Dissertations / Theses on the topic 'Textile fabrics Testing'

This research develops three efficient textile flaw detection methods to facilitate automated textile inspection for the textile-related industries. Their novelty lies in detecting flaws with knowledge directly extracted from textile images, unlike existing methods which detect flaws with empirically specified texture features. The first two methods treat textile flaw detection as a texture classification problem, and consider that defect-free images of a textile fabric normally possess common latent images, called basis-images. The inner product of a basis-image and an image acquired from this fabric is a feature value of this fabric image. As the defect-free images are similar, their feature values gather in a cluster, whose boundary can be determined by using the feature values of known defect-free images. A fabric image is considered defect-free, if its feature values lie within this boundary. These methods extract the basis-images from known defect-free images in a training process, and require less consideration than existing methods on the degree of matching of a textile to the texture features specified for the textile. One method uses matrix singular value decomposition (SVD) to extract these basis-images containing the spatial relationship of pixels in rows or in columns. The alternative method uses tensor decomposition to find the relationship of pixels in both rows and columns within each training image and the common relationship of these training images. Tensor decomposition is found to be superior to matrix SVD in finding the basis-images needed to represent these defect-free images, because extracting and decomposing the tri-lateral relationship usually generates better basis-images. The third method solves the textile flaw detection problem by means of texture segmentation, and is suitable for online detection because it does not require texture features specified by experience or found from known defect-free images. The method detects the presence of flaws by using the contrast between regions in the feature images of a textile image. These feature images are the output of a filter bank consisting of Gabor filters with scales and rotations. This method selects the feature image with maximal image contrast, and partitions this image into regions with morphological watershed transform to facilitate faster searching of defect-free regions and to remove isolated pixels with exceptional feature values. Regions with no flaws have similar statistics, e.g. similar means. Regions with significantly dissimilar statistics may contain flaws and are removed iteratively from the set which initially contains all regions. Removing regions uses the thresholds determined by using Neyman-Pearson criterion and updated along with the remaining regions in the set. This procedure continues until the set only contains defect-free regions. The occurrence of the removed regions indicates the presence of flaws whose extents are decided by pixel classification using the thresholds derived from the defect-free regions. A prototype textile inspection system is built to demonstrate the automatic textile inspection process. The developed methods are proved reliable and effective by testing them with a variety of defective textile images. These methods also have several advantages, e.g. less empirical knowledge of textiles is needed for selecting texture features.
published_or_final_version
Industrial and Manufacturing Systems Engineering
Doctoral
Doctor of Philosophy

The role of the interior designer in providing for fire safe interiors is an important one. The textile end-products they specify play an important part in the start and/or spread of interior fires. Furthermore, the rate of developments in textile testing and products makes it difficult for designers to keep abreast of the latest information. This thesis provides a program for updating interior designers on fire safe interior textiles. A one hour update program was developed as part of the thesis and delivered to members of the Southwest Regional Chapter of ASID in Roanoke, Virginia. An analysis of data from a survey showed that participants believe there is a need for an educational program such as this course and that they would attend a five hour CEU course developed on this subject. Responses to questions on textile fibers, standard tests, and new products on the market supported the perceived need for continuing education on the subject of fire safe textiles. The course evaluation in turn, determined that some areas of the program needed to be revised. This thesis provides a packaged program which can be easily updated. Furthermore, anyone with a textile background can use this program in preparing and delivering a CEU course on fire safety and interior textiles.
Master of Science

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.

