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Cationização de amidos de tuberosas tropicais para fabricação de papéis /Horimoto, Lídia Kazumi, 1977- January 2006 (has links)
Orientador: Claudio Cabello / Banca: Claudio Angeli Sansígolo / Banca: José Luis Agapito Fernandes / Resumo: Apesar dos amidos serem quimicamente iguais, a organização e funcionalidade desses polímeros dependem das propriedades físico-químicas de cada fonte botânica. Esses amidos podem sofrer diferentes modificações com a finalidade de aperfeiçoar certas características para aplicações industriais específicas. Dentre os amidos modificados, os catiônicos são largamente utilizados na fabricação de papel/papelão a fim de aumentar sua resistência física e mecânica. Neste trabalho, amidos de mandioca, batata doce e mandioquinha salsa foram cationizados com o reagente 3-cloro-2-hidroxipropil-trimetilamônio que em meio alcalino reage com o amido tornando-o carregado positivamente.As amostras foram submetidas a diferentes tempos de reação (0,5 a 24 horas) e relação molar de hidróxido de sódio/monômero. Os melhores parâmetros encontrados para as amostras foram de 6 horas de reação e relação molar de 2,0 NaOH/monômero, que resultaram em maiores DS (grau de substituição) e rendimento percentual, determinados a partir do teor de nitrogênio presente em cada amostra. Em seguida os amidos catiônicos com os melhores parâmetros foram submetidos a diferentes tratamentos após a derivatização: etanol a 25%, etanol a 50% e água a temperatura de 35°C, para avaliar a interferência dos sais residuários no grau de substituição das amostras derivatizadas. A seguir essas amostras de amidos catiônicos de mandioca, batata doce e mandioquinha salsa foram aplicadas em folhas de papel, onde testes físicos-mecânicos como resistências ao rasgo, arrebentamento, tração, permeância ao ar entre outros foram realizados com a finalidade de verificar a influência da adição de diferentes tipos de amido. / Abstract: In spite of starches are chemically the same, the organization of biopolymers and the functionality of the starches depend on physical and chemical properties of each botanical source, which can undergo modifications with the purpose of improving certain characteristics for specific industrial applications. Among the modified starches, the cationic are widely used in the papermaking process in order to increase their physical and mechanical resistances. In this study, cassava, sweet potato and Peruvian carrot starches were cationized with 3-chloro-2-hydroxypropyltrimethylammonium choride reagent, that in a high pH reacts with starch become it positively loaded. The samples were submitted to different reaction time (0.5 to 24 hours) and the NaOH/monomer mole ratio. The best parameters found for the samples were of 6 hours of reaction time and 2.0 NaOH/monomer mole ratio, which resulted in larger degree of substitution (DS) and reaction efficiency (RE), determined by the 3 content of nitrogen present in each sample. Then the cationic starches with the best parameters were submitted to different treatments after derivatization: ethanol at 25%, ethanol at 50% and water at the temperature of 35°C, in order to evaluate the interference of the residual salts in the degree of substitution of the derivatized samples. In the sequence, these samples of cationic cassava, sweet potato and Peruvian carrot starches were applied in sheets of paper, where physical and mechanical tests such as air resistance, bursting strength, tensile strength, internal tearing resistance, among others, were performed with the purpose of verifying the influence of the addition of different types of starch. / Mestre
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Élaboration et application d’agents fixateurs de colorants à base de chitosane pour l’industrie papetière / Elaboration of chitosan-based dyes fixing agents for paper applicationsAltounian, Anais 18 December 2018 (has links)
