Effects of Jetting Parameters and Sodium Silicate-Based Binder on Droplet Formation

Binder jetting additive manufacturing is one of the 3D printing technologies currently used to manufacture 3D geometries. In this process, a liquid binder agent is ejected to a desired position of a substrate. The binder’s properties and the jetting condition used for form droplets can affect the formability of the geometries. Herein, we optimized the solid content and jetting condition of a sodium silicate-based inorganic binder, for 3D printing. To observe the range of single droplet formation, the behavior of the discharged droplets was analyzed by Z value, which is the inverse of the Ohnesorge number. As the solid content increased, a higher driving voltage was required to form the droplets to overcome viscous dissipation. For 40S(Z = 4.33) with a content of 40 wt%, the droplet tail from the nozzle was stretched further. The droplets of 25S(Z = 15.09) with a content of 25 wt% were accompanied by satellite droplets. The jetting condition was optimized for 25S, which was capable of ejection at various driving voltages. Stable single droplets were formed at a driving voltage of 20 V and a dwell time of 4 μs. In addition, when ethylene glycol and glycerol were added into 25S as a humectant, stable droplets were formed under the optimum jetting condition, and each droplets was in the range of 2.70 < Z < 15.09.

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Printability and Setting Time of CSA Cement with Na2SiO3 and Gypsum for Binder Jetting 3D Printing

Materials ◽

10.3390/ma14112811 ◽

2021 ◽

Vol 14 (11) ◽

pp. 2811

Author(s):

Okpin Na ◽

Kangmin Kim ◽

Hyunjoo Lee ◽

Hyunseung Lee

Keyword(s):

3D Printing ◽

Sodium Silicate ◽

Setting Time ◽

Sodium Silicate Solution ◽

Preliminary Test ◽

Silicate Solution ◽

Calcium Sulfoaluminate Cement ◽

Calcium Sulfoaluminate ◽

Parametric Studies ◽

Binder Jetting

The purpose of this study is to optimize the composition of CSA (calcium sulfoaluminate) cement with sodium silicate (Na2SiO3) and gypsum for binder jetting 3D printing. The preliminary test was carried out with an applicator to decide the proper thickness of one layer before using the 3D printer. A liquid binder was then selected to maintain the shape of the particles. Based on the results, the optimal mixture of dry materials and a liquid activator was derived through various parametric studies. For dry materials, the optimum composition of CSA cement, gypsum, and sand was suggested, and the liquid activator made with sodium silicate solution and VMA (viscosity modified agent) were selected. The setting time with gypsum and sodium silicate was controlled within 30 s. In case of the delayed setting time and the rapid setting mixture, the jetting line was printed thicker or thinner and the accuracy of the printout was degraded. In order to adjust the viscosity of the liquid activator, 10% of the VMA was used in 35% of sodium silicate solution and the viscosity of 200–400 cP was suitable to be sprayed from the nozzle. With this optimal mixture, a prototype of atypical decorative wall was printed, and the compressive strength was measured at about 7 MPa.

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Jettable fluid space and jetting characteristics of a microprint head

Journal of Fluid Mechanics ◽

10.1017/jfm.2012.440 ◽

2012 ◽

Vol 713 ◽

pp. 109-122 ◽

Cited By ~ 5

Author(s):

Loke-Yuen Wong ◽

Guan-Hui Lim ◽

Thiha Ye ◽

F. B. Shanjeera Silva ◽

Jing-Mei Zhuo ◽

...

Keyword(s):

Pulse Length ◽

Droplet Formation ◽

Shear Mode ◽

Ohnesorge Number ◽

Single Droplet ◽

Short Channel ◽

Initial Droplet ◽

Wide Range ◽

Model Fluid ◽

Droplet On Demand

AbstractThe influence of fluid droplet properties on the droplet-on-demand jetting of a Newtonian model fluid (water–isopropanol–ethylene glycol ternary system) has been studied. The composition of the fluid was adjusted to investigate how the Ohnesorge number ($\mathit{Oh}$) influences droplet formation (morphology and speed) by a microfabricated short-channel shear-mode piezoelectric transducer. The fluid space for satellite-free single droplet formation was indeed found to be bound by upper and lower $\mathit{Oh}$ limits, but these shift approximately linearly with the piezo pulse voltage amplitude ${V}_{o} $, which has a stronger influence on jetting characteristics than pulse length. Therefore the jettable fluid space can be depicted on a ${V}_{o} {{\ndash}}\mathit{Oh}$ diagram. Satellite-free droplets of the model fluid can be jetted over a wide $\mathit{Oh}$ range, at least 0.025 to 0.5 (corresponding to $Z= {\mathit{Oh}}^{\ensuremath{-} 1} $ of 40 to 2), by adjusting ${V}_{o} $ appropriately. Air drag was found to dominate droplet flight, as may be expected. This can be accurately modelled to yield droplet formation time, which turned out to be $20\text{{\ndash}} 30~\lrm{\ensuremath{\mu}} \mathrm{s} $ under a wide range of jetting conditions. The corresponding initial droplet speed was found to vary linearly with ${V}_{o} $, with a fluid-dependent threshold but a fluid-independent slope, and a minimum speed of about $2~\mathrm{m} ~{\mathrm{s} }^{\ensuremath{-} 1} $. This suggests the existence of iso-velocity lines that run substantially parallel to the lower jetting boundary in the ${V}_{o} {{\ndash}}\mathit{Oh}$ diagram.

