EP 1083260 A2 20010314 - Twin wire former
Title (en)
Twin wire former
Title (de)
Doppelsiebformer
Title (fr)
Section de formage à deux toiles
Publication
Application
Priority
DE 19943369 A 19990910
Abstract (en)
The double fourdrinier section (10), of a papermaking or cardboard prodn. machine, has two continuous fourdriniers (14,16) which form an entry gap (18) between them for the pulp feed from the stock inlet (23) to be converted into a web (12). An applicator (26) to deliver a filling suspension is on both sides of the double-fourdrinier stretch (24), after the entry gap (18) between them, with facing suction units (28,32,34). The fourdriniers are aligned on the vertical (V) or at an angle ( alpha ) to the vertical of (-) 30 degrees to (+) 30 degrees and especially (-) 20 degrees to (+) 20 degrees and pref. (-) 5 degrees to (+) 5 degrees on both sides of the double fourdrinier path. The filling suspension is composed of water with a filling material of kaolin, clay, CaCO3 as ground GCC or precipitated PCC, zeolite, TiO2, bentonite and/or other mineral materials, singly or in combinations. The filling suspension additionally carries fine and fiber materials, retention agents and/or other auxiliary processing agents. At the entry gap (18) between the fourdriniers for the pulp feed, one fourdrinier (16) of the pair (14,16) passes around a web shaping suction roller (22) before they come together in a vertical double-fourdrinier stretch (24) for the web formation zone (32). The web formation zone has at least one web development shoe (32) in a number of zone sections and especially 1-4 and pref. 1-3 sections (32'.32,32'). Where the pulp is converted into a web (12), the action of the shoe (32) is augmented by facing bars (36). Further water is extracted from the wet web (12) by at least one flat suction unit (34) in the vertical double-fourdrinier stretch (24), after the shoe structure (32), followed by a suction roller (28) for additional water extraction. At least one applicator (26) for the filling suspension is on the opposite side of the double fourdrinier to the flat suction unit (34) and the opposite side to the shoe structure (32) and the opposite side to the suction roller (28). After the filling suspension has been delivered into the double-fourdrinier stretch with the wet web, the collected extracted water is separated for processing apart from the collected water before the addition of the filling suspension. The entry gap (18) for the pulp feed, between the fourdriniers, is under the vertical double-fourdrinier stretch (24).
Abstract (de)
Ein Doppelsiebformer 10 einer Maschine zur Herstellung einer Faserstoffbahn 12 wie insbesondere einer Papier- oder Kartonbahn umfaßt zwei umlaufende endlose Sieben 14, 16, die unter Bildung eines Stoffeinlaufspaltes 18 zusammenlaufen. Innerhalb einer sich an den Stoffeinlaufspalt 18 anschließenden Doppelsiebstrecke 24, die genau vertikal oder unter einem Winkel α zur Vertikalen V verläuft, wobei dieser Winkel α zweckmäßigerweise in einem Bereich von etwa -30° bis etwa +30°, insbesondere in einem Bereich von etwa -20° bis etwa +20° und vorzugsweise in einem Bereich von etwa -5° bis etwa +5° liegt, auf beiden Doppelsiebseiten jeweils wenigstens ein Applikator 26 zum Auftragen einer Füllstoffsuspension vorgesehen. Vorzugsweise liegt jeder Applikator 26 jeweils einem auf der anderen Doppelsiebseite vorgesehenen Saugerelement 28, 32, 34 gegenüber. <IMAGE>
IPC 1-7
IPC 8 full level
D21F 9/00 (2006.01)
CPC (source: EP)
D21F 9/003 (2013.01)
Designated contracting state (EPC)
AT DE FI IT SE
DOCDB simple family (publication)
EP 1083260 A2 20010314; EP 1083260 A3 20010711; EP 1083260 B1 20041103; AT E281556 T1 20041115; DE 19943369 A1 20010322; DE 50008487 D1 20041209
DOCDB simple family (application)
EP 00116688 A 20000802; AT 00116688 T 20000802; DE 19943369 A 19990910; DE 50008487 T 20000802