scholarly journals Influence of Infill Patterns Generated by CAD and FDM 3D Printer on Surface Roughness and Tensile Strength Properties

2021 ◽  
Vol 11 (16) ◽  
pp. 7272
Author(s):  
Mohammadreza Lalegani Dezaki ◽  
Mohd Khairol Anuar Mohd Ariffin ◽  
Ahmad Serjouei ◽  
Ali Zolfagharian ◽  
Saghi Hatami ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Tensile Strength ◽  
Computer Aided Design ◽  
Fused Deposition Modeling ◽  
Tensile Tests ◽  
Strength Analysis ◽  
Element Analysis ◽  
Fused Deposition ◽  
Dog Bone ◽  
Wide Range

Fused deposition modeling (FDM) is a capable technology based on a wide range of parameters. The goal of this study is to make a comparison between infill pattern and infill density generated by computer-aided design (CAD) and FDM. Grid, triangle, zigzag, and concentric patterns with various densities following the same structure of the FDM machine were designed by CAD software (CATIA V5®). Polylactic acid (PLA) material was assigned for both procedures. Surface roughness (SR) and tensile strength analysis were conducted to examine their effects on dog-bone samples. Also, a finite element analysis (FEA) was done on CAD specimens to find out the differences between printing and simulation processes. Results illustrated that CAD specimens had a better surface texture compared to the FDM machine while tensile tests showed patterns generated by FDM were stronger in terms of strength and stiffness. In this study, samples with concentric patterns had the lowest average SR (Ra) while zigzag was the worst with the value of 6.27 µm. Also, the highest strength was obtained for concentric and grid samples in both CAD and FDM procedures. These techniques can be useful in producing highly complex sandwich structures, bone scaffolds, and various combined patterns to achieve an optimal condition.

scholarly journals The Effects of Combined Infill Patterns on Mechanical Properties in FDM Process

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2792
Author(s):  
Mohammadreza Lalegani Dezaki ◽  
Mohd Khairol Anuar Mohd Ariffin
Keyword(s):  
Mechanical Properties ◽  
Computer Aided Design ◽  
Fused Deposition Modeling ◽  
Strength Analysis ◽  
Element Analysis ◽  
Fused Deposition ◽  
Deposition Modeling ◽  
3D Printed ◽  
Complex Features ◽  
Aided Design

Fused deposition modeling (FDM) is commonly used to print different products with highly complex features. Process parameters for FDM are divided into controllable or uncontrollable parameters. The most critical ones are built orientation, layer thickness, infill pattern, infill density, and nozzle diameter. This study investigates the effects of combined infill patterns in 3D printed products. Five patterns (solid, honeycomb, wiggle, grid, and rectilinear) were combined in samples to analyze their effects on mechanical properties for tensile strength analysis. Polylactic acid (PLA) samples were printed in different build orientations through two directions: flat and on-edge. The limitation was that the software and machine could not combine the infill patterns. Thus, the patterns were designed and assembled in computer aided design (CAD) software. Finite element analysis (FEA) was used to determine the patterns’ features and results showed honeycomb and grid have the highest strength while their weights were lighter compared to solid. Moreover, 0° samples in both flat and on-edge direction had the strongest layer adhesion and the best quality. In contrast, perpendicular samples like 60° and 75° showed poor adhesion and were the weakest specimens in both flat and on-edge, respectively. In brief, by increasing the build orientation, the strength decreases in this study.

