<p>Edge wicking, i.e. in-plane wetting, is an important parameter for liquid packaging board products. Before filling of the products at the dairy the web is being sterilised with hydrogen peroxide (H2O2). A tube is shaped and cut into packages which mean that new surfaces are created. If a short stop occurs in the sterilising bath the raw edges exposed to H2O2 could absorb the liquid and when the package later is being filled this absorption could lead to tube burst. For the end products it is also important to prevent the liquid from penetrating the raw edges of the board in order to maintain the functionality and fresh look of the package.</p><p>To control edge wicking different kinds of internal hydrophobic sizing agents are used. Alkyl ketene dimer (AKD) is the most common size in neutral sizing and rosin in conjunction with alum is the traditional acidic sizing agent. AKD and rosin size are often used in combination (dual sizing) to make the board hydrophobic.</p><p>The objective of this work was to examine the effects of the sizing agents on different pulps in different dosages. The pulps used in the sheet preparation were unbleached kraft pulp as well as bleached and unbleached CTMP refined to different levels. Apart from varying the size dosages, the wet sheets were also pressed at different levels to vary the density. The major part of the study included dual sizing but a minor part also concerned mono sized sheets.</p><p>The parameters investigated on the laboratory sheets were STFI-Density, hydrogen peroxide edge wicking, pressurised edge wicking, lactic acid edge wicking (LA) and AKD and rosin size content.</p><p>In hydrogen peroxide edge wicking the amount of size was the central source of improved wick index. The retention was therefore of great significance for the results. The dual sized sheets were found to give least edge wicking, due to the synergy effect between AKD and alum rosin size. The kraft pulps gave sheets with satisfactory edge wicking even at the lowest size dosage (1 kg/t) while CTMP required a dosage of 4 kg/t to reach the same wick index.</p><p>To achieve acceptable pressurised edge wicking values the most important parameter was found to be the density of the sheets. The kraft pulp sheets gave the lowest edge penetration while the high freeness CTMP sheets did not give satisfactory penetration resistant even at the highest size dosage.</p><p>The edge wicking of lactic acid could be prevented by sizing with AKD only. Sheets made from mono sized sheets containing rosin size did not manage to avoid a large in-plane wetting of the board structure. Hence, dual sizing to improve the edge wicking of lactic acid is not necessary. The density was found not to be an important parameter in lactic acid edge wicking, all the pulps got equal edge wicking regardless of density. Retention above 1 kg/t AKD in sheets was enough to prevent penetration. Retention above 1.5 kg/t AKD in sheet did not improve the edge wicking any further.</p><p>No significant difference in sizeability between unbleached and bleached CTMP was observed.</p>

Edge wicking, i.e. in-plane wetting, is an important parameter for liquid packaging board products. Before filling of the products at the dairy the web is being sterilised with hydrogen peroxide (H2O2). A tube is shaped and cut into packages which mean that new surfaces are created. If a short stop occurs in the sterilising bath the raw edges exposed to H2O2 could absorb the liquid and when the package later is being filled this absorption could lead to tube burst. For the end products it is also important to prevent the liquid from penetrating the raw edges of the board in order to maintain the functionality and fresh look of the package. To control edge wicking different kinds of internal hydrophobic sizing agents are used. Alkyl ketene dimer (AKD) is the most common size in neutral sizing and rosin in conjunction with alum is the traditional acidic sizing agent. AKD and rosin size are often used in combination (dual sizing) to make the board hydrophobic. The objective of this work was to examine the effects of the sizing agents on different pulps in different dosages. The pulps used in the sheet preparation were unbleached kraft pulp as well as bleached and unbleached CTMP refined to different levels. Apart from varying the size dosages, the wet sheets were also pressed at different levels to vary the density. The major part of the study included dual sizing but a minor part also concerned mono sized sheets. The parameters investigated on the laboratory sheets were STFI-Density, hydrogen peroxide edge wicking, pressurised edge wicking, lactic acid edge wicking (LA) and AKD and rosin size content. In hydrogen peroxide edge wicking the amount of size was the central source of improved wick index. The retention was therefore of great significance for the results. The dual sized sheets were found to give least edge wicking, due to the synergy effect between AKD and alum rosin size. The kraft pulps gave sheets with satisfactory edge wicking even at the lowest size dosage (1 kg/t) while CTMP required a dosage of 4 kg/t to reach the same wick index. To achieve acceptable pressurised edge wicking values the most important parameter was found to be the density of the sheets. The kraft pulp sheets gave the lowest edge penetration while the high freeness CTMP sheets did not give satisfactory penetration resistant even at the highest size dosage. The edge wicking of lactic acid could be prevented by sizing with AKD only. Sheets made from mono sized sheets containing rosin size did not manage to avoid a large in-plane wetting of the board structure. Hence, dual sizing to improve the edge wicking of lactic acid is not necessary. The density was found not to be an important parameter in lactic acid edge wicking, all the pulps got equal edge wicking regardless of density. Retention above 1 kg/t AKD in sheets was enough to prevent penetration. Retention above 1.5 kg/t AKD in sheet did not improve the edge wicking any further. No significant difference in sizeability between unbleached and bleached CTMP was observed.

