This application is a national stage of International Application No.: PCT/DE2010/000337, which was filed on Mar. 25, 2010, and which claims priority to German Patent Application Nos.: DE 10 2009 016 996.2, which was filed in Germany on Apr. 8, 2009; and to DE 10 2009 017 729.9, which was filed in Germany on Apr. 11, 2009, and which are both herein incorporated by reference.
The invention relates to an apparatus for compacting a fiber web according to the precharacterizing part of claim 1.
From EP-A-0-859 076, there is known an apparatus for compacting the fibers of a fiber web of natural and/or synthetic fibers of any type, wherein a belt/drum-type compaction of the fiber web is performed. Said apparatus comprises the following features and respectively is designed as indicated hereunder:
The apparatus of the above type has the advantage that the initial fiber web, i.e. the fiber web advancing voluminously, will be compacted between the two endless belts in a slowly increasing manner and with uniform pressure from above and below, while not being subjected to shearing stress, and will be wetted at the needling drum only when being tightly held between the two endless belts.
This known apparatus is distinguished particularly by an intensive wetting generated directly on the drum. Further, after the second endless belt has been led away, there can be directly performed, on the drum, a needling process with the aid of a second nozzle bar which now is oriented directly towards the fiber web arranged on the drum. This arrangement, however, is very complex and too expensive for some products.
Known from EP 1 126 064 B1 is a device wherein the compacting and the first netting of the nonwoven are simplified. This known device provides a belt-to-belt compacting and comprises the following features and respectively is designed as indicated hereunder:
The known apparatus are able to accomplish a slow compressing of the fiber web consisting of loose, not rigidly interconnected fibers, and the wetting process in the pressed state. Since the fiber web is compressed and wetted in this state, it will happen that, after the wetting and after detachment from the fiber web which is to be needled further on, single fibers still remain attached to the compressing endless belt (the compacting belt), which fibers will contaminate the belt and ultimately hinder a permanent optimal treatment of the subsequent fiber web.
To avoid the above described disadvantage, the belt-drum compacting according to WO 2004/046444 A1 provides that the nozzle bar arranged between the rollers guiding the compacting belt is oriented in such a manner that the water jets will impinge onto the fiber web only behind the compression region when seen in the transport direction of the fiber web.
Such an orientation of the nozzle bar will achieve an invariably effective wetting of the pressed fiber web wherein, however, the fiber web will be detached from the pressing endless belt by the water jets. At the same time, the compacting belt will be rinsed to be free of adhering fibers, and these fibers will be returned to the fiber strand. However, the described approach is possible only in a belt-drum compacting process.
From WO 2008/107549 A2, there is known a device for treatment of a non-woven wherein the web of fibers and filaments arranged on a revolving transport belt will be transferred onto the lower side of a second transport belt by application of water jets from below through the transport belt. The two transport belts have a distance larger than the thickness of the nonwoven web. By different speeds of the transport belts, the weight per surface unit of the nonwoven web can be influenced. However, by means of the two transport belts moving at different speeds, no compacting of the nonwoven web is effected. Compacting can be performed only by a further belt system, which causes considerable constructional expenditure.
DE 10 2005 055 939 B3 discloses a nozzle bar for generating fluid jets serving for compacting a fiber web. The nozzle strip comprises an exchangeable nozzle strip comprising the exit openings for the fluid. The exit openings can be arranged parallel to each other in a row, but also in two or more rows. The mutual distance and the diameter of the exit openings are dictated by the intended use. The fluid used can be pressurized water but, generally also overheated vapor.
It is an object of the present invention to improve an apparatus, known from EP 1 126 064 B1, which is provided for compacting a material web made of fibers and/or filaments, comprising a first revolving endless belt which carries the material web and is tensioned around guide rollers, and a second endless belt which is tensioned around guide rollers and revolves in the direction opposite to the first belt at the same speed, wherein the first and second endless belts, forming a conical compacting region in a first region in the conveying direction of the material web, run at an angle toward each other, whereby the material web located between the belts is increasingly pressed, wherein, subsequent to the first region, a first nozzle beam is disposed for a first fluid application onto the material web still located between the two endless belts, wherein the two belts in this region of the first fluid application are in each case guided to run in a tensioned manner in a straight direction.
