Optimization of a heatset dryer

The objective of the thesis was to examine the possibilities in designing better performing nozzles for the heatset drying oven in Forest Pilot Center. To achieve the objective, two predesigned nozzle types along with the replicas of the current nozzles in the heatset drying oven were tested on a pilot-scale dryer. During the runnability trials, the pilot dryer was installed between the last printing unit and the drying oven. The two sets of predesigned nozzles were consecutively installed in the dryer. Four web tension values and four different impingement air velocities were used and the web behavior during the trial points was evaluated and recorded. The runnability in all trial conditions was adequate or even good. During the heat transfer trials, each nozzle type was tested on at least two different nozzle-to-surface distances and four different impingement air velocities. In a test situation, an aluminum plate fitted with thermocouples was set below a nozzle and the temperature measurement of each block was logged. From the measurements, a heat transfer coefficient profile for the nozzle was calculated. The performance of each nozzle type in tested conditions could now be rated and compared. The results verified that the predesigned simpler nozzles were better than the replicas. For runnability reasons, there were rows of inclined orifices on the leading and trailing edges of the current nozzles. They were believed to deteriorate the overall performance of the nozzle, and trials were conducted to test this hypothesis. The perpendicular orifices and inclined orifices of a replica nozzle were consecutively taped shut and the performance of the modified nozzles was measured as before, and then compared to the performance of the whole nozzle. It was found out, that after a certain nozzle-to-surface distance the jets from the two nozzles would collide, which deteriorates the heat transfer.

The Impact of Aspen and Alder on the Quality of NHBK

The purpose of this work was to study the effect of aspen and alder on birch cooking and the quality of the pulp produced. Three different birch kraft pulps were studied. As a reference, pure aspen and alder were included. The laboratory trials were done at the UPM Research Centre in Lappeenranta, Finland. The materials used were birch, aspen and alder mill chips that were collected around the area of South-Carelia in Finland. The chips used in the study were pulped using a standard kraft process. The pulps including birch fibres were ECF-bleached at laboratory scale to a target brightness of 85 %. The bleached pulps were beaten at low consistency by a laboratory Voith Sulzer refiner and tested for optical and physical properties. The theoretical part is a study of hardwoods that takes into accounts the differences between birch, aspen and alder. Major sub-areas were fibre and paper-technical properties as well as chemical composition and their influence on the different properties. The pulp properties of birch, aspen and alder found in previous studies were reported. Russian hardwood forest resources were also investigated. The fundamentals of kraft pulping and bleaching were studied at the end of theoretical part. The major effect of replacing birch with aspen and alder was the deterioration (lowering) of tensile and tear strengths. In other words, addition of aspen and alder to a birch furnish reduced strength properties. The reinforcement ability of the tested pulps was the following: 100 % birch > 80 % birch, 20 % aspen > 70 % birch, 20 % aspen, 10 % alder. The second thing noted was that blending of birch together with aspen and alder give better smoothness, optical properties and also formation. It can be concluded, that replacement of birch with alder during cooking by more than 10 % can negatively affect on the paper-technical properties of birch pulp. Mixing pure birch and aspen pulps would be more beneficial when producing printing paper made from chemical pulp.

Measurement and Improvement of Wet Paper Web Strength

Various strength properties of paper are measured to tell how well it resists breaks in a paper machine or in printing presses. The most often measured properties are dry tensile strength and dry tear strength. However, in many situations where paper breaks, it is not dry. For example, in web breaks after the wet pressing the dry matter content can be around 45%. Thus, wet-web strength is often a more critical paper property than dry strength. Both wet and dry strength properties of the samples were measured with a L&W tensile tester. Originally this device was not designed for the measurement of the wet web tensile strength, thus a new procedure to handle the wet samples was developed. The method was tested with Pine Kraft (never dried). The effect of different strength additives on the wet-web and dry paper tensile strength was studied. The polymers used in this experiment were aqueous solution of a cationic polyamidoamine-epichlorohydrin resin (PAE), cationic hydrophilised polyisocyanate and cationic polyvinylamine (PVAm). From all three used chemicals only Cationic PAE considerably increased the wet web strength. However it was noticed that at constant solids content all chemicals decreased the wet web tensile strength. So, since all chemicals enhanced solid content it can be concluded that they work as drainage aids, not as wet web strength additives. From all chemicals only PVAm increased the dry strength and two other chemicals even decreased the strength. As chemicals were used in strong diluted forms and were injected into the pulp slurry, not on the surface of the papersheets, changes in samples densities did not happen. Also it has to be noted that all these chemicals are mainly used to improve the wet strength after the drying of the web.

