Ink-jet printing offers an ideal answer to the emerging trends and demands of depositing at ambient temperatures picoliter droplets of oxide solutions into functional thin films and device components with a high degree of pixel precision. It is a direct single-step mask-free patterning technique that enables multi-layer and 3D patterning. This method is fast, simple, easily scalable, precise, inexpensive and cost effective compared to any of other methods available for the realization of the promise of flexible, and/or stretchable electronics of the future on virtually any type of substrate. Because low temperatures are used and no aggressive chemicals are required for ink preparation, ink-jet technique is compatible with a very broad range of functional materials like polymers, proteins and even live cells, which can be used to fabricate inorganic/organic/bio hybrids, bio-sensors and lab-on-chip architectures. After a discussion of the essentials of ink-jet technology, this thesis focuses particularly on the art of designing long term stable inks for fabricating thin films and devices especially oxide functional components for electronics, solar energy conversion, opto-electronics and spintronics. We have investigated three classes of inks: nanoparticle suspension based, surface modified nanoparticles based, and direct precursor solution based. Examples of the films produced using these inks and their functional properties are: 1) In order to obtain magnetite nanoparticles with high magnetic moment and narrow size distribution in suspensions for medical diagnostics, we have developed a rapid mixing technique and produced nanoparticles with moments close to theoretical values (APL 2011 and Nanotechnology 2012). The suspensions produced have been tailored to be stable over a long period of time. 2)In order to design photonic band gaps, suspensions of spherical SiO2 particles were produced by chemical hydrolysis (JAP 2010 and JNP 2011 - not discussed in the thesis). 3) Using suspension inks, (ZnO)1-x(TiO2)x composite films have been printed and used to fabricate dye sensitized solar cells (JMR 2012). The thickness and the composition of the films can be easily tailored in the inkjet printing process. Consequently, the solar cell performance is optimized. We find that adding Ag nanoparticles improves the ‘metal-bridge’ between the TiO2 grains while maintaining the desired porous structure in the films. The photoluminescence spectra show that adding Ag reduces the emission intensity by a factor of two. This indicates that Ag atoms act as traps to capture electrons and inhibit recombination of electron-hole pairs, which is desirable for photo-voltaic applications. 4) To obtain and study room temperature contamination free ferromagnetic spintronic materials, defect induced and Fe doped MgO and ZnO were synthesized ‘in-situ’ by precursor solution technique (preprints). It is found that the origin of magnetism in these materials (APL 2012 and MRS 2012) is intrinsic and probably due to charge transfer hole doping. 5) ITO thin films were fabricated via inkjet printing directly from liquid precursors. The films are highly transparent (transparency &gt;90% both in the visible and IR range, which is rather unique as compared to any other film growth technique) and conductive (resistivity can be ~0.03 Ω•cm). The films have nano-porous structure, which is an added bonus from ink jetting that makes such films applicable for a broad range of applications. One example is in implantable biomedical components and lab-on-chip architectures where high transparency of the well conductive ITO electrodes makes them easily compatible with the use of quantum dots and fluorescent dyes. In summary, the inkjet patterning technique is incredibly versatile and applicable for a multitude of metal and oxide deposition and patterning. Especially in the case of using acetate solutions as inks (a method demonstrated for the first time by our group), the oxide films can be prepared ‘in-situ’ by direct patterning on the substrate without any prior synthesis stages, and the fabricated films are stoichiometric, uniform and smooth. This technique will most certainly continue to be a versatile tool in industrial manufacturing processes for material deposition in the future, as well as a unique fabrication tool for tailorable functional components and devices. / <p>QC 20120907</p>

There are two objectives of this study.The first one was to study the new instrument Deltack fromPrufbau, and with the new knowledge, study the interaction between blanket and paper.Deltack is a new instrument to measure the ink splitting force. Blankets from an earlier study doneby GATF have been montered on 12 different Deltack print forms and those have together with Deltackbeen the base for this project.This study together with information from GATF’s study shows that some of the blankets have ahigher capability to adsorb ink. Those blankets generate a sharper shape on the force curve, they havea lower dot gain, but they print not as good solid.

The objective of the research was to develop fundamental understanding of the process of deposition of complex mixtures by the inkjet method. The rheological properties and DOD drop formation dynamics of carbon black pigmented inkjet inks were investigated. It was found that the suspension microstructure responses to bulk motions, leading to shear rate and time dependent shear viscosity. However, DOD drop formation dynamics of highly pigmented inkjet ink and pure Newtonian fluid is similar even though shear rate up to 105 s-1 exists during inkjet jetting process. A proposed explanation for these observations is that the shearing time during DOD drop ejection is insufficient for changing and stabilizing the microstructure of the suspension. The effects of signal amplitude and jetting frequency on DOD drop formation dynamics of pure Newtonian fluids were investigated. A transition of DOD drop formation dynamics when the inkjet nozzle is switched from idle to jetting was identified. A qualitative investigation of DOD drop impaction and post-impaction behavior on inkjet paper and textiles was carried out. Dynamics of DOD drop accumulation and spreading on the substrates and final ink distribution show drastic differences between these two substrates.

