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[{"key": "dc.contributor.author", "value": "Oksanen, Antti", "language": null, "element": "contributor", "qualifier": "author", "schema": "dc"}, {"key": "dc.date.accessioned", "value": "2022-07-11T10:03:13Z", "language": null, "element": "date", "qualifier": "accessioned", "schema": "dc"}, {"key": "dc.date.available", "value": "2022-07-11T10:03:13Z", "language": null, "element": "date", "qualifier": "available", "schema": "dc"}, {"key": "dc.date.issued", "value": "2012", "language": null, "element": "date", "qualifier": "issued", "schema": "dc"}, {"key": "dc.identifier.isbn", "value": "978-951-39-9353-5", "language": null, "element": "identifier", "qualifier": "isbn", "schema": "dc"}, {"key": "dc.identifier.uri", "value": "https://jyx.jyu.fi/handle/123456789/82272", "language": null, "element": "identifier", "qualifier": "uri", "schema": "dc"}, {"key": "dc.description.abstract", "value": "In this thesis the surface chemistry of fibres and z-directional paper structure were modified in order\r\nto improve the material efficiency of the fibres in the papermaking process. Material efficiency was\r\nestimated by measuring dewatering characteristics, wet web strength properties and end product\r\nquality from pulp and paper specimens. Chemical and mechanical pulps were modified by removing\r\nspecific carbohydrates from the fibre and fines surface or alternatively polysaccharides were added to\r\nthe fibre surface. Enzymes were utilised for the partial hydrolysis of cellulose and hemicelluloses from\r\nthe fibre, whereas polysaccharides such as uncharged xyloglucan and cationic starch were added to\r\npulp suspension or sprayed into wet paper sheets. The benefit of using uncharged chemicals is that\r\nthey do not interfere with process waters like charged additives. Paper sheets of layered furnish\r\nstructures were prepared with a multilayer sheet former. The effect of stratification of filler and\r\nchemical and mechanical pulps on papermaking and paper properties were evaluated. Additionally,\r\ntwo novel methods for analysis of z-directional furnish distribution in the paper were developed.\r\nAccording to the results, dewatering characteristics of mechanical and chemical pulps in forming,\r\nwet pressing and drying sections can be enhanced by the use of hydrolytic enzymes. However, the role\r\nof different wood carbohydrates differs depending on the pulp type and structure of the dewatering\r\nsection. Modification of merely the cellulose part of fibre seems to enhance dewatering in the forming\r\nsection and in the drying section with both mechanical and chemical pulps. In general, nearly 1%\r\nhydrolysis of wood carbohydrates of TMP (thermomechanical pulp) was found to be necessary to\r\nenhance the dewatering in the forming section. In the case of TMP, it was also found that the\r\ncombined partial hydrolysis/removal of cellulose and galactoglucomannan enables higher wet pressing\r\npressure and thus dewatering without loss of bulk of the paper.\r\nThe introduction of xyloglucan-based chemicals and cationic starch into paper had positive\r\ninfluences on the dry strength properties of paper, as expected. Interestingly, xyloglucan-based\r\ntreatments also increased the initial wet strength and drying forces of the paper samples, contrary to\r\nthe effect of cationic starch. The cross-linking of xyloglucan with borate and the introduction of\r\naldehyde groups to xyloglucan were found to further enhance both wet and dry paper strength\r\nproperties. Aldehyde-xyloglucan was noted as being the most effective of the applied chemicals. The\r\nformation of covalent hemiacetal bonds due to aldehyde groups in the wet fibre network (before\r\nhydrogen bonds are created) was expected to have an important role in the strengthening of wet paper\r\nsamples after wet pressing. Xyloglucan and xyloglucan-borate complex were also found to improve\r\nthe bonding ability of the dried and re-pulped fibre. The xyloglucan-based treatment of the fibre\r\nsurface could thus increase the strength of paper made of recovered fibres.