EP1236818A1 - Process and device for producing isotropic non-wovens - Google Patents

Abstract

The invention relates to a process and an apparatus for manufacturing of a nonwoven. In order to be able to cost-effectively produce a nonwoven, which is to a great extent isotropic in machine and cross direction, a double-layer web is produced according to the invention by one single web forming device, where the one partial web consists of mainly lengthwise oriented fibers and the other partial web laid in zigzag-the cross-fiber partial web-consists of mainly crosswise oriented fibers. The primary fleece for the cross-fiber partial web is taken off the web forming process at a several times higher speed than the fleece of the other, slower partial web. Both partial webs are redirected and oriented to each other in such a way, that they can be brought together to form a double-layer complete web. This double-layer web produced in a cost-effective way is then bonded to form a nonwoven which is to a great extent isotropic.

Description

The invention relates to a method for producing a in terms of strength and elongation in the longitudinal and transverse directions behave approximately the same, i.e. isotropic Nonwoven fabric and a corresponding manufacturing plant.

It is known that nonwovens are used in the nonwoven process, especially with the widespread carding process, preferably longitudinal fibers prefer a higher one Strength and less elasticity in the longitudinal direction of the fibers possess compared to the corresponding Values in the direction transverse to the preferred fiber layer. This inequality the strength values in the longitudinal and transverse directions is independent of the type of consolidation for all nonwovens to observe does not only occur with thermal solidified, but also with mechanically consolidated Nonwovens, e.g. So with needle fleece or also with More nonwovens; the latter are at least on one Side of the nonwoven fabric meshed the fibers.

While there are efforts to lengthen the fibers to counteract the fleece formation process, however, can so that in the end only little effects are achieved. The deflections of the fibers achievable in the nonwoven formation process in the transverse direction are what the angle and / or what the Proportion of transverse fibers in relation to the total fiber mass arrives, only modestly. Become multiple the crimped fibers are used or the fibers are at the removal of the fleece from the card, what increases the longitudinal elasticity of the nonwoven fabric formed from it, but the transverse strength is only insignificant.

Various proposals deal with this, the Manufacturing-related anisotropy of the fleece later in the consolidation process to eliminate or at least reduce. Some put in connection with active nonwovens of these suggestions for a special meshing technique which should bring a higher transverse strength (cf. DD 283 169 A5, DD 283 171 A5, DD 288 634 A5). Another starting point to improve cross-strength is during the solidification, in particular the meshing process Insert transverse threads with them in the Integrate nonwoven (see e.g. DD 285 383 A5). With the The method mentioned here can be the transverse strength of a Nonwoven fabric improved only to an insufficient extent become.

In the field of nonwoven fabric production, especially needle punched nonwovens, it is common to use a clutter Non-woven of moderate width by zig-zag cross laying a new nonwoven web of greater width and greater fiber mass per unit area and this new nonwoven web e.g. mechanically solidified by needles (see e.g. the book publication "Nonwovens - raw materials, manufacture, application, Properties, testing ", edited by W. Albrecht, H. Fuchs, W. Kittelmann, Wiley-VCH, Weinheim, 2000, ISBN 3-527-29535-6, page 158, tasks of the nonwoven layer). In the one created by zigzag-shaped laying of a pile Nonwoven web, the fibers are essentially transverse to the running direction this nonwoven web oriented with the consequence that the Strength now higher in the transverse direction than in the longitudinal direction is non-uniformity - albeit in reverse Form - in principle persists.

That is why one has already gone over to the zigzag shape to stretch transverse fleece in front of the needles and the fibers move from the transverse position into an oblique to Fleece edge (at a preferred angle α) To bring direction. And that is when you stretch one Cross fiber fleece the fibers about half under one Angle + α and the other half symmetrically under one Angle -α on; the fibers are crossed in the fleece (cf. the above-mentioned book publication "Nonwovens", Page 165 ff on fleece stretching). By such a stretch the strength values in the longitudinal and transverse directions approximated each other and the anisotropy essentially be eliminated. It also allows this type of manufacture a fleece template, in principle, the use of other processes than needling to bond the fleece. adversely here, however, is that the directions of highest strength not parallel or transverse to the side edges of the nonwoven web, but lie under the said angle ± α. To the firmness To be able to use the web optimally, would have to be done when assembling of cut parts at an angle α be cut out of the nonwoven web. Because of that accruing, unusable, in principle triangular blended parts However, this option is used for cost reasons used in exceptional cases at most.

Another also in the field of knitted nonwoven technology horizontal proposal (cf. DE 198 43 078 A1) for generation a largely isotropic, voluminous nonwoven with a high standing fiber content provides from one uniform fiber pile with preferably longitudinal fibers by placing it in a zigzag shape submit stronger fleece of any width. Because the fibers this stronger fleece thus formed transversely to its longitudinal direction are oriented, this fleece points in the transverse direction the higher strength. The further processing of this The fleece is made transversely to the working direction of the fleece leveler of the primary pile and across the orientation of the fibers. By mechanically strengthening the fleece thus presented By meshing at least one flat side, the strength is increased in the longitudinal direction because of the meshing many fibers deflected in the working direction when meshing become. The low longitudinal strength of the zigzag shape laid template can thus solidify through the mesh increases, thus reducing the non-uniformity. However, this approach can only be used to a very limited extent complete alignment of longitudinal and transverse strength is achieved become. And that depends on the approximation of the strength values in the longitudinal and transverse directions of the fiber mass of the Fleece per unit area and depending on the proportion of fibers, which are brought lengthwise by meshing can, i.e. on the degree of meshing. Otherwise, this type the manufacture of fleece to the mechanical solidification of the Non-woven fabric bound by meshing.

Another, also in the field of active nonwovens proposal lying in accordance with DD 292 489 A5 uses several Fiber layers in the fleece with different orientations, parallel or crossing fibers running across the edge of the web. That is in the in the mentioned publication presented method the nonwoven fabric from two separate Layers built up, one of which preferably longitudinally oriented fibers and the other preferably has transversely oriented fibers. The different fiber layers are first produced by separate fleece formers and are after unification to a common fleece of a mechanical Fleece consolidation supplied by meshing. With such double-layered nonwovens can be used isotropic nonwovens with a high standing fiber content. Disadvantageous However, this procedure requires two separate ones Laid former. Because of the necessary, considerable Investment costs are based on the area unit Cost price of the end product very expensive, so that the knitted nonwovens produced in this way may no longer competitive can be offered on the market.