Abstract The tube flow fractionation method used in this thesis is one of the field flow separation processes, which can be used to fractionate particles over the entire size range of pulp particles (1&#8211;5000 µm) with high selectivity. The classification of particles in different size categories enables the fractional analysis of samples. According to this thesis, particle length is the most significant individual shape factor in particle classification for different size categories using tube flow fractionation. The fractional approach investigated in this thesis offers an interesting tool for investigating different pulp types more thoroughly than many other conventional laboratory methods such as the Bauer-McNett classification of pulp or the hyperwashing of DIP samples. The tube flow fractionator can be used to replace the Bauer-McNett device to determine the mass percentages of pulp sample fractions. Furthermore, pulp fractionation can be done quickly with the tube flow fractionation method and the results achieved are also comparable to the Bauer-McNett classification. The utilisation of recycled raw material in paper production is likely to continue to increase in the near future. This fact leads to even more heterogeneous raw material becoming one of the major challenges in deinked pulp production. Changes in the quality of raw material such as age or paper type have a notable effect on the deinkability of pulp. This creates a need to develop new methods for measuring DIP properties; in particular, information about the ink-releasing rate and ink particle size would be useful in controlling the deinking process. If DIP is fractionated with tube flow fractionation, it is possible to study the ink size distribution and ink content inside each fraction, thus obtaining fractional information on the ink release rate and ink particle size. A comparison of different DIP raw materials and process solutions can be performed with the fractional analysis presented in this thesis. It was noticed that aging had a negative effect on the slushing rate of LWC and SC raw material, but not on ONP. The ink detachment of LWC and SC was poorer when furnishes aged. However, the aging of LWC and SC did not result in a significant fragmentation of ink particles. In contrast, strong ink fragmentation is typical of aged ONP furnishes. The fractional approach gives new insight into deinking mechanisms, and could be essential for finding optimal deinking process conditions, for example in a pulping process or flotation environment. The method would also enable enhanced control of different DIP process stages and would contribute to creating a more efficient process with better waste management and improved final product quality. / Tiivistelmä Tässä työssä käytetyllä putkivirtausfraktioinnilla, joka on eräs kenttävirtausfraktioinnin sovellus, voidaan luokitella hyvin selektiivisesti erikokoisia (1&#8211;5000 µm) partikkeleita. Partikkeleiden luokittelu partikkelikooltaan erikokoisiin jakeisiin mahdollistaa näytteiden fraktionaalisen analyysin. Tässä työssä todettiin, että partikkelin pituus on tärkein yksittäinen muototekijä, joka vaikuttaa partikkelien fraktioitumiseen eri kokoluokkiin putkivirtausfraktioinnissa. Työssä tutkittu fraktionaalinen menetelmä mahdollistaa paljon syvällisemmän paperisulppujen analyysin kuin monet perinteiset laboratorioanalyysit, kuten Bauer McNett -luokittelu tai siistausmassojen hyperpesu. Putkivirtausfraktionaattorilla voidaan korvata Bauer McNett -luokittelu massasulppujen eri fraktioiden massaosuuksien määrityksessä. Lisäksi massojen fraktiointi putkivirtausfraktionaattorilla on nopea ja luotettava menetelmä, ja saadut tulokset ovat vertailukelpoisia Bauer McNett -luokittelulla saatujen tulosten kanssa. Kierrätyspaperiraaka-aineen kasvava hyödyntäminen paperin tuotannossa jatkunee lähivuosina. Tämä tarkoittaa, että siistausprosessissa hyödynnettävän raaka-aineen laatuvaihtelut aiheuttavat entistä suurempia haasteita. Muutokset raaka-aineen laadussa, kuten paperin ikä tai käytetty paperityyppi vaikuttavat huomattavasti massan siistattavuuteen. Näistä tekijöistä johtuen on tarvetta kehittää uusia mittausmenetelmiä määrittää siistausmassojen ominaisuuksia. Erityisesti musteen irtoaminen ja mustepartikkeleiden kokojen määritys voisi auttaa musteenpoistoprosessin ohjauksessa. Jos siistausmassa fraktioidaan putkivirtausfraktionaattorilla, on mahdollista tutkia mustekokojakaumia ja mustepitoisuuksia eri fraktioissa ja näin saadaan tietoa mustepartikkeleiden irtoamisesta ja mustepartikkelien koosta. Fraktionaalisella analyysilla on tässä työssä tutkittu eri siistausmassojen raaka-aineita ja prosessiratkaisuja. Työssä huomattiin, että LWC- ja SC-paperin ikääntymisellä on negatiivinen vaikutus paperin sulputtumisnopeuteen pulpperissa, mutta sanomalehtipaperilla vastaavaa ilmiötä ei huomattu. Musteen irtoaminen oli huonompaa LWC- ja SC-paperin ikääntyessä. Kuitenkaan ikääntyminen ei vaikuttanut LWC- ja SC-paperin mustepartikkeleiden pilkkoutumiseen merkittävästi. Sen sijaan sanomalehtipaperilla havaittiin voimakasta mustepartikkeleiden pilkkoutumista raaka-aineen ikääntyessä. Fraktionaalinen tutkiminen antaa uuden näkökulman musteenpoistomekanismeihin ja voisi olla hyödyllinen, kun etsitään optimaalisia musteenpoisto-olosuhteita esimerkiksi pulpperointiin tai flotaatioon. Menetelmä voisi mahdollistaa myös eri siistausprosessin osaprosessien säätämisen. Lisäsi menetelmän avulla voitaisiin saada tehostettua prosesseja ja parannettua laatua sekä saada prosesseista ympäristöystävällisempiä.

