The use of optical brighteners for synthetic fibers in detergents

It has been demonstrated that the choice of the right optical brightening agent for use in the dope or for topic‐brightening in the textile‐mill has a big influence on the ability of the fiber to be further brightened in the wash‐bath, on the lightfastness and the washfastness of the white, and very often also on the colored wash‐load. The investigation also deals with the mutual influence of brighteners applied during the production of the fiber or the fabric and those used in detergents. Ways are described to overcome undesired changes in the hues of pastel shades. Some aspects of the visual assessment and measurement of whitening effects are discussed.