Ändra sökning
Avgränsa sökresultatet
1234567 1 - 50 av 404
RefereraExporteraLänk till träfflistan
Permanent länk
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Träffar per sida
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sortering
  • Standard (Relevans)
  • Författare A-Ö
  • Författare Ö-A
  • Titel A-Ö
  • Titel Ö-A
  • Publikationstyp A-Ö
  • Publikationstyp Ö-A
  • Äldst först
  • Nyast först
  • Skapad (Äldst först)
  • Skapad (Nyast först)
  • Senast uppdaterad (Äldst först)
  • Senast uppdaterad (Nyast först)
  • Disputationsdatum (tidigaste först)
  • Disputationsdatum (senaste först)
  • Standard (Relevans)
  • Författare A-Ö
  • Författare Ö-A
  • Titel A-Ö
  • Titel Ö-A
  • Publikationstyp A-Ö
  • Publikationstyp Ö-A
  • Äldst först
  • Nyast först
  • Skapad (Äldst först)
  • Skapad (Nyast först)
  • Senast uppdaterad (Äldst först)
  • Senast uppdaterad (Nyast först)
  • Disputationsdatum (tidigaste först)
  • Disputationsdatum (senaste först)
Markera
Maxantalet träffar du kan exportera från sökgränssnittet är 250. Vid större uttag använd dig av utsökningar.
  • 1.
    Abtahi, Farhad
    et al.
    KTH-School of Technology and Health.
    Ji, Guangchao
    KTH-School of Technology and Health.
    Lu, Ke
    KTH-School of Technology and Health.
    Rödby, Kristian
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Björlin, Anders
    Kiwok AB.
    Östlund, Anders
    Kiwok AB.
    Seoane, Fernando
    Högskolan i Borås, Akademin för vård, arbetsliv och välfärd. KTH-School of Technology and Health.
    Lindecrantz, Kaj
    KTH-School of Technology and Health.
    Textile-Electronic Integration in Wearable Measurement Garments for Pervasive Healthcare Monitoring2015Konferensbidrag (Övrigt vetenskapligt)
  • 2.
    Abtahi, Farhad
    et al.
    KTH-School of Technology and Health.
    Lu, Ke
    KTH-School of Technology and Health.
    Guangchao, Li
    KTH-School of Technology and Health.
    Rödby, Kristian
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Seoane, Fernando
    Högskolan i Borås, Akademin för vård, arbetsliv och välfärd. KTH-School of Technology and Health.
    A Knitted Garment using Intarsia Technique for Heart Rate Variability Biofeedback: Evaluation of Initial Prototype.2015Konferensbidrag (Övrigt vetenskapligt)
  • 3. Abylaev, Mansur
    Kyrgyz textile companies’ resilience features in the post-Soviet regionalization processes2013Konferensbidrag (Refereegranskat)
    Abstract [en]

    The Kyrgyz textile industry is a fast growing sector since the last decade. The combination of international market conjuncture and low input factors were the main reasons for the development of the textile sector. Legal and political modification of the international trade system is a risk for the whole industry's resilience. The purpose of the paper is to identify the vulnerable points of doing business in the context of economic transformation from planned Soviet to free market economy.

  • 4.
    Adekunle, K.
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Cho, S.-W.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Ketzscher, R.
    Skrifvars, M.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Mechanical properties of natural fiber hybrid composites based on renewable thermoset resins derived from soybean oil, for use in technical applications2012Ingår i: Journal of Applied Polymer Science, ISSN 0021-8995, E-ISSN 1097-4628, Vol. 124, nr 6, s. 4530-4541Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Natural fiber composites are known to have lower mechanical properties than glass or carbon fiber reinforced composites. The hybrid natural fiber composites prepared in this study have relatively good mechanical properties. Different combinations of woven and non-woven flax fibers were used. The stacking sequence of the fibers was in different orientations, such as 0°, +45°, and 90°. The composites manufactured had good mechanical properties. A tensile strength of about 119 MPa and Young's modulus of about 14 GPa was achieved, with flexural strength and modulus of about 201 MPa and 24 GPa, respectively. For the purposes of comparison, composites were made with a combination of woven fabrics and glass fibers. One ply of a glass fiber mat was sandwiched in the mid-plane and this increased the tensile strength considerably to 168 MPa. Dynamic mechanical analysis was performed in order to determine the storage and loss modulus and the glass transition temperature of the composites. Microstructural analysis was done with scanning electron microscopy.

  • 5.
    Adekunle, K.
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Cho, S.-W.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Patzelt, C.
    Blomfeldt, T.
    Skrifvars, M.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Impact and flexural properties of flax fabrics and Lyocell Fiber reinforced bio-based thermoset for automotive and structural applications2012Konferensbidrag (Refereegranskat)
  • 6.
    Adekunle, K.
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Ghoreishi, R.
    Ehsani, M.
    Cho, S.-W.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Skrifvars, M.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Jute fiber reinforced methacrylated soy bean oil based thermoset composites prepared by vacuum injection molding technique2012Ingår i: Journal of Biobased Materials and Bioenergy, ISSN 1556-6560, E-ISSN 1556-6579, Vol. 6, nr 2, s. 172-177Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Bio-based composites based on soybean oil thermoset resin were manufactured with vacuum injection molding technique. Methacrylated soybean oil (MMSO) was processed with vacuum injection molding technique without blending with styrene. The composites produced had comparatively good mechanical properties like jute composite reinforced acrylated epoxidised soybean oil (AESO) resin blended with styrene. Although the tensile strength of the jute reinforced AESO composites are slightly higher than the jute reinforced MMSO composites which was attributed to blending of AESO with styrene. However, the difference in Youngs' modulus was negligible because they have approximately equal stiffness between 2.6 GPa and 2.8 GPa. The jute reinforced AESO composites showed relatively higher flexural strengths and moduli than the MMSO counterparts. This difference was also attributed to the blending of AESO with reactive diluent such as styrene. In order to determine the dimensional stability of the composite manufactured, water absorption test was carried out and the conclusion was that the moisture uptake of the jute reinforced composites was the same, this was expected.