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Synergistic application of continuous granulation and selective laser sintering 3D printing for the development of pharmaceutical dosage forms with enhanced dissolution rates and physical properties

10.1101/2021.02.13.430988 ◽

2021 ◽

Cited By ~ 1

Author(s):

Rishi Thakkar ◽

Yu Zhang ◽

Jiaxiang Zhang ◽

Mohammed Maniruzzaman

Keyword(s):

Solid State ◽

3D Printing ◽

Physical Properties ◽

Dosage Forms ◽

Flow Properties ◽

Printing Process ◽

Powder Bed ◽

Printing Processes ◽

Binder Jetting ◽

Physical Mixtures

AbstractThis study demonstrated the first case of combining novel continuous granulation with powder-based pharmaceutical 3-dimensional (3D) printing processes to enhance the dissolution rate and physical properties of a poorly water-soluble drug. Powder bed fusion (PBF) and binder jetting 3D printing processes have gained much attention in pharmaceutical dosage form manufacturing in recent times. Although powder bed-based 3D printing platforms have been known to face printing and uniformity problems due to the inherent poor flow properties of the pharmaceutical physical mixtures (feedstock). Moreover, techniques such as binder jetting currently do not provide any solubility benefits to active pharmaceutical ingredients (APIs) with poor aqueous solubility (>40% of marketed drugs). For this study, a hot-melt extrusion-based versatile granulation process equipped with UV-Vis process analytical technology (PAT) tools for the in-line monitoring of critical quality attributes (i.e., solid-state) of indomethacin was developed. The collected granules with enhanced flow properties were mixed with vinylpyrrolidone-vinyl acetate copolymer and a conductive excipient for efficient sintering. These mixtures were further characterized for their bulk properties observing an excellent flow and later subjected to a PBF-3D printing process. The physical mixtures, processed granules, and printed tablets were characterized using conventional as well as advanced solid-state characterization. These characterizations revealed the amorphous nature of the drug in the processed granules and printed tablets. Further, the in vitro release testing of the tablets with produced granules as a reference standard depicted a notable solubility advantage (100% drug released in 5 minutes at >pH 6.8) over the pure drug and the physical mixture. Our developed system known as DosePlus combines innovative continuous granulation and PBF-3D printing process which can potentially improve the physical properties of the bulk drug and formulations in comparison to when used in isolation. This process can further find application in continuous manufacturing of granules and additive manufacturing of pharmaceuticals to produce dosage forms with excellent uniformity and solubility advantage.Abstract Figure

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A Single Droplet Formation from Swelled Micelles by Radiation Pressure of a Focused Infrared Laser Beam

Journal of the American Chemical Society ◽

10.1021/ja9617350 ◽

1996 ◽

Vol 118 (47) ◽

pp. 11968-11969 ◽

Cited By ~ 37

Author(s):

Jun-ichi Hotta ◽

Keiji Sasaki ◽

Hiroshi Masuhara

Keyword(s):

Laser Beam ◽

Radiation Pressure ◽

Droplet Formation ◽

Infrared Laser ◽

Single Droplet ◽

Infrared Laser Beam

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A Review on Additive Manufacturing of Ceramics

Volume 1: Additive Manufacturing; Manufacturing Equipment and Systems; Bio and Sustainable Manufacturing ◽

10.1115/msec2019-2886 ◽

2019 ◽

Author(s):

Brooke Mansfield ◽

Sabrina Torres ◽

Tianyu Yu ◽

Dazhong Wu

Keyword(s):

Mechanical Properties ◽

Additive Manufacturing ◽

3D Printing ◽

Computer Aided Design ◽

Ceramic Materials ◽

Complex Geometries ◽

Laminated Object Manufacturing ◽

Challenges And Opportunities ◽

Aided Design ◽

Binder Jetting

Abstract Additive manufacturing (AM), also known as 3D printing, has been used for rapid prototyping due to its ability to produce parts with complex geometries from computer-aided design files. Currently, polymers and metals are the most commonly used materials for AM. However, ceramic materials have unique mechanical properties such as strength, corrosion resistance, and temperature resistance. This paper provides a review of recent AM techniques for ceramics such as extrusion-based AM, the mechanical properties of additively manufactured ceramics, and the applications of ceramics in various industries, including aerospace, automotive, energy, electronics, and medical. A detailed overview of binder-jetting, laser-assisted processes, laminated object manufacturing (LOM), and material extrusion-based 3D printing is presented. Finally, the challenges and opportunities in AM of ceramics are identified.