The object of the invention is a method and a system to demonstrate the manufacture of a nonwoven, which with respect the longitudinal and transverse directions are largely isotropic is, the maximum strength values parallel or transverse can be reached to the web side edge, which also at low Investment costs can be produced and which ones can solidify by any method.

This object is achieved according to the invention with regard to the manufacturing process through the entirety of the features of claim 1 and with regard to the manufacturing plant by the whole of the features of claim 11 solved.

According to the invention, a two-layer fleece is made from one produced only fleece, the one Fiber layer predominantly longitudinally oriented fibers and the other zigzag-shaped fiber layer predominantly across contains oriented fibers. The zigzag fiber layer is deflected and combined with the other fiber layer. This double-layer, inexpensive, largely isotropic fleece template can then after a any process can be consolidated into a nonwoven.

It is true when making nonwovens for uniformity the local density over the surface of a nonwoven known to combine several piles into a fleece, wherein at least one nonwoven device with two Fleece customers or several in a row Fleece-forming devices are used (cf. the aforementioned book publication "Nonwovens", page 157 f about fleece formation). This involves in at least one nonwoven formation process or in several, running simultaneously Fleece formation processes from the same raw fibers or raw fiber mixture at least two separate piles of the same width formed, which led through different paths and then at the same speed and in the same direction and transverse position again to a common fleece be united. Due to the layered construction of the Fleece through several piles resembles any local Differences in density largely. Then it will be like this Nonwoven produced by any method to a nonwoven solidified. With this technique, however, this cannot be done Ratio of longitudinal and transverse strength in significant Influence wise.

Fig. 1

eine perspektivische Darstellung eines zweilagigen Vorlagevlieses zur Bildung eines Vliesstoffes, welches aus einer unteren Vlieslage mit längs orientierten Fasern und aus dem oben liegenden Querfaser-Teilvlies zusammengesetzt ist,

Fig. 2

eine perspektivische Darstellung eines dreilagigen Vorlagevlieses mit mittig angeordnetem Querfaser-Teilvlies und oberer und unterer Vlieslage mit längs orientierten Fasern,

Fig. 3

ein erstes Ausführungsbeispiel einer Anlage zur Herstellung eines mehrlagigen, isotropen Vliesstoffes, bei dem die Arbeitsrichtung der Vliesbildungseinrichtung und die Einrichtung zur Verfestigung des Vliesstoffes in einer geradlinigen Flucht liegen, bei der allerdings im Zuge des schnelleren bzw. des Querfaser-Teilvlieses eine zweimalige, sich kompensierende Umlenkung um 90° stattfindet, nämlich zuerst eine bloße Umlenkung des schnelleren Teilvlieses in eine quer verlaufende Richtung und dann eine prozeß-immanente 90°-Umlenkung durch das zick-zack-förmige Legen des schnelleren Teilvlieses zu dem Querfaser-Teilvlies,

Fig. 4

ein zweites Ausführungsbeispiel einer Anlage zur Herstellung eines mehrlagigen, isotropen Vliesstoffes mit ebenfalls fluchtender Arbeitsrichtung bezüglich Vliesbildung und Weiterverarbeitung des Vollvlieses, wobei ebenfalls im Zuge des schnelleren bzw. des Querfaser-Teilvlieses eine zweimalige, sich kompensierende Umlenkung um 90° stattfindet, und zwar hier zuerst das zickzakförmige Legen des schnelleren Teilvlieses zu dem Querfaser-Teilvlies unter einer ersten 90°-Umlenkung und dann eine weitere Umlenkung dessellben zurück in die ursprüngliche Richtung,

Fig. 5

ein drittes Ausführungsbeispiel einer Anlage zur Herstellung eines mehrlagigen, isotropen Vliesstoffes, bei dem die Arbeitsrichtung des Vliesbildungseinrichtung einerseits und die der Einrichtung zur Verfestigung des Vliesstoffes andererseits rechtwinklig zueinander angeordnet sind und bei der sowohl im Zuge des langsameren Teilvlieses als auch im Zuge des Querfaser-Teilvlieses jeweils eine Umlenkung um 90° stattfindet, und zwar beim Querfaser-Teilvlies bedingt durch das zickzakförmige Legen und beim langsameren Teilvlies bedingt durch das Erfordernis nach einer übereinstimmenden Laufrichtung und Querpostion,

Fig. 6

eine perspektivische, isolierte Darstellung einer raumsparend ausgebildeten Vliesumlenkeinrichtung.

Expedient embodiments of the invention can be found in the subclaims; otherwise, the invention is explained below with reference to an embodiment shown in the drawing; show:

Fig. 1

1 shows a perspective view of a two-layer template nonwoven to form a nonwoven fabric, which is composed of a lower nonwoven layer with longitudinally oriented fibers and of the transverse fiber partial nonwoven lying on top,

Fig. 2

3 shows a perspective representation of a three-layer template fleece with a central cross-fiber partial fleece and an upper and lower fleece layer with longitudinally oriented fibers,

Fig. 3

a first embodiment of a plant for producing a multi-layer, isotropic nonwoven, in which the working direction of the nonwoven forming device and the device for strengthening the nonwoven lie in a straight line, but in the course of the faster or the cross-fiber partial nonwoven, a two-way, compensating Redirection by 90 ° takes place, namely first a mere redirection of the faster partial fleece in a transverse direction and then a process-inherent 90 ° redirection by the zigzag-shaped laying of the faster partial fleece to the cross fiber partial fleece,

Fig. 4

a second embodiment of a plant for the production of a multi-layer, isotropic nonwoven with likewise aligned working direction with regard to nonwoven formation and further processing of the full nonwoven, a two, compensating deflection by 90 ° also taking place in the course of the faster or the cross-fiber partial nonwoven, here first the zigzag-shaped laying of the faster partial fleece to the cross-fiber partial fleece under a first 90 ° deflection and then a further deflection of the same back in the original direction,

Fig. 5

a third embodiment of a system for producing a multi-layer, isotropic nonwoven, in which the working direction of the nonwoven forming device on the one hand and that of the device for strengthening the nonwoven on the other hand are arranged at right angles to one another and in which both in the course of the slower partial nonwoven and in the course of the transverse fiber partial nonwoven in each case a deflection by 90 ° takes place, namely in the case of the cross-fiber partial nonwoven due to the zigzag-shaped laying and in the slower partial nonwoven due to the requirement for a matching running direction and transverse position,

Fig. 6

a perspective, isolated representation of a space-saving designed non-woven deflection device.