  • 7.
    Adekunle, Kayode
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Bio-based Composites from Soybean Oil Thermosets and Natural Fibers2011Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    In order to reduce over-dependency on fossil fuels and to create an environment that is free of non-degradable plastics, and most importantly to reduce greenhouse gas emission, bio-based products are being developed from renewable resources through intense research to substitute conventional petrochemical-based plastics with renewable alternatives and to replace synthetic fibers with natural fibers. Many authors have done quite a lot of work on synthesizing polymers from renewable origin. Polylactic acid (PLA) has been developed and characterized, and it was found that it has enormous potential and can serve as an alternative to conventional thermoplastics in many applications. Modification of the plant oil triglycerides has been discussed by many authors, and research is still going on in this area. The challenge is how to make these renewable polymers more competitive in the market, and if possible to make them 100% bio-based. There is also a major disadvantage to using a bio-based polymer from plant oils because of the high viscosity, which makes impregnation of fibers difficult. Although natural fibers are hydrophilic in nature, the problem of compatibility with the hydrophobic matrix must be solved; however, the viscosity of the bio-based resin from plant oils will complicate the situation even more. This is why many authors have reported blending of the renewable thermoset resin with styrene. In the process of solving one problem, i.e reducing the viscosity of the renewable thermoset resin by blending with reactive diluents such as styrene, another problem which we intended to solve at the initial stage is invariably being created by using a volatile organic solvent like styrene. The solution to this cycle of problems is to synthesize a thermoset resin from plant oils which will have lower viscosity, and at the same time have higher levels of functionality. This will increase the crosslinking density, and they can be cured at room temperature or relatively low temperature. In view of the above considerations, the work included in this thesis has provided a reasonable solution to the compounded problems highlighted above. Three types of bio-based thermoset resins were synthesized and characterized using NMR, DSC, TGA, and FT-IR, and their processability was studied. The three resins were subsequently reinforced with natural fibers (woven and non-woven), glass fibers, and Lyocell fiber and the resulting natural fiber composites were characterized by mechanical, dynamic mechanical, impact, and SEM analyses. These composites can be used extensively in the automotive industry, particularly for the interior components, and also in the construction and furniture industries. Methacrylated soybean oil (MSO), methacrylic anhydride-modified soybean oil (MMSO), and acetic anhydride-modified soybean oil (AMSO) were found to be suitable for manufacture of composites because of their lower viscosity. The MMSO and MSO resins were found to be promising materials because composites manufactured by using them as a matrix showed very good mechanical properties. The MMSO resin can completely wet a fiber without the addition of styrene. It has the highest number of methacrylates per triglyceride and high crosslink density.

  • 8.
    Adekunle, Kayode
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Patzelt, Christian
    Kalantar, Adib
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Skrifvars, Mikael
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Mechanical and Viscoelastic Properties of Soybean Oil Thermoset Reinforced with Jute Fabrics and Carded Lyocell Fiber2011Ingår i: Journal of Applied Polymer Science, ISSN 0021-8995, E-ISSN 1097-4628, Vol. 122, nr 5, s. 2855-2863Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Composites and hybrid composites were manufactured from renewable materials based on jute fibers, regenerated cellulose fibers (Lyocell), and thermosetting polymer from soybean oil. Three different types of jute fabrics with biaxial weave architecture but different surface weights, and carded Lyocell fiber were used as reinforcements. Hybrid composites were also manufactured by combining the jute reinforcements with the Lyocell. The Lyocell composite was found to have better mechanical properties than other composites. It has tensile strength and modulus of about 144 MPa and 18 GPa, respectively. The jute composites also have relatively good mechanical properties, as their tensile strengths and moduli were found to be between 65 and 84 MPa, and between 14 and 19 GPa, respectively. The Lyocell-reinforced composite showed the highest flexural strength and modulus, of about 217 MPa and 13 GPa, respectively. In all cases, the hybrid composites in this study showed improved mechanical properties but lower storage modulus. The Lyocell fiber gave the highest impact strength of about 35 kJ/m2, which could be a result of its morphology. Dynamic mechanical analysis showed that the Lyocell reinforced composite has the best viscoelastic properties.

  • 9.
    Adekunle, Kayode
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Skrifvars, Mikael
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Synthesis of reactive soybean oils for use as thermoset resins in composites.2007Konferensbidrag (Refereegranskat)
  • 10.
    Adekunle, Kayode
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Åkesson, Dan
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Skrifvars, Mikael
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Synthesis of reactive soybean oils for use as biobased thermoset resins in structural natural fibre composites2008Konferensbidrag (Refereegranskat)
  • 11.
    Adekunle, Kayode
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Åkesson, Dan
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Skrifvars, Mikael
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Synthetic modification of reactive soybean oils for use as biobased thermoset resins in structural natural fiber composites2008Konferensbidrag (Övrigt vetenskapligt)
  • 12.
    Adekunle, Kayode
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Åkesson, Dan
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Skrifvars, Mikael
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Synthetic modification of reactive soybean oils for use as biobased thermoset resins in structural natural fiber composites2008Ingår i: Polymer Preprints, ISSN 0551-4657, Vol. 49, nr 1, s. 279-Artikel i tidskrift (Refereegranskat)
  • 13.
    Agnhage, Tove
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. University Lille 1, France; Soochow University, China.
    Eco-designed functionalization of polyester fabric2017Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [sv]

    Den höga miljöpåverkan från textilfärgning och efterbehandling, på grund av hög vattenförbrukning, dess förorening, och ineffektiv användning av energi, är idag välkänt. För att minska miljöpåverkan föreslår forskningsvärlden användning av färgämnen från naturliga resurser. Syftet med att använda dessa är att ge nya attribut till textilier utan att göra avkall på miljömässig hållbarhet. Attribut som ges kan vara färg och/eller andra egenskaper. En nackdel är dock att användningen av bio-baserade färgämnen är inte fri från att belasta miljön. Det blir därför av största betydelse att bedöma denna miljöpåverkan och förbättra miljöprofilen. Sådana studier är dock i allmänhet sällsynta.

    Studien som presenteras i denna avhandling har inkluderat miljöpåverkans- bedömning, med hjälp av livscykelanalys (LCA), i designprocessen av en multifunktionell polyester (PET) väv via naturliga antrakinoner. Genom att göra så har ett eko-design tillvägagångssätt använts, med avsikt att bana väg för miljömässigt hållbar bio-funktionalisering av textil.

    Antrakinonerna erhölls från rot extrakt av växten krapp (Rubia tinctorum L.), och hänvisas till som krapp färgämne. Frågeställningar var därför formulerade relaterat till användningen av krapp färgämne. Tre forskningsfrågor har besvarats: (I) Kan krapp färgämne verka multifunktionellt på en PET väv? (II) Hur ser miljöprofilen ut, från färgningsprocessen av PET med krapp färgämne, och hur kan den förbättras? (III) Vilka är de största utmaningarna med att använda LCA för att bedöma miljökonsekvenserna av textilfärgning med växtbaserade färgämnen?

