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Artykuły w czasopismach na temat "Cellulose fibre"

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Ouajai, Sirisart, Peerachai Ruangwilairat, Kitti Ongwongsakul, Thanawadee Leejarkpai i Robert A. Shanks. "Morphology and Structure of Modified Oil Palm Empty Fruit Bunch Cellulose Fibre". Advanced Materials Research 93-94 (styczeń 2010): 607–10. http://dx.doi.org/10.4028/www.scientific.net/amr.93-94.607.

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Oil palm empty fruit bunch (OPEFB) cellulose fibre has been widely used as a reinforcing filler in polymer composites. Surface modification of OPEFB fibre was aimed enhancing inter-phase adhesion with a poly(lactic acid) matrix. In this study, the OPEFB fibres were pre-treated in a sodium hydroxide solution. Surface compositions and thermal stability of the fibres were studied using ATR-FTIR and TGA techniques, respectively. The pre-treatment resulted in the removal of non-cellulosic components leaving purer fibres. In addition, an acetylation of OPEFB cellulose fibres by acetic anhydride was conducted under solvent free condition at room temperature (30 °C). The acetylation reaction was catalyzed by iodine. The degree of substitution monitored by solid state 13C NMR depended upon reaction time and molar ratio of OPEFB cellulose and acetic anhydride. Crystalline structure and morphology of the partial acetylated fibres were investigated using WAXD and SEM, respectively.
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Cordin, Michael, i Thomas Bechtold. "Physical properties of lyocell-reinforced polypropylene composites from intermingled fibre with varying fibre volume fractions". Journal of Thermoplastic Composite Materials 31, nr 8 (19.10.2017): 1029–41. http://dx.doi.org/10.1177/0892705717734594.

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Polypropylene (PP)-cellulose fibre blends exhibit substantial potential for the production of high-performance textile fibre–reinforced composites. The production of reinforced parts from PP-cellulose composites through thermal shaping of intermingled fibre blends is a strategy to form parts which exhibit superior mechanical properties. In this study, the use of intermingled fibre slivers with different ratios of lyocell fibres (CLY) and PP fibres as raw materials for thermally formed composites was investigated. Such a concept will maximize the interface between the reinforcement fibres and polymer matrix. The cellulose fibres remain oriented along the direction in which the drawing process was performed, which forms the basis for tailored fibre placement in technical production. Because of good surface contact between the cellulose fibre surface and PP matrix, no special coupling agents were required to improve the interfacial adhesion between the two different polymers. The share of CLY and PP fibres in the composite varied from 50% w/w CLY content, up to 70% w/w CLY. Besides analysis of the mechanical properties, such as tensile strength and E-modulus, attention was directed towards moisture sorption of the composites. The rate of sorption and amount of water bound in the composite were found to be dependent on the cellulose fibre content. Composites with a higher CLY content exhibited a more rapid and higher moisture uptake. In water saturated state, the ultimate tensile strength of composites reduced from 160 MPa to 90 MPa, which is an indicator for a reduced adhesion between the CLY surface and PP matrix. The results indicate the potential of the intermingled fibre concept blend for the efficient manufacturing of composite parts.
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Sobczak, L., A. Limper, H. Keuter, K. Fischer i A. Haider. "Polypropylene-cellulose Innovative Compounding Technology". Polymers from Renewable Resources 3, nr 1 (luty 2012): 27–32. http://dx.doi.org/10.1177/204124791200300103.

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Lightweight construction and recyclability are essential factors when it comes to meeting environmental targets. Natural fibre-reinforced composites (NFCs) have an important role to play here. The density of natural fibre materials is up to 50% lower than that of the reinforcing fibres traditionally used for plastics, such as glass fibres, and as well as being fully recyclable the composites offer 100% thermal energy recovery.
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Sumithra, Murugesan, i Gayathri Murugan. "Extraction and characterization of natural fibres form Elettaria Cardamomum". Tekstilna industrija 69, nr 2 (2021): 30–33. http://dx.doi.org/10.5937/tekstind2102030s.

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Natural fibres are one of the good alternative sources for replacing synthetic fibres and reinforcing polymer matrices because of their eco-friendly nature. The present study was undertaken to investigate the fibres extract from Elettaria Cardamomum plant. The extracted Elettaria Cardamomum fibre was treated with NaOH for softening. Natural cellulose fibres extracted from Elettaria Cardamomum stems (ECS) have been characterized for their chemical composition and physical properties.The chemical composition of Elettaria Cardamomumstems (ECS) fi bres is, cellulose 60.44%, lignin 25.25%, wax 0.53%, ash 5.45%. Regarding physical properties of the fibres, single fibre strength was evaluated and the result was compared with cotton fibre and linen fibre.
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Stevulova, Nadezda, Viola Hospodarova, Vojtech Vaclavik, Tomas Dvorsky i Tomas Danek. "Characterization of cement composites based on recycled cellulosic waste paper fibres". Open Engineering 8, nr 1 (10.11.2018): 363–67. http://dx.doi.org/10.1515/eng-2018-0046.

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AbstractNowadays, there is paying an attention to the utilization of natural, renewable and biodegradable resources of raw materials of lignocellulosic character, residues from agricultural crops and wood processing as well as waste from papermaking industry in building composite materials preparing. Also recycled fibres coming from waste paper are considered as valuable material. The objective of this study is to utilize these recycled cellulosic fibres into cement composites and characterise their impact on resulting physical and mechanical properties of fresh and hardened cement composites. Manufactured cement composites contained 0.2%, 0.3% and 0.5% addition of cellulosic fibres. In fresh fibre cement mixtures reduction in workability with increasing amount of cellulose fibres was noticed. Density as well as compressive and flexural strength of 28 and 90 days hardened fibre cement composites was tested. Distribution of cellulosic fibres with 0.5% addition in hardened fibre cement composites was also observed. The results of density determination of 28 and 90 days hardened fibre cement composites showed reduction in their values related to weight lighter concretes. Compressive strengths of fibre cement composites have shown decreasing character with increasing added amount of cellulosic fibres into the mixture up to 0.5%. Maximal decrease in compressive strength values was observed in composites containing 0.5% of cellulosic fibres. However, obtained strength parameter values of hardened composites had satisfying results for their application in construction as non-load bearing building material.
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Abdullah, ABM, Maruf Abony, MT Islam, MS Hasan, MAK Oyon i Md Bokhtiar Rahman. "Extraction and Proximate Study of Sansevieria Trifasciata L. As Fibre Source for Textile and Other Uses". Journal of the Asiatic Society of Bangladesh, Science 46, nr 2 (29.06.2021): 155–62. http://dx.doi.org/10.3329/jasbs.v46i2.54411.

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Natural fibres are getting importance for their sustainable development in their uses in mitigation of climate change and ecological balance. A fibre extraction retting method is formulated and proximate chemical composition and various physical properties such as tensile strength, elongation, diameter along with fibre, cellulose, lignin and ash content were determined. This preliminary observation indicates its potential to be used as a source of fibre for textile and non-textile uses such as woven, nonwoven, composite, blanded and a good source of α-cellulose, microcrystalline cellulose, nano-cellulose and lignin-based products. Asiat. Soc. Bangladesh, Sci. 46(2): 155-162, December 2020
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Ardanuy, Mònica, Marcelo Antunes i Jose Ignacio Velasco. "Preparation and Characterization of Cellulosic Fibre-Reinforced Polypropylene Foams". Advanced Materials Research 123-125 (sierpień 2010): 1183–86. http://dx.doi.org/10.4028/www.scientific.net/amr.123-125.1183.

