Patent · US Expired

Process for upgrading of thermomechanical pulp to higher quality pulp

US6361650B1 · kind B1 · utility

10Cited by

3References

5Claims

0Family size

Assignee

Valmet Fibertech AB · SE

Inventors

Ove Danielsson · Stockholm, SE
Bo Falk · Järfälla, SE
Ulf G. Karlsson · Trosa, SE
Kenneth Kjellström · Torup, SE

Key dates

Filing date	Aug 21, 2001
Grant date	Mar 26, 2002
Priority date	—
Expiry date	Aug 21, 2021

Classification

Technology area (CPC D)Textiles; Paper
CPC primaryD21D1/20
WIPO fieldTextile and paper machines
WIPO sectorMechanical engineering

Abstract

Processes are disclosed for processing low consistency newsprint pulp including refining the pulp in a first refiner to a consistency of greater than 2%, screening the processed pulp with a slotted screen basket with a slot width of from 0.05 to 0.15 mm, with the withdrawal of the primary reject portion being greater than 50%, withdrawing the accept portion for further processing, dewatering the reject portion to provide a high consistency pulp, refining the high consistency pulp in a second refiner, screening the processed high width consistency pulp with a slotted screen basket having a slot of less than 0.15 mm, and combining the two accept portions for the further processing steps.

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