The paper industry invests substantial effort to improve fibers and particularly to improve the brightness and light scattering ability of fibers. Conventionally, paper pulps are whitened by chemical bleaching methods. Paper pulp also contains various fillers and additives to enhance properties of the paper. The present invention provides a procedure by which brightness and light scattering ability of the fiber can be improved by addition of a silica/alumina additive. The present invention thus provides a method to brighten paper without the use of chlorine or peroxide chemical bleaching systems which often have a negative effect on opacity as brightness is increased.
USPTO Backgrounds
USPTO Backgrounds