Elintarvikekelpoisten painovärien vertailu offsetpainatuksessa

Tässä diplomityössä tutkittiin kolmen eri painovärivalmistajan elintarvikekelpoisia arkkioffsetpainovärisarjoja ja verrattiin niitä keskenään. Tavoitteena oli löytää optimaalinen elintarvikekartonkipakkausten painamiseen soveltuva arkkioffsetpainoväri. Työn kirjallisessa osassa selvitettiin yleisesti offsetpainatusprosessia, painovärien koostumusta ja elintarvikekelpoisten painovärien eroavaisuutta verrattuna perinteisiin offsetpainoväreihin. Kirjallisuusosassa tuotiin esille myös niitä tekijöitä, joilla elintarvikekelpoisuus määritellään. Näistä yksi tärkeä osa-alue on migraatio-ongelmat, joka on lainsäädännön kannalta ajankohtainen. Kokeellista osaa varten koepainovärejä painettiin taivekartongille arkkioffsetpainokoneella. Painetuista arkeista tehtiin mittauksia, joissa käytettiin densitometrisia, kolorimetrisia, kromatografisia ja aistinvaraisia menetelmiä. Näillä pyrittiin tuomaan esille eroavaisuuksia tutkittavana olleiden painovärien välille. Koeajojen ja mittausten perusteella analysoitiin painatuksen laatua, painettavuutta, painovärien elintarvikekelpoisuutta ja kestävyyttä. Työn tulosten perusteella ei voida suoraan osoittaa, että jokin painovärisarja olisi toimivampi kuin toinen. Yksi johtopäätös olikin, että painovärien koostumusta ja painatusprosessia on mahdollista modifioida monella tavalla, jolloin voidaan parantaa joitakin painovärin ominaisuuksia. Yleisesti kokeet osoittivat, että perinteinen aistinvarainen tapa testata painovärin elintarvikekelpoisuutta on hyvin subjektiivinen ja antaa arveluttavia tuloksia. Koetuloksista oli kuitenkin havaittavissa, että uuden sukupolven vähemmän migraatiota aiheuttavat painovärit ovat elintarvikekelpoisempia kuin aikaisempien kehitysasteiden painovärisarjat.

Agile CRM System Implementation Project

The application of information technology (IT) in customer relationship management (CRM) is growing rapidly as many companies implement CRM systems to support their numerous customer facing activities. However, failure rates of CRM projects remain notably high as they deliver scant solutions and poor user acceptance. As a consequence, it is justified to study previously researched CRM success factors and apply them to CRM system implementation. The aim of this master’s thesis was to get acquainted with relevant academic theories, frameworks and practices concerning CRM and agile development, and use them to generate a modified CRM project strategy to support the successful execution of the case company’s, Process Vision Oy, CRM implementation project. The empirical CRM system implementation project was conducted simultaneously with writing this thesis. Its theoretical findings could be transferred into practice through active participation in the CRM system development and deployment work. The project’s main goal was to produce and take into use a functioning CRM system. The goal was met, since at the time of printing this thesis the first system release was successfully published to its users at Process Vision’s marketing and sales departments. The key success elements in the CRM project were cyclic, iterative system development, customer oriented approach, user inclusion and flexible project management. Implying agile development practices ensured being able to quickly respond to changes arising during the progress of the CRM project. Throughout modelling of the core sales process formed a strong basis, on which the CRM system’s operational and analytical functionalities were built. End users were included in the initial specification of system requirements and they provided feedback on the system’s usage. To conclude, the chosen theoretical CRM roadmaps and agile development practices proved as beneficial in the successful planning and execution of the agile CRM system implementation project at Process Vision.

