Claims
- 1. An improved process for delignification and bleaching of an oxygen delignified chemical wood pulp comprising the steps of:
- a) producing a slurry of chemical wood pulp under alkaline conditions; and
- b) adding to the slurry a hydrogen peroxide bleaching agent in a range of about 0.5% to 5% by weight of oven-dry pulp, and an effective amount of a dicyandiamide bleaching activator to produce a delignified and bleached wood pulp having a brightness value of about 72.5% ISO or greater and a kappa value of about 3.2 or less.
- 2. An improved process for delignification and bleaching of an oxygen delignified chemical wood pulp comprising the steps of:
- a) producing a slurry of chemical wood pulp under alkaline conditions from the oven-dry pulp to be treated; and
- b) adding to the slurry a hydrogen peroxide bleaching agent in an amount of about 2% by weight of oven-dry pulp, and an effective abount of a dicyandiamide bleaching activator to produce a delignified and bleached wood pulp having a brightness value of about 72.5% ISO or greater and a kappa value of about 3.2 or less.
- 3. The process for delignification and bleaching according to claim 2 and wherein:
- a) the dicyandiamide bleaching activator is about 50% by weight of the hydrogen peroxide bleaching agent added to the slurry.
Parent Case Info
This is a continuation of application Ser. No. 08/331,935 filed Oct. 31, 1994, now U.S. Pat. No. 5,620,563.
US Referenced Citations (4)
Continuation in Parts (1)
|
Number |
Date |
Country |
Parent |
331935 |
Oct 1994 |
|