scholarly journals Optimization of the Filler Concentration on Fused Filament Fabrication 3D Printed Polypropylene with Titanium Dioxide Nanocomposites

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3076
Author(s):  
Nectarios Vidakis ◽  
Markos Petousis ◽  
Emmanouil Velidakis ◽  
Lazaros Tzounis ◽  
Nikolaos Mountakis ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Extrusion Process ◽  
Mechanical Analysis ◽  
International Standards ◽  
Volume Index ◽  
Filler Concentration ◽  
Fused Filament Fabrication ◽  
Melt Mixing ◽  
Force Microscopy ◽  
3D Printed

Polypropylene (PP) is an engineered thermoplastic polymer widely used in various applications. This work aims to enhance the properties of PP with the introduction of titanium dioxide (TiO2) nanoparticles (NPs) as nanofillers. Novel nanocomposite filaments were produced at 0.5, 1, 2, and 4 wt.% filler concentrations, following a melt mixing extrusion process. These filaments were then fed to a commercially available fused filament fabrication (FFF) 3D printer for the preparation of specimens, to be assessed for their mechanical, viscoelastic, physicochemical, and fractographic properties, according to international standards. Tensile, flexural, impact, and microhardness tests, as well as dynamic mechanical analysis (DMA), Raman, scanning electron microscopy (SEM), melt flow volume index (MVR), and atomic force microscopy (AFM), were conducted, to fully characterize the filler concentration effect on the 3D printed nanocomposite material properties. The results revealed an improvement in the nanocomposites properties, with the increase of the filler amount, while the microstructural effect and processability of the material was not significantly affected, which is important for the possible industrialization of the reported protocol. This work showed that PP/TiO2 can be a novel nanocomposite system in AM applications that the polymer industry can benefit from.

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

Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1589 ◽  
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.

scholarly journals Enhanced Mechanical, Thermal and Antimicrobial Properties of Additively Manufactured Polylactic Acid with Optimized Nano Silica Content

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 1012
Author(s):  
Nectarios Vidakis ◽  
Markos Petousis ◽  
Emanuel Velidakis ◽  
Nikolaos Mountakis ◽  
Lazaros Tzounis ◽  
...  
Keyword(s):  
Polylactic Acid ◽  
Three Dimensional ◽  
Antibacterial Properties ◽  
Antimicrobial Properties ◽  
Sio2 Nanoparticles ◽  
International Standards ◽  
Fused Filament Fabrication ◽  
Melt Mixing ◽  
Screening Process ◽  
3D Printed

The scope of this work was to create, with melt mixing compounding process, novel nanocomposite filaments with enhanced properties that industry can benefit from, using commercially available materials, to enhance the performance of three-dimensional (3D) printed structures fabricated via fused filament fabrication (FFF) process. Silicon Dioxide (SiO2) nanoparticles (NPs) were selected as fillers for a polylactic acid (PLA) thermoplastic matrix at various weight % (wt.%) concentrations, namely, 0.5, 1.0, 2.0 and 4.0 wt.%. Tensile, flexural and impact test specimens were 3D printed and tested according to international standards and their Vickers microhardness was also examined. It was proven that SiO2 filler enhanced the overall strength at concentrations up to 1 wt.%, compared to pure PLA. Atomic force microscopy (AFM) was employed to investigate the produced nanocomposite extruded filaments roughness. Raman spectroscopy was performed for the 3D printed nanocomposites to verify the polymer nanocomposite structure, while thermogravimetric analysis (TGA) revealed the 3D printed samples’ thermal stability. Scanning electron microscopy (SEM) was carried out for the interlayer fusion and fractography morphological characterization of the specimens. Finally, the antibacterial properties of the produced nanocomposites were investigated with a screening process, to evaluate their performance against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus).

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

Fibers ◽  
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.

scholarly journals Electrical and magnetic properties of 0–3 Ba(Fe1∕2Nb1∕2)O3/PVDF composites

2017 ◽  
Vol 07 (06) ◽  
pp. 1750036 ◽  
Author(s):  
Hars Ranjan ◽  
Uttam K. Mahto ◽  
K. P. Chandra ◽  
A. R. Kulkarni ◽  
A. Prasad ◽  
...  
Keyword(s):  
Data Storage ◽  
Ac Conductivity ◽  
Average Crystallite Size ◽  
Negative Temperature ◽  
Filler Concentration ◽  
X Ray Diffraction ◽  
Melt Mixing ◽  
Force Microscopy ◽  
Electrical And Magnetic Properties ◽  
Hopping Model

