Academic literature on the topic 'Stereolithography SLA'
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Journal articles on the topic "Stereolithography SLA"
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Huang, Jigang, Qin Qin, and Jie Wang. "A Review of Stereolithography: Processes and Systems." Processes 8, no. 9 (September 11, 2020): 1138. http://dx.doi.org/10.3390/pr8091138.
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Being the earliest form of additive manufacturing, stereolithography (SLA) fabricates 3D objects by selectively solidifying the liquid resin through a photopolymerization reaction. The ability to fabricate objects with high accuracy as well as a wide variety of materials brings much attention to stereolithography. Since its invention in the 1980s, SLA underwent four generations of major technological innovation over the past 40 years. These innovations have thus resulted in a diversified range of stereolithography systems with dramatically improved resolution, throughput, and materials selection for creating complex 3D objects and devices. In this paper, we review the four generations of stereolithography processes, which are scanning, projection, continuous and volumetric stereolithography. For each generation, representative stereolithography system configurations are also discussed in detail. In addition, other derivative technologies, such as scanning–projection, multi-material, and magnetically assisted stereolithography processes, are also included in this review.
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Tilendo, Amierson Castro, and Bryan B. Pajarito. "Reinforcement of Stereolithography Resin with Silica-Based Fillers." Materials Science Forum 890 (March 2017): 74–77. http://dx.doi.org/10.4028/www.scientific.net/msf.890.74.
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This study investigated the improvement of hardness and flexural properties of a commercial stereolithography (SLA) resin by reinforcement with silica-based fillers. Three types of fillers were studied: synthetic amorphous silica, milled fiberglass, and geothermal scale powder. Particle size and aspect ratio of fillers were estimated from scanning electron microscopy (SEM) images, while chemical structure was characterized by attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy. Fillers were added to SLA resin at 0, 10, and 20 vol%. Hardness and flexural properties of SLA composites are higher than unfilled resin. Moreover, both hardness and flexural properties of SLA composites are improved according to type (milled fiberglass > synthetic amorphous silica > geothermal scale powder) and loading (20 vol% > 10 vol%). The observed effect of filler type and loading on hardness and flexural properties of SLA composites is due to aspect ratio, intrinsic properties and dispersion of filler.
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Pham, D. T., and C. Ji. "A study of recoating in stereolithography." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 217, no. 1 (January 1, 2003): 105–17. http://dx.doi.org/10.1243/095440603762554659.
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Recoating in a stereolithography apparatus (SLA) involves dipping the part being built into a vat containing liquid resin and sweeping a blade over the top of the part. There are two problems with the recoating opearation in existing SLA systems. Firstly, the process is slow because the blade sweep speed is usually restricted to minimize disturbances to the resin surface and also because, after each sweep, the machine has to wait idly for any disturbances to subside and the resin surface to become level before scanning by the laser can be performed. In a part made up of hundreds or thousands of layers, these measures considerably lengthen the build time. The second problem is the difficulty of ensuring that the thickness of the generated layers is even and accurate in parts that incorporate upward-facing concave areas. For such parts, recoated layers may be either thinner or thicker than specified. In the worst case, the part may become delaminated or the blade may strike the cured resin during recoating, resulting in build failure. This paper reports on an experimental study of the recoating operation. The paper discusses the setting of parameters controlling the operation and proposes guidelines for producing good quality SLA parts while reducing build times.
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Zheng, Yihao, Yancheng Wang, Roland K. Chen, Sagar Deshpande, Noah S. Nelson, Steven R. Buchman, and Albert J. Shih. "Tissue transformation mold design and stereolithography fabrication." Rapid Prototyping Journal 23, no. 1 (January 16, 2017): 162–68. http://dx.doi.org/10.1108/rpj-10-2015-0133.
