Klara Kostajnšek

Dr. Klara Kostajnšek

University of Ljubljana, Faculty of Natural Sciences and Engineering, Department of Textiles, Graphic Arts and Design, 1000 Ljubljana, Slovenia
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Research Focus & Metrics

Academic Career Length

16Years (2011-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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20 June 2011 in Textile Research Journal
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Rasa UrbasRasa Urbas
Rasa Urbas
Klara KostajnšekKlara Kostajnšek
Klara Kostajnšek
KDKrste Dimitrovski
Krste Dimitrovski
The aim of our work was to establish whether very good to excellent UV (ultraviolet) protective properties of fabrics can be obtained through a suitable fabric construction and yarn colour, at the same time ensuring suitable air permeability. For this purpose, six different fabric structures divided into three groups were employed. The samples were made in blue and red combinations of weft with different sequences and proportions between the upper and lower weave threads. A comparison of different fabric structures and colours was attempted to enable the assessment of the impact of the mentioned parameters on both, UV protective properties and air permeability of fabrics. The analysis comprised the investigation of physical and permeability properties, as well as the colour measurements on twelve different cotton fabrics. The research indicated excellent UV protection (>60) in all samples. UV protection depended on their construction and in a sufficiently closed structure, also on the colour of the used yarn. There was no significant difference between the samples in blue and red. In addition to excellent UV protection, four samples (one double-weft and three double fabrics) also demonstrated very high air permeability, which was 3–5 times higher than in the one-layer sample, which demonstrated the best UV protective properties. The research has shown that fabrics with a very high ultraviolet protective factor value and good air permeability can be made by using a suitable construction and yarn colours that sufficiently absorb UV light; the latter being particularly important for light summer cotton clothes.

27 January 2021 in Polymers
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Klara KostajnšekKlara Kostajnšek
Klara Kostajnšek
Živa ZupinŽiva Zupin
Živa Zupin
AHAleš Hladnik
Aleš Hladnik
KDKrste Dimitrovski
Krste Dimitrovski
This paper deals with the possibility of a fast and accurate assessment of the number, size, and distribution of pores in transparent woven fabrics based on light penetration. The procedure of analyzing the pore structure in the fabrics based on a digital image is presented in detail. Fabric pores are treated as image particles and analyzed with the Java-based image processing software ImageJ. The obtained data relate to the constructional parameters of the fabric that allow for further analysis, provide the possibility to compare structurally similar or different samples as well as double check the results generated by optical or other means. This paper describes work on plain and similar to plain weaves. The conducted analysis revealed several expected and some unexpected results. Among the former, we can list the range of pore sizes in the examined woven fabrics, the distribution of pores in regard to their similarity, and the effect of dents. Examples of the latter are the magnitude of the cumulative percentage of pores in regard to the weave and the degree to which they participate in the inter-yarn and inter-fiber pores.

17 April 2024 in Polymers
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DGDunja Šajn Gorjanc
Dunja Šajn Gorjanc
Klara KostajnšekKlara Kostajnšek
Klara Kostajnšek
The demand for hygienic nonwovens has increased, especially since 2020. As expected, the market for nonwovens showed an increase during the COVID-19 outbreak, especially in the medical and hygienic nonwovens sector. The aim of this study is to analyse the influence of the permeability properties of hygienic nonwovens that have been mechanically, chemically, and thermally bonded. Hygienic nonwovens are lightweight (from 20 to 120 g/m2), produced by carding (roller carding), and are bonded using three different bonding processes (mechanical, thermal, and chemical). Hygienic nonwovens are intended for protective clothing in hospitals. For the experimental part, the seven different nonwovens used for hygienic purposes were produced using the dry laying process. The samples were produced in Tosama, a factory for sanitary supplies. The research results show that the nonwoven bonding processes have a significant influence on the structural, mechanical, and permeability properties.

31 October 2024 in Polymers
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Klara KostajnšekKlara Kostajnšek
Klara Kostajnšek
MBMatejka Bizjak
Matejka Bizjak
GEGözde Ertekin
Gözde Ertekin
MEMustafa Ertekin
Mustafa Ertekin
Para-aramid fibers, known for their remarkable strength and thermal stability, are frequently employed in protective textiles for military and aerospace applications. However, continuous exposure to ultraviolet (UV) radiation can damage their protective characteristics. This study analyzes the ultraviolet protection factor (UPF) and UV transmittance of woven fabrics produced from 30/2 Ne spun para-aramid yarns in the warp and 10 Ne core-spun yarns in the weft. The weft yarns consisted of three sheath fibers—para-aramid, meta-aramid, and polyester—in combination with different specialty core materials. The results show significant differences in UPF before and after UV exposure, with para-aramid sheaths giving the highest improvement. UV exposure caused structural changes in the fibers, resulting in increased UV protection, particularly in fabrics with para-aramid sheaths. This study concludes that the combination of para-aramid fibers with specific core materials significantly enhances UV protection, making them well-suited for applications in high UV exposure environments.

14 January 2021 in Polymers
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Klara KostajnšekKlara Kostajnšek
Klara Kostajnšek
KDKrste Dimitrovski
Krste Dimitrovski
HKHüseyin Kadoğlu
Hüseyin Kadoğlu
PÇPinar Çelik
Pinar Çelik
GBGuldemet Basal
Guldemet Basal
MBMatejka Bizjak
Matejka Bizjak
Elasticity and recovery are important for clothing comfort, especially in the manufacture of apparel and sportswear. Recently, yarns containing PBT (polybutylene terephthalate), which are able to develop good elastic properties with high recovery after a finishing process (e.g., thermal treatment), have been used for this purpose. The aim of this work is to give a comprehensive overview of the use of PBT yarns in woven structure, with the aim of improving the elastic properties of cotton-like fabrics. The experimental part was divided into three main sequences to investigate the fabric properties (physical, elastic, UPF, comfort) influenced by (1) PBT-containing yarn structure, (2) weave and fabric structure (basic weaves and complex weaves) with PBT in weft direction, and (3) processing sequence—thermal treatment of PBT yarns or fabrics after weaving. According to the results, PBT-containing yarns have great potential for the production of lightweight elastic fabrics. The advantages of improving the elastic properties of fabrics by incorporating a relatively small amount of PBT yarns into the fabric only in certain areas, thereby minimally affecting the production costs, are demonstrated by a product with partially elastic areas obtained after thermal treatment.

21 August 2019 in Autex Research Journal
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Klara KostajnšekKlara Kostajnšek
Klara Kostajnšek
RURaša Urbas
Raša Urbas
KDKrste Dimitrovski
Krste Dimitrovski
Knowing the reflection, transmission, and absorption properties of the yarns from which the woven fabric is made, prediction of a fabric’s UV-protective properties is simple. Using the geometrical properties of monofilament yarns and fabrics, which were determined optically, and following the cover factor theory, we have determined the areas of fabrics covered with no yarns, only one yarn, and two yarns. From a special selected set of high-module polyethylene terephthalate (PET) monofilament materials (e.g., fabrics), we have elaborated a method for determining the reflection, transmission, and absorption of yarns. By first defining the differently covered areas of fabrics, we were able to use them in a mathematical model for calculating and predicting the UV-protective properties of the fabrics. The calculated and measured values of the UV-protective properties of the selected test fabrics were highly correlated, with a correlation coefficient >0.98.