2022_29/2

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    STUDY OF THE INFLUENCE OF ANTIMICROBIAL AGENTS ON THE OPERATIONAL AND HYGIENIC PROPERTIES OF CELLULOSE MATERIALS
    (Technical University of Liberec, ) Paraska, Olga; Kovtun, Hrystyna; Hes, Lubos; Horiashchenko, Serhiy; Technická univerzita v Liberci
    At the present stage of development of society, in pandemic conditions, people are experiencing the growing influence of man-made factors (energy flows of internal and external origin, ionizing radiation, etc.), some drugs, pathogenic microflora (fungi, viruses, bacteria, intracellular parasites). The origination of a critical mass of parasitogens can be prevented by using, in addition to traditional methods of prevention and treatment, textile materials with certain additional properties obtained by antimicrobial treatment. The aim is to study the change in the operational and hygienic properties of cellulosic materials after treatment with antimicrobials. To assess the effect of antimicrobials (biguanide derivatives and quaternary ammonium salts) on the operational and hygienic properties of cellulosic materials (cotton fabric) the following indicators were taken into account: strength, stiffness, wrinkle recovery, capillarity of materials, structural and morphological characteristics. The results of research have confirmed the possibility of using solutions of antimicrobial agents for effective processing of wares, without destructive effects on the structure of cellulosic materials; allowed to introduce a research methodology to provide antimicrobial properties of cellulosic materials of different assortment.
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    FASTNESS PROPERTIES IMPROVEMENT OF FLUORESCENT PIGMENTS
    (Technical University of Liberec, ) Islam, Md. Khayrul; Mamun Kabir, Shekh Md.; Hosen, Md. Dulal; Islam, Md. Azharul; Technická univerzita v Liberci
    The resistance of the material to a change of its color characteristics during exposure to sunlight, rubbing and washing as domestic and laundry and other various ways are referred to as color fastness of dyes or pigments. In this research, 100% cotton and blended fabrics were dyed with fluorescent pigments i.e. Shining Flu Pink-F17 and Papillion Orange-FGRN in exhaust dyeing method. The improvement of color fastness properties, i.e. color fastness to washing, rubbing, perspiration and light were observed with the treatment of using antioxidants and UV-absorbers. There were eight samples of dyed fabrics (Four samples of 100% cotton knit fabric and four samples of 60/40 cottonpolyester blended fabrics) treated with 1% (v/v) of antioxidants i.e. Gallic acid, L-Ascorbic acid and UV absorbers i.e. 2-hydroxy-4 methoxy-benzophenone, 4-4 dimethoxy-benzophenone respectively. The treatment of antioxidant L-Ascorbic acid and UV absorber 4-4 dimethoxy-benzophenone provides satisfactory improvement of fastness properties than other antioxidants and UV absorbers. The results were mainly interpreted in terms of color strength, visual assessment of evenness and fastness ratings.
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    THE INFLUENCE OF CORE - SHELL RATIO ON CHARACTERISTICS OF MICROCAPSULES CONTAINING CINNAMON ESSENTIAL OIL APPLIED TO AROMATHERAPEUTIC TEXTILES
    (Technical University of Liberec, ) Huong, Chu Dieu; Thi Chinh Thuy, Dao; Thi Tu Trinh, Nguyen; Technická univerzita v Liberci
    Microencapsulation is one of the techniques to prepare the functional textiles. In this paper the essential cinnamon oil loaded microcapsules were prepared by solvent evaporation method. In the microencapsulation process, the core - shell ratio was changed by altering the cinnamon oil content in four levels of 0.15, 0.25, 0.35 and 0.45 g while the other components remained unchanged. The microcapsule characteristics including shape and morphology, size and size distribution, microencapsulation efficiency in dependence on the core-shell ratio were investigated. The antimicrobial capacity and the fragrance durability of interlock knitted fabric coated with the elaborated microcapsules were evaluated. The results showed that cinnamon oil was microencapsulated successfully in the spherical microcapsules. When the cinnamon oil content increased, the microcapsule size decreased and the size distribution became broader, the microcapsules were more porous and more aggregate, the fragrance intensity of the fabric treated with microcapsules increased while the activity against E. coli bacteria decreased. According to the results, the microcapsules elaborated with 0.15 g of cinnamon oil was recommended for the treatment of interlock cotton knitted fabric to apply in aroma and antimicrobial textiles.
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    FRAME MODEL OF UNIAXIAL STRETCHING OF 1x1 RIB KNITS
    (Technical University of Liberec, ) Yelina, Tetiana; Halavska, Liudmyla; Bobrova, Svitlana; Shcherban, Volodymyr; Dzykovych, Tetiana; Technická univerzita v Liberci
    One of the nowadays challenges is the development of scientific sound models of knitwear deformations. The paper is devoted to developing an algorithm for constructing a frame model of rib 1x1 knits stretched in the course or wale direction. In the process of uniaxial stretching, the shape of the sample depends on the tensile forces orientation. A frame model of a deformed knitted structure, and an algorithm of construction of a mesh frame, are developed during the study. The frame model makes it possible to find coordinates of intermeshing points of every stitch. Then yarn characteristic points can be determined that, in turn, serve as input data for the construction of 3D model of rib 1x1 structure under uniaxial tensile deformations at the yarn level of detail. The study provides a graphical tool for formalization of geometric transformation that happen during 2D deformations of knitted structures, characterized by gradual change of the specimens width crosswise to the loading direction. This model is intended to become a part of a general deformation model of knitted fabrics.
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    STUDY OF RIB KNITS COURSEWISE TENSILE PROCESS
    (Technical University of Liberec, ) Yelina, Tetiana; Halavska, Liudmyla; Bobrova, Svitlana; Lytvynenko, Nataliya; Dzykovych, Tetiana; Technická univerzita v Liberci
    Stretchability of knitwear is one of the most important factors of wearing comfort. Elasticity of knitted structures in course wise direction is usually higher than along wales and often characterized by crosswise shrinkage. Existing methods of knitting program development do not consider the real rate of wale wise shrinkage of rib knitted structure under the course wise extension. During the study experimental research has been carried out to fulfill empirical data on the relationship between samples’ length and width under uniaxial course wise elongation. A range of samples of rib 1×1, 2×2, 3×3, 4×4 and 5×5 knits, made of cotton, bamboo, polyacrylonitrile (PAN), wool/acrylic blend and wool yarn, were stretched with a tensile machine WDW-05M. In the process of stretching the width of each specimen was defined in the moments of extension by 50, 100, 150, 200, 250 and 300 per cent. It has been found that linear approximation can be applied to describe the dependence of specimen’s width on its relative course wise elongation. It was found that the stitch height/width ratio changes unevenly. In the beginning of the process of course wise stretching of a rib knitted structure, it does exist, such an interval, where an increase of the knit’s linear size along the courses occurs without a significant shrinkage in the wale wise direction. It is suggested to name the upper limit of this interval as “unidimensional extension limit” and define it as an extension of a standard (100×50mm) specimen, at which its width decreases by 10%. It was found as well that the value of this index significantly depends on the ribbing variation and much less on the type of raw materials.