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The preparation and characterization of cellulosic fibre-reinforced polypropylene composite foams is presented. The cellulose fibres were isolated from a barley straw obtained from local sources. They were compounded with the polymer in the melt state to obtain composites with nominal concentrations of 10 and 20% by weight. After compression-moulding the composite samples were foamed in a high-pressure batch-process employing CO2 as foaming agent. The effects of the fibre loading on the basics characteristics of the foams was investigated.
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Schmidt, Vivian Consuelo Reolon, i João Borges Laurindo. "Characterization of foams obtained from cassava starch, cellulose fibres and dolomitic limestone by a thermopressing process". Brazilian Archives of Biology and Technology 53, nr 1 (luty 2010): 185–92. http://dx.doi.org/10.1590/s1516-89132010000100023.

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Cassava starch, dolomitic limestone and eucalypt cellulose fibres were used to prepare foam trays that could be used to pack foodstuffs. The influence of the cellulose fibre concentration in the composite formulation was investigated using 5, 10, 15, 20, 30 and 40% of fibres. The results indicated that an increase in cellulose fibre concentration promoted a decrease in density and tensile strength of the foam samples. The tensile strength at break for foam trays containing 5% of cellulose fibres was 3.03MPa, whilst the commercial trays of expanded polystyrene used to pack foods in supermarkets presented a tensile strength of 1.49 MPa. The elongation at break of the foam trays obtained in this work varied slightly with increase in cellulose fibre concentration, the values being about 20% lower than the elongation at break observed for commercial foam trays of expanded polystyrene. Thus, the materials developed in this work represented a possible alternative to the use of EPS foam trays for packing dry foods. The trays' properties need to be improved for their use with moist foods.
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Ruan, Yong-Ling. "Rapid cell expansion and cellulose synthesis regulated by plasmodesmata and sugar: insights from the single-celled cotton fibre". Functional Plant Biology 34, nr 1 (2007): 1. http://dx.doi.org/10.1071/fp06234.

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Higher plants comprise mixtures of some 40 different cell types, and this often complicates the interpretation of data obtained at the tissue level. Studies for a given cell type may provide novel insights into the mechanisms underlying defined cellular and developmental processes. In this regard, the cotton fibre represents an excellent single-cell model to study the control of rapid cell elongation and cellulose synthesis. These single cells, initiated from the ovule epidermis at anthesis, typically elongate to ~3–5 cm in the tetraploid species before they switch to intensive secondary cell wall cellulose synthesis. By maturity, more than 94% of fibre weight is cellulose. To unravel the mechanisms of fibre elongation and cellulose synthesis, two hypotheses have been examined: (a) that sucrose degradation and utilisation mediated by sucrose synthase (Sus) may play roles in fibre development and (b) that symplastic isolation of the fibre cells may be required for their rapid elongation. Reverse genetic and biochemical analyses have revealed the critical role that Sus plays in fibre initiation and early elongation. Late in development, plasma-membrane and cell wall association of Sus protein seems to be involved in rapid cellulose synthesis. Cell biology and gene expression studies showed a temporary closure of fibre plasmodesmata (PD), probably due to the deposition of callose, at the rapid phase of elongation. The duration of the PD closure correlates positively with the final fibre length attained. These data support the view that PD closure may be required for fibres to achieve extended elongation. The branching of PD towards the secondary cell wall stage is postulated to function as a molecule sieve for tight control of macromolecule trafficking into fibres to sustain intensive cellulose synthesis.
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Auernhammer, Julia, Tom Keil, Binbin Lin, Jan-Lukas Schäfer, Bai-Xiang Xu, Markus Biesalski i Robert W. Stark. "Mapping humidity-dependent mechanical properties of a single cellulose fibre". Cellulose 28, nr 13 (14.07.2021): 8313–32. http://dx.doi.org/10.1007/s10570-021-04058-4.

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AbstractModelling of single cellulose fibres is usually performed by assuming homogenous properties, such as strength and Young’s modulus, for the whole fibre. Additionally, the inhomogeneity in size and swelling behaviour along the fibre is often disregarded. For better numerical models, a more detailed characterisation of the fibre is required. Herein, we report a method based on atomic force microscopy to map these properties along the fibre. A fibre was mechanically characterised by static colloidal probe AFM measurements along the longitudinal direction of the fibre. Thus, the contact stress and strain at each loading point could be extracted. Stress–strain curves were be obtained along the fibre. Additionally, mechanical properties such as adhesion or dissipation were mapped. Local variations of the effective fibre radius were recorded via confocal laser scanning microscopy. Scanning electron microscopy measurements revealed the local macroscopic fibril orientation and provided an overview of the fibre topography. By combining these data, regions along the fibre with higher adhesion, dissipation, bending ability and strain or differences in the contact stress when increasing the relative humidity could be identified. This combined approach allows for one to obtain a detailed picture of the mechanical properties of single fibres. Graphic abstract
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Rozprawy doktorskie na temat "Cellulose fibre"

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Larsson, Per A. "Dimensional Stability of Paper : Influence of Fibre-Fibre Joints and Fibre Wall Oxidation". Licentiate thesis, KTH, Fiberteknologi, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4635.