The one to be discussed using various exemplary embodiments The invention relates to a system and a method for producing a multi-layer isotropic nonwoven, the in any way, preferably by meshing the near-surface Fibers, mechanically at least on one flat side is consolidated, with at least one layer in the template fleece is provided with transversely oriented fibers. The invention producible at low investment costs Nonwoven is said to be longitudinal and transverse behave largely isotropically, with the maximum strength values reached parallel or across the web edge become.

It is the method according to the invention or the corresponding one Production plant therefore, in a cost-effective way a multi-layer template fleece for the subsequent nonwoven consolidation provide. The multi-layer full fleece 4, which is to be consolidated into a nonwoven fabric from at least one partial fleece 5 with essentially longitudinally oriented fibers 3 'and another, from one zigzag-shaped pile of existing cross-fiber partial fleece 1 with essentially transversely oriented fibers 3, such as this in perspective in Figure 1 for a two-layer template fleece is shown. It is not of primary importance here whether the cross-oriented partial fleece 1 or the lengthways oriented partial fleece 5 above or below in full fleece 4 lies. This is more a question of the hardening process used and the later use of the Nonwoven. For the rest, the two sub-fleeces have rough Approximation of approximately the same basis weight. in the concrete case, however, will depend on the one used Solidification process and later use of the nonwoven fabric a distribution of the fiber quantities of the Nonwoven fabric on the two partial nonwovens 1 and 5 empirically choose.

In Figure 2, a three-layer template fleece 6 is in perspective shown, which is a "straight line" on the top and bottom Partial fleece 5 'or 5 "with predominantly longitudinally oriented Fibers 3 ', whereas the transverse fiber partial nonwoven arranged between them 1 "predominantly transversely oriented fibers 3 ' contains. For the three-layer structure of the template fleece is a center arrangement of the cross fiber partial fleece 1 "essential.

The other versions deal only with the inexpensive and rational production of a two-layer template fleece 4. The in the various embodiments 3, 4 and 5 shown plants for manufacturing Such a nonwoven generally includes the following system components: First, a device for dry fleece formation be provided, basically of any type can be, but it must be said restrictively that only such fleece-forming devices arrive in Bertracht to which at least two fleeces move locally at the same time or let Flore take off and for those also considerable Differences in the removal speed of the nonwovens possible are. In connection with fleece formation processes in particular to the book publication already mentioned above "Nonwovens - raw materials, manufacture, application, Properties, testing ", published by W. Albrecht, H. Fuchs, W. Kittelmann, Wiley-VCH, Weinheim, 2000, ISBN 3-527-29535-6. This textbook goes in chapter 4 "Dry process" (pages 137-228) on the various Process for the dry production of nonwovens and treated in sub-chapter 4.1.2 "nonwovens using the carding process", especially on pages 145-157 and mechanical aspects of nonwoven production on cards. Since to the knowledge of the applicant only in the case of carding machines or carding machines, several fleece customers are known are, which also with appropriate equipment of the Sets on the customer rollers with very different Speeds can be operated at the in Figure 3 illustrated embodiment of a fleece formation card 10 indicated.

The fleece formation card 10 has two fleece pick-ups 11 and 12 arranged offset in height. The one, shown in Figure 3 below fleece taker 11 is designed due to the appropriate equipment of the sets on the take-off rollers in such a way that it allows a much higher removal speed v _{2 of} the partial fleece removed there than on the other fleece taker indicated in Figure 3 above 12; the decrease speed there is only v ₁ . The ratio v ₁ / v _{2 of} the two take-off speeds will be discussed in more detail below. At this point it should only be mentioned that in the event that an approximately equal fiber mass is taken from both customers per unit of time, the pile taken off at the lower, faster-running customer 11 is lighter according to the speed ratio in the basis weight than that at the other customer 12 slower removed pile 5. By zigzag-shaped laying of the faster partial fleece to a slower-running cross-fiber partial fleece 1, however, its basis weight is increased again in accordance with the speed ratio v ₁ / v ₂ .

In the further explanations, only the shortened ones will be used Terms "faster fleece taker 11", "faster partial fleece 2 "," slower fleece taker 12 "and" slower Partial fleece 5 "used.

What about the fleece customers 11 and 12 in the specific case actually decreased fiber mass or the mass ratio arrives, this essentially depends on the solidification process and the intended use of the Nonwoven. For example, if the nonwoven fabric to be mesh-strengthened, it can be quite clear lower fiber mass fraction for the slower Partial fleece 5 with longitudinal fibers (e.g. 35% by weight) compared to the faster partial fleece 2 with the later across aligned fibers (e.g. 65% by weight) make sense because through the solidification mesh or the wales of longitudinal fiber portion in the nonwoven again is increased. In general it can be said that from the Fleece forming device for the faster partial fleece 2 in rough approximation allowing an inequality of ± 20% by weight an approximately equal fiber mass per unit time taken becomes like for the slower partial fleece 5. The spectrum of Mass distribution can therefore range from about 30:70 to 70:30.

The faster partial fleece 2 is shown in all in FIGS. 4 and 5 shown variants of the invention at least indirectly a fleece laying device 14, 22 and 45 associated with which the faster partial fleece 2 zigzag-shaped to one Cross fiber partial fleece 1 can be placed. The partial fleece is the fleece laying device in any case by conveyor belts fed what, however, in the simplified, principle 3 and 5 is not shown. at the embodiment shown in Figure 4 is Conveyor belt 21 for feeding the faster partial fleece 2 to the fleece laying device 22. Because of the zigzag shape Laying the faster partial fleece 2 becomes a cross-fiber partial fleece 1 with preferably transverse to the longitudinal direction of the Nonwoven web oriented fibers 3 generated. Because of the zigzag shape Lay the faster partial fleece 2 to the cross fiber partial fleece 1 becomes its running speed reduced and also its basis weight in the corresponding Extent increased. In connection with the zigzag-shaped Laying fleeces is also on the mentioned textbook "Nonwovens" referenced in the subsection 4.1.2.3 "Fleece formation" (pages 157-165) on process and machine technology Individual aspects of cross-laying or zigzag-shaped Laying of floras especially when forming cross-oriented ones Fleeces come in. There will be different Designs of fleece layers, namely among other things Steep arm layer (camelback) and horizontals are distinguished. In the embodiments Figures 3 and 5 are for simplicity half swing arm layers as fleece laying device 14 and 45 indicated, whereas in the embodiment according to Figure 4 a horizontal layer as a fleece laying device 22 shown in principle in the type of a car layer is.

