Materials that can block heat transfer are collectively referred to as thermal insulation materials. 3 ways of heat transfer: conduction, convection and radiation, the three way is the proportion of ordinary brick buildings in the heat exchange in 10% to 20%: conduction, convection, radiation 70%, metal building heat exchange ratio: 25% 20% 55% for conduction, convection, radiation.
Heat exchange is carried out through the conduction pathway, which is generally blocked by porous material or filling gas:
The porous materials are divided into two kinds of solid materials, such as bubble like solid materials and particles. Heat insulation materials with a large number of openings or more openings are more insulated than those with a large number of closed pores due to their closer contact with the direction of heat transfer.
Filling gas. Most of the heat in the heat insulation material is transmitted from the gas in the pore. Therefore, the thermal conductivity of insulating materials is largely determined by the type of filling gas. If helium or hydrogen is filled in cryogenic engineering, it can be used as the first order approximation. It is considered that the thermal conductivity of insulating material is equal to the thermal conductivity of these gases, because the thermal conductivity of helium and hydrogen is relatively large. Vacuum is the most barrier to conduction, but it is difficult to realize mass production in the field of material application, and cost is also a key factor restricting its development.
To solve the air convection caused by heat exchange is relatively easy to implement, properties of plastic films generally have the air barrier, we produce EPE, PET or XPE are aluminum surface insulation materials, can prevent convection air barrier penetration.
The last one is the radiation, thermal radiation accounted for a large proportion in the heat exchange building, to prevent or reduce heat radiation is the most effective method is to use the high light reflection material, we produce aluminum bubble film, bubble film of pure aluminum composite, pure aluminum composite pearl cotton and other products, can be very effective in preventing heat the radiation exchange.