Patent ID: 6187135
Filing Date: 2001-02-13
Classification: D21B,D21C,Y02W

Abstract:
In an improved process for making recycled paper wherein fibers in waste paper stocks are dispersed, extracted from cleaned and screened furnish, refined to achieve required level of freeness of a furnish, and deposited on a wire and dewatered,the improvement comprising a process for improving strength properties of recycled paper comprising the steps of:replacing disk refiners, beaters and kneaders by agitators;removing fibril fragments from cleaned and screened furnish by a fiber extractor that extracts fibril fragments and does not extract short and long fibers;applying an effective amount of dispersion aids to a pulper;maintaining a pH of furnish at a head box of paper machine at least 5.5 and at highest 6.5;applying an appropriate amount of dry strength additives to furnish.