Installation and method for producing single or multi-layer fleece

Abstract

The invention relates to an installation and a method having at least one carding machine (1) designed for producing a fibrous web (3) by an aerodynamic process, a first transport belt (4) designed for transporting the fibrous web (3) from the carding machine to a consolidation device, a consolidation device designed for compressing the fibrous web (3) into a fleece (24), a drafting device (10) downstream in the material conveying direction designed for stretching the fleece (24) by at least 1.5 times, and a bonding device downstream in the material conveying direction.

Description

[Technical field]

[0001] The present invention relates to an apparatus and method for producing single- or multi-layer fleeces. [Background technology]

[0002] In the case of the production of approximately isotropic fleeces, for example in the case of nonwoven fabrics used for wiping cloths or hygiene products, the carded fiber web is folded in a cross wrapper to produce a fleece having a MD / CD ratio of 1.3:1 to 2.1:1, which is further bonded downstream of the cross wrapper. 2 If a fleece having a weight of 30 g / m is to be produced, the carding machine 2 This produces a fiber web of 1000 mm / min, which enters a subsequent fleece lamination device, where it is folded in four layers to produce the desired MD / CD ratio. The multi-layer fleece then enters the cross-wrapper at a speed of, for example, 22 m / min into a drafting and bonding station and is then wound up at a speed of 80 m / min. In this case, the lighter the fleece produced by the carding machine, the more sensitive the folding or cross-wrapping process in the cross-wrapper, since the air currents and the high speeds have a very strong influence on the folding process. Furthermore, the cross-wrapper is a very expensive investment for the plant operator, which takes up a lot of space due to the L-shaped material flow and at the same time undesirably limits the production quality and yield.

[0003] For example, from EP 0 777 771 B1, devices for the aerodynamic production of fiber webs, also called air-laid carding machines, are known. These air-laid carding machines make it possible to produce nearly isotropic fiber webs. A disadvantage is the low production speed at high fleece weights. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] European Patent No. 0777771 Summary of the Invention [Problem to be solved by the invention]

[0005] The object of the present invention is to provide an apparatus and a method for producing single- or multi-layer fleeces, which can be used flexibly and which allows for the production of approximately isotropic fleeces with high productivity. [Means for solving the problem]

[0006] The present invention solves the problem posed by the teaching of claims 1 and 12, further advantageous features of the invention are characterized in the dependent claims.

[0007] According to the technical teaching according to claim 1, an installation for producing a single- or multi-layer fleece has at least one carding machine designed for generating a fibrous web by an aerodynamic process and a first conveying belt designed for conveying the fibrous web from the carding machine to a compacting device, the compacting device designed for compressing the fibrous web into a fleece.

[0008] The aerodynamic production of the fibrous web provides it with a high degree of isotropy, which can otherwise only be achieved in wet-laid or air-laid processes, unlike those processes, for example by air-laid carding machines, which allows the processing of a wide range of fiber lengths, fiber finenesses and fiber types.

[0009] For efficient further processing of the large quantities of the produced fiber web, the invention provides for a drafting device arranged downstream in the material conveying direction, which is designed to stretch the fleece by at least 1.5 times. The fleece can then be bonded in different ways.

[0010] In this case, the system is designed in such a way that isotropic fleeces can be produced with high productivity without a fleece lamination device. The productivity of the system is higher than when using a conventional carding machine with a subsequent fleece lamination device, and the investment is significantly lower. 2 For the same unit weight of the final product, the productivity can be doubled according to the invention. Another advantage is the lower error rate in the production of fleeces, since when folding thin fleeces or fiber webs, the edges often turn back, which results in different overlaps across the cross section.

[0011] In this case, the installation can comprise at least one further carding machine, formed for producing a further fiber web by an aerodynamic process. If there is space, any number of carding machines can be arranged in a row, whose fiber webs are then processed together. By varying the number of carding machines used, the final product can be varied almost arbitrarily in weight per unit area and productivity, when the fleece is stretched by 1.5 to 4 times. The installation is more flexible and cheaper than an installation with a conventional carding machine and a fleece lamination device. The same or different fiber qualities can be used.

