Hard Coating
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Two of the more common
types of hard coats are:
Thermally cured hard coating
The lens is slowly passed through a liquid bath of a solvent based hardcoat where the coating solution adheres to both convex and concave sides of the lens. The hardcoat is then allowed to cure in a high temperature oven until stable.
U.V. cured hard coating
A liquid hardcoat solution is applied to the concave side (backside) of the lens using a spinning process. Lenses are then cured under a UV (Ultra Violet) light for a specific amount of time.