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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Textile fibre from six cultivars of harakeke (Phormium tenax)

Cruthers, Natasha Marie, n/a January 2005 (has links)
The object of this study was to identify microscopic differences among six selected cultivars of harakeke traditionally used by Maori in weaving. The cultivars were Arawa, Makaweroa, Paretaniwha, Takaiapu, Takirikau, and Tapamangu. The effectiveness of different microscopy techniques for taking measurements of the dimensions of ultimate fibres using a factorial experimental design was investigated in part A. Constant variables were geographical location, location of specimens along the leaf, season (winter), individual plant, fan, north-facing fan, and age of plant (approximately seven years), and cultivars (Paretaniwha and Tapamangu). Experimental variables were the microscopy techniques used and measurement axis. Techniques selected use on further cultivars in part B were transverse sections of leaf specimens 4 m thick, embedded in Paraplast� and observed using LM, and non-fixed ultimate fibres observed using SEM. In part B the dimensions of ultimate fibres from the six selected cultivars of harakeke were measured, and analysed (ANOVA and Tukey's HSD), and the transverse section shapes of fibre aggregates were observed. Transverse widths of ultimate fibres ranged from 10.15 m (Takaipu) -12.80 m (Paretaniwha). Ultimate fibre lengths ranged from 3735 m (Takirikau) - 4751 m (Makaweroa). The cultivars prizes for muka, Arawa and Makaweroa, had the longest and finest ultimate fibre bundles more uniform in transverse-sectional shape than the other cultivars studied and perhaps this explains their selection for extraction of muka. Takirikau had a high yield of ultimate fibre bundles, and perhaps this makes extraction of muka worthwhile. Paretaniwha differed from the other five cultivars studied having an average number of ultimate fibre bundles per unit width that were narrow and non-uniform in shape, and composed of short, thick, ultimate fibre cells. The microscopic structure of muka from six selected cultivars of harakeke used traditionally for weaving varied and may explain differences perceived by weavers, and that different end uses are preferred for various cultivars.
32

Textile fibre from six cultivars of harakeke (Phormium tenax)

Cruthers, Natasha Marie, n/a January 2005 (has links)
The object of this study was to identify microscopic differences among six selected cultivars of harakeke traditionally used by Maori in weaving. The cultivars were Arawa, Makaweroa, Paretaniwha, Takaiapu, Takirikau, and Tapamangu. The effectiveness of different microscopy techniques for taking measurements of the dimensions of ultimate fibres using a factorial experimental design was investigated in part A. Constant variables were geographical location, location of specimens along the leaf, season (winter), individual plant, fan, north-facing fan, and age of plant (approximately seven years), and cultivars (Paretaniwha and Tapamangu). Experimental variables were the microscopy techniques used and measurement axis. Techniques selected use on further cultivars in part B were transverse sections of leaf specimens 4 m thick, embedded in Paraplast� and observed using LM, and non-fixed ultimate fibres observed using SEM. In part B the dimensions of ultimate fibres from the six selected cultivars of harakeke were measured, and analysed (ANOVA and Tukey's HSD), and the transverse section shapes of fibre aggregates were observed. Transverse widths of ultimate fibres ranged from 10.15 m (Takaipu) -12.80 m (Paretaniwha). Ultimate fibre lengths ranged from 3735 m (Takirikau) - 4751 m (Makaweroa). The cultivars prizes for muka, Arawa and Makaweroa, had the longest and finest ultimate fibre bundles more uniform in transverse-sectional shape than the other cultivars studied and perhaps this explains their selection for extraction of muka. Takirikau had a high yield of ultimate fibre bundles, and perhaps this makes extraction of muka worthwhile. Paretaniwha differed from the other five cultivars studied having an average number of ultimate fibre bundles per unit width that were narrow and non-uniform in shape, and composed of short, thick, ultimate fibre cells. The microscopic structure of muka from six selected cultivars of harakeke used traditionally for weaving varied and may explain differences perceived by weavers, and that different end uses are preferred for various cultivars.
33

An investigation into the properties of cotton fibres as used in nonwoven fabrics

Lutseke, Nothando Sazikazi January 1989 (has links)
The purpose of this investigation was to determine the properties that characterise cotton fibres in the various stages in the CPNF process as well as to determine which fibre characteristics a r e required to entangle the fibres to produce a successful CPNF . The criteria adopted in this work for a successful CPNF include: 1. the tensile strength of the fabrics 2. a well-defined pattern 3. absorbency and wicking The properties selected for investigation were 1. the cotton fibre surface (using SEM and DSC analyses) 2. the degree of degradation of the cotton fibre as a result of the CPNF process (using cellulose fluidity measurements) 3. the non-cellulosic content of the fibre (using IR, DSC, and Chemical analyses) 4. fibre friction 5. absorbency and wicking 6. tensile properties Analysis of the results indicates clearly what the fundamental properties of the cotton fibre must be for a successful cotton CPNF to be manufactured. The conclusions also indicate the necessary properties a man-made fibre must have to produce a successful CPNF.
34

The recovery of sodium hydroxide from cotton scouring effluents.

