Visual presentation for monitoring layer-wise curing quality in DLP 3D printing

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Lifang Wu ◽  
Zechao Liu ◽  
Yupeng Guan ◽  
Kejian Cui  ◽  
Meng Jian ◽  
...  

Purpose This paper aims to address the problem of uncertain product quality in digital light processing (DLP) three-dimensional (3D) printing, a scheme is proposed to qualitatively estimate whether a layer is printed with the qualified quality or not cured . Design/methodology/approach A thermochromic pigment whose color fades at 45°C is prepared as the indicator and it is mixed with the resin. A visual surveillance framework is proposed to monitor the visual variation in a period of the entire curing process. The exposure region is divided into 30 × 30 sub-regions; gray-level variation curves (curing curves) in all sub-regions are classified as normal or abnormal and a corresponding printing control strategy is designed to improve the percentage of qualified printed objects. Findings The temperature variation caused by the releasing reaction heat on the exposure surface is consistent in different regions under the homogenized light intensity. The temperature in depth begins to rise at different times. The temperature in the regions near the light source rises earlier, and that far from the light source rises later. Thus, the color of resin mixed with the thermochromic pigment fades gradually over a period of the entire solidification process. The color variation in the regions with defects of bubbles, insufficient material filling, etc., is much different from that in the normal curing regions. Originality/value A temperature-sensitive organic chromatic chemical pigment is prepared to present the visual variation over a period of the entire curing process. A novel 3D printing scheme with visual surveillance is proposed to monitor the layer-wise curing quality and to timely stop the possible unqualified printing resulted from bubbles, insufficient material filling, etc.

2021 ◽  
Vol 27 (2) ◽  
pp. 421-428
Author(s):  
Rudranarayan Kandi ◽  
Pulak Mohan Pandey ◽  
Misba Majood ◽  
Sujata Mohanty

Purpose This paper aims to discuss the successful fabrication of customized tubular scaffolds for tracheal tissue engineering with a novel route using solvent-based extrusion 3D printing. Design/methodology/approach The manufacturing approach involved extrusion of polymeric ink over a rotating predefined pattern to construct customized tubular structure of polycaprolactone (PCL) and polyurethane (PU). Dimensional deviation in thickness of scaffolds were calculated for various layer thicknesses of 3D printing. Physical and chemical properties of scaffolds were investigated by scanning electron microscope (SEM), contact angle measurement, Fourier Transform Infrared Spectroscopy (FTIR) and X-ray diffraction (XRD). Mechanical characterizations were performed, and the results were compared to the reported properties of human native trachea from previous reports. Additionally, in vitro cytotoxicity of the fabricated scaffolds was studied in terms of cell proliferation, cell adhesion and hemagglutination assay. Findings The developed fabrication route was flexible and accurate by printing customized tubular scaffolds of various scales. Physiochemical results showed good miscibility of PCL/PU blend, and decrease in crystalline nature of blend with the addition of PU. Preliminary mechanical assessments illustrated comparable mechanical properties with the native human trachea. Longitudinal compression test reported outstanding strength and flexibility to maintain an unobstructed lumen, necessary for the patency. Furthermore, the scaffolds were found to be biocompatible to promote cell adhesion and proliferation from the in vitro cytotoxicity results. Practical implications The attempt can potentially meet the demand for flexible tubular scaffolds that ease the concerns such as availability of suitable organ donors. Originality/value 3D printing over accurate predefined templates to fabricate customized grafts gives novelty to the present method. Various customized scaffolds were compared with conventional cylindrical scaffold in terms of flexibility.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Sapam Ningthemba Singh ◽  
Vavilada Satya Swamy Venkatesh ◽  
Ashish Bhalchandra Deoghare

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.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yuran Jin ◽  
Shoufeng Ji ◽  
Li Liu ◽  
Wei Wang

PurposeMore and more enterprises have realized the importance of business model innovation. However, the model tools for it are still scarce. There is a clear research gap in this academic field. Therefore, the aim of this study is to put forward a visual business model innovation model.Design/methodology/approachThe scientific literature clustering paradigm of grounded theory is used to design business model innovation theory model (BMITM). BMITM and the business model innovation options traced back from 870 labels in the grounded process are integrated into a unified framework to build the business model innovation canvas (BMIC).FindingsBMIC composed of three levels and seven modules is successfully developed. 145 business model innovation options are designed in BMIC. How to use BMIC is explained in detail. Through the analysis of innovation hotspots, the potential business model innovation directions can be found. A new business model of clothing enterprises using 3D printing is innovated with BMIC as an example.Research limitations/implicationsCompared with the previous tools, BMIC owns a clearer business model innovation framework and provides a problem-oriented business model innovation process and mechanism.Practical implicationsBMIC provides a systematic business model innovation solution set and roadmap for business model innovation practitioners.Originality/valueBMIC, a new tool for business model innovation is put forward for the first time. “Mass Selection Customization-Centralized Manufacturing” designed with BMIC for the clothing enterprises using 3D printing is put forward for the first time.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yangwei Wang ◽  
Peilun Lv ◽  
Jian Li ◽  
Liying Yu ◽  
Guodong Yuan ◽  
...  