Painotuotteen hinnoittelu kypsillä markkinoilla

Tämä tutkimus tarkastelee hinnoittelua graafisen teollisuuden pk-sektorin kirjapainoissa. Alalla vallitseva markkinatilanne on kiristynyt siirryttäessä kysyntä-/teknologiaelinkaaren kasvujaksolta kypsään vaiheeseen. Tutkimus pyrkii antamaan vastauksen hinnoittelun tarvitsemaan toimintaan tarkastelemalla hinnoittelun ”ongelmien järjestelmää”. Tutkimus on toiminta-analyyttisen metodologian mukaisena tutkimuksena toteutettu case-tutkimus, jossa empirian tutkimusmetodeina ovat kvalitatiiviset puolistruktuuriset teemahaastattelut ja kvantitatiiviset tilastolliset tarkastelut toimialan kehityksestä. Tutkimustuloksina todetaan alalla vallinneen pitkän voimakkaan kannattavuuden jakson muokanneen case-yrityksen hinnoitteluperiaatteita, jotka vastaavat huonosti muuttuneeseen markkinatilanteeseen. Tutkimuksessa esitetään pk-yrittäjien rationaalisuuden ero talousteorioiden edellyttämästä instrumentaalisesta rationaalisuudesta.

Paperin aistinvarainen arviointi

Paperin tärkeiden teknisten ominaisuuksien lisäksi myös paperin aistinvaraiset ominaisuudet ovat nousseet merkittäviksi parametreiksi paperia luonnehdittaessa. Aistinvaraisilla ominaisuuksilla tarkoitetaan ominaisuuksia, jotka ihminen aistii käsitellessään tuotetta. Tällaisia ominaisuuksia ovat esimerkiksi paperin karheus, liukkaus, jäykkyys sekä ääni paperia selattaessa. Paperin aistinvaraiset ominaisuudet luovat lukijalle mielikuvan lukemastaan lehdestä lehden sisällön lisäksi. Tämän työn tavoitteena oli kehittää olemassa olevan aistinvaraisten ominaisuuksien arviointiraadin toimintaa. Arviointimenetelmän tilalle pyrittiin löytämään toinen menetelmä sekä kehittämään uusi tulosten raportointimalli. Työssä käytettiin kahta subjektiivista arviointimenetelmää, parivertailua ja ranking-menetelmää. Tuloksia verrattiin aiemmin käytössä olleen referenssimenetelmän tuloksiin. Näytteistä arvioitiin karheus, liukkaus, tahmeus, jäykkyys, selailtavuus, äänen voimakkuus ja äänen laatu. Näiden lisäksi näytteiden miellyttävyyttä arvioitiin parivertailua käyttäen. Arvioitsijoiden yksimielisyyttä selvitettiin parivertailun yhteydessä. Näytteet olivat painamattomia, mutta painokoneen läpi menneitä lehtiformaattiin taitettuja. Visuaalisissa arvioinneissa käytettiin painettuja näytteitä samasta paperivalikoimasta. Arviointimenetelmien tuloksia vertailtaessa, voidaan menetelmien välillä havaita muutamia eroja. Sekä parivertailussa että ranking-menetelmässä näytteet jakaantuivat lähes kokonaan annetulle arviointiskaalalle, kun referenssimenetelmällä ne kasautuivat hyvin pienelle alueelle. Ranking-menetelmässä näytteet jakautuivat vielä laajemmalle kuin parivertailussa. Parivertailu erotteli näytteet paremmin toisistaan kuin referenssimenetelmä. Ranking-menetelmän ja parivertailun välillä vastaavaa eroa erotuskyvyssä ei havaittu. Tulosten perusteella voidaan sanoa, että parivertailu

Computational visual quality of digitally printed images

The problem of understanding how humans perceive the quality of a reproduced image is of interest to researchers of many fields related to vision science and engineering: optics and material physics, image processing (compression and transfer), printing and media technology, and psychology. A measure for visual quality cannot be defined without ambiguity because it is ultimately the subjective opinion of an “end-user” observing the product. The purpose of this thesis is to devise computational methods to estimate the overall visual quality of prints, i.e. a numerical value that combines all the relevant attributes of the perceived image quality. The problem is limited to consider the perceived quality of printed photographs from the viewpoint of a consumer, and moreover, the study focuses only on digital printing methods, such as inkjet and electrophotography. The main contributions of this thesis are two novel methods to estimate the overall visual quality of prints. In the first method, the quality is computed as a visible difference between the reproduced image and the original digital (reference) image, which is assumed to have an ideal quality. The second method utilises instrumental print quality measures, such as colour densities, measured from printed technical test fields, and connects the instrumental measures to the overall quality via subjective attributes, i.e. attributes that directly contribute to the perceived quality, using a Bayesian network. Both approaches were evaluated and verified with real data, and shown to predict well the subjective evaluation results.

