WO2008046924A1

WO2008046924A1 - Molded item, non-woven fabric, and production and use thereof

Info

Publication number: WO2008046924A1
Application number: PCT/EP2007/061245
Authority: WO
Inventors: Joachim Bauer; Dirk Nissen; Giorgio Lesage; Jean Claude Intile
Original assignee: Rieter Technologies A.G.; Rieter Automatik Gmbh
Priority date: 2006-10-19
Filing date: 2007-10-19
Publication date: 2008-04-24
Also published as: DE102006035361A1

Abstract

The invention relates to a molded item, a non-woven fabric, and a method for forming the non-woven fabric (1), wherein the non-woven fabric (1) has a large number of filaments (5), wherein the filaments (5) are arranged in at least one first outer layer (2), preferably a second outer layer (3) and a middle layer (4), of the non-woven material (1). The non-woven material (1) forms a network of the filaments (5) in the middle layer (4), preferably in each one of the layers (2,3,4). Said individual filaments (5) touch other filaments (5) and thus form numerous contact points (7). The filaments (5) are attached to each other at least at many of the contact points (7). The network of the middle layer (4) has a pressure-resistant structure which opposes pressure in at least the Z-direction in such a way that the non-woven fabric (1), and with it the item (23), are bend-resistant through stabilization of at least one of the outer layers (2,3). The invention claims in addition a method for producing a molded item (23) out of a non-woven fabric (1) with a large number of filaments (5), wherein the non-woven fabric is placed as a semi-finished product into a mold (20), the mold (20) is closed, and the non-woven fabric (1) is exposed to a predetermined molding force or a predetermined molding pressure at a predetermined temperature, and finally the mold (20) is opened in order to withdraw the molded item (23). The temperature, the molding pressure, or the molding force and/or the molding time, are selected in such a way that, by means of the influence thereof, bonds are newly formed at the contact points (7), and the non-woven fabric (1) is fixed in the shape predetermined by the mold (20).

Description

Shaped article, nonwoven fabric and its manufacture and use

The present invention relates to a molded article comprising a nonwoven fabric having a plurality of filaments and a method for producing a shaped article of a nonwoven fabric having a plurality of filaments, wherein the nonwoven fabric is inserted as a semi-finished product in a mold, the mold gas-tight and hot steam is introduced into the mold at a predetermined pressure for a predetermined time, then the steam is released from the mold and the mold is opened to remove the molded article. The present invention further relates to a nonwoven fabric of a plurality of filaments having at least a first outer layer, preferably a second outer layer and an intermediate layer, wherein each of the filaments is in at least two, preferably three of the layers and the nonwoven fabric has a planar extent in x and y-direction and a thickness in the z-direction and a method for forming such a nonwoven fabric and its application.

Nonwoven molded articles are finding increasing use in industrial applications, particularly in the automotive industry, as they have good acoustic and pleasant haptic properties. In the automotive industry, they are commonly used for cowling in the engine, passenger or luggage compartment. They usually contain light fiber material for noise absorption, but must be stiffened to provide sufficient structural strength. In addition, these parts should be light in weight and as thin as possible in order to occupy little space and not overly increase vehicle weight. To achieve optimal properties of the product To achieve this, the requirements for noise absorption, dimensional stability and small thickness must be coordinated, although they often contradict each other.

From US 6,756,332 B2, the structure for a headliner of a vehicle is known, which is a laminate of at least three individual layers. Between two outer layers, an intermediate layer is arranged, wherein the outer layers for the rigidity of the article and the inner layer for the noise absorption of the article are designed. In each layer is a mixture of different fibers, which are connected by binding fibers. Each of the three layers is independent of each other and therefore can be made with different fibers. The three layers are finally glued together with two adhesive layers to form a stiff and sound absorbing sandwich product. The disadvantage of this product is that it is expensive and therefore expensive to manufacture. In addition, adhesive is needed to make the sandwich structure in each case, which may cause difficulties in recycling the product.

US 5,591,289 also discloses a laminate for automotive applications and a method of making the same. The article described here is intended to replace fiberglass roof linings. On both sides of an intermediate layer fibers of an outer layer are applied and needled with the fibers of the intermediate layer. For the production of the article, different fibers and binders are used in the individual layers, whereby again a very complex product is produced here. By combining different layers, the manufacturing process becomes time-consuming and thus expensive. Also, the durability of the product, especially at high mechanical and thermal stresses, severely limited, since the individual layers can separate again. As well There is also a problem with this product when recycling, as a variety of materials are used for the production of the article.

