published_or_final_version / abstract / toc / Electrical and Electronic Engineering / Master / Master of Philosophy

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published_or_final_version / abstract / Industrial and Manufacturing Systems Engineering / Doctoral / Doctor of Philosophy

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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.

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.