EP1236818B1 - 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 behaving approximately the same, i. isotropic Nonwoven fabric and a corresponding manufacturing plant.

It is known that nonwovens, because of the fleece forming process, in particular the widespread carding method, a higher one prefers longitudinally orienting fibers Strength and lower elasticity in the laid fiber longitudinal direction own compared to the corresponding ones 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 solidification for all nonwovens So it's not just thermal solidified, but also in mechanically solidified Nonwovens, e.g. So with needle fleeces or at More nonwovens; in the latter case are at least one Side of the nonwoven fabric meshed the fibers.

Although there are efforts, a longitudinal orientation of the fibers but can counteract the web formation process so that in the end only minor effects are achieved. The in the web formation process achievable deflections of the fibers 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 modest. Be multiple the crimped fibers are used or the fibers are added the decrease of the fleece from the carding compressed, what indeed increases the longitudinal elasticity of the nonwoven fabric formed therefrom, but the transverse strength only insignificant.

Various proposals are concerned with production-related anisotropy of the web later in the solidification process eliminate or at least reduce. In connection with nonwoven fabrics put some these suggestions in a special meshing technique which should bring a higher transverse strength (see DD 283 169 A5, DD 283 171 A5, DD 288 634 A5). Another starting point for improving transverse strength is during the solidification, in particular the Verstaschungsvorganges Cross threads with insert and this while in the Nonwoven fabric to integrate (see, for example, DD 285 383 A5). With the Here mentioned method can be the transverse strength of a Nonwoven, however, improved only to an insufficient extent become.

In the field of nonwoven production, especially needle-punched nonwovens, It is customary, a made by a clutter Nonwoven moderate width by zig-zag cross-laying too a new nonwoven web of greater width and larger pulp per unit area and this new nonwoven web e.g. mechanically by needling (see, for example, the book publication Nonwovens - Raw Materials, Manufacture, Application, Properties, Examination ", edited by W. Albrecht, H. Fuchs, W. Kittelmann, Wiley-VCH, Weinheim, 2000, ISBN 3-527-29535-6, page 158, Tasks of the non-wovens). In the one created by the zig-zag-shaped laying of a pile Nonwoven web, the fibers are substantially transverse to the direction this nonwoven web oriented with the result that the Strength now higher in the transverse direction than in the longitudinal direction that is, non-uniformity - albeit in reverse Form - in principle persists.

Therefore, one has already passed over to the zig-zag stretched cross-webs before needling and The fibers thereby from the transverse position in an oblique to Fleece edge (at a preferred angle α) extending To bring direction. And that is when stretching a Querfaservlieses the fibers about half under one Angle + α and the other half symmetrical under one Angle -α; the fibers are thus arranged crossed in the fleece (see the above-mentioned book publication "Nonwovens", Page 165 ff on nonwoven stretching). By such a straightening can the strength values in the longitudinal and in the transverse direction approximated and the anisotropy substantially be eliminated. In addition, this type of production allows a nonwoven template in principle, the use of other methods as the needles for nonwoven bonding. adversely However, here is that the directions of highest strength not parallel or transverse to the side edges of the nonwoven web, but lie below the said angle ± α. To the strength To be able to use the railway optimally, would have to be in the assembly Cut these obliquely at the angle α be cut out of the nonwoven web. Because of it accumulating, unusable, in principle triangular Veschnitteile However, for cost reasons, this option exceptionally made use of in exceptional cases.

Another also in the field of effective technology lying proposal (see DE 198 43 078 A1) for the production a largely isotropic, bulky active nonwoven fabric with high standing fiber content provides from one uniform batt with preferably longitudinally oriented fibers by zigzagging put the same first to provide stronger nonwoven of any width. Because the fibers this stronger nonwoven web thus formed transversely to its longitudinal direction are oriented, this web has in the transverse direction the higher strength. The further processing of this Nonwoven takes place transversely to the working direction of the nonwoven former of the primary pile and transverse to the orientation of the fibers. By mechanical solidification of the thus submitted nonwoven by meshing at least one flat side is the strength increased in the longitudinal direction, because by the intermeshing Many fibers are deflected in the working direction during meshing become. The low longitudinal strength of the zigzag-shaped template can thus be strengthened by the stitch increases and so the nonuniformity can be reduced. However, this procedure can only be very limited achieved a complete alignment of longitudinal and transverse strength become. And that depends on the approximation of the strength values in the longitudinal and transverse direction of the fiber mass of Fleece per unit area and on the proportion of fibers, which are brought by the meshing in the longitudinal direction can, i. from the degree of meshing. Otherwise, this is art the nonwoven production of the mechanical strengthening of the Nonwoven fabric bound by interlocking.

Another, also in the field of nonwovens lying proposal according to DD 292 489 A5 uses several Fiber layers in nonwoven with differently oriented, parallel or transverse to the web edge running, intersecting fibers. And that is in the mentioned in the publication featured the nonwoven fabric from two separate Layers constructed, one of which is preferably longitudinally oriented fibers and the other preferably has transversely oriented fibers. The different fiber layers are initially produced by separate web formers and are after the union to a common fleece of a mechanical Web stabilization supplied by meshing. With such double-layered nonwovens can be isotropic nonwoven fabrics produce with high standing fiber content. Disadvantageous However, this method requires the requirement of two separate ones Laid former. Due to the required, considerable Investment costs are related to the area unit Cost price of the final product very expensive, so that the u.U. no longer competitive can be offered on the market.

The object of the invention is a method and a system for producing a nonwoven fabric, which relates to the longitudinal and the transverse direction is largely isotropic is, with the maximum strength values parallel or transverse be reached to the web page edge, which also at low Investment costs can be produced and which is solidify by any method.

