ISO 1833-18-2020 pdf download.Textiles一Quantitative chemical analysis一 Part 18: Mixtures of silk with wool or other animal hair (method using sulfuric acid). This document specifies a method, using sulfuric acid, to determine the mass percentage of silk, after removal of non-fibrous matter, in textiles made of mixtures of — silk with — wool or other animal hair. 2 Normative references The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 1833-1, Textiles — Quantitative chemical analysis — Part 1: General principles of testing 3 Terms and definitions No terms and definitions are listed in this document. ISO and IEC maintain terminological databases for use in standardization at the following addresses: — ISO Online browsing platform: available at https://www.iso.org/obp — IEC Electropedia: available at http://www.electropedia.org/ 4 Principle The silk fibre is dissolved from a known dry mass of the mixture with a mass fraction of 75 % sulfuric acid. NOTE Wild silk, such as tussah silk, are not completely soluble in a mass fraction…