Instead of the connection of individual short fibers, WO 2004/088025 proposes inter alia the use of filaments. In order to realize the various conflicting requirements of noise absorption and stiffness in the article, coarse fibers in a layer of the product are fused with fine fibers in the outer layer of the product. The resulting product already has many advantages, as it can be made recyclable and noise reduction and in particular noise reduction for technical products already well realized. However, it is also disadvantageous in this product that the production process is very cost-intensive, since different fibers have to be produced and connected to one another.

From AT 207674 a textile nonwoven fabric is known having a top and bottom and a central zone. On the upper and lower sides, the fibers are confused, while in the middle zone of the web they are predominantly approximately perpendicular to the surfaces of the nonwoven fabric. The production of this textile nonwoven fabric is carried out with rotating screening drums, which loose fiber material is supplied. The fiber material fed to the screen rolls together with an air stream is separated from the air stream on the screen rolls and pressed together to form a nonwoven and subsequently solidified. To solidify the nonwoven binder are applied or applied after the web formation. This is done z. B. by spraying the web with powdered or liquid binders or by dipping. The nonwoven provided with the binder is finally solidified in a drying chamber or in a hot press after the production of the actual nonwoven fabric to the textile nonwoven fabric. A disadvantage of this nonwoven fabric and its production is that the nonwoven fabric is produced by short staple fibers. While the fibers of the nonwoven fabric in the middle zone are oriented approximately perpendicular to the surfaces of the nonwoven textile fabric, they do not add substantial strength to the nonwoven fabric due to their loose placement in the middle layer. Also, the strength is severely limited by the shortness of the fibers and their consequent involvement in the nonwoven fabric.

From DE 100 84 561 T1 also a nonwoven fabric and its preparation is known. There are described therein various types of fibers or filaments, such as spun-fleece fibers (spunlaying process), meltblown (meltblown), homofibers, bicomponent fibers, biconstituent fibers and various bonding processes for producing connection points of the filaments in the nonwoven, which also in can be used in the present invention. The nonwoven fabric described in DE 100 84 561 T1 has two parallel surfaces in which there are continuous fibers that are bent out of this particular plane to form loops and then to be incorporated into the other surface. The loops form according to the description of this document U-shaped waves with open channels between the waves. These open channels are intended to create a liquid absorbency which serves to apply the personal care absorbent article nonwoven fabric described therein. Due to this application, it is obvious that a particular rigidity of the product is not desired. It is trying to create a pliable fleece through the fiber loops and the open channels. Only for fixing the two surfaces, if necessary, a post-treatment of the nonwoven fabric is provided, which is to be achieved for example by Heißluftbonding after the formation of the nonwoven fabric or by admixture of binder. With such a fiber fleece is among other things by the open waves achieved in the central region of the nonwoven fabric and the short integration of the fibers in the two parallel surfaces only a low tensile and compressive strength of the nonwoven fabric. For personal care absorbent articles this may be sufficient, but not for construction articles where high strength is required.

WO 2005/054558 A2 likewise describes a nonwoven web which has two parallel surface layers, which are connected to filaments which extend from one surface into the other surface of the nonwoven and are oriented in this intermediate layer substantially at right angles to the surface layers. By a certain distribution of the filaments in the surface layers and the intermediate layer, a stiffness of the nonwoven fabric is achieved. Although such a nonwoven fabric is already more stable than the aforementioned nonwoven fabrics, a high rigidity, so that the material could be used as a construction material, but this is only possible in exceptional cases.

The object of the present invention is therefore to avoid the abovementioned disadvantages and to provide an article and a production method for an article which is inexpensive and yet has properties such as noise absorption and rigidity which make it suitable as a technical component, in particular in the automotive industry, To find use, as well as to provide a nonwoven fabric which has a high intrinsic stability and thus can be used as a semi-finished for the use of stable technical applications.

The object is achieved with an article and a production method and a nonwoven fabric and a method according to the independent patent claims.

The molded article according to the present invention comprises a nonwoven fabric having a plurality of filaments. The filaments are in at least a first one Outer layer, preferably arranged in a second outer layer, as well as in an intermediate layer of the nonwoven fabric. The nonwoven fabric forms, at least in the intermediate layer, preferably also in the one or both outer layers, a network of the filaments, wherein the individual filaments touch other of the filaments and thereby form a plurality of points of contact. The filaments are connected to each other at at least many, sometimes even at all of the points of contact, so that the network of the intermediate layer has a pressure-stable structure, which counteracts pressure at least in the z-direction, so that the nonwoven and thus the article by stabilizing at least one the outer layers is rigid. The shaped article according to the invention thereby becomes particularly stiff, since the filaments mutually support each other in the form of a network or a matrix and thus also stabilize the planarly extending shaped article essentially orthogonally in its z-direction. The connected points of contact are often called bonding points. Among other things, they are essential for the formation of the networks and the properties introduced into the semifinished product and the final article by these networks.

