Permanganate number of pulp, Useful Method UM 251 (2025)
This method provides for the determination of the relative “hardness” or bleachability of chemical pulps (1) having a permanganate number below 35.
This Useful Method covers two variations in a single procedure. One procedure is for low lignin content pulps having a permanganate number less than 20; and a second procedure is for higher lignin content pulps having permanganate numbers of between 20 and 35. For pulps above permanganate number of 35, use TAPPI T 236 “Kappa Number of Pulp.”
TAPPI Standard T 236 “Kappa Number of Pulp,” may be used for all types and grades of chemical and semi-chemical wood pulps, including higher lignin content pulps with yields as high as 70%.