Testing the properties of composites of materials screening low- and medium-frequency electromagnetic fields

The aim of the project was to develop model solutions in materials and clothing with properties that screen low- and medium-frequency electromagnetic fields (in the 50 Hz - 30 MHz range) for workers who are occupationally exposed to those fields.To determine the dependence of the efficiency of screening an electromagnetic field on the structure of the material, principles for model constructions of flat textiles with properties that screen low- and medium-frequency electromagnetic fields were developed. Numerical simulations were conducted regarding screening an electromagnetic field by selecting eight models of structure of textiles for four different frequencies ( 50 Hz, 1 kHz, 500 kHz, 27 MHz). The modelling concerned the transmitting structure built into the textile that acted as the active component, whose structured defined the screening of the electromagnetic field. The results of the simulation made a qualitative assessment of the screening properties of the selected structures of materials possible. Then eight textiles were produced.To supplement the tested materials, three materials available on the market were selected with active carbon and two basalt materials with steel yarn. Altogether, thirteen materials, including two wovens and eleven textiles, were selected to test the efficiency of screening low- and medium-frequency electromagnetic fields.Criteria for assessing clothing protecting against low- and medium-frequency electromagnetic fields were developed in view of meeting the requirements of directive 89/686/EEC.