment and theory. The experimental results show that the bonding quality of the adjacent filaments is weakened with increasing of deposition velocity. In addition, on the premise of guaranteeing every point in the building process to remain at the optimal temperature, the quantitative relationships between interval and filled area, deposition velocity are investigated by using the technique of deactivate and reactivate element of finite element. On the base of the quantitative relationships, the variable deposition velocity printing method is proposed for the first time. Namely, to reap the best bonding quality of filaments the time of completing one layer can be determined according to the filled area, and then, the optimal deposition velocity can be obtained according to the quantitative relationship between the interval and the deposition velocity. Printing the model at this speed can obtain the part with the best bonding quality between adjacent layers.
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Bian, Min, and Mei Yang. "Decoupling Control for Unwinding Tension Control Systems." Applied Mechanics and Materials 262 (December 2012): 367–71. http://dx.doi.org/10.4028/www.scientific.net/amm.262.367.
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During the printing process, invariable tension is very important to make sure the high printing quality. It’s well known that the relation of tension and tape velocity is strong-coupling based on the model of tension control, the modeling of tension possesses varies a lot in the control process, and various disturbances are inevitable during printing. All of these make the tension control systems unstable and affect the printing quality. This paper purposes a method to decrease the strong-coupling relation between speed and tension and control the speed-tension accurately. Based on the shaft-less printing press, the unwinding tension model and servo driver model are given. Decoupling controller is designed in this paper, and simulation results show that this method can improve the coupling degree and control performance.
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Brumm, Pauline, Hans Sauer, and Edgar Dörsam. "Scaling Behavior of Pattern Formation in the Flexographic Ink Splitting Process." Colloids and Interfaces 3, no. 1 (March 13, 2019): 37. http://dx.doi.org/10.3390/colloids3010037.
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We considered pattern formation, i.e. viscous fingering, in the ink splitting process between an elastic flexographic printing plate and the substrate. We observed an unexpected scaling behavior of the emerging pattern length scale (i.e., finger width) as a function of printing velocity, fluid viscosity, surface tension, and plate elasticity coefficients. Scaling exponents depended on the ratio of the capillary number of the fluid flow, and the elastocapillary number defined by plate elasticity and surface tension. The exponents significantly differed from rigid printing plates, which depend on the capillary number only. A dynamic model is proposed to predict the scaling exponents. The results indicate that flexo printing corresponded to a self-regulating dynamical equilibrium of viscous, capillary, and elastic forces. We argue that these forces stabilize the process conditions in a flexo printing unit over a wide range of printing velocities, ink viscosities, and mechanical process settings.
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Lei, Mingju, Qinghua Wei, Mingyang Li, Juan Zhang, Rongbin Yang, and Yanen Wang. "Numerical Simulation and Experimental Study the Effects of Process Parameters on Filament Morphology and Mechanical Properties of FDM 3D Printed PLA/GNPs Nanocomposite." Polymers 14, no. 15 (July 29, 2022): 3081. http://dx.doi.org/10.3390/polym14153081.
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The selection of optimal process parameters has a decisive effect on the quality of 3D printing. In this work, the numerical and experimental methods were employed to investigate the FDM printing deposition process of PLA/GNPs nanocomposite. The effect of process parameters on cross-sectional morphology and dimension of the deposited filament, as well as the mechanical property of the FDM printed specimens were studied. The extrusion and the deposition process of the molten PLA/GNPs nanocomposite was simulated as a fluid flow by the paradigm of CFD, the effects of printing temperature and shear rate on thermal-physical properties, such as viscosity and surface tension, were considered in models. Under the assumptions of non-Newtonian fluid and creep laminar flow, the deposition flow was controlled by two key parameters: the nozzle temperature and the nozzle velocity. The numerical model was verified by experiments from four aspects of thickness, width, area, and compactness of the deposited PLA/GNPs nanocomposite filament cross-section. Both the numerical simulation and experiment results show that with the increase of nozzle temperature and nozzle velocity, the thickness, area, and compactness of the deposited filament decreases. While the width of deposited filament increased with the increase of nozzle temperature and decrease of nozzle velocity. The decrease in thickness and the increase in width caused by the change of process parameters reached 10.5% and 24.7%, respectively. The tensile strength of the printed PLA/GNPs specimen was about 61.8 MPa under the higher nozzle temperatures and velocity condition, an improvement of 18.6% compared to specimen with the tensile strength of 52.1 MPa under the lower nozzle temperatures and velocity condition. In addition, the experimental results indicated that under the low nozzle velocity and nozzle temperature condition, dimensional standard deviation of the printed specimens decreased by 52.2%, 62.7%, and 68.3% in X, Y, and Z direction, respectively.
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Ng, Wei Long, Xi Huang, Viktor Shkolnikov, Guo Liang Goh, Ratima Suntornnond, and Wai Yee Yeong. "Controlling Droplet Impact Velocity and Droplet Volume: Key Factors to Achieving High Cell Viability in Sub-Nanoliter Droplet-based Bioprinting." International Journal of Bioprinting 8, no. 1 (October 28, 2021): 424. http://dx.doi.org/10.18063/ijb.v8i1.424.
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Three-dimensional (3D) bioprinting systems serve as advanced manufacturing platform for the precise deposition of cells and biomaterials at pre-defined positions. Among the various bioprinting techniques, the drop-on-demand jetting approach facilitates deposition of pico/nanoliter droplets of cells and materials for study of cell-cell and cell-matrix interactions. Despite advances in the bioprinting systems, there is a poor understanding of how the viability of primary human cells within sub-nanoliter droplets is affected during the printing process. In this work, a thermal inkjet system is utilized to dispense sub-nanoliter cell-laden droplets, and two key factors – droplet impact velocity and droplet volume – are identified to have significant effect on the viability and proliferation of printed cells. An increase in the cell concentration results in slower impact velocity, which leads to higher viability of the printed cells and improves the printing outcome by mitigating droplet splashing. Furthermore, a minimum droplet volume of 20 nL per spot helps to mitigate evaporation-induced cell damage and maintain high viability of the printed cells within a printing duration of 2 min. Hence, controlling the droplet impact velocity and droplet volume in sub-nanoliter bioprinting is critical for viability and proliferation of printed human primary cells.
