Throughout history, the spread of microorganisms has caused much damage including infectious diseases and deaths. Ever since humans realized the impact of bacteria especially on population health many efforts have been done to combat the spread of pathogens. Textiles, as suitable environments for the growth of microorganisms are one of the major sources of epidemics. Therefore, producing antibacterial textiles can lessen the chances of transmission of microorganisms. In spite of effective protection antibacterial textiles offer, lack of comfort can result in less interest in the products from the users. The aim of this project is to use valve-jet printing as a resource-efficient finishing method to produce antibacterial textiles and measure its effect on comfort properties. As a natural, non-toxic, and biodegradable antibacterial agent, chitosan was chosen to be printed on cotton fabric. An ink with 0.5 w/v% concentration of chitosan dissolved in 1.5v/v% acetic acid was prepared and printed on cotton fabric through ChromoJet printer. The fabric was cured at 150°C for 1 minute to stabilize the chitosan on cotton. Three types of printed fabrics were produced with different number of printing passes. The samples were characterized by various methods to investigate the performance of printed chitosan ink on the antibacterial and comfort properties of the cotton fabric. Results indicate a successful printing of chitosan ink on cotton fabric through valve-jet printing method. Results further showed that multiple printing passes of chitosan ink on cotton fabric can result in higher antibacterial activity. However, with excessive increase of chitosan, the fabric compromises the hand feel and softness. Results also showed an increase in air permeability with the increment in the amount of chitosan on the cotton fabric, whereas capillary rise decreased with the increase of chitosan amount. Contact angle measurement and hydrostatic pressure test showed that between the printed and not-printed samples no big difference was observed in terms of hydrophilicity. The result of the thesis is of great importance as they introduce new printing process for the fabrication of antibacterial textile with comfort properties for various applications.

Rapporten behandlar ett kandidatarbete i maskinteknik som utfördes tillsammans med Evomatic AB i Karlshamn. Syftet med detta examensarbete var att genom inlärda kunskaper under utbildningen utveckla och generera en lösning som möjliggör automatiskt utbyte av gripfingrar på ett gripdon som används i ett av Evomatics automatiserade robotsystem.  Genom en behovsanalys togs en kravspecifikation fram tillsammans med företaget som innehåller de krav och önskemål som företaget ställer på produkten. Kravspecifikationen beskriver specifikt och detaljerat de krav som ställs på produkten, i vårt fall var de främsta kraven att produkten skulle motstå ett visst vridmoment och hålla sig inom måtten för de anslutande delarna, huvudkravet var att produkten helt automatiserat utföra sin arbetsuppgift.  Efter att ha identifierat kundbehovet samt etablerat kravspecifikationen genomfördes en konceptgenerering där ett antal olika lösningskoncept togs fram genom brainstorming och brainwriting. De för- och nackdelar med respektive koncept ställdes mot varandra i en konceptsållningsmatris, för att tydliggöra slutsatsen om vilket koncept som var mest lämpligt och praktiskt genomförbart.  Det valda konceptet vidareutvecklades och tillverkades genom bl.a 3D-printing för att sedan genomgå ett funktionstest för att tydligt visa dess svagheter och styrkor i praktiken. Funktionstestet gav ett nära önskvärt resultat med bra respons från intressenten.  Slutsatsen som drogs utifrån det resultat som testet genererade var att konceptet i helhet fungerar som tänkt, med utrymme för förbättringar som uppmärksammades under testningstillfället. Dessa förbättringar implementerades i en slutlig version av konceptet för att möjliggöra framtagning av prisbild och jämförelse mot tidigare lösning. / This report represents a final degree project in mechanical engineering which was performed in cooperation with Evomatic AB, located in Karlshamn. The purpose of this thesis was to, through the knowledge learned during the education, develop and generate a solution that enables the automatic exchange of gripper fingers on a gripper unit used in one of Evomatic´s automated robot systems.  Through a needs analysis, a specification of requirements was generated together with the company, containing the requirements and wishes of the solution. This specification describes the requirements of the product in detail, in our case the main requirements were that the product should withstand a certain amount of torque, stay within the dimensions of the connecting components, but the main requirement was that the product would successfully perform its task automatically.  After having identified the customer need and established the specification of requirements, a concept development process was carried out where a number of different ideas were developed through brainstorming and brainwriting. The pros and cons with each concept were contrasted in a concept screening matrix, in order to clarify the conclusion of which concept was most suitable and practically feasible.  The chosen concept was further developed and manufactured through, among other things, 3D printing and then underwent a functional test to clearly show its weaknesses and strengths in practice. The functional test gave a close to desirable result with a good response from the company. Conclusively, the result generated by the test showed that the concept filled its function and purpose, with room for improvement, which was noted during the testing. These improvements were implemented in the final version of the concept as a 3D-model, to make it possible to produce a price point compared to the previous solution used.

