Light-Dependent Properties of Finishing and Leather Defects

The uniformity of the colour in leathers for the furnishing and automotive sectors is a particularly important feature, especially for white or light-coloured articles, intended to the high-end market; on these articles any colour alteration can be very visible and unpleasant, with possible technical and economic consequences for the producers. In a previous study, we analysed the possible causes behind the formation of some peculiar pink/salmon stains on different kinds of white/beige/light-coloured leather furnishing items, where we focalized our attention on TiO2 properties and its possible interaction with some organic-based antioxidants. In recent years, due to many other similar cases of defects that occurred to tanners and to upholstery traders, we decided to enhance the investigations concerning this topic. More in detail we analysed, defective leathers, powder pigments and chemicals, in order to identify the possible role of some substances in this issue, with particular reference to some antioxidants and aluminosilicates, where several diagnostic techniques have been utilised, as ATR-IR (Attenuated Total Reflectance IR Spectroscopy), SEM-EDX (Scanning Electron Microscopy-Energy Dispersive X-ray Analysis), XRF (X-ray Fluorescence spectrometry), GC-MS (Gas Chromatography-Mass Spectrometry), and DSC/TGA (Differential scanning calorimetry/Thermogravimetry) equipment.