Solar film insulation principle

- Jan 02, 2019-

Solar film insulation principle

The birth of the solar film has completely changed the life of our bare sun in the sun, and the principle of heat insulation of the solar film is not from the special research of the laboratory, but it is the accidental discovery of a great inventor. The inventor is Thomas Alva Edison, who is known as the "king of the world's invention." In 1888, after Edison invented the phonograph, he turned his attention to the R&D film. During the experiment, he took a series of photos and showed them quickly and continuously on the screen to create the illusion of movement. The vectors of these photos It is the well-known "film". At this time, he found a very interesting phenomenon, that is, the film that is also exposed to strong light and strong heat, the deeper the color, the more it can block the heat emitted by the absorption lamp. Edison remembered this discovery in his work notes. It was precisely this accidental discovery that laid the theoretical foundation for the early solar film.

In modern solar film production technology, aluminum, gold, copper, silver and other metals are often made into layers of dense high-insulation metal film by vacuum spraying or magnetron sputtering [1]. The electrons (free electrons) in the outer layer of the metal material are generally not bound by the nucleus. When illuminated by light waves, the electric field of the light wave causes the free electrons to absorb the energy of the light, and the oscillation of the same frequency as the light is generated, and the oscillation is released again. Light of the same frequency as light is called reflection of light. The higher the conductivity of the metal, the shallower the penetration depth and the higher the reflectivity. These metal layers selectively reflect various thermal energy sources in the sun, including infrared, ultraviolet, and visible heat, and then combine with the color of the film to absorb solar heat radiation, and then release it twice, with outdoor The air flow takes away some of the heat, which effectively acts as a heat insulator.

Metal reflective materials for anti-riot membranes mostly use materials of high conductivity such as gold, silver, aluminum and copper. The reflectivity of several metal reflective films at different wavelengths is as follows:

Metal Type 800nm Reflectance % 650nm Reflectance % 500nm Reflectance %

Aluminum Aluminum 86.7 90.5 91.8

Silver Silver 9.2 98.8 97.9

Gold Gold 98.0 95.5 47.7

Copper Copper 98.1 96.6 60.0