    Det kan konkluderas att det finns potential för krapp färgämne att verka multifunktionellt på PET. Baserat på uppmuntrande resultat är en rekommendation för det framtida arbetet att fokusera på kvalitén hos de attribut som presenterats och deras förbättringspotential, både i färgning via färgbad och via foulard. LCA driven processoptimering av textilfärgningen förbättrade i varje miljöpåverkans- kategori som studerats. Emellertid har flera utmaningar identifierats som måste 

    övervinnas för att LCA skall kunna bidra till en hållbar användning av multifunktionella växtbaserade färgämnen för textil. De största utmaningarna är bristen på tillgängliga data i forskningsstadiet och den tvärvetenskapliga forskningsarenan. Det är tänkt att om dessa utmaningar bemästras kan LCA bidra till en hållbar bio-funktionalisering av textil.

  • 14.
    Agnhage, Tove
    et al.
    Högskolan i Borås, Institutionen Textilhögskolan.
    Nierstrasz, Vincent
    Högskolan i Borås, Institutionen Textilhögskolan.
    Perwuelz, A.
    Guan, J.P.
    Chen, G.Q.
    Eco-design innovative methods for fabric finishing2014Konferensbidrag (Övrigt vetenskapligt)
  • 15.
    Ainamo, Antti
    Högskolan i Borås, Institutionen Textilhögskolan.
    Rethinking design fashion: New materiality, smart products, and upcycling2014Ingår i: Swedish Design Research Journal, ISSN 2000-964X, Vol. 12, nr 2, s. 53-60Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Manufacturing operations in much of textile fashion have migrated from the developed economies to developing countries in search of cost economies. Consideration for the natural environment has been lost in the process due to lack of clarity what corporation or some other participant in what kind of an economy is most responsible. This paper is intended as a thought piece on how new materialisms offers an approach to bring back responsible concern for the natural environment in textile fashion and, perhaps, beyond.

  • 16. Ali, Majid
    et al.
    Bashir, Tariq
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Persson, Nils-Krister
    Skrifvars, Mikael
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Optimization of oCVD Process for the Production of Conductive Fibers2011Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    Electro active textile fibers are key components in smart and interactive textile applications. In our previous study, we produced poly(3,4-ethylenedioxythiophene) (PEDOT) coat edviscose fibers by using oxidative chemical vapordeposition (OCVD) technique. We tried FeCl3 as oxidant and found optimum reaction conditions at which better electrical as well as mechanical properties of conductive fibers could be achieved.

  • 17. Ali, Majid
    et al.
    Bashir, Tariq
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Persson, Nils-Krister
    Skrifvars, Mikael
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Stretch Sensing Properties of PEDOT Coated Conductive Yarns Produced by OCVD Process2011Konferensbidrag (Refereegranskat)
  • 18.
    Alvelind, Cornelia
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Gustafsson, Britta
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Kvinnors rättigheter: En studie om arbetsförhållanden inom textilindustrin2018Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Idag är majoriteten av de som arbetar inom textilindustrin kvinnor. Långa arbetsdagar, låga löner, dåliga arbetsförhållanden och förtryckande kulturella normer är bara några av de faktorer som bidrar till att kvinnors rättigheter kränks varje dag. Denna studie syftar till att belysa kvinnors arbetsförhållanden samt undersöka möjliga lösningar för att förbättra deras tillvaro. I tidigare forskning diskuteras det sociala ansvar företag har i förhållande tillmänskliga rättigheter, vidare uppmärksammas det en avsaknad av tydligt fokus gällandekvinnors rättigheter implementerat i industrin. Det empiriska material som ligger till grund förstudiens undersökning baseras på en kombination av litteraturstudier, kvalitativa intervjuer samt en analys baserat på tryckt och visuellt material. Litteraturstudien gav upphov till en analysmodell med ett fokus på tre områden: intressentteorin, mänskliga rättigheter och kulturella skillnader, som ansågs väsentliga i arbetet för att förbättra kvinnors arbetsförhållanden. Övrigt empiriskt material användes för att få en ökad förståelse över de förhållanden som råder för kvinnorna i industrin samt till underlag för diskussion tillförbättringar. Resultatet av studien presenteras i en analys av kvinnors rättigheter och hur de idag bristfälliga arbetsförhållandena i klädindustrin kan förbättras samt förslag på hur aktörer kan utnyttja denna information för att nå dessa mål. Studien bekräftar att det förekommer allvarliga brister i arbetsförhållandena för kvinnor i textilindustrin men att det finns möjliga medel för att förbättra dem.

  • 19.
    Andersson, Bengt-Åke
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Johansson, Andreas
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Förbränning och termiska system för hållbar utveckling2009Ingår i: Vetenskap för profession, ISSN 1654-6520, nr 10, s. 79-81Artikel i tidskrift (Övrigt vetenskapligt)
  • 20.
    Aronsson, Julia
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Torn to be worn?: Cotton fibre length of shredded post-consumer garments2017Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    In 2015 the global fibre consumption was 96.7 million tonnes, which is an increase of 3.1% from the year before. Our high textile consumption has led to an increasing demand of raw materials and generation of textile waste. Only in Europe, a total amount of 4.3 million tonnes of apparel waste each year is sent to either incineration or landfills. Approximately 50% of the clothes we discard and donate are composed of cotton. In the future, the cotton production is predicted to stagnate since the world population is increasing and arable land to greater extent will be needed for food production. Thereby, it is important that we utilize the cotton waste generated. One of the most commonly used processes for recycling textile waste is the shredding process. In this method, textile waste is shredded back into their constituent fibres. The drawback with the shredding process is that the fibre length is reduced. The fibre length is an important property since it has a high influence on textile processing such as yarn production and final product quality. The aim of this thesis was to investigate how post-consumer cotton garments with different degree of wear affects the fibre length obtained in the shredding process. This was performed by analysing the input fibre length as well as the output fibre length. Additionally, several parameters were investigated: fabric construction and yarn structure. Degree of wear was categorized into two levels: low and high degree of wear. The fabric constructions used in this study were single-jersey and denim. The yarn structure were analysed in terms of yarn count, yarn twist and manufacturing process.  The result showed that the fibre length before shredding was statistically significant longer for the materials with low degree of wear compared to high degree of wear. After shredding, it was shown that the fibre length reduction was lower for the materials with high degree of wear. This indicates that longer fibres give higher fibre length reduction. In addition, it was found that finer yarn gives higher fibre length reduction. The result also showed that the yarn manufacturing process has a great influence on the ease of shredding and the fibre length obtained in the end.  Based on the result in this thesis it can be concluded that the shredding process needs to be improved in order to preserve the fibre length. The area of post-consumer textile waste is complex and the result showed that there is many underlying parameters that need to be taken into account to further develop the shredding process. 

