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  • 301.
    Ramamoorthy, Sunil Kumar
    et al.
    University of Borås, School of Engineering.
    Kundu, Chanchal Kumar
    Adekunle, Kayode
    University of Borås, School of Engineering.
    Bashir, Tariq
    University of Borås, School of Engineering.
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Regenerated Cellulose Fiber Reinforced Composites2013Conference paper (Refereed)
    Abstract [en]

    Wood pulp based regenerated cellulose fibers like Lyocell and viscose which are from natural origin have high and even quality; used to develop superior composites with good properties. In this project, Lyocell and viscose fibers were reinforced in chemically modified soybean based bio-matrix, acrylated epoxidized soybean oil (AESO) by compression molding technique. The composites are characterized for mechanical performance by tensile, flexural and impact tests, viscoelastic performance by dynamical mechanical thermal analysis (DMTA) and morphological analysis by scanning electron microscopy (SEM). In general, Lyocell composites had better tensile and flexural properties than viscose based composites. The same goes with elastic and viscous response of the composites. Hybrid composites were formed by fiber blending; on addition of Lyocell to viscose based composites improved the properties. The amount of Lyocell and viscose fibers used determined the properties of hybrid composites and the possibility of tailoring properties for specific application was seen. Hybrid composites showed better impact strength. Morphological analysis showed that the viscose composites had small fiber pull out whereas Lyocell composites had few pores. Hybrid composite analysis showed that they had uneven spreading of matrix; delamination occurred on constant heating and cooling. To overcome the above mentioned issue and to reduce the water absorption, surface modification of the fiber was done by alkali treatment and silane treatment. The effect of treatment is done through swelling, water absorption and morphological analysis tests. The properties could be increased on proper modification of the fibers. The results show the good potential of these composites to be used in automotives and construction industries.

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    FULLTEXT01
  • 302.
    Ramamoorthy, Sunil Kumar
    et al.
    University of Borås, School of Engineering.
    Kundu, Chanchal Kumar
    Baghaei, Behnaz
    University of Borås, School of Engineering.
    Adekunle, Kayode
    University of Borås, School of Engineering.
    Bashir, Tariq
    University of Borås, School of Engineering.
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Green Composites Based On Regenerated Cellulose Textile Fibers For Structural Composites2013Conference paper (Refereed)
    Abstract [en]

    Composites were manufactured from regenerated cellulose and biobased matrix by compression molding. The reinforcing materials used were Lyocell and viscose, while the matrix used was chemically modified soybean oil. Hybrid composites were prepared by mixing both the fibers. The total fiber content in the composites was between 40-60 weight %. Lyocell based composites had better tensile properties than viscose based composites; composites consisting 60 weight % Lyocell impregnated with matrix had tensile strength of 135 MPa and tensile modulus of 17 GPa. These composites also showed better flexural properties; flexural strength of 127 MPa and flexural modulus of 7 GPa. Dynamic mechanical thermal analysis results showed that these composites had good viscoelastic properties. Viscose based composites had better percentage elongation; these composites also showed relatively good impact and viscoelastic properties. Hybrid composites showed good mechanical and viscoelastic properties. Scanning electron microscope images showed that the composites had good fiber-matrix adhesion.

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    FULLTEXT01
  • 303.
    Ramamoorthy, Sunil Kumar
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Skrifvars, Mikael
    University of Borås, Faculty of Textiles, Engineering and Business.
    BIOCOMPOSITES FROM SURFACE MODIFIED REGENERATED CELLULOSE FIBERS AND LACTIC ACID THERMOSET BIORESIN2016Conference paper (Refereed)
    Abstract [en]

    Abstract:

    Thermoset bioresin was synthesized from lactic acid and glycerol, and the resin was characterized for it to be used in composite applications. On the other hand, regenerated cellulose fibers were surface treated to improve the physico–chemical interactions at the fiber–matrix interface. The effect of surface treatments, silane and alkali, on regenerated cellulose fibers was studied by using the treated fibers as reinforcement in lactic acid thermoset bioresin. Mechanical tests were used as indicator of the improvement of the interfacial strength. Fiber surface treatments and the effect on adhesion to the matrix were characterized using microscopy images and thermal conductivity. Mechanical properties of the composites showed an increase when treated with silane as the bi-functional silane molecule acts as link between the regenerated cellulose fiber and the bioresin.

    Porosity volume decreased significantly on silane treatment due to improved interface and interlocking between fiber and matrix. Decrease in water absorption and increase in contact angle confirmed the change in the hydrophilicity of the composites. The storage modulus increased when the reinforcements were treated with silane whereas the damping intensity decreased for the same composites indicating a better adhesion between fiber and matrix on silane treatment. Thermogravimetric analysis indicated that the thermal stability of the reinforcement altered after treatments. The resin curing was followed using differential scanning calorimetry and the necessity for post-curing was recommended. Finite element analysis was used to predict the thermal behavior of the composites and a non-destructive resonance analysis was performed to ratify the modulus obtained from tensile testing. The changes were also seen on composites reinforced with alkali treated fiber. Microscopy images confirmed the good adhesion between the silane treated fibers and the resin at the interface.