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Purpose To obtain a vascularized autologous bone graft by in-vivo tissue transformation, a biocompatible tissue transformation mold (TTM) is needed. An ideal TTM is of high geometric accuracy and X-ray radiolucent for monitoring the bone tissue formation. The purpose of this study is to present the TTM design and fabrication process, using 3D reconstruction, stereolithography (SLA) and silicone molding. Design/methodology/approach The rat mandible, the targeted bone graft, was scanned by micro-computed tomography (CT). From the micro-CT images, the 3D mandible model was identified and used as the cavity geometry to design the TTM. The TTM was fabricated by molding the biocompatible and radiolucent silicone in the SLA molds. This TTM was implanted in a rat for in vivo tests on its biocompatibility and X-ray radiolucency. Findings SLA can fabricate the TTM with a cavity shape that accurately replicates that of the rat mandible. The bone formation inside of the silicone TTM can be observed by X-ray. The TTM is feasible for in vivo tissue transformation for vascularized bone reconstruction. Research limitations/implications Research of the dimensional and geometrical accuracy of the TTM cavity is required in the future study of this process. Practical implications The TTM fabricated in this presented approach has been used for in-vivo tissue transformation. This technique can be implemented for bone reconstruction. Originality/value The precision fabrication of the TTMs for in-vivo tissue transformation into autogenous vascularized bone grafts with complex structures was achieved by using SLA, micro-CT and silicone molding.
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Pan, Wenyang, Thomas J. Wallin, Jérémy Odent, Mighten C. Yip, Bobak Mosadegh, Robert F. Shepherd, and Emmanuel P. Giannelis. "Optical stereolithography of antifouling zwitterionic hydrogels." Journal of Materials Chemistry B 7, no. 17 (2019): 2855–64. http://dx.doi.org/10.1039/c9tb00278b.
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This paper reports the rapid 3D printing of tough (toughness, UT, up to 141.6 kJ m−3), highly solvated (ϕwater ∼ 60 v/o), and antifouling hybrid hydrogels for potential uses in biomedical, smart materials, and sensor applications, using a zwitterionic photochemistry compatible with stereolithography (SLA).
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Mukhtarkhanov, Muslim, Asma Perveen, and Didier Talamona. "Application of Stereolithography Based 3D Printing Technology in Investment Casting." Micromachines 11, no. 10 (October 19, 2020): 946. http://dx.doi.org/10.3390/mi11100946.
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Advanced methods for manufacturing high quality parts should be used to ensure the production of competitive products for the world market. Investment casting (IC) is a process where a wax pattern is used as a sacrificial pattern to manufacture high precision casting of solid metal parts. Rapid casting is in turn, a technique that eases the IC process by combining additive manufacturing (AM) technologies with IC. The use of AM technologies to create patterns for new industrial products is a unique opportunity to develop cost-effective methods for producing investment casting parts in a timely manner. Particularly, stereolithography (SLA) based AM is of interest due to its high dimensional accuracy and the smooth surface quality of the printed parts. From the first appearance of commercially available SLA printers in the market, it took a few decades until desktop SLA printers became available to consumers at a reasonable price. Therefore, the aim of this review paper is to analyze the state-of-the-art and applicability of SLA based 3D printing technology in IC manufacturing, as SLA based AM technologies have been gaining enormous popularity in recent times. Other AM techniques in IC are also reviewed for comparison. Moreover, the SLA process parameters, material properties, and current issues are discussed.
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Kazemi, Mehdi, and Abdolreza Rahimi. "Stereolithography process optimization for tensile strength improvement of products." Rapid Prototyping Journal 24, no. 4 (May 14, 2018): 688–97. http://dx.doi.org/10.1108/rpj-05-2015-0049.
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Purpose Stereolithography (SLA) is a broadly used technology in the field of rapid prototyping. One of the disadvantages of SLA is poor mechanical properties of its products. To approach the mechanical properties of original part, the mechanical properties of SLA part, such as tensile strength, should be optimized. In this process, there are many parameters that affect the tensile strength of parts. However, the “layer thickness”, “fabrication orientation” and “post curing time” are the most significant ones. Hence, the purpose of this study is to investigate the influence of these parameters on tensile strength of SLA parts. Design/methodology/approach According to the obtained results from experiments based on the “full factorial” method, an empirical equation was developed for the tensile strength in terms of the effective parameters by using regression analysis. Considering this empirical equation, the process parameters were optimized to maximize the tensile strength by using genetic algorithm. Finally, the tensile tests of the specimens were simulated via the general-purpose finite element package of ABAQUS. Findings The outputs of the numerical simulations were in good agreement with experimental results. Both experimental and numerical results show that the increase of layer thickness and the decrease in post curing time increase the tensile strength. Furthermore, the tensile strength of parts produced in vertical orientation is higher than that of parts produced in horizontal orientation. Originality/value This is a complete study about the tensile strength of the SLA parts from experimental and analytical viewpoints.