  • 21. Arshad, Khubaib
    et al.
    Skrifvars, Mikael
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Vivod, Vera
    Valh, Julija
    Voncina, Bojana
    Biodegradation of natural textile materials in soil2014Ingår i: Tekstilec, ISSN 0351-3386, Vol. 57, nr 2, s. 118-132Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    World is facing numerous environmental challenges, one of them being the increasing pollution both in the atmosphere and landfi lls. After the goods have been used, they are either buried or burnt. Both ways of disposal are detrimental and hazardous to the environment. The term biodegradation is becoming more and more important, as it converts materials into water, carbon dioxide and biomass, which present no harm to the environment. Nowadays, a lot of research is performed on the development of biodegradable polymers, which can “vanish” from the Earth surface after being used. In this respect, this research work was conducted in order to study the biodegradation phenomenon of cellulosic and non-cellulosic textile materials when buried in soil, for them to be used in our daily lives with maximum effi ciency and after their use, to be disposed of easily with no harmful eff ects to the environment. This research indicates the time span of the use life of various cellulosic and non-cellulosic materials such as cotton, jute, linen, fl ax, wool when used for the reinforcement of soil. The visual observations and applied microscopic methods revealed that the biodegradation of cellulose textile materials proceeded in a similar way as for non-cellulosic materials, the only difference being the time of biodegradation. The non-cellulosic textile material (wool) was relatively more resistant to microorganisms due to its molecular structure and surface. Keywords: biodegradation, composting, natural textile materials, FT-IR

  • 22.
    Artur, Cavaco-Paulo
    et al.
    University of Minho, Braga, Portugal.
    Nierstrasz, VincentHögskolan i Borås, Akademin för textil, teknik och ekonomi.Wang, QiangJiangnan University, Wuxi, China.
    Advances in Textile Biotechnology 2nd Edition2019Samlingsverk (redaktörskap) (Refereegranskat)
    Abstract [en]

    Description

    Advances in Textile Biotechnology, Second Edition examines the latest in biotechnology for the fiber and textile industry. This new edition has been fully revised to include the current essential areas of development in the field, covering both natural and synthetic fibers. Chapters cover the latest technology in bioprocessing for bast fiber, PVA, polyester, wool and silk before exploring issues of enzyme stability. Essential areas of application and development are then considered, including biomedical textiles, silk materials for biotechnological applications, bacterial cellulose, the ink jetting of enzymes, and the role of enzymes, wool and silk fibers.

    Containing groundbreaking research, this book will be essential reading for manufacturers, designers and engineers in the textiles industry, textile and fiber scientists, and academic researchers and postgraduate students working in the area of textile technology.

    Key Features

    • Provides a thorough overview of current and future focuses of biotechnology in the fiber and textile industry
    • Presents fully revised content, with a new focus on biosynthesis and bioprocessing for novel textile fibers, both synthetic and natural
    • Enables readers to understand and utilize the benefits of biotechnology for the manufacture and production of textiles

    Readership

    Textile manufacturers, designers and engineers in the textile industry; textile and fibre scientists; academic researchers and postgraduate students in textile technology; experts in the biology, chemical and environmental engineering industries

  • 23.
    Asadi, Milad
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Bashir, Tariq
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Skrifvars, Mikael
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Development of eco-friendly flame retardant polypropylene fibers2017Konferensbidrag (Refereegranskat)
  • 24.
    Backe, Carin
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Enhancing textile electrode performance: Regulating moisture management through textile structure2017Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    The medical field has been a part of the smart textile area for quite some time. With time come technological advancement and the two fields converge on more and more areas. One such area is that of using textile electrodes, textrodes, for measuring bioelectrical activity, such as heart rate for ECG analysis. There are many components that make for a successful textile electrode and though many studies have been made in the subject there are several aspects that still are difficult. By using textile electrodes the problem with skin irritation from electrolyte gels, commonly used for conventional electrodes, is avoided, however dry textrodes create disturbances in the output signal (heart rate) while subjected to movement and internal dimensional changes. The addition of moisture to a textrode has shown to decrease these intermittent disturbances but the knowledge about fundamental textile structural influence in the matter has not been fully investigated. This study investigates a flat, a 2-thread fleece and an open structure, and their relation to moisture both as textile structures and as textrodes. This way the possibilities of utilising moisture to increase performance in a textrode purpose can be examined and to what extent the textile structure plays a part in that exploitation. The material composition of textile structures also affects their properties The introduction of assistive materials, polyester and viscose, into the Shieldex (conductive yarn) structures is done to test core moisture management properties such as surface tension, absorption and moisture content, and correlate them to electrical properties necessary for textrode function. In the end the gap between textile structure and end product in form of a textrode is closed as the impedance and microclimate of the textrodes are studied. This is mainly to tie together the fundamental textile structures with a complex textile construction. In conclusion the complexity is also confirmed as structural, materialistic and external influences has an impact on the results. The influence of moisture on lowered resistance and impedance in the structures is confirmed but the impact of textile structure can also be seen. The 2-thread fleece and open structures often has a more positive impact on results and therefore has the possibility of enhancing performance of a textrode for bioelectrical signal monitoring. With these results a more effective way of producing long-lasting, patient-friendly, textrodes can be derived and in the future lead to better care in the medical areas.

  • 25.
    Backe, Carin
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Skelte, Gabrielle
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Piezoelektriska filament: från garn till textil applikation2015Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    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.

  • 26.
    Backe, Carin
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Skelte, Gabrielle
    Rundqvist, Karin
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Sandsjö, Leif
    Högskolan i Borås, Akademin för vård, arbetsliv och välfärd.
    Persson, Nils-Krister
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Piezoelektriska strumpor för rörelsemonitorering - En känslighetsanalys2015Ingår i: Abstracts - Medicinteknikdagarna 2015, Svensk förening för medicinsk teknik och fysik , 2015, s. 60-Konferensbidrag (Övrigt vetenskapligt)
  • 27.
    Baghaei, Behnaz
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Development of thermoplastic biocomposites based on aligned hybrid yarns for fast composite manufacturing2015Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    The interest in natural fibres as reinforcement for composite materials has been steadily increasing due to their attractive mechanical properties and the possibility of making more eco-friendly materials. Currently, various alternatives are being introduced for commercial applications, as fibres such as hemp, jute and flax exhibit properties, which make them appropriate for structural composite components. Biocomposites offer reductions in weight and cost and have less reliance on foreign oil resources, making them attractive. Several investigations have revealed that the full utilisation of fibre mechanical properties in the final composites can be exploited, provided an aligned fibre orientation is chosen. In fact, a major challenge for natural fibre reinforced composites is to achieve high mechanical performance at competitive prices. The use of commingled/hybrid yarns is one of the more promising methods for manufacturing structural thermoplastic composites.

