Method and device for treating a web of fibrous material

The method comprises guiding a fibrous material web (2) over a treatment path between first and second revolving bearing surfaces (4.1, 4.2), and clamping the fibrous material web in a first treatment path section (3.1) between the bearing surfaces. The bearing surfaces are moved apart from each other in a second treatment path section (3.2) within the treatment path to a predetermined distance, which is larger than the thickness of the fiber web in the first treatment path section. The bearing surfaces in the second treatment path section run parallel to the predetermined distance. The method comprises guiding a fibrous material web (2) over a treatment path between first and second revolving bearing surfaces (4.1, 4.2), and clamping the fibrous material web in a first treatment path section (3.1) between the bearing surfaces. The bearing surfaces are moved apart from each other in a second treatment path section (3.2) within the treatment path to a predetermined distance, which is larger than the thickness of the fiber web in the first treatment path section. The bearing surfaces in the second treatment path section run parallel to the predetermined distance. The first bearing surface is formed by the surface of strips. The first bearing surface in the second treatment path section is positively guided by guiding elements. The predetermined distance of the second treatment path section is adjusted over the guiding elements. The strip has a gripping element distributed over a total width. The gripping elements are temporarily connected to the guiding elements. An expansion additive ensures that the fibrous material web expands in the second treatment path section. A negative pressure above and/or below the fibrous material web is used as expansion additive and/or a chemical releasing an over pressure is used within the fibrous material web. A stabilizing agent ensures that the fibrous material web not collapses again in its initial thickness, which is present in the first treatment path section, after the second treatment path section. The chemical is used as the stabilizing agent and increases the viscosity of the material web and/or its gas content. An independent claim is included for a device for treating a running fibrous material web in a treatment path between bearing surfaces. Die Erfindung betrifft ein Verfahren und eine Vorrichtung zur Behandlung einer laufenden Faserstoffbahn (2), bei dem die Faserstoffbahn (2) über eine Behandlungsstrecke (3)