Method for measuring dielectric losses in textile materials

Authors: DUBRAVKO ROGALE, SNJEŽANA FIRŠT ROGALE, ŽELJKO KNEZIĆ

Company/Institution: UNIVERSITY OF ZAGREB FACULTY OF TEXTILE TECHNOLOGY

Country: Croatia

e-mail: > dubravko.rogale@ttf.unizg.hr

web: https://www.ttf.unizg.hr/

Parts of protective clothing made of artificial polymer materials are connected using a high-tech method with a high-frequency electromagnetic field, which ensures airtight and watertight connections. The energy required and the bonding time depend on a number of parameters. One of the most important is the dielectric loss factor in the material. The dielectric losses are known for pure and homogeneous materials (polyurethane, polyamide, polyester, etc.), but the problem of determining the dielectric losses arises when, for example, textile materials are coated with one type of material (e.g. polyurethane) and made of another type of material (e.g. polyester), where the fabric or knitted fabric consists of variable geometric structures with air spaces in the presence of dyes and other textile finishing materials. The dielectric losses can then be measured using a special measuring method consisting of a variable frequency generator, a measuring bridge, a bridge equilibrium indicator, a measuring capacitor with the tested material and a computer to calculate the dielectric losses based on the measured parameters (reactance and ohmic resistance) of the sample in the measuring capacitor.