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Dietrich, Christian Andreas, Andreas Ender, Stefan Baumgartner, and Albert Mehl. "A validation study of reconstructed rapid prototyping models produced by two technologies." Angle Orthodontist 87, no. 5 (May 1, 2017): 782–87. http://dx.doi.org/10.2319/01091-727.1.
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ABSTRACT Objective: To determine the accuracy (trueness and precision) of two different rapid prototyping (RP) techniques for the physical reproduction of three-dimensional (3D) digital orthodontic study casts, a comparative assessment using two 3D STL files of two different maxillary dentitions (two cases) as a reference was accomplished. Materials and Methods: Five RP replicas per case were fabricated using both stereolithography (SLA) and the PolyJet system. The 20 reproduced casts were digitized with a highly accurate reference scanner, and surface superimpositions were performed. Precision was measured by superimposing the digitized replicas within each case with themselves. Superimposing the digitized replicas with the corresponding STL reference files assessed trueness. Statistical significance between the two tested RP procedures was evaluated with independent-sample t-tests (P < .05). Results: The SLA and PolyJet replicas showed statistically significant differences for trueness and precision. The precision of both tested RP systems was high, with mean deviations in stereolithographic models of 23 (±6) μm and in PolyJet replicas of 46 (±13) μm. The mean deviation for trueness in stereolithographic replicas was 109 (±4) μm, while in PolyJet replicas, it was 66 (±14) μm. Conclusions: Comparing the STL reference files, the PolyJet replicas showed higher trueness than the SLA models. But the precision measurements favored the SLA technique. The dimensional errors observed in this study were a maximum of 127 μm. In the present study, both types of reproduced digital orthodontic models are suitable for diagnostics and treatment planning.
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Curti, Carlo, Daniel J. Kirby, and Craig A. Russell. "Stereolithography Apparatus Evolution: Enhancing Throughput and Efficiency of Pharmaceutical Formulation Development." Pharmaceutics 13, no. 5 (April 25, 2021): 616. http://dx.doi.org/10.3390/pharmaceutics13050616.
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Pharmaceutical applications of 3D printing technologies are growing rapidly. Among these, vat photopolymerisation (VP) techniques, including Stereolithography (SLA) hold much promise for their potential to deliver personalised medicines on-demand. SLA 3D printing offers advantageous features for pharmaceutical production, such as operating at room temperature and offering an unrivaled printing resolution. However, since conventional SLA apparatus are designed to operate with large volumes of a single photopolymer resin, significant throughput limitations remain. This, coupled with the limited choice of biocompatible polymers and photoinitiators available, hold back the pharmaceutical development using such technologies. Hence, the aim of this work was to develop a novel SLA apparatus specifically designed to allow rapid and efficient screening of pharmaceutical photopolymer formulations. A commercially available SLA apparatus was modified by designing and fabricating a novel resin tank and build platform able to 3D print up to 12 different formulations at a single time, reducing the amount of sample resin required by 20-fold. The novel SLA apparatus was subsequently used to conduct a high throughput screening of 156 placebo photopolymer formulations. The efficiency of the equipment and formulation printability outcomes were evaluated. Improved time and cost efficiency by 91.66% and 94.99%, respectively, has been confirmed using the modified SLA apparatus to deliver high quality, highly printable outputs, thus evidencing that such modifications offer a robust and reliable tool to optimize the throughput and efficiency of vat photopolymerisation techniques in formulation development processes, which can, in turn, support future clinical applications.
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Burke, Gavin, Declan M. Devine, and Ian Major. "Effect of Stereolithography 3D Printing on the Properties of PEGDMA Hydrogels." Polymers 12, no. 9 (September 3, 2020): 2015. http://dx.doi.org/10.3390/polym12092015.