In particular, the intermediate layer of the molded article may have different thicknesses and thus be adapted according to the requirements of the shape of the article. The article is made of a homogeneous material since the same filaments are used both in the outer layers and in the intermediate layer. By a variation of the network, in particular in the intermediate layer, different properties can be introduced into the molded article. Thus, the design of the network, for example, with different thickness, density or filament cross sections to influence the different requirements of the product. The article can thus be adapted to the specific requirements, without a material mix would be required. This results in significant advantages, both in terms of the production, since the article is not made of different made separately layers, but is homogeneous with respect to its material. In addition, there are significant advantages in terms of. The recycling of the article, since only one uniform material can be used. Due to the fact that the filaments pass through all the layers of the article, a special connection of the individual layers is not required. Accordingly, unlike the prior art, it is not a nonwoven fabric which is sandwiched by individual discrete elements. The product properties are influenced by the design of the networks and the filaments used. The filaments in the individual layers are, however, identical in each case, ie the filaments used differ only within the scope of their production inaccuracies.

The properties of the article according to the invention are at least partially already determined by the semifinished product, i. through the nonwoven in itself, intended. The resulting features and advantages are described in detail in connection with the nonwoven fabric and its manufacture. It should not be discussed separately at this point. Nevertheless, the advantages of the corresponding characteristics of the nonwoven also apply to the article itself.

While the nonwoven fabric as semifinished product is substantially homogeneously formed along its planar extent in the xy direction, the nonwoven fabric in the article advantageously has regions of differently pronounced properties such as air flow resistance, porosity, Poisson's number, modulus of elasticity, thickness, density, strength and matched with this acoustic properties. It can thus be created an article, which receives individual areas according to the respective requirements. These areas are obtained by the deformation of the nonwoven fabric into the shape of the final article. Thus, an article can be created which has areas of higher strength, for example, for attachment of the article to other components, or for better resistance to a wind of the vehicle and other areas with better soundproofing and / or sound absorption. In addition, the properties can still be influenced by the arrangement of appropriate functional layers on the outer layers of the nonwoven fabric.

Influence on the properties of the article can advantageously take place in that regions with different density of the connections of the contact points and / or thickness of the respective layers are present in the article. The density of the connections of the contact points corresponds to the number of connection points per room element. Both changes affect the strength and acoustic properties of the item and can be customized. The density of the compounds is changed, for example, by releasing the compounds present in the semifinished product and recreating them in more or less large numbers, sizes or shapes. The thickness of the article is varied by more or less compressing the semi-finished product and fixing the joints in this compressed layer.

It is particularly advantageous if the thickness of the article can be changed substantially by changing the thickness of the intermediate layer. The interlayer of the nonwoven fabric has by the position of the filaments, which here have a clearer z-component than in the outer layers, rather the possibility that they by reducing this z-component in favor of the x or y component of the alignment of the filaments causes a smaller thickness of the article.

Advantageously, the thickness of the article is between 2 and 30 mm, preferably between 1, 5 and 15 mm. If the nonwoven fabric from which the article is made is compressed particularly strongly, the result is, for example, a thickness of 2 mm. In this area, the article is particularly well suited for attachment to other components, since here the Strength of the article is particularly high. In areas where more acoustic properties of the article are required, thicker areas, in particular up to 30 mm, are particularly advantageous, as this creates pores in which the sound can be absorbed very well. Even if, starting from the nonwoven material, a substantial reduction in the thickness is achieved, it is still possible to increase the thickness of the article in comparison to the nonwoven fabric of the semifinished product by pulling the filaments apart and fixing them in this position.

In particular, for applications in the automotive sector, it is advantageous if the article has a basis weight between 200 and 2,500 g / m ² , preferably 500 -1800 g / m ² . With such basis weight, there is a good tradeoff between strength and acoustic performance properties without making the article excessively heavy. Of course, the basis weight may be increased beyond this specified level if correspondingly heavy materials are additionally applied to the nonwoven fabric.