Effect of heat treatment on crystallinity and mechanical properties of flexible structures 3D printed with fused deposition modeling

2021 ◽  
pp. 152808372110649
Author(s):  
Ajay Jayswal ◽  
Sabit Adanur
Keyword(s):  
Heat Treatment ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Fused Deposition Modeling ◽  
Scanning Calorimetry ◽  
Fused Deposition ◽  
Dog Bone ◽  
Heat Treated ◽  
Deposition Modeling ◽  
3D Printed

Fused Deposition Modeling (FDM) is a widely used 3D printing technique, which works based on the principle of melted polymer extrusion through nozzle(s) and depositing them on a build plate layer by layer. However, products manufactured with this method lack proper mechanical strength. In this work, 2/1 twill weave fabric structures are 3D printed using poly (lactic) acid (PLA). The ultimate tensile strength in the warp and weft directions and the modulus (stiffnesses) are measured for non-heat-treated (NHT) samples. The printed samples were heat-treated (HT) to improve the strength and stiffness. The variation in ultimate tensile strength is statistically insignificant in warp direction at all temperatures; however, the tensile strength in weft direction decreased after heat treatment. The modulus in warp direction increased by 31% after heat treatment while in the weft direction it decreased after heat treatment. Differential scanning calorimetry (DSC) tests showed the highest crystallinity at 125°C. The properties of the twill fabrics were compared with a standard dog-bone (DB) specimen using uniaxial tensile tests, Differential scanning calorimetry tests, and optical microscope (OM). For dog-bone specimens, the maximum values of crystallinity, ultimate tensile strength, and modulus were found to be at 125°C. The maximum crystallinity percentages are higher than that of the NHT samples. The ultimate tensile strength of NHT DB specimen 3D printed in horizontal orientation improved after heat treatment. The ultimate tensile strength of DB samples in vertical directions increased after heat treatment as well. The stiffness increased in both directions for DB samples.

A Robust True Direct-Print Technology for Tissue Engineering

2007 ◽  
Author(s):  
B. Li ◽  
T. Dutta Roy ◽  
C. M. Smith ◽  
P. A. Clark ◽  
K. H. Church
Keyword(s):  
Tissue Engineering ◽  
Computer Aided Design ◽  
Fused Deposition Modeling ◽  
Three Dimensional ◽  
Layer By Layer ◽  
Fused Deposition ◽  
Wide Range ◽  
Computer Aided ◽  
Liquid Material ◽  
Print Process

Numerous solid freeform fabrication (SFF) or rapid prototyping (RP) techniques have been employed in the field of tissue engineering to fabricate specially organized three-dimensional (3-D) structures such as scaffolds. Some such technologies include, but are not limited to, laminated object manufacturing (LOM), three-dimensional printing (3-DP) or ink-jet printing, selective laser sintering (SLS), and fused deposition modeling (FDM). These techniques are capable of rapidly producing highly complex 3-D scaffolds or other biomedical structures with the aid of a computer-aided design (CAD) system. However, they suffer from lack of consistency and repeatability, since most of these processes are not fully controlled and cannot reproduce the previous work with accuracy. Also, these techniques (excluding FDM) are not truly direct-print processes. Certain material removing steps are involved, which in turn increases the complexity and the cost of fabrication. The FDM process has good repeatability; however, the materials that can be used are limited due to the high temperature needed to melt the feedstock. Some researchers also reported that the scaffolds fabricated by FDM lack consistency in the z-direction. In this paper, we will present a true direct-print technology for repeatedly producing scaffolds and other biomedical structures for tissue engineering with the aid of our Computer Aided Biological (CAB) tool. Unlike other SFF techniques mentioned above, our direct-print process fabricates scaffolds or other complex 3-D structures by extruding (dispensing) a liquid material onto the substrate with a prescribed pattern generated by a CAD program. This can be a layer-by-layer 2.5 dimension build or a true 3-D build. The dispensed liquid material then polymerizes or solidifies, to form a solid structure. The flexibility in the types of materials that can be extruded ranges from polymers to living cells, encapsulated in the proper material. True 3-D structures are now possible on a wide range of substrates, including even in vivo. Some of the advantages of the process are a) researchers have full control over the patterns to be created; b) it is a true direct-print process with no material removing steps involved; c) it is highly consistent and repeatable; and d) it is highly efficient and cost-effective. This paper will first give a detailed description of the CAB tool. Then, it will present a detailed process for printing polycaprolactone (PCL) into a defined 3-D architecture, where the primary focus for these constructs is for use in tissue engineering applications. Finally, mechanical characterization results of the printed scaffolds will be included in the paper.

