Gpcp IP Holdings LLC

Kevin M Holtman

Jeffrey A Lee

Yu Chen

Brian S Hammes

Daniel W Sumnicht

Jeffery J Boettcher

Jeffrey J Boettcher

Daniel E Miller

A method of producing high yield chemical cellulosic pulp includes: (a) chemically pulping wood chips to separate lignin and liberate cellulosic fibers from the wood chips to generate a cellulosic pulp; (b) washing and screening the pulp of step (a); (c) pre-treating the washed pulp with oxygen; (d) optionally washing the treated pulp of step (c); (e) bleaching the pre-treated pulp in an extended duration oxidative bleaching stage; (f) optionally washing the bleached pulp of step (e); and (g) optionally further oxidatively or reductively bleaching the bleached pulp in a shorter duration bleaching stage, wherein the bleached pulp is produced at a yield of greater than 60% based on the weight of the pulped wood chips (dry basis).

High yield chemical pulping and bleaching process

Recycle fiber bleaching includes an oxygen pre-treatment to activate the fiber for further bleaching. A preferred method of making a high brightness papermaking pulp from recycled cellulose fiber includes: (a) pre-treating a first recycled cellulosic fiber mix with oxygen, said first recycled cellulosic fiber mix having a first high Kappa number prior to pre-treatment and a reduced Kappa number after pre-treatment that is lower than said first high Kappa number; and (b) blending the pre-treated first recycled cellulosic fiber mix with the reduced Kappa number with a second recycled cellulosic fiber mix having a second Kappa number lower than the first high Kappa number of the first recycled cellulosic fiber mix; and (c) oxidatively bleaching the blended recycled cellulosic fiber mix of step (b); and optionally (d) reductively bleaching the blended recycled cellulosic fiber mix of step (c).

Oxygen treatment of high kappa fibers

Absorbent sheet is manufactured utilizing a low charge density debonder composition comprising an imidazolinium surfactant-containing constituent selected from the group consisting of: (i) cationic imidazolinium surfactants with alkylalkenylhydroxy substitution; (ii) zwitterionic imidazolinium surfactants; and (iii) an ion paired surfactant mixture including a zwitterionic imidazolinium surfactant and a cationic surfactant and, in admixture with the imidazolinium surfactant-containing constituent, (iv) a nonionic surfactant.

Manufacture of absorbent paper with low charge density imidazolinium containing debonder compositions

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Appleton, WI, United States of America

Kevin M Holtman