It is particularly advantageous if the density of the connections of the contact points in the intermediate layer in the nonwoven fabric of the starting material is lower than in the outer layers. For the article of the end product, these junctions of the contact points can be increased at least in a single area to the density of the outer layers. This means that the article in this area is largely completely compressed. A distinction between the individual outer layers and the intermediate layer will be very difficult to determine in this highly compressed state of the final product. The former liner can disappear completely in such an area, or at best be visible as a thin suture-like line. A highly compressed area of the article may be isolated or multiple, in equal or different extents in the article, but the complete article may also be so compressed depending on the required properties of the article. Due to its mechanical properties, in particular its dimensional stability and / or its acoustic properties, the article according to the invention is particularly suitable for applications in the automotive industry. The article is not limited to such applications. For example, an application in other areas in which, for example, sound absorption and / or sound insulation is required, may well be useful. Especially when an effective sound absorption on a small space or with a relatively low basis weight is required, the article of the invention is advantageously used. Thus, buildings, ships or aircraft can be very advantageously equipped with this material.

Particularly advantageous application of the article in the automotive industry as headliner, engine encapsulation, heat shield, underbody, Radhaus-, engine compartment, interior or trunk lining. In all of these areas, some structural strength of the material is required without allowing a large thickness or weight.

In particular, in comparison to articles of the prior art with, for example, the same dimensions as the thickness and / or the same basis weight, the article according to the invention has better acoustic and / or mechanical properties. For this purpose, predetermined, in particular standardized, measuring methods can be used for this, as described, for example, in DIN 53455, DIN EN63, DIN 53453, DIN 52215, DIN 29053, DIN EN ISO 10534-1, EN 20527-1 / 2, DIN EN ISO 157 or ASTM C - 384. The so-called alpha cabin and the ISOKELL in accordance with the globally recognized Rieter standard can also be used to determine comparative values. By appropriate design of the nonwoven fabric as a starting material and reshaping of the article corresponding desired properties can be achieved. Advantageously, the acoustic properties of the article on thickness, density, modulus of elasticity, Poisson's number, porosity and / or air flow resistance, the filaments, the nonwoven fabric and / or the networks of the individual layers and / or additional applied materials and their on or determined multiple arrangement. In this case, the filaments can be different cross sections or different materials which produce different acoustic properties by influencing the absorption or reflection of the sound.

The article according to the invention advantageously has different insulation, absorption and / or reflection behavior in the individual layers. While in a denser outer layer rather an insulation of the sound will be done, the looser liner and the second, in this case then defined porous outer layer is rather used for absorbing the sound. By designing the individual layers depending on the individual task of the article or individual areas within the article, this different insulation, absorption and / or reflection behavior can be influenced.

The insulation, absorption and / or reflection behavior of the individual layers, based on the nonwoven fabric used, and according to the requirements of the article can be influenced in the production of the article by changing the networks of the individual layers. In this case, the connecting points as well as the position of the filaments are newly fixed in comparison with the nonwoven fabric used and thereby produce changed insulation, absorption and / or reflection behavior.

The mechanical behavior of the article according to the invention is determined by the physical properties of the filaments and / or the networks of the layers, such as in particular the modulus of elasticity, area moment of inertia, tensile strength, flexural strength, impact resistance. All these Parameters can be influenced in the article according to the invention by the corresponding design of the nonwoven fabric and the deformation of the nonwoven fabric in the final article. They may be varied completely or partially in the article depending on the requirements in the article. The nonwoven already contains the basic properties of the final article, which are then brought to the required size in the manufacture of the end article.

The networks of the individual layers in the article cause an inherent stability of the article, so that a particular in the automotive industry required low sagging of the article, often called Sagging, even at higher temperatures, for example at temperatures between 80 ⁰ C and 100 ⁰ C is obtained. Furthermore, the behavior of the article can be influenced by the choice of polymers.

In comparison with articles of the prior art, for example, with the same thickness and / or the same basis weight, the article according to the invention has a higher thermoformability. In particular, when the nonwoven fabric in the outer layers has long portions of the filaments, e.g. Loops, these can be warped against each other and fixed again when heated. By warping against each other, which takes place more strongly in one outer layer than in the other outer layer, the article can be given a shape which deviates far from the original position of the semi-finished product and thus obtain, for example, pot-shaped bulges which are suitable for fastening the article to a substructure or geometric specifications of other components for better use of space can follow.

Are in the article areas, in particular beads or ribs as stiffening areas or eyes as mounting areas, arranged, the article can be particularly well attached, ie screwed, be. In addition, the inherent stability of the article is further enhanced by the Ribs are formed accordingly. Through the eyes it is possible to determine the distance of the article from a substructure. This distance may be important for the acoustic properties, for example the absorption properties of the article when installed.