Ett vanligt återkommande problem inom pappersindustrin är fläckar på den färdiga produkten. BillerudKorsnäs Gävle har genom undersökningar kommit fram till att en del fläckar som just nu uppkommer till stor del består av Alkyl keten dimer, AKD. AKD är ett lim som tillsätts i mälden för att öka hydrofobiciteten hos pappret eller kartongen. AKD partikeln skyddas av ett hölje bestående av katjonisk polymer för att partikeln lättare ska fästa på träfibrerna i processen. Om detta hölje blir instabilt ökar risken för bildning av agglomerat och en sämre retention på pappersmaskinen vilket i sin tur kan orsaka fläckar på den färdiga kartongen. Detta arbete för att undersöka stabiliteten hos AKD har därför gjorts.   För att undersöka stabiliteten hos AKD har olika processparametrars inverkan på AKD partikelns stabilitet undersökts. Tester gjordes på två olika AKD och de processparametrar som testats i detta arbete är temperatur, pH och salthalt. Även prover från processen har tagits ut för att undersöka om rena AKD prover kan relateras till processen. Proverna undersöktes i en flödescytometer för att detektera graden av hydrofobicitet hos partiklarna i proverna.   Resultaten visade att det testade temperaturspannet inte påverkade stabiliteten hos AKD partikeln nämnvärt. Försöken där pH förändrades kunde påvisa påverkan hos stabiliteten. Detta innebär att AKD i processen påverkas, och att uppkomsten av fläckar i kartongen delvis kan bero på instabiliteten hos AKD partikeln vid förändring av pH i processen. Stabiliteten hos ett utspätt prov påverkades inte nämnvärt under ett tidsintervall på 60 dagar. / A recurring problem in the paper industry is spots on the finished product. Through previous studies, Billerudkorsnäs Gävle has detected one of the sources of these stains to be Alkyl keten dimer (AKD). AKD is a glue that is added to the ground pulp to increase the hydrophobicity of the paper or cardboard. The AKD particle is protected by a cationic polymer to make it easier for the particle to attach to the fibers in the process. If the polymer becomes instable, the risk of the AKD particles forming agglomerate increases and the retention in the paper machine decrease, which can lead to stains on the finished cardboard. This work with the aim of investigation of the stability of AKD has therefore been done.   To investigate the stability of AKD, the impact of different process parameters on the AKD particle has been studied. Test has been done with two different AKD, and the process parameters tested in this work were temperature, pH and salinity. Samples from the process has also been studied to investigate if the pure AKD samples could be related to the process. All the samples were analyzed in a flow cytometry to detect the degree of hydrophobicity of the particles in the samples.   The result showed that the tested temperature range did not affect the stability of the AKD particles. The experiments where the pH were changed showed that the stability of the particles were affected. This means that AKD in the process is affected, and that the appearance of stains in the carton may partly be due to the instability of the AKD particle in changing the pH of the process. The stability of a diluted sample was not significantly affected over a 60 day time interval.

Ziel dieser Arbeit war es, die mechanistischen Abläufe bei der Papierleimung mit ASA besser zu verstehen und weiter aufzuklären, um vor allem Wechselwirkungen mit Füllstoffen und anderen chemischen Additiven zu minimieren. Dazu sollten analytische Verfahrensmethoden entwickelt werden, welche die bilanztechnische Verfolgung von ASA und dessen Reaktionsprodukten ermöglichen, um anschließend den Einfluss und die Wechselwirkungen verschiedenster Parameter auf die ASA-Leimung untersuchen zu können. Weiterhin sollte bei Untersuchungen zur Emulgierung versucht werden, die wichtigsten Einflussgrößen auf die Partikelgröße, Stabilität und Hydrolyse des ASA aufzuzeigen. Im ersten Teil der Arbeit konnten bei den Untersuchungen zur Emulgierung wichtige Einflussgrößen auf die Partikelgröße, Stabilität und Hydrolyse von ASA-Emulsionen aufgeklärt werden. Weiterhin wurde eine Methode zur genauen Bestimmung der Reaktionskinetik der ASA-Hydrolyse sowie der Ablagerungsneigung entwickelt. Bei den Untersuchungen zur analytischen Bestimmung wurde über die NIR-Spektroskopie ein einfaches Analyseverfahren zur exakten quantitativen Bestimmung von ASA und AKD entwickelt. Es wurde gefunden, dass eine quantitative Erfassung von synthetischen Leimungsmitteln (ASA / AKD) mittels NIR in den Regionen der CH2-Schwingungen um 4300 cm-1 und 5750 cm-1 mit hoher statistischer Genauigkeit möglich ist. Der Methodenfehler für die Bestimmung von AKD liegt bei ± 0,010 % und bei ± 0,013 % für ASA. Dadurch ist eine wesentlich genauere Bewertung von Wechselwirkungen bei der Leimung als bisher möglich, da nicht nur die Leimungswirkung, sondern über NIR auch Menge und Art (gebunden / ungebunden) an Leimungsmittel in einer bisher nicht erreichbaren Messzeit betrachtet werden können. Mittels HPLC und Pyrolyse-GC/MS konnten die erstellten NIR-Kalibrationen erfolgreich validiert werden. Im letzten Teil der Arbeit wurden Wechselwirkungen von ASA mit Füllstoffen und chemischen Additiven aufgeklärt, sowie mechanistische Grundlagen zur Leimung mit ASA erarbeitet. Hier hat sich gezeigt, dass der Mechanismus der ASA-Leimung nicht nur, wie oft in der Literatur beschrieben, auf eine Veresterung mit den Hydroxylgruppen der Cellulose zurückzuführen ist. Vielmehr ist die optimale Wirkung von Leimungsmitteln sehr stark von deren Verteilung, Mobilität und Orientierung abhängig. Weiterhin konnte festgestellt werden, dass der größte Anteil des Leimungsmittels im Papier in ungebundener (hydrolisierter) Form vorliegt und somit zur Wanderung (Migration) durch das Papiergefüge befähigt ist. Trotzdem kann der hydrolisierte Anteil deutlich zur Hydrophobierung des Papiers beitragen, wenn dieser richtig orientiert und fein verteilt ist. Schlecht orientierte Leimungsmittel tragen nicht zur Leimung bei bzw. können diese sogar reduzieren. In der vorliegenden Arbeit wurden unter Einsatz moderner Methoden wichtige Grundlagen zur Papierleimung mit ASA erarbeitet. Dabei wurden insbesondere Beiträge zu den Themen Emulgierung, Hydrolyse- und