SOP- pH OF WATER EXTRACT FROM WET PROCESSED TEXTILES. TEST METHOD: AATCC TEST METHOD 81-2016 APPARATUS AND MATERIAL: 1. 2. 3. 4. 5. pH meter with 0.1 unit graduations. Laboratory hot plate with a magnetic stirrer. Beakers, glass. Distilled water. Buffer solutions, pH 4.0, 7.0, 10.0 or others as needed. CALIBRATION: Calibrate the pH meter in accordance with the manufacturer’s instructions(Daily). PROCEDURE. 1. The garment/fabric which is required to be tested is laid out on a clean surface. 2. If the fabric is supposed to be tested, the sample should be cut around 7cm away from the selvage. 3. If a garment is supposed to be tested, need to test all types of fabric which include within the garment. 4. Use a digital weighing scale which is having 0.01accuracy level to measure the weight of the sample. 5. Obtain a 10 ± 0.1 g specimen of the material to be tested. 6. Keep the 10 ± 0.1 g specimen on a clean surface and using a clean scissor cut the test specimen into small pcs and store them in nonreactive polythene bags and properly label them. 7. Collect distilled water from the water distillation system and test the pH of distilled water using calibrated pH meter. And record the pH of the water (pH should be within 6.0-7.0 range). 8. Obtain a clean calibrated glass beaker and clean it using distilled water. And 250 ml of distilled water is measured out into the glass beaker. 9. Check the water level of the beaker on the eye level while keeping it on a flat surface. 10. Clean the magnet, watch glass, and temperature sensor of the magnetic hot plate by using distilled water. 11. Keep the beaker on the magnetic hot plate & put the magnet into the 250ml water-filled beaker and close the beaker using watch glass. Then place the temperature sensor accordingly. 12. Turn on the magnetic hot plate and set the temperature and stir R.P.M. 13. Let distilled water for boiling. Once distilled water reaches its boiling temperature, start the stopwatch. Let the distilled water boil for 10min. 14. Then add 10g of cut fabric samples to the boiling water and cover the beaker with a watch glass and let them boil for 10 min. 15. Take out the beaker from the hot plate and let it cool to room temperature. 16. Once cool down, brew the extract into another clean glass beaker which is already cleaned by distilled water. 17. Check the pH of the extract using a daily calibrated pH meter. 18. Record the pH of the extract together with temperature (Extract should be at room temperature) 19. Electrode of the pH meter need to be clean using distilled water or deionized water and needs to dry the electrode in each and every successive reading. 20. If the tested specimen does not meet the buyer’s requirement, advise the washing plant to take action to ensure meet the required pH level (Acidic wash, basic wash or increase the number of washing cycles) 21. After fix the issues check again until achieve buyer requirement
