Dana Křemenáková

Technical University of Liberec | TUL · Department of Material Engineering

This paper investigates the electromagnetic interference shielding effect and wearing comfort properties of a sandwich material consisting of a surface layer, an electromagnetic interference shielding layer, a thermal insulation layer, and a lining layer. The main aim is to research its potential as a winter jacket’s material for shielding electrom...

With the rapid development of modern science and technology, a kind of invisible pollution named electromagnetic radiation has increasingly attracted the attention of all sectors of society. Therefore, electromagnetic shielding protective clothing is widely used by people for daily life and work. More and more scholars and researchers are paying at...

The efficient absorption of wound exudate and the prevention of soft tissue infection are major concerns in wound repair. Good antibacterial agents and unique wound dressing structures can effectively reduce wound infection, thereby accelerating wound healing. In some double-layer asymmetric wound dressings, antimicrobial agents are incorporated in...

With the development of social science and technology and the improvement of people's living standards, people have put forward higher and higher requirements for the comfort of clothing. In the complex system of the environment-clothing-human body, the thermal comfort of the human body mainly depends on the balance of energy exchange between the h...

The development in the areas of clothing and technical textiles has been described in this chapter. The trends in functional and smart textiles are shown. The basic advantages of textile structures as construction materials are mentioned. The future prognosis of the textile industry focuses on implementing more ecological production, reducing energ...

The changing preferences drive the future of textile products from mass produced to custom-built outputs. The predominant long-term development trend in the field is the integration of fields of chemistry, physics, and engineering for the construction of new textile structures. These clothing textiles are expected to be capable of adaptation to cha...

Paraffin wax (PW) is a typical phase change materials (PCMs) that has been used for thermal energy storage. However, the leakage and low thermal conductivity of PW has limited its application and thermal energy storage efficiency. In this work, PW/expanded graphite (EG) composites were prepared via the melting-blending method. The morphology and th...

Wide applications of plastic/polymer optical fiber (POF), ranging from communication and line lighting, through safety ensuring to decoration purposes and special fashion, have been developed and commercialized because they are light, soft, inexpensive, easily processable, have a large numerical aperture, and are easy to handle. The functionality,...

Fiber engineering and materials science are key technologies driving the development of next-generation textile systems. Exciting new opportunities arise at the interfaces—integrated science—between these divergent disciplines. This chapter aims to discuss some special aspects of the technical design of fibers, yarns, and fabrics. The concept of id...

This paper presents one efficient and accurate EMI shielding performance simulation method for metal particles coated with nonwoven textile-based material with the optimized textile module using the finite element method (FEM) based on the waveguide model. Copper particles coated polyester nonwoven materials with three contents of copper were made...

As more and more attention is paid to the thermal comfort of clothing, academic research on the heat transfer properties of textile materials is becoming more and more important. In recent years, the application of simulation software to analyze the heat transfer properties of fabrics has become a research hotspot. In this paper, the ANSYS workbenc...

High thermostability of phase change materials is the critical factor for producing phase change thermoregulated fiber (PCTF) by melt spinning. To achieve the production of PCTF from melt spinning, a composite phase change material with high thermostability was developed, and a sheath-core structure of PCTF was also developed from bicomponent melt...

Non-woven fabrics are widely used in technical textiles applications and functional clothing. The geometrical model of non-woven structures for special clothing is the significant start point for simulating their properties. This paper demonstrates the application of the statistical fiber-based geometrical method, which can be used to build the non...

The aim of this research was the preparation and characterization of hybrid prepreg tapes from glass multifilament roving (circular cross-section). The fiber, roving, and tape strength distribution was characterized by exploratory data analysis tools (especially quantile-quantile plot) and modeled by the three parameters’ Weibull distribution. For...

A textile material’s electromagnetic interference (EMI) shielding effectiveness mainly depends on the material’s electrical conductivity and porosity. Enhancing the conductivity of the material surface can effectively improve the electromagnetic shielding effectiveness. However, the use of highly conductive materials increases production cost, and...