scholarly journals Strength produced parts by fused deposition modeling

2020 ◽  
Vol 5 (2) ◽  
pp. 057-062
Author(s):  
Juraj Beniak ◽  
Miloš Matúš ◽  
Ľubomír Šooš ◽  
Peter Križan
Keyword(s):  
Tensile Strength ◽  
Fused Deposition Modeling ◽  
Lower Cost ◽  
Strength Properties ◽  
Fused Deposition ◽  
Wide Range ◽  
Deposition Modeling ◽  
Manufacturing Technologies ◽  
Operation Cost

The aim of using additive manufacturing technologies is to be able to produce a wide range of component designs on a single device, using a wide range of materials and minimizing material consumption. There are several technologies that work on different principles. The present article is focused on Fused Deposition Modeling (FDM) technology, which is focused on the application of layers of semi-molten polymer. The advantage is the lower cost for obtaining of FDM device, but also the low operation cost. The output of production are complex components designed for prototyping, but also for final use. Due to the fact that there is requirement to produce parts also for final use, it is necessary to know the strength properties of the parts after production. Because the structure of parts volume is not homogeneous, it is not possible to subject it to conventional calculations and simulations, but it is necessary to take into account the specifics that are produced during production by FDM technology. The present paper shows the results of experimental determination of the tensile strength of manufactured parts. A series of samples with different properties was used on the FDM device and the tensile strength of the components was subsequently measured. The measured values ​​were compared and evaluated.

scholarly journals Properties of 3D Printable Poly(lactic acid)/Poly(butylene adipate-co-terephthalate) Blends and Nano Talc Composites

2020 ◽  
Vol 2020 ◽  
pp. 1-16 ◽  
Author(s):  
Wattanachai Prasong ◽  
Paritat Muanchan ◽  
Akira Ishigami ◽  
Supaphorn Thumsorn ◽  
Takashi Kurose ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Tensile Strength ◽  
Lactic Acid ◽  
3D Printing ◽  
Fused Deposition Modeling ◽  
Thermal Characteristic ◽  
Rheological Behaviour ◽  
Poly Lactic Acid ◽  
Elongation At Break ◽  
Fused Deposition

Biodegradable poly(lactic acid) (PLA) filaments have been widely used in the fused deposition modeling (FDM) 3D printing technology. However, PLA has low toughness and low thermal resistance that affects printability and restricts its industrial applications. In this study, PLA was compounded with 0 to 40 wt% of poly(butylene adipate-co-terephthalate) (PBAT) and varied content of nano talc at 0 to 40 wt% in a twin screw extruder. The compounds were reextruded to filaments using a capillary rheometer. PLA/PBAT blends and their composite filaments were printed with a FDM 3D printing machine. Morphology, rheological behaviour, thermal characteristic, surface roughness, and mechanical property of 3D printing of the blends and the composites were investigated. Complex viscosity of the blends and the composites increased with increase of the PBAT and the nano talc contents. The incorporation of the nano talc enhanced crystallization temperature and reduced the coefficient of volume expansion of the composites. It was found that the PLA/PBAT blends and composites were excellent in both printability and dimension stability at PBAT content 10-30 wt% and nano talc up to 10 wt%. Interestingly, it was possible to print the composite filaments at an angle up to 75° during the overhang test without a supporter. From the vertical specimens, the surface roughness improved due to the incorporation of the nano talc. Tensile strength of the blends and the composites decreased, whereas elongation at break increased when the PBAT and the nano talc contents were increased. The reduction of tensile strength was attributed to agglomeration of the PBAT dispersed phase and less adhesion between the nano talc and the matrix. It can be noted that the composite 3D printing product showed superior elongation at break up to 410% by adding nano talc 1 wt%. This result suggests that the ductile 3D printable PLA/PBAT blend and the PLA/PBAT-nano talc composite products can be prepared, which shows potential for the commercialized scale.