Toiminnanohjausjärjestelmä tarrapainolle

Tämä diplomityö on selostus tarraetikettejä valmistavalle yritykselle talon sisäisesti toteutetusta toiminnanohjausjärjestelmän kehitysprojektista. Projektissa luotiin ohjelmisto tukemaan yrityksen keskeisimpiä toimintoja, kuten myyntiä, asiakkuuksien hallintaa, tuotantoa, materiaalihallintoa sekä johdon päätöksentekoa. Työssä tarkastellaan ensin yrityksen menettelytapoja ja valmistusmenetelmiä, ja kerätään niistä konkreettisia vaatimuksia järjestelmälle. Nämä yhdistetään muista tutkimuksista kerättyihin toiminnanohjausjärjestelmien mahdollisuuksiin ja riskeihin sekä laaditaan näistä projektin tavoitteet. Seuraavaksi käydään läpi toteutuksessa tehdyt suunnitteluratkaisut ja niihin johtaneet seikat. Toteutetut toiminnot ja ominaisuudet esitellään perusteluineen. Lopuksi analysoidaan projektin onnistumista peilaten sitä muihin aiheeseen liittyviin tutkimustuloksiin. Käyttöönottoprosessin vaiheet ja siinä esiintyneet ongelmat käydään myös lyhyesti läpi.

Computational Evaluation of Print Unevenness According to Human Vision

Print quality and the printability of paper are very important attributes when modern printing applications are considered. In prints containing images, high print quality is a basic requirement. Tone unevenness and non uniform glossiness of printed products are the most disturbing factors influencing overall print quality. These defects are caused by non ideal interactions of paper, ink and printing devices in high speed printing processes. Since print quality is a perceptive characteristic, the measurement of unevenness according to human vision is a significant problem. In this thesis, the mottling phenomenon is studied. Mottling is a printing defect characterized by a spotty, non uniform appearance in solid printed areas. Print mottle is usually the result of uneven ink lay down or non uniform ink absorption across the paper surface, especially visible in mid tone imagery or areas of uniform color, such as solids and continuous tone screen builds. By using existing knowledge on visual perception and known methods to quantify print tone variation, a new method for print unevenness evaluation is introduced. The method is compared to previous results in the field and is supported by psychometric experiments. Pilot studies are made to estimate the effect of optical paper characteristics prior to printing, on the unevenness of the printed area after printing. Instrumental methods for print unevenness evaluation have been compared and the results of the comparison indicate that the proposed method produces better results in terms of visual evaluation correspondence. The method has been successfully implemented as ail industrial application and is proved to be a reliable substitute to visual expertise.

Influence of plasma modification on surface properties and offset printability of coated paper