Au cours des dernières années, des progrès ont été faits dans le domaine papetier. De plus, le développement de nouveaux matériaux biosourcés a fait l’objet de nombreux sujets de recherche. L’élaboration de fixateurs de colorants alimentaires anioniques à base de chitosane destinés à l’industrie papetière, s’inscrit donc dans ce contexte R & D. Ce projet, proposé par la société Colorey et mené à bien en collaboration avec le laboratoire d’Ingénierie des Matériaux Polymères (IMP, UMR 5223), a consisté en l’utilisation de chitosane (unique polycation naturel) tel quel pour la coloration en surface du papier, ou modifié avec le chlorure de glycidyltriméthylammonium (GTMAC) sous la forme de chitosane quaternarisé (Chi-GTMAC), pour la coloration dans la masse. Ce dernier procédé de coloration requiert un pH neutre ou légèrement alcalin, ce qui est incompatible avec la solubilisation du chitosane, qui nécessite un milieu aqueux acide. C’est pourquoi le Chi-GTMAC, comportant des fonctions triméthylammonium comme charges positives indépendantes du pH, a été mis au point. La stabilité thermique et la solubilité à tout pH de chaque échantillon, ont été évaluées afin de déterminer leur capacité à supporter ou non les températures de séchage du processus papetier, et leur potentiel d’utilisation au sein du pulpeur pour la coloration dans la masse. Puis, l’efficacité de certains dérivés à colorer la pâte et à fixer le colorant a été étudiée à l’aide d’un plan d’expérience. Le chitosane a, quant à lui, été testé en solution aqueuse acide comme agent fixateur pour la coloration de surface du papier préformé / Over the past years, progresses have been achieved in the field of the paper industry. Moreover, the development of biosourced materials has been studied under intense investigations.The elaboration of chitosan-based fixing agents of anionic food dyes intended to paper industry is in line with this R & D context. This project, proposed by the company Colorey and carried out in collaboration with IMP laboratory (UMR 5223), consisted in using chitosan (the only natural polycation) as such for the surface dyeing of paper or, modified with the glycidyltrimethylammonium chloride (GTMAC) as quaternized chitosan (Chi-GTMAC), for the mass dyeing of the pulp. This last process required a neutral or slightly alkaline pH within the pulper, which cannot allow the solubilization of chitosan. Hence, chitosan was derivatized into Chi-GTMAC, bearing trimethylammonium moieties as pH-independent functional groups. The thermal stabilities and the aqueous solubilities as a function of pH of these derivatives were investigated in order to determine whether they could support the drying temperature of the papermaking process or whether they could be used within the pulper for mass coloration. Then, the efficiency of some of the obtained derivatives to color the pulp and to fix dyes was determined thanks to a designed of experiments. Chitosan, for its part, has been tested as fixing agent for surface coloration of paper
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Aplicação de nanoceluloses em fibras não branqueadas para obtenção de papéis. / Application of nanocelulose in unbleached fibers for papermaking.Cruces Cerro, Jorge 18 August 2016 (has links)
Atualmente, o Brasil é o maior fabricante de celulose branqueada de eucalipto do mundo. Geralmente as fibras virgens de Eucalyptus spp. são utilizadas na fabricação de papéis para imprimir, tissue e especiais. Papéis para embalagens, tipicamente Kraftliners, precisam de uma grande resistência mecânica e são produzidos principalmente a partir de pastas Kraft de coníferas não branqueadas. Por outro lado, nanoceluloses fabricadas a partir de biomassa são consideradas um dos materiais sustentáveis mais interessantes para o século, com excelentes propriedades como baixa densidade, elevadas propriedades mecânicas, alta hidrofilicidade, grande área superficial