The Surface of the Cotton Fiber

Experiments designed to complement microscopical studies and to attempt a practical evaluation of the effectiveness of various agents which impart resistance to dry soil are reported. Various methods of applying soil to fabric were evaluated, as was the ef fectiveness of a number of soil retardants. Soils included carbon blacks of a range of particle sizes, a natural clay, and a synthetic soil whose formula approximated the com position of natural soil, containing fatty materials. Fabrics were also soiled by foot traffic on the floor. Results were interpreted from reflectance data and from radioactive tracer assays of weight of soil takeup. In attempting to elucidate the mechanism of dry soiling. the effects of textile construction, electrical charge on the fiber, particle size of soil as related to topography of fiber surface, surface hardness, reducing surface rough ness. and lowering surface energy were considered. It was shown that soil takeup is directly related to specific surface. It was found that grey cotton is slightly more re sistant to soil than bleached cotton, and that increased smoothness of fiber. even to com plete obliteration of native rugosities, did not necessarily impart soil resistance to cotton fabrics. The most successful types of antisoiling agents for dry soils appear to be col loidal particulate applications such as silica or alumina, and additive finishes which lower surface energy of the tiber. Only a few of the typical commercially available soil re tardants were used in these studies. The project was a short term one and the experi ments were designed for the study of the mechanism of soiling of cotton textiles which would be subject to in-place cleauing. Many new soil retardants were marketed after the experiments had been initiated.