Seedlac is dissolved in an aqueous-alkali solution, filtered, dewaxed and bleached with Sodium Hypochlorite to the desired color. The shellac is then precipitated from the solution with Sulphuric acid and dried.
Seedlac is dissolved in an aqueous-alkali solution, filtered, dewaxed and bleached with Sodium Hypochlorite to the desired color. The shellac is then precipitated from the solution with Sulphuric acid and dried.
Applications for Dewaxed Bleached Shellac are :-
Fruit coating, chocolate coating, protective coating is capsule & tablets in pharmaceuticals, varnishes for paints and printing inks, wood coatings, hot stiffening, cosmetics, electrical industries etc.
Dewaxed Bleached Shellac (Physical Data) | |
---|---|
Colour | max. 1.5 |
Acid Value | 75 - 90 |
Ash Content | max. % 0.5 |
Insolubility in hot alcohol | max. % 0.2 |
Moisture | max. % 5.0 |
Saponification Value | 210 - 250 |
Wax Content | max. % 0.2 |
Heavy Metals | max. ppm 5 |
Arsenic | max. ppm 3 |