After the two partial fleeces, namely the slower partial fleece 5 and the zig-zag cross fiber partial fleece 1 can be brought together to form a common full fleece 4 they both need to be more than just matched Width, but must also be regarding the Transverse position in the same position and with the same web speed be brought together. About this measurement condition To be able to fulfill apply to those used according to the invention Fleece laying devices generally certain process conditions, so that the above Geometry conditions, i.e. same Width and equal speed of the cross fiber partial fleece 1 and the slower partial fleece 5, complied with can be.

30,0° (sin α = ½),

ca. 19,5° (sin α = 1/3),

ca. 14,5° (sin α = ¼) oder

ca. 11,5° (sin α = 1/5).

Namely, the zigzag-shaped partial layers within the transverse fiber partial fleece 1 must be deposited at such an angle α, the sine value of which corresponds to the value of a real fraction of the form 1 / n with n as an integer under seven. In other words, the zigzag-shaped partial layers within the cross-fiber partial fleece 1 must optionally be deposited at one of the angles α mentioned below:

30.0 ° (sin α = ½),

approx. 19.5 ° (sin α = 1/3),

approx. 14.5 ° (sin α = ¼) or

approx. 11.5 ° (sin α = 1/5).

For this purpose, the faster partial nonwoven 2 must be removed from the nonwoven forming device at a speed v ₂ that is a corresponding integer multiple times greater than the slower partial nonwoven with the removal speed v ₁ . The ratio of the removal speeds or the reciprocal v ₂ / v ₁ already mentioned is therefore preferably two, three, four or five. The two fleece takers 11 and 12 running at different speeds must therefore run regardless of their possibly changing absolute speed with a fixed speed ratio according to one of the values mentioned. The higher the speed ratio v ₂ / v ₁ , the smaller the possible angle α between the zigzag-shaped partial layers within the transverse fiber partial fleece 1 and the more the fibers 3 of the output pile are actually transversely within the transverse fiber partial fleece 1 oriented. On the other hand, an excessively high speed ratio v ₂ / v _{1 of} the fleece takers 11 and 12 not only causes problems with the fleece removal but also with the zigzag-shaped laying of the cross fiber partial fleece 1. A technically feasible upper limit appears at a speed ratio v ₂ / v ₁ to be reached in the amount of about 5 to 7. A further increase would only increase the technical and operational difficulties and hardly bring any further advantages to the finished nonwoven in terms of textile technology.

By zigzag-shaped laying of the faster partial fleece 2 in a fleece laying device 14, 22 or 45 (figures 3, 4 or 5) to the cross fiber partial fleece 1 takes place a process-inherent way a redirection of the web running direction by 90 ° instead. On the other hand, the cross-fiber partial nonwoven so formed 1 and the slower partial fleece 5 at the same Direction, lateral position and speed merged become. That is why in the different embodiments a nonwoven deflection device in the production plant 17, 28 and 43 provided that such Parallel run of the partial nonwovens to be brought together, what follows below in connection with the individual Embodiments will be discussed again. It should only be mentioned at this point that the fleece deflection device 17, 28 and 43 of the different exemplary embodiments each different within the production plant arranged or different sub-fleeces assigned. In this regard and the resulting ones Consequences differ in the embodiment of the Figures 3, 4 and 5 from each other.

A plant and process component essential to the invention in the present case is the fleece deflection device 17, 28 or 43, in all different embodiments is provided, albeit in different assignments. It is common to all exemplary embodiments that the Fleece deflection device 17, 28 or 43, regardless of to which the sub-fleece it is assigned, in any case that assigned partial fleece with regard to its seen in the floor plan Direction of travel deflected by a right angle. Furthermore, in agreement for all embodiments is that the Fleece deflector with regard to its deflecting Part, namely the fleece deflecting rod 18, 30 or 43 - in Floor plan seen - roughly the same position as the effective part the respective fleece laying device 14, 22 and 45 for the faster partial fleece and arranged at different heights is.

In connection with the positional equality of these two System components and the relevant benchmarks it should be mentioned on the one hand that the laying rollers (in FIG. 4 the reference number 25) of the fleece laying devices 14, 22, 45 brush a square when moving back and forth. On the other hand lies the fleece deflecting rod 18, 30, 43 of the fleece deflecting devices 17, 28, 43 each diagonally in a square same size. These two named squares of the fleece laying device on the one hand and the fleece deflector on the other must be in the same position in the floor plan.

After the slower partial fleece 5 and the cross fiber partial fleece 1 are merged into the full fleece 4 is in the Production plant finally a device 13 for solidification the full nonwoven 4 arranged to form a nonwoven, the only indicated in a generalized manner in FIG. 3 is. Basically here comes the entire range of known ones Nonwoven bonding process into consideration. In this The connection is again related to the above. Textbook "Nonwovens" referenced in chapter 6 "Nonwoven Bonding" (pages 269-399) to the known processes for bonding nonwovens, in particular also for strengthening the mesh of nonwovens, received. On the consolidation of the multi-layer template fleece for a nonwoven fabric is not discussed in more detail below, but only noted that a mesh strengthening with wales in the longitudinal direction of the textile and also regarding the use of the nonwoven seems to offer the most benefits.

After the similarities of the different embodiments of Figures 3, 4 and 5 are mentioned now go into more detail on the individual exemplary embodiments themselves, which - as I said - essentially consists of the Type of assignment of the fleece deflection device essential to the invention differ.

