Off-line low-e glass
Low-E glass(Low emissivity glass) is also called low radiation coated glass, it is one kind of special glass which coated with multilayer of very low surface radiation rate of metal or other compounds on the quality float glass by using magnetic sputtering method. It has low thermal conductivity and high light transmittance, ensuring visible light transmittance and reducing light pollution based on prevention of heat losses.
According to glass coating technology , it has online Low-E coated glass and offline Low-E coated glass.
Off-line low-e glass:
Variety and Property
Because of the constraints of offline Low-E glass crafts and glass film structure, it can not have monolithic use, can not be late tempered, laminated, even produce hot-bending glass. And offline Low-E glass can't exist independently in the air, so it is difficult to meet the requirements of the patch in construction industry.
Offline Low-E glass is used magnetron sputtering process, single silver or double silver functional film is formed on the surface of the glass. The two sides of the silver should be coupled with a multilayer dielectric film. This film has poor firmness and the silver is easily oxidized, which belongs to the "Soft Film". Offline Low-E glass should be processed to hollow glass in a short time, and the edge of the film should be removed in the composition process. Due to the weak respiration of hollow glass, water vapor, sulfide, oxide can enter the cavity easily, leading to the gradual loss of thermal insulation performance and discoloration in the appearance of offline Low-E glass, so it must be processed into hollow glass in a very short period of time. With this feature shelf life of the best product sold by the current offline manufacturers is only 10 years.
Energy Saving and Durability
Offline Low-E glass is used metallic silver as functional radiation film of far infrared thermal radiation, its initial rate can reach 0.1 to 0.15, which is similar to offline heat transfer coefficient K value at the beginning. But the contaction between silver and micro-sulfur and oxygen in the air will occur chemical reaction, once the film has slight oxidation, its radiation rate will be significantly large, thus leading to the increase of heat transfer coefficient K value in the glass, meanwhile, its thermal insulation performance becomes bad, if too serious, it can even cause the discoloration of glass film.
For more information,please contact: Omar Sui