GB/T 2910.7-2025 Textiles - Quantitative chemical analysis - Part 7: Mixtures of polyamide with certain other fibers (method using formic acid)
1 Scope
This document specifies a method, using formic acid, to determine the fiber content, after removal of non-fibrous matter, in a two-component mixture of polyamide with certain other fibers as follows:
—polyamide; with
—cotton, viscose, cupro, modal, lyocell, flax, ramie, hemp, polyester, polyethylene, polypropylene, chlorofiber, acrylic, glass fiber, elastomultiester, elastolefin, melamine, wool, or animal hair fibers.
This document does not apply to two-component mixtures of polyamide with wool or other animal hair fibers, the content of which exceeds 25%.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions 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.
GB/T 2910.1 Textiles - Quantitative chemical analysis - Part 1: General principles of testing (GB/T 29101-2009, ISO 1833-1:2006, IDT)
3 Terms and definitions
There are no terms and definitions defined in this document.
4 Principle
The polyamide is dissolved out from a mixture with known dry mass, with aqueous formic acid. The residue is collected, washed, dried, and weighed; its mass, corrected if necessary, is expressed as a percentage of the dry mass of the mixture. The mass percentage of the other fiber is found by the difference.
Foreword i
Introduction iv
1 Scope
2 Normative references
3 Terms and definitions
4 Principle
5 Reagents
6 Apparatus
7 Test procedure
8 Calculation and expression of results
9 Precision
Bibliography
