Engineering Thermoplastics for Additive Manufacturing: A Critical Perspective with Experimental Evidence to Support Functional Applications

Background Among additive manufacturing techniques, the filament-based technique involves what is referred to as fused deposition modeling (FDM). FDM materials are currently limited to a selected number of polymers. The present study focused on investigating the potential of using high-end engineering polymers in FDM. In addition, a critical review of the materials available on the market compared with those studied here was completed. Methods Different engineering thermoplastics, ranging from industrial grade polycarbonates to novel polyetheretherketones (PEEKs), were processed by FDM. Prior to this, for innovative filaments based on PEEK, extrusion processing was carried out. Mechanical properties (i.e., tensile and flexural) were investigated for each extruded material. An industrial-type FDM machine (Stratasys Fortus® 400 mc) was used to fully characterize the effect of printing parameters on the mechanical properties of polycarbonate. The obtained properties were compared with samples obtained by injection molding. Finally, FDM samples made of PEEK were also characterized and compared with those obtained by injection molding. Results The effect of raster to raster air gap and raster angle on tensile and flexural properties of printed PC was evidenced; the potential of PEEK filaments, as novel FDM material, was highlighted in comparison to state of the art materials. Conclusions Comparison with injection molded parts allowed to better understand FDM potential for functional applications. The study discussed pros and cons of the different materials. Finally, the development of novel PEEK filaments achieved important results offering a novel solution to the market when high mechanical and thermal properties are required.

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Effect of Porosity on Mechanical Properties of 3D Printed Polymers: Experiments and Micromechanical Modeling Based on X-Ray Computed Tomography Analysis

Polymers ◽

10.3390/polym11071154 ◽

2019 ◽

Vol 11 (7) ◽

pp. 1154 ◽

Cited By ~ 27

Author(s):

Wang ◽

Zhao ◽

Fuh ◽

Lee

Keyword(s):

Computed Tomography ◽

Mechanical Properties ◽

Additive Manufacturing ◽

Fused Deposition Modeling ◽

Micromechanical Model ◽

Micromechanical Modeling ◽

X Ray ◽

Fused Deposition ◽

3D Printed ◽

X Ray Computed

Additive manufacturing (commonly known as 3D printing) is defined as a family of technologies that deposit and consolidate materials to create a 3D object as opposed to subtractive manufacturing methodologies. Fused deposition modeling (FDM), one of the most popular additive manufacturing techniques, has demonstrated extensive applications in various industries such as medical prosthetics, automotive, and aeronautics. As a thermal process, FDM may introduce internal voids and pores into the fabricated thermoplastics, giving rise to potential reduction on the mechanical properties. This paper aims to investigate the effects of the microscopic pores on the mechanical properties of material fabricated by the FDM process via experiments and micromechanical modeling. More specifically, the three-dimensional microscopic details of the internal pores, such as size, shape, density, and spatial location were quantitatively characterized by X-ray computed tomography (XCT) and, subsequently, experiments were conducted to characterize the mechanical properties of the material. Based on the microscopic details of the pores characterized by XCT, a micromechanical model was proposed to predict the mechanical properties of the material as a function of the porosity (ratio of total volume of the pores over total volume of the material). The prediction results of the mechanical properties were found to be in agreement with the experimental data as well as the existing works. The proposed micromechanical model allows the future designers to predict the elastic properties of the 3D printed material based on the porosity from XCT results. This provides a possibility of saving the experimental cost on destructive testing.

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EFFECT OF EXTRUSION PROCESS PARAMETERS ON MECHANICAL PROPERTIES OF 3D PRINTED PLA PRODUCT

Journal of Mechanical Engineering and Mechatronics ◽

10.33021/jmem.v6i2.1573 ◽

2021 ◽

Vol 6 (2) ◽

pp. 119

Author(s):

Nanang Ali Sutisna ◽

Rakha Amrillah Fattah

Keyword(s):

Mechanical Properties ◽

Additive Manufacturing ◽

Fused Deposition Modeling ◽

Extrusion Process ◽

Experimental Procedure ◽

Fused Deposition ◽

Novel Approach ◽

Deposition Modeling ◽

3D Printed ◽

3D Digital Models

The method of producing items through synchronously depositing material level by level, based on 3D digital models, is named Additive Manufacturing (AM) or 3D-printing. Amongs many AM methods, the Fused Deposition Modeling (FDM) technique along with PLA (Polylactic acid) material is commonly used in additive manufacturing. Until now, the mechanical properties of the AM components could not be calculated or estimated until they've been assembled and checked. In this work, a novel approach is suggested as to how the extrusion process affects the mechanical properties of the printed component to obtain how the parts can be manufactured or printed to achieve improved mechanical properties. This methodology is based on an experimental procedure in which the combination of parameters to achieve an optimal from a manufacturing experiment and its value can be determined, the results obtained show the effect of the extrusion process affects the mechanical properties.