[0012] If several carding machines are arranged in a row, the transport belt for transporting the fiber web from a first carding machine in the material transport direction can be arranged at least partially below the other carding machines, in which case the transport belt can be guided underground or arranged between the supports of the carding machines.

[0013] Upstream of the compaction device, a separate conveyor belt can be arranged which is designed to receive the fibrous webs one above the other, in which case it is not necessary to synchronize the separate conveyor belts and the withdrawal belts of the carding machine with each other.

[0014] Due to the carding machine being configured as an air-laid carding machine, a compact and space-saving carding machine can be used, which is capable of producing fiber webs with a low weight per unit area and of processing fibers with a large length variation in comparison with other carding machines which operate according to the random fleece principle or aerodynamic processes.

[0015] The consolidation device can be formed, for example, as at least one pair of rolls which compress the fibrous web without changing the structure or orientation of the fibers. The drafting device which follows comprises at least one upper and one lower drafting means which can stretch the fleece by 1.5 to 4 times. The drafting means each consist of an assembly of rolls or conveyor belts with a smooth surface or are equipped with needles or wires.

[0016] Further flexibility of the plant can be achieved in that at least one unwinding station is arranged downstream of the drafting device and upstream of the bonding device in the material conveying direction, which is designed for introducing, for example, a further carded fleece or a layer of paper or tissue into the plant below and / or above the fleece. A very flexible plant is obtained in which various fibers with different fiber lengths and different unit weights can be introduced and processed individually or together.

[0017] The subsequent bonding device can be configured as a hydrodynamic bonding device or as a thermobonder. The hydrodynamic bonding device is configured as a water jet bonding device and comprises several water bars with an attached suction device which can operate at a pressure of 40-400 bar. By means of the water jet bonding device, a fleece or several layers of fleeces can be bonded, joined and / or structured to one another. By means of specially configured nozzle devices or in combination with a web as fibrous material and / or a top structuring belt which seals the fleece, a structuring of the fleece and thus a patterned surface is possible. Alternatively, the bonding and structuring can also take place on a not shown drum with a structuring shell, which is arranged upstream of the dryer.

[0018] A dryer may be arranged downstream of the hydrodynamic bonding device in the material transport direction.

[0019] The method according to the invention for producing single- or multi-layered fleeces provides for the production of at least one fiber web with a MD / CD ratio of 1.0:1 to 1.2:1 from fibers with a fiber length of 10 to 60 mm and a fiber fineness of 0.5 to 30 dtex by an aerodynamic process. The fiber web is then consolidated and the resulting fleece is stretched at least 1.5 times and then bonded. The method according to the invention makes it possible to produce isotropic fleeces without a fleece lamination device with high productivity. By stretching the fleece, isotropic fleeces with almost any unit weight can be produced at high production rates. Compared to wet-laid or air-laid processes, the process effort is significantly lower and a greater variety of fibers can be processed in terms of length, fineness and type.

[0020] The productivity of the plant can be further increased by producing at least one further second fiber web which is placed on the first fiber web and consolidated together with it into a fleece. Any number of fiber webs can be produced separately, placed one above the other and adapted to the final weight via stretching. This concept is essentially limited only by the space requirements for arranging more than four carding machines in a row.

[0021] In this case, the fibrous webs arranged above and below all preferably have the same properties as the first fibrous web, however, the invention also contemplates the possibility of producing and processing together fibrous webs of different fiber qualities, both fibrous webs having approximately the same isotropic properties.

[0022] The fiber web can be stretched at a stretch ratio of 1.5 to 4 times, preferably 2 times.

[0023] For example, the fiber web of each carding machine is 20 to 400 g / m 2 and producing at a speed of 15 to 200 m / min, preferably 80 g / m 2 It has a unit weight of 1000 and can be produced at a speed of 80 m / min.

[0024] Further flexibility of the method can be achieved by bonding the stretched fleece together with at least one further fleece, which is introduced into the installation by an unwinding station. In this case, the additional fleece, which can be configured, for example, as a carded fleece or as a layer of paper or tissue, can be arranged above and / or below the fleece. This allows a great deal of choice, for example in hygiene products, since the stretched fleece can be covered or sealed on one side with another, preferably light, fleece quality.

