Fatty Soil Retention and the Influence of Particulate and Fatty Soils on Yellowing of an Unfinished Dacron/Cotton Blend Fabric

Abstract

The retention of individual fatty soils, in both the presence and absence of clay soil, on repeatedly soiled, aged, and washed unfinished Dacron/cotton blend was studied by means of a double-label radioactive tracer analysis. Fatty soil retention was influenced by unsaturation, polarity and chain length, but the presence of clay soil was not a significant factor under the experimental conditions employed. Fabric yellowing was measured on samples soiled with clay and pairs of fatty soils and on appropriate controls. None of the organic soils caused observable yellowing in the absence of clay. While clay soil alone contributed significantly to residual yellowness, additional yellowing occurred on samples soiled with clay, oleic acid, and triolein. It was hy pothesized that the yellowing behavior observed when clay, oleic acid and triolein were present was due primarily to the embedding of pigmented particulate soil in a polymerized fatty film during the second clay soiling process.

Aging of oily soils on textile materials: A literature review

“…They, as well as Rounds et al (25), suggested that secondary bonds, i.e., hydrogen bonds, between the carbonyl groups of oxidized lard and the hydroxyl groups of cotton were responsible for the decreased removal.…”

“…Some properties of oily soils that are important from the detergency point of view are their molecular size (25)(26)(27), viscosity (28,29), polarity (30,31), and solubility (32,33) in detergent solutions at the wash temperature. Oily soils with low viscosity are more readily removed.…”

“…The polar oils studied, stearyl alcohol and stearic acid, underwent a more gradual change in removal at the melting point, which is more consistent with the solubilization mechanism or mesomorphic phase formation (32,33). Rounds et al (25) found that a shorter molecule such as palmitic acid was easier to remove than a longer molecule such as stearic acid. These two compounds differ in their alkane portion, stearic acid having two more methylene groups, with melting points of 71.5 and 63°C for stearic and palmitic acids, respectively.…”

“…Rounds et al (25) suggested that hydrogen bonding between the triglyceride carbonyl groups and cellulose hydroxyl groups, along with the size of the triglyceride molecules, may cause these fatty soils to resist removal from cotton by detergency forces. Researchers thought that aging of oils and their difficult removal are related both to chemical changes in the oils upon oxidation and to the wicking and diffusion of oils within the fibrous substrate.…”

“…It was mentioned previously that oily soil is largely responsible for the adherence and retention of particulate soil. The combination of oily and particulate soil was shown to have a synergistic effect on discoloration by Rounds et al (25) and Webb and Obendorf (64). They theorized that clay catalyzes the autoxidation and polymerization of the unsaturated oils, trapping pigmented clay in an oily matrix.…”