AATCC 81-2001 pH of the WaterExtract from Wet Processed 1 Textiles.
1. Purpose and Scope
1.1 This test method determines the pH of wet processed textiles either scoured or bleached.
1.2 To make a quantitative determination, the chemicals which influence pH must be removed from the textile specimen, collected as a water extract and then accurately measured by a pH meter. 2. Principle
2.1 The specimen is boiled in distilled or deionized water. The waterextract is cooled to room temperature and the pH is determined.
3. Terminology
3.1 bleaching, n.- elimination of unwanted coloring matter from a textile substrate by oxidative or reductive chemical treatment.
3.2pH, n.the negative logarithm of the effective hydrogen ion concentration or hydrogen ion activity in gram equiva. lents per liter used in expressing both acidity and alkalinity on a scale whose values run from 0-14 with 7 representing neutrality, numbers less than 7 increasing acidity and numbers greater than 7 in- creasing alkalinity.
3.3 wet processing, n.-in lextile manufaetwring. a collective term for pro- cesses included in preparation, dyeing, printing and finishing in which the textile material is treated with a liquid, normally water, or with chemicals in solution or dispersion in a liquid.
4. Safety Precautions NOTE: These safety precautions are for information purposes only. The precautions are ancilary to the testing procedures and are not intended to be all inclusive. It is the user’s responsibility to use safe and proper techniques in handling materials in this test method. Manufacturers MUST be consulted for specific details such as material safety data sheets and other manufacturer’s recommendations. All OSHA standards and rules must also be consulted and followed.
4.1 Good laboratory practices should be followed. Wear safety glasses in all laboratory areas.
4.2 All chemicals should be handled with care.
5. Uses and Limitations
5.1 pH can be used to determine the suitability of wet processed textiles for subsequent dyeing and/or finishing operations or to evaluate the washing and/or neutralizing efficiency following any wet processing operation.
5.2 This method should be used in con- junction with AATCC Test Method 144, Alkali in Wet Processed Textiles: Total, in order to quantitatively determine the amount of an alkali present. While pH gives an indication of relative alkali or acid content, the exact amount can be masked by the presence of strong buffer- ing agents.
6. Apparatus and Materials
6.1 pH meter with 0. I unit graduations.
6.2 Beakers, glass, 400 mL.
6.3 Buffer solutions, pH 4.0, 7.0, 10.0 or others as needed.AATCC 81 pdf download.