Zugl.: Aachen, Techn. Hochsch., Diss., 2008.

Den här studien undersöker två ullgarner som beställts med samma kravspecifikation från olika leverantörer, A och B. Garnerna används av ett företag som väver mattor. Ullgarnerna har upplevts som olika i produktion och problem uppstår i väven som öglor och ojämna stadkanter. Syftet med studien är att fastställa vad som skiljer garnerna åt och hur detta kan uttryckas i en garnspecifikation för att få mer likvärdiga garner. Analys av litteratur och artiklar genomfördes för att få en bättre förståelse för ull och hur olika egenskaper hos fibrer kan påverka olika processer. Utifrån dessa har det bestämts vilka tester som bör utföras. Tester utfördes först på garnnivå där garnernas styrka, töjning och elasticitet testades i en dragprovare, fuktinnehållet mättes och en inneboende spänning i garnerna skattades genom att mäta självsnodden. På fibernivå mättes bredden, längden, krusigheten och andel medullerade fibrer, som är fibrer med en större kärna än vanliga ullfibrer. De tester som visade på signifikanta skillnader genomfördes på färgade garner för att verifiera de skillnader som upptäcktes mellan leverantörernas ofärgade garner. Med resultaten från testerna och litteratursökningen diskuterades viktiga tillägg i den befintliga garnspecifikationen. Dessa ansågs bland annat kunna vara fiberlängd och fiberbredd som kan anges med både medelvärde och fördelning, andel medullerade fibrer, E-modul och att mäta de mekaniska egenskaperna med cN/tex istället för enbart Newton för att få ett mer anpassad värde som tar hänsyn till variationerna i ull. Slutsatsen för uppsatsen blev att garnerna skiljer sig tillräckligt åt på fibernivå för att de ska bete sig olika som visats i de mekaniska egenskaperna. Det finns en skillnad i hur garnerna töjer sig vilket skulle kunna förklara problemen som uppstår i väven. Utöver att enbart specificera parametrar kan testmetoder och standarder samt hur resultaten ska analyseras diskuteras med garnleverantörer. / This study investigates two yarns made of 100 % wool that have been ordered with the same specification but from different suppliers. The yarns are used by a company that produces carpets. During weaving these yarns don’t behave the same and therefore problems have appeared in production. The aim with this study is to investigate why the two yarns behave differently. A literature study has been conducted to assemble information about wool properties and how these can have an affect on different processing steps typical for wool. From these findings it was concluded which tests to perform during this study. Tests that measured tensile properties, moisture content and twist liveliness were first performed on uncoloured yarns. At fiber level the fibre width, length and crimp as well as proportions of medullated fibres were measured. A medullated fibers is a fiber with a bigger core than a regular wool fibre. Tests that showed significant differences were also carried out on coloured yarns to see if the differences remains after dyeing. Together with the test results and information from litteratur it's discussed how differences in parameters are related to the yarn properties and if it's possible to translate these findings into new demands for a yarn specification. These were considered to be fiber width and length specified with both a mean and distribution, proportion of medullated fibres, E-module and to specify the mechanical properties with cN/tex instead of only Newton to get a value that is more true to the variations in wool. It's concluded that the yarns differ sufficiently at fiber level to give them different properties, which shows in the mechanical properties. There is a difference in the two yarns ability to stretch and this can explain problems that arise during weaving. In addition to suggest parameters to specify it's discussed how desiding a standard to follow for measures and how to analyze the results could help to ensure demands in the specification.

Techn. Hochsch., Diss.--Aachen, 2006.