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

According to the invention, a two-ply web of a single web forming device, wherein the one Fiber layer mainly longitudinally oriented fibers and the other zig-zag shaped fiber layer predominantly across containing oriented fibers. The zigzag-shaped fiber layer is deflected and combined with the other fiber layer. These two-ply, inexpensively manufactured, largely isotropic nonwoven original can then after a solidified to a nonwoven fabric.

Although it is in the manufacture of nonwovens for uniformity the local density across the surface of a nonwoven fabric known to unite several flores into a fleece, wherein at least one web forming means with two Fleece or several in line behind each other set up Fleece forming devices are used (see. the cited book publication "Nonwovens", page 157 f over web formation). In this case, in at least one web formation process or in several, simultaneously expiring Nonwoven forming processes from the same raw fibers or raw fiber mixture at least two separate piles of the same width formed, which led over different ways and afterwards at the same speed and the same direction as well as transverse position again to a common fleece to be united. Due to a layered structure of the Fleece by several Flore resemble any local Density differences largely off. Then it will be like this produced fleece by any method to a nonwoven fabric solidified. With this technique, however, not the Ratio of longitudinal and transverse strength in significant Influence way.

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 QuerfaserTeilvlieses 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 QuerfaserTeilvlieses 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.

Advantageous embodiments of the invention can be taken from the subclaims; Moreover, the invention with reference to an embodiment shown in the drawing is explained below; show:

Fig. 1

a perspective view of a two-layer original fleece to form a nonwoven fabric, which is composed of a lower nonwoven layer with longitudinally oriented fibers and from the overhead cross-fiber part fleece,

Fig. 2

a perspective view of a three-layer original fleece with centrally arranged cross-fiber part fleece and upper and lower nonwoven layer with longitudinally oriented fibers,

Fig. 3

a first embodiment of a plant for producing a multi-layer, isotropic nonwoven fabric in which the working direction of the web forming means and the means for solidifying the nonwoven fabric are in a rectilinear flight, but in the course of the faster or QuerfaserTeilvlieses a two times, compensating deflection to 90 ° takes place, namely first a mere deflection of the faster part fleece in a transverse direction and then a process-inherent 90 ° deflection by the zigzag-shaped laying of the faster part fleece to the cross-fiber part fleece,

Fig. 4

a second embodiment of a plant for producing a multi-layer, isotropic nonwoven fabric also with aligned working direction with respect to web formation and further processing of the full web, which also takes place in the course of faster or QuerfaserTeilvlieses a two-time, compensating deflection by 90 °, here first the zigzag Laying the faster part fleece to the cross-fiber part fleece under a first 90 ° deflection and then another deflection back to the original direction,

Fig. 5

a third embodiment of a plant for producing a multi-layer isotropic nonwoven fabric, in which the working direction of the web forming means on the one hand and the means for solidifying the nonwoven fabric on the other hand are arranged at right angles to each other and in both in the course of the slower part fleece and in the course of cross-fiber part fleece in each case a deflection by 90 ° takes place, namely the cross-fiber part web due to the zigzag-shaped laying and the slower part web due to the need for a matching running direction and transverse position,

Fig. 6

a perspective, isolated view of a space-saving trained Vliesumlenkeinrichtung.

The to be discussed with reference to various embodiments The invention relates to a system and a method for producing a multilayer isotropic nonwoven fabric, the in any way, preferably by meshing the near-surface Fibers, at least on one flat side mechanically is solidified, wherein at least one layer in the template fleece is provided with transverse oriented fibers. The invention producible at low investment costs Nonwoven should be with respect to the longitudinal and the transverse direction behave largely isotropically, with the maximum strength values reached parallel or transverse to the web page edge become.

It is in the method according to the invention or the corresponding Production facility therefore, in a cost effective manner a multilayer original fleece for the subsequent nonwoven consolidation provide. The multilayer full fleece 4, which is to be solidified into a nonwoven fabric exists from at least one partial web 5 with substantially longitudinally oriented fibers 3 'and another, from a Zig-zag-shaped pile existing cross-fiber part fleece 1 with substantially transverse oriented fibers 3, such as this perspective view in Figure 1 for a two-layer original fleece is shown. It is not of primary importance here whether the transverse oriented part fleece 1 or the longitudinal oriented part fleece 5 above or below in the full fleece 4 lies. This is more a question of the solidification process used and the later intended use of the Nonwoven. Incidentally, the two partial webs in coarse Approximation with each other about the same basis weight. in the concrete case, however, depending on the used Solidification method and later use of the nonwoven fabric, a division of the fiber quantities of Nonwoven fabric on the two part webs 1 and 5 empirically choose.

In FIG. 2, a three-layer original fleece 6 is in perspective represented, which underside and upper side each a »linear "Part fleece 5 'or 5" with predominantly longitudinally oriented Fibers 3 ', whereas the interposed cross-fiber part fleece 1 "predominantly transverse oriented fibers 3 ' contains. For the three-layer construction of the template fleece is a center arrangement of the transverse fiber part web 1 "essential.

