Improvement in Wash Fastness of Dyed Silk by Aftertreatment with ‎Commercial Syntan/Metal Salts

Silk yarns were dyed by using ‎commercial basic, reactive and ‎pre-metallised acid dyes. An ‎aftertreatment with a commercial ‎synthetic tanning agent (syntan) ‎was applied to the dyeings and the ‎aftertreated dyeings were further ‎treated with metal salts in an ‎attempt to improve wash fastness ‎properties. When all samples ‎‎(untreated, syntanned and ‎syntanned/ backtanned speciments) ‎were subjected five times to a ‎repeated wash testing (ISO ‎‎105CO1), it was found that the ‎fastness, to repeated wash testing, ‎was improved, as expected by an ‎aftertreatment with the commercial ‎syntan. Further, significant, the ‎two-stage, syntan/metal salts ‎aftertreatment raised the level of ‎wash fastness of the syntanned ‎samples. ‎