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Available. Open Access. Open Access
Article
Publication date: 12 March 2018

Fengyuan Liu, Srichand Hinduja and Paulo Bártolo

This paper aims to describe the control software of a novel manufacturing system called plasma-assisted bio-extrusion system (PABS), designed to produce complex multi-material and…

1334

Abstract

Purpose

This paper aims to describe the control software of a novel manufacturing system called plasma-assisted bio-extrusion system (PABS), designed to produce complex multi-material and functionally graded scaffolds for tissue engineering applications. This fabrication system combines multiple pressure-assisted and screw-assisted printing heads and plasma jets. Control software allows the users to create single or multi-material constructs with uniform pore size or pore size gradients by changing the operation parameters, such as geometric parameters, lay-down pattern, filament distance, feed rate and layer thickness, and to produce functional graded scaffolds with different layer-by-layer coating/surface modification strategies by using the plasma modification system.

Design/methodology/approach

MATLAB GUI is used to develop the software, including the design of the user interface and the implementation of all mathematical programing for both multi-extrusion and plasma modification systems.

Findings

Based on the user definition, G programing codes are generated, enabling full integration and synchronization with the hardware of PABS. Single, multi-material and functionally graded scaffolds can be obtained by manipulating different materials, scaffold designs and processing parameters. The software is easy to use, allowing the efficient control of the PABS even for the fabrication of complex scaffolds.

Originality/value

This paper introduces a novel additive manufacturing system for tissue engineering applications describing in detail the software developed to control the system. This new fabrication system represents a step forward regarding the current state-of-the-art technology in the field of biomanufacturing, enabling the design and fabrication of more effective scaffolds matching the mechanical and surface characteristics of the surrounding tissue and enabling the incorporation of high number of cells uniformly distributed and the introduction of multiple cell types with positional specificity.

Details

Rapid Prototyping Journal, vol. 24 no. 2
Type: Research Article
ISSN: 1355-2546

Keywords

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Article
Publication date: 20 June 2017

Reza Gheisari, Paulo Bártolo, Nicholas Goddard and Marco Andre das Neves Domingos

The use of microstereolithography (μSL) parts as micro-injection molding (μIM) tools greatly reduces the time and cost to product and offers unique solutions for complex design…

605

Abstract

Purpose

The use of microstereolithography (μSL) parts as micro-injection molding (μIM) tools greatly reduces the time and cost to product and offers unique solutions for complex design issues. However, they present challenges to designers because of their strength, thermal characteristics and shorter lifetimes as compared to other mold materials. The purpose of this study is to use SL to build rapid injection mold tools directly combining micro features for short-run production.

Design/methodology/approach

In total, three tool inserts were produced. Two different μSL mold inserts were produced and evaluated in terms of different build approaches of micro features. One of the inserts includes micro features built horizontally, while the other one collaborates features built vertically, both having same geometrical dimensions. To evaluate the replication capability of prototype tools, two different thicknesses were set for micro features, that is, 30 and 120 μm. The mold inserts were assembled on a metallic mold frame and tested with polypropylene (PP).

Findings

It was observed that using inappropriate resin to fabricate the mold inserts can lead to inaccurate geometrical dimensions of the tool. Therefore, the material with high glass transition temperature (Tg) and low thermal conductivity is preferred. Also, the results of this research work showed that the processed material and technology play an important role both on part quality and tool life. After investigating the tool failure mechanisms during the injection, it was observed that tool failure occurred mainly because of excessive flexural stresses and ejection forces during the cavity filling and part ejection phases, respectively.

Originality/value

The paper describes the capability of μSL mold inserts for the production of small batches of micro-cantilevers which are used in MEMS relays.

Details

Rapid Prototyping Journal, vol. 23 no. 4
Type: Research Article
ISSN: 1355-2546

Keywords

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Article
Publication date: 22 August 2017

Eduardo Castro e Costa, José Pinto Duarte and Paulo Bártolo

In this paper, the authors aim to address the potential of mass personalization for ceramic tableware objects. They argue that additive manufacturing (AM) is the most adequate…

2237

Abstract

Purpose

In this paper, the authors aim to address the potential of mass personalization for ceramic tableware objects. They argue that additive manufacturing (AM) is the most adequate approach to the production of such objects.

Design/methodology/approach

The authors review the manufacturing of ceramic tableware objects, both traditional techniques and AM processes, and assess which available AM technologies are suitable for the research purpose.

Findings

The authors consider binder jetting and material extrusion as the most suitable processes for the production of ceramic objects to be integrated into a mass personalization system of ceramic tableware.

