Dissertations / Theses: 'Papermaking'

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Amundson, Charles. "Evaluating a new handsheet forming model based on deposition and smoothing /." Thesis, Connect to this title online; UW restricted, 2002. http://hdl.handle.net/1773/5561.

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Stoor, T. (Tuomas). "Air in pulp and papermaking processes." Doctoral thesis, University of Oulu, 2006. http://urn.fi/urn:isbn:9514280784.

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Abstract A pulp suspension consists of water, fibres, fines, fillers and chemicals, but air or other gases are also present in practically all pulping processes either in dissolved form or as bubbles. Dissolved gases seldom disturb the processes, but they are readily converted to gaseous form when conditions change. The gas bubbles affect the properties of the pulp suspension, reduce the accuracy of certain measurements, interfere with the runability of the papermachine and detract from the quality of the end-product. Gases are removed from the process by either mechanical or chemical means, resulting in increased investments and operational costs. The aim of this work was to study the behaviour of gas in pulp and papermaking processes with laboratory, pilot-scale and mill-scale experiments. Five main areas of the research can be identified: 1. Occurrence of gases in pulp and paper mill processes, 2. Dissolution, precipitation and hold-up of gases in the pulp suspension and mill water, 3. Effects of gases on certain consistency measurements, centrifugal pumping and operation of the hydrocyclone. 4. Measurement of the gas content of the pulp suspension by compression, radiometric, microwave and sonar methods and 5. Removal of gases with a centrifugal pump equipped with vacuum pump or hydrocyclone equipped light reject removal. The results show that the dissolution and precipitation of gas is strongly dependent on the pulp and water properties. Dissolved and colloidal material reduces the solubility potential of gas, but also accelerates the precipitation of dissolved gases in gaseous form. The hold-up of precipitated gas bubbles was found to be much more pronounced in hydrophobic mechanical pulps than in lignin-free chemical pulps. The accuracy of consistency measurements was affected by free gas in the pulp suspension, requiring special attention when assessing the results. The operation of pressure screens and hydrocyclones was affected only at high volumes of free gas in the feed suspension. According to the experiments, a reliable gas content measurement can be achieved by in-line radiometric, microwave or sonar methods, and also by the off-line compression method if a representative sample is obtained. A centrifugal pump equipped with a gas removing unit is designed mainly to ensure undisturbed pumping, whereas its gas removal efficiency remains quite low, especially with small bubbles and at a low gas content. The gas removal efficiency of a hydrocyclone equipped with light reject removal is good, but decreases with small precipitated bubbles. These results offer new information of the behaviour of the gas in pulp suspensions and white water and underline the importance of the bubble generation mechanism in this context.

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Pande, Harshad. "Kenaf fibres for pulping and papermaking." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ41265.pdf.

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Solberg, Johan. "The papermaking tradition of Central Asia." Thesis, University of Iowa, 2018. https://ir.uiowa.edu/etd/6291.

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This paper examines the establishment of papermaking in Central Asia in the 7th to 8th century CE. Additionally, it examines the historical and contemporary status of papermaking in Uzbekistan based on primary sources gathered during a research trip, and historical sources. Both textual research and experimental papermaking research were conducted for this paper. Designed as a foundation for further study, this paper includes early textual sources mentioning papermaking, information gathered from interviews, personal observations, and maps highlighting areas of importance. The first part surveys the development of the discussion surrounding the establishment of the craft in the region. By combining early and contemporary research and highlighting and discussing new sources, possible scenarios of the establishment of papermaking in Central Asia are further investigated. Pursuing this line of inquiry, the paper provides a full overview of the history and development of the different papermaking regions of Uzbekistan, following a detailed description of the tradition in the city of Kokand based on first-hand accounts from the early 20th century. The second part of this paper includes a description of the author’s process of recreating historical tools, techniques and paper based on data and information gathered during the research trip as well as information drawn from historical sources. In addition, the author explores different theories such as the debate about which raw materials were used, and hypotheses regarding the development of the paper mould.

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Yum, Hyejung. "Traditional Korean papermaking : history, techniques and materials." Thesis, Northumbria University, 2008. http://nrl.northumbria.ac.uk/3209/.

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This study investigated the history of traditional Korean papermaking within its historical context: the relationship with the development of papermaking techniques in neighbouring countries were examined though primary focus was given to the development of materials and tools used. In order to understand the characteristics of historical Korean paper and the development of tools and materials used over time, surveys on Korean and Japanese collections at the British Library and a private Korean collection were carried out. Korean objects dated between the 12th and the 18th century were examined. The data collected from the surveys was compiled in a database and analysed. The data analysis revealed that the thickness of paper was closely related to the thickness of bamboo splints used in manufacture of papermaking screens. Research also included a summary of morphological characteristics and photomicrographs of fibres from nine indigenous plants which were used for traditional Korean papermaking. These standard fibre samples were used as reference to identify the fibres of unknown paper objects surveyed. This fibre identification confirmed the main material to be paper mulberry and, additionally, provided information on supplementary materials including rice straw, reed, hemp, and mechanical wood pulp of coniferous origin — a material that has not been recognised as one of the common supplementary materials in previous studies. In order to provide a better understanding of the materials and tools used in traditional papermaking in Korea, three papermaking experiments were carried out. Firstly, a papermaking experiment was conducted using a mucilaginous substance derived from the roots of Hibiscus Manihot, which has been employed as a formation aid for considerable time in Korea and Japan. Paper samples were then analysed to investigate the physical influence of the substance on the sample sheets. Secondly, a fixed laid screen was designed and sheets were produced using it. The intention here was to support a hypothesis which was proposed by the author in order to explain a possible chronological development of papermaking mould structure in China and its potential spread to neighbouring countries. The last experiment was conducted to simulate a technique of papermaking with reclaimed paper. Although the use of reclaimed paper was recorded in early literature, details of the process were unknown.

