Prep: 20 total 5x5 inch blue polyester fabric swatches were used for testing (10 per cleaner). Each fabric swatch was measured for reflectance, redness/greenness, and yellowness/blueness with a colorimeter 5 times in 3 separate areas (0.5x0.5) where the fabric would eventually be stained. The three areas were treated as individual coupons. The 5 measurements for each area were averaged together and used as the representative measurements of the specified area/coupon. Each area was stained with the clay and left to air dry for 24 hours. Colorimeter measurements of each stain were then recorded.
Washing procedure: The fabric swatches were washed in a washing machine with 45 mL of Liquid Laundry Detergent and 6.5 gallons of water on a normal washing cycle set for a medium load. The water used has a water hardness level of 63 PPM mg/L. The washing cycle consisted of a wash step (~12 mins), a rinse step (~14 mins), and a spin step (~5 mins). The fabric swatches were washed heated with a temperature range of 105F-125F in their respective cleaners. The fabric swatches were then left to air dry. After drying, the colorimeter was used to re measure the 3 staining areas on each fabric swatch.
Analysis:
Detergency: Unadjusted measure of the percentage the cleaned fabric was returned to its original state (uses only L values/measures of lightness)
% Detergency= 100X((Lclean-Ldirty)/(Linitial-Ldirty))
Where:
L=reflectance (0 black - 100 White)