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Article
Publication date: 16 October 2018

Ranvijay Kumar, Rupinder Singh and Ilenia Farina

Three-dimensional printing (3DP) is an established process to print structural parts of metals, ceramic and polymers. Further, multi-material 3DP has the potentials to be…

Abstract

Purpose

Three-dimensional printing (3DP) is an established process to print structural parts of metals, ceramic and polymers. Further, multi-material 3DP has the potentials to be a milestone in rapid manufacturing (RM), customized design and structural applications. Being compatible as functionally graded materials in a single structural form, multi-material-based 3D printed parts can be applied in structural applications to get the benefit of modified properties.

Design/methodology/approach

The fused deposition modelling (FDM) is one of the established low cost 3DP techniques which can be used for printing functional/ non-functional prototypes in civil engineering applications.

Findings

The present study is focused on multi-material printing of primary recycled acrylonitrile butadiene styrene (ABS), polylactic acid (PLA) and high impact polystyrene (HIPS) in composite form. Thermal (glass transition temperature and heat capacity) and mechanical properties (break load, break strength, break elongation, percentage elongation at break and Young’s modulus) have been analysed to observe the behaviour of multi-material composites prepared by 3DP. This study also highlights the process parameters optimization of FDM supported with photomicrographs.

Originality/value

The present study is focused on multi-material printing of primary recycled ABS, PLA and HIPS in composite form.

Details

PSU Research Review, vol. 2 no. 2
Type: Research Article
ISSN: 2399-1747

Keywords

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Article
Publication date: 19 February 2021

Furkan Ulu, Ravi Pratap Singh Tomar and Ram Mohan

PolyJet technology allows printing complex multi-material composite configurations using Voxel digital designs' capability, thus allowing rapid prototyping of 3D printed

Abstract

Purpose

PolyJet technology allows printing complex multi-material composite configurations using Voxel digital designs' capability, thus allowing rapid prototyping of 3D printed structural parts. This paper aims to investigate the processing and mechanical characteristics of composite material configurations formed from soft and hard materials with different distributions and sizes via voxel digital print design.

Design/methodology/approach

Voxels are extruded representations of pixels and represent different material information similar to each pixel representing colors in digital images. Each geometric region of a digitally designed part represented by a voxel can be printed with a different material. Multi-material composite part configurations were formed and rapidly prototyped using a PolyJet printer Stratasys J750. A design of experiments composite part configuration of a soft material (Tango Plus) within a hard material matrix (Vero Black) was studied. Composite structures with different hard and soft material distributions, but at the same volume fractions of hard and soft materials, were rapidly prototyped via PolyJet printing through developed Voxel digital printing designs. The tensile behavior of these formed composite material configurations was studied.

Findings

Processing and mechanical behavior characteristics depend on materials in different regions and their distributions. Tensile characterization obtained the fracture energy, tensile strength, modulus and failure strength of different hard-soft composite systems. Mechanical properties and behavior of all different composite material systems are compared.

Practical implications

Tensile characteristics correlate to digital voxel designs that play a critical role in additive manufacturing, in addition to the formed material composition and distributions.

Originality/value

Results clearly indicate that multi-material composite systems with various tensile mechanical properties could be created using voxel printing by engineering the design of material distributions, and sizes. The important parameters such as inclusion size and distribution can easily be controlled within all slices via voxel digital designs in PolyJet printing. Therefore, engineers and designers can manipulate entire morphology and material at each voxel level, and different prototype morphologies can be created with the same voxel digital design. In addition, difficulties from AM process with voxel printing for such material designs is addressed, and effective digital solutions were used for successful prototypes. Some of these difficulties are extra support material or printing the part with different dimension than it designed to achieve the final part dimension fidelity. Present work addressed and resolved such issued and provided cyber based software solutions using CAD and voxel discretization. All these increase broad adaptability of PolyJet AM in industry for prototyping and end-use.

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Article
Publication date: 19 June 2019

Christopher-Denny Matte, Michael Pearson, Felix Trottier-Cournoyer, Andrew Dafoe and Tsz Ho Kwok

The purpose of this paper is to introduce a novel technique for printing with multiple materials using the DLP method. Digital-light-processing (DLP) printing uses a…

Abstract

Purpose

The purpose of this paper is to introduce a novel technique for printing with multiple materials using the DLP method. Digital-light-processing (DLP) printing uses a digital projector to selectively cure a full layer of resin using a mask image. One of the challenges with DLP printing is the difficulty of incorporating multiple materials within the same part. As the part is cured within a liquid basin, resin switching introduces issues of cross-contamination and significantly increased print time.

