In this study the influence of variations in alkali resistance (R18) of cellulose on the quality of the viscose product in terms of carbohydrate content have been examined. The dissolution pattern of hemicellulose in the first steps of the viscose process with different running parameters has been determined. Furthermore the correlation between R18 and hemicellulose content has been studied. Mercerization and pressing was performed in a viscose micro plant at MoRe Research with varying process settings using samples with different R18 and known carbohydrate content. The carbohydrate content was thereafter determined in both the deducted lye and in the alkali cellulose in order to study the dissolution pattern of hemicellulose. A comparison was made in terms of carbohydrate content between speciality celluloses with varying R18 for determining the correlation between the variables. The study showed a clear influence from R18 on the amount of hemicellulose continuing in the viscose process after the pressing. Variations in NaOHconcentration in the mercerization and the press factor in pressing have also a significant effect on the dissolution of hemicellulose while the temperature in mercerization did not have a distinguishable impact. Finally the study also indicated a linear relationship between R18 and the hemicellulose content in speciality cellulose from Domsjö Fabriker.

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A preocupação mundial em relação aos impactos ambientais e seus reflexos positivos ou negativos na natureza têm mobilizado diversos setores da indústria. O processo de fabricação da viscose quando não controlado é altamente poluidor, causando impactos ao meio ambiente. Portanto, a escolha da sua matéria-prima pode amenizar esses problemas. O objetivo deste trabalho é analisar comparativamente os tecidos de malha fabricados com fibras de viscose convencional eucalipto e outras - com fibras de viscose obtidas a partir do bambu. Para a análise foram escolhidas as seguintes matérias-primas: fios 100% viscose convencional (fiação de anéis e jato de ar) e fios 100% viscose de bambu (fiação de anéis) e fabricadas malhas com gramaturas médias estatisticamente iguais. Os tecidos foram beneficiados e realizados os ensaios de gramatura, tendência à formação de pilling e resistência à solidez à água. Os resultados experimentais mostraram que não existem diferenças significativas entre as características estudadas. / The global concern regarding the environmental impacts has assembled several industry sectors. This study has as a goal to analyze relatively two types of mesh fabrics: viscose, which can be produced through cellulose regeneration obtained by bamboo or from other trees or plants, and thus, it can be chosen one or the other within a sustainable development context. This manufacturing process of viscose is highly pollutant, provoking negative impacts to the environment. Therefore, the choice of raw material might reduce these issues relating to sustainability. This comparison also has an objective to open a space for discussions regarding to sustainability concept in textile sector, which many studies are limited to analyze the results comparing materials only, not considering the process as a whole, from the choice of raw material, obtention, cultivation, transformation, to the final product, including the lifecycle, the durability and disposal of a fashion product. The experimental results showed that no significant differences between the characteristics studied.

A preocupação mundial em relação aos impactos ambientais e seus reflexos positivos ou negativos na natureza têm mobilizado diversos setores da indústria. O processo de fabricação da viscose quando não controlado é altamente poluidor, causando impactos ao meio ambiente. Portanto, a escolha da sua matéria-prima pode amenizar esses problemas. O objetivo deste trabalho é analisar comparativamente os tecidos de malha fabricados com fibras de viscose convencional eucalipto e outras - com fibras de viscose obtidas a partir do bambu. Para a análise foram escolhidas as seguintes matérias-primas: fios 100% viscose convencional (fiação de anéis e jato de ar) e fios 100% viscose de bambu (fiação de anéis) e fabricadas malhas com gramaturas médias estatisticamente iguais. Os tecidos foram beneficiados e realizados os ensaios de gramatura, tendência à formação de pilling e resistência à solidez à água. Os resultados experimentais mostraram que não existem diferenças significativas entre as características estudadas. / The global concern regarding the environmental impacts has assembled several industry sectors. This study has as a goal to analyze relatively two types of mesh fabrics: viscose, which can be produced through cellulose regeneration obtained by bamboo or from other trees or plants, and thus, it can be chosen one or the other within a sustainable development context. This manufacturing process of viscose is highly pollutant, provoking negative impacts to the environment. Therefore, the choice of raw material might reduce these issues relating to sustainability. This comparison also has an objective to open a space for discussions regarding to sustainability concept in textile sector, which many studies are limited to analyze the results comparing materials only, not considering the process as a whole, from the choice of raw material, obtention, cultivation, transformation, to the final product, including the lifecycle, the durability and disposal of a fashion product. The experimental results showed that no significant differences between the characteristics studied.

The lubrication of dry viscose fibres by a two component finish, and the lubrication of wet Iyocell fabric against metal, with various aqueous lubricant systems, has been studied. Secondary ion mass spectrometry (SIMS) was investigated as a means of providing direct chemical information from finished fibre surfaces. The composition and distribution of a two component finish applied to viscose fibres was determined successfully. When applying finish from a bath, the surface composition of the finished fibres was not controlled by the bath conditions. Increasing the concentration of finish in the bath did, however, increase the total amount of finish deposited, and increasing the concentration of antistat relative to lubricant in the bath increased the amount of antistat relative to lubricant deposited on the finished fibres. Fibre friction was determined using the capstan method. The friction forces, measured for finished viscose fibres, were correlated with the finish application conditions. Increasing the emulsion concentration in the finish bath reduced fibre/metal friction, but finish component ratio, emulsion concentration, dip time and bath temperature did not affect fibre/fibre friction. Spray applying the finish resulted in unfinished regions on the fibre surfaces and the electrical resistance of fibre bundles was not reduced. Bath application of finish did lower electrical resistance in comparison with unfinished fibre, but none of the bath deposition variables had a significant effect on electrical resistance.

Environmental concerns have brought about a push to replace non-biodegradable products that are made from non-renewable resources. Investigations regarding use of wood fibers and other biomass as a raw material for biodegradable foams and sponges are an example of such a replacement. Foams made at least partially of biomass can be created using cellulose from wood fibers once the cellulose is converted into a fluid form. Polyurethane foams can be made from polyols containing as much as 50% biomass by combined dissolution of wood and starch. Sponges can be made completely from cellulose regenerated from a viscose rayon solution, and the effect of using wood fibers as reinforcement material within the cellulose matrix of such sponges was studied. The effect of fiber content and fiber length on absorbance, swelling, density, air to cellulose ratios, bound water, and tensile was determined.

The effect of acetic acid on the cellulose content of viscose is negligible upon standing. The sodium zincate method fails to give satisfactory results in the determination of initial sulfur:cellulose a ratio in the crumbs. / Master of Science

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