Dyeing and Printing of Textiles — Flashcards

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Dyeing is the process of adding color to fibers, yarns, or fabrics using dyes. Dyes are substances that permanently attach to the material and give it a specific color by absorbing and reflecting cert…

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Dyes contain chromophores that give them color and auxochromes that intensify the color and make the dye water-soluble. When light hits the dyed fabric, some wavelengths are absorbed and others are re…

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The dye on the fabric absorbs all wavelengths of visible light except red, which is reflected. Our eyes detect this reflected red light, making the fabric appear red.

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Natural dyes are classified into three types: 1. **Vegetable dyes** – from plants (e.g., madder root for red, indigo leaves for blue). 2. **Animal dyes** – from insects (e.g., cochineal from insects f…

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Vegetable dyes are natural dyes extracted from plants like roots, leaves, and flowers. Examples: Madder (red dye from roots), Indigo (blue dye from leaves).

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Cochineal is a red animal dye obtained from the dried bodies of female insects called *Coccus cacti*.

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Mineral dyes are coloring agents made from metal salts or oxides. Example: Iron buff, a rust-colored dye formed when fabric is dipped in iron-rich water and exposed to air.

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Synthetic dyes were first developed in 1856 from coal tar. They replaced many natural dyes due to their brighter colors and better fastness.