Fused filament fabrication of biodegradable polylactic acid reinforced by nanoclay as a potential biomedical material

Fused filament fabrication (FFF) is one of the most common 3D printing techniques having considerable potential in various fields such as pharmaceutical, medical, aerospace, and automotive. One of the impediments of FFF components is their lower mechanical performance compared with those from conventional fabrication methods. This work aims to investigate the effect of adding nanoclay due to being nontoxic to the biodegradable polylactic acid (PLA) polymer matrix for medical applications. PLA granules were melt-compounded by a twin-screw extruder with nanoclay at 2 and 4 wt.%, and then, PLA and PLA/nanoclay filaments were produced using a single-screw extruder. An L9 orthogonal array of the Taguchi approach was utilized as the design of the experiment tool to study the process in detail considering nanoclay content, nozzle temperature and raster angle as material and processing parameters. The dispersion of nanoclay in the PLA matrix was assessed by X-ray diffraction test. The results indicated that the tensile strength was enhanced by 4.6% and 15.3% using the addition of 2 and 4 wt.% of nanoclay, respectively. The microscopic observations showed that the bonding between the rasters and between the contours and rasters was improved by increasing the temperature, and consequently, led to higher tensile strength values. The results revealed that the tensile strength of 38.9 MPa was obtained at the optimum condition.

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Tensile properties of the FFF-processed thermoplastic polyurethane (TPU) elastomer

10.21203/rs.3.rs-299979/v1 ◽

2021 ◽

Author(s):

Budi Arifvianto ◽

Teguh Nur Iman ◽

Benidiktus Tulung Prayoga ◽

Rini Dharmastiti ◽

Urip Agus Salim ◽

...

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Low Cost ◽

Thermoplastic Polyurethane ◽

High Strength ◽

Tensile Tests ◽

Uniaxial Tensile ◽

Fused Filament Fabrication ◽

Raster Angle ◽

Manufacturing Techniques

Abstract Fused filament fabrication (FFF) has become one of the most popular, practical, and low-cost additive manufacturing techniques for fabricating geometrically-complex thermoplastic polyurethane (TPU) elastomer. However, there are still some uncertainties concerning the relationship between several operating parameters applied in this technique and the mechanical properties of the processed material. In this research, the influences of extruder temperature and raster orientation on the mechanical properties of the FFF-processed TPU elastomer were studied. A series of uniaxial tensile tests was carried out to determine tensile strength, strain, and elastic modulus of TPU elastomer that had been printed with various extruder temperatures, i.e., 190–230 °C, and raster angles, i.e., 0–90°. Thermal and chemical characterizations were also conducted to support the analysis in this research. The results obviously showed the ductile and elastic characteristics of the FFF-processed TPU, with specific tensile strength and strain that could reach up to 39 MPa and 600%, respectively. The failure mechanisms operating on the FFF-processed TPU and the result of stress analysis by using the developed Mohr’s circle are also discussed in this paper. In conclusion, the extrusion temperature of 200 °C and raster angle of 0° could be preferred to be applied in the FFF process to achieve high strength and ductile TPU elastomer.

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An experimental study of FDM parameters effects on tensile strength, density, and production time of ABS/Cu composites

Journal of Elastomers & Plastics ◽

10.1177/0095244320916838 ◽

2020 ◽

pp. 009524432091683 ◽

Cited By ~ 2

Author(s):

Mojtaba Nabipour ◽

Behnam Akhoundi

Keyword(s):

Tensile Strength ◽

Taguchi Method ◽

Fused Deposition Modeling ◽

Signal To Noise Ratio ◽

Three Dimensional ◽

Acrylonitrile Butadiene Styrene ◽

Production Time ◽

Fused Deposition ◽

Raster Angle ◽

Nozzle Temperature

Recently, applications of three-dimensional (3-D) printers have extensively been increased in various industries. Fused deposition modeling process is one of the most widely used 3-D printing methods in this area due to its simplicity, reliability, and the ability to produce complex parts made of thermoplastic materials. In this research, composite sample parts consisted of copper particles with a constant 25 wt% of metallic powder as a filler and acrylonitrile butadiene styrene granules as a polymeric matrix. A filament production line to acquire printable filaments was applied and its optimum parameters were reported. Four printing parameters involved nozzle diameter, layer height, raster angle, and nozzle temperature were chosen in three levels for investigation of composite samples’ tensile strength, density, and production time as a new study. The Taguchi method, a well-known design of experiment tool, was employed to find the effect of each parameter and optimum levels with including the main effect, signal-to-noise ratio, and analysis of variance. Finally, optimum composite specimens manufactured by 3-D printer verified Taguchi method analysis and results.

