PRINCIPLES FOR DEVELOPING LIQUID MIXTURES FOR SCREENING WIDE FREQUENCY RANGE ELECTROMAGNETIC FIELDS

Abstract

Purpose: A liquid material based on commercially available paints and fine iron ore concentrate has been created. With a filler content of 60-70 %, the coefficients of shielding of the electric field of industrial frequency is 2,6-9,1; magnetic field of industrial frequency is 4,5-6,2; electromagnetic field of ultrahigh frequency is 4,4-8,5. At the same time, the reflection coefficients of electromagnetic waves are at least twice lower than those of metal screens. Method: A calculation tool is provided for converting the weight content into the volume content of the shielding filler. This makes it possible to apply the Lorentz and Maxwell-Garnett ratios to predict the electrical and magnetic properties of metal dielectrics. To determine the reliability of adhesion of the obtained mixtures with the application surfaces, the study of the chemical and colloidal properties of the mixtures for application on gypsum board has been performed. Scientific novelty: It is established that the reduction of surface tension, surface wetting angle, work of adhesion, cohesion and wetting forces, spreading coefficient are within the limits that ensure the reliability and durability of adhesion of the material to surfaces. Results: It is shown that the reduction of the protective properties on the water-dispersion carrier is due to the oxidation of the filler. Liquid compositions are made on the basis of a number of paints and varnishes and iron ore concentrates, which can cover large surfaces in various shapes and configurations. Practical significance: In order to use the obtained mixtures in the fields of ensuring the electromagnetic compatibility of electrical and electronic equipment, it is necessary to increase the protective properties. This is possible by increasing the concentration of the shielding filler or increasing the specific conductivity of materials in the solid state by adding to the liquid mixture of fine material with high conductivity.