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Stereolithography (SLA)-based 3D printing has proven to have several advantages over traditional fabrication techniques as it allows for the control of hydrogel synthesis at a very high resolution, making possible the creation of tissue-engineered devices with microarchitecture similar to the tissues they are replacing. Much of the previous work in hydrogels for tissue engineering applications have utilised the ultraviolet (UV) chamber bulk photopolymerisation method for preparing test specimens. Therefore, it is essential to directly compare SLA 3D printing to this more traditional approach to elucidate the differences in hydrogels prepared by each fabrication method. Polyethyleneglycol dimethacrylate (PEGDMA) is an ideally suited material for a comparative study of the impact that SLA fabrication has on performance, as the properties of traditional UV chamber-cured hydrogels have been extensively characterised. The present study was conducted to compare the material properties of PEGDMA hydrogels prepared using UV chamber photopolymerisation and SLA 3D printing. From the subsequent testing, SLA-fabricated hydrogels were shown to maintain similar thermal and chemical performance to UV chamber-cured hydrogels but had a higher compressive strength and tensile stiffness, as well as increased hydrophilicity. These differences are attributed to the increased exposure to UV light SLA samples received compared to traditionally UV chamber-cured samples.
Dissertations / Theses on the topic "Stereolithography SLA"
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Sager, Benay. "Stereolithography Characterization for Surface Finish Improvement: Inverse Design Methods for Process Planning." Diss., Available online, Georgia Institute of Technology, 2006, 2006. http://etd.gatech.edu/theses/available/etd-04092006-155545/.
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Thesis (Ph. D.)--Mechanical Engineering, Georgia Institute of Technology, 2006.Dr. David W. Rosen, Committee Chair ; Dr. Farrokh Mistree, Committee Member ; Dr. W. Jack Lackey, Committee Member ; Dr. Cliff Henderson, Committee Member ; Dr. Ali Adibi, Committee Member.
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Saldanha, António Miguel Costa Quintela de. "Desenvolvimento de uma máquina de limpeza e de cura para peças impressas em SLA." Master's thesis, 2019. http://hdl.handle.net/10362/76467.
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A manufatura aditiva (MA) tem crescido nos últimos anos. A sua inicial função
de prototipagem rápida e aceleramento do processo de desenvolvimento de
produto é ainda a sua principal função, embora existam desenvolvimentos no
sentido de usar estas técnicas para o fabrico de produtos de utilização final
como já se começa a verificar em várias empresas. Devido às suas
características, os processos de manufatura aditiva parecem ter o seu espaço no
mercado, em especial na produção de pequenas séries e produtos
personalizados.
As peças fabricadas por MA com a tecnologia Stereolithography (SLA), após
serem retiradas da impressora, encontram-se revestidas de resina não curada e
as próprias peças estão apenas parcialmente curadas, pelo que nesta fase devese
utilizar um solvente para retirar toda a resina não curada da superfície de
modo a obter um melhor acabamento superficial. Após as peças estarem limpas
é necessário curar totalmente as peças para estas obterem as suas propriedades
finais.
Esta dissertação aborda o desenvolvimento de uma máquina que realiza a
limpeza e cura de peças impressas pela tecnologia SLA, construída com uma
combinação de peças obtidas por MA e processos convencionais. A impressora
utilizada durante a prototipagem foi a Original Prusa i3 MK3.
A metodologia de desenvolvimento de produto foi aplicada com
estabelecimento de necessidades e especificações que levaram à geração e
seleção de conceitos. Foi produzido um protótipo do conceito mais promissor e
este foi testado para estabelecer as especificações finais.
Por fim, foi desenvolvido um custo de prototipagem com o material e energia
utilizados para calcular o custo total unitário do protótipo e realizar uma
aproximação de um eventual produto final, através de duas opções
apresentadas.
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Tshimanga, Ilunga Jeanmark. "Particle image velocimetry measurements of blood flow in aneurysms using 3D printed flow phantoms." Diss., 2019. http://hdl.handle.net/10500/27390.
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Cardiovascular diseases (CVD) remain one of the leading causes of deaths worldwide. The formation and
presence of aneurysm is a very important question in the study of this CVDs. An aneurysm is a balloon-like
bulge on a blood vessel which forms over time. An aneurysm is usually considered to be a result of weakening
of the blood vessel walls, this definition has stood over many years without being conclusively proven.
Eventually, the aneurysm could clot or burst due to degradation of the aneurysm wall and accumulation of
blood. The latter would lead to internal bleeding and result in a stroke. Local hemodynamics have been found
to be very important in the study of the evolution of an aneurysm. In this study, a steady flow experimental
investigation was conducted using planar Particle Image Velocimetery (PIV) on a rigid flow phantom of an
idealised geometry consisting of a curve parent artery and a spherical aneurysm located on the outer convex
side of the curvature. The flow phantom was fabricated directly using a commercially available desktop
Stereolithography (STL) 3D printer instead of the more conventional investment casting method using a core.
