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  • 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
    University of Borås, Faculty of Textiles, Engineering and Business.
    Björlin, Anders
    Kiwok AB.
    Östlund, Anders
    Kiwok AB.
    Seoane, Fernando
    University of Borås, Faculty of Caring Science, Work Life and Social Welfare. KTH-School of Technology and Health.
    Lindecrantz, Kaj
    KTH-School of Technology and Health.
    Textile-Electronic Integration in Wearable Measurement Garments for Pervasive Healthcare Monitoring2015Conference paper (Other academic)
  • 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
    University of Borås, Faculty of Textiles, Engineering and Business.
    Seoane, Fernando
    University of Borås, Faculty of Caring Science, Work Life and Social Welfare. KTH-School of Technology and Health.
    A Knitted Garment using Intarsia Technique for Heart Rate Variability Biofeedback: Evaluation of Initial Prototype.2015Conference paper (Other academic)
  • 3. Abylaev, Mansur
    Kyrgyz textile companies’ resilience features in the post-Soviet regionalization processes2013Conference paper (Refereed)
    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.

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  • 4.
    Adekunle, K.
    et al.
    University of Borås, School of Engineering.
    Cho, S.-W.
    University of Borås, School of Engineering.
    Ketzscher, R.
    Skrifvars, M.
    University of Borås, School of Engineering.
    Mechanical properties of natural fiber hybrid composites based on renewable thermoset resins derived from soybean oil, for use in technical applications2012In: Journal of Applied Polymer Science, ISSN 0021-8995, E-ISSN 1097-4628, Vol. 124, no 6, p. 4530-4541Article in journal (Refereed)
    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.
    University of Borås, School of Engineering.
    Cho, S.-W.
    University of Borås, School of Engineering.
    Patzelt, C.
    Blomfeldt, T.
    Skrifvars, M.
    University of Borås, School of Engineering.
    Impact and flexural properties of flax fabrics and Lyocell Fiber reinforced bio-based thermoset for automotive and structural applications2012Conference paper (Refereed)
  • 6.
    Adekunle, K.
    et al.
    University of Borås, School of Engineering.
    Ghoreishi, R.
    Ehsani, M.
    Cho, S.-W.
    University of Borås, School of Engineering.
    Skrifvars, M.
    University of Borås, School of Engineering.
    Jute fiber reinforced methacrylated soy bean oil based thermoset composites prepared by vacuum injection molding technique2012In: Journal of Biobased Materials and Bioenergy, ISSN 1556-6560, E-ISSN 1556-6579, Vol. 6, no 2, p. 172-177Article in journal (Refereed)
    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
    University of Borås, School of Engineering.
    Bio-based Composites from Soybean Oil Thermosets and Natural Fibers2011Doctoral thesis, comprehensive summary (Other academic)
    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.

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  • 8.
    Adekunle, Kayode
    et al.
    University of Borås, School of Engineering.
    Patzelt, Christian
    Kalantar, Adib
    University of Borås, School of Engineering.
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Mechanical and Viscoelastic Properties of Soybean Oil Thermoset Reinforced with Jute Fabrics and Carded Lyocell Fiber2011In: Journal of Applied Polymer Science, ISSN 0021-8995, E-ISSN 1097-4628, Vol. 122, no 5, p. 2855-2863Article in journal (Refereed)
    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.