Järbo Garn is a wholesaler in the textile industry. The companys position on the market is under changing circumstances. Therefore Järbo Garn needs to find new ways of developing their marketing. The thesis explores ways for Järbo Garn to do this, by examining different possibilities for the company to strengthen their relationship to their customers and retailers. The thesis is based on theories from three different fields; marketing, Public Relations and organizational communication. Different models is being used to analyze the material, such as the SWOT-analysis, the model of the marketing concept and the four-step Public Relations process. The material was gathered through qualitative interviews, group surveys and web-based surveys. Those methods was based on the theories of Steinar Kvale and Jan Trost. The interviews was done with representatives from Järbo Garn and their retailers. Surveys was sent out to the companys potential customers. The result shows that Järbo Garn have a good relationship with their retailers, who in general are satisfied with Järbo Garns products and services. Though, the staff may be in need of gathering the information about the retailers needs in one place. Some recommendations are given to Järbo Garn from the retailers, where develop the website appears most frequently. The result from the interviews also shows that the company lacks extensive knowledge of their customer, since the information given is minor. Some interesting hints about the customers needs is gathered from the result of the surveys. First, we learn that the customer prefers to shop in specialized stores or online. Then, we see that the customer finds most inspiration from digital channels like forums, blogs and social media. Last, we learn that the customers value quality and that they’re not loyal to any specific brand. In the end, the discussion leads us to believe that the borders between marketing, Public Relations and organizational communication are getting more and more unclear. It finally seems like the appliance of theories from these three fields are a good way of analyzing the situation of different organizations.

Piezoelektriska material används flitigt i olika sensorer då de kan generera en mätbar elektrisk signal vid tryck eller töjning. Arbetet utreder hur ett piezoelektriskt garn innehållandes Polyvinyldiflourid (PVDF) påverkas av faktorer som långvarig mekanisk deformation, fukt och värme. Fokus har legat på det piezoelektriska garnets egenskaper men projektet undersöker också hur integrering i tyg samt applicering i en textil produkt fungerar. Det piezoelektriska garnet har utsatts för ett stort antal tester. I de flesta tester har proverna utvärderats genom cyklisk deformation i en extensometer. Det piezoelektriska garnet har undersökts genom experiment i laboratoriemiljö, praktiska tester i textila applikationer samt vid statistisk analys. Det kan konstateras att yttre faktorer så som fukt och temperatur har inverkan på garnets piezoelektriska effekt. Långvariga tester avslöjar hur garnet uppvisar en längdförändring vid deformation som bidrar till garnets minskade signalstyrka. Garnet kan framgångsrikt integreras i tyg genom sömnad vid rätt inställning för stygnlängd, där högre stygnlängd ger bättre resultat. Samma metod kan användas för att konstruera en piezoelektrisk sensor som appliceras i en träningsstrumpa. Slutsatsen av detta arbete är att parametrar som fukt, krypningsbeteende samt strukturell variation i de individuella PVDF-filamenten har en betydande effekt på det piezoelektriska garnets elektriska signal. Potential i garnets förmåga att fungera som sensor kan ses genom att garnet integrerats med tyg på ett framgångsrikt sätt i en träningsstrumpa för mätning av fotnedsättning. Det kvarstår mycket gällande forskning kring piezoelektriska filament och garn. Vidare forskning i ämnet kommer kunna leda till nya innovativa applikationsmöjligheter som kan komma till nytta inom olika delar av samhället, inte minst inom medicinska användningsområden. / Piezoelectric materials are frequently used in different sensors as they can generate a measurable electrical signal during applied pressure or when subjected to extension. This project examines how a piezoelectric yarn containing Polyvinylidene fluoride (PVDF) is affected when exposed to moisture, heat and long-term mechanical deformation. Focus has been directed towards investigating the properties of the piezoelectric yarn as well as how it can be applied in textile fabrics and textile applications. The piezoelectric yarn has been subjected to a series of tests. Most of the samples have undergone cyclic deformation in an extensometer during tests. The piezoelectric yarn has been examined by experiments in laboratory environment, practical tests in textile applications as well as by statistical analysis. It can be stated that factors such as moisture and temperature have influence on the piezoelectric effect of the yarn. Long-term tests reveal how the yarn displays a change in length while undergoing deformation, which contributes to the diminished signal strength of the yarn. The piezoelectric yarn can successfully be integrated in a piece of fabric by the means of sewing when using correct stitch- length, where higher stitch-length gives a higher signal output. The same method can be applied to construct a piezoelectric sensor used in a training sock. This project can conclude that parameters such as moisture, creep-behaviour and structural variation within the PVDF-filaments have a significant effect on the signal created by the piezoelectric yarn. The potential of the yarn as a sensor can be seen by successfully applying it to a textile structure as well as in a training sock that can monitor the fore and rear foot while running. It can be stated that much remains to be studied in this particular research area regarding piezoelectric filaments and yarns. Further research in the subject will lead to new innovative applications that can be of use in different parts of society, not to say the least in the area of medicine.