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Influence of Process Parameters on Tensile Strength of Additive Manufactured PLA Parts using Taguchi Method

International Journal of Recent Technology and Engineering - 2 ◽

10.35940/ijrte.c6191.098319 ◽

2019 ◽

Vol 8 (3) ◽

pp. 7635-7639

Keyword(s):

Tensile Strength ◽

Layer Thickness ◽

Fused Deposition Modeling ◽

Optimal Parameter ◽

Fused Filament Fabrication ◽

Influence Of Process Parameters ◽

Layer Height ◽

Fused Deposition ◽

Deposition Modeling ◽

Nozzle Temperature

Influence of layer thickness nozzle temperature and angle on tensile strength of PLA fabricated with FDM (FFF) was experimentally investigated. Polylactic Acid (PLA) is a semi-crystalline and bio-friendly thermoplastic polymer has identified as important material in different applications due to its mechanical characteristics. Fused Deposition Modeling (FDM) is a one of the proved technology in Fused Filament Fabrication (FFF) technique in additive manufacturing process. In present investigation different specimens were fabricated using FDM technique with different layer height and different layer angles for finding influence of these manufacturing parameters on tensile strength of the specimen. Specimens were fabricated and tested as per ASTM D638 standard. It is clearly observed that tensile strength is more for +450 /-450 layer angle than the +00 /-0 0 layer angle for a given layer height(h=0.10 mm, h=0.15mm and h=0.20mm).The TAGUCHI analysis is carried with nozzle temperature, layer thickness and angle finding optimal values. It has been observed that, the optimal parameter is angle, which is equal to 30 0 .the ANOVA variation of angle layer with tensile strength has been observed that 18.10-31.90.

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Effect of the filling percentage on tensile strength in 3D desktop printing for different printing patterns, using a randomized design of experiments

Enfoque UTE ◽

10.29019/enfoque.v10n4.503 ◽

2019 ◽

Vol 10 (4) ◽

pp. 13-27

Author(s):

Juan Carlos Parra Mena ◽

Erling Ricardo Gallardo Vizuete ◽

Erick Damian Torres Peñaloza

Keyword(s):

Tensile Strength ◽

Design Of Experiments ◽

Polylactic Acid ◽

Fused Deposition Modeling ◽

Single Factor ◽

Fused Filament Fabrication ◽

Fused Deposition ◽

Randomized Design ◽

Filling Pattern ◽

Deposition Modeling

The evaluation of the tensile strength of printed parts by means of fused deposition modeling (FDM) or fused filament fabrication (FFF) is essential, since parts whose resistance does not differ significantly depending on the percentage of filling used can be obtained, optimizing the use of the material. The present work details the analysis of polylactic acid (PLA) specimens manufactured according to ASTM D 638 with different percentages for the most commonly used filling patterns (Honeycomb, Octagram, Stars, Archimedean, Hilbert and Triangles). With the help of an analysis of variance and a design of experiments with a single factor, the appropriate percentages for printing parts according to the desired filling pattern are obtained.

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Research on the Fused Deposition Modeling of Polyether Ether Ketone

Polymers ◽

10.3390/polym13142344 ◽

2021 ◽

Vol 13 (14) ◽

pp. 2344

Author(s):

Ruoxiang Gao ◽

Jun Xie ◽

Jinghui Yang ◽

Chaojie Zhuo ◽

Jianzhong Fu ◽

...

Keyword(s):

Tensile Strength ◽

Fused Deposition Modeling ◽

Fused Deposition ◽

Polyether Ether Ketone ◽

Raster Angle ◽

Deposition Modeling ◽

Ether Ketone ◽

Nozzle Temperature ◽

Warpage Deformation ◽

Printing Speed

As a special engineering polymer, polyether ether ketone (PEEK) has been used widely due to its excellent mechanical properties, high thermal stability, and chemical resistance. Fused deposition modeling (FDM) is a promising process for fabricating PEEK parts. However, due to the semi-crystalline property and high melting point of PEEK, determining appropriate process parameters is important to reduce warpage deformation and improve the mechanical properties of PEEK. In this article, the influence of raster angle and infill density was determined by single factor experiment, which are the two most important parameters. The results showed that samples with 0°/90° raster angle and 50% infill density had the best comprehensive properties in terms of warpage deformation, tensile strength, and specific strength. Subsequently, based on the results above, the effects of printing speed, nozzle temperature, platform temperature, raster width, and layer thickness were analyzed by orthogonal experiment. The results indicated that platform temperature had the greatest impact on warpage deformation while printing speed and nozzle temperature were significant parameters on tensile strength. Through optimization, warpage deformation of the samples could be reduced to almost 0 and tensile strength could increase by 19.6% (from 40.56 to 48.50 MPa). This will support the development of FDM for PEEK.

