scholarly journals Assessment of Static Mechanical Properties of Additively Manufactured Polylactic Acid (PLA) on Entry-Level FDM 3D Printer

2021 ◽  
Vol 58 (2) ◽  
pp. 176-184
Author(s):  
Constantin-Romica Stoica ◽  
Raluca Maier ◽  
Anca Istrate ◽  
Andrei-Cristian Mandoc
Keyword(s):  
Mechanical Properties ◽  
Polylactic Acid ◽  
Fused Deposition Modelling ◽  
Technical Data ◽  
Entry Level ◽  
Fused Deposition ◽  
Dog Bone ◽  
Static Mechanical ◽  
Printing Direction ◽  
Static Mechanical Properties

The paper presents the study on the static mechanical properties of PLA (Polylactic Acid) produced with entry-level additive technologies using three printing directions. During the experimental work were tested a total of 15 �dog bone� ASTM D638-14 standard specimens made from additively manufactured polymer (PLA) through FDM (Fused Deposition Modelling) technique, where the material and rectilinear pattern infill geometry and infill percentage of 100% were constant and the printing orientation was varied. Usually technical data sheets that are delivered by filament materials producers include the most satisfactory data which are valid for only one specific printing direction. The printing direction is deliberately selected, in such way that the best material characteristics are achieved. In addition to this matter, as the additive manufacturing market grew significantly in the past couple of years, the filament production market showed a consequential growth. The aftermath of this expansion had a direct impact towards the quality and costs of the filaments used for 3D printing, in order to satisfy both the low-end and high-end users. Therefore, in this frame, the present research provides entry-level additively manufactured PLA performances showing significant changes depending on the different printing directions and determine the build orientation influence on the mechanical properties, in the aim of providing aid for both mechanical designer and product manufacturer at the stage of the printed product mechanical properties.

Effect of heat treatment on mechanical properties of 3D printed polylactic acid parts

2021 ◽  
Vol 63 (1) ◽  
pp. 73-78
Author(s):  
Pulkin Gupta ◽  
Sudha Kumari ◽  
Abhishek Gupta ◽  
Ankit Kumar Sinha ◽  
Prashant Jindal
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Polylactic Acid ◽  
Recrystallization Temperature ◽  
Fused Deposition Modelling ◽  
Fused Deposition ◽  
Dog Bone ◽  
Heat Treated ◽  
Maximum Decrease ◽  
3D Printed

Abstract Fused deposition modelling (FDM) is a layer-by-layer manufacturing process type of 3D-printing (3DP). Significant variation in the mechanical properties of 3D printed specimens is observed because of varied process parameters and interfacial bonding between consecutive layers. This study investigates the influence of heat treatment on the mechanical strength of FDM 3D printed Polylactic acid (PLA) parts with constant 3DP parameters and ambient conditions. To meet the objectives, 7 sets, each containing 5 dog-bone shaped samples, were fabricated from commercially available PLA filament. Each set was subjected to heat treatment at a particular temperature for 1 h and cooled in the furnace itself, while one set was left un-treated. The temperature for heat treatment (Th) varied from 30 °C to 130 °C with increments of 10 °C. The heat-treated samples were characterized under tensile loading of 400 N and mechanical properties like Young’s modulus (E), Strain % ( ε ) and Stiffness (k) were evaluated. On comparing the mechanical properties of heat-treated samples to un-treated samples, significant improvements were observed. Heat treatment also altered the geometries of the samples. Mechanical properties improved by 4.88 % to 10.26 % with the maximum being at Th of 110 °C and below recrystallization temperature (Tr) of 65 °C. Deformations also decreased significantly at higher temperatures above 100 °C, by a maximum of 36.06 %. The dimensions of samples showed a maximum decrease of 1.08 % in Tr range and a maximum decrease of 0.31 % in weight at the same temperature. This study aims to benefit the society by establishing suitable Th to recover the lost strength in PLA based FDM 3D printed parts.

scholarly journals On the Relationship between Mechanical Properties and Crystallisation of Chemically Post-Processed Additive Manufactured Polylactic Acid Pieces

