Applied Sciences

Research

Jump to: Review

13 pages, 3360 KiB

Open AccessArticle

Impact of Bimodal Particle Size Distribution Ratio of Functional Calcium Carbonate Filler on Thermal and Flowability Properties of Polyamide 12

by Fabio Ippolito, Gunter Hübner, Tim Claypole and Patrick Gane

Appl. Sci. 2021, 11(2), 641; https://doi.org/10.3390/app11020641 - 11 Jan 2021

Cited by 3 | Viewed by 2697

Abstract

In previous investigations, it was shown that the melting, as well as crystallization behavior of polyamide 12, could be manipulated by adjusting the particle size distribution of calcium carbonate as a functional filler. It was demonstrated that the melt properties of this compound [...] Read more.

In previous investigations, it was shown that the melting, as well as crystallization behavior of polyamide 12, could be manipulated by adjusting the particle size distribution of calcium carbonate as a functional filler. It was demonstrated that the melt properties of this compound show a significant dependency on the filler volume-based particle size. As finer and narrower the calcium carbonate particles in the polymer matrix become, the less influence the filler has on the melting properties, influencing the melt flow less significantly than the same surface amount of broad size distribution coarse calcium carbonate filler particles. However, due to increased nucleation, the crystallization behavior on cooling showed a markedly more rapid onset in the case of fine sub-micrometer filler particle size. To control further and optimize the thermal response properties of a filling compound for improved properties in additive manufacturing processing through selective laser sintering, the possibility to combine precisely defined particle size distributions has been studied, thereby combining the benefits of each particle size range within the chosen material size distribution contributes to the matrix. The melt flow at 190 °C, the melting speed, melting and crystallization point as well as crystallization time at 170 °C were analyzed. The thermal and flow properties of a polyamide 12 matrix can potentially be optimized with a combination of a precise amount of coarse and fine calcium carbonate filler. The improvements were exemplified using a twin-screw extruder for compounding, indicating the potential for optimizing functionally filled polymer in additive manufacturing. Full article

(This article belongs to the Special Issue Material Development for Additive Manufacturing and Injection Moulding)

► Show Figures

Figure 1

23 pages, 8359 KiB

Open AccessArticle

Rheological Behaviour of Highly Filled Materials for Injection Moulding and Additive Manufacturing: Effect of Particle Material and Loading

by Marko Bek, Joamin Gonzalez-Gutierrez, Christian Kukla, Klementina Pušnik Črešnar, Boris Maroh and Lidija Slemenik Perše

Appl. Sci. 2020, 10(22), 7993; https://doi.org/10.3390/app10227993 - 11 Nov 2020

Cited by 44 | Viewed by 4851

Abstract

Within this paper, we are dealing with a mixture of thermoplastic polymer that is filled with inorganic fillers at high concentrations up to 60 vol.%. A high number of particles in the compound can substantially change the rheological behaviour of the composite and [...] Read more.

Within this paper, we are dealing with a mixture of thermoplastic polymer that is filled with inorganic fillers at high concentrations up to 60 vol.%. A high number of particles in the compound can substantially change the rheological behaviour of the composite and can lead to problems during processing in the molten state. The rheological behaviour of highly filled materials is complex and influenced by many interrelated factors. In the present investigation, we considered four different spherical materials: steel, aluminium alloy, titanium alloy and glass. Particles with similar particle size distribution were mixed with a binder system at different filling grades (30–60 vol.%). We showed that the rheological behaviour of highly filled materials is significantly dependent on the chemical interactions between the filler and matrix material. Moreover, it was shown that the changes of the particle shape and size during processing lead to unexpected rheological behaviour of composite materials as it was observed in the composites filled with glass beads that broke at high contents during processing. Full article

(This article belongs to the Special Issue Material Development for Additive Manufacturing and Injection Moulding)

► Show Figures

Figure 1

12 pages, 2860 KiB

Open AccessArticle

Rheology and Curability Characterization of Photosensitive Slurries for 3D Printing of Si₃N₄ Ceramics

by Xingbang Li, Jingxian Zhang, Yusen Duan, Ning Liu, Jinhua Jiang, Ruixin Ma, Hongan Xi and Xiaoguang Li

Appl. Sci. 2020, 10(18), 6438; https://doi.org/10.3390/app10186438 - 16 Sep 2020

Cited by 26 | Viewed by 3791

Abstract

Among a series of 3D printing techniques, stereolithography provides a new route to produce ceramic architectures with the advantages of high-precision and short cycle time. However, up to now the stereolithography of non-oxide ceramics still face complex and difficult problems. This work focused [...] Read more.