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Papper är ett mycket mångsidigt material. Trots detta finns det ett flertal egenskaper som begränsar papperets användbarhet. Ett av de större problemen med cellulosa- och lignocellulosafibrer är att de sänker sin fria energi genom att sorbera vatten, och denna sorption förändrar papperets dimensioner. Detta fenomen kallas vanligtvis för bristfällig dimensionsstabilitet och uppträder i form av registerfel vid flerfärgstryck eller som krullning, buckling och vågiga papperskanter vid utskrift, kopiering och lagring, eller med en vidare definition som förkortad livslängd hos lådor på grund av mekanosorptivt kryp. Avsikten med denna avhandling har varit att studera och kvantifiera vilka egenskaper som styr, och hur de påverkar, den vatteninducerade dimensionsförändringen som sker hos ett fibernätverk, samt hur dess dimensionsstabilitet kan förbättras. Detta har studerats både genom att ändra fiberns fuktsorptionsegenskaper och genom att förändra adhesionen och kontaktgraden mellan fibrerna i fiber-fiberfogarna. Fogegenskaperna har också varierats genom att tillverka laboratorieark torkade under inspänning samt ark torkade fritt för att minimera mängden inbyggda spänningar i arket. Blekt kraftmassa har behandlats med polyelektrolytmultilager (PEM) för att förbättra adhesionen mellan fibrerna och för att öka kontaktgraden mellan fibrerna i fogen. Kontaktgraden har även minskats genom förhorning av fibrerna före arkformning. För de ark som fick torka fritt gav PEM-behandlingen en ökad hygroexpansionskoefficient, det vill säga dimensionsförändringen normaliserad mot förändringen i fuktinnehåll, vid samma förändring i relativ luftfuktighet medan förhorningen minskade hygroexpansionskoefficienten något. Om arken emellertid torkades under inspänning observerades ingen skillnad i hygroexpansionskoefficient mellan de olika fibermodifieringarna. Detta tolkades som ett resultat av en ökad kontaktzon och en större utbredning ut ur fogens plan, när arken torkades utan inspänning. En utbredning som medför att en större del av fiberns transversella expansion överförs som expansion i pappersplanet. Fibrernas fuktsorptionsegenskaper förändrades genom natriumperjodatoxidering av 1,4-glukanernas C2-C3-bindning. Detta skapade sannolikt tvärbindningar i fiberväggen som förbättrade fiberväggens tålighet både genom att låsa fibrillerna närmare varandra och genom att ta bort potentiella adsorptionssäten som annars är tillgängliga för vattenadsorption. Perjodatoxidationen minskar också fibrernas kristallinitet och således frigjorde oxidationen hydroxylgrupper där vattenmolekyler kan adsorbera. Detta innebar att oxidationen både minskade och ökade interaktionen mellan vatten och fibervägg, men dock på olika strukturell nivå. Tvärbindningarna visade sig också märkbart reducera sorptionshastigheten när arken utsattes för en förändrad luftfuktighet så länge de inte tidigare utsatts för relativa luftfuktigheter nära mättnad. Som ett resultat av den lägre förändringen i fuktinnehåll vid en förändring i luftfuktighet från 20 till 85 % RF minskade dimensionsförändringens amplitud för de tvärbundna arken upp till 30 %. Emellertid uppvisade de tvärbundna arken en högre hygroexpansionskoefficeint, vilket innebär att de blev mer känsliga för absoluta förändringar i fuktinnehåll.
Paper is a very versatile material. Nevertheless, there are several factors limiting its usefulness, and one of the major issues is that cellulosic and ligno-cellulosic fibres lower their free energy by sorbing water and this water changes the dimensions of the paper. This phenomenon is usually referred to as a lack of dimensional stability and is often evident as misregister during multicolour printing or curl, cockle and wavy edges during printing, copying and storage or, with a wider definition, also as a shortened life-time of boxes during storage due to mechano-sorptive creep. The work described in this thesis aims to study and quantify the importance of the different mechanisms causing water-induced dimensional changes in a fibre network and to investigate how to improve the dimensional stability of ligno-cellulosic materials. This has been done both by altering the fiber properties such as the moisture sorptivity and by changing the adhesion and degree of contact within the fibre-fibre joints. The properties of the fibre-fibre joints have been varied by drying laboratory sheets both under restraint and freely to minimise the generation of built-in stresses. Bleached kraft fibres were treated using the polyelectrolyte multilayer (PEM) technique to improve the adhesion between the fibres and to increase the molecular contact within the joints. In contrast, the degree of contact was impaired by hornifying the fibres before sheet preparation. For sheets allowed to dry freely, the PEM-treatment increased the hygroexpansion coefficient, i.e. the dimensional movement normalised with respect to the change in moisture content, when subjected to changes in relative humidity whereas the hornification process resulted in a slightly lowered hygroexpansion coefficient. However, when the sheets were dried under restraint, the different joint and fibre modifications led to no difference in hygroexpansion coefficient. This was interpreted as being a result of an increase in the total contact zone between the fibres when the sheets were dried under restraint, with a greater extension in the outof- plain direction of the joint resulting in a transfer of a larger part of the transverse swelling to the in-plane expansion. The sorptivity of the fibres was changed by oxidising the C2-C3 bond of the 1,4- glucans with periodate. This most likely created covalent cross-links in the fibre wall both improved the integrity of the fibre wall by locking adjacent fibril lamellae to each other and also removed possible sites for water sorption onto the cellulose surfaces. Periodate oxidation also led to a decrease in the crystallinity of the cellulose within the fibres, making more cellulose hydroxyl groups available for the adsorption of water molecules. This means that the oxidation both decreased and increased the interaction between the fibre wall and moisture but, on two different structural levels. The crosslinks significantly reduced the sorption rate when the papers was subjected to changes in relative humidity, as long as the fibres were not subjected to humidities close to saturation. The smaller change in moisture content when the relative humidity was changed between 20 and 85 % RH meant that the dimensional stability of the crosslinked sheets was increased. On the other hand, the hygroexpansion coefficient was increased in the case of papers made from fibres with the highest degree of oxidation, i.e. the sheets became more sensitive to absolute changes in moisture content.
QC 20101117
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Larsson, Per. "Dimensional Stability of Paper Influence of Fibre-Fibre Joints and Fibre Wall Oxidation". Licentiate thesis, KTH, Fibre and Polymer Technology, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4635.

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Papper är ett mycket mångsidigt material. Trots detta finns det ett flertal egenskaper som begränsar papperets användbarhet. Ett av de större problemen med cellulosa- och lignocellulosafibrer är att de sänker sin fria energi genom att sorbera vatten, och denna sorption förändrar papperets dimensioner. Detta fenomen kallas vanligtvis för bristfällig dimensionsstabilitet och uppträder i form av registerfel vid flerfärgstryck eller som krullning, buckling och vågiga papperskanter vid utskrift, kopiering och lagring, eller med en vidare definition som förkortad livslängd hos lådor på grund av mekanosorptivt kryp.

Avsikten med denna avhandling har varit att studera och kvantifiera vilka egenskaper som styr, och hur de påverkar, den vatteninducerade dimensionsförändringen som sker hos ett fibernätverk, samt hur dess dimensionsstabilitet kan förbättras. Detta har studerats både genom att ändra fiberns fuktsorptionsegenskaper och genom att förändra adhesionen och kontaktgraden mellan fibrerna i fiber-fiberfogarna. Fogegenskaperna har också varierats genom att tillverka laboratorieark torkade under inspänning samt ark torkade fritt för att minimera mängden inbyggda spänningar i arket.

Blekt kraftmassa har behandlats med polyelektrolytmultilager (PEM) för att förbättra adhesionen mellan fibrerna och för att öka kontaktgraden mellan fibrerna i fogen. Kontaktgraden har även minskats genom förhorning av fibrerna före arkformning. För de ark som fick torka fritt gav PEM-behandlingen en ökad hygroexpansionskoefficient, det vill säga dimensionsförändringen normaliserad mot förändringen i fuktinnehåll, vid samma förändring i relativ luftfuktighet medan förhorningen minskade hygroexpansionskoefficienten något. Om arken emellertid torkades under inspänning observerades ingen skillnad i hygroexpansionskoefficient mellan de olika fibermodifieringarna. Detta tolkades som ett resultat av en ökad kontaktzon och en större utbredning ut ur fogens plan, när arken torkades utan inspänning. En utbredning som medför att en större del av fiberns transversella expansion överförs som expansion i pappersplanet.

Fibrernas fuktsorptionsegenskaper förändrades genom natriumperjodatoxidering av 1,4-glukanernas C2-C3-bindning. Detta skapade sannolikt tvärbindningar i fiberväggen som förbättrade fiberväggens tålighet både genom att låsa fibrillerna närmare varandra och genom att ta bort potentiella adsorptionssäten som annars är tillgängliga för vattenadsorption. Perjodatoxidationen minskar också fibrernas kristallinitet och således frigjorde oxidationen hydroxylgrupper där vattenmolekyler kan adsorbera. Detta innebar att oxidationen både minskade och ökade interaktionen mellan vatten och fibervägg, men dock på olika strukturell nivå. Tvärbindningarna visade sig också märkbart reducera sorptionshastigheten när arken utsattes för en förändrad luftfuktighet så länge de inte tidigare utsatts för relativa luftfuktigheter nära mättnad. Som ett resultat av den lägre förändringen i fuktinnehåll vid en förändring i luftfuktighet från 20 till 85 % RF minskade dimensionsförändringens amplitud för de tvärbundna arken upp till 30 %. Emellertid uppvisade de tvärbundna arken en högre hygroexpansionskoefficeint, vilket innebär att de blev mer känsliga för absoluta förändringar i fuktinnehåll.


Paper is a very versatile material. Nevertheless, there are several factors limiting its usefulness, and one of the major issues is that cellulosic and ligno-cellulosic fibres lower their free energy by sorbing water and this water changes the dimensions of the paper. This phenomenon is usually referred to as a lack of dimensional stability and is often evident as misregister during multicolour printing or curl, cockle and wavy edges during printing, copying and storage or, with a wider definition, also as a shortened life-time of boxes during storage due to mechano-sorptive creep.

The work described in this thesis aims to study and quantify the importance of the different mechanisms causing water-induced dimensional changes in a fibre network and to investigate how to improve the dimensional stability of ligno-cellulosic materials. This has been done both by altering the fiber properties such as the moisture sorptivity and by changing the adhesion and degree of contact within the fibre-fibre joints. The properties of the fibre-fibre joints have been varied by drying laboratory sheets both under restraint and freely to minimise the generation of built-in stresses.

