Dragana D. Cerovic

Dielectric investigation of some woven fabrics

In this paper, we have investigated the temperature dependence of dielectric properties (relative dielectric permeabilities and dielectric tangents of losses) for woven fabrics of hemp, jute, flax, cotton, polyester (PES), cotton-PES mixture, and wool. The measurements have been carried out at a temperature range from −50 to 50 °C in the electric periodic field at a frequency 1 MHz in vacuum. For the same specimens, the values of the dielectric properties have also been measured at an air temperature of 21 °C and at relative humidities of 40%, 60%, and 80%. At different frequencies from 80 kHz to 5 MHz, the dielectric properties have been measured at a relative humidity of 40% and at a temperature of 21 °C. An investigation of the dielectric properties of woven fabrics can provide a better understanding of the relation between the dielectric properties of woven fabrics and the different raw material compositions, temperatures, relative air humidities, and frequencies for specimens. Hence, this investigati...

Assessment of Electrical Behavior of Non‐Woven Textile Materials

Non‐woven textile materials have been increasingly used for a variety of applications in industry and daily life. This imposes a need for the investigation of electrical properties in different conditions of their usage. In the scope of this investigation, electrical conductivity and dielectric properties such as relative dielectric permeability and dielectric loss tangent of various polyester non‐woven textile materials were determined. Experimental values of frequency were in the limits of 80 kHz to 2 MHz at relative environmental humidity of 30%. In addition, aimed at discovering the behaviour of investigated material from the aspect of electrical conductivity in various conditions of environmental humidity, the electrical conductance was measured both at 30% and 80% of relative environmental humidity in the electric periodic field at the frequency of 1 MHz. All measurements were realised at the temperature of 30° C. Obtained results showed that with the increase of frequency of electric periodic field electrical conductivity of tested samples increases, while the values of dielectric properties decrease. Furthermore, it was found that the increase of relative environmental humidity provokes the increase of electrical conductivity of tested non‐woven samples.Non‐woven textile materials have been increasingly used for a variety of applications in industry and daily life. This imposes a need for the investigation of electrical properties in different conditions of their usage. In the scope of this investigation, electrical conductivity and dielectric properties such as relative dielectric permeability and dielectric loss tangent of various polyester non‐woven textile materials were determined. Experimental values of frequency were in the limits of 80 kHz to 2 MHz at relative environmental humidity of 30%. In addition, aimed at discovering the behaviour of investigated material from the aspect of electrical conductivity in various conditions of environmental humidity, the electrical conductance was measured both at 30% and 80% of relative environmental humidity in the electric periodic field at the frequency of 1 MHz. All measurements were realised at the temperature of 30° C. Obtained results showed that with the increase of frequency of electric periodic field...

Structural design of face fabrics and the core as a premise for compression behavior of 3D woven sandwich fabric

In this work, an experimental study on compression properties of two E-glass 3D woven fabrics, known as integrally woven sandwich fabrics, has been presented. Compression properties of 2D face fabrics and the core, as structural parts of integrally woven sandwich fabric, have also been investigated. Compression behavior of the samples (compressibility, compression work, and compressive resilience) was analyzed from the aspect of the weave design of face fabrics and the core structure (shape and density of the pile yarns). Results of the investigation showed that “8” shaped core structure, the greater surface density of the pile yarns, and the less compact structure of face fabrics ensure better compression properties of 3D fabrics. Specific weave design of face fabrics and the structure of the core significantly influence the behavior of 3D fabrics during successive increases, followed by a gradual decrease of pressure. During the loading of 3D woven structures, three regions of curves can clearly be seen compared to two regions which are registered at 2D face fabrics. Concerning 3D woven fabrics, the first region represents compression of the core, the second region is prolonged core compression and the third region refers to the simultaneous compression of pile yarns in the core and face fabrics. The density of pile yarns plays an important role in the region 1. In region 2, both the shape and density of the pile yarns are significant. Influence of the weave of face fabrics on compression behavior of 3D fabric can be noticed to a lesser extent in the region 2 and, especially in the region 3, where highly packed yarns assemblies are created.

Evaluation of the quality of clothing fabrics in terms of their compression behaviour before and after abrasion

In this work, the compression behaviour of clothing woven fabrics, before and after abrasion on the Martindale’s device, has been examined. Plain and 3/1 twill weave fabrics from cotton and cotton/polyester fiber blends served as experimental material. Compression behaviour of the investigated fabrics was analyzed taking the compressibility, thickness loss, and compressive resilience into consideration. Obtained results showed that the changes of compression properties are in a function of the structural parameters of tested fabrics, as well as damages caused by abrasion. Besides, the results of compressibility, thickness loss, and compressive resilience enabled establishing the quality of examined fabrics based on values of complex criterion. Calculated value of complex criterion pointed to the conclusion that abrasion causes the reduction of quality of tested fabrics in a small extent. Twill weave fabric made of cotton/polyester fiber blends is characterized by the best quality while cotton plain weave fabric has the worst quality, before as well as after abrasion.