Patent · US Expired

Method of processing printed waste matter

US5518580A · kind A · utility

14Cited by
4References
12Claims
0Family size

Assignee

Inventors

Key dates

Filing dateAug 22, 1994
Grant dateMay 21, 1996
Priority date
Expiry dateAug 22, 2014

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY02W30/64
  • WIPO fieldTextile and paper machines
  • WIPO sectorMechanical engineering

Abstract

The present invention relates to a method of processing printed waste paper, in particular waste paper containing at least 80% newsprint or magazine paper by digestion, various cleaning steps, flotation or washing and disintegrating, the latter with a high consistency of at least 20%, and possibly bleaching. The invention is characterized by the fact that a final second disintegrating step, arranged possibly before a bleaching step, with treatment of the waste paper under strong kneading action of individual bar-shaped or block-shaped kneading elements of both the stator and the rotor of the disintegrating machine which are arranged in a kneading chamber thereof which is delimited by two concentric cylindrical surfaces, at temperatures between 20.degree. and 110.degree. C., and preferably 38.degree. to 65.degree. C., and with a specific power consumption of between 30 and 100, and preferably 80, kilowatt hours/ton oven-dried pulp.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.