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  • 9.
    Adekunle, Kayode
    et al.
    University of Borås, School of Engineering.
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Synthesis of reactive soybean oils for use as thermoset resins in composites.2007Conference paper (Refereed)
  • 10.
    Adekunle, Kayode
    et al.
    University of Borås, School of Engineering.
    Åkesson, Dan
    University of Borås, School of Engineering.
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Synthesis of reactive soybean oils for use as biobased thermoset resins in structural natural fibre composites2008Conference paper (Refereed)
  • 11.
    Adekunle, Kayode
    et al.
    University of Borås, School of Engineering.
    Åkesson, Dan
    University of Borås, School of Engineering.
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Synthetic modification of reactive soybean oils for use as biobased thermoset resins in structural natural fiber composites2008Conference paper (Other academic)
  • 12.
    Adekunle, Kayode
    et al.
    University of Borås, School of Engineering.
    Åkesson, Dan
    University of Borås, School of Engineering.
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Synthetic modification of reactive soybean oils for use as biobased thermoset resins in structural natural fiber composites2008In: Polymer Preprints, ISSN 0551-4657, Vol. 49, no 1, p. 279-Article in journal (Refereed)
  • 13.
    Adelsten, Tiffany Min
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Gakic, Sevala
    University of Borås, Faculty of Textiles, Engineering and Business.
    Minska styvheten och öka stickbarheten för pappersgarn tvinnat med viskosgarn2022Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    To achieve the Global Goals 2030, we as a society will need to significantly reduce our global ecological footprint. The textile industry of today accounts for a significant part of this ecological footprint both through use of land, climate-affecting emissions, soil- and water pollution and more. This has led to an increasing demand for more sustainable solutions in the textile industry. There are a number of types of yarn that have a lower environmental impact. Many of them however have quite a lower market share today. One of these materials that we chose to take a closer look at was paper yarn, which in it’s production consumes significantly less resources than other usual yarns on the market (Fakirov 2015). However, the development of use of paper yarn has so far been limited by its rigidity and poor knitability. This project has aimed to try to reduce the stiffness of the paper yarn and increase its knitability. This was done by twisting different numbers of twist/meter of viscose yarn, around the paper yarn. We twisted a single-threaded 17 tex hemp viscose yarn around the paper yarn at 100, 300 and 500 twist/meter with the core-spun method. Then the yarn was treated with fatty acid to counteract the brittleness and prepare it for knitting. The yarn was knitted on a circular knitting machine with a single jersey stitch. Tests done on yarn were tensile testing and friction testing. The tricot also was subjected to tensile testing (rupture), stiffness testing and abrasion testing. Viscose mixed yarn knitwear was found to have a softer feeling of the fabric compared to just knitted paper yarn. During tensile testing of tricot, it was found that a larger proportion of viscose adds more strength as higher pressure was needed as well as time to achieve a stretch in the tricot. Twisting with different twists of viscose yarn has been shown to cause small differences in knitability as there were occasional holes in the paper yarn knit during the knitting process. Yarns of 300 and 500 twist/meter, however, had the most weak points without showing visible holes on the fabric. Differences in the stiffness of the tricot were noticeable between all the fabrics, however, it was not possible to obtain useful results from the stiffness tester as this test method was probably unsuitable for the selected tricot binding because the fabric rolled. 

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  • 14.
    Agnhage, Tove
    University of Borås, Faculty of Textiles, Engineering and Business. University Lille 1, France; Soochow University, China.
    Eco-designed functionalization of polyester fabric2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    There is an increased awareness of the textile dyeing and finishing sector’s high impact on the environment due to high water consumption, polluted wastewater, and inefficient use of energy. To reduce environmental impacts, researchers propose the use of dyes from natural sources. The purpose of using these is to impart new attributes to textiles without compromising on environmental sustainability. The attributes given to the textile can be color and/or other characteristics. A drawback however, is that the use of bio-sourced dyes is not free from environmental concerns. Thus, it becomes paramount to assess the environmental impacts from using them and improve the environmental profile, but studies on this topic are generally absent.

    The research presented in this thesis has included environmental impact assessment, using the life cycle assessment (LCA) tool, in the design process of a multifunctional polyester (PET) fabric using natural anthraquinones. By doing so an eco-design approach has been applied, with the intention to pave the way towards eco-sustainable bio-functionalization of textiles.

    The anthraquinones were obtained from the root extracts of the madder plant (Rubia tinctorum L.), referred to as madder dye. The research questions were therefore formulated related to the use of madder dye. Three research questions have been answered: (I) Can madder dye serve as a multifunctional species onto a PET woven fabric? (II) How does the environmental profile of the dyeing process of PET with madder dye look like, and how can it be improved? (III) What are the main challenges in using LCA to assess the environmental impacts of textile dyeing with plant-based dyes?

    It is concluded that there is a potential for the madder dye to serve as a multifunctional species onto PET. Based on the encouraging result, a recommendation for future work would be to focus on the durability of the functionalities presented and their improvement potential, both in exhaustion dyeing and pad-dyeing. LCA driven process optimization of the exhaustion dyeing enabled improvement in every impact category studied. However, several challenges have been identified which need to be overcome for the LCA to contribute to the sustainable use of multifunctional plant-based species in textile dyeing. The main challenges are the lack of available data at the research stage and the interdisciplinary nature of the research arena. It is envisaged that if these challenges are addressed, LCA can contribute towards sustainable bio-functionalization of textiles. 

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    spikblad
  • 15.
    Agnhage, Tove
    et al.
    University of Borås, Swedish School of Textiles.
    Nierstrasz, Vincent
    University of Borås, Swedish School of Textiles.
    Perwuelz, A.
    Guan, J.P.
    Chen, G.Q.
    Eco-design innovative methods for fabric finishing2014Conference paper (Other academic)
  • 16.
    Ainamo, Antti
    University of Borås, Swedish School of Textiles.
    Rethinking design fashion: New materiality, smart products, and upcycling2014In: Swedish Design Research Journal, ISSN 2000-964X, Vol. 12, no 2, p. 53-60Article in journal (Refereed)
    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.

