Thermal Analysis on Directional Freezing of Nano Aqueous Suspensions in Graphene Aerogel 3D Printing Process

2016 ◽  
Author(s):  
Guanglei Zhao ◽  
Chi Zhou ◽  
Dong Lin
Keyword(s):  
3D Printing ◽  
Waiting Time ◽  
Temperature Evolution ◽  
Process Efficiency ◽  
Transfer Model ◽  
Graphene Aerogel ◽  
Flexible Tool ◽  
Printed Materials ◽  
Directional Freezing ◽  
Efficiency And Reliability

This paper presented a novel 3D printing technique to fabricate graphene aerogel based on directional freezing. Thermal property of the graphene ink is one of key factors in this process which affects the material integrity and morphology as well as process efficiency and reliability. The major objective of this paper is to develop a heat transfer model to efficiently and reliably predict the temperature evolution of the printed materials and the waiting time between the layers for any input geometry. The simulation results show that the input geometry significantly affects the temperature evolution and waiting time. The proposed technique can not only improve the process efficiency and reliability, it can also serve as a flexible tool to predict and control the microstructure of the printed graphene aerogels.

scholarly journals Thermal Analysis of Directional Freezing Based Graphene Aerogel Three-Dimensional Printing Process

2017 ◽  
Vol 5 (1) ◽  
Author(s):  
Guanglei Zhao ◽  
Dong Lin ◽  
Chi Zhou
Keyword(s):  
Three Dimensional ◽  
Process Efficiency ◽  
Transfer Model ◽  
Graphene Aerogel ◽  
Flexible Tool ◽  
Efficiency And Effectiveness ◽  
Simulation And Experiment ◽  
Printed Materials ◽  
Directional Freezing ◽  
And Control

A novel directional freezing based three-dimensional (3D) printing technique is applied to fabricate graphene aerogel (GA). Thermal property of the graphene ink is one of the key impacts on the material morphology and process efficiency/reliability. We develop a heat transfer model to predict temperature evolution of the printed materials and then estimate layer waiting time based on it. The proposed technique can not only improve the process efficiency and reliability but also serve as a flexible tool to predict and control the microstructure of the printed graphene aerogels. Both the simulation and experiment results demonstrate the efficiency and effectiveness of the proposed approach.

APPLICATION OF 3D PRINTING TECHNOLOGY FOR RAPID TOOLING IN SHEET METAL FORMING

2020 ◽  
Vol 3 ◽  
pp. 20-30
Author(s):  
M.A. SEREZHKIN ◽  
D.O. KLIMYUK ◽  
A.I. PLOKHIKH
Keyword(s):  
3D Printing ◽  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Rapid Tooling ◽  
Printing Technology ◽  
3D Printing Technology ◽  
3D Printed ◽  
Printed Materials ◽  
Printing Parameters

The article presents the study of the application of 3D printing technology for rapid tooling in sheet metal forming for custom or small–lot manufacturing. The main issue of the usage of 3D printing technology for die tooling was discovered. It is proposed to use the method of mathematical modelling to investigate how the printing parameters affect the compressive strength of FDM 3D–printed parts. Using expert research methods, the printing parameters most strongly affecting the strength of products were identified for further experiments. A method for testing the strength of 3D–printed materials has been developed and tested.

scholarly journals Cost-Effectively 3D-Printed Rigid and Versatile Interpenetrating Polymer Networks

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4544
Author(s):  
Osman Konuray ◽  
Arnau Sola ◽  
Jordi Bonada ◽  
Agnieszka Tercjak ◽  
Albert Fabregat-Sanjuan ◽  
...  
Keyword(s):  
3D Printing ◽  
Polymer Networks ◽  
Complex Form ◽  
Interpenetrating Polymer Networks ◽  
Dual Processing ◽  
Digital Light Processing ◽  
Superior Mechanical Properties ◽  
3D Printed ◽  
Acrylate Resin ◽  
Printed Materials

Versatile acrylate–epoxy hybrid formulations are becoming widespread in photo/thermal dual-processing scenarios, especially in 3D printing applications. Usually, parts are printed in a stereolithography or digital light processing (DLP) 3D printer, after which a thermal treatment would bestow the final material with superior mechanical properties. We report the successful formulation of such a hybrid system, consisting of a commercial 3D printing acrylate resin modified by an epoxy–anhydride mixture. In the final polymeric network, we observed segregation of an epoxy-rich phase as nano-domains, similar to what was observed in a previous work. However, in the current work, we show the effectiveness of a coupling agent added to the formulation to mitigate this segregation for when such phase separation is undesired. The hybrid materials showed significant improvement of Young’s modulus over the neat acrylate. Once the flexible, partially-cured material was printed with a minimal number of layers, it could be molded into a complex form and thermally cured. Temporary shapes were readily programmable on this final material, with easy shape recovery under mild temperatures. Inspired by repairable 3D printed materials described recently, we manufactured a large object by printing its two halves, and then joined them covalently at the thermal cure stage with an apparently seamless union.

