9 RESULTS OF PHASE 2 TESTING

9.1 COLOR CHANGE

The cotton samples changed color least during light-aging, and there was no significant difference between samples washed with the different surfactants (tables 5, 6). In contrast, the wool yellowed to an extent that was easily seen by the naked eye, although the differences between samples was not significant. Measuring the color change data for the wool samples indicated that the sample treated with Orvus yellowed most, followed by the sample treated only with water. Imbentin showed the least yellowing.

9.2 TENSILE STRENGTH CHANGE

Both the wool and cotton samples showed a significant weakening after aging, but there were no significant differences between the surfactant treatments. All values lay within one standard deviation of the mean (figs. 8, 9).

9.3 pH

Aging produced a decrease in pH in all samples, but the use of the surfactants did not produce any significant further decrease in pH relative to water (see tables 5, 6).