Tryckeribranschen är en ekonomiskt pressad bransch som söker nya besparingsmetoder. En av metoderna är att minska insatsvaran tryckfärg med färgreduceringsprogramvara. Rapporten undersöker möjligheterna med färgreduceringssystem. Detta genom att studera hur man använder sig av färgreducering och hur det påverkar trycket. Studien avser besvara: • Hur stor färgminskning kan man använda sig av utan negativa konsekvenser på bildkvalitén? • Hur går man tillväga för att skapa den färgminskningen? • Överensstämmer total färgförändring och visuell bedömning av tryck? För att få svar på dessa frågor togs en testform fram med nödvändiga bilder och färgfält som sedan genomgick en rad färgreduktioner. Testformen utvärderades digitalt med avseende på TAC och total färgförändring. Därefter trycktes testformen och utvärderades visuellt av en testgrupp och uppmättes för att visa färgförändring efter tryck. Resultatet av undersökningen visar att det går att färgreducera tryck utan avsevärda negativa konsekvenser på bildkvalitén. En reducering från 300 % TAC till en TAC mellan 240 % och 210 % är fullt möjlig för att få en besparing och vara inom standard för total färgförändring. Detta går att göra väldigt lätt med en programvara som Alwan CMYK Optimizer ECO, med enbart förvalda inställningar och en inställd Total Ink Limit mellan 240 % och 210 %. Resultatet visade även en stark korrelation mellan den visuella bedömningen och den totala färgförändring, som tyder att både metoder är lämpliga för bedömning av tryck.