Lead-free Ba(Fe[Formula: see text]Nb[Formula: see text]O3/PVDF 0–3 composites were fabricated using melt-mixing technique. X-ray diffraction, scanning electron microscopy, dielectric, impedance, ac conductivity, magnetic force microscopy (MFM) and vibrating sample magnetometer studies were undertaken to characterize the samples. Average crystallite size of the Ba(Fe[Formula: see text]Nb[Formula: see text]O3 powder, estimated using Williamson–Hall approach, was found to be [Formula: see text][Formula: see text]nm. The filler particles of [Formula: see text][Formula: see text][Formula: see text]m were found to disperse in the polymer matrix of all the composites. Filler concentration-dependent values of real and imaginary parts of complex permittivity showed increasing trend and were seen to follow Bruggeman and Furukawa equations. The data for ac conductivity exhibited negative temperature coefficient of resistance character of the test materials and were found to obey Jonscher’s power law. The correlated barrier hopping model was found to explain satisfactorily the mechanism of charge transport occurring in the system. MFM confirmed the presence of magnetic phases in the composites. Typical magnetization versus applied field curves indicated the possibility of magnetoelectric coupling in the system. Hence, the present composites have shown themselves as potential multi-functional candidate materials for use in high density data storage applications.

Bending performance enhancement by nanoparticles for FFF 3D printed nylon and nylon/Kevlar composites

2020 ◽  
pp. 002199832096352
Author(s):  
Yachao Wang ◽  
Jing Shi ◽  
Zhihui Liu
Keyword(s):  
Flexural Strength ◽  
Performance Enhancement ◽  
Matrix Material ◽  
Extrusion Process ◽  
Thermoplastic Composites ◽  
Fused Filament Fabrication ◽  
Bending Performance ◽  
Bending Modulus ◽  
The Matrix ◽  
3D Printed

Fused filament fabrication (FFF) has been a major 3D printing technique for making thermoplastic products for decades. However, FFF printing for thermoplastic composites with aligned continuous fibers has been reported with limited success for only several years. In this study, we introduce an enhanced FFF-based approach by incorporating nanoparticles to the thermoplastic composites with continuous fibers. Our investigation focuses on the bending properties of FFF-printed fiber reinforced composites with and without nanoparticles. With Nylon 6 (PA 6) being the matrix material, nanocomposite filaments are obtained by adding carbon nanotubes (CNTs), graphene nano platelets (GNPs), or amino (NH2-) functionalized GNPs. Various PA 6 matrix nanocomposite filaments are prepared through mixing and filament extrusion process. The nanocomposite filaments are then 3D printed with or without continuous Kevlar fiber prepreg filaments. For 3D printed pure PA 6, the addition of 1 wt% GNP-NH2 increases the flexural strength and bending modulus by 334% and 315%, respectively. For 3D printed PA 6/Kevlar composite, the addition of 1 wt% GNP-NH2 increases the flexural strength and bending modulus by 195% and 35%, respectively. However, the addition of CNTs or GNPs (up to 1 wt%) is less effective as compared with GNP-NH2. The underlying mechanisms are discussed based on the matrix/fiber interfacial analysis.

Dynamic Mechanical Analysis of ABS From Hybrid Additive Manufacturing by Fused Filament Fabrication and Shot Peening

2020 ◽  
Author(s):  
Haitham Hadidi ◽  
Brady Mailand ◽  
Tayler Sundermann ◽  
Ethan Johnson ◽  
Rakeshkumar Karunakaran ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Dynamic Mechanical Analysis ◽  
Shot Peening ◽  
Extrusion Process ◽  
Dynamic Mechanical Properties ◽  
Mechanical Analysis ◽  
Layer By Layer ◽  
Fused Filament Fabrication ◽  
Dynamic Mechanical