    Commingled yarns of thermoplastic and reinforcing fibres offer a potential for cost-effective production of composite parts, thanks to reduced applied pressures and impregnation times during processing. Besides economic advantages, there is also direct control over fibre placements and ease of handling of fibres in yarn process. The yarn technologies provide homogenous distribution of reinforcing fibre and matrix. Variation in natural fibre properties has been a major problem facing composite manufacturers, compared to carbon and glass fibres that have well-defined production processes. This issue can be addressed by regenerated cellulose fibres. These fibres can be reproduced easily with high surface evenness and even quality, making it possible to get consistent results, which is not possible with natural fibres. Combination of natural and regenerated cellulose fibre brings together the best of both materials. The end result is a product with superior properties, which could not be obtained by the individual components.

    This thesis describes the development of aligned hybrid yarns with low fibre twist, for high performance natural (hemp) and man-made (Lyocell) cellulose fibre-reinforced biocomposites, suitable for use in structural or semi-structural applications. The properties of composites in terms of fibre orientation, off-axis angle and alkali treatment were investigated, focusing on determining void%, water absorption, mechanical and thermo-mechanical properties. The results show that combining hemp and Lyocell in PLA composite leads to the reduction of moisture absorption and can improve the mechanical properties. The mechanical properties of the composites were highly affected by the fibre direction. The alkali treatment on hemp fibre improved the mechanical properties of the composites.

  • 28.
    Baghaei, Behnaz
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Berglin, Lena
    Högskolan i Borås, Institutionen Textilhögskolan.
    Skrifvars, Mikael
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Tailoring of the mechanical and thermal properties of hemp/PLA hybrid yarn composites2013Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    In this study, we worked on improving the orientation of hemp fibres in composites by using our recent development of co-wrapped yarn structures. We investigated the influence of fibre content and wrap density on the properties of composites. Composites were fabricated by compression moulding of 0/90 bidirectional prepregs. Compared to neat PLA, the tensile and flexural modulus and the strength of the PLA-hemp composites were significantly higher as a result of the increased fibre content. Impact strength of the composites decreased initially up to 10 mass % fibre loading, but even higher fibre loading caused an improvement in impact strength. From the DMTA results, it was evident that incorporation of the fibres gives a considerable increase in storage modulus and a decrease in tan δ values. From the general trend in the results obtained, it can be affirmed that co-wrapped hybrid yarn with lower wrapping density leads to lower mechanical properties in the composite. The study performed with DSC revealed that the crystallisation temperature of the hemp-reinforced PLA composites decreased compared to pure PLA, which indicates that the hemp fibres hinder the migration and diffusion of PLA molecular chains to the surface of the nucleus in the composites.

  • 29.
    Baghaei, Behnaz
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Berglin, Lena
    Högskolan i Borås, Institutionen Textilhögskolan.
    Skrifvars, Mikael
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Tailoring of the mechanical and thermal properties of hemp/PLA hybrid yarn composites2013Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    In this study, we worked on improving the orientation of hemp fibres in composites by using our recent development of co-wrapped yarn structures. We investigated the influence of fibre content and wrap density on the properties of composites. Composites were fabricated by compression moulding of 0/90 bidirectional prepregs. Compared to neat PLA, the tensile and flexural modulus and the strength of the PLA-hemp composites were significantly higher as a result of the increased fibre content. Impact strength of the composites decreased initially up to 10 mass % fibre loading, but even higher fibre loading caused an improvement in impact strength. From the DMTA results, it was evident that incorporation of the fibres gives a considerable increase in storage modulus and a decrease in tan δ values. From the general trend in the results obtained, it can be affirmed that co-wrapped hybrid yarn with lower wrapping density leads to lower mechanical properties in the composite. The study performed with DSC revealed that the crystallisation temperature of the hemp-reinforced PLA composites decreased compared to pure PLA, which indicates that the hemp fibres hinder the migration and diffusion of PLA molecular chains to the surface of the nucleus in the composites.

  • 30.
    Baghaei, Behnaz
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Skrifvars, Mikael
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Berglin, Lena
    Högskolan i Borås, Institutionen Textilhögskolan.
    Hybrid natural fibre reinforcements and prepregs for thermoplastic composites with improved performance and properties2014Konferensbidrag (Övrigt vetenskapligt)
  • 31.
    Baghaei, Behnaz
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Skrifvars, Mikael
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Berglin, Lena
    Högskolan i Borås, Institutionen Textilhögskolan.
    Ramamoorthy, Sunil Kumar
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Hemp/PLA Co-Wrapped Hybrid Yarns For Structured Thermoplastic Composites2013Konferensbidrag (Refereegranskat)
    Abstract [en]

    In recent years, natural fibre-reinforced polymer composites have been attracting attention from the viewpoint of reducing the impact on the natural environment. Currently, the use of thermoplastic resins in composites is clearly of higher potential than the use of thermoset. There are many thermoplastic polymers derived from renewable raw materials, which are also biodegradable. Polylactic acid (PLA) is one such candidate, and it shows rather good properties that are suitable for applications that do not require long-term durability or elevated mechanical performance at higher temperatures. In order to make their possible use in many technical applications more attractive, the mechanical properties of the PLA can be enhanced by using reinforcements. Hemp fibres can be considered to be a good choice for reinforcing polymer composites, due to their high stiffness, strength, and aspect ratio. Highly ordered textile reinforcements, such as interlaced woven fabrics and unidirectional fabrics made from natural-fibre yarns, perform considerably better than random non-woven mats in natural-fibre composites. At present, the commercially available plant-fibre yarns are not intended for structural composites, but for textiles, which have entirely different demands on the yarns. Thus, work is needed to tailor-make the best plant-fibre yarn for reinforcement of composites. This also includes investigation of the possibility of combining plant-fibre yarns with the matrix polymer in fibre form into one hybrid yarn (a composite preform), and how to do it (twisting or blending). It is well known that fibres provide the highest strength and stiffness when they are continuous and aligned in the direction of the applied load. Natural fibres are naturally discontinuous and conventional spun staple yarns tend to be highly twisted, which leads to fibre misalignment and poor resin wet-out. The structured natural-fibre composites reported so far are based on twisted yarns produced by long-established conventional spinning methods, mainly ring spinning. In this paper, we report our work on improving the orientation of hemp fibres in composites by using our recent development of co-wrapped yarn structures. This novel co-wrapped yarn consists of low twist and very fine hemp yarns next to PLA filaments in the core part, which are wrapped by PLA filaments. By varying the composition of hybrid yarn, it is possible to vary the hemp fibre content from 10 to 45 wt %. An exciting recent advancement has been a new family of aligned natural-fibre reinforcements, which has overcome these issues by using low twist yarns. We also report the influence of fibre content and wrap density (number of wraps per unit length) on the properties of composites. Before compression moulding, multilayer 0/90 bidirectional hybrid yarn prepregs were prepared by winding the hybrid yarn around a steel rectangular frame. We investigated the mechanical and thermo-mechanical properties of hemp-reinforced PLA composites. Compared to neat PLA, the tensile and flexural modulus and the strength of the PLA-hemp composites were significantly higher as a result of the increased fibre content. Impact strength of the composites decreased initially up to 10 wt % fibre loading, but even higher fibre loading caused an improvement in impact strength. From the DMTA results, it is evident that incorporation of the fibres gives a considerable increase in storage modulus and a decrease in tan δ values. These results show the reinforcing effect of hemp on PLA matrix. From the general trend in the results obtained, it can be affirmed that co-wrapped hybrid yarn with lower wrapping density leads to lower mechanical properties in the composite. The study performed with DSC revealed that the glass transition temperature and the crystalline melting point of PLA were not affected significantly after reinforcement with hemp. The crystallisation temperature of the hemp-reinforced PLA composites decreased compared to pure PLA, which indicates that the hemp fibres hinder the migration and diffusion of PLA molecular chains to the surface of the nucleus in the composites. No noteworthy differences in calorimetric data from DSC for composites were observed between the hybrid yarn preforms with different wrapping density. Future work will concentrate on efforts to evaluate the biodegradability of these developing and promising composites.

