DE202018004272U1 - Nonwoven fabric structure with several layers - Google Patents

Abstract

Nonwoven fabric structure (1) having a first layer (2) of a fiber composite and a second layer (3) of a fiber composite, said first and second layers (2, 3) being oriented in a transverse (22) and longitudinal (23) direction of said nonwoven fabric structure (1 ) are arranged successively in the vertical thickness direction (24), and wherein the first and the second layer (2, 3) in at least two connecting regions (20) by mechanical bonding of the fiber composites are interconnected, and wherein, based on the longitudinal direction (23) of Nonwoven fabric structure (1) at least in sections, the at least two connecting portions (20) taken in the transverse direction (22) of the nonwoven fabric structure (1) each have a width (30) of at most 5 cm and at least a distance (32) of at least Have 1 cm. Nonwoven fabric structure (1) having a first layer (2) of a fiber composite and a second layer (3) of a fiber composite, said first and second layers (2, 3) being oriented in a transverse (22) and longitudinal (23) direction of said nonwoven fabric structure (1 ) are arranged successively in the vertical thickness direction (24), and wherein the first and the second layer (2, 3) in at least two connecting regions (20) by mechanical bonding of the fiber composites are interconnected, and wherein, based on the longitudinal direction (23) of Nonwoven fabric structure (1) at least in sections, the at least two connecting portions (20) taken in the transverse direction (22) of the nonwoven fabric structure (1) each have a width (30) of at most 5 cm and at least a distance (32) of at least Have 1 cm.

Description

The present invention relates to a nonwoven fabric structure having a first and a second layer of a fiber composite.

Are currently in textile technology different layers connected together, this is usually done by sewing with a thread. However, such a thread may be disadvantageous, especially in the case of high-performance materials with comparatively thin layers, for example because of the additional weight. Depending on the field of application, other disadvantages may also arise, see below in detail.

The present invention is based on the technical problem of specifying a particularly advantageous nonwoven fabric structure with several layers.

According to the invention, this object is achieved with the nonwoven structure according to claim 1 and the production method according to claim 12. Accordingly, the fiber composite layers of the nonwoven fabric structure are or are connected to one another by means of mechanical consolidation. Thus, for example, by needle or preferably hydroentangling fibers of different fiber composite layers entwined with each other, which holds the layers together. This does not take place over a large area over the entire nonwoven fabric structure, but only in some areas, namely in solidification areas.

The solidification areas, each taken in the transverse direction of the nonwoven fabric structure, each have a width of at most 5 cm and each other a distance of at least 1 cm (the distance is taken as the smallest distance in the transverse direction, not as the center-to-center distance). Further advantageous upper limits of the width are in the order of naming increasingly preferred at most 4 cm, 3 cm, 2 cm or 1 cm (with possible lower limits for example. At least 0.2 cm, 0.5 cm or 0.8 cm ). Further advantageous lower limits of the distance are in the order of naming increasingly preferred at least 2 cm, 3 cm, 4 cm, 5 cm, 6 cm, 7 cm, 8 cm, 9 cm or 10 cm (with possible upper limits for example. At most 30 cm, 20 cm or 15 cm). In each case the distance between mutually adjacent connecting areas is considered.

To put it simply, the connection areas should not be provided too wide and at a certain distance from each other. There remain intermediate areas in which the fiber composites are not intertwined and thus not "compressed". Figuratively speaking, the nonwoven structure in the intermediate areas is "fluffier", the fiber density (per volume element) is lower, so it is more air trapped. Depending on the field of application, this may, for example, be advantageous in terms of feel or wear comfort, protective clothing may also require increased thermal insulation.

Especially with fire or heat protection textiles, there may be requirements to the effect that a direct fire (flashover) must be withstood for a certain period of time or a certain thermal carryover may not be exceeded. An example of quantification in the clothing sector is the so-called TPP value (Thermal Protective Performance), which is determined according to the NFPA 1971 standard. In this context, the present subject may be advantageous in comparison to the above-mentioned sewing of fiber composite layers, for example, insofar as by omission of the thread also a possible bridge or weak point can be switched off (a refractory or otherwise adapted thread, however, means additional effort) , The bonding by means of mechanical strengthening in areas leaves the respective layer properties in principle unchanged, the layers are not interrupted as in the case of the thread.

