There are many standards to measure the transparency of some plastics, such as light transmittance, haze, refractive index birefringence and dispersion.
According to the transmittance of the material, it can be divided into: transparent materials: the transmittance of visible light with a wavelength of 400nm-800nm is above 80%; translucent materials: the transmittance of visible light from 400nm to 800nm is 50%- Between 80%; opaque materials: the refractive index of visible light from 400 nm to 800 nm is below 50%. According to the above classification, resins can be divided into transparent resins: mainly including PMMA, PC, PS, PET, PES, J.D series, CR-39, SAN (also known as AS), TPX, HEMA, BS (also known as K resin) etc.; Translucent resin: PP, PA; Opaque resin: ABS, POM, PTFE, PF, etc.
The principle of improving the transparency of plastics: reducing the crystallinity, controlling the quality of cleanliness, increasing the refractive index, and reducing birefringence.
Adding to improve the transparency of plastics, nucleating agents can be added, which is the most effective way to increase the light transmittance of transparent resins, and it can promote the crystallization of small molecular substances. It can play the role of crystal nucleus in the resin.
Blending to improve the transparency of plastics is to add other resins to the transparent resin to improve the transparency.
Biaxial stretching improves the transparency of plastics, which can break the original crystal particles in the product and reduce the crystal size to achieve the purpose of improving light transmittance.