Vladimir Bajzik

Air permeability and light transmission of weaves

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.

Influence of washing/ironing cycles on selected properties of cotton type weaves

Describes an experiment designed to investigate the influence of washing/ironing cycles and softening after sanforization on the hand grade, shrinkage and surface roughness of three selected cotton weaves for men’s shirts. Constructs the ANOVA type models with or without interactions, on the basis of the experimental results.

Surface Roughness and Fractal Dimension

Surface roughness is one of the main characteristics of fabric responsible for hand feeling. By using KES, the surface height variation (SHV) trace is obtained. For characterization of roughness the mean absolute deviation (MAD; denoted by Kawabata as SMD) is usually used. The main aim of this work is quantitative description of complexity of roughness based on the SHV. The procedure of surface complexity parameters evaluation from SHV traces is described. The core is inspection of power spectral density and variogram (or autocorrelation function) behavior and classification of SHV signal to some groups. For individual groups, fractal dimension and surface roughness characteristics are computed by suitable methods. Proposed procedure was checked on the simulated SHV profiles and on practical examples.

Thermal resistance models of selected fabrics in wet state and their experimental verification

This study investigated the structural model of textile fabrics affected by moisture. The model has been verified through five fleece fabrics made up of various textile materials and subjected to several mechanical surface treatment levels. Thermal resistance is one of the key parameters of thermal comfort along with water vapor permeability. In recent times, a keen interest has been focused on the mathematical modelling of this parameter and its experimental verification. However, most of these efforts are made to describe dryness in thermal resistance of fabrics, ignoring the wet condition found in protective and outdoor clothing. To determine the thermal resistance value of the studied fabrics, the ALAMBETA semiautomatic nondestructive thermal tester was used. The findings show that the proposed model displays substantial harmony with the experimental data.

Protective Clothing Using Nanofibers

Currently many different types of protective garments are used designed to protect the wearer against biological contamination (e.g., bacteria) and mechanical impurities (such as dust, drops of technical fluids, etc.). Their disadvantage is that, thanks to the materials used in the requirement of a high level of protection for the user, a very low permeability even to zero, so that for example, do not allow to remove moisture and heat from the users body and thus their use is quite uncomfortable, and conversely, in case of the requirement of good breathability and high comfort of application have very little effectiveness in detecting biological and mechanical impurities, which is not sufficient for a number of disciplines.

Surface roughness of heat protective clothing textiles

The surface roughness is one of the main parts of hand prediction. Classical method of surface roughness measurements is based on the surface profile measurement. Characteristic of roughness is then variation coefficient of surface profile (surface height variation). The main aim of this work is to estimate the surface profile complexity by using variogram (structure function). The surface profile variation is classified to the group according to short‐ and long‐range dependence. The concept of fractal dimension is proposed especially for long‐term correlation cases. The applicability of the proposed approach is demonstrated on the typical heat protective clothing fabrics and compared with the results of surface roughness evaluated by the KES system.

Effect of Biopolishing On Warm–Cool Feeling of Knitted Fabric: A Subjective and An Objective Evaluations

Abstract Soft and clean surface of fabric without any floating fibers is one of the factors important for better marketing of clothing. The most common method for having such clean fabric surface is the removal of protruding (floating) fiber from the surface of the fabric. Many studies have proved that enzymatic treatment, commonly called biopolishing, removes the floating fibers from the surface of fabric and gives a smooth surface to the fabric. This study is an effort to assess and measure the impact of biopolishing of knitted fabric through objective and subjective evaluation on warm-cool feeling of fabric because of change in surface profile of the fabric. For testing purposes, 31 knitted fabric samples of various kinds were produced. Alambeta has been used for measuring thermal absorptivity values of fabric. Thermal absorptivity is an indicator of warm-cool feeling. For subjective evaluation, a group of 30 people were asked to give their opinion about warm-cool feeling. Both subjective and objective assessments confirm that biopolishing has a significant impact on warm-cool feeling. Fabric gives cool feeling after biopolishing. This study explores that clean surface will have higher thermal absorptivity and will give cool feeling when it will be touched by human skin.

Effect of the Process of Lamination Microporous Nanofiber Membrane on the Evaporative Resistance of the Two-Layer Laminate

This thesis deals with the assessment of the effect of the process of lamination microporous nanofiber membrane on the overall evaporative resistance of the two-layer laminate. For most multi-layer materials, lamination process is due to the deterioration of some properties of the whole laminate, particularly to the increase of the evaporative resistance. The authors of this thesis investigate the effect of the lamination primarily on the evaporative resistance of two-layer laminates. The study deals with the relations of volume porosity with the values of the evaporative resistance of the laminate too. In this thesis are both measured the separated layers of selected materials (upper material and the membrane), then the surface materials with the coated lamination points and subsequently created two-layer laminates.

Thermal Absorptivity Model of Knitted Rib Fabric and its Experimental Verification

Abstract Thermal absorptivity is an indicator of warm and cool feeling of textile materials. An equation based on thermal absorptivity of polyester in solid form, porosity of a fabric, and relative contact area of human skin and fabric surface has been developed to characterize thermal absorptivity of fabric. For verification of suggested model, 15 knitted rib fabrics were produced using 100% polyester yarn and having different surface profile. ALAMBETA semiautomatic non-destructive instrument has been used for measuring the effective thermal absorptivity of knitted rib fabric. It was found that the suggested simple theoretical model exhibits significant agreement with the measured thermal absorptivity values of knitted rib fabric, which endorsed the approach applied.

Polyurethane Coating on a Supporting Layer of Polymeric Nanofibers

Suitability of nanofiber layers for various applications is given by their morphological structure and physical properties. Structure of polymer nanofibre layers is characterized by very small diameter of the fibers and by large specific surface. For these features can polymer nanofibre membranes be widely used for special purposes- sport ,army and outdoor clothing. Thanks to the diameter and large specific surface the polymer nanofibre layers were used as a supporting structure for polyurethane hydrophilic coating. The main goal was to create 100 per cent wind resistant and water resistant coating with increased ability of steam permeability.