Viscose Rayon: An Absorbing Problem. An Investigation into the Impact Conservation Wet Cleaning Treatments have on Historic Woven Viscose Rayon Fabrics; with a Supplementary Analysis of Current Techniques for Identifying Man-Made Fibres

摘要

Viscose rayon has been in production for over a century, however, minimal literatureudis available on its conservation. Pre-1940s viscose rayon has poorer wet strength than laterudversions. The fiber’s manufacture has influence on its wet strength and progressiveudimprovements to processing methods have improved this characteristic. The implications forudconservation wet cleaning treatments on examples from different eras were investigated. Tensileudstrength testing was conducted on three sets of specimens from different times – c.1940s,udc.1960s and c.1980/90s – each subjected to a controlled wet cleaning treatment. Results showedudthe two later viscose rayons lost significant strength in the wet state, up to 50%. The c.1940sudfabric had a greater strength reduction of around 80% - however, degradation from a blackudcolorant present affected the results. This highlighted the risk that degradation, even when notudvisible macroscopically, can become significantly exacerbated in wetted viscose rayon. Furtherudtensile tests on specimens subjected to wet cleaning and then air dried showed a return ofudstrength upon drying, suggesting that no apparent immediate permanent impact was had onudfibers. This research has shown it can be suitable to wet clean viscose rayon, although suchudtreatment may be less appropriate for older more degraded versions.