Investigating Commercial Filaments for 3D Printing of Stiff and Elastic Constructs with Ligament-Like Mechanics

The current gold standard technique for treatment of anterior cruciate ligament (ACL) injury is reconstruction with autograft. These treatments have a relatively high failure and re-tear rate. To overcome this, tissue engineering and additive manufacturing are being used to explore the potential of 3D scaffolds as autograft substitutes. However, mechanically optimal polymers for this have yet to be identified. Here, we use 3D printing technology and various materials with the aim of fabricating constructs better matching the mechanical properties of the native ACL. A fused deposition modeling (FDM) 3D printer was used to microfabricate dog bone-shaped specimens from six different polymers—PLA, PETG, Lay FOMM 60, NinjaFlex, NinjaFlex-SemiFlex, and FlexiFil—at three different raster angles. The tensile mechanical properties of these polymers were determined from stress–strain curves. Our results indicate that no single material came close enough to successfully match reported mechanical properties of the native ACL. However, PLA and PETG had similar ultimate tensile strengths. Lay FOMM 60 displayed a percentage strain at failure similar to reported values for native ACL. Furthermore, raster angle had a significant impact on some mechanical properties for all of the materials except for FlexiFil. We therefore conclude that while none of these materials alone is optimal for mimicking ACL mechanical properties, there may be potential for creating a 3D-printed composite constructs to match ACL mechanical properties. Further investigations involving co-printing of stiff and elastomeric materials must be explored.

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Proper Blends of Biodegradable Polycaprolactone and Natural Rubber for 3D Printing

Polymers ◽

10.3390/polym12102416 ◽

2020 ◽

Vol 12 (10) ◽

pp. 2416

Author(s):

Thossapit Wissamitanan ◽

Charoenyutr Dechwayukul ◽

Ekwipoo Kalkornsurapranee ◽

Wiriya Thongruang

Keyword(s):

Mechanical Properties ◽

3D Printing ◽

Natural Rubber ◽

Shape Recovery ◽

Fused Deposition Modeling ◽

Melt Flow ◽

Melt Flow Rate ◽

Fused Deposition ◽

Compression Set ◽

Deposition Modeling

Flexible thermoplastic elastomers (TPE) were prepared for fused deposition modeling (FDM) or 3D printing. These materials can be used for medical purposes such as disposable soft splints and other flexible devices. Blends of 50% epoxidized natural rubber (ENR-50) and block rubber (Standard Thai Rubber 5L (STR5L)) with polycaprolactone (PCL) were produced and compared. The purpose of this study was to investigate the properties of natural rubber (NR) and PCL in simple blends with PCL contents of 40%, 50%, and 60% by weight (except at 75% for morphology study) in the base mixture (NR/PCL). The significant flow factors for FDM materials, such as melting temperature (Tm) and melt flow rate (MFR), were observed by differential scanning calorimetry (DSC) and via the melt flow index (MFI). In addition, the following mechanical properties were also determined: tensile strength, compression set, and hardness. The results from DSC showed that the melting temperature changed slightly (1–2 °C) with amount of PCL used, and there was a suspicious point in the 50/50 blends with both types of rubber. The lowest melting enthalpy of both blends was found at the 50/50 blended composition. The MFI results showed that PCL significantly affected the melt flow rate of both blends. The ENR-50/PCL blend flowed better than the STR5L/PCL blend. The conclusion was that this was due to the morphology of its phase structure having better uniformity than that of the STR5L/PCL blend. In compression set testing or measuring shape recovery, rubber directly influenced the recovery in all blends. The ENR-50/PCL blend had less recovery than the STR5L/PCL blend, probably due to the functional effects of epoxide groups and polarity mismatch. The hard phase PCL significantly affected the hardness of samples but improved shape recovery of the material. The ENR-50/PCL blend had better tensile properties than the STR5L/PCL blend. The elongation at break of both blends improved with a high rubber content. Hence, the ENR-50/PCL blend was superior to STR5L/PCL for printing purposes due to its better miscibility, uniformity, and flow, which are the keys to success for optimizing the fused deposition modeling conditions as well as the overall mechanical properties of products. Most blends in this study were only slightly different, but the 50/50 blend of ENR-50/PCL seemed to be near optimal for 3D printing.