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Comparison of FDM-printed and compression molded tensile samples

Materials Testing ◽

10.1515/mt-2020-621005 ◽

2020 ◽

Vol 62 (10) ◽

pp. 985-992

Author(s):

Robin Roj ◽

Jessica Nürnberg ◽

Ralf Theiß ◽

Peter Dültgen

Keyword(s):

Mechanical Properties ◽

Private Consumption ◽

Fused Deposition Modeling ◽

Time Cost ◽

Quality Factors ◽

Fused Deposition ◽

Deposition Modeling ◽

Manufacturing Techniques ◽

Plastic Components ◽

Plastic Parts

Abstract Since the processing of plastics by additive manufacturing techniques, for example, fused deposition modeling, has become quite common, it is mainly used for the production of unique pieces for private consumption as well as for prototyping in industry. In order to professionally manufacture plastic components in large amounts, due to time, cost, and quality factors, injection molding is more suitable. Nevertheless, it is of great interest to print plastic parts in small batch series for technical tasks. In this paper, FDM-produced tensile samples, made from 16 materials, printed in three orientations, are compared to compression molded components. In addition to ordinary filaments, composite materials with metal-, carbon-, wood-, and stone-additives are also examined. While some cavities emerged in both printed and molded samples, the results support the hypothesis that the mechanical properties depend on the components’ densities.

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Low-Cost Additive Manufacturing Techniques Applied to the Design of Planar Microwave Circuits by Fused Deposition Modeling

Polymers ◽

10.3390/polym12091946 ◽

2020 ◽

Vol 12 (9) ◽

pp. 1946 ◽

Cited By ~ 1

Author(s):

Héctor García-Martínez ◽

Ernesto Ávila-Navarro ◽

Germán Torregrosa-Penalva ◽

Alberto Rodríguez-Martínez ◽

Carolina Blanco-Angulo ◽

...

Keyword(s):

Additive Manufacturing ◽

Manufacturing Process ◽

Fused Deposition Modeling ◽

Low Cost ◽

Microwave Frequency ◽

Microwave Circuits ◽

Fused Deposition ◽

Microwave Electronic ◽

Deposition Modeling ◽

Manufacturing Techniques

This work presents a study on the implementation and manufacturing of low-cost microwave electronic circuits, made with additive manufacturing techniques using fused deposition modeling (FDM) technology. First, the manufacturing process of substrates with different filaments, using various options offered by additive techniques in the manufacture of 3D printing parts, is described. The implemented substrates are structurally analyzed by ultrasound techniques to verify the correct metallization and fabrication of the substrate, and the characterization of the electrical properties in the microwave frequency range of each filament is performed. Finally, standard and novel microwave filters in microstrip and stripline technology are implemented, making use of the possibilities offered by additive techniques in the manufacturing process. The designed devices were manufactured and measured with good results, which demonstrates the possibility of using low-cost 3D printers in the design process of planar microwave circuits.

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A Review Study on Mechanical Properties of Obtained Products by FDM Method and Metal/Polymer Composite Filament Production

Journal of Nanomaterials ◽

10.1155/2020/6187149 ◽

2020 ◽

Vol 2020 ◽

pp. 1-9

Author(s):

Ümit Çevik ◽

Menderes Kam

Keyword(s):

Mechanical Properties ◽

Additive Manufacturing ◽

Polymer Composite ◽

Fused Deposition Modeling ◽

Three Dimensional ◽

Production Method ◽

Context Analysis ◽

Fused Deposition ◽

Composite Filament ◽

Metal Polymer

In addition to traditional manufacturing methods, Additive Manufacturing (AM) has become a widespread production technique used in the industry. The Fused Deposition Modeling (FDM) method is one of the most known and widely used additive manufacturing techniques. Due to the fact that polymer-based materials used as depositing materials by the FDM method in printing of parts have insufficient mechanical properties, the technique generally has limited application areas such as model making and prototyping. With the development of polymer-based materials with improved mechanical properties, this technique can be preferred in wider application areas. In this context, analysis of the mechanical properties of the products has an important role in the production method with FDM. This study investigated the mechanical properties of the products obtained by metal/polymer composite filament production and FDM method in detail. It was reviewed current literature on the production of metal/polymer composite filaments with better mechanical properties than filaments compatible with three-dimensional (3D) printers. As a result, it was found that by adding reinforcements of composites in various proportions, products with high mechanical properties can be obtained. Thus, it was predicted that the composite products obtained in this way can be used in wider application areas.