Originality/value

This paper provides an original overview of traditional and innovative techniques in ceramic manufacturing, exposing not only its differences but also its commonalities. Such overview supports the conceptual design of original equipment.

Details

Rapid Prototyping Journal, vol. 23 no. 5
Type: Research Article
ISSN: 1355-2546

Keywords

Available. Open Access. Open Access
Article
Publication date: 11 December 2024

Julian M. Müller, Nikolai Kazantsev, Richard Allmendinger, Amirhossein Salehi-Amiri, Jacqueline Zonichenn Reis, Shaden Jaradat, Helena Bartolo and Paulo Jorge Da Silva Bartolo

This conceptual paper aims to present a perspective on how to engineer sustainability through the prism of Industry 4.0 technologies and outline propositions to guide future…

132

Abstract

Purpose

This conceptual paper aims to present a perspective on how to engineer sustainability through the prism of Industry 4.0 technologies and outline propositions to guide future research.

Design/methodology/approach

This study presents a literature review developing four research propositions, focusing on the nine leading technologies underpinning Industry 4.0 to engineer economic, environmental and social sustainability dimensions.

Findings

The authors derive benefits and challenges of Industry 4.0 technologies across all three business model elements: value creation, value delivery and value capture. The authors derive those for the economic, environmental and social dimensions of sustainability. Thereupon, we develop several propositions for future research.

Practical implications

The authors provide suggestions to practice how to better achieve value in all three sustainability dimensions through implementing a business model perspective, ecosystem thinking, societal demands and Data Governance and AI integration.

Social implications

By linking societal aspects of Industry 4.0 technologies with environmental, and economic aspects, the authors provide several suggestions how to implement Industry 4.0. For instance, policymakers are recommended to support entire ecosystems than isolated solutions.

Originality/value

The paper contributes to extant literature by conceptualising how Industry 4.0 can leverage value in reaching sustainability in all three dimensions and produce broader ecosystems-wide impacts.

Details

Sustainability Accounting, Management and Policy Journal, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 2040-8021

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Article
Publication date: 1 July 2006

Paulo Bartolo, Joel Vasco, Bruno Silva and Carlos Galo

Laser milling is a recent process in mould making, providing several advantages over traditional mould making technologies by reducing manufacturing time, shortening the number of…

1274

Abstract

Purpose

Laser milling is a recent process in mould making, providing several advantages over traditional mould making technologies by reducing manufacturing time, shortening the number of machining operations and avoiding expensive electrodes. This paper investigates the influence of the operating conditions on both the surface quality and material removal for two types of materials commonly used in mould making.

Design/methodology/approach

Laser scanning strategies and operating parameters like scanning speed and laser frequency and power were tested, regarding surface quality and material removal rate. The most representative parameter of the real surface quality, Rk, the core roughness parameter, is used to characterise the surface finishing on all cavities.

Findings

The findings of this research work suggest that it is possible to significantly reduce processing time by increasing the hatch spacing up to a value close to the laser beam spot diameter, without compromising surface quality. Lower pulse frequencies and laser power are more appropriate whenever surface quality is an issue. Higher material removal rates are achieved by increasing both the pulse frequency till an optimum value and laser power. The increase of scanning speed reduces the material removal rate by decreasing the overlap degree between individual laser pulses.

Originality/value

The originality is to correlate the influence of the operating conditions of laser milling on both the surface quality and material removal for different types of materials.

Details

Assembly Automation, vol. 26 no. 3
Type: Research Article
ISSN: 0144-5154

Keywords

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Article
Publication date: 16 January 2009

Pedro Gonçalves Martinho, Paulo Jorge Bártolo and António Sérgio Pouzada

This paper aims to explore the influence of the materials used in moulding blocks of hybrid moulds on the injection moulding setup and the properties of the mouldings.

1162

Abstract

Purpose

This paper aims to explore the influence of the materials used in moulding blocks of hybrid moulds on the injection moulding setup and the properties of the mouldings.

Design/methodology/approach

An instrumented (pressure and temperature) hybrid mould with exchangeable moulding blocks, produced by rapid prototyping and tooling techniques (RPT), was used to produce polypropylene tubular mouldings. The configuration of the mould was varied with combinations of moulding block materials, namely, an epoxy resin composite processed by vacuum casting and steel. The processing conditions were adjusted to obtained steady processing conditions. The mouldings were assessed in terms of the microstructure and the shrinkage.