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Experimental study and modeling the tensile strength of 3D‐printed aluminium polylactic acid (PLA) parts using artificial neural networks

F1000Research ◽

10.12688/f1000research.73796.1 ◽

2021 ◽

Vol 10 ◽

pp. 1286

Author(s):

Chockalingam Palanisamy ◽

Hong Kiat Aaron Tay Hong Kiat

Keyword(s):

Neural Network ◽

Tensile Strength ◽

Tensile Test ◽

Layer Thickness ◽

Polylactic Acid ◽

Processing Parameters ◽

Ann Model ◽

High Layer ◽

3D Printed ◽

Artificial Neural

Background: High quality 3D printed products are in high demand, resulting in an increase in the production of 3D printed parts with precise tolerances, improved surface roughness, and overall durability. The processing parameters of 3D printers have a significant impact on the quality of 3D printed parts. Three-dimensionally printed parts must be durable, especially in terms of tensile strength, and its impact on the printer's process parameters must be investigated. Methods: Tensile test specimens were printed in the Makerbot 3D printer with aluminium polylactic acid (PLA) material. The three controllable input parameters taken into consideration were layer thickness, infill density and number of shells. The three levels for each of the respective parameters were 0.1mm, 0.2mm and 0.3mm for layer thickness; 2,3 and 4 for number of shells; 20% 40% and 60% for Infill density. Tensile testing was carried out on the specimens and data was tabulated. Using these data, an artificial neural network model was created using Matlab R2021b software’s neural network toolbox (alternatively Scilab can be used). Results: A high layer thickness (0.3mm) and a 40% infill density were found to be the most effective among all other parameters. The specimen with the lowest layer thickness of 0.1mm, four shells, and a 20% infill density had the highest tensile strength. With the tensile test data, a Matlab ANN model was developed. Validation was done by comparing the values obtained from the model with the experimental data by using random layer thickness, infill density, and number of shells. Conclusions: In conclusion, higher layer thickness has lower tensile strengths. However, as the number of shells and infill density increases, the tensile strength increases. In summary an ANN model was successfully developed and validated to predict 3D printed aluminium parts.

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Embedding Ultra-High-Molecular-Weight Polyethylene Fibers in 3D-Printed Polylactic Acid (PLA) Parts

Polymers ◽

10.3390/polym11111825 ◽

2019 ◽

Vol 11 (11) ◽

pp. 1825 ◽

Cited By ~ 2

Author(s):

Amza ◽

Zapciu ◽

Eyþórsdóttir ◽

Björnsdóttir ◽

Borg

Keyword(s):

Molecular Weight ◽

Tensile Strength ◽

3D Printing ◽

High Molecular Weight ◽

Polylactic Acid ◽

Strength Tests ◽

Raster Angle ◽

Uhmwpe Fibers ◽

3D Printed ◽

Ultra High Molecular Weight

This study aims to assess whether ultra-high-molecular-weight polyethylene (UHMWPE) fibers can be successfully embedded in a polylactic acid (PLA) matrix in a material extrusion 3D printing (ME3DP) process, despite the apparent thermal incompatibility between the two materials. The work started with assessing the maximum PLA extrusion temperatures at which UHMWPE fibers withstand the 3D printing process without melting or severe degradation. After testing various fiber orientations and extrusion temperatures, it has been found that the maximum extrusion temperature depends on fiber orientation relative to extrusion pathing and varies between 175 °C and 185 °C at an ambient temperature of 25 °C. Multiple specimens with embedded strands of UHMWPE fibers have been 3D printed and following tensile strength tests on the fabricated specimens, it has been found that adding even a small number of fiber strands laid in the same direction as the load increased tensile strength by 12% to 23% depending on the raster angle, even when taking into account the decrease in tensile strength due to reduced performance of the PLA substrate caused by lower extrusion temperatures.