The other versions treat only the cost and rational production of a two-layer original fleece 4. The in the various embodiments Figures 3, 4 and 5 shown plants for manufacturing of such a nonwoven generally comprise the following plant components: First, a device for dry web formation must be provided, in principle, of any type may be limiting, but it must be said that Only such web forming facilities in Bertracht arrive at which locally offset at the same time at least two nonwovens or Flore lose weight and where significant Differences in the rate of acceptance of the nonwovens possible are. In connection with web forming process in particular to the already mentioned above book publication Nonwovens - Raw Materials, Manufacture, Application, Properties, Testing ", issued by W. Albrecht, H. Fuchs, W. Kittelmann, Wiley-VCH, Weinheim, 2000, ISBN 3-527-29535-6. This textbook is in chapter 4 "Dry process" (pages 137-228) on the various Process for the dry production of nonwovens and treated in subchapter 4.1.2 "Nonwoven fabrics after the carding process", especially on pages 145-157. and technical aspects of nonwoven production on cards. As to the knowledge of the applicant only in carding or carding several fleece known which are also equipped with the appropriate equipment Trimmings on the doffer rollers with very different Speeds can be operated at the in Figure 3 illustrated embodiment a web forming carding 10 indicated.

The web-forming card 10 has two height-offset arranged fleece pickups 11 and 12. The one, indicated in Figure 3 below vliesabnehmer 11 is formed due to appropriate equipment of trimmings to the doffer rollers such that it allows a much higher rate of decrease v _{2 of} the part of nonwoven fabric 2 removed there, as at the other, in Figure 3 above indicated fleece 12; There, the decrease speed is only v ₁ . On the ratio v ₁ / v _{2 of} the two rates of decrease will be discussed in more detail below. At this point, it should merely be mentioned that in the event that an approximately equal mass of fibers is removed at both customers per unit time, at the lower, faster moving customer 11 removed pile is lighter according to the speed ratio in the basis weight than that at the other customer 12 slower Removed pile 5. Due to the zigzag-shaped laying of the faster part fleece to a slower running cross-fiber part fleece 1 whose basis weight according to the speed ratio v ₁ / v _2, however, increased again.

In the other versions are only the shortened Terms "faster fleece 11", "faster fleece 2 "," slower fleece 12 "and" slower Partial Fleece 5 "used.

What about the fleece customers 11 and 12 in the specific case actually taken fiber mass or the mass ratio this depends essentially on the solidification process and the intended use of the product to be produced Nonwoven fabric from. If the nonwoven fabric, for example be stitched together, so can quite a clear lower pulp content for the slower Partial non-woven fabric 5 with longitudinally oriented fibers (for example 35% by weight) compared to the faster part fleece 2 with the later across oriented fibers (e.g., 65% by weight), because through the bonding loops or the wales of the longitudinally extending fiber content in the nonwoven fabric again is increased. Generally it can be said that of the Web formation device for the faster part fleece 2 in coarse, an inequality of ± 20% by weight permitting approximation an approximately equal mass of fibers taken per unit time becomes like for the slower Teilvlies 5. The spectrum of the So mass distribution can range from about 30:70 to 70:30.

The faster part fleece 2 is at all in the figures 3, 4 and 5 variants of the invention shown at least indirectly a fleece laying device 14, 22 and 45 assigned, with which the faster part fleece 2 zigzag-shaped to a Cross-fiber part fleece 1 can be placed. The part fleece becomes the Fleece laying device in each case by conveyor belts fed, but in the simplified, principle Representation of Figures 3 and 5 is not shown. at the embodiment shown in Figure 4 is the Conveyor belt 21 for feeding the faster part fleece second to the web laying apparatus 22. By the zig-zag Laying the faster part fleece 2 is a cross-fiber part fleece 1 with preferably transversely to the longitudinal direction of Nonwoven web oriented fibers 3 produced. By the zig-zag Laying the faster part fleece 2 to the cross-fiber part fleece 1 is the one whose running speed reduced and also its basis weight in appropriate Extent increased. In the context of the zigzag-shaped Laying nonwovens is also on the mentioned textbook "Nonwovens" referred to in Subchapter 4.1.2.3 "Web formation" (pages 157-165) on process and machine technology Individual aspects of crosslapping or zig-zagging Laying florets in particular while making cross-oriented Fleece enters. There are different Designs of nonwovens, namely u.a. Steilarmleger (Camelback) and Horizontalleger distinguished. In the embodiments Figures 3 and 5 are simplicity Half pendulum working Steilarmleger as fleece laying device 14 and 45 indicated, whereas in the embodiment according to Figure 4 a Horizontaleger as fleece laying device 22 shown in principle in the design of a Wagenleger is.

After the two Teilvliese, namely the slower Teilvlies 5 and the zigzag-shaped cross-fiber part fleece 1 are brought together to form a common nonwoven 4 They both need not just agree Beyond that, but beyond that Transverse position equal position and with matching path velocity be merged. To this measure condition to meet, apply to the invention used Nonwoven laying apparatus generally has certain process conditions, so that the o.g. Geometry conditions, i. same Width and same speed of the cross-fiber part fleece 1 and the slower nonwoven fabric 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 zig-zag-shaped partial layers within the transverse fiber partial web 1 must be deposited at an angle α whose sine value corresponds to the value of a true fraction of the form 1 / n with n as a whole number less than seven. In other words, the zig-zag-shaped partial layers within the cross-fiber part web 1 must be optionally deposited under one of the following angles α:

30.0 ° (sin α = ½),

about 19.5 ° (sin α = 1/3),

about 14.5 ° (sin α = ¼) or

about 11.5 ° (sin α = 1/5).

The faster part fabric 2 must for this purpose with a larger to a corresponding integral multiple speed v ₂ are removed from the web formation device, as the slower part of non-woven with the decrease in speed _V1. The already mentioned ratio of the deceleration rates or the reciprocal v ₂ / v ₁ is therefore preferably two, three, four or five. Thus, regardless of their possibly changing absolute speed, the two non-woven takers 11 and 12 running at different speeds must run at a fixed speed ratio corresponding to one of the stated values. The higher the speed ratio v ₂ / v ₁ , the lower the possible angle α between the zig-zag partials within the cross-fiber part batt 1, and the sooner the fibers 3 of the exit batt are actually transversely within the cross-fiber batt 1 oriented. On the other hand, prepares too high a speed ratio of the nonwoven pickup v ₂ / v ₁ 11 and 12 not only problems in the web doffing but also in the zigzag-shaped laying of the cross-fiber partial web 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 provide hardly any further advantages in terms of textile technology on the finished nonwoven fabric.