Ablagerungsneigung, analytische Bestimmung, Wechselwirkungen sowie Mechanismen von ASA geleistet. Diese Ergebnisse zeigen Möglichkeiten auf, wie in Unternehmen der Papierindustrie zukünftig ASA-Leimungsmittel gezielter dosiert, Produktionsstörungen vermieden und Kosten reduziert werden können. / The purpose of this work was to develop a deeper understanding of the mechanisms in ASA sizing and to minimise interactions with fillers and other chemical additives. Therefore analytical test methods were developed, to enable a simple mass balance approach for ASA and its reaction products. Afterwards, the influence of various factors affecting ASA sizing and retention could be investigated and explained. Furthermore, the most important factors which influence particle size, stability, and hydrolysis of ASA emulsions had to be determined. In the first part of this work, studies regarding the emulsification of ASA were carried out. Here, the most important factors with regard to particle size, stability, and hydrolysis of ASA emulsions were investigated. Furthermore, a method for the exact determination of ASA hydrolysis as well as the agglomeration tendency was developed. For the investigations regarding the analytical determination, a fast and easy-to-use method for the quantification of ASA and AKD has been developed. The investigations have shown that a quantitative determination of synthetic sizing agents (ASA / AKD) is possible using NIR spectroscopy. With the help of multivariate data analysis and PLS regression, mainly the region of the CH2-bands around 4300 cm-1 and 5750 cm-1 were evaluated. The prediction error (RMSEP) for the determination of AKD is 0.01 %, and 0.013 % for ASA. Even an analysis of the percentage of bound and unbound ASA / AKD is possible by NIR spectroscopy of extracted paper samples. Thus, a fast and detailed investigation of mechanisms as regards sizing is possible. The developed NIR methods were validated using HPLC and Pyrolysis-GC/MS. In the last part of the work, interactions of ASA with fillers and chemical additives were investigated, and mechanisms of ASA sizing were studied. It was shown that the mechanism of ASA sizing - as often described in the literature - can not only be attributed to the esterification with the hydroxyl groups of the cellulose. In fact, the optimal effect of sizing agents is much more dependant on a fine distribution, mobility and orientation of ASA molecules. It was observed that the main part of the ASA is present in an unbound (hydrolysed) form and therefore is able to migrate through the paper structure. However, the hydrolysed ASA can significantly contribute to sizing when it is finely distributed and well orientated. Sizing agents orientated in the opposite do not contribute to sizing but they can even decrease the existing sizing level. To summarize, it can be concluded that, in this work important fundamentals as regards ASA sizing were developed using modern test methods. Thereby important contributions were made to the topics of emulsification, hydrolysis- and emulsion-stability, analytical determination, interactions and mechanisms of ASA. These results show possibilities how ASA sizing agents can be used more effectively, process disturbances avoided, and costs reduced.

Ce travail de thèse a été conduit dans le but d’élaborer des papiers résistants à l’eau liquide et ayant des propriétés antifongiques, ce par utilisation de composés biosourcés. Deux approches ont été proposées : soit une modification en surface par enduction, soit une modification des fibres de cellulose. Dans le cas de la modification en surface, deux formulations d’enductions ont été étudiées. La première, composée de chitosane et de carbonate de calcium précipité (PCC) modifié, a été utilisée pour limiter le développement de moisissures et améliorer la résistance des papiers à l’eau. La formulation incorporant 20 % de PCC modifié a montré un retard de croissance significatif de la souche fongique sélectionnée en tant que souche cible. La seconde formulation, destinée à améliorer la résistance à l’eau des papiers, par enduction d'un latex prévulcanisé d’hévéa, a montré de très bons résultats, conduisant à une réduction de près de 95 % de l’absorption d’eau liquide. Toutefois, une perte d’opacité des papiers a été observée après pénétration de l’eau dans le matériau. Par conséquent, une seconde approche a été proposée, basée sur la modification physico-chimique des fibres de cellulose. Un procédé d’hybridation a été utilisé, permettant l’adsorption d’acide stéarique sur le PCC synthétisé in situ à la surface des fibres de cellulose. Un compromis entre la rétention des charges, la résistance à l’eau et les propriétés mécaniques a pu être proposé. Après détermination des conditions optimales de mise à l’échelle industrielle du procédé d’hybridation, un essai industriel a pu être réalisé et a conduit à des résultats prometteurs. / The present work investigates the creation of water-resistant and antifungal papers by using biobased compounds. Two approaches were developed: A surface modification by coating or a cellulose fibre modification. For the coating approach, two formulations were studied. The first one, consisting in chitosan and modified precipitated calcium carbonate (PCC) was mainly used to limit the development of molds while improving paper water resistance. The formulation incorporating 20 % of modified PCC showed a significant increase of the lag phase of the target fungal strain. The second coating formulation, especially designed to improve papers water resistance by a coating layer of prevulcanized natural rubber latex, showed very positive results, leading to 95 % reduction of liquid water absorption but with a negative impact on the material opacity after water penetration. As a consequence, physico-chemical modification of cellulose fibre was investigated in a second approach. An hybridization process was used, leading to stearic acid adsorption on in situ PCC synthesized at the surface of cellulosic fibres. A compromise between fillers retention, water resistance and mechanical properties was found. After determination of optimal conditions carried out to an industrial scale up, an industrial pilot was performed and gave promising results.

