Metso Paper Karlstad Ab

Valmet Aktiebolag

Hans Ivarsson

Frank Stephen Hada

Jeffrey Dean Holz

Paul Douglas Beuther

Ingvar Berndt Erik Klerelid

Johan Ragard

Ingvar B Klerelid

Karl-Johan Tolfsson

Magnus Hoegman

Johnny Anerud

Andreas Hjaertqvist

Stefan Moden

Anders Ottosson

Allan Grimm

Johan Ulf Rågård

Jonas Cederloef

Stefan Thyberg

Sune Wendelsson

Martin Raedman

Anna Danielsson

Ingvar Klerelid

Johan Ulf Ragard

Magnus HÖGMAN

Andreas HJÄRTQVIST

Jonas CEDERLÖF

Johnny ÅNerud

Martin RÅDMAN

The invention relates to a method of producing a structured fibrous web of paper suitable for tissue products. The method comprises forming a fibrous web and conveying the formed fibrous web on a water receiving felt () to a dewatering nip. An endless steel belt () with a smooth steel surface is passed through the nip together with the fibrous web and the water receiving felt () wherein the endless steel belt is heated by heaters (HE, HE). After the dewatering nip, the fibrous web is conveyed by the endless steel belt () to an endless textured fabric () which is permeable to air and to which the web is transferred from the endless steel belt () in a transfer nip. The textured fabric () runs at a lower speed than the endless belt (). After the transfer to the textured fabric (), the fibrous web is carried by the textured fabric () to a drying cylinder (). The transfer nip is formed by two rolls of which one is a suction roll within the loop of the textured fabric. The transfer nip has a length which is 5 mm-40 mm. The endless steel belt () has a width that exceeds the width of the textured fabric (). The invention also relates to a corresponding machine.

Method and a machine for producing a tissue web

The invention relates to a method of making a structured fibrous web (W). The method comprises forming a fibrous web (W) and conveying the formed fibrous web on a water receiving felt () to a dewatering nip (PN) formed by a first press unit () and a second press unit () and where an endless belt () is passed through the nip together with the fibrous web(W) and the water receiving felt (), The endless belt has a side which is covered by a polymer and which contacts the fibrous web (W) in the dewatering nip (PN). After the dewatering nip, the web (W) is transferred with a speed difference to an endless structured clothing () which is permeable to air and has protruding knuckles () on the side that contacts the fibrous web (W) and which protruding knuckles () give the structured clothing () a topographic surfacearea which, for a given length of the structured clothing () in the machine direction and a given width of the structured clothing in the cross machine direction, exceeds the plain surface area of a part of the endless belt () having an equal length and width. The structured clothing is operated at a speed which is so much lower than the speed of the endless belt () that the relative difference in speed between the endless belt () and the structured () fabriccorresponds to the relative difference in surface area between the endless belt () and the structured clothing. In this way, the fibers of the fibrous web (W) will be evenly distributed on the structured clothing (). The invention also relates to a creped fibrous web (W) having a basis weight in the range of 14 g/m-40 g/m, and having a three-dimensional structure formed by depressed regions () and elevated regions (). The fibers of the fibrous web (W) are 20 evenly distributed over the surface of the creped fibrous web (W).

Method of making a structured fibrous web and a creped fibrous web

The invention relates to a steel-made Yankee cylinder () that comprises a cylindrical shell () having two axial ends (). An end wall () is connected to each axial end () by a circumferential weld bead (). The cylindrical shell has an inner surface () in which circumferential grooves () are formed. From the outermost circumferential groove () at each axial end () to the circumferential weld bead () at that axial end () the wall thickness (T) of the cylindrical shell is either constant or decreasing and the depth (d) of the circumferential grooves increases axially from the outermost circumferential groove ().

Steel-made yankee cylinder

An apparatus for transferring a wet paper web from a press nip to a drying cylinder of a papermaking machine, and for structuring the web, includes an impermeable transfer belt that passes through the press nip along with the paper web, and a permeable structuring fabric for transfer of the web onto the drying cylinder, the structuring fabric being arranged in a loop within which a suction transfer device is disposed. A web-contacting surface of the belt has a non-uniform distribution of microscopic-scale depressions, and a suction zone of the transfer device includes a transfer point spaced a distance D from the press nip. The belt is arranged to bring the web into contact with the structuring fabric in the suction zone for a length L, such that suction is exerted on the paper web to transfer the paper web from the belt onto the structuring fabric at the transfer point.

Apparatus with an impermeable transfer belt in a papermaking machine, and associated methods

A papermaking machine for making paper includes a forming section, a press section, and a drying section. The paper web is pressed between two press members while enclosed between a press felt and a transfer belt having non-uniformly distributed microscopic depressions in its surface, the web following the transfer belt from the press to a transfer point at which the web is transferred via a suction transfer device onto a structuring fabric, the web then being dried on a drying cylinder. The transfer point is spaced a distance D from the press nip selected based on machine speed, a basis weight of the web, and the surface characteristics of the transfer belt, such that within the distance D a thin water film between the web and the transfer belt at least partially dissipates to allow the web to be separated from the transfer belt.

Methods employing an impermeable transfer belt in a papermaking machine

An apparatus for transferring a wet paper web from a press nip to a drying cylinder () of a papermaking machine, and for structuring the web, comprises an impermeable transfer belt () having a web-contacting surface, the wet paper web passing through the press nip enclosed between a press felt () and the transfer belt, and a permeable structuring fabric () for transfer of the web onto the drying cylinder, the structuring fabric having a structured surface and being arranged in a loop within which a suction transfer device () is disposed, said suction transfer device having a suction zone (). According to the invention the web-contacting surface of the belt has a non-uniform distribution of microscopic-scale depressions, and that the suction zone includes a transfer point () spaced a distance D from the press nip along which the belt runs, the belt being arranged to bring the web into contact with the structuring fabric in the suction zone for a length L, such that suction is exerted on the paper web to transfer the paper web from the belt onto the structuring fabric. at the transfer point.

Papermaking machine employing an impermeable transfer belt, and associated methods

Growing community of inventors

Karlstad, Sweden

Hans Ivarsson