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1

Ozone Effect On the Properties of Aramid Fabric

Wang Y., Wiener J., Militky J., Mishra R., Zhu G.

Autex Research Journal

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2017

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Vol. 17, no. 2

164--169

EN

The limitation of aramid fiber is its surface property, which results in its very poor interfacial adhesion to most of commercial resins. In order to improve the surface property of the aramid fiber, ozone treatment was carried out in this work. The aramid fabrics were evaluated in terms of surface morphology, wicking effect, tensile property, and ball bursting test. The results showed that the surface morphology of aramid fabrics did not undergo an obvious change; the wicking effect increased slightly with an increase in ozone treatment time; the tenacity and elongation of aramid fibers and fabrics did not significant change after ozone treatment, but the tenacity and elongation of aramid yarns showed significant improvement after ozone treatment, and increased with the increase of ozone treatment time; the ball bursting load and penetration displacement had a slight increase as well after ozone treatment. Therefore, ozone treatment could be one method to improve the surface property of the aramid fiber.

2

3D Numerical Simulation of Laminar Flow and Conjugate Heat Transfer through Fabric

Zhu G., Kremenakova D., Wang Y., Militky J., Mishra R., Wiener J.

Autex Research Journal

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2017

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Vol. 17, no. 1

53--60

EN

The air flow and conjugate heat transfer through the fabric was investigated numerically. The objective of this paper is to study the thermal insulation of fabrics under heat convection or the heat loss of human body under different conditions (fabric structure and contact conditions between the human skin and the fabric). The numerical simulations were performed in laminar flow regime at constant skin temperature (310 K) and constant air flow temperature (273 K) at a speed of 5 m/s. Some important parameters such as heat flux through the fabrics, heat transfer coefficient, and Nusselt number were evaluated. The results showed that the heat loss from human body (the heat transfer coefficient) was smallest or the thermal insulation of fabric was highest when the fabric had no pores and no contact with the human skin, the heat loss from human body (the heat transfer coefficient) was highest when the fabric had pores and the air flow penetrated through the fabric.

3

Ozonation: a green source for oxidized cotton

Maqsood H. S., Wiener J., Baheti V., Eldeeb M., Militky J.

Fibres & Textiles in Eastern Europe

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2016

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Vol. 24, no. 1 (115)

19--21

EN

Research was carried out on the oxidation of cellulose by ozone treatment. It is considered as environment friendly in comparison with the existing oxidation methods used in industry for a long time. This treatment is used in different applications such as the scouring / bleaching of cotton fabrics and in improving the properties of Kraft pulp cellulose in the paper industry. In this study, the effect of Ozone treatment on cotton yarn properties was investigated. This investigation can help in obtaining the maximum crystalline percentage of cotton for the production of nano-crystalline cellulose. Two-ply cotton ring spun yarn was treated with ozone gas for different time periods. Yarn tensile properties, wickability, the copper number and physical appearance were observed. It is evident that yarn tensile properties deteriorate drastically after a certain time, while the wickability and copper number increase simultaneously.

PL

Badano oksydacje celulozy za pośrednictwem ozonu. Jest to metoda uważana jako ekologiczna w porównaniu do innych stosowanych w przemyśle metod oksydacji. Tego rodzaju obróbka stosowana jest w różnego rodzaju procesach takich jak odtłuszczanie i bielenie wyrobów bawełnianych oraz dla polepszenia właściwości masy celulozowej w przemyśle papierniczym. W artykule przedstawiono wpływ obróbki ozonem na właściwości przędz bawełnianych. Badania te są przydatne dla uzyskania maksymalnej procentowej zawartości struktur krystalicznych w bawełnie przy produkcji nano-krystalicznej celulozy. Bawełniane przędze obrączkowe poddawano działaniu ozonu w różnych przedziałach czasowych. Następnie badano właściwości wytrzymałościowe zwilżalność, liczbę miedziową i inne właściwości fizyczne. Stwierdzono, że podczas obróbki ozonem właściwości wytrzymałościowe zmniejszają się drastycznie podczas gdy zwilżalność i liczba miedziowa ulegają zwiększeniu.

4

Study on the Wicking Property of Cotton Fabric

Zhu G., Militky J., Wang Y., Sundarlal B V, Křemenaková D

Fibres & Textiles in Eastern Europe

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2015

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Vol. 23, no. 2 (110)

137—140

EN

In order to study the heat and moisture comfort, the wicking property of textiles has been used as an important and effective index. In this paper, the wicking behaviour of cotton fabric in the warp and weft directions was investigated in terms of the wicking height, rate of wicking, mass increment distribution per centimetre of the wicking height, and the durative wicking height after removal of the wicking liquid reservoir. The results showed that the wicking height square had a good correlation with the time in both the warp and weft directions. The wicking rate was higher in the weft direction than that in the warp, especially at the beginning of the wicking process. The mass increment of fabric per centimetre of the wicking height was inversely proportional to the wicking height; the mass of water absorbed in the fabric did not have a significant difference in the weft and warp directions.