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Kim, Yonghun, Kyung-Soo Kim, and Seok-Kyoon Kim. "Velocity-Sensorless Decentralized Tension Control for Roll-to-Roll Printing Machines." IEEE Access 8 (2020): 93682–91. http://dx.doi.org/10.1109/access.2020.2995126.
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Walter, K., and J. F. Devlin. "Application of 3D Printing to the Manufacturing of Groundwater Velocity Probes." Groundwater Monitoring & Remediation 37, no. 2 (March 8, 2017): 71–77. http://dx.doi.org/10.1111/gwmr.12210.
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Wang, Jie, and George T. C. Chiu. "Control of Drop Volume and Drop Jetting Velocity in Inkjet Printing." IFAC-PapersOnLine 55, no. 27 (2022): 37–43. http://dx.doi.org/10.1016/j.ifacol.2022.10.485.
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Gómez-Blanco, Juan C., Victor Galván-Chacón, David Patrocinio, Manuel Matamoros, Álvaro J. Sánchez-Ortega, Alfonso C. Marcos, María Duarte-León, Federica Marinaro, José B. Pagador, and Francisco M. Sánchez-Margallo. "Improving Cell Viability and Velocity in μ-Extrusion Bioprinting with a Novel Pre-Incubator Bioprinter and a Standard FDM 3D Printing Nozzle." Materials 14, no. 11 (June 5, 2021): 3100. http://dx.doi.org/10.3390/ma14113100.
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Bioprinting is a promising emerging technology. It has been widely studied by the scientific community for the possibility to create transplantable artificial tissues, with minimal risk to the patient. Although the biomaterials and cells to be used are being carefully studied, there is still a long way to go before a bioprinter can easily and quickly produce printings without harmful effects on the cells. In this sense, we have developed a new μ-extrusion bioprinter formed by an Atom Proton 3D printer, an atmospheric enclosure and a new extrusion-head capable to increment usual printing velocity. Hence, this work has two main objectives. First, to experimentally study the accuracy and precision. Secondly, to study the influence of flow rates on cellular viability using this novel μ-extrusion bioprinter in combination with a standard FDM 3D printing nozzle. Our results show an X, Y and Z axis movement accuracy under 17 μm with a precision around 12 μm while the extruder values are under 5 and 7 μm, respectively. Additionally, the cell viability obtained from different volumetric flow tests varies from 70 to 90%. So, the proposed bioprinter and nozzle can control the atmospheric conditions and increase the volumetric flow speeding up the bioprinting process without compromising the cell viability.
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Baeza-Campuzano, Alberto, Javier Morales-Castillo, and Víctor M. Castaño. "The influence of the gap diameter on the polymer thread temperature and velocity at the exit of the 3D printer nozzle." Polimery 67, no. 7-8 (September 8, 2022): 337–45. http://dx.doi.org/10.14314/polimery.2022.7.6.
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Using the example of acrylonitrile-butadiene-styrene (ABS) copolymer, the effect of the gap (thread) diameter for five printing velocity at 230°C on the thread temperature and velocity at the nozzle exit was investigated using the ANSYS Fluent simulation program. It was shown that the change of the gap diameter had a significant impact on the tested parameters.
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Yang, Yong Gang, and Fu Ping Liu. "Study on the Relationships between Offset Ink Tack Value and its Viscosity, the Separation Velocity." Advanced Materials Research 332-334 (September 2011): 1704–8. http://dx.doi.org/10.4028/www.scientific.net/amr.332-334.1704.
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In order to find out the variation law of ink stickiness during the printing, the ink tack value under 9 different linear velocities of ink distributing roller was tested, and the relation equations between tack value and the roller linear velocity were built up. At the same time, the plastic viscosities of 8 offset inks and their tack values under 9 separation velocities were also tested. The study results showed that the higher the linear speed was, the larger the tack value was, and it would stay in a relatively high tack value (regarded as infinite tack value). Also, the printing ink having high viscosity may possess low tack value.
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Wang, Dier, and Jun Zhang. "Two improved scanning path planning algorithms and a 3D printing control system with circular motion controller." Rapid Prototyping Journal 28, no. 4 (December 28, 2021): 695–703. http://dx.doi.org/10.1108/rpj-08-2020-0190.
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Purpose This paper aims to improve the infilling efficiency and the quality of parts forming. It proposes two improved scanning path planning algorithm based on velocity orthogonal decomposition. Design/methodology/approach The algorithms this paper proposes replace empty paths and corners with circular segments, driving each axis synchronously according to the SIN or COS velocity curve to make the extruder always moves at a constant speed at maximum during the infilling process. Also, to support the improved algorithms, a three-dimensional (3D) printing control system based on circular motion controller is also designed. Findings The simulation and experiment results show that the improved algorithms are effective, and the printing time is shortened more significantly, especially in the case of small or complex models. What’s more, the optimized algorithm is not only compact in shape but also not obvious in edge warping. Research limitations/implications The algorithms in this paper are not applicable to traditional motion controllers. Practical implications The algorithms in this paper improve the infilling efficiency and the quality of parts forming. Social implications There are no social implications in this paper. Originality/value The specific optimization method of parallel-line scanning algorithm based on velocity orthogonal decomposition is replacing the empty paths with arc corners. And the specific optimization method of contour offsetting algorithm based on velocity orthogonal decomposition is to add connection paths between adjacent contours and turn all straight corners into arcs. What’s more, the 3D printing control system based on the circular motion controller can achieve multi-axis parallel motion to support these two improved path scanning algorithms.
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LIU, LIN, XUJIE LU, and JIHUA CHEN. "DYNAMIC MEMBRANE TECHNOLOGY FOR PRINTING WASTEWATER REUSE." International Journal of Modern Physics B 23, no. 06n07 (March 20, 2009): 1943–48. http://dx.doi.org/10.1142/s0217979209061871.
