Effects of vacuum exposure on mechanical properties of thermoplastic materials

2021 ◽  
Vol 40 (1) ◽  
Author(s):  
Tiago Rodrigues Dos Santos ◽  
Isla Kalleny Marques Brandão ◽  
Mateus Silva Sant'Ana ◽  
Pedro Henrique dos Santos Alves ◽  
Rana Mayeli Piêgas Taborda ◽  
...  

The present paper proposes the study of the behavior of three thermoplastic materials: acrylonitrile butadiene styrene (ABS), poly(lactic acid) (PLA), and polyethylene glycol terephthalate (PETG), processed by additive manufacturing type fused deposition modelling (FDM) when exposed to low vacuum. The experiment was composed of three moments consisting of tridimensional modeling and manufacturing of the specimens, drying process and vacuum exposure for 24 hours, according to American Society for Testing and Materials (ASTM) D6653/D6653M standards, and bending test for the determination of mechanical properties, based on ASTM D790 standards. The vacuum chamber tests exposed oscillations in the pressure indicating gases releasing from the specimen, but none of the samples showed visible deformations. Subjecting the materials exposed to low vacuum to bending tests and comparing them to the unexposed material, we observed a significant increase in the calculated modulus of elasticity and a change in the slope of graphic force versus deflection in all materials. This behavior demonstrates that it is possible to submit polymeric materials to vacuum, and low vacuum exposure can be a treatment for thermoplastic materials. In the future, a study using a spectrometer will be necessary to verify which gases are present during pressure oscillation in the chamber, thus making it possible to understand which factor has increased the mechanical properties of the materials. In sequence, experiments will be necessary to validate the vacuum exposure as a form of treatment of materials and to verify the possibility of applying thermoplastics commonly used in additive manufacturing for low-impact space applications.

Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 651 ◽  
Author(s):  
David Moises Baca Lopez ◽  
Rafiq Ahmad

The application of single homogeneous materials produced through the fused deposition modelling (FDM) technology restricts the production of high-level multi-material components. The fabrication of a sandwich-structured specimen with different material combinations using conventional thermoplastics such as poly (lactic acid) (PLA), acrylonitrile butadiene styrene (ABS) and high impact polystyrene (HIPS) through the filament-based extrusion process can demonstrate an improvement on its properties. This paper aims to assess among these materials, the best material sandwich-structured arrangement design, to enhance the mechanical properties of a part and to compare the results with the homogeneous materials selected. The samples were subjected to tensile testing to identify the tensile strength, elongation at break and Young’s modulus of each material combination. The experimental results demonstrate that applying the PLA-ABS-PLA sandwich arrangement leads to the best mechanical properties between these materials. This study enables users to consider sandwich structure designs as an alternative to manufacturing multi-material components using conventional and low-cost materials. Future work will consider the flexural tests to identify the maximum stresses and bending forces under pressure.


2021 ◽  
Author(s):  
M. Hossein Sehhat ◽  
Ali Mahdianikhotbesara ◽  
Farzad Yadegari

Abstract Additive Manufacturing (AM) can be deployed for space exploration purposes, such as fabricating different components of robots’ bodies. The produced AM parts should have desirable thermal and mechanical properties to withstand the extreme environmental conditions, including the severe temperature variations on moon or other planets which cause changes in parts’ strengths and may fail their operation. Therefore, the correlation between operational temperature and mechanical properties of AM fabricated parts should be evaluated. In this study, three different types of polymers, including polylactic acid (PLA), polyethylene terephthalate glycol (PETG), and acrylonitrile butadiene styrene (ABS), were used in Fused Deposition Modeling (FDM) process to fabricate several parts. The mechanical properties of produced parts were then investigated at various temperatures to generate knowledge on the correlation between temperature and type of material. When varying the operational temperature during tensile tests, the material’s glass transition temperature was found influential in determining the type of material failure. Among the materials used, ABS showed the best mechanical properties at all temperatures due to its highest glass transmission temperatures. The results of statistical analysis indicated the temperature as the significant factor on tensile strength while the change in material did not show a significant effect.


Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 672 ◽  
Author(s):  
Elena Verdejo de Toro ◽  
Juana Coello Sobrino ◽  
Alberto Martínez Martínez ◽  
Valentín Miguel Eguía ◽  
Jorge Ayllón Pérez

New technologies are offering progressively more effective alternatives to traditional ones. Additive Manufacturing (AM) is gaining importance in fields related to design, manufacturing, engineering and medicine, especially in applications which require complex geometries. Fused Deposition Modelling (FDM) is framed within AM as a technology in which, due to their layer-by-layer deposition, thermoplastic polymers are used for manufacturing parts with a high degree of accuracy and minimum material waste during the process. The traditional technology corresponding to FDM is Polymer Injection Moulding, in which polymeric pellets are injected by pressure into a mould using the required geometry. The increasing use of PA6 in Additive Manufacturing makes it necessary to study the possibility of replacing certain parts manufactured by injection moulding with those created using FDM. In this work, PA6 was selected due to its higher mechanical properties in comparison with PA12. Moreover, its higher melting point has been a limitation for 3D printing technology, and a further study of composites made of PA6 using 3D printing processes is needed. Nevertheless, analysis of the mechanical response of standardised samples and the influence of the manufacturing process on the polyamide’s mechanical properties needs to be carried out. In this work, a comparative study between the two processes was conducted, and conclusions were drawn from an engineering perspective.