Synthetische Hochleistungswerkstoffe, in Faserform, haben sich bisher in Gebieten wie dem Freizeitsport (Klettersport, Segelsport), Seetechnik (Ankerleinen, Zugleinen) und Schutzausrüstung (Ballistik, Arbeitsschutzbekleidung) bewehrt. Die Einführung von Hochleistungsfasern in weiteren Anwendungsfeldern wird durch Schwachstellen im Materialverhalten der Fasern selbst verhindert. So gilt unter Anwendern und Entwicklern das Problemfeld des inneren Verschleißes der textilen Halbzeuge bei Belastung auf Zug und Biegung, durch gegenseitiges Schädigen der Garne, als Haupthindernis zur weiteren Verbreitung von Textilstrukturen aus synthetischen Hochleistungspolymeren. Es kann davon ausgegangen werden, dass die Lebensdauer von z.B. Seilen und Bändern aus Hochleistungsfasern signifikant erhöht werden kann, falls es gelingt, bestimmte Schädigungsmechanismen wie Alterung durch Strahlung, aggressive Medieneinflüsse und inneren Verschleiß auszuschließen bzw. zu mindern. Da eine, wie auch immer geartete, nachträgliche Ausrüstung oder Modifizierung der Hochleistungsfasern durch den Weiterverarbeiter (z.B. Seilerei, Weberei, Konfektionär etc.) oder individuelle Bereitstellungen durch die Hersteller ausgeschlossen ist, werden für die Erarbeitung von Lösungsansätzen folgende Randbedingungen vorgeschlagen: die Modifikation des Endverbundes erfolgt nicht durch Veränderungen an der Hochleistungsfaser, sondern durch zusätzlich eingebrachte Hilfsfasern. Das Einbringen der Hilfsfasern soll mit in der Textiltechnik üblicher Weise vorhandener Maschinentechnik möglich sein. Die Ausrüstung der Hilfsfasern erfolgt vorrangig durch Additive, primär mittels Compoundierung im Schmelzspinnprozess. Die vorliegende Arbeit wird zunächst versuchen die Auswirkungen dynamischer Belastungsprozesse auf textile Zug- und Tragmittel aus Hochleistungsfasern zu erfassen. Nach Aufnahme des Schadbildes werden dann die ausgerüsteten Hilfsfasern charakterisiert, d.h. es werden solche mechanischen und physikalischen Parameter erfasst und deren Änderung beschrieben, welche in dem zu erwartenden tribologischen System aus Hochleistungsfaser und Hilfsfasern ausschlaggebend sind. / Advanced synthetic materials, in the shape of synthetic high-performance fibers, are well established in areas such as leisure sports (climbing, sailing), maritime technology (anchor lines, load lines) and reinforced protective equipment (ballistics, protective work clothing). The introduction of high-performance fibers in other fields of application is hindered by deficiencies in the material behavior of the fibers themselves. Whereas the problem of inner wear of the textile-semi-finished products, due to tension and bending loads, causes mutual harm to the fibers. This is considered being the main obstacle to the further spread of textile structures made of synthetic high-performance polymers among users and developers. It can be assumed that a significantly increase of lifetime, of e.g. fiber ropes and narrow fabrics, can be achieved if it succeeds, to exclude certain damage mechanisms such as aging resulting from radiation, aggressive media influences and inner wear. Since any subsequently equipment or modification of high-performance fibers by the manipulators (e.g. rope factory) or individual deployments by the manufacturer are excluded, the following general conditions are suggested for the development of approaches in this work. The modification of the final textile product is not been carried out due to changes on the high-performance fiber, but by additionally introduced assisting fibers. Introducing the assisting fibers to the textile product needs to be carried out on textile technology in common ways on existing machinery. The modification of the assisting fibers will be carried out, primarily through commercially available additives, during compounding in the melt spinning process. This paper will first attempt to capture the effect of dynamic load processes on textile-based tension and hoist members, made of high-performance fibers. After recording the damage structure, the equipped assisting fibers are characterized then. The investigations are including such mechanical and physical parameters, which are crucial in the expected tribological system of high-performance fiber and assisting fibers.