Design/methodology/approach

The material handling challenges are investigated and addressed by taking inspiration from automated storage and retrieval systems and using an active cleaning solution. The material tower is a compact design to facilitate the storage and retrieval of different materials during the printing process. A spray mechanism is used for actively cleaning excess resin from the part between material changes.

Findings

Challenges encountered within the multi-material DLP technology are addressed and the experimental prototype validates the proposed solution. The system has a cleaning effectiveness of over 90 per cent in 15 s with the build area of 72 inches, in contrast to the previous work of 50 per cent cleaning effectiveness in 2 min with only 6 inches build area. The method can also hold more materials than the previous work.

Originality/value

The techniques from automated storage and retrieval system is applied to develop a storage system so that the time complexity of swapping is reduced from linear to constant. The whole system is sustainable and scalable by using a spraying mechanism. The design of the printer is modular and highly customizable, and the material waste for build materials and cleaning solution is minimized.

Details

Rapid Prototyping Journal, vol. 25 no. 5
Type: Research Article
ISSN: 1355-2546

Keywords

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Article
Publication date: 2 June 2021

Huachao Mao, Wenxuan Jia, Yuen-Shan Leung, Jie Jin and Yong Chen

This paper aims to present a multi-material additive manufacturing (AM) process with a newly developed curing-on-demand method to fabricate a three-dimensional (3D) object…

Abstract

Purpose

This paper aims to present a multi-material additive manufacturing (AM) process with a newly developed curing-on-demand method to fabricate a three-dimensional (3D) object with multiple material compositions.

Design/methodology/approach

Unlike the deposition-on-demand printing method, the proposed curing-on-demand printheads use a digital light processing (DLP) projector to selectively cure a thin layer of liquid photocurable resin and then clean the residual uncured material effectively using a vacuuming and post-curing device. Each printhead can individually fabricate one type of material using digitally controlled mask image patterns. The proposed AM process can accurately deposit multiple materials in each layer by combining multiple curing-on-demand printheads together. Consequently, a three-dimensional object can be fabricated layer-by-layer using the developed curing-on-demand printing method.

Findings

Effective cleaning of uncured resin is realized with reduced coated resin whose height is in the sub-millimeter level and improved vacuum cleaning performance with the uncleaned resin less than 10 µm thick. Also, fast material swapping is achieved using the compact design of multiple printheads.

Originality/value

The proposed multi-material stereolithography (SL) process enables 3D printing components using more viscous materials and can achieve desired manufacturing characteristics, including high feature resolution, fast fabrication speed and low machine cost.

Details

Rapid Prototyping Journal, vol. 27 no. 5
Type: Research Article
ISSN: 1355-2546

Keywords

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Article
Publication date: 25 October 2018

Micaela Ribeiro, Olga Sousa Carneiro and Alexandre Ferreira da Silva

An issue when printing multi-material objects is understanding how different materials will perform together, especially because interfaces between them are always…

Abstract

Purpose

An issue when printing multi-material objects is understanding how different materials will perform together, especially because interfaces between them are always created. This paper aims to address this interface from a mechanical perspective and evaluates how it should be designed for a better mechanical performance.

Design/methodology/approach

Different interface mechanisms were considered, namely, microscopic interfaces that are based on chemical bonding and were represented with a U-shape interface; a macroscopic interface characterized by a mechanical interlocking mechanism, represented by a T-shape interface; and a mesoscopic interface that sits between other interface systems and that was represented by a dovetail shape geometry. All these different interfaces were tested in two different material sets, namely, poly (lactic acid)–poly (lactic acid) and poly (lactic acid)–thermoplastic polyurethane material pairs. These two sets represent high- and low-compatibility materials sets, respectively.

Findings

The results showed, despite the materials’ compatibility level, multi-material objects will have a better mechanical performance through a macroscopic interface, as it is based on a mechanical interlocking system, of which performance cannot be achieved by a simple face-to-face interface even when considering the same material.

Originality/value

The paper investigates the importance of interface design in multi-material 3D prints by fused filament fabrication. Especially, for parts intended to be subjected to mechanical efforts, simple face-to-face interfaces are not sufficient and more robust and macroscopic-based interface geometries (based on mechanical interlocking systems) are advised. Moreover, such interfaces do not raise esthetic problems because of their working principle; the 3D printing technology can hide the interface geometries, if required.