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    fulltext
  • 304.
    Ramamoorthy, Sunil Kumar
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Skrifvars, Mikael
    University of Borås, Faculty of Textiles, Engineering and Business.
    Persson, Anders
    University of Borås, Faculty of Textiles, Engineering and Business.
    A Review of Natural Fibers Used in Biocomposites: Plant, Animal and Regenerated Cellulose Fibers2015In: Polymer Reviews, ISSN 1558-3724, Vol. 55, no 1, p. 107-162Article in journal (Refereed)
    Abstract [en]

    Natural fibers today are a popular choice for applications in composite manufacturing. Based on the sustainability benefits, biofibers such as plant fibers are replacing synthetic fibers in composites. These fibers are used to manufacture several biocomposites. The chemical composition and properties of each of the fibers changes, which demands the detailed comparison of these fibers. The reinforcement potential of natural fibers and their properties have been described in numerous papers. Today, high performance biocomposites are produced from several years of research. Plant fibers, particularly bast and leaf, find applications in automotive industries. While most of the other fibers are explored in lab scales they have not yet found large-scale commercial applications. It is necessary to also consider other fibers such as ones made from seed (coir) and animals (chicken feather) as they are secondary or made from waste products. Few plant fibers such as bast fibers are often reviewed briefly but other plant and animal fibers are not discussed in detail. This review paper discusses all the six types of plant fibers such as bast, leaf, seed, straw, grass, and wood, together with animal fibers and regenerated cellulose fibers. Additionally, the review considers developments dealing with natural fibers and their composites. The fiber source, extraction, availability, type, composition, and mechanical properties are discussed. The advantages and disadvantages of using each biofiber are discussed. Three fabric architectures such as nonwoven, woven and knitted have been briefly discussed. Finally, the paper presents the overview of the results from the composites made from each fiber with suitable references for in-depth studies.

  • 305.
    Rao, P. V. Kameswara
    et al.
    Indian Institute of Technology Delhi, Hauz Khas, New Delhi, India.
    Rawal, Amit
    Indian Institute of Technology Delhi, Hauz Khas, New Delhi, India; Fraunhofer Institute of Industrial Mathematics (ITWM), Fraunhofer-Platz 1, D-67663 Kaiserslautern, Germany.
    Kumar, Vijay
    University of Borås, Faculty of Textiles, Engineering and Business.
    Rajput, Krishn Gopal
    Indian Institute of Technology Delhi, Hauz Khas, New Delhi, India.
    Compression-recovery model of absorptive glass mat (AGM) separator guided by X-ray micro-computed tomography analysis2017In: Journal of Power Sources, ISSN 0378-7753, E-ISSN 1873-2755, Vol. 365, p. 389-398Article in journal (Refereed)
    Abstract [en]

    Absorptive glass mat (AGM) separators play a key role in enhancing the cycle life of the valve regulated lead acid (VRLA) batteries by maintaining the elastic characteristics under a defined level of compression force with the plates of the electrodes. Inevitably, there are inherent challenges to maintain the required level of compression characteristics of AGM separators during the charge and discharge of the battery. Herein, we report a three-dimensional (3D) analytical model for predicting the compression-recovery behavior of AGM separators by formulating a direct relationship with the constituent fiber and structural parameters. The analytical model of compression-recovery behavior of AGM separators has successfully included the fiber slippage criterion and internal friction losses. The presented work uses, for the first time, 3D data of fiber orientation from X-ray micro-computed tomography, for predicting the compression-recovery behavior of AGM separators. A comparison has been made between the theoretical and experimental results of compression-recovery behavior of AGM samples with defined fiber orientation characteristics. In general, the theory agreed reasonably well with the experimental results of AGM samples in both dry and wet states. Through theoretical modeling, fiber volume fraction was established as one of the key structural parameters that modulates the compression hysteresis of an AGM separator.

  • 306.
    Rawal, Amit
    et al.
    Indian Institute of Technology Delhi, New Delhi, India; Fraunhofer Institute for Industrial Mathematics (ITWM), Kaiserslautern, Germany; Institut für Textil- und Verfahrenstechnik, Denkendorf, Germany.
    Kumar, Vijay
    University of Borås, Faculty of Textiles, Engineering and Business.
    Hietel, Diemtar
    Fraunhofer Institute for Industrial Mathematics (ITWM), Kaiserslautern, Germany.
    Dauner, Martin
    Institut für Textil- und Verfahrenstechnik, Denkendorf, Germany.
    Modulating the Poisson’s ratio of articular cartilage via collagen fibril alignment2017In: Materials letters (General ed.), ISSN 0167-577X, E-ISSN 1873-4979, Vol. 194, p. 45-48Article in journal (Refereed)
    Abstract [en]

    Articular cartilage possesses unique structure and composition giving rise to unusual mechanical behavior. Typically, it is a structurally graded material that displays variation in mechanical properties along the depth. In this communication, the geometrical probability approach has been used for predicting the in-plane Poisson’s ratio in the surface and middle zones of articular cartilage. The presented model has formulated a relationship between the Poisson’s ratio and collagen fibril alignment. A comparison has been made between the theoretical and experimental findings of Poisson’s ratio in the surface and middle zones of human patella cartilage, as obtained from the literature.

