Dissertations / Theses: 'Printing process'

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Yusof, Mohd Sallehuddin Bin. "Printing fine solid lines in flexographic printing process." Thesis, Swansea University, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.595794.

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Solid lines are essential to enable printing of conducting tracks for various electronic applications. In the flexographic printing process, the behaviour of the printing plate plays a vital role in how ink is printed onto the substrate as it deforms when passing through the printing nip. This deformation is dependent on the material properties of the plate, the geometry of the lines and the pressure within the printing nip. These will influence the printed track width and the ink film thickness, which will affect the electrical performance of the printed conductors. This thesis will focus on experiments on Flexographic printing capabilities in printing ultra fine solid lines. The development of a measurement technique which leads to successfully capturing the printing plate line geometry details through the application of interferometry techniques, will be demonstrated. This information is used in a Finite Element models to predict the deformation and consequent increase in line width using both a linear and non linear material models, the latter being based on a hyperelastic representation. A series of experiments on a bench top printer and a web press machine to determine the capabilities and the limitation of the Flexographic printing process in printing fine solid is also presented. Through the experiments conducted the link between the IGT -Fl printer and an industrial scale web press machine has been established where the success in study on certain printing parameters and its affects lead to a successful prints of 50llm line width with 50llm line gaps. The experiments also point the importance of light engagement pressures within the printing train and the requirements for using ani lox cylinders having fine engraving. The work also shows than process parameters (e.g. contact pressures) that are important for graphics printing have a similar effect when the processes is used to print fine line features.

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Arbrim, Ferati. "3D printing with pellets and smart monitoring of the printing process." Thesis, Högskolan i Halmstad, Akademin för företagande, innovation och hållbarhet, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-44696.

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Additive manufacturing (AM) is a set of different techniques which use layer by layer deposition principle to join material together and manufacture three-dimensional objects from a CAD file. One of the most known and popular techniques within AM is Fused Deposition Modeling (FDM). Generally, the FDM process starts with a feedstock of filament which is pushed through an extruder head, which liquefies the filament and deposits it down on the print bed according to a specific pattern specified by the CAD file. This technique has found great success within the industry and has been adopted by many companies across many different applications such as automotive, aerospace and medical for rapid prototyping. The disadvantage with filaments is that the diameter tolerances are quite small which makes it expensive and difficult to manufacture. Another problem with 3D printing is the waste of money and time due to failed prints, both in the industry but also with private users. This is a result of not having a monitoring system that overwatches the printing process and stops the print when it detects defects, as the user usually does not stand by the printer and watch the whole process. The main aim of this study is to modify a desktop 3D printer to suit and install a pellet extruder and to investigate the feasibility of process monitoring for desktop printers. To evaluate the printability of the pellet extruder, tensile test artifacts are printed with PLA 4043D and TPE_S16300C in two different raster orientations and three different layer thicknesses, further, the influence of raster orientation and layer thickness on ultimate tensile strength is evaluated. Raster orientation refers to the different directions of the individual bead paths within a layer and layer thickness refers to the height of each layer that is deposited along the Z-axis. In this study, the pellet extruder was successfully installed on the Sovol SV01 printer. The open-source process monitoring system called the spaghetti detective was used during the experiments to monitor the 3D printing process. It uses a failure detection system (AI) to detect defects and automatically stop a print if defects are detected and alert the user via email or text. The tensile test artifacts were only printed with TPE_SE16300C and due to limitations in the pellet extruder, it is observed that tensile test samples were difficult to 3D print with PLA4043D. Regardless of the layer thickness, the 45°/-45° raster orientation produced a slightly higher ultimate tensile strength than the 0°/90° raster orientation. As for the influence of layer thickness on ultimate tensile strength, the increase of layer thickness in the 0°/90° raster orientation led to a decrease in ultimate tensile strength. In the 45°/-45° raster orientation no clear conclusion could be made as the differences were insignificant.

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Gante, Lokesha Renukaradhya Karthikesh. "Metal Filament 3D Printing of SS316L : Focusing on the printing process." Thesis, KTH, Maskinkonstruktion (Avd.), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-259686.