According to the invention, it is provided, in a first embodiment, that, in the region of the first fluid application, the two belts are not guided in parallel extension relative to each other. The two belts, the transport belt carrying the material web consisting of fibers and/or filaments, as well as the compacting belt generating the pressing effect, extend at an acute angle relative away from each other when viewed in the transport direction of the web. Preferably, the guidance of the belts is adjustable in correspondence to the type of fibers or filaments or other conditions. Thus, it can be provided that the fluid application is performed in a region in which the web is hardly held in a pressed state anymore. Particularly, it is possible that the first fluid application is performed by means of two serially arranged, mutually parallel rows of exit openings for the fluid. It can be provided in this arrangement that, in the nozzle bar, a nozzle strip comprising the openings has two rows of exit openings, or that two nozzle bars are arranged behind each other. The latter arrangement makes it possible to perform the fluid application with different pressure values.
In an arrangement for first fluid application onto the material web arranged in a pressed state between the transport and compacting belts, which is performed by two nozzle bars, it can be provided that the two belts are guided in such a manner that the material web is still held in a pressed state during the application by the fluid jets of the first nozzle bar, but is hardly or not at all pressed anymore during the application of the fluid jets of the second nozzle bar. In case of a slight pressing process by the compacting belt or a pressing process not performed anymore, the fibers adhering in the screen tissue of the compacting belt will be driven back into the material web by the fluid jets of the second nozzle bar and, from there, be integrated into the composite structure.
The same inventive idea is realized in a second embodiment which provides the following: In the region of the first fluid application, the two belts are guided parallel to each other in a first section and are guided non-parallel to each other in a subsequent second section. A first fluid application is to be understood herein as the treatment of the fiber web by fluid jets of a single nozzle bar or a plurality of nozzle bars arranged closely behind each other.
By way of modification of the above, the following is provided:
According to this alternative embodiment of the invention, it is provided that the two belts in the second section are tensioned to extend away from each other at an acute angle. In the first section, the two belts are guided parallel to each other, which can be performed in that the two belts are together deflected by a first guide roller and, subsequently, by means of a further guide roller, the compacting belt is guided away from the web-carrying transport belt at an acute angle. In this section, the compacting belt will run in the direction of a further guide roller which preferably is adjustably supported to allow for adjustment of the angle at which the transport and compacting bands extend away from each other.
Further, it can be provided that, for forming the first section, the two belts which are respectively guided around two guide rollers, extend parallel to each other in the thus formed section.
In this arrangement, said common wrap-around movement around the two guide rollers can be performed in the same direction or alternately. Also in these arrangements, it is provided that, starting from the second guide roller, the compacting belt is guided at an acute angle away from the transport belt carrying the web. In this second section, the compacting band runs in the direction of a second guide roller which preferably is adjustably supported to allow for adjustment of the angle at which the transport and compacting bands extend away from each other.
According to one embodiment of the invention, a respective nozzle bar is arranged in the first and in the second section alike. Thus, in this first section, there is performed a first application, a wetting, of the fiber web held in a pressed state between the two parallel belts. In the second section, a further nozzle bar is arranged so that the wetted nonwoven will now be once more treated and compacted through the structure of the compacting belt wherein, in this second section, the compacting belt extends away from the nonwoven-carrying transport belt at an acute angle.
In case of a slight or ceased pressing performed by the compacting belt in the second section, fibers adhering in the screen tissue of the compacting belt will be driven back into the material web by the fluid jets of the second nozzle bar and, from there, be integrated into the composite structure.
In this arrangement, it can be provided that the fluid application in the two successive sections is performed with different pressure values and also different hole spacings and hole diameters.
Exemplary embodiments of the invention will be explained hereunder with reference to the drawings. In this context, the term “fiber web” is to designate a non-compacted pile of fibers and/or filaments which is delivered by a pile producer in non-compacted form (material web prior to first compacting, fluid application). The term “nonwoven” is used for the material web after the latter has undergone a first compacting.
A transport belt 1 formed as an endless screen belt (first endless belt) is held in a tensioned state around guide rollers U,U1 and will rotate in clockwise sense as indicated by the arrow (
On transport belt 1, there is supplied a non-compacted fiber web F (pile) e.g. from a carding machine, not shown, and will run on the transport belt in the direction of guide roller U. By the guide roller U1 shown on the lefthand side in
Following guide roller U, transport belt 1 and compacting belt 2 will extend away from each other at an acute angle while tensioned in straight directions. The compacting belt 2 runs in the direction of guide roller U2-J, and the transport belt 1 runs in the direction of a further guide roller, not shown in
In this region, following guide roller U, a first nozzle bar D is arranged above the fiber web covered by compacting belt 2. Said nozzle bar cooperates with a suction device A arranged below the transport belt 1 carrying the fiber web and, by the fluid jets W directed onto the fiber web, will effect a first slight compacting of the structure. When water jets are discharged by the nozzle bar D, the fiber web F will be wetted in this region. The fiber web F has now been compacted into a slightly consolidated nonwoven (initial nonwoven) V and will leave the region of compacting belt 2 at a site below guide roller U2-J. There follow further devices, not shown, for fluid application, further compacting and/or structuring of the nonwoven.