Advantageously, at least individual regions of the article, in particular the stiffening regions and attachment regions of the article, are compressed more strongly than regions with higher acoustic requirements. The stronger compression allows a defined attachment of the article. There are fewer free spaces between the individual fibers or filaments, which would be changed in an undefined manner, for example, when the article is screwed onto a substructure. Compressed areas can also be targeted as areas with better insulation properties. In areas with better absorbent properties, a bulkier material is advantageous to better reduce the sound levels.

The article can be compressed more or less to meet the required requirements. In particular, the orientation of the filaments in the intermediate layer changes. It may happen that in strongly compressed areas of the article, the filaments in the intermediate layer similar to the filaments in the outer layers have a pronounced orientation in the x-y direction of the nonwoven fabric. In general, however, the different layers are still recognizable on closer analysis. It is possible that in the intermediate layer, the orientation of the filaments, for example, preferably in the y-direction, while the filaments in the outer layers are preferably aligned in the x direction.

In the inventive method for producing a shaped article of a nonwoven fabric having a plurality of filaments of the nonwoven fabric is inserted as a semi-finished product in a mold, the mold closed, and the nonwoven fabric is subjected to a predetermined deformation force or a predetermined deformation pressure at a predetermined temperature. Subsequently, the mold is opened to remove the molded article. The filaments of the nonwoven fabric are arranged in at least one first outer layer, preferably in a second outer layer and in an intermediate layer of the nonwoven fabric. The nonwoven fabric forms in the intermediate layer, preferably in each one of the layers, a network of filaments, wherein the individual filaments touch other of the filaments and thereby form a plurality of points of contact. The filaments are connected to each other at at least many of the points of contact. The network of the intermediate layer has a pressure-stable structure, which counteracts a pressure at least in the z-direction, so that the nonwoven fabric is resistant to bending by stabilizing at least one of the outer layers.

As a result of the influence of the temperature, the deformation force or the deformation pressure and / or the deformation time at the contact points, compounds are reshaped and the nonwoven fabric is fixed in the form predetermined by the shape. With the aid of a predefined semifinished product in the form of a nonwoven fabric with an intermediate layer and one or two outer layers, the method according to the invention creates a shaped article with particularly high stability and design freedom. The semifinished product assumes the shape given by the shape. The resulting article is fixed in this form by the connection points of the semifinished product are more or less solved by the temperature and the deformation forces acting on the joints or the deformation forces in connection with a corresponding deformation time and fixed again in the new form after cooling , Due to the temperature and the deformation pressures acting on the connection points or deformation forces, the joints are soft or completely dissolved. By forming the semi-finished new or different contact points, which after cooling of the Cure the article again and thus keep the article in the new form. Depending on how much the semifinished product is compressed in the mold, starting from the nonwoven fabric, a more or less thick product with different properties is produced. While at the more compressed locations, for example, it is suitable to be bolted to a substructure, the product may be designed at the less compressed locations to include particularly good mechanical or acoustic properties. It is thus an article to produce, which produces starting from a simple and uniform semi-finished product with different properties in different areas of the product. Even in the areas which are essentially responsible for acoustic concerns, the network-like structure of the intermediate layer provides a very high stability, which opens up a variety of new uses for the article.

It is particularly advantageous if in the production process a nonwoven fabric with bicomponent filaments or biconstituent filaments, in particular of thermoplastic material combinations, for example of PET, PBT, PP, PE or PA as a structural component and CoPET, CoPBT, PBT, PP or PE as an adhesive component of the filaments is used. The structural component and the adhesive component preferably have different melting temperatures or melting temperature ranges and can be made soft by the targeted setting of a specific steam temperature. Thus, it is possible that the PET used, for example, is still relatively strong, while the corresponding Co-PET already begins to melt. If the contact points are connected to the Co-PET, they can be released at the corresponding melting temperature of the Co-PET and brought into a new position. After cooling below the melting temperature, the co-PET solidifies again and fixes the contact point in its new position. The new connection of the contact points may be a different size, strength and / or a have different angles of the interconnected filaments. It is also possible to increase or decrease the number of connections of the contact points, depending on the requirements of the final product.

Advantageously, the temperature and / or the deformation pressure or the deformation force acts on the nonwoven fabric for less than 60 seconds. This ensures a rapid deformation of the nonwoven fabric and thus a cost-effective manufacturing process.

For melting at least one of the polymers of the filament, it is advantageous if the applied temperature has in the range of the melting temperature of this polymer. At a minimum, the temperature should be below the melting temperature of the second polymer of the filament to maintain the basic structure of the nonwoven fabric. Of course, it is also possible to use instead of filaments with different materials and a monofilament, which is connected to fusible adhesives. The temperature is then adjusted so that the adhesive melts rather than the monofilament.