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 941 ◽  
Author(s):  
A.P. Valerga ◽  
S.R. Fernandez-Vidal ◽  
F. Girot ◽  
A.J. Gamez
Keyword(s):  
Mechanical Properties ◽  
Polylactic Acid ◽  
Maximum Stress ◽  
Fused Deposition Modelling ◽  
Material Behaviour ◽  
Time Consumption ◽  
Fused Deposition ◽  
Wide Range ◽  
Hardness Scale ◽  
The Relationship

Nowadays, improvement of the surface finish of parts manufactured by fused deposition modelling is a well-studied topic. Chemical post-treatments have proven to be the best technique in terms of time consumption and smoothness improvement. However, these treatments modify the structure of the material and, consequently, its mechanical properties. This relationship was studied in this work. In this case, on the basis of a previous study on crystallisation, polylactic acid pieces were subjected to different post-treatments to evaluate their effects on the sample’s mechanical properties, i.e., tensile strength and hardness. Models were obtained according to their percentage of crystallisation, which was related to the different treatments, as well as immersion time. Dramatic changes were obtained within a wide range of material behaviour with some treatments. Specifically, changes were obtained in the maximum stress (from 55 to 20 MPa), in elongation (from 3% to 260%), and in the hardness scale (Shore D to A).

Effect of Printing Parameters on the Mechanical Properties of Parts Fabricated with Open-Source 3D Printers in PLA by Fused Deposition Modeling

2020 ◽  
Vol 22 (4) ◽  
pp. 895-908
Author(s):  
M. Ouhsti ◽  
B. El Haddadi ◽  
S. Belhouideg
Keyword(s):  
Mechanical Properties ◽  
Polylactic Acid ◽  
Fused Deposition Modeling ◽  
Acrylonitrile Butadiene Styrene ◽  
Fused Deposition Modelling ◽  
Fused Deposition ◽  
3D Printers ◽  
Deposition Modeling ◽  
Printed Materials ◽  
Printing Parameters

Abstract3D polymer-based printers have become easily accessible to the public. Usually, the technology used by these 3D printers is Fused Deposition Modelling (FDM). The majority of these 3D printers mainly use acrylonitrile butadiene styrene (ABS) and polylactic acid (PLA) to fabricate 3D objects. In order for the printed parts to be useful for specific applications, the mechanical properties of the printed parts must be known. The aim of this study is to determine the tensile strength and elastic modulus of printed materials in polylactic acid (PLA) according to three important printing parameters such as deposition angle, extruder temperature and printing speed. The central composite design (CCD) was used to reduce the number of tensile test experiments. The obtained results show that the mechanical properties of printed parts depend on printing parameters. Empirical models relating response and process parameters are developed. The analysis of variance (ANOVA) was used to test the validity of models relating response and printing parameters. The optimal printing parameters are determined for the desired mechanical properties.

Manufacturing complex Al2O3 ceramic structures using consumer-grade fused deposition modelling printers

2020 ◽  
Vol 26 (6) ◽  
pp. 1035-1048 ◽  
Author(s):  
Nicholas A. Conzelmann ◽  
Lovro Gorjan ◽  
Fateme Sarraf ◽  
Lily D. Poulikakos ◽  
Manfred N. Partl ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Ceramic Powder ◽  
Compressive Force ◽  
Ethylene Vinyl Acetate ◽  
Ceramic Particle ◽  
Fused Deposition Modelling ◽  
Content Type ◽  
Fused Deposition ◽  
Debinding Process ◽  
Printing Direction

Purpose This study aims to fabricate complex ceramic tetrahedron structures, which are challenging to produce by more conventional methods such as injection molding. To achieve this aim, thermoplastic-ceramic composite filaments were developed and printed with unmodified, consumer-grade, fused deposition modelling (FDM) printers instead. Design/methodology/approach Al2O3 ceramic powder was mixed with ethylene vinyl acetate polymer as a binder (50 Vol.- per cent) to form a filament with a constant diameter of 1.75 mm. After the printing and thermal treatment stages, the shrinkage and mechanical properties of cuboid and tetrahedron structures were investigated. Findings The shrinkage of the parts was found to be anisotropic, depending on the orientation of the printing pattern, with an increase of 2.4 per cent in the (vertical) printing direction compared to the (horizontal) printing layer direction. The alignment of the ceramic particle orientations introduced by FDM printing was identified as a potential cause of the anisotropy. This study further demonstrates that using a powder bed during the thermal debinding process yields sintered structures that can withstand twice the compressive force. Originality/value Ceramic FDM had previously been used primarily for simple scaffold structures. In this study, the applicability of ceramic FDM was extended from simple scaffolds to more complex geometries such as hollow tetrahedra. The structures produced in this study contain dense parts printed from multiple contiguous layers, as compared to the open structures usually found in scaffolds. The mechanical properties of the complex ceramic parts made by using this FDM technique were also subjected to investigation.