In the production plant shown in FIG. 3, the fleece deflecting device 17, which is shown in simplified form only with the fleece deflecting rod 18, is assigned to the faster partial fleece and is functionally arranged in front of the fleece laying device 14. In front of the fleece laying device 14, which is also greatly simplified and shown as an oscillating steep-arm layer, the faster partial fleece 2 is "temporarily" brought in a direction transverse to the working direction 7 and the transverse fiber partial fleece 1 is laid out from this transverse direction, which also results in a process-immanent manner - A 90 ° deflection takes place. As a result, the faster partial nonwoven 2 or the transverse fiber partial nonwoven 1 is deflected twice in its course — as seen in the plan — with these two deflections being compensated for in the result. The running direction 8 of the combined full nonwoven 4 coincides - seen in plan - with the working direction 7 of the nonwoven formation card 10; both directions 7 and 8 are arranged in a common line of alignment. The slower partial fleece 5 is transported by means of a fleece conveyor belt 15 over the fleece deflection device 17 and the fleece laying device 14 arranged underneath. Only in a position moved away from the nonwoven laying device in the working direction is the slower partial nonwoven 5 deposited on the transverse fiber partial nonwoven 1 carried by the nonwoven conveyor belt 16 at the same transverse position and corresponding speed v ₁ ; the partial nonwovens are pressed together by a pair of pressure rollers 19 before they are carried by the nonwoven conveyor belt 16 into the nonwoven strengthening device 13.

In Figure 4, only a middle section of the production system is shown, that is, the formation of the fleece itself and the removal of the two partial fleeces 2 and 5 at different speeds v ₁ and v ₂ on the one hand and the device for solidifying the full fleece 4 into a non-woven material on the other hand are shown of Figure 4 omitted. The slower partial nonwoven 5 is carried in a straight line through the production plant by the nonwoven conveyor belt 20, ie this plant is also stretched or straight, in which the working direction 7 of the nonwoven former and the further processing direction 8 coincide.

In a further agreement with the exemplary embodiment according to FIG. 3, the fleece deflection device 28 is also assigned to the running of faster partial fleece 2 or transverse fiber partial fleece 1 in the system according to FIG. However, in deviation from FIG. 3, in the exemplary embodiment according to FIG. 4, the fleece deflection device 28 is assigned to the transverse fiber partial fleece 1 and is functionally arranged according to the fleece laying device. For the rest, the fleece deflection device 28 is shown completely, albeit limited to the functionally essential parts, in FIG. 4, which will be discussed in more detail below. The fleece laying device 22, which is designed as a flat horizontal laying device in the manner of a wagoner, is also shown in more detail in FIG. 4, even if it is only shown in the functionally essential elements. The faster partial nonwoven 2 is fed to the nonwoven laying device 22 on a nonwoven conveyor belt 21 and deposited there on a pair of vertically offset and vertically spaced, ie non-contacting intermediate conveyor belts 24, 24 'of an upper carriage (belt 24) and a laying carriage (belt 24') with laying rollers 25 , which move synchronously but counter to each other horizontally in time with the zigzag-shaped laying. The faster partial fleece 2 (speed v ₂ ) is placed on the fleece conveyor belt 23, which moves transversely to the conveyor belt 21 and the intermediate belts 24, 24 'at the slower speed v _1, in a zigzag shape and in a web width that matches the original width ,

By zigzag laying the pile to the cross fiber partial fleece 1 there is a 90 ° deflection inherent in the process of the partial fleece. By the downstream of the fleece laying device 22 Fleece deflection device 28 can this by a another 90 ° deflection compensated again and the original Direction 7/8 can be brought back. The fleece deflector 28 is above the fleece conveyor belt 20 arranged for the slower partial fleece 5 and with her for the part determining the deflection of the cross fiber partial fleece, namely with the fleece deflecting rod 30 - seen in plan - arranged in the same position as the fleece laying device 22, but what in the perspective view of Figure 4 is not quite clear.

To bridge the height difference of the storage level the fleece laying device 22 on the one hand and the fleece deflection device 28 on the other hand is in the fleece conveyor belt 23 a stroke distance 26 is provided by a clever arrangement of deflection and guide rollers the belt run of the fleece conveyor belt 23 L-shaped and angled into the steep upward stroke is transferred. The promotional Run of the fleece conveyor belt 23 on which the Cross fiber partial fleece is located in the stroke section 26 about. To the cross fiber partial fleece safely on this steep section to guide, is also an L-shaped support band 27 provided, which with a steep Part of the conveyor belt of the nonwoven conveyor belt, which is effective in conveying 23 is touching in the area of the stroke 26. The Cross-fiber partial fleece is therefore in the stroke distance between Fleece conveyor belt 23 and touching support belt 27 held and transported upwards. The upper leg of the L-shaped guided support band 27 extends approximately horizontally and above the fleece deflecting device 28 Run of the fleece conveyor belt 23 of the stroke section 26 is sufficient slightly in this approximately horizontal leg of the Support belt 27 into it, so that the cross-fiber partial fleece conveyed upwards can be stored there. From the horizontal The leg of the support tape becomes the cross-fiber partial fleece then on the guide belt 32 of the fleece deflection device 28 to hand over.

The fleece deflection device shown in more detail in FIG. 4 28 consists essentially of a driven, in a rectangle guided over non-rotating turning bars 29, 30, endless guide band 32. Adjacent, at one each Turning bar, merging dreams of the guide belt close one with their side edges - seen in plan - At least approximately a right angle, but the respective flat sides of the guide belt essentially are arranged parallel to each other. Such leadership of the Belt is only possible with the same belt run if a sliding deflection takes place on the turning bars. The turning bars must therefore not rotate. Conveniently, it is superficially smooth and hardened Tube.

The guide belt 32 of the fleece deflection device 28 is driven at the speed of the associated partial fleece, which in the exemplary embodiment shown in FIG. 4 is carried out by a plurality of drive roller pairs 31, one of which is arranged on this side and the other on the other side of the guide belt. In the exemplary embodiment according to FIG. 4, the required running speed of the guide belt 32 is the - lower - speed v _{1 of} the transverse fiber partial fleece 1. At this point it should be noted that also in the example according to FIG. 5, where the fleece deflection device 43 is assigned to the slower partial fleece 5 , this is driven at the lower speed v _{1 of} this partial fleece. Only in the exemplary embodiment according to FIG. 3 is the nonwoven deflection device 17 assigned to the faster partial nonwoven 2 and must therefore be driven at the higher speed v _{2 of} this partial nonwoven, which could prove to be a certain disadvantage, at least if there are no friction-reducing devices on the turning bars.