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Polymer Composites Used in Rapid Prototyping Technology

Advances in Manufacturing Science and Technology ◽

10.2478/amst-2019-0003 ◽

2020 ◽

Vol 44 (1) ◽

pp. 15-20

Author(s):

Katarzyna Bulanda ◽

Mariusz Oleksy ◽

Rafał Oliwa ◽

Grzegorz Budzik ◽

Tadeusz Markowski

Keyword(s):

Mechanical Properties ◽

3D Printing ◽

Fused Deposition Modeling ◽

New Materials ◽

Fused Deposition ◽

The Matrix ◽

Molded Parts ◽

Deposition Modeling ◽

Injection Molded ◽

The Impact

AbstractNew materials and filaments dedicated to 3D printing were obtained using the fused deposition modeling method, and the properties of the produced materials were investigated. Polylactide was used as a polymer base for the assays because of the desired properties of the polymer, mainly biodegradability, and the matrix was refilled by the addition of metallic nanofillers, such as bronze, copper, brass, and steel. For the composites obtained, mechanical properties were investigated to determine the dependence of the obtained results on the content and type of filler used and on the method of fabrication of the fittings. It was found that the additives present in the polymer matrix increased the fluidity of the material. The best results were obtained for the compositions with bronze and steel in which the mass flow rate was 72.97 and 79.99 g/10 min, respectively. The filled material that had lower hardness was measured by Rockwell and the impact strength was measured by Charpy. In addition, it was found that injection-molded parts obtained much better mechanical properties than those obtained by 3D printing.

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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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Investigating the Mechanical Behavior of 3D Printed PLA-Coco Coir Composites

Materials Science Forum ◽

10.4028/www.scientific.net/msf.1046.125 ◽

2021 ◽

Vol 1046 ◽

pp. 125-132

Author(s):

Paul Eric C. Maglalang ◽

Blessie A. Basilia ◽

Araceli Magsino Monsada

Keyword(s):

Mechanical Properties ◽

Particle Size ◽

3D Printing ◽

Fused Deposition Modelling ◽

Coir Fiber ◽

Fiber Concentration ◽

Fused Deposition ◽

Twin Screw ◽

Raster Angle ◽

Composite Filament

It is quite amazing that the use of 3D printing techniques, especially the Fused Deposition Modelling (FDM) has delivered such significance in terms of cost reduction, time saver features where a different variety of thermoplastic and composite materials (Biodegradable and Non-biodegradable) are well developed. Different sectors have continually developed natural organic materials that are also both structurally composite in nature. Similarly, the use of different fibers that are abundantly accessible and considered as renewable resources which can be optionally combined with other biodegradable materials is a great challenge through the use of the FDM printing method. The study aims to determine the effect of different particle size and raster angle at a certain fiber concentration which could affect the mechanical properties of the composite by developing a printable composite filament made of Polylactic Acid (PLA) and Coco Coir materials using a filament maker and FDM printer. The composite filament was fabricated and optimized using a twin-screw extruder and 3D Devo Filament maker. 3D printing of samples for mechanical testing was conducted using three (3) raster angles (45o, 60o, and 75o) and various particle sizes of coco coir fiber reinforcement in the PLA matrix. Results showed that the < 74μm particle size of the coco-coir exhibited a 24% and 175% increase in tensile strength and izod impact strength compared to the pure PLA at 60o and 75o raster angles, respectively. Likewise, the reinforcement of <149μm particle size coco coir at 45o raster angle contributes to an increase of 4.8% flexural and 176% compressive strength compared to pure PLA. The study concludes that there is an improvement in the mechanical properties of the PLA-Coco Coir composite at a certain particle size and raster angle in 3D printing.

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3D Printing PLA Waste to Produce Ceramic Based Particulate Reinforced Composite Using Abundant Silica-Sand: Mechanical Properties Characterization

Polymers ◽

10.3390/polym12112579 ◽

2020 ◽

Vol 12 (11) ◽

pp. 2579

Author(s):

Waleed Ahmed ◽

Sidra Siraj ◽

Ali H. Al-Marzouqi

Keyword(s):

Mechanical Properties ◽

Composite Material ◽

3D Printing ◽

Fused Deposition Modeling ◽

Testing Machine ◽

Silica Sand ◽

Fused Deposition ◽

Mechanical Properties Characterization ◽

And Control ◽

The Impact

Due to the significant properties of silica, thermostatics can be enhanced using silica-additives to maximize the quality of polymer compounds and transform plastics into tailored properties. The silica additives can enhance the handling and quality performance of composites and thermoplastic polymers due to their diverse potential. Besides, using silica as an additive in different characteristics can allow granulates and powders to flow easily, minimize caking, and control rheology. On the other hand, the eruption of 3D printing technology has led to a massive new waste source of plastics, especially the polylactic acid (PLA) that is associated with the fused deposition modeling (FDM) process. In this paper, the impact on the mechanical properties when silica is mixed with waste PLA from 3D printing was studied. The PLA/silica mixtures were prepared using different blends through twin extruders and a Universal Testing Machine was used for the mechanical characterization. The result indicated that increasing silica composition resulted in the increase of the tensile strength to 121.03 MPa at 10 wt%. Similar trends were also observed for the toughness, ductility, and the yield stress values of the PLA/silica blends at 10 wt%, which corresponds to the increased mechanical property of the composite material reinforced by the silica particles. Improvement in the mechanical properties of the developed composite material promotes the effective recycling of PLA from applications such as 3D printing and the potential of reusing it in the same application.