  • 32.
    Baghaei, Behnaz
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Skrifvars, Mikael
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Masoud, Salehi
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Aligned hemp yarn reinforced biocomposites: porosity, water absorption, thermal and mechanical properties2014Konferensbidrag (Refereegranskat)
  • 33.
    Baghaei, Behnaz
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Temmink, Robin
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Skrifvars, Mikael
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    RECYCLING OF END-OF-LIFE TEXTILE MATERIALS BY FABRICATION OF GREEN COMPOSITES2017Konferensbidrag (Refereegranskat)
    Abstract [en]

    Material recycling requires rather pure and non-contaminated waste streams, which can be converted by technical processes into new materials and products by economically and technically feasible techniques. It is also required that there is a secondary market for these recycled materials, and preferably in use areas with high economic value. End-of-life textiles cannot yet be recycled as a raw material in a feasible way. Structural composites are an excellent use area for recycled materials, as they are durable and light-weight products, with excellent mechanical properties.

    In this study, denim woven fabrics as end-of-life textiles were employed to improve the mechanical and thermal properties of high bio-content epoxy resin. Entropy Resin, manufacturer of commercial bio-based epoxy resin, claimed that bio-based content of system is 37 % and the resin is derived from by-products of industrial processes including wood pulp and biofuel. Bioepoxy was used as bio resins in composite manufacturing, and a conventional polyester resin served as a reference material. To create a wide scope of possibilities the composites were manufacturing using the four techniques: (1) vacuum infusion (VI), (2) resin transfer moulding (RTM), and (3) hand lay-up (HND). To determine the suitability for structural applications the biocomposites were tested for their mechanical and thermal properties. Mechanical tests for tensile, flexural strength and impact behaviour were conducted on composites. Moreover, viscoelastic properties of the composites were evaluated through dynamic mechanical analysis (DMA). Fabricated composites were characterised regarding porosity, water absorption and analysed through microscopic images of the composite cross section. Different manufacturing technique showed varying results. For bioepoxy both HND and VI give superior mechanical properties over RTM, as the latter gives a higher void content, and lower tensile and flexural properties.

  • 34.
    Bakare, Fatimat O.
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Ramamoorthy, Sunil Kumar
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Åkesson, Dan
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Skrifvars, Mikael
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Thermomechanical properties of bio-based composites made from a lactic acid thermoset resin and flax and flax/basalt fibre reinforcements2016Ingår i: Composites. Part A, Applied science and manufacturing, ISSN 1359-835X, E-ISSN 1878-5840, Vol. 83, s. 176-184Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Low viscosity thermoset bio-based resin was synthesised from lactic acid, allyl alcohol and pentaerythritol. The resin was impregnated into cellulosic fibre reinforcement from flax and basalt and then compression moulded at elevated temperature to produce thermoset composites. The mechanical properties of composites were characterised by flexural, tensile and Charpy impact testing whereas the thermal properties were analysed by dynamic mechanical thermal analysis (DMTA) and thermogravimetric analysis (TGA). The results showed a decrease in mechanical properties with increase in fibre load after 40 wt.% for the neat flax composite due to insufficient fibre wetting and an increase in mechanical properties with increase fibre load up to 60 wt.% for the flax/basalt composite. The results of the ageing test showed that the mechanical properties of the composites deteriorate with ageing; however, the flax/basalt composite had better mechanical properties after ageing than the flax composite before ageing.

  • 35.
    Bakare, Fatimat Oluwatoyin
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Skrifvars, Mikael
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Wang, Yanfei
    Afshar, Shahrzad Javanshir
    Esmaeli, Nima
    Åkesson, Dan
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Morphological and mechanical properties of a biobased composite from a lactic acid based thermoset resin and viscose fiber reinforcement2014Konferensbidrag (Refereegranskat)
  • 36.
    Bakare, Fatimat Oluwatoyin
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Skrifvars, Mikael
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Wang, Yanfei
    Afshar, Shahrzad Javanshir
    Esmaeli, Nima
    Åkesson, Dan
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Synthesis and Preparation of Biobased Composites with A Novel Thermoset Resin from Lactic Acid2014Konferensbidrag (Refereegranskat)
  • 37.
    Barghi, Hamidreza
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Functionalization of Synthetic Polymers for Membrane Bioreactors2014Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Membrane bioreactors (MBRs) show great promise for productivity improvement and energy conservation in conventional bioprocesses for wastewater reclamation. In order to attain high productivity in a bioprocess, it is crucial to retain the microorganisms in the bioreactors by preventing wash out. This enables recycling of the microorganisms, and is consequently saving energy. The main feature of MBRs is their permeable membranes, acting as a limitative interface between the medium and the microorganisms. Permeation of nutrients and metabolites through the membranes is thus dependent on the membrane characteristics, i.e. porosity, hydrophilicity,and polarity. The present thesis introduces membranes for MBRs to be used in a continuous feeding process, designed in the form of robust, durable, and semi-hydrophilic films that constitute an effective barrier for the microorganisms, while permitting passage of nutrients and metabolites. Polyamide 46 (polytetramethylene adipamide), a robust synthetic polymer, holds the desired capabilities, with the exception of porosity and hydrophilicity. In order to achieve adequate porosity and hydrophilicity, bulk functionalization of polyamide 46 with different reagents was performed. These procedures changed the configuration from dense planar to spherical, resulting in increased porosity. Hydroxyethylation of the changed membranes increased the surface tension from 11.2 to 44.6 mJ/m2. The enhanced hydrophilicity of PA 46 resulted in high productivity of biogas formation in a compact MBR, due to diminished biofouling. Copolymerization of hydrophilized polyamide 46 with hydroxymethyl 3,4-ethylenedioxythiophene revealed electroconductivity and hydrophilic properties, adequate for use in MBRs. To find either the maximal pH stability or the surface charge of the membranes having undergone carboxymethylation, polarity and the isoelectric point (pI) of the treated membranes were studied by means of a Zeta analyzer. The hydroxylated PA 46 was finally employed in a multilayer membrane bioreactor and compared with hydrophobic polyamide and PVDF membranes. The resulting biogas production showed that the hydroxylated PA 46 membrane was, after 18 days without regeneration, fully comparable with PVDF membranes.