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As environmental regulations become rigid and the cost of freshwater increases, wastewater is considered as a major resource in China. The paper presented a study on the implementation of the advanced treatment process using dynamic membrane (DM) in reusing of printing wastewater. The DM was well formed by circulating 1.5g/L of PAC in 20 minutes, the trans-membrane pressure of 200 kPa and the cross-flow velocity of 0.75m/s. The printing effluents were treated in effluent treatment plants comprising a physicochemical option followed by biological process. The treated effluent contained chemical oxygen demand (COD), color and turbidity in the range of 45-60 mg/L, 0.030-0.045 (absorbance at 420 nm) and 3-5 NTU. The results showed that the COD, color and turbidity removal efficiencies of the DM permeate were 84%, 85% and 80%, respectively. The wastewater treated by DM was reused as process water and the final concentrated retentate could be discharged directly into sewage treatment works with no additional treatments. Cleaning and regeneration of DM were very convenient if necessary. The proper process was that the polluted DM was cleaned with tap water at high cross-flow velocity. When irreversible pollutants accumulate, it would be rinsed with chemicals tested and the membrane flux would be restored up to 95%. The result showed that DM was considered as a promising method for purification aimed at reuse of printing wastewater, resulting in direct environmental and economic benefits.
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Guo, Wenjing, Jiyong Hu, and Xiong Yan. "Influence of process parameters on the characteristics of electrohydrodynamic-printed UV-curing conductive lines on the fabric." Journal of Micromechanics and Microengineering 32, no. 3 (February 4, 2022): 035003. http://dx.doi.org/10.1088/1361-6439/ac4825.
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Abstract As a similar technology to the near-field static electrospinning, the emerging electrohydrodynamic (EHD) printing technology with digital printing process and compatibility of viscous particle-blended inks is one of the simplest methods of fabricating multifunctional electronic textiles. With increasing demands for textile-based conductive lines with controllable width and excellent electrical performance, it is of great importance to know the influence of key process parameters on the morphology and electrical properties of EHD-printed UV-curing conductive lines on the fabric. This work will systematically explore the effect of the EHD printing process parameters (i.e. applied voltage, direct-writing height, flow rate and moving velocity of the substrate) on the morphology and electrical performance of the EHD-printed textile-based conductive lines, especially focus on the diffusion and penetration of inks on the rough and porous fabric. The UV-curing nano-silver ink with low temperature and fast curing features was selected, and the line width and electrical resistance of printed lines under different process parameters were observed and measured. The results showed that, unlike previous results about EHD printing on smooth and impermeable substrates, the ink diffusion related to fabric textures had a greater effect on the fabric-based conductive line width than the applied voltage and direct-writing height in the case of a stable jet. Meanwhile, the relationship between the line width and the flow rate met the equation of d = 407.28 × Q 1 2 , and the minimum volume on fabric per millimeter was 0.67 μl to form continuous line with low electrical resistance. Additionally, the higher substrate moving velocity resulted in a smaller line width, while it deteriorated the thickness uniformity and electrical property of printed lines. Generally, due to the effect of surface structure of the fabric on the spreading and penetrating behavior of inks, the flow rate and the substrate moving velocity are two significant parameters ensuring the electrical property of printed lines. It is believed that these findings will provide some guides for applying EHD printing technology into flexible electronics on the woven fabric.
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Liu, Zhen, Pande Zhang, Ming Yan, Xin Ren, Yimin Xie, and Guozhi Huang. "The Application Study of Specific Ankle-Foot Orthoses for Stroke Patients by 3D Printing Somos NeXt." Journal of Biomaterials and Tissue Engineering 9, no. 6 (June 1, 2019): 745–50. http://dx.doi.org/10.1166/jbt.2019.2052.
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Objective: To investigate the effects of specific ankle-foot orthoses (AFOs) fabricated by 3D printing Somos NeXt on patients with stroke. Method: The ankle and foot were scanned by Artec 3D scanner. The model was performed with finite element analysis (FEA) using the software Abaqus to optimize the structure. Based on the structural optimization, AFOs were fabricated by 3D printing technique of Somos NeXt. Gait parameters were measured using the Gait Watch system. Seven sensors were bound to the sacrum, anterior side in the middle segment of the bilateral femoral femur, the median side at the proximal end of the bilateral tibia, and dorsal part of the bilateral foot. Results: The AFOs fabricated by 3D printing Somos NeXt significantly improved the temporalspatial parameters including velocity (20.75 vs. 17.38 cm/s) and stride length (47.88 vs. 43.63 cm), as well as increased cadence (52.5 vs. 48.75 times/min), while slightly decreased gait cycle (2.57 vs. 2.80 cm) and double limb support phase (34.00 vs. 37.13%). The AFOs also improved symmetry parameters such as the step length difference (9.75 vs. 15.25 cm), step length ratio (1.87 vs. 3.98), and swing phase ratio (0.99 vs. 0.75). Conclusion: The AFOs fabricated by 3D printing Somos NeXt have a significant effect on the improvement of velocity and stride length in patients with stroke.
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Jalaal, Maziyar, Martin Klein Schaarsberg, Claas-Willem Visser, and Detlef Lohse. "Laser-induced forward transfer of viscoplastic fluids." Journal of Fluid Mechanics 880 (October 9, 2019): 497–513. http://dx.doi.org/10.1017/jfm.2019.731.
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Laser-induced forward transfer (LIFT) is a nozzle-free printing technology that can be used for two- and three-dimensional printing. In LIFT, a laser pulse creates an impulse inside a thin film of material that results in the formation of a liquid jet. We experimentally study LIFT of viscoplastic materials by visualizing the process of jetting with high-speed imaging. The shape of the jet depends on the laser energy, focal height, surface tension and material rheology. We theoretically identify the characteristic jetting velocity and how it depends on the control parameters, and define non-dimensional groups to classify the regimes of jetting. Based on the results, we propose the optimal conditions for printing with LIFT technology.
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Zheng, Xin, and Yan Fei Gao. "Analysis and Structure Optimization of the Wind Distribution of Nozzle in the Gravure Printing Drying System." Applied Mechanics and Materials 731 (January 2015): 411–15. http://dx.doi.org/10.4028/www.scientific.net/amm.731.411.
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The drying system plays an important role in printing speed and energy consumption of gravure printing machine. Nozzle is a factor which decides heated air distribution in drying system finally. This research makes a model for the structure of nozzle and takes a numerical simulation analysis of heated air field with hydrodynamic theory. The defect of structure is found through the distribution of velocity, temperature and trajectories. A crosswind landing area is added around outlet area of nozzle. In this study, it is evaluated that the distribution of the wind field. It is found that the velocity and pressure of heated air in the vortex area between substrate and nozzle by the cross-wind board can be improved from the simulation results. The study has significance on optimizing the structure of nozzle and improving efficiency of drying system.
