Photokestävyys

Photokestävyys, often translated as lightfastness or fade resistance, refers to the ability of a material to resist degradation or color change when exposed to light. This phenomenon is particularly relevant for pigments, dyes, inks, and other colorants used in applications such as paints, textiles, printing, and plastics. Light, especially ultraviolet (UV) radiation, can break down the chemical bonds within these materials, leading to fading, yellowing, or a shift in hue.

The photokestävyys of a substance is typically measured on a scale, such as the Blue Wool Scale, where higher numbers indicate greater resistance to fading. Various factors influence photokestävyys, including the chemical structure of the colorant, the presence of UV stabilizers, and the intensity and duration of light exposure. Materials with high photokestävyys are essential for products intended for outdoor use or applications where long-term color stability is crucial, such as architectural coatings, automotive finishes, and art supplies. Understanding and assessing photokestävyys is vital for ensuring the longevity and aesthetic integrity of colored products.