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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Conservation of intaglio prints : conservation principles applied during the printing process can improve the life span of prints

Vergara, Jose, n/a January 1989 (has links)
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.
2

Using Multicoloured Halftone Screens for Offset Print Quality Monitoring

Bergman, Lars January 2005 (has links)
<p>In the newspaper printing industry, offset is the dominating printing method and the use of multicolour printing has increased rapidly in newspapers during the last decade. The offset printing process relies on the assumption that an uniform film of ink of right thickness is transferred onto the printing areas. The quality of reproduction of colour images in offset printing is dependent on a number of parameters in a chain of steps and in the end it is the amount and the distribution of ink deposited on the substrate that create the sensation and thus the perceived colours. We identify three control points in the offset printing process and present methods for assessing the printing process quality in two of these points:</p><p>• Methods for determining if the printing plates carry the correct image</p><p>• Methods for determining the amount of ink deposited onto the newsprint</p><p>A new concept of colour impression is introduced as a measure of the amount of ink deposited on the newsprint. Two factors contribute to values of the colour impression, the halftone dot-size and ink density. Colour impression values are determined on gray-bars using a CCD-camera based system. Colour impression values can also be determined in an area containing an arbitrary combination of cyan magenta and yellow inks. The correct amount of ink is known either from a reference print or from prepress information. Thus, the deviation of the amount of ink can be determined that can be used as control value by a press operator or as input to a control system.</p><p>How a closed loop controller can be designed based on the colour impression values is also shown.</p><p>It is demonstrated that the methods developed can be used for off-line print quality monitoring and ink feed control, or preferably in an online system in a newspaper printing press.</p> / Report code: LiU-TEK-LIC-2005:02.
3

Using multicoloured halftone screens for offset print quality monitoring

Bergman, Lars January 2005 (has links)
In the newspaper printing industry, offset is the dominating printing method and the use of multicolour printing has increased rapidly in newspapers during the last decade. The offset printing process relies on the assumption that an uniform film of ink of right thickness is transferred onto the printing areas. The quality of reproduction of colour images in offset printing is dependent on a number of parameters in a chain of steps and in the end it is the amount and the distribution of ink deposited on the substrate that create the sensation and thus the perceived colours. We identify three control points in the offset printing process and present methods for assessing the printing process quality in two of these points: • Methods for determining if the printing plates carry the correct image • Methods for determining the amount of ink deposited onto the newsprint A new concept of colour impression is introduced as a measure of the amount of ink deposited on the newsprint. Two factors contribute to values of the colour impression, the halftone dot-size and ink density. Colour impression values are determined on gray-bars using a CCD-camera based system. Colour impression values can also be determined in an area containing an arbitrary combination of cyan magenta and yellow inks. The correct amount of ink is known either from a reference print or from prepress information. Thus, the deviation of the amount of ink can be determined that can be used as control value by a press operator or as input to a control system. How a closed loop controller can be designed based on the colour impression values is also shown. It is demonstrated that the methods developed can be used for off-line print quality monitoring and ink feed control, or preferably in an online system in a newspaper printing press. / <p>Report code: LiU-TEK-LIC-2005:02</p>
4

INTEGRATED DESIGN OF BINDER JET PRINT PRODUCED HYDRAULIC AUTOMATIC VALVE SYSTEM

Heming Liu (14380014) 18 January 2023 (has links)
<p>Binder jet printing (BJP) is an additive manufacturing (AM) method which has the potential to be applied to high annual volumes in the automotive industry. Binder jet printing provides an excellent opportunity to innovate transmission valve body components. The three-layer design and complex hydraulic control system channels of valve body housing formulated a new electro-hydraulic system with the brand-new features inherited from BJP. For the valve body, the features of BJP brought a revolutionary new idea for both the valves and hydraulic channel design. The spool valve was housed with a sleeve that integrates orifices and port controls. The hydraulic channel layout of the valve body assembly was greatly simplified and space-saving. The support components had also been replaced with a lightweight design while maintaining the same functionality. Integrated design of Binder jet print produced hydraulic automatic valve system presented an entirely new design, whose static performance was compared to that of the conventional 948TE ZF9HP48 transmission valve body. Similar performance indicated that a valve body design featuring BJP would have great potential for various industrial applications.</p>
5