Further preferred embodiments can be found in the dependent claims and the entire disclosure, wherein in the representation of the features is not always distinguished in detail between device and process or use aspects; In any case, implicitly, the disclosure must be read with regard to all categories of claims. Thus, for example, when describing a nonwoven fabric structure made in a particular manner, this is also to be read as disclosing a corresponding manufacturing method, and vice versa.

The "fiber composite" of the respective layer can generally also be a substantially unconsolidated pile, preferably a consolidated pile, ie a consolidated fiber fleece. Its fibers are stuck together within the layer due to fiber-to-fiber entanglement. The fiber composite layers are or are each solidified before joining each other. Preferably, the fiber composite layers are each binder-free (without binder) held together, so solely due to fiber entanglement. In general, a fiber composite layer can, for example, also be a melt-blown layer (melt blown), for example produced by extruding a polymer melt through small nozzles. A melt blown z. B. be provided from melamine, so fireproof, s. u. in detail. However, the term fiber composite layer preferably refers to a consolidated pile which has at least staple fibers (generally also in admixture with continuous fibers), preferably consisting of staple fibers.

The "longitudinal direction" of the nonwoven fabric structure corresponds to the machine direction in the production, ie the direction of the feed. The nonwoven fabric structure is then, for example, guided lengthwise over rollers or wound up after production as a roll product. The transverse direction is perpendicular to it and thereby flat in the nonwoven fabric structure. In the example of the rolled product, its width is taken in the transverse direction. The thickness direction is perpendicular to the longitudinal and transverse directions, it is perpendicular to the flat nonwoven structure.

In a preferred embodiment, the connection areas are each part of a connecting line. In this case, on the one hand, the connecting regions may themselves each have a line shape, ie be elongate in the longitudinal direction of the nonwoven fabric structure. On the other hand, however, a respective connection region may also be arranged linearly as a discrete point together with a multiplicity of further connection regions. Such a connecting line, which is made up of successive connection points, can result, for example, in the case of hydroentanglement by pulsing the water jets, see below in detail.

Whether constructed of dots or each one continuous connecting region, the connecting lines each extend along the longitudinal direction of the nonwoven fabric structure. This should not preclude a proportionate extent in the transverse direction, ie the connecting lines can also be at an angle, namely, in particular, extend back and forth between reversal points (in a zigzag shape, see below in detail).

According to a preferred embodiment, the connecting lines have a varying distance from each other over the length of the nonwoven structure. You can each have, for example, a just mentioned zigzag course. Seen in supervision, the connecting lines can then z. B. surround rhombuses, so be arranged diamond-shaped. This can be achieved, for example, by solidifying to connect the fiber composite layers with a plurality of beams, which are offset in the transverse direction relative to each other, see below in detail. The diamond shape is only one possibility, it is also possible, for example, connecting lines with a curved extension, so that the connecting lines can describe at least to a certain extent also circular or elliptical forms. In general, the connecting lines with varying spacing can, for example, be advantageous insofar as the nonwoven fabric structure thus has certain stability in the longitudinal and transverse directions (the pockets or intermediate areas do not go under a transverse load).

In an alternative preferred embodiment, the connecting lines along the longitudinal direction at a constant distance from each other. As with the variant just discussed, the distance is also taken here in the transverse direction, but it does not vary. In other words, the connecting lines are parallel to one another, preferably they are also parallel to the longitudinal direction. Although the fiber composite layers of such a nonwoven fabric structure can possibly be pushed apart somewhat in the transverse direction when there is a thrust or compression load, ie can rise (between the connecting lines), an advantage may lie in the simpler production. The latter can be especially relevant with a view to mass production.

In the present case, for the sake of simplicity, in the present case, preference is generally given to two connecting regions or lines, although there will sometimes be significantly more connecting regions or lines across the width of the nonwoven structure, depending also on the overall width of the nonwoven fabric structure. For example, at least 3, 4, 5, 6, 7, or 8 connection regions / lines may exist with respect to 1 m width, with possible (independent) upper limits at z. B. at most 40, 30, 20 or 15 connection areas / lines (each in the order of naming increasingly preferred).

