GB/T 42695-2023Textiles—Quantitative chemical analysis—Mixtures of kapok with certain other fibers (English PDF)

1 Scope

This document describes a method of chemical analysis for the determination of the fiber content of two-component mixtures of kapok with certain other fibers after removal of non-fibrous matter.

This document applies to two-component mixtures of kapok and certain natural protein fibers (silk, sheep wool, other animal hair fibers), certain native cellulose fibers (cotton, flax, ramie), certain regenerated cellulose fibers (viscose fiber, modal fiber, lyocell fiber, copper ammonia fiber), polyester fiber, polypropylene fiber, polyethylene fiber, polyamide fiber, polyacrylonitrile fiber, certain modified acrylic fibers, polyurethane elastic fiber, polyvinyl alcohol fiber, acetate fiber or triacetate.

This document does not apply to mixtures where cotton fibers or regenerated cellulose have been subjected to severe chemical degradation, nor does it apply to mixtures in which there are durable finishing agents or reactive dyes that cannot be completely removed in the kapok, making them insoluble.

Note: See Appendix A for the qualitative identification method of kapok.

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 version corresponding to that date is applicable to this document; for undated references, the latest version (including all amendments) is applicable to this document.

GB/T 2910.1, Textiles - Quantitative chemical analysis - Part 1: General principles of testing

GB/T 2910.4, Textiles - Quantitative chemical analysis - Part 4: Mixtures of certain protein and certain other fibers (method using hypochlorite)

5 Two-component mixtures of kapok and certain native cellulose fibers (cotton, flax, ramie) (method using formic acid/zinc chloride)

5.2.2 Formic acid/zinc chloride solution: Add 20 g of anhydrous zinc chloride (mass fraction >98%) and 68 g of anhydrous formic acid; add water to 100 g.

5.2.3 Dilute ammonia solution: Take 20 mL concentrated ammonia water (density rho = 0.880 g/mL) and use water to dilute it to 1 L.

6 Two-component mixtures

of kapok and certain regenerated cellulose fibers (viscose fiber, modal fiber, lyocell fiber, copper ammonia fiber) (method using sodium hypochlorite)

10 Two-component mixtures of kapok and polyvinyl alcohol

fiber (method using hydrochloric acid)

The involved principle, reagents, apparatus, test procedure, calculation and presentation of results shall be carried out according to the method using hydrochloric acid in FZ/T 01132-2016, and the d value of kapok is 1.01.

11 Mixtures of kapok and acetate fiber or triacetate fiber

(method using 75% formic acid)

The involved principle, reagents, apparatus, test procedure, calculation and presentation of results shall be carried out in accordance with 10.1 of GB/T 38015-2019, and the d value of kapok is 1.01.

12 Precision

For a homogeneous mixture of textile materials, at the 95% confidence level, the confidence limits of the test results of the method using formic acid/zinc chloride do not exceed ±2%, and the confidence limits of the test results of other methods do not exceed ±1%.

13 Test report

The test report shall include the following.

a) method in this document adopted.

b) the measured results of all components or a single component of the mixture.

d) details of the special pretreatment used to remove sizing agent or finishing agent, if adopted;

d) each single value and its average value, accurate to 0.1%.

e) notes that the above results are based on:

1) net dry mass percentage;

2) percentage combined with the conventional moisture regain;

3) percentage including the conventional moisture regain and the fiber loss in pretreatment; […]