Low temperature bleaching

摘要

An ozone bleached pulp substantially free of chlorine and having a viscosity equivalent to a viscosity of at least 30 cP and a kappa no. of 10 ml for Northern sofwood pulp and a method of producing same. The method applies a solution of water and a freezing point reducing agent to the chemical pulp, then cools the pulp to a temperature below 0 DEG C and then subjects the pulp to an ozone bleaching step at the reduced temperature to produce a bleached pulp.