Thesis (M.S.)--Oregon State University, 2005. / Printout. Includes bibliographical references (leaves 66-72). Also available on the World Wide Web.

Thesis (M.S.)--Wisconsin State University-La Crosse, 1967. / Includes bibliographical references (leaves [83]-87).

Como qualquer material fabricado a partir de fibras de madeira, o papel também apresenta variações dimensionais decorrentes de modificações no seu teor de umidade. O presente trabalho aborda o comportamento desta propriedade do papel, denominada higroexpansibilidade, medida em papel reprográfico fabricado a partir de fibras de eucalipto, durante o processo de produção em uma máquina industrial. O estudo foi realizado com amostras de papel de 75 g/m2, coletadas em diversos pontos de uma máquina comercial, operando à velocidade de 1256 m/min. No estudo, encontram-se dados de higroexpansibilidade medidos ao longo da máquina de papel, desde a seção de formação até o acabamento, e na direção transversal da folha na enroladeira. A análise dos resultados permite a verificação de influências das operações e tratamentos envolvidos na fabricação do papel (formação, prensagem, secagem e acabamento) sobre a sua higroexpansibilidade. Os resultados das medições desta propriedade são discutidos em termos de efeitos provenientes das condições operacionais estabelecidas para a fabricação do papel, permitindo reconhecer influências da orientação de fibras, do processo de secagem e da restrição ao encolhimento, da aplicação de amido superficial e da aplicação de tensões na direção longitudinal e transversal do papel. Para comparação e suporte à discussão de resultados, foram também medidas propriedades estruturais, de resistência e propriedades elásticas do papel. Na conclusão do trabalho, são apresentadas sugestões para controle e minimização da higroexpansibilidade do papel destinado ao uso final, com enfoque em ações a serem tomadas, no que se refere ao ajuste do processo de fabricação. Finalmente, apresentam-se comentários sobre futuros trabalhos que poderão ser desenvolvidos, a fim melhor entender fenômenos adicionais relacionados à higroexpansibilidade e buscar alternativas para seu controle, por se tratar de uma propriedade cada vez mais importante para os processos de impressão e operações de conversão, cujos efeitos podem limitar o desempenho e a utilização final do papel. / Like any material made from wood fibers, the paper also exhibits dimensional changes as a result of change in moisture content. This work deals with the behavior of this paper property, called hygroexpansivity, which was measured in reprographic paper manufactured from eucalyptus fibers, during the production process in an industrial paper machine. The study was developed using 75 g/m2 paper samples collect in different positions of a commercial paper machine running at the speed of 1256 m/min. In the study, data of hygroexpansivity measured along the paper machine can be found from the forming section up to the finishing section and from the cross machine direction at the reel. The analysis of the results reveals the effects of the operations and treatments involved in the papermaking (formation, pressing, drying and finishing) on the hygroexpansivity. The measurements results of this property are discussed with focus on the effects of the operating conditions established for the papermaking operation, what leads to the recognition of the effects of the fiber orientation, drying process, shrinkage restraint, starch sizing and tensions applied to the paper in machine direction and cross machine direction. For comparison purposes and result discussion support, some structural, strength and elastic paper properties were also measured. In the conclusion of the study, some suggestions for control and minimization of hygroexpansivity of the end use paper are presented, focusing on actions to be taken, which are related to the adjustment of papermaking process. Finally, comments referred to future work for better understanding of additional hygroexpansivity mechanisms are also mentioned, in order to suggest future investigation of control alternatives for this property, since it’s importance has been more and more highlighted in printing and conversion operations because, at times, it can limit the performance and usefulness of paper.

The interest in this study was initiated by the rapid global transition of paper usage to digital systems in teaching and learning at tertiary institutions, particularly those that are signatories to the Talloires Declaration, which include Rhodes University (RU). It was discovered that there are two earlier studies (Leslie et al. 2009; Amutenya et al. 2009) that investigated and proposed recommendations towards sustainable paper usage at Rhodes University (RU). This study then investigated the response of RU to the proposed recommendations of the above mentioned studies and evaluated the conditions that promote and constrain sustainable paper usage in teaching and learning, and the attitudes of users thereof.