The aim of this work was to establish a range of suitable process parameters which can be utilized to produce needlepunched nonwoven fabrics for geotextile applications. Nonwoven fabrics were produced from 100% PP, a blend of 50/50% PP/kenaf and 100% kenaf fibres. The depths of needle penetration of 4, 7 and 10 mm, stroke frequencies of 250, 350 and 450 strokes/min and mass per unit area of 300, 600 and 900 g/m2 were utilized for producing the fabrics, on a Dilo loom. The effect of depth of needle penetration, stroke frequency and mass per unit area on the fabric properties, namely, tensile strength, puncture resistance, pore size, water permeability and transmissivity were analysed. In addition, the effect of chemicals, namely, 10% ammonium hydroxide (NH4OH), 10% sodium chloride (NaCl) and 3% sulphuric acid (H2SO4) solutions on degradation of the fabric was also studied. The results have shown that density, thickness and nominal weight of the needlepunched nonwoven fabrics were related to each other and they were influenced by stroke frequency, depth of needle penetration and feed rate of the needlepunching process. The increase in nominal weight of the fabrics also increases thickness and density of the fabrics. The tensile strength and puncture resistance of the fabrics increased with the increases in stroke frequency, depth of needle penetration and fabric mass per unit area. However, lower tensile strength and puncture resistance were achieved in the fabrics produced at lower stroke frequency, lower depth of needle penetration and lower mass per unit area. Bigger pores were resulted in the fabrics produced at lower stroke frequency, lower depth of needle penetration and lower mass per unit area, however, pore size decreased with increases in stroke frequency, depth of needle penetration and mass per unit area. Water permeability depends on the pore size, properties of the fibres, stroke frequency, depth of needle penetration and mass per unit area. Higher tensile strength and higher puncture resistance were achieved in the needlepunched nonwoven fabrics produced from 100% PP fibres, therefore, they are suitable for some load-bearing geotextile applications, such as reinforcement and separation. However, higher water permeability was achieved in the fabrics produced from 100% kenaf fibres, therefore, they are ideal for geotextile applications where good water permeability is required. Higher values for transmissivity were obtained in the fabrics produced from a blend of 50/50% PP/kenaf fibres, therefore they are suitable for drainage applications. The fabrics produced from a blend of 50/50% PP/kenaf fibres achieved better values of tensile strength, puncture resistance, pore size and water permeability in comparison to that produced from 100% PP and 100% kenaf fibres. However, better tensile strength and puncture resistance were achieved in the fabrics produced from 100% PP fibres and bigger pore size and higher water permeability were achieved in the fabrics produced from 100% kenaf fibres. Therefore, it can be suggested that the nonwoven fabrics produced from a blend of 50/50% PP/kenaf fibres can fulfil almost all requirements of geotextile applications, such as, filtration, separation, reinforcement and drainage. The fabrics produced from 100% PP fibres were not damaged or deteriorated when treated with all the three chemicals due to chemical inertness of polypropylene. However, the fabrics produced from a blend of 50/50% PP/kenaf and 100% kenaf fibres were damaged and deteriorated when treated with H2SO4.

The Sonochemistry Centre at Coventry University is one of a group of organisations working on a project to develop a new technology for producing antimicrobial textiles. This technology involves the use of an ultrasonic process (sonochemical) to generate and impregnate fabrics with antibacterial metal oxide nanoparticles. The expectation is that these textiles can be produced at an affordable price for routine use in hospitals as uniforms, curtains, hospital bed sheets and linen. The aim of this PhD project was to assess the antibacterial activity of fabrics impregnated with ZnO and CuO NPs against a variety of Gram positive and Gram negative bacteria. The testing was principally carried out according to the absorption method from ISO 20743:2007. Research was also extended to compare different methods of assessing antibacterial activity of textile fabrics. These included disc diffusion tests and shake flask tests in saline or nutrient broth. Overall the results from absorption tests demonstrated that both the ZnO and CuO impregnated fabrics showed very good levels of antibacterial activity (A>2) against the test bacteria (Staphylococcus aureus, Methicillin-resistant Staphylococcus aureus, Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa). During the optimisation of lab scale process to the pilot scale, two different types of CuO fabrics were produced to test and compare the antibacterial activity. One type of fabrics were impregnated with pre-made CuO nanoparticles by a ‘throwing the stones’ technology termed TTS and the other with sonochemically formed nanoparticles (in-situ), same as the lab process. The results indicated that the fabrics impregnated with sonochemically formed NPs displayed better antibacterial