EP 0371786 A2 19900606 - Web forming method and apparatus.
Title (en)
Web forming method and apparatus.
Title (de)
Verfahren und Vorrichtung zur Herstellung von Bahnen.
Title (fr)
Procédé et dispositif de formation de bandes continues.
Publication
Application
Priority
FI 885606 A 19881201
Abstract (en)
A method for forming a paper or paperboard web from a fibrous material in the wire section of a paper making machine or equivalent machine comprising a bottom wire loop (2;102) with the main portion of its top run being horizontal or substantially horizontal, and a top wire loop (10;110) working in conjunction with the bottom wire loop; wherein in the method fibre slurry coming out of the headbox (1;101) of the paper making machine is fed to the first part (2a; 102a) of the top run of said bottom wire loop (2;102), which forms the first dewatering zone after which the partly formed fibre layer is led to the second dewatering zone, in the area of which said top wire loop (10;110) moves to cover said partly formed fibre layer in such a way that water removal from the fibre layer continues it least in two stages in the area of said second dewaterlng zone, whereupon the top wire loop (10;110) is separated from the nearly formed web (W) that is led to follow the run of the bottom wire loop (2;102) forward to the next processing stages of the web (W), wherein the method is characterized in that in the single-wired dewatering zone (2a;102a), after the initial water removal is carried out through the bottom wire (2;102), water removal through the bottom wire (2;102) is prevented by means of an element group (9; 109) operating in contact with the inner surface of the horizontal top run of the bottom wires; that in said water-removal prevention area water is removed from the web (W) through the top wire in the first stage or stages of the double-wired second dewatering zone, which stages comprise a relatively long, planar wire table extending from the headbox to the forming roll (6 in Fig. 1), or from the headbox to the last supporting element (109 in Fig. 2); and that after the first dewatering stage or stages of the double-wired zone water is removed in a curved double-wired dewatering zone (b) (Fig. 1) or zones (Ro, C) (Fig. 2), after which the web (W) is led to follow the bottom wire (2;102).
IPC 1-7
IPC 8 full level
D21F 1/00 (2006.01); D21F 1/48 (2006.01); D21F 3/00 (2006.01); D21F 9/00 (2006.01)
CPC (source: EP KR)
D21F 1/00 (2013.01 - KR); D21F 1/48 (2013.01 - EP); D21F 3/00 (2013.01 - EP); D21F 9/003 (2013.01 - EP)
Designated contracting state (EPC)
AT DE ES FR GB IT SE
DOCDB simple family (publication)
EP 0371786 A2 19900606; EP 0371786 A3 19901122; CA 2004123 A1 19900601; CN 1045828 A 19901003; FI 885606 A0 19881201; FI 885606 A 19900602; JP H02191792 A 19900727; KR 900010147 A 19900706
DOCDB simple family (application)
EP 89312431 A 19891129; CA 2004123 A 19891129; CN 89109546 A 19891201; FI 885606 A 19881201; JP 31087289 A 19891201; KR 890017916 A 19891201