  • 307.
    Rawal, Amit
    et al.
    Indian Institute of Technology Delhi; Fraunhofer Institute for Industrial Mathematics (ITWM); Institut für Textil- und Verfahrenstechnik.
    Kumar, Vijay
    University of Borås, Faculty of Textiles, Engineering and Business.
    Saraswat, Harshvardhan
    MLV Textile & Engineering College.
    Weerasinghe, Dakshitha
    Institut für Textil- und Verfahrenstechnik.
    Hietel, Dietmar
    Fraunhofer Institute for Industrial Mathematics (ITWM).
    Dauner, Martin
    Institut für Textil- und Verfahrenstechnik.
    Creating three-dimensional (3D) fiber networks with out-of-plane auxetic behavior over large deformations2017In: Journal of Materials Science, ISSN 0022-2461, E-ISSN 1573-4803, Vol. 52, no 5, p. 2534-2548Article in journal (Refereed)
    Abstract [en]

    Fiber networks with out-of-plane auxetic behavior have been sporadically investigated. One of the major challenges is to design such materials with giant negative Poisson’s ratio over large deformations. Here in, we report a systematic investigation to create three-dimensional (3D) fiber networks in the form of needlepunched nonwoven materials with out-of-plane auxetic behavior over large deformations via theoretical modeling and extensive set of experiments. The experimental matrix has encapsulated the key parameters of the needlepunching nonwoven process. Under uniaxial tensile loading, the anisotropy coupled with local fiber densification in networks has yielded large negative Poisson’s ratio (up to −5.7) specifically in the preferential direction. The in-plane and out-of-plane Poisson’s ratios of fiber networks have been predicted and, subsequently, compared with the experimental results. Fiber orientation was found to be a core parameter that modulated the in-plane Poisson’s ratio of fiber networks. A parametric analysis has revealed the interplay between the anisotropy of the fiber network and the out-of-plane Poisson’s ratio based upon constant volume consideration.

  • 308.
    Sagen, Silje
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Borg, Jenny
    University of Borås, Faculty of Textiles, Engineering and Business.
    Tivell, Sara
    University of Borås, Faculty of Textiles, Engineering and Business.
    Att specificera ullgarn: en jämförande undersökning av ullgarn för mattor2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This study investigates two yarns made of 100 % wool that have been ordered with the same specification but from different suppliers. The yarns are used by a company that produces carpets. During weaving these yarns don’t behave the same and therefore problems have appeared in production. The aim with this study is to investigate why the two yarns behave differently. A literature study has been conducted to assemble information about wool properties and how these can have an affect on different processing steps typical for wool. From these findings it was concluded which tests to perform during this study. Tests that measured tensile properties, moisture content and twist liveliness were first performed on uncoloured yarns. At fiber level the fibre width, length and crimp as well as proportions of medullated fibres were measured. A medullated fibers is a fiber with a bigger core than a regular wool fibre. Tests that showed significant differences were also carried out on coloured yarns to see if the differences remains after dyeing. Together with the test results and information from litteratur it's discussed how differences in parameters are related to the yarn properties and if it's possible to translate these findings into new demands for a yarn specification. These were considered to be fiber width and length specified with both a mean and distribution, proportion of medullated fibres, E-module and to specify the mechanical properties with cN/tex instead of only Newton to get a value that is more true to the variations in wool. It's concluded that the yarns differ sufficiently at fiber level to give them different properties, which shows in the mechanical properties. There is a difference in the two yarns ability to stretch and this can explain problems that arise during weaving. In addition to suggest parameters to specify it's discussed how desiding a standard to follow for measures and how to analyze the results could help to ensure demands in the specification.

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  • 309.
    Sandsjö, Leif
    et al.
    University of Borås, Faculty of Caring Science, Work Life and Social Welfare.
    Ragnerius, Anna
    Signals and Systems/Chalmers.
    Widelund, Frida
    Signals and Systems/Chalmers.
    Candefjord, Stefan
    Signals and Systems/Chalmers.
    Rundqvist, Karin
    University of Borås, Faculty of Textiles, Engineering and Business.
    Nilsson, Erik
    Swerea/IVF.
    Persson, Nils-Krister
    University of Borås, Faculty of Textiles, Engineering and Business.
    A piezoelectric smart textile sock for gait analysis - A feasibility study2016Conference paper (Other academic)
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    Abstract
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    Poster
  • 310.
    Santamala, Harri
    et al.
    Aalto University, School of Engineering, Department of Applied Mechanics.
    Livingston, R
    Aalto University, School of Engineering, Department of Applied Mechanics.
    Sixta, Herbert
    Aalto University, Aalto University, School of Chemistry, Department of Forest Products Technology.
    Hummel, M
    Aalto University, School of Chemistry, Department of Forest Products Technolog.
    Skrifvars, Mikael
    University of Borås, Faculty of Textiles, Engineering and Business.
    Saarela, Olli
    Aalto University, School of Engineering, Department of Applied Mechanics.
    Advantages of regenerated cellulose fibres as compared to flax fibres in the processability and mechanical performance of thermoset composites2016In: Composites Part A: Applied Science and Manufacturing, ISSN 1359-835X, Vol. 84, p. 377-385Article in journal (Refereed)
    Abstract [en]

    Man-made cellulosic fibres (MMCFs) have attracted widespread interest as the next generation of fibre reinforced composite. However, most studies focused entirely on their performance on single fibre level and little attention has been paid to their behaviour on a larger application scale. In this study, MMCFs were utilized as reinforcement in unidirectionally (UD) manufactured thermoset composites and compared to several commercial UD flax fibre products. Specimens were prepared using a vacuum bag based resin infusion technique and the respective laminates characterized in terms of void fraction and mechanical properties. MMCF laminates had comparable or better mechanical performance when compared to flax fibre laminates. Failure mechanisms of MMCF laminates were noted to differ from those of flax-reinforced laminates. The results demonstrate the potential of MMCFs as a viable alternative to glass fibre for reinforcement on a larger scale of UD laminates. These results were utilized in the Biofore biomaterial demonstration vehicle.

  • 311.
    Satomi, Mika
    et al.
    University of Borås, Swedish School of Textiles.
    Lundstedt, Lotta
    University of Borås, Swedish School of Textiles.
    Dumitrescu, Delia Mihaela
    University of Borås, Swedish School of Textiles.
    Persson, Anna
    University of Borås, Swedish School of Textiles.
    Repetition2011Other (Other academic)
    Abstract [en]

    “Repetition” is a Fashion Design and E-textile design project, which explore the use of thermo-chromic ink fabric and its interaction when designing a garment for performance art centering the body and movement as its design element.