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As a cutting edge manufacturing methodology, 3D printing or additive manufacturing (AM) brings much more attention to the fabrication of complex structure, especially in the manufacturing of metal parts.A number of various metal AM techniques have been studied and commercialized. However, most of them are expensive and less available, in comparison with Selective Laser Melting manufactured stainless steel 316L component.The purpose of this Master Thesis is to introduce an innovative AM technique which focuses on material extrusion-based 3D printing process for creating a Stainless Steel 316L part using a metal-polymer composite filament. The Stainless Steel test specimen was printed using an Fused Deposition Modelling based 3D printer loaded with a metal infused filament, followed by industrial standard debinding and sintering process. Investigation was performed on the specimen to understand the material properties and their behaviour during the postprocessing method. In addition effects of debinding, sintering and comparison of the test Specimen before and after debinding stages was also carried out. Metal polymer filaments for 3D printing could be an alternative way of making metal AM parts.
Som en avancerad tillverkningsmetodik ger 3D-printing eller additiv tillverkning (AM) mycket mer uppmärksamhet vid tillverkning av komplex struktur, särskilt vid tillverkning av metallkomponenter. Ett antal olika AM-tekniker vid tillverkningen av olika typer av metallkomponenter har studerats och kommersialiserats.De flesta av dessa AM-tekniker är dyra och mindre tillgängliga, i jämförelse med Selective Laser Melting vid tillverkningen av en komponent i rostfritt stål 316L. Syftet med detta examensarbete är att introducera en innovativ AM-teknik som fokuserar på materialsträngsprutningsbaserad 3D-printingprocess för att skapa ekomponent i rostfritt stål 316Lkomponent med ett metallpolymerkompositfilament. Ett prov bestående av rostfritt stål skrevs ut med en FDM-baserad 3D-skrivare laddad med filament av polymer och metal, följt av industriell avdrivnings-och sintringsprocess. Provet studerades för att förstå materialegenskaperna och dess beteende under efterbehandlingsmetoden. Dessutom genomfördes också resultat från avdrivning och sintring på provet och en jämförelse av provet före och efter avdrivnlngssteget. Metallpolymertrådar för 3D-printing kan vara ett alternativt sätt att tillverka AM-metallkomponenter.

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Nagubadi, Rajendra. "Fluting in Heatset Web Offset Printing Process." Fogler Library, University of Maine, 2007. http://www.library.umaine.edu/theses/pdf/NagubadiR2007.pdf.

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Salgado-Bierman, Andrés. "In-process measurement of micro-contact printing." Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/105681.

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Thesis: S.B., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2016.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 42-43).
In micro contact printing, a polymer stamp with sub micron features is use to pattern a substrate. Micro contact printing has many applications including micro machined circuits and miniaturized biological test kits. Success in printing has been achieved in limited batch processing of plate to plate printing. The physics and chemistry of stamp contact and ink transfer has been studied. To make micro contact printing economically viable developments have been made to advance a roll to roll configuration. Roll to roll processing offers the potential of high volume low cost micro manufacturing similar to the high volume achieved by roll to roll processing for traditional lithography. Roll to roll micro contact printers have been built at the lab scale. The process has been demonstrate to have the potential for rapid high volume production. The current limitation is in the quality of the print. Features on the stamp are printed with defects such as breaks or undesired patterning. The source of failure lies with the contact of the stamp; the stamp either breaking contact or collapsing to allow areas outside of the features to make contact. A barrier to better understanding and controlling contact during the printing process has been a lack of in-process measurement. This thesis examines the use of a new optical set-up to monitor stamp contact in-process on a lab level roll to roll micro contact printer. Image based measures of stamp contact quality are presented.
by Andrés Salgado-Bierman.
S.B.

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Fox, Ian James. "Ink flow within the screen-printing process." Thesis, Swansea University, 2002. https://cronfa.swan.ac.uk/Record/cronfa42565.

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Screen-printing is one of the oldest printing processes, yet its market share remains very limited due to its slower printing speeds compared to the other available processes. This is mainly because of the reciprocating motion of the squeegee upon the printing screen. In order for screen-printing to become more competitive, the concept of a high-speed continuous belt screen-printing press was developed. However, this will produce an increase in squeegee wear and friction of the squeegee upon the screen. For this reason, this work investigated the use of a roller squeegee that could rotate across the screen. It has been proven that screen-printing with a roller squeegee can be successfully achieved. Additionally, in terms of density and tone gain, these images were comparable to those produced with traditional blade squeegees. A numerical model has been developed to simulate the characteristics that will be encountered within the ink film when printing with a roller squeegee. Numerical simulations were run where the settings corresponded to the parameters utilised in experimental trials. Here, it was discovered that an increase in squeegee diameter will increase the ink film on the squeegee and will also increase the contact width of the screen upon the substrate. This will have the effect of increasing the pumping capacity of the squeegee, which will therefore increase the ink deposit. This was confirmed in the experimental trials. It was also shown that the locking of the squeegee increased the shear mechanism within the ink film, resulting in a reduction in the ink viscosity within the nip contact region. This had the effect of reducing the ink film thickness on the squeegee, which reduces the pumping capacity of the squeegee, thus producing a reduced ink deposit. Additionally, this work is the first method that has been able to estimate the height of the ink deposit for a range of halftone open areas where the results correspond almost identically to the actual printed heights of the prints obtained in experimental studies. This work has improved the fundamental understanding of the mechanics and the process physics within the ink transfer mechanism in the screen-printing process. Use of experimental and numerical models has resulted in new theories being developed that will further the knowledge of the process. This has led to the design and manufacture of a high-speed rotary screen-printing press that will enable high-speed, continuous screen-printing.

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Richards, Blair. "A comparison of staggered position one angle process color printing with four angle and one angle process color printing /." Online version of thesis, 1988. http://hdl.handle.net/1850/10419.