Bleached kraft fibres were treated using the polyelectrolyte multilayer (PEM) technique to improve the adhesion between the fibres and to increase the molecular contact within the joints. In contrast, the degree of contact was impaired by hornifying the fibres before sheet preparation. For sheets allowed to dry freely, the PEM-treatment increased the hygroexpansion coefficient, i.e. the dimensional movement normalised with respect to the change in moisture content, when subjected to changes in relative humidity whereas the hornification process resulted in a slightly lowered hygroexpansion coefficient. However, when the sheets were dried under restraint, the different joint and fibre modifications led to no difference in hygroexpansion coefficient. This was interpreted as being a result of an increase in the total contact zone between the fibres when the sheets were dried under restraint, with a greater extension in the outof- plain direction of the joint resulting in a transfer of a larger part of the transverse swelling to the in-plane expansion.

The sorptivity of the fibres was changed by oxidising the C2-C3 bond of the 1,4- glucans with periodate. This most likely created covalent cross-links in the fibre wall both improved the integrity of the fibre wall by locking adjacent fibril lamellae to each other and also removed possible sites for water sorption onto the cellulose surfaces. Periodate oxidation also led to a decrease in the crystallinity of the cellulose within the fibres, making more cellulose hydroxyl groups available for the adsorption of water molecules. This means that the oxidation both decreased and increased the interaction between the fibre wall and moisture but, on two different structural levels. The crosslinks significantly reduced the sorption rate when the papers was subjected to changes in relative humidity, as long as the fibres were not subjected to humidities close to saturation. The smaller change in moisture content when the relative humidity was changed between 20 and 85 % RH meant that the dimensional stability of the crosslinked sheets was increased. On the other hand, the hygroexpansion coefficient was increased in the case of papers made from fibres with the highest degree of oxidation, i.e. the sheets became more sensitive to absolute changes in moisture content.

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Svensson, Anna. "Nanocomposites made from nanoporous cellulose fibre". Licentiate thesis, KTH, Fiberteknologi, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-103342.

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This thesis explores how to use the dry nanoporous structure of cellulosic fibres in new types of composite materials. A large effort was also given on how to correctly characterize the structure of fibres where the wet structure has been preserved also in the dry state. Delignified wood fibres have an open fibrillar structure in their water-swollen state. In the present work, this open fibrillar structure was preserved in the dry state by performing a liquid exchange procedure and the samples were thereafter carefully dried with Ar(g). The samples of never-dried TEMPO-oxidized dissolving pulp had a specific surface area of 130 m2/g in the dry state, as measured using the Brunauer, Emmet, and Teller (BET) Nitrogen gas adsorption method. This open structure was also revealed using field emission scanning electron microscopy (FE-SEM). The water-swollen and dry open structures were thoroughly characterized for various pulps. A new method for determining the pore size of water-swollen delignified cellulosic fibres is presented. By combining the results from solid state nuclear magnetic resonance NMR, measuring the specific surface area [m2/g] in the water-swollen state, with fibre saturation point (FSP), measuring the pore volume of fibres in water-swollen state [mass water/mass fibre], the average pore size can be determined without the need of assuming a certain pore geometry. The dry nanoporous structure was then used as a scaffold for in-situ polymerization, to demonstrate how the properties of the fibrils in the fibre wall can be exploited without the need to disintegrate the fibre wall. Both poly(methylmethacrylate) (PMMA) and poly(butylacrylate) (PBA) were successfully used as the polymeric matrix, and both nanocomposites (i.e., fibre/PMMA and fibre/PBA) had a fibre content of approximately 20 w%. The structure of the composites was characterized using SEM and Atomic Force Microscopy (AFM) operated in the phase imaging mode. The AFM results indicate that the cellulose aggregates and polymeric matrix were successfully mixed on a nanoscale, creating a nanocomposite of interpenetrating polymer molecules and cellulose fibrils, rather than a microcomposite, when using microscopic cellulose fibres. The water absorption capacity of the nanocomposites was reduced significantly, indicating that almost all nanopores in the fibre wall were successfully filled with matrix polymer. The mechanical properties were investigated, showing the importance of nanosized reinforcement compared to fibres of micrometer size.

QC 20121011

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Almgren, Karin M. "Wood-fibre composites : Stress transfer and hygroexpansion". Doctoral thesis, KTH, Träkemi och massateknologi, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-12309.

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Wood fibres is a type of natural fibres suitable for composite applications. The abundance of wood in Swedish forests makes wood-fibre composites a new and interesting application for the Swedish pulp and paper industry. For large scale production of composites reinforced by wood fibres to be realized, the mechanical properties of the materials have to be optimized. Furthermore, the negative effects of moisture, such as softening, creep and degradation, have to be limited. A better understanding of how design parameters such as choice of fibres and matrix material, fibre modifications and fibre orientation distribution affect the properties of the resulting composite material would help the development of wood-fibre composites. In this thesis, focus has been on the fibre-matrix interface, wood-fibre hygroexpansion and resulting mechanical properties of the composite. The importance of an efficient fibre-matrix interface for composite properties is well known, but the determination of interface properties in wood-fibre composites is difficult due to the miniscule dimensions of the fibres. This is a problem also when hygroexpansion of wood fibres is investigated. Instead of tedious single-fibre tests, more straightforward, macroscopic approaches are suggested. Halpin-Tsai’s micromechanical models and laminate analogy were used to attain efficient interface characteristics of a wood-fibre composite. When Halpin-Tsai’s model was replaced by Hashin’s concentric cylinder assembly model, a value of an interface parameter could be derived from dynamic mechanical analysis. A micromechanical model developed by Hashin was used also to identify the coefficient of hygroexpansion of wood fibres. Measurements of thickness swelling of wood-fibre composites were performed. Back-calculation through laminate analogy and the micromechanical model made it possible to estimate the wood-fibre coefficient of hygroexpansion. Through these back-calculation procedures, information of fibre and interface properties can be gained for ranking of e.g. fibre types and modifications. Dynamic FT-IR (Fourier Transform Infrared) spectroscopy was investigated as a tool for interface characterization at the molecular level. The effects of relative humidity in the test chamber on the IR spectra were studied. The elastic response of the matrix material increased relative to the motion of the reinforcing cellulose backbone. This could be understood as a stress transfer from fibres to matrix when moisture was introduced to the system, e.g. as a consequence of reduced interface efficiency in the moist environment. The method is still qualitative and further development is potentially very useful to measure stress redistribution on the molecular level.
QC20100714
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Kihlman, Martin. "Dissolution of cellulose for textile fibre applications". Licentiate thesis, Karlstads universitet, Avdelningen för kemiteknik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-12798.

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This thesis forms part of a project with the objective of developing and implementing a novel, wood-based, process for the industrial production of cellulose textile fibres. This new process should not only be cost effective but also have far less environmental impact then current processes. Natural and man-made fibres are usually plagued with problems (e.g. economic and environmental) and are unsuitable in meeting growing demands. The focus of this thesis was therefore to investigate the dissolution of cellulose derived from various pulps in novel aqueous solvent systems.             It was shown that cellulose could be dissolved in a NaOH/H2O solvent at low temperatures (<0°C) and that such an alkaline solvent can be improved regarding the solubility, stability and rheological properties of the cellulose dopes formed if different additives (salts or amphiphilic molecules) are used. The effect of different kinds of pretreatment (individually and combined) and the influence of pulp properties on cellulose accessibility and dissolution were also evaluated. These pretreatments affected, as expected, some characteristic properties of the pulps mainly by reducing the DP but also, for example, changing the composition of the carbohydrates. Not only did the pretreatment affect the solubility it also increased the stability of the cellulose dopes, resembling the effect of chemical additives to the NaOH system. According to multivariate data analysis it was established that, of the pulp properties analyzed, only the composition of carbohydrates and the DP had a significant influence on the solubility of the pulps used in this study. Finally, it was emphasized that the dissolution of cellulose pulps seemed to be controlled by a very complex interaction between both kinetic and thermodynamic parameters.
CelluNova
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Paterson, Daniel Thomas. "Understanding rapid dewatering of cellulose fibre suspensions". Thesis, University of British Columbia, 2016. http://hdl.handle.net/2429/58195.

