dispersiovärjäyksenä

Dispersiovärjäys, known in English as disperse dyeing, is a dyeing process used primarily for synthetic fibers. These fibers, such as polyester, nylon, and acetate, are hydrophobic and do not readily accept water-soluble dyes. Disperse dyes are specifically designed for these materials. They are non-ionic, finely dispersed solid particles that are applied to the fiber from an aqueous dispersion. The dyeing process typically occurs at elevated temperatures, often under pressure, to facilitate the penetration of the dye molecules into the fiber structure.

The mechanism involves the dye particles being suspended in water with the help of dispersing agents. When the fabric is immersed in this dyebath, the dye particles are adsorbed onto the fiber surface. Under heat, the dye molecules sublime or dissolve slightly, allowing them to diffuse into the amorphous regions of the synthetic fiber. As the material cools, the dye molecules become trapped within the fiber, creating a colored effect. The fastness properties of disperse dyeing, such as lightfastness and washfastness, are generally good, especially for polyester. This method is crucial for achieving vibrant and durable colors on common synthetic textiles used in apparel and home furnishings.