scholarly journals Current State and Challenges of Natural Fibre-Reinforced Polymer Composites as Feeder in FDM-Based 3D Printing

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2289
Author(s):  
Nishata Royan Rajendran Royan ◽  
Jie Sheng Leong ◽  
Wai Nam Chan ◽  
Jie Ren Tan ◽  
Zainon Sharmila Binti Shamsuddin
Keyword(s):  
Mechanical Properties ◽  
Natural Fibre ◽  
Critical Discussion ◽  
Fused Deposition Modelling ◽  
Preparation Methods ◽  
Fused Deposition ◽  
Current State ◽  
Future Challenges ◽  
Raster Angle ◽  
Fibre Reinforced Polymer

As one of the fastest-growing additive manufacturing (AM) technologies, fused deposition modelling (FDM) shows great potential in printing natural fibre-reinforced composites (NFRC). However, several challenges, such as low mechanical properties and difficulty in printing, need to be overcome. Therefore, the effort to improve the NFRC for use in AM has been accelerating in recent years. This review attempts to summarise the current approaches of using NFRC as a feeder for AM. The effects of fibre treatments, composite preparation methods and addition of compatibilizer agents were analysed and discussed. Additionally, current methods of producing feeders from NFRCs were reviewed and discussed. Mechanical property of printed part was also dependent on the printing parameters, and thus the effects of printing temperature, layer height, infill and raster angle were discussed, and the best parameters reported by other researchers were identified. Following that, an overview of the mechanical properties of these composites as reported by various researchers was provided. Next, the use of optimisation techniques for NFRCs was discussed and analysed. Lastly, the review provided a critical discussion on the overall topic, identified all research gaps present in the use of NFRC for AM processes, and to overcome future challenges.

scholarly journals Temperature-Dependent Creep Behavior and Quasi-Static Mechanical Properties of Heat-Treated Wood

Forests ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 968
Author(s):  
Dong Xing ◽  
Xinzhou Wang ◽  
Siqun Wang
Keyword(s):  
Mechanical Properties ◽  
Creep Behavior ◽  
Cell Walls ◽  
Treated Wood ◽  
Crosslinking Reaction ◽  
Depth Sensing ◽  
Temperature Dependent ◽  
Heat Treated ◽  
Static Mechanical ◽  
Static Mechanical Properties

In this paper, Berkovich depth-sensing indentation has been used to study the effects of the temperature-dependent quasi-static mechanical properties and creep deformation of heat-treated wood at temperatures from 20 °C to 180 °C. The characteristics of the load–depth curve, creep strain rate, creep compliance, and creep stress exponent of heat-treated wood are evaluated. The results showed that high temperature heat treatment improved the hardness of wood cell walls and reduced the creep rate of wood cell walls. This is mainly due to the improvement of the crystallinity of the cellulose, and the recondensation and crosslinking reaction of the lignocellulose structure. The Burgers model is well fitted to study the creep behavior of heat-treated wood cell walls under different temperatures.

scholarly journals Energy and Eco-Impact Evaluation of Fused Deposition Modeling and Injection Molding of Polylactic Acid

2021 ◽  
Vol 13 (4) ◽  
pp. 1875
Author(s):  
Emmanuel Ugo Enemuoh ◽  
Venkata Gireesh Menta ◽  
Abdulaziz Abutunis ◽  
Sean O’Brien ◽  
Labiba Imtiaz Kaya ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Injection Molding ◽  
Polylactic Acid ◽  
Fused Deposition Modeling ◽  
Plastic Injection Molding ◽  
Measurement Models ◽  
Fused Deposition ◽  
Dog Bone ◽  
Deposition Modeling ◽  
Plastic Injection

