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Article

Yashwant Kumar Modi and Kiran Kumar Sahu

This study aims to optimize the process parameters of ZPrinter® 450 for measured porosity (MP) and compressive strength (CS) of calcium sulfate-based porous bone scaffold…

Abstract

Purpose

This study aims to optimize the process parameters of ZPrinter® 450 for measured porosity (MP) and compressive strength (CS) of calcium sulfate-based porous bone scaffold using Taguchi approach.

Design/methodology/approach

Initially, a porous scaffold with smallest pore size that can be de-powdered completely is identified through a pilot study. Five printing parameters, namely, layer thickness (LT), build orientation (BO), build position (BP), delay time (DT) and binder saturation (BS), each at three levels have been optimized for MP and CS of the fabricated scaffolds using L27 orthogonal array (OA), signal-to-noise ratio and analysis of variance (ANOVA).

Findings

The scaffolds with 600 µm pores could be de-powdered completely. Optimum levels of parameters are LT2, BO1, BP2, DT1 and BS1 for MP and LT1, BO1, BP2, DT1 and BS2 for CS. The ANOVA reveals that the BS (49.12%) is the most and BP (8.34%) is the least significant parameter for MP. LT (50.84%) is the most, BO (33.79%) is second most and DT (2.59%) is the least significant parameter for CS. Taguchi confirmation test and linear regression models indicate a good agreement between predicted and experimental values of MP and CS. The experimental values of MP and CS at the optimum levels of parameters are found 38.12% and 1.29 MPa, respectively.

Originality/value

The paper presents effect of process parameters of ZPrinter® 450 on MP and CS of calcium sulfate-based porous scaffolds. Results may be used as guideline for powder bed binder jetting three-dimensional printing of ceramic scaffolds.

Details

Rapid Prototyping Journal, vol. 27 no. 2
Type: Research Article
ISSN: 1355-2546

Keywords

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Article

Hoejin Kim, Yirong Lin and Tzu-Liang Bill Tseng

The usage of additive manufacturing (AM) technology in industries has reached up to 50 per cent as prototype or end-product. However, for AM products to be directly used…

Abstract

Purpose

The usage of additive manufacturing (AM) technology in industries has reached up to 50 per cent as prototype or end-product. However, for AM products to be directly used as final products, AM product should be produced through advanced quality control process, which has a capability to be able to prove and reach their desire repeatability, reproducibility, reliability and preciseness. Therefore, there is a need to review quality-related research in terms of AM technology and guide AM industry in the future direction of AM development.

Design/methodology/approach

This paper overviews research progress regarding the QC in AM technology. The focus of the study is on manufacturing quality issues and needs that are to be developed and optimized, and further suggests ideas and directions toward the quality improvement for future AM technology. This paper is organized as follows. Section 2 starts by conducting a comprehensive review of the literature studies on progress of quality control, issues and challenges regarding quality improvement in seven different AM techniques. Next, Section 3 provides classification of the research findings, and lastly, Section 4 discusses the challenges and future trends.

Findings

This paper presents a review on quality control in seven different techniques in AM technology and provides detailed discussions in each quality process stage. Most of the AM techniques have a trend using in-situ sensors and cameras to acquire process data for real-time monitoring and quality analysis. Procedures such as extrusion-based processes (EBP) have further advanced in data analytics and predictive algorithms-based research regarding mechanical properties and optimal printing parameters. Moreover, compared to others, the material jetting progresses technique has advanced in a system integrated with closed-feedback loop, machine vision and image processing to minimize quality issues during printing process.

Research limitations/implications

This paper is limited to reviewing of only seven techniques of AM technology, which includes photopolymer vat processes, material jetting processes, binder jetting processes, extrusion-based processes, powder bed fusion processes, directed energy deposition processes and sheet lamination processes. This paper would impact on the improvement of quality control in AM industries such as industrial, automotive, medical, aerospace and military production.

Originality/value

Additive manufacturing technology, in terms of quality control has yet to be reviewed.

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Article

Javier Navarro, Matthew Din, Morgan Elizabeth Janes, Jay Swayambunathan, John P. Fisher and Maureen L. Dreher

This paper aims to study the effects of part orientation during the 3D printing process, particularly to the case of using continuous digital light processing (cDLP) technology.

Abstract

Purpose

This paper aims to study the effects of part orientation during the 3D printing process, particularly to the case of using continuous digital light processing (cDLP) technology.

Design/methodology/approach

The effects of print orientation on the print accuracy of microstructural features were assessed using microCT imaging and mechanical properties of cDLP microporous scaffolds were characterized under simple compression and complex biaxial loading. Resin viscosity was also quantified to incorporate this factor in the printing discussion.

Findings

The combined effect of print resin viscosity and the orientation and spacing of pores within the structure alters how uncrosslinked resin flows within the construct during cDLP printing. Microstructural features in horizontally printed structures exhibited greater agreement to the design dimensions than vertically printed constructs. While cDLP technologies have the potential to produce mechanically isotropic solid constructs because of bond homogeneity, the effect of print orientation on microstructural feature sizes can result in structurally anisotropic porous constructs.

