Jiří Militký and Dana. Křemenáková
The strength of fibers and fibrous bundles is a very important parameter, especially for industrial applications of textile structures. It is possible to use simulations…
Abstract
The strength of fibers and fibrous bundles is a very important parameter, especially for industrial applications of textile structures. It is possible to use simulations, particularly for smaller samples. This paper describes the bundle strength of PET filaments from a statistical point of view. The small bundles from 2 till 10 filaments were tested. The simulation-based bundle breaking process combined with bootstrapping was used for estimating bundle strength.
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Jiri Militky and Vladimir Bajzik
Examines wool/polyester blended fabrics with a view to finding the optimal blend in relation to suitable utility, surface and handling properties. Concludes that a simple general…
Abstract
Examines wool/polyester blended fabrics with a view to finding the optimal blend in relation to suitable utility, surface and handling properties. Concludes that a simple general mixing rule is possible for use in producing the required optimum blends.
Jiří Militký and Dana Křemenáková
The purpose of the paper is to describe the construction of utility value U based criterion suitable for expressing pseudodistance in the area of computer aided textile design…
Abstract
The purpose of the paper is to describe the construction of utility value U based criterion suitable for expressing pseudodistance in the area of computer aided textile design. The possibility to use of this approach for evaluation of generalized distance between properties of target fabrics and properties of fabrics created by computer aided textile design will be discussed. The application of U and corresponding pseudodistance is demonstrated on the example of characterization of the effect of catalysts on the quality of crease resistant finished fabrics under laboratory conditions. The target fabric was selected according to the requirements to minimize the influence of finishing on the loss of mechanical properties and surfaeabrasion on one hand and improve the recovery angles on the other hand. The program complex written in MATLAB is briefly mentioned.
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Jiří Militký and Marie Havrdová
It is well‐known that clean room textiles are acting as a barrier protecting humans against the surrounding atmosphere or vice versa. These textiles are produced in the limited…
Abstract
It is well‐known that clean room textiles are acting as a barrier protecting humans against the surrounding atmosphere or vice versa. These textiles are produced in the limited range of porosity and the air permeability. The porosity calculated from fabric geometry and the air permeability of two typical clean room textiles of Czech production are measured. The variation of air permeability is described by the analysis based on the coefficient of variation and spatial autocorrelation. The air permeability of composite textiles of multiple layers is predicted from a simple model. This model is based on the idea of a combination of air pressure drop in individual layers. The predicted air permeability is compared with experimental measurements.
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Jiří Militký, Arun Aneja and Dana Křemenáková
In this century, textiles will not only offer the best functional features of natural and synthetic fibres, but will be highly engineered systems targeted to provide complex…
Abstract
In this century, textiles will not only offer the best functional features of natural and synthetic fibres, but will be highly engineered systems targeted to provide complex functionalities for technical applications. Biotechnology, fibre engineering and materials science will be key technologies driving the development of these next generation textile systems. Exciting new opportunities will arise at the interfaces - integrated science - between these divergent disciplines. In the general parts of this lecture the factors influencing future trends in the fibre industry and application of fibrous structures are discussed. The core of presentation is specification of cotton and polyester fibres properties required for apparel production and expressing the selected properties changes due to variation of air humidity.
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Dana Křemenáková, Barbora Meryová, Jiří Militký and Vít Lédl
The main aim of this work is evaluation of side emitting plastic optical fibers (POF) illumination intensity changes in dependence on the distance from light source. Illumination…
Abstract
The main aim of this work is evaluation of side emitting plastic optical fibers (POF) illumination intensity changes in dependence on the distance from light source. Illumination intensity is measured along straight and bent fibers. The special devices for these measurements realization are described. The dependence of light intensity on the distance from light source for straight optical fibers is expressed by the exponential type model with two parameters, i.e. illumination intensity at the input into fiber and fiber attenuation factor. Preliminary results of measurement of light intensity in bent state are discussed. Influence of ratio between fiber diameter and bending cylinder diameter on the illumination intensity changes is presented.
