The invention relates to a method to produce a linerboard exhibiting a high bending resistance and a high compression strength, which in turn provides high resistance to interflute buckling and sagging in a thereof formed corrugated board. This is achieved by the inventive combination of an optimized fiber refining level of the furnish in each layer of the linerboard, the separate formation of the top layer and the use of a multi-layer headbox to form the two-layered ply. In addition, the linerboard made according to the invention provides good printing properties in a thereof produced corrugated board, especially in flexographic printing, without the fluting structure being negatively affected.

A shoe press has a shoe on which a radial inner surface of a press jacket slides. In a method of operating the shoe press, lubricating fluid is introduced between the shoe and the press jacket for lubricating purposes. The press jacket has at least one polymer layer into which a reinforcing structure is integrated, the reinforcing structure including at least one reinforcing thread. The lubricating fluid, the at least one polymer layer, and/or the at least one reinforcing thread is/are designed such that the lubricating fluid reaches the at least one reinforcing thread of the reinforcing structure and produces a color change in same in the event the polymer layer breaks. There is also described a shoe press, the inclusion of a press jacket in such a shoe press, and a machine with such a shoe press.

There is provided a method of producing a containerboard, comprising the step of pressing a web formed from a pulp comprising NSSC pulp in an extended nip press, such as a shoe press, wherein the line load in the extended nip press is above 1200 kN/m. Further, there is provided a corrugated board comprising a liner and a fluting, wherein the fluting is formed from a pulp comprising NSSC pulp, the density of the fluting is above 725 kg/m3 and the geometric SCT index (ISO 9895) of the fluting is above 37 Nm/g.

The present invention relates to a method for dewatering a web comprising microfibrillated cellulose, wherein the method comprises the steps of: providing a suspension comprising between 50 wt-% to 100 wt-% of microfibrillated cellulose based on total dry weight, forming a fibrous web of said suspension on a support wherein said web has a dry content of 1-25% by weight, applying a dewatering felt into direct contact with the fibrous web, conducting said fibrous web, arranged between said dewatering felt and said support, through at least one shoe press equipment, drying the dewatered web to form a film which film has an Oxygen Transmission Rate (OTR) value (23° C., 50% RH) below 100 cc/m.sup.2/24 h according to ASTM D-3985.

A tissue machine (1) has a Yankee (3) and a shoe roll (4) that forms a nip with the Yankee (3). The nip has a maximum extension from an entry point (7) to an exit point (8). A flexible belt (9) forms an outer circumference of the roll (4). A fabric (10) carries a fibrous web (W) to the nip and passes through the nip with the web. The fabric (10) reaches the circumference of the roll (4) at a first contact point (11) and wraps the roll (4) from the first contact point to the nip. A mechanical support (12) inside the belt (9) supports the belt (9) between the first contact point (11) and the nip. The fabric (10) wraps the roll (4) from the first contact point (11) by more than 80°. The invention also relates to a method of operating the machine.

There is provided a method of producing a containerboard, comprising the step of pressing a web formed from a pulp comprising NSSC pulp in an extended nip press, such as a shoe press, wherein the line load in the extended nip press is above 1200 kN/m. Further, there is provided a corrugated board comprising a liner and a fluting, wherein the fluting is formed from a pulp comprising NSSC pulp, the density of the fluting is above 725 kg/m.sup.3 and the geometric SCT index (ISO 9895) of the fluting is above 37 Nm/g.

There is provided a method of producing a containerboard having a geometric SCT index of 37.0-42.0 Nm/g when measured according to ISO 9895:2008, comprising the steps of: —providing a pulp having a Schopper-Riegler (SR) value of 15-19 when measured according to ISO 5267-1:1999, wherein at least 70% by dry weight of the pulp is NSSC pulp; —forming a web from the pulp; —pressing the web in a press section comprising a shoe press, wherein the shoe press comprises a shoe press belt having discontinuous grooves and the line load in the shoe press is in the range of 1400-2000 kN/m; —drying the web from the press section in a drying section to obtain said containerboard.

A method for treating a pulp web in a paper or tissue machine with an extended-nip press unit. This extended-nip press unit includes a shoe press roll with a revolving press belt and a backing roll, where the pulp web is dewatered in the extended press nip between the backing roll and the press belt and where the pulp web is carried on the revolving press belt of the press roll after the extended press nip to a transfer fabric that receives the pulp web. The transfer fabric is guided over a stationary transfer device in the transfer area. A corresponding device for treating the pulp web.

A tissue machine (1) has a Yankee (3) and a shoe roll (4) that forms a nip with the Yankee (3). The nip has a maximum extension from an entry point (7) to an exit point (8). A flexible belt (9) forms an outer circumference of the roll (4). A fabric (10) carries a fibrous web (W) to the nip and passes through the nip with the web. The fabric (10) reaches the circumference of the roll (4) at a first contact point (11) and wraps the roll (4) from the first contact point to the nip. A mechanical support (12) inside the belt (9) supports the belt (9) between the first contact point (11) and the nip. The fabric (10) wraps the roll (4) from the first contact point (11) by more than 80°. The invention also relates to a method of operating the machine.

There is provided a method of producing a containerboard, comprising the step of pressing a web formed from a pulp comprising NSSC pulp in an extended nip press, such as a shoe press, wherein the line load in the extended nip press is above 1200 kN/m. Further, there is provided a corrugated board comprising a liner and a fluting, wherein the fluting is formed from a pulp comprising NSSC pulp, the density of the fluting is above 725 kg/m.sup.3 and the geometric SCT index (ISO 9895) of the fluting is above 37 Nm/g.