Happevärvid

Happevärvid, also known as acid dyes, are a class of synthetic dyes characterized by their anionic nature. They are primarily used for dyeing protein fibers such as wool, silk, and nylon, as well as modified acrylic fibers. The dyeing process typically involves an acidic dyebath.

These dyes are known for their bright and vibrant colors, offering a wide spectrum of hues. They exhibit good lightfastness and washfastness on suitable substrates, although their performance can vary depending on the specific dye and fiber. The chemical structure of acid dyes involves acidic groups, such as sulfonic acid groups, which impart water solubility and allow them to form ionic bonds with the positively charged sites on protein fibers under acidic conditions.

The application of happevärvid is a relatively straightforward process, often carried out at elevated temperatures. The pH of the dyebath is crucial for achieving optimal dye uptake and levelness. Different types of acid dyes exist, including leveling acid dyes, milling acid dyes, and metal-complex acid dyes, each offering distinct properties in terms of fastness, build-up, and application methods. Historically, they were among the first synthetic dyes developed and played a significant role in the industrialization of textile dyeing.