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Quasi-Static Characterization of Polyamide-Based Discontinuous CFRP Manufactured by Additive Manufacturing and Injection Molding

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.809.386 ◽

2019 ◽

Vol 809 ◽

pp. 386-391 ◽

Cited By ~ 1

Author(s):

Patrick Striemann ◽

Daniel Hülsbusch ◽

Michael Niedermeier ◽

Frank Walther

Keyword(s):

Mechanical Properties ◽

Additive Manufacturing ◽

Injection Molding ◽

Mechanical Characterization ◽

Length Distribution ◽

Deep Understanding ◽

Raw Material ◽

Void Content ◽

Fused Deposition ◽

Printing Direction

Generating serial components via additive manufacturing (AM) a deep understanding of process-related characteristics is necessary. The extrusion-based AM called fused layer manufacturing (FLM), also known as fused deposition modeling (FDM™) or fused filament fabrication (FFF) is an AM process for producing serial components. Improving mechanical properties of AM parts is done by adding fibers in the raw material to reinforce the polymer. The study aims to create a more detailed comprehension of FLM and process-related characteristics with their influence on the composite.Thereby, a short carbon fiber-reinforced polyamide (CarbonX™ Nylon, 3DXTECH, USA) with 12.5 wt.‑% fiber content, 7 μm fiber diameter, and 150 to 400 µm fiber length distribution was investigated. To separate process-related characteristics of FLM, reference specimens were fabricated via injection molding (IM) with single-batch material. For the mechanical characterization, quasi-static tensile tests were carried out in accordance to DIN 527‑2. Quality assessment including void content and void distribution was performed via micro-computed tomography (CT).The mechanical characterization clarifies effects on mechanical properties depending on process-related characteristics of FLM. CT scans show higher void contents of FLM specimens compared to IM specimens and void orientation dependent on printing direction. FLM shows process-related characteristics which generally strengthen mechanical properties of polymers. Nevertheless, tensile strength of FLM specimens decrease by more than 28% compared to quasi-homogenous IM specimens.

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Recycling of PA-12 in Additive Manufacturing and the Improvement of its Mechanical Properties

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.674.9 ◽

2016 ◽

Vol 674 ◽

pp. 9-14 ◽

Cited By ~ 5

Author(s):

Piret Mägi ◽

Andres Krumme ◽

Meelis Pohlak

Keyword(s):

Mechanical Properties ◽

Additive Manufacturing ◽

Fused Deposition Modeling ◽

Selective Laser Sintering ◽

Raw Material ◽

Positive Finding ◽

Polyamide 12 ◽

Fused Deposition ◽

Micro Injection Moulding ◽

Moulding Machine

This study explores possible ways to make Additive Manufacturing (AM) a cradle-to-cradle process, that is, use the leftover from one process as the raw material for another process. The main goal of this study is to develop a set of new polymeric blends with innovative properties, suitable for using in 3-D printing of prosthetic limbs using Fused Deposition Modeling (FDM) technology. Sustainable acting is achieved by reusing polymeric material left over from Selective Laser Sintering (SLS) processes for making raw material for FDM processes. Test specimens of polyamide 12 (PA-12) in its virgin form and used- , un-sintered form alongside specimens of used PA blended with TPU, aramid, or graphite, were produced in a micro-injection moulding machine and then tested for their mechanical properties. This paper provides information about the differences in mechanical characteristics of these different material blends. An unexpected but positive finding was that the differences between virgin and recycled PA-12 are insignificant. The aforementioned additives influenced PA-12 by producing specimens that responded with predictable characteristics which is a significant accomplishment as it lays the groundwork for the next stages of the project.

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Parallel non-dominated sorting genetic algorithm-II for optimal part deposition orientation in additive manufacturing based on functional features

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1177/0954406217737105 ◽

2017 ◽

Vol 232 (19) ◽

pp. 3384-3395 ◽

Cited By ~ 6

Author(s):

Renkai Huang ◽

Ning Dai ◽

Dawei Li ◽

Xiaosheng Cheng ◽

Hao Liu ◽

...