    Download (pdf)
    performance conceptual text
    Download (jpg)
    photo from the performance at the Ambience 11
    Download (jpg)
    photo from the performance at the Ambience 11
  • 312.
    Satomi, Mika
    et al.
    University of Borås, Swedish School of Textiles.
    Nilsson, Linnéa
    University of Borås, Swedish School of Textiles.
    Vallgårda, Anna
    University of Borås, Swedish School of Textiles.
    Worbin, Linda
    University of Borås, Swedish School of Textiles.
    Recurring Patterns2011Other (Other academic)
    Abstract [en]

    What if your furniture expresses appreciation when you sit on them? Or what if they call for attention if they have been empty for too long? Textiles always change expression over time due to use and exposure to sunlight, moist, etc. The textile on these pouffes changes expressions in a dynamic interplay with their use. A bright pattern is gradually revealed when someone sits on them but hid again when they stand idle by. In other words, their patterns are recurring in both space and time.

    Download (jpg)
    stool 1
    Download (jpg)
    stool 2
  • 313.
    Satomi, Mika
    et al.
    University of Borås, Swedish School of Textiles.
    Nilsson, Linnéa
    University of Borås, Swedish School of Textiles.
    Vallgårda, Anna
    University of Borås, Swedish School of Textiles.
    Worbin, Linda
    University of Borås, Swedish School of Textiles.
    Recurring Patterns2011Other (Other academic)
    Abstract [en]

    What if your furniture expresses appreciation when you sit on them? Or what if they call for attention if they have been empty for too long? Textiles always change expression over time due to use and exposure to sunlight, moist, etc. The textile on these pouffes changes expressions in a dynamic interplay with their use. A bright pattern is gradually revealed when someone sits on them but hid again when they stand idle by. In other words, their patterns are recurring in both space and time.

    Download (jpg)
    stool 1
    Download (jpg)
    stool 2
  • 314.
    Satomi, Mika
    et al.
    University of Borås, Swedish School of Textiles.
    Worbin, Linda
    University of Borås, Swedish School of Textiles.
    Scholtz, Barbro
    Textilt Motstånd: Textile Resistance2011Other (Other academic)
    Abstract [en]

    Textilt Motstånd / Textile Resistance is a collaborative project between Smart Textiles Design Lab and Syntjuntan. The project explores design possibilities of raw textile materials that can be used as textile music instruments, which will be used by Syntjuntan in their music performances.

    Download (pdf)
    Ambience 11 exhibition catalog text
    Download (jpg)
    a photo of a knitted interface
    Download (jpg)
    a photo of a knitted interface, detail
    Download (jpg)
    a photo of a knitted interface
    Download (jpg)
    a photo of a embroidered circuit
    Download (jpg)
    a photo of a conductive knit dress worn by a violin player
  • 315. Schneegass, Stefan
    et al.
    Hassib, Mariam
    Zhou, Bo
    Cheng, Jingyuan
    Seoane, Fernando
    University of Borås, Faculty of Caring Science, Work Life and Social Welfare. KTH-School of Technology and Health.
    Amft, Oliver
    Lukowicz, Paul
    Schmidt, Albrecht
    SimpleSkin: towards multipurpose smart garments2015In: Proceedings of the 2015 ACM International Joint Conference on Pervasive and Ubiquitous Computing and Proceedings of the 2015 ACM International Symposium on Wearable Computers, ACM Publications, 2015, p. 241-244Conference paper (Refereed)
  • 316.
    Schulz, Anika
    University of Borås, Faculty of Textiles, Engineering and Business.
    Supercritical carbon dioxide as a green media for simultaneous dyeing and functionalisation: A study on disperse dyeing and silicone functionalisation for water repellency of polyester fabric2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Textile processing methods such as conventional exhaustion dyeing, pre-treatments and printing consume high amounts of water and use partly toxic and hazardous chemicals which are non-degradable. These chemicals (e.g. excess amount of dye, additives and catalysts) remain partially in the waste-water which is drained out and ends up polluting the environment. The supercritical carbon dioxide dyeing technology presents an eco-friendly and water-free method with reduced use of chemicals and energy. The benefits of such technology are currently not overcoming the relative high investment costs which impede its full implementation into the textile industry. This study presents an approach to extent the application of the eco-friendly supercritical carbon dioxide technology. It combines the well-studied supercritical carbon dioxide dyeing process for polyester with the functionalisation process to obtain water repellent surface properties. As water repellent (substance) environmentally benign silicones are used. Results showed that the simultaneous dyeing and functionalisation process was feasible assessed by the compatibility of the dye and silicone in the system. Silicone and dye did not interfere in each other’s functionality (colour strength and water contact angle). Further the process temperature and silicone molecular weight showed no influence on the colour strength of the fabric whereas the water contact angle (water repellence) increased with increasing temperature. The resulting polyester fabric showed acceptable colour strength yet did not obtain sufficient water repellent properties despite the increase in water contact angle of the treated samples to the untreated reference sample. The poor water repellence is suggested to be caused by the hydrophobic functional groups of the silicones oriented towards each other rather than toward the outer fabric surface. Overall the thesis is promoting research which combines eco-friendly technologies including environmental benign chemicals for the textile industry. Silicones are widely used in textile processing not only as water repellents, but also as anti-foaming agents, lubricants and softeners. Therefore a water-free and eco-friendly application method can benefit a wide range of finishing processes.