  • 38.
    Bashir, Tariq
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Bakare, Fatimat
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Baghaei, Behnaz
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Mehrjerdi, Adib Kalantar
    Skrifvars, Mikael
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Influence of different organic solvents and oxidants on insulating and film-forming properties of PEDOT polymer2013Ingår i: Iranian polymer journal, ISSN 1026-1265, E-ISSN 1735-5265, Vol. 22, nr 8, s. 599-611Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Processing of conjugate polymers has always been a challenge because of their poor solubility and infusibility in organic and inorganic solvents. The processibility and applications of intrinsically conductive polymers (ICPs) can be enhanced by producing their solutions or dispersions in different suitable solvents. It can also be achieved by preparing un-doped or electrically neutral polymers, which can further be transformed in semiconductor after oxidation/reduction reaction. The present study focuses on the preparation of active dispersions of poly (3,4-ethylenedioxythiophene) (PEDOT) conductive polymer in various organic solvents. For this purpose, the polymerization of 3,4-ethylenedioxythiophene (EDOT) monomer was carried out in three different organic solvents, ethanol, 1-butanol and acetonitrile with two commonly used oxidants, ferric (III) chloride (FeCl3) and ferric (III) p-toluenesulfonate (FepTS). In this regard, the oxidant and monomer solutions with variable molar concentrations (0.25, 0.5, 1.0 M) were prepared in particular solvents and then these solutions were mixed with different monomer/oxidant volume ratios. The obtained dispersions of PEDOT can readily be polymerized on the surface of different materials after solvent evaporation and a uniform film can be achieved. The effect of molar as well as volume concentrations of EDOT monomer and oxidant on insulating (undoped/neutral) and film forming properties of PEDOT was investigated. These dispersions were applied on a transparent PET film and cellulosic fibers (viscose), dried at room temperature and analyzed using scanning electron microscope (SEM), optical microscope and ATR-FTIR spectroscopic analysis. The electrical characterization of undoped PEDOT-coated fibers was performed on Keithly picoammeter. This study contributes to obtain a simpler and instantaneous polymerization method of PEDOT preparation and to enhance its application area.

  • 39.
    Bashir, Tariq
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Fast, Lars
    Skrifvars, Mikael
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Persson, Nils-Krister
    Högskolan i Borås, Institutionen Textilhögskolan.
    Electrical Resistance Measurement Methods and Electrical Characterization of Poly(3,4-ethylenedioxythiophene)- Coated Conductive Fibers2012Ingår i: Journal of Applied Polymer Science, ISSN 0021-8995, E-ISSN 1097-4628, Vol. 124, nr 4, s. 2954-2961Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Textile fibers and yarns of high conductivity, and their integration into wearable textiles for different electronic applications, have become an important research field for many research groups throughout the world. We have produced novel electrically conductive textile yarns by vapor-phase polymerization (VPP) of a conjugated polymer, poly(3,4-ethylenedioxythiophene) (PEDOT), on the surface of commercially available textile yarns (viscose). In this article, we have presented a novel setup for electrical resistance measurements, which can be used not only for fibrous structures but also for woven structures of specific dimensions. We have reported a two-point resistance- measuring method using an already manufactured setup and also a comparison with the conventionally used method (so-called crocodile clip method). We found that the electrical properties of PEDOT-coated viscose fibers strongly depend on the concentration of oxidant (FeCl3)and the doping (oxidation) process of PEDOT. To evaluate the results, we used mass specific resistance values of PEDOT-coated viscose yarns instead of normal surface resistance values. The voltage–current (V–I) characteristics support the ohmic behavior of coated fibers to some extent. Monitoring of the charging effect of the flow of current through conductive fibers for prolonged periods of time showed that conductivity remains constant. The change in electrical resistance values with increase in the length of coated fibers was also reported. The resistance measuring setup employed could also be used for continuous measurement of resistance in the production of conductive fibers, as well as for four-point resistance measurement.

  • 40.
    Bashir, Tariq
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Skrifvars, M.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Persson, N-K.
    [external].
    Functionalization of textile yarns by coating with conjugated polymer (PEDOT) for smart textile applications2012Konferensbidrag (Övrigt vetenskapligt)
  • 41.
    Bashir, Tariq
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Skrifvars, Mikael
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Persson, Nils-Krister
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    High-strength electrically conductive fibers: functionalization of polyamide, aramid and polyester fibers with PEDOT polymer2017Ingår i: Polymers for Advanced Technologies, ISSN 1042-7147, E-ISSN 1099-1581, Vol. 29, nr 1, s. 310-318, artikel-id 10.1002/pat.4116Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this work, high-performance fibers such as aramid (Twaron), polyamide (PA6), polyester (PET), and hybrid Twaron/PA6 fibers were transformed into electroactive fibers by coating them with conjugated polymer, poly(3,4-ethylenedioxythiophene) (PEDOT) through vapor phase polymerization (VPP) method. The VPP is considered as an efficient technique for depositing CPs on different substrates regardless of their lower solubility in various solvents. In this paper, PEDOT-coated high-performance fibers were prepared under already optimized reaction conditions, and then a comparison between electrical, thermal, and mechanical properties of different fibers, before and after coating, was made. The obtained coated fibers were characterized through scanning electron microscope (SEM), thermogravimetric analysis (TGA), 2-probe electrical resistance measurement method, and tensile testing. It was revealed that at particular reaction conditions, all high performance textile substrates were successfully converted into electroactive fibers. The voltage-current (V-I) characteristics showed that PEDOT-coated polyester fibers exhibited highest conductivity value among all other substrate fibers. The active PEDOT layers on high performance fibers could behave as an antistatic coating to minimize the risks associated with static charges at work places. Also, the obtained fibers have potential to be used as smart materials for various medical, sports, and military applications.