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  • 17.
    Akintunde, Moyinoluwa
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business. Department of Microbiology, University of Ibadan, Ibadan, Nigeria.
    Adebayo-Tayo, B C
    Department of Microbiology, University of Ibadan, Ibadan, Nigeria.
    Ishola, M M
    Department of Energy and Environment, Göteborg Energi, Gothenburg, Sweden.
    Zamani, Akram
    University of Borås, Faculty of Textiles, Engineering and Business.
    Sárvári Horváth, Ilona
    University of Borås, Faculty of Textiles, Engineering and Business.
    Bacterial Cellulose Production from agricultural Residues by two Komagataeibacter sp. Strains2022In: Bioengineered, ISSN 2165-5979, E-ISSN 2165-5987, Vol. 13, no 4, p. 10010-10025Article in journal (Refereed)
    Abstract [en]

    Agricultural residues are constantly increasing with increased farming processes, and improper disposal is detrimental to the environment. Majority of these waste residues are rich in lignocellulose, which makes them suitable substrate for bacterial fermentation in the production of valueadded products. In this study, bacterial cellulose (BC), a purer and better form of cellulose, was produced by two Komagataeibacter sp. isolated from rotten banana and kombucha drink using corncob (CC) and sugarcane bagasse (SCB) enzymatic hydrolyzate, under different fermentation conditions, that is, static, continuous, and intermittent agitation. The physicochemical and mechanical properties of the BC films were then investigated by Fourier Transformed Infrared Spectroscopy (FTIR), Thermogravimetry analysis, Field Emission Scanning Electron Microscopy (FESEM), and Dynamic mechanical analysis. Agitation gave a higher BC yield, with Komagataeibacter sp. CCUG73629 producing BC from CC with a dry weight of 1.6 g/L and 1.4 g/L under continuous and intermittent agitation, respectively, compared with that of 0.9 g/L in HS medium. While BC yield of dry weight up to 1.2 g/L was obtained from SCB by Komagataeibacter sp. CCUG73630 under continuous agitation compared to that of 0.3 g/L in HS medium. FTIR analysis showed BC bands associated with cellulose I, with high thermal stability. The FE-SEM analysis showed that BC fibers were highly ordered and densely packed. Although the BC produced by both strains showed similar physicochemical and morphological properties, the BC produced by the Komagataeibacter sp. CCUG73630 in CC under intermittent agitation had the best modulus of elasticity, 10.8 GPa and tensile strength, 70.9 MPa. [GRAPHICS]

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  • 18. Ali, Majid
    et al.
    Bashir, Tariq
    University of Borås, School of Engineering.
    Persson, Nils-Krister
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Optimization of oCVD Process for the Production of Conductive Fibers2011Conference paper (Other academic)
    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.

  • 19. Ali, Majid
    et al.
    Bashir, Tariq
    University of Borås, School of Engineering.
    Persson, Nils-Krister
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Stretch Sensing Properties of PEDOT Coated Conductive Yarns Produced by OCVD Process2011Conference paper (Refereed)
  • 20.
    Alvelind, Cornelia
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Gustafsson, Britta
    University of Borås, Faculty of Textiles, Engineering and Business.
    Kvinnors rättigheter: En studie om arbetsförhållanden inom textilindustrin2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Today, the majority of the employees working in the textile industry are women. Long days, low wages, poor working conditions and oppressive cultural norms are just a few of the factors that contribute to violations against the rights of these women every day. This paper aims to highlight the working conditions of these women and examine possible solutions to improve their living conditions. Reviews of previously conducted research finds that social responsibility is discussed in relation to the human rights, furthermore, there is a lack of clear focus on female rights implemented in the industry. The empirical investigation of this study is based on a combination of literature reviews and qualitative interviews in addition to analysis of printed and visual material. The literature study provided three different focus areas: the stakeholder theory, human rights and cultural differences, found essential to the subject of improving women’s working conditions which were used to develop a model of analysis. Additional empirical investigations were applied in the process of gaining a better understanding of the conditions of the women working in the industry as well as foundation for further discussion of possible improvements. The result of this study is presented through an analysis regarding how women’s rights and the poor working conditions in the textile industry can be improved, as well as suggestions on how operators can utilize this information to achieve these goals. This study confirms that serious shortcomings regarding the working conditions of women exists in the textile industry but also that there are possible means to improve them.

  • 21.
    Andersson, Bengt-Åke
    et al.
    University of Borås, School of Engineering.
    Johansson, Andreas
    University of Borås, School of Engineering.
    Förbränning och termiska system för hållbar utveckling2009In: Vetenskap för profession, ISSN 1654-6520, no 10, p. 79-81Article in journal (Other academic)
  • 22.
    Aronsson, Julia
    University of Borås, Faculty of Textiles, Engineering and Business.
    Torn to be worn?: Cotton fibre length of shredded post-consumer garments2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    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. 