The turning bars 29, 30 can be wrapped in the guide belt Area each with a variety of grid-like distributed, friction-reducing devices be provided. This can be in the pipe wall of the turning bars, but freely movable balls that are held captive act on the guide band can roll away. Another way to Reduced friction is a nationwide Air cushion in the contact area between turning bar 29, 30 and build up the guide band 32. In this case, that would be the area wrapped around by the guide band is distributed in a grid pattern arranged air outlet holes to be arranged, those from the inside the tubular turning bars made of compressed air in the Excess is supplied. The guide band then swims to a certain extent on a compressed air film that is also a dissipates any frictional heat. The risk of electrostatic The guide belt would also be less charged, especially if the compressed air were well humidified. Though the guide belt 32 could be almost thanks to the compressed air film Lead over the turning bars without resistance, however would need a certain amount to generate the necessary compressed air Power can be applied, however, without further ado can be accepted.

Of the four turning bars 29, 30 used to guide the guide band 32 are required in a rectangle and the are arranged at the "corners" of the rectangle, namely the turning bar provided with the reference number 30 in FIG. 4, a special role. Only the two on this one, hereinafter referred to as the fleece deflecting rod 30 converging dreams of the guide belt 32 touch at all the cross fiber partial fleece to be deflected. Just about this Fleece deflecting rod 30, the transverse fiber partial fleece 1 is thus deflected. The other three turning bars are only used for Guide the guiding tape in a closed rectangle. The special fleece deflecting rod 30 is also - in plan seen - about the same position as the fleece laying device 22 and arranged above it.

The fleece deflection device essential to the invention has except the deflection of the partial fleece at least in the embodiment according to Figure 4 also the task of an exact match of the two partial fleece to be combined in the width direction herbeizugühren. For this purpose, from the endless guide belt leading, non-rotating turning bars 29, 30 at least one turning bar parallel to the plane the adjacent dreams can be swiveled in the sense of a tape run correction stored and with an appropriate swivel drive Mistake. After the fleece deflecting rod 30 immediately arranged at the confluence of the two sub-fleeces 1 and 5 would be the fleece deflecting rod 30 for the tape running correction most appropriate in so far as it is with the least Time delay between rule intervention and new one Belt run position a control-related width positioning would enable. U.U. it is appropriate that the Fleece deflecting bar 30 diagonally opposite turning bar to pivot in the same way and with one Swivel drive to be provided. With synchronous, but opposing Swiveling of the two swiveling rods would have a uniform base voltage despite the control intervention over the entire width of the guide belt. Moreover this would result in an overall more stable tape run, i.e. the risk of control instability the tape run control would be lower.

So that the guide belt of the fleece deflection device in In terms of a broad control positioning technology good can operate, the guide belt must be thermal regardless or age-related stretching or shrinking be kept under a certain band tension. To this The purpose is two adjacent turning bars of the fleece deflection device 28 parallel to the plane of the adjacent dreams in For the purpose of tensioning the guide belt 32, it is displaceably mounted and provided with a corresponding displacement drive. The two are expediently displaceable in this sense Turning bars parallel to the two opposite Sides of the spanned by the turning bars Rectangular. With such an alignment of the Movability does not result in changes in angle when tensioning within the rectangle and therefore no influence to the width position of the belt run.

For the sake of completeness in connection with the in FIG. 4 embodiment mentioned mentions a variant, in the - similar to the designs according to the Figures 3 and 5 - within the from the two non-woven fabrics 1st and 5 full fleece united the transverse layer partial fleece 1 below and the slower partial fleece 5 is arranged at the top. To For this purpose, the fleece transport pand 20, which carries the slower partial fleece 5, via the fleece deflection device 28 away and to a further back in the plant provided on a separate fleece transport belt Association office to be continued. On the other hand, this separate one, according to the direction of further processing 8 aligned fleece transport pand installed on which this is in the direction of further processing deflected transverse layer partial fleece 1 from the fleece deflection device 28 can be filed.

The top arrangement of the slower partial fleece with the longitudinally aligned fibers for the subsequent Mesh solidification of the full nonwoven to a nonwoven certain mesh consolidation processes, structural and operational Benefits.

In the third part of Figure 5 and again very simplified shown embodiment of a Production plant is the fleece deflection device, which only is represented by its fleece deflecting rod 43, the slower one Partial fleece 5 assigned. In the place of the fleece deflecting rod 43 one would have to have a fleece deflector after the example of Figure 4 or after the example of Figure 6 imagine. That deflected on the fleece deflecting rod 43 slower partial nonwoven 5 is on the nonwoven conveyor belt 44th filed, which it carries in the direction of 8. That too Cross fiber partial fleece 1 is inherent in the process due to the zigzag shape Lay the faster partial fleece 2 to that Cross fiber partial fleece 1 in the transverse to the working direction 7 of Fleece forming device further processing direction 8 diverted. The fleece laying device 45 places the zigzag-shaped Partial layers of the cross fiber partial fleece 1 on the lower one Fleece conveyor belt 46, which is also parallel to Processing direction 8 runs. Again, here are the fleece deflecting rod 43 and the fleece laying device 45 offset in height from each other but - in the floor plan - the same position arranged. That on the upper fleece conveyor belt 44 slower partial fleece transported on a downward gradient 5 is placed on the lower fleece conveyor belt 46 Cross fiber partial fleece 1 to the two-layer full fleece 4 merged, which then solidified into a nonwoven can be. In the embodiment of Figure 5 can also the fleece conveyor belt 44 when integrated accordingly Fleece edge detectors and adjustable belt guide rollers inside of the tape run can be used, a matching Transverse position of the slower partial fleece 5 with the To bring about cross fiber partial fleece 1.

The production plant indicated in Figure 5 runs - in In contrast to the straight-line systems according to FIGS. 3 or 4 - angled as a whole; the working direction 7 of Fleece formation card and the further processing direction 8 form a right angle with each other.

The footprint for the one shown in Figure 4, however also to be thought in the systems according to FIGS. 3 or 5 Fleece deflection device 28 is relatively large. It can be accepted that the spanned by the guide belt 32, approximately square rectangle a side length of about that Two and a half times the working width of the fleece formation card Has. It is therefore advisable to use the fleece deflector to be provided in the raised position so that they are attached to the ceiling construction the factory floor or on a production line spanning supporting structure can be hung can, without taking up valuable space on the hall floor to take.