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3D Printing in Dentistry—State of the Art

Operative Dentistry ◽

10.2341/18-229-l ◽

2020 ◽

Vol 45 (1) ◽

pp. 30-40 ◽

Cited By ~ 14

Author(s):

A Kessler ◽

R Hickel ◽

M Reymus

Keyword(s):

3D Printing ◽

Clinical Application ◽

Industrial Revolution ◽

Rapid Development ◽

Selective Laser Sintering ◽

Three Dimensional ◽

Fused Filament Fabrication ◽

Digital Light Processing ◽

Materials Used ◽

Binder Jetting

SUMMARY Three-dimensional (3D) printing is a rapidly developing technology that has gained widespread acceptance in dentistry. Compared to conventional (lost-wax technique) and subtractive computer numeric controlled methods, 3D printing offers process engineering advantages. Materials such as plastics, metals, and ceramics can be manufactured using various techniques. 3D printing was introduced over three decades ago. Today, it is experiencing rapid development due to the expiration of many patents and is often described as the key technology of the next industrial revolution. The transition to its clinical application in dentistry is highly dependent on the available materials, which must not only provide the required accuracy but also the necessary biological and physical properties. The aim of this work is to provide an up-to-date overview of the different printing techniques: stereolithography, digital light processing, photopolymer jetting, material jetting, binder jetting, selective laser sintering, selective laser melting, and fused filament fabrication. Additionally, particular attention is paid to the materials used in dentistry and their clinical application.

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Preparation of Nano Silver Paste and Applications in Transparent Electrodes via Electric-Field Driven Micro-Scale 3D Printing

Nanomaterials ◽

10.3390/nano10010107 ◽

2020 ◽

Vol 10 (1) ◽

pp. 107 ◽

Cited By ~ 2

Author(s):

Hongke Li ◽

Xiaoyang Zhu ◽

Zhenghao Li ◽

Jianjun Yang ◽

Hongbo Lan

Keyword(s):

3D Printing ◽

Electric Field ◽

Solid Content ◽

No Oxidation ◽

Basic Material ◽

Transparent Electrodes ◽

Printing Technology ◽

Silver Paste ◽

Nano Silver ◽

Micro Scale

Nano-silver paste, as an important basic material for manufacturing thick film components, ultra-fine circuits, and transparent conductive films, has been widely used in various fields of electronics. Here, aiming at the shortcomings of the existing nano-silver paste in printing technology and the problem that the existing printing technology cannot achieve the printing of high viscosity, high solid content nano-silver paste, a nano-silver paste suitable for electric-field-driven (EFD) micro-scale 3D printing is developed. The result shows that there is no oxidation and settlement agglomeration of nano-silver paste with a storage time of over six months, which indicates that it has good dispersibility. We focus on the printing process parameters, sintering process, and electrical conductivity of nano-silver paste. The properties of the nano-silver paste were analyzed and the feasibility and practicability of the prepared nano-silver paste in EFD micro-scale 3D printing technology were verified. The experiment results indicate that the printed silver mesh which can act as transparent electrodes shows high conductivity (1.48 Ω/sq) and excellent transmittance (82.88%). The practical viability of the prepared nano-silver paste is successfully demonstrated with a deicing test. Additionally, the experimental results show that the prepared silver mesh has excellent heating properties, which can be used as transparent heaters.

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Possibilities of Preoperative Medical Models Made by 3D Printing or Additive Manufacturing

Journal of Medical Engineering ◽

10.1155/2016/6191526 ◽

2016 ◽

Vol 2016 ◽

pp. 1-6 ◽

Cited By ~ 20

Author(s):

Mika Salmi

Keyword(s):

Additive Manufacturing ◽

3D Printing ◽

3D Modeling ◽

Mechanical Engineering ◽

3D Model ◽

Model Reconstruction ◽

3D Model Reconstruction ◽

Wide Range ◽

Printing Processes ◽

Binder Jetting

Most of the 3D printing applications of preoperative models have been focused on dental and craniomaxillofacial area. The purpose of this paper is to demonstrate the possibilities in other application areas and give examples of the current possibilities. The approach was to communicate with the surgeons with different fields about their needs related preoperative models and try to produce preoperative models that satisfy those needs. Ten different kinds of examples of possibilities were selected to be shown in this paper and aspects related imaging, 3D model reconstruction, 3D modeling, and 3D printing were presented. Examples were heart, ankle, backbone, knee, and pelvis with different processes and materials. Software types required were Osirix, 3Data Expert, and Rhinoceros. Different 3D printing processes were binder jetting and material extrusion. This paper presents a wide range of possibilities related to 3D printing of preoperative models. Surgeons should be aware of the new possibilities and in most cases help from mechanical engineering side is needed.

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