The silica aerogel composite thermal insulation material can well inhibit the above three ways of heat conduction.

The size of the thermal conductivity of a solid, from the perspective of thermal insulation materials, is only related to the inherent thermal conductivity of the material itself and the density of the material. In order to reduce the density of the material, the general heat insulation materials adopt the method of making pores. The porous silica aerogel composite heat insulation material developed by our company has achieved the extreme in this regard; the porosity of the material accounts for more than 90% of the entire volume, so the material density is extremely low, only four parts of water. One or so.

However, because most insulation materials contain a large number of pores, the convective heat conduction of the gas contained in the pores becomes a key heat conduction way. According to research, convective heat conduction is only related to gas properties and pore size. Different thermal insulation materials use different methods to reduce the convective heat conduction of the material. For example, polyurethane foam is filled with freon gas in the pores, and the thermal conductivity of this gas is only one-third of that of air, thus obtaining superior thermal insulation performance. However, because it can severely destroy the ozone layer, it has been replaced by carbon dioxide, etc. However, carbon dioxide, etc., as a filled polyurethane material, has the problem of high thermal conductivity. This material takes another approach, which is to reduce the diameter of the pores to reduce the thermal conductivity of the air in the pores. In this material prepared by a special process, the average diameter of the pores is only 50-60 nanometers, which is about one thousandth of the diameter of the hair, and the average free path of air molecules is about 70 nanometers. In such a small gap, the air can hardly flow, thereby inhibiting the convection and heat conduction of the air.

In addition, due to the existence of a large number of tiny holes, this material has almost an infinite number of hole walls, and these hole walls can be regarded as radiation reflecting surfaces and refracting surfaces. This material with a thickness of one millimeter contains tens of thousands of reflective and refraction surfaces, which effectively blocks radiation and heat conduction. At the same time, in order to better suppress the radiant heat conduction of the material, some nano-level anti-radiation substances are added to this material, which can reflect/absorb heat radiation well. Therefore, this material also has a good inhibitory effect on radiant heat conduction.