Advantageously, the temperature is introduced by introducing hot steam into the mold after it has been closed and released from it before it is opened. The required temperature is thereby produce quickly and inexpensively.

If the mold is closed in a gas-tight manner, uniform heating of the semifinished product can be achieved and the steam can be kept uniform in the mold at least temporarily during the forming process.

In order to achieve a particularly rapid production of the article, the mold is opened immediately after the release of the steam from the mold and the article is removed from the mold immediately after opening the mold.

Due to the compression of the semifinished product, in particular the network of the intermediate layer is compressed. This looser network, originally looser compared to the outer layer, is more or less compressed by the shape and thus determines the outer contour of the article, while still stabilizing the outer layers and thus resulting in an overall stable article.

In order to be able to melt one of the components of the semifinished product particularly quickly, it is advantageous if the mold is preheated prior to insertion of the nonwoven fabric into the mold. As a result, a faster heat transfer is effected in the nonwoven fabric, whereby the forming process is even faster feasible. Additional materials can be applied before the forming process and / or after the forming process or by further subsequent process steps. They can also be applied to the still present as semi-finished nonwoven fabric as well as during the forming process. The nonwoven fabric can be brought to the required forming temperature within the mold or before being placed in the mold.

The following descriptions of the nonwoven fabric according to the invention and its advantages, as well as the advantageous embodiments of the nonwoven fabric, can also be applied to the finished end product produced with this nonwoven fabric. The molded article made from the nonwoven largely still has the advantages of the semifinished product. It is therefore quite advantageous to introduce at least some of the product properties required later in the finished article during the production of the semi-finished product. In the manufacture of the article, these properties can then be further modified, for example reinforced or attenuated. The nonwoven fabric according to the invention consists of a plurality of filaments having a first outer layer, a second outer layer and an intermediate layer, wherein each of the filaments is in at least two, preferably all three of the layers and the nonwoven fabric has a planar extent in the x and y directions and has a thickness in the z-direction. According to the invention, the nonwoven fabric in the intermediate layer, preferably in each of the individual layers, forms a network of the filaments, with the individual filaments contacting others of the filaments and thereby forming a multiplicity of points of contact. The filaments are interconnected at many of the points of contact. The network of the intermediate layer has a pressure-stable structure at least in the z-direction. The structure is designed such that it counteracts a pressure at least in the z-direction, so that the nonwoven fabric is resistant to bending by stabilizing at least one of the outer layers. The outer layer is so stable that it can be bent or even kinked only with comparatively large forces. It is stabilized by the structure of the liner especially against kinking. As a result, a nonwoven fabric is obtained, which is inherently stable even with larger Abstützabständen than comparable nonwovens of the prior art and less deflects or even buckles.

Due to the different layers of the nonwoven fabric, which are interconnected by the filaments, a certain basic strength of the nonwoven fabric is already produced. A separation of the individual layers is avoided by the extension of the filaments into the individual layers and by the thus created connection of the three layers. To increase this strength is now still provided that the filaments in the individual layers point or line touch and are connected to at least many of these points of contact. As a result, a stable network, one can also call it matrix, is formed, in which very short filament sections between the individual Contact points arise. As a result of the fact that the filament sections are mutually supported on relatively short lengths, a stable network, in the manner of a space frame, is obtained, which results overall in a stable nonwoven fabric. The nonwoven fabric counteracts by the stable network, in particular the intermediate layer of deformation from a predetermined state, since the individual free filament sections are very short and the filaments in the individual layers are mutually supported. The required in a deformation of the nonwoven fabric bending of the individual filament sections is thus possible only with greater effort and bending a variety of filament sections. The matrix of the intermediate layer has a pressure-stable structure at least in the z-direction and thus also supports the two outer layers. These outer layers are held in position by the sturdy intermediate layer and together result in a stable nonwoven fabric, since they are prevented from buckling under a corresponding load. It is thus obtained a nonwoven, which is particularly well suited for technical applications, since it already has a great inherent stability. The nonwoven fabric can therefore be used over large areas cantilevered.

Advantageously, the nonwoven fabric according to the invention is a semi-finished product which can be further processed to form an end product. By targeted shaping of the nonwoven fabric, for example, by edges or beads, the carrying capacity of the nonwoven fabric can be further increased. In this case, additional connections can be created at the points of contact. The many connected contact points of the semifinished product serve as a good starting condition for the stability of the end product. The further processing of the semifinished product can also take place in that the nonwoven fabric is pressed in some places and connecting points are permanently created in this state in new form and / or other number. The end product thus has different thicknesses and strengths. As a result, the nonwoven fabric can be used in many ways and produces a stable product which, inter alia, has heat-insulating or sound-insulating properties. The surfaces of the final product can thus also be produced with high strength.