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  • 23. Aronsson, Julia
    et al.
    Persson, Anders
    University of Borås, Faculty of Textiles, Engineering and Business. The Swedish School of Textiles.
    Tearing of post-consumer cotton T-shirts and jeans of varying degree of wear2020In: Journal of Engineered Fibers and Fabrics, E-ISSN 1558-9250, Vol. 15, p. 1-9Article in journal (Refereed)
    Abstract [en]

    The demand for textile fibres is growing quickly. However, global cotton production has stabilized around 25 Mton/year. This is a sound development since cotton cultivation causes major sustainable development issues. Even if regenerated cellulose fibre production steadily grows, it is still only from a sixth to a fifth of cotton volumes. Hence, it is essential to find resource-efficient routes to generate alternatives to virgin cotton. There are many promising research initiatives that discover the possibility to utilize waste streams of neat cotton and cotton in fibre blends as raw materials for dissolving pulp for regeneration into, for example, viscose or Lyocell. However, there is a much simpler and energy-efficient route at hand. If fabrics are disintegrated mechanically, the separated fibres can be turned into yarn again. However, since fibre length is a key parameter to accomplish strong and durable textiles, fibre length loss upon tearing should be minimized. This study evaluates how fibre length distribution alters upon tearing of post-consumer cotton waste of two different constructions: denim and single jersey; and different degrees of wear, rendering four different fractions: (1) barely worn denim, (2) rather worn denim, (3) barely worn single-jersey and (4) rather worn single-jersey. Before tearing, the garments were dissembled, their yarns were characterized, fibre length distributions were manually determined for (1)–(4). Length analysis of the recovered fibres after tearing revealed that the length drop was most severe for (a) the finer single-jersey and (b) the barely worn fractions. The findings suggest that significant wear does not exclude from mechanical recycling.

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  • 24. Arshad, Khubaib
    et al.
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Vivod, Vera
    Valh, Julija
    Voncina, Bojana
    Biodegradation of natural textile materials in soil2014In: Tekstilec, ISSN 0351-3386, Vol. 57, no 2, p. 118-132Article in journal (Refereed)
    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

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  • 25.
    Artur, Cavaco-Paulo
    et al.
    University of Minho, Braga, Portugal.
    Nierstrasz, VincentUniversity of Borås, Faculty of Textiles, Engineering and Business.Wang, QiangJiangnan University, Wuxi, China.
    Advances in Textile Biotechnology 2nd Edition2019Collection (editor) (Refereed)
    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

  • 26.
    Arya, Mina
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business. Faculty of Textiles, Engineering and Business (Swedish Centre for Resource Recovery), University of Borås, 510 90 Borås, Sweden.
    Malmek, Else-Marie
    Juteborg AB, 426 79 Västra Frölunda, Sweden.
    Ecoist, Thomas Koch
    Ecoist AB, 262 72 Ängelholm, Sweden.
    Pettersson, Jocke
    RISE Research Institutes of Sweden, 431 53 Mölndal, Sweden.
    Skrifvars, Mikael
    University of Borås, Faculty of Textiles, Engineering and Business. Faculty of Textiles, Engineering and Business (Swedish Centre for Resource Recovery), University of Borås, 510 90 Borås, Sweden.
    Khalili, Pooria
    University of Borås, Faculty of Textiles, Engineering and Business. Faculty of Textiles, Engineering and Business (Swedish Centre for Resource Recovery), University of Borås, 510 90 Borås, Sweden.
    Enhancing Sustainability: Jute Fiber-Reinforced Bio-Based Sandwich Composites for Use in Battery Boxes2023In: Polymers, E-ISSN 2073-4360, Vol. 15, no 18, article id 3842Article in journal (Refereed)
    Abstract [en]

    The rising industrial demand for environmentally friendly and sustainable materials has shifted the attention from synthetic to natural fibers. Natural fibers provide advantages like affordability, lightweight nature, and renewability. Jute fibers’ substantial production potential and cost-efficiency have propelled current research in this field. In this study, the mechanical behavior (tensile, flexural, and interlaminar shear properties) of plasma-treated jute composite laminates and the flexural behavior of jute fabric-reinforced sandwich composites were investigated. Non-woven mat fiber (MFC), jute fiber (JFC), dried jute fiber (DJFC), and plasma-treated jute fiber (TJFC) composite laminates, as well as sandwich composites consisting of jute fabric bio-based unsaturated polyester (UPE) composite as facing material and polyethylene terephthalate (PET70 and PET100) and polyvinyl chloride (PVC) as core materials were fabricated to compare their functional properties. Plasma treatment of jute composite laminate had a positive effect on some of the mechanical properties, which led to an improvement in Young’s modulus (7.17 GPa) and tensile strength (53.61 MPa) of 14% and 8.5%, respectively, as well as, in flexural strength (93.71 MPa) and flexural modulus (5.20 GPa) of 24% and 35%, respectively, compared to those of JFC. In addition, the results demonstrated that the flexural properties of jute sandwich composites can be significantly enhanced by incorporating PET100 foams as core materials. 