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Rapid dewatering of cellulose fibre suspensions is a fundamental process in many unit operations in the production of pulp and paper. Understanding dewatering behaviour can be applied to optimizing designs of industrial equipment. In this project, we assess the suitability of a well-established modeling approach, referred to as the base model, at capturing the one dimensional dewatering behaviour of cellulose fibre suspensions seen experimentally. This modeling approach requires two closure relationships determined experimentally, i.e. compressive yield stress and permeability. Experimental equipment has been designed, constructed, and operated to obtain the closure relationships and collect dewatering results for validation of the model. Two experimental techniques, with close agreement, have been developed for the collection of compressive yield stress. Permeability results are obtained through Darcian permeation experiments. Two approaches, neglecting and accounting for flow induced compaction, were developed. Results were found to fall within values seen in the literature. The base model provided good representation of ideal nylon fibre suspension trials. These solid fibres are representative of the base models constitutive equation for an infinite solid phase rearrangement rate constant. The base model poorly represents the cellulose fibre suspensions' dewatering behaviour. The suggested source of discrepancy is the further dynamic due to the dewatering of the individual porous cellulose fibres which results in a finite solid phase rearrangement rate constant. The base model is expanded upon in hopes of capturing this rate dependent behaviour. This extended model, with the determined closure relationships, captured load versus solid volume fraction profiles at varying dewatering rates better than the base model for cellulose fibre suspensions. Further improvements in representation were seen through close representation of the solid phase velocity profiles found experimentally during dewatering. Various cellulose fibre suspensions were investigated to begin a catalog of different dewatering behaviours seen through variations in pulp production variables. Investigations included varying fibre species, pulping processes, levels of low consistency refining, and impacts of dewatering chemical additives.
Applied Science, Faculty of
Mechanical Engineering, Department of
Graduate
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Bergström, Roger. "Fibre flow mechanisms". Doctoral thesis, KTH, Fiber- och polymerteknik, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-240.

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The flow behaviour, and primarily the floc-floc interaction, of pulp paper suspensions have been studied visually. Analogy models based on these observations have been developed as well as the identification of important parameters of floc break-up in low shear rate flow fields. Floc compressions and the locations of voids (areas of lower fibre concentration) where found to influence the floc splitting mechanism. Based on this investigation an equipment for measuring the load carrying ability of fibre flocs and networks was designed, and the effect of measurement geometry, network structure and fibre suspension concentration was investigated. The load carrying ability with concentration increases rapidly when going from 1% to 2% in initial suspension concentration. A model handling the fibre floc behaviour during extension and compression has been developed, and some basic flocculated flow mechanisms are discussed on an analogy basis. A modified Voigt element is use, describing mainly the compressional behaviour and plastic behaviour of loose fibre network structures. Further the pos- sibility of stress chain formation is discussed on a fibre level as well as on a floc level. The effect of fibre flow (shear field) occurring in the forming zone of a roll former has been studied in detail. Basic forming mechanisms on floc scale has been investi- gated, and the effect of running parameters like dewatering pressure and jet-to-wire speed difference as well as the fibre type and concentration of the pulp suspension has been evaluated. It is evident that floc elongation increases with shear rate (jet-to-wire speed difference) and lower dewatering rate. The latter is because the fibre floc is subjected to the shear field longer due to slower immobilisation. Shorter fibre tends to create weaker networks, which promotes a higher elongation of the flocs.
QC 20100901
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Solberg, Daniel. "Adsorption kinetics of cationic polyacrylamides on cellulose fibres and its influence on fibre flocculation". Licentiate thesis, KTH, Fibre and Polymer Technology, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-1665.

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The adsorption of cationic polyacrylamide (C-PAM) and silicananoparticles onto a model surface of silicon oxide wascompared with the adsorption of C-PAM to fibres and theirinfluence on flocculation of a fibre suspension. An increase inionic strength affects the polyelectrolyte adsorption indifferent ways for these two systems. With the silica surface,an increase in the ionic strength leads to a continuousincrease in the adsorption. However, on a cellulose fibre, theadsorption increases at low ionic strength (1 to 10 mM NaCl)and then decreases at higher ionic strength (10 to 100 mMNaCl). It was shown that the adsorption of nanoparticles ontopolyelectrolyte-covered surfaces has a great effect on both theadsorbed amount and the thickness of the adsorbed layer. Theresults showed that electrostatic interactions were thedominating force for the interaction between both the fibresand the polyelectrolytes, and between the polyelectrolytes andthe silica particles. Furthermore, at higher NaClconcentrations, a significant non-ionic interaction between thesilicon oxide surface/particles and the C-PAM was observed.

The adsorption rate of C-PAM onto fibres was rapid andquantitative adsorption was detected in the time range between1 and 8 s at polyelectrolyte addition levels below 0.4 mg/g.Conversely, an increase in the amount of added polymer leads toan increased polymer adsorption up to a quasi-static saturationlevel. However, after a few seconds this quasi-staticsaturation level was significantly lower than the level reachedat electrostatic“equilibrium”. The adsorbed amountof charges at full surface coverage after 1 to 8 s contact timecorresponded to only 2 % of the total fibre charge, whereasafter 30 minutes it corresponded to 15 % of the total fibrecharge. This shows that a full surface coverage at shortcontact times is not controlled by surface charge. Based onthese results, it is suggested that a combination of anon-equilibrium charge barrier against adsorption and ageometric restriction can explain the difference between theadsorption during 1 to 8 s and the adsorption after 30 minutes.With increasing time, the cationic groups are neutralised bythe charges on the fibre as the polyelectrolyte reconforms to aflat conformation on the surface.

The addition of a high concentration of C-PAM to a fibresuspension resulted in dispersion rather than flocculation.This behaviour is most likely due to an electrostericstabilisation of the fibres when the polyelectrolyte isadsorbed. Flocculation of the fibre suspension occurred at lowadditions of C-PAM. A maximum in flocculation was found ataround 50 % surface coverage and dispersion occurred above 100% surface coverage. It was also shown that for a given level ofadsorbed polymer, a difference in adsorption time between 1 and2 seconds influenced the flocculation behaviour. An optimum inflocculation at 50 % surface coverage in combination with theimportance of polymer reconformation time at these shortcontact times showed that the C-PAM induced fibre flocculationagrees with La Mer and Healy’s description of bridgingflocculation.

A greater degree of flocculation was observed with theaddition of silica nanoparticles to the fibre suspension thanin the single polyelectrolyte system. Flocculation increased asa function of the concentration of added nanoparticles until0.5 mg/g. At higher additions the flocculation decreased againand this behaviour is in agreement with an extended model formicroparticle-induced flocculation. An increase in flocculationwas especially pronounced for the more extended silica-2particles. This effect is attributed to the more extendedpolyelectrolyte layer, since the adsorbed amount wasessentially the same for both silica particles.

Finally it was found that fines from the wood fibres had asignificant effect on the flocculation. When fines were added,a greater degree of flocculation was detected. Furthermore, itwas also more difficult to redisperse the fibres with polymerin the presence of fines.

Keywords:Adsorption, bridging, cationic polymers,cellulose fibres, electrosteric stabilisation flocculation,ionic strength, nanoparticle, polyelectrolyte, reconformation,retention aids and silica

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Tawari, Akram. "Development of a cellulose acetate hollow-fine-fibre membrane". Thesis, Stellenbosch : University of Stellenbosch, 2010. http://hdl.handle.net/10019.1/4253.

