Date of Award
Bachelor of Science
Paper Science and Engineering
Dr. Brian Scheller
Fluorescent Whitening Agents (FWAs) are commonly used in many areas of the pulp and paper industry. FWAs are also known as Optical Brightening Agents (OBAs) and generically as fluorescent dyes. Nearly one-third of all FWAs manufactured are used in the pulp and paper industry. FWAs work by converting ultraviolet light into blue-white light in the visible region. When FWAs are used in coatings with latex binders, the fluorescent dyes have a tendency to migrate toward the basesheet during drying. This is due to mainly to the lack of suitable carrier for the dye. Previous research has shown that the addition of highly polar polymers, such a polyvinyl alcohol, will help keep the dyes evenly distributed throughout the coating structure. If the dyes accumulate near the bottom of the structure, they will not be activated by the ultraviolet radiation, and are therefore significantly less effective. The purpose of this research project is to determine what effect coating viscosity and polymer additives have on FWAs in latex coatings. After the completion of research and data analysis, it was determined that an increase in coating viscosity effectively caused an increase in fluorescence and the apparent whiteness of the coated papers containing FWAs. It was also concluded that the fully hydrolyzed polyvinyl alcohol was the most effective FWA optimizing agent.
Keywords: Florescence, brightness, whiteness, Fluorescent Whitening Agents
Comensoli, Mark P., "The Effect of Viscosity and Polymer Additives on Fluorescent Dyes in Latex Coatings" (1995). Paper Engineering Senior Theses. 14.