\r\nContrary to cationic starch, xyloglucan was found to recover the strength properties decreased by\r\ntreatments with hydrolytic enzymes. The uncharged nature, the high affinity to cellulose and the\r\nsimilarity of the XG backbone and cellulose chain may explain the results. Thus, the enzymatic\r\ntreatment of pulp followed by xyloglucan modification of the fibre network offers an interesting\r\npossibility to enhance dewatering characteristics at the same time without any deterioration of dry\r\nstrength properties. Water adsorbing polysaccharides forming a gel layer on the surface of the fibre\r\nwere concluded to play an important role in the material efficiency of the fibre.\r\nThe reduction of softwood pulp content in fine paper combined with the stratification of TMP in the\r\nmiddle layer and hardwood pulp in the surface layer, enhanced wet web strength and dry sheet\r\nsmoothness at the same time. The stratification of fillers into surface layers contributed to enhanced\r\ntensile strength compared to an even addition of filler to all layers. The result is probably due to the\r\nnon-linear relationship between filler content and tensile strength. Additionally, it was noted that the\r\nutilisation of 10 to 20% of TMP enabled a 10% addition of filler without any deterioration in the wet\r\nweb tension holding ability.\r\nThe results of this thesis demonstrate that the material efficiency of the fibre can be improved by\r\nutilising several unconventional methods. The modification of fibre surface chemistry and fibre\r\nnetwork structure in the thickness direction of the paper can substantially improve production\r\nefficiency and improve end product quality. The results of this thesis can be utilised for example in\r\nenhancing the recyclability of pulp fibres, reducing the basis weight of paper and board or in utilising\r\ncoarse (low energy) pulp in papermaking.", "language": "en", "element": "description", "qualifier": "abstract", "schema": "dc"}, {"key": "dc.description.provenance", "value": "Submitted by Paivi Vuorio (paelvuor@jyu.fi) on 2022-07-11T10:03:13Z\r\nNo. of bitstreams: 0", "language": "en", "element": "description", "qualifier": "provenance", "schema": "dc"}, {"key": "dc.description.provenance", "value": "Made available in DSpace on 2022-07-11T10:03:13Z (GMT). No. of bitstreams: 0\r\n Previous issue date: 2012", "language": "en", "element": "description", "qualifier": "provenance", "schema": "dc"}, {"key": "dc.language.iso", "value": "eng", "language": null, "element": "language", "qualifier": "iso", "schema": "dc"}, {"key": "dc.relation.ispartofseries", "value": "Jyv\u00e4skyl\u00e4n yliopisto. Fysiikan laitos. Research report", "language": null, "element": "relation", "qualifier": "ispartofseries", "schema": "dc"}, {"key": "dc.relation.haspart", "value": "<b>Artikkeli I:</b> Oksanen, A., Edelmann, K., Kataja-aho, J., and Suurn\u00e4kki, A. (2011) Enhancing dewatering of thermomechanical pulp (TMP) based papermaking through enzymatic treatment.\r\n<i>Holzforschung, 65, 787\u2013795.</i> DOI: <a href=\"https://doi.org/10.1515/HF.2011.083\"target=\"_blank\"> 10.1515/HF.2011.083</a>", "language": null, "element": "relation", "qualifier": "haspart", "schema": "dc"}, {"key": "dc.relation.haspart", "value": "<b>Artikkeli II:</b> Oksanen, A., Lehmonen J., and Pere, J. (2009). Improving paper making process by controlled modification of pulp carbohydrates. <i>TAPPI Press - TAPPI Engineering, Pulping and\r\nEnvironmental Conference 2009 - Innovations in Energy, Fiber and Compliance. Memphis,\r\nUSA, 2191\u20132216.</i> <a href=\"https://imisrise.tappi.org/TAPPI/Products/09/EPE/09EPE85.aspx\"target=\"_blank\"> Full text</a>", "language": null, "element": "relation", "qualifier": "haspart", "schema": "dc"}, {"key": "dc.relation.haspart", "value": "<b>Artikkeli III:</b> Oksanen, A., Rantanen, T., Retulainen, E., Salminen, K., and Brumer, H. (2011). Improving Wet Web Runnability and Paper Quality by an Uncharged Polysaccharide. <i>Journal of Biobased Materials and Bioenergy, 5, 1\u20135.