Environment Influence on the Properties of Functional Parts Made of HIPS Material

2021 ◽  
Vol 105 (1) ◽  
pp. 431-440
Author(s):  
Pavel Šafl ◽  
Jana Zimáková ◽  
Tomáš Binar
Keyword(s):  
Electron Microscope ◽  
3D Printing ◽  
Tensile Test ◽  
Uv Light ◽  
Starting Material ◽  
Climatic Chamber ◽  
3D Printed ◽  
Formation Of Cracks ◽  
Printed Materials ◽  
Degree Of Degradation

The aim of this work is to study the climatic influences on 3D printed materials. This study focuses on the HIPS material, which was chosen as the starting material for further studies. The material in the field of 3D printing is known for its rapid photooxidation, which results in the formation of cracks in the final product. A climatic chamber was used for degradation, in which UV light, heat and increased humidity were applied to the material. The degree of degradation was then checked by tensile test and electron microscope.

Thermal Conductivity Testing Apparatus for 3D Printed Materials

2017 ◽  
Author(s):  
Tiffaney Flaata ◽  
Gregory J. Michna ◽  
Todd Letcher
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Additive Manufacturing ◽  
3D Printing ◽  
Polymer Composite ◽  
Heat Exchangers ◽  
Fused Deposition ◽  
3D Printed ◽  
Printed Materials ◽  
Metal Polymer

Additive manufacturing, the layer-by-layer creation of parts, was initially used for rapid prototyping of new designs. Recently, due to the decrease in the cost and increase in the resolution and strength of additively manufactured parts, additive manufacturing is increasingly being used for production of parts for end-use applications. Fused Deposition Modeling (FDM), a type of 3d printing, is a process of additive manufacturing in which a molten thermoplastic material is extruded to create the desired geometry. Many potential heat transfer applications of 3d printed parts, including the development of additively manufactured heat exchangers, exist. In addition, the availability of metal/polymer composite filaments, first used for applications such as tooling for injection molding applications and to improve wear resistance, could lead to increased performance 3d printed heat exchangers because of the higher thermal conductivity of the material. However, the exploitation of 3d printing for heat transfer applications is hindered by a lack of reliable thermal conductivity data for as-printed materials, which typically include significant void fractions. In this experimental study, an apparatus to measure the effective thermal conductivity of 3d printed composite materials was designed and fabricated. Its ability to accurately measure the thermal conductivity of polymers was validated using a sample of acrylic, whose conductivity is well understood. Finally, the thermal conductivities of various 3d printed polymer, metal/polymer composite, and carbon/polymer composite filaments were measured and are reported in this paper. The materials used are acrylonitrile butadiene styrene (ABS), polylactic acid (PLA), stainless steel/PLA, Brass/PLA, and Bronze/PLA.

Utility and cost–effectiveness of 3D-printed materials for clinical use

2019 ◽  
Vol 3 (4) ◽  
pp. 209-218 ◽  
Author(s):  
Julian Vitali ◽  
Matthew Cheng ◽  
Michael Wagels
Keyword(s):  
Cost Effectiveness ◽  
3D Printing ◽  
Relevant Literature ◽  
Clinical Use ◽  
Surgical Guides ◽  
Rigorous Testing ◽  
Clinical Benefits ◽  
3D Printed ◽  
Surgical Adjunct ◽  
Printed Materials

This review summarizes the utility of 3D-printing as a surgical adjunct, reviewing the cost–effectiveness. The relevant literature was analyzed outlining the utility and/or cost–effectiveness of 3D-printing for clinical use. Compared with existing methods, the evidence suggests an advantage of using 3D-printing as a technology in the treatment of complex clinical cases. However, in high frequency cases, the additional preoperative expenses are not justified. Considerable evidence of its clinical benefits exists for the application of 3D-printed anatomical models and teaching tools. However, the evidence supporting 3D-printing’s use as surgical guides or implantable devices is less clear. Furthermore, caution must exist when using these devices in the clinical setting due to a paucity of rigorous testing, global regulation and long-term data.

scholarly journals 3D Printing at Micro-Level: Laser-Induced Forward Transfer and Two-Photon Polymerization

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2034
Author(s):  
Muhammad Arif Mahmood ◽  
Andrei C. Popescu
Keyword(s):  
3D Printing ◽  
Single Photon ◽  
Future Research ◽  
Two Photon ◽  
Micro Fluidics ◽  
Level Laser ◽  
Forward Transfer ◽  
The Difference ◽  
Printed Materials ◽  
Two Photon Polymerization

