Textiles - Quantitative chemical analysis Part 11: Mixtures of certain chlorofibres and certain other fibres
(method using carbon disulfide Sulfuric acid)
1 Scope
This document describes a method, using sulfuric acid, to determine the mass percentage of chlorofibres in the binary mixture of chlorofibres and certain other fibres, after removal of non-fibrous matter, in textiles made of
- natural and regenerated cellulose fibres, such as cotton, flax, hemp, ramie, viscose, cupro, modal, lyocell with
- polyester, polypropylene, polyethylene, elastomultiester, elastolefin and polypropylene/polyamide bicomponent.
Note 1: Annexes A and B provides the qualitative identification methods for elastomultiester and elastolefin respectively.
Note 2: Polypropylene/polyamide bicomponent is sheath-core composite fibre with polypropylene fibre as the sheath and polyamide fibre as the core.
2 Normative references
The following documents contain requirements 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 (including any amendments) applies.
GB/T 2910.1 Textiles - Quantitative chemical analysis - Part 1: General principles of testing (GB/T 2910.1-2009, ISO 1833-1:2006, IDT)
3 Terms and definitions
No terms and definitions are listed in this document.
4 Principle
The cellulose fibre is dissolved out from a known dry mass of the mixture, with 75 % (mass fraction) sulfuric acid. The residue is collected, washed, dried and weighed; its mass is expressed as a percentage of the dry mass of the mixture. The proportion of cellulose fibre is found by the difference.
5 Reagents
Use the reagents described in GB/T 2910.1 together with those given in 5.1 and 5.2.
5.1 Sulfuric acid, 75 % (mass fraction): it is prepared by adding carefully 700 ml of concentrated sulfuric acid (ρ= 1.84 g/ml at 20 °C) to 350 ml of distilled water. After the solution has cooled to room temperature, dilute it to 1L with water. The concentration is not critical within the range 73 % to 77 % (mass fraction) sulfuric acid.
5.2 Ammonia, dilute solution: dilute 80mL of ammonia (density ρ=0.880g/mL at 20℃) to 1L with water.
6 Apparatus
Use the apparatus described in GB/T 2910.1 together with those given in 6.1 and 6.2.
6.1 Conical flask, minimum capacity 500 ml, glass-stoppered.
6.2 Heating apparatus suitable for maintaining the temperature of the flask at 50℃±5℃.
7 Test procedure
Follow the general procedure given in GB/T 2910.1, and then proceed as follows.
Foreword I
Introduction V
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
Annex A (Informative) Identification method for elastomultiester
Annex B (Informative) Identification method for elastolefin