Keyword(s):

Genetic Algorithm ◽

Additive Manufacturing ◽

Surface Quality ◽

Surface Finish ◽

Fused Deposition Modeling ◽

Fused Deposition ◽

Industrial Grade ◽

Build Time ◽

Functional Features

Surface finish, especially the surface finish of functional features, and build time are two important concerns in additive manufacturing. A suitable part deposition orientation can enhance the surface quality of functional features and reduce the build time. This article proposes a novel method to obtain an optimum part deposition orientation for industrial-grade 3D printing based on fused deposition modeling process by considering two objective functions at a time, namely adaptive feature roughness (the weighted sum of all feature roughnesses) and build time. First, mesh segmentation and level classification of features are carried out. Then, models for evaluation of adaptive feature roughness and build time are established. Finally, a non-dominated sorting genetic algorithm-II based on Compute Unified Device Architecture is used to obtain the Pareto-optimal set. The feasible of the algorithm is evaluated on several examples. Results demonstrate that the proposed parallel algorithm obtains a limiting solution that enhances the surface quality of functional features significantly and reduces average running time by 94.8% compared with the traditional genetic algorithm.

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3D printers in dentistry: a review of additive manufacturing techniques and materials

Clinical and Laboratorial Research in Dentistry ◽

10.11606/issn.2357-8041.clrd.2021.188502 ◽

2021 ◽

Author(s):

Leonardo Portilha Gomes da Costa ◽

Stephanie Isabel Díaz Zamalloa ◽

Fernando Amorim Mendonça Alves ◽

Renan Spigolon ◽

Leandro Yukio Mano ◽

...

Keyword(s):

Additive Manufacturing ◽

3D Printing ◽

Fused Deposition Modeling ◽

Dental Materials ◽

Clinical Results ◽

Digital Light Processing ◽

Fused Deposition ◽

3D Printers ◽

Manufacturing Techniques ◽

Printed Materials

3D printers manufacture objects used in various dental specialties. Objective: This literature review aims to explore different techniques of current 3D printers and their applications in printed materials for dental purposes. Methods: The online PubMed databases were searched aiming to find applications of different 3D printers in the dental area. The keywords searched were 3D printer, 3D printing, additive manufacturing, rapid prototyping, 3D prototyping, dental materials and dentistry. Results: From the search results, we describe Stereolithography (SLA), Digital Light Processing (DLP), Material Jetting (MJ), Fused Deposition Modeling (FDM), Binder Jetting (BJ) and Dust-based printing techniques. Conclusion: 3D printing enables different additive manufacturing techniques to be used in dentistry, providing better workflows and more satisfying clinical results.

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Mechanical characterization of polylactic acid, polycaprolactone and Lay-Fomm 40 parts manufactured by fused deposition modeling, as a function of the printing parameters

ITECKNE Innovación e Investigación en Ingeniería ◽

10.15332/iteckne.v16i2.2354 ◽

2019 ◽

Vol 16 (2) ◽

pp. 25-31 ◽

Cited By ~ 1

Author(s):

Jessica Zuleima Parrado-Agudelo ◽

Carlos Narváez-Tovar

Keyword(s):

Mechanical Properties ◽

Elastic Modulus ◽

Yield Stress ◽

Fused Deposition Modeling ◽

Material Selection ◽

Ultimate Tensile Stress ◽

Ultimate Stress ◽

Fused Deposition ◽

Raster Angle ◽

Printing Parameters

This study aims to determine the mechanical properties of parts manufactured by Fused Deposition Modeling (FDM) using three biocompatible polymer materials: Polylactic Acid (PLA), Polycaprolactone (PCL) and Lay-Fomm 40. Also, it was analyzed the influence of different printing parameters, material selection, infill percentage, and raster angle, over the mechanical properties. The samples were subjected to tension and compression tests using a universal testing machine, and elastic modulus, yield stress, and ultimate stress were obtained from the stress-strain curves. PLA samples have the highest elastic modulus, yield stress and ultimate stress for both compression and tension tests, for example, the ultimate tensile stress with infill percentage of 30 % and raster angle of 0-90° has an average value of 41.20 MPa, while PCL samples had an ultimate tensile stress average value of 9.68 MPa. On the other hand, Lay-Fomm40 samples had the highest elongations, with percentage values between 300 and 600 %. Finally, ANOVA analysis showed that the choice of the material is the leading printing parameter that contributes to the mechanical properties, with percentages of 84.20% to elastic modulus, 93.30% to yield stress, and 82.44% to ultimate stress. The second important factor is the raster angle, with higher strengths for the 0-90° when compared to 45-135°. On the other hand, the contribution of the infill percentage to the mechanical properties was no statistically significant. The obtained results could be useful for material selection and 3D printing parameters definition for additive manufacturing of scaffolds, implants, and other structures for biomedical and tissue engineering applications.

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