There is limited knowledge about energy and carbon emission performance comparison between additive fused deposition modeling (FDM) and consolidation plastic injection molding (PIM) forming techniques, despite their recent high industrial applications such as tools and fixtures. In this study, developed empirical models focus on the production phase of the polylactic acid (PLA) thermoplastic polyester life cycle while using FDM and PIM processes to produce American Society for Testing and Materials (ASTM) D638 Type IV dog bone samples to compare their energy consumption and eco-impact. It was established that energy consumption by the FDM layer creation phase dominated the filament extrusion and PLA pellet production phases, with, overwhelmingly, 99% of the total energy consumption in the three production phases combined. During FDM PLA production, about 95.5% of energy consumption was seen during actual FDM part building. This means that the FDM process parameters such as infill percentage, layer thickness, and printing speed can be optimized to significantly improve the energy consumption of the FDM process. Furthermore, plastic injection molding consumed about 38.2% less energy and produced less carbon emissions per one kilogram of PLA formed parts compared to the FDM process. The developed functional unit measurement models can be employed in setting sustainable manufacturing goals for PLA production.

Quasi-static mechanical properties of novel generalized Resch-pattern composite foldcores

2020 ◽  
pp. 095440622094000
Author(s):  
Antao Deng ◽  
Bin Ji ◽  
Xiang Zhou
Keyword(s):  
Mechanical Properties ◽  
Design Method ◽  
Absorption Capacity ◽  
Woven Fabrics ◽  
Geometric Design ◽  
Honeycomb Core ◽  
Reinforced Plastic ◽  
Static Mechanical ◽  
Laminate Thickness ◽  
Static Mechanical Properties

A new geometric design method for foldcores based on the generalized Resch patterns that allow face-to-face bonding interfaces between the core and the skins is proposed. Based on the geometric design method, a systematic numerical investigation on the quasi-static mechanical properties of the generalized Resch-based foldcores made of carbon fiber-reinforced plastic (CFRP) woven fabrics subjected to compression and shear loads is performed using the finite element method that is validated by experiments. The relationships between the mechanical properties and various geometric parameters as well as laminate thickness of the generalized Resch-based CFRP foldcores are revealed. Additionally, the mechanical properties of the generalized Resch-based CFRP foldcore are compared to those of the standard Resch-based, Miura-based foldcore, the honeycomb core, and the aluminum counterpart. It is found that the generalized Resch-based CFRP foldcore performs more stably than the honeycomb core under compression and has higher compressive and shear stiffnesses than the standard Resch-based and Miura-based foldcores and absorbs as nearly twice energy under compression as the Miura-based foldcore does. When compared with the aluminum counterpart, the CFRP model has higher weight-specific stiffness and strength but lower energy absorption capacity under shearing. The results presented in this paper can serve as the useful guideline for the design of the generalized Resch-based composite foldcore sandwich structures for various performance goals.

A Study on Estimation of S-N Curves for Structural Steels Based on their Static Mechanical Properties

2014 ◽  
Vol 891-892 ◽  
pp. 1639-1644 ◽  
Author(s):  
Kazutaka Mukoyama ◽  
Koushu Hanaki ◽  
Kenji Okada ◽  
Akiyoshi Sakaida ◽  
Atsushi Sugeta ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Evaluation Method ◽  
Materials Science ◽  
Estimation Method ◽  
Structural Steels ◽  
Metallic Materials ◽  
Fatigue Reliability ◽  
Regression Parameters ◽  
Static Mechanical ◽  
Static Mechanical Properties

The aim of this study is to develop a statistical estimation method of S-N curve for iron and structural steels by using their static mechanical properties. In this study, firstly, the S-N data for pure iron and structural steels were extracted from "Database on fatigue strength of Metallic Materials" published by the Society of Materials Science, Japan (JSMS) and S-N curve regression model was applied based on the JSMS standard, "Standard Evaluation Method of Fatigue Reliability for Metallic Materials -Standard Regression Method of S-N Curve-". Secondly, correlations between regression parameters and static mechanical properties were investigated. As a result, the relationship between the regression parameters and static mechanical properties (e.g. fatigue limit E and static tensile strength σB) showed strong correlations, respectively. Using these correlations, it is revealed that S-N curve for iron and structural steels can be predicted easily from the static mechanical properties.

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