By the zigzag-shaped laying of the faster part fleece 2 in a fleece laying device 14, 22 and 45 (FIGS 3, 4 or 5) to the cross-fiber part fleece 1 finds process-immanent way a deflection of the web running direction held at 90 °. On the other hand, the thus formed cross-fiber part fleece 1 and the slower part fleece 5 at the same Direction, lateral position and speed merged become. Therefore, in the different embodiments the production plant each still a Vliesumlenkeinrichtung 17, 28 and 43, respectively, which provide such Parallel run of leading together to partial webs, which is further below in relation to the individual Embodiments will be discussed again. It should be mentioned at this point only that the Vliesumlenkeinrichtung 17, 28 and 43 of the different embodiments each different within the production plant arranged or different Teilvliesen assigned. In this regard and the resulting Consequences differ the embodiment of the Figures 3, 4 and 5 from each other.

A presently quite essential to the invention plant and process component is the Vliesumlenkeinrichtung 17, 28 and 43, in all different embodiments is provided, albeit in different assignment. Consistent with all embodiments is that the Fleece diverter 17, 28 or 43, regardless of which of the part fleeces it is assigned, in each case the assigned part fleece with respect to its seen in plan view Direction of rotation is deflected by a right angle. Further agreeing for all embodiments is that the Fleece diverter with respect to its deflection effective Part, namely the Vliesumlenkstange 18, 30 and 43 - im Plan view - approximately the same position as the effective part the respective Fleece laying device 14, 22 and 45 for the faster part fleece and arranged offset in height to her is.

In the context of the positional equality of these two Plant components and the relevant orientation variables be mentioned on the one hand, that the laying rollers (in Figure 4 reference numeral 25) of the fleece layers 14, 22, 45 brush a square when going back and forth. On the other hand is the fleece deflection bar 18, 30, 43 of the web deflection 17, 28, 43 each diagonally in a square same size. These two named squares of the fleece laying device on the one hand or the Vliesumlenkeinrichtung on the other must be in the same position in the floor plan.

After the slower part fleece 5 and the cross-fiber part fleece 1 are combined to the full web 4, is in the Production plant finally a device 13 for solidifying of the nonwoven fabric 4 is arranged to a nonwoven fabric, the indicated only in Figure 3 in a generalizing manner is. Here is basically the entire range of known Nonwoven bonding process into consideration. In this Context is again on the o.g. Textbook "Nonwovens" referred to in Chapter 6 "Nonwoven bonding" (p 269-399) on the known methods for web bonding, in particular also for the stitch bonding of nonwovens, received. On the solidification of the multilayer template fleece to a nonwoven fabric will not be discussed in detail below, but merely noted that a stitch consolidation with textile wafers lying in the web longitudinal direction and also with respect to the use of the nonwoven fabric seems to offer the most benefits.

After so far the matches of the different embodiments Figures 3, 4 and 5 are mentioned, be now discussed in more detail on the individual embodiments, which - as I said - essentially by the Type of assignment of the inventively essential Vliesumlenkeinrichtung differ.

In the production plant shown in Figure 3, there, the simple illustrated there only with the Vliesumlenkstange 18 Vliesumlenkeinrichtung 17 associated with the faster part fleece and functionally the Fleece laying device 14 before ordered. In front of the also greatly simplified and illustrated as oscillating working Steilarmleger Vlieslegevorrichtung 14, the faster part fleece 2 is "temporarily" placed in a direction transverse to the direction 7 direction and laid out of this transverse direction, the cross-fiber part fleece 1, which also - in process-immanent manner - A 90 ° deflection takes place. As a result, the faster part fleece 2 and the cross-fiber part fleece 1 in its course twice - in plan view - deflected, with these two deflections compensate in the result. The running direction 8 of the united Vollvlieses 4 agrees - seen in plan view - with the working direction 7 of the web forming card 10 match; both directions 7 and 8 are arranged in a common alignment line. The slower part fleece 5 is transported by means of a fleece transport belt 15 over the fleece deflection device 17 and the fleece laying device 14 arranged therebelow. Only in a position moved away from the fleece laying device in the working direction is the slower part fleece 5 deposited on the transverse fiber fleece 1 carried by the fleece transport belt 16 with the same transverse position and coinciding speed v ₁ ; by a pressure roller pair 19, the part webs are pressed together before they are supported by the nonwoven conveyor belt 16 in the nonwoven fabric hardening device 13.

4 shows only a central section of the production plant is shown, ie the web formation itself and the decrease of the two part webs 2 and 5 with different speeds v ₁ and v ₂ on the one hand and the means for solidification of the full web 4 to a nonwoven fabric on the other are in the illustration omitted from Figure 4. The slower part fleece 5 is carried straight from the nonwoven conveyor belt 20 through the production line, ie, this system is stretched or rectilinear, ie in which the working direction 7 of the web forming device and the further processing direction 8 match.