2019 ◽  
Vol 10 (2) ◽  
pp. 173-181
Author(s):  
Muammel M. Hanon ◽  
Márk Kovács ◽  
László Zsidai

3D printing of Acrylonitrile Butadiene Styrene (ABS) and Poly Lactic Acid (PLA) were used to prepare specimens utilising fused deposition modelling (FDM) technology. Two colours of PLA filament were printed; white and grey, whereas ABS only in white colour. Determining the tribological properties of 3D printed samples have been carried out, through obtaining the frictional features of different 3D printable filaments. Alternating-motion system employed for measuring the tribological factors. Studying the difference between static and dynamic friction factors and the examination of wear values were included. A comparison among the tribological behaviour of the 3D printed polymers has been investigated. The printed white ABS and PLA specimens show insignificant differences in the results tendency. On the contrary, the grey PLA exhibits a considerable variation due to the incredible growth in the coefficient of friction and wear average as well.


2019 ◽  
Vol 821 ◽  
pp. 137-143 ◽  
Author(s):  
Pavan Kumar Gurrala ◽  
Brijesh Tripathi

In the current technological evolution, additive manufacturing is taking a lead role in manufacturing of components for both prototyping as well as finished products. Metallization of the polymer parts has high potential to add value in-terms of metallic luster, improved strength, long shelf-life and better radiation resistance. Standard acid copper plating process has been adopted for deposition of copper on polymer parts manufactured by fused deposition modelling (FDM) technique. The parameters namely the etching time, voltage and the surface finish of the manufactured FDM parts are studied for their influence on the surface quality. Experiments have been designed using design of experiments strategy. Experiments have been conducted and surface roughness has been measured. Influence of each of the three parameters has been discussed in detail. For the reported process the optimal value of etching time of Acrylonitrile Butadiene Styrene (ABS) has been found in the range of 30 to 60 minutes along with applied voltage in the range of 1.5 to 2.5 Volts for copper electroplating.


2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Michele Gabrio Antonelli ◽  
Pierluigi Beomonte Zobel ◽  
Francesco Durante ◽  
Terenziano Raparelli

This paper describes the results of research projects developed at the University of L’Aquila by the research group of the authors in the field of biomedical engineering, which have seen an important use of additive manufacturing technologies in the prototyping step and, in some cases, also for the realization of preindustrialization prototypes. For these projects, commercial 3D printers and technologies such as fused deposition modelling (FDM) were used; the most commonly used polymers in these technologies are acrylonitrile butadiene styrene (ABS) and polylactic acid (PLA). The research projects concern the development of innovative actuators, such as pneumatic muscles and soft pneumatic actuators (SPAs), the development of active orthoses, such as a lower limb orthosis and, finally, the development of a variable-stiffness grasper to be used in natural orifice transluminal endoscopic surgery (NOTES). The main aspects of these research projects are described in the paper, highlighting the technologies used such as the finite element analysis and additive manufacturing.


2020 ◽  
Vol 26 (10) ◽  
pp. 1733-1738
Author(s):  
André Luiz Alves Guimarães ◽  
Vicente Gerlin Neto ◽  
Cesar Renato Foschini ◽  
Maximiliano dos Anjos Azambuja ◽  
Luiz Antonio Vasques Hellmeister

Purpose The purpose of this paper is to investigate and discuss the influence of printing parameters on the mechanical properties of acrylonitrile butadiene styrene (ABS) print by fused deposition modelling (FDM). The mechanical properties of ABS are highly influenced by printing parameters, and they determine the final product quality of printed pieces. Design/methodology/approach For the paper’s purpose, five main parameters (extrusion temperature, infill pattern, air gap, printing speed and layer thickness) were selected and varied during ABS printing on an open-source and self-replicable FDM printer. Three different colors of commercially available ABS were also used to investigate color and printing parameter’s influence on the tensile strength. Findings The research results suggest that two parameters (infill pattern and layer thickness) were most influential on the mechanical properties of print ABS, being able to enhance its tensile strength. Another key influential factor was material color selected prior to printing, which influenced the tensile strength of the print specimen. Originality/value This study provides information on print parameters’ influence on the tensile strength of ABS print on replicable open-source three-dimensional (3D) printers. It also suggests the influence of materials’ color on print pieces’ tensile strength, indicating a new parameter for materials selection for 3D printing.


Nanomaterials ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2567
Author(s):  
Madison Bardot ◽  
Michael D. Schulz

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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