Originality/value

This work is useful to elucidate on the specific capabilities of 3D printing cDLP technology. The orientation of the part can be used to optimize the printing process, directly altering parameters such as the supporting structures required, print time, layering, shrinkage or surface roughness. This study further detailed the effects on the mechanical properties and the print accuracy of the printed scaffolds.

Details

Rapid Prototyping Journal, vol. 25 no. 6
Type: Research Article
ISSN: 1355-2546

Keywords

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Article

A.R. Mirhabibi, F. Moztarzadeh, A. Aghajani Bazazi, M. Solati, A. Maghsoudipour and M.H. Sarrafi

Long afterglow Sr2MgSi2O7 (SMS) phosphor was prepared by Douby's methods at high temperature and reductive atmosphere. The excitation and emission spectra of this phosphor…

Abstract

Long afterglow Sr2MgSi2O7 (SMS) phosphor was prepared by Douby's methods at high temperature and reductive atmosphere. The excitation and emission spectra of this phosphor showed that both had broad bands and that the main emission peak at 469 nm was due to 4f‐5d transitions of Eu+2 and implied that the luminescence centres Eu+2 occupied the Sr+2 sites in the Sr2MgSi2O7 host. The phosphor doped only with Eu ions did not demonstrate the long afterglow phenomenon, but when co‐doped with Dy+3 ions in the SMS matrix, significant long afterglow was observed.

Details

Pigment & Resin Technology, vol. 33 no. 4
Type: Research Article
ISSN: 0369-9420

Keywords

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Article

Marco Leite, André Varanda, António Relógio Ribeiro, Arlindo Silva and Maria Fátima Vaz

The purpose of this paper is to investigate the effect of a sealing protective treatment on the water absorption and mechanical properties of acrylonitrile butadiene…

Abstract

Purpose

The purpose of this paper is to investigate the effect of a sealing protective treatment on the water absorption and mechanical properties of acrylonitrile butadiene styrene (ABS)-printed parts by fused deposition modelling. Protective products include aqueous acetone solutions with different concentrations, polyurethane wood sealer and aqueous acrylic-based varnish.

Design/methodology/approach

Open porosity was estimated by the absorption coefficient and the total amount of water retained, obtained from water absorption tests. Mechanical characterization was performed by compressive and tensile tests. Different specimens with different build directions and raster angles were used.

Findings

The treatments with acetone solutions were not effective in reducing the porosity of ABS parts, as the amount of acetone that reduces effectively the porosity will also affect the sample dimensional stability. The polyurethane treatment was found to reduce the absorption coefficient, but the maximum water content and the open porosity remain almost unchanged in comparison with the ones obtained for untreated specimens. The treatment with an acrylic-based varnish was found to preserve the dimensional stability of the specimens, to reduce the open porosity and to maintain the compression and tension properties of the specimens in different build directions and raster angles.

Originality/value

Surface modification for water tight applications of ABS 3D printing parts enables new designs where both sealing and the preservation of mechanical properties are important. As per the knowledge of the authors, the water absorption and the mechanical behaviour of ABS 3D printed parts, before and after treatment, were not previously investigated.

Details

Rapid Prototyping Journal, vol. 24 no. 1
Type: Research Article
ISSN: 1355-2546

Keywords

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Article

Hsin-Chieh Wu and Tin-Chih Toly Chen

This study aims to investigate issues of quality and quality control (QC) in three-dimensional (3D) printing by reviewing past work and current practices. Possible future…

Abstract

Purpose

This study aims to investigate issues of quality and quality control (QC) in three-dimensional (3D) printing by reviewing past work and current practices. Possible future developments are also discussed.

Design/methodology/approach

After a discussion of the major quality dimensions of 3D-printed objects, the applications of some QC techniques at various stages of the product life cycle (including product design, process planning, incoming QC, in-process QC and outgoing QC) are introduced.

Findings

The application of QC techniques to 3D printing is not uncommon. Some techniques (e.g. cause-and-effect analysis) have been applied extensively; others, such as design of experiments, have not been used accurately and completely and therefore cannot optimize quality. Taguchi’s method and control charts can enhance the quality of 3D-printed objects; however, these techniques require repetitive experimentation, which may not fit the work flow of 3D printing.

Originality/value

Because quality issues may discourage customers from buying 3D-printed products, enhancing 3D printing quality is imperative. In addition, 3D printing can be used to manufacture diverse products with a reduced investment in machines, tools, assembly and materials. Production economics issues can be addressed by successfully implementing QC.

Details

Rapid Prototyping Journal, vol. 24 no. 3
Type: Research Article
ISSN: 1355-2546

Keywords

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Abstract

Purpose

The purpose of this study is to explore a methodology for connecting microelectromechanical system sensors – i.e. inertial measurement unit (IMU) – to an Arduino-based microcontroller, using graphene-based conductive filament and flexible thermoplastic polyurethane (FTPU) filament and low-cost dual material extrusion technology.

