Detergency Studies

A survey of the literature and the practice of detergency as applied to textiles has indicated that the manufacture of successful detergents has progressed further than has the fundamental science of detergency. Many of the basic factors in soiling of textile fibers and fabrics, and in cleaning of the soiled materials, are not yet fully recognized and satisfactorily understood. Better answers are needed to questions such as these: What forces hold particles of soil in contact with fibers? How deeply does dirt penetrate into yarns and fabrics, and how tenaciously is it held therein? How does a detergent act in removing dirt particles from fibers? What part of the dirt in or on a fiber is removable by detergent processes? The work on detergency reported in the three papers published below was done at the Institute of Textile Technology. The first two present an initial study of the mechanisms of soiling of cloth, and of the cleaning of soiled cloth, using mixed pigment-oil soils. By using a pigment whose presence can be accurately determined by chemical analysis, a definite im provement in the quantitative understanding of these processes has been made; this technique appears to be new. The washing of lightly and severely soiled sam ples has demonstrated that there is a qualitative as well as a quantitative difference between the two, and thus has contributed to the understanding of how solid soil clings to cloth. The third paper reports a study of the effect of various soiling mixtures and storage conditions upon the ease of washing of soiled cloth. It was found that soiled cloth becomes more difficult to wash after it has been stored for several weeks or months unless the oils in the mixtures used to soil the cloth are inert to the oxidizing action of air and unless the storage conditions are dry. Use of oils which undergo oxidative polymerization (particularly linseed and tung oils) was found to lead to permanent binding of pigment soil and cloth; this process appeared to be aided by the presence of moisture. The work reported in the three papers was done in order to establish a basis for comparative laboratory testing of detergents and washing processes and for other studies of practical value in textile detergency.