Although 3D printing technologies have been around for many years, the fabrication of flow phantoms by
direct printing is still largely under-explored. This thesis details the results of investigation into the optimal
printing and post-printing procedures required to produce a flow phantom of suitable clarity and transparency.
Other important areas of concern such as the geometric accuracy, surface topography and refractive index of
the final model are also investigated. A planar PIV is conducted to study the impact of flow rates on the local
flow field in and around the aneurysm and their impact on the wall shear stress. It was found that direct 3D
printing is appropriate for the fabrication of flow phantoms suitable for PIV or other flow visualisation
techniques. It reduces the complexities and time needed compared to the conventional investment casting
methods. It was observed that the optical properties of the printed material such as the high refractive index
(RI) and the transmittivity of light could cause a problem in large models. From the PIV measurements it was
found that flow rates affect the flow field in both the parent artery and the aneurysm. First, high velocities
were observed on the outer curvature of the parent artery. Secondly the centre of rotation in the aneurysm is
not at the geometric centre but is displaced slightly in the direction of the flow. Finally, the flow rate affects
the angle in which flow enters the aneurysm from the parent vessel. This change in the flow angle affects the
flow within the aneurysm. A higher flow rate in the parent artery increases the incident angle which brings the
centre of rotation closer to the geometric centre of the aneurysm, this changes the location and magnitude of
high velocities and hence the local wall shear stress (WSS) on the wall of the aneurysm. This may have
implications in the evolution of aneurysms.Mechanical and Industrial Engineering
Book chapters on the topic "Stereolithography SLA"
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Kwon, Hong Kyu, and Jung Sik Kim. "Hybrid Tooling Using High Speed Cutting and Ceramic Filled SLA (StereoLithography Apparatuses) Technologies." In Materials Science Forum, 351–54. Stafa: Trans Tech Publications Ltd., 2007. http://dx.doi.org/10.4028/0-87849-431-6.351.
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Mwema, Fredrick M., and Esther T. Akinlabi. "Metal-Arc Welding Technologies for Additive Manufacturing of Metals and Composites." In Advances in Civil and Industrial Engineering, 94–105. IGI Global, 2020. http://dx.doi.org/10.4018/978-1-7998-4054-1.ch005.
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Additive manufacturing (AM) technology has been extensively embraced due to its capability to produce components at lower cost while achieving complex detail. There has been considerable emphasis on the development of low-cost AM technologies and investigation of production of various materials (metals, polymers, etc.) through AM processes. The most developed techniques for AM of products include stereolithography (SLA), fused deposition modelling (FDM), laser technologies, wire-arc welding techniques, and so forth. In this chapter, a review of the wire-arc welding-based technologies for AM is provided in two-fold perspective: (1) the advancement of the arc welding process as an additive manufacturing technology and (2) the progress in the production of metal/alloys and composites through these technologies. The chapter will provide important insights into the application of arc welding technology in additive manufacturing of metals and composites for advanced applications in the era of Industry 4.0.
Conference papers on the topic "Stereolithography SLA"
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Van Derlofske, John F., David D. Lamb, and Lloyd W. Hillman. "Stereolithography Apparatus (SLA) Prototyping of Aspheric Surfaces for Automotive Illumination." In International Congress & Exposition. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 1999. http://dx.doi.org/10.4271/1999-01-0302.
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Kataria, Alok, and David W. Rosen. "Building Around Inserts: Methods for Fabricating Complex Devices in Stereolithography." In ASME 2000 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2000. http://dx.doi.org/10.1115/detc2000/mech-14206.
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Abstract One of the most common Rapid Prototyping (RP) technologies, the stereolithography apparatus (SLA) fabricates 3-dimensional parts using a layer-based, additive fabrication process by tracing part cross-sections on the top surface of a vat of liquid photopolymer. Typically, usage of the SLA process has been limited to piece parts. We are interested in greatly expanding the application of SLA and other RP technologies by fabricating assemblies of parts as working mechanisms or static, complex structures which we call “live” or “smart” models. To accomplish this, we are investigating methods for building around embedded components, where these components are motors, printed circuit boards, metal bushings, etc. In this paper, we present example prototypes to illustrate the power of building around inserts (embedded components). We report on our problem formulation and a solution approach in the form of a procedure for building around inserts. We believe that our procedure and results lend insight into promising new applications of SLA technology, as well as novel methods of implementing additional functionality into SLA and other RP technologies.