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Matyumza, Ntombozuko C. "Improved filler retention by co-flocculation of fines and filler particles." Thesis, Stellenbosch : Stellenbosch University, 2005. http://hdl.handle.net/10019.1/37370.

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Thesis (MScFor)--Stellenbosch University, 2005.
ENGLISH ABSTRACT: The retention of filler particles and drainage are important aspects of papermaking. A number of important paper properties depend in the quality and quantity of filler retained in the paper. Fines, fillers and pulp fibres all have a negative charge and are kept apart by electrostatic forces. This causes a decrease in the effectiveness of cationic retention aids thereby causing a high cationic demand. This in turn implies that the retention of fines and filler particles in a formed sheet is not efficient, especially in the presence of anionic trash. In order to improve printability, print quality and dimensional stability, a large percentage of mineral pigments / fillers either in the form of internal loading or external coating should be added. It was found that coflocculation of fines and filler particles resulted in an even distribution of filler particles in the form of miero-flocs and the filler retention was maintained. Opacity was improved without much reduction in paper strength. An increased filler content without coflocculation of fines reduced sheet strength properties. The filler particles interfered with the development of fibre-to-fibre bonds and occupied spaces that otherwise might have contained fibres. This study showed that the most beneficial effect of coflocculation of filler with fines was obtained, with regards to paper strength, opacity, filler retention and printability, when the charge of the fibre furnish was maintained at -0.1 leu with the 0.1% addition of cationic PAM retention aid.
AFRIKAANSE OPSOMMING: Twee belangrike aspekte van papiervervaardiging is die retensie van vulstowwe en ontwatering. 'n Aantal belangrike papiereienskappe is afhanklik van die hoeveelheid en kwaliteit van vulstowwe wat in papier voorkom. Veselpuin, vulstowwe en pulp-vesels is almal negatief gelaai, gevolglik verseker elektrostatiese kragte dat hierdie deeltjies los van mekaar bly. Laasgenoemde verminder die doeltreffendheid van kationiese retensiemiddels en dit gee aanleiding tot 'n hoë kationiese aanvraag. Die retensie van veselpuin en vulstof deeletjies in papier is gewoonlik nie voldoende in die teenwoordigheid van anioniese afvalkomponente nie. Om aan papier verbeterde drukeienskappe, drukkwaliteit en dimensionele stabiliteit te gee, moet 'n groot persentasie minerale pigmente en/of vulstowwe as 'n interne lading of eksterne bestryking voorsien word. Daar is bevind dat kot1okkulasie van fynstowwe en vulstofdeeltjies, 'n egalige verspreiding van vulstof-partikels as mikro-t1okke tot gevolg het en dat vulstof-retensie op aanvaarbare vlakke behou is. Ook is ondeurskynendheid verbeter sonder 'n beduidende verswakking in die papiersterkte. 'n Toename in vulstofinhoud, sonder kot1okkulasie van fynstowwe, het die papier sterkte-eienskappe verlaag. Vulstofdeeltjies bëinvloed die ontwikkeling van vesel-tot-vesel binding. Hierdie deeltjies beset ruimtes wat andersins deur vesels benut sou word. Hierdie studie het getoon dat die voordeligste effek van kot1okkulasie van vulstowwe met fynstowwe verkry is, ten opsigte van papiersterkte, ondeurskynendheid, vulstof retensie en drukeienskappe, wanneer die lading van die pulpsuspensie by -0.1 leu gehou was met 'n byvoeging van 0.1% kationiese PAM retensie-hulpmiddel.

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Ingalsbe, Dana I. "Relating mechanical properties of paper to papermaking variables." Available online, Georgia Institute of Technology, 2005, 2001. http://etd.gatech.edu/theses/available/ipstetd-1031/.

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Lobosco, Vinicius. "On the Modelling of Mechanical Dewatering in Papermaking." Doctoral thesis, KTH, Fibre and Polymer Technology, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3702.

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Most of the water fed into a paper machine is removedmechanically in the forming and press sections. One of thefactor which has an important influence on mechanicaldewatering, i.e. in both forming and pressing, is thestress-strain behaviour of the fibre network.

The focus of this thesis is on the development of improvedmathematical descriptions of the stress-strain behaviourexhibited by fibre networks in the forming and press sections.The first part of the thesis presents a physically based modelof the forming and densification of fibre mats in twin-wireformers. The model can calculate the ecect of the applicationof a varied load through the forming section. It was developedfrom mass and momentum balances of the fibre and liquid phases,the fibre mat stress-porosity relation and an expression forthe permeability as a function of the porosity. The fibre-matstress-porosity relation used is rate-independent and presentshysteresis. Simulations have been conducted to study theeffects of roll pressure, blade pulses, wire tension andbeating. The effect of sequential blade pressure pulses afterthe forming roll on the dewatering and the concentrationgradients could be characterised. The simulations alsoexhibited rewetting by expansion when the fibre mats left theforming roll. Increasing wire tension resulted in increaseddewatering, but the rate of increase diminished rapidly withincreasing tension. The simulation results also indicated thatbeating has a large influence on dewatering.