Self-oscillating synthetic vocal fold (VF) models are often used to study human voice production. In this thesis, a method for fabricating multi-layer self-oscillating synthetic VF models using silicone 3D printing is presented. Multi-material 3D printing enables faster fabrication times with more complex geometries than traditional casting methods and builds a foundation for producing VF models with potentially more life-like geometries, materials, and vibratory characteristics. The printing method in this study used a custom dual extruder and slicing software to print UV-curable liquid silicone into a gel-like support matrix. The extruder was fabricated using high-torque stepper motors with high resolution leadscrews for precise extrusion and retraction. The custom slicing software accounted for challenges with printing a low-viscosity uncured silicone and was capable of allowing the user to visually observe the effects of print settings on print paths before finalizing the g-code. Three validation tests were conducted to demonstrate the 3D printer’s ability to print ultra-soft silicone with the desired range of stiffness, change between materials quickly, and print a material stiffness gradient. Two types of VF models were printed in this study, a previously-designed model with multiple distinct layers (“EPI” model), and the same model but with a vertical stiffness gradient (VSG) in the superficial lamina propria layer. The EPI model was chosen to demonstrate the ability to 3D print a multi-layer model, and the VSG model was chosen to demonstrate the ability to print multi-material VFs with geometric and material properties that are difficult to fabricate using traditional casting methods. Sixteen VFs (i.e., eight pairs) of each model type were printed, and their vibratory responses were recorded, including onset pressure, frequency, and glottal width. A micro-CT scanner was used to evaluate the external geometric accuracy of the models. One-centimeter cubes were 3D printed and tensile tested to characterize the material properties of each set of VF models. The material and phonatory properties of both the EPI and VSG VF models were found to be comparable to human data and to previous data acquired using synthetic VF models fabricated via other methods. In this thesis, the 3D printing methodology is summarized, the setup and results of the validation and VF model tests are reported and discussed, and recommendations for future work are provided.

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>

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.