Details

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

Keywords

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Article
Publication date: 25 June 2020

Yee Ling Yap, Swee Leong Sing and Wai Yee Yeong

Soft robotics is currently a rapidly growing new field of robotics whereby the robots are fundamentally soft and elastically deformable. Fabrication of soft robots is…

Abstract

Purpose

Soft robotics is currently a rapidly growing new field of robotics whereby the robots are fundamentally soft and elastically deformable. Fabrication of soft robots is currently challenging and highly time- and labor-intensive. Recent advancements in three-dimensional (3D) printing of soft materials and multi-materials have become the key to enable direct manufacturing of soft robots with sophisticated designs and functions. Hence, this paper aims to review the current 3D printing processes and materials for soft robotics applications, as well as the potentials of 3D printing technologies on 3D printed soft robotics.

Design/methodology/approach

The paper reviews the polymer 3D printing techniques and materials that have been used for the development of soft robotics. Current challenges to adopting 3D printing for soft robotics are also discussed. Next, the potentials of 3D printing technologies and the future outlooks of 3D printed soft robotics are presented.

Findings

This paper reviews five different 3D printing techniques and commonly used materials. The advantages and disadvantages of each technique for the soft robotic application are evaluated. The typical designs and geometries used by each technique are also summarized. There is an increasing trend of printing shape memory polymers, as well as multiple materials simultaneously using direct ink writing and material jetting techniques to produce robotics with varying stiffness values that range from intrinsically soft and highly compliant to rigid polymers. Although the recent work is done is still limited to experimentation and prototyping of 3D printed soft robotics, additive manufacturing could ultimately be used for the end-use and production of soft robotics.

Originality/value

The paper provides the current trend of how 3D printing techniques and materials are used particularly in the soft robotics application. The potentials of 3D printing technology on the soft robotic applications and the future outlooks of 3D printed soft robotics are also presented.

Details

Rapid Prototyping Journal, vol. 26 no. 8
Type: Research Article
ISSN: 1355-2546

Keywords

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Article
Publication date: 22 July 2019

Md. Hazrat Ali, Shaheidula Batai and Dastan Sarbassov

This study highlights the demand for low-cost and high accuracy products through the design and development of new 3D printing technologies. Besides, significant progress…

Abstract

Purpose

This study highlights the demand for low-cost and high accuracy products through the design and development of new 3D printing technologies. Besides, significant progress has been made in this field. A comparative study helps to understand the latest development in materials and future prospect of this technology.

Design/methodology/approach

Nevertheless, a large amount of progress still remains to be made. While some of the works have focused on the performances of the materials, the rest have focused on the development of new methods and techniques in additive manufacturing.

Findings

This paper critically evaluates the current 3D printing technologies, including the development and optimizations made to the printing methods, as well as the printed objects. Meanwhile, previous developments in this area and contributions to the modern trend in manufacturing technology are summarized briefly.

Originality/value

The paper can be summarized in three sections. Firstly, the existing printing methods along with the frequently used printing materials, as well as the processing parameters, and the factors which influence the quality and mechanical performances of the printed objects are discussed. Secondly, the optimization techniques, such as topology, shape, structure and mechanical property, are described. Thirdly, the latest development and applications of additive manufacturing are depicted, and the scope of future research in the relevant area is put forward.

Details

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

Keywords

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Article
Publication date: 3 April 2017

Eujin Pei, Giselle Hsiang Loh, David Harrison, Henrique de Amorim Almeida, Mario Domingo Monzón Verona and Rubén Paz

The purpose of this paper is to extend existing knowledge of 4D printing, in line with Khoo et al. (2015) who defined the production of 4D printing using a single…

Abstract

Purpose

The purpose of this paper is to extend existing knowledge of 4D printing, in line with Khoo et al. (2015) who defined the production of 4D printing using a single material, and 4D printing of multiple materials. It is proposed that 4D printing can be achieved through the use of functionally graded materials (FGMs) that involve gradational mixing of materials and are produced using an additive manufacturing (AM) technique to achieve a single component.

Design/methodology/approach

The latest state-of-the-art literature was extensively reviewed, covering aspects of materials, processes, computer-aided design (CAD), applications and made recommendations for future work.

Findings

This paper clarifies that functionally graded additive manufacturing (FGAM) is defined as a single AM process that includes the gradational mixing of materials to fabricate freeform geometries with variable properties within one component. The paper also covers aspects of materials, processes, CAD, applications and makes recommendations for future work.