Ziel dieser Arbeit war es, die mechanistischen Abläufe bei der Papierleimung mit ASA besser zu verstehen und weiter aufzuklären, um vor allem Wechselwirkungen mit Füllstoffen und anderen chemischen Additiven zu minimieren. Dazu sollten analytische Verfahrensmethoden entwickelt werden, welche die bilanztechnische Verfolgung von ASA und dessen Reaktionsprodukten ermöglichen, um anschließend den Einfluss und die Wechselwirkungen verschiedenster Parameter auf die ASA-Leimung untersuchen zu können. Weiterhin sollte bei Untersuchungen zur Emulgierung versucht werden, die wichtigsten Einflussgrößen auf die Partikelgröße, Stabilität und Hydrolyse des ASA aufzuzeigen. Im ersten Teil der Arbeit konnten bei den Untersuchungen zur Emulgierung wichtige Einflussgrößen auf die Partikelgröße, Stabilität und Hydrolyse von ASA-Emulsionen aufgeklärt werden. Weiterhin wurde eine Methode zur genauen Bestimmung der Reaktionskinetik der ASA-Hydrolyse sowie der Ablagerungsneigung entwickelt. Bei den Untersuchungen zur analytischen Bestimmung wurde über die NIR-Spektroskopie ein einfaches Analyseverfahren zur exakten quantitativen Bestimmung von ASA und AKD entwickelt. Es wurde gefunden, dass eine quantitative Erfassung von synthetischen Leimungsmitteln (ASA / AKD) mittels NIR in den Regionen der CH2-Schwingungen um 4300 cm-1 und 5750 cm-1 mit hoher statistischer Genauigkeit möglich ist. Der Methodenfehler für die Bestimmung von AKD liegt bei ± 0,010 % und bei ± 0,013 % für ASA. Dadurch ist eine wesentlich genauere Bewertung von Wechselwirkungen bei der Leimung als bisher möglich, da nicht nur die Leimungswirkung, sondern über NIR auch Menge und Art (gebunden / ungebunden) an Leimungsmittel in einer bisher nicht erreichbaren Messzeit betrachtet werden können. Mittels HPLC und Pyrolyse-GC/MS konnten die erstellten NIR-Kalibrationen erfolgreich validiert werden. Im letzten Teil der Arbeit wurden Wechselwirkungen von ASA mit Füllstoffen und chemischen Additiven aufgeklärt, sowie mechanistische Grundlagen zur Leimung mit ASA erarbeitet. Hier hat sich gezeigt, dass der Mechanismus der ASA-Leimung nicht nur, wie oft in der Literatur beschrieben, auf eine Veresterung mit den Hydroxylgruppen der Cellulose zurückzuführen ist. Vielmehr ist die optimale Wirkung von Leimungsmitteln sehr stark von deren Verteilung, Mobilität und Orientierung abhängig. Weiterhin konnte festgestellt werden, dass der größte Anteil des Leimungsmittels im Papier in ungebundener (hydrolisierter) Form vorliegt und somit zur Wanderung (Migration) durch das Papiergefüge befähigt ist. Trotzdem kann der hydrolisierte Anteil deutlich zur Hydrophobierung des Papiers beitragen, wenn dieser richtig orientiert und fein verteilt ist. Schlecht orientierte Leimungsmittel tragen nicht zur Leimung bei bzw. können diese sogar reduzieren. In der vorliegenden Arbeit wurden unter Einsatz moderner Methoden wichtige Grundlagen zur Papierleimung mit ASA erarbeitet. Dabei wurden insbesondere Beiträge zu den Themen Emulgierung, Hydrolyse- und Ablagerungsneigung, analytische Bestimmung, Wechselwirkungen sowie Mechanismen von ASA geleistet. Diese Ergebnisse zeigen Möglichkeiten auf, wie in Unternehmen der Papierindustrie zukünftig ASA-Leimungsmittel gezielter dosiert, Produktionsstörungen vermieden und Kosten reduziert werden können. / The purpose of this work was to develop a deeper understanding of the mechanisms in ASA sizing and to minimise interactions with fillers and other chemical additives. Therefore analytical test methods were developed, to enable a simple mass balance approach for ASA and its reaction products. Afterwards, the influence of various factors affecting ASA sizing and retention could be investigated and explained. Furthermore, the most important factors which influence particle size, stability, and hydrolysis of ASA emulsions had to be determined. In the first part of this work, studies regarding the emulsification of ASA were carried out. Here, the most important factors with regard to particle size, stability, and hydrolysis of ASA emulsions were investigated. Furthermore, a method for the exact determination of ASA hydrolysis as well as the agglomeration tendency was developed. For the investigations regarding the analytical determination, a fast and easy-to-use method for the quantification of ASA and AKD has been developed. The investigations have shown that a quantitative determination of synthetic sizing agents (ASA / AKD) is possible using NIR spectroscopy. With the help of multivariate data analysis and PLS regression, mainly the region of the CH2-bands around 4300 cm-1 and 5750 cm-1 were evaluated. The prediction error (RMSEP) for the determination of AKD is 0.01 %, and 0.013 % for ASA. Even an analysis of the percentage of bound and unbound ASA / AKD is possible by NIR spectroscopy of extracted paper samples. Thus, a fast and detailed investigation of mechanisms as regards sizing is possible. The developed NIR methods were validated using HPLC and Pyrolysis-GC/MS. In the last part of the work, interactions of ASA with fillers and chemical additives were investigated, and mechanisms of ASA sizing were studied. It was shown that the mechanism of ASA sizing - as often described in the literature - can not only be attributed to the esterification with the hydroxyl groups of the cellulose. In fact, the optimal effect of sizing agents is much more dependant on a fine distribution, mobility and orientation of ASA molecules. It was observed that the main part of the ASA is present in an unbound (hydrolysed) form and therefore is able to migrate through the paper structure. However, the hydrolysed ASA can significantly contribute to sizing when it is finely distributed and well orientated. Sizing agents orientated in the opposite do not contribute to sizing but they can even decrease the existing sizing level. To summarize, it can be concluded that, in this work important fundamentals as regards ASA sizing were developed using modern test methods. Thereby important contributions were made to the topics of emulsification, hydrolysis- and emulsion-stability, analytical determination, interactions and mechanisms of ASA. These results show possibilities how ASA sizing agents can be used more effectively, process disturbances avoided, and costs reduced.