activity than the pre-made NPs. Leaching of the antibacterial agents in to saline was investigated using a shake flask method. CuO and ZnO coated fabrics prepared at laboratory scale were tested against Staphylococcus aureus, Acinetobacter baumannii and Escherichia coli. It was found that leachates prepared by shaking the fabrics in saline for 3 hours showed no antibacterial activity for CuO fabrics. However, leachates from ZnO fabrics showed an excellent activity after 24 ± 3 hours against all three bacterial species. Flow cytometry (FC) was investigated as an alternative to standard agar plate count (PC) methods for the determination of viable cell numbers. There was a general agreement between the results from agar plate counts and flow cytometry except that post incubation counts were greater with FC. The higher numbers of viable cells detected with FC may have been due to the presence of viable but not culturable cells (VBNC). Viable cells were observed by fluorescence microscopy in post incubation samples in which no viable cells were detected on nutrient agar plates. Cytotoxicity studies were conducted on ZnO and CuO fabrics from the pilot scale (both in-situ and TTS) against human dermal fibroblast cells (HDF) and human hepatocellular carcinoma cells (HepG2) using a MTT assay to determine cell viability. The results showed that ZnO and CuO are not toxic to HDF cells. However, cytotoxicity was seen in HepG2 cells with cell viability decreasing by > 14% for all the fabrics after 24 hours.

Thesis (MVerbruikerswet)--University of Stellenbosch, 2005.
ENGLISH ABSTRACT: The aim of the study was to investigate the compatibility of cotton/nylon and cotton/polyester warpknit terry towelling fabrics with industrial laundering procedures. The literature review focused, on the one hand, on the manufacture, finishing and structure of warp-knit terry towelling fabrics as well as on the physical structure, chemical nature and characteristics of the textile fibres used in the manufacturing of the towelling. On the other hand, a full exposition of the industrial laundering processes is provided, with specific reference to aspects that can have an effect on the towelling fabrics during the wash and tumble-drying cycles. Chapters Three and Four are reports on two research projects that can each be read independently. The aim of the first project was to determine the effect of industrial laundering procedures on the durability of cotton warp-knit terry towelling fabrics with a synthetic base structure. The tensile strength of cotton warp-knit terry towelling samples with a synthetic base structure was determined in the warp and weft directions and after 10, 20, 30, 40, and 50 wash cycles as well as wash and tumble-drying cycles. The tensile strengths in the warp direction of the washed terry towelling samples decreased significantly (p < 0.001) after 50 wash cycles. In contrast to this, the tensile strength in the weft direction increased, although not significantly (p > 0.05). As far as the comparison of the effect of industrial wash and wash and tumble-drying cycles is concerned, the tensile strengths in the warp direction of the towelling samples that were washed and washed/tumble-dried, were significantly lower (p < 0.001) after 20 and after 50 laundering cycles. As far as the tensile strengths in the weft direction were concerned, a similar pattern as with the wash and wash/tumble-drying processes, occurred. The tensile strengths initially increased and then gradually decreased. Furthermore, the tumble-drying process had greater damaging effects after 40 laundering cycles (p = 0.043) and especially after 50 laundering cycles (p < 0.0001). The aim of the second research project was to compare the durability of cotton warp-knit terry towelling fabrics with a nylon base structure with cotton warp-knit terry towelling fabrics with a polyester base structure after they had been subjected to industrial laundering processes. It was first established whether cotton/nylon and cotton/polyester warp-knit terry towelling fabrics are comparable. Secondly, the durability of cotton/nylon and cotton/polyester terry towelling fabrics was compared by determining the tensile strengths of the samples in the warp direction after they have been subjected to 50 industrial wash as well as wash and tumble-drying cycles. The two groups of untreated samples were regarded as similar on the basis of the percentage of fibre composition, knit fabric structure, knit density, mass and tensile strength. After 50 industrial wash cycles the tensile strengths of the cotton/nylon and cotton/polyester warp-knit terry towelling samples decreased significantly (p < 0.05). But there was no significant difference (p > 0.05) between the tensile strengths of the cotton/nylon and the cotton/polyester terry towelling samples after 50 washing cycles. There was a highly significant difference (p < 0.001) between the tensile strengths of the cotton/nylon and the cotton/polyester terry towelling samples after 50 wash and tumble-drying cycles. The tensile strength of the cotton/polyester terry towelling samples remained practically unchanged after the 50 wash/tumble-drying cycles, with the tensile strength of the cotton/nylon terry towelling samples decreased significantly (p < 0.001).
