Drivers of mechanical performance variance in 3D ‐printed fused filament fabrication parts: An Onyx FR case study

Additive manufacturing has experienced remarkable growth in recent years due to the customisation, precision, and cost savings compared to conventional manufacturing techniques. In parallel, materials with great potential have been developed, such as PC-ISO polycarbonate, which has biocompatibility certifications for use in the biomedical industry. However, many of these synthetic materials are not capable of meeting the mechanical stresses to which the biological structure of the human body is naturally subjected. In this study, an exhaustive characterisation of the PC-ISO was carried out, including an investigation on the influence of the printing parameters by fused filament fabrication on its mechanical behaviour. It was found that the effect of the combination of the printing parameters does not have a notable impact on the mass, cost, and manufacturing time of the specimens; however, it is relevant when determining the tensile, bending, shear, impact, and fatigue strengths. The best combinations for its application in biomechanics are proposed, and the need to combine PC-ISO with other materials to achieve the necessary strengths for functioning as a bone scaffold is demonstrated.

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Mechanical Properties of 3D-Printed Acrylonitrile–Butadiene–Styrene TiO2 and ATO Nanocomposites

Polymers ◽

10.3390/polym12071589 ◽

2020 ◽

Vol 12 (7) ◽

pp. 1589 ◽

Cited By ~ 2

Author(s):

Nectarios Vidakis ◽

Markos Petousis ◽

Athena Maniadi ◽

Emmanuel Koudoumas ◽

Marco Liebscher ◽

...

Keyword(s):

Mechanical Properties ◽

Mechanical Performance ◽

Sno2 Nanoparticles ◽

Three Dimensional ◽

Acrylonitrile Butadiene Styrene ◽

International Standards ◽

Fused Filament Fabrication ◽

Melt Mixing ◽

3D Printed ◽

Butadiene Styrene

In order to enhance the mechanical performance of three-dimensional (3D) printed structures fabricated via commercially available fused filament fabrication (FFF) 3D printers, novel nanocomposite filaments were produced herein following a melt mixing process, and further 3D printed and characterized. Titanium Dioxide (TiO2) and Antimony (Sb) doped Tin Oxide (SnO2) nanoparticles (NPs), hereafter denoted as ATO, were selected as fillers for a polymeric acrylonitrile butadiene styrene (ABS) thermoplastic matrix at various weight % (wt%) concentrations. Tensile and flexural test specimens were 3D printed, according to international standards. It was proven that TiO2 filler enhanced the overall tensile strength by 7%, the flexure strength by 12%, and the micro-hardness by 6%, while for the ATO filler, the corresponding values were 9%, 13%, and 6% respectively, compared to unfilled ABS. Atomic force microscopy (AFM) revealed the size of TiO2 (40 ± 10 nm) and ATO (52 ± 11 nm) NPs. Raman spectroscopy was performed for the TiO2 and ATO NPs as well as for the 3D printed nanocomposites to verify the polymer structure and the incorporated TiO2 and ATO nanocrystallites in the polymer matrix. The scope of this work was to fabricate novel nanocomposite filaments using commercially available materials with enhanced overall mechanical properties that industry can benefit from.

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Experimental, Computational, and Dimensional Analysis of the Mechanical Performance of Fused Filament Fabrication Parts

Polymers ◽

10.3390/polym13111766 ◽

2021 ◽

Vol 13 (11) ◽

pp. 1766

Author(s):

Iván Rivet ◽

Narges Dialami ◽

Miguel Cervera ◽

Michele Chiumenti ◽

Guillermo Reyes ◽

...