com reatividade química e elevado valor econômico. Desde 2012 o uso de nanoceluloses na fabricação de papel ganhou impulso. As nanoceluloses têm sido adicionadas em pastas mecânicas e Kraft branqueadas para fabricação do papel, incrementando notavelmente as suas propriedades mecânicas, mas há preocupações sobre a diminuição da drenabilidade, da porosidade e da opacidade do papel. Poucos estudos foram desenvolvidos visando a aplicação de nanoceluloses em fibras não branqueadas, ainda que tenham aplicações em pastas branqueadas e/ou mecânicas. Portanto, o presente trabalho visa desenvolver o uso de nanoceluloses para melhorar as propriedades mecânicas em fibras não branqueadas. Em primeiro lugar, tomaram-se os finos primários do branqueamento de celulose de Pasta Kraft de Eucalipto como a matéria-prima para produzir dois tipos de nanocelulose. A celulose microfibrilada (MFC) é produzida diretamente por homogeneização mecânica utilizando equipamento Masuko. A celulose nanofibrilada (CNF) é produzida por oxidação mediada por TEMPO e homogeneizada por GEA. Em segundo lugar, selecionaram-se com as fibras virgens de Pasta Kraft Marrom de Pinho (PKPM) com número Kappa 36,1 e Pasta Kraft de Eucalipto Não Branqueada (PKEP), obtida na saída de estágio de deslignificação com oxigênio, com número Kappa 9,21, e todas as fibras foram refinadas até atingir o mesmo grau Shopper-Riegler (33±1 SR). Os experimentos com PKPM são conduzidas como uma referência a papéis Kraftliners tradicionais, com ou sem nanocelluloses. Também obteve folhas manuais com pasta branqueada Kraft de eucalipto, adicionando nanoceluloses, para compreender o efeito da lignina presente em PKEP. A receita e os aditivos químicos aplicados aqui são os mesmos que na produção industrial. Os principais resultados são: o uso de CNF (ou MFC) e agentes químicos, separadamente, na pasta PKEP, aumenta as resistências mecânicas dos papéis, no entanto, quando aplicadas CNF (ou MFC) em PKMP sem aditivos químicos, as resistências à tração e a estouro diminuem, e a resistência ao rasgo permanece constante. Como a terceira parte do estudo, delineamento de experimentos teve a configuração composto central com o ponto central em 1% de CNF (ou MFC) e 1% de agentes químicos (polímero+amido+cola), e seus pontos axiais foram 0,3%-1,7% de CNF (ou MFC), e 0,15%-0,85% de agentes químicos. O ponto ótimo de equilíbrio dos índices de rasgo (mN.m2/g) /estouro (kPa.m2/g) /tração (N.m/g) de (10,00/2,25/36,56 para CNF e 12,88/4,25/57,62 para MFC), obteve-se com a adição de 1,03% de CNF e 0,65% de amido, ou com a adição de menos de 0,01% de MFC e de 1% de amido. Finalmente, foram aplicadas CNF ou MFC por impregnação direta no centro da direção-z, considerando que o papel tem forças que interagem em 3D. Os resultados mostram que a PKEP atinge a qualidade do Kraftliner de pinus obtendo um índice de tração de 52,58 N.m/g utilizando 1% de CNF, ou 47,40 N.m/g utilizando 1% de MFC. Também, o custo de utilização do CNF ou MFC na fabricação do papel é avaliado, resultando em estimativas de 0,9494 US$/kg ou 0,3036 US$/kg, com a adição de 1% de CNF ou 1% de MFC, respectivamente, em pasta PKEP. Este trabalho mostra que a aplicação de nanocelulose em Kraftliner tradicional com fibras de pinus com todos os agentes químicos não tem vantagens reais. No entanto, o uso de CNF e MFC tecnicamente e economicamente tem vantagens superiores em pasta Kraft de eucalipto não branqueada (e deslignificada com oxigênio), obtendo-se propriedades superiores às de fibras longas. / Nowadays, Brazil is the largest manufacturer of Bleached Eucalyptus Kraft Pulp in the world. Mostly the Eucalyptus spp. virgin fibres are used in papermaking to manufacture printing, tissue and specialty papers. Packaging papers, typically Kraftliners, have high demands for mechanical strength and are made mostly from Unbleached Softwood Kraft Pulp. Other side, nanocelluloses from biomass are considered one of the most