Global Patent Index - EP 1225270 A3

EP 1225270 A3 20030827 - Process for conditioning a moving web

Title (en)

Process for conditioning a moving web

Title (de)

Verfahren zur Konditionierung eines umlaufenden Bandes

Title (fr)

Procédé pour le conditionnement d' une bande en mouvement

Publication

EP 1225270 A3 20030827 (DE)

Application

EP 01125586 A 20011026

Priority

DE 10102199 A 20010118

Abstract (en)

[origin: EP1225270A2] To clean a continuous blanket (10), in contact with the web (54) at a papermaking or cardboard production machine, the cleaning action is controlled in zones across the blanket width. Measurements are taken over the width of the web or blanket, for at least one web characteristic profile, and especially the web lateral moisture content profile and/or at least one blanket characteristic profile and especially the water content in the blanket and/or the blanket permeability. The blanket is conditioned and cleaned in zones according to the measurements. To clean and condition a continuous blanket, at a paper/cardboard production machine, a mean value is derived for each zone to set a cleaning intensity according to the measured deviation from the mean. The blanket is cleaned at least partially by a traversing jet spray tube, where at least one of the jets has a zonal control. The cleaning system also has a moving suction tube over the zone width, with a ceramic body and surface slits. Moving metal tongues determine the vacuum applied through each slit against the blanket. The moving suction tube can have a short length. The volume of applied cleaning fluid is set according to variable nominal values for the zones, and it is diluted externally, to be applied to the web through the traversing tube jets, or a number of fixed jets for the zones, each with a control valve. The cleaning fluid is a mixture of water and conditioning chemicals. The conditioning chemicals are fed to a unit, which is only used for chemical cleaning, with a controlled delivery to the blanket zones. The cleaning action is through a number of applicators (46,48) across the blanket width. The blanket characteristics are determined by an on-line measurement unit (44), linked to the applicators in a closed control circuit. A set mean characteristic value is used and/or a given characteristic ratio is set between the upper blanket (101) and the lower blanket (102) to give the required dry content and/or lateral moisture content profile after each press nip (50). Directly after the web press section, the lateral moisture content profile is measured and/or the amount of extracted water is measured at the catch trough and/or through the suction tube, to set the actions at the cleaning and conditioning zones across the blanket. An Independent claim is included for a suction tube, with a ceramic body, across the blanket width. The tube surface has slits, with metal tongues to set the slit dimensions and control the vacuum applied to the blanket.

IPC 1-7

D21F 1/32; D21F 7/12

IPC 8 full level

D21F 1/32 (2006.01)

CPC (source: EP US)

D21F 1/325 (2013.01 - EP US)

Citation (search report)

Designated contracting state (EPC)

AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR

DOCDB simple family (publication)

EP 1225270 A2 20020724; EP 1225270 A3 20030827; EP 1225270 B1 20061011; AT E342397 T1 20061115; CA 2368330 A1 20020718; CA 2368330 C 20100323; DE 10102199 A1 20020801; DE 50111190 D1 20061123; US 2002129914 A1 20020919; US 6716316 B2 20040406

DOCDB simple family (application)

EP 01125586 A 20011026; AT 01125586 T 20011026; CA 2368330 A 20020117; DE 10102199 A 20010118; DE 50111190 T 20011026; US 3209001 A 20011231