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Biodegradable Poly(Lactic Acid) Nanocomposites for Fused Deposition Modeling 3D Printing

Nanomaterials ◽

10.3390/nano10122567 ◽

2020 ◽

Vol 10 (12) ◽

pp. 2567

Author(s):

Madison Bardot ◽

Michael D. Schulz

Keyword(s):

Mechanical Properties ◽

Lactic Acid ◽

3D Printing ◽

Fused Deposition Modeling ◽

Ecological Crisis ◽

Poly Lactic Acid ◽

Fused Deposition Modelling ◽

Fused Deposition ◽

Biodegradable Poly ◽

Deposition Modeling

3D printing by fused deposition modelling (FDM) enables rapid prototyping and fabrication of parts with complex geometries. Unfortunately, most materials suitable for FDM 3D printing are non-degradable, petroleum-based polymers. The current ecological crisis caused by plastic waste has produced great interest in biodegradable materials for many applications, including 3D printing. Poly(lactic acid) (PLA), in particular, has been extensively investigated for FDM applications. However, most biodegradable polymers, including PLA, have insufficient mechanical properties for many applications. One approach to overcoming this challenge is to introduce additives that enhance the mechanical properties of PLA while maintaining FDM 3D printability. This review focuses on PLA-based nanocomposites with cellulose, metal-based nanoparticles, continuous fibers, carbon-based nanoparticles, or other additives. These additives impact both the physical properties and printability of the resulting nanocomposites. We also detail the optimal conditions for using these materials in FDM 3D printing. These approaches demonstrate the promise of developing nanocomposites that are both biodegradable and mechanically robust.

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3D Printing of Fiber-Reinforced Plastic Composites Using Fused Deposition Modeling: A Status Review

Materials ◽

10.3390/ma14164520 ◽

2021 ◽

Vol 14 (16) ◽

pp. 4520

Author(s):

Salman Pervaiz ◽

Taimur Ali Qureshi ◽

Ghanim Kashwani ◽

Sathish Kannan

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

3D Printing ◽

Fused Deposition Modeling ◽

Fiber Reinforced Polymers ◽

Fiber Reinforced ◽

Reinforced Polymers ◽

Fused Deposition ◽

Frp Composites ◽

Deposition Modeling

Composite materials are a combination of two or more types of materials used to enhance the mechanical and structural properties of engineering products. When fibers are mixed in the polymeric matrix, the composite material is known as fiber-reinforced polymer (FRP). FRP materials are widely used in structural applications related to defense, automotive, aerospace, and sports-based industries. These materials are used in producing lightweight components with high tensile strength and rigidity. The fiber component in fiber-reinforced polymers provides the desired strength-to-weight ratio; however, the polymer portion costs less, and the process of making the matrix is quite straightforward. There is a high demand in industrial sectors, such as defense and military, aerospace, automotive, biomedical and sports, to manufacture these fiber-reinforced polymers using 3D printing and additive manufacturing technologies. FRP composites are used in diversified applications such as military vehicles, shelters, war fighting safety equipment, fighter aircrafts, naval ships, and submarine structures. Techniques to fabricate composite materials, degrade the weight-to-strength ratio and the tensile strength of the components, and they can play a critical role towards the service life of the components. Fused deposition modeling (FDM) is a technique for 3D printing that allows layered fabrication of parts using thermoplastic composites. Complex shape and geometry with enhanced mechanical properties can be obtained using this technique. This paper highlights the limitations in the development of FRPs and challenges associated with their mechanical properties. The future prospects of carbon fiber (CF) and polymeric matrixes are also mentioned in this study. The study also highlights different areas requiring further investigation in FDM-assisted 3D printing. The available literature on FRP composites is focused only on describing the properties of the product and the potential applications for it. It has been observed that scientific knowledge has gaps when it comes to predicting the performance of FRP composite parts fabricated under 3D printing (FDM) techniques. The mechanical properties of 3D-printed FRPs were studied so that a correlation between the 3D printing method could be established. This review paper will be helpful for researchers, scientists, manufacturers, etc., working in the area of FDM-assisted 3D printing of FRPs.

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The Surface Characteristics, Microstructure and Mechanical Properties of PEEK Printed by Fused Deposition Modeling with Different Raster Angles

Polymers ◽

10.3390/polym14010077 ◽

2021 ◽

Vol 14 (1) ◽

pp. 77

Author(s):

Sasa Gao ◽

Ruijuan Liu ◽

Hua Xin ◽

Haitao Liang ◽

Yunfei Wang ◽

...