The main aim of the present study was to investigate the effect of microwave irradiation time on the photocatalytic and physiological comfort characteristics of zinc-oxide-nanorod-coated cotton fabrics. An ultra-fast technique was employed to grow the zinc oxide nanorods on cotton fabrics using a microwave-assisted hydrothermal method. The axial (l...

The main aim of this review is to discuss and explain breakthrough solutions and main improvements in the construction of textile machinery originating in Czech Republic and their influence on processing and quality of textile products. Open-end spinning, jet weft insertion and jet looms, perpendicularly layered nonwovens and needleless electrospin...

Far infrared (FIR) textiles are a new category of functional textiles that have presumptive health and well-being functionality and are closely related to human thermo-physiological comfort. FIR exerts strong rotational and vibrational effects at the molecular level, with the potential to be biologically beneficial. In general, after absorbing eith...

In the current research, we present a single-step, one-pot, room temperature green synthesis approach for the development of functional poly(tannic acid)-based silver nanocomposites. Silver nanocomposites were synthesized using only tannic acid (plant polyphenol) as a reducing and capping agent. At room temperature and under mildly alkaline conditi...

The fabrics with electromagnetic interference (EMI) have been used in various fields. However, most studies related to the EMI fabrics focused on the improvement of the final electromagnetic shielding effectiveness (EM SE) by adjusting the preparation parameters while the breathability of the EMI fabrics was affected and the visible surficial patte...

This work deals with the influence of washing and moisture on the change of air-permeability of cotton fabrics and the impact of different types of seams on air-permeability. It turns out that the effect of the kind of seams does not significantly affect the air-permeability. Repeatable washing has a much more significant impact when the fabric is...

Coronavirus belongs to the novel virulent strains of the respiratory viruses. It is an invisible enemy having significant threats to human health. The major trouble is that the spread of coronavirus is not limited to its transmission from human to human (by contact, fomites, and droplets) but also continue to transmit from contaminated surfaces to...

The main aim of this work is to develop TiO2 nanoflowers coated polyester (PET) fabric for antibacterial and UV protection applications. The TiO2 nanoflowers were grown on PET fabric by a two-step method. In first step, the polyester fabric was seeded using sol-gel method and in second step the nanoflowers were grown on the seeded PET fabric by hyd...

COVID-19, classified as SARS-CoV-2, is causing an ongoing global pandemic. The pandemic has resulted in the loss of lives and has caused economic hardships. Most of the devices used to protect against the transmission of the novel COVID-19 disease are related to textile structures. Hence, the challenge for textile professionals is to design and dev...

Fly ash (FA) is a particulate waste generated from the combustion of coal in thermal power plants. The reuse of fly ash as filler in the epoxy matrix has been studied by many researchers. In this review article, the impact of fly ash morphology and content of fly ash filler on the epoxy matrix‘s mechanical property has been discussed from several a...

Polytetrafluoroethylene (PTFE) is a synthetic fluoropolymer known for its excellent hydrophobic properties. In this work, samples from PTFE dispersions with different combinations of water and carbon microparticles were prepared using an electrospraying method. The morphologies and sizes of carbon particles were investigated and the properties of l...

The commercial availability of inorganic/organic precursors for sol-gel formulations is very high and increases day by day. In textile applications, the precursor-synthesized sol-gels along with functional chemicals can be deposited onto textile fabrics in one step by rolling, padding, dip-coating, spraying or spin coating. By using this technology...

Wide applications of plastic/polymer optical fiber (POF) ranging from communication to decoration have been developed and commercialized, because they are light, soft, inexpensive, easy processing, large numerical aperture, and easy to handle. The most significant features of POF are reviewed, including the materials, properties, and possible appli...

The preparation of functional fabrics with enhanced electrical properties requires a suitable selection of surface modification and particulate systems as fillers. The best choice would be to use materials with low fiber diameters, good shape stability and comfort related properties. In this study, composite nonwoven fabric “Milife” with surface co...