Among a series of 3D printing techniques, stereolithography provides a new route to produce ceramic architectures with the advantages of high-precision and short cycle time. However, up to now the stereolithography of non-oxide ceramics still face complex and difficult problems. This work focused on the analysis of rheological and curing ability of Si₃N₄ photocurable slurries. The effects of monomer type, coarse silicon powder, solid loading and ambient temperature on the rheological behavior were intensively studied. The relationships between powder characteristic (involving refractive index, absorbance and the introduce of coarse silicon powder), monomer type and curing ability were discussed in detail. It is expected that this study may benefit the development of Si₃N₄ or other non-oxide ceramic slurries for stereolithography. Full article

(This article belongs to the Special Issue Material Development for Additive Manufacturing and Injection Moulding)

► Show Figures

Figure 1

20 pages, 6220 KiB

Open AccessArticle

Research and Implementation of Axial 3D Printing Method for PLA Pipes

by Haiguang Zhang, Wenguang Zhong, Qingxi Hu, Mohamed Aburaia, Joamin Gonzalez-Gutierrez and Herfried Lammer

Appl. Sci. 2020, 10(13), 4680; https://doi.org/10.3390/app10134680 - 7 Jul 2020

Cited by 10 | Viewed by 3037

Abstract

Additive manufacturing has been applied in many fields, but its layer-by-layer fabrication process leads to a weak inter-layer bond strength of printed parts, so it cannot meet the higher requirements for mechanical properties of the industry. At present, many researchers are studying the [...] Read more.

Additive manufacturing has been applied in many fields, but its layer-by-layer fabrication process leads to a weak inter-layer bond strength of printed parts, so it cannot meet the higher requirements for mechanical properties of the industry. At present, many researchers are studying the printing path planning method to improve the mechanical properties of printed parts. This paper proposes a method to plan the printing path according to the actual stress of pipe parts, and introduces the realization process of an algorithm in detail, and obtains the printing control G-code. Additionally, a 5-axis material extrusion platform was built to realize the printing of polylactic acid pipes with plane and space skeleton curves, respectively, which verified the feasibility and applicability of the method and the correctness of the planning path with standard material extrusion filaments. Finally, the tensile and bending experiments prove that axial printing enhances the mechanical properties of pipe parts. Full article

(This article belongs to the Special Issue Material Development for Additive Manufacturing and Injection Moulding)

► Show Figures

Figure 1

12 pages, 3999 KiB

Open AccessArticle

SHS Produced TiB₂-Si Powders for Selective Laser Melting of Ceramic-Based Composite

by Le Liu, Sofiya Aydinyan, Tatevik Minasyan and Irina Hussainova

Appl. Sci. 2020, 10(9), 3283; https://doi.org/10.3390/app10093283 - 8 May 2020

Cited by 7 | Viewed by 2625

Abstract

One of the main limitations for widespread additive manufacturing is availability and processability of the precursor materials feedstock. For the first time, this study reports the development of a “pomegranate-like” structured TiB₂-Si ceramic-metalloid powder feedstock suitable for selective laser melting (SLM) [...] Read more.

One of the main limitations for widespread additive manufacturing is availability and processability of the precursor materials feedstock. For the first time, this study reports the development of a “pomegranate-like” structured TiB₂-Si ceramic-metalloid powder feedstock suitable for selective laser melting (SLM) of ceramic-based composite. The powder was produced via self-propagating high temperature synthesis (SHS) at a moderate combustion temperature of 1530 °C. The effective activation energy in the Ti-B-Si system for the slow step of the combustion process was estimated as 184 kJ. Conditions of SHS process demonstrated a strong influence on the properties of produced powders and, therefore, on SLM parameters and properties of the printed materials. The powders have demonstrated a high performance for manufacturing bulks of 56 wt%TiB₂–44 wt%Si ceramic-based composite. Full article