PL

Badanie właściwości zasysania wody jest ważnym wskaźnikiem wykorzystywanym podczas oceny komfortu cieplnego tkanin. W pracy badano właściwości zasysania wody (efekt knota) tkanin bawełnianych w kierunku wątku i osnowy ze szczególnym uwzględnieniem wysokości zasysania, szybkości zasysania, rozkładu przyrostu masy cieczy na centymetr wysokości zasysania oraz czasu utrzymania się wysokości zasysania po usunięciu tkaniny ze zbiornika z cieczą. Wyniki pokazały, że kwadrat wysokości zasysania jest zależny od czasu, zarówno w przypadku osnowy jak i wątku. Szybkość zasysania jest wyższa w kierunku wątku, w szczególności na początku procesu zasysania. Rozkład przyrostu masy cieczy na centymetr wysokości zasysania był odwrotnie proporcjonalny do wysokości zasysania; nie odnotowano znaczącej różnicy w ilości zaabsorbowanej wody w tkaninie w kierunku wątku i osnowy.

5

Investigation Of Sound Absorption Properties Of Bark Cloth Nonwoven Fabric And Composites

Rwawiire S., Tomkova B., Gliscinska E., Krucinska I., Michalak M., Militky J., Jabbar A.

Autex Research Journal

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2015

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Vol. 15, no. 3

173--180

EN

The quest for sound-absorbing materials that are not only environmentally friendly, but also sustainable is the foremost reason for natural fibre-acoustic materials. Bark cloth is a natural non-woven fabric that is largely produced from Ficus trees. An exploratory investigation of bark cloth a non-woven material and its reinforcement in epoxy polymer composites has been fabricated and investigated for the sound absorption properties so as to find the most suitable applications and also to see whether bark cloth can be used in some applications in place of man-made fibres. Three types of material species were investigated with their respective composites. The fibre morphology showed bark cloth to be a porous fabric that showed promising sound absorption properties at higher frequencies. The sound absorption results of four-layer material selections of Ficus natalensis, Ficus brachypoda and Antiaris toxicaria bark cloth showed sound absorption coefficient of 0.7; 0.71 and 0.91 at f > 6400 Hz, respectively. The bark cloth reinforced laminar epoxy composites had reduced sound absorption coefficients, which ranged from 0.1 to 0.35, which was attributed to decreased porosity and vibration in the bark cloth fibre network.

6

Air Permeability of Polyester Nonwoven Fabrics

Zhu G., Kremenakova D., Wang Y., Militky J.

Autex Research Journal

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2015

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Vol. 15, no. 1

8--12

EN

Air permeability is one of the most important properties of non-woven fabrics in many applications. This paper aims to investigate the effects of thickness, porosity and density on the air permeability of needle-punched non-woven fabrics and compare the experimental values with two models which are based on hydraulic radius theory and drag theory, respectively. The air permeability of the samples was measured by an air permeability tester FX3300. The results showed that the air permeability of non-woven fabrics decreased with the increase in thickness and density of samples, increased with the increase of porosity, and the air permeability was not directly proportional to the pressure gradient. Meanwhile, the prediction model based on hydraulic radius theory had a better agreement with experimental values than the model based on drag theory, but the values were much higher than the experimental results, especially for higher porosity and higher pressure gradient.

7

An analysis of effective thermal conductivity of heterogeneous materials

Zhu G., Kremenakova D., Wang Y., Militky J., Mazari F. B.

Autex Research Journal

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2014

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Vol. 14, no. 1

14--21

EN

Effective thermal conductivity (ETC) is a very important index for evaluating the thermal property of heterogeneous materials, which include more than two different kinds of materials. Several analytical models were proposed for predicting the ETC of heterogeneous materials, but in some cases, these models cannot provide very accurate predictions. In this work, several analytical models and numerical simulations were studied in order to investigate the differences among them. In addition, some factors which would influence the ETC of heterogeneous materials were investigated by numerical simulation. The results demonstrated that the numerical simulation can provide very accurate prediction, indicated that different analytical models should be selected to predict specific problems based on their assumptions, and suggested that more variables need to be considered in order to improve these analytical models, such as inclusion shape, inclusion size, distribution of inclusions and contact area. Besides, numerical method could be an effective and reliable way to obtain the ETC of heterogeneous materials with any kind of complicated structures.

8

Image Processing Based Method Evaluating Fabric Structure Characteristics

Shady E., Qashqary K., Hassan M., Militky J.