In a further agreement with the exemplary embodiment according to FIG. 3, the fleece deflection device 28 is also assigned to the course of faster part fleece 2 or transverse fiber part 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 fleece 1 and is functionally ordered according to the fleece laying device. Moreover, the Vliesumlenkeinrichtung 28 is completely, although limited to the functionally essential parts, shown in Figure 4, which will be discussed in more detail below. Also designed as a flat-building Horizontalleger in Wagenlegerbauart fleece laying device 22 is shown in Figure 4 in more detail, although shown only in the functionally essential elements. The faster part fleece 2 is fed to the fleece laying device 22 on a nonwoven conveyor belt 21 and stored there offset on a pair vertically spaced, ie not touching arranged intermediate conveyor belts 24, 24 'of a superstructure (tape 24) and a laying carriage (tape 24') with laying rollers 25 , which move synchronously but in opposite directions to each other in the rhythm of the zig-zag laying. In this case, the faster part fleece 2 (speed v ₂ ) is deposited on the transverse to the conveyor belt 21 and the intermediate ribbons 24, 24 'at the slower speed v ₁ moving non-woven conveyor belt 23 in a zigzag shape and in a consistent with the original width web width ,

By the zigzag-shaped laying of the pile to the cross-fiber part fleece 1, a 90 ° deflection is inherent in the process of the partial web. By the nonwoven laying device 22 downstream Fleece diverter 28 may this by a further 90 ° deflection compensated again and the original Direction 7/8 be brought back. The fleece deflection device 28 is above the nonwoven conveyor 20 arranged for the slower Teilvlies 5 and with their for the deflection of the cross-fiber part fleece decisive part, namely with the Vliesumlenkstange 30 - seen in plan view - positionally identical to the fleece laying device 22 angeordet, However, what in the perspective view of Figure 4 not very clear.

To bridge the height difference of the storage level the Fleece laying device 22 on the one hand and the Vliesumlenkeinrichtung 28 on the other hand is in the non-woven conveyor belt 23rd a stroke 26 provided by ingenious arrangement of deflection and guide rollers of the tape run of the non-woven conveyor belt 23 Angled in an L-shape and into the steep Upward stroke is transferred. The subsidizing Trum of the non-woven conveyor belt 23, on which the Cross-fiber part nonwoven is, goes into the stroke 26th above. To secure the cross-fiber part fleece on this steep section to lead, is also a L-shaped guided support band 27 is provided, which with a steep running Part of the conveying strand of the fleece conveyor belt 23 in the region of the stroke 26 is touching. The Cross-fiber part fleece is thus in the stroke distance between Non-woven conveyor belt 23 and touching support belt 27 held and transported up. The upper leg of the L-shaped Guided support band 27 extends approximately horizontally and above the web deflection 28. The promotional Run of the non-woven conveyor belt 23 of the stroke 26 is sufficient slightly in this approximately horizontal leg of Support band 27 into it, so that the upwardly conveyed cross-fiber part fleece can be stored there. From the horizontal Leg of the support band is the cross-fiber part fleece then on the guide band 32 of the web deflection 28th to hand over.

The Vliesumlenkeinrichtung shown in detail in Figure 4 28 consists essentially of a driven, in a rectangle guided over non-rotating turning bars 29, 30, endless leader 32. Neighboring, to each one Turning bar into one another merging strands of the guide band close with their side edges - seen in plan view - At least approximately right angle, but the respective flat sides of the guide band substantially are arranged parallel to each other. Such a leadership of Bandes is only possible with constant tape running, though on the turning bars a sliding deflection takes place. The turning bars must not rotate so. 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 part fleece, which is carried out in the embodiment shown in Figure 4 by a plurality of drive roller pairs 31, one of which is located on this side and the other beyond the guide belt. In the embodiment of Figure 4, the required running speed of the guide belt 32 is the - lower - speed v _{1 of} the cross-fiber part web 1. At this point it should be immediately noted that even in the example of Figure 5, where the web deflection 43 is associated with the slower nonwoven fabric 5 , This is driven at the lower speed v _{1 of} this Teilvlieses. Only in the embodiment of Figure 3, the local Vliesumlenkeinrichtung 17 is associated with the faster Teilvlies 2 and must therefore be driven at the higher speed v _{2 of} this Teilvlieses, which could turn out at least in waiver of Reibungsvermindernde facilities on the turner bars as a certain disadvantage.

The turning bars 29, 30 can be wrapped in the guide band Area each with a variety of grid-like distributed, friction-reducing facilities be provided. This can be in the pipe wall the turning bars embedded, but freely movable captive held balls act over the guide band can roll away. Another way to Friction reduction is a nationwide Air cushion in the contact area between turning bar 29, 30 and guide band 32 build. In this case would be in the raster-like distributed by the leader tape area arranged to arrange air outlet holes, which from the interior the tubular turning bars made of compressed air in the Excess is supplied. The leader band then floats to a certain extent on a compressed air film, which is also a dissipates any frictional heat. The danger of electrostatic Charging the leader band would also be less especially if the compressed air would be well moistened. Though could the guide band 32 thanks to the compressed air film almost without resistance over the turning bars, however would have a certain for the production of the necessary compressed air Power applied, but 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 arranged at the "corners" of the rectangle, plays one, namely the turning bar provided with the reference number 30 in FIG. a special role. Only the two on this one, following Tweeterumlenkstange 30 mentioned turning bar converging strands of leader tape 32 touch at all the deflected cross-fiber part fleece. Only about this Fleece deflecting 30 so the cross-fiber part fleece 1 is deflected. The other three turning bars are only for Guide the guide band in a closed rectangle. The special Fleeceumlenkstange 30 is also - in plan seen - approximately the same position to Fleece laying device 22 and arranged above it.