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Liang, Yan Mei, Chang Xian Cheng, and Zhao Xia Wang. "Study of Cyclical Fluctuation during the Paper Transmission of Inkjet Printing System." Applied Mechanics and Materials 312 (February 2013): 450–54. http://dx.doi.org/10.4028/www.scientific.net/amm.312.450.
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With the gradually maturing super-speed inkjet printing technology, people are pursuing steadier and higher speed as well as better quality presswork for the sake of increasing economic benefit. To provide an overview of the velocity fluctuation of the inkjet machine platform and the cyclical fluctuation of the incremental encoder, external clock and corresponding internal clock were applied separately to print the equally spaced lines under the same platform speed. Then a magnifier was used to measure distance between the lines, according to which the velocity fluctuation mentioned above can be obtained. Thus conclusion can be drawn from the fluctuation analysis that the velocity cycle of platform is 60mm, however, number of those produced by the incremental encoder is up to 3, including 60mm influenced by the platform, 300mm produced by the perimeter of encoders pressure wheel and 600mm produced by the circumference of dance roller. Furthermore, dance roller contributes more influence on narrow coated paper. Through this research, inkjet technician can do directional compensation for every factors to reduce the fluctuation.
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Fakhari, Ahmad, Célio Fernandes, and Francisco José Galindo-Rosales. "Mapping the Volume Transfer of Graphene-Based Inks with the Gravure Printing Process: Influence of Rheology and Printing Parameters." Materials 15, no. 7 (March 31, 2022): 2580. http://dx.doi.org/10.3390/ma15072580.
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It is a common practice to add rheology modifiers to functional inks, such as graphene inks, to optimize the rheological properties so that they can be printed with a certain printing technique. This practice may lead to inks formulations with poorer electrical, optical, and mechanical performance upon its application, which are of paramount importance in printed electronics. In this study, we demonstrate for three different commercial graphene-based inks that it is possible to control the amount of ink transferred to the flat surface by tweaking printing parameters, such as the velocity and the length scale of the gravure cell, without modifying the rheology of the ink. Finally, the results are summarized in printing maps based on dimensionless numbers, namely, the capillary and Reynolds numbers.
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Jiang, Ling, Mengjie Wu, Qiuping Yu, Yuxia Shan, and Yuyan Zhang. "Investigations on the Adhesive Contact Behaviors between a Viscoelastic Stamp and a Transferred Element in Microtransfer Printing." Coatings 11, no. 10 (September 30, 2021): 1201. http://dx.doi.org/10.3390/coatings11101201.
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Microtransfer printing is a sophisticated technique for the heterogeneous integration of separately fabricated micro/nano-elements into functional systems by virtue of an elastomeric stamp. One important factor influencing the capability of this technique depends on the adhesion between the viscoelastic stamp and the transferred element. To provide theoretical guidance for the control of adhesion in the transfer printing process, a finite element model for the viscoelastic adhesive contact between a polydimethylsiloxane (PDMS) stamp and a spherical transferred element was established, in which the adhesive interaction was modeled by the Lennard-Jones surface force law. Effects of the unloading velocity, preload, and thermodynamic work of adhesion on the adhesion strength, characterized by the pull-off force, were examined for a loading-dwelling-unloading history. Simulation results showed that the unloading path deviated from the loading path due to the viscoelastic property of the PDMS stamp. The pull-off force increased with the unloading velocity, and the increasing ratio was large at first and then became low. Furthermore, the influence of the preload on increasing the pull-off force was more significant under larger unloading velocity than that under smaller unloading velocity. In addition, the pull-off force increased remarkably with the thermodynamic work of adhesion at a fixed maximum approach.
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Elistratkin, Mikhail, Nataliya Alfimova, Daniil Podgornyi, Andrey Olisov, Vladimir Promakhov, and Natalia Kozhukhova. "Influence of Equipment Operation Parameters on the Characteristics of a Track Produced with Construction 3D Printing." Buildings 12, no. 5 (May 3, 2022): 593. http://dx.doi.org/10.3390/buildings12050593.
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Additive technologies are widely used in various industries. However, nowadays, the large-scale implementation of these technologies in the construction industry is difficult, due to a lot of open practical and scientific questions in terms of both building mixtures and 3D printing equipment. When performing studies focused on the development of cost-effective mixtures based on readily available raw materials for building extrusion 3D printing, it was found that the final result was determined by the rheology of the building mixture, the speed of the screw, and other factors. The article studied the combined effect on the extrusion of the building mixture and the parameters of the printed track of such factors as the thickness of the layer, the linear printhead traversed velocity of the forming device, and the speed of rotation of the screw. We aimed to establish relationships between the above factors, providing an increase in the stability of the printing process and the quality of the resulting structure. To carry out the research, an experimental program and original methods were developed, involving printing in different regimes using a laboratory construction 3D printer. Based on the regression analysis of the data obtained, it was found that the process of 3D printing by extrusion methods cannot be described by a linear function. It was found that a change in the linear speed of the nozzle movement can increase the yield of the mixture, and also lead to track stretching and the degradation of some parameters. The boundary value, in this case, is the layer thickness of 0.77–0.8 of the nozzle width. The response of the system to changes in the linear printhead traversed velocity and the frequency of rotation of the screw occurs in different ways. A change in the linear printhead traversed velocity at the optimal height of the layer has a slight effect on its width. Reducing the speed of rotation of the screw leads to a decrease in the overall dynamics of the mixture flow and an increase in its viscosity due to its thixotropic nature. When the previous speed of rotation of the mixture is restored, the dynamics of the flow are restored with a noticeable delay. In general, this is recommended to ensure the highest dynamics of the printing process. For the laboratory construction 3D printer and the building mixture used in the article, the regime with the following parameters was recommended: a linear printhead traversed velocity of 900 mm/min; an extruder frequency of 25 rpm; and a relative layer thickness of 0.8 (of the nozzle width). This regime provides the optimal ratio of performance/quality and the stability of track parameters.