The properties of the paper surface play a crucial role in ensuring suitable quality and runnability in various converting and finishing operations, such as printing. Plasma surface modification makes it possible to modify the surface chemistry of paper without altering the bulk material properties. This also makes it possible to investigate the role of the surface chemistry alone on printability without influencing the porous structure of the pigment-coated paper. Since the porous structure of a pigment coating controls both ink setting and optical properties, surface chemical changes created by a plasma modification have a potential to decouple these two effects and to permit a better optimization of them both. The aim of this work was to understand the effects of plasma surface modification on paper properties, and how it influences printability in the sheet-fed offset process. The objective was to broaden the fundamental understanding of the role of surface chemistry on offset printing. The effects of changing the hydrophilicity/ hydrophobicity and the surface chemical composition by plasma activation and plasma coatings on the properties of coated paper and on ink-paper interactions as well as on sheet-fed offset print quality were investigated. In addition, the durability of the plasma surface modification was studied. Nowadays, a typical sheet-fed offset press also contains units for surface finishing, for example UVvarnishing. The role of the surface chemistry on the UV-varnish absorption into highly permeable and porous pigment-coated paper was also investigated. With plasma activation it was possible to increase the surface energy and hydrophilicity of paper. Both polar and dispersion interactions were found to increase, although the change was greater in the polar interactions due to induced oxygen molecular groups. The results indicated that plasma activation takes place particularly in high molecular weight components such as the dispersion chemicals used to stabilize the pigment and latex particles. Surface composition, such as pigment and binder type, was found to influence the response to the plasma activation. The general trend was that pilot-scale treatment modified the surface chemistry without altering the physical coating structure, whereas excessive laboratory-scale treatment increased the surface roughness and reduced the surface strength, which led to micro-picking in printing. It was shown that pilot-scale plasma activation in combination with appropriate ink oils makes it possible to adjust the ink-setting rate. The ink-setting rate decreased with linseed-oil-based inks, probably due to increased acid-base interactions between the polar groups in the oil and the plasma-treated paper surface. With mineral-oil-based inks, the ink setting accelerated due to plasma activation. Hydrophobic plasma coatings were able to reduce or even prevent the absorption of dampening water into pigmentcoated paper, even when the dampening water was applied under the influence of nip pressure. A uniform hydrophobic plasma coating with sufficient chemical affinity with ink gave an improved print quality in terms of higher print density and lower print mottle. It was also shown that a fluorocarbon plasma coating reduced the free wetting of the UV-varnish into the highly permeable and porous pigment coating. However, when the UV-varnish was applied under the influence of nip pressure, which leads to forced wetting, the role of the surface chemical composition seems to be much less. A decay in surface energy and wettability occurred during the first weeks of storage after plasma activation, after which it leveled off. However, the oxygen/carbon elemental ratio did not decrease as a function of time, indicating that ageing could be caused by a re-orientation of polar groups or by a contamination of the surface. The plasma coatings appeared to be more stable when the hydrophobicity was higher, probably due to fewer interactions with oxygen and water vapor in the air.

Voyage pittoresque de Scandinavie. Cahier de vingt-quatre vues, avec descriptions ... : [C. É. Bourgevin Vialart, Count de Saint-Morys].

Author from BnF. - Year of printing from the preface.

Voyage pittoresque de Scandinavie. Cahier de vingt-quatre vues, avec descriptions ... : [C. É. Bourgevin Vialart, Count de Saint-Morys].

Author from BnF. - Year of printing from the preface.

Tilaus-toimitusprosessin kehittäminen eräässä painotalossa

Tämä diplomityö on tehty painotaloon. Yrityksen tilaus-toimitusketjua on kehitetty ennen diplomityötä. Muutoksen kohteena on ollut toimintamallit, laatu, läpäisy ja tuotanto- ja varastotilojen layout, lisäksi koneitakin on uusittu ja korjattu runsaasti. Muutosten yhteydessä henkilöstöä sopeutettiin vastaamaan uutta toimintamallia ja samalla myös johtamisen vastuu jaettiin uudelleen. Diplomityö koostuu kolmesta merkittävästä osasta ja sen tarkoituksena on kuvata sisäiset prosessit ja kehittää valittuja ongelmia. Ensimmäinen osa käsittelee leania ja sen teoriaa. Lisäksi määritellään lean-työkalut, joita työssä hyödynnetään. Toinen osa keskittyy kuvaamaan työn käytännön osuutta, jossa selvitetään prosessin nykytilaa. Suuri osa tätä diplomityötä on työn tutkimista ja sen kuvaamista yksinkertaisilla prosessikuvauksilla. Nykytilan kuvauksessa etsittiin myös ongelmakohtia, joita käytetään osittain tämän työn kehitysprojekteissa. Ongelmakohtien listan avulla voidaan toteuttaa jatkossa jatkuvan parantamisen projekteja. Kolmas osa työstä liittyy valittujen kehitysprojektien toteutukseen. Ensin työssä kuvataan jatkuvan parantamisen projektien työskentelytavat ja perustellaan syyt projektien valintaan. Valinnan jälkeen kuvataan valittujen projektien toteuttaminen ja lopuksi käydään läpi tulokset. Lisäksi yhteenvedossa esitellään työstä syntyvät jatkotoimenpide-ehdotukset. Kehitysprojektien tuloksien perusteella pystyttiin arvioimaan tulevia kehityskohteita ja niihin käytettäviä työkaluja. Koska kyseessä oli pilottiprojekti, oppimista tapahtui paljon ja tulokset saattavat näyttää positiivisimmilta kun kehitystoimintaa jatketaan. Tuloksina syntyivät prosessikuvaukset melkein jokaiseen työvaiheeseen. Tämän lisäksi prosessikuvausten yhteydessä syntyneitä kehitysehdotuksia voidaan pitää tuloksina. Ensimmäinen kehitysprojekteista oli työmääräimen kehittäminen. Työmääräintä muutettiin informatiivisemmaksi, mutta muu parantaminen jäi diplomityön ulkopuolelle. Toinen kehitysprojekti oli varastotuotteiden hallinnan kehittäminen, jossa aloitettiin ennakoida asiakkaan tilauksia ja varastojen arvot saatiin paremmin hallintaan. Tuloksia saavutetaan enemmän, mikäli toimintaa laajennetaan. Viimeisenä kehitysprojektina oli työpisteen toiminnan kehittäminen. Kehittämisessä keskityttiin pohjapiirroksen järkevöittämiseen, työtapojen vakiointiin ja lean-työkalu 5S toteutukseen. Työpisteen tehokkuutta saatiin nostettua jonkun verran, tosin painopiste oli uuden toimintatavan oppimisessa.