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.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yuezong Wang ◽  
Jinghui Liu ◽  
Mengfei Guo ◽  
LiuQIan Wang

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.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Chien-Ho Ko

Purpose Additive manufacturing of concrete (AMoC) is an emerging technology for constructing buildings. However, due to the nature of the concrete property and constructing buildings in layers, constraints and limitations are encountered while applying AMoC in architecture. This paper aims to analyze the constraints and limitations that may be encountered while using AMoC in architecture. Design/methodology/approach A descriptive research approach is used to conduct this study. First, basic notions of AMoC are introduced. Then, challenges of AMoC, including hardware, material property, control and design, are addressed. Finally, strategies that may be used to overcome the challenges are discussed. Findings Factors influencing the success of AMoC include hardware, material, control methods, manufacturing process and design. Considering these issues in the early design phase is crucial to achieving a successful computer-aided design (CAD)/computer-aided manufacturing (CAM) integration to bring CAD and CAM benefits into the architecture industry. Originality/value In three-dimensional (3D) printing, objects are constructed layer by layer. Printing results are thus affected by the additive method (such as toolpath) and material properties (such as tensile strength and slump). Although previous studies attempt to improve AMoC, most of them focus on the manufacturing process. However, a successful application of AMoC in architecture needs to consider the possible constraints and limitations of concrete 3D printing. So far, research on the potential challenges of applying AMoC in architecture from a building lifecycle perspective is still limited. The study results of this study could be used to improve design and construction while applying AMoC in architecture.


2017 ◽  
Vol 89 (6) ◽  
pp. 791-796
Author(s):  
Yasser A. Nogoud ◽  
Attie Jonker ◽  
Shuhaimi Mansor ◽  
A.A.A. Abuelnuor

Purpose This paper aims to propose a spreadsheet method for modeling and simulation of a retraction system mechanism for the retractable self-launching system for a high-performance glider. Design/methodology/approach More precisely, the method is based on parametric link design using Excel spreadsheets. Findings This method can be used for kinematic and dynamic analysis, graphical plotting and allows simulation of control kinematics with the ability to make quick and easy parametric changes to a design. It also has the ability to calculate the loads imposed on each component in the control system as a function of input loads and position. Practical implications This paper shows that it is possible to model complex control systems quickly and easily using spreadsheet programs already owned by most small companies. The spreadsheet model is a parametric model, and it gives a simple visual presentation of the control system with interactive movement and control by the user. Originality/value This spreadsheet model in conjunction with a simple CAD program enables the rapid and cost-effective development of control system components.


Author(s):  
Lifang Wu ◽  
Miao Yu ◽  
Yisong Gao ◽  
Dong-Ming Yan ◽  
Ligang Liu

2018 ◽  
Vol 24 (9) ◽  
pp. 1421-1427 ◽  
Author(s):  
Feng Liu ◽  
Shaoai Xie ◽  
Yan Wang ◽  
Jianjun Yu ◽  
Qinghua Meng

PurposeThe titania (titanium dioxide) is one of the important functional additives in the photosensitive resin and encounters the problem of stabilization in the photosensitive resin for 3D printing. This study aims to achieve enhancement in stabilization by preparation of the polymerizable titania andin situlaser-induced crystallization during 3D printing.Design/methodology/approachA type of polymerizable titania (AAEM@TiO2) was designed and prepared from tetrabutyl titanate (TBT) and 2-(acetoacetoxy)ethyl methacrylate (AAEM) via the sol–gel process, which was characterized by Fourier-transform infrared (FTIR) spectra, ultraviolet–visible (UV-Vis) spectra, surface bonding efficiency (SBE) and settling height (H). AAEM acted on both bonding to the titania and polymerization with the monomer in resin for stabilization. The polymerizable titania could be converted to the pigmented titania by means of laser-induced crystallization. The photosensitive resin was then formulated on the basis of optimization and used in a stereolithography apparatus (SLA) for 3D printing.FindingsThe stabilization effect of AAEM on TiO2was achieved and the mechanism of competition in the light-consuming reactions during photocuring was proposed. The ratio of nAAEM/nTBTin AAEM@TiO2, the concentration of AAEM@TiO2and photoinitiator (PI) used in the photosensitive resin were optimized. The anatase crystal form was indicated by X-ray diffraction (XRD) and clustering of nanocrystals was revealed by scanning electron microscopy (SEM) after SLA 3D printing.Originality/valueThis investigation provides a novel method of pigmentation by preparation of the polymerizable titania andin situlaser-induced crystallization for SLA 3D printing.


2019 ◽  
Vol 25 (3) ◽  
pp. 496-514 ◽  
Author(s):  
Nataraj Poomathi ◽  
Sunpreet Singh ◽  
Chander Prakash ◽  
Rajkumar V. Patil ◽  
P.T. Perumal ◽  
...  

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.


Sign in / Sign up

Export Citation Format

Share Document