Keyword(s):

Dimensional Analysis ◽

Mechanical Performance ◽

Cost Savings ◽

Acrylonitrile Butadiene Styrene ◽

Tensile Tests ◽

Uniaxial Tensile ◽

Zone Model ◽

Key Factors ◽

Fused Filament Fabrication ◽

3D Printed

Process parameters in Additive Manufacturing (AM) are key factors in the mechanical performance of 3D-printed parts. In order to study their effect, a three-zone model based on the printing pattern was developed. This modelization distinguished three different zones of the 3D-printed part, namely cover, contour, and inner; each zone was treated as a different material. The cover and contour zones were characterized via uniaxial tensile tests and the inner zones via computational homogenization. The model was then validated by means of bending tests and their corresponding computational simulations. To reduce the number of required characterization experiments, a relationship between the raw and 3D-printed material was established by dimensional analysis. This allowed describing the mechanical properties of the printed part with a reduced set of the most influential non-dimensional relationships. The influence on the performance of the parts of inter-layer adhesion was also addressed in this work via the characterization of samples made of Polycarbonate Acrylonitrile Butadiene Styrene (ABS/PC), a polymeric material well known for its poor adhesion strength. It was concluded that by using this approach, the number of required testing configurations could be reduced by two thirds, which implies considerable cost savings.

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A review on fibre reinforced composite printing via FFF

Rapid Prototyping Journal ◽

10.1108/rpj-01-2019-0004 ◽

2019 ◽

Vol 25 (6) ◽

pp. 972-988 ◽

Cited By ~ 4

Author(s):

Isaac Ferreira ◽

Margarida Machado ◽

Fernando Alves ◽

António Torres Marques

Keyword(s):

High Performance ◽

Mechanical Performance ◽

Fused Filament Fabrication ◽

Content Type ◽

Performance Improvements ◽

Different Types ◽

Significant Research ◽

Comprehensive Survey ◽

3D Printed ◽

Reinforced Thermoplastics

Purpose In industry, fused filament fabrication (FFF) offers flexibility and agility by promoting a reduction in costs and in the lead-time (i.e. time-to-market). Nevertheless, FFF parts exhibit some limitations such as lack of accuracy and/or lower mechanical performance. As a result, some alternatives have been developed to overcome some of these restrictions, namely, the formulation of high performance polymers, the creation of fibre-reinforced materials by FFF process and/or the design of new FFF-based technologies for printing composite materials. This work aims to analyze these technologies. Design/methodology/approach This work aims to study and understand the advances in the behaviour of 3D printed parts with enhanced performance by its reinforcement with several shapes and types of fibres from nanoparticles to continuous fibre roving. Thus, a comprehensive survey of significant research studies carried out regarding FFF of fibre-reinforced thermoplastics is provided, giving emphasis to the most relevant and innovative developments or adaptations undergone at hardware level and/or on the production process of the feedstock. Findings It is shown that the different types of reinforcement present different challenges for the printing process with different outcomes in the part performance. Originality/value This review is focused on joining the most important researches dedicated to the process of FFF-printed parts with different types reinforcing materials. By dividing the reinforcements in categories by shape/geometry and method of processing, it is possible to better quantify performance improvements.

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Influence of 3D-Printed TPU Properties for the Design of Elastic Products

Polymers ◽

10.3390/polym13152519 ◽

2021 ◽

Vol 13 (15) ◽

pp. 2519

Author(s):

Lucía Rodríguez-Parada ◽

Sergio de la Rosa ◽

Pedro F. Mayuet

Keyword(s):

Elastic Properties ◽

Fused Filament Fabrication ◽

Vertical Orientation ◽

Design Engineers ◽

Solid Geometry ◽

Internal Structures ◽

3D Printed ◽

The Difference ◽

Design And Manufacture

The design of products with elastic properties is a paradigm for design engineers because the properties of the material define the correct functionality of the product. Fused filament fabrication (FFF) allows for the printing of products in thermoplastic polyurethanes (TPU). Therefore, it offers the ability to design elastic products with the freedom of forms that this technology allows and also with greater variation of elastic properties than with a conventional process. The internal structures and the variation in thickness that can be used facilitate the design of products with different elastic realities, producing variations in the elasticity of the product with the same material. This work studies the influence of the variation of internal density as a function of basic geometries in order to quantify the difference in elasticity produced on a product when it is designed. Likewise, a case study was carried out with the creation of a fully elastic computer keyboard printed in 3D. The specimens were subjected to compression to characterize the behavior of the structures. The tests showed that the elasticity varies depending on the orientation and geometry, with the highest compressive strength observed in the vertical orientation with 80% lightening. In addition, the internal lightening increases the elasticity progressively but not uniformly with respect to the solid geometry, and also the flat faces favour the reduction in elasticity. This study classifies the behavior of TPU with the aim of being applied to the design and manufacture of products with specific properties. In this work, a totally flexible and functional keyboard was designed, obtaining elasticity values that validate the study carried out.