The second part of the thesis presents two models of therate-dependent stress-strain behaviour of the fibre networkthat is observed in wet pressing. The first model was based onthe approach pioneered by Perzyna (1966) for strain-ratedependent plasticity and was quite satisfactory for calculatingthe stress-strain behaviour of the fibre network in singlepress nips. It was successfully applied for studyingdensification and dewatering in both normal wet pressing andhigh temperature wet pressing. However, the first model onlyincludes rate dependence in the compression phase of thecompressionexpansion cycle; the expansion phase is treated asbeing rate independent

The second model of the stress-strain behaviour of the fibrenetwork treats both compression and expansion as being ratedependent, according to experimental observations. It is basedon the idea that the wet fibre web may be conceived as alayered network of restricted swelling gels. A swollen fibre isa restricted gel, the inner swelling pressure in a swollenfibre wall being balanced by the stresses in the fibre wallstructure. The observed rate dependence of wet webs in bothcompression and expansion phases was attributed to the flow ofwater out of and into the fibre walls. The second model gavepredictions that are in good agreement with results fromuniaxial experiments using pressure pulses of arbitrary shapefor both a single pulse and a sequence of pulses. It maytherefore be used as a general model for the rheologicalbehaviour of the wet fibre network in wet pressing, providedthe model parameters are estimated from experimental data withsmall experimental error.

KEYWORDS:Paper, modelling, dewatering, forming, wetpressing, fibre network stress, rheology, hysteresis,intra-fibre water, compressibility, structural stress,stress-strain, restricted gels, swelling.

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Ingalsbe, Dana L. "Relating mechanical properties of paper to papermaking variables." Diss., Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/7038.

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Raghem-Moayed, Amir. "Characterization of fibre suspension flows at papermaking consistencies." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq41040.pdf.

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Holm, Richard. "Fluid mechanics of fibre suspensions related to papermaking." Doctoral thesis, Stockholm, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-100.

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Walker, David. "Structural mechanisms of sheet formation in papermaking systems." Thesis, University of Manchester, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.305584.

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Jacobs, Roberta Sue. "The papermaking properties of Washington State wheat straw /." Thesis, Connect to this title online; UW restricted, 1999. http://hdl.handle.net/1773/5604.

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Saarimaa, Ville. "Pectic acids in mechanical pulping and papermaking : Akademic dissertation /." Åbo : Åbo Akademi University, 2007. http://catalogue.bnf.fr/ark:/12148/cb41176965r.

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15

Oliveira, Marcius Henrique de. "Wet web strength development of paper." Thesis, McGill University, 2007. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=101155.

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The adhesion of wet fibers is usually explained by the presence of capillary forces, which keep the swollen fibers together. These bonds are due to the free water present outside the wall of the swollen fibers. However, what happens when the free water is being removed and the tensile strength of the wet web continues to increase is not well understood. Tensile strength's measurements of refined fibers in presence of polyelectrolytes and mineral particles suggest that no enhancement of bonding occurs between the fibers when the free water is gone. The addition of microfibrils tends to enhance the wet web strength. This indicates strongly that fiber entanglement due to mechanical interactions may be the major interaction responsible for keeping the swollen fibers together in the transient region where neither capillary forces nor hydrogen bonding dominate.
The interactions between fibers, precipitated calcium carbonated (PCC) and retention aids, revealed that the wet web strength of PCC-filled handsheets is detrimental in the presence of flocculated PCC particles, while no detrimental effect is observed in the presence of stable PCC particles. Friction generated by the deposition of small and/or single particles on the fiber surface can explain their enhancement of strength, whereas bigger particles may prevent the entanglement of fibers. Finally, the addition of polyelectrolytes to swollen fibers reduces the wet web strength. The presence of an additional polymer layer results in an increased electrosteric repulsion between fibers, which decreases the friction between fibers. This reduction of friction makes the fibers slide more easily over each other, resulting in poor wet web strength.

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Moss, Patricia A. "A study of the frozen hydrated structure of pulp." Thesis, University of Manchester, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.245273.

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Hooper, Rebecca Louise. "Calcium carbonate fillers in rosin-sized papers." Thesis, Loughborough University, 1993. https://dspace.lboro.ac.uk/2134/32797.

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Calcium carbonate is one of the preferred fillers for the paper industry. This research compared the physical and chemical properties of calcium carbonates produced by different methods and their use with a novel rosin sizing system. The effectiveness of a polymeric retention agent, which flocculates particles during paper production, has also been examined.

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Chung, Young Ho. "An evaluation of factors impacting optimum repulping and minimum chloroform generation during sodium hypochlorite repulping." Oxford, Ohio : Miami University, 2003. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=miami1059075420.

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Thesis (M.S.)--Miami University, Dept. of Paper Science and Engineering, 2003.
Title from first page of PDF document. Document formatted into pages; contains xii, 90 p. Includes bibliographical references (p. 88-90).

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Hyensjö, Marko. "Fibre Orientation Modelling Applied to Contracting Flows Related to Papermaking." Doctoral thesis, KTH, Mekanik, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4762.