AFRIKAANSE OPSOMMING: Die doel van die studie was om ondersoek in te stel na die versoenbaarheid van katoen/nylon- en katoen/poliëster- skeringgebreide terriestofhanddoeke met industriële versorgingsprosedures. In die literatuuroorsig is daar enersyds gefokus op die vervaardiging, afwerking en struktuur van skeringgebreide terriehanddoekstowwe asook op die fisiese struktuur, chemiese aard en eienskappe van die tekstielvesels waarvan die handdoeke vervaardig is. Andersyds is ’n volledige uiteensetting van industriële versorgingsprosedures gegee, met spesifieke verwysing na aspekte wat tydens die was- en tuimeldrogingsiklusse ’n uitwerking op die handdoekstowwe kan hê. Hoofstukke drie en vier is opgeskryf as twee navorsingsprojekte wat elk ‘n geheel vorm. Die doel van die eerste projek was om die effek van industriële versorgingsprosedures op die duursaamheid van katoen skeringgebreide terriestofhanddoeke met ‘n sintetiese basisstruktuur te bepaal. Die breeksterkte van katoen skeringgebreide terriestofmonsters met ’n sintetiese basisstruktuur is in die skering- en inslagrigtings tydens en na afloop van 10, 20, 30, 40, en 50 was- asook was- en tuimeldrogingsiklusse bepaal. Die breeksterktes in die skeringrigting van die gewaste terriestofmonsters het betekenisvol afgeneem (p < 0.001) na 50 wassiklusse. In teenstelling hiermee het die breeksterktes in die inslagrigting toegeneem, hoewel nie betekenisvol nie (p > 0.05). Wat die vergelyking van die effek van industriële was- en was en tuimeldrogingsiklusse betref, is die breeksterktes in die skeringrigting van die handdoekmonsters wat gewas en gewas/getuimeldroog is, beduidend laer (p < 0.001) na 20 en na 50 versorgingsiklusse. Wat die breeksterktes in die inslagrigting betref het ‘n soortgelyke patroon by die was- en was/tuimeldrogingprosesse voorgekom. Die breeksterktes neem aanvanklik toe en daarna geleidelik af. Verder het die tuimeldrogingsproses na 40 versorgingsiklusse (p = 0.043) en veral na 50 versorgingsiklusse (p < 0.0001) ’n groter skadelike effek getoon. Die doel van die tweede navorsingsprojek was om die duursaamheid van katoen skeringgebreide terriestowwe met ’n nylon basisstruktuur te vergelyk met katoen skeringgebreide terriestowwe met ’n poliëster basisstruktuur nadat dit aan industriële versorgingsprosedures blootgestel is. Daar is eerstens vasgestel of katoen/nylon en katoen/poliëster terriehanddoekstowwe vergelykbaar is. Tweedens is die duursaamheid van katoen/nylon en katoen/poliëster terriestowwe vergelyk deur die breeksterktes van die monsters in die skeringrigting te bepaal nadat dit aan 50 industriële wasasook was- en tuimeldrogingsiklusse blootgestel is. Die twee groepe onbehandelde monsters is as soortgelyk beskou op grond van die persentasie veselsamestelling, breistofstruktuur, breidigtheid, massa en breeksterkte. Na 50 industriële wassiklusse het die breeksterktes van die katoen/nylon en katoen/poliëster skeringgebreide terriestofmonsters betekenisvol (p < 0.05) afgeneem. Daar was egter nie ’n betekenisvolle verskil (p > 0.05) tussen die breeksterktes van die katoen/nylon en katoen/poliëster terriestofmonsters na 50 wassiklusse nie. Daar was ’n hoogs betekenisvolle verskil (p < 0.001) tussen die breeksterktes van die katoen/nylon en katoen/poliëster terriestofmonsters na die 50 was/tuimeldrogingsiklusse. Die breeksterkte van die katoen/poliëster terriestofmonsters het na die 50 was/tuimeldrogingsiklusse feitlik onveranderd gebly terwyl die breeksterkte van die katoen/nylon terriestofmonsters hoogs betekenisvol (p < 0.001) afgeneem het.