Abstract The mechanical properties of 3D printed polymers parts are process parameter dependent. Defects such as inadvertent voids between deposited rasters and layers lead to weakness in produced parts, which results in inferior mechanical properties as compared to injection molding. An alternative method to change energy absorption and stiffness of a polymer is hybrid additive manufacturing (AM). Hybrid-AM is the use of additive manufacturing with one or more secondary processes that are fully coupled and synergistically affect part quality, functionality, and/or process performance. In this study, fused filament fabrication (FFF) was coupled with layer-by-layer shot peening to study the dynamic mechanical properties of ABS 430 polymer using dynamic mechanical analysis (DMA). FFF is a heated extrusion process. Shot peening is a mechanical surface treatment that impinges a target with a stochastically dispersed, high velocity stream of beads. Compressive residual stress was imparted to preferential layer intervals during printing to modify the elasticity (stiffness), viscosity, toughness, and glass transition temperature. Viscoelastic and dynamic mechanical properties are important to the performance of polymers in automotive, aerospace, electronics, and medical components. Coupling printing and peening increased the storage and loss moduli as well as the tangent delta. DMA results suggest that preferential layer sequences exist that possess higher elasticity and better absorb energy upon sinusoidal dynamic loading.

scholarly journals Three-Dimensional Printed Antimicrobial Objects of Polylactic Acid (PLA)-Silver Nanoparticle Nanocomposite Filaments Produced by an In-Situ Reduction Reactive Melt Mixing Process

Biomimetics ◽  
2020 ◽  
Vol 5 (3) ◽  
pp. 42 ◽  
Author(s):  
Nectarios Vidakis ◽  
Markos Petousis ◽  
Emmanouel Velidakis ◽  
Marco Liebscher ◽  
Lazaros Tzounis
Keyword(s):  
Polylactic Acid ◽  
Silver Nanoparticle ◽  
Antimicrobial Properties ◽  
P Value ◽  
In Situ Reduction ◽  
Fused Filament Fabrication ◽  
Melt Mixing ◽  
3D Printed ◽  
Reactive Melt

In this study, an industrially scalable method is reported for the fabrication of polylactic acid (PLA)/silver nanoparticle (AgNP) nanocomposite filaments by an in-situ reduction reactive melt mixing method. The PLA/AgNP nanocomposite filaments have been produced initially reducing silver ions (Ag+) arising from silver nitrate (AgNO3) precursor mixed in the polymer melt to elemental silver (Ag0) nanoparticles, utilizing polyethylene glycol (PEG) or polyvinyl pyrrolidone (PVP), respectively, as macromolecular blend compound reducing agents. PEG and PVP were added at various concentrations, to the PLA matrix. The PLA/AgNP filaments have been used to manufacture 3D printed antimicrobial (AM) parts by Fused Filament Fabrication (FFF). The 3D printed PLA/AgNP parts exhibited significant AM properties examined by the reduction in Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) bacteria viability (%) experiments at 30, 60, and 120 min duration of contact (p < 0.05; p-value (p): probability). It could be envisaged that the 3D printed parts manufactured and tested herein mimic nature’s mechanism against bacteria and in terms of antimicrobial properties, contact angle for their anti-adhesive behavior and mechanical properties could create new avenues for the next generation of low-cost and on-demand additive manufacturing produced personal protective equipment (PPE) as well as healthcare and nosocomial antimicrobial equipment.

scholarly journals On the Mechanical Response of Silicon Dioxide Nanofiller Concentration on Fused Filament Fabrication 3D Printed Isotactic Polypropylene Nanocomposites

Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2029
Author(s):  
Nectarios Vidakis ◽  
Markos Petousis ◽  
Emmanouil Velidakis ◽  
Lazaros Tzounis ◽  
Nikolaos Mountakis ◽  
...  
Keyword(s):  
3D Printing ◽  
Silicon Dioxide ◽  
Mechanical Response ◽  
Mechanical Performance ◽  
Microstructural Analysis ◽  
Melt Flow Index ◽  
International Standards ◽  
Flow Index ◽  
Fused Filament Fabrication ◽  
Melt Mixing

Utilization of advanced engineering thermoplastic materials in fused filament fabrication (FFF) 3D printing process is critical in expanding additive manufacturing (AM) applications. Polypropylene (PP) is a widely used thermoplastic material, while silicon dioxide (SiO2) nanoparticles (NPs), which can be found in many living organisms, are commonly employed as fillers in polymers to improve their mechanical properties and processability. In this work, PP/SiO2 nanocomposite filaments at various concentrations were developed following a melt mixing extrusion process, and used for FFF 3D printing of specimens’ characterization according to international standards. Tensile, flexural, impact, microhardness, and dynamic mechanical analysis (DMA) tests were conducted to determine the effect of the nanofiller loading on the mechanical and viscoelastic properties of the polymer matrix. Scanning electron microscopy (SEM), Raman spectroscopy and atomic force microscopy (AFM) were performed for microstructural analysis, and finally melt flow index (MFI) tests were conducted to assess the melt rheological properties. An improvement in the mechanical performance was observed for silica loading up to 2.0 wt.%, while 4.0 wt.% was a potential threshold revealing processability challenges. Overall, PP/SiO2 nanocomposites could be ideal candidates for advanced 3D printing engineering applications towards structural plastic components with enhanced mechanical performance.