Thermal comfort properties of 3-Dimensional knitted spacer fabrics have been studied in order to replace the existing polyurethane foams in the car seat and back supports. The influence of different characteristics of spacer fabrics, like structure, areal density, thickness and density on thermo-physiological performance has been studied. The poten...

Standard polymer optical fibre (POF) is a dielectric wave guide transferring light or infrared radiation across its axis by the mechanism of total internal reflection on the interface of two materials with different refractive indices [1]. The main requirement for classical POF is to prevent side emission causing loss of transferred light. In the s...

In this paper, the thermal properties of polyester/polyethylene nonwoven thermal wraps of varying thicknesses treated with aerogel were analyzed and compared. The microscopic images were taken by confocal microscope and image analysis to compare the physical structure of the aerogel treated nonwoven fabrics. Thermal conductivity and thermal resista...

Among many other materials for the reinforcement of composites, technical fabrics are increasingly being used, especially from glass tows, which have good mechanical properties. In this paper, glass fiber based tapes containing special types of resins, in pre-condensate form with application in technology of composites preparation by precise windin...

Electromagnetic interference takes place due to the increase in complexity of electronic devices/systems in the form of higher packing density for quick response. To overcome its adverse effects, the effective shielding of components is needed abundantly. This leads to an increase of undesirable influence of electromagnetic signals and troublesome...

At present, phosphorescent materials are used in a variety of fields from medical applications to common subjects - such as children's toys glows in the dark. Our research deals with the use of phosphorescent materials in the garment industry, especially for use in clothes with high visibility. From this point of view, the lifetime (glowing time) o...

Start Optical fibers are one category of specialty fibers originally developed for light transmission (fiber optic) and information (optical cables). The fiber consists of a core surrounded by a cladding. Standard polymer optical fiber (POF) is transferring light across its axis by the mechanism of total internal reflection. In the side emitting pl...

Polytetrafluoroethylene (PTFE) which is also called as "TEFLON" is a synthetic fluoropolymer of tetrafluoroethylene that has wide applications due to its differentiating properties. In this study, different PTFE dispersions for preparation of polytetrafluoroethylene mesoporous active membranes doped by basalt and carbon particles which were created...

The utilization of 3-Dimensional (3D) porous textile materials by the civil and mechanical engineers for improved thermo-acoustic environment has widened the research scope. Unconventional three-dimensional textile material which grabs the attention of the researchers for multi-functional applications is spacer fabrics. Since spacer fabrics have su...

Thin polymeric optical fiber (POF) with good illumination is appreciated when POF is utilized as the luminous element in fabric structure. The CO2 laser cutting is employed to create a micro-lens in POF end to optimize the light gathering or light distribution in textile fields. The image analysis implies that the end shape varies from a polynomial...

A strong and even side illuminating effect is required for plastic optical fibers (POFs) in illuminating applications. In consideration of good flexibility and illumination, side emitting POFs with 2 and 3 mm core diameters are preferred, especially in active illuminating safety textiles. However, the side illumination intensity of side emitting PO...

The nano fibrous assemblies (membranes) are extremely thin in the order of a few microns only. They have often relatively smaller porosity compared to micro fibrous membranes. Thus by considering their porosity as well as thickness, the nano fibrous membranes do not offer so huge real surface area as is evaluated from standard approach (surface are...

In this research work, the effect of various construction parameters and structural characteristics of weft knitted spacer fabric on the compressive behavior and energy absorption capability was studied. The potential compression mechanism of the fabric was identified with support of the compression stress-strain curve, work done and efficiency at...

Porosity of textiles is one of the main factors influencing their thermal conductivity and insulation. Porosity in textile fabrics is the combination of fiber porosity, yarn packing density, and voids due to fabric construction. It is shown that assemblies from very fine fibers tend to suppress radiation and convection heat transfers because of hug...

Nowadays, the utilization of 3-Dimensional (3D) porous textile materials by the civil and mechanical engineers for improved acoustical environment and shear behavior during composite forming has widened the research scope. Since spacer textile fabrics have superior functional characteristics such as acoustical, thermal and shear characteristics com...