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Song, Xuan, Zhuofeng Zhang, Zeyu Chen, and Yong Chen. "A Stereolithography-Based Sugar Foaming Method for Porous Strucutre Fabrication." In ASME 2016 11th International Manufacturing Science and Engineering Conference. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/msec2016-8826.
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Porous structure has wide application in industry, thanks to some of its special properties such as low density, low thermal conductivity, high surface area and efficient stress transmission. Both templating and foaming agent methods are used to fabricate porous structures. However, these methods can only produce simple geometries. In recent years, many research studies have been done to use additive manufacturing (AM), e.g. stereolithography (SLA), in the fabrication of porous structure, but the porosity that can be achieved is relatively small due to their limited accuracy in building micro-scale features on a large area. This paper presents a projection based SLA process to fabricate porous polymer structures using sugar as the foaming agent. With a solid loading of 50wt% of the sugar in the resin, the method can achieve a porosity over 50%. This method can be used to increase the porosity achieved by current SLA methods by over 100%.
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Kirschman, C. F., C. C. Jara-Almonte, A. Bagchi, R. L. Dooley, and A. A. Ogale. "Computer Aided Design of Support Structures for Stereolithographic Components." In ASME 1991 International Computers in Engineering Conference and Exposition. American Society of Mechanical Engineers, 1991. http://dx.doi.org/10.1115/cie1991-0055.
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Abstract Stereolithography is a process used to rapidly produce polymer components directly from a computer representation of the part. Support structures, required for all parts built this way, are used to support a component during the build but are removed once building is complete. They anchor the component to the platform and prevent distortion, and are designed simultaneously with the component. A software package to aid the designer is under development at Clemson University. The Clemson Intelligent Design Environment for Stereolithography (CIDES) serves as an interface between the CAD systems and the SLA, cornbining utilities and research efforts. One aspect of this is the automatic support generation algorithm, which designs support structures using knowledge gained from experimentation and experts. The algorithm uses a stereolithographic format representation of a part and gives the user several design options. It then produces both base and projection supports. Output is in slice-ready form.
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Ye, Hang, Chi Zhou, and Wenyao Xu. "Image Based Slicing and Tool Path Planning for Hybrid Stereolithography Additive Manufacturing." In ASME 2016 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/detc2016-60245.
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Hybrid stereolithograpgy (SLA) process synthesizes the laser scanning based SLA system and mask projection based SLA system. It adopts laser as the energy source for scanning the border of a 2D pattern, whereas a mask image is used to solidify the interior area. By integrating the merits of the two subsystems, the hybrid SLA process can achieve relatively high surface quality without sacrificing the productivity. For the hybrid system, closed polygon contours are required to direct laser scanning, and a binary image is also needed for mask projection. We proposed a novel image based slicing method. This method can convert the 3D model into a series of binary images directly, and each image is corresponding to the cross-session of the model at a specific height. Based on the resultant binary image, we use image processing method to gradually shrink the image. The contours of shrunk image are traced and then restored as polygons to direct the laser spot movement. The final shrunk image will serve as the input for mask projection. The experimental result of several test cases demonstrate that proposed method is substantially more time-efficient than traditional approaches.
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Rebaioli, Lara, and Irene Fassi. "Experimental Investigation of Microfluidic Feature Manufacturing by Digital Light Processing Stereolithography." In ASME 2020 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/detc2020-22415.
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Abstract Lab on Chips (LOCs) are devices, mostly based on microfluidics, that allow to perform one or several chemical, biochemical or biological analysis in a miniaturized format on a single chip. The Additive Manufacturing processes, and in particular the Digital Light Processing stereolithography (DLP-SLA), could quickly produce a complete LOC with high resolution 3D features in a single step, i.e. without the need for assembly processes, and using low cost and user-friendly desktop machines. However, the potential of DLP-SLA to produce non-planar channels or channels with complex sections has not been fully investigated yet. This study proposes a benchmark artifact (including also some channels with their axis lying in a plane parallel to the machine building platform) aiming at assessing the capability and performance of DLP-SLA for manufacturing microfeatures for microfluidic devices. A proper experimental campaign was performed to evaluate the effect of the main process parameters (namely, layer thickness and exposure time) on the process performance. The results pointed out that both the process parameters influence the quality and dimensional accuracy of the analyzed features.
