The yellowing problem: Causes and possible technical solutions

摘要

One of the most common and undesirable defects of this light-coloured leather is alteration in colour, with particular reference to localised or widespread yellowing effects on the surface of the material. Numerous factors may cause this type of defect, depending on the complexity of the matrix and the variability of the traditional or innovative production processes used, such as the intrinsic fragility, photosensitivity and thermo-sensitivity of the finishing polymers, the chemical instability of some components of the finishing pigments, the presence of photosensitive chemical additives, the migration of the leather components or assembly components of the products (greases, fillers, plasticisers, glues, etc.), as well as the indirect contribution of environmental and thermo- climatic factors capable of negatively impacting the performance of the material.