Method and machine for producing a material web in a paper machine

Abstract

A method for producing a web of fibrous material includes the steps of: (a) low-water processing of cellulose-containing fibers into individual fibers and/or fiber bundles; (b) forming of the individual fibers and/or the fiber bundles in an air stream into a planar laid fibrous structure using a dry forming method; (c) moistening the individual fibers and/or the fiber bundles by way of a fluid; (d) solidifying the planar laid fibrous structure by applying pressure in a press nip; and (e) heating the individual fibers and/or the fiber bundles upstream from the step of solidifying (d) so as to increase a temperature of the individual fibers and/or the fiber bundles in the step of solidifying (d).

What is claimed is: 
     
         1 . A method for producing a web of fibrous material, the method comprising the steps of:
 (a) low-water processing of a plurality of cellulose-containing fibers into at least one of a plurality of individual fibers and a plurality of fiber bundles;   (b) forming of at least one of the plurality of individual fibers and the plurality of fiber bundles in an air stream into a planar laid fibrous structure using a dry forming method;   (c) moistening at least one of the plurality of individual fibers and the plurality of fiber bundles by way of a fluid;   (d) solidifying the planar laid fibrous structure by applying pressure in a press nip; and   (e) heating at least one of the plurality of individual fibers and the plurality of fiber bundles upstream from the step of solidifying (d) so as to increase a temperature of at least one of the plurality of individual fibers and the plurality of fiber bundles in the step of solidifying (d).   
     
     
         2 . The method according to  claim 1 , wherein the fluid is water. 
     
     
         3 . The method according to  claim 1 , wherein the step of heating (e) is carried out by at least one of (i) a plurality of infrared heating elements and (ii) a plurality of heated contact surfaces. 
     
     
         4 . The method according to  claim 1 , wherein the step of heating (e) is carried out by at least one of (i) a plurality of infrared heating elements, which are a plurality of electrically heated infrared heating elements, and (ii) a plurality of heated contact surfaces, which is a revolving screen or a roll. 
     
     
         5 . The method according to  claim 1 , wherein the step of heating (e) is carried out by the fluid in the step of moistening (c), the fluid being preheated. 
     
     
         6 . The method according to  claim 1 , wherein the step of heating is carried out by introducing steam before or during the step of forming (b). 
     
     
         7 . The method according to  claim 1 , wherein the step of heating (e) is carried out in a range of greater than or equal to 30° C. and less than or equal to 100° C. 
     
     
         8 . The method according to  claim 7 , wherein the step of heating (e) is carried out in a range of greater than or equal to 45° C. and less than or equal to 95° C. 
     
     
         9 . A machine for producing a web of fibrous material, the machine comprising:
 a device configured for low-water processing of a plurality of cellulose-containing fibers into at least one of a plurality of individual fibers and a plurality of fiber bundles;   a dry forming unit configured for forming at least one of the plurality of individual fibers and the plurality of fiber bundles in an air stream into a planar laid fibrous structure;   a moistening unit configured for moistening of at least one of the plurality of individual fibers and the plurality of fiber bundles by way of a fluid;   a press nip configured for solidifying the planar laid fibrous structure by applying pressure; and   a heating device which is upstream from the press nip and is configured for increasing a temperature of at least one of the plurality of individual fibers and the plurality of fiber bundles in the press nip.   
     
     
         10 . The machine according to  claim 9 , wherein the machine is configured for executing a method for producing the web of fibrous material, the method including the steps of:
 (a) low-water processing of the plurality of cellulose-containing fibers into at least one of the plurality of individual fibers and the plurality of fiber bundles;   (b) forming of at least one of the plurality of individual fibers and the plurality of fiber bundles in the air stream into the planar laid fibrous structure using a dry forming method;   (c) moistening at least one of the plurality of individual fibers and the plurality of fiber bundles by way of the fluid;   (d) solidifying the planar laid fibrous structure by applying the pressure in the press nip; and   (e) heating at least one of the plurality of individual fibers and the plurality of fiber bundles upstream from the step of solidifying (d) so as to increase the temperature of at least one of the plurality of individual fibers and the plurality of fiber bundles in the step of solidifying (d).   
     
     
         11 . The machine according to  claim 9 , wherein the fluid is water. 
     
     
         12 . The machine according to  claim 9 , wherein the heating device includes at least one of (i) a plurality of infrared heating elements and (ii) a plurality of heated contact surfaces. 
     
     
         13 . The machine according to  claim 9 , wherein the heating device includes at least one of (i) a plurality of infrared heating elements, which are a plurality of electrically heated infrared heating elements, and (ii) a plurality of heated contact surfaces, which is a revolving screen or a roll. 
     
     
         14 . The machine according to  claim 9 , wherein the heating device is operatively connected with the moistening unit and thereby is configured for heating the fluid. 
     
     
         15 . The machine according to  claim 9 , wherein the heating device is operatively connected with at least one of (i) the device configured for low-water processing and (ii) the dry forming unit.