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Thesis (MScEng (Process Engineering))--University of Stellenbosch, 2010.
ENGLISH ABSTRACT: The goal of this study is to produce cellulose acetate (CA) hollow-fine-fibre membranes with good water flux performance in the 95 – 96% salt retention range for brackish water desalination from first principles. First, the acceptable range of fibre dimensions was determined by means of a collapse pressure calculation using the elastic buckling pressure equation (thin shell assumption). Second, the pressure drop across the fibre wall in the hollow-fine fibre was determined by using the Hagen-Poiseuille equation, in order to determine how this would affect the chosen fibre dimensions. It was determined that the acceptable range of fibre dimensions was 222 – 247 m, and the wall thickness was 50 m. Fibres with these dimensions exhibited a high resistance to brackish water operating pressure of 20 – 25 bar, without collapse. The pressure drop calculations of these dimensions showed a sufficiently low pressure drop across the fibres. A dry-wet spinning technique was used for the preparation of the hollow-fine-fibre membranes. Hollow-fine fibres were spun using CA dissolved in a suitable solvent and non-solvent mixture comprising acetone and formamide. The effects of the dope composition and spinning parameters such as solvent to non-solvent ratio, bore fluid ratio, take-up speed, dope extrusion rate and heat treatment on the membrane morphology and performance were investigated. The spun fibres showed a good morphological structure, with no macrovoids (sponge-like structure), which is favourable for reverse osmosis (RO) applications. The hollow-fine-fibre membranes showed a good brackish water desalination performance within brackish water operating conditions. Statistical analysis was used to generate a fabrication formulation for producing cellulose acetate hollow-fine-fibre membrane for brackish water desalination with improved salt retention and flux. A three-level three-factor factorial was used to the study of the effect of spinning parameters (solvent to non-solvent ratio, bore fluid ratio and air gap distance). A regression equation was successfully established and was used to predictably produce membranes with good performance within the limits of the factors studied. RO performance of these hollow-fine-fibre membranes was good: The salt retention ranged from 96 to 98% and the permeate flux ranged from 60 to 46 L/m2.d (2 000 ppm, NaCl, 20 bar, 24 oC).
AFRIKAANSE OPSOMMING: Die studie het ten doel gehad om selluloseasetaat holveselmembrane vanaf eerste beginsels vir brakwaterontsouting te ontwikkel. Die ontsoutingsvlakke van die membrane moet tussen 95 en 96% lê met ’n aanvaarbare waterproduksievermoë. Aanvaarbare deursneë vir die holvesels is eerstens bepaal deur platval-berekeninge met behulp van die inmekaarvouvergelyking uit te voer (dunwand aanname). Hierna is drukval oor die wand van die holvesel met behulp van die Hagen-Poiseuille vergelyking bepaal ten einde vas te stel hoe dit die gekose dimensies sal beïnvloed. Daar is vasgestel dat vesel deursneë tussen 222 en 247 um met ’n 50 um wand aanvaarbaar is. Vesels met hierdie dimensies het ’n hoë weerstand teen inval getoon by brakwater opereringsdrukke tussen 20 en 25 bar. ’n Droë-nat spintegniek is in die voorbereiding van die holveselmembrane gebruik. Holvesel membrane is met ’n selluloseasetaat stroop gespin wat uit ’n oplosmiddel (asetoon) en nieoplossmiddel (formamied) bestaan het. Die effek van die spinstroop samestelling en spinparameters soos die oplosmiddel tot nieoplosmiddel verhouding, lumen-vloeistof verhouding, opneemspoed, spinstroop ekstrusie tempo en hittebehandeling op membraan morfologie en werkverrigting is ondersoek. Die gespinde vesels toon ’n sponsagtige struktuur sonder die teenwoordigheid van enige mikroleemtes wat voordelig is vir tru-osmose toepassings. Die holvesel membrane het aanvaarbare brakwater ontsoutings werkverrigting. Statistiese analise is gebruik in die generasie van produksieformulasies vir die produksie van brakwater ontsoutingsmembrane met verbeterde retensie en vloed. ’n Drie-vlak driefaktoriaal ontwerp is tydens die studie gebruik om die effek van spinparameters (oplosmiddel tot nie-oplosmiddel verhouding, lumen vloeistof verhouding, en lug-gaping) te ondersoek. ’n Regressie vergelyking is suksesvol daargestel en gebruik om voorspelbaar membrane met goeie werkverrigting binne die limiete van die studie te produseer. Die tru-osmose werkverrigting van die membrane was goed: die sout retensie het tussen 96 en 98% gelê en die permeaatvloed tussen 60 en 46 L/m2.d (2 000 ppm NaCl, 20 bar, 24oC).
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Källgren, Rasmus. "Influence of level of cellulose oxidation and surface treatment on the adhesion between cellulose beads". Thesis, KTH, Skolan för kemi, bioteknologi och hälsa (CBH), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-276412.

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With the growing impact of climate change on both political decisions and how companies develop their products, it is increasingly important to find environmentally friendly alternatives to fossil-based materials. One of the more interesting materials in this respect is cellulose, which is the world's most naturally occurring polymer and can be used in a variety of applications. One way to modify the fibers and to change their properties is to use a method called Layer-by-Layer (LbL) treatment where two polymers of opposite charge are alternately adsorbed to the fiber surface. Another possibility is to oxidize the cellulose in the fibers to obtain a higher charge. This means that the fibers can adsorb a higher amount of cationic additives and that the fibers swell more which means that they are plasticized and can create stronger joints between the fiber surfaces in the dry state, which results in stronger dry fiber networks. However, wood-based fibers are small and inhomogeneous, both chemically and morphologically, which means that it is necessary to use model systems to be able to clarify, in detail, how treated and untreated surfaces interact with each other at a molecular level. One model system that can be used to investigate how cellulose fibers are affected by coating using the LbL method is to use spherical beads made from regenerated cellulose. In the present work, these beads were treated with polyallylamine hydrochloride (PAH) and hylauronic acid (HA) as well as with PAH and alginate (Alg) before being allowed to dry together and then subjected to tensile testing to clarify the adhesion between the surfaces. The beads were treated with five and ten bi-layers of these polymers, respectively, and then dried together on an AKD-coated surface, to avoid adhesion to the underlying surface, to examine the adhesion between the beads. The adhesion increased when treated with LbL and became higher upon adsorption of multiple layers of polyelectrolytes and the Alg / PAH system showed the greatest increase. Ten-layer samples of Alg / PAH were also tested after a solution of calcium chloride was added during drying, resulting in poorer adhesion between the beads.
Med klimatfrågans växande inverkan på både politiska beslut och hur företagen utvecklar sina produkter så läggs det allt större vikt vid att hitta miljövänliga alternativ till fossilbaserade material. Ett av de mer intressanta materialen är cellulosa vilket är världens mest naturligt förekommande polymer och som kan användas i en rad olika tillämpningar. Ett sätt att modifiera fibrerna och att ändra deras egenskaper är att använda sig av en metod som kalls Layer-by-layer (LbL) behandling där två polymerer mot motsatt laddning växelvis adsorberas till fiberytan. En annan möjlighet är att oxidera cellulosan i fibrerna så att de erhåller de en högre laddning. Detta innebär dels att fibrerna kan adsorbera en högre mängd katjoniska tillsatskemikalier samt att fibrerna sväller mera vilket innebär att de plasticeras och kan skapa starkare fogar mellan fiberytorna i torrt tillstånd vilket resulterar i starkare torra fibernätverk. Vedbaserade fibrer är dock små och inhomogena såväl kemiskt som morfologiskt vilket innebär att det är nödvändigt att använda modellsystem för att kunna klarlägga, i detalj, hur behandlade och icke behandlade ytor växelverkar med varandra på en molekylär nivå. Ett modellsystem som kan användas för att undersöka hur cellulosafibrer påverkas av att beläggas med hjälp av LbL metoden är att använda sig av sfäriska kulor tillverkade från regenererad cellulosa. I föreliggande arbete behandlades dessa kulor med polyallylaminhydroklorid (PAH) och hylauronsyra (HA) samt med PAH och alginat (Alg) innan de tilläts torka ihop och därefter utsattes för dragprovning för att klarlägga adhesionen mellan ytorna. Kulorna behandlades med fem respektive tio bilager av dessa polymerer och torkades sedan ihop på en AKD-belagd yta, för att undvika adhesion till den underliggande ytan, för att undersöka adhesionen mellan kulorna. Adhesionen ökade när de behandlades med LbL och blev högre vid adsorption av flera lager polyelektrolyter och systemet med Alg/PAH resulterade i den största ökningen. Prover med tio lager av Alg/PAH testades även efter att en lösning av kalciumklorid tillsattes under torkningen vilket resulterade i en sämre adhesion mellan kulorna.
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Książki na temat "Cellulose fibre"

