Date of Award


Degree Name

Bachelor of Science


Pulp and Paper Technology


A new staining technique has been developed for the colorimetric separation of unbleached neutral sulfite semichemical fibers from other types of fibers. It involves the use of two reagents, a 2% solution by weight of p-nitroaniline in 3N HCl and Herzbergs stain. The former solution is applied to the fibers, the excess is removed, and Herzberg stain is applied. This process will produce an orange color on groundwood, a brownish green color on unbleached neutral sulfite semichemical fibers, and a color on chemical fibers and bleached neutral sulfite semichemical hardwood fibers that will vary from blue to deep purple, depending upon the type of fiber and cook. The new technique produces much better color separations between these classes of fiber cooks than those obtained through the use of *C* stain or Herzberg stain, when used alone.