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Taroni, Michele. "Thin film models of the screen-printing process." Thesis, University of Oxford, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.540261.

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Nawaby, Arghavan Victoria. "Process optimization and monitoring in the printing industry." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0007/NQ42802.pdf.

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Bougàs, Aristotelis Platon. "Influence of ink sequence on color's hue and saturation in four color halftone screen printing /." Online version of thesis, 1993. http://hdl.handle.net/1850/11080.

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Vergara, Jose, and n/a. "Conservation of intaglio prints : conservation principles applied during the printing process can improve the life span of prints." University of Canberra. Applied Science, 1989. http://erl.canberra.edu.au./public/adt-AUC20061109.172054.

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This research into intaglio printing, its materials and techniques, deals with the three main conservation problems specific to the process. They are: acidity of the paper, buckling and/or tearing along the printed edge of the plate caused by excess pressure during printing, and yellow/brown staining, or halo, around the printed image. Research done in the cause of this study reveals that these problems are not confined to contemporary printmaking practices, as believed by some conservators, but can be traced back to the historic beginnings of the Intaglio Printing. The results of the analyses and tests performed in this investigation indicate that these problems can be partially, if not completely, eliminated by simple and inexpensive improvements to the process of printing. 1 - An alkaline solution, used to dampen the paper prior to printing, will act as a buffer, making the paper resistant to future attack from acids. Importantly, it will also accelerate the drying of the ink, which is essential to the production of a thick solid ink-film. 2 - Excessive pressure during printing destroys the natural resilience of the paper within the printed area and should be kept to a minimum. Plates that have not been bevelled sufficiently can also be very harmful to the paper, cutting and/or tearing paper fibres. These problems are not visually evident after printing, but are ultimately very detrimental to the life of the print. 3 - The traditional method of drying prints, between blotters and under weight, is a major cause of the yellow/brown staining, or halo, formed around the printed image. The vehicle in the ink, a product of linseed oil, normally dries by polymerization and oxidation reaction with oxygen from the atmosphere. Press-drying retards this reaction causing the paper to absorb part of the vehicle. Air-drying accelerates the drying process, producing a much thicker and stronger ink-film and reducing absorption of the vehicle into the paper. Although air-drying will produce buckling, this can be easily remedied after seven days by dampening the print and press-drying.

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Handy, John R. "Line reproduction in mapping utilizing the four color process model /." Online version of thesis, 1992. http://hdl.handle.net/1850/11167.

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Ba'adarani, Amal A. "A study on doubling in the offset printing process /." Online version of thesis, 1989. http://hdl.handle.net/1850/11546.

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Ibrahim, David N. M. "Mathematical modelling of the electro-thermal ribbon printing process." Thesis, Manchester Metropolitan University, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.359738.

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Braunstein, Daniel J. (Daniel Judah). "Real time process monitoring of solder paste stencil printing." Thesis, Massachusetts Institute of Technology, 1994. http://hdl.handle.net/1721.1/35374.

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El, Baradai Oussama. "Elaboration of flexible lithium - ion electrodes by printing process." Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENI036/document.

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Le travail présenté dans ce mémoire concerne la réalisation des batteries souples lithium-ion. Il a comme objectif le développement de nouveaux procédés comme l'impression par sérigraphie pour la fabrication de batteries et le remplacement des polymères issus de la chimie de synthèse par des matériaux bio-sourcés utilisables en milieu aqueux. Les résultats obtenus ont montré qu'il est possible de formuler des encres aqueuses à base des matériaux actifs classiquement utilisés pour l'élaboration d'électrodes (anode et cathode) de batterie Li-ion mais avec des liants dérivés de cellulose en substitution du PVDF qui intègre les formulations standards. Cette encre, dont les propriétés rhéologiques sont compatibles avec le procédé d'impression sérigraphique, permet l'obtention d'électrodes présentant des propriétés spécifiques aux bons fonctionnements de la batterie. Les résultats obtenus ont montré que cette technique d'impression du séparateur pouvait être utilisée pour remplacer la technique de déposition classique des matières actives sur les collecteurs de courant, basée sur un procédé d'enduction à lame (blade coating). Enfin, une batterie lithium-ion imprimée a pu être élaborée en utilisant la stratégie d'impression recto/verso du séparateur avec l'intégration des collecteurs de courant pendant la phase d'impression, validant ainsi cette nouvelle technique d'assemblage
The work presented in this manuscript describes the manufacturing of lithium-ion batteries on papers substrates by printing technique. Its aim is the development of new up scalable and large area techniques as screen printing for the fabrication of lithium-ion batteries and the replacement of conventional toxic components by bio-sourced one and water based solvent. First results shows how it is possible to formulate cellulose based ink tailored for screen printing technology with suitable properties for lithium-ion batteries requirements. Electrodes were manufactured and tested from a physical and electrochemical point of view and two strategies were proposed to enhance performances. Finally, by considering results obtained for the electrodes, a full cell was manufactured with a new assembling strategy based on: front / reverse printing approach and the embedding of the current collectors during printing stage. As a final point cells were characterized and compared with others obtained by conventional assembling strategies

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Habib, MD Ahasan. "Designing Bio-Ink for Extrusion Based Bio-Printing Process." Diss., North Dakota State University, 2019. https://hdl.handle.net/10365/32045.