Advantageously, the networks of the outer layers, at least in the x- / y-direction, a tensile and pressure-stable structure. This structure supports the possibility to produce a semi-finished product and later a final product, which has a high intrinsic stability and can be used self-supporting over large areas. If the outer layers are "tailor-made" under tension and pressure, they together with the pressure-stable interlayer create a very stable fleece.

A great advantage of the present invention is that the networks of the individual layers can be formed depending on the mechanical and / or acoustic requirements of the semifinished product or of the end product. They can also be formed largely independently of each other, so that a semi-finished product is created that can optimally meet the individual requirements of the finished product.

Act the individual networks of a deformation of the nonwoven fabric from the predetermined state, so they are designed so that the individual matrices can withstand depending on the expected force just this expected force, so a product is created that with minimal use of materials optimal strength receives.

The nonwoven fabric is already characterized increased stability and strength that the filaments in the intermediate layer are connected together to form a network or a matrix. This strength can be further increased if the filaments are also connected to one another in one or each of the outer layers to form a network. Thus, the filaments assist each other in the absorption of forces acting on the nonwoven fabric. This will be the case for most nonwovens of the invention. But it is also possible that one or both outer layer / s in the Nonwoven fabric already treated, processed or manufactured such that they cover the network of the intermediate layer in a film-like manner.

Advantageously, the nonwoven fabric extends flat. This is the ideal shape when the nonwoven fabric is to be used as a semi-finished product for further technical application. The surface may be flat or curved one or more times. It can already be introduced in the production of the nonwoven fabric, a certain basic shape in the cross section of the nonwoven web. From the flat semifinished product of the nonwoven fabric according to the invention results in a variety of applications and further processing options, as they are known in technical applications. Of course, the use of the nonwoven fabric does not exclude non-technical applications, if the respective rigid material properties of the nonwoven fabric do not interfere or even help for these other applications.

It is particularly advantageous if the nonwoven fabric is formed such that the filaments in the outer layers are oriented substantially in the x and y directions of the nonwoven fabric. The filaments in the intermediate layer have a more pronounced orientation in the z-direction of the nonwoven fabric compared to the filaments in the outer layers. By the interaction of the longitudinal and transverse oriented filaments in the individual matrices an already stable basic structure of the nonwoven fabric is obtained, which causes a particularly stable formation of the nonwoven fabric by the inventive compound of the filaments at their points of contact. By aligning the filaments in the matrix of the outer layers, a stability of the nonwoven fabric in the x and / or y direction is obtained. The more aligned in the z direction filaments of the matrix of the intermediate layer ensure stability of the nonwoven orthogonal, ie in the z-direction to the surface of the nonwoven fabric. In addition, the matrix of the intermediate layer keeps the matrices of the outer layers in shape. The nonwoven fabric is thus very stable against tensile, compressive and / or shear forces, which from different directions act on the nonwoven fabric. The connection of the filaments at their points of contact also causes a shifting of the individual filaments against each other due to shear forces acting on the nonwoven fabric is made difficult, so that in this way a particularly high stability of the nonwoven fabric is achieved. Of course, the orientations of the filaments in the outer layers and the intermediate layer gradually merge, so that the orientation in the z-direction of the filaments in the intermediate layer will be most pronounced in the middle of the intermediate layer.

If the filaments in the outer layers in the x-direction extend at least 1.5 times, preferably at least 3 times the thickness of the nonwoven fabric, or even a multiple thereof, for example 10 or 20 times the thickness of the nonwoven fabric, then very particularly advantageous causes a high strength of the nonwoven fabric is produced. The filaments form in the networks of the outer layers loops whose lengths have the minimum values mentioned. This results in bonded contact points of the filaments in the network, which produce a particularly good cohesion of the filaments. Also, the molded article of such a nonwoven fabric has a high strength and deformability, since the filaments in the outer layers even with a deformation of the nonwoven fabric, for example, during deep drawing of the nonwoven still hold together well and have sufficient overlap. In regions of the article that are strongly deformed in the z direction, the extent of the filaments in the outer layers can also be less than three times the thickness of the nonwoven due to the high warpage.

Advantageously, filament sections of one layer are supported on filament sections of an adjacent layer. If they are also connected to one another at such points of contact, a displacement of the two outer layers against each other is effectively impeded. The individual layers thus adhere firmly to each other, creating a very resistant nonwoven fabric is obtained. Due to the better cohesion of the individual layers is not only avoided in this way that the two outer layers can be pulled apart, but also the overall stability of the nonwoven fabric is increased.