In a preferred embodiment, at least one of the fiber overbond layers has a weight per unit area of at most 80 g / m ² , in the order of entry more preferably at most 70 g / m ² , 60 g / m ² , 50 g / m ² , 40 g / m ² or 30 g / m ² . Possible lower limits may (independently of), for example, be at least 10 g / m ² , 20 g / m ² and 25 g / m ² . In other words, at least one of the layers is comparatively thin; this is preferably true for exactly one of the fiber composite layers. The weight per unit area of the other fiber composite layer may thus be greater, for example, by a factor of 1.5 or 2, a possible upper limit may be at most 5 times. In production, the thin layer is preferably at the top, that is to say facing the solidification unit, for example the water-jet beam. The thin layer may be advantageous in this regard, because the water jets they penetrate well and thus can also act on the other (lower) position.

In a preferred embodiment, the fiber composite of one of the layers is less strongly solidified than the fiber composite of the other layer. As stated above, the two fiber composite layers are usually solidified in each case starting from a pile in each case before they are joined together. In this case, for example, the energy input into the less solidified fiber composite layer may be less than in the other layer. If the Flor example. By means of hydroentanglement solidified, for example, the water jet pressure or the density of the nozzles may be lower. When connecting the fiber composite layers, the less solidified layer is preferably provided at the top, that is to say facing the solidification unit, cf. the above comments on the thin layer. When connecting can then, for example, the water jet well through the less solidified layer also act on the other layer.

According to a preferred embodiment, at least one of the layers inherently flame-retardant fibers, for example. To a weight percentage of at least 40%, 50%, 60%, 70% and 80% (in the order of naming increasingly preferred). The fiber composite layer can also consist exclusively of flame-retardant fibers (100%), but it may also be, for example, upper limits at 95% and 90%. In the application, the layer with the inherently flame retardant fibers may then preferably be outside or at least further out than the other layer, for example in the case of the protective clothing on the outwardly facing surface or in the case of a seat cover on the outer surface facing away from the seat.

In general, the "inherently flame-retardant fibers" can be, for example, viscose FR, aramid (meta-aramid or para-aramid), polyimide (in particular polyimide / amide), polybenzyl, p-phenylene - 2 , 6 - benzobisoxazole, phenolic, melamine, polyacrylate, polyacrylonitrile, oxidized polyacrylonitrile (Preox) and / or polyphenylene sulfide fibers. It can be provided both one of these individual fiber types as a single fiber and a mixture of several of these individual fiber types. Most preferably, the inherently flame retardant fibers comprise Preox fibers, either as a single fiber or in a blend. In general, the property "inherently flame-retardant" refers to fibers which are flame-retardant due to their original material properties, which therefore, for example, are not given the flame retardant properties by a chemical aftertreatment (a protective film).

The other fiber composite layer may preferably not inherently comprise flame retardant fibers, for example cellulose, polyester, polypropylene, polyethylene, polyethylene terephthalate and / or bicomponent polyethylene fibers, the latter being preferred, such as polyethylene / polyethylene terephthalate (PE / PET ) or polyethylene / polypropylene (PE / PP). In the case of the garments, these layers, which are usually located inside, can be advantageous, for example, with regard to wearing comfort. Seat and upholstery upholstery can result in increased seating comfort. For example, a non-inherently flame retardant fiber may also be based on ultra-high molecular weight polyethylene (commercially available, for example, under the trade name Dyneema), which may provide high tear / cut resistance.

In the context of this disclosure, the term "fiber" is generally also to be read on continuous fibers; a respective fiber composite layer preferably comprises at least a proportion of staple fibers; mixtures of endless and staple fibers are also possible. Likewise, however, a respective fiber composite layer can also consist exclusively of staple fibers, which is also preferred in certain variants.

