A modified LBM for non-Newtonian effect of cement paste flow in 3D printing

2019 ◽  
Vol 25 (1) ◽  
pp. 22-29 ◽  
Author(s):  
Weiwei Wu ◽  
Xiaodiao Huang ◽  
Yuanyuan Li ◽  
Chenggang Fang ◽  
Xianhui Jiang
Keyword(s):  
3D Printing ◽  
Numerical Solution ◽  
Cement Paste ◽  
Three Dimensional ◽  
Shear Thickening ◽  
Past Research ◽  
Screw Extruder ◽  
Content Type ◽  
Initial Yield Stress ◽  
Stability And Accuracy

Purpose The screw extruder is applied in cement-three-dimensional (3D) printing. The cement paste flow in 3D printing is the typical Herschel–Bulkley fluid. To understand the flow in the channel, the improved lattice Boltzmann method (LBM) is proposed. Design/methodology/approach For Herschel–Bulkley flow, an improved LBM is presented to avoid the poor stability and accuracy. The non-Newtonian effect is regard as a special forcing term. The Poiseuille flow is taken to discuss the detailed process of the method. With the method, the analytical solution and numerical solution are obtained and compared. Then, the effect of the initial yield stress on the numerical solution is both explored by the shear-thickening fluid and the shear-thinning fluid. Moreover, the variations of the relative errors under different lattice nodes and different power-law indexes are analyzed. Finally, the method is applied into the simulation of the flow in the extruder of cement-3D printing. Findings The results show that the improved method is effective for Herschel–Bulkley fluids, which can simulate the flow in the extruder stably and accurately. Practical implications The simulation can contribute to understand the cement paste flow in the screw extruder, which helps to optimize the structure of the extruder in the following periods. Originality/value The improve method provide a new way to analyze the flow in the extruder of cement-3D printing. Also, in the past research, LBM for Herschel–Bulkley fluid is ignored, whereas the study can provide the reference for the numerical simulation.

A review on the role of 3D printing in the fight against COVID-19: safety and challenges

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Sapam Ningthemba Singh ◽  
Vavilada Satya Swamy Venkatesh ◽  
Ashish Bhalchandra Deoghare
Keyword(s):  
Supply Chain ◽  
3D Printing ◽  
Three Dimensional ◽  
Content Type ◽  
Medical Supplies ◽  
Future Challenges ◽  
Safety And Reliability ◽  
3D Printed ◽  
Comprehensive Study

Purpose During the COVID-19 pandemic, the three-dimensional (3D) printing community is actively participating to address the supply chain gap of essential medical supplies such as face masks, face shields, door adapters, test swabs and ventilator valves. This paper aims to present a comprehensive study on the role of 3D printing during the coronavirus (COVID-19) pandemic, its safety and its challenges. Design/methodology/approach This review paper focuses on the applications of 3D printing in the fight against COVID-19 along with the safety and challenges associated with 3D printing to fight COVID-19. The literature presented in this paper is collected from the journal indexing engines including Scopus, Google Scholar, ResearchGate, PubMed, Web of Science, etc. The main keywords used for searches were 3D printing COVID-19, Safety of 3D printed parts, Sustainability of 3D printing, etc. Further possible iterations of the keywords were used to collect the literature. Findings The applications of 3D printing in the fight against COVID-19 are 3D printed face masks, shields, ventilator valves, test swabs, drug deliveries and hands-free door adapters. As most of these measures are implemented hastily, the safety and reliability of these parts often lacked approval. The safety concerns include the safety of the printed parts, operators and secondary personnel such as the workers in material preparation and transportation. The future challenges include sustainability of the process, long term supply chain, intellectual property and royalty-free models, etc. Originality/value This paper presents a comprehensive study on the applications of 3D printing in the fight against COVID-19 with emphasis on the safety and challenges in it.

