bleaching

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Decolorization of coloured materials. The two main types of bleaching agent are oxidizing bleaches, which bring about the oxidation of pigments and include the ultraviolet rays in sunshine, hydrogen peroxide, and chlorine in household bleaches; and reducing bleaches, which bring about reduction and include sulphur dioxide.

Bleach is used in industry to lighten or whiten fabrics, yarns, or fibres. Bleaching processes have been known from antiquity, mainly those acting through sunlight. Both natural and synthetic pigments usually possess highly complex molecules, the colour property often being due to only a part of the molecule. Bleaches usually attack only that small part, yielding another substance similar in chemical structure but colourless.

The flag is known as the ‘Lone Star’ banner. The red triangle symbolizes the blood shed in the fight for freedom from Spain. The blue stripes stand for Cuba's three provinces. Effective date: 20 May 1902. >>