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- ItemDETERMINATION OF TENSION FOR ARAMID AND CARBON YARNS WHILE WEAVING INDUSTRIAL FABRICS(Technical University of Liberec, ) Shcherban, Volodymyr; Kolysko, Oksana; Melnyk, Gennadiy; Kolysko, Marijna; Shcherban, Yuriiy; Shchutska, Ganna; Technická univerzita v LiberciResulting from researches conducted to determine tension for para-aramid, meta-aramid, and carbon multifilament yarns during their contact with the operative parts of the weaving looms as part of the industrial fabrics formation process, we have found out that in threading areas the tension is increasing driven by variation of values of the friction forces in the contact area. It has been proven that tension degree of para-aramid, meta-aramid, and carbon multifilament yarns before industrial fabric formation area is influenced by (1) tension before cylindrical guide surface of an operative part, (2) radius of the cylindrical guide surface curve of the operative part, (3) contact angle between yarns and cylindrical guide surface of an operative part, (4) mechanical, physical and structural properties of para-aramid, metaaramid, and carbon multifilament yarns. It allowed (yet at the initial stage of design of technological process of industrial fabric formation) to determine para-aramid, meta-aramid, and carbon multifilament yarns tension before formation area depending on (1) form of threading line for yarns at the weaving loom, (2) mechanical, physical and structural properties of para-aramid, meta-aramid, and carbon multifilament yarns and industrial fabrics. The paper contains experimental research of interaction of para-aramid, metaaramid, and carbon multifilament yarns and cylindrical guide surfaces of the operative parts of automatic weaving looms. Based on experimental researches regression dependencies have been obtained between para-aramid, meta-aramid, and carbon multifilament yarns tension value after cylindrical guide surfaces of the operative part and (1) tension before cylindrical guide surface of the operative part, (2) radius of the cylindrical guide surface curve of the operative part, (3) contact angle between yarns and cylindrical guide surface of the operative part. Consecutive application of these regression dependencies allows to determine para-aramid, meta-aramid, and carbon multifilament yarns tension before industrial fabrics formation area. Analysis of regression dependencies allowed to find out values of technological parameters when para-aramid, meta-aramid, and carbon multifilament yarns tension before industrial fabrics formation area will be of minimum value. It will allow to minimize tension of para-aramid, metaaramid, and carbon multifilament yarns while manufacturing resulting in (1) yarn breakages reduction, (2) better productivity of weaving looms due to reduced stoppage time, (3) improved quality of manufactured industrial fabrics. Therefore, we can argue that suggested technological solutions are practically attractive. In view of this, it is reasonable to say that it is possible to directionally regulate the process of para-aramid, meta-aramid, and carbon multifilament yarns tension change while manufacturing industrial fabrics on the weaving looms through selection of values of guides’ geometrical parameters.
- ItemFEATURES OF THE PRIMARY PREPARATION OF HEMP STRAW STALKS SUITABLE FOR OBTAINING CELLULOSECONTAINING MATERIALS AND PAPER(Technical University of Liberec, ) Putintseva, Svitlana; Tikhosova, Anastasiia; Krahlyk, Vira; Kapitonov, Artem; Technická univerzita v LiberciThe features of the primary preparation of hemp straw stalks suitable for obtaining cellulosecontaining materials and paper are considered in the article. The primary processes of the preparation of hemp raw materials for pulp production, which include harvesting, storage of straw stalks, transportation, and primary processing of raw materials suitable for obtaining cellulose-containing materials, are described. Methods of shortening stems and fibers applied in the pulping process are studied in detail. Technological methods of shortening straw stalks of technical hemp and cleaning raw materials from grains and garbage impurities are mentioned. The necessity of applying the processes of stalks crushing and wet purification of chopped straw stalks of technical hemp is proved.
- ItemTHE PROCESS OF MAKING BATIK AND THE DEVELOPMENT OF INDONESIAN BAKARAN MOTIFS(Technical University of Liberec, ) Supriyadi, Slamet; Prameswari, Nadia Sigi; Technická univerzita v LiberciBatik is one of the original handicrafts recognized by UNESCO as Indonesia's cultural heritage. Therefore, this research aims to explore the development of good quality innovative Indonesian batik designs for Micro, Small Medium Enterprise (MSMEs). This is practice based research with data collected through observation and interviews. The result showed that the designs of Bakaran motifs contain elements of the Pati city history, Central Java, Indonesia. The making of batik motif in this research also went through digitalization process for the efficiency of making the next batik. Therefore, the international community is expected to determine the beginning and ending process used by Micro, Small Medium Enterprise (MSMEs) craftsmen in producing good quality batik. Further research needs to be carried out to explore the development of batik Bakaran designs using Druju (Acanthus ilicifolius) flower motifs.
- ItemCOLOR PERCEPTION ESTIMATIONS OF METAMERIC PAIRS UNDER DIFFERENT ILLUMINANCE LEVELS(Technical University of Liberec, ) Mukthy, Azmary Akter; Vik, Michal; Viková, Martina; Technická univerzita v LiberciLEDs or light emitting diodes of the lighting class dominate both the indoor and outdoor lighting industries today due to their accuracy and consumer-friendly color temperature. In the context of color science, it is necessary to analyze both the spectral power distribution of lighting and the human characteristics of color perception under these lights. In this article, we provide estimates of the appearance of eleven metameric pairs under LEDs with four correlated color temperatures and six illuminance levels, using color difference formulas based on the CIELAB, CAM02-UCS, and CAM16-UCS models to verify our estimates. We followed ASTM D4086 standard visual methods for detecting metamerism and for estimating the magnitude of a metameric color difference. Our investigations found that color appearance models are more reliable than CIELAB in evaluating color difference under various LED conditions. CAM16-UCS more accurately predicted the color difference estimates between all three formulas. Our comparative study confirms that the variation in the estimates with the CCT and illuminance levels of the LED sources depends on the color appearance model used. The results also showed that in order to determine the color difference of metameric pairs, optimal conditions regarding the colorimetric properties of the samples and the variability of the observer should be considered separately. We noticed an increasing correlation trend with increasing illuminance. However, there was no such increase or decrease trend in CCTs. The trend of the STRESS change in the color appearance models showed the influence of the chromatic adaptation, but the establishment of adaptation patterns is far beyond the scope of this work. Although our research has had limitations on correlated color temperature and illuminance, we believe that it can be beneficial for the lighting application to ensure correct lighting decisions when assessing the color differences of metameric pairs.
- ItemINVESTIGATION OF ANTIMICROBIAL PROPERTIES OF TEXTILE MATERIALS AFTER WASHING(Technical University of Liberec, ) Martirosyan, Irina; Pakholiuk, Olena; Golodyuk, Galyna; Lutskova, Viktoria; Lubenets, Vira; Technická univerzita v LiberciThis work is devoted to the study of antimicrobial properties of cellulose-containing textile materials treated with new safe biocidal products of thiosulfonate structure. A resource-saving method of providing antimicrobial properties to cellulose-containing textile materials is presented. High antimicrobial activity of biocidal products after washing was established. The duration of action and expediency of their use in the textile industry are proved. It is shown that after 10 washes the treated tissues lose only 14-15% of antimicrobial properties.