3 D printing technology and experimental study of chitosan gel using atomized solidification liquid-assisted extrusion molding

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yangwei Wang ◽  
Peilun Lv ◽  
Jian Li ◽  
Liying Yu ◽  
Guodong Yuan ◽  
...  
Keyword(s):  
3D Printing ◽  
Three Dimensional ◽  
Theoretical Research ◽  
Error Sources ◽  
Printing Technology ◽  
Content Type ◽  
Printing Ink ◽  
Printing Parameters ◽  
Chitosan Gel ◽  
Printing Method

Purpose This paper aims to propose a suitable atomizing solidification chitosan (CS) gel liquid extrusion molding technology for the three dimensional (3D) printing method, and experiments verify the feasibility of this method. Design/methodology/approach This paper mainly uses experimental means, combined with theoretical research. The preparation method, solidification forming method and 3D printing method of CS gel solution were studied. The CS gel printing mechanism and printing error sources are analyzed on the basis of the CS gel ink printing results, printing performance with different ratios of components by constructing a gel print prototype, experiments evaluating the CS gel printing technology and the effects of the process parameters on the scaffold formation. Findings CS printing ink was prepared; the optimal formula was found; the 3 D printing experiment of CS was completed; the optimal printing parameters were obtained; and the reliability of the forming prototype, printing ink and gel printing process was verified, which allowed for the possibility to apply the 3 D printing technology to the manufacturing of a CS gel structure. Originality/value This study can provide theoretical and technical support for the potential application of CS 3 D printed gels in tissue engineering.

Research on the printing error of tilted vertical beams in delta-robot 3D printers

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yuezong Wang ◽  
Jinghui Liu ◽  
Mengfei Guo ◽  
LiuQIan Wang
Keyword(s):  
3D Printing ◽  
Kinematic Model ◽  
Three Dimensional ◽  
3D Printer ◽  
Simulation Approach ◽  
Content Type ◽  
Printing Quality ◽  
Delta Robot ◽  
Error Generation ◽  
Error Simulation

Purpose A three-dimensional (3D) printing error simulation approach is proposed to analyze the influence of tilted vertical beams on the 3D printing accuracy. The purpose of this study is to analyze the influence of such errors on printing accuracy and printing quality for delta-robot 3D printer. Design/methodology/approach First, the kinematic model of a delta-robot 3D printer with an ideal geometric structure is proposed by using vector analysis. Then, the normal kinematic model of a nonideal delta-robot 3D robot with tilted vertical beams is derived based on the above ideal kinematic model. Finally, a 3D printing error simulation approach is proposed to analyze the influence of tilted vertical beams on the 3D printing accuracy. Findings The results show that tilted vertical beams can indeed cause 3D printing errors and further influence the 3D printing quality of the final products and that the 3D printing errors of tilted vertical beams are related to the rotation angles of the tilted vertical beams. The larger the rotation angles of the tilted vertical beams are, the greater the geometric deformations of the printed structures. Originality/value Three vertical beams and six horizontal beams constitute the supporting parts of the frame of a delta-robot 3D printer. In this paper, the orientations of tilted vertical beams are shown to have a significant influence on 3D printing accuracy. However, the effect of tilted vertical beams on 3D printing accuracy is difficult to capture by instruments. To reveal the 3D printing error mechanisms under the condition of tilted vertical beams, the error generation mechanism and the quantitative influence of tilted vertical beams on 3D printing accuracy are studied by simulating the parallel motion mechanism of a delta-robot 3D printer with tilted vertical beams.

Bioprinting in ophthalmology: current advances and future pathways

2019 ◽  
Vol 25 (3) ◽  
pp. 496-514 ◽  
Author(s):  
Nataraj Poomathi ◽  
Sunpreet Singh ◽  
Chander Prakash ◽  
Rajkumar V. Patil ◽  
P.T. Perumal ◽  
...  
Keyword(s):  
3D Printing ◽  
Cardiac Tissue ◽  
Human Life ◽  
Three Dimensional ◽  
3D Models ◽  
Eye Diseases ◽  
Biological Research ◽  
Content Type ◽  
Almost All ◽  
Time Of Operation

Purpose Bioprinting is a promising technology, which has gained a recent attention, for application in all aspects of human life and has specific advantages in different areas of medicines, especially in ophthalmology. The three-dimensional (3D) printing tools have been widely used in different applications, from surgical planning procedures to 3D models for certain highly delicate organs (such as: eye and heart). The purpose of this paper is to review the dedicated research efforts that so far have been made to highlight applications of 3D printing in the field of ophthalmology. Design/methodology/approach In this paper, the state-of-the-art review has been summarized for bioprinters, biomaterials and methodologies adopted to cure eye diseases. This paper starts with fundamental discussions and gradually leads toward the summary and future trends by covering almost all the research insights. For better understanding of the readers, various tables and figures have also been incorporated. Findings The usages of bioprinted surgical models have shown to be helpful in shortening the time of operation and decreasing the risk of donor, and hence, it could boost certain surgical effects. This demonstrates the wide use of bioprinting to design more precise biological research models for research in broader range of applications such as in generating blood vessels and cardiac tissue. Although bioprinting has not created a significant impact in ophthalmology, in recent times, these technologies could be helpful in treating several ocular disorders in the near future. Originality/value This review work emphasizes the understanding of 3D printing technologies, in the light of which these can be applied in ophthalmology to achieve successful treatment of eye diseases.

