scholarly journals Thermal mechanical characterization of copolyester for additive manufacturing using FDM

Author(s):  
Khaoula Abouzaid ◽  
Sofiane Guessasma ◽  
Sofiane Belhabib ◽  
David Bassir ◽  
Abdelkrim Chouaf

The main purpose of this study is to highlight the thermal and mechanical characterization of printed copolyester-based polymer. The variety of benefits of this material, such as its food contact compliance and important mechanical properties, have proved to be effective in huge field of applications, including medical sector and packaging uses. However, it has not received much attention for 3D printing processes. As the printing temperature is a key parameter of fused deposition modeling (FDM) process, the present study is started by analyzing its effect on the mechanical properties of printed copolyester under tensile loading. Indeed, the determination of temperature optimal values to print this material with FDM process is done based on tensile properties, including tensile strength, Young's modulus, ultimate tensile and yield strength, ductility and fracture toughness. The fracture properties of printed copolyester are also discussed using “scanning electron microscopy” (SEM). The results indicate a strong effect of the extrusion temperature on tensile properties. In addition, the analysis of copolyester sample microstructure reveals several damage mechanisms within the printed parts that reflect different types of wires fracture form subjected to the same tensile loading.

2021 ◽  
pp. 089270572110530
Author(s):  
Nagarjuna Maguluri ◽  
Gamini Suresh ◽  
K Venkata Rao

Fused deposition modeling (FDM) is a fast-expanding additive manufacturing technique for fabricating various polymer components in engineering and medical applications. The mechanical properties of components printed with the FDM method are influenced by several process parameters. In the current work, the influence of nozzle temperature, infill density, and printing speed on the tensile properties of specimens printed using polylactic acid (PLA) filament was investigated. With an objective to achieve better tensile properties including elastic modulus, tensile strength, and fracture strain; Taguchi L8 array has been used for framing experimental runs, and eight experiments were conducted. The results demonstrate that the nozzle temperature significantly influences the tensile properties of the FDM printed PLA products followed by infill density. The optimum processing parameters were determined for the FDM printed PLA material at a nozzle temperature of 220°C, infill density of 100%, and printing speed of 20 mm/s.


Author(s):  
Shajahan Bin Maidin ◽  
Zulkeflee Abdullah ◽  
Ting Kung Hieng

One of the disadvantages of fused deposition modeling (FDM) is waste produced during the printing processes. This investigation focuses on using 100% recycled Acrylonitrile Butadiene Styrene (ABS) for the FDM process. The recycling begins with re-granule the waste ABS material and produces it into a new filament. The new recycled filament was used to print the test specimen. Investigation on the mechanical properties and the surface quality of the test specimen and comparison with standard ABS specimen was done. The result shows that the recycled ABS can be produced into filament with 335°C of extrusion temperature and 1.5 mm/s travel speed of the extruder conveyor. The surface roughness of recycled specimen is 6.94% higher than the standard ABS specimen. For ultimate tensile strength, there is a small difference in X and Y orientation between the standard and the recycled ABS specimen which are 22.93% and 19.98%, respectively. However, in Z orientation, it is 52.33% lower. This investigation proves that ABS can be recycled without significantly affecting its mechanical properties.


Author(s):  
Adugna D. Akessa ◽  
Hirpa G. Lemu ◽  
Aboma W. Gebisa

Additive manufacturing technology is a process of joining materials to make objects from 3D model data, usually layer upon layer, contrary to conventional manufacturing technologies, which mostly use subtractive process. The technology has developed from the earlier days of rapid prototyping to sophisticated rapid manufacturing in the last 20 years and can create parts directly from CAD model without the use of tooling. This technology is predicted to revolutionize many sectors of manufacturing by reducing component lead-time, material waste, energy usage, etc. Though there is significant progress in the field, there are still a number of challenges including characterization of mechanical properties. This paper presents a study conducted to characterize the mechanical properties of ABS-M30 materials whose specimens are fabricated using different printing parameters. To understand the mechanical properties, it is vital to study the effects of the printing parameters on 3D printed parts. For this purpose, Design of Experiment (DOE) is used. The printing parameters of the machine (Fortus 450mc Fused Deposition Modeling (FDM) machine) such as raster orientation, air gap, and raster width, were examined to test Tensile strengths and 3-point bend strength of the tested specimens. The study shows that, raster orientation and air gap has more effect on mechanical properties of ABS-M30 products where raster width has less effect.