Using Multicoloured Halftone Screens for Offset Print Quality Monitoring

Bergman, Lars January 2005 (has links)
In the newspaper printing industry, offset is the dominating printing method and the use of multicolour printing has increased rapidly in newspapers during the last decade. The offset printing process relies on the assumption that an uniform film of ink of right thickness is transferred onto the printing areas. The quality of reproduction of colour images in offset printing is dependent on a number of parameters in a chain of steps and in the end it is the amount and the distribution of ink deposited on the substrate that create the sensation and thus the perceived colours. We identify three control points in the offset printing process and present methods for assessing the printing process quality in two of these points: • Methods for determining if the printing plates carry the correct image • Methods for determining the amount of ink deposited onto the newsprint A new concept of colour impression is introduced as a measure of the amount of ink deposited on the newsprint. Two factors contribute to values of the colour impression, the halftone dot-size and ink density. Colour impression values are determined on gray-bars using a CCD-camera based system. Colour impression values can also be determined in an area containing an arbitrary combination of cyan magenta and yellow inks. The correct amount of ink is known either from a reference print or from prepress information. Thus, the deviation of the amount of ink can be determined that can be used as control value by a press operator or as input to a control system. How a closed loop controller can be designed based on the colour impression values is also shown. It is demonstrated that the methods developed can be used for off-line print quality monitoring and ink feed control, or preferably in an online system in a newspaper printing press. / <p>Report code: LiU-TEK-LIC-2005:02.</p>
6

Samband mellan viskositet på färg och kassation från tryckmaskin / The relationship between ink viscosity and rejects from the printing machine

Hellberg, Ellen January 2023 (has links)
AstraZeneca är en av världens främsta tillverkare av läkemedel. Agenda 2030 ställer höga krav på läkemedelsföretagen vad gäller att höja den globala folkhälsan och samtidigt bidra till en hållbar produktion. På PET Respules i Södertälje tillverkas flytande astmamedicin i plastampuller med steril BFS-teknik. Dessa plastampuller ges tilltryck genom tampontryckteknik. Tilltrycket innehåller batchunik information som utgångsdatum, produkt och dos och är en viktig process för patientsäkerhet och spårbarhet. För att säkra denna process är tryckmaskinerna utrustade med kalibrerad visionteknik som ställer krav på tryckprocessen. Tryckfärgen som används blandas med lösningsmedel för att sänka viskositeten och påverka färgens egenskaper. Viskositet har inte tidigare använts som parameter vid felsökning av färgblandningen vilket har resulterat i att bedömningen av huruvida färgblandningen varit lös (låg viskositet) eller tjock (hög viskositet) varit subjektiv. Genom experimentella försök och stickprov undersöktes sambandet mellan färgens viskositet och kassation från tryckmaskin. Detta genom att testa flera olika förhållanden mellan tryckfärg och lösningsmedel samtidigt och övervaka hur viskositeten betedde sig över tid. Testerna visade att det finns ett spann på viskositet mellan 350-622,4 mPa·s där ingen kassation kopplat till tryckfärgen förekommer. Det gick även konstatera att färgblandning med för lös viskositet genererar problem med övriga komponenter och att resultaten möjliggör standardisering av arbetssätt kopplat till hantering av tryckfärg. / AstraZeneca is one of the world's leading pharmaceutical manufacturers. Agenda 2030 places high demands on pharmaceutical companies regarding improving global public health while contributing to sustainable production. At PET Respules in Södertälje, liquid asthma medication is manufactured and packed in plastic ampoules using sterile BFS technology. These plastic ampoules are printed using pad printing technology. The print contains batch-specific information such as expiration date, product, dose, and is an important process for patient safety and traceability. To ensure this process, the printing machines are equipped with calibrated vision control system that sets requirements for the printing process. The printing ink used is mixed with a solvent to reduce viscosity and affect the properties of the color. Viscosity has not previously been used as a parameter in troubleshooting the color mixture, resulting in the assessment of whether the color mixture has been loose (low viscosity) or thick (high viscosity) being subjective. Through experimental trials and random sampling, the correlation between color viscosity and rejection from the printing machine was examined. This was done by testing several different ratios between printing ink and solvent simultaneously and monitoring how viscosity behaved over time. The tests showed that there is a range of viscosity between 350-622,4 mPa·s where no rejection related to the printing ink occurs. It was also found that a color mixture with excessively low viscosity generates problems with other components, and the results enable the standardization of work processes related to handling the printing ink.
7