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Cao, Le, and A. Ni Wang. "Analysis on Gravure Hot-Air Drying Parameters Based on Matlab." Applied Mechanics and Materials 416-417 (September 2013): 1363–67. http://dx.doi.org/10.4028/www.scientific.net/amm.416-417.1363.
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This paper illustrated the importance of determining reasonable gravure hot-air drying parameters. On the basis of residual solvent detection via gas chromatographic method, the effect of hot-air velocity, hot-air temperature and primal solvent content on residual solvent was analyzed. According to polynomial regression analysis, curve fitting was conducted, and mathematical model of various parameters, average drying velocity and unit energy consumption was constructed to optimize printing dryer and guide practical production.
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Baeza-Campuzano, Alberto, and Victor M. Castaño. "The effect of printing velocity on the temperature and viscosity of the polymer thread at the nozzle exit in 3D printers." Polimery 66, no. 2 (February 17, 2021): 127–38. http://dx.doi.org/10.14314/polimery.2021.2.6.
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Fused Deposition Modelling (FDM) is a powerful method for advanced additive manufacturing of polymeric materials, due to its simplicity and low cost. However, the process implies complex phenomena which are not fully understood yet. In particular, the effect of viscosity on the printed thread is a key parameter to control if good quality products are to be obtained. Experimental data of two grades of acrylonitrile-butadiene- styrene copolymer (ABS) was employed to analyse, by using ANSYS Fluent simulation package, six printing velocities at a temperature of 230°C. A drastic temperature change was observed as the printing velocity increases, confirming the effect of viscosity on the shear created on the wall of the nozzle transversal to the printing bed. The polymers analysed present different viscosity behavior even under the same angular frequency range (0.1 to 100 rad/s), and testing temperature (230°C), which could lead to inhomogeneities. Our results allow taking into account these parameters as part of the design criteria.
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Yelamanchi, Bharat, Eric MacDonald, Nancy G. Gonzalez-Canche, Jose G. Carrillo, and Pedro Cortes. "The Mechanical Properties of Fiber Metal Laminates Based on 3D Printed Composites." Materials 13, no. 22 (November 21, 2020): 5264. http://dx.doi.org/10.3390/ma13225264.
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The production and mechanical properties of fiber metal laminates (FMLs) based on 3D printed composites have been investigated in this study. FMLs are structures constituting an alternating arrangement of metal and composite materials that are used in the aerospace sector due to their unique mechanical performance. 3D printing technology in FMLs could allow the production of structures with customized configuration and performance. A series of continuous carbon fiber reinforced composites were printed on a Markforged system and placed between layers of aluminum alloy to manufacture a novel breed of FMLs in this study. These laminates were subjected to tensile, low velocity and high velocity impact tests. The results show that the tensile strength of the FMLs falls between the strength of their constituent materials, while the low and high velocity impact performance of the FMLs is superior to those observed for the plain aluminum and the composite material. This mechanism is related to the energy absorption process displayed by the plastic deformation, and interfacial delamination within the laminates. The present work expects to provide an initial research platform for considering 3D printing in the manufacturing process of hybrid laminates.
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Guan, Xiaomin, Jiefang Xing, Hongjuan Zhu, and Wanjun Zhu. "Numerical simulation of the water-based ink transfer process in roll-to-roll gravure printing based on fluid–solid interactions." AIP Advances 12, no. 7 (July 1, 2022): 075015. http://dx.doi.org/10.1063/5.0092123.
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The roll-to-roll gravure printing ink transfer process plays an important role in enhancing printing quality and saving on costs. The static analysis and fluid–solid interaction method are used for the first time to conduct a systematic study on the coupling between the fluid flow state and the solid deformation in the whole process of roll-to-roll gravure printing. The static compression stage, the initial moment of ink transfer, and the process of ink passing through the gap between two rollers and the separation of the ink layer with the rotation of two rollers are considered. The effect of ink layer thickness on the ink transfer process is studied. At a printing pressure of 0.2 MPa and a printing velocity of 200 rpm, the ink thickness has a great influence on the ink flow state, which leads to backflow; the phenomenon causes irregularities in the effective ink transfer ratio. The critical ink layer thickness is 70 µm under the above gravure printing conditions. This should not be exceeded to ensure the stability of ink transfer. Under the above printing conditions, when the ink layer thickness is in the range of 30–50 µm, there is no ink backflow phenomenon and the width of the ink flow channel is relatively large, and the effective ink ratio is almost stable at 50%. This study is helpful for controlling the ink quantity in the gravure printing, providing strong theoretical support for the improvement of the gravure printing process, and promoting the application of the water-based ink.
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Chu, Hong Yan, Xiao Lin Zhang, Lei Su, Rui Qing Shen, and Li Gang Cai. "Research of Transferring Characteristics of Ink among Rollers." Applied Mechanics and Materials 532 (February 2014): 427–34. http://dx.doi.org/10.4028/www.scientific.net/amm.532.427.
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In order to improve the printing quality and know the process of ink transferring well, ink flowing among ink rollers is simulated by using CFX. Firstly ink transferring characteristics between two rollers are analyzed. An experiment is carried out to test the accuracy of this simulation analysis. Then ink transferring characteristics among three and five rollers are analyzed respectively. The general characteristics of ink transferring among rollers are got by comparing the velocity of ink flowing, ink pressure and ink transfer ratio from those simulations. What is more, the accuracy of the simulation analysis is verified by experiment. And this research provides a reference to general characteristics of ink transferring in the actual printing process, and its important for the printing color quality control and has a better application prospect.
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Travieso-Rodriguez, J. Antonio, Ramon Jerez-Mesa, Jordi Llumà, Oriol Traver-Ramos, Giovanni Gomez-Gras, and Joan Josep Roa Rovira. "Mechanical Properties of 3D-Printing Polylactic Acid Parts subjected to Bending Stress and Fatigue Testing." Materials 12, no. 23 (November 22, 2019): 3859. http://dx.doi.org/10.3390/ma12233859.
