The Principle of Microporosity in the Production of High Performance Thermal Insulating Materials

摘要

Knowledge of the coefficient of thermal conductivity of the materials used is of great importance in the production of thermal insulation materials for high temperature applications. Thermal conductivity is either the only or the most important parameter for evaluating the application of these materials. Heat is transported by various physical processes: conduction, radiation, convection. The effective coefficient of thermal conductivity has a minimum which is dependent on porosity and density. With increasing temperatures, the minimum shifts to lower porosities. For practical use that means: every thermal insulation material has an optimal porosity or density at specific application temperatures.