In general, an advantage of the present nonwoven structure may also be that it is also possible to embed further materials between the fiber composite layers. In general, for example, a thread or a plurality of threads can be introduced between the layers, offset in the transverse direction to each other. A respective thread can in this case be held on a respective spool and unwound continuously with the feed between the layers; in the nonwoven structure, the respective thread then extends in the longitudinal direction

In a preferred embodiment, a further layer is embedded between the first and second layers. This may, for example, be a woven or knitted layer, a net or a mesh or even a film (which, for example, tears open in the joining regions). Furthermore, the further layer may also be a fiber composite layer, for example a melt blown or preferably a consolidated nonwoven fabric. As the material, a synthetic chemical fiber may be preferable in this respect, particularly based on ultrahigh molecular weight polyethylene (commercially available, for example, under the trade name Dyneema). These fibers (the further layer) can be characterized by a high tensile strength and, for example, provide some cut protection. In general terms, embedding the further layer opens up the possibility of optimizing the nonwoven structure to different requirement profiles.

In a preferred embodiment, a metal grid or -gelege between the first and second fiber composite layer is embedded, in particular a Stahlgelege. With regard to the nonwoven fabric structure, this can result in a special cut protection, that is to say, for example, in the case of the protective clothing, to prevent cutting damage or injuries. In the case of the seat covers there is a vandalism protection. With the main subject matter of the invention, a particularly advantageous interaction may exist in that the metal net or joint is then held securely embedded on the one hand in the connecting regions. On the other hand, for example Case of bonding by hydroentanglement, the embedding of the metal also largely done without machine wear. If, on the other hand, the fiber composite layers were sewn together as described above, the needle would be subject to high wear during repeated piercing of the metal net or fabric (blunting, etc.), which increases the running costs (material costs and downtime during set-up).

The invention also relates to a garment having a nonwoven fabric structure disclosed herein. It may, for example, be a protective jacket or pants. Here are applications in the military or police area as conceivable as the equipment of firefighters. In the case of protective clothing, the "fluffy" intermediate regions can be advantageous with regard to thermal insulation (see above); in addition, for example, cut protection can be implemented.

Further, the invention also relates to a seat with a seat cover having a nonwoven fabric structure disclosed herein. In this context, the thermal protection z. B. be advantageous insofar as the seat cover can shield the foam core of the seat, which is usually a high fire load, to some extent. In case of fire, therefore, spreading to the foam core is at least delayed, which can delay the spread of fire altogether. Preferably, it may be a seat in the transport environment, in general, for example, also a motor vehicle, it is preferably a public or mass transport. In addition to aircraft and ships in particular an application in rail transport can be beneficial, so trains can be equipped with appropriate seats or seat covers. Preferably, in this regard, a metal net or -gelege be embedded as vandalism protection, see the front.

As already mentioned, the disclosure also relates to a production method in which the fiber composite layers are stacked together and bonded together by mechanical consolidation. This is preferably done by hydroentanglement. The nozzles of a corresponding water jet beam can then be grouped together, for example, in groups, the groups being spaced from each other in the transverse direction (by at least 1 to 10 cm, see the above information on the distance between the connection regions). For example, at least 2, 4, 6, 8 or 10 nozzles can be grouped per group, with possible (independent) upper limits in the case of, for example, at most 30, 25 or 20.

As an alternative to hydroentanglement, mechanical consolidation can generally also be a needle consolidation, and a combination of needle and hydroentanglement is also possible.

In a preferred embodiment, the hydroentanglement is pulsed, so the water exits at the nozzles with a varying pressure over time. In this case, the water outlet can be completely interrupted between two pulses, but also in a continuous water leakage pulses by pressure or quantity variation is possible (between a minimum and a maximum quantity or pressure value). In general, the pulsing and the resulting interruptions along the connecting lines can give a smooth (not too stiff) nonwoven structure, so a good drape. The nonwoven fabric structure is easier to bend, which may be advantageous, for example, in terms of wearing comfort and / or workability.

In a preferred embodiment, the fiber composite of at least one of the layers is inhomogeneously solidified prior to bonding. So it is less strongly consolidated in some areas than in other areas. The connection areas or lines are then placed in the less solidified areas. Since the fiber composite layer is less strongly solidified there, for example, the water jet can act well when joining both layers and their fibers devour each other.

One possibility for providing a less strongly consolidated region in some areas is to dissolve their fiber composite in some areas before connecting. This can be done, for example, mechanically by combing out. The corresponding fiber composite layer may previously also be solidified homogeneously, in the course of triggering / combing the fiber composite is partially loosened, so figuratively speaking, some fibers are plucked out.