scholarly journals Low cost digital fabrication approach for thumb orthoses

2017 ◽  
Vol 23 (6) ◽  
pp. 1020-1031 ◽  
Author(s):  
Miguel Fernandez-Vicente ◽  
Ana Escario Chust ◽  
Andres Conejero
Keyword(s):  
3D Printing ◽  
Computer Aided Design ◽  
Low Cost ◽  
Three Dimensional ◽  
Recovery Process ◽  
Digital Fabrication ◽  
Cost Comparison ◽  
Content Type ◽  
Custom Made ◽  
The Impact

Purpose The purpose of this paper is to describe a novel design workflow for the digital fabrication of custom-made orthoses (CMIO). It is intended to provide an easier process for clinical practitioners and orthotic technicians alike. It further functions to reduce the dependency of the operators’ abilities and skills. Design/methodology/approach The technical assessment covers low-cost three-dimensional (3D) scanning, free computer-aided design (CAD) software, and desktop 3D printing and acetone vapour finishing. To analyse its viability, a cost comparison was carried out between the proposed workflow and the traditional CMIO manufacture method. Findings The results show that the proposed workflow is a technically feasible and cost-effective solution to improve upon the traditional process of design and manufacture of custom-made static trapeziometacarpal (TMC) orthoses. Further studies are needed for ensuring a clinically feasible approach and for estimating the efficacy of the method for the recovery process in patients. Social implications The feasibility of the process increases the impact of the study, as the great accessibility to this type of 3D printers makes the digital fabrication method easier to be adopted by operators. Originality/value Although some research has been conducted on digital fabrication of CMIO, few studies have investigated the use of desktop 3D printing in any systematic way. This study provides a first step in the exploration of a new design workflow using low-cost digital fabrication tools combined with non-manual finishing.

Methodology of technological evolution for three-dimensional printing

2016 ◽  
Vol 116 (1) ◽  
pp. 122-146 ◽  
Author(s):  
Sangsung Park ◽  
Juhwan Kim ◽  
Hongchul Lee ◽  
Dongsik Jang ◽  
Sunghae Jun
Keyword(s):  
3D Printing ◽  
Quantitative Methods ◽  
Three Dimensional ◽  
Principal Component ◽  
Technological Evolution ◽  
Time Series Regression ◽  
Printing Technology ◽  
Content Type ◽  
3D Printing Technology ◽  
The Future

Purpose – An increasing amount of attention is being paid to three-dimensional (3D) printing technology. The technology itself is based on diverse technologies such as laser beams and materials. Hence, 3D printing technology is a converging technology that produces 3D objects using a 3D printer. To become technologically competitive, many companies and nations are developing technologies for 3D printing. So to know its technological evolution is meaningful for developing 3D printing in the future. The paper aims to discuss these issues. Design/methodology/approach – To get technological competitiveness of 3D printing, the authors should know the most important and essential technology for 3D printing. An understanding of the technological evolution of 3D printing is needed to forecast its future technologies and build the R & D planning needed for 3D printing. In this paper, the authors propose a methodology to analyze the technological evolution of 3D printing. The authors analyze entire patent documents related to 3D printing to construct a technological evolution model. The authors use the statistical methods such as time series regression, association analysis based on graph theory, and principal component analysis for patent analysis of 3D printing technology. Findings – Using the proposed methodology, the authors show the technological analysis results of 3D printing and predict its future aspects. Though many and diverse technologies are developed and involved in 3D printing, the authors know only a few technologies take lead the technological evolution of 3D printing. In this paper, the authors find this evolution of technology management for 3D printing. Practical implications – If not all, most people would agree that 3D printing technology is one of the leading technologies to improve the quality of life. So, many companies have developed a number of technologies if they were related to 3D printing. But, most of them have not been considered practical. These were not effective research and development for 3D printing technology. In the study, the authors serve a methodology to select the specific technologies for practical used of 3D printing. Originality/value – Diverse predictions for 3D printing technology have been introduced in many academic and industrial fields. Most of them were made by subjective approaches depended on the knowledge and experience of the experts concerning 3D printing technology. So, they could be fluctuated according to the congregated expert groups, and be unstable for efficient R & D planning. To solve this problem, the authors study on more objective approach to predict the future state of 3D printing by analyzing the patent data of the developed results so far achieved. The contribution of this research is to take a new departure for understanding 3D printing technology using objective and quantitative methods.