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  • 27.
    Asadi, Milad
    University of Borås, Faculty of Textiles, Engineering and Business.
    Graphene: a vision to the future of smart E-Textile application2022Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Smart textile is a term referring to the textiles that could interact with their environment, receiving input and giving output based on their applications. Among smart textiles, electrically driven smart textiles (E-textiles) are being produced by various methods and materials integrated with textile substances. Graphene is one of these compounds that could be integrated into the polymer or integrated into the textile materials such as fibres. Therefore, other elements could be doped or immobilised on the graphene nanosheets for a wider range of applications, such as catalytic and electrocatalytic systems.  

    However, finding the most applicable and efficient method to integrate graphene into the textile fibres and further establishing a method for catalyst immobilisation are challenging and require focused research.  

    Therefore, this doctoral thesis focused on the innovative concept of integration of graphene and immobilisation of iron nanoparticles on it. Evidence from the systematic experiments was gathered for the case of dip-coating of polyester textiles with graphene oxide dispersion and enhancing the electrostatic bonding between fibres and graphene oxide nanosheets. In the second step, systematic experiments were gathered for the case of immobilisation of an inorganic catalyst (zerovalent iron) on textile supports. The goal of this thesis is to establish the feasibility of a mild and applicable method for textile material supports, which requires low temperature and mild pH, and further fabrication of heterogeneous catalytic and electrocatalytic systems for wastewater treatment. Polyester was chosen as the textile support material for graphene oxide coating and catalyst immobilisation due to its availability and cost-effectiveness.  

    The thesis has four distinct parts related to (a) Pre-surface-charge modification of the polyester for strong electrostatic bonding between polyester and graphene, (b) Design a continuous yarn coating system for mass production of graphene-coated conductive yarns, (c) Immobilisation of Fe0 on graphene-coated polyester textiles and optimising their feasibility in catalytic systems and (d) Design and prove the feasibility of knitting a fully textile-based reactor having two anodic and cathodic sections by using rGO-Fe0 yarns and stainless-steel multifilament yarns, respectively as a concept of electro-Fenton wastewater treatment.  

    Diverse analytical and instrumental techniques were used to monitor the surface modification of the polyester textiles and conductivity of the resulting textiles; moreover, the electromechanical and electrothermal properties of the graphene-modified textiles were examined. Further, the efficiency of catalyst immobilisation, physio-chemical properties of the immobilised catalyst, and their catalytical activities in dye removal from the water was studied. Results showed that surface charge modification of polyester fabric with both chitosan and hexadecylpyridinium chloride (HDPC) gives the most homogeneous graphene coating, resulting in high conductivity and very good fastness. Furthermore, results from scanning electron microscope (SEM), Differential scanning calorimetry (DSC), and UV/Visible spectrophotometry prove the success of immobilisation of zerovalent iron on the graphene-modified textiles. 

    The novelty of the research presented in this doctoral thesis is primarily attributed to the novelty of a hybrid graphene-catalyst immobilisation-grafting on polyester textile supports for wastewater treatment applications. The final concept of the thesis is to introduce the potential for assembling a fully textile-based reactor for Electro-Fenton wastewater treatments.

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  • 28.
    Asadi, Milad
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Bashir, Tariq
    University of Borås, Faculty of Textiles, Engineering and Business.
    Skrifvars, Mikael
    University of Borås, Faculty of Textiles, Engineering and Business.
    Development of eco-friendly flame retardant polypropylene fibers2017Conference paper (Refereed)
  • 29.
    Asadi, Milad
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Persson, Nils-KristerUniversity of Borås, Faculty of Textiles, Engineering and Business.G Martinez, JoseMehraeen, ShayanEdwin, JagerEscobar, FreddyShazed, Aziz
    Woven and knitted artificial muscles for wearable devices2019Conference proceedings (editor) (Refereed)
    Abstract [en]

    Diseases of the nervous system, traumas, or natural causes can reduce human muscle capacity. Robotic exoskeletons are forthcoming to support the movement of body parts, e.g. assist walking or aid rehabilitation. Current available devices are rigid and driven by electric motors or pneumatic actuators, making them noisy, heavy, stiff and noncompliant. We are developing textile based assistive devices that can be worn like clothing being light, soft, compliant and comfortable. We have merged advanced textile technology with electroactive polymers. By knitting and weaving electroactive yarns, we are developing soft textile actuators ("Knitted Muscles") that can be used in wearable assistive devices. We will present the latest progress increase the performance and to rationalise the fabrication. In addition we will show some demonstrators of the textile exoskeletons.