[0025] The bonding of the stretched fleece, alone or in combination with the fleece coming from the unwinding station, can be carried out hydrodynamically or thermally, depending on the type of fibre.

[0026] Further measures for improving the present invention are detailed below in conjunction with the illustrated description of preferred embodiments of the present invention. [Brief description of the drawings]

[0027] [Figure 1] 1 shows a first embodiment of the installation and method according to the invention; [Figure 2a] FIG. 2 shows a detailed view of the first embodiment of the drafting device. [Figure 2b] FIG. 2 shows a detailed view of a second embodiment of a drafting device. [Diagram 3] 2 shows a second embodiment of the installation and method according to the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] The installation 100 according to the invention comprises at least one first carding machine 1, which may be formed as an air-laid carding machine. The carding machine 1 is fed via a feeder 2 with fibres or a fibre web, which may consist of natural or synthetic fibres (cotton, viscose, lyocell, hemp, pulp, polyester, polyamide, polypropylene, polyolefin) or a mixture of these fibres. It is preferably capable of processing fibres having a length of 10 to 60 mm and a dtex of 0.5 to 30. The working width of the carding machine 1 may be between 1.5 and 3.8 m. For example, at a production speed of 80 m / min, it is possible to process fibres having a density of 80 g / m 2 The produced fibrous web 3 with a weight of is placed on a first transport belt 4 which leads the fibrous web 3 to a compaction device formed in this example as a pair of rolls 6. The compaction device has the task of compressing the fibrous web without changing the structure in the orientation of the fibers.

[0029] To produce random fleeces, other aerodynamic processes can also be used, which can produce a fiber web with high isotropy in the drying process. Airlay carding machines have the advantage that they can process different lengths and different types of fibers (natural / synthetic), with a wide processing range (fleece weight, fiber fineness) and high quality.

[0030] As an alternative to the roll pair 6, the compaction can also take place by means of a belt rotating with the rolls, in which case the rolls are preferably formed as perforated plate rolls. Another option for compaction can be hydromechanical prebonding, which has the advantage that the slightly prebonded fleece can be deformed more evenly afterwards.

[0031] If a higher unit weight per unit area is required for the final product, the installation 100 comprises at least one further carding machine, which can also be formed as an air-laid carding machine. In this embodiment, the fibrous web 3 of the first carding machine 1 is guided under the following carding machine 1a in the material conveying direction by means of a conveying belt 4 and is handed over to another conveying belt 5. The second carding machine 1a is also fed via a feeder 2a with fibres or fibre flocks, which can be identical to the fibres of the first carding machine 1. However, the fibres can also be different, so that a multi-layer fleece with layers of different fibres can be produced. In this embodiment, the second fibrous web 3 produced also has a weight of 80 g / m at a production speed of 80 m / min. 2 The second fibrous web 3a is also delivered to a transport belt 5 on which both fibrous webs 3, 3a are combined. Synchronisation of the transport belts 4, 5 is not necessary. At 80 m / min the total weight is 160 g / m 2 The subsequent compaction device into which the two fibrous webs 3, 3a enter is in this example formed as a pair of rolls and compacts both layers of the fibrous webs 3, 3a without altering the orientation of the fibers, thus resulting in a fleece 24. The final product has a density of 40 g / m 24. Since the weight of the roll should be such that the roll is made of a nonwoven material, downstream of the compaction device a drafting device 10 is arranged which can be formed as a nonwoven material stretcher.

[0032] In the first embodiment according to FIG. 2a, the drafting device 10 is formed as a fleece stretcher, which may comprise an inlet region 11 with two conveyor belts, which are angled relative to one another. The angle of the conveyor belts, which are angled relative to one another, may be settable, as may the speed of each individual conveyor belt. In the conveyor belts, which are angled relative to one another, the fleece 24 is precompressed and reduced in thickness, so that it can enter between the upper and lower drafting means 12, 13. Both drafting means 12, 13 consist of rows of rolls which are offset relative to one another, so that the rolls of the upper drafting means 12 at least partially protrude into the gussets of the rolls of the lower drafting means 13. At least some of the rolls are driven and both drafting means 12, 13 are operated at different roll speeds, so that the fleece is stretched between the rolls. In this case, the number of revolutions of the rolls can be continuously increased from the inlet region 11 to the outlet region 14. For this, the rolls are preferably equipped with individual drives, so that the draft is variably adjustable along the drafting device. Via the speed difference of the rolls from the inlet region 11 to the outlet region 14, the mass of the fleece 24 in the cross-section can be reduced, so that the fleece 24 is stretched substantially evenly over the entire cross-section. Preferably, the upper drafting means 12 is subjected to a force or weight load. Preferably, the distance of the upper drafting means 12 to the lower drafting means 13 can be reduced from the inlet region 11 to the outlet region 14. The outlet region 14 of the drafting device 10 can be formed as a conveyor belt adapted to the increased fleece conveying speed.