3D printing towards implementing Industry 4.0: sustainability aspects, barriers and challenges

2022 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Abrar Malik ◽  
Mir Irfan Ul Haq ◽  
Ankush Raina ◽  
Kapil Gupta
Keyword(s):  
3D Printing ◽  
Industry 4.0 ◽  
Large Scale ◽  
Industrial Revolution ◽  
Energy Savings ◽  
Three Dimensional ◽  
Global Market ◽  
Printing Industry ◽  
Enabling Factors ◽  
Content Type

Purpose Environmental degradation has emerged as one of the major limitations of industrial revolution and has led to an increased focus towards developing sustainable strategies and techniques. This paper aims to highlight the sustainability aspects of three-dimensional (3D) printing technology that helps towards a better implementation of Industry 4.0. It also aims to provide a brief picture of relationships between 3D printing, Industry 4.0 and sustainability. The major goal is to facilitate the researchers, scholars, engineers and recommend further research, development and innovations in the field. Design/methodology/approach The various enabling factors for implementation of Industry 4.0 are discussed in detail. Some barriers to incorporation of 3D Printing, its applications areas and global market scenario are also discussed. A through literature review has been done to study the detailed relationships between 3D printing, Industry 4.0 and sustainability. Findings The technological benefits of 3D printing are many such as weight savings, waste minimization and energy savings. Further, the production of new 3D printable materials with improved features helps in reducing the wastage of material during the process. 3D printing if used at a large scale would help industries to implement the concept of Industry 4.0. Originality/value This paper focuses on discussing technological revolution under Industry 4.0 and incorporates 3D printing-type technologies that largely change the product manufacturing scenario. The interrelationships between 3D printing, Industry 4.0 and sustainability have been discussed.

Soft-tissue-mimicking using silicones for the manufacturing of soft phantoms by fresh 3D printing

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Aitor Tejo-Otero ◽  
Arthur Colly ◽  
Edwin-Joffrey Courtial ◽  
Felip Fenollosa-Artés ◽  
Irene Buj-Corral ◽  
...  
Keyword(s):  
Soft Tissue ◽  
3D Printing ◽  
Three Dimensional ◽  
Mechanical Analysis ◽  
Living Tissue ◽  
Scanning Calorimetry ◽  
Content Type ◽  
Microscopy Analysis ◽  
3D Printed ◽  
Liver Phantom

Purpose The purpose of this study is to use the Freeform Reversible Embedding of Suspended Hydrogels (FRESH) additive manufacturing (AM) technique for manufacturing a liver phantom which can mimic the corresponding soft living tissue. One of the possible applications is surgical planning. Design/methodology/approach A thermo-reversible Pluronic® F-127-based support bath is used for the FRESH technique. To verify how three-dimensional (3D)-printed new materials can mimic liver tissue, dynamic mechanical analysis and oscillation shear rheometry tests are carried out to identify mechanical characteristics of different 3D printed silicone samples. Additionally, the differential scanning calorimetry was done on the silicone samples. Then, a validation of a 3D printed silicone liver phantom is performed with a 3D scanner. Finally, the surface topography of the 3D printed liver phantom was fulfiled and microscopy analysis of its surface. Findings Silicone samples were able to mimic the liver, therefore obtaining the first soft phantom of the liver using the FRESH technique. Practical implications Because of the use of soft silicones, surgeons could practice over these improved phantoms which have an unprecedented degree of living tissue mimicking, enhancing their rehearsal experience before surgery. Social implications An improvement in surgeons surgery skills would lead to a bettering in the patient outcome. Originality/value The first research study was carried out to mimic soft tissue and apply it to the 3D printing of organ phantoms using AM FRESH technique.