Crack formation in concrete structures due to various load and non-load factors leading to degradation of service life is very common. Repair and maintenance operations are, therefore, necessary to prevent cracks propagating and reducing the service life of the structures. Accessibility to affected areas can, however, be difficult and the reconstruction and maintenance of concrete buildings are expensive in labor and capital. Autonomous healing by encapsulated bacteria-based self-healing agents is a possible solution. In this study, a novel bacteria-based healing agent was investigated in order to test the self-healing efficiency of the specimens in comparison to the commonly used healing agents made of lactic acid derivatives. (PLA). The novel integrated healing agent is a non-toxic, biodegradable dissolved inorganic carbon substrate derived from wastewater that has been used as an encapsulation material for spores of cohnii bacteria in the Bacillus gene family and for nutrients made up of yeast extract. This dissolved inorganic carbon substrate is a bioplastic made by the bacteria in wastewater known as alkanoate derivatives (AKD). To assess the effect of these healing agents on the mortar characteristics, quantification and characterization of the self-healing were conducted. The quantification of the self-healing efficiency was performed by various experimental techniques such as light microscopy, water permeability, chloride ion permeability, and thermogravimetric analysis whereas the material characterization was investigated by x-ray diffraction and environmental scanning electron microscope. Moreover, a statistical analysis was performed to study the correlation of self-healing efficiency between various experimental techniques. The incorporated dosages of healing agents adopted were 2.6% and 5% by weight of cement. Complete immersion in water was considered to be the condition of treatment of the specimen for healing at two separate periods of 28 and 56 days. The crack widths investigated were in the range of 0.04 to 0.8 mm. The quantification and characterization tests indicated that bacterial containing mortar series especially PLA and AKD at 5% dosage displayed a higher self-healing performance and an indication of precipitated calcium carbonate in the crack mouth. However, the results from the chloride migration test didn’t show any influence by the self-healing healing agents. Furthermore, the statistical analysis identified a major impact of the internal crack geometry on the difference in self-healing ratios, also in the cases where effective crack width is equal. / Sprickbildning i betongkonstruktioner p.g.a. olika laster och lastoberoende faktorer som leder till förkortning av livslängden är mycket vanligt förekommande. Reparation och underhåll är därför nödvändiga för att förhindra att sprickorna propagerar och reduceras konstruktionernas livslängd. Möjligheterna att komma åt de skadade partierna kan dock vara svåra och reparationerna är vanligen både arbetsintensiva och kostsamma. Självläkning med ingjutna bakteriebaserade, självläkande tillsatser är en möjlig lösning på problemet. I denna studie undersöktes en ny bakteriebaserat självläkande tillsats för att prova den självläkande förmågan i jämförelse med vanligt förekommande självläkande tillsatser av mjölksyrederivat (PLA). Den nya integrerade självläkande tillsatsen är en giftfri, biologiskt nedbrytningsbar, oorganisk kolsubstratslösning utvunnen ur avloppsvatten, en tillsats som har använts som ett inkapslingsmaterial för sporer från cohnii-bakterier från bacillussläktet och från näringsämnen framställda ur jästextrakt. Denna kolsubstratslösning är en bioplast framställd ur avloppsvatten och känd som alkanoatderivat (AKD). För att bestämma effekten av dessa självläkande tillsatser på cement bruks egenskaper genomfördes kvantifiering och karakterisering av självläkningen. Kvantifieringen av självläkningens effektivitet utfördes genom olika experimentella metoder såsom ljusmikroskopi, vattengenomsläpplighet, kloridjonstransport och termogravimetriska analyser medan materialkarakteriseringen utfördes med röntgendiffraktion och svepelektronmikroskop (ESEM). Vidare genomfördes en statistisk analys för att undersöka korrelationen mellan olika experimentella metoder. De doser av självläkande tillsatser som användes var 2,6 och 5 % av cementvikten. Fullständig nedsänkning i vatten ansågs vara den lämpligaste lagringen för självläkning under två olika tidsperioder på 28 respektive 56 dygn. De sprickbredder som studerades låg i intervallet 0.04 till 0.8 mm. Försöken kring kvantifiering och karakterisering indikerade att bruken innehållande bakterier, i synnerhet 5 % PLA och AKD, utvecklade en högre form av självläkande beteende och en förekomst av kalciumkarbonat i sprickspetsen. Resultaten från försöken kring kloridtransport visade emellertid inga tecken på någon effekt från de självläkande tillsatserna. Vidare identifierades i den statistiska analysen att inre sprickbildning har stor betydelse för självläkningseffekten även i fall där den effektiva sprickbredden är lika stor.