The influence of porosity, crystallinity and interlayer adhesion on the tensile strength of 3D printed polylactic acid (PLA)

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Natalia von Windheim ◽  
David W. Collinson ◽  
Trent Lau ◽  
L. Catherine Brinson ◽  
Ken Gall
Keyword(s):  
Tensile Strength ◽  
Polylactic Acid ◽  
Thermal Stresses ◽  
Structural Characteristics ◽  
Experimental Studies ◽  
Fused Filament Fabrication ◽  
Content Type ◽  
Force Microscopy ◽  
3D Printed ◽  
Printing Parameters

Purpose The purpose of this study is to understand how printing parameters and subsequent annealing impacts porosity and crystallinity of 3D printed polylactic acid (PLA) and how these structural characteristics impact the printed material’s tensile strength in various build directions. Design/methodology/approach Two experimental studies were used, and samples with a flat vs upright print orientation were compared. The first experiment investigates a scan of printing parameters and annealing times and temperatures above the cold crystallization temperature (Tcc) for PLA. The second experiment investigates annealing above and below Tcc at multiple points over 12 h. Findings Annealing above Tcc does not significantly impact the porosity but it does increase crystallinity. The increase in crystallinity does not contribute to an increase in strength, suggesting that co-crystallization across the weld does not occur. Atomic force microscopy (AFM) images show that weld interfaces between printed fibers are still visible after annealing above Tcc, confirming the lack of co-crystallization. Annealing below Tcc does not significantly impact porosity or crystallinity. However, there is an increase in tensile strength. AFM images show that annealing below Tcc reduces thermal stresses that form at the interfaces during printing and slightly “heals” the as-printed interface resulting in an increase in tensile strength. Originality/value While annealing has been explored in the literature, it is unclear how it affects porosity, crystallinity and thermal stresses in fused filament fabrication PLA and how those factors contribute to mechanical properties. This study explains how co-crystallization across weld interfaces is necessary for crystallinity to increase strength and uses AFM as a technique to observe morphology at the weld.

scholarly journals Fused Filament Fabrication Three-Dimensional Printing Multi-Functional of Polylactic Acid/Carbon Black Nanocomposites

2021 ◽  
Vol 7 (3) ◽  
pp. 52
Author(s):  
Nectarios Vidakis ◽  
Markos Petousis ◽  
Emmanuel Velidakis ◽  
Nikolaos Mountakis ◽  
Peder Erik Fischer-Griffiths ◽  
...  
Keyword(s):  
3D Printing ◽  
Carbon Black ◽  
Polylactic Acid ◽  
Complex Geometry ◽  
Three Dimensional ◽  
Antibacterial Properties ◽  
Fused Filament Fabrication ◽  
Melt Mixing ◽  
Screening Process ◽  
3D Printed

Conductive Polymer Composites (CPCs) have recently gained an extensive scientific interest as feedstock materials in Fused Filament Fabrication (FFF) Three-dimensional (3D) printing. Polylactic Acid (PLA), widely used in FFF 3D printing, as well as its Carbon Black (CB) nanocomposites at different weight percentage (wt.%) filler loadings (0.5, 1.0, 2.5 and 5.0 wt.%), were prepared via a melt mixing filament extrusion process in this study and utilized to manufacture FFF 3D printed specimens. The nanocomposites were examined for their electrical conductivity. The highest loaded 3D printed CPC (5.0 wt.%) was tested as an electrothermal Joule heating device. Static tensile, flexural, Charpy’s impact and Vickers microhardness mechanical properties were investigated for the neat and PLA/CB 3D printed nanocomposites. Dynamic Mechanical Analysis (DMA) revealed a stiffening mechanism for the PLA/CB nanocomposites. Scanning Electron Microscopy (SEM) elucidated the samples’ internal and external microstructural characteristics. The PLA/CB 5.0 wt.% nanocomposite demonstrated also antibacterial properties, when examined with a screening process, against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). It can be envisaged that the 3D printed PLA/CB CPCs exhibited a multi-functional performance, and could open new avenues towards low-cost personalized biomedical objects with complex geometry, amongst others, i.e., surgery tools, splints, wearables, etc.

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