Microwave Technology of Liquid-Glass Heat-Insulating Materials Based on a Granular Product

Abstract

The paper investigates the properties of liquid glass thermal insulation products obtained on the basis of granular products under the influence of microwave radiation. Due to the volumetric heat release in the thickness of the liquid glass composition, it is possible to obtain homogeneously structured materials by applying the technology of simultaneous porosization with volumetric expansion of both granules and binder. Thanks to volumetric heating and the mechanism of "non-thermal" effect of microwave radiation on the processing objects, the duration and temperature of their heating is significantly reduced, as well as the operational properties of the products are improved. The properties of materials obtained by this technology are compared with the properties of materials obtained by binding pre-swollen granules. It was proved that the simultaneous swelling of granules with a binder made it possible to obtain materials of a monolithic, uniformly porous structure with high physical and mechanical parameters and an order of magnitude lower indicators of water absorption and sorption moisture due to the dense packing of the granules and the uniform distribution of the binder in the intergranular space. The developed technology for the production of composite materials in the form of heat-insulating products of various configurations by means of simultaneous porosization with volume expansion of granules and binding under the action of microwave radiation allows to obtain materials with a better set of operational characteristics than in the case of binding pre-swollen granules at lower energy costs for their production because it excludes the stage of separate swelling of the granules. The resulting composite thermal insulation materials do not deform and have a fairly high strength for their average density. They are practically incompressible, and this is a very important fact, since the compression of heat insulating materials over time leads to an increase in its thermal conductivity and a decrease in the heat-shielding properties of the structure.