This master’s thesis is aimed at process of enzymatic hydrolysis of lignocellulosic material – waste paper as a source of raw material for production of liquid biofuels. In the theoretical part of this work are summarized previously used methods of hydrolysis and lignocellulosic materials used for the process of hydrolysis as a source of fermentable sugars for fermentation technology. The different types of waste paper are evaluated from the composition and usability with consideration to the papermaking process in order to select the appropriate type of waste paper for the enzymatic hydrolysis process. In the next part of this work are suggested technological premises and procedures for the preparation of raw materials and the subsequent enzymatic hydrolysis of these pre–treated materials. In the experimental part were optimized parameters of enzymatic hydrolysis using the Novozymes company enzyme package. Enzymatic degradation of cellulose to reducing sugars was observed using Somogyi – Nelson method. For the verification of hydrolysis conditions were used model materials with high cellulose content – pulp and filter paper. Conditions, which seems to be the best after testing on the model materials, were verified on specific waste paper materials – offset cardboard, recycled paper, matte MYsol paper and for comparison again on model materials – pulp and filter paper. The highest yields was achieved with the use of cardboard, which was further tested using various combinations of pretreatment to material for purpose of increase the yields of hydrolysis.

This work introduces usable, washable garments made from woven and knitted paper to the field of fashion. With the rise of mass production and over consumption, the value of clothes and textiles decreases, and the pollution from non-renewable materials increases. By utilizing paper in clothes as a new sustainable textile alternative, working with the aesthetics of pleats to elongate the body, and the transformative effects of the corset to build and shape the body, displacing the gender, to work with androgyny as a way to showcase the finish work reference historical gender normatives in Buddhist art. This work depicts a collection with emphasis on the body (wearer of clothing and social construction) and construction (which uses the body and tradition), tradition (expectation and displacement) whilst also working with future issues of sustainability using exclusively paper textile.

<p>In the wish to replace oil-based chemicals and materials with such based on biodegradable and renewable resources, this work has been performed. In a biorefinary concept, waste birch bark from paper pulp mills and timber production has been evaluated as a potential source for polyesters. </p><p>In the present thesis investigations are made on synthesis of epoxy-functionalized polyesters from the birch outer bark aliphatic suberin ω-hydroxy fatty acid, <em>cis</em>-9,10-epoxy-18-hydroxyoctadecanoic acid. Studies of accessibility and reactivity of cellulose have been performed as a first step to enable covalent attachment or grafting of the epoxy-functionalized polyesters to cellulose.<em> </em></p><p><em>Candida antarctica</em> lipase B (Novozym 435) is reported to be an efficient catalyst for condensation polymerization of <em>cis</em>-9,10-epoxy-18-hydroxyoctadecanoic acid to form poly(9,10-epoxy-18-hydroxyoctadecanoic acid) with high molecular weight (M_w). Performed in toluene in the presence of molecular sieves a M_w of 20000 (reaction time 68 h, M_w/M_n 2.2) was obtained. Performed in bulk without any drying agent a M_w of 15000  was obtained at a much shorter reaction time (reaction time 3h, M_w/M_n 2.2). Further the same lipase has been used for succesful co-polymerizations of <em>cis</em>-9,10-epoxy-18-hydroxyoctadecanoic acid with lactones. By combining condensation and ring-opening polymerization, epoxy-functionalized linear polyesters and cyclic oligomers have been synthesized. For example, co-polymerization of <em>cis</em>-9,10-epoxy-18-hydroxy-octadecanoic acid and ε-caprolactone performed in toluene in the presence of molecular sieves gave mainly cyclic oligomers, especially at shorter reaction times. Co-polymerization performed in bulk gave linear polyesters with a M_wof35000 (reaction time 24 h, M_w/M_n6), irrespective molecular sieves were added or not. </p><p>The epoxy-functionalized polyesters could be used for surface modification of pulp fibres and cellulose fibrils, which further can be used for production of new valuable composite materials with improved features. Knowledge of how different processing conditions affect the structure of cellulose is an important tool in the work to achieve successful grafting of produced polyesters to cellulose fibres/fibrils. CP/MAS ¹³C-NMR spectroscopy has been used to study structural changes caused by the dissolving pulp process. An irreversible increase in average fibril aggregate width from raw pulp to final pulp during the process is shown. This increase in aggregate width could negatively influence the reactivity of the cellulose.</p><p> </p><p> </p>