Findings

Due to the properties of the moulding block obtained by RPT being different from tool steel, the injection moulding processing conditions and the plastics parts properties are different when hybrid moulds are used. The cycle time depends on the moulding block properties and must be adjusted to the desired running temperature. The morphology of the mouldings is strongly affected by the thermal properties of the moulding block materials. When different materials are used in the core and the cavity asymmetric structures develop in the part. The shrinkage of the mouldings, when resin cores are used is also affected by the deformation of the core caused by the injection pressure.

Originality/value

This paper makes a contribution to understanding the morphology of semi‐crystalline mouldings obtained using hybrid moulds and enhances the importance of the core deformation on the shrinkage of the mouldings.

Details

Rapid Prototyping Journal, vol. 15 no. 1
Type: Research Article
ISSN: 1355-2546

Keywords

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Article
Publication date: 7 August 2007

J. Vasco, P. J. Bártolo, B. Silva and C. Galo

Laser milling is a non‐conventional layer‐by‐layer material removal technology suitable for machining a wide range of materials. This technology is particularly suitable to…

2128

Abstract

Purpose

Laser milling is a non‐conventional layer‐by‐layer material removal technology suitable for machining a wide range of materials. This technology is particularly suitable to produce microstructures inside cavities, also obtained by other conventional processes, though with larger material removal rates, or for the direct development of microcavities not requiring high removal rates. This paper seeks to evaluate the capacity of laser milling for manufacturing of mould inserts.

Design/methodology/approach

The paper examined several specific features of laser milling, important for the manufacturing of mould inserts, such as walls verticality, unselected illuminating areas, due to an incorrect STL removal volume definition, aspiration process and orientation, to prevent welding of re‐solidified particles on the surface. Two mould inserts were produced too, assembled on a metallic mould frame and tested with different injection conditions.

Findings

The findings suggest that laser milling is a suitable technology to produce small mould insert for injection moulding, though injection conditions are different as one moves from macroscopic to microscopic injected parts. New design guidelines must be undertaken jointly with the assessment of laser milling performance to make mould microcavities. One of the major difficulties of this process is to keep the side walls vertical plus the generation of undesirable machined volumes, due to unselected illuminating areas below the STL volume, corresponding to the volume to be removed, whenever laser milling is used to operate with structures previously machined. To prevent welding of re‐solidified particles on the surface a proper aspiration must also be considered.

Originality/value

The paper describes the benefits of laser milling technology.

Details

Assembly Automation, vol. 27 no. 3
Type: Research Article
ISSN: 0144-5154

Keywords

Available. Content available
Article
Publication date: 23 January 2007

Ian Gibson

204

Abstract

Details

Rapid Prototyping Journal, vol. 13 no. 1
Type: Research Article
ISSN: 1355-2546

Available. Content available
Article
Publication date: 14 June 2011

Ian Campbell

371

Abstract

Details

Rapid Prototyping Journal, vol. 17 no. 4
Type: Research Article
ISSN: 1355-2546

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Article
Publication date: 2 January 2018

Izél Van Heerden, Annabel Fossey and Gerrie J. Booysen

Poland’s syndrome patients often seek medical interventions to improve their aesthetic appearances. Design and manufacturing technologies make it possible to produce custom-made…

237

Abstract

Purpose

Poland’s syndrome patients often seek medical interventions to improve their aesthetic appearances. Design and manufacturing technologies make it possible to produce custom-made implants for such medical conditions. The purpose of this study was to compare the 3D digital geometries that were designed using Magics and Geomagic® Freeform® for two anonymous case studies of Poland’s syndrome patients.

Design/methodology/approach

Computed tomography data were acquired and processed in Mimics® to isolate the pectoralis muscles in STL file format. STL files were imported into Magics and Geomagic® Freeform® to design 3D digital geometries. Thereafter, comparative analyses were performed of the respective 3D digital geometries.

Findings

The angle between the vertical and oblique planes for both sides of the thorax was 6.5° for the female and 14° for the male. The surface areas and volumes of the geometries for the female were smaller than the male. Deviation analyses between the healthy side and reconstructed side of a thorax showed that 73 per cent of the test points for Magics and 78 per cent for Geomagic® Freeform® fell in the nominated tolerance region of >−5 and <+5 mm for the female. For the male, it was 83 per cent for Magics and 88 per cent for Geomagic® Freeform®.

Practical implications

Geomagic® Freeform® provides a more versatile design environment; however, the STL editor Magics may be an option to design 3D geometries for less intricate and less contoured implants.

Originality/value

This was a first attempt to compare the 3D geometries for Poland’s syndrome designed with an STL editor to those designed with a computer-aided design program.

Details

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

Keywords

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