[0033] Preferably, the surfaces of the rolls of the upper and lower drafting means 12, 13 are smooth or equipped with wires or needles, which makes it possible to avoid shrinkage of the fleece. Lateral guides in the drafting device 10 prevent the fleece 24 from being stretched beyond the desired working width.

[0034] FIG. 2b shows a second embodiment of the drafting device 10, which may also comprise an inlet region 11 with two conveyor belts, which are also angled relative to one another. The angle of the conveyor belts, which are adjusted relative to one another, may be settable, as may the speed of each individual conveyor belt. In the conveyor belts, which are adjusted relative to one another, the fleece 24 is precompressed and reduced in thickness, so that the fleece can enter between the upper and lower drafting means 12, 13. In this embodiment, the upper and lower drafting means 12, 13 are formed as conveyor belts, which are operated at different speeds, so that the stretching of the fleece takes place between the conveyor belts, which may be, for example, 2. The upper and lower drafting means 12, 13 may also be angled and / or spaced relative to one another in order to allow adaptation to different fleece thicknesses. In particular, in the case of this embodiment, in which the respective speeds of the upper and lower drafting means 12, 13 are kept equal over the drafting section, the outlet region 14 is formed as a conveyor belt and may be set in different speed ranges depending on the stretching factor. Preferably, the conveyor belts of the drafting means 12, 13 can also be provided with needles on the surface facing the fleece 24.

[0035] Downstream of the draft device, 40 g / m at 160 m / min 2The fleece 24, which has a weight of 100 g, e.g. stretched twice in the drafting device 10, is bonded, which can be carried out in a subsequent hydrodynamic bonding device. This bonding device comprises a number of water bars 20, which intertwine the fibers with one another by means of water jets. Under the water bars 20, a rotating conveyor belt 21 can be arranged, under which a suction device is arranged. The conveyor belt 21 is perforated to drain the water of the water bars 20. Alternatively to this embodiment, the fleece 24 can be sealed between the two conveyor belts and bonded by means of water jets. In this case, the fleece is not only bonded, but can also be structured and / or perforated. Another option to this illustrated embodiment can be by bonding on a rotating drum with suction from the inside, which besides bonding also structures and / or perforates the fleece 24. Depending on the application, the water bars can be operated with a water pressure of 40-400 bar. Downstream of the bonding device, the fleece 24 is dried in a dryer, which may be configured as a drum or belt dryer, and wound up in a winding station 25 .

[0036] An alternative embodiment of the installation 100 is shown in FIG. 3 in which at least one or two unwinding stations 15 are arranged downstream of the drafting device 10. The unwinding stations are designed for introducing a thin layer of, for example, a synthetic carded fleece 15a under and / or on top of the fleece 24 into the installation, so that the fleece 24 consisting of isotropic fibers is covered with one or two further layers of carded fleece 15a. The layer of thin synthetic carded fleece 15a may have a thickness of, for example, 30 g / m 2 Alternatively to the synthetic carded fleece 15a introduced by the unwinding station 15, a thin fleece made of tissue or paper can also be used.