This diploma thesis deals with issue of quality monitoring and final product testing at the AKD line. Output of this thesis is calculation of testing time optimization by Weibull distribution. In the beginning reader is familiar with AKD device, what quality management is and ways how to test final products in electrotechnical manufacturing. Main goal of this thesis is to describe differences between testing methods and optimize Burn-In testing method.

Sizing (hydrophobization) is one of the most important process steps within the added-value chain of about 1/3rd of the worldwide produced paper & board products. Even though sizing with so-called reactive sizing agents, such as alkenyl succinic anhydride (ASA) was implemented in the paper industry decades ago, there is no total clarity yet about the detailed chemical and physical mechanisms that lead to their performance. Previous research was carried out on the role of different factors influencing the sizing performance, such as bonding between ASA and cellulose, ASA hydrolysis, size revision as well as the most important interactions with stock components, process parameters and additives during the paper making process. However, it was not yet possible to develop a holistic model for the explanation of the sizing performance given in real life application. This thesis describes a novel physico-chemical approach to this problem by including results from previous research and combining these with a wide field of own basic research and a newly developed method that allows tracing back the actual localization of ASA within the sheet structure. The carried out measurements and trial sets for the basic field of research served to evaluate the stock and process parameters that most dominantly influence the sizing performance of ASA. Interactions with additives other than retention aids were not taken into account. The results show that parameters, such as the content of secondary fibers, the degree of refining, the water hardness as well as the suspension conductivity, are of highest significance. The sample sets of the trials with the major impacting parameters were additionally analyzed by a newly developed localization method in order to better understand the main influencing factors. This method is based on optical localization of ASA within the sheet structure by confocal white light microscopy. In order to fulfill the requirements at magnification rates of factor 100 optical zoom, it was necessary to improve the contrast between ASA and cellulose. Therefore, ASA was pretreated with an inert red diazo dye, which does not have any impact on neither the sizing nor the handling properties of ASA. Laboratory hand sheets that were sized with dyed ASA, were analyzed by means of their sizing performance in correlation to measurable ASA agglomerations in the sheet structure. The sizing performance was measured by ultrasonic penetration analysis. The agglomeration behavior of ASA was analyzed automatically by multiple random imaging of a sample area of approx. 8650 µm² with a minimum resolution for particles of 500 nm in size. The gained results were interpreted by full factorial design of experiments (DOE). The trials were carried out with ASA dosages between 0% and 0.8% on laboratory hand sheets, made of 80% bleached eucalyptus short fiber kraft pulp and 20% northern bleached softwood kraft pulp, beaten to SR° 30, produced with a RDA sheet former at a base weight of 100 g/m² oven dry. The results show that there is a defined correlation between the ASA dosage, the sizing performance and the number and area of ASA agglomerates to be found in the sheet structure. It was also possible to show that the agglomeration behavior is highly influenced by external factors like furnish composition and process parameters. This enables a new approach to the explanation of sizing performance, by making it possible to not only examine the performance of the sizing agent, but to closely look at the predominant position where it is located in the sheet structure. These results lead to the explanation that the phenomenon of sizing is by far not a pure chemical process but rather a more physical one. Based on the gained findings it was possible so far to optimize the ASA sizing process in industrial-scale by means of ~ 50% less ASA consumption at a steady degree of sizing and improved physical sheet properties.

Sizing (hydrophobization) is one of the most important process steps within the added-value chain of about 1/3rd of the worldwide produced paper & board products. Even though sizing with so-called reactive sizing agents, such as alkenyl succinic anhydride (ASA) was implemented in the paper industry decades ago, there is no total clarity yet about the detailed chemical and physical mechanisms that lead to their performance. Previous research was carried out on the role of different factors influencing the sizing performance, such as bonding between ASA and cellulose, ASA hydrolysis, size revision as well as the most important interactions with stock components, process parameters and additives during the paper making process. However, it was not yet possible to develop a holistic model for the explanation of the sizing performance given in real life application. This thesis describes a novel physico-chemical