Browsing by Author "Hes, Luboš"
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- ItemA New Approach for Thermal Resistance Prediction of Different Composition Plain Socks in Wet State (Part 2)(Sciendo, 2020-01-01) Mansoor, Tariq; Hes, Luboš; Bajzík, VladimírSocks' comfort has vast implications in our everyday living. This importance increased when we have undergone an effort of low or high activity. It causes the perspiration of our bodies at different rates. In this study, plain socks with different fiber composition were wetted to a saturated level. Then after successive intervals of conditioning, these socks are characterized by thermal resistance in wet state at different moisture levels. Theoretical thermal resistance is predicted using combined filling coefficients and thermal conductivity of wet polymers instead of dry polymer (fiber) in different models. By this modification, these mathematical models can predict thermal resistance at different moisture levels. Furthermore, predicted thermal resistance has reason able correlation with experimental results in both dry (laboratory conditions moisture) and wet states.
- ItemA New Stitching Technology for Improved Thermal Insulation of 3D Nowoven Assemblies(SPRINGER, VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS, 2019-02-01) Saeed, Hassan; Roedel, Hartmut; Krzywinski, Sybille; Hes, Luboš3D fabrics are in various forms and shapes and are used in different applications of technical textiles. The functional purpose of their use is primarily to create a barrier or maintain a distance between two mediums. Fabrics from knitting or weaving machines are mostly not in their end product shape. They have to be joined with different forms of joining methods, mostly sewing to obtain its final form. Usually the conventional method of sewing compresses the 3D fabrics at points of needle insertion and the fabrics do not perform along stitch line as they perform in rest of their plane. Spacer stitching is a new joining method developed, which particularly addresses the problems related to compressions along stitch lines. Spacer stitching samples are tested with skin model and the thermal resistance along stitch line are compared with conventional lockstitch sewing method. With the help of infrared technology, thermal emissions have been studied for spacer stitching and conventional lockstitch, compared and presented in this paper.
- ItemA non-destructive single plate method for measurement of thermal resistance of polymer sheets and fabrics(2019-01-01) Doležal, Ivan; Hes, Luboš; Bal, KausikMeasurement of thermal resistance of polymer sheets and fibrous layers is important in various applications including those within the engineering, ergonomics, clothing design and personal protective equipment fields. Standard methods for measurement of thermal resistance of plain materials are generally time consuming, expensive and often require the sample to be cut. Moreover, the temperature difference between the surfaces of both plates surrounding the sample must be known, as well as the sample thickness. This article describes a new measuring device named the Thermoscope. The Thermoscope is not limited by the aforementioned requirements and is able to evaluate the thermal resistance of polymer sheets and textiles by touching the sample on one surface alone. Simultaneously, the other surface is kept in thermal contact with the supporting base. The accuracy of this device was compared with the Alambeta thermal insulation tester. Effects of various base materials on measurement precision were also studied.
- ItemAnalýza standardní metody pro hodnocení hydrostatické odolnosti textilií(Technická Univerzita v Liberci, 2011-01-01) Lečbychová, Jitka; Hes, LubošPredmetem práce je zkoumání závislosti mezi normovanými a vyššími rychlostmi merení hydrostatické odolnosti textilií. Teoretická cást je venována komfortu nošení, na který úzce navazuje problematika polopropustných membrán. V experimentální cásti jsou predstaveny a diskutovány konkrétní hodnoty vodních sloupcu jak z hlediska rychlostí merení, tak z hlediska zvolených materiálu. Na tomto základe jsou stanoveny koeficienty mezi stredne rychlou normovanou a vyšší rychlostí. V záveru jsou zváženy možnosti využití výsledku ke konstrukci jednoduchého stroje pro rychlejší merení hydrostatické odolnosti.
