Investigations for Wax Coated 3D Printed Hybrid Patterns for Partial Dentures

Three Dimensional ◽

Surface Hardness ◽

Dimensional Accuracy ◽

Processing Technique ◽

Patient Specific ◽

Fused Deposition ◽

Abstract In this work, 3D printed master patterns of acrylonitrile butadiene styrene (ABS) thermoplastic material have been used for the preparation of Ni-Cr based functional prototypes as partial dentures (PD). The study started with patient specific three dimensional (3D), CAD data (fetched through scanning). This data was used for preparation of .STL file for printing of master patterns on fused deposition modeling (FDM) setup. The 3D printed master patterns were further wax coated to reduce the surface irregularities (as cost effective post processing technique). The hybrid patterns were subjected to investment casting for the preparation of Ni-Cr based PD. The finally prepared functional prototypes as PD were optimized for dimensional accuracy, surface finish and surface hardness as responses. The results are visualized and supported by photomicrographs and in-vitro analysis.

On the Post-Processing of 3D-Printed ABS Parts

Polymers ◽

10.3390/polym13101559 ◽

2021 ◽

Vol 13 (10) ◽

pp. 1559

Author(s):

Mohammad Reza Khosravani ◽

Jonas Schüürmann ◽

Filippo Berto ◽

Tamara Reinicke

Keyword(s):

Surface Treatment ◽

Three Dimensional ◽

Experimental Tests ◽

Fracture Load ◽

Post Processing ◽

Fused Deposition ◽

Dog Bone ◽

Application of Additive Manufacturing (AM) has significantly increased in the past few years. AM also known as three-dimensional (3D) printing has been currently used in fabrication of prototypes and end-use products. Considering the new applications of additively manufactured components, it is necessary to study structural details of these parts. In the current study, influence of a post-processing on the mechanical properties of 3D-printed parts has been investigated. To this aim, Acrylonitrile Butadiene Styrene (ABS) material was used to produce test coupons based on the Fused Deposition Modeling (FDM) process. More in deep, a device was designed and fabricated to fix imperfection and provide smooth surfaces on the 3D-printed ABS specimens. Later, original and treated specimens were subjected to a series of tensile loads, three-point bending tests, and water absorption tests. The experimental tests indicated fracture load in untreated dog-bone shaped specimen was 2026.1 N which was decreased to 1951.7 N after surface treatment. Moreover, the performed surface treatment was lead and decrease in tensile strength from 29.37 MPa to 26.25 MPa. Comparison of the results confirmed effects of the surface modification on the fracture toughness of the examined semi-circular bending components. Moreover, a 3D laser microscope was used for visual investigation of the specimens. The documented results are beneficial for next designs and optimization of finishing processes.

Three-dimensional printing of anatomically accurate, patient specific intracranial aneurysm models

Journal of NeuroInterventional Surgery ◽

10.1136/neurintsurg-2015-011686 ◽

2015 ◽

Vol 8 (5) ◽

pp. 517-520 ◽

Cited By ~ 40

Author(s):

Jeff R Anderson ◽

Walker L Thompson ◽

Abdulaziz K Alkattan ◽

Orlando Diaz ◽

Richard Klucznik ◽

...

Keyword(s):

Statistical Significance ◽

Three Dimensional ◽

Cerebral Aneurysms ◽

Patient Specific ◽

Parent Artery ◽

Significant Group ◽

Fused Deposition ◽

Deposition Modeling ◽

ObjectiveTo develop and validate a method for creating realistic, patient specific replicas of cerebral aneurysms by means of fused deposition modeling.MethodsThe luminal boundaries of 10 cerebral aneurysms, together with adjacent proximal and distal sections of the parent artery, were segmented based on DSA images, and corresponding virtual three-dimensional (3D) surface reconstructions were created. From these, polylactic acid and MakerBot Flexible Filament replicas of each aneurysm were created by means of fused deposition modeling. The accuracy of the replicas was assessed by quantifying statistical significance in the variations of their inner dimensions relative to 3D DSA images. Feasibility for using these replicas as flow phantoms in combination with phase contrast MRI was demonstrated.Results3D printed aneurysm models were created for all 10 subjects. Good agreement was seen between the models and the source anatomy. Aneurysm diameter measurements of the printed models and source images correlated well (r=0.999; p<0.001), with no statistically significant group difference (p=0.4) or observed bias. The SDs of the measurements were 0.5 mm and 0.2 mm for source images and 3D models, respectively. 3D printed models could be imaged with flow via MRI.ConclusionsThe 3D printed aneurysm models presented were accurate and were able to be produced inhouse. These models can be used for previously cited applications, but their anatomical accuracy also enables their use as MRI flow phantoms for comparison with ongoing studies of computational fluid dynamics. Proof of principle imaging experiments confirm MRI flow phantom utility.