The change of the spontaneous polarization due to a change of temperature is known as the pyroelectric effect and is restricted to crystalline, non-centrosymmetric and polar matter. Its main application is the utilization in infrared radiation sensors, but usage for waste heat energy harvesting or chemical catalysis is also possible. A precise quantification, i.e. the measurement of the pyroelectric coefficient p, is inevitable to assess the performance of a material. Hence, a comprehensive overview is provided in this work, which summarizes and evaluates the available techniques to characterize p. A setup allowing the fully automated measurement of p by utilizing the Sharp-Garn method and the measurement of ferroelectric hysteresis loops is described. It was used to characterize and discuss the behavior of p with respect to the temperature of the doped bulk III-V compound semiconductors gallium nitride and aluminum nitride and thin films of doped hafnium oxide, as reliable data for these materials is still missing in the literature. Here, the nitride-based semiconductors show a comparable small p and temperature dependency, which is only slightly affected by the incorporated dopant, compared to traditional ferroelectric oxides. In contrast, p of HfO2 thin films is about an order of magnitude larger and seems to be affected by the present dopant and its concentrations, as it is considered to be responsible for the formation of the polar orthorhombic phase.:1. Motivation and Introduction 2. Fundamentals 2.1. Dielectrics and their Classification 2.2. Polarization 2.3. Pyroelectricity 2.4. Ferroelectricty 2.5. Phase Transitions 2.6. Applications and Figures of Merit 3. Measurement Methods for the Pyroelectric Coefficient 3.1. General Considerations 3.1.1. Heating Concepts 3.1.2. Thermal Equilibrium 3.1.3. Electric Contact 3.1.4. Separation of Contributions 3.1.5. Thermally Stimulated Currents 3.2. Static Methods 3.2.1. Charge Compensation Method 3.2.2. Hysteresis Measurement Method 3.2.3. Direct Electrocaloric Measurement 3.2.4. Flatband Voltage Shift 3.2.5. X-ray Photoelectron Spectroscopy Method 3.2.6. X-ray Diffraction and Density Functional Theory 3.3. Dynamic Methods 3.3.1. Temperature Ramping Methods 3.3.2. Optical Methods 3.3.3. Periodic Pulse Technique 3.3.4. Laser Intensity Modulation Methods 3.3.5. Harmonic Waveform Techniques 4. Pyroelectric and Ferroelectric Characterization Setup 4.1. Pyroelectric Measurement Setup 4.1.1. Setup and Instrumentation 4.1.2. Automated Sharp-Garn Evaluation of Pyroelectric Coefficients 4.1.3. Further Examples 4.2. Hysteresis Loop Measurements 4.2.1. Instrumentation 4.2.2. Measurement and Evaluation 4.2.3. Examples 5. Investigated Material Systems 5.1. III-Nitride Bulk Semiconductors GaN and AlN 5.1.1. General Structure and Spontaneous Polarization 5.1.2. Applications 5.1.3. Crystal Growth and Doping 5.1.4. Pyroelectricity 5.2. Hafnium Oxide Thin Films 5.2.1. General Structure and Applications 5.2.2. Polar Properties in Thin Films 5.2.3. Doping Effects 5.2.4. Pyro- and Piezoelectricity 6. Results 6.1. The Pyroelectric Coefficient of Free-standing GaN and AlN 6.1.1. Sample Preparation 6.1.2. Pyroelectric Measurements 6.1.3. Lattice Influence 6.1.4. Slope Differences 6.2. Pyroelectricity of Doped Hafnium Oxide 6.2.1. Sharp-Garn Measurement on Thin Films 6.2.2. Effects of Silicon Doping 6.2.3. Dopant Comparison 7. Summary and Outlook A. Pyroelectric Current and Phase under Periodic Thermal Excitation B. Loss Current Correction for Shunt Method C. Conductivity Correction D. Comparison of Pyroelectric Figures of Merit Bibliography Publication List Acknowledgments / Die Änderung der spontanen Polarisation durch eine Änderung der Temperatur ist bekannt als der pyroelektrische Effekt, welcher auf kristalline, nicht-zentrosymmetrische und polare