- ItemEffect of composition of knitted fabrics on their cooling efficiency at simulated sweating(Natl Inst Science Communication-Niscair, 2011-01-01) Hes, Luboš; Ursache, MarianaCooling efficiency of selected underwear knits in the simulated condition of fabric wetting by means of single sweating pulse has been experimentally investigated. The method is based on non-traditional use of the small skin model Permetest with a very short time of measurement. Cooling efficiency has been calculated as the product of cooling heat flow and wet area after application of 0.5 mL of water on the fabric surface to simulate the sweating impulse. It is found that the highest cooling level is exhibited by the knitted fabrics containing polyester filaments with grooved surface, which conducts the liquid moisture along the fabric plane.
- ItemThe Effect Of Finishing Treatment On Thermal Insulation And Thermal Contact Properties Of Wet Fabrics(Ege Universitesi, 2012-01-01) Bajzík, Vladimír; Hes, LubošComfort properties of textiles became important part of marketing of clothing with high added value in last decades. The most important parameters characterizing thermo physiological comfort of sport and protective garments are thermal resistance and water vapour permeability. Contrary to common textiles, protective and functional garments and some technical textiles are also used in wet state, which affects their comfort properties. However, these properties can be improved by application of special finishing agents. The objective of this paper is to investigate the effect of moisture on thermal comfort properties of 3 different cotton fabrics which were subject to 5 different finishing treatments. Thermal conductivity, thermal resistance, thermalabsorptivity and water vapour permeability of fabrics in dry and wet state were measured. Wet state of the studied fabrics was achieved by means of the so called "sweating impulse". The achieved results were treated by means of advanced statistics and displayed in diagrams. It was found the presence of moisture affected substantively all thermal-insulation and thermal-contact properties.
- ItemEffect of moisture content on thermophysiological properties of terry knitted socks followed by thermal resistance comparison among different skin models(Fiber Society, 2018-01-01) Mansoor, Tariq; Hes, Luboš; Bajzík, Vladimír; Skenderi, ZenunSocks comfort has great significance in our daily life. This significance even increased when we underwent a work of low or high activity. It causes the sweating of our body with different rates. In this study, terry socks with differential fibre composition were produced on the same knitting machine with homogeneous yarn linear densities and wetted to a saturated level. Then after successive intervals of conditioning, the socks are characterized by thermal resistance, thermal absorbitivity and relative cooling effect in dry and wet states. Hydrophobic have best results followed by semi hydrophilic and hydrophilic. Thermal resistance in dry state measured on Thermal Foot Model has a correlation (r²) of 0.64 and 0.55 is observed with Permetest and Alambeta, respectively.
- ItemEffect of preheat setting process on heat, mass and air transfer in plain socks(2019-02-01) Mansoor, Tariq; Hes, Luboš; Skenderi, Zenun; Siddique, Hafiz Faisal; Hussain, Sajid; Javed, AsifSocks are prevented against wrinkle formation by preheat setting in greige form prior to wet processing. The current study is proposed to analyze the effect of socks presetting process on thermopysiological and wicking properties of comfort. In this analysis, main yarn linear density, plaiting yarn composition and number of needles are taken as variable on same machine setting. Sock samples were analyzed for comfort parameters (thermal conductivity, thermal resistivity, thermal absorptivity, thermal diffusivity, relative water vapor permeability (RWVP (%)), evaporation resistance (Ret), air permeability, vertical wicking, absorbency and color strength (K/S) value) after various processes (preheat setting, dyeing and postheat setting). The statistical analysis showed that preheat set process significantly affects vertical wicking, K/S value, absorbency, thermal conductivity, thermal resistivity and thermal diffusivity, respectively. While thermal absorptivity, air permeability, porosity, RWVP (%) and R-et couldn't show a significant impact.