Design/methodology/approach

A series of electrical tests were carried out to determine the maximum resistance the conductive paths may take to connect printed circuit boards (PCB). To select the most suitable printing material, three types of conductive filaments were examined. Then an experiment was carried out to find the best printing parameters in terms of printing speed, printing temperature and layer height to minimise resistivity. The size of the conductive path was also analysed. A final prototype was designed and printed according to optimised printing settings and maximum allowable resistances for each line and considering different geometries and printing strategies to reduce cross-contamination among paths.

Findings

For the Black Magic 3D conductive filament, the printing speed and layer height played a significant role regarding resistivity, while the printing temperature was not very important. The infill pattern of the conductive paths had to be aligned with the expected current path, while using air gaps between two adjacent paths resulted in the best approach to reducing cross-contamination. Moreover, the cross-section size of the conductive path did not affect the volume resistivity. When combined with FTPU filament constraints, the prototype yielded suitable electrical performance and printing quality when printed at a temperature of 220°C, speed of 20 mm/s and layer height of 0.2 mm.

Originality/value

This paper explores a systematic methodology for the additive manufacturing of commercial conductive material using low-cost extrusion technology to connect complex electronics when data transmission is a key feature.

Details

Rapid Prototyping Journal, vol. 26 no. 2
Type: Research Article
ISSN: 1355-2546

Keywords

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Article

Mustafa Ayyildiz

This paper aims to discuss the utilization of artificial neural networks (ANNs) and multiple regression method for estimating surface roughness in milling medium density…

Abstract

Purpose

This paper aims to discuss the utilization of artificial neural networks (ANNs) and multiple regression method for estimating surface roughness in milling medium density fiberboard (MDF) material with a parallel robot.

Design/methodology/approach

In ANN modeling, performance parameters such as root mean square error, mean error percentage, mean square error and correlation coefficients (R2) for the experimental data were determined based on conjugate gradient back propagation, Levenberg–Marquardt (LM), resilient back propagation, scaled conjugate gradient and quasi-Newton back propagation feed forward back propagation training algorithm with logistic transfer function.

Findings

In the ANN architecture established for the surface roughness (Ra), three neurons [cutting speed (V), feed rate (f) and depth of cut (a)] were contained in the input layer, five neurons were included in its hidden layer and one neuron was contained in the output layer (3-5-1).Trials showed that LM learning algorithm was the best learning algorithm for the surface roughness. The ANN model obtained with the LM learning algorithm yielded estimation training values R2 (97.5 per cent) and testing values R2 (99 per cent). The R2 for multiple regressions was obtained as 96.1 per cent.

Originality/value

The result of the surface roughness estimation model showed that the equation obtained from the multiple regressions with quadratic model had an acceptable estimation capacity. The ANN model showed a more dependable estimation when compared with the multiple regression models. Hereby, these models can be used to effectively control the milling process to reach a satisfactory surface quality.

Details

Sensor Review, vol. 39 no. 5
Type: Research Article
ISSN: 0260-2288

Keywords

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Article

Julien Gardan

This paper aims to present a technical approach to evaluate the quality of textures obtained by an inkjet during binder jetting in 3D printing on a powder bed through…

Abstract

Purpose

This paper aims to present a technical approach to evaluate the quality of textures obtained by an inkjet during binder jetting in 3D printing on a powder bed through contours detection to improve the quality of the surface printed according to the result of the assembly between the inkjet and a granular product.

Design/methodology/approach

The manufacturing process is based on the use of computer-aided design and a 3D printer via binder jetting. Image processing measures the edge deviation of a texture on the granular surface with the possibility of implementing a correction in an active assembly through a “design for manufacturing” (DFM) approach. Example application is presented through first tests.

Findings

This approach observes a shape alteration of the printed image on a 3D printed product, and the work used the image processing method to improve the model according to the DFM approach.

Originality/value

This paper introduces a solution for improving the texture quality on 3D printed products realized via binder jetting. The DFM approach proposes an active assembly by compensating the print errors in upstream of a product life cycle.

Details

Assembly Automation, vol. 37 no. 2
Type: Research Article
ISSN: 0144-5154

Keywords

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Article

Justin Favero, Sofiane Belhabib, Sofiane Guessasma and Hedi Nouri

Assembling items to achieve bigger parts seems to be the solution to counterbalance the dimension limits of 3D printing. This work aims to propose an approach to achieve…

Abstract

Purpose

Assembling items to achieve bigger parts seems to be the solution to counterbalance the dimension limits of 3D printing. This work aims to propose an approach to achieve optimal assembling.

Design/methodology/approach

Acrylonitrile butadiene styrene polymer samples were printed using fused deposition modelling (FDM). These samples were assembled and the precise contribution of interfacial shearing and tension was measured using simple tensile experiments.

Findings

The results achieved show the correlation between the printing orientation and the assembling angle. It could be proved that rupture by an interfacial decohesion mechanism of glued parts can be avoided by simple adaptation of the assembling junction.

Practical implications

Design of large parts using FDM is no more a limitation if assembling configurations are adapted based on the knowledge gained about the interfacial phenomena occurring at the junction position.

Originality/value

The unbalanced contribution of shearing and tension at the interface defines new assembling profiles that exclude flat junctions.

Details

Rapid Prototyping Journal, vol. 25 no. 1
Type: Research Article
ISSN: 1355-2546

Keywords

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