  • 30.
    Asres, Bersabeh Zemedagegnehu
    University of Borås, Faculty of Textiles, Engineering and Business.
    Viskostygs inverkan på plagg efter tvätt.: Hur krympning av viskos påverkar plaggets passform, mått och konstruktion för en klänning2020Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This study is developed in collaboration with a small company that works with women's clothing. The company has had recurring problems with the fit of their viscose dress. The purpose of the study is to analyze the effect of the viscose material shrinkage after laundering on the fit of the garment such as balance, ease, length and the garment dimension. Viscose is one of the finest textile materials for dresses sewing because of its properties such as it’s fine shine, drapes well and it have high absorbent. In contrast, viscose material tends to lose strength when wet, which affects garment fit due to viscoses shrinkage after laundering. The study is performed through comparing of three production processes of a dress to get the best fit and dimensions. For sample A and B, the same pattern construction is used, except for sample B, the viscose fabric was pre-washed in advance. While for sample C fabric samples was washed and the number of shrinkage is calculated . Pattern construction was adjusted by adding the results of shrinkage . The three sample dresses were sewn with the same viscose fabric, and the fit were tasted by one person in size Medium .The dress samples were measured both before and after laundering. The result of prototype C showed that the dress has shrunk to the best fit and meets the desired garment sizes in comparison with prototypes A and B. The study showed that garments that are sewn in viscose material change both in fit and size after washing. Washing viscose material before cutting will not ensure that the sewn garment will not shrink or that the garments will retain its dimension after washing. The change in pattern design gives better results.

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  • 31.
    Aziz, Shazed
    et al.
    Division of Sensor and Actuator Systems, Department of Physics, Chemistry, and Biology (IFM), Linköping University, Linköping, SE‐581 83 Sweden.
    Martinez, Jose G.
    Division of Sensor and Actuator Systems, Department of Physics, Chemistry, and Biology (IFM), Linköping University, Linköping, SE‐581 83 Sweden.
    Salahuddin, Bidita
    Australian Institute for Innovative Materials, University of Wollongong, Innovation Campus, Squires Way, North Wollongong, NSW, 2522 Australia.
    Persson, Nils-Krister
    University of Borås, Faculty of Textiles, Engineering and Business.
    Jager, Edwin W. H.
    Division of Sensor and Actuator Systems, Department of Physics, Chemistry, and Biology (IFM), Linköping University, Linköping, SE‐581 83 Sweden.
    Fast and High-Strain Electrochemically Driven Yarn Actuators in Twisted and Coiled Configurations2021In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 31, no 10, article id 2008959Article in journal (Refereed)
    Abstract [en]

    Commercially available yarns are promising precursor for artificial muscles for smart fabric-based textile wearables. Electrochemically driven conductive polymer (CP) coated yarns have already shown their potential to be used in smart fabrics. Unfortunately, the practical application of these yarns is still hindered due to their slow ion exchange properties and low strain. Here, a method is demonstrated to morph poly-3,4-ethylenedioxythiophene:poly-styrenesulfonate (PEDOT:PSS) coated multifilament textile yarns in highly twisted and coiled structures, providing >1% linear actuation in <1 s at a potential of +0.6 V. A potential window of +0.6 V and -1.2 V triggers the fully reversible actuation of a coiled yarn providing >1.62% strain. Compared to the untwisted, regular yarns, the twisted and coiled yarns produce >9x and >20x higher strain, respectively. The strain and speed are significantly higher than the maximum reported results from other electrochemically operated CP yarns. The yarn’s actuation is explained by reversible oxidation/reduction reactions occurring at CPs. However, the helical opening/closing of the twisted or coiled yarns due to the torsional yarn untwisting/retwisting assists the rapid and large linear actuation. These PEDOT:PSS coated yarn actuators are of great interest to drive smart textile exoskeletons.

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  • 32.
    Backe, Carin
    University of Borås, Faculty of Textiles, Engineering and Business.
    Enhancing textile electrode performance: Regulating moisture management through textile structure2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    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.

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  • 33.
    Backe, Carin
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Skelte, Gabrielle
    University of Borås, Faculty of Textiles, Engineering and Business.
    Piezoelektriska filament: från garn till textil applikation2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    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.

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  • 34.
    Backe, Carin
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Skelte, Gabrielle
    Rundqvist, Karin
    University of Borås, Faculty of Textiles, Engineering and Business.
    Sandsjö, Leif
    University of Borås, Faculty of Caring Science, Work Life and Social Welfare.
    Persson, Nils-Krister
    University of Borås, Faculty of Textiles, Engineering and Business.
    Piezoelektriska strumpor för rörelsemonitorering - En känslighetsanalys2015In: Abstracts - Medicinteknikdagarna 2015, Svensk förening för medicinsk teknik och fysik , 2015, p. 60-Conference paper (Other academic)
  • 35.
    Baghaei, Behnaz
    University of Borås, Faculty of Textiles, Engineering and Business.
    Development of thermoplastic biocomposites based on aligned hybrid yarns for fast composite manufacturing2015Doctoral thesis, comprehensive summary (Other academic)
    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.