- ItemEffective Water Vapour Permeability of Wet Wool Fabric and Blended Fabrics(Inst Chemical Fibres, 2013-01-01) Boguslawska-Baczek, Monika; Hes, LubošThe water vapour permeability of fabrics is one of the most important factors determining wearer comfort. Contrary to commonly accepted theories, outerwear is often used in a wet state, which has an influence on their properties. However, common standard measuring instruments mostly do not enable reliable measurement of wet fabrics due to the long time of measurement, during which the fabrics get dry. This paper presents the fast instrument - Permetest, which provides reliable measurement of the water vapour permeability of fabrics in a dry and wet state. By means of the instrument, the relative and effective water vapour permeability of different wool fabrics in a dry and wet state were determined and the results discussed. The main contribution of the measurement was the determination of the exact ratio between the level of heat flux density of the heat flow penetrating the wet fabric, having a cooling effect, and that of the heat flux density of the heat flow caused by moisture evaporation from the fabric surface, also having a cooling effect.
- ItemEmpirical modeling of sound absorption properties of natural nonwoven fabric (Antiaris toxicaria barkcloth)(2017-01-04) Rwawiire, Samson; Tomková, Blanka; Militký, Jiří; Hes, Luboš; Kale, Bandu Madhukar; Jabbar, AbdulThe desire to mitigate climate change due to greenhouse gas emissions has led to the exploration of plant fibers as alternative materials for various industrial applications acoustics inclusive. In this investigation, sound absorption properties of barkcloth, a nonwoven fabric from Antiaris toxicaria were characterized. Theoretical empirical sound absorption models based on Delany and Bazley such as Miki, Wu and Allard – Champoux were utilized to validate the experimental data. The empirical models were in agreement with experimental data; Incorporation of an air-gap between the fabric layers had a positive influence on the overall sound absorption behavior of barkcloth fabrics rendering the fabric a good sound absorption material. © 2016 Trans Tech Publications, Switzerland.
- ItemENHANCEMENT OF HYDROSTATIC RESISTANCE AND MECHANICAL PERFORMANCE OF WATERPROOF BREATHABLE LAMINATED FABRICS(AUTEX, TECHNICAL UNIV LODZ, FAC MATERIALS TECHNOLOGY & TEXTILE, UL ZEROMSKIEGO 116, LODZ, 90-924, POLAND, 2019-03-01) Razzaque, Abdur; Těšinová, Pavla; Hes, LubošWaterproof breathable laminated fabrics have the special property that permits water vapour to pass through but protects by preventing the entrance of liquid water. Different characteristic properties of the layered constructions of these fabrics have good influence on their hydrostatic resistance and mechanical performance. This research study presents an experiment to enhance the hydrostatic resistance and tensile strength of four different types of hydrophobic membrane laminated waterproof fabrics by considering their breathability as well. For this purpose, water repellent coating based on C-6-fluorocarbon resin along with polysiloxane hydrophobic softening agent was applied on these four different types of laminated fabrics using pad-dry-cure method. The coated fabrics were characterised by performing different experiments to evaluate the effect of coating on their hydrostatic resistance and mechanical property as well as on water vapour permeability and air permeability. From the test results and analysis of variance (ANOVA), it was found that hydrostatic resistance and tensile strength of the laminated fabrics were enhanced after coating along with proper water repellent property, whereas there were no significant changes in their water vapour permeability and air permeability.
- ItemHeat, Moisture and Air Transfer Properties of Selected Woven Fabrics in Wet State(Hong Kong Polytechnic Univ, 2008-01-01) Hes, LubošThe most important parameters characterizing thermophysiological comfort of sport and protective garments are thermal resistance, water vapour permeability and air permeability. Contrary to common textiles, protective and functional garments and some technical textiles like textile dressings are also used in wet state, which affects their comfort properties. However, common measuring instruments mostly do not enable reliable measurement of wet fabrics, due to long time of measurement, during which the fabrics get dry. In this paper two fast measuring PC evaluated instruments ALAMBETA and PERMETEST commercial instruments are described, which provide reliable non-destructive measurement of thermal conductivity, thermal resistance and water vapour permeability of fabrics in dry and wet state. By means of these instruments, thermal resistance and water vapour permeability of heavy cotton and cotton/PES woven fabrics wet state were experimentally determined and results were discussed. The effect of structure and composition oil the above mentioned properties of these fabrics has been investigated as well. Some surprising results were achieved: with increasing fabrics humidity. the air permeability almost linearly decreased, whereas the total cooling heat flow (due to water evaporation from the wet fabric surface) slowly increased.
