Method and apparatus for producing a multilayer paper web
US4477313A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 22, 1982 |
| Grant date | Oct 16, 1984 |
| Priority date | — |
| Expiry date | Sep 22, 2002 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD21F9/006
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
In the production of multi-ply paper in a twin-wire former of the kind in which the wires define a curved forming zone, preferably a former of roll type with a smooth-faced forming roll, a substantially improved layer purity is produced in that the discharges from a first and at least succeeding portion of the curved forming zone are collected separately as different fractions. The first fraction collected nearest the multilayer headbox is returned in a first separate circuit to be used for diluting a first high consistency pulp to a first stock of headbox consistency, from which stock a first layer is to be formed directly on the outer wire in relation to the curved forming zone. At least a portion of a second fraction collected at a greater distance from the multilayer headbox is returned in a second separate circuit to be used for diluting a second high consistency pulp to a second stock of headbox consistency, from which a second layer is to be formed superimposed on the first layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.