ISO 2916:1975 pdf download.Wool — Determination of alkali content.
INTRODUCTION
This International Standard is based on the IWTO test method 21-69 drawn up by the International Wool Textil Organization.
1 SCOPE AND FIELD OF APPLICATION
This International Standard specifies a method for the determination of the alkali content of wool.
The method is applicable to undyed wool in any form; for example, loose fibres, card sliver, tops, yarn or fabric. It can be used with dyed wool if the amount of dye extracted in the course of the test does not affect the determination of the end-point of the titration.
2 PRINCIPLE
Extraction of the alkali from a weighed quantity of wool by immersion in dilute boric acid solution. Determination of the amount of alkali extracted, by titration with a standard volumetric solution of hydrochloric acid.
4 APPARATUS
4.1 Conical flasks with glass stoppers, capacity 250 ml.
4.2 Erlenmeyer flasks, capacity 250 ml.
4.3 Microburette. 2 ml.
4.4 Pipettes, 50 and 100 ml.
4.5 Weighing bottle with lid.
4.6 Sintered-glass crucible, with pore diameter between
100and160μm.
4.7 Analytical balance, accurate to 0,000 5g.
5 SAMPLING AND PREPARATION OF TEST SPECIMENS
Take a representative sample of mass not less than 10 g from the material to be tested.
If the dichloromethane extract of the sample is greater than 1 % degrease with dichloromethane as follows:
Extract the sample with dichloromethane for 1 h in a Soxhlet apparatus, at the minimum rate of 6 cycles per hour. Evaporate the dichloromethane from the cleaned sample and remove all vegetable matter and foreign substances from the wool. If the sample is yarn or cloth, dissect into short lengths of yarn (approximately 1 cm) and leave to attain equilibrium with the laboratory atmosphere. Felted materials that cannot be dissected into yarn must first be cut up into small pieces.ISO 2916:1975 pdf download.