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

Mechanical and morphological investigations of 3D printed recycled ABS reinforced with bakelite–SiC–Al2O3

10.1177/0954406219860163 ◽

2019 ◽

Vol 233 (17) ◽

pp. 5933-5944 ◽

Cited By ~ 2

Author(s):

Rupinder Singh ◽

Inderpreet Singh ◽

Ranvijay Kumar

Keyword(s):

Three Dimensional ◽

Morphological Properties ◽

Fused Deposition ◽

Software Configuration ◽

Twin Screw ◽

Deposition Modeling ◽

3D Printed ◽

Commercial Applications

The utilization of thermosetting waste is a serious issue as it is not recycled commercially due to inherent molecular properties and high technology cost. This research details the study of the mechanical behavior and surface analysis with energy-dispersive X-ray spectroscopy and scanning electron microscope of three-dimensional printed parts of the waste thermosetting polymer, bakelite (BAK) as the reinforcement along with ceramic particles (SiC and Al2O3) in recycled thermoplastic acrylonitrile butadiene styrene matrix for sustainability. The process involves twin-screw extrusion for the preparation of filament, followed by 3D printing of functional prototypes on fused deposition modeling setup. The 3D printed parts prepared with fused deposition modeling were used for the testing of mechanical, thermal, and morphological properties. The results of the present study suggests that for commercial applications recycling of thermoplastic up to 10 wt% can be easily performed without a change in any hardware/ software configuration of the fused deposition modeling setup and the ceramic concentration in thermoplastic-thermosetting blends further led to better mechanical and surface properties.

Quality Control in 3D Printing: Accuracy Analysis of 3D-Printed Models of Patient-Specific Anatomy

Materials ◽

10.3390/ma14041021 ◽

2021 ◽

Vol 14 (4) ◽

pp. 1021

Author(s):

Bernhard Dorweiler ◽

Pia Elisabeth Baqué ◽

Rayan Chaban ◽

Ahmed Ghazy ◽

Oroa Salem

Keyword(s):

Wall Thickness ◽

Large Scale ◽

Vascular Anatomy ◽

3D Models ◽

Patient Specific ◽

Stl File ◽

Fused Deposition ◽

3D Printed ◽

The Mean

As comparative data on the precision of 3D-printed anatomical models are sparse, the aim of this study was to evaluate the accuracy of 3D-printed models of vascular anatomy generated by two commonly used printing technologies. Thirty-five 3D models of large (aortic, wall thickness of 2 mm, n = 30) and small (coronary, wall thickness of 1.25 mm, n = 5) vessels printed with fused deposition modeling (FDM) (rigid, n = 20) and PolyJet (flexible, n = 15) technology were subjected to high-resolution CT scans. From the resulting DICOM (Digital Imaging and Communications in Medicine) dataset, an STL file was generated and wall thickness as well as surface congruency were compared with the original STL file using dedicated 3D engineering software. The mean wall thickness for the large-scale aortic models was 2.11 µm (+5%), and 1.26 µm (+0.8%) for the coronary models, resulting in an overall mean wall thickness of +5% for all 35 3D models when compared to the original STL file. The mean surface deviation was found to be +120 µm for all models, with +100 µm for the aortic and +180 µm for the coronary 3D models, respectively. Both printing technologies were found to conform with the currently set standards of accuracy (<1 mm), demonstrating that accurate 3D models of large and small vessel anatomy can be generated by both FDM and PolyJet printing technology using rigid and flexible polymers.

3D Printed Clamps for In Vitro Tensile Tests of Human Gracilis and the Superficial Third of Quadriceps Tendons

Applied Sciences ◽

10.3390/app11062563 ◽

2021 ◽

Vol 11 (6) ◽

pp. 2563

Author(s):

Ivan Grgić ◽

Vjekoslav Wertheimer ◽

Mirko Karakašić ◽

Željko Ivandić

Keyword(s):

3D Printing ◽

Tensile Tests ◽

Biomechanical Properties ◽

Testing Procedure ◽

Laboratory Equipment ◽

Fused Deposition ◽

Custom Made ◽

Recent soft tissue studies have reported issues that occur during experimentation, such as the tissue slipping and rupturing during tensile loads, the lack of standard testing procedure and equipment, the necessity for existing laboratory equipment adaptation, etc. To overcome such issues and fulfil the need for the determination of the biomechanical properties of the human gracilis and the superficial third of the quadriceps tendons, 3D printed clamps with metric thread profile-based geometry were developed. The clamps’ geometry consists of a truncated pyramid pattern, which prevents the tendons from slipping and rupturing. The use of the thread application in the design of the clamp could be used in standard clamping development procedures, unlike in previously custom-made clamps. Fused deposition modeling (FDM) was used as a 3D printing technique, together with polylactic acid (PLA), which was used as a material for clamp printing. The design was confirmed and the experiments were conducted by using porcine and human tendons. The findings justify the usage of 3D printing technology for parts manufacturing in the case of tissue testing and establish independence from the existing machine clamp system, since it was possible to print clamps for each prepared specimen and thus reduce the time for experiment setup.