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Tissue regeneration using in-vitro scaffold becomes a vital mean to mimic the in-vivo counterpart due to the insufficiency of animal models to predict the applicability of drug and other physiological behavior. Three-dimensional (3D) bio-printing is an emerging technology to reproduce living tissue through controlled allocation of biomaterial and cell. Due to its bio-compatibility, natural hydrogels are commonly considered as the scaffold material in bio-printing process. However, repeatable scaffold structure with good printability and shape fidelity is a challenge with hydrogel material due to weak bonding in polymer chain. Additionally, there are intrinsic limitations for bio-printing of hydrogels due to limited cell proliferation and colonization while cells are immobilized within hydrogels and don’t spread, stretch and migrate to generate new tissue. The goal of this research is to develop a bio-ink suitable for extrusion-based bio-printing process to construct 3D scaffold. In this research, a novel hybrid hydrogel, is designed and systematic quantitative characterization are conducted to validate its printability, shape fidelity and cell viability. The outcomes are measured and quantified which demonstrate the favorable printability and shape fidelity of our proposed material. The research focuses on factors associated with pre-printing, printing and post-printing behavior of bio-ink and their biology. With the proposed hybrid hydrogel, 2 cm tall acellular 3D scaffold is fabricated with proper shape fidelity. Cell viability of the proposed material are tested with multiple cell lines i.e. BxPC3, prostate stem cancer cell, HEK 293, and Porc1 cell and about 90% viability after 15-day incubation have been achieved. The designed hybrid hydrogel demonstrate excellent behavior as bio-ink for bio-printing process which can reproduce scaffold with proper printability, shape fidelity and higher cell survivability. Additionally, the outlined characterization techniques proposed here open-up a novel avenue for quantifiable bio-ink assessment framework in lieu of their qualitative evaluation.

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Laughlin, Kelly. "An investigation of amplitude & frequency modulated screening on dot gain and variability /." Online version of thesis, 1994. http://hdl.handle.net/1850/12162.

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Sun, Changlong. "Investigation into Ink Transfer Media for the Lithographic Printing Process." Thesis, University of Leeds, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.485639.

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This study focused on ink transfer media for the lithographic print process. Rubber blanket is the offset media for ink transfer from plate to substrate. Performance of the rubber blanket is important for successful image reproduction. Thus, this ', project intended to develop a blanket for the lithographic print process that has good sheet release, good ink release, good dot reproduction, good solid reproduction (no pin-holing) and low swelling. The blanket should also maintain its compressibility and be capable of running metallic inks, UV inksÃ‚Â· and conventional inks with no significant detrimental effect to the printing surface. Various surface layer compounds for a lithographic print blanket were formulated, with the aid of Minitab, and blankets were made according to the designed formulations. Evaluation work on the blankets for hardness, solvent resistance, critical surface tension, ink transfer, durability and quality of print was then carried out. Consequently, correlations of these characteristics with each blanket material component were studied. It was found that the hardness and the durability of the blanket were influenced by the content of the crosslinking agent and the reinforcing agent within the rubber compound. The solvent resistance and the ink transfer of a 'blanket were influenced by the content of nitrile within the rubber compound. The critical surface tension could be controlled by the change of speed of compound drying and the ingredients or by surface treatment. Following the studies carried, a blanket having significantly improved performance properties was developed. Also, interactions between blanket wash solvents and surface layer' rubber of blanket were studied with the help of FT-IR and GC-MS. It was found that solvent penetration into the surface rubber of a blanket, upon prolonged contact, was the main cause for blanket swell. Plasticisers were easily extracted from the surface rubber of a blanket by the blanket wash solvent, which resulted in a c:1taD&e I()i performance.

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Mitchell, M. C. "An experimental and analytical investigation of screen printing process fundamentals." Thesis, Nottingham Trent University, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.266912.

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Galla, Matthew Peter. "Process development for three dimensional printing of metal loaded binders." Thesis, Massachusetts Institute of Technology, 1994. http://hdl.handle.net/1721.1/11610.

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Michaels, Steven P. (Steven Patrick). "Production of metal parts using the three dimensional printing process." Thesis, Massachusetts Institute of Technology, 1993. http://hdl.handle.net/1721.1/8191.

