Question

When a dye is formed on the fiber or cloth by a chemical reaction at the time of dyeing, the process is known as:

• A. synthesis
• B. direct dyeing
• C. vat dyeing
• D. absorption

Answer 1

The correct option is B direct dyeing

Direct Dye is a class of dyestuff's that are applied directly to the substrate in a neutral or alkaline bath. They produce full shades on cotton and linen without mordant and can also be applied to rayon, silk, and wool. Direct dyes give bright shades but exhibit poor wash fastness. Various after treatments are used to improve the wash fastness of direct dyes, and such dyes are referred to as 'after treated direct colors". Direct dyes are molecules that adhere to the fabric molecules without help from other chemicals.