The inventively essential Vliesumlenkeinrichtung except the deflection of the nonwoven fabric at least in the embodiment according to Figure 4 also the task of an exact match of the two partial webs to be united in the width direction herbeizugühren. For this purpose is of the endless guide band leading, non-rotating turning bars 29, 30 at least one turning bar parallel to the plane the adjacent dreams in the sense of a tape correction pivot stored and with a corresponding pivot drive Mistake. After the fleece deflection bar 30 immediately arranged at the convergence point of the two part webs 1 and 5 is, the fleece deflection bar 30 for the tape running correction most likely to be the least likely Time delay between control intervention and newer Bandlaufposition a control technical width positioning would allow. U.U. is it appropriate that the Fleece deflection bar 30 diagonally opposite turning bar in the same way to hold swivel and with a To provide swivel drive. At synchronous, but opposite Swiveling the two swivel-mounted rods would despite regular intervention a uniform Basndspannung over the entire width of the guide band result. Furthermore this would result in an overall more stable tape run, i.e. the danger of a regulatory instability the tape running control would be lower.

Thus, the guide band of Vliesumlenkeinrichtung in the Sense of control technology width positioning well operate, the guide tape must be regardless of thermal or aging-related strains or shrinkage always be kept under a certain belt tension. To this Purpose are two adjacent turning bars of Vliesumlenkeinrichtung 28 parallel to the level of the adjacent dreams in the Sense of tensioning the guide belt 32 slidably mounted and provided with a corresponding displacement drive. Conveniently, the two are displaceable in this sense Turning bars parallel to the two opposite Sides of the spanned by the turning bars Rectangles can be moved. In such an orientation of Displaceability caused during clamping no angle changes within the rectangle and thus no influence to the width position of the tape run.

For the sake of completeness, in connection with the Figure 4 illustrated embodiment mentions a variant, in the - similar to the versions of the Figures 3 and 5 - within the from the two Teilvliesen. 1 and 5 united Vollvlieses the Querlagen-Teilvlies 1 below and the slower part fleece 5 is arranged at the top. To For this purpose, on the one hand the fleece transport 20, which the slower part fleece 5 carries, on the Vliesumlenkeinrichtung 28 away and to a further back in the plant provided on a separate fleece transport band Association are continued. On the other hand just this separate, according to the processing direction 8 aligned fleece transport pand installed be on which in the finishing direction deflected transverse layer partial web 1 of the Vliesumlenkeinrichtung 28 can be stored.

The top-side arrangement of the slower part fleece with the longitudinally oriented fibers has for the subsequent Stitch bonding of the full web to a nonwoven web certain stitch consolidation processes structural and operational Advantages.

In the third in Figure 5 fragmentary and turn very simplistic embodiment illustrated a Production plant is the nonwoven diverter, which only is represented by its fleece deflection bar 43, the slower one Partial fleece 5 assigned. At the location of the fleece deflection bar 43 would have to be a Vliesumlenkeinrichtung on the model of Figure 4 or on the model of FIG 6 introduce. The deflected at the fleece deflection rod 43 slower part fleece 5 is on the non-woven conveyor belt 44th filed, which carries it in the direction of 8. That too Cross-fiber part fleece 1 is process-immanent by the zig-zag Laying the faster part fleece 2 to the Cross-fiber part web 1 in the transverse to the direction of 7 of Nonwoven forming device lying downstream processing 8 diverted. The fleece laying device 45 places the zigzag Partial layers of the cross-fiber part fleece 1 on the lower Nonwoven conveyor belt 46 from which also parallel to Further processing direction 8 runs. Again, here are again the nonwoven deflecting rod 43 and the nonwoven laying device 45 offset from each other but - in plan - position equal arranged. The on the upper fleece conveyor belt 44th transported in a downgrade slower partial web 5 is deposited with the deposited on the lower non-woven conveyor belt 46 Cross-fiber part webs 1 to the two-ply full web 4 merged, which then solidified into a nonwoven fabric can be. In the embodiment of Figure 5 can also the non-woven conveyor belt 44 when integrated accordingly Nonwoven edge detectors and adjustable tape guide rollers within the tape run to be exploited, a matching Transverse position of the slower Teilvlieses 5 with the Cross-fiber part fleece 1 bring about.

The indicated in Figure 5 production plant runs - in Contrary to the rectilinear systems according to the figures 3 or 4 - as an angled whole; the working direction 7 of Web formation carding and the further processing direction 8 enclose a right angle with each other.

The footprint requirement for those shown in Figure 4, but also in the systems according to the figures 3 or 5 to think Fleece deflector 28 is relatively large. It can be accepted be that the tensioned by the guide belt 32, approximately square rectangle a side length of about the Two and a half times the working width of the web forming card Has. Therefore, it is expedient, the Vliesumlenkeinrichtung provided in the raised position so that they on the Dekkenkonstruktion the factory floor or at one of the production line overhanging supporting structure are suspended can avail without taking up valuable space at 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 the Guide strip 51 of Vliesumlenkeinrichtung 50 space-saving in two different, spaced apart Levels led. And that is at the of the fleece deflection rod 54 running strand of the guide band and in the in the same horizontal plane opposite, parallel Each strand of this strand entwined to 180 ° Deflection roller 52, 52 'arranged. The diameter This deflection rollers determines the distance between the two levels of leader tape 51. In addition to the smaller footprint has the web 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. From the four turning bars 54, 55 are each two in plan view, at least approximately congruent but about the roll diameter offset in height, so close to each other. After this here two opposite strands of the guide band the guide rollers 52, 52 'strongly entwine, it lends itself, of These guide rollers at least one for driving the guide belt 51 of the web deflection and to use to provide a corresponding rotary drive. If both guide rollers 52, 52 'used to drive the guide band should be considered, that both deflection rollers Although equally fast, but in the opposite direction have to run around. To synchronize the two to be driven Deflection rollers would be a reverse gear in this case with a 1: 1 ratio between two guide rollers makes sense. Beyond the drive, the guide rollers can also used for tensioning the guide band by in the direction of the entrapping dreams linearly movable stored and provided with a corresponding displacement drive are.