</i> DOI: <a href=\"https://doi.org/10.1166/jbmb.2011.1144\"target=\"_blank\"> 10.1166/jbmb.2011.1144</a>", "language": null, "element": "relation", "qualifier": "haspart", "schema": "dc"}, {"key": "dc.relation.haspart", "value": "<b>Artikkeli IV:</b> Oksanen, A., Retulainen, E., Rantanen, T., and Brumer, H. (2010). Improving recyclability of chemical pulp by introducing non-charged cross-linked polysaccharide on fiber surface. <i>TAPPI PEERS Conference and 9th Research Forum on Recycling. Norfolk, USA, 1, 59-87.</i> <a href=\"https://imisrise.tappi.org/TAPPI/Products/10/EPE/10EPE04.aspx\"target=\"_blank\"> Full text</a>", "language": null, "element": "relation", "qualifier": "haspart", "schema": "dc"}, {"key": "dc.relation.haspart", "value": "<b>Artikkeli V:</b> Oksanen, A., Retulainen, E., Kataja-aho, J., Somerkallio, M., Xu, C., and Brumer, H. (2012). Non-charge polysaccharides \u2013 Effects on runnability of wet web and efficiency of fibre material. <i>International Paperworld IPW, (6), 51-55.</i>", "language": null, "element": "relation", "qualifier": "haspart", "schema": "dc"}, {"key": "dc.relation.haspart", "value": "<b>Artikkeli VI:</b> Oksanen, A., Salminen, K., and Kouko, J. (2007). Enhanced quality - strength and cost efficiency by means of layering. <i>Paperi ja Puu - Paper and Timber. 89(4), 242\u2013245.</i>", "language": null, "element": "relation", "qualifier": "haspart", "schema": "dc"}, {"key": "dc.relation.haspart", "value": "<b>Artikkeli VII:</b> Oksanen, A., Salminen, K., Kouko, K., and Retulainen, E. (2012). The effects of TMP and filler stratifying on wet web runnability and end product quality of fine paper. <i>Nordic Pulp and Paper Research Journal, 27(1), 130-136.</i> DOI: <a href=\"https://doi.org/10.3183/NPPRJ-2012-27-01-p130-136\"target=\"_blank\"> 10.3183/NPPRJ-2012-27-01-p130-136</a>", "language": null, "element": "relation", "qualifier": "haspart", "schema": "dc"}, {"key": "dc.rights", "value": "In Copyright", "language": null, "element": "rights", "qualifier": null, "schema": "dc"}, {"key": "dc.title", "value": "Improving the material efficiency of furnishes in papermaking by stratification and chemical modifications", "language": null, "element": "title", "qualifier": null, "schema": "dc"}, {"key": "dc.type", "value": "doctoral thesis", "language": null, "element": "type", "qualifier": null, "schema": "dc"}, {"key": "dc.identifier.urn", "value": "URN:ISBN:978-951-39-9353-5", "language": null, "element": "identifier", "qualifier": "urn", "schema": "dc"}, {"key": "dc.contributor.faculty", "value": "Faculty of Mathematics and Science", "language": "en", "element": "contributor", "qualifier": "faculty", "schema": "dc"}, {"key": "dc.contributor.faculty", "value": "Matemaattis-luonnontieteellinen tiedekunta", "language": "fi", "element": "contributor", "qualifier": "faculty", "schema": "dc"}, {"key": "dc.contributor.organization", "value": "University of Jyv\u00e4skyl\u00e4", "language": "en", "element": "contributor", "qualifier": "organization", "schema": "dc"}, {"key": "dc.contributor.organization", "value": "Jyv\u00e4skyl\u00e4n yliopisto", "language": "fi", "element": "contributor", "qualifier": "organization", "schema": "dc"}, {"key": "dc.type.coar", "value": "http://purl.org/coar/resource_type/c_db06", "language": null, "element": "type", "qualifier": "coar", "schema": "dc"}, {"key": "dc.relation.issn", "value": "0075-465X", "language": null, "element": "relation", "qualifier": "issn", "schema": "dc"}, {"key": "dc.rights.accesslevel", "value": "openAccess", "language": null, "element": "rights", "qualifier": "accesslevel", "schema": "dc"}, {"key": "dc.type.publication", "value": "doctoralThesis", "language": null, "element": "type", "qualifier": "publication", "schema": "dc"}, {"key": "dc.rights.url", "value": "https://rightsstatements.org/page/InC/1.0/", "language": null, "element": "rights", "qualifier": "url", "schema": "dc"}]
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