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Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, February 1994.
Includes bibliographical references (leaf 81).
Three Dimensional Printing is a process for the rapid fabrication of three dimensional parts directly from computer models. A solid object is created by printing a sequence of two dimensional layers. The creation of each layer involves the spreading of a thin layer of powdered material followed by the selective joining of powder in the layer by ink-jet printing of a binder material. Commands to modulate the binder stream are derived from CAD data. Unbound powder temporarily supports unconnected portions of the component, allowing overhangs, undercuts and internal volumes to be created. The unbound powder is removed upon process completion, leaving the finished part. The Three Dimensional Printing process was initially developed to create alumina/silica molds for metal casting. A new process was developed to allow the 3DP system to directly fabricate metal parts. Stainless steel powder was layered in the powder bed and selectively joined by a latex polymer binder. Upon process completion, the powder bed was fired in an oven to cure the polymer in the printed regions. The resulting green part, a metal powder/polymer composite, could then be removed from the powder bed. The green part had properties similar to parts produced by the Metal Injection Molding process used in industry. Two sizes of spherical stainless steel powder, 20 and 75[mu]m, were used to print parts. These powders produced parts with green densities approaching 60%. Two types of water-based, thermosetting acrylic polymers, one an emulsion and the other a sol, were used as binders. These binder materials were compatible with the existing printhead and produced parts with satisfactory green strength. Using techniques borrowed from the fields of Powder Metallurgy and Metal Injection Molding, post-processing methods to debind, sinter and infiltrate the green printed parts were developed. An infiltrated 3D Printed part was used as a tooling insert to injection mold several polypropylene parts. Many new printing phenomena, previously unseen during the printing of alumina/silica parts, were observed during the creation of a printing process for metal parts. A process development strategy was devised which allowed these new printing problems to be systematically solved. The 3D Printing process was analyzed by dividing it into discrete steps and then modifying each of these steps to allow printing of metal parts. This process development strategy is generic and can be used to adapt the 3D Printing process to other materials systems in the future.
by Steven P. Michaels.
M.S.

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Broggio, Jorge A. (Jorge Antonio) 1975. "Fluid damping with elastic medium in 3-D printing process." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/9569.

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Beynon, David George. "Plate to substrate ink transfer in the flexographic printing process." Thesis, Swansea University, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.595861.

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Investigations have been conducted into the transfer of ink from the plate to the substrate in flexographic printing. Four experimental trials have been conducted at full press scale in order to investigate process parameters including substrate type and the effect of over printing previously printed ink. In order that the shape of printed dots could be analysed methods for the determination of plate dot circularity and printed dot circularity were developed. Accurate measurement of the printing plates used in the experimental investigations has revealed significant differences in nominally identical patches within the same plate. Dot size and geometry was found to be permanently altered through the application of pressure in the plate/anilox nip. The volume of ink supplied to the plate is found to have the largest effect on ink transfer to the substrate. Increases in anilox volume and engagement between plate and substrate are found to increase ink spreading. Decreasing viscosity reduces ink transfer to the plate from the anilox which in tum results in lower ink spreading for individual dots. Joined dots however show an increase in ink spreading due to increased entrapment of ink at the nip entrance. The shape of printed dots is found to be affected by the volume of ink transfer and by engagement. Larger dot volumes increase dot circularity and larger engagements reduce dot circularity. The effect of under printed ink on ink transfer of subsequently printed ink is dependent on the coverage of under printed ink and the substrate being printed. For non porous substrate the under printed ink acts as a barrier to ink spreading. On porous substrate the density of samples is increased due to the under print filling surface pores increasing ink spreading for subsequently printed ink. The effect of under print is visible for all substrates and over print coverage's.

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Hasan, Muhammad Noman. "Numerical Analysis of Droplet and Filament Deformation for Printing Process." University of Akron / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=akron1405951774.

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Chen, Ted. "A study of color image quality with respect to screen angle arrangement in multicolor halftone printing /." Online version of thesis, 1987. http://hdl.handle.net/1850/9674.

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Adamcewicz, Justine E. "A study on the effects of dot gain, print contrast and tone reproduction as it relates to increased solid ink density on stochastically screened images verus conventionally screened images /." Online version of thesis, 1994. http://hdl.handle.net/1850/11989.

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Anderson, John Thomas. "An investigation into the physical aspects of the screen printing process." Thesis, Swansea University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.521493.

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Ercan, Saybil Nuray. "The influence of process parameters on filament size distribution." Fogler Library, University of Maine, 2001. http://www.library.umaine.edu/theses/pdf/ErcanSN2001.pdf.

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Davis, Claude David. "Effects of exposure on the printing characteristics of the association product process /." Online version of thesis, 1988. http://hdl.handle.net/1850/10317.

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Lim, Michael Gerald Go. "A study on understanding the use of process color-based color communication systems to print synthetic colors accurately and consistently /." Online version of thesis, 1994. http://hdl.handle.net/1850/11884.

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Chen, Li-Wen. "Multiple comparisons on near neutral calibration process among different printing processes." Connect to this title online, 2008. http://etd.lib.clemson.edu/documents/1211398568/.

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Laghi, Vittoria <1992&gt. "Study of innovative steel 3D-printing process for structural engineering applications." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2021. http://amsdottorato.unibo.it/9726/1/Tesi_Dottorato_Laghi_rev_def.pdf.