Laser-induced forward transfer (LIFT) and two-photon polymerization (TPP) have proven their abilities to produce 3D complex microstructures at an extraordinary level of sophistication. Indeed, LIFT and TPP have supported the vision of providing a whole functional laboratory at a scale that can fit in the palm of a hand. This is only possible due to the developments in manufacturing at micro- and nano-scales. In a short time, LIFT and TPP have gained popularity, from being a microfabrication innovation utilized by laser experts to become a valuable instrument in the hands of researchers and technologists performing in various research and development areas, such as electronics, medicine, and micro-fluidics. In comparison with conventional micro-manufacturing methods, LIFT and TPP can produce exceptional 3D components. To gain benefits from LIFT and TPP, in-detail comprehension of the process and the manufactured parts’ mechanical–chemical characteristics is required. This review article discusses the 3D printing perspectives by LIFT and TPP. In the case of the LIFT technique, the principle, classification of derivative methods, the importance of flyer velocity and shock wave formation, printed materials, and their properties, as well as various applications, have been discussed. For TPP, involved mechanisms, the difference between TPP and single-photon polymerization, proximity effect, printing resolution, printed material properties, and different applications have been analyzed. Besides this, future research directions for the 3D printing community are reviewed and summarized.

scholarly journals 3D printers in dentistry: a review of additive manufacturing techniques and materials

2021 ◽  
Author(s):  
Leonardo Portilha Gomes da Costa ◽  
Stephanie Isabel Díaz Zamalloa ◽  
Fernando Amorim Mendonça Alves ◽  
Renan Spigolon ◽  
Leandro Yukio Mano ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
Fused Deposition Modeling ◽  
Dental Materials ◽  
Clinical Results ◽  
Digital Light Processing ◽  
Fused Deposition ◽  
3D Printers ◽  
Manufacturing Techniques ◽  
Printed Materials

3D printers manufacture objects used in various dental specialties. Objective: This literature review aims to explore different techniques of current 3D printers and their applications in printed materials for dental purposes. Methods: The online PubMed databases were searched aiming to find applications of different 3D printers in the dental area. The keywords searched were 3D printer, 3D printing, additive manufacturing, rapid prototyping, 3D prototyping, dental materials and dentistry. Results: From the search results, we describe Stereolithography (SLA), Digital Light Processing (DLP), Material Jetting (MJ), Fused Deposition Modeling (FDM), Binder Jetting (BJ) and Dust-based printing techniques. Conclusion: 3D printing enables different additive manufacturing techniques to be used in dentistry, providing better workflows and more satisfying clinical results.

scholarly journals Stabilization of Electrospun Nanofiber Mats Used for Filters by 3D Printing

Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1618 ◽  
Author(s):  
Kozior ◽  
Trabelsi ◽  
Mamun ◽  
Sabantina ◽  
Ehrmann
Keyword(s):  
3D Printing ◽  
Fused Deposition Modeling ◽  
Water Pressure ◽  
Volume Ratio ◽  
Fused Deposition ◽  
Rigid Objects ◽  
Deposition Modeling ◽  
3D Printed ◽  
Printed Materials ◽  
Nanofiber Mats

Electrospinning is a well-known technology used to create nanofiber mats from diverse polymers and other materials. Due to their large surface-to-volume ratio, such nanofiber mats are often applied as air or water filters. Especially the latter, however, have to be mechanically highly stable, which is challenging for common nanofiber mats. One of the approaches to overcome this problem is gluing them on top of more rigid objects, integrating them in composites, or reinforcing them using other technologies to avoid damage due to the water pressure. Here, we suggest another solution. While direct 3D printing with the fused deposition modeling (FDM) technique on macroscopic textile fabrics has been under examination by several research groups for years, here we report on direct FDM printing on nanofiber mats for the first time. We show that by choosing the proper height of the printing nozzle above the nanofiber mat, printing is possible for raw polyacrylonitrile (PAN) nanofiber mats, as well as for stabilized and even more brittle carbonized material. Under these conditions, the adhesion between both parts of the composite is high enough to prevent the nanofiber mat from being peeled off the 3D printed polymer. Abrasion tests emphasize the significantly increased mechanical properties, while contact angle examinations reveal a hydrophilicity between the original values of the electrospun and the 3D printed materials.

Synchronous Transfer Model of Bus Timetabling for Regional Public Transit

2012 ◽  
Vol 226-228 ◽  
pp. 2356-2361
Author(s):  
Jian Zhang ◽  
Wei Wang ◽  
Bin Ran ◽  
Wen Quan Li
Keyword(s):  
Waiting Time ◽  
Public Transportation ◽  
Field Data ◽  
Public Transit ◽  
Transfer Model ◽  
Transfer Time ◽  
Proposed Model ◽  
Software Program ◽  
Transfer Station

This study is an attempt to optimize the timetable synchronously for regional public transit. Based on the re-interpretation of transfer time in public transportation, a transfer model of bus timetabling is established, which has the objective to minimize the total waiting time of transfer passengers at the transfer station, and it is found as a linear integer model through analysing the established model. Thus, to solve the model, the LINGO software is applied and the corresponding program is designed. Finally, the model is tested against the field data, taking some bus lines in one city as example, using the solution software. The results indicate that the proposed model is reasonable, the timetable is improved, and the solution software program is effective as well.

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