Georgia-pacific Consumer Products LP

Fort James Corporation

Georgia-pacific Corporation

Hazen Charles Thomas

Wayne Frederick Winkler

Jeffrey A Lee

Terry P Witkowski

Michael Paul Bouchette

Henry Chou

David J DiPietro

Andrew C Palm

Robert J Clausing

Stephanie Keen

A process for high temperature peroxide bleaching of pulp in which pulp is retained at high temperature and pressure to increase bleaching activity but in which the pulp is cooled prior to discharge from the pressure vessel below the flash point thereby resulting in lower energy, nonviolent discharge. Through the use of a heat exchanger, the cooling of the pulp can be performed using recycled filtrate containing residual peroxide, which encourages further bleaching during atmospheric retention. The heat exchanger is also used to heat a water stream, which can be used earlier in the pulping process, resulting in cost savings because energy within the system is retained to a greater degree.

Process for high temperature peroxide bleaching of pulp with cool discharge

A method of processing papermaking fiber includes characterizing the initial color of the pulp and the color of the pulp after treatment with a phloroglucinol stain. The color response of the pulp to the stain has been found to be a better indicator of processing needs for secondary pulps in particular and in any event is selective for untreated groundwood as opposed to conventional groundwood identification methods. The color difference is used to target a suitable product for the pulp, to aid in bleaching/deinking strategy or to enable optimization of fiber blending for particular products. In a preferred embodiment the process includes determining changes in CIE L*, a*, b* and brightness values before and after staining of the pulp.

Process for using a phloroglucinol color delta to control blending, deinking and bleaching of groundwood-containing secondary pulp

An improved process for the separation of cellulosic fiber from difficult to process coated and inked paper products is disclosed and claimed. This process readily separates the paper pulp fraction substantially free of contaminants from such waste paper products as single and two side polymeric coated board having wet strength resin, single and two side polymeric coated board having no wet strength resin, single and two-sided glossy printer trimmings, ultraviolet (UV) cured ink coated stocks, and mixtures thereof. Preferred embodiments include a process in an inclined pressure vessel equipped with agitating and rotating means operative to reflux the waste material with respect to the inclined axis of the vessel in the presence of steam and chemical aids for a sufficient period of time so as to bring about repulping and separation of the paper fiber fraction and formation of a contaminant-collecting polymer phase. The recovered paper pulp fraction is suitable as a feedstock in the manufacture of a variety of paper products including paper tissue and paper towel products.

Method for removing contaminants from fibers in recycle fiber pulping

Growing community of inventors

Green Bay, WI, United States of America

Hazen Charles Thomas