GB/T 7569-2008Wool -- Determination of alkali content (English PDF)

Foreword

This revised standard adopts ISO 2916. 1975 "Determination of the alkali content of wool." this standard and ISO 2916. 1975 as compared to the main differences are as follows.

1. Increased Normative references a chapter;

2. Added test distilled water requirements;

3. Increasing the calculation result decimal point digits;

4. Modify the alkali content of the formula, the concentration of Ba replaced by the symbol T, increasing the molar mass M, and redefine the K value;

5. Increasing the provision of test results error range of requirements;

6. Added Appendix A (informative).

This standard replaces GB/T 7569-1987 "Determination of the alkali content of wool." this standard compared with GB/T 7569-1987, the main changes are as follows.

1. Added test distilled water requirements;

2. Increasing the calculation result decimal point digits;

3. Dry mass of said sample by a 2g to 1g;

4. Modify the formula of alkali content, increasing the molar mass M, and redefine the K value;

5. Added Appendix A.

Appendix A of this standard is an informative annex.

The standard proposed by China Textile Industry Association.

This standard by the National Standardization Technical Committee Textile basic standards Sub-Committee (SAC/TC209/SC1) centralized.

This standard wool and linen by the Shanghai Textile Research Institute of Science and Technology is responsible for drafting.

1 Scope

This standard specifies the method for determination of alkali content of wool.

This standard applies to undyed wool and its products, but also applies to the testing process does not affect the amount of dye staining products titration end point.

2 Normative references

The following documents contain provisions which, through reference in this standard and become the standard terms. For dated references, subsequent Amendments (not including errata content) or revisions do not apply to this standard, however, encourage the parties to the agreement are based on research Whether the latest versions of these documents. For undated reference documents, the latest versions apply to this standard.

Preparation of GB/T 601 chemical reagent standard titration solution GB/T 6682 analytical laboratory use specifications and test methods (GB/T 6682-1992, neq ISO 3696. 1987) GB/T 8170 numerical rounding rules Principle 3 Extracting a certain quality of wool in alkaline solution of boric acid, alkali extracted with hydrochloric acid standard titration solution titration to calculate containing Alkali.

4 Reagents

In the analysis reagents used were of analytical grade and distilled water for the three water GB/T 6682 regulations.

4.1 10g/L of boric acid (H3BO3) was added.

Take 10.00g of boric acid dissolved in distilled water and diluted to 1000mL.

4.2 hydrochloric acid standard titration solution [Ba (HCl) = 0.05mol/L].

According to GB/T 601 Preparation and calibration.

4.3 methyl red - methylene blue indicator.

Formulated as follows.

a) Take 1g of methyl red dissolved in absolute ethanol and diluted to 1000mL;

b) under heating conditions 4mL10g/L methylene blue solution and 96mL absolute ethanol;

c) The above two solutions were mixed with 1.1 volume.

5 Instruments

5.1 plug Erlenmeyer flask. capacity 250mL.

5.2 Erlenmeyer flask. capacity 250mL.

5.3 Pipette. Capacity 50mL, 100mL.

5.4 microburette. capacity 2mL.

5.5 weighing bottle, dryer.

5.6 Analytical balance. accuracy 0.0002g.

5.7 thermostatic oven. to maintain the drying temperature 105 °C ± 2 °C.

5.8 mechanical oscillator.

5.9 Glass filter pan. Capacity 30mL ~ 50mL, pore diameter of 40µm ~ 80µm.