(This article belongs to the Special Issue Material Development for Additive Manufacturing and Injection Moulding)

► Show Figures

Graphical abstract

14 pages, 6113 KiB

Open AccessArticle

Solution Extrusion Additive Manufacturing of Biodegradable Polycaprolactone

by Jian-Ming Chen, Demei Lee, Jheng-Wei Yang, Sheng-Han Lin, Yu-Ting Lin and Shih-Jung Liu

Appl. Sci. 2020, 10(9), 3189; https://doi.org/10.3390/app10093189 - 3 May 2020

Cited by 16 | Viewed by 3008

Abstract

Polycaprolactone (PCL) is a resorbable semicrystalline polymer that degrades slowly via hydrolysis and has applications in medical implants and drug delivery. As a result of its low melting point, PCL can be processed easily by conventional polymer processing techniques. However, the additive manufacturing [...] Read more.

Polycaprolactone (PCL) is a resorbable semicrystalline polymer that degrades slowly via hydrolysis and has applications in medical implants and drug delivery. As a result of its low melting point, PCL can be processed easily by conventional polymer processing techniques. However, the additive manufacturing of PCL remains a challenge, mainly due to the fact that there are no commercially available filaments for traditional fused deposition modeling (FDM). Furthermore, when the materials are fabricated via FDM for drug delivery applications, the high temperature may deactivate the incorporated drugs/biomolecules. This study investigates the solution extrusion additive manufacturing of PCL using a lab-developed solution-type device. The device comprises a solution extrusion feeder, driving stepper motors, a power source, a syringe equipped with a dispensing tip, an accumulation platform, and a control interface. The influences of different manufacturing parameters on part quality were evaluated. The experimental results suggest that the tensile strength of the additively manufactured parts increases with fill density but decreases with the ratio of PCL to dichloromethane (DCM) and moving speed of the dispensing tip. Parts fabricated by 90° print orientation of infill exhibited the greatest mechanical strength. The fabricated parts tend to heal the gaps among strips after additive manufacturing, but tiny pores can still be seen on the surfaces. Full article

(This article belongs to the Special Issue Material Development for Additive Manufacturing and Injection Moulding)

► Show Figures

Figure 1

15 pages, 1968 KiB

Open AccessArticle

Novel Hybrid PETG Composites for 3D Printing

by Mária Kováčová, Jana Kozakovičová, Michal Procházka, Ivica Janigová, Marek Vysopal, Ivona Černičková, Jozef Krajčovič and Zdenko Špitalský

Appl. Sci. 2020, 10(9), 3062; https://doi.org/10.3390/app10093062 - 28 Apr 2020

Cited by 45 | Viewed by 6074

Abstract

This paper is focused on the preparation of novel hybrid polymer composite materials for 3D filaments. As the reinforcing filler, expanded graphite, carbon fibers, and combinations thereof were used in various ratios up to 10%. The mechanical and thermal properties of virgin and [...] Read more.

This paper is focused on the preparation of novel hybrid polymer composite materials for 3D filaments. As the reinforcing filler, expanded graphite, carbon fibers, and combinations thereof were used in various ratios up to 10%. The mechanical and thermal properties of virgin and recycled polyethylene phthalate glycol-modified (PETG) composite materials were determined. Almost all prepared composite materials were suitable for 3D printing and they have enhanced mechanical properties compared to the neat PETG matrices. Addition of the fillers to both polymer matrices has an only slight effect on the thermal stability, but the addition of carbon fibers significantly reduced the thermal expansion coefficient. The composites from cheaper recycled PETG have comparable properties to virgin PETG composites, which is of economic and ecological importance. New and cheaper materials can help expand 3D printing to manufacturing plants and the use of 3D printers for special applications. Full article

(This article belongs to the Special Issue Material Development for Additive Manufacturing and Injection Moulding)

► Show Figures

Graphical abstract

17 pages, 2362 KiB

Open AccessArticle

Modification of Interfacial Interactions in Ceramic-Polymer Nanocomposites by Grafting: Morphology and Properties for Powder Injection Molding and Additive Manufacturing

by Santiago Cano, Ali Gooneie, Christian Kukla, Gisbert Rieß, Clemens Holzer and Joamin Gonzalez-Gutierrez

Appl. Sci. 2020, 10(4), 1471; https://doi.org/10.3390/app10041471 - 21 Feb 2020

Cited by 10 | Viewed by 3144

Abstract

The adhesion of the polymer to ceramic nanoparticles is a key aspect in the manufacturing of ceramic parts by additive manufacturing and injection molding, due to poor separation results in separation during processing. The purpose of this research is to investigate, by means [...] Read more.