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    fulltext
  • 317.
    Seipel, Sina
    University of Borås, Faculty of Textiles, Engineering and Business.
    Ink Jetting of Photochromic Ink: Towards the Design of a Smart Textile Sensor2020Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Smart textiles have been a hot topic in research for several decades; however, comparatively few products can be found on the market. Resource-efficient processes can boost the breakthrough of smart and functional textiles, which often necessitate high-cost materials and only require small batches.

    This thesis provides a technology-driven approach with resource-efficient solutions for the production of UV-sensing textiles, while pointing out the challenges of the new materials, which are created when novel production processes are used. The performance of UV-sensing textiles produced by ink jetting and UV curing of ink with commercial photochromic dyes is primarily explored. Several steps in the development of a UV-sensing textile are covered in thesis; development and jetting performance of the photochromic UV-curable inkjet ink, optimization of the color performance of photochromic prints using production process parameters by tuning color kinetics, and evaluation of the durability and textile character of photochromic textiles. Other focuses included in the thesis are dyeing of photochromic textiles with supercritical carbon dioxide (scCO2), novel ways of stabilizing photochromic prints and ink jetting of functional ink for sports and work wear.

    It was shown that physical properties of the ink and temperature affected the jetting behavior of the ink. A discrepancy between the drop formation of UV-curable photochromic ink and existing models for jetting of inkjet ink was highlighted. Reversibly color-changing textiles can be produced with inkjet printing and UV curing of photochromic inks. The combination of the resource-efficient processes with the photochromic material required the introduction of an extended kinetic model to describe the coloration reaction of prints. An essential finding was that the kinetics of photochromic dyes in UV-curable ink applied on polyester fabric could be tuned using fabrication parameters during printing and curing in a continuous resource-efficient production process. By changing fabrication parameters during production, the prints’ crosslinking density is influenced and hence dye kinetics can be modified as a result of matrix rigidity of the UV ink. Furthermore, fabrication parameters influence and can be used to improve print durability as of abrasion and washing. Also, printing with photochromic UV-curable ink did not affect the fabric properties significantly in regards to flexibility and surface morphology. With the results obtained, photochromic textiles can be produced resource-efficiently using inkjet printing and UV curing, as well as scCO2 dyeing to boost the cost-effective and flexible production of smart textile UV sensors.

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    fulltext
    Download (pdf)
    omslag
    Download (pdf)
    spikblad
  • 318.
    Seipel, Sina
    University of Borås, Faculty of Textiles, Engineering and Business.
    Resource-efficient production of a textile UV-sensor for healthcare applications2017In: Books of abstracts: Aachen-Dresden-Denkendorf International Textile Conference, Stuttgart, 2017, 2017Conference paper (Other academic)
  • 319.
    Seipel, Sina
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Yu, Junchun
    University of Borås, Faculty of Textiles, Engineering and Business.
    Viková, Martina
    Technical University of Liberec.
    Vik, Michal
    Technical University of Liberec.
    Nierstrasz, Vincent
    University of Borås, Faculty of Textiles, Engineering and Business.
    Inkjet printing and UV-LED curing of photochromic dyes for functional and smart textile applications2018In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 8, no 50, p. 28395-28404Article in journal (Refereed)
    Abstract [en]

    Health concerns as a result of harmful UV-rays drive the development of UV-sensors of different kinds. In this research, a UV-responsive smart textile is produced by inkjet printing and UV-LED curing of a specifically designed photochromic ink on PET fabric. This paper focuses on tuning and characterizing the colour performance of a photochromic dye embedded in a UV-curable ink resin. The influence of industrial fabrication parameters on the crosslinking density of the UV-resin and hence on the colour kinetics is investigated. A lower crosslinking density of the UV-resin increases the kinetic switching speed of the photochromic dye molecules upon isomerization. By introducing an extended kinetic model, which defines rate constants kcolouration, kdecayand kdecolouration, the colour performance of photochromic textiles can be predicted. Fabrication parameters present a flexible and fast alternative to polymer conjugation to control kinetics of photochromic dyes in a resin. In particular, industrial fabrication parameters during printing and curing of the photochromic ink are used to set the colour yield, colouration/decolouration rates and the durability, which are important characteristics towards the development of a UV-sensor for smart textile applications.

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    fulltext
  • 320.
    Seipel, Sina
    et al.
    University of Borås, Swedish School of Textiles.
    Yu, Junchun
    University of Borås, Swedish School of Textiles.
    Nierstrasz, Vincent
    University of Borås, Swedish School of Textiles.
    Development of a Textile UV-Sensor2014Conference paper (Other academic)
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    FULLTEXT01
  • 321.
    Seipel, Sina
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Yu, Junchun
    University of Borås, Faculty of Textiles, Engineering and Business.
    Nierstrasz, Vincent
    University of Borås, Faculty of Textiles, Engineering and Business.
    Digital inkjet printing as flexible and resource-saving production technique for a smart textile UV-sensor2016Conference paper (Other academic)
  • 322.
    Seipel, Sina
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Yu, Junchun
    University of Borås, Faculty of Textiles, Engineering and Business.
    Periyasamy, Aravin
    Technical University of Liberec.
    Viková, Martina
    Technical University of Liberec.
    Vik, Michal
    Technical University of Liberec.
    Nierstrasz, Vincent
    University of Borås, Faculty of Textiles, Engineering and Business.
    Resource-Efficient Production of a Smart Textile UV Sensor Using Photochromic Dyes: Characterization and Optimization2018In: Narrow and Smart Textiles / [ed] Prof. Dr. Yordan Kyosev, Prof. Dr. Boris Mahltig, Prof. Dr. Anne Schwarz-Pfeiffer, Springer Publishing Company, 2018, p. 251-257Chapter in book (Refereed)
  • 323.
    Seoane, Fernando
    et al.
    University of Borås, School of Engineering.
    Ferreira, Javier
    University of Borås, School of Engineering.
    Marquez, Juan Carlos
    University of Borås, School of Engineering.
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Conductive Polymer Films as Textrodes for Biopotential Sensing2011Conference paper (Other academic)
    Abstract [en]