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Effects of extruder temperatures and raster orientations on mechanical properties of the FFF-processed polylactic-acid (PLA) material

Rapid Prototyping Journal ◽

10.1108/rpj-10-2019-0270 ◽

2021 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Budi Arifvianto ◽

Yuris Bahadur Wirawan ◽

Urip Agus Salim ◽

Suyitno Suyitno ◽

Muslim Mahardika

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Elastic Modulus ◽

Polylactic Acid ◽

Tensile Tests ◽

Degree Of Crystallinity ◽

Content Type ◽

Raster Angle ◽

Loading Axis ◽

Mohr’S Circle

Purpose The purpose of this study is to investigate the influences of extruder temperatures and raster orientations on the mechanical properties of polylactic-acid (PLA) material processed by using fused filament fabrication (FFF). Design/methodology/approach In this research, the PLA specimens were first printed with nozzle or extruder temperatures of 205°C, 215°C and 225°C and then evaluated in terms of their physical, chemical and mechanical properties. An appropriate extruder temperature was then selected based on this experiment and used for the printing of the other PLA specimens having various raster orientations. A series of tensile tests were carried out again to investigate the influence of raster orientations on the tensile strength, tensile strain and elastic modulus of those FFF-processed PLA materials. In the end, the one-way ANOVA was applied for the statistical analysis and the Mohr’s circle was established to aid in the analysis of the data obtained in this experiment. Findings The result of this study shows that the chemistry, porosity, degree of crystallinity and mechanical properties (tensile strength, strain and elastic modulus) of the PLA material printed with a raster angle of 0° were all insensitive to the increasing extruder temperature from 205°C to 225°C. Meanwhile, the mechanical properties of such printed PLA material were obviously influenced by its raster orientation. In this case, a PLA material with a raster orientation parallel to its loading axis, i.e. those with a raster angle of θ = 0°, was found as the strongest material. Meanwhile, the raster configuration-oriented perpendicular to its loading axis or θ = 90° yielded the weakest PLA material. The results of the tensile tests for the PLA material printed with bidirectional raster orientations, i.e. θ = 0°/90° and 45°/−45° demonstrated their strengths with values falling between those of the materials having unidirectional raster θ = 0° and 90°. Furthermore, the result of the analysis by using a well-known Mohr’s circle confirmed the experimental tensile strengths and the failure mechanisms of the PLA material that had been printed with various raster orientations. Originality/value This study presented consistent results on the chemistry, physical, degree of crystallinity and mechanical properties of the FFF-processed PLA in responding to the increasing extruder temperature from 205°C to 225°C applied during the printing process. Unlike the results of the previous studies, all these properties were also found to be insensitive to the increase of extruder temperature. Also, the result of this research demonstrates the usability of Mohr’s circle in the analysis of stresses working on an FFF-processed PLA material in responding to the changes in raster orientation printed in this material.

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

Rapid Prototyping Journal ◽

10.1108/rpj-08-2020-0205 ◽

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.

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On mechanical, thermal and morphological investigations of almond skin powder-reinforced polylactic acid feedstock filament

Journal of Thermoplastic Composite Materials ◽

10.1177/0892705719886010 ◽

2019 ◽

pp. 089270571988601 ◽

Cited By ~ 36

Author(s):

Rupinder Singh ◽

Ranvijay Kumar ◽

Pawanpreet ◽

Mohit Singh ◽

Jatenderpal Singh

Keyword(s):

Polylactic Acid ◽

Mechanical Performance ◽

Melt Flow Index ◽

Extrusion Process ◽

Melt Processing ◽

Flow Index ◽

Twin Screw Extrusion ◽

Fused Filament Fabrication ◽

Screw Extrusion ◽

Twin Screw

The almond skin powder is one of the biodegradable and biocompatible food wastes that can be used as reinforcement in polylactic acid (PLA) for preparation of biomedical scaffolds/implants (for high mechanical performance) by fused filament fabrication. The present study deals with the melt processing of almond skin powder as reinforcement from 0 wt% to 5 wt% in the PLA matrix by twin-screw extrusion process. The results of the study suggested that reinforcing the almond skin powder as 2.5 wt% in the PLA matrix mechanically strengthens the feedstock filaments but the increase in the proportion up to 5 wt% reduces the mechanical strength to a significant level. A similar trend has been observed in differential scanning calorimeter observations for thermal stability analysis. As regard to the rheological property is concerned, the melt flow index shows a significant reduction with reinforcement of almond skin powder in PLA. The results are also supported by photomicrographic analysis (for surface properties) and Taguchi-based optimization of twin-screw extrusion process parameters (for multifactor optimization).

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