Simpson, Alison Elizabeth. January 1994 (has links)
This dissertation describes the characterisation of, and development of a novel integrated waste management strategy for, hydroxide scouring effluents produced during cotton processing. Such effluents are typical of mineral salt-rich waste waters which are not significantly biodegradable in conventional treatment plants. The proposed strategy focuses on two complementary concepts: process-oriented waste minimisation adopts a systematic approach to identifying potential problems and solutions of waste reduction in the manufacturing process itself; while add-on controls reduce the impact of the waste after it has been generated, by recycling and treatment. The basic procedures for ensuring effective water and chemical management within the scouring process are described. Examples are given of factory surveys, which have resulted in significant chemical and water savings, reduced effluent discharge costs, maximum effluent concentration, and minimum pollutant loading and volume. Pilot-plant investigations demonstrate the technical and economic feasibility of a four stage treatment sequence of neutralisation (using carbon dioxide gas), cross-flow microfiltration, nanofiltration and electrochemical recovery to remove colour and impurities from the scouring effluent and produce directly reusable sodium hydroxide and water. Fouling and scaling of the cross-flow microfiltration, nanofiltration and electrochemical membranes are minimal and reversible if the operation is carried out under carefully selected conditions. A long anode coating life is predicted. Current efficiencies for the recovery of sodium hydroxide (up to 20 % concentration) are 70 to 80 % and the electrical power requirements are 3 500 to 4 000 kWh/tonne of 100 % NaOH. Pilot-plant trials are supplemented by extensive laboratory tests and semi-quantitative modelling to examine specific aspects of the nanofiltration and electrochemical stages in detail. Electromembrane fouling and cleaning techniques, and other anode materials are evaluated. The effects of solution speciation chemistry on the performance of the nanofiltration membrane is evaluated using a combination of speciation and membrane transport modelling and the predicted results are used to explain observed behaviour. Based on the results of pilot-plant trials and supplementary laboratory and theoretical work, a detailed design of an electrochemically-based treatment system and an economic analysis of the electrochemical recovery system are presented. The effects of rinsing variables, processing temperatures, and background rinse water concentrations on the plant size requirements and capital costs are determined. The implementation of the waste management concepts presented in this dissertation will have significant impact on water and sodium hydroxide consumption (decreasing these by up to 95 and 75 % respectively), as well as effluent volumes and pollutant loadings. / Thesis (Ph.D.)-University of Natal, Durban, 1994.
35

South African National Accreditation System accreditation : a case study of a university of technology textile testing laboratory

Jaftha, Desiree Virginia January 2008 (has links)
Thesis (MTech (Quality))Cape Peninsula University of Technology, Cape Town, 2008. / The South African Government provides support to the clothing and textile industry by making funding available through programs in the Department of Science and Technology, such as the Tshumisano Technology Stations Program. The Technology Stations Program in particular supports a Technology Station in Clothing and Textiles (TSCT) at the Cape Peninsula University of Technology (CPUT), serving the needs for technology support and skills upgrading of the industry in the Western Cape, and in some instances, nationally. The TSCT testing laboratory provides testing services to small medium and large companies in South Africa at a reduced cost. The laboratory emphasises that customers should have fabrics tested before production commences. In this regard, the company will know the quality of the fabric or garment being purchased or manufactured. The laboratory technicians and assistants undergo a 'Woolworths' certification process on their test methods on an annual basis. The Woolworths certification is customer based. The laboratory is faced on a daily bases with the problem that more and more of their customers request that the facility should seek higher 'accreditation', as opposed to the current 'certification' it currently holds. The TSCT testing laboratory in addition has a responsibility to satisfy all of its customer certification and accreditation needs. Against this background, the management of the CPUT TSCT testing laboratory is now seeking accreditation from the South African National Accreditation System (SANAS) to widen the spectrum of its testing abilities. The primary research objectives of this dissertation are: To determine what the requirements are for SANAS accreditation by the CPUT TSCT testing laboratory. To determine if the CPUT TSCT testing laboratory is subject to a forced intervention for SANAS accreditation. To determine the criteria required for the CPUT TSCT testing laboratory accreditation. To determine the benefits that could be gleaned from this accreditation. To determine the effectiveness of the laboratory system, with regard to the fact that in addition to testing, the laboratory is used for teaching and learning. Descriptive research will serve as the research type, as it will describe an existing phenomena taking place. The research will be theoretical in nature and conducted in terms of both positivistic and phenomenological paradigms. Case study research will serve as research method. Data collection for the proposed research will be conducted using questionnaires. The CPUT Clothing and Textile Technology Department will serve as sampling frame, while the sample of respondents will be drawn on the basis of probability sampling. The sample will include lecturing staff, students, industry testing customers, textile test laboratory technicians, administration and support staff, all of whom are directly involved with the operation or make use of the laboratory facilities.

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