  • 42.
    Bashir, Tariq
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Skrifvars, Mikael
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Persson, Nils-Krister
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Production of conductive yarns by chemical vapour deposition technique of PEDOT viscose fibres2010Konferensbidrag (Refereegranskat)
  • 43.
    Bashir, Tariq
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Skrifvars, Mikael
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Persson, Nils-Krister
    Surface Modification of Conductive PEDOT Coated Textile Yarns with Silicone Resin2011Ingår i: Materials technology (New York, N.Y.), ISSN 1066-7857, E-ISSN 1753-5557, Vol. 26, nr 3, s. 135-139Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Electroactive textile fibres and fabrics have been used in smart and interactive clothing for medical,military and sports applications. The improved surface properties of conductive textiles are required for their successful integration in all of the above mentioned applications. This paper presents the production of conductive poly(3,4-ethylenedioxythiophene) (PEDOT) coated viscose yarns in longer length, i.e. 5 m, and the surface modification of the coated yarns by treating with silicone solution. The structural properties of silicone coated conductive yarns were then investigated by Fourier transform infrared spectroscopy and thermogravimetric analysis. The effect of silicone coating on the mechanical, electrical and hydrophobic properties was also evaluated and then compared with the PEDOT coated viscose yarns without surface treatment. Results show that the mechanical and hydrophobic properties of conductive yarns were improved by surface modification with silicone without affecting their structural properties. The surface modified PEDOT coated yarns could be used as pressure and stretch sensors in health care applications.

  • 44.
    Bengtsson, Magnus
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Modelling energy and size distribution in cone crushers2019Ingår i: Minerals Engineering, Vol. 139Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The modelling of breakage in compression breakage has traditionally been done using population balance modelling, and the research has been developed over the last decades into advanced dynamic models. This paper presents a model for predicting particle size distribution and energy consumption. The particle size distribution model is derived using a first-order differential equation for how the coefficient of variance depends on the compression length. The coefficient of variance model is combined with a bimodal Weibull distribution to predict the cumulative size distribution. The power consumption is modelled in a similar way using Weibull analysis to determine the relationship between power consumption and the coefficient of variance.

  • 45.
    Berggren Torell, Viveka
    Högskolan i Borås, Institutionen Textilhögskolan.
    "It must be a little more close fitting...: On football clothes' contributions to constructions of femininity2012Konferensbidrag (Övrigt vetenskapligt)
  • 46.
    Berggren Torell, Viveka
    et al.
    Högskolan i Borås, Institutionen Textilhögskolan.
    Knuts, Eva
    Soft, colorful and unique2012Konferensbidrag (Övrigt vetenskapligt)
  • 47.
    Bergmark Giesler, Linn
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Abrahamsson, Anna
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Trådlös laddning med en textil: Kan en broderad spole möjliggöra induktionsladdning av en mobiltelefon?2019Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    The development of electronic textiles has increased significantly during the last ten years. By integrating electronic components or using conductive thread you can create textiles with different technical functions. CEVT is a innovation company within the automotive industry who have gained interest in electronic textiles. The department of innovation want to explore the possibility to integrate electronic textiles into future cars. The mission they have assigned us is a sub-goal in a larger end goal in which we will investigate whether one can develope a textile that can charge a phone wirelessly. To do this, a textile transmitter coil must be produced to enable the induction charging, which is what wireless charging really means. The method that was chosen to produce the textile transmitter coil was embroidery and the conductive thread that was used was a silver plated polyamide thread (HC12) from Sheildex. The thread had a resistance of <100 Ω per meter and some difficulties arose early on, where the resistance of the embroidered coil was to high. To reduce the resistance multiple stitches were sewn together and the conductive thread was also used as a lower thread. The resistance of the final coil had an average of almost 15 Ω which was significantly higher than desired. Tests were made to measure the inductive capability of the embroidered coil. This was done by measuring the power transmission between an embroidered coil and a Samsung Galaxy s8 reciever coil. The results showed that a power transmission was enabled, which means that it works. Though the power transmission was a lot lower when compaired to a commercial transmitter coil that was tested at the same time. The project did not result in a fabric that could wirelessly charge a mobile phone. Nevertheless, the test results showed that it is possible, since a power transmission did occur between the textile coil and the coil from the Samsung. Further research and optimization of the textile coil would be required to realize the induction charging textile. Two interesting ways to go would be by using another embroidery technique called Fibre Tailored Placement (FTP) or by developing a new conductive embroidery thread, with a lower resistance.

  • 48. Bergström, Jenny
    et al.
    Clark, Brendon
    Frigo, Alberto
    Mazé, Ramia
    Redström, Johan
    Vallgårda, Anna
    Högskolan i Borås, Institutionen Textilhögskolan.
    Becoming materials: material forms and forms of practice2010Ingår i: Digital Creativity, ISSN 1462-6268, E-ISSN 1744-3806, Vol. 21, nr 3, s. 155-172Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    As a result of development toward ‘smart’ materials, materials now enable an expanding range of aesthetic expressions and user experiences. These materials are fundamentally temporal in their capacity to assume multiple, discrete states of expression that can be repeatedly and minutely controlled. These materials come to be, or become, only over time and in context—they are becoming materials. Thus, in the development and application of such materials, we must engage more extensively with the experience of materials in practices of design and of use. This paper introduces and discusses the concept of becoming materials—as well as the implications for practice—through a series of examples from our own practice-led research within art, design and architecture. Coming to terms with the implications for material practices of design and of use, we suggest, requires the development of new concepts and methods for doing and studying the design of becoming materials.

  • 49. Billig, S.
    et al.
    Agrawal, P.B.
    Birkemeyer, C.
    Nierstrasz, Vincent
    Högskolan i Borås, Institutionen Textilhögskolan.
    Warmoeskerken, M.M.C.G.
    Zimmerman, W.
    Biodegradation of diverse PET materials by polyester hydrolases from Thermobifida fusca and Fusarium solani2014Konferensbidrag (Refereegranskat)
  • 50.
    Biswas, Tuser
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Infirri, Rosalinda Sardo
    Hagman, Susanna
    Berglin, Lena
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    An assistive sleeping bag for children with autism spectrum disorder2018Ingår i: Fashion and Textiles, ISSN 2198-0802, Vol. 5, nr 1, artikel-id 18Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Children suffering from autism spectrum disorder are often reported to encounter sleeping disorder several causes such as hypersensitivity as a result of irregular brain and muscle functions. Disturbance in sleep affects not only their health but also daytime activities including the risk of other cognitive and behavioral impairments. Such hindrance in sleep has been demonstrated to treat therapeutically by measures like the application of deep pressure touch and full body vibration which can be beneficially integrated into the sleeping environment such as on the textile-based platform around the bed. With such a vision, this pilot design project aimed to develop a smart textile based sleeping bag incorporated with sensors to detect awakening stage of the child and thereby actuating stimuli for assuaging the child to fall asleep. To serve the purpose, a micro-controllable body movement detection sensor, based on conductive yarns connected to a vibrating motor was prosperously embedded at the interior of the sleeping bag along with weighted slots to exert deep touch and soothing sensation in the form of wearable technology.

1234567 1 - 50 av 404
RefereraExporteraLänk till träfflistan
Permanent länk
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf