Date of Award


Degree Name

Bachelor of Science


It is the purpose of this thesis to attempt to evaluate the repulpability of coated papers that contain latex as a binder, and also to evaluate the effects of an alum-rosin sizing system on the latex particles, as well as any bundles of fibers or fibers and coating.

It has been found that SBR latex will break up with the greatest difficulty, probably due to its added stability imparted by the carboxyl group attached to it. The PVAC and acrylic latexes break up much easier than the SBR under the same conditions, with the acrylic breaking up more readily than the PVAC. This trend is evident at all addition levels of the latexes from 100% down to 25%.

The alum-rosin sizing system does have an effect on the latexes, generally causing from one to two and a half times the build up on the dynamic screen than did the 100% starch sample under the same conditions. The amount of buildup is a function of particle size. The bigger the particle, the larger the amount of buildup. This effect is more pronounced at higher levels of addition, but is evident at all levels of latex. The rosin-alum sizing system has a larger effect on coated papers with latex as a binder than on coated papers containing starch as the only adhesive.