The adhesion of the polymer to ceramic nanoparticles is a key aspect in the manufacturing of ceramic parts by additive manufacturing and injection molding, due to poor separation results in separation during processing. The purpose of this research is to investigate, by means of molecular dynamics simulations and experimental methods, the role of improved interfacial interactions by acrylic acid grafting-high density polyethylene on the adhesion to zirconia nanoparticles and on the composite properties. The polymer grafting results in high adhesion to the nanoparticles, increases the nanoparticles dispersion and improves the viscoelastic and mechanical properties required for additive manufacturing and injection molding. Full article

(This article belongs to the Special Issue Material Development for Additive Manufacturing and Injection Moulding)

► Show Figures

Graphical abstract

Review

Jump to: Research

28 pages, 20660 KiB

Open AccessReview

An Overview of Material Extrusion Troubleshooting

by Giselle Hsiang Loh, Eujin Pei, Joamin Gonzalez-Gutierrez and Mario Monzón

Appl. Sci. 2020, 10(14), 4776; https://doi.org/10.3390/app10144776 - 11 Jul 2020

Cited by 49 | Viewed by 13159

Abstract

Material extrusion (ME) systems offer end-users with a more affordable and accessible additive manufacturing (AM) technology compared to other processes in the market. ME is often used to quickly produce low-cost prototyping with the freedom of scalability where parts can be produced in [...] Read more.

Material extrusion (ME) systems offer end-users with a more affordable and accessible additive manufacturing (AM) technology compared to other processes in the market. ME is often used to quickly produce low-cost prototyping with the freedom of scalability where parts can be produced in different geometries, quantities and sizes. As the use of desktop ME machines has gained widespread adoption, this review paper discusses the key design strategies and considerations to produce high quality ME parts, as well as providing actional advice to aid end-users in quickly identifying and efficiently troubleshooting issues since current information is often fragmented and incomplete. The systemic issues and solutions concerning desktop ME processes discussed are not machine-specific, covering categories according to printer-associated, deposition-associated and print quality problems. The findings show that the majority of issues are associated with incorrect printer calibration and parameters, hardware, material, Computer Aided Design (CAD) model and/or slicing settings. A chart for an overview of ME troubleshooting is presented allowing designers and engineers to straightforwardly determine the possible contributing factors to a particular problem. Full article

(This article belongs to the Special Issue Material Development for Additive Manufacturing and Injection Moulding)

► Show Figures

Figure 1

10 pages, 880 KiB

Open AccessReview

Concepts and Terminologies in 4D Printing

by Eujin Pei, Giselle Hsiang Loh and Seokwoo Nam

Appl. Sci. 2020, 10(13), 4443; https://doi.org/10.3390/app10134443 - 27 Jun 2020

Cited by 17 | Viewed by 3487

Abstract

4D printing (4DP) is a promising technology that enables additive manufactured parts to be programmed for actuation, reducing the need for external power or electromechanical systems. As this area of research has grown exponentially, this review paper aims to define and establish fundamental [...] Read more.

4D printing (4DP) is a promising technology that enables additive manufactured parts to be programmed for actuation, reducing the need for external power or electromechanical systems. As this area of research has grown exponentially, this review paper aims to define and establish fundamental concepts and terminologies used in the field of 4DP. The objective is to encourage researchers to adopt a more consistent approach and a standardized set of vocabulary associated with this emerging field. Even though the paper covers the most widely used definitions, the multidisciplinary nature may mean that certain words could be used interchangeably or have a different meaning in another context. Full article

(This article belongs to the Special Issue Material Development for Additive Manufacturing and Injection Moulding)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Material Development for Additive Manufacturing and Injection Moulding

Share This Special Issue

Special Issue Editors

Special Issue Information

Keywords

Published Papers (10 papers)

Research

Review

Further Information

Guidelines

MDPI Initiatives

Follow MDPI