Fabrication of nanocellulose/PEGDA hydrogel by 3D printing

2018 ◽  
Vol 24 (8) ◽  
pp. 1265-1271 ◽  
Author(s):  
Aimin Tang ◽  
Qinwen Wang ◽  
Shan Zhao ◽  
Wangyu Liu
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
3D Structure ◽  
Three Dimensional ◽  
Aqueous Dispersion ◽  
Compression Modulus ◽  
Content Type ◽  
Precise Control ◽  
Light Curing ◽  
Equilibrium Swelling Ratio

Purpose Nanocellulose is characterised by favourable biocompatibility, degradability, nanostructure effect, high modulus and high tensile strength and has been widely applied in various fields. The current research in the field of new nanocellulose materials mainly focuses on the hydrogel, aerogel and the tissue engineering scaffold. All of these are three-dimensional (3D) porous materials, but conventional manufacturing technology fails to realise precise control. Therefore, the method of preparing structural materials using 3D printing and adopting the nanocellulose as the 3D printing material has been proposed. Then, how to realise 3D printing of nanocellulose is the problem that should be solved. Design/methodology/approach By adding the photosensitive component polyethyleneglycol diacrylate (PEGDA) in the aqueous dispersion system of nanocellulose, the nanocellulose was endowed with photosensitivity. Then, nanocellulose/PEGDA hydrogels were prepared by the additive manufacturing of nanocellulose through light curing. Findings The results showed that the nanocellulose/PEGDA hydrogels had a uniform shape and a controllable structure. The nanocellulose supported the scaffold structure in the hydrogels. Prepared with 1.8 per cent nanocellulose through 40 s of light curing, the nanocellulose/PEGDA hydrogels had a maximum compression modulus of 0.91 MPa. The equilibrium swelling ratio of the nanocellulose/PEGDA hydrogel prepared with 1.8 per cent nanocellulose was 13.56, which increased by 44 per cent compared with that of the PEGDA hydrogel without nanocellulose. Originality/value The paper proposed a method for rapidly prototyping the nanocellulose with expected properties, which provided a theoretical basis and technological reference for the 3D additive manufacturing of nanocellulose 3D structure materials with a controlled accurate architecture.

Fast production of customized three-dimensional-printed hand splints

2020 ◽  
Vol 26 (1) ◽  
pp. 134-144 ◽  
Author(s):  
Diana Popescu ◽  
Aurelian Zapciu ◽  
Cristian Tarba ◽  
Dan Laptoiu
Keyword(s):  
3D Printing ◽  
Three Dimensional ◽  
Online Application ◽  
Content Type ◽  
3D Cad ◽  
Aesthetic Appearance ◽  
3D Printed ◽  
Manufacturing Time ◽  
Practical Implications

Purpose This paper aims to propose a new solution for producing customized three-dimensional (3D)-printed flat-shaped splints, which are then thermoformed to fit the patient’s hand. The splint design process is automated and is available to clinicians through an online application. Design/methodology/approach Patient anthropometric data measured by clinicians are associated with variables of parametric 3D splint models. Once these variables are input by clinicians in the online app, customized stereo lithography (STL) files for both splint and half mold, in the case of the bi-material splint, are automatically generated and become available for download. Bi-materials splints are produced by a hybrid manufacturing process involving 3D printing and overmolding. Findings This approach eliminates the need for 3D CAD-proficient clinicians, allows fast generation of customized splints, generates two-dimensional (2D) drawings of splints for verifying shape and dimensions before 3D printing and generates the STL files. Automation reduces splint design time and cost, while manufacturing time is diminished by 3D printing the splint in a flat position. Practical implications The app could be used in clinical practice. It meets the demands of mass customization using 3D printing in a field where individualization is mandatory. The solution is scalable – it can be extended to other splint designs or to other limbs. 3D-printed tailored splints can offer improved wearing comfort and aesthetic appearance, while maintaining hand immobilization, allowing visually controlled follow-up for edema and rapidly observing the need for revision if necessary. Originality/value An online application was developed for uploading patient measurements and downloading 2D drawings and STL files of customized splints. Different models of splints can be designed and included in the database as alternative variants. A method for producing bi-materials flat splints combining soft and rigid polymers represents another novelty of the research.

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