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  • 36.
    Baghaei, Behnaz
    et al.
    University of Borås, School of Engineering.
    Berglin, Lena
    University of Borås, Swedish School of Textiles.
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Tailoring of the mechanical and thermal properties of hemp/PLA hybrid yarn composites2013Conference paper (Other academic)
    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.

  • 37.
    Baghaei, Behnaz
    et al.
    University of Borås, School of Engineering.
    Berglin, Lena
    University of Borås, Swedish School of Textiles.
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Tailoring of the mechanical and thermal properties of hemp/PLA hybrid yarn composites2013Conference paper (Other academic)
    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.

  • 38.
    Baghaei, Behnaz
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Compiet, Sam
    Department of Textile Technology, Faculty of Textiles, Engineering and Business, University of Borås, SE-501 90, Borås, Sweden.
    Skrifvars, Mikael
    University of Borås, Faculty of Textiles, Engineering and Business.
    Mechanical properties of all-cellulose composites from end-of-life textiles2020In: Journal of polymer research, ISSN 1022-9760, E-ISSN 1572-8935, Vol. 27, no 9Article in journal (Refereed)
    Abstract [en]

    This paper reports the recycling of end-of-life cellulose containing textiles by fabrication of all-cellulose composites (ACCs). Discharged denim fabrics were used as the reinforcement while dissolved cellulose from two different cellulose resources was used as the matrix phase. Virgin cotton fibres and recovered cotton from polyester/cotton (polycotton) waste fabrics were used to form the matrix phase. The process comprises preparing a 6 wt% cellulose solution by dissolving cellulose solution in a ionic liquid, 1-butyl-3-methyl imidazolium acetate ([BMIM][Ac]), this solution acted as a precursor for the matrix component. The denim fabrics were first embedded in the cellulose/IL solution followed by removal of the IL by washing to form the composite. The effect of reuse of the recovered IL by distillation was also investigated. The mechanical properties of the obtained ACCs were determined regarding tensile, impact and flexural properties. Fabricated ACC composite laminates were further characterised regarding structure by scanning electron microscopy.

  • 39.
    Baghaei, Behnaz
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Johansson, Belinda
    Skrifvars, Mikael
    University of Borås, Faculty of Textiles, Engineering and Business.
    Kadi, Nawar
    University of Borås, Faculty of Textiles, Engineering and Business.
    All-Cellulose Composites Properties from Pre- and Post-Consumer Denim Wastes: Comparative Study2022In: Journal of Composites Science, E-ISSN 2504-477X, Vol. 6, no 5, article id 130Article in journal (Other (popular science, discussion, etc.))
    Abstract [en]

    This study reports the recycling of discarded denim textiles by the production of all-cellulose composites (ACCs). Discarded denim fabrics were shredded into fibers and then made into nonwoven fabrics by carding and needle punching. The produced nonwoven fabrics were converted to ACCs by one-step and two-step methods using an ionic liquid (IL), 1-butyl-3-methyl imidazolium acetate ([BMIM][Ac]). In this study, the effect of different ACC manufacturing methods, denim fabrics with different contents (a 100% cotton denim (CO) and a blend material (cotton, poly-ester and elastane (BCO)) and reusing of IL as a recycled cellulose solvent on the mechanical pro-perties of the formed ACCs were investigated. The ACCs were characterized according to their tensile and impact properties, as well as their void content. Microscopic analysis was carried out to study the morphology of a cross-section of the formed composites. The choice of the one-step method with recycled IL, pure IL or with a blend material (BCO) had no influence on the tensile properties. Instead, the result showed that the two-step method, with and without DMSO, will influence the E-modulus but not the tensile strength. Regarding the impact properties of the samples, the only factor likely to influence the impact energy was the one-step method with CO and BCO.

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  • 40.
    Baghaei, Behnaz
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business. Högskolan i Borås.
    Skrifvars, Mikael
    University of Borås, Faculty of Textiles, Engineering and Business.
    All-Cellulose Composites: A Review of RecentStudies on Structure, Properties and Applications2020In: Molecules, ISSN 1431-5157, E-ISSN 1420-3049, ISSN 1420-3049, Vol. 25, no 2Article in journal (Refereed)
    Abstract [en]

    Nowadays, there is greater demand for greener materials in societies due to environmental consciousness, depleting fossil fuels and growing ecological concerns. Within the foreseeable future, industries and suppliers will be required to be more aware of challenges faced due to the availability of resources and use more sustainable and renewable raw materials. In this context, cellulose can be expected to become a vital resource for materials owing to its abundance, versatility as a biopolymer, several different forms and potential applications. Thus, all-cellulose composites (ACCs) have gained significant research interest in recent years. ACC is a class of biocomposites in which the matrix is a dissolved and regenerated cellulose, while the reinforcement is undissolved or partly dissolved cellulose. This review paper is intended to provide a brief outline of works that cover recent progress in the manufacturing and processing techniques for ACCs, various cellulose sources, solvents and antisolvents, as well as their properties.