Fibres & Textiles in Eastern Europe

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2012

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Vol. 20, no. 6A (95)

86--90

EN

A digital image processing approach was developed to evaluate fabric structure characteristics and to recognise the weave pattern utilising a Wiener filter. Images of six different groups were obtained and used for analysis. The groups included three different fabric structures with two different constructions for each. The approach developed decomposed the fabric image into two images, each of which included either warp or weft yarns. Yarn boundaries were outlined to evaluate the fabric surface characteristics and further used to identify the areas of interlaces to detect the fabric structure. The results showed success in evaluating the surface fabric characteristics and detecting the fabric structure for types of fabrics having the same colors of warp and weft yarns. The approach was also able to obtain a more accurate evaluation for yarn spacing and the rational fabric cover factor compared to the analytical techniques used to estimate these characteristics.

PL

Przy zastosowaniu filtra Winera opracowano cyfrową metodę analizy obrazu umożliwiającą ocenę struktury tkanin oraz rozpoznawanie splotu. Zbadano obraz sześciu zróżnicowanych grup tkanin, o 3 rożnych splotach i 2 strukturach, uzyskując dwa obrazy dla każdej tkaniny, z których każdy obejmuje przędze osnowy lub wątku. Wyznaczono wizualne granice nitek osnowy i wątku w celu oceny właściwości powierzchni tkaniny i identyfikacji obszarów przeplotów dla zbadania struktury tkaniny. Badania dla oceny właściwości powierzchni tkaniny i jej struktury dla tkanin o takich samych kolorach przędz wątku i osnowy zakończyły się sukcesem. Dokonano również oceny rozstawu przędzy i współczynnika pokrycia tkaniny i stwierdzono, że metoda ta jest dokładniejsza niż dotychczas stosowane metody analityczne.

9

Structural design engineering of woven fabric by soft computing: part II - non-plain weave

Mishra R., Kremenakova D., Behera B K, Militky J.

Autex Research Journal

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2011

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Vol. 11, no. 2

42--46

EN

The maximum weavability limit is predicted by extending Peirce's geometrical model for non-plain weaves for circular and racetrack cross-sections by soft computing. This information is helpful to weavers in that attempts to weave impossible constructions can be avoided, thus saving time and money. It also helps in anticipating difficulties in weaving and in taking the necessary steps in warp preparation. The relationship between the cover factors in the warp and weft directions is demonstrated for circular and racetrack cross-sections for plain, twill, basket and satin weave. Non-plain weave fabric affords further flexibility for increasing fabric mass and fabric cover. As such, they enlarge the scope of the fabric designer.

10

Structural design engineering of woven fabric by soft computing: part I - plain weave

Mishra R., Kremenakova D., Behera B K, Militky J.

Autex Research Journal

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2011

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Vol. 11, no. 2

37--41

EN

An attempt has been made to optimise the engineering attributes of a plain weave fabric according to certain requirements. A simplified algorithm was used to solve fabric geometrical model equations, and relationships were obtained between useful fabric parameters such as thread spacing and crimp, fabric cover and crimp, warp and weft cover. Such relationships help in guiding the direction for moderating fabric parameters. The full potential of the Peirce fabric geometrical model for plain weave has been exploited by soft computing. The interrelationships between different fabric parameters for jammed structures, non-jammed structures and special cases in which the cross-threads are straight were obtained using a suitable algorithm. It is hoped that the fabric designer will benefit from the flexibility in choosing fabric parameters for achieving any end use with the desired fabric properties.

11

Exploration of univariate data in the textile metrology

Militky J., Meloun M.

Zeszyty Naukowe. Włókiennictwo / Politechnika Łódzka

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2000

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z. 58

165-173

EN

The main aim of data analysis in textile metrology is the extraction of relevant information from measurements. This contribution is focused to most frequent task, i.e univariate data treatment based on the analysis of experimentally determined values Xi, i=1,...N. The system of exploratory data analysis based on concept of quantile estimation is proposed. The main part of this contribution is devoted to the description of several graphical tools for data summarization and exploration. Selected techniques are used for analysis of the strength of basalt fibers at small gauge length. The program package ADSTAT for realization of the above-mentioned techniques is briefly described.

12

Data based probability models in the textile metrology

Militky J., Meloun M.

Zeszyty Naukowe. Włókiennictwo / Politechnika Łódzka

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2000

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z. 58

155-164

EN

The main aim of data analysis in textile metrology is the extraction of relevant information from measurements and creation of probability models. This contribution is focused to most frequent task, i.e univariate data treatment based on the analysis of experimentally determined values Xi, i=1,...N. The main part of this contribution is devoted to the description and camparison of data distribution with theoretical ones. Selected techniques are used for analysis of the strength of basalt fibers at small gauge length.

13

Data analysis for quality control in the textile branch

Militky J., Meloun M., Kupka K.

Zeszyty Naukowe. Włókiennictwo / Politechnika Łódzka

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2000

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z. 58

43-50

EN

The Box Cox transformation are given for construction of asymmetric quantiles and control limits for control charts. It is shown on simulated and real data that the transformation may significantly improve applicability of control charts.