In this paper, a novel approach is utilized to investigate the deformation mechanisms at the microstructural level in 3D printed alloys. The complex in-situ heat treatments during 3D printing leaves a unique and complicated microstructure in the as-built 3D printed metals, particularly alloys. The microstructure is made of a hierarchical stacking of some interconnected geometrical shapes, namely meltpools, grains, and cells. These are connected to each other by boundaries that might have different element compositions, and consequently, material properties, compared to the interior region of each geometrical unit. Deformation mechanisms in this microstructure are still highly unexplored, mainly because of the challenges on the way of performing experiments at the micrometer length scale. In this work, we establish an image processing framework that directly converts the SEM images taken from the microstructure of 3D printed 316L stainless steel alloys into CAD models. The model of the complicated microstructure is then scaled up, and the scaled model is 3D printed using polymeric materials. For 3D printing these samples, two polymers with contrasting mechanical properties are used. Distribution of these two polymers mimics the arrangement of soft and stiff regions in the microstructure of 3D printed alloys. These representative samples are subjected to mechanical loads and digital image correlation is utilized to investigate the deformation mechanisms, particularly the delocalization of stress concentration and also the crack propagation, at the microstructural level of 3D printed metals. Besides experiments, computational modeling using finite element method is also performed to study the same deformation mechanisms at the microstructure of 3D printed 316L stainless steel. Our results show that the hierarchical arrangement of stiff and soft phases in 3D printed alloys delocalizes the stress concentration and has the potential to make microstructures with significantly improved damage tolerance capabilities. / Master of Science / Many researchers have studied the impacts of laser parameters on the bulk material properties of SLM printed parts; few if any have studied how these parts break at a microstructural level. In this work we show how SLM printed parts with complex microstructures including grains, meltpools, and cells, deform and break. The cellular network that occurs in some SLM printed parts leads to a multi-material hierarchical structure, with a stiff network of thin boundaries, and a bulk "matrix" of soft cell material. This leads to similar properties as some composites, whereby the stiff network of cell boundaries leads to increased damage tolerance. We show both computationally through finite element analysis, and experimentally through multi-material 3D fabrication, that the microstructure leads to increased crack length in failure, as well as lower toughness loss and strength loss in the event of a crack. Essentially, the complex nature of the formation of these parts (high heating and cooling rates from laser melting) leads to a beneficial microstructure for damage tolerance that has not been studied from this perspective before.

Atualmente, as artes gráficas vivem um momento de grande desenvolvimento tecnológico, principalmente em relação às novas tecnologias de impressão sem fôrma, popularmente conhecidas como impressão digital. O objetivo central desta pesquisa é compreender as mudanças dos métodos produtivos provocadas pela adoção da tecnologia de impressão digital pela indústria gráfica. Este trabalho propõe o levantamento dos principais sistemas de impressão sem fôrma adotados pelas gráficas, identificando as tendências tecnológicas de impressão sem fôrma desenvolvidas especialmente para a indústria gráfica. Visa, ainda, investigar quais recursos de impressão de dados variáveis foram viabilizados por esta tecnologia, analisando o impacto destes novos sistemas de impressão gráfica sobre a impressão de dados variáveis ou impressão personalizada. A pesquisa também apresenta um conjunto de trabalhos gráficos relevantes ou inovadores que utilizam a impressão de dados variáveis com o objetivo de apontar as possibilidades produtivas de impressão de dados variáveis viabilizadas por esta tecnologia. A análise dos resultados da pesquisa visa documentar o novo cenário da impressão digital dentro da indústria gráfica, as tecnologias de impressão sem fôrma mais empregadas por este setor, e as diferentes alternativas produtivas de impressão de dados variáveis. / Nowadays, the graphic arts are in a great moment of technological development, especially in new printing technologies without a printing plate, which is popularly known as digital print. The main objective of this research is to understand the changes in production methods by the adoption of digital printing technology for the printing industry. This paper proposes the research of the leading computer to press systems adopted by graphics and the identification of print technology trends without a printing plate, specially developed for the printing industry, as well as investigate which variable data printing capabilities were enabled by this technology, analyzing the impact of these new graphic printing systems on variable data printing and custom printing. The survey also presents a set of relevant and innovative graphic works that use variable data printing in order to point out the productive possibilities of variable data printing, enabled by this technology. The analysis of the survey results aims to document the new situation of digital printing in the printing industry, the printing technologies without a printing plate more used in this area and the different productive alternatives of variable data printing.