interesting sustainable materials for the Century, with excel properties such as low density, high mechanical properties, high hydrophilicity, large surface area with chemical reactivity and high economic value. Since 2012 the use of nanocellulose in papermaking experienced a great momentum. Nanocelluloses are added in bleached or mechanical pulp in papermaking to increase significantly the mechanical properties, but there are concerns about the decreasing of the drainability, the porosity and the opacity of the paper. A very few studies were developed on the application of nanocelluloses in an unbleached Kraft pulp, even there are its applications on bleached pulps and mechanical pulps. Therefore, the present work aims to develop the application of nanocelluloses to increase the mechanical properties of the unbleached fibers, specifically for Kraftliners, and show the way to replace the softwood fibers with the low-cost hardwood fibers. Firstly, the primary fines from bleaching area of Eucalyptus Kraft pulp, obtained from an industrial residue, was the raw material for nanocellulose production of two nanocelluloses. The microfibrillated celluloses (MFC) are produced with direct mechanical homogenization using Masuko. The nanofibrillated cellulose (NCF) is produced with oxidation mediated by TEMPO and homogenization using GEA. Secondly, as virgin fibers were selected the Unbleached Pine Kraft Pulp (USKP) with Kappa number 36.1 and the Unbleached Eucalyptus Kraft Pulp (UEKP) just after the oxygen delignification stage with the Kappa number 9.21. All the fibres (USKP and UEKP) was refining at the same Shopper-Riegler (33±1 SR). USKP experiments are conducted as reference to traditional Kraftliners, with or without nanocelluloses. Also the virgin bleached Eucalyptus Kraft pulp with nanocelluloses addition for the handsheet paper helps to understand the role of lignin in UEKP. The recipe and chemicals applied here are the same of the industrial production. The main results are: the use CNF (or MFC) and chemical agents, separately, in UEKP, promote the mechanical resistances, however when applied CNF (or MFC) in UPKP without chemicals, the tensile and burst properties decreased and tear remains constant. As the third group of the study, the design of the experiments was conducted in the star configuration with centre point as 1% CNF (or MFC) and 1.00% chemical agents (polymers+starch+chemical agents) and, the axial points were 0.3%-1.7% NCF (or MFC) and 0.15%-0.85 of chemical agents. The optimum point from the balanced tear (mN.m2/g) /burst (kPa.m2/g) /tensile (N.m/g) index point of view with 10.00/2.25/36.56 for (1.03% CNF and 0.65% starch) and 12.88/4.25/57.62 for (<0.001% MFC and 1% starch). Finally, it is applied here the direct impregnation of the center of z-direction with 1% of CNF and MFC, considering that the paper has 3D interacting forces. The results show that the UEKP reaches the pinus Kraftliner quality with 52.58 N.m/g (Tensile Index) using 1% CNF or 47.40 N.m/g using 1% MFC. Also, the cost of use CNF or MFC in papermaking is evaluated, resulting in the estimates of 0.9494 US$/kg or 0.3036 US$/kg, the addition of 1% CNF or 1% MFC in UEKP. This work shows that the application of nanocellulose in traditional Kraftliner with pinus fibres with all chemical agents has no real advantages. However, the use of CNF and MFC technically and economically has superior advantages in Eucalyptus unbleached (and oxygen delignified) Kraft pulp, resulting in such properties superior to those of long fibres.
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Optical characteristics of paper as a function of fiber classification.Parsons, Shirley R. (Shirley Robinson) 01 January 1941 (has links)
No description available.
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Chemo-enzymatic modification of high-kappa kraft pulps with laccaseChandra, Richard P. 07 1900 (has links)
No description available.