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  • 41.
    Baghaei, Behnaz
    et al.
    University of Borås, School of Engineering.
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Berglin, Lena
    University of Borås, Swedish School of Textiles.
    Hybrid natural fibre reinforcements and prepregs for thermoplastic composites with improved performance and properties2014Conference paper (Other academic)
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  • 42.
    Baghaei, Behnaz
    et al.
    University of Borås, School of Engineering.
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Berglin, Lena
    University of Borås, Swedish School of Textiles.
    Ramamoorthy, Sunil Kumar
    University of Borås, School of Engineering.
    Hemp/PLA Co-Wrapped Hybrid Yarns For Structured Thermoplastic Composites2013Conference paper (Refereed)
    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.

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  • 43.
    Baghaei, Behnaz
    et al.
    University of Borås, School of Engineering.
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Masoud, Salehi
    University of Borås, School of Engineering.
    Aligned hemp yarn reinforced biocomposites: porosity, water absorption, thermal and mechanical properties2014Conference paper (Refereed)
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  • 44.
    Baghaei, Behnaz
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Temmink, Robin
    University of Borås, Faculty of Textiles, Engineering and Business.
    Skrifvars, Mikael
    University of Borås, Faculty of Textiles, Engineering and Business.
    RECYCLING OF END-OF-LIFE TEXTILE MATERIALS BY FABRICATION OF GREEN COMPOSITES2017Conference paper (Refereed)
    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.

  • 45.
    Bakare, Fatimat O.
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Ramamoorthy, Sunil Kumar
    University of Borås, Faculty of Textiles, Engineering and Business.
    Åkesson, Dan
    University of Borås, Faculty of Textiles, Engineering and Business.
    Skrifvars, Mikael
    University of Borås, Faculty of Textiles, Engineering and Business.
    Thermomechanical properties of bio-based composites made from a lactic acid thermoset resin and flax and flax/basalt fibre reinforcements2016In: Composites. Part A, Applied science and manufacturing, ISSN 1359-835X, E-ISSN 1878-5840, Vol. 83, p. 176-184Article in journal (Refereed)
    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.

  • 46.
    Bakare, Fatimat Oluwatoyin
    et al.
    University of Borås, School of Engineering.
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Wang, Yanfei
    Afshar, Shahrzad Javanshir
    Esmaeli, Nima
    Åkesson, Dan
    University of Borås, School of Engineering.
    Morphological and mechanical properties of a biobased composite from a lactic acid based thermoset resin and viscose fiber reinforcement2014Conference paper (Refereed)
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  • 47.
    Bakare, Fatimat Oluwatoyin
    et al.
    University of Borås, School of Engineering.
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Wang, Yanfei
    Afshar, Shahrzad Javanshir
    Esmaeli, Nima
    Åkesson, Dan
    University of Borås, School of Engineering.
    Synthesis and Preparation of Biobased Composites with A Novel Thermoset Resin from Lactic Acid2014Conference paper (Refereed)
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  • 48.
    Barghi, Hamidreza
    University of Borås, School of Engineering.
    Functionalization of Synthetic Polymers for Membrane Bioreactors2014Doctoral thesis, comprehensive summary (Other academic)
    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.

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  • 49.
    Bashir, Tariq
    et al.
    University of Borås, School of Engineering.
    Bakare, Fatimat
    University of Borås, School of Engineering.
    Baghaei, Behnaz
    University of Borås, School of Engineering.
    Mehrjerdi, Adib Kalantar
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Influence of different organic solvents and oxidants on insulating and film-forming properties of PEDOT polymer2013In: Iranian polymer journal, ISSN 1026-1265, E-ISSN 1735-5265, Vol. 22, no 8, p. 599-611Article in journal (Refereed)
    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.

  • 50.
    Bashir, Tariq
    et al.
    University of Borås, School of Engineering.
    Fast, Lars
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Persson, Nils-Krister
    University of Borås, Swedish School of Textiles.
    Electrical Resistance Measurement Methods and Electrical Characterization of Poly(3,4-ethylenedioxythiophene)- Coated Conductive Fibers2012In: Journal of Applied Polymer Science, ISSN 0021-8995, E-ISSN 1097-4628, Vol. 124, no 4, p. 2954-2961Article in journal (Refereed)
    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.

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