Search results

Multi-jet deposition of the materials is a matured technology used for graphic printing and 3 D printing for a wide range of materials. The multi-jet technology is fine-tuned for liquids with a specific range of viscosity and surface tension. However, the use of multi-jet for low viscosity fluids like water is not very popular. This paper aims to demonstrate the technique, particularly for the water-ice 3 D printing. 3 D printed ice parts can be used as patterns for investment casting, templates for microfluidic channel fabrication, support material for polymer 3 D printing, etc.

Multi-jet ice 3 D printing is a novel technique for producing ice parts by selective deposition and freezing water layers. The paper confers the design, embodiment and integration of various subsystems of multi-jet ice 3 D printer. The outcomes of the machine trials are reported as case studies with elaborate details.

The prismatic geometries are realized by ice 3 D printing. The accuracy of 0.1 mm is found in the build direction. The part height tends to increase due to volumetric expansion during the phase change.

The present paper gives a novel architecture of the ice 3 D printer that produces the ice parts with good accuracy. The potential applications of the process are deliberated in this paper.

Isolated communities face a variety of inconveniences including severe remoteness, poor roads and extreme climate conditions, resulting in the lack of security of supply chains and exorbitant prices for cargo delivery. This paper aims to investigate the present advantages and prospects of applying 3-D printing to improve economics and everyday life of remote communities, reindeer herder case taken as an example.

This study covers the use of a low-cost open-source 3-D printer (RepRap) capable of fused filament fabrication to reduce operating costs for nomadic reindeer herder groups. Three case studies are provided for reindeer-specific applications to probe economic and technical viability of the technology, namely, ear-tags, electric fence components and lasso accessories.

3-D printed objects feature technical characteristics similar to those of analogues available on the market while reducing the price by 63 per cent. Distributed 3-D printing reduces the cost of raw materials by 68 per cent and shipping costs by 50 because of lower trip frequency. If all reindeer herders globally were to adopt distributed manufacturing of the three aforementioned sample items only, their annual savings from such solution would amount to US$2m. The paper discovers other economic, entrepreneurial, technical and environmental opportunities offered by 3-D printing put to service the needs of remote communities.

As the paper is the first-ever study of 3-D printing potential applied to the reindeer husbandry case, it is based on a more thorough analysis of the techno-economic feasibility of the technology, while cultural and entrepreneurial factors have been discussed as preconditions only.

The paper might serve as a valuable source of information for entrepreneurs, as well as for students and academics for further case studies in this area.

In remote conditions, 3-D printing offers a more sustainable way of good manufacturing. Numerous open source designs already available for specialists, financial effectiveness, environmental benefits and vast opportunities for entrepreneurs are among the most promising advantages of the technology.

A review on additive manufacturing (AM) of shape memory polymer composites (SMPCs) is put forward to highlight the progress made up to date, conduct a critical review and show the limitations and possible improvements in the different research areas within the different AM techniques. The purpose of this study is to identify academic and industrial opportunities.

This paper introduces the reader to three-dimensional (3 D) and four-dimensional printing of shape memory polymers (SMPs). Specifically, this review centres on manufacturing technologies based on material extrusion, photopolymerization, powder-based and lamination manufacturing processes. AM of SMPC was classified according to the nature of the filler material: particle dispersed, i.e. carbon, metallic and ceramic and long fibre reinforced materials, i.e. carbon fibres. This paper makes a distinction for multi-material printing with SMPs, as multi-functionality and exciting applications can be proposed through this method. Manufacturing strategies and technologies for SMPC are addressed in this review and opportunities in the research are highlighted.

This paper denotes the existing limitations in the current AM technologies and proposes several directions that will contribute to better use and improvements in the production of additive manufactured SMPC. With advances in AM technologies, gradient changes in material properties can open diverse applications of SMPC. Because of multi-material printing, co-manufacturing sensors to 3D printed smart structures can bring this technology a step closer to obtain full control of the shape memory effect and its characteristics. This paper discusses the novel developments in device and functional part design using SMPC, which should be aided with simple first stage design models followed by complex simulations for iterative and optimized design. A change in paradigm for designing complex structures is still to be made from engineers to exploit the full potential of additive manufactured SMPC structures.

Advances in AM have opened the gateway to the potential design and fabrication of functional parts with SMPs and their composites. There have been many publications and reviews conducted in this area; yet, many mainly focus on SMPs and reserve a small section to SMPC. This paper presents a comprehensive review directed solely on the AM of SMPC while highlighting the research opportunities.

The material-jetting-type (MJ) 3-D printing technology has advantages in resolution and color printing. During the printing process, a leveling technique is needed to precisely control the thickness and flatness of each layer. Roller-type leveling mechanism has been adopted in commercial MJ 3-D printers, but it is lack of research on roller leveling process parameters and establishing experimental procedures. Therefore, in this study, a roller-type leveling mechanism for a MJ color 3 D printer was developed, and experimental approaches were utilized to determine process parameters.

The roller-type leveling mechanism was chosen to provide functions of flattening and removal of excess material. The parameters studied were roller speed and rotational direction. Surface roughness, Ra, of printed single-layered specimens was measured at 15 locations for plane roughness and along five lines for line roughness to evaluate the leveling results. Adopting suitable parameters, color samples with and without leveling were printed for comparison and verification.

According to plane roughness results, forward rotation achieved better leveling. Plane roughness was the major criteria to determine roller speed with the assistance of standard deviation of line roughness. The best parameters of the self-developed MJ color 3-D printer were found to be rolling forward at 1,100 rpm. In addition, printed color samples showed great improvement in surface roughness with leveling and no obvious color mixing after leveling.

Leveling is important to achieve desired layer thickness, smooth surface and good color quality in color 3-D printing. For MJ 3-D printing, only patents were revealed regarding roller design, but paper publications have not been presented. This research practically proposed to use experimental approach to understand the effects of roller operating parameters and to find the suitable ones based on surface roughness results.

This research established the experimental procedures and also suggested guidelines of experimentally obtaining suitable roller leveling process parameters. Developers can refer to this study results to design and adjust leveling mechanism in a new MJ 3-D printer.

The experimental approach can be applied to similar MJ 3-D printing systems if different materials are introduced or the platform speed is changed. The observed trends suggested several guidelines to plan limited experiments only to obtain suitable roller process parameters.

In flexible electronics applications, organic inks are mostly used for inkjet printing. Three-dimensional (3 D) printing technology has the advantages of low cost, high speed and good precision in modern electronic printing. The purpose of this study is to solve the high cost of traditional printing and the pollution emissions of organic ink. It is necessary to develop a water-based conductive ink that is easily degradable and can be 3 D printed. A nano-silver ink printed circuit pattern with high precision, high conductivity and good mechanical properties is a promising strategy.

The researched nano-silver conductive ink is mainly composed of silver nanoparticles and resin. The effect of adding methyl cellulose on the ink was also explored. A simple 3 D circuit pattern was printed on photographic paper. The line width, line length, line thickness and conductivity of the printed circuit were tested. The influence of sintering temperature and sintering time on pattern resistivity was studied. The relationship between circuit pattern bending performance and electrical conductivity is analyzed.

The experimental results show that the ink has the characteristics of low silver content and good environmental protection effect. The printing feasibility of 3 D printing circuit patterns on paper substrates was confirmed. The best printing temperature is 160°C–180°C, and the best sintering time is 30 min. The circuit pattern can be folded 120°, and the cycle is folded more than 60 times. The minimum resistivity of the circuit pattern is 6.07 µΩ·cm. Methyl cellulose can control the viscosity of the ink. The mechanical properties of the pattern have been improved. The printing method of 3 D printing can significantly reduce the sintering time and temperature of the conductive ink. These findings may provide innovation for the flexible electronics industry and pave the way for alternatives to cost-effective solutions.

In this study, direct ink writing technology was used to print circuit patterns on paper substrates. This process is simple and convenient and can control the thickness of the ink layer. The ink material is nonpolluting to the environment. Nano-silver ink has suitable viscosity and pH value. It can meet the requirements of pneumatic 3 D printers. The method has the characteristics of simple process, fast forming, low cost and high environmental friendliness.

In this era of Fourth Industrial Revolution, also known as Industry 4.0, additive manufacturing (AM) has been recognized as one of the nine technologies of Industry 4.0 that will revolutionize different sectors (such as manufacturing and industrial production). Therefore, this study aims to focus on “Additive Manufacturing Education” and the primary aim of this study is to investigate the impacts of AM technology at selected South African universities and develop a proposed framework for effective AM education using South African universities as the case study.

Quantitative research approach was used in this study, that is, a survey (questionnaire) was designed specifically to investigate the impacts of the existing AM technology/education and the facilities at the selected South African universities. The survey was distributed to several students (undergraduate and postgraduate) and the academic staffs within the selected universities. The questionnaire contained structured questions based on five factors/variables and followed by two open-ended questions. The data were collected and analyzed using statistical tools and were interpreted accordingly (i.e. both the closed and open-ended questions). The hypotheses were stated, tested and accepted. In conclusion, the framework for AM education at the universities was developed.

Based on different literature reviewed on “framework for AM technology and education”, there is no specific framework that centers on AM education and this makes it difficult to find an existing framework for AM education to serve as a landscape to determine the new framework for AM education at the universities. Therefore, the results from this study made a significant contribution to the body of knowledge in AM, most especially in the area of education. The significant positive responses from the respondents have shown that the existing AM in-house facilities at the selected South African universities is promoting AM education and research activities. This study also shows that a number of students at the South African universities have access to AM/3D printing lab for design and research purposes. Furthermore, the findings show that the inclusion of AM education in the curriculum of both the science and engineering education is South Africa will bring very positive results. The introduction of a postgraduate degree in AM such as MSc or MEng in AM will greatly benefit the South African universities and different industries because it will increase the number of AM experts and professionals. Through literature review, this study was able to identify five factors (which includes sub-factors) that are suitable for the development of a framework for AM education, and this framework is expected to serve as base-line or building block for other universities globally to build/develop their AM journey.

The survey was distributed to 200 participants and 130 completed questionnaires were returned. The target audience for the survey was mainly university students (both undergraduate and postgraduate) and the academics who have access to AM machines or have used the AM/3D printing lab/facilities on their campuses for both academic and research purposes. Therefore, one of the limitations of the survey is the limited sample size; however, the sample size for this survey is considered suitable for this type of research and would allow generalization of the findings. Nevertheless, future research on this study should use larger sample size for purpose of results generalization. In addition, this study is limited to quantitative research methodology; future study should include qualitative research method. Irrespective of any existing or developed framework, there is always a need to further improve the existing framework, and therefore, the proposed framework for AM education in this study contained only five factors/variables and future should include some other factors (AM commercialization, AM continuous Improvement, etc.) to further enhance the framework.

This study provides the readers and researchers within the STEM education, industry or engineering education/educators to see the importance of the inclusion of AM in the university curriculum for both undergraduate and postgraduate degrees. More so, this study serves as a roadmap for AM initiative at the universities and provides necessary factors to be considered when the universities are considering or embarking on AM education/research journey at their universities. It also serves as a guideline or platform for various investors or individual organization to see the need to invest in AM education.

The contribution of this study towards the existing body of knowledge in AM technology, specifically “AM education research” is in the form of proposed framework for AM education at the universities which would allow the government sectors/industry/department/bodies and key players in AM in South Africa and globally to see the need to invest significantly towards the advancement of AM technology, education and research activities at various universities.

This study aims to investigate the material extrusion additive manufacturing (MEAM) deposition parameters for creating viable 3-D printed polyvinylidene fluoride (PVDF) structures with a balanced mix of mechanical and electrical properties.

Different combinations of deposition conditions are tested, and the influence of these parameters on the final dimensional accuracy, semi-crystalline phase microstructure and effective mechanical strength of MEAM homopolymer PVDF printed parts is experimentally assessed. Considering printed part integrity, appearance, print time and dimensional accuracy, MEAM parameters for PVDF are suggested.

A range of viable printing parameters for MEAM fabricated PVDF Kynar 740 objects of different heights and in-plane length dimensions was determined. For PVDF structures printed under the suggested conditions, the mechanical response and the microstructure development related to Piezoelectric response are reported.

This research first reports on a range of parameters that have been confirmed to facilitate effective MEAM printing of 3-D PVDF objects, presents effects of the individual parameters and gives the mechanical and microstructure properties of PVDF structures fabricated under the suggested deposition conditions.

The tear strength (Ts) is a significant property for any kind of soft polymeric material such as rubber, elastomer, viscoelastic material and its composites, to quantify the suitability of a material for any shape memory applications. Many times, the soft elastomeric polymer material has to be capable enough to deform to a maximum extent of displacement but at the same time, it has to withstand the maximum load without fail. Along with shape recovery properties (i.e. the ability to recover its shape from programmed to the original), the success of the shape memory cycle is mainly depending on its stiffness and strength. It has to resist tear during stretching (i.e. programming stage) as repeatedly subjected to deformation, and, hence, it is important to study the tear behaviour for shape memory polymers (SMPs) and their composites. The purpose of the work is to investigate the effect of parameters on Ts of 4D printed specimen using Taguchi method.

The objective of the work is to tailor the Ts of SMPs by reinforcing the graphene nano particles (GNPs) in a blended photopolymer (PP) resin with flexible PP and hard PP resin. In this study, a total of nine experiments were designed based on the L9 orthogonal array (OA) using the design of experiments (DOEs). All the shape memory photopolymer composite’s (SMPPCs) specimens are fabricated using masked stereolithography (MSLA), also known as resin three-dimensional printing (R3DP) technique.

Specimens are tested using universal testing machine (UTM) for maximum tear force (F_max) and displacement (δ) caused by tearing the specimen to evaluate the strength against the tear. The results showed that the Wt.% of resin blend highly influenced both F_max and δ, while GNPs also had an impact on δ. The specimens are offering more tear resistance for those specimens blended with less Wt.% of flexible PP at the same time the specimens enable more δ for those specimens reinforced with 0.3 Wt.% GNPs at 10-s exposure time. The optimum combinations are A1, B1 and C3 for the F_max and T_s and at the same time A1, B3 and C3 for δ.

To customise the tear resistance of SMPPCs using MSLA 3 D printing, this study suggested a blend of PP resins reinforced with GNPs. This opens up a new path for creating novel, inexpensive multi-functional 4-dimensional (4D) printed parts.

The use of flexible PP and hard PP resin blends, fabricating the SMPPCs specimens using 3 D printed MSLA technology, investigating the effect of GNPs, resin blend and exposure time, optimizing the process parameters using Taguchi and the work were all validated using confirmation tests and regression analysis using test train method, which increases the originality and novelty.

In the past decade, three-dimensional (3D) printing has gained attention in areas such as medicine, engineering, manufacturing art and most recently in education. In biomedical, the development of a wide range of biomaterials has catalysed the considerable role of 3D printing (3DP), where it functions as synthetic frameworks in the form of scaffolds, constructs or matrices. The purpose of this paper is to present the state-of-the-art literature coverage of 3DP applications in tissue engineering (such as customized scaffoldings and organs, and regenerative medicine).

This review focusses on various 3DP techniques and biomaterials for tissue engineering (TE) applications. The literature reviewed in the manuscript has been collected from various journal search engines including Google Scholar, Research Gate, Academia, PubMed, Scopus, EMBASE, Cochrane Library and Web of Science. The keywords that have been selected for the searches were 3 D printing, tissue engineering, scaffoldings, organs, regenerative medicine, biomaterials, standards, applications and future directions. Further, the sub-classifications of the keyword, wherever possible, have been used as sectioned/sub-sectioned in the manuscript.

3DP techniques have many applications in biomedical and TE (B-TE), as covered in the literature. Customized structures for B-TE applications are easy and cost-effective to manufacture through 3DP, whereas on many occasions, conventional technologies generally become incompatible. For this, this new class of manufacturing must be explored to further capabilities for many potential applications.

This review paper presents a comprehensive study of the various types of 3DP technologies in the light of their possible B-TE application as well as provides a future roadmap.