Technical Development of Hybrid Rapid Tooling Technology

2013 ◽  
Vol 664 ◽  
pp. 830-834
Author(s):  
Chil Chyuan Kuo ◽  
Sheng Jie Su ◽  
Shiou Ru Shiu
Keyword(s):  
Surface Roughness ◽  
Tensile Strength ◽  
Fused Deposition Modeling ◽  
Rapid Tooling ◽  
Manufacturing Cost ◽  
Improvement Rate ◽  
Composite Surface ◽  
Fused Deposition ◽  
Deposition Modeling ◽  
Tooling Technology

The surface finish of fused deposition modeling (FDM) processed part is excessively rough due to stair stepping effect. In addition, the tensile strength of rapid tooling fabricated by FDM is inferior to that fabricated by plastic injection molding. A hybrid rapid tooling technology is developed to improve the surface roughness and increase the tensile strength of rapid tooling fabricated by FDM using epoxy-based composite in this work. Improvement rate of tensile strength of rapid tooling is 2.34 times of the add rate of epoxy-based composite. Surface roughness improvement rate of up to 92.94% can be achieved. Hybrid rapid tooling technology owns low manufacturing cost, simple manufacturing process and good flexibility.

scholarly journals Design and development of open source portable multi-functional three-dimensional bio-printing extrusion system for hydrogel-based scaffolds fabrication

2021 ◽  
Author(s):  
Pouya Behrouzi ◽  
Mahmood Zali ◽  
Mahdi Muhaddesi ◽  
Alireza Hashemi ◽  
Arezoo Khoradmehr ◽  
...  
Keyword(s):  
Computer Aided Design ◽  
Fused Deposition Modeling ◽  
Three Dimensional ◽  
Thermal Control ◽  
Numerical Control ◽  
Cnc Machine ◽  
Design And Development ◽  
Element Analysis ◽  
3D Print ◽  
Fused Deposition

Abstract Three-dimensional (3D) bio-printing has been shown up as a state of the art and creative technological solution to nowadays tissue engineering and stem cell research challenges toward human tissue regeneration and construction of artificial living organs. Thereby, using hydrogel-based bio-inks to 3D print living microenvironments is a crucial strategy to reconstruct basically functional living scaffolds in order to shape human living organs based on digital 3D computer-aided design (CAD) inputs. The focus of this paper lies on design and development of a portable multi-functional 3D bio-printing extruder for fabrication of hydrogel-based highly complex living tissues using advanced methods invented along this study. The presented article, precisely optimizes the process of fabricating 3D printed scaffolds by redesigning of an integrated gel-extrusion system capable of controlling the adjustability of thermal condition of bio-inks. Also a UV crosslink module is utilized in the bottom of the extruder to cure hydrogel scaffolds consisting of photo-reacting agents to provide a novel bio-printing experience for end users. As a result, the integrated extrusion system is easily portable and compatible with almost any computer numerical control (CNC) machine. Therefore, it could be simply installed on or removed from any CNC machine or fused deposition modeling (FDM) 3D printing system considering that all the control units remain adjustable. The whole system parameters and the performance of tissue fabrication regarding this developed portable multi-functional 3D bio-printing extruder have been tested and practically confirmed. The thermal control system performance has also been simulated using finite element analysis (FEA) and computational fluid dynamics (CFD) methods. Thus, certified documents have been provided and depicted in this paper.

Quantitative strength analysis for 3D-printed specimens in a Tri-Hexagon pattern

2021 ◽  
pp. 095440622110211
Author(s):  
Sourabh Tandon ◽  
Ruchin Kacker ◽  
KG Sudhakar
Keyword(s):  
Tensile Strength ◽  
Fused Deposition Modeling ◽  
Acrylonitrile Butadiene Styrene ◽  
Strength Properties ◽  
Strength Analysis ◽  
Layer By Layer ◽  
Sem Images ◽  
Fused Deposition ◽  
Deposition Modeling ◽  
Suitable Combination