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Over the last decade, Additive Manufacturing (AM) has gained wide importance on several industrial fields, with however severe limitations in the dimensions on the outcomes, constrained to the limits imposed by the printer environment. As such, the applications of these innovative manufacturing technologies in construction have been limited to few explorations on small pieces, to be used as connection parts. With the advent of a new weld-based AM process, referred to as Wire-and-Arc Additive Manufacturing (WAAM), the scale of the printed outcomes increased up to several meters span, thus becoming suitable for real-scale applications in construction. Nonetheless, the outcomes from the printing process require specific considerations for structural design purposes in terms of geometrical irregularities and marked anisotropy As such, the study is focused on the characterization of WAAM-produced 308LSi stainless steel for structural applications and divided in three parts: Part A, Part B and Part C. Part A and B are devoted to study the so-called “continuous printing” strategy, to realize planar elements, and “dot-by-dot printing” strategy, to realize lattice and rod-like elements, respectively. Both parts are articulated as follows: (i) definition of a suitable design approach from the specifics of the printing process; (ii) experimental characterization of the WAAM-produced elements from the microstructural, geometrical and mechanical points of view; (iii) calibration of an orthotropic material model and definition of first design guidelines (according to Eurocode provisions); (iv) exploration of topologically-optimized shapes for new structural members realized with WAAM. Part C is devoted to present new technologies and future developments on WAAM applications in construction. It is articulated as follows: (i) presentation of a new mobile 3D printing system; (ii) exploration of new perspectives for real-time monitoring systems.

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Patel, Shachi. "Determining the effect of printing ink sequence for process colors on color gamut and print quality in flexography /." Online version of thesis, 2009. http://hdl.handle.net/1850/8020.

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Latanision, Ivan M. "A comparison between the staggered position one-angle screening and the multi-angle screening method in terms of misregistration when printing process color on newsprint /." Online version of thesis, 1992. http://hdl.handle.net/1850/11251.

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36

Esterman, Marcos. "Characterization of the powder/binder interaction in the three dimensional printing process." Thesis, Massachusetts Institute of Technology, 1990. http://hdl.handle.net/1721.1/13671.

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Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1990.
Title as it appears in the Sept. 1990 M.I.T. Graduate List: Characterization of powder/binder interaction in the three dimensional printing process.
Includes bibliographical references (leaves 131-132).
by Marcos Esterman, Jr.
M.S.

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37

Hale, Melinda (Melinda Rae). "Manufacturing conductive patterns on polymeric substrates : development of a microcontact printing process." Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/81752.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2013.
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (p. 215-233).
The focus of this research was to develop a process suitable for creating very high resolution conductive patterns on polymer substrates, in a way that can be scaled to high volume manufacturing. The original motivation for this work came from the problem of manufacturing electrodes on microfluidic devices (which in volume production are commonly formed from polymers), but the findings of this work also have applications in flexible electronics, optics, surface patterning, organic micromanufacturing, and photovoltaics. After an initial exploration of various micromanufacturing processes, microcontact printing (μCP) was chosen as the most promising technique for further study. By using μCP to directly pattern conductive inks, this work has demonstrated previously unachievable printing: feature sizes down to 5μm, using liquid inks on polymer substrates, with a process that can be scaled to high-volume production. An understanding of the mechanisms of direct liquid ink transfer was used to identify relevant process input and output factors, and then the process sensitivities of those factors were investigated with a careful design of experiments. From the empirical data, a process model was built with generalized variables. This model was then used to successfully predict behavior of other inks and other substrates, thus validating the model and showing that it is extendable for future work. By developing an empirically verified model of ink transfer at the micron scale, this work has enabled a process for low cost, high volume microfeature patterning over large areas on polymer substrates.
by Melinda Hale.
Ph.D.

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38

Elliott, Amelia M. "The Effects of Quantum Dot Nanoparticles on Polyjet Direct 3D Printing Process." Diss., Virginia Tech, 2014. http://hdl.handle.net/10919/46632.

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Additive Manufacturing (AM) is a unique method of fabrication that, in contrast to traditional manufacturing methods, builds objects layer by layer. The ability of AM (when partnered with 3D scanning) to clone physical objects has raised concerns in the area of intellectual property (IP). To address this issue, the goal of this dissertation is to characterize and model a method to incorporate unique security features within AM builds. By adding optically detectable nanoparticles into transparent AM media, Physical Unclonable Function (PUFs) can be embedded into AM builds and serve as an anti-counterfeiting measure. The nanoparticle selected for this work is a Quantum Dot (QD), which absorbs UV light and emits light in the visible spectrum. This unique interaction with light makes the QDs ideal for a security system since the challenge (UV light) is a different signal from the response (the visible light emitted by the QDs). PolyJet, the AM process selected for this work, utilizes inkjet to deposit a photopolymer into layers, which are then cured with a UV light. An investigation into the visibility of the QDs within the printed PolyJet media revealed that the QDs produce PUF patterns visible via fluorescent microscopy. Furthermore, rheological data shows that the ink-jetting properties of the printing media are not significantly affected by QDs in sufficient concentrations to produce PUFs. The final objective of this study is to characterize the effects of the QDs on photocuring. The mathematical model to predict the critical exposure of the QD-doped photopolymer utilizes light scattering theory, QD characterization results, and photopolymer-curing characterization results. This mathematical representation will contribute toward the body of knowledge in the area of Additive Manufacturing of nanomaterials in photopolymers. Overall, this work embodies the first investigations of the effects of QDs on rheological characteristics of ink-jetted media, the effects of QDs on curing of AM photopolymer media, visibility of nanoparticles within printed AM media, and the first attempt to incorporate security features within AM builds. Finally, the major scientific contribution of this work is the theoretical model developed to predict the effects of QDs on the curing properties of AM photopolymers.
Ph. D.