Thus, by adjustment of guide roller U2-J, it is possible to set the angle β between the transport belt 1 carrying the nonwoven V and the compacting belt 2, i.e. the path between the point K from which the compacting belt 2 is not in contact with the nonwoven V anymore, and the passage of the fluid jets W through the compacting belt 2.
Further, it is also possible to set an angle β such that the fluid jets W passing through the compacting belt 2 will impinge onto the nonwoven V when the compacting belt 2 is still in contact with nonwoven V. Also in this case, the transport belt 1 and the compacting belt 2 do not extend parallel to each other; the angle β is only flatter than in the situations according to
In the embodiment according to
Said alternative embodiment of the invention and the corresponding variants will now be explained with reference to
A transport belt 1 formed as an endless screen belt (first endless belt) is held in a tensioned state around guide rollers U,U1 and will rotate in clockwise sense as indicated by the arrow (
On transport belt 1, there is supplied a non-compacted fiber web F (pile) e.g. from a carding machine, not shown, and will run on the transport belt in the direction of guide roller U. By the guide roller U1 shown on the lefthand side in
In a first section AB1, the transport belt 1 and the compacting belt 2 run parallel while holding the nonwoven between them in a pressed state.
After guide roller U2-P, in second section AB2, the transport belt 1 and the compacting belt 2 extend away from each other at an acute angle β while tensioned in straight directions. The compacting belt 2 runs in the direction of the adjustable guide roller U2-J, and the transport belt 1 runs in the direction of a further guide roller. The adjustability of guide roller U2-J is visualized by the double arrow.
In said first section AB1, after guide roller U, a first nozzle bar D1 is arranged above the fiber web covered by compacting belt 2. Said nozzle bar cooperates with a suction device A1 arranged below the transport belt 1 carrying the fiber web and, by the fluid jets W1 directed onto the fiber web, will effect a slight compacting of the structure. When water jets are discharged by the nozzle bar D1, the fiber web will be wetted in this region. The fiber web F has now been compacted into a slightly consolidated non-woven (initial nonwoven) V and, past guide roller UP-P, will reach the second section AB2 in which the transport belt 1 and the compacting belt 2 extend away from each other at an acute angle β while being tensioned in a linear direction. In the second section AB2, a second nozzle bar D2 is arranged above the compacting belt 2. Below the transport belt 1 carrying the nonwoven V, a suction device 2 is arranged. Herein, the treatment of the nonwoven V is performed by the fluid jets W2 which will pass through the structure (screen belt) of compacting belt 2, then will reach the surface of the nonwoven V and the will pass through the structure of the transport belt 1. The nozzle bars D1 and D2 are arranged closely behind each other with respect to the total path of the fiber web F within the entire system and together will effect a first application of fluid onto the material web as provided according to the sense of the invention.
In the embodiment according to
Thus, by adjustment of guide roller U2-J, the angle β between the transport belt 1, carrying the nonwoven V, and the compacting belt 2 can be adjusted, i.e. the distance between the point K from which the compacting belt 2 has no contact with the nonwoven V anymore, and the passage of fluid jets W2 through the compacting belt 2 (
Further, it is also possible to set an angle β in the second section AB2 such that the fluid jets W2 passing through the compacting belt 2 will impinge onto the nonwoven V when the compacting belt 2 is still in contact with nonwoven V. Also in this case, the transport belt 1 and the compacting belt 2 do not extend parallel to each other; the angle β is only flatter than in the situations according to
Number | Date | Country | Kind |
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10 2009 016 996 | Apr 2009 | DE | national |
10 2009 017 729 | Apr 2009 | DE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
---|---|---|---|---|
PCT/DE2010/000337 | 3/25/2010 | WO | 00 | 12/28/2011 |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO2010/115400 | 10/14/2010 | WO | A |
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Number | Date | Country |
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10 2005 055 939 | Feb 2007 | DE |
0 859 076 | Aug 1998 | EP |
0 972 873 | Jan 2000 | EP |
1 126 064 | Aug 2001 | EP |
WO 2004046444 | Jun 2004 | WO |
WO 2008107549 | Sep 2008 | WO |
WO 2008110134 | Sep 2008 | WO |
Number | Date | Country | |
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20120096694 A1 | Apr 2012 | US |