" The Navy Clothing and Textile Research Facility (NCTRF) has been conducting fabric research for many decades. This project is a joint effort in establishing new test methods for evaluating the thermal protection garments provide. As a result of this project a new full scale test facility was constructed and is now operational. In this facility, a new traversing manikin test has been developed and will hopefully become a recognized test standard in the future. The traversing manikin test is designed to work with current test methods but also to provide a more detailed evaluation of a garment. Incorporated into the facility is the ability to reconfigure the fire source to recreate design fires that resemble those likely to occur onboard naval ships. While the data gather thus far is limited, it is believed with future testing a large set of data will be available to allow a cross comparison of this test with established test methods. "

Thesis (MSc )--University of Stellenbosch, 2001.
ENGLISH ABSTRACT: Washing and cleansing in an aqueous washing solution is a complex process involving the interaction of numerous physical and chemical processes. Investigations indicate that various factors present during repeated laundering might have an adverse effect on textile fabrics. Little is known, however, about the effect of the different mechanical wash actions on the deterioration of textiles. The automatic washing machines commonly used in South African households are often broadly classified as top loaders and front loaders. On closer inspection, however, it becomes clear that marked differences exist between the horizontal drum machines (H), vertical drum agitator type (V(A)) and vertical drum impeller type machines (V(/)). The effect of laundering on the wear life of textile fabrics has been extensively investigated, but a serious need for research on the effect of the different mechanical washing actions of the different washing machines on textile fabrics exists on both national and international level. A number of factors have an effect on textile deterioration during washing, e.g. number of washes, temperature of wash liquid, detergent type as well as fabric finishes and water quality. Fabric properties like changes in tensile strength, print deterioration and fraying, as well as electron microscope photographs, were used as indicators of mechanical deterioration to textiles. The broad aim of this exploratory study was firstly, to compare the effect of repeated washing in different domestic automatic washing machines (commonly used in South Africa) on the possible mechanical damage to textile fabrics and, secondly, to compare the soil removal efficiency of the mechanical wash actions of the different machines. An experimental study was therefore decided on. The washing of the test fabrics, as well as the testing, was carried out under controlled conditions in a laboratory. Apart from the different mechanical wash actions of the individual machines, the effect of the variables wash temperature, level of detergent and number of washes, was also investigated. This was done by measuring tensile strength, print deterioration and fraying propensity on samples laundered repeatedly at 40°C or 60°C, with and without detergent in the washing liquid, and comparing the colour change measured on laboratory-soiled test fabrics after washing. Analysis of the mechanical wash actions of the seven washing machines compared in this study indicated conspicuous differences among machines. It can be concluded that the mechanical wash action in the category V(A) machines is the most severe, and causes the highest reduction in tensile strength, the greatest print deterioration and the highest degree of fraying. These machines did not, however, exhibit greater soil removal efficiency than the other two categories of washing machines. The machines from category H did not exhibit a significantly different soil removal efficiency than those from category V(A), but their mechanical wash action proved to be less severe. Category V(/) machines seem to have the most delicate wash action and will probably cause the slightest fabric deterioration over the long term, but unfortunately produces poor soil removal efficiency results. This study also confirmed that washing fabrics in water alone causes more deterioration of tensile strength in fabrics than washing with detergent in the wash solution. Due to the limited scope and exploratory nature of this research/study, certain aspects of automatic washing machine processes could not be tested empirically. Recommendations for future research and implications for consumers were formulated.
