GB/T 2910.5-2009Textiles -- Quantitative chemical analysis -- Part 5: Mixtures of viscose, cupro or modal and cotton fibers (method using sodium zincate) (English PDF)

Foreword

GB/T 2910 "Textiles-Quantitative Chemical Analysis" consists of the following parts.

- Part 1. General principles of testing;

- Part 2. Ternary fiber mixtures;

- Part 3. Mixtures of acetate and certain other fibers (method using acetone);

- Part 4. Mixtures of certain protein and certain other fibers (method using

hypochlorite);

- Part 5. Mixtures of viscose, cupro or modal and cotton fibers (method using

sodium zincate);

- Part 6. Mixtures of viscose or certain types of cupro or modal or lyocell and cotton

fibers (method using formic acid and zinc chloride);

- Part 7. Mixtures of polyamide and certain other fibers (method using formic acid);

- Part 8. Mixtures of acetate and triacetate fibers (method using acetone);

- Part 9. Mixtures of acetate and triacetate fibers (method using benzyl alcohol);

- Part 10. Mixtures of triacetate or polylactide and certain other fibers (method using

dichloromethane);

- Part 11. Mixtures of cellulose and polyester fibers (method using sulfuric acid);

- Part 12. Mixtures of acrylic, certain modacrylics, certain chlorofibers, certain

elastanes and certain other fibers (method using dimethylformamide);

- Part 13. Mixtures of certain chlorofibers and certain other fibers (method using

carbon disulfide/acetone);

- Part 14. Mixtures of acetate and certain chlorofibers (method using acetic acid);

- Part 15. Mixtures of jute and certain animal fibers (method by determining nitrogen

content);

- Part 16. Mixtures of polypropylene fibers and certain other fibers (method using

xylene);

- Part 17. Mixtures of chlorofibers (homopolymers of vinyl chloride) and certain

other fibers (method using sulfuric acid);

- Part 18. Mixtures of silk and wool or hair (method using sulfuric acid);

- Part 19. Mixtures of cellulose fibers and asbestos (method by heating);

- Part 20. Mixtures of elastane and some other fibers (method of using

dimethylacetamide);

Textiles - Quantitative chemical analysis - Part 5.

Mixtures of viscose, cupro or modal and cotton fibres

(method using sodium zincate)

1 Scope

This part of GB/T 2910 specifies a method, using sodium zincate, to determine the

percentage of viscose, cupro or modal fibre, after removal of non-fibrous matter, in

textiles made of binary mixtures of

- viscose or most of the current cupro or modal fibres, and

- raw, scoured, kiered or bleached cotton.

Where a cupro or modal fibre is present, a preliminary test should be carried out to

see whether it is soluble in the reagent.

This part is not applicable to the mixtures in which the cotton has suffered extensive

chemical degradation. It is also not applicable to viscose, cupro or modal fibre in

which there exists un-removable durability finishing agent or reactive dyes, so that it

cannot be completely dissolved.

2 Normative references

The articles contained in the following documents have become this part of GB/T

2910 when they are quoted herein. For the dated documents so quoted, all the

modifications (excluding corrections) or revisions made thereafter shall not be

applicable to this part. For the undated documents so quoted, the latest editions shall

be applicable to this part.

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 Principle

The viscose, cupro or modal fibre is dissolved from a known dry mass of the mixture,

with sodium zincate solution. The residue is collected, washed, dried and weighed; its

corrected mass is expressed as a percentage of the dry mass of the mixture. The

percentage of viscose, cupro or modal fibre is found by the difference.

vigorously on the mechanical shaker for (20 ± 1) min. Filter the contents of the flask

through the weighed filter crucible. Apply suction to the crucible to remove excess

liquor, again replace the residue in the flask by means of forceps, add 100 mL of

ammonia solution, and shake the flask for 5 min on the mechanical shaker. Filter the

contents of the flask through the same weighed filter crucible and wash any fibres

from the flask into the crucible with water. Wash the crucible and residue with 100 mL

of acetic acid solution, and then thoroughly with water. Do not apply suction until each

washing liquor has drained under gravity. Finally, drain the crucible using suction, dry

the crucible and residue, then cool and weigh them.

7 Calculation and expression of results

Calculate the results as described in the general instructions of GB/T 2910.1. The

value of d for raw, scoured, kiered, or bleached cotton is 1,02.

......