![Page 1: Measurement of dielectric properties of textile materials and their applications](https://reader035.vdocument.in/reader035/viewer/2022070515/5879a8871a28ab082c8b757b/html5/thumbnails/1.jpg)
MEASUREMENT OF DIELECTRIC PROPERTIES OF TEXTILE MATERIALS AND THEIR APPLICATIONS
Compiled ByMd. Isarot HossanID: 142014001Department of Textile EngineeringGreen University of Bangladesh
![Page 2: Measurement of dielectric properties of textile materials and their applications](https://reader035.vdocument.in/reader035/viewer/2022070515/5879a8871a28ab082c8b757b/html5/thumbnails/2.jpg)
CONTENTIntroduction.Dielectric properties depend on.Dielectric Properties of Polymers.Measurement Methods of Dielectric Properties
of Fibers and Textiles.Factors affecting Measurement of Dielectric
PropertiesApplications of Dielectric Properties in
Textiles
![Page 3: Measurement of dielectric properties of textile materials and their applications](https://reader035.vdocument.in/reader035/viewer/2022070515/5879a8871a28ab082c8b757b/html5/thumbnails/3.jpg)
INTRODUCTION.Fibers and textile materials have been the subject of study in relation to electrical and dielectric behavior for a long time. Research on the electrical and dielectric properties of such materials has been carried out in many directions.
![Page 4: Measurement of dielectric properties of textile materials and their applications](https://reader035.vdocument.in/reader035/viewer/2022070515/5879a8871a28ab082c8b757b/html5/thumbnails/4.jpg)
DIELECTRIC PROPERTIES DEPEND ON
Textile materials such as fabrics and yarns are basically assemblies of fibers. The fibers are generally made of linear long chain polymers and have a large length to diameter ratio.Hence, the behavior of textile materials as dielectrics depends on the dielectric behavior of the fibers and also on the fiber forming polymers.
![Page 5: Measurement of dielectric properties of textile materials and their applications](https://reader035.vdocument.in/reader035/viewer/2022070515/5879a8871a28ab082c8b757b/html5/thumbnails/5.jpg)
DIELECTRIC PROPERTIES OF POLYMERS.
Based on such studies, the following types of molecular motion and their associated dielectric relaxation were identified:
(i) Primary main chain motion in both crystalline and amorphous regions,(ii) Secondary main chain motion in both crystalline and amorphous regions,(iii) Side chain motions, and(iv) Impurity motions.
![Page 6: Measurement of dielectric properties of textile materials and their applications](https://reader035.vdocument.in/reader035/viewer/2022070515/5879a8871a28ab082c8b757b/html5/thumbnails/6.jpg)
DIELECTRIC PROPERTIES OF POLYMERS.
The relaxation processes that occur in a particular polymer are denoted as α,β,γ,σ in the order of the increasing frequency at which they occur for a fixed temperature.
![Page 7: Measurement of dielectric properties of textile materials and their applications](https://reader035.vdocument.in/reader035/viewer/2022070515/5879a8871a28ab082c8b757b/html5/thumbnails/7.jpg)
MEASUREMENT METHODS OF DIELECTRIC PROPERTIES OF FIBERS AND TEXTILES..
Shaw and Windle reported a measurement technique at 3 GHz using a modified cavity resonator which is schematically shown in Figure1. When a cavity is excited to resonance at a frequency f0, in the fundamental or TM010 mode, the electric field in the cavity is directed parallel to the cylinder axis.
![Page 8: Measurement of dielectric properties of textile materials and their applications](https://reader035.vdocument.in/reader035/viewer/2022070515/5879a8871a28ab082c8b757b/html5/thumbnails/8.jpg)
MEASUREMENT METHODS OF DIELECTRIC PROPERTIES OF FIBERS AND TEXTILES….
The effectiveness of such a resonator for dielectric constant measurements is due to the fact that when a dielectric specimen is placed in the cavity the resonance frequency is changed and such change in frequency can be related quantitatively to the dielectric properties of the specimen.
![Page 9: Measurement of dielectric properties of textile materials and their applications](https://reader035.vdocument.in/reader035/viewer/2022070515/5879a8871a28ab082c8b757b/html5/thumbnails/9.jpg)
MEASUREMENT METHODS OF DIELECTRIC PROPERTIES OF FIBERS AND TEXTILES….
Fig. 1 — Cross-sectional view of cylindrical cavity resonator (A – type N cable connectors, B – plugs to permit specimen to be inserted along axis of resonator, C – cylinder wall, and D – end plates perpendicular to cylinder axis)
![Page 10: Measurement of dielectric properties of textile materials and their applications](https://reader035.vdocument.in/reader035/viewer/2022070515/5879a8871a28ab082c8b757b/html5/thumbnails/10.jpg)
MEASUREMENT METHODS OF DIELECTRIC PROPERTIES OF FIBERS AND TEXTILES….
Fig. 2 — Cavity resonator for use with a single fiber at 26 GHz
![Page 11: Measurement of dielectric properties of textile materials and their applications](https://reader035.vdocument.in/reader035/viewer/2022070515/5879a8871a28ab082c8b757b/html5/thumbnails/11.jpg)
FACTORS AFFECTING MEASUREMENT OF DIELECTRIC PROPERTIES
Various factors that affect the measured values of dielectric Properties. Some of the major external and internal factors are given below: External Factors. Frequency-between 500 Hz and 3 MHz Temperature-mixture in a temperature range
0.5° – 95° C Internal Factors Moisture-between 0% and 25% Packing Density-should not vary with mass
![Page 12: Measurement of dielectric properties of textile materials and their applications](https://reader035.vdocument.in/reader035/viewer/2022070515/5879a8871a28ab082c8b757b/html5/thumbnails/12.jpg)
APPLICATIONS OF DIELECTRIC PROPERTIES IN TEXTILES
Moisture Content Measurement in Textiles. Evenness Measurement in Textiles. Dielectric Heating of Textiles. Sensor Type Applications in Textiles.
![Page 13: Measurement of dielectric properties of textile materials and their applications](https://reader035.vdocument.in/reader035/viewer/2022070515/5879a8871a28ab082c8b757b/html5/thumbnails/13.jpg)
ANY QUESTION???
![Page 14: Measurement of dielectric properties of textile materials and their applications](https://reader035.vdocument.in/reader035/viewer/2022070515/5879a8871a28ab082c8b757b/html5/thumbnails/14.jpg)
THANK YOU