Description

TAPPI T236 – Kappa Number of Pulp

Kappa number is a key test method for determining the level of lignin remaining in a sample of finished or in-process pulp. It is thus a measure of the completeness of the pulping process for many kinds of chemical and semi-chemical pulps, both bleached and semi-bleached.

This kappa number standard applies to many kinds of chemical, semi-chemical, unbleached and semi-bleached pulps within the kappa number range 1 to 100. Above a kappa number of 100, precision of the test may decrease, and the relationship between kappa number and lignin content may decrease, depending mainly upon the wood species from which the pulp is made.