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3D Printed Hierarchical Honeycombs with Carbon Fiber and Carbon Nanotube Reinforced Acrylonitrile Butadiene Styrene

Journal of Composites Science ◽

10.3390/jcs5020062 ◽

2021 ◽

Vol 5 (2) ◽

pp. 62

Author(s):

Michel Theodor Mansour ◽

Konstantinos Tsongas ◽

Dimitrios Tzetzis

Keyword(s):

Carbon Fibers ◽

Mechanical Performance ◽

Acrylonitrile Butadiene Styrene ◽

Experimental Tests ◽

Fused Filament Fabrication ◽

Element Analysis ◽

Compression Performance ◽

Honeycomb Structures ◽

3D Printed ◽

Butadiene Styrene

The mechanical properties of Fused Filament Fabrication (FFF) 3D printed specimens of acrylonitrile butadiene styrene (ABS), ABS reinforced with carbon fibers (ABS/CFs) and ABS reinforced with carbon nanotubes (ABS/CNTs) are investigated in this paper using various experimental tests. In particular, the mechanical performance of the fabricated specimens was determined by conducting compression and cyclic compression testing, as well as nanoindentation tests. In addition, the design and the manufacturing of hierarchical honeycomb structures are presented using the materials under study. The 3D printed honeycomb structures were examined by uniaxial compressive tests to review the mechanical behavior of such cellular structures. The compressive performance of the hierarchical honeycomb structures was also evaluated with finite element analysis (FEA) in order to extract the stress-strain response of these structures. The results revealed that the 2nd order hierarchy displayed increased stiffness and strength as compared with the 0th and the 1st hierarchies. Furthermore, the addition of carbon fibers in the ABS matrix improved the stiffness, the strength and the hardness of the FFF printed specimens as well as the compression performance of the honeycomb structures.

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Mechanical Performance of Fused Filament Fabricated and 3D-Printed Polycarbonate Polymer and Polycarbonate/Cellulose Nanofiber Nanocomposites

Fibers ◽

10.3390/fib9110074 ◽

2021 ◽

Vol 9 (11) ◽

pp. 74

Author(s):

Nectarios Vidakis ◽

Markos Petousis ◽

Emmanouil Velidakis ◽

Mariza Spiridaki ◽

John D. Kechagias

Keyword(s):

3D Printing ◽

Mechanical Performance ◽

Matrix Material ◽

Mechanical Analysis ◽

Cellulose Nanofiber ◽

Fused Filament Fabrication ◽

Melt Mixing ◽

The Matrix ◽

3D Printed ◽

Printing Parameters

In this study, nanocomposites were fabricated with polycarbonate (PC) as the matrix material. Cellulose Nanofiber (CNF) at low filler loadings (0.5 wt.% and 1.0 wt.%) was used as the filler. Samples were produced using melt mixing extrusion with the Fused Filament Fabrication (FFF) process. The optimum 3D-printing parameters were experimentally determined and the required specimens for each tested material were manufactured using FFF 3D printing. Tests conducted for mechanical performance were tensile, flexural, impact, and Dynamic Mechanical Analysis (DMA) tests, while images of the side and the fracture area of the specimens were acquired using Scanning Electron Microscopy (SEM), aiming to determine the morphology of the specimens and the fracture mechanism. It was concluded that the filler’s ratio addition of 0.5 wt.% created the optimum performance when compared to pure PC and PC CNF 1.0 wt.% nanocomposite material.