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This paper aims to analyse the mechanical properties response of polylactic acid (PLA) parts manufactured through fused filament fabrication. The influence of six manufacturing factors (layer height, filament width, fill density, layer orientation, printing velocity, and infill pattern) on the flexural resistance of PLA specimens is studied through an L27 Taguchi experimental array. Different geometries were tested on a four-point bending machine and on a rotating bending machine. From the first experimental phase, an optimal set of parameters deriving in the highest flexural resistance was determined. The results show that layer orientation is the most influential parameter, followed by layer height, filament width, and printing velocity, whereas the fill density and infill pattern show no significant influence. Finally, the fatigue fracture behaviour is evaluated and compared with that of previous studies’ results, in order to present a comprehensive study of the mechanical properties of the material under different kind of solicitations.
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Park, Sung Jun, Shang Hoon Seo, and Jae Woo Joung. "Fine Micro Patterning of Conductive Line by Using Direct Inkjet Printing." Key Engineering Materials 326-328 (December 2006): 257–60. http://dx.doi.org/10.4028/www.scientific.net/kem.326-328.257.
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A novel selective metallization process to fabricate the fine conductive line based on drop-on-demand (DoD) inkjet printing was studied. Direct inkjet printing is an alternative and costeffective technology for patterning and fabricating objects directly from design or image files without making masks and patterns. The conductive ink used in this experiment consists of 1 to 50 nm silver particles that are homogeneously suspended in an organic carrier. A piezo-electric inkjet print head driven by a bipolar voltage signal is used to dispense 20-40μm diameter droplets. Repeatability of circuitry fabrication is closely related to the formation of steady, satellite-free droplets. Therefore, the ability to form small and stable droplets with a same size, constant velocity and the correct flight angle must be taken into consideration for fine and precise conductive lines. In this study, parameters affecting the pattern formation such as drop formation, drop placement accuracy and velocity deviation between each nozzle have been investigated. As a result, direct inkjet patterning systems equipped with several functioning modules and fine metallic patterns have been developed.
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Yang, Yong Gang. "Research on the Tack Value of Offset Printing Ink." Advanced Materials Research 314-316 (August 2011): 1401–5. http://dx.doi.org/10.4028/www.scientific.net/amr.314-316.1401.
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In order to find out the variation law of ink stickiness during the printing, the ink tack value under 9 different linear velocities of ink distributing roller was tested, and the relation equations between tack value and the roller linear velocity were built up. At the same time, the plastic viscosities of 8 offset inks and their tack values under 9 separation velocities were also tested. The study results showed that the higher the linear speed was, the larger the tack value was, and it would stay in a relatively high tack value (regarded as infinite tack value). Also, the printing ink having high viscosity may possess low tack value.
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Xu, Heqi, Dulce Maria Martinez Salazar, and Changxue Xu. "Investigation of Cell Concentration Change and Cell Aggregation Due to Cell Sedimentation during Inkjet-Based Bioprinting of Cell-Laden Bioink." Machines 10, no. 5 (April 28, 2022): 315. http://dx.doi.org/10.3390/machines10050315.
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Recently, even though 3D bioprinting has made it possible to fabricate 3D artificial tissues/organs, it still faces several significant challenges such as cell sedimentation and aggregation. As the essential element of 3D bioprinting, bioink is usually composed of biological materials and living cells. Guided by the initially dominant gravitational force, cells sediment, resulting in the non-uniformity of the bioink and the decrease in the printing reliability. This study primarily focuses on the quantification of cell sedimentation-induced cell concentration change and cell aggregation within the bioink reservoir during inkjet-based bioprinting. The major conclusions are summarized as follows: (1) with 0.5% (w/v) sodium alginate, after around 40-min printing time, almost all the cells have sedimented from the top region. The cell concentration at the bottom is measured to be more than doubled after 60-min printing time. On the contrary, due to the slow cell sedimentation velocity with 1.5% and 3% (w/v) sodium alginate, the uniformity of the bioink is still highly maintained after 60-min printing; and (2) more cell aggregates are observed at the bottom with the printing time, and severe cell aggregation phenomenon has been observed at the bottom using 0.5% (w/v) sodium alginate starting from 40-min printing time. With the highest cell concentration 2 × 106 cells/mL, 60.9% of the cells have formed cell aggregates at 40-min printing time. However, cell aggregation is dramatically suppressed by increasing the polymer concentration.
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Kryou, Christina, Ioannis Theodorakos, Panagiotis Karakaidos, Apostolos Klinakis, Antonios Hatziapostolou, and Ioanna Zergioti. "Parametric Study of Jet/Droplet Formation Process during LIFT Printing of Living Cell-Laden Bioink." Micromachines 12, no. 11 (November 16, 2021): 1408. http://dx.doi.org/10.3390/mi12111408.
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Bioprinting offers great potential for the fabrication of three-dimensional living tissues by the precise layer-by-layer printing of biological materials, including living cells and cell-laden hydrogels. The laser-induced forward transfer (LIFT) of cell-laden bioinks is one of the most promising laser-printing technologies enabling biofabrication. However, for it to be a viable bioprinting technology, bioink printability must be carefully examined. In this study, we used a time-resolved imaging system to study the cell-laden bioink droplet formation process in terms of the droplet size, velocity, and traveling distance. For this purpose, the bioinks were prepared using breast cancer cells with different cell concentrations to evaluate the effect of the cell concentration on the droplet formation process and the survival of the cells after printing. These bioinks were compared with cell-free bioinks under the same printing conditions to understand the effect of the particle physical properties on the droplet formation procedure. The morphology of the printed droplets indicated that it is possible to print uniform droplets for a wide range of cell concentrations. Overall, it is concluded that the laser fluence and the distance of the donor–receiver substrates play an important role in the printing impingement type; consequently, a careful adjustment of these parameters can lead to high-quality printing.
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Pan, Yanqiao, and Liangcai Zeng. "Simulation and Validation of Droplet Generation Process for Revealing Three Design Constraints in Electrohydrodynamic Jet Printing." Micromachines 10, no. 2 (January 29, 2019): 94. http://dx.doi.org/10.3390/mi10020094.