Enhancing performance of paper coatings by tailor-made plastic pigments

The paper industry is constantly looking for new ideas for improving paper products while competition and raw material prices are increasing. Many paper products are pigment coated. Coating layer is the top layer of paper, thus by modifying coating pigment also the paper itself can be altered and value added to the final product. In this thesis, synthesis of new plastic and hybrid pigments and their performance in paper and paperboard coating is reported. Two types of plastic pigments were studied: core-shell latexes and solid beads of maleimide copolymers. Core-shell latexes with partially crosslinked hydrophilic polymer core of poly(n-butyl acrylate-co-methacrylic acid) and a hard hydrophobic polystyrene shell were prepared to improve the optical properties of coated paper. In addition, the effect of different crosslinkers was analyzed and the best overall performance was achieved by the use of ethylene glycol dimethacrylate (EGDMA). Furthermore, the possibility to modify core-shell latex was investigated by introducing a new polymerizable optical brightening agent, 1-[(4-vinylphenoxy)methyl]-4-(2-henylethylenyl)benzene which gave promising results. The prepared core-shell latex pigments performed smoothly also in pilot coating and printing trials. The results demonstrated that by optimizing polymer composition, the optical and surface properties of coated paper can be significantly enhanced. The optimal reaction conditions were established for thermal imidization of poly(styrene-co-maleimide) (SMI) and poly(octadecene-co-maleimide) (OMI) from respective maleic anhydride copolymer precursors and ammonia in a solvent free process. The obtained aqueous dispersions of nanoparticle copolymers exhibited glass transition temperatures (Tg) between 140-170ºC and particle sizes from 50-230 nm. Furthermore, the maleimide copolymers were evaluated in paperboard coating as additional pigments. The maleimide copolymer nanoparticles were partly imbedded into the porous coating structure and therefore the full potential of optical property enhancement for paperboard was not achieved by this method. The possibility to modify maleimide copolymers was also studied. Modifications were carried out via N-substitution by replacing part of the ammonia in the imidization reaction with amines, such as triacetonediamine (TAD), aspartic acid (ASP) and fluorinated amines (2,2,2- trifluoroethylamine, TFEA and 2,2,3,3,4,4,4-heptafluorobuthylamine, HFBA). The obtained functional nanoparticles varied in size between 50-217 nm and their Tg from 150-180ºC. During the coating process the produced plastic pigments exhibited good runnability. No significant improvements were achieved in light stability with TAD modified copolymers whereas nanoparticles modified with aspartic acid and those containing fluorinated groups showed the desired changes in surface properties of the coated paperboard. Finally, reports on preliminary studies with organic-inorganic hybrids are presented. The hybrids prepared by an in situ polymerization reaction consisted of 30 wt% poly(styrene- co-maleimide) (SMI) and high levels of 70 wt% inorganic components of kaolin and/or alumina trihydrate. Scanning Electron Microscopy (SEM) images and characterization by Fourier Transform Infrared Spcetroscopy (FTIR) and X-Ray Diffraction (XRD) revealed that the hybrids had conventional composite structure and inorganic components were covered with precipitated SMI nanoparticles attached to the surface via hydrogen bonding. In paper coating, the hybrids had a beneficial effect on increasing gloss levels.