[0037] According to this embodiment, the installation is configured for producing a single- or multi-layered fleece 24, which may consist of a fiber web 3, 3a of the carding machine 1, 1a only or with an underlying and / or an underlying carded fleece 15a. In this case, material combinations of fibers per unit area weight in arcs with different numbers and / or 1 to 3 fiber baths are obtained. In this case, the installation 100 is configured in such a way that an isotropic fleece 24 can be produced with high productivity without a fleece lamination device. The MD / CD ratio is 1.5:1 to 2.1:1 after bonding. [Explanation of symbols]

[0038] 100 equipment 1,1a Card machine 2,2a Feeder 3,3a Fiber web 4 Conveyor belt 5 Conveyor belt 6 rolls 10 Draft device 11 Entrance area 12 Top Draft Instruments 13. Lower draft measures 14 Exit area 15 Unwinding station 15a Carded fleece 20 Water Bar 21 Conveyor belt 22 Suction device 23 Dryer 24 Fleece 25 Winding Station

Claims

1. At least one carding machine (1) formed for generating a fiber web (3) by an aerodynamic process, and a first conveyor belt (4) formed for conveying the fiber web (3) from the carding machine (1) to a densifying device, wherein the densifying device is formed for compressing the fiber web (3) into a fleece (24), in a facility (100) for manufacturing a single-layer or multi-layer fleece, downstream in the material conveyance direction, a drafting device (10) formed for stretching the fleece (24) by at least 1.5 times is arranged, and downstream in the material conveyance direction, a bonding device is arranged, characterized by the facility.

2. The facility (100) is characterized by comprising at least one further carding machine (1a) formed for generating a further fiber web (3a) by an aerodynamic process, according to claim 1.

3. The facility according to claim 2, characterized in that the conveyor belt (4) is arranged at least partially under a further carding machine (3a).

4. The facility according to claim 2, characterized in that upstream of the densifying device, a conveyor belt (5) formed for receiving the fiber webs (3, 3a) stacked one above the other is arranged.

5. The facility according to claim 1 or 2, characterized in that the carding machine (3, 3a) is formed as an air-laid carding machine.

6. The facility according to claim 1, characterized in that the densifying device is formed as at least a pair of rolls (6) or a roll with a rotating belt or a hydraulic mechanical bonding device.

7. The facility according to claim 1, characterized in that the bonding device is formed as a hydrodynamic bonding device or a thermo-bonder.

8. The facility according to claim 1, characterized in that the drafting device (10) comprises at least one upper and lower drafting means (12, 13), and these drafting means each consist of a roll or a conveyor belt.

9. The facility according to claim 8, characterized in that the drafting means (12, 13) comprise needles or wires.

10. The facility according to claim 7, characterized in that a dryer (23) is arranged downstream of the hydrodynamic bonding device in the material conveyance direction.

11. At least one unwind station (15) is arranged downstream of the drafting device (10) and upstream of the bonding device in the material conveying direction for introducing the fleece (15a) under and / or above the fleece (24) into the facility (100). The facility according to claim 1, characterized in that.

12. A method for manufacturing a single-layer or multi-layer fleece, comprising: At least one fiber web (3) having an MD / CD ratio of 1.0:1 to 1.2:1 is generated from fibers having a fiber length of 10 to 60 mm and a fiber fineness of 0.5 to 30 dtex by an aerodynamic process. This fiber web is consolidated, and the resulting fleece (24) is stretched at least 1.5 times and then bonded. A method characterized by that.

13. At least one another second fiber web (3a) is arranged on the first fiber web (3) and consolidated with the first fiber web into the fleece (24). Another second fiber web (3a) has the same characteristics as the first fiber web (3). The method according to claim 12, characterized in that.

14. The bonding is performed hydrodynamically or thermally. The method according to claim 12 or 13, characterized in that.

15. The hydrodynamic bonding is performed by a water jet of 40 to 400 bar. The method according to claim 14, characterized in that.

16. The bonded fleece (24) has an MD / CD ratio of 1.5:1 to 2.1:

1. The method according to claim 15, characterized in that.

17. The fiber web (3) has a basis weight of 20 to 400 g / m ２ and is produced at a speed of 15 to 200 m / min, preferably having a basis weight of 80 g / m ２ and being produced at a speed of 80 m / min, the method according to claim 12, characterized in that.

18. The stretching is performed 1.5 to 4 times, preferably 2 times. The method according to claim 12, characterized in that.

19. The stretched fleece (24) is bonded together with at least one another fleece (15a), and the fleece (15a) is arranged under and / or above the fleece (24). The method according to claim 12 or 13, characterized in that.

Images