- ItemHodnocení komfortních vlastností funkčního prádla fy CRAFT při simulaci vlivu potu(Technická Univerzita v Liberci, 2008-01-01) Antonovová, Vladěna; Hes, LubošÚčelem této práce je zhodnotit komfortní vlastnosti funkčního prádla firmy CRAFT\regm{} při simulaci vlivu potu. V teoretické části práce je popsán současný stav funkčního prádla na trhu, vysvětlen pojem funkční prádlo a jaké jsou nejpoužívanější materiály. Je vytvořen přehled českých výrobců a prodejců prádla s vysokou přidanou hodnotou. Pozornost je věnována termofyziologickému komfortu textilií, kde jsou rovněž popsány základní poznatky o termoregulačních funkcích lidského těla. Praktická část je věnována seznámení s firmou CRAFT\regm{}, kde jsou představeny patentové materiály, základní principy a technologie používané při výrobě funkčního prádla. V této části jsou uvedené informace o provedeném vlastním marketingovém průzkumu formou dotazování mezi uživateli funkčního prádla CRAFT\regm{}. V experimentální části práce bylo provedeno měření tepelně-izolačních a tepelně-kontaktních vlastností na čtyřech vzorcích firmy CRAFT\regm{}. Měření proběhlo na přístroji Alambeta za sucha a za vlhka na principu potního impulsu. Dále pak byla naměřena propustnost vodních par přístrojem Permetest. Naměřené hodnoty jsou statisticky zpracovány a graficky vyjádřeny. Výsledky měření jsou vyhodnoceny a porovnány s výsledky vlastního marketingového průzkumu.
- ItemHodnocení paropropustnosti smart textilií pro sport(Technická Univerzita v Liberci, 2011-01-01) Heinisch, Tereza; Hes, LubošTato práce se zabývá problematikou hodnocení paropropustnosti smart textilií. V práci jsou podrobně popsány jednotlivé normy, vztahující se k hodnocení paropropustnosti a přístroje, které se k testování používají. V experimentální části jsou vybrané metody otestovány. Tyto metody jsou vyhodnoceny a naměřené hodnoty paropropustnosti vzájemně porovnány. V závěru práce je popsán návrh vybavení mezinárodní laboratoře pro testování paropropustnosti.
- ItemHodnocení paropropustnosti textilií při marketingu ochranných oděvů(Technická Univerzita v Liberci, 2007-01-01) Hájková, Alena; Hes, LubošCílem této práce bylo vypracování stručného přehledu českých firem, pro které je znalost paropropustnosti nezbytná při marketingu jejich výrobků; přiblížení problematiky komfortu textilií, zj. termofyziologického komfortu. Součástí práce je měření vzorků pro firmu Hannah Czech a.s., zpracování statistiky z tohoto měření a srovnání. V rámci této práce bude též proveden marketingový výzkum, jehož cílem je zjištění znalostí prodejců resp. uživatelů o způsobech hodnocení paropropustnosti ochranných a outdoorových oděvů.
- ItemHodnocení paropropustnosti vlnařských textilií ve vlhkém stavu(Technická Univerzita v Liberci, 2012-01-01) Šmídová, Barbora; Hes, LubošTato diplomová práce se zaměřuje na komfort textilií a to především na komfort termofyziologický. Práce je rozdělena do dvou hlavních částí. První, teoretická část se zabývá způsobem hodnocení termofyziologického komfortu s důrazem na přístroj Permetest. V druhé části jsou teoretické poznatky využity v prováděných experimentech. Součástí práce je i zkoumání paropropustnosti materiálů na přístroji Permetest. Testování bylo prováděno při různých úrovních zavlhčení materiálu. Cílem práce bylo zjistit vliv vlhkosti na paropropustnost materiálů vyrobených z vlny a polyesteru a ze směsi těchto materiálů.