Research limitations/implications

This paper examines the relationship between FGAM and 4D printing and defines FGAM as a single AM process involving gradational mixing of materials to fabricate freeform geometries with variable properties within one component. FGAM requires better computational tools for modelling, simulation and fabrication because current CAD systems are incapable of supporting the FGAM workflow.

Practical implications

It is also identified that other factors, such as strength, type of materials, etc., must be taken into account when selecting an appropriate process for FGAM. More research needs to be conducted on improving the performance of FGAM processes through extensive characterisation of FGMs to generate a comprehensive database and to develop a predictive model for proper process control. It is expected that future work will focus on both material characterisation as well as seamless FGAM control processes.

Originality/value

This paper examines the relationship between FGAM and 4D printing and defines FGAM as a single AM process that includes gradational mixing of materials to fabricate freeform geometries with variable properties within one component.

Details

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

Keywords

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Article
Publication date: 18 July 2018

Mohammad Abu Hasan Khondoker, Asad Asad and Dan Sameoto

This paper aims to target to print functionally gradient materials (FGM) devices made of immiscible polymers in multi-material fused deposition modelling (FDM) systems…

Abstract

Purpose

This paper aims to target to print functionally gradient materials (FGM) devices made of immiscible polymers in multi-material fused deposition modelling (FDM) systems. The design is intended to improve adhesion of dissimilar thermoplastics without the need for chemical compatibilization so that filaments from many different sources can be used effectively. Therefore, there is a need to invent an alternative solution for printing multiple immiscible polymers in an FDM system with the desired adhesion.

Design/methodology/approach

In this study, the authors have developed a bi-extruder for FDM systems which can print two thermoplastics through a single nozzle with a static intermixer to enhance bonding between input materials. The system can also change the composition of extrudates continuously.

Findings

The uniqueness of this extruder is in its easy access to the internal channel so that a static intermixer can be inserted, enabling deposition of mechanically interlocked extrudates composed of two immiscible polymers. Without this intermixer, the bi-extruder extrudes with simple side-by-side co-extrusion having no mechanical interlocking. The bi-extruder was characterized by printing objects using pairs of materials including polylactic acid, acrylonitrile butadiene styrene and high impact polystyrene. Microscope images of the cross-sections of the extrudates confirm the ability of this bi-extruder to control the composition as desired. It was also found that the mechanically interlocked extrudates composed of two immiscible polymers substantially reduces adhesion failures within and between filaments.

Originality/value

In this study, the first-ever FDM extruder with a mechanical blending feature next to the nozzle has been designed and used to successfully print FGM objects with improved mechanical properties.

Details

Rapid Prototyping Journal, vol. 24 no. 6
Type: Research Article
ISSN: 1355-2546

Keywords

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Article
Publication date: 19 October 2015

Jacob P. Moore and Christopher B. Williams

– This paper aims to seek to fill a gap in the literature by characterizing the fatigue life and microstructure of a printed elastomer material, the TangoBlackPlus material.

Abstract

Purpose

This paper aims to seek to fill a gap in the literature by characterizing the fatigue life and microstructure of a printed elastomer material, the TangoBlackPlus material.

Design/methodology/approach

Because the TangoBlackPlus material is marketed as “rubber-like”, the printed elastomer specimens were tested according to the ASTM D4482-11 “Test Method for Rubber Property Extension Cycling Fatigue”. The microstructure of the printed material and multi-material interface was examined by slicing specimens and examining them under an optical microscope.

Findings

Findings are developed to show the relationship between elongation and expected fatigue life. Findings also indicate that the smoother, non-support encased “glossy” surface finish option for PolyJet parts improve the fatigue life of components and that there are a number of microscopic voids in the TangoBlackPlus material that seem to be concentrated at layer and print head boundaries.

Research limitations/implications

This paper provides a glimpse into the fatigue properties and microstructure of printed elastomeric parts, a previously unstudied area. This work is limited in that it only looks at specimens created in a single orientation, on a single machine, with a single material. More work is needed to understand the general fatigue properties of printed elastomers and the factors that influence fatigue life in these materials.

Practical implications

The authors provide several design guidelines based on the findings and previous work that can be used to increase the fatigue life of printed elastomer components.

Originality/value

As additive manufacturing (AM) technology moves from a prototyping tool to a tool used to create end use products, it is important to examine the expected lifespan of AM components. This work adds to the understanding of the expected product lifecycle of printed elastomer components that will likely be expected to withstand large repeated loading conditions.

Details

Rapid Prototyping Journal, vol. 21 no. 6
Type: Research Article
ISSN: 1355-2546

Keywords

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