Materie beschränkt ist. Er findet vor allem Anwendung in Infrarot-Strahlungsdetektoren, bietet aber weitere Anwendungsfelder wie die Niedertemperatur-Abwärmenutzung oder die chemische Katalyse. Eine präzise Quantifizierung, d. h. die Messung des pyroelektrischen Koeffizienten p, ist unabdingbar, um die Leistungsfähigkeit eines Materials zu bewerten. Daher bietet diese Arbeit u.a. einen umfassenden Überblick und eine Bewertung der verfügbaren Messmethoden zur Charakterisierung von p. Weiterhin wird ein Messaufbau beschrieben, welcher die voll automatisierte Messung von p mit Hilfe der Sharp-Garn Methode und auch die Charakterisierung der ferroelektrischen Hystereseschleife ermöglicht. Aufgrund fehlerender Literaturdaten wurde dieser Aufbau anschließend genutzt, um den temperaturabhängigen pyroelektrischen Koeffizienten der dotierten III-V-Verbindungshalbleiter Gallium- und Aluminiumnitrid sowie dünner Schichten bestehend aus dotiertem Hafniumoxid zu messen und zu diskutieren. Im Vergleich zu klassichen ferroelektrischen Oxiden zeigen dabei die nitridbasierten Halbleiter einen geringen pyroelektrischen Koeffizienten und eine kleine Temperaturabhängigkeit, welche auch nur leicht durch den vorhandenen Dotanden beeinflusst werden kann. Dagegen zeigen dünne Hafniumoxidschichten einen um eine Größenordnung größeren pyroelektrischen Koeffizienten, welcher durch den anwesenden Dotanden und seine Konzentration beeinflusst wird, da dieser verantwortlich für die Ausbildung der polaren, orthorhombischen Phase gemacht wird.:1. Motivation and Introduction 2. Fundamentals 2.1. Dielectrics and their Classification 2.2. Polarization 2.3. Pyroelectricity 2.4. Ferroelectricty 2.5. Phase Transitions 2.6. Applications and Figures of Merit 3. Measurement Methods for the Pyroelectric Coefficient 3.1. General Considerations 3.1.1. Heating Concepts 3.1.2. Thermal Equilibrium 3.1.3. Electric Contact 3.1.4. Separation of Contributions 3.1.5. Thermally Stimulated Currents 3.2. Static Methods 3.2.1. Charge Compensation Method 3.2.2. Hysteresis Measurement Method 3.2.3. Direct Electrocaloric Measurement 3.2.4. Flatband Voltage Shift 3.2.5. X-ray Photoelectron Spectroscopy Method 3.2.6. X-ray Diffraction and Density Functional Theory 3.3. Dynamic Methods 3.3.1. Temperature Ramping Methods 3.3.2. Optical Methods 3.3.3. Periodic Pulse Technique 3.3.4. Laser Intensity Modulation Methods 3.3.5. Harmonic Waveform Techniques 4. Pyroelectric and Ferroelectric Characterization Setup 4.1. Pyroelectric Measurement Setup 4.1.1. Setup and Instrumentation 4.1.2. Automated Sharp-Garn Evaluation of Pyroelectric Coefficients 4.1.3. Further Examples 4.2. Hysteresis Loop Measurements 4.2.1. Instrumentation 4.2.2. Measurement and Evaluation 4.2.3. Examples 5. Investigated Material Systems 5.1. III-Nitride Bulk Semiconductors GaN and AlN 5.1.1. General Structure and Spontaneous Polarization 5.1.2. Applications 5.1.3. Crystal Growth and Doping 5.1.4. Pyroelectricity 5.2. Hafnium Oxide Thin Films 5.2.1. General Structure and Applications 5.2.2. Polar Properties in Thin Films 5.2.3. Doping Effects 5.2.4. Pyro- and Piezoelectricity 6. Results 6.1. The Pyroelectric Coefficient of Free-standing GaN and AlN 6.1.1. Sample Preparation 6.1.2. Pyroelectric Measurements 6.1.3. Lattice Influence 6.1.4. Slope Differences 6.2. Pyroelectricity of Doped Hafnium Oxide 6.2.1. Sharp-Garn Measurement on Thin Films 6.2.2. Effects of Silicon Doping 6.2.3. Dopant Comparison 7. Summary and Outlook A. Pyroelectric Current and Phase under Periodic Thermal Excitation B. Loss Current Correction for Shunt Method C. Conductivity Correction D. Comparison of Pyroelectric Figures of Merit Bibliography Publication List Acknowledgments