AFRIKAANSE OPSOMMING: Was en skoonmaak in 'n waterige oplossing is 'n komplekse proses wat 'n interaksie tussen verskeie fisiese en chemiese prosesse behels. Ondersoeke dui aan dat verskeie van die faktore teenwoordig tydens herhaalde wasprosesse 'n nadelige effek op tekstielstowwe mag he. Baie min is egter bekend oor die effek van die verskillende meganiese wasaksies op die degenerasie van tekstiele. Die outomatiese wasmasjiene wat algemeen in Suid-Afrikaanse huishoudings gebruik word, word dikwels breedweg geklassifiseer as bolaaiers en voorlaaiers. By nadere ondersoek word dit egter duidelik dat daar opvallende verskille bestaan tussen die horisontale drom masjiene (H), die vertikale drom roerder tipe ((V)A)) en die vertikale drom stuwer tipe (V(/)) masjiene. Die effek van was op die draleeftyd van tekstielstowwe is uitvoerig ondersoek, maar daar bestaan op beide nasionale en internasionale vlak In ernstige behoefte aan navorsing oor die effek van die verskillende meganiese wasaksies van die verskillende wasmasjiene op tekstielstowwe. Faktore 5005 die aantal wasse, temperatuur van die wasoplossing, detergent tipe, water kwaliteit en tekstielstoftipe en -afwerking(s) het In effek of tekstieldegenerasie gedurende was. Tekstielstofeienskappe 5005 veranderinge in die breeksterkte van die tekstielstof of die tekstielstofmassa per eenheidsarea, agteruitgang van bedrukking, rafeling, sowel as elektronmikroskoop foto's word as aanduiding van meganiese degenerasie t.o.v. tekstiele beskou. Die oorkoepelende doe I van hierdie eksploratiewe studie was eerstens, om die effek te vergelyk van herhaalde was in verskillende outomatiese wasmasjiene (algemeen in gebruik in Suid-Afrika) op die moontlike meganiese beskadiging aan tekstielstowwe, en tweedens, om die doeltreffendheid van vuilverwydering op die wasaksies van die verskillende masjiene te vergelyk. Daar is gevolglik op In eksperimentele studie besluit. Die was van die tekstielstowwe, sowel as die laboratoriumtoetse, is onder gekontroleerde atmosferiese toestande in In laboratorium uitgevoer. Afgesien van die verskillende meganiese wasaksies van die individuele masjiene, is die effek van die veranderlikes westemperetuur, detergentv!ak en aanta! wasse ook ondersoek. Dit is gedoen deur die bepaling van breeksterkte en die meting van die mate van agteruitgang van bedrukking en mate van geneigdheid tot rafeling van kledingstowwe na herhaalde was by 40°C en 60°C, met en sonder detergent in die wasvloeistof. Die kleurverandering na was is ook gemeet op laboratorium gevlekte monsters. Die analise van die meganiese wasaksie van die sewe wasmasjiene wat in hierdie studie vergelyk is, het opvallende verskille tussen masjiene uitgewys. Daar kan tot die gevolgtrekking gekom word dat die meganiese wasaksie in kategorie V(A) masjiene die ergste is, wat gevolglik die grootste verlaging in breeksterkte en die meeste afieruitgang van bedrukking en rafeling veroorsaak het. Hierdie masjiene het egter nie meer doeltreffende vuilverwydering tot gevolg gehad in vergelyking met die ander kategoriee van wasmasjiene nie. Die masjiene in kategorie H het nie 'n betekenisvolle verskil in doeltreffenheid van vuilverwydering van die van kategorie V(A) getoon nie, maar die meganiese wasaksie was minder straf. Kategorie V(/) masjiene het blykbaar die mees delikate wasaksie en sal moontlik die minste tekstielstof degenerasie oor die langtermyn toon, maar ongelukkig is die resultate t.o. v. die doeltreffendheid van vuilverwydering swak. Die studie bevestig dat die was van tekstielstowwe in water aileen 'n groter verlaging in breeksterkte van tekstielstowwe veroorsaak as wat die geval is wanneer met 'n detergent in die wasvloeistof gewas word. Weens die beperkte omvang en eksploratiewe aard van die studie kon sekere aspekte van die outomatiese wasprosesse nie empiries getoets word nie. Aanbevelings vir toekomstige navorsing en implikasies vir verbruikers is geformuleer.

