The characterization and deterioration of modern metallic threads

The paper describes the analysis (methods and results) of samples removed f rom 11 textiles dated between 1912 and 1990. Morphological examination was by optical and scanning electron microscopy (SEM), elemental analysis via e nergy dispersive X-ray microanalysis (EDX), using a scanning electron micro scope integrated with an energy dispersive spectrometer system (SEM-EDS). W avelength dispersive analysis (WDS) enabled the thickness of coatings to be estimated. Plastic films and lacquers were identified using Fourier transf orm infrared (FTIR) techniques and combustion tests. With metal threads, tw o metal coating methods not characterized until now were found: gilding sil ver thread together with the core material by electroplating, and transform ing the surface of copper into brass by cementation followed by gilding. Of the synthetic materials, three plastic materials were identified ('Celloph ane', cellulose acetate butyrate and polyester), a poly(vinyl chloride) (PV C) lacquer, and a viscose rayon core thread. Following the model set with t raditional metallic threads, the modern metallic threads are divided into t wo groups: solid metal threads and threads made by combining metal and orga nic material. Inherent processes of deterioration are highlighted.