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Predicting the effect of build orientation and process temperatures on the performance of parts made by fused filament fabrication

Rapid Prototyping Journal ◽

10.1108/rpj-04-2021-0084 ◽

2021 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Fernando Moura Duarte ◽

José António Covas ◽

Sidonie Fernandes da Costa

Keyword(s):

Molecular Diffusion ◽

Operating Conditions ◽

Fused Filament Fabrication ◽

Content Type ◽

Build Orientation ◽

Thermal Boundary Conditions ◽

Chamber Temperature ◽

3D Printed ◽

Time Required

Purpose The performance of the parts obtained by fused filament fabrication (FFF) is strongly dependent on the extent of bonding between adjacent filaments developing during the deposition stage. Bonding depends on the properties of the polymer material and is controlled by the temperature of the filaments when they come into contact, as well as by the time required for molecular diffusion. In turn, the temperature of the filaments is influenced by the set of operating conditions being used for printing. This paper aims at predicting the degree of bonding of realistic 3D printed parts, taking into consideration the various contacts arising during its fabrication, and the printing conditions selected. Design/methodology/approach A computational thermal model of filament cooling and bonding that was previously developed by the authors is extended here, to be able to predict the influence of the build orientation of 3D printed parts on bonding. The quality of a part taken as a case study is then assessed in terms of the degree of bonding, i.e. the percentage of volume exhibiting satisfactory bonding between contiguous filaments. Findings The complexity of the heat transfer arising from the changes in the thermal boundary conditions during deposition and cooling is well demonstrated for a case study involving a realistic 3D part. Both extrusion and build chamber temperature are major process parameters. Originality/value The results obtained can be used as practical guidance towards defining printing strategies for 3D printing using FFF. Also, the model developed could be directly applied for the selection of adequate printing conditions.

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Effect of nozzle diameter on mechanical and geometric performance of 3D printed carbon fibre-reinforced composites manufactured by fused filament fabrication

Rapid Prototyping Journal ◽

10.1108/rpj-10-2020-0250 ◽

2021 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Jesús Miguel Chacón ◽

Miguel Ángel Caminero ◽

Pedro José Núñez ◽

Eustaquio García-Plaza ◽

Jean Paul Bécar

Keyword(s):

Surface Roughness ◽

Carbon Fibre ◽

Mechanical Performance ◽

Dimensional Accuracy ◽

Nozzle Diameter ◽

Fused Filament Fabrication ◽

Manufacturing Costs ◽

Content Type ◽

3D Printed ◽

Composite Samples

Purpose Fused filament fabrication (FFF) is one of the most popular additive manufacturing (AM) technologies due to its ability to build thermoplastic parts with complex geometries at low cost. The FFF technique has been mainly used for rapid prototyping owing to the poor mechanical and geometrical properties of pure thermoplastic parts. However, both the development of new fibre-reinforced filaments with improved mechanical properties, and more accurate composite 3D printers have broadened the scope of FFF applications to functional components. FFF is a complex process with a large number of parameters influencing product quality and mechanical properties, and the effects of the combined parameters are usually difficult to evaluate. An array of parameter combinations has been analysed for improving the mechanical performance of thermoplastic parts such as layer thickness, build orientation, raster angle, raster width, air gap, infill density and pattern, fibre volume fraction, fibre layer location, fibre orientation and feed rate. This study aims to assess the effects of nozzle diameter on the mechanical performance and the geometric properties of 3D printed short carbon fibre-reinforced composites processed by the FFF technique. Design methodology approach Tensile and three-point bending tests were performed to characterise the mechanical response of the 3D printed composite samples. The dimensional accuracy, the flatness error and surface roughness of the printed specimens were also evaluated. Moreover, manufacturing costs, which are related to printing time, were evaluated. Finally, scanning electron microscopy images of the printed samples were analysed to estimate the porosity as a function of the nozzle diameter and to justify the effect of nozzle diameter on dimensional accuracy and surface roughness. Findings The effect of nozzle diameter on the mechanical and geometric quality of 3D printed composite samples was significant. In addition, large nozzle diameters tended to increase mechanical performance and enhance surface roughness, with a reduction in manufacturing costs. In contrast, 3D printed composite samples with small nozzle diameter exhibited higher geometric accuracy. However, the effect of nozzle diameter on the flatness error and surface roughness was of slight significance. Finally, some print guidelines are included. Originality value The effect of nozzle diameter, which is directly related to product quality and manufacturing costs, has not been extensively studied. The presented study provides more information regarding the dependence of the mechanical, microstructural and geometric properties of short carbon fibre-reinforced nylon composite components on nozzle diameter.

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