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).

Claims

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.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawing, wherein:

[0023] FIG. 1 is a schematic representation of an embodiment of a machine according to the present invention.

[0024] Corresponding reference characters indicate corresponding parts throughout the several views. The exemplification set out herein illustrates one embodiment of the invention, and such exemplification is not to be construed as limiting the scope of the invention in any manner.

DETAILED DESCRIPTION OF THE INVENTION

[0025] FIG. 1 shows a schematic representation of one possible embodiment of a machine according to the present invention. Following low-water processing, in which the individual fibers and/or fiber bundles 6consisting for example of fibrous recycled material or fluff cellulose or virgin fiber celluloseare formed in the air stream by way of defibration machines, the individual fibers and/or fiber bundles 6 are fed in the air stream to a distribution channel 7 of machine 1 and are distributed evenly in a direction transverse to the direction of travel 15 of machine 1. The individual fibers and/or fiber bundles 6 sink downwards in the air stream in distribution channel 7 onto a revolving screen 13 and form a laid fibrous structure 12. This forming step 2 in dry forming device 2 is followed by a heating step 3. In this example, a heating device 8 is shown, which is designed as an infrared emitter. The formed laid fibrous structure is heated. This is followed by a moistening step 4, in which a moistening device 9, which is designed as a nozzle for applying water, is used to moisten the laid fibrous structure. In subsequent consolidation step 5, fibrous structure 12 is passed through a press nip 5, which is formed by two press rollers 10, 11. Solidification step 5 greatly reduces the thickness of laid fibrous structure 12. One of the press rollers 10, 11 can have a textured surface to produce a textured fibrous web 14.

COMPONENT IDENTIFICATION LISTING

[0026] 1 Machine [0027] 2 Forming step, dry forming device [0028] 3 Heating step [0029] 4 Moisturizing step [0030] 5 Consolidation step, press nip [0031] 6 Individual fibers, fiber bundles [0032] 7 Distribution channel [0033] 8 Heating device [0034] 9 Moisturizing device [0035] 10 Press roll [0036] 11 Press roll [0037] 12 Laid fibrous structure [0038] 13 Screen [0039] 14 Fibrous web [0040] 15 Direction of machine travel

[0041] While this invention has been described with respect to at least one embodiment, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.