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Vares, Sirje. Cellulose fibre concrete. Espoo, Finland: Technical Research Centre of Finland, 1997.

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Akbulut, Huseyin. The properties and performance of cellulose fibre reinforced stone mastic asphalt. [s.l: The Author], 1999.

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Platts, R. E. Development of "stud hugger" systems for insulating walls with cellulose fibre insulation: Report for the Housing Technology Incentives Program, Canada Mortgage and Housing Corporation. Ottawa, Ont: Canada Mortgage and Housing Corporation, 1995.

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Sfiligoj Smole, Majda, Silvo Hribernik, Manja Kurečič, Andreja Urbanek Krajnc, Tatjana Kreže i Karin Stana Kleinschek. Surface Properties of Non-conventional Cellulose Fibres. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-10407-8.

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Kamide, Kenji. Regenerated cellulose fiber industry: A history of technological and economical advances. Fukuoka-shi, Japan: Kyushu University Press, 2006.

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Suleman, A. U. M. AFM studies of cellulosic fibres. Manchester: UMIST, 1996.

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Peltonen, Petri. Asphalt mixtures modified with tall oil pitches and cellulose fibres. Espoo, Finland: VTT, Technical Research Centre of Finland, 1992.

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Cellulosic materials: Fibers, networks, and composites. Boston, Mass: Kluwer Academic Publishers, 2002.

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Ohlemiller, T. J. Forced smolder propagation and the transition to flaming in cellulosic insulation. Gaithersburg, MD: U.S. Dept. of Commerce, National Bureau of Standards, 1985.

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Hussain, A. J. Fractal simulation of material damage accumulation in cellulosic fibres. Manchester: UMIST, 1996.

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Części książek na temat "Cellulose fibre"

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Rana, Sohel, Shama Parveen, Subramani Pichandi i Raul Fangueiro. "Development and Characterization of Microcrystalline Cellulose Based Novel Multi-scale Biocomposites". W Advances in Natural Fibre Composites, 159–73. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-64641-1_15.

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Njuguna, James, Paul Wambua, Krzysztof Pielichowski i Kambiz Kayvantash. "Natural Fibre-Reinforced Polymer Composites and Nanocomposites for Automotive Applications". W Cellulose Fibers: Bio- and Nano-Polymer Composites, 661–700. Berlin, Heidelberg: Springer Berlin Heidelberg, 2011. http://dx.doi.org/10.1007/978-3-642-17370-7_23.

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Onyianta, Amaka Joy, i Rhodri Williams. "The Use of Sedimentation for the Estimation of Aspect Ratios of Charged Cellulose Nanofibrils". W Advances in Natural Fibre Composites, 195–203. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-64641-1_17.

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Mathew, Lovely, M. K. Joshy i Rani Joseph. "Isora Fibre: A Natural Reinforcement for the Development of High Performance Engineering Materials". W Cellulose Fibers: Bio- and Nano-Polymer Composites, 291–324. Berlin, Heidelberg: Springer Berlin Heidelberg, 2011. http://dx.doi.org/10.1007/978-3-642-17370-7_11.

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de Lhoneux, B., E. Baes i T. Avella. "Ultrastructural Aspects of Fibre—Matrix Bond in Cellulose Cement Composites". W Interfaces in New Materials, 129–38. Dordrecht: Springer Netherlands, 1991. http://dx.doi.org/10.1007/978-94-011-3680-8_13.

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Yang, Muhamad Firdaus Muhamad, Hisham Hamid i Ahmad Makarimi Abdullah. "Potential Use of Cellulose Fibre Composites in Marine Environment—A Review". W Engineering Applications for New Materials and Technologies, 25–55. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-72697-7_3.

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Rusina, O., R. Kirmeier, A. Molinero, C. R. Rambo i H. Sieber. "Manufacturing of Highly-Porous SIC-Ceramics from SI-Filled Cellulose Fibre Papers". W Ceramic Transactions Series, 169–76. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2012. http://dx.doi.org/10.1002/9781118407820.ch16.

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Gooch, Jan W. "Cellulose Fiber". W Encyclopedic Dictionary of Polymers, 128. New York, NY: Springer New York, 2011. http://dx.doi.org/10.1007/978-1-4419-6247-8_2111.

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Srinivasababu, Nadendla. "Mechanical Performance of Nanoclay-Cellulose Fibre Particulate Composites Fabricated by Modified Two Stage Wet/Hand Layup Method". W Nanoclay Reinforced Polymer Composites, 239–61. Singapore: Springer Singapore, 2016. http://dx.doi.org/10.1007/978-981-10-0950-1_10.

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Kasakov, M. Ye, L. L. Kalachyeva, Yu N. Movchan i G. M. Butyrin. "Influence of Thermal and Electrical-Chemical Treatments on Some Properties of Carbon Fibre Materials from Hydrated Cellulose". W MICC 90, 204–8. Dordrecht: Springer Netherlands, 1991. http://dx.doi.org/10.1007/978-94-011-3676-1_25.

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Streszczenia konferencji na temat "Cellulose fibre"

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Hospodarova, Viola, Nadezda Stevulova, Vojtech Vaclavik, Tomas Dvorsky i Jaroslav Briancin. "Cellulose Fibres as a Reinforcing Element in Building Materials". W Environmental Engineering. VGTU Technika, 2017. http://dx.doi.org/10.3846/enviro.2017.104.

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Nowadays, construction sector is focusing in developing sustainable, green and eco-friendly building materials. Natural fibre is growingly being used in composite materials. This paper provides utilization of cellulose fibres as reinforcing agent into cement composites/plasters. Provided cellulosic fibres coming from various sources as bleached wood pulp and recycled waste paper fibres. Differences between cellulosic fibres are given by their physical characterization, chemical composition and SEM micrographs. Physical and mechanical properties of fibre-cement composites with fibre contents 0.2; 0.3and 0.5% by weight of filler and binder were investigated. Reference sample without fibres was also produced. The aim of this work is to investigate the effects of cellulose fibres on the final properties (density, water absorbability, coefficient of thermal conductivity and compressive strength) of the fibrecement plasters after 28 days of hardening. Testing of plasters with varying amount of cellulose fibres (0.2, 0.3 and 0.5 wt. %) has shown that the resulting physical and mechanical properties depend on the amount, the nature and structure of the used fibres. Linear dependences of compressive strength and thermal conductivity on density for plasters with cellulosic fibres adding were observed.
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Ciambella, Jacopo, i David C. Stanier. "Orientation Effects in Short Fibre-Reinforced Elastomers". W ASME 2014 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/imece2014-40430.