    Introduction: After several years of progresses in textile technology and wearable measurement instrumentation, applications of wearable textile-electronics systems are arising providing a stable background for commercial applications. So far, the available commercial solutions are centered on fitness applications and mostly based in the acquisition of heart rate through Textile Electrodes (Textrodes) based on metallic threads or on conductive rubber compounds. Methods and Materials: In this work a novel material approach is presented to produce Textrodes for acquisition of Electrocardiographic (ECG) signals using a conductive polypropylene (PP1386 from Premix, Finland) polymer material. The polymer was film extruded into thin films, and used as such in the Textrode. Conductive Polymer Films (CPF) have been used to produce Textrodes, and its measurement performance has been compared with the ECG signals obtained with commercial Textrode fabrics and conventional Ag/AgCl electrodes. In order to set up the same measurement conditions, a chest strap tailored to host the testing electrodes has been used. Results: The close resemblance of the ECG acquired with the textile fabric electrodes, the Ag/AgCl electrodes and the PP1386 CPF electrodes suggest that the Polymer Electrodes PP1386 are a feasible alternative to the current textile fabrics that use silver thread as conductive material and also to conductive rubber material. Discussion & Conclusion: The availability of the Conductive Polymer Electrode PP1386 in a film form allows the manufacturing of electrodes by conventional textile processes, like lamination or sewing, therefore facilitating the transition from lab prototyping to industrial manufacturing. Replacing the traditional silver thread as conductive element in the fabrication of Textrodes will definitely reduce the material cost per Textrode. Biocompatibility issues and manufacturability issues must be addressed but the exhibited functional performance is showing encouraging results.

  • 324.
    Seoane, Fernando
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Soroudi, Azadeh
    University of Borås, Faculty of Textiles, Engineering and Business.
    Abtahi, Farhad
    KTH, Medicinsk teknik.
    Lu, Ke
    KTH-School of Technology and Health.
    Skrifvars, Mikael
    University of Borås, Faculty of Textiles, Engineering and Business.
    Printed Electronics Enabling a Textile-friendly Interconnection between Wearable Measurement Instrumentation & Sensorized Garments2016Conference paper (Refereed)
  • 325.
    Siddharth, Shukla
    et al.
    Indian Institute of Technology Delhi, Hauz Khas, New Delhi, India.
    Kumar, Vijay
    University of Borås, Faculty of Textiles, Engineering and Business.
    Kameswara Rao, P.V.
    Indian Institute of Technology Delhi, Hauz Khas, New Delhi, India.
    Sharma, Sumit
    Indian Institute of Technology Delhi, Hauz Khas, New Delhi, India.
    Sebők, Dániel
    University of Szeged, Interdisciplinary Excellence Center, Department of Applied and Environmental Chemistry, H-6720 Szeged, Rerrich Béla tér 1, Hungary.
    Szenti, Imre
    University of Szeged, Interdisciplinary Excellence Center, Department of Applied and Environmental Chemistry, H-6720 Szeged, Rerrich Béla tér 1, Hungary.
    Rawal, Amit
    Indian Institute of Technology Delhi, Hauz Khas, New Delhi, India.
    Kukovecz, Akos
    University of Szeged, Interdisciplinary Excellence Center, Department of Applied and Environmental Chemistry, H-6720 Szeged, Rerrich Béla tér 1, Hungary.
    Probing the three-dimensional porous and tortuous nature of absorptive glass mat (AGM) separators2020In: Journal of Energy Storage, E-ISSN 2352-152X, Vol. 2017, no 101003Article in journal (Refereed)
    Abstract [en]

    The valve regulated lead acid (VRLA) battery is a predominant electrochemical storage system that stores energy in a cheap, reliable and recyclable manner for innumerable applications. The absorptive glass mat (AGM) separator is a key component, which is pivotal for the successful functioning of the VRLA battery. Herein, the intricate three-dimensional (3D) porous structure of AGM separators has been unveiled using X-ray micro-computed tomography (microCT) analysis. X-ray microCT has quantified a variety of fiber and structural parameters including fiber orientation, porosity, tortuosity, pore size distribution, pore interconnectivity and pore volume distribution. A predictive model of hydraulic tortuosity has been developed based upon some of these fiber and structural parameters. Moreover, the pore size distribution extracted via X-ray microCT analysis has served as a benchmark for making a comparison with the existing analytical model of the pore size distribution of AGM separators. Pore size distributions obtained via the existing analytical model and through X-ray microCT analysis are in close agreement.