However, the fiber composite layer can also be produced originally with an inhomogeneous degree of solidification, for example by the energy input over the transverse direction is not constant when solidifying the pile (but less in the less solidified areas). Alternatively, or also in conjunction therewith, an inhomogeneity can also be achieved already during the laying of the pile, for example by varying the air flow in the case of an air-laid pile. The pile laying can be done, for example, in a so-called airlaid carding.

A preferred embodiment relates to the production of the above-described connecting lines with varying spacing, which describe, for example, diamond shapes or the like can. This is preferably achieved with at least two bars, which are relatively offset over time in the transverse direction. The bars may also generally be needle bars, with at least one group of needles arranged on each of them. Preference is given to water jet beams, each having at least one group of nozzles. Due to the relative offset in the transverse direction of the distance between the groups (needles or nozzles) is varied, resulting in a corresponding course of the connecting lines, see the front.

The disclosure also relates to the use of a presently disclosed nonwoven fabric structure for heat protection textiles, in particular for protective clothing and / or seat covers. Reference is expressly made to the above remarks.

• - aufeinandergelegt, und dann
• - durch mechanisches Verfestigen in den mindestens zwei Verbindungsbereichen miteinander verbunden.

The subject matter of the disclosure is in particular also a method for producing a nonwoven fabric structure, as well as apparatus which is set up to carry out a corresponding method. According to the method, the first and the second layer

• - superimposed, and then
• - Connected by mechanical strengthening in the at least two connecting areas.

The mechanical solidification preferably takes place by hydroentanglement.

Preferably, the hydroentanglement is pulsed, so the water exits at corresponding nozzles with a varying pressure over time.

Preferably, the fiber composite of at least one of the first and / or second layer is solidified in regions to a lesser extent before bonding by mechanical strengthening, in the at least two solidification areas.

Preferably, the fiber composite of the at least one layer, which is partially consolidated before joining to a lesser extent, partially dissolved prior to bonding by mechanical strengthening.

Preferably, the fiber composite of the at least one layer, which is partially solidified to a lower degree prior to bonding, produced by solidification of a pile, the solidification of the pile and / or a previous pile laying done inhomogeneous in such a way that the fiber composite then partially before bonding is solidified to a lesser degree.

Preferably, the mechanical strengthening takes place for joining the layers with at least two beams, along which the nonwoven fabric structure is guided in the longitudinal direction, wherein the beams are displaced relative to each other in the transverse direction.

The subject of the disclosure is also the use of a nonwoven fabric structure for heat protection textiles, in particular protective clothing and / or seat covers.

In the following, the invention will be explained in more detail with reference to embodiments, wherein the individual features in the context of the independent claims in another combination may be essential to the invention and continue to distinguish not in detail between the different categories of claims.

list of figures

• 1 Parts of a nonwoven fabric structure according to the invention in an exploded view;
• 2 a nonwoven fabric structure according to the invention in a plan view;
• 3 a nonwoven fabric structure according to the invention in a schematic section;
• 4 bonding the layers of the nonwoven fabric structure by hydroentanglement;
• 5 a way to create connecting lines with varying distances.

1 shows parts of a nonwoven fabric structure according to the invention 1 namely a first location 2 a fiber composite and a second layer 3 a fiber composite. In between is another location 4 arranged, namely a Stahlgelege. Shown is an exploded view in the nonwoven fabric structure 1 are the layers 2 . 3 . 4 to each other.

2 shows the nonwoven fabric structure 1 in a top view, from the top to the first location 2 looking back. You can see several connection areas 20 in the form of connecting lines 21 are provided or arranged. Relative to a transverse direction 22 the nonwoven structure 1 have the connection areas 20 on the one hand a limited width 30 (from about 1 cm), cf. the synopsis with 3 , Between the connection areas 20 is also each a distance 32 provided by about 10 cm.

The cut according to 3 is perpendicular to the longitudinal direction 23 and thereby parallel to the transverse direction 22 and a thickness direction 24 , As discussed in detail below, the layers become 2 . 3 by local hydroentanglement in the connection areas 20 connected together, there the fibers of one fiber composite are entwined with those of the other. As is apparent from the schematic representation according to 3 Obviously, the layers are 2 . 3 there due to the additional consolidation also slightly compressed, so compressed.