ABS (Acrylonitrile Butadiene Styrene) and PLA (Polylactic acid) are the most commonly used thermoplastic materials in the AM (Additive Manufacturing) to build objects adding layer by layer. Addition of reinforcement such as carbon fibres to these materials is common to enhance strength properties. This work aims the fabrication of ABS, PLA, and PLA+CF specimens using the FDM (Fused Deposition Modeling). Subsequently, the tensile strength of printed specimens at Tri-Hexagon pattern for various % infills with different orientations is investigated. For a desired strength, the analysis facilitates the designer to choose suitable combination of specimen orientation at a specific infill and pattern. PLA+CF and ABS specimens with Tri-hexagon pattern at 0° orientation retain considerable strength when infill % gets lowered, whereas, virgin PLA observes higher strength stability at 90° orientation. The magnitudes of Ultimate tensile strength increased with infill %. The peak strength for PLA+CF specimen (with 100% infill without any pattern) at 0° and 90° orientation was 22% and 5% more, respectively, compared to 45° orientation. SEM images reveal a decrease in strength with ABS and PLA specimens due to the presence of voids between the layers, whereas showed strong bonding between CF and PLA matrix. Tri-Hexagon pattern showed better strength than the honeycomb, line, and rectilinear, especially at lower infills. Specimens both with and without Tri-hexagonal pattern observed superior ductile characteristics at 0° and 90° orientation, whereas most inferior at 45°.

Assessment of a Virtual Functional Prototyping Process for the Rapid Manufacture of Passive-Dynamic Ankle-Foot Orthoses

2013 ◽  
Vol 135 (10) ◽  
Author(s):  
Elisa S. Schrank ◽  
Lester Hitch ◽  
Kevin Wallace ◽  
Richard Moore ◽  
Steven J. Stanhope
Keyword(s):  
Elastic Modulus ◽  
Computer Aided Design ◽  
Prediction Accuracy ◽  
Fused Deposition Modeling ◽  
Dimensional Accuracy ◽  
Bending Stiffness ◽  
Cad Model ◽  
Functional Characteristics ◽  
Element Analysis ◽  
Fused Deposition

Passive-dynamic ankle-foot orthosis (PD-AFO) bending stiffness is a key functional characteristic for achieving enhanced gait function. However, current orthosis customization methods inhibit objective premanufacture tuning of the PD-AFO bending stiffness, making optimization of orthosis function challenging. We have developed a novel virtual functional prototyping (VFP) process, which harnesses the strengths of computer aided design (CAD) model parameterization and finite element analysis, to quantitatively tune and predict the functional characteristics of a PD-AFO, which is rapidly manufactured via fused deposition modeling (FDM). The purpose of this study was to assess the VFP process for PD-AFO bending stiffness. A PD-AFO CAD model was customized for a healthy subject and tuned to four bending stiffness values via VFP. Two sets of each tuned model were fabricated via FDM using medical-grade polycarbonate (PC-ISO). Dimensional accuracy of the fabricated orthoses was excellent (average 0.51 ± 0.39 mm). Manufacturing precision ranged from 0.0 to 0.74 Nm/deg (average 0.30 ± 0.36 Nm/deg). Bending stiffness prediction accuracy was within 1 Nm/deg using the manufacturer provided PC-ISO elastic modulus (average 0.48 ± 0.35 Nm/deg). Using an experimentally derived PC-ISO elastic modulus improved the optimized bending stiffness prediction accuracy (average 0.29 ± 0.57 Nm/deg). Robustness of the derived modulus was tested by carrying out the VFP process for a disparate subject, tuning the PD-AFO model to five bending stiffness values. For this disparate subject, bending stiffness prediction accuracy was strong (average 0.20 ± 0.14 Nm/deg). Overall, the VFP process had excellent dimensional accuracy, good manufacturing precision, and strong prediction accuracy with the derived modulus. Implementing VFP as part of our PD-AFO customization and manufacturing framework, which also includes fit customization, provides a novel and powerful method to predictably tune and precisely manufacture orthoses with objectively customized fit and functional characteristics.

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