The classification of the polaroid
The first category: iodine polaroid. The polaroid is composed of pva and iodine, this type of polaroid in polarized light will have a lot of share the big cake, is the current mainstream products. Iodine is a polaroid is easier to get higher transmittance and optical properties of high degree of polarization. But its heat resistance and moisture resistant to belongs to the poor.
The second category: dye is a polaroid. With this type of polaroid has two color than dyes to replace to iodine production polaroid. The polaroid than iodine is a polaroid high heat resistance and moisture resistant, when used under harsh environment. But this kind of polaroid in high transmittance and high polarization degree of two kinds of no iodine on the optical properties of polaroid is more easy to obtain.