Abstract The amount of printing ink in a pulp suspension produced from recovered paper and its impact on overall brightness is commonly estimated from the reflectance-based ink content measured at a wavelength of 700 nm or 950 nm. The method uses a light scattering coefficient that can be measured from a slightly translucent test medium, i.e. of an opacity less than 97%. This is the case with machine-made papers in most instances. Alternatively, suitable opacity can be achieved by preparing a standard low-grammage sheet on a wire screen, but this results in poor retention of fibre fines, mineral fillers and printing inks, which is especially detrimental to ink measurement when the pulp suspension contains substantial amounts of printing inks. Hence opaque pads are often prepared on filter paper to achieve high retention. Unfortunately their high opacity prevents measurement of the light scattering coefficient, and thus a constant coefficient must be used for the determination of ink content. The aim of this thesis was to clarify the effects of retention and fine material changes on the light scattering coefficient in ink content measurement. The results showed that the light scattering properties of pulp in the wavelength region used for ink content analysis do not remain constant when the fine material content varies. The grade of the recovered paper, hyperwashing and flotation alter the fine material content and thus affect the light scattering. Printing ink also affects light scattering, but its practical impact is smaller than that of fibre fines and mineral fillers. The light scattering coefficient used for each ink content measurement needs to be representative, otherwise a systematic bias in ink content measurements may result from changes in the nature of the fine material and in its content. It is recommended that the light scattering coefficient should be measured in order to avoid this. The measurement should preferably be performed from a low-grammage sheet prepared on filter paper, as this ensures high retention and a measured value that represents better the initial state of the pulp suspension. / Tiivistelmä Mustepitoisuusmittaus perustuu hajaheijastukseen joko 700 nm tai 950 nm aallonpituudella ja sitä käytetään usein arvioitaessa keräyspaperista valmistetun massasuspension soveltuvuutta painopaperien valmistukseen ja painomusteen vaikutusta massan vaaleuteen. Mustepitoisuuden mittauksessa käytetään valonsirontakerrointa, joka voidaan mitata hieman läpikuultavasta näytteestä eli näytteen opasiteetin on oltava pienempi kuin 97 %. Tämä opasiteettiraja toteutuu useimmiten paperikoneella tehdyille painotuotteille. Riittävän alhainen opasiteetti saavutetaan myös valmistamalla standardin mukainen matalaneliömassainen arkki viiralle, mutta tämä johtaa kuitumaisten hienoaineiden, mineraalisten täyteaineiden ja painomusteiden alhaiseen retentioon. Matala retentio on erityisen haitallinen piirre mustemittauksen kannalta massoilla, jotka sisältävät huomattavia määriä painomusteita. Siten usein valmistetaan läpikuultamattomia arkkeja suodatinpaperin päälle, joiden retentio on korkea. Korkeasta opasiteetista johtuen näistä arkeista ei voida määrittää valonsirontakerrointa, jolloin mustepitoisuuden määritys perustuu vakiokertoimeen. Tämän väitöskirjan tavoitteena oli selvittää retention ja hienoaineiden muutoksien vaikutuksia valonsirontakertoimeen ja mustemittaustulokseen. Tutkimuksen tulokset osoittivat että valonsirontakerroin, joka mitataan mustepitoisuuden yhteydessä, ei pysy vakiona hienoainepitoisuuden muuttuessa. Hienoainepitoisuuteen ja siten valonsirontakertoimeen vaikuttavat keräyspaperin laji, hyperpesu ja vaahdotus. Myös painomuste vaikuttaa valonsirontakertoimeen, mutta käytännössä vaikutuksen suurusluokka on pienempi kuin hieno- ja täyteaineilla. Mustepitoisuuden määrityksessä käytetyn valonsirontakertoimen on oltava edustava, muutoin arvot voivat olla systemaattisesti virheellisiä hienoainemäärän tai laadun muuttuessa. Virheen välttämiseksi olisi suositeltavaa määrittää valonsirontakerroin mustepitoisuusanalyysin yhteydessä. Tämä olisi mahdollista tehdä suodatinpaperin päälle valmistetusta matalaneliömassaisesta arkista, jolloin saavutetaan korkea retentio ja näin mitattu arvo edustaa paremmin massasuspension alkuperäistä tilaa.

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Published Article / This paper surveys the current state and capabilities of Three Dimensional Printing (3DP). Based on its technical background - the ink jet printing as known from the printer and plotter industry - a classification structure has been developed and proposed. Different printing techniques and process concepts, together with their advantages and limitations are described and analysed. A large variety of manufacturing applications such as rapid pattern making and rapid tooling using the 3DP process directly or as core technology, as well as further implications in design and engineering analysis, medicine, and architecture are presented and evaluated. Some research issues are also discussed. An attempt, based on the state of the art, to show weaknesses and opportunities, and to draw conclusions about the future of this important process wraps up this paper.

Previous reports have shown that several tattoo inks available on the Swedish market contain prohibited substances. Although the regulatory framework has been in place since 2012, there is a lack of clarity about whether the contents of tattoo inks meet regulatory requirements or not. The purpose of this study was to find out if an active supervision is conducted to determine if the regulations on tattoo inks are met, focusing on the content of prohibited substances. 43 Swedish municipalities were given a survey about their experiences in conducting supervision of tattoo artists. Most municipalities have used the regulation (2012:503) on tattoo inks. Parts that involves giving information to the customer, labeling of tattoo ink containers and sterility have been more common in the supervision than the parts related to control of the tattoo inks content. It is today difficult and time consuming to verify the state of tattoo ink contents and to compare with the available lists included in the legislation. The study suggests the introduction of a simpler, standardized method for investigating whether a tattoo color contains prohibited substances or not.

This work explores the techniques of printing and preparation, in combination with technical mistakes. It aims to show how to use technical mistakes in different printing and preparation techniques as a design method to find accidental aesthetic expressions using the stripe as a tool to enhance and clarify the methods modification. The method confronts today’s textile industry by showing how these mistakes could develop into new expressions within textile design when fast -fashion is no longer an obligation. The stripe is a common shape, and is explored to clarify the method ans show how different techniques can change the stripes in various ways. This resulted in to three pieces each representing a technique; one transfer printed, one digital printed and one with the starting point in screen print. They present examples of how more time for developing mistakes in textile design can lead to development of the common shape of a stripe, broaden the technical limitations, and give a value to mistakes in the textile industry. By taking the method further more mistakes could be developed, and how to produce the developed designs in the industry could be investigated.