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Dornfeld, William H. "Direct Dynamic Testing of Stereolithographic Models." In ASME 1994 International Gas Turbine and Aeroengine Congress and Exposition. American Society of Mechanical Engineers, 1994. http://dx.doi.org/10.1115/94-gt-271.
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Model testing has long been used to validate, augment, or replace structural analysis. Choice of the extent of model usage depends on the time, budget, and skills available, and upon the complexity of the structure and the consequences of the results. In particular, plastic models have seen significant usage in understanding the static and dynamic behavior of many different industrial structures. Today’s ability to generate scaled plastic models directly from 3D CAD geometry models via stereolithography (SLA) has opened a new chapter on model testing. SLA models are easily size-scaled and quickly produced, and some SLA polymers have mechanical properties that are well suited for dynamic testing. The use of SLA models makes possible early testing and accelerated test development work that can reduce costs and shrink the product development cycle. This paper describes the elements of using SLA plastic models for dynamic testing, including size and frequency scaling. Examples of SLA applications at Textron Lycoming for rap/shaker testing and for holography are discussed.
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Xu, Kai, and Yong Chen. "Mask Image Planning for Deformation Control in Projection-Based Stereolithography Process." In ASME 2012 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/detc2012-71523.
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In this research, we investigate the shrinkage related deformation control for a mask-image-projection-based Stereolithography process (MIP-SL). Based on a Digital Micromirror Device (DMD), MIP-SL uses an area-processing approach by dynamically projecting mask images onto a resin surface to selectively cure liquid resin into layers of an object. Consequently, the related additive manufacturing process can be much faster with a lower cost than the laser-based Stereolithography Apparatus (SLA) process. However, current commercially available MIP-SL systems are based on Acrylate resins, which have bigger shrinkages than epoxy resins that are widely used in the SLA process. Consequently controlling size accuracy and shape deformation in the MIP-SL process is challenging. To address the problem, we evaluate different image exposing strategies for projection mask images. A mask image planning method and related algorithms have been developed for the MIP-SL process. The planned mask images have been tested by using a commercial MIP-SL machine. The experimental results illustrate that our method can effectively reduce the deformation by as much as 32%. A discussion on the test results and future research directions are also presented.
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Ye, Hang, Sonjoy Das, and Chi Zhou. "Investigation of Separation Force for Bottom-Up Stereolithography Process From Mechanics Perspective." In ASME 2015 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/detc2015-47673.
Full textAbstract:
Relative to the free surface stereolithography (SLA) process, the bottom-up process has several advantages that include better vertical resolution, higher material filling rate, less production time, and less waste of photopolymer materials. However, one of the major concerns of the bottom-up SLA process is that the built-up part may break due to the resultant force generated during the pulling up process. This resultant force may become significant if the adhesive mechanism between the two contact surfaces (i.e., newly cured layer and the bottom of the resin vat) produces a strong bonding characteristic. In this work, the traction force is monitored using FlexiForce® force sensors. The experimental data are analyzed in order to obtain the initial guess for the fracture properties of the separation process. Then the separation process has been modelled based on the concept of Cohesive Zone Model (CZM) in order to study crack propagation behavior in the field of fracture mechanics. The classic bi-linear traction-separation law is adopted in the present work as the nominal constitutive law that relates the resultant traction stress and the separation distance between the two contact surfaces. The results from simulation are compared with experimental data, a good agreement for maximum traction force is found, and the discrepancy is discussed.
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Wu, Siqi, and Erol Sancaktar. "3D-Printed Polymeric Metamaterial Recovery Behavior After Large Deformation." In ASME 2020 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/detc2020-22361.
Full textAbstract:
Abstract Human-made lattice mechanical metamaterials have recently been shown to exhibit better stiffness or tunable properties than natural materials. We demonstrated that body-centered-cubic (BCC) metamaterials made by 3D-printer stereolithography (SLA) display good recovery properties after undergoing cyclic large compressive deformation. Our experimental results reveal that the strut thickness of BCC metamaterials affect the recovery and mechanical behaviors during compression.