  • 326.
    Sjöberg, Elisabeth
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Evervall, Jesper
    University of Borås, Faculty of Textiles, Engineering and Business.
    Separation av rensenor: En renare framtid2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Creating a thread of tendons from reindeers is something that the Sami people have done since ancient times. The Sami people have always taken care of the whole animal after slaughter. The process of developing the thread is completely manual. The tendons used by the Sami people are dried and a mechanical separation method pulls the fibres apart. The fibres then get twisted together after first being moist with saliva to make them stick to each other. This method is time consuming and therefore not suitable for industrial production. Several studies have shown research that has been made on collagen and fibrils. Experiments with different chemical constellations has been tested to find the most efficient solution for separating the fibres without damage. It appears that different chemicals are needed for the separation depending on the type of animal the tendon comes from. Whether it comes from mammalian or non-mammalian. Trying a combination of mechanical and chemical process to find out if that could contribute to a more efficient process is something that has been tested in this report, hoping to find an optimal solution to simplify the separation for the Sami people. These tests were made on dried tendon by placing the tendons in different solutions; three with mechanical pre-treatment and three with no pre-treatment. Then one of each pre-treated tendon was put in the same type of solution. The three solutions that were tested with phosphate buffered saline (PBS), deionized water and trypsin. This report has focused on an experimental study, which means that the results from these tests only can show signs of different behaviours depending of the solution. Because the tendons have different appearance it causes to not give an exact result. The test shows that the mechanical separation destroyed the orientation of the collagen, which made it more complicated to detach the fibers from each other. It also created damage on the fibres that led to shorter fibre length. The most successful solution turned out to be the trypsin solution with no pre-treatment. It was much easier to separate the fibres from each other. It showed no damage on the fibres, they came out even and the length of the fibres came out much longer. The tendon that had been in deionized water with no pre-treatment did show almost as good results as the trypsin test. From an economical and environmental point of view it would seem preferable to use deionized water rather than to use trypsin. This study can also show that microorganism in a humid environment can have good impact to dissolve the structure of the tendon.

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  • 327.
    Skelte, Gabrielle
    University of Borås, Faculty of Textiles, Engineering and Business.
    Enhancing colour development of photochromic prints on textile: Physical stabilisation during UV-radiation exposure2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Textile UV-radiation sensors has lately been introduced to the field of smart textiles. Inkjet printing has been used as means of application due to the effective and resource efficient process. UV-LED radiation curing has been used in combination with inkjet printing in favour of low energy requirements, solvent free solution and reduced risk of clogging in the print heads. The problems arising when exposing photochromic prints to UV-radiations are that oxygen inhibition during the curing and photo-oxidation in the print reduces the prints ability to develop colour. It is the oxygen in the air in combination with UV-radiation that gives the photo-oxidating behavior. The aim of the study is to with the aid of physical protection reduce the effect of oxygen inhibition and photo-oxidation in the prints. Three types of physical treatments were used, wax coating, protein based impregnation and starch based impregnation. Treatments were applied before curing as well as after curing and the colour development after activation during 1 min of UV-radiation was measured with a spectrophotometer. Multiple activations were also tested to see how the treatments affected the fatigue behaviour of the prints over time. The aim was to have as high colour development as possible reflecting reduced oxygen inhibition and photo-oxidation. Results showed significantly higher colour development for samples treated with wax and whey powder before curing, but reduced colour development for amylose impregnation. Over time whey powder before curing showed highest colour development due to highest initial colour development. Lowest fatigue was seen for washed samples containing the chemical stabiliser HALS, showing an increased colour development. In reference to earlier studies the protective properties of wax and whey powder is due to their oxygen barrier properties protecting the print. The tested treatments have shown that it is possible to reduce the effect of photo-oxidation during curing leading to prints giving higher colour development. This gives a great stand point when improving existing and future application of photochromic prints on textiles.