In order to reduce the space requirement of the fleece deflection device, is in the embodiment shown in Figure 6 Guide belt 51 of the fleece deflection device 50 saves space in two different, spaced from each other Levels. And that's on the fleece deflecting rod 54 running run of the guide belt and in the in the same horizontal plane opposite, parallel One strand of each strand wrapped at 180 ° Deflection roller 52, 52 'arranged. The diameter this deflection roller determines the distance between the two levels of the guide belt 51. In addition to the smaller space requirement the fleece deflection device 50 according to FIG. 6 has the further advantage a compact design. This means that the supporting structure for the individual components such as rollers, turning bars etc.. is more compact and stiffer. Of the four turning bars 54, 55 are two at least in plan view approximately congruent but about the roller diameter offset in height, i.e. close to each other. After this here two opposite strands of the guide belt the deflection rollers 52, 52 'tightly wrapped around, it offers itself from this deflecting rollers at least one for driving the guide belt 51 to use the fleece deflector and with to provide a corresponding rotary drive. If both deflection rollers 52, 52 'used to drive the guide belt should be taken into account that both guide rollers equally fast, but in the opposite direction have to circulate. To synchronize the two to be driven Deflection rollers would be a reversing gear in this case with a 1: 1 ratio between the two guide rollers makes sense. In addition to the drive, the deflection rollers can also can be used to tension the guide tape by can be moved linearly in the direction of the dreams that surround it stored and provided with a corresponding slide drive are.

In connection with the three-layer template fleece 6 shown in FIG. 2, it should be mentioned for the sake of completeness that this would require a fleece formation card with three different fleece removers or two different fleece formation cards arranged in tandem, which together have the three fleece removers. On such a nonwoven formation device, three separate partial nonwovens 5 ', 2, 5 "are formed in one and the same nonwoven formation process from the same raw fibers or raw fiber mixture and are each removed from the three different, offset arranged nonwoven takers. The middle nonwoven taker is v ₂ operated, whereas the other two fleece takers run more slowly (v ₁ ). The two slower partial fleeces 5 ', 5 "are removed from them from the fleece formation process. The faster partial fleece 2 removed from the faster fleece taker is laid in a zigzag shape to the transverse fiber partial fleece 1, with a process-inherent deflection taking place. Subsequently, the transverse fiber partial nonwoven 1 and the slower partial nonwovens 5 ', 5 "are brought into mutual agreement with respect to their running, for which the exemplary embodiments shown in FIGS. 3, 4 or 5 can serve as a model. The three partial nonwovens 5', 1 and 5 "are then combined with one another at the same speed v ₁ , the same direction and the same transverse position to form a three-layer full nonwoven 6, which can finally be consolidated into a nonwoven.

Claims (19)

A process for producing a nonwoven fabric, comprising the following process steps:

on a fleece forming device (10) with two fleece removers (11, 12), two separate partial nonwovens (2, 5) are formed from the same raw fibers or raw fiber mixture in one and the same fleece formation process, the partial nonwoven removed from one fleece taker (11) - hereinafter referred to as "faster partial nonwoven (2)" - is called at a speed (v ₂ ) several times higher than that (v ₁ ) of the other partial nonwoven - hereinafter referred to as "slower partial nonwoven (5)" - removed from the nonwoven formation process (10), > The faster partial nonwoven (2) is zigzag-shaped to form a new partial nonwoven - hereinafter referred to as "transverse fiber partial nonwoven (1)" - with a width that matches the width of the slower partial nonwoven (5) and with a running speed ( v ₁ ) of the slower partial fleece (5) corresponding speed (v ₁ ), the fibers (3) preferably being oriented transversely to the longitudinal direction of the transverse fiber partial fleece (1), the transverse fiber partial nonwoven (1) and the slower partial nonwoven (5) are brought into mutual agreement with respect to their running and combined at the same speed (v ₁ ), the same direction and the same transverse position to form a two-layer nonwoven (4) called full nonwoven below, > The full nonwoven (4) thus submitted is consolidated into a nonwoven (13). Method according to claim 1,
characterized in that
the faster partial nonwoven (2) is first deflected (17) in a running direction transverse to the working direction (7) of the nonwoven forming device (10) and only zigzag-shaped from this running direction to the transverse fiber partial nonwoven (1) and thereby process- is again diverted (14) so that its direction of travel - seen in plan - is in alignment with the working direction (7) of the nonwoven forming device (10) that the slower partial nonwoven (5) on the nonwoven deflecting device (17) for the faster partial nonwoven and guided past the fleece laying device (14) for laying the cross-fiber partial fleece and then both partial fleeces are combined to form the full fleece (4). (Figure 3) Method according to claim 1,
characterized in that
the faster partial nonwoven (2) is laid in a zigzag shape directly to the transverse fiber partial nonwoven (1) and in the process is inherently diverted into a working direction lying transverse to the working direction (7) of the nonwoven forming device (10) and that the transverse fiber partial nonwoven ( 1) is then diverted from this transverse working direction back into a direction parallel to the working direction (7) of the fleece-forming device (10) and into a corresponding alignment with the slower partial fleece (5). (Figure 4) Method according to claim 1,
characterized in that
the faster partial nonwoven (2) is laid in a zigzag shape directly to the transverse fiber partial nonwoven (1) and in the process is inherently diverted into a working direction transverse to the working direction (7) of the nonwoven forming device (10) and that the slower partial nonwoven ( 5) is diverted in this transverse working direction and in a matching alignment with the transverse fiber partial fleece (1). (Figure 5) Method according to claim 1,
characterized in that
the zigzag-shaped partial layers within the transverse fiber partial fleece (1) are deposited at such an angle (α), whose sine value corresponds to the value of a real fraction of the form l / n with n as an integer under 7. Method according to claim 5,
characterized in that
the zigzag-shaped partial layers within the cross-fiber partial fleece can optionally be placed at one of the following angles (α): 30.0 ° (sin α = ½), approx. 19.5 ° (sin α = 1/3) , approx. 14.5 ° (sin α = ¼) or approx. 11.5 ° (sin α = 1/5). Method according to claim 1,
characterized in that
the faster partial nonwoven (2) is removed from the nonwoven forming device (10) at a speed (v ₂ ) that is an integral multiple times greater than the slower partial nonwoven (5, speed v ₁ ), preferably with the two, three, four or five times the speed (v ₂ ). Method according to claim 1,
characterized in that
A roughly the same size fiber mass per unit of time is taken from the nonwoven formation device (10) for the faster partial nonwoven (2) in rough approximation, allowing an inequality of ± 20% by weight as for the slower partial nonwoven (5). Method according to claim 1,
characterized in that
the faster partial nonwoven (2) is removed from the nonwoven forming device (10) on a nonwoven doffer (11) lower in the vertical position and the slower partial nonwoven (5) is removed on a nonwoven doffer (12) higher in the vertical position. Method according to claim 1,
characterized in that
on a fleece forming device in one and the same fleece formation process from the same raw fibers or raw fiber mixture, three separate partial nonwovens (5 ', 1, 5 ") are formed and in each case removed from three different, vertically staggered nonwoven customers, the one being removed from one, preferably middle, nonwoven customer faster partial fleece with the multiple times higher speed (v ₂ ) than the other two, slower partial fleeces (5 ', 5 ") are removed from the fleece formation process, that the faster partial fleece is laid in a zigzag shape to the transverse fiber partial fleece (1) that the cross-fiber partial nonwoven (1) and the slower partial nonwovens (5 ', 5 ") are brought into mutual agreement with respect to their running and at the same speed (v ₁ ), same direction and same transverse position to a three-layer full nonwoven (6) be united and this is consolidated into a nonwoven. Plant for producing a nonwoven fabric, comprising the following plant components: a fleece formation card (10) with two vertically offset fleece takers (11, 12), the one, preferably lower fleece taker - hereinafter referred to as "faster fleece taker (11)" - is designed in such a way that it has a much higher removal speed (v ₂ ) of the partial nonwoven removed there - hereinafter referred to as "faster partial nonwoven (2)" - allowed than the removal speed (v ₁ ) of the other nonwoven consumer, hereinafter referred to as "slower nonwoven taker (12)", on which a subsequently "slower partial nonwoven (5) "said partial fleece is removable, > A fleece laying device (14, 22, 45) assigned to the faster fleece taker (11) and connected to it by fleece conveyor belts for zigzag-shaped laying of the faster partial fleece (2) into a new, hereinafter referred to as "transverse fiber partial fleece (1)" Partial fleece with a width corresponding to the original width of the faster partial fleece (2) and preferably with fibers (3) oriented transversely to the longitudinal direction of the transverse fiber partial fleece (1), > Another device (17, 28, 43) for aligning the cross-fiber partial fleece (1) to the slower partial fleece (5) at the same speed (v ₁ ), the same direction and the same transverse position for the purpose of bringing together a full fleece (4) mentioned below multi-layer fleece, finally a device (13) for solidifying the full nonwoven (4) into a nonwoven. System according to claim 11,
characterized in that
the device for the mutual alignment of cross-fiber partial nonwoven (1) and slower partial nonwoven (5) for the purpose of bringing together the partial nonwovens (1, 5) to form the full nonwoven (4), one of the partial nonwovens (2, 5 or 1), offset in height from the nonwoven laying device (14, 22, 45) arranged fleece deflection device (17, 28, 43) which deflects the assigned partial fleece (2, 1, 5) by a right angle with respect to its running direction as seen in the plan, the fleece deflection device (17, 28, 43 ) with respect to its deflecting (18, 30, 43) part - seen in plan - approximately the same position as the effective part of the fleece laying device (14, 22, 45) for the faster partial fleece (2). System according to claim 11,
characterized in that
the fleece deflection device (17) is assigned to the faster partial fleece (2) and is functionally arranged upstream of the fleece laying device (14), so that in the course of the faster partial fleece (2) or transverse fiber partial fleece (1) due to a double deflection which compensates for the result Running direction (8) of the combined full nonwoven (4) is arranged in a plan with the working direction (7) of the nonwoven formation card (10) in a matching line of alignment. (Figure 3) System according to claim 11,
characterized in that
the fleece deflection device (28) is assigned to the cross-fiber partial fleece (1) and is functionally arranged downstream of the fleece laying device (22), so that in the course of the faster partial fleece (2) or cross-fiber partial fleece (1) due to a double deflection which compensates for the result the running direction (8) of the combined full fleece (4) is arranged in a plan with the working direction (7) of the fleece formation card (10) in a matching line of alignment (8). (Figure 4) System according to claim 11,
characterized in that
the fleece deflecting device (43) is assigned to the slower partial fleece (5) and that both the running direction of the slower partial fleece (5), recognizable in the plan, - namely through the fleece deflecting device (43) - and that of the faster partial fleece (2) and the resultant one Cross-fiber partial fleece (1) - namely by the fleece laying device (45) - are deflected by 90 °, so that the running direction (8) of the full fleece (1 and 5) combined from the partial fleece (4) in plan crosswise to the working direction ( 7) the fleece formation card (10) is arranged. (Figure 5) System according to claim 11,
characterized in that
the height-offset to the fleece laying device (22) arranged fleece deflection device (28) consists essentially of a driven, in a square polygon, preferably in a rectangle over non-rotating turning rods (29, 30), endless guide belt (32), the adjacent, each of which of a turning bar merging dreams with respect to the side edges of the guide band (32) form an at least approximately right angle with one another, as viewed in plan view, but are arranged essentially parallel to one another with the respective flat side of the guide band (32), one (30) of the four turning bars (29, 30), hereinafter referred to as the nonwoven deflecting bar (30), seen in plan view in approximately the same position as the nonwoven laying device (22), and the partial nonwoven (1) to be deflected by the two strands of the guide belt (30) converging on the nonwoven deflecting bar (30) 32) is guided and is diverted with it. System according to claim 11,
characterized in that
the guide belt (32) of the fleece deflection device (17, 28, 43) is driven at the speed (v ₁ , v ₂ ) of the assigned partial fleece (2, 1, 5). System according to claim 11,
characterized in that
the turning bars (29, 30) are each provided with a large number of friction-reducing devices arranged in a grid pattern in the area wrapped by the guide band (32). System according to claim 11,
characterized in that
the guide belt (51) of the fleece deflecting device (50) is guided in a space-saving manner in two different, mutually inclined or spaced apart planes, in each case approximately in the middle of the run of the guide band (51) running from the fleece deflecting rod (54) and in the diametrically opposite strand a deflecting roller (52, 52 ') wrapped around these strands at 90 ° or 180 ° is arranged.

Images