Abstract
The interactions between the calcium ion exchanging capacity and zeta potential of zeolites in hard water were discussed using eight kinds of zeolite, i.e., 3A, three 4As varying in particle size, 5A, synthetic mordenite and natural ptilolite. The coagulation of zeolites and its deposition onto the fabrics of sharkskin, 40'S broad and lawn of cotton fibers in the laundering process were investigated by Terg-O-Tometer.
1. The ion exchanging capacity of three zeolite 4As were superior to the other zeolites, and the order were:
4As>3A>X>natural ptilolite-synthetic mordenite>5A.
The capacity of ion exchanging were not influenced by the particle size of 4A zeolites.
2. The negative zeta potential of zeolites having low calcium ion exchanging capacity (ptilolite, mordenite and 5A) were lowered in hard water. By contrast, that of zeolites having high calcium ion exchanging capacity (4As, 3A and X) were not lowered.
3. It was ascertained by a quantitative method that, comparing with the latter zeolites, the former zeolites tended to coagulate and deposit onto the fabrics in hard water, particularly onto the tight texture sharkskin. Similar results were also confirmed by the scanning electron micrographs of the laundered fabrics.