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Enhanced performance and functionality of titanium dioxide papermaking pigments with controlled morphology and surface coatingNelson, Kimberly Lynn 06 July 2007 (has links)
Novel, tailored titanium dioxide pigments with controllable nanoscale morphological features were shown to significantly enhance the optical and strength properties of paper. The opacifying power of synthesized polycrystalline TiO2 particles in a cellulose matrix was found experimentally to be superior to that of a commercial rutile pigment, depending on the crystal structure of the synthesized particles. High aspect ratio polycrystalline rutile pigments composed of a linear linkage of several individual rutile crystals gave 6% more opacity than the commercial rutile pigment. Theoretical light scattering calculations using the T-Matrix Method showed the light scattering efficiency of linearly arranged polycrystalline rutile particles to depend on number and size of crystals composing the particle and confirmed the higher efficiency of the synthesized polycrystalline rutile pigments over commercial rutile. The opacifying power of hollow polycrystalline rutile particles was found experimentally to be superior to that of a commercial rutile pigment in a highly pressed bleached fiber matrix, depending on cavity size, while the opacifying power of silica-rutile titania core-shell particles was found comparable to commercial rutile at constant titania loading. The light scattering efficiency of titania core-shell particles was shown to be dependant on the light scattering efficiency of the core material. The overall particle shape and aspect ratio of titania core-shell and hollow nanoparticles were shown to be tunable by choosing an appropriate template and coating thickness in layer-by-layer or sol-gel templating synthesis. Inorganic-cellulose core-shell and hollow cellulose nanoparticles were prepared by self-encapsulation with regenerated cellulose via precipitation of cellulose in a polyacrylic acid hydrogel layer surrounding inorganic particle templates in 4-Methylmorpholine N-oxide (NMMO) monohydrate solution. This discrete encapsulation of inorganic pigments with a thin, uniform cellulose shell was found to increase the bondability improvement between the particles and a polysaccharide substrate. The crystallinity of several carbohydrate polymers was shown to significantly affect the bondability of encapsulated core-shell particles.
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Aplicação de nanoceluloses em fibras não branqueadas para obtenção de papéis. / Application of nanocelulose in unbleached fibers for papermaking.Jorge Cruces Cerro 18 August 2016 (has links)
Atualmente, o Brasil é o maior fabricante de celulose branqueada de eucalipto do mundo. Geralmente as fibras virgens de Eucalyptus spp. são utilizadas na fabricação de papéis para imprimir, tissue e especiais. Papéis para embalagens, tipicamente Kraftliners, precisam de uma grande resistência mecânica e são produzidos principalmente a partir de pastas Kraft de coníferas não branqueadas. Por outro lado, nanoceluloses fabricadas a partir de biomassa são consideradas um dos materiais sustentáveis mais interessantes para o século, com excelentes propriedades como baixa densidade, elevadas propriedades mecânicas, alta hidrofilicidade, grande área superficial com reatividade química e elevado valor econômico. Desde 2012 o uso de nanoceluloses na fabricação de papel ganhou impulso. As nanoceluloses têm sido adicionadas em pastas mecânicas e Kraft branqueadas para fabricação do papel, incrementando notavelmente as suas propriedades mecânicas, mas há preocupações sobre a diminuição da drenabilidade, da porosidade e da opacidade do papel. Poucos estudos foram desenvolvidos visando a aplicação de nanoceluloses em fibras não branqueadas, ainda que tenham aplicações em pastas branqueadas e/ou mecânicas. Portanto, o presente trabalho visa desenvolver o uso de nanoceluloses para melhorar as propriedades mecânicas em fibras não branqueadas. Em primeiro lugar, tomaram-se os finos primários do branqueamento de celulose de Pasta Kraft de Eucalipto como a matéria-prima para produzir dois tipos de nanocelulose. A celulose microfibrilada (MFC) é produzida diretamente por homogeneização mecânica utilizando equipamento Masuko. A celulose nanofibrilada (CNF) é produzida por oxidação mediada por TEMPO e homogeneizada por GEA. Em segundo lugar, selecionaram-se com as fibras virgens de Pasta Kraft Marrom de Pinho (PKPM) com número Kappa 36,1 e Pasta Kraft de Eucalipto Não Branqueada (PKEP), obtida na saída de estágio de deslignificação com oxigênio, com número Kappa 9,21, e todas as fibras foram