approach to this problem by including results from previous research and combining these with a wide field of own basic research and a newly developed method that allows tracing back the actual localization of ASA within the sheet structure. The carried out measurements and trial sets for the basic field of research served to evaluate the stock and process parameters that most dominantly influence the sizing performance of ASA. Interactions with additives other than retention aids were not taken into account. The results show that parameters, such as the content of secondary fibers, the degree of refining, the water hardness as well as the suspension conductivity, are of highest significance. The sample sets of the trials with the major impacting parameters were additionally analyzed by a newly developed localization method in order to better understand the main influencing factors. This method is based on optical localization of ASA within the sheet structure by confocal white light microscopy. In order to fulfill the requirements at magnification rates of factor 100 optical zoom, it was necessary to improve the contrast between ASA and cellulose. Therefore, ASA was pretreated with an inert red diazo dye, which does not have any impact on neither the sizing nor the handling properties of ASA. Laboratory hand sheets that were sized with dyed ASA, were analyzed by means of their sizing performance in correlation to measurable ASA agglomerations in the sheet structure. The sizing performance was measured by ultrasonic penetration analysis. The agglomeration behavior of ASA was analyzed automatically by multiple random imaging of a sample area of approx. 8650 µm² with a minimum resolution for particles of 500 nm in size. The gained results were interpreted by full factorial design of experiments (DOE). The trials were carried out with ASA dosages between 0% and 0.8% on laboratory hand sheets, made of 80% bleached eucalyptus short fiber kraft pulp and 20% northern bleached softwood kraft pulp, beaten to SR° 30, produced with a RDA sheet former at a base weight of 100 g/m² oven dry. The results show that there is a defined correlation between the ASA dosage, the sizing performance and the number and area of ASA agglomerates to be found in the sheet structure. It was also possible to show that the agglomeration behavior is highly influenced by external factors like furnish composition and process parameters. This enables a new approach to the explanation of sizing performance, by making it possible to not only examine the performance of the sizing agent, but to closely look at the predominant position where it is located in the sheet structure. These results lead to the explanation that the phenomenon of sizing is by far not a pure chemical process but rather a more physical one. Based on the gained findings it was possible so far to optimize the ASA sizing process in industrial-scale by means of ~ 50% less ASA consumption at a steady degree of sizing and improved physical sheet properties.:Acknowledgment I Abstract III Table of Content V List of Illustrations XI List of Tables XVI List of Formulas XVII List of Abbreviations XVIII 1 Introduction and Problem Description 1 1.1 Initial Situation 1 1.2 Objective 2 2 Theoretical Approach 3 2.1 The Modern Paper & Board Industry on the Example of Germany 3 2.1.1 Raw Materials for the Production of Paper & Board 5 2.2 The Sizing of Paper & Board 8 2.2.1 Introduction to Paper & Board Sizing 8 2.2.2 The Definition of Paper & Board Sizing 10 2.2.3 The Global Markets for Sized Paper & Board Products and Sizing Agents 11 2.2.4 Physical and Chemical Background to the Mechanisms of Surface-Wetting and Penetration 13 2.2.4.1 Surface Wetting 14 2.2.4.2 Liquid Penetration 15 2.2.5 Surface and Internal Sizing 17 2.2.6 Sizing Agents 18 2.2.6.1 Alkenyl Succinic Anhydride (ASA) 19 2.2.6.2 Rosin Sizes 19 2.2.6.3 Alkylketen Dimer (AKD) 23 2.2.6.4 Polymeric Sizing Agents (PSA) 26 2.2.7 Determination of the Sizing Degree (Performance Analysis) 28 2.2.7.1 Cobb Water Absorption 29 2.2.7.2 Contact Angle Measurement 30 2.2.7.3 Penetration Dynamics Analysis 31 2.2.7.4 Further Qualitative Analysis Methods 33 2.2.7.4.1 Ink Stroke 33 2.2.7.4.2 Immersion Test 33 2.2.7.4.3 Floating Test 34 2.2.7.4.4 Hercules Sizing Tester (HST) 34 2.2.8 Sizing Agent Detection (Qualitative Analysis) and Determination of the Sizing Agent Content (Quantitative Analysis) 35 2.2.8.1 Destructive Methods 35 2.2.8.2 Non Destructive Methods 36 2.3 Alkenyl Succinic Anhydride (ASA) 36 2.3.1.1 Chemical Composition and Production of ASA 37 2.3.1.2 Mechanistic Reaction Models 39 2.3.1.3 ASA Application 42 2.3.1.3.1 Emulsification 42 2.3.1.3.2 Dosing 44 2.3.1.4 Mechanistic Steps of ASA Sizing 46 2.3.2 Physico-Chemical Aspects during ASA Sizing 48 2.3.2.1 Reaction Plausibility 48 2.3.2.1.1 Educt-Product Balance / Kinetics 48 2.3.2.1.2 Energetics 51 2.3.2.1.3 Sterics 52 2.3.2.2 Phenomena based on Sizing Agent Mobility 53 2.3.2.2.1 Sizing Agent Orientation 54 2.3.2.2.2 Intra-Molecular Orientation 55 2.3.2.2.3 Sizing Agent Agglomeration 55 2.3.2.2.4 Fugitive Sizing / Sizing Loss / Size Reversion 56 2.3.2.2.5 Sizing Agent Migration 58 2.3.2.2.6 Sizing Reactivation / Sizing Agent Reorientation 59 2.3.3 Causes for Interactions during ASA Sizing 60 2.3.3.1 