Atualmente, as artes gráficas vivem um momento de grande desenvolvimento tecnológico, principalmente em relação às novas tecnologias de impressão sem fôrma, popularmente conhecidas como impressão digital. O objetivo central desta pesquisa é compreender as mudanças dos métodos produtivos provocadas pela adoção da tecnologia de impressão digital pela indústria gráfica. Este trabalho propõe o levantamento dos principais sistemas de impressão sem fôrma adotados pelas gráficas, identificando as tendências tecnológicas de impressão sem fôrma desenvolvidas especialmente para a indústria gráfica. Visa, ainda, investigar quais recursos de impressão de dados variáveis foram viabilizados por esta tecnologia, analisando o impacto destes novos sistemas de impressão gráfica sobre a impressão de dados variáveis ou impressão personalizada. A pesquisa também apresenta um conjunto de trabalhos gráficos relevantes ou inovadores que utilizam a impressão de dados variáveis com o objetivo de apontar as possibilidades produtivas de impressão de dados variáveis viabilizadas por esta tecnologia. A análise dos resultados da pesquisa visa documentar o novo cenário da impressão digital dentro da indústria gráfica, as tecnologias de impressão sem fôrma mais empregadas por este setor, e as diferentes alternativas produtivas de impressão de dados variáveis. / Nowadays, the graphic arts are in a great moment of technological development, especially in new printing technologies without a printing plate, which is popularly known as digital print. The main objective of this research is to understand the changes in production methods by the adoption of digital printing technology for the printing industry. This paper proposes the research of the leading computer to press systems adopted by graphics and the identification of print technology trends without a printing plate, specially developed for the printing industry, as well as investigate which variable data printing capabilities were enabled by this technology, analyzing the impact of these new graphic printing systems on variable data printing and custom printing. The survey also presents a set of relevant and innovative graphic works that use variable data printing in order to point out the productive possibilities of variable data printing, enabled by this technology. The analysis of the survey results aims to document the new situation of digital printing in the printing industry, the printing technologies without a printing plate more used in this area and the different productive alternatives of variable data printing.

The master thesis deals with design of multi material FDM 3D printer. In the first part, current market situation and possible principles of multi material printing are described. Possible variants of individual construction nodes are described in the next part and then the selected variant is processed into a design solution. The benefit of this thesis is a proposal of solution for the automatic printing head exchange, which is practically not concerned by printer manufacturers.

Synthetic, self-oscillating vocal fold (VF) models are physical models whose life-like vibration is induced and perpetuated by fluid flow. Self-oscillating VF models, which are often fabricated life-size from soft silicone elastomers, are used to study various aspects of voice biomechanics. Despite their many advantages, the development and use of self-oscillating VF models is limited by the casting process used to fabricate the models. Consequently, this thesis focuses on the development of 3D printing processes for fabricating silicone VF models. A literature review is first presented which describes three types of material extrusion 3D printing processes for silicone elastomers, namely direct ink writing (DIW), embedded 3D printing, and removable-embedded 3D printing. The review describes each process and provides recent examples from literature that show how each has been implemented to create silicone prints. An embedded 3D printing process is presented wherein a set of multi-layer VF models are fabricated by extruding silicone ink within a VF-shaped reservoir filled with a curable silicone support matrix. The printed models successfully vibrated during testing, but lacked several desirable characteristics which were present in equivalent cast models. The advantages and disadvantages of using this fabrication process are explored. A removable-embedded 3D printing process is presented wherein shapes were fabricated by extruding silicone ink within a locally-curable support matrix then curing the silicone ink and proximate matrix. The printing process was used to fabricate several geometries from a variety of silicone inks. Tensile test results show that printed models exhibit relatively high failure strains and a nearly isotropic elastic modulus in directions perpendicular and parallel to the printed layers. A set of single-material VF models were printed and subjected to vibration testing. The printed models exhibited favorable vibration characteristics, suggesting the continued use of this printing process for VF model fabrication. A micro-slicing process is presented which is capable of creating gcode for 3D printing multiple materials in discrete and mixed ratios by utilizing a previously-sliced single-material shape and a material definition. An important advantage of micro-slicing is its ability to create gcode with a mixed-material gradient. Initial test results and observations are included. This micro-slicing process could be used in material extrusion 3D printing