Denna rapport har tagits fram för att undersöka och sprida information om trikå av pappersgarn från bananväxten manillahampa ”musa textilis”. Behovet av skonsamma och mindre miljöpåverkande material är väldigt aktuellt inom beklädnadsindustrin. Många av de material som används idag tär på miljön och världens resurser. Studien undersöker pappersgarns mekaniska egenskaper och färgbarhet. Detta görs för garn med olika tjocklek samt pappersgarn blandat med andra material. En studieresa gjordes till Japan för att besöka leverantörerna av pappersgarnet. I Japan visade företagets vice VD produkter de tagit fram av garnet och i många fall var det en blandning av papper och mer vanliga material som bomull och viskos, som gjorde slutprodukten mjukare. För att tillverka trikå av pappersgarn har olika bindningar och metoder prövats fram. Materialprover stickades upp i bindningen piké Lacoste över fyra sticksystem. Tester gjordes för dimensionsförändring, färghärdighet, nötningshärdighet och noppbildning samt dragprovning på garnnivå. Kawabata systemet (används för att mäta de mekaniska egenskaperna hos ett material) har använts som utgångspunkt för att undersöka ett materials komfort och egenskaper. Ytan och styrkan på ett material har studerats. Tyg stickat av pappersgarn känns styvare och hårdare än tyg stickat av bomull eller viskos, vilket resultatet av dragprovningen kan bekräfta. Pappersgarn är styvare jämfört med referensproverna bomull ”gossypium”, viskos och polyester. Garn av papper har dock goda egenskaper som stickad vara, där det inte påvisas någon större krympning eller töjning. Pappersgarn visar inga tecken på noppbildning och har en god färghärdighet efter att materialet har färgats enligt konventionell metod för cellulosabaserade material.

Färgning av polyester (PET) sker i temperaturer omkring 130℃ och som en följd av den höga värmen migrerar oligomerer ut ur PET-fibern. Dessa oligomerer skapar därefter problem i form av vita fällningar och avlagringar, som leder till en reducering av maskinernas effektivitet, samt försämring av materialets utseende. En vanligt förekommande metod för att begränsa problemet är att tillsätta hjälpkemikalier i färgbadet. Novozymes A/S hävdar att genomförda studier med PET-garn och enzymet cutinase NS59038 har visat en minskning av det vita damm som kan ses på garnet i samband med migration av oligomerer. Eftersom enorma mängder PET produceras globalt varje år skulle endast en liten minskning av mängden kemikalier innebära en stor skillnad. Kemikalier som ersätts med andra kemikalier kan ifrågasättas om det är en bra metod eller om det bestrider syftet. Ur ett hållbarhetsperspektiv kan enzymer ses som ett bättre alternativ eftersom de enligt Jajpura (2017) är biologiskt hållbara, formar sällan någon biprodukt och dess reaktion kräver oftast mildare förhållanden. Hjälpkemikalien Sera Con P-NSI används av Ludvig Svensson AB som färgar garn av den flamskyddade polyesterfibern Trevira CS. Syftet med projektet har därmed varit att undersöka om enzymet cutinase NS59038 är ett alternativ till hjälpkemikalien Sera Con P-NSI, för att reducera de problem som uppstår med oligomerer i färgningsprocessen med Trevira CS. Garnets egenskaper har jämförts genom visuell analys med mikroskop, viktförändring, reflektionsspektrofotometer och dragprovning. Metoder som använts i syfte att detektera oligomerer har varit FTIR, UV-vis spektrofotometer och svart svavelfilterpapper. Utifrån genomförda analyser av garnets vikt, styrka, färgupptagning och visuell bedömning har det inte kunnat konstateras att cutinase NS59038 skulle vara ett alternativ till Sera Con P-NSI. Resultat från analysmetoderna visade skillnader i medelvärde, men inget samband mellan val av färgrecept och garnets egenskap har detekterats. De olika färgningsförsöken visade inte någon förekomst av fällningar/avlagringar som med använda testmetoder har kunnat bekräftas som oligomerer. Resultaten bedömdes därmed inte som