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The main goal of this work was to develop numerical models for studying the behaviour of fibres in an accelerated flow. This is of special interest for e.g. papermaking. The early stage of the paper manufacturing process determines most of the final properties of a paper sheet. The complexity of studying the flow of fibre suspensions both experimentally and numerically emphasises a need for new ideas and developments. By means of solving the evolution of a convective-dispersion equation, i.e. the Fokker-Planck equation, a fully 3D approach with respect to the position and the two fibre angles, polar and azimuthal angles, following a streamline is presented. As an input to the fibre orientation model the turbulent flow field is solved by Computational Fluid Dynamics (CFD) with second-order closure in the turbulence model. In this work two new hypotheses have been presented for the variation of the non-dimensional rotational diffusivity with non-dimensional fibre length, Lf /η and the Reynolds number based on the Taylor micro-scale of the turbulence, Reλ Parameters for the two new hy- potheses and earlier models are determined with the aim of achieving a general relation and a value of the rotational dispersion coeffcient of stiff fibres in an anisotropic turbulent fluid flow. Earlier modelling work has been focused on solving the planar approach, i.e. assuming all fibres to be in one plane. This planar approach is discussed and compared with the fully 3D approach and its validity is evaluated. The optimization of parameters for the different hypotheses correlated on a central streamline, showed a good agreement with an independent experimental result in the undisturbed region. Moreover, it is particularly interesting that the boundary layer region and the wake region are predicted fairly well and the phenomena are well described, which has not been the case earlier. It seems that the new hypothesis based on the variation of the non-dimensional fibre length, Lf /η gives the best correlation in these shear-layer regions. Further- more it was established that the planar approach fails to predict shear layers, i.e. the boundary layer and the wake regions. As emphasized in the theory section, the planar formulation is strictly valid only if all fibres are oriented in one plane, which is not the case in the shear layers. In the undisturbed region, the 3D and the planar approaches, agree in their results. This leads to the conclusion that both approaches are suitable when shear layers are not studied.
QC 20100812

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Hyensjö, Marko. "Fibre orientation modelling applied to contracting flows related to papermaking /." Stockholm : Mekanik, Mechanics, Kungliga Tekniska högskolan, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4762.

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Rioux, Robert A. "Mechanical Testing of Coated Paper Systems." Fogler Library, University of Maine, 2008. http://www.library.umaine.edu/theses/pdf/RiouxRA2008.pdf.

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Warren, Clifton F. (Clifton Foster). "Desorption of high molecular weight cationic polyacrylamide from bleached kraft pulp fibers by pH adjustment and alum addition." Thesis, McGill University, 1986. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=65337.

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Mathews, Jeffrey David. "Surface charge characterization of pulp fibers and charge distributions in papermaking slurry /." Thesis, Connect to this title online; UW restricted, 2002. http://hdl.handle.net/1773/5504.

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Guerrero, Serrato Alexander. "Investigation of wet paper cohesive properties." Thesis, Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/24682.

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Weller, Morag Catherine. "A microscopic investigation of the surfaces of Kraft pulp papermaking fibres." Thesis, McGill University, 2009. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=32505.

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To maintain its innovative and competitive edge the forestry sector is focused on conducting research into more efficient ways of manufacturing current products and generating new markets for by-products and technologies. It is the surface of pulp fibres which are of fundamental importance to the pulp and paper industry. A better understanding of the chemistry and morphology of Kraft pulp fibres is the primary motivation for this Master's thesis study. Through this work, we will show that simple and straight applications of newer technologies (X-ray photoelectron spectroscopy, Atomic Force microscopy, Optical Microscopy and Differential Scanning Calorimetry) could be employed by the pulp and paper industry to determine the surface chemistry of Kraft Pulp fibres (and therefore other lignocellulosic fibres). The effect that variability in the surface composition of such fibres has on industrial applications is commented on.
Pour maintenir son avantage innovateur et concurrentiel, le secteur de sylviculture est concentré sur la recherché dans des manières plus efficaces de produire des produits et des marchés courants pour des sous-produits et des technologies. C'est l'extérieure des fibres de pâte qui est d'importance fondamentale pour l'industrie de pâte et papier. Une meilleure compréhension de la chimie et de la morphologie des fibres de pâte Kraft est le raisonnement primaire pour cette thèse de maîtrise. Dons çe recherche nous démontrons que des applications simple et directes de nouvelles technologies (spectroscopie de photoélectron de rayon X, microscopie atomique de force, microscopie optique, analyse entalbique différentiel) peuvent être utilisés par l'industrie de pâte et papier pour déterminer la composition extérieure des fibres de pâte Kraft (et donc d'autre fibres lignocellulosique.) L'effect de la variabilité en composition extérieure sur des applications industrielles sera aussi étudié.

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Vanerek, Alois. "Filler retention in papermaking by polymeric and microparticulate retention aid systems." Thesis, McGill University, 2004. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=85655.

