AATCC 15-2008 Colorfastness to Perspiration

AATCC 15-2008 Colorfastness to Perspiration. 6. Preparation of Reagent 6.1 Prepare the acid perspiration solution by filling a 1 L volumetric flask half full of distilled water. Add the following chemicals and mix to be sure that all chemicals are thoroughly dissolved: 10 ± 0.01 g sodium chloride (NaCl) 1 ± 0.01 g lactic acid, USP 85% 1 ± 0.01 g sodium phosphate, dibasic, anhydrous (Na 2 HPO 4 ) 0.25 ± 0.001 g histidine monohydro chloride (C 6 H 9 N 3 O 2 ⋅HCl⋅H 2 O) (see 13.6) Fill the volumetric flask with distilled water to the 1 L mark. 6.2 Test the pH of the solution with a pH meter. If it is not 4.3 ± 0.2 discard it and prepare a new one, making sure all ingredients are weighed accurately. The use of pH test paper is not recommended for this purpose because of its lack of accuracy. 6.3 Do not use perspiration solution that is more than three days old (see 13.7). 7. Verification 7.1 Verification checks on the opera- tion of the test and apparatus should be made routinely and the results kept in a log. The following observations and corrective actions are extremely important to avoid incorrect test results. 7.2 Use an inhouse perspiration fabric with a mid-range visual grade on the most heavily stained stripe of the multifiber cloth as a calibration specimen and conduct a perspiration test using three specimens. Verification checks should be performed periodically as well as each time a new lot of multifiber or undyed adjacent fabric is used. 7.2.1 Nonuniform color transfer may be due to improper wetout procedures or may be a result of uneven pressure on the specimens due to warped plates in the tester. Check the wetout procedures to be sure that the balance is accurate and that the procedure is being carefully fol- lowed. Check all plates to be sure they are in good condition and not warped. 8. Test Specimen 8.1 Number and size of specimens. 8.1.1 Cut one 6 × 6 ± 0.2 cm specimen from each sample and an equal size piece of multifiber test fabric. Do not use mul- tifiber test fabric that has fused edges because it might have thickness variations at the edges which would cause uneven compression during testing. If the fiber or fibers in the dyed fabric are not present in the multifiber test fabric,...