Process Parameters 61 2.3.3.1.1 Temperature 61 2.3.3.1.2 pH-Value 62 2.3.3.1.3 Water Hardness 63 2.3.3.2 Fiber Types 64 2.3.3.3 Filler Types 65 2.3.3.4 Cationic Additives 66 2.3.3.5 Anionic Additives 67 2.3.3.6 Surface-Active Additives 68 2.4 Limitations of State-of-the-Art ASA-Sizing Analysis 69 2.5 Optical ASA Localization 71 2.5.1 General Background 71 2.5.2 Confocal Microscopy 72 2.5.2.1 Principle 72 2.5.2.2 Features, Advantage and Applicability for Paper-Component Analysis 74 2.5.3 Dying / Staining 75 3 Discussion of Results 77 3.1 Localization of ASA within the Sheet Structure 77 3.1.1 Choice of Dyes 77 3.1.1.1 Dye Type 78 3.1.1.2 Evaluation of Dye/ASA Mixtures 80 3.1.1.2.1 Maximum Soluble Dye Concentration 80 3.1.1.2.2 Thin Layer Chromatography 81 3.1.1.2.3 FTIR-Spectroscopy 82 3.1.1.3 Evaluation of the D-ASA Emulsion 84 3.1.1.4 Paper Chromatography with D-ASA & F-ASA Emulsions 85 3.1.1.5 Evaluation of the D-ASA Emulsion’s Sizing Efficiency 86 3.1.2 The Localization Method 87 3.1.2.1 The Correlation between ASA Distribution and Agglomeration 88 3.1.2.2 Measurement Settings 89 3.1.2.3 Manual Analysis 90 3.1.2.4 Automated Analysis 92 3.1.2.4.1 Automated Localization / Microscopy Measurement 92 3.1.2.4.2 Automated Analysis / Image-Processing 93 3.1.2.5 Result Interpretation and Example Results 96 3.1.2.6 Reproducibility 97 3.1.2.7 Sample Mapping 98 3.1.3 Approaches to Localization-Method Validation 102 3.1.3.1 Raman Spectroscopy 102 3.1.3.2 Confocal Laser Scanning Fluorescent Microscopy 102 3.1.3.3 Decolorization 103 3.2 Factors Impacting the Sizing Behavior of ASA 104 3.2.1 ASA Type 105 3.2.2 Emulsion Parameters 107 3.2.2.1 Hydrolyzed ASA Content 107 3.2.2.2 ASA/Starch Ratio 109 3.2.2.3 Emulsion Age 110 3.2.3 Stock Parameters 111 3.2.3.1 Long Fiber/Short Fiber Ratio 111 3.2.3.2 Furnish Type 112 3.2.3.3 Degree of Refining 114 3.2.3.4 Filler Type/Content 116 3.2.4 Process Parameters 119 3.2.4.1 Temperature 119 3.2.4.2 pH-Value 120 3.2.4.3 Conductivity 122 3.2.4.4 Water Hardness 123 3.2.4.5 Shear Rate 125 3.2.4.6 Dwell Time 127 3.2.4.7 Dosing Position & Dosing Order 128 3.2.4.8 Drying 130 3.2.4.9 Aging 131 3.3 Factors Impacting the Localization Behavior of ASA 132 3.3.1 Degree of Refining 132 3.3.2 Sheet Forming Conductivity 135 3.3.3 Water Hardness 136 3.3.4 Retention Aid (PAM) 137 3.3.5 Contact Curing 138 3.3.6 Accelerated Aging 139 3.4 Main Optimization Approach 141 3.4.1 Optimization of ASA Sizing Performance Characteristics 142 3.4.2 Emulsion Modification 144 3.4.2.1 Lab Trials / RDA Sheet Forming 146 3.4.2.2 TPM Trials 147 3.4.2.3 Industrial-Scale Trials 149 3.4.2.4 Correlation between Sizing Performance Optimization and Agglomeration Behavior on the Example of PAAE 152 3.5 Holistic Approach to Sizing Performance Explanation 154 4 Experimental Approach 157 4.1 Characterization of Methods, Measurements and Chemicals used for the Optical Localization-Analysis of ASA 157 4.1.1 Characterization of used Chemicals 157 4.1.1.1 Preparation of Dyed-ASA Solutions 157 4.1.1.2 Thin Layer Chromatography 157 4.1.1.3 Fourier Transformed Infrared Spectroscopy 157 4.1.1.4 Emulsification of ASA 158 4.1.1.5 Paper Chromatography 159 4.1.1.6 Particle Size Measurement 159 4.1.2 Optical Analysis of ASA Agglomerates 160 4.1.2.1 Microscopy 160 4.1.2.2 Automated Analysis 163 4.1.2.2.1 Adobe Photoshop 163 4.1.2.2.2 Adobe Illustrator 164 4.1.2.3 Confocal Laser Scanning Fluorescent Microscopy 166 4.2 Characterization of Used Standard Methods and Measurements 166 4.2.1 Stock and Paper Properties 166 4.2.1.1 Stock pH, Conductivity and Temperature Measurement 166 4.2.1.2 Dry Content / Consistency Measurement 167 4.2.1.3 Drainability (Schopper-Riegler) Measurement 167 4.2.1.4 Base Weight Measurement 168 4.2.1.5 Ultrasonic Penetration Measurement 168 4.2.1.6 Contact Angle Measurement 169 4.2.1.1 Cobb Measurement 169 4.2.1.2 Air Permeability Measurements 170 4.2.1.3 Tensile Strength Measurements 170 4.2.2 Preparation of Sample Sheets 171 4.2.2.1 Stock Preparation 171 4.2.2.2 Laboratory Refining (Valley Beater) 171 4.2.2.3 RDA Sheet Forming 171 4.2.2.4 Additive Dosing 173 4.2.2.5 Contact Curing 174 4.2.2.6 Hot Air Curing 174 4.2.2.7 Sample Aging 174 4.2.2.8 Preparation of Hydrolyzed ASA 175 4.2.2.9 Trial Paper Machine 175 4.2.2.10 Industrial-Scale Board Machine 177 4.3 Characterization of used Materials 178 4.3.1 Fibers 178 4.3.1.1 Reference Stock System 178 4.3.1.2 OCC Fibers 179 4.3.1.3 DIP Fibers 179 4.3.2 Fillers 180 4.3.3 Chemical Additives 180 4.3.3.1 ASA 180 4.3.3.2 Starches 181 4.3.3.3 Retention Aids 181 4.3.3.4 Poly Aluminum Compounds 181 4.3.3.5 Wet Strength Resin 181 4.3.4 Characterization of used Additives 182 4.3.4.1 Solids Content 182 4.4 Description of Implemented Advanced Data Analysis- and Visualization Methods 183 4.4.1 Design of Experiments (DOE183 4.4.2 Contour Plots 184 4.4.3 Box-Whisker Graphs 185 5 Conclusion 186 6 Outlook for Further Work 191 7 Bibliography 192 Appendix 207 7.1 Localization Method Reproducibility 207 7.2 DOE - Coefficient Lists 208 7.2.1 Trial 3.3.4 – Impact of Retention Aid (PAM) on Agglomeration Behavior and Sizing Performance 208 7.2.2 Trial 3.3.5 – Impact of Contact Curing on Agglomeration Behavior and Sizing Performance 208 7.2.3 Trial 3.3.6 – Impact of Accelerated Aging on Agglomeration Behavior and Sizing Performance 209