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Mineral pigments are added to paper with the aim of improving its optical and printing properties. The colloidal behavior of calcium carbonate filler shows a dependence on the quality of water used in suspensions, presence of dissolved and colloidal substances and type of polymer used as a retention aid. The role of the retention aids is to attach colloidal particles, such as fines and mineral pigments, to pulp fibers before or during the paper is made. Two very different single-component retention aids were utilized in calcium carbonate fillers destabilization and deposition on fibers. Cationic polyethylenimine destabilized or facilitated deposition of the filler on fibers by a charge neutralization mechanism while cationic polyacrylamide flocculated or deposited the filler on fibers via a bridging mechanism.
In the presence of anionic dissolved and colloidal substances, the amount of cationic polyacrylamide had to be increased in order to achieve the same degree of pigment flocculation. The reason for the increase was due to the fact that the cationic polyacrylamide formed a polyelectrolyte complex with the anionic substances, namely sulfonated kraft lignin. The reaction between cationic polyacrylamide and lignin was found to be nearly stoichiometric. Low molecular weight cationic polyacrylamide formed mostly colloidal complexes while high molecular weight cationic polyacrylamide formed predominantly coacervate complexes; this was mainly due to differences in characteristic times of lignin association with the cationic polyacrylamide, clustering of polyacrylamide molecules and reconformation of polymer chains.
The performance of two-component retention aid systems consisting of a cationic polyacrylamide and anionic microparticles were evaluated by deposition of calcium carbonate filler on pulp fibers. Kaolin clay and bentonite were used to heteroflocculate polyacrylamide-covered surfaces of the fibers and pigment. Due to their inability to delaminate, kaolin clay and acid-treated montmorillonite showed no effect of calcium carbonate filler deposition. After cation exchange with sodium-rich solutions, which caused the montmorillonite to delaminate, the montmorillonite flocculation efficiency considerably improved. Kaolin clay neither delaminated after the cation exchange nor improved calcium carbonate deposition. Bentonite was found to completely delaminate when using polyacrylamide-treated fibers. When added to a suspension of fibers, filler and cationic polyacrylamide, bentonite was found to be in a form of stacks containing on average four platelets.
An alternative way to paper filling with pigment was tested on stationary sheets and on slow and fast Fourdrinier pilot paper machines. Using a secondary headbox on the pilot paper machines, a high degree of loading (above 30%) could be achieved using positive clay or calcium carbonate fillers. However, the fillers lowered the paper strength as they interfered with the fiber-fiber bonding in a similar fashion found in conventionally filled papers.

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Sinden, Jane. "The electrokinetic aspect of cellulose fibres used in the papermaking process." Thesis, University of Reading, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.244904.

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Håkansson, Mikael. "Connecting Process Variables to Product Properties in Papermaking: A Multivariate Approach." Licentiate thesis, Luleå tekniska universitet, Signaler och system, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-25731.

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In paper-making there are numerous of parameters that control the final outcome of the paper. This thesis examines the connections between paper properties and influential factors in the manufacturing process, by looking at the entire fiber line from the incoming wood chips to the actual finished paper. The analysis is done by studying how important process variables connect to the properties of the paper, and also by investigating the possibilities of modeling how these affect the final product.There are numerous factors that affect the final outcome of a manufactured paper. Five of these; wood type, cooking time, refining energy input, amount of starch and roll pressure in the paper machine, have been investigated in a series of laboratory experiments. A factorial designed experiment was set up to investigate the mentioned factors impact on paper properties. Focus in the study was laid on two aspects. One was to investigate interaction effects among the process variables and the significance of theseinteraction effects as well as the main effects. For the second part it was possible to utilize these interaction effects and deduce which combinations of factor levels that could result in equal output levels of certain paper parameters.Being able to predict the paper quality as accurately as possible is another importantaspect in paper-making. In the second study in the thesis the relation between the paper properties and process variations are charted. Through different multivariate methods prediction models were created based on the data gathered in the designed experiments. The underlying correlation structures in the data could be used in conjunction with the design factors to derive models that connected process parameters to paper properties. With the help of these models it is possible to predict what paper property levels toexpect when altering process variables.
Godkänd; 2014; 20140217 (mikhak); Nedanstående person kommer att hålla licentiatseminarium för avläggande av teknologie licentiatexamen. Namn: Mikael Håkansson Ämne: Signalbehandling/Signal Processing Uppsats: Connecting Process Variables to Product Properties in Papermaking: A Multivariate Approach Examinator: Professor Johan Carlson, Institutionen för system- och rymdteknik, Luleå tekniska universitet Diskutant: Professor Olle Hagman, Institutionen för teknikvetenskap och matematik, Luleå tekniska universitet Tid: Fredag den 11 april 2014 kl 13.00 Plats: A109, Luleå tekniska universitet

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Hoffman, David William. "Bursting strength control on a linerboard machine." Thesis, McGill University, 1985. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=63326.

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Muurinen, Esa. "Organosolv pulping a review and distillation study related to peroxyacid pulping /." OuLu : Oulun yliopisto, 2000. http://catalog.hathitrust.org/api/volumes/oclc/47152371.html.

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Lu, Chen Pelton Robert H. "Mechanisms of filler flocculation with PEO/cofactor dual-component flocculants /." *McMaster only, 2003.

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Ashok, Kumar. "Passage of fibres through screen apertures." Thesis, University of British Columbia, 1991. http://hdl.handle.net/2429/30849.

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Passage of fibres suspended in water through apertures of dimensions greater than a fibre length and less than a fibre diameter has been examined at flow conditions approximating those in a pulp screen (large velocity parallel to the wall upstream of the aperture compared to the flow velocity within the aperture). Fibre behaviour was characterized in terms of three components: penetration of the leading tip into the aperture, rotation of the fibres on the downstream edge of the aperture, and fibre bending. Dimensionless numbers for each of these factors were derived from simple mass and force balances of fibres at an aperture entry. Experimental measurements of the magnitude of fibre passage were made on a single aperture located in a flow channel and in multiple apertures in a device simulating a commercial pulp screen in cross-section. For stiff fibres, it was found that fibre passage changed greatly with the ratio of fibre length to aperture width (L/W). When L/W was less than 2, the relationship between fibre passage and aperture velocity was approximately an exponential curve. The passage data correlated well with the penetration parameter. On the other hand, when L/W > 2, up to measured values of L/W = 6, the relationship between fibre passage and aperture velocity corresponded to a cumulative probability distribution curve. This latter behaviour, and the absence of a correlation with penetration and rotation parameters, was ascribed to contact between the tip of the rotating fibre and the upstream wall of the aperture. This was confirmed by experimental observations. Flexible long (L/W > 2) fibres showed behaviour between the two cases described above. The above observations were found to hold qualitatively for elevated concentrations up to a crowding factor of 4, multiple apertures, and the presence of pulses induced by a rotor of the type found in pulp screens. Accordingly, it appears that the findings are likely to hold in pulp pressure screens. An implication of this finding is that long stiff fibres may be best separated from short ones by choosing an aperture size such that L/W > 2 for the long fibre fraction and < 2 for the short fibre fraction.
Applied Science, Faculty of
Chemical and Biological Engineering, Department of
Graduate