Supernatural - Polar

Lüdicke, Katharina 17 November 2023 (has links)
Das gletscherähnliche und amorphe Modell “Supernatural - Polar“ für den Wettbewerb “Entdeckung“ ist aus meinem Konzept “SculptuReal“ 2019 entstanden. Um den Umgang mit künstlerischer Plastik für ein breiteres Publikum spannend und erfahrbar zu machen, entwarf ich eine App, mit der Skulpturen über das Interface eines Smartphones oder Tablets leicht “erspielt“ und durch das 3D-Druckverfahren ins Reelle übertragen werden können.
8

Cutting Into Relief

Bass, Matthew L. 20 March 2013 (has links)
The following is an examination of the ideas and decisions that went into an art exhibition held in gallery 303 of the Harris Fine Art Center February 1-13, 2013. The exhibition explores the relationships of the artwork, artist, viewer, and space. The catalyst for the above mentioned exploration is a process of making art using linoleum relief printing. The subject of the artwork is an in-depth examination of the material and printing process. It is my contention that such a close look at the art making process reveals the attitudes and decisions that we make with any human endeavor.
9

Stabilisierung von Mikrosieben durch Druckverfahren

Wolf, Franziska 27 January 2011 (has links) (PDF)
Eine spezielle Art poröser Membranen sind die sogenannten Mikrosiebe. Ihre Dicke ist geringer als der Durchmesser der Poren und sie besitzen eine einheitliche Porengröße und eine dichte Porenpackung. Sie zeichnen sich somit durch eine hohe Trennschärfe aus und eignen sich daher und aufgrund ihres geringen Filtrationswiderstandes besonders für den Einsatz als Filtrationsmedien. Ein Prinzip, um Mikrosiebe herzustellen, ist die Partikel-assistierte Benetzung. Bei dieser Methode wird ein polymerisierbares organisches Öl zusammen mit Kieselgelpartikeln auf einer Wasseroberfläche gespreitet. Nach dem Auspolymerisieren des Öls und dem anschließenden Entfernen der Partikel erhält man die gewünschten Mikrosiebe, welche an den Stellen, an denen sich zuvor die Kieselgelpartikel befanden, Poren besitzen. Die Porengröße der Siebe ist dabei über die Größe der verwendeten Partikel in weiten Grenzen (ca. zwischen 20 nm und 1000 nm) einstellbar und die Größe und Form des Mikrosiebes wird lediglich durch die Flächengröße und -form der zur Herstellung verwendeten Wasseroberfläche vorgegeben. Jedoch ist die mechanische Stabilität der Mikrosiebe für die gewünschte Anwendung als Filtrationsmedium oftmals nicht zufriedenstellend. Daher ist eine Stabilisierung erforderlich. Eine Möglichkeit, diese Stabilisierung zu erreichen, ist das Aufbringen einer externen makroporösen Stützstruktur. Im Rahmen dieser Arbeit wird die Möglichkeit vorgestellt mittels der Drucktechnik des sog. Inkjet-Druckens eine potentielle Stützstruktur auf ein solches Mikrosieb zu applizieren und dieses somit zu stabilisieren.
10

Elaboration of flexible lithium - ion electrodes by printing process / Réalisation d’électrodes souples pour batteries lithium-ion par procédé d’impression

El Baradai, Oussama 24 April 2014 (has links)
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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