- ItemHodnocení paropropustnosti vybraných oděvů na prodejně sportovního zboží za přítomnosti klienta(Technická Univerzita v Liberci, 2008-01-01) Rýznerová, Kateřina; Hes, LubošPurpose of labour was parameters of comfort assessment on outlet shop HUDYsport. I offer to client measure their winter jacket. I consecrate to issue of thermal comfort and thermocontrol of human body roughly. Work include their answer and effect of measurements. Of resume arise is able to effect to sale. Resume of work point to guiltlessness parameter whitch they meet at acquisition. In resume is credential understandable parameter to contriver.
- ItemImproved abrasion resistance of textile fabrics due to polymer coatings(SAGE PUBLICATIONS INC, 2455 TELLER RD, THOUSAND OAKS, CA 91320 USA, 2019-01-01) Wortmann, Martin; Frese, Natalie; Hes, Luboš; Hes, Luboš; Goelzhaeuser, Armin; Moritzer, Elmar; Ehrmann, AndreaTextile fabrics are often subject to abrasion, starting from exposed parts of garments to a variety of technical textiles. Abrasion protection by usual coatings, however, can significantly decrease the water vapor transport through a fabric which is often not desired, especially in the case of garments. In our paper, we report on an approach to combine increased abrasion resistance with sufficient water vapor transport properties. For this, different polymers (poly(methyl methacrylate), acrylonitrile butadiene styrene, or amorphous polyamides) were coated on cotton and polyester woven fabrics. The results of abrasion tests against sandpaper show significantly increased abrasion resistance. The absolute evaporation resistance, measured by a Permetest testing device, was only slightly increased up to values still acceptable for typical garments. Images of all coatings by helium ion microscopy deliver an explanation for the measuring results. Polymer coatings on the polyester fabric resulted in a slight reduction of the hydrophobicity, while coating the cotton fabric severely increased the contact angles of the originally superhydrophilic material.
- ItemAn indirect method for fast evaluation of surface moisture absorptivity of shirt and underwear fabrics(2000-01-01) Hes, LubošCustomers wearing shirts understand, that the feeling of comfort when wearing shirts in hot days should depend on their vater vapour permeability and their moisture sorption capacity, but both these parameters do not characterise the thermal contact comfort feeling of shirt fabrics in wet state. In order to explain the thermal contact comfort of superficially wetted shirts, a new parameter called moisture absorptivity was introduced and a simple equation of the moisture transfer between the fabric and skin was derived in the paper. Since the direct measurement of the moisture absorptivity is complicated, an indirect method for its experimental determination was described and used for the evaluation of thermal comfort of fabrics contacting wet human skin.
- ItemKlamné informace o komfortu textilií při marketingu(Technická Univerzita v Liberci, 2009-01-01) Jágrová, Lenka; Hes, LubošÚčelem této práce je seznámit čtenáře s klamnými informacemi při komfortu textilií. V první části je uveden stručný přehled o sensorickém a termofyziologickém komfortu textilií a o způsobech jeho hodnocení. V následujích kapitolách jsem se konkrétně snažila popsat vybrané textilní výrobky a jejich marketingové nadhodnocení či podhodnocení. Konkrétně jsem se zabývala zimními bundami, které jsem změřila na přístrojích Alambeta a Permetest. Výsledky se bohužel někdy neshodovaly s informacemi poskytujícími výrobcem. Dále jsem se zabývala bambusovou viskózou, vláknem Solar a novinkou firmy Ultrasport textilním výrobkem zvaným {\clqq}double face``. V poslední kapitole jsem udělala marketingový průzkum.