To absorb forces from all directions, the network is three-dimensional. The individual filament sections are thereby supported in all directions and cause a uniform resistance of the nonwoven fabric or of the article produced therefrom.

The individual filament sections resist deformation of the nonwoven fabric due to reinforcement by the other filamentary sections bonded thereto in all directions. The nonwoven fabric thus becomes resistant to compressive and tensile loads and maintains a high intrinsic stability.

In particular, it is achieved with the nonwoven fabric according to the invention that filament sections resist deflection due to the reinforcement by the other filament sections connected to them. The filament sections are usually supported short, so that particularly kink-resistant bars are achieved in the form of filament sections. Also, the fact that not only point-like connections, but also linear connections of the filament sections arise at their points of contact, reinforcements of the individual filament sections are obtained in terms of their overall cross-section. Again, this serves to resist deformation or deflection of the entire nonwoven fabric and the article.

Advantageously, the nonwoven fabric is designed in such a way that the network counteracts a local longitudinal expansion of at least one outer layer, which would have to occur during deflection of the nonwoven fabric from the pre-given state. The one or both outer layers act thus as a stiffening element of the nonwoven fabric. The area moment of inertia is increased by the structure according to the invention compared with a conventional nonwoven fabric. The article produced therefrom thus has a high intrinsic stability and, even with large Abstützabständen and no or few reinforcements meet the permissible for example in the automotive industry and given sag.

It is particularly advantageous if the network is designed such that it counteracts a tensile force and / or a shearing force and thus a local longitudinal expansion in any direction. It is thus produced a tear-resistant nonwoven, which is deformable beyond only a relatively large amount of force. In particular, the nonwoven fabric is caused to carry at least its own weight over a larger area without significant deflection or deformation. This is obtained by the one hand loose construction, in particular the intermediate layer and the low basis weight thereby achievable with simultaneous inner stiffening of the nonwoven fabric. The nonwoven fabric is thereby also stable to a compressive force, which is absorbed to a large extent by the crosslinked intermediate layer.

In order to increase the absorption of a compressive force, it is advantageous if in the intermediate layer and / or in at least one outer layer, but depending on the compressive strength in the intermediate layer, the ratio of length to diameter of a plurality of filament sections is selected such that the individual filament sections can absorb relatively large pressure forces in the sense of a stable buckling bar without buckling.

Preferably, the network of the intermediate layer with respect to its ability to absorb pressure is formed substantially uniformly, so that no partial weak points of the nonwoven fabric arise, at which the nonwoven fabric could buckle. In particular, it is advantageous if no linear extending vulnerabilities that would allow buckling along these vulnerabilities.

For some applications of the end product, it is advantageous if the nonwoven fabric in the x-z or y-z cross-section, in particular with respect to the two outer layers is asymmetrical. Thus, acting on the respective outer layer different tensile and compressive forces can be absorbed. Depending on the installation position of the end article can thus be created under minimum possible weight and minimal use of material, a nonwoven, which can be optimally adapted to the requirements. Thus, depending on the load direction, the matrix or the network of an outer layer, for example, much thicker than the other outer layer are created, which can be taken into account the different recording of tensile and compressive forces. Thus, for example, the matrix of the outer layer, which is loaded more on pressure, made thicker than the matrix of loaded on train outer layer. Due to the lower use of material, the dead weight is reduced, which causes further advantages in terms of carrying capacity and weight when installed in the technical object.

In order to optimally utilize the load-bearing capacity of the nonwoven fabric, it may be advantageously provided that the density of the nonwoven fabric in the matrices or the networks of the outer layers is higher than in the matrix or the network of the intermediate layer. In particular, when the nonwoven fabric is to be subjected to deflection, this is advantageous, since in this way the area moment of inertia of the nonwoven fabric is increased when more material is arranged in the outer layers of the nonwoven fabric. The intermediate layer then serves as a stable spacer for the two outer layers.

Advantageously, the filaments of the nonwoven fabric are bicomponent filaments or biconstituent filaments. They consist of different ones Materials that have different properties, such as different melting temperatures. In one embodiment of such filaments of the melting at a higher temperature core of the filament is surrounded by a melting at a lower temperature sheath. Hereby, by bonding the nonwoven fabric, the nonwoven fabric can be permanently bonded and used to transmit force by briefly melting and then solidifying the outer component of the bicomponent filament. Of course, the invention is not limited to such bicomponent filaments or biconstituent filaments. For example, it is also possible to use monocomponent filaments which are melted to form the compound itself or are combined with adhesives. The adhesives can be dissolved and