For the sake of completeness, it should be mentioned in connection with the three-layer original nonwoven 6 shown in FIG. 2 that a nonwoven forming card with three different nonwoven inks or two different nonwoven webs erected in tandem in succession would be required, which together have the three nonwoven inks. On such a web forming device are in one and the ohfasern same web formation process of the same _R or Rohfasergemisch three separate partial webs 5 ', 2, 5 are formed "and in each case in the three different, staggered nonwoven customers removed. The middle nonwoven pickup is with the multiply higher speed ₂ , whereas the two other nonwoven inks run more slowly (v ₁ ), from which the two slower part fleeces 5 ', 5 "are removed from the web formation process. The faster nonwoven fabric 2 taken off at the faster nonwoven taker is laid in a zigzag-shaped manner to form the cross-fiber part non-woven fabric 1, whereby a deflection takes place in-process. Subsequently, the transverse fiber part web 1 and the slower part webs 5 ', 5 "are brought into mutual agreement with respect to their course, for which the embodiments shown in Figures 3, 4 or 5 can serve as a model and 5 "are then combined with each other at the same speed v ₁ , the same direction and the same transverse position to form a three-ply solid fleece 6, which can be finally solidified into a nonwoven fabric.

Claims (19)

1. Method for the production of a non-woven, comprising the following method steps:

   two separate part-webs (2, 5) are formed from the same crude fibres or crude-fibre mixture in one and the same web formation process on a web formation device (10) having two web doffers (11, 12), and

   the part-web doffed on the one web doffer (11), referred to below as the "faster part-web (2)", is doffed from the web formation process (10) at a multiply higher speed (v₂) than that (v₁) of the other part-web, referred to below as the "slower part-web (5)",

   the faster part-web (2) is laid in a zigzag-shaped manner to form a new part-web, referred to below as the "cross-fibre part-web (1)", with a width corresponding to the width of the slower part-web (5) and at a speed (v₁) corresponding to the running speed (v₁) of the slower part-web (5), the fibres (3) being oriented preferably transversely to the longitudinal direction of the cross-fibre part-web (1),

   the cross-fibre part-web (1) and the slower part-web (5) are brought into mutual correspondence as regards their run and are combined, at a mutually identical speed (v₁), identical direction and identical transverse position, to form a two-ply web referred to below as the full web (4),

   the full web (4) prelaid in this way is consolidated (13) to form a non-woven.
2. Method according to Claim 1, characterized in that the faster part-web (2) is first deflected (17) into a running direction lying transversely to the working direction (7) of the web formation device (10) and is laid only out of this running direction in a zigzag-shaped manner, to form the cross-fibre part-web (1) and at the same time it is deflected (14) once again inherently to the process, so that, as seen in horizontal projection, its running direction lies in alignment with the working direction (7) of the web formation device (10), and in that the slower part-web (5) is led past the web deflection device (17) for the faster part-web and past the web laying device (14) for laying the cross-fibre part-web, and the two part-webs are subsequently combined to form the full web (4). (Figure 3)
3. Method according to Claim 1, characterized in that the faster part-web (2) is laid in a zigzag-shaped manner directly to form the cross-fibre part-web (1) and is at the same time deflected inherently to the process into a working direction lying transversely to the working direction (7) of the web formation device (10), and in that the cross-fibre part-web (1) is subsequently deflected again out of this transversely running working direction into one parallel to the working direction (7) of the web formation device (10) and into corresponding alignment with the slower part-web (5). (Figure 4)
4. Method according to Claim 1, characterized in that the faster part-web (2) is laid in a zigzag-shaped manner directly to form the cross-fibre part-web (1) and is at the same time deflected inherently to the process into a working direction lying transversely to the working direction (7) of the web formation device (10), and in that the slower part-web (5), too, is deflected into this transversely running working direction and into corresponding alignment with the cross-fibre part-web (1). (Figure 5)
5. Method according to Claim 1, characterized in that the zigzag-shaped part-plies within the cross-fibre part-web (1) are deposited at an angle (α) such that the sine value of the latter corresponds to the value of a proper fraction of the form 1/n with n as a whole number below 7.
6. Method according to Claim 5, characterized in that the zigzag-shaped part-plies within the cross-fibre part-web are deposited selectively at one of the angles (α) referred to below: 30.0º (sin α = ½), approx. 19.5º (sin α = 1/3), approx. 14.5º (sin α = ¼) or approx. 11.5º (sin α = 1/5).
7. Method according to Claim 1, characterized in that the faster part-web (2) is doffed from the web formation device (10) at a speed (v₂) higher by an integral multiple than the slower part-web (5, speed v₁), specifically preferably at a twofold, threefold, fourfold or fivefold speed (v₂).
8. Method according to Claim 1, characterized in that, in a rough approximation allowing an inequality of ±20 % by weight, an approximately identical fibre mass per unit time is doffed from the web formation device (10) for the faster part-web (2) to that for the slower part-web (5).
9. Method according to Claim 1, characterized in that the faster part-web (2) is doffed from the web formation device (10) at a web doffer (11) placed lower in terms of height position and the slower part-web (5) at a web doffer (12) placed higher in terms of height position.
10. Method according to Claim 1, characterized in that three separate part-webs (5', 1, 5'') are formed from the same crude fibres or crude-fibre mixture in one and the same web formation process on a web formation device and are in each case doffed at three different web doffers arranged so as to be offset in terms of height, the faster part-web doffed at the one, preferably middle web doffer being doffed from the web formation process at a multiply higher speed (v₂) than the other two slower part-webs (5', 5''), in that the faster part-web is laid in a zigzag-shaped manner to form the cross-fibre part-web (1), and in that, subsequently, the cross-fibre part-web (1) and the slower part-webs (5', 5'') are brought into mutual correspondence as regards their run and are combined, with a mutually identical speed (v₁), identical direction and identical transverse position, to form a three-ply full web (6), and the latter is consolidated to form a non-woven.
11. Plant for the production of a non-woven, comprising the following plant components:

    a web formation card (10) with two web doffers (11, 12) arranged so as to be offset in terms of height, the one, preferably lower web doffer, referred to below as the "faster web doffer (11)", being designed in such a way that it permits a multiply higher doffing speed (v₂) of the part-web doffed there, referred to below as the "faster part-web (2)", than the doffing speed (v₁) of the other web doffer, referred to below as the "slower web doffer (12)", at which a part-web referred to below as the "slower part-web (5)" can be doffed,

    a web laying device (14, 22, 45), assigned to the faster web doffer (11) and connected to the latter by means of web conveyor belts, for the zigzag-shaped laying of the faster part-web (2) to form a new part-web, referred to below as the "cross-fibre part-web (1)", with a width corresponding to the original width of the faster part-web (2) and with fibres (3) oriented preferably transversely to the longitudinal direction of the cross-fibre part-web (1),

    a further device (17, 28, 43) for the alignment of the cross-fibre part-web (1) with the slower part-web (5) with an identical speed (v₁), identical direction and identical transverse position, for the purpose of convergence to form a multi-ply web referred to below as the full web (4),

    finally, a device (13) for consolidating the full web (4) to form a non-woven.
12. Plant according to Claim 11, characterized in that the device for the mutual alignment of the cross-fibre part-web (1) and of the slower part-web (5) for the purpose of convergence of the part-webs (1, 5) to form the full web (4) contains a web deflection device (17, 28, 43) which is assigned to one of the part-webs (2, 5 or 1) and is arranged so as to be offset in terms of height with respect to the web laying device (14, 22, 45) and which deflects the assigned part-web (2, 1, 5) through a right angle with respect to the running direction of the latter, as seen in horizontal projection, the web deflection device (17, 28, 43) being arranged in terms of its deflection-active part (18, 30, 43), as seen in horizontal projection, in an approximately identical position to the active part of the web laying device (14, 22, 45) for the faster part-web (2).
13. Plant according to Claim 11, characterized in that the web deflection device (17) is assigned to the faster part-web (2)-and functionally precedes the web laying device (14), in such a way that, in horizontal projection, the running direction (8) of the combined full web (4) is arranged in corresponding alignment with the working direction (7) of the web formation card (10) in the run of the faster part-web (2) or cross-fibre part-web (1) on account of a double deflection having a mutually compensating outcome. (Figure 3)
14. Plant according to Claim 11, characterized in that the web deflection device (28) is assigned to the cross-fibre part-web (1) and functionally follows the web laying device (22), in such a way that, in horizontal projection, the running direction (8) of the combined full web (4) is arranged in corresponding alignment (8) with the working direction (7) of the web formation card (10) in the run of the faster part-web (2) or cross-fibre part-web (1) on account of a double deflection having a mutually compensating outcome. (Figure 4)
15. Plant according to Claim 11, characterized in that the web deflection device (43) is assigned to the slower part-web (5), and in that both the running direction, evident in horizontal projection, of the slower part-web (5), specifically through the web deflection device (43), and that of the faster part-web (2) and of the cross-fibre part-web (1) emanating from the latter, specifically through the web laying device (45), are deflected in each case through 90º, so that, in horizontal projection, the running direction (8) of the full web (4) combined from the part-webs (1 and 5) is arranged transversely to the working direction (7) of the web formation card (10). (Figure 5)
16. Plant according to Claim 11, characterized in that the web deflection device (28) arranged so as to be offset in terms of height with respect to the web laying device (22) consists essentially of a driven endless guide belt (32) which is led in a quadrangular polygon, preferably in a right angle, via non-rotating turning bars (29, 30) and of which the adjacent strands merging one into the other in each case at a turning bar form with one another with respect to the side edges of the guide belt (32) an at least approximately right angle, as seen in horizontal projection, but are arranged essentially parallel to one another with the respectively flat side of the guide belt (32), one (30) of the four turning bars (29, 30), referred to below as the web deflection bar (30), being arranged in an approximately identical position to the web laying device (22), as seen in horizontal projection, and the part-web (1) to be deflected being guided by the two strands of the guide belt (32) which converge at the web deflection bar (30) and being deflected by the said guide belt.
17. Plant according to Claim 11, characterized in that the guide belt (32) of the web deflection device (17, 28, 43) is driven at the speed (v₁, v₂) of the assigned part-web (2, 1, 5).
18. Plant according to Claim 11, characterized in that the turning bars (29, 30) are provided, in the region looped around by the guide belt (32), in each case with a multiplicity of friction-reducing devices arranged so as to be distributed in a grid-like manner.
19. Plant according to Claim 11, characterized in that the guide belt (51) of the web deflection device (50) is led in a space-saving way in two different planes arranged at an inclination to one another or spaced apart from one another, in that that strand of the guide belt (51) which runs off from the web deflection bar (54) and the diametrically opposite strand have arranged on them, approximately centrally, in each case a deflection roller (52, 52') looped around at 90º or at 180º by the strand.

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