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39

Dougherty, Joy. "The construction of gender relations and sexuality in the printing labour process." Thesis, Queensland University of Technology, 1995.

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This thesis examines the ways in which gender relations and sexuality are constructed in workplaces within the printing industry, in order to understand how the sexual division of labour - which keeps women workers concentrated in 'unskilled', low status jobs in the bindery, and largely excluded from the male dominated printing trades - is maintained and reproduced. This study focuses on four structures of gender relations in the workplace: sexual division of labour, discrimination, power and sexuality, and explores these structures on three levels: structure, practice and subjectivity. The study analyses the printing labour process in terms of the theoretical issues of gender, sexuality and power from a feminist historical materialist perspective. There is a focus on the dialectical relationship between structure and subjectivity which reproduces both gendered subjectivity and structures of inequality between women and men, through the mediation of social practices and discourses operating in the printing labour process. The research process incorporates a feminist philosophy of 'research with' rather than 'research on', which suggests research methods that explore social relations in their everyday context. In order to explore the ways in which femininity, masculinity and sexuality are constructed, and the ways in which these constructions reproduce the sexual division of labour, the daily social practices operating in five Brisbane printing firms were observed. Two of the five case studies are of large 'hi-tech' printing firms owned and managed by men; three are of small 'low tech' printing firms owned and managed by women. In each case, the methods used are participant observation, informal conversations with workers, informal group discussions, unstructured interviews with management and representatives from the union, employer organisation and industry training council, and documentary analysis. An historical outline of women's participation in the Australian printing industry provides a context for the case studies. The findings from the case studies indicate that little has changed in the patterns of gender relations observed in the printing industry historically, and over the fouryear period of this study. In the two large firms of this study, a conventional sexual division of labour was maintained, women were marginalised, underrepresented, concentrated in low-paid and low status jobs, casualised, and generally perceived by male workers and management as inferior workers. On the other hand, in the small firms, the sexual division of labour was disrupted to varying degrees, women were central to the organisation of work and numerically dominant, women were spread across all the trades, were not casualised, and were valued as workers. In theoretical terms, the findings support other researchers' explanations of how gender and sexuality are socially constructed in the workplace, highlighting the role of the technology/masculinity link in defining the feminine as nontechnological, and thus contributing to the exclusion of women from technical jobs. In addition, the findings point to the significance of the dialectical relationship between structure and subjectivity in reproducing the structures of inequality between women and men, and highlight how this relationship is mediated by practices and discourses operating in the printing labour process. The findings also add to the theorisation of the key role of women managers in achieving sex equality in organisations. In practice, based on the small number of printing firms in this study, it appears that small firms provide the most favourable environment for women, both as employees and managers, in terms of access to non-traditional occupations,multiskilling, recognition of prior learning and informal training, job satisfaction, autonomy and support.

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Dimitrov, D., Beer N. De, and T. Centner. "Product and process innovations by means of rapid technologies." Journal for New Generation Sciences, Vol 4, Issue 1: Central University of Technology, Free State, Bloemfontein, 2006. http://hdl.handle.net/11462/487.

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Published Article
Over the past few years, methods of layered manufacturing (LM) have advanced substantially to the point where they now provide vital strategic benefits to various organisations. One area of application where LM technologies have begun to reach a critical mass is in the development and production of high-performance tooling in different forming processes. With these tooling capabilities now available, the next challenge becomes the development of optimal process chains to minimise lead times and production costs, while still ensuring high quality of castings. The relevant issues that influence where a break-even point will be between different process chains and thereby also the point of selection between such optimal process chains according to different situations include among others:

the size of production runs,
part size and complexity, and
the cast materials involved.

This paper reflects some of the experiences gained from an investigation towards developing a set of generic rules (guidelines) for the design of optimal process chains for sand casting prototypes of automotive components using LM methods, and more specifically the 3D Printing process.

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41

Shaw, Philip T. "A study of vegetable sourced colourants for use in screen process ink production." Thesis, Middlesex University, 2000. http://eprints.mdx.ac.uk/10691/.