refinadas até atingir o mesmo grau Shopper-Riegler (33±1 SR). Os experimentos com PKPM são conduzidas como uma referência a papéis Kraftliners tradicionais, com ou sem nanocelluloses. Também obteve folhas manuais com pasta branqueada Kraft de eucalipto, adicionando nanoceluloses, para compreender o efeito da lignina presente em PKEP. A receita e os aditivos químicos aplicados aqui são os mesmos que na produção industrial. Os principais resultados são: o uso de CNF (ou MFC) e agentes químicos, separadamente, na pasta PKEP, aumenta as resistências mecânicas dos papéis, no entanto, quando aplicadas CNF (ou MFC) em PKMP sem aditivos químicos, as resistências à tração e a estouro diminuem, e a resistência ao rasgo permanece constante. Como a terceira parte do estudo, delineamento de experimentos teve a configuração composto central com o ponto central em 1% de CNF (ou MFC) e 1% de agentes químicos (polímero+amido+cola), e seus pontos axiais foram 0,3%-1,7% de CNF (ou MFC), e 0,15%-0,85% de agentes químicos. O ponto ótimo de equilíbrio dos índices de rasgo (mN.m2/g) /estouro (kPa.m2/g) /tração (N.m/g) de (10,00/2,25/36,56 para CNF e 12,88/4,25/57,62 para MFC), obteve-se com a adição de 1,03% de CNF e 0,65% de amido, ou com a adição de menos de 0,01% de MFC e de 1% de amido. Finalmente, foram aplicadas CNF ou MFC por impregnação direta no centro da direção-z, considerando que o papel tem forças que interagem em 3D. Os resultados mostram que a PKEP atinge a qualidade do Kraftliner de pinus obtendo um índice de tração de 52,58 N.m/g utilizando 1% de CNF, ou 47,40 N.m/g utilizando 1% de MFC. Também, o custo de utilização do CNF ou MFC na fabricação do papel é avaliado, resultando em estimativas de 0,9494 US$/kg ou 0,3036 US$/kg, com a adição de 1% de CNF ou 1% de MFC, respectivamente, em pasta PKEP. Este trabalho mostra que a aplicação de nanocelulose em Kraftliner tradicional com fibras de pinus com todos os agentes químicos não tem vantagens reais. No entanto, o uso de CNF e MFC tecnicamente e economicamente tem vantagens superiores em pasta Kraft de eucalipto não branqueada (e deslignificada com oxigênio), obtendo-se propriedades superiores às de fibras longas. / Nowadays, Brazil is the largest manufacturer of Bleached Eucalyptus Kraft Pulp in the world. Mostly the Eucalyptus spp. virgin fibres are used in papermaking to manufacture printing, tissue and specialty papers. Packaging papers, typically Kraftliners, have high demands for mechanical strength and are made mostly from Unbleached Softwood Kraft Pulp. Other side, nanocelluloses from biomass are considered one of the most interesting sustainable materials for the Century, with excel properties such as low density, high mechanical properties, high hydrophilicity, large surface area with chemical reactivity and high economic value. Since 2012 the use of nanocellulose in papermaking experienced a great momentum. Nanocelluloses are added in bleached or mechanical pulp in papermaking to increase significantly the mechanical properties, but there are concerns about the decreasing of the drainability, the porosity and the opacity of the paper. A very few studies were developed on the application of nanocelluloses in an unbleached Kraft pulp, even there are its applications on bleached pulps and mechanical pulps. Therefore, the present work aims to develop the application of nanocelluloses to increase the mechanical properties of the unbleached fibers, specifically for Kraftliners, and show the way to replace the softwood fibers with the low-cost hardwood fibers. Firstly, the primary fines from bleaching area of Eucalyptus Kraft pulp, obtained from an industrial residue, was the raw material for nanocellulose production of two nanocelluloses. The microfibrillated celluloses (MFC) are produced with direct mechanical homogenization using Masuko. The nanofibrillated cellulose (NCF) is produced with oxidation mediated by TEMPO and homogenization using GEA. Secondly, as virgin fibers were selected the Unbleached Pine Kraft Pulp (USKP) with Kappa number 36.1 and the Unbleached Eucalyptus Kraft Pulp (UEKP) just after the oxygen delignification stage with the Kappa number 9.21. All the fibres (USKP and UEKP) was refining at the same Shopper-Riegler (33±1 SR). USKP experiments are conducted as reference to traditional Kraftliners, with or without nanocelluloses. Also the virgin bleached Eucalyptus Kraft pulp with nanocelluloses addition for the handsheet paper helps to understand the role of lignin in UEKP. The recipe and chemicals applied here are the same of the industrial production. The main results are: the use CNF (or MFC) and chemical agents, separately, in UEKP, promote the mechanical resistances, however when applied CNF (or MFC) in UPKP without chemicals, the tensile and burst properties decreased and tear remains constant. As the third group of the study, the design of the experiments was conducted in the star configuration with centre point as 1% CNF (or MFC) and 1.00% chemical agents (polymers+starch+chemical agents) and, the axial points were 0.3%-1.7% NCF (or MFC) and 0.15%-0.85 of chemical agents. The optimum point from the balanced tear (mN.m2/g) /burst (kPa.m2/g) /tensile (N.m/g) index point of view with 10.00/2.25/36.56 for (1.03% CNF and 0.65% starch) and 12.88/4.25/57.62 for (<0.001% MFC and 1% starch). Finally, it is applied here the direct impregnation of the center of z-direction with 1% of CNF and MFC, considering that the paper has 3D interacting forces. The results show that the UEKP reaches the pinus Kraftliner quality with 52.58 N.m/g (Tensile Index) using 1% CNF or 47.40 N.m/g using 1% MFC. Also, the cost of use CNF or MFC in papermaking is evaluated, resulting in the estimates of 0.9494 US$/kg or 0.3036 US$/kg, the addition of 1% CNF or 1% MFC in UEKP. This work shows that the application of nanocellulose in traditional Kraftliner with pinus fibres with all chemical agents has no real advantages. However, the use of CNF and MFC technically and economically has superior advantages in Eucalyptus unbleached (and oxygen delignified) Kraft pulp, resulting in such properties superior to those of long fibres.
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The Potato Famine Paper: Joy, Grief, and Beauty in the Face of Ancestral StruggleMatthews, Andrea 11 May 2023 (has links)
No description available.
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The political ecology of the Japanese paper industryPenna, Ian Unknown Date (has links)
The Japanese paper and paperboard industry has grown to be one of the largest in the world. It manufactures a range of products for sale primarily within Japan, and consumes organic fibre for these products from dispersed domestic and foreign forests, plantations and cities. This dissertation examines the links between the development and structure of the industry and its use of papermaking fibre. It takes a political ecology perspective and uses an industrial structure/consumption-production chain approach to show how the industry’s development and structure continue to depend on company control over fibre flows and the restructuring of products, product distribution and manufacture, the fibre supply chain and fibre resources. As with the modern global paper/board industry, the recent growth of the Japanese industry has been characterised by cycles of capacity expansion, market collapse, excess capacity and low prices and profits. Manufacturers and general trading companies involved in the industry have tried to support growth in the use of paper/board and counter these cycles by restructuring production, distribution, ownership and fibre supply. This restructuring helps protect the flow of fibre through the industry and concentrated it in particular companies. Obtaining increasing quantities of suitably-priced fibre has been at the base of the industry’s development.
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The political ecology of the Japanese paper industryPenna, Ian Unknown Date (has links)
The Japanese paper and paperboard industry has grown to be one of the largest in the world. It manufactures a range of products for sale primarily within Japan, and consumes organic fibre for these products from dispersed domestic and foreign forests, plantations and cities. This dissertation examines the links between the development and structure of the industry and its use of papermaking fibre. It takes a political ecology perspective and uses an industrial structure/consumption-production chain approach to show how the industry’s development and structure continue to depend on company control over fibre flows and the restructuring of products, product distribution and manufacture, the fibre supply chain and fibre resources. As with the modern global paper/board industry, the recent growth of the Japanese industry has been characterised by cycles of capacity expansion, market collapse, excess capacity and low prices and profits. Manufacturers and general trading companies involved in the industry have tried to support growth in the use of paper/board and counter these cycles by restructuring production, distribution, ownership and fibre supply. This restructuring helps protect the flow of fibre through the industry and concentrated it in particular companies. Obtaining increasing quantities of suitably-priced fibre has been at the base of the industry’s development.
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