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  • 328.
    Skrifvars, M.
    University of Borås, School of Engineering.
    Development of regenerated cellulose reinforcement fabrics and their use in structural composites2012Conference paper (Other academic)
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  • 329.
    Skrifvars, M.
    et al.
    University of Borås, School of Engineering.
    Ramamoorthy, Sunil Kumar
    Baghaei, Behnaz
    Development of regenerated cellulose reinforcements and their use in structural composites for automotive applications2012Conference paper (Other academic)
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    FULLTEXT01
  • 330.
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Biopolymers and green polymers: the materials for sustainable textiles?2009Conference paper (Other academic)
  • 331.
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Conductive textile fibres for smart textiles: novel concepts and applications2010Conference paper (Refereed)
  • 332.
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Development of functional fibres for textiles and composites2014Conference paper (Other academic)
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  • 333.
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Development of natural fibre composites for automotive applications2013Conference paper (Other academic)
  • 334.
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Development of regenerated cellulose reinforcement fabrics and their use in structural composites2013Conference paper (Other academic)
  • 335.
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Natural fibers for structural composite applications: concepts and opportunities2014Conference paper (Refereed)
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    FULLTEXT01
  • 336.
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Polymerteknikens mångsidiga nytta2009In: Vetenskap för profession, ISSN 1654-6520, Vol. 10, p. 83-88Article in journal (Other academic)
  • 337.
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Preparation of conductive viscose fibres by vapour deposition polymerisation of polythiophene2010Conference paper (Refereed)
  • 338.
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Research on funcional fibres at University of Borås2009Conference paper (Other academic)
  • 339.
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Structural composites from cellulose reinforcements: material concepts and production strategies2014Conference paper (Refereed)
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    FULLTEXT01
  • 340.
    Skrifvars, Mikael
    et al.
    University of Borås, School of Engineering.
    Baghaei, Behnaz
    University of Borås, School of Engineering.
    Kumar Ramamoorthy, Sunil
    University of Borås, School of Engineering.
    Berglin, Lena
    University of Borås, Swedish School of Textiles.
    Development of hybrid natural fibre reinforcements for structural composites: Concepts and opportunities2013Conference paper (Refereed)
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    FULLTEXT01
  • 341.
    Skrifvars, Mikael
    et al.
    University of Borås, School of Engineering.
    Baghaei, Behnaz
    University of Borås, School of Engineering.
    Kumar Ramamoorthy, Sunil
    University of Borås, School of Engineering.
    Rajan, Rathish
    Berglin, Lena
    University of Borås, Swedish School of Textiles.
    Regenerated cellulose fibres for structural composites2014Conference paper (Other academic)
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    FULLTEXT01
  • 342.
    Skrifvars, Mikael
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Baghaei, Behnaz
    University of Borås, Faculty of Textiles, Engineering and Business.
    Rissanen, Marja
    Tampere University of Technology.
    Ramamoorthy, Sunil Kumar
    University of Borås, Faculty of Textiles, Engineering and Business.
    Mechanical and thermal characterization of compression moulded polylactic acid natural fiber composites reinforced with hemp and Lyocell fibers2014In: Journal of Applied Polymer Science, ISSN 0021-8995, E-ISSN 1097-4628, Vol. 131, no 15Article in journal (Refereed)
  • 343.
    Skrifvars, Mikael
    et al.
    University of Borås, School of Engineering.
    Cho, Sung-Woo
    Hemanathan, Kumar
    Mahimaisenen, Pirabasenan
    Adekunle, Kayode
    University of Borås, School of Engineering.
    Regenerated cellulose fibre reinforced case in films: Effect of plasticizer and fibre content2013Conference paper (Refereed)
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  • 344.
    Skrifvars, Mikael
    et al.
    University of Borås, School of Engineering.
    Persson, Maria
    University of Borås, School of Engineering.
    Cho, Sung-Woo
    University of Borås, School of Engineering.
    Resorbable porous scaffolds fabricated via melt spinning and weaving of the fibres: novel means for engineering bone tissues2011Conference paper (Refereed)
  • 345.
    Skrifvars, Mikael
    et al.
    University of Borås, School of Engineering.
    Rajan, Rathish
    Joseph, Kuruvilla
    Assessing thermal characteristics of polyhydroxybutyrate based composites reinforced with different natural fibres2009Conference paper (Refereed)
  • 346.
    Skrifvars, Mikael
    et al.
    University of Borås, School of Engineering.
    Rajan, Rathish
    Riihivuori, Johanna
    Järvelä, Pentti
    Mechanical and water absorption behaviour of textile composites on chemical treatment of reinforcements2013Conference paper (Other academic)
  • 347.
    Skrifvars, Mikael
    et al.
    University of Borås, School of Engineering.
    Ramamoorthy, Sunil Kumar
    University of Borås, School of Engineering.
    Baghaei, Behnaz
    University of Borås, School of Engineering.
    Development Of Regenerated Cellulose Reinforcements And Their Use In Structural Composites For Automotive Applications2013Conference paper (Refereed)
    Abstract [en]

    There is need for the bio‐based materials which could fully or partly replace the synthetic materials in automotive components. Several studies have been suggested to incorporate natural fiber based materials into automotives, and regenerated cellulose fibers could have a great potential several automotive applications. In the paper we will describe ongoing research where we study non‐woven viscose and Lyocell as well as uniaxial continuous viscose filament reinforcements for the use in structural composites. Hybrid reinforcements based on regenerated cellulose fibers and glass fibers have also been studied, with the intention to optimize the reinforcement durability. The uniaxial viscose filament reinforcements were prepared by a winding technique, and we have also combined the viscose filament with continuous hemp yarns as well as different thermoplastic yarns. Both thermoset and thermoplastic composites were then produced by compression moulding with a pressure of 40 bar and at the temperature between 160‐170°C for 5 minutes. The resulting composites have been characterized regarding mechanical and thermal properties.

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  • 348.
    Skrifvars, Mikael
    et al.
    University of Borås, School of Engineering.
    Rehnby, Weronika
    University of Borås, Swedish School of Textiles.
    Gustafsson, Maria
    Coating of textile fabrics with conductive polymers for smart textile applications2008Conference paper (Refereed)
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  • 349.
    Skrifvars, Mikael
    et al.
    University of Borås, School of Engineering.
    Soroudi, Azadeh
    University of Borås, School of Engineering.
    Melt spinning of carbon nanotube modified polypropylene conducting nanocomposite fibres2009In: Solid State Phenomena, ISSN 1012-0394, E-ISSN 1662-9779, ISSN 1012-0394, Vol. 151, p. 43-47Article in journal (Refereed)
    Abstract [en]

    Blends of polypropylene with multi-walled carbon nanotubes (CNT) have been prepared and melt spun to fibre filaments. The resulted filaments have been characterised regarding conductivity, thermal properties, and morphology. DSC suggests that carbon nanotubes act as nucleating sites in polypropylene and the TGA shows a high increase in thermal stability. Conductivity around 0.001 S/cm are achieved for both as-spun fibre and drawn fibre. A higher load of CNT up to 15 wt % increases the conductivity to 2.8 S/cm in as-spun fibre, but due to a high fibre diameter variation during spinning resulting in fibre breakage, melt spinning is very difficult. This is due to a non-uniform stress distribution during the drawing steps which can be a result of a non-homogeneous PP-CNT blend and the spinning machine process limitations. Differences in conductivities for extruded rods, as-spun fibre and drawn fibre which are made from the same blends, suggests that the crystallinity can affect the conductivity of the PP/CNT fibre.

  • 350.
    Skrifvars, Mikael
    et al.
    University of Borås, School of Engineering.
    Soroudi, Azadeh
    University of Borås, School of Engineering.
    Melt spinning of carbon nanotube modified polypropylene for electrically conducting nanocomposite fibres2008Conference paper (Refereed)
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