2020 ◽  
Vol 26 (4) ◽  
pp. 707-717 ◽  
Author(s):  
John C.S. McCaw ◽  
Enrique Cuan-Urquizo

Purpose While additive manufacturing via melt-extrusion of plastics has been around for more than several decades, its application to complex geometries has been hampered by the discretization of parts into planar layers. This requires wasted support material and introduces anisotropic weaknesses due to poor layer-to-layer adhesion. Curved-layer manufacturing has been gaining attention recently, with increasing potential to fabricate complex, low-weight structures, such as mechanical metamaterials. This paper aims to study the fabrication and mechanical characterization of non-planar lattice structures under cyclic loading. Design/methodology/approach A mathematical approach to parametrize lattices onto Bèzier surfaces is validated and applied here to fabricate non-planar lattice samples via curved-layer fused deposition modeling. The lattice chirality, amplitude and unit cell size were varied, and the properties of the samples under cyclic-loading were studied experimentally. Findings Overall, lattices with higher auxeticity showed less energy dissipation, attributed to their bending-deformation mechanism. Additionally, bistability was eliminated with increasing auxeticity, reinforcing the conclusion of bending-dominated behavior. The analysis presented here demonstrates that mechanical metamaterial lattices such as auxetics can be explored experimentally for complex geometries where traditional methods of comparing simple geometry to end-use designs are not applicable. Research limitations/implications The mechanics of non-planar lattice structures fabricated using curved-layer additive manufacturing have not been studied thoroughly. Furthermore, traditional approaches do not apply due to parameterization deformations, requiring novel approaches to their study. Here the properties of such structures under cyclic-loading are studied experimentally for the first time. Applications for this type of structures can be found in areas like biomedical scaffolds and stents, sandwich-panel packaging, aerospace structures and architecture of lattice domes. Originality/value This work presents an experimental approach to study the mechanical properties of non-planar lattice structures via quasi-static cyclic loading, comparing variations across several lattice patterns including auxetic sinusoids, disrupted sinusoids and their equivalent-density quadratic patterns.


Author(s):  
Abigail Chaffins ◽  
Mohan Yu ◽  
Pier Paolo Claudio ◽  
James B. Day ◽  
Roozbeh (Ross) Salary

Abstract Fused deposition modeling (FDM), is a direct-write material extrusion additive manufacturing process, which has emerged as a method of choice for the fabrication of a wide range of biological tissues and structures. FDM allows for non-contact, multi-material deposition of a broad spectrum of functional materials for tissue engineering applications. However, the FDM process is intrinsically complex, consisting of a multitude of parameters as well as material-machine interactions, which may adversely influence the mechanical properties, the surface morphology, and ultimately the functional integrity of fabricated bone scaffolds. Hence, process optimization in addition to physics-based characterization of the FDM process would be inevitably a need. The overarching goal of this research work is to fabricate biocompatible, porous bone scaffolds, incorporating autologous human bone marrow mesenchymal stem cells (hBMSCs), for the treatment of osseous fractures, defects, and eventually diseases. The objective of this work is to investigate the mechanical properties of several triply periodic minimal surface (TPMS) bone scaffolds, fabricated using fused deposition modeling (FDM) additive manufacturing process. In this study, biocompatible TPMS bone scaffolds were FDM-deposited, based on a medical-grade polymer composite, composed of polyamide, polyolefin, and cellulose fibers (named PAPC-II). In addition, the experimental characterization of the TPMS bone scaffolds was on the basis of a single factor experiment. The compression properties of the fabricated bone scaffolds were measured using a compression testing machine. Furthermore, a digital image processing program was developed in the MATLAB environment to characterize the morphological properties of the fabricated bone scaffolds.


2016 ◽  
Vol 22 (2) ◽  
pp. 387-404 ◽  
Author(s):  
Jonathan Torres ◽  
Matthew Cole ◽  
Allen Owji ◽  
Zachary DeMastry ◽  
Ali P. Gordon

Purpose This paper aims to present the influences of several production variables on the mechanical properties of specimens manufactured using fused deposition modeling (FDM) with polylactic acid (PLA) as a media and relate the practical and experimental implications of these as related to stiffness, strength, ductility and generalized loading. Design/methodology/approach A two-factor-level Taguchi test matrix was defined to allow streamlined mechanical testing of several different fabrication settings using a reduced array of experiments. Specimens were manufactured and tested according to ASTM E8/D638 and E399/D5045 standards for tensile and fracture testing. After initial analysis of mechanical properties derived from mechanical tests, analysis of variance was used to infer optimized production variables for general use and for application/load-specific instances. Findings Production variables are determined to yield optimized mechanical properties under tensile and fracture-type loading as related to orientation of loading and fabrication. Practical implications The relation of production variables and their interactions and the manner in which they influence mechanical properties provide insight to the feasibility of using FDM for rapid manufacturing of components for experimental, commercial or consumer-level use. Originality/value This paper is the first report of research on the characterization of the mechanical properties of PLA coupons manufactured using FDM by the Taguchi method. The investigation is relevant both in commercial and consumer-level aspects, given both the currently increasing utilization of 3D printers for component production and the viability of PLA as a renewable, biocompatible material for use in structural applications.


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