Spacer fabrics consist of three layers of fabrics which have ability to complement and maximize the essential thermal clothing comfort for various applications. Clothing comfort is also defined by the tactile sensations felt by a subject through the mechanical interactions between the body and the garment. In this research work, the thermal and com...

An experimental and image analysis procedure were used to study the intra-ply shear behaviour of 3-dimensional weft knitted spacer fabrics. In this work, the picture frame fixture was designed to determine its suitability for measuring intra-ply shear behaviour of 3D spacer fabric. The nonlinear behavior of shear force versus shear angle and the de...

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...

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. The...

Plastic optical fiber (POF) is highly appreciated for its applications in glowing textiles. However, fabricating thin POF with good side illuminating effect is a challenge due to the complicated manufacturing processes. CO2 laser treatment is normally applied to enhance the surface roughness without significant influence on other properties of mate...

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,...

CO2 laser treatment can increase the surface roughness of plastic optical fibres (POFs) with the diameter of 0.5 mm and enhance the input intensity and attenuation coefficient accordingly, which is supposed to weaken the side emission of POFs in long distance above 375 mm. TiO2 particles were applied to improve the increasing optical loss of POFs b...

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,...

Convective heat transfer plays a very important role in thermal resistance of textiles due to its porous structure, and the thermal resistance of textiles will be quite different when they are investigated under different testing standards and conditions. Nowadays, however, there is still no commercial instrument for evaluating the thermal resistan...

Flex fatigue behaviour of plastic optical fibres (POFs) with the diameters of 0.2 and 0.3 mm under different pretensions is measured with fatigue life curve by flexometer. The fatigue sensitivity coefficient is calculated by the linear fitting curve of normalised stress versus logarithm of bending cycles. The residual modulus is investigated during...

This paper analyzes the relationship between technological parameters of spinning of 100% CV Vortex yarns of different counts and its selected geometrical parameters (a lead of helix of wrapping fibre ribbon, yarn diameter) as well as yarn properties. The number of twist of wrapping fibre layer is determined. The effect of the yarn delivery speed,...

Generally, the thermal property of textiles is predicted without considering convective and radiative heat transfer, but heat transfer through nonwoven fabrics may include conduction through solid fibers, conduction through air in the interfiber spaces, free convection, and radiation due to its unique structure. Therefore, the purpose of this work...

The purpose of the paper is to describe the construction of utility value U based criterion suitable for expressing pseudo-distance in the area of computer aided products design. The application of pseudo-distance is demonstrated on the example of characterization of the effect of catalysts on the quality of crease resistant finished fabrics under...

In the side emitting plastic optical fibres (SEPOF) the light leaks out from their surface. The main aim of this contribution is evaluation of SEPOF loss of illumination intensity in dependence on the distance from light source and prediction of real illumination length. The special device for measurement of light intensity on surface and cross sec...

In this research, the impact of UV-weathering is evaluated for flex fatigue of side emitting plastic optical fibers (POFs). Two different brand POFs (trade names: Grace & Hypoff) with three different diameters each are used for the experiment. All POFs are tested for the number of bending cycles to break before weathering and after 1 year equivalen...

Mechanical tensile failure of naked plastic optical fiber (POF) is significant for its applications in shining textiles and was investigated by Instron. The results indicate that both two parameter Weibull distribution and three parameter Weibull distribution could be utilized for the evaluation of tensile failure and the elastic-plastic behavior o...

Mechanical properties are significant for plastic optical fibers in weaving or knitting processes in textile applications. Both core and cladding in plastic optical fiber contribute to the mechanical properties. Nanoindentation is a promising method to investigate the mechanical properties (hardness, stiffness and Young's modulus) in nanoscale disp...

An exploratory work has been carried out in the field of three phase composites in which flyash nanoparticles were incorporated in addition with 2D and 3D glass woven fabrics while preparing composites. These flyash nanoparticles were prepared by high energy ball milling technique & its effect on functional properties of composites were observed. F...