Development of three-dimensional printing filaments based on poly(lactic acid)/hydroxyapatite composites with potential for tissue engineering

Journal of Composite Materials ◽

10.1177/0021998320988568 ◽

2021 ◽

pp. 002199832098856

Author(s):

Marcela Piassi Bernardo ◽

Bruna Cristina Rodrigues da Silva ◽

Luiz Henrique Capparelli Mattoso

Keyword(s):

Tissue Engineering ◽

Lactic Acid ◽

Three Dimensional ◽

Poly Lactic Acid ◽

Scanning Calorimetry ◽

Three Dimensional Printing ◽

Fused Deposition ◽

Deposition Modeling ◽

Injured bone tissues can be healed with scaffolds, which could be manufactured using the fused deposition modeling (FDM) strategy. Poly(lactic acid) (PLA) is one of the most biocompatible polymers suitable for FDM, while hydroxyapatite (HA) could improve the bioactivity of scaffold due to its chemical composition. Therefore, the combination of PLA/HA can create composite filaments adequate for FDM and with high osteoconductive and osteointegration potentials. In this work, we proposed a different approache to improve the potential bioactivity of 3D printed scaffolds for bone tissue engineering by increasing the HA loading (20-30%) in the PLA composite filaments. Two routes were investigated regarding the use of solvents in the filament production. To assess the suitability of the FDM-3D printing process, and the influence of the HA content on the polymer matrix, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM) were performed. The HA phase content of the composite filaments agreed with the initial composite proportions. The wettability of the 3D printed scaffolds was also increased. It was shown a greener route for obtaining composite filaments that generate scaffolds with properties similar to those obtained by the solvent casting, with high HA content and great potential to be used as a bone graft.

Experimental study on the accuracy and surface quality of printed versus machined holes in PEI Ultem 9085 FDM specimens

Rapid Prototyping Journal ◽

10.1108/rpj-12-2019-0306 ◽

2021 ◽

Vol 27 (11) ◽

pp. 1-12

Author(s):

Giovanni Gómez-Gras ◽

Marco A. Pérez ◽

Jorge Fábregas-Moreno ◽

Guillermo Reyes-Pozo

Keyword(s):

Surface Quality ◽

Three Dimensional ◽

Dimensional Accuracy ◽

Technological Parameters ◽

Content Type ◽

Fused Deposition ◽

Comparison Of The Results ◽

Through Hole

Purpose This paper aims to investigate the quality of printed surfaces and manufacturing tolerances by comparing the cylindrical cavities machined in parts obtained by fused deposition modeling (FDM) with the holes manufactured during the printing process itself. The comparison focuses on the results of roughness and tolerances, intending to obtain practical references when making assemblies. Design/methodology/approach The experimental approach focuses on the comparison of the results of roughness and tolerances of two manufacturing strategies: geometric volumes with a through-hole and the through-hole machined in volumes that were initially printed without the hole. Throughout the study, both alternates are explained to make appropriate recommendations. Findings The study shows the best combinations of technological parameters, both machining and three-dimensional printing, which have been decisive for obtaining successful results. These conclusive results allow enunciating recommendations for use in the industrial environment. Originality/value This paper fulfills an identified need to study the dimensional accuracy of the geometries obtained by additive manufacturing, as no experimental evidence has been found of studies that directly address the problem of the FDM-printed part with geometric and dimensional tolerances and desirable surface quality for assembly.

Dimensional accuracy of FDM-printed polymer parts

Rapid Prototyping Journal ◽

10.1108/rpj-04-2019-0115 ◽

2019 ◽

Vol 26 (2) ◽

pp. 288-298 ◽

Cited By ~ 1

Author(s):

Oğuzhan Emre Akbaş ◽

Onur Hıra ◽

Sahar Zhiani Hervan ◽

Shahrad Samankan ◽

Atakan Altınkaynak

Keyword(s):