<p>Graphic paper is experiencing severe competition from other materials and, most of all, from other media. This means there is a great need to improve paper quality while reducing raw material and production costs. Polyelectrolyte multilayer (PEM) treatment (i.e., consecutively adding cationic and anionic polyelectrolytes to the charged surface of wood fibres and fines, to form layers of these polyelectrolytes on the fibres/fines) has in recent years been found to offer great potential both to introduce new properties and to improve the mechanical properties of papers made of the treated fibres.</p><p>The main objective of this thesis was to develop a strategy for the PEM treatment of cationic and anionic starch to improve the mechanical properties of paper made of thermomechanical pulp (TMP), since PEM treatment of fibres has displayed great potential to improve the mechanical properties of sheets made of chemical pulp. Mechanical pulp, however, has a large fine material content. Since the fine material is highly charged, polyelectrolyte consumption would be unacceptably high if the entire pulp were PEM treated, so we applied PEM treatment only to a fibre fraction of the pulps in most trials in the present work. The polyelectrolytes used for PEMs have so far mostly been well-defined, expensive ones unsuitable for use in standard paper grades; to develop a more economically realistic alternative, we used cationic and anionic starches.</p><p>PEM formation on SiO₂ surfaces from three differently charged cationic and anionic starches was first evaluated at three different salt levels using quartz crystal microbalance with dissipation (QCM-D) and stagnation point adsorption reflectometry (SPAR). The starch combinations displaying the highest potential for stable PEM formation at higher salt concentrations were then evaluated on an entire TMP pulp, as well as on a fraction of the pulp to reduce the amount of starch needed for PEM formation.</p><p>The results indicate that it is possible to form PEMs from cationic and anionic starch on a SiO₂ surface. The charge density, salt concentration, and combination of starches all influenced PEM formation. PEM formation on mechanical fibres produced large improvements in the mechanical properties of the sheets made of the treated fibres, and the tensile index, stretch-at-break, Z-strength, and Scott bond values all increased. Fractionating the pulp and PEM treating only a fraction of the pulp, the long fibre and middle fraction, produced large decreases in the amount of starch needed and large improvements in the mechanical properties of the sheets when no fine material was subsequently added. As untreated fine material was subsequently added, the improvement in mechanical properties decreased. PEM formation produced almost no reduction in formation and only a slight increase in sheet density.</p> / <p>Grafiskt papper är under hård konkurrens från andra material och, framför allt, andra media.  På grund av detta finns det ett stort behov av att förbättra papperskvalitén samtidigt som råmaterial- och produktionskostnader sänks. Polyelektrolyt-multiskikt (multiskikt) på massa (dvs. växelvis adsorption av katjoniska och anjoniska polyelektrolyter till träfibrer och finmaterial) har på senare år visat sig ha bra potential både för att ge nya egenskaper och för att förbättra de mekaniska egenskaperna hos papper gjorda av behandlad fiber.</p><p>Huvudsyftet med denna avhandling var att utveckla en strategi för multiskiktsbehandling med katjonisk och anjonisk stärkelse för att förbättra de mekaniska egenskaperna hos papper gjort av behandlad termomekanisk massa (TMP). Multiskiktsbehandling av fiber har visat stor potential för att ge förbättrade mekaniska egenskaper till ark gjorda av behandlad kemisk massa. Mekanisk massa innehåller dock en stor andel högladdat finmaterial som kan öka mängden polyelektrolyt som krävs för multiskiktsbehandling, därför multiskiktsbehandlas bara en fraktion av massan i de flesta experiment i detta arbete. De polyelektrolyter som använts för multiskikt har hittills mest varit väldefinierade och dyra, och därmed opassande för användning i vanliga papperskvalitéer. För att utveckla ett mer realistiskt alternativ så användes katjonisk och anjonisk stärkelse i detta arbete.</p><p>Multiskiktsuppbyggnad på SiO₂-ytor av tre katjoniska och tre anjoniska stärkelser med olika laddningsdensitet utvärderades först vid tre olika saltnivåer genom att använda kvartskristal‑mikrogravimetri (QCM-D) och reflektometri (SPAR). Stärkelsekombinationerna som uppvisade störst potential för en stabil multiskiktsuppbyggnad på högre saltkoncentrationer blev sedan utvärderade på en hel TMP-massa, men även på en fraktion av massan för att minska mängden stärkelse som krävdes för multiskiktsuppbyggnad.</p><p>Resultaten visar på att det är möjligt att bygga upp multiskikt av katjonisk och anjonisk stärkelse på en SiO₂-yta. Laddningsdensiteten, saltkoncentrationen och kombinationen av stärkelser var faktorer som påverkade multiskiktsuppbyggnaden. Multiskiktsuppbyggnad på mekaniska fibrer gav stora förbättringar av de mekaniska egenskaperna hos ark gjorda av behandlad fiber, och dragindex, töjning, Z-styrka och Scott bond-värde ökade. Fraktionering av massan och multiskiktsbehandling av endast en del av massan, långfiber- och mellanfraktion, innebar att mycket mindre stärkelse behövdes och gav stora förbättringar av de mekaniska egenskaperna hos arken om inget obehandlat finmaterial tillsattes efteråt. Då obehandlat finmaterial tillsattes så blev förbättringarna hos de mekaniska egenskaperna mindre. Multiskitsuppbyggnad gav nästan ingen reduktion av formationen och endast en liten ökning i arkdensitet.</p>

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