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33

Cong, Rongjuan Pelton Robert H. "PEO/poly(vinyl phenol-co-styrene sulfonate) aqueous complex formation /." *McMaster only, 2002.

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34

Xu, Yaling Pelton Robert H. "Calcium carbonate adhesion in paper /." *McMaster only, 2005.

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35

Rigopoulos, Apostolos. "Estimation and control of sheet forming processes." Thesis, Georgia Institute of Technology, 1995. http://hdl.handle.net/1853/10215.

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36

Rodriguez, Reynaldo A. "Improving fiber yield by reducing pulping knots." Thesis, Georgia Institute of Technology, 1986. http://hdl.handle.net/1853/10289.

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37

Park, Chang Shin. "A dynamic behavior of pulp floc and fibers in the papermaking process." Diss., Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/7044.

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38

Poraj-Kozminski, Agatha. "Alkyl ketene dimer and precipitated calcium carbonate interactions in wet-end papermaking." Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=99008.

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This thesis investigates the interactions between alkyl ketene dimer (AKD) and precipitated calcium carbonate (PCC). Although the mechanisms behind AKD sizing and reactions with cellulose have been studied in-depth, methods describing AKD retention are poorly understood. The aim of this research was to determine the conditions and time-scale under which AKD and PCC heteroflocculate, and to determine the influence of PCC on non-retained AKD. We also wanted to understand the mechanisms behind AKD interactions with cPAM, and perform experiments on the twin-wire sheet former. We outline a procedure for creating an AKD emulsion coated by cationic starch and free of extraneous substances. We find that AKD and PCC each homoflocculate, but no heteroflocculation occurs between the two chemicals. This suggests that PCC and AKD do not directly interact. Instead, starch removal from the AKD particle surface aids the homoflocculation of PCC (via polymer bridging). This indicates that the alkaline environment is the most significant factor contributing to AKD hydrolysis. More importantly, we find that AKD and PCC are not likely to interact in the whitewater cycle. This refutes the general idea that PCC lowers AKD retention. Adsorption kinetic experiments revealed that although cationic AKD and cPAM do not flocculate, cPAM does increase the retention of AKD by assisting its deposition onto fibers. Asymmetrical polymer bridging explains both the increase in AKD retention and the behavior of AKD flocculation kinetics with cPAM. Although the initial kinetics are nearly independent of cPAM dosage, excess cPAM delays the achievement of maximum possible AKD retention due to starch and cPAM re-conformation. Lastly, it was found that the addition of cPAM results in an increase in the bond strength between AKD and fibers, thereby eliminating AKD detachment. Studies on the twin-wire sheet former found that cPAM increases the first-pass retention of AKD three-fold. The twin-wire former was proven to be a useful tool for studying AKD retention.

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39

Rooke, Paul Edward. "Applying combined neural network and physical modelling to retention processes in papermaking." Thesis, University of Manchester, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.613427.

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This thesis presents a novel approach for modelling complex papermaking systems via a combination of existing techniques. The project has addressed the question of modelling the process known as retention on production paper machines using a semiphysical method. This method combines both complicated physical analysis of key papermaking equipment and the use of neural networks to model the dynamic components and interactions that cannot be readily modelled via physical equations. This approach was adopted to satisfy the requirements of the sponsoring company, English China Clays International (ECCI), that the finished modelling methodology should be readily adaptable to different papermaking situations, as required. A semiphysical model was determined to meet all the criteria set by ECCI. The development of the semi physical modelling method is described through the stages of first application in a laboratory scale application (a pilot paper machine), to the final testing and validation of the technique on real data, gathered on industrial papermachines. Neural networks and their application to retention modelling are also described in this thesis, as their usage was employed in parts of the semiphysical model structure. Also, the concept of neural network error compensators are discussed. This is a novel application of a neural network to predict and then correct the modelling error of a system, thereby increasing the accuracy of the final result.

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40

Taylor, William Kenneth. "The effects of varous papermaking processes on the surface properties of hardwood pulps." Thesis, University of Reading, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.321323.

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41

Vander, Wielen Lorraine C. "Dielectric barrier discharge-initiated fiber modification." Available online, Georgia Institute of Technology, 2005, 2005. http://etd.gatech.edu/theses/available/ipstetd-1054/.

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42

Triantafillopoulos, Nicholas G. "Fluid dynamics of short-dwell blade coater ponds and their relationship to cross directional coat weight nonuniformities." Diss., Georgia Institute of Technology, 1991. http://hdl.handle.net/1853/5592.

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43

Zhao, Boxin Pelton Robert H. "The interactions of pressure sensitive adhesive with paper surfaces." *McMaster only, 2004.

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44

Laitinen, Tarja. "Thiosulfate pitting corrosion of stainless steels in paper machine environment /." Espoo, Finland : VTT, Technical Research Centre of Finland, 1999. http://www.vtt.fi/inf/pdf/publications/1999/P399.pdf.