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The following investigation aims to determine the potential of plant material to produce pigments capable of acting as alternatives to the standard range of process (CMYK) colours used in screen printing. A review of the literature on so-called `natural dyes' reveals the extent of the pre-synthetic (1857) use of a range of dye-plants in the textile and related industries over a period of many centuries. Several plant sources are identified for investigation in the context of this study. Chemical, botanical and historical aspects of these plants are described along with notes on their cultivation and nomenclature. The necessary thickeners and other additives that may be required for the production of a stable ink formulation are also discussed. The establishment of the Cat Hill Ink Garden is described as well as a discussion of other sources of raw material supply. Methods of aqueous extraction, lake production, comparative light fastness and spectral reflectance testing are all described and test results are provided in appendix form. The environmental, economic and health and safety aspects of the new inks is contrasted with the commercial oil-based product as well as a brief discussion of their potential for commercial development. Printed examples by the author and several of his students form the final part of the study and demonstrate the use of both CMYK and other non-primary ink formulations.

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42

Pawlow, Eric Matthew. "The effects of fluctuations in solid ink density on color variation for conventional and gray component replacement separations when printing process color on newsprint /." Online version of thesis, 1993. http://hdl.handle.net/1850/11676.

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43

Wang, Dein. "An investigation of the applicability of Walker and Fetsko ink transfer equation on and the influence of ink viscosity on heat set ink used on the web offset process /." Online version of thesis, 1987. http://hdl.handle.net/1850/8839.

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Hamblyn, Simon Mark. "The role of the plate in the ink transfer process in flexographic printing." Thesis, Swansea University, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.550883.

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45

Harris, Christopher L. (Christopher Lee). "Characterization of dimensional variability and part bleeding using the three dimensional printing process." Thesis, Massachusetts Institute of Technology, 1990. http://hdl.handle.net/1721.1/13054.

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46

Williams, Paul A. (Paul Andrew). "Three dimensional printing : a new process to fabricate prototypes directly from CAD models." Thesis, Massachusetts Institute of Technology, 1990. http://hdl.handle.net/1721.1/14078.

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Thienen, Stefan, and Thomas Gellner. "Flexible and easy to engineer servo-hydraulic actuators using 3D printing manufacturing process." Technische Universität Dresden, 2020. https://tud.qucosa.de/id/qucosa%3A71208.

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Already since some time, Bosch Rexroth offers solutions as compact servo hydraulic actuators (SHA). Because there are lot of requests from the market, we thought about reducing the inquiry processing time and delivery time by designing a kit system for the SHA solutions. This system should be flexible enough to cover different technical solutions (e.g. cylinder), functionalities and design styles [... aus dem Text]

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48

Grau, Jason Elliot. "Fabrication of engineered ceramic components by the slurry-based three dimensional printing process." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/9584.

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Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1998.
Includes bibliographical references (p. 227-234).
The slurry-based 3DP process is a novel process that has been developed for fabricating engineered ceramic components. The process is a solid freeform fabrication (SFF) technique that builds components directly from a computer CAD file on a layer-by-layer basis. Solid-liquid interactions play a primary role in the process physics of each stage of the process. The formation of the powder bed is the first critical step in the slurry-based 3DP process. Powder bed microstructure is controlled by slurry stability and the slip casting rate. Capillary pressure must be controlled to produce crack-free powder beds. A critical saturation thickness (CST) was identified above which powder beds would crack. The CST increased with variables that reduced the capillary pressure. Conditions to fabricate crack-free powder beds using a multi-layer slurry deposition process were outlined. Solid-liquid interactions also affected the rate of infiltration of liquid into the powder bed. The rate of liquid infiltration affected the binder infiltration into the powder bed and the slip casting rate of the slurry. Slip casting rates of the slurry differed for regions of the powder bed printed with binder. The differential casting kinetics lead to two phenomena: density variation and slurry migration. The packing density of powder beds was higher in regions printed with binder, indicating that the density was higher in regions with lower casting rates. Slurry migration occurred due to the difference in liquid flux over the binder-printed region compared to the unprinted region of the powder bed. A model of the slip casting process was developed to identify variables to minimize the differential casting kinetics. The contact angle of the solvent and volume fraction of binder printed into the part affect the casting rate. The relative magnitude of the contact angles was calculated for a given volume fraction of binder to match the casting kinetics. This fundamental understanding of the solid-liquid interactions indicates routes to fabricate engineered ceramic components from numerous materials systems. Alumina components with green densities greater than 60% theoretical and sintered densities greater than 99% were fabricated. The general process has also been applied to silicon nitride.
by Jason E. Grau.
Ph.D.

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49

Neff, Joel Emerson. "Investigation of the effects of process parameters on performance of gravure printed ITO on flexible substrates." Thesis, Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/29625.

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Thesis (M. S.)--Mechanical Engineering, Georgia Institute of Technology, 2009.
Committee Chair: Melkote, Shreyes; Committee Co-Chair: Danyluk, Steven; Committee Member: Graham, Samuel. Part of the SMARTech Electronic Thesis and Dissertation Collection.

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Mc, Cormick Josephine. "The application of CAD/CAM technology in the remediation of the viscosity printing process." Thesis, University of Ulster, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.400962.

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Dissertations / Theses on the topic 'Printing process'

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