Experimental Data ◽

Numerical Model ◽

Feed Rate ◽

Dimensional Accuracy ◽

Strip Width ◽

Content Type ◽

Fused Deposition ◽

Nozzle Temperature

Purpose This paper aims to analyze experimentally and numerically the effect of the nozzle temperature and feed rates on the dimensions of the fused deposition modeling (FDM) polymer parts. Design/methodology/approach In total, 30 strips per sample were printed with the same width as the nozzle diameter. The strips were printed with one vertical movement of the nozzle head. The width of the strips was measured with a caliper at five locations. A linear regression model was created based on the experimental data to understand the correlation between the strip width deviation and the parameters of interest. Numerical simulations were performed to predict the swell of the polymer exiting the nozzle using finite element method combined with level set method. The experimental results were then used to validate the models. Findings The average accuracy of polylactic acid (PLA) samples was better than that of acrylonitrile butadiene styrene (ABS) samples. The average strip width had a tendency to increase with increasing temperature for PLA samples, whereas ABS samples showed mixed behavior. The strip width decreased with increasing feed rate for most cases. The measurement positions had a major effect on strip width when compared to nozzle temperature and feed rate. The numerical model predictions were in good agreement with the experimental data. A few discrepancies were observed at high feed rates and nozzle temperatures. Originality/value This study will contribute to gaps in knowledge regarding the effect of processing conditions on dimensional accuracy of FDM-printed parts. The developed numerical model can be efficiently used to predict the dimensional accuracy of FDM-printed parts.

3D-Printed Soft Structure of Polyurethane and Magnetorheological Fluid: A Proof-of-Concept Investigation of its Stiffness Tunability

Micromachines ◽

10.3390/mi10100655 ◽

2019 ◽

Vol 10 (10) ◽

pp. 655 ◽

Cited By ~ 1

Author(s):

Seong-Woo Hong ◽

Ji-Young Yoon ◽

Seong-Hwan Kim ◽

Sun-Kon Lee ◽

Yong-Rae Kim ◽

...

Keyword(s):

Permanent Magnets ◽

Thermoplastic Polyurethane ◽

Three Dimensional ◽

Magnetorheological Fluid ◽

Three Dimensional Printing ◽

Fused Deposition ◽

Deposition Modeling ◽

3D Printed ◽

Dimensional Printing

In this study, a soft structure with its stiffness tunable by an external field is proposed. The proposed soft beam structure consists of a skin structure with channels filled with a magnetorheological fluid (MRF). Two specimens of the soft structure are fabricated by three-dimensional printing and fused deposition modeling. In the fabrication, a nozzle is used to obtain channels in the skin of the thermoplastic polyurethane, while another nozzle is used to fill MRF in the channels. The specimens are tested by using a universal tensile machine to evaluate the relationships between the load and deflection under two different conditions, without and with permanent magnets. It is empirically shown that the stiffness of the proposed soft structure can be altered by activating the magnetic field.

Volume 4: 21st Design for Manufacturing and the Life Cycle Conference; 10th International Conference on Micro- and Nanosystems ◽

Design of Self-Supported 3D Printed Parts for Fused Deposition Modeling

10.1115/detc2016-60569 ◽

2016 ◽

Author(s):

Fabian Lischke ◽

Andres Tovar

Keyword(s):

Numerical Model ◽

Beam Theory ◽

Critical Factor ◽

Material Model ◽

Analytical Models ◽

Element Analysis ◽

Fused Deposition ◽

One of the primary challenges faced in Additive Manufacturing (AM) is reducing the overall cost and printing time. A critical factor in cost and time reduction is post-processing of 3D printed (3DP) parts, of which removing support structures is one of the most time consuming steps. Support is needed to prevent the collapse of the part or certain areas under its own weight during the 3D printing process. Currently, the design of self-supported 3DP parts follows a set of empirical guide lines. A trial and error process is needed to produce high quality parts by Fused Depositing Modeling (FDM). The usage of chamfer angle with a max 45° angle form the horizontal for FDM is a common example. Inclined surfaces with a smaller angle are prone to defects, however no theoretical basis has been fully defined, therefore a numerical model is needed. The model can predict the problematic areas at a print, reducing the experimental prints and providing a higher number of usable parts. Physical-based models have not been established due to the generally unknown properties of the material during the AM process. With simulations it is possible to simulate the part at different temperatures with a variety of other parameters that have influence on the behavior of the model. In this research, analytic calculations and physical tests are carried out to determine the material properties of the thermoplastic polymer Acrylonitrile - Butadiene - Styrene (ABS) f or FDM at the time of extrusion. This means that the ABS is going to be extruded at 200°C to 245°C and is a viscous material during part construction. Using the results from the physical and analytical models, i.e., Timoshenko’s modified beam theory for micro-structures, a numerical material model is established to simulate the filament deformation once it is deposited onto the part. Experiments were also used to find the threshold for different geometric specifications, which could then be applied to the numerical model to improve the accuracy of the simulation. The result of the finite element analysis is compared to experiments to show the correlation between the prediction of deflection in simulation and the actual deflection measured in physical experiments. A case study was conducted using an application that optimizes topology of complex geometries. After modeling and simulating the optimized part, areas of defect and errors were determined in the simulation, then verified and and measured with actual 3D prints.