As between the connection areas 20 but a distance 31 remains are the fiber composites of the layers 2 . 3 in the intermediate areas 35 still "fluffy", which is advantageous in terms of thermal properties, cf. the description introduction in detail. With regard to fire protection and fire retardancy can be at least one of the layers 2 . 3 be constructed of inherently flame-retardant fibers, see. also the introduction to the description.

4 illustrates the preparation of the nonwoven fabric structure 1 namely local consolidation along the connecting lines 21 , These are on a beam 40 arranged nozzles 41 not equidistant over the entire beam 40 distributed but spaced apart. For the sake of clarity, each connection line is present here 21 just one nozzle 41 In practice, a group of approximately 10-20 nozzles is provided there in each case. From a respective nozzle 41 occurs a respective water jet 42 from what the entanglement of the fibers of different layers 2 . 3 causes. So that the water jets 42 good on both layers 2 . 3 can act, the top layer has a basis weight of only about 30 g / m ² . With regard to further possibilities for improving the connection process, reference is made to the introduction to the description (for example, previously inhomogeneous solidification, etc.).

5 illustrates a variant in which a plurality of beams for connecting 40 are provided over time in the transverse direction 22 be offset relative to each other. As a result, the connecting lines have 21 over the length of the nonwoven fabric structure 1 not a constant, but a varying distance. In the present case, they are crossed over, forming a diamond-shaped pattern.

Claims (11)

Nonwoven fabric structure (1) with a first layer (2) of a fiber composite and a second layer (3) of a fiber composite, wherein the first and second layers (2, 3) are arranged successively in a thickness direction (24) perpendicular to the transverse (22) and longitudinal (23) directions of the nonwoven structure (1), and wherein the first and the second layer (2, 3) in at least two connecting regions (20) are connected to one another by mechanical hardening of the fiber composites, and wherein, based on the longitudinal direction (23) of the nonwoven fabric structure (1) at least in sections, the at least two connecting regions (20) in the transverse direction (22) of the nonwoven fabric structure (1) taken - each have a width (30) of at most 5 cm and - Have a distance (32) of at least 1 cm to each other. Nonwoven fabric structure (1) according to Claim 1 in which the at least two connecting regions (20) taken in the transverse direction (22) of the nonwoven fabric structure (1) each have a width (30) of at most 1 cm and - have a distance (32) of at least 10 cm , Nonwoven fabric structure (1) according to Claim 1 or 2 in which the at least two connecting regions (20) are each part of a respective connecting line (21), the at least two connecting lines (21) each extending along the longitudinal direction (23) of the nonwoven fabric structure (1). Nonwoven fabric structure (1) according to one of the preceding claims, in which the at least two connecting lines (21) have a spacing (32), taken in the transverse direction (22) of the nonwoven fabric structure (1), along the longitudinal direction (23) of the nonwoven fabric structure (1 ) varies. Nonwoven fabric structure (1) according to one of Claims 1 to 3 in which the at least two connecting lines (21) have a spacing (32), taken in the transverse direction (22) of the nonwoven fabric structure (1), which is constant along the longitudinal direction (23) of the nonwoven fabric structure (1). Nonwoven fabric structure (1) according to one of the preceding claims, in which at least one of the layers (2, 3) has a weight per unit area of at most 80 g / m ² . Nonwoven fabric structure (1) according to one of the preceding claims, in which, at least apart from the connecting regions (20), the fiber composite of one of the layers (2, 3) is solidified to a lesser extent than the fiber composite of the other layer (2, 3). A nonwoven fabric structure (1) according to any one of the preceding claims, wherein the fiber composite of at least one of the layers (2, 3) inherently comprises flame retardant fibers. Nonwoven fabric structure (1) according to any one of the preceding claims, in which a further layer (4) is placed between the first layer (4) with respect to the thickness direction (24) first and second layer (2, 3) is arranged, preferably a Metallgelege. Garment comprising a nonwoven fabric structure (1) according to any one of the preceding claims. Seat with a seat cover, which has a nonwoven structure (1) according to one of Claims 1 to 9 having.

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