Keyword(s):

Mechanical Properties ◽

Failure Mechanism ◽

Fused Deposition Modeling ◽

Mechanical Performance ◽

Surface Hardness ◽

Surface Characteristics ◽

Fused Deposition ◽

Microstructure And Mechanical Properties ◽

Raster Angle ◽

Deposition Modeling

Additive manufacturing provides a novel and robust way to prepare medical product with anatomic matched geometry and tailored mechanical performance. In this study, the surface characteristics, microstructure, and mechanical properties of fused deposition modeling (FDM) prepared polyether-ether-ketone (PEEK) were systematically studied. During the FDM process, the crystal unit cell and thermal attribute of PEEK material remained unchanged, whereas the surface layer generally became more hydrophilic with an obvious reduction in surface hardness. Raster angle has a significant effect on the mechanical strength but not on the failure mechanism. In practice, FDM fabricated PEEK acted more like a laminate rather than a unified structure. Its main failure mechanism was correlated to the internal voids. The results show that horizontal infill orientation with 30° raster angle is promising for a better comprehensive mechanical performance, and the corresponding tensile, flexural, and shear strengths are (76.5 ± 1.4) MPa, (149.7 ± 3.0) MPa, and (55.5 ± 1.8) MPa, respectively. The findings of this study provide guidelines for FDM-PEEK to enable its realization in applications such as orthopedic implants.

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Prediction of tensile strength of fused deposition modeling (FDM) printed PLA using classic laminate theory

Engineering Solid Mechanics ◽

10.5267/j.esm.2021.12.002 ◽

2022 ◽

Vol 10 (1) ◽

pp. 13-24 ◽

Cited By ~ 1

Author(s):

Shilpesh R. Rajpurohit ◽

Harshit K. Dave ◽

Kamlakar P. Rajurkar

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Fused Deposition Modeling ◽

Constitutive Models ◽

Limited Information ◽

Layer Height ◽

Fused Deposition ◽

Raster Angle ◽

Laminate Theory ◽

Deposition Modeling

The application of Fused Deposition Modeling (FDM) is restricted due to limited information about the mechanical properties of printed parts. Therefore, it is required to determine the mechanical properties of the FDM properties to avail the full benefit of the FDM process. In the present study, Classic Laminate Theory (CLT) has been employed at the different configurations of layer thickness and raster width. The required elastic constant of material for CLT has been experimentally obtained through FDM printed Polylactic Acid (PLA) unidirectional specimens at 0°, 45° and 90° for different combinations of layer height and raster width. For these different combinations of layer height and raster width, constitutive models were developed to predict the tensile properties of the PLA parts. Tensile strength of the FDM printed bi-directional specimens has been experimentally obtained to validate the proposed CLT model results. The experimental tensile strength data is in good agreement with the data predicted by the proposed CLT model. Higher tensile strength and modulus were achieved with 0° raster angle compared to 90° raster angle. In the case of a bi-directional printed specimen, higher tensile strength was obtained with 45°/-45° raster angle followed by 30°/-60° and 0°/90° raster angle.

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FDM 3D Printing of Polymers Containing Natural Fillers: A Review of their Mechanical Properties

Polymers ◽

10.3390/polym11071094 ◽

2019 ◽

Vol 11 (7) ◽

pp. 1094 ◽

Cited By ~ 53

Author(s):

Valentina Mazzanti ◽

Lorenzo Malagutti ◽

Francesco Mollica

Keyword(s):

Mechanical Properties ◽

3D Printing ◽

Fused Deposition Modeling ◽

Natural Fibers ◽

Acrylonitrile Butadiene Styrene ◽

Processing Parameters ◽

Fused Deposition ◽

Additive Formulation ◽

Deposition Modeling ◽

3D Printed

As biodegradable thermoplastics are more and more penetrating the market of filaments for fused deposition modeling (FDM) 3D printing, fillers in the form of natural fibers are convenient: They have the clear advantage of reducing cost, yet retaining the filament biodegradability characteristics. In plastics that are processed through standard techniques (e.g., extrusion or injection molding), natural fibers have a mild reinforcing function, improving stiffness and strength, it is thus interesting to evaluate whether the same holds true also in the case of FDM produced components. The results analyzed in this review show that the mechanical properties of the most common materials, i.e., acrylonitrile-butadiene-styrene (ABS) and PLA, do not benefit from biofillers, while other less widely used polymers, such as the polyolefins, are found to become more performant. Much research has been devoted to studying the effect of additive formulation and processing parameters on the mechanical properties of biofilled 3D printed specimens. The results look promising due to the relevant number of articles published in this field in the last few years. This notwithstanding, not all aspects have been explored and more could potentially be obtained through modifications of the usual FDM techniques and the devices that have been used so far.

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