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Droplet generation process can directly affect process regulation and output performance of electrohydrodynamic jet (E-jet) printing in fabricating micro-to-nano scale functional structures. This paper proposes a numerical simulation model for whole process of droplet generation of E-jet printing based on the Taylor-Melcher leaky-dielectric model. The whole process of droplet generation is successfully simulated in one whole cycle, including Taylor cone generation, jet onset, jet break, and jet retraction. The feasibility and accuracy of the numerical simulation model is validated by a 30G stainless nozzle with inner diameter ~160 μm by E-jet printing experiments. Comparing numerical simulations and experimental results, period, velocity magnitude, four steps in an injection cycle, and shape of jet in each step are in good agreement. Further simulations are performed to reveal three design constraints against applied voltage, flow rate, and nozzle diameter, respectively. The established cone-jet numerical simulation model paves the way to investigate influences of process parameters and guide design of printheads for E-jet printing system with high performance in the future.
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Cheng, Yih-Lin, and Tzu-Wei Tseng. "Study on driving waveform design process for multi-nozzle piezoelectric printhead in material-jetting 3D printing." Rapid Prototyping Journal 27, no. 6 (June 17, 2021): 1172–80. http://dx.doi.org/10.1108/rpj-05-2019-0120.
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Purpose Material-jetting (MJ) three-dimensional (3D) printing processes are competitive due to their printing resolution and printing speed. Driving waveform design of piezoelectric printhead in MJ would affect droplet formation and performance, but there are very limited studies on it besides patents and know-hows by commercial manufacturers. Therefore, in this research, the waveform design process to efficiently attain suitable parameters for a multi-nozzle piezoelectric printhead was studied. Therefore, this research aims to study the waveform design process to efficiently attain suitable parameters for a multi-nozzle piezoelectric printhead. Design/methodology/approach Ricoh’s Gen4L printhead was adopted. A high-speed camera captured pictures of jetted droplets and droplet velocity was calculated. The waveforms included single-, double- and triple-pulse trapezoidal patterns. The effects of parameters were investigated and the suitable ones were determined based on the avoidance of satellite drops and preference of higher droplet velocity. Findings In a single-pulse waveform, an increase of fill time (Tf) decreased the droplet velocity. The maximum velocity happened at the same pulse width, the sum of fill time and hold time (Tf + Th). In double- and triple-pulse, a voltage difference (Vd) above zero in the holding stage was adopted except the last pulse to avoid satellite drops. Suitable parameters for the selected resin were obtained and the time-saving design process was established. Research limitations/implications Based on the effects of parameters and observed data trends, suggested procedures to determine suitable parameters were proposed with fewer experiments. Practical implications This study has verified the feasibility of suggested design procedures on another resin. The required number of trials was reduced significantly. Originality/value This research investigated the process of driving waveform design for the multi-nozzle piezoelectric printhead. The suggested procedures of finding suitable waveform parameters can reduce experimental trials and will be applicable to other MJ 3D printers when new materials are introduced.
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Huang, Long, Robert R. Stewart, Nikolay Dyaur, and Jose Baez-Franceschi. "3D-printed rock models: Elastic properties and the effects of penny-shaped inclusions with fluid substitution." GEOPHYSICS 81, no. 6 (November 2016): D669—D677. http://dx.doi.org/10.1190/geo2015-0655.1.
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3D printing techniques (additive manufacturing) using different materials and structures provide opportunities to understand porous or fractured materials and fluid effects on their elastic properties. We used a 3D printer (Stratasys Dimension SST 768) to print one “solid” cube model and another with penny-shaped inclusions. The 3D printing process builds materials, layer by layer, producing a slight “bedding” plane, somewhat similar to a sedimentary process. We used ultrasonic transducers (500 kHz) to measure the P- and S-wave velocities. The input printing material was thermoplastic with a density of [Formula: see text], P-wave velocity of [Formula: see text], and S-wave velocity of [Formula: see text]. The solid cube had a porosity of approximately 6% and a density of [Formula: see text]. Its P-wave velocity was [Formula: see text] in the bedding direction and [Formula: see text] normal to bedding. We observed S-wave splitting with fast and slow velocities of 879 and [Formula: see text], respectively. Quality factors for P- and S-waves were estimated using the spectral-ratio method with [Formula: see text] ranging from 15 to 17 and [Formula: see text] from 24 to 27. By introducing penny-shaped inclusions along the bedding direction in a 3D printed cube, we created a more porous volume with density of [Formula: see text] and porosity of 24%. The inclusions significantly decreased the P-wave velocity to 1706 and [Formula: see text] parallel and normal to the bedding plane. The fast and slow S-wave velocities also decreased to 812 and [Formula: see text]. A fluid substitution experiment, performed with water, increased (20%–46%) P-wave velocities and decreased (9%–10%) S-wave velocities. Theoretical predictions using Schoenberg’s linear-slip theory and Hudson’s penny-shaped theory were calculated, and we found that both theories matched the measurements closely (within 5%). The 3D printed material has interesting and definable properties and is an exciting new material for understanding wave propagation, rock properties, and fluid effects.
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Verbeeten, Wilco M. H., Rob J. Arnold-Bik, and Miriam Lorenzo-Bañuelos. "Print Velocity Effects on Strain-Rate Sensitivity of Acrylonitrile-Butadiene-Styrene Using Material Extrusion Additive Manufacturing." Polymers 13, no. 1 (January 1, 2021): 149. http://dx.doi.org/10.3390/polym13010149.
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The strain-rate sensitivity of the yield stress for Acrylonitrile-Butadiene-Styrene (ABS) tensile samples processed via material extrusion additive manufacturing (ME-AM) was investigated. Such specimens show molecular orientation and interstitial voids that affect the mechanical properties. Apparent densities were measured to compensate for the interstitial voids. Three different printing speeds were used to generate ME-AM tensile test samples with different molecular orientation. Printing velocities influenced molecular orientation and stretch, as determined from thermal shrinkage measurements. Likewise, infill velocity affected the strain-rate dependence of the yield stress. The ABS material manifests thermorheollogically simple behavior that can correctly be described by an Eyring flow rule. The changing activation volume, as a result of a varying print velocity, scales linearly with the molecular orientation, as captured in an estimated processing-induced pre-strain. Therefore, it is suggested that ME-AM processed ABS shows a deformation-dependent activation volume. This paper can be seen as initial work that can help to improve quantitative predictive numerical tools for ME-AM, taking into account the effects that the processing step has on the mechanical properties.