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The large strain behaviour of a short fibre-reinforced composite is studied through numerical simulations. The reinforcing fibres yield the macroscopic response transversely isotropic which is indeed the case of many reinforcements currently used in composites: short carbon fibres, cellulose whiskers, carbon nanotubes. As a result of the analysis, it is shown that the reorientation of the fibres that takes place at large strain has a significant effect on the overall material response by changing the axis of isotropy. This behaviour can be adequately described by using a transversely isotropic model whose strain energy function depends on three invariants: two isotropic and one representing the stretch along the direction of the fibres. To assess its capabilities, the model is compared to the results of experiments carried out by the authors on nickel-coated chopped carbon fibres in a vulcanised natural rubber matrix for which the fibre orientation is achieved by controlling an external magnetic field prior to curing. Possible applications include micro-sized propulsion devices and actuators.
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Naqiya, F. M. Z., I. Ahmad i O. B. Airianah. "Resistant-hemicelluloses toward successive chemical treatment during cellulose fibre extraction". W THE 2017 UKM FST POSTGRADUATE COLLOQUIUM: Proceedings of the University Kebangsaan Malaysia, Faculty of Science and Technology 2017 Postgraduate Colloquium. Author(s), 2018. http://dx.doi.org/10.1063/1.5027975.

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Souza, N. F., J. A. Pinheiro, N. F. Vasconcelos, M. F. Rosa, J. P. S. Morais, A. R. Cassales i M. S. M. S. Filho. "CRYSTALLOGRAPHIC CHARACTERISATION OF CELLULOSE NANOWHISKERS FROM OIL PALM FIBRE WASTE". W International Symposium on Crystallography. São Paulo: Editora Edgard Blücher, 2015. http://dx.doi.org/10.5151/phypro-sic100-092.

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Saavedra Flores, Erick I., Senthil Murugan, Michael I. Friswell i Eduardo A. de Souza Neto. "Fully Coupled Three-Scale Finite Element Model for the Mechanical Response of a New Bio-Inspired Composite". W ASME 2011 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. ASMEDC, 2011. http://dx.doi.org/10.1115/smasis2011-4946.

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This paper proposes a fully coupled three-scale finite element model for the mechanical description of an alumina/magnesium alloy/epoxy composite inspired in the mechanics and architecture of wood cellulose fibres. The constitutive response of the composite (the large scale continuum) is described by means of a representative volume element (RVE, corresponding to the intermediate scale) in which the fibre is represented as a periodic alternation of alumina and magnesium alloy fractions. Furthermore, at a lower scale the overall constitutive behavior of the alumina/magnesium alloy fibre is modelled as a single material defined by a large number of RVEs (the smallest material scale) at the Gauss point (intermediate) level. Numerical material tests show that the choice of the volume fraction of alumina based on those volume fractions of crystalline cellulose found in wood cells results in a maximisation of toughness in the present bio-inspired composite.
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Cennamo, Nunzio, Carlo Trigona, Salvatore Graziani, Luigi Zeni, Francesco Arcadio, Giovanna Di Pasquale i Antonino Pollicino. "Extrinsic plasmonic optical fiber sensors based on POFs and bacterial cellulose slab waveguides". W Seventh European Workshop on Optical Fibre Sensors (EWOFS 2019), redaktorzy Kyriacos Kalli, Gilberto Brambilla i Sinead O. O'Keeffe. SPIE, 2019. http://dx.doi.org/10.1117/12.2539335.

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Funar-Timofei, Simona, Ludovic Kuruntzi, Walter Fabian i Daniela Ionescu. "Structure-Affinity Modeling of Azo Dye Adsorption on Cellulose Fibre by MLR". W The 12th International Electronic Conference on Synthetic Organic Chemistry. Basel, Switzerland: MDPI, 2008. http://dx.doi.org/10.3390/ecsoc-12-01283.

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Chan, Wei Bin, Siew Wei Phang i Li Wan Yoon. "Thermal and biodegradability study for garden waste cellulose fibre in thermoplastic starch composite". W 13TH INTERNATIONAL ENGINEERING RESEARCH CONFERENCE (13TH EURECA 2019). AIP Publishing, 2020. http://dx.doi.org/10.1063/5.0001496.

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Karlovits, Igor. "Lignocellulosic bio-refinery downstream products in future packaging applications". W 10th International Symposium on Graphic Engineering and Design. University of Novi Sad, Faculty of technical sciences, Department of graphic engineering and design,, 2020. http://dx.doi.org/10.24867/grid-2020-p2.

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The concept of efficient utilisation of renewable bio-based materials (biomass feedstock) is the driving force in the green transformation to a more sustainable and circular society. Biorefineries or biochemical platforms convert and utilise different sources of biomass into fuels and other beneficial derivates like fibres and other bio-based chemicals. These can be used as building blocks for many potentially useful applications. In this review, we shall describe the current state of the art and trends in the conversion of lignocellulosic feedstock into materials which can be primarily used in packaging applications. The three main constituents (cellulose, hemicellulose and lignin) are being re-engineered into new products with higher added value. The main goal of all these downstream products is that they do not compete with animal feed and food applications. The main downstream products of different kind of transformations are different natural fibres which can be further processed into micro or nano fibrillated state and used for a broad application of fields from ink, adhesive and packaging materials. Also, fibres and its derivates can be bonded successfully into bio-composites or fibre-based foams applications for the protective packaging applications. Hemicellulose, as a second most abundant component, has been researched for applications in adhesives and paper and paperboard coatings. Lignin which is currently utilised as an energy source for the paper industry, has been recently actively researched. Lignin-based biopolymers have a potential to be used in many different applications from additives in the barrier coatings on the packaging to active packaging and even as lignin-based foams. All these applications are currently in the development stages and cover niche market segments, but are expected to grow and to be used in future markets.
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Mondal, Sabyasachi, Puja Agarwala, Suvankar Dutta, Vishvas Naik-Nimbalkar, Pratik Pande i Sunil Dhumal. "Cellulosic fibre drying: fundamental understanding and process modeling". W 21st International Drying Symposium. Valencia: Universitat Politècnica València, 2018. http://dx.doi.org/10.4995/ids2018.2018.7384.

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Process modeling of conveyer dryer for cellulosic fibre drying demands many fundamental insights. Present study highlights detailed cellulosic fibre drying aspects like mass transfer correlation relating mass transfer rate with process conditions, normalized drying curve and critical moisture content. Cellulosic fibre drying follows falling rate period, where rate of mass transfer decreases with moisture content. Conveyer dryer process model for commercial cellulosic fibre drying was developed and validated successfully. Moderate drying strategy derived based on developed process model and drying fundamentals was deployed at commercial scale which helped in reducing the moisture variability. Keywords: Cellulosic fibre, Conveyor dryer, Process Model, Sherwood number, Moderate drying
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Raporty organizacyjne na temat "Cellulose fibre"

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Kosny, Jan, David W. Yarbrough, William A. Miller, Thomas Petrie, Phillip W. Childs i Azam M. Syed. 2006/07 Field Testing of Cellulose Fiber Insulation Enhanced with Phase Change Material. Office of Scientific and Technical Information (OSTI), grudzień 2008. http://dx.doi.org/10.2172/983811.

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Mizell, Steve A., i Craig A. Shadel. Radiological results for samples collected on paired glass- and cellulose-fiber filters at the Sandia complex, Tonopah Test Range, Nevada. Office of Scientific and Technical Information (OSTI), marzec 2016. http://dx.doi.org/10.2172/1242391.

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Lundy, Erika L., Daniel D. Loy i Stephanie L. Hansen. Influence of Distillers Grains from a Cellulosic Ethanol Process Utilizing Corn Kernel Fiber on Nutrient Digestibility of Lambs and Steer Feedlot Performance. Ames (Iowa): Iowa State University, styczeń 2015. http://dx.doi.org/10.31274/ans_air-180814-1273.

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