Jirí Militký, Jitka Rubnerová and Václav Klicoka
Visual and subjective methods for evaluation of surface appearance irregularity of chemically bonded nonwovens are compared. The image analysis system LUCIA is used for estimation…
Abstract
Visual and subjective methods for evaluation of surface appearance irregularity of chemically bonded nonwovens are compared. The image analysis system LUCIA is used for estimation of characteristics describing appearance. The analysis of subjective and objective estimates of surface appearance irregularity is realized by the coefficient of variation and by the ANOVA type model.
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Guocheng Zhu, Dana Kremenakova, Yan Wang and Jiri Militky
Clothing comfort has been one important and complex area which is the result of a balanced process of heat and moisture/liquid exchange between the human body, the clothing system…
Abstract
Purpose
Clothing comfort has been one important and complex area which is the result of a balanced process of heat and moisture/liquid exchange between the human body, the clothing system and the environment. And the clothes will represent different properties when they are in different conditions, which have great influence on human comfort. Therefore, the purpose of this paper is to investigate the hygroscopicity-exothermicity property of plain cotton fabric.
Design/methodology/approach
A real-time testing device for monitoring the temperature change of cotton fabrics after adsorbing liquids was constructed, and serveral liuqids such as water, NaCl solution with different concentrations, NaOH solution with different concentrations, and urea solution with different concentrations were used in this work.
Findings
It was found out that absorption of liquids by cotton fabric was followed by the liberation of heat, which increased the temperature of cotton fabric as well as the temperature of surrounding environment, and the process of temperature increase was much shorter than the process of temperature decrease. In addition, the released heat energy were different according to different liquids as well as the concentrations of liquid solutions.
Originality/value
There have some studies in the heat of water/vapor sorption of textiles. Here the temperature changes of surrounding environment and fabric after absorbing different liquids were real-time observed and recorded.
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Rajesh Mishra, Arumugam Veerakumar and Jiri Militky
– The purpose of this paper is to investigate effect of material properties in 3D knitted fabrics on thermo-physiological comfort.
Abstract
Purpose
The purpose of this paper is to investigate effect of material properties in 3D knitted fabrics on thermo-physiological comfort.
Design/methodology/approach
In the present study six different spacer fabrics were developed. Among these six fabrics, it was classified into two groups for convenient analysis of results, the first group has been developed using polyester/polypropylene blend with three different proportion and second group with polyester/polypropylene/lycra blend having another three different composition. As a spacer yarn, three different types of 88 dtex polyester monofilament yarn and polyester multifilament yarns (167 dtex and 14.5 tex) were used and 14.5 tex polypropylene and 44 dtex lycra multifilament yarns were also used for the face and back side of the spacer fabrics (Table I). These fabrics were developed in Syntax Pvt Ltd Czech Republic.
Findings
The main influence on the water vapour permeability of warp knitted spacer fabrics is the kind of raw material, i.e. fibre wetting and wicking. Also there is no correlation between air permeability and water vapour permeability. It is found that both air permeability and thermal conductivity are closely related to the fabric density. It is also found that the fabric characteristics of spacer fabric show a very significant effect on the air permeability, thermal conductivity and mechanical properties of spacer fabric. Therefore, selection of spacer fabric for winter clothing according to its fabric characteristics.
Practical implications
The main objective of the present study is to produce spacer knitted 3D fabrics suitable for defined climatic conditions to be used as clothing or in sports goods.
Originality/value
New 3D knitted spacer fabrics can be produced with improved comfort properties.
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Jiri Militky, Marie Travnickova and Vladimir Bajzik
The main aim of this contribution is characterization of fabric porosity by the light transmission and comparison of this characteristic with air permeability and idealized…
Abstract
The main aim of this contribution is characterization of fabric porosity by the light transmission and comparison of this characteristic with air permeability and idealized geometrical structure of selected weaves. For characterization of air permeability the classical apparatus has been used. The transmission of light through fabrics has been measured on the system LUCIA for image analysis. The porosity of textiles has been evaluated from corresponding construction parameters and idealized models of fabric geometry. The dependencies between the above mentioned characteristics were formalized by using regression analysis.