Cette thèse s’inscrit dans le cadre du projet européen 3D-LightTrans ayant pour objectifs la fabrication à grande à échelle et à bas coût de pièces composites. Pour parvenir à ces objectifs, des semi-produits sous forme de tissus 3D de mèches comélées ont été réalisés. Le but de ces travaux est de caractériser le comportement mécanique de ces tissus en vue d’analyser leur formabilité et d’être en mesure de prédire leur comportement pendant les processus de mise en forme utilisés lors de la fabrication des pièces composites. Le premier objectif de ces travaux était de caractériser expérimentalement le comportement mécanique des tissus 3D. Après avoir effectué un état de l’art ayant permis de définir les types et paramètres d’essais à utiliser pour la caractérisation du comportement des tissus, l’analyse des résultats de ces différents essais a permis de mettre en évidence les spécificités du comportement des tissus 3D. Le deuxième objectif des travaux était de modéliser le comportement des tissus par une approche numérique. Le choix s’étant porté sur une approche à l’échelle mésoscopique, le comportement mécanique des mèches comélées a été caractérisé expérimentalement. Les limitations du logiciel GeoFab quant à son utilisation pour la génération de modèles CAO de mailles élémentaires de tissus 3D ont été identifiées. Des améliorations permettant de répondre à ces limitations ont été proposées et leur faisabilité démontrée. Un modèle CAO d’une sous partie de la maille élémentaire d’un des tissus a alors été généré. Après avoir modélisé le comportement des mèches comélées en se basant sur les résultats de leur caractérisation expérimentale, des premières simulations éléments finis ayant permis d’obtenir des résultats encourageants ont été réalisés
This thesis is part of the European project 3D-LightTrans whose objectives are the large scale and low-cost manufacturing of composite parts. To achieve these goals, semi-finished products in the form of 3D fabrics of commingled yarns were produced. The purpose of this work is to characterize the mechanical behavior of these fabrics in order to investigate their formability and be able to predict their behavior during the forming processes used for the manufacturing of composite parts. The first objective of the work was to characterize experimentally the 3D fabrics mechanical behavior. A state of the art was realized in order to define the types and test parameters to use. The analysis of these test results allowed to highlight the specific 3D fabrics mechanical behaviour. The second objective of the work was to model the fabrics behavior using a numerical method. A mesoscopic scale approach having been selected, experimental characterization of the commingled yarns mechanical behavior was necessary. Then, GeoFab software limitations on its use for the generation of CAD models of 3D fabrics unit cells were identified. Improvements to address these limitations have been proposed and their feasibility was demonstrated. A CAD model of a sub part of one of the fabrics unit cell was then generated. After having modeled the commingled yarns behaviour using experimental results, finite element simulations were performed on fabric CAD model and first encouraging results were obtained