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Chen, Qi Feng, Shi Lin Yuan, Guang Xue Chen, Bao Lin Tang, and Jing Lei Tai. "Study on the Uniform Distributed Mechanics of Ink Droplet in Inkjet Printing Equipment." Advanced Materials Research 236-238 (May 2011): 1505–7. http://dx.doi.org/10.4028/www.scientific.net/amr.236-238.1505.
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This paper studied on the hydrokinetics and uniform distributed mechanics of supplying ink pressure for the inkjet printing system based on the, and the advanced testing equipment. According to the analysis of theoretical calculation and CFD, we designed a new type of equipment for supplying ink, including the structure of the transition pipe. This supplying ink equipment could make the ink droplets distribute under the equal pressure on the cross direction. The experiments showed that this new supplying ink equipment could make the ink droplets distribute under the equal pressure and uniform velocity on the cross direction, so it greatly improved the imaging effects for the inkjet printing system.
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Yang, Yong Gang. "Study on the Relationships between Plastic Viscosity and Tack Value of Offset Printing Ink." Applied Mechanics and Materials 723 (January 2015): 814–18. http://dx.doi.org/10.4028/www.scientific.net/amm.723.814.
Full textAbstract:
In order to find out the variation law of ink stickiness during the printing, the ink tack value under 9 different linear velocities of ink distributing roller was tested, and the relation equations between tack value and the roller linear velocity were built up. At the same time, the plastic viscosities of 8 offset inks and their tack values under 9 separation velocities were also tested. The study results showed that the higher the linear speed was, the larger the tack value was, and it would stay in a relatively high tack value (regarded as infinite tack value). Also, the printing ink having high viscosity may possess low tack value.
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Piri, Hossein, Xiaotao T. Bi, Hui Li, and Haijiang Wang. "3D-printed fuel-cell bipolar plates for evaluating flow-field performance." Clean Energy 4, no. 2 (June 2020): 142–57. http://dx.doi.org/10.1093/ce/zkaa007.
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Abstract In the last decade, many researchers have focused on developing fuel-cell flow-field designs that homogeneously distribute reactants with an optimum pressure drop. Most of the previous studies are numerical simulations and the few experimental studies conducted have used very simple flow-field geometries due to the limitations of the conventional fabrication techniques. 3D printing is an excellent rapid prototyping method for prototyping bipolar plates (BPPs) to perform experiments on new flow-field designs. The present research investigates the applicability of different 3D-printed BPPs for studying fluid-dynamic behaviour. State-of-the-art flow-field designs are fabricated using PolyJet 3D printing, stereolithographic apparatus (SLA) 3D printing and laser-cutter technologies, and the pressure-drop and velocity profiles are measured for each plate. The results demonstrate that SLA BPPs have great promise in serving as a screening tool in modifying flow-field design with a small feature size.
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Posmyk, Andrzej, and Przemysław Marzec. "INFLUENCE OF 3D PRINTING technology OF AUTOMOTIVE PARTS MADE OF PLASTICS ON THEIR TRIBOLOGICAL PROPERTIES." Tribologia 294, no. 6 (April 12, 2021): 65–70. http://dx.doi.org/10.5604/01.3001.0014.8338.
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This paper presents results of tribological examinations of chosen automotive subassemblies made of plastics by using of 3D-printing. The influence of chosen technological parameters, i.e. plastic temperature, the velocity of printing head, and the height of deposited simple layer on wear of samples produced of PA 12 polymer rubbing against hard anodised sliding guide of car sunroof is defined. It was found that samples printed at minimal temperature (t = 240°C), a minimal height of deposited simple layer (h = 0,1 mm), and a minimal (40 mm/s) and maximal (v = 60 mm/s) deposition velocity show the minimal wear. Examining under similar conditions (p = 0.4 MPa, v = 2.5 m/s, reciprocating movement) of samples made by using press moulding cut out from car sub-assemblies for a comparison were carried out. As a result of experiments, it was concluded that the wear intensity of roller stretching drive belt made from composite (PA15GF) and the wear intensity of the belt itself during sliding, caused by seizure of bearing, is so high that menaces engine with damage.
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Yang, Yong Gang. "Study on the Relation between Ink Tack Value and Wavers Velocity." Advanced Materials Research 314-316 (August 2011): 1350–53. http://dx.doi.org/10.4028/www.scientific.net/amr.314-316.1350.
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In order to find out the variation law of ink tack during the printing, the ink tack value under 9 different linear velocities of ink distributing roller was tested with an electric ink tack-o-meter in this article, and the relation equations between tack value and the roller linear velocity were built up. The study results showed that the higher the linear speed was, the larger the tack value was, and it would stay in a relatively high tack value (regarded as infinite tack value). At the same time, the relationships between ink tack and the roller linear velocity was different for various inks, so did the infinite tack value.
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Chao, Yanpu, Hao Yi, Fulai Cao, Yaohui Li, Hui Cen, and Shuai Lu. "Experimental Analysis of Wax Micro-Droplet 3D Printing Based on a High-Voltage Electric Field-Driven Jet Deposition Technology." Crystals 12, no. 2 (February 17, 2022): 277. http://dx.doi.org/10.3390/cryst12020277.
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High-voltage electric field-driven jet deposition technology is a novel high resolution micro scale 3D printing method. In this paper, a novel micro 3D printing method is proposed to fabricate wax micro-structures. The mechanism of the Taylor cone generation and droplet eject deposition was analyzed, and a high-voltage electric field-driven jet printing experimental system was developed based on the principle of forming. The effects of process parameters, such as pulse voltages, gas pressures, pulse width, pulse frequency, and movement velocity, on wax printing were investigated. The experimental results show that the increasing of pulse width and duration of pulse high voltage increased at the same pulse frequency, resulting in the micro-droplet diameter being increased. The deposited droplet underwent a process of spreading, shrinking, and solidifying. The local remelting and bonding were acquired between the contact surfaces of the adjacent deposited droplets. According to the experiment results, a horizontal line and a vertical micro-column were fabricated by adjusting the process parameters; their size deviation was controlled within 2%. This research shows that it is feasible to fabricate the micro-scale wax structure using high-voltage electric field-driven jet deposition technology.