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Haze
December 5, 2007
The optical properties of a substrate are controlled by its internal and external structure. This appears in clear substrates as haze, which is due to light scattering. The haze is composed of two parts: surface haze and internal haze. The surface haze is due to surface roughness, which exceeds about 1/6 the wave length of light. Internal haze is due to the scattering of small particles in the film, as well as variations in density (amorphous and crystalline rejoins) within the substrate.
In amorphous polymers such as polystyrene (PS), there is no internal haze due to scattering at the crystal/amorphous interface because the polymers contain no crystals and the polymer is very clear. This is in contrast to high density polyethylene (HDPE), which is highly crystalline and has high haze values due to the crystals in the substrate film.
Posted by Eldridge M. Mount on December 5, 2007 | Comments (0)