tillräckliga för att konstatera om cutinase NS59038 påverkar garnets kvalitet i jämförelse med hjälpkemikalien Sera Con P-NSI. / In the dyeing process of polyester (PET) the temperature goes up to around 130℃ and as a result oligomers migrate out of the PET fiber. These oligomers create problems as white precipitates that deposits on the material and the inside of machines. This leads to a reduction in machine efficiency, as well as a change of material appearance. One common method for limiting the problem is to add help chemicals in conjunction with the dyeing process. According to results from previous studies, Novozymes A/S claims that the enzyme cutinase NS59038 has reduced the white dust on the yarn of polyester. Based on the enormous quantity of PET that are produced every year, even a small reduction of the chemicals that are used would mean a huge difference. Chemicals that replace other chemicals can be questioned whether or not it can be seen as an alternative or if it disputes the purpose. From a sustainable point of view enzymes could according to Jajpura (2017) be seen as a better alternative because they are biodegradable, their reaction seldom form any byproduct and often requires less energy. The help chemical Sera Con P-NSI is used by Ludvig Svensson AB and is added to the dye bath in the dyeing process of the specific polyester Trevira CS (a flame retardant polyester fiber). The purpose of the project has thus been to investigate whether the enzyme cutinase NS59038 is an alternative to the help chemical Sera Con P-NSI, to reduce the problems with oligomers in the dyeing process of Trevira CS. The properties of the yarn have been compared by visual analysis with microscope, weight change, measurement of the color change with spectrophotometer and tensile strength. Methods used to detect oligomers have been FTIR, UV-vis spectrophotometer and black sulfur filter paper. Based on the analysis of the weight of the yarn, strength, color uptake and visual assessment, it can not be established that cutinase NS59038 would be an alternative to Sera Con P-NSI. Results from the analysis methods show differences in the mean, but no connection between the choice of dye recipe and the properties of the yarn can be detected. None of the precipitates that was predicted to arise on the surface of the yarn was ever detected. The results are therefore not considered sufficient to determine whether cutinase NS59038 affects the quality of the yarn compared to the help chemical Sera Con P-NSI.

This master thesis studies the recycling prospects of textiles. The textile industry contributes negatively to the global environmentthrough the release of greenhouse gases and consumption of resources. In order to achieve a circular textile industry, textiles must be recyclable by both chemical and mechanical means. Here, the focus is on mechanical extraction of staple fibres, particularly cotton, for reentry into yarn production. Experiments show that used, but undamaged, cotton sateen and cotton twill responds differently to abrasion with stochastic surfaces. Previous studies on the conventional shredding processes have shown positive impact from lubricants on extracted fibre lengths, by reducing inter-fibre friction. In the present study on abrasion, variables such as alignment of the weave pattern, lubrication and load are shown to have little to no impact on extracted fibre length, but notable effects on overall fibre quality. These analyses are supported by manual length assessment, electron micrographs and tensile tests using load cells. Furthermore, simple tests and observations on structured diamond surfaces constructed through chemical vapor deposition are promising for mechanical fibre release directly from a woven fabric. Suggestions are made on continued research in this field.