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45

Stone, Karen S. "No place like home." Thesis, Griffith University, 2022. http://hdl.handle.net/10072/420485.

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The focus of this Master of Visual Art (Research) is an examination of how, from the perspective of a single, older, non–home owning, Australian woman, the meaning of the term ‘home’ explores ways of expressing my insecure and deeply embodied notion of home. The research locates itself through multi-disciplinary definitions of home as a place/space we inhabit materially as a physical structure; as an internal space of feeling and emotion; through familial relationships and cultural influences; and through gender relations and defined domestic roles. The research outcomes have emerged out of my lived experience of ‘home’, and have been developed through a phenomenological, practice-led studio approach. The research outcomes comprise large-scale, handmade floral paper panels, made using my unique papermaking processes, recycled clothing, memory, and floral domestic pattern, as a way of expressing personal, limiting, notions of home. Through somatic, material, and performative methodologies, I contemplate what is forming as the most significant evolution of the notion of ‘home’, as embodied in both the process and the resultant paper art works. The challenge has been to unpick the label of home as an engendered space, when the words ‘home’, ‘domestic’ and ‘self-worth’ are inextricably linked. The outcome of this research proposes that the concept of the home resonates throughout our lives.
Thesis (Masters)
Master of Visual Arts (MVA)
Queensland College of Art
Arts, Education and Law
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46

Karakus, Saffet. "Physical, chemical, soda pulping and papermaking properties of Kenaf as a function of growth." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape11/PQDD_0001/MQ41002.pdf.

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47

Petzold, James Christian. "The application of electrochemical techniques to the study of the surface of papermaking woodpulps." Thesis, University of Reading, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.333172.

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48

Novotny, Michael. "Breaking the chains : A technological and industrial transformation beyond papermaking: Technology management of incumbents." Doctoral thesis, KTH, Industriell ekonomi och organisation (Inst.), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-191261.

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In recent years, the necessity and opportunity for transforming pulp and paper mills into integrative units for large-scale output of biochemicals, biomaterials, and biofuels have come up in discussions of industrial renewal in the Northern hemisphere (mainly in Canada, Sweden and Finland). This transformation is related to technology shifts as well as changing business models based on new bioproducts due to profoundly new market conditions. The aim of this dissertation is to analyse how wood-based biomass industries – with an emphasis on incumbent pulp and paper industries (PPIs) – are managing this industrial and technological transformation that is taking place beyond the papermaking paradigm. Innovation theories on mature industries, their incumbents, and their propensity for technological lock-in and inertia are well-known. How new entrants and incumbents manage these large shifts is seen as central in understanding the dynamics of new, large-scale sustainable technologies on the one hand and the renewal of large, mature process industries on the other. Three research questions are addressed. First, where are the knowledge and technology frontiers developing in this transformation? Second, how are incumbents of PPIs are managing large market and technology shifts based on existing capabilities and knowledge bases? Third, what are the key mechanisms behind the transformation of PPIs from a process-industry perspective? The hermeneutical insights into the system of biomass technologies in general and the PPI industries in particular were gained by using a qualitative case-study approach, which formed the basis for four research articles and for outlining the empirical context and key words search of the quantitative bibliometric methods in a fifth research article. The research findings and main contributions address an identification of the, analytical, “formal”, science-based technology frontiers from a knowledge base perspective. Old industrialised forest/PPI nations tended to specialize in rather slow growing, forest-based frontiers. They seem to have stayed close to the research trajectories of their woody raw material and knowledge base with the exception of North America. However, this not the entire explanation of transformation and technology development. Chemical pulp mills, in several cases developed into biorefineries, are the nexus of the emerging development block. They are contributing with products in a bioeconomy that is actively moving away from fossils and polluting materials (such as cement, cotton, plastics). In addition, demo plants (potentially nurturing hundreds of bioproducts) that are present at mill sites and involve different stakeholders, can act as the interface between analytical and synthetic knowledge bases that otherwise are difficult to combine in the upscaling phases of process industries. The response of PPI organizations to shifts in both technology and business models is also explained by the concept of diverging innovations of non-assembled products. These are part of a diversification of an industry from a forest industry perspective, and also of a diversification that may enter trajectories of several by-products and side-streams of the pulp “biorefinery” mill, and have analogies to a product-tree and to the material transformation flow of its production systems. But it is also a phenomenon of synergies in a broader multi-sectorial perspective, i.e. new sets of related products/processes that are able to replace industries of non-assembled products under the above-mentioned, new market conditions. The phenomenon of diverging innovations can be regarded as both an empirical contribution – the breaking up of a closed integrated process industry into something new with several emerging and integrative industries as a response to the large shifts in papermaking and sustainable needs in society – and as a theoretical remark on the model for non-assembled products presented by Utterback (1994).
Under de senaste åren har nödvändigheten och möjligheten att omvandla massa- och pappersbruk till integrerade produktionsenheter för storskalig produktion av biokemikalier, biomaterial och biobränslen uppkommit i diskussioner om industriell förnyelse på norra halvklotet - främst i Kanada, Sverige och Finland. Denna omvandling är relaterad till teknikskiften samt förändrade affärsmodeller baserade på nya bioprodukter och kraftigt ändrade marknadsförutsättningar. Syftet med avhandlingen är att analysera hur vedbaserade industrier – med betoning på befintliga massa- och pappersindustrin - hanterar denna industriella och tekniska omvandling utanför det traditionella papperstillverkningsparadigmet. Innovationsteorier om mogna branscher, deras benägenhet för teknisk inlåsning och tröghet är välkända. Hur nya och etablerade aktörer hanterar dessa stora förändringar ses som central för att förstå dynamiken i ny, storskalig, hållbar teknik å ena sidan och förnyelse av mogna processindustrier å andra sidan. Tre forskningsfrågor behandlas. Först, var utvecklas kunskaps- och teknikfronter i denna omvandling? För det andra, hur hanterar etablerade aktörer i massa- och pappersindustrin stora marknads- och teknologiskiften baserade på befintliga kunskapsbaser? För det tredje, vilka är de huvudmekanismerna bakom omvandlingen av massa- och pappersindustrin ur ett processindustriellt perspektiv? Förståelsen för det biomasseteknologiska systemet i allmänhet och massa- och pappersindustrin i synnerhet erhölls genom att använda kvalitativa fallstudier och metoder. De låg till grund för fyra forskningsartiklar och utmejslade den empiriska kontexten för kvantitativa, bibliometriska metoder i en femte forskningsartikel. Forskningsresultaten utgörs bl a av en identifiering av analytiska, "formella", vetenskapligt baserade teknikfronter. Äldre skogsindustriländer tenderar att specialisera sig i långsamväxande, skogsbaserade teknikfronter. De följer forskningsbanor närmare deras vedråvaru- och kunskapsbaser (med undantag av Nordamerika). Men det är inte hela förklaringen till teknikutvecklingen och dess omställningspotential. Kemiska massabruk, i flera fall utvecklade till bioraffinaderier, kan utgöra hävstången för ett framväxande utvecklingsblock. De bidrar med produkter i en bioekonomi som aktivt rör sig bort från fossila och resursineffektiva material och processer (såsom cement, bomull, plast). Dessutom kan demonstrationsanläggningar härbärgera en storskalig testmiljö för hundratals bioprodukter som är placerade i närheten av massafabriker och som involverar forsknings-, industri- och samhällsintressenter. De kan ävenfungera som gränssnitt mellan analytiska och syntetiska kunskapsbaser som annars är svåra att kombinera i uppskalningsfaser. Massa- och pappersindustrins omvandling förklaras också av begreppet divergerande innovationer av icke-sammansatta produkter. Dessa är delvis en diversifiering av en bransch ur ett skogsindustriellt perspektiv, delvis en diversifiering som kan generera i biprodukter och sidoströmmar, som har analogier med produktträd och påminner om det materiella transformationsflödet i det egna produktionssystemet. Divergerande innovationer kan ge ett synergifenomen ur ett bredare sektoriellt perspektiv, dvs nya uppsättningar av produkter och processer som kan ersätta industrier med icke-sammansatta produkter under de nya marknadsförhållandena som ovan beskrivits. Fenomenet med divergerande innovationer kan betraktas som både ett empiriskt bidrag - att bryta upp en sluten, integrerad processindustri till något nytt med flera framväxande och integrerande näringar som ett svar på de stora förändringarna i industrin och i samhället – och också som en kritik av modellen för icke-sammansatta produkter som tidigare presenterats av Utterback (1994).

QC 20160829

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49

Hannuksela, Tea. "Mannans in mechanical pulping and papermaking : naturally existing aids and promising wet-end additives." Université Joseph Fourier (Grenoble), 2004. http://www.theses.fr/2004GRE10039.

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Les interactions et les effets des galactoglucomannanes (GGM) dans la fabrication de la pâte à papier et du papier mécanique ont été étudiés. Les GGMs se sont aisément libérés au cours du raffinage de la pâte ainsi que les produits lipophiles du bois qui produisent une émulsion de gouttelettes colloi͏̈dales. Les GGMs peuvent, de façon stérique, stabiliser cette émulsion contre l'agrégation causée par la présence d'électrolytes ou de certains additifs. Cependant, les GGMs sont résorbés sur les fibres après un blanchiment alcalin au peroxyde à cause de la perte des groupements acétyle. Sous leur forme acétylée les GGMs sont aussi sorbés sur les fibres des pâtes chimiques, qui sont souvent ajoutés dans la pâte pour améliorer les propriétés du papier produit. La sorption des GGM en elle-même améliore aussi les propriétés de résistance du papier. L'objectif de cette étude était donc de comprendre les effets des GGMs et d'évaluer l'usage d'autres mannanes pour obtenir des effets désirables
The interactions and effects of galactoglucomannans (GGM) in mechanical pulp and papermaking were evaluated. The GGMs are readily released during refining of pulp, simultaneously with wood extractives that form a colloidal emulsion. The GGMs can sterically stabilise the emulsion against aggregation induced by electrolytes or certain additives. The GGMs are, however, resorbed enta the fibre surfaces after an alkaline peroxide bleaching of the pulp due to the loss of acetyl groups. Ln its acetylated form, the GGM is nevertheless also sorbed enta the fibres of chemical pulp which is often added as reinforcement fibres to the furnish. The sorption of GGMs in itself also enhances the paper strength properties. The objective of this study was thus to understand the effects of GGMs in mechanical pulping and papermaking and to evaluate the use of other mannanes in order to obtain desired effects

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50

Hannuksela, Tea I. "Mannans in mechanical pulping and papermaking : naturallly existing aids and promising wet-end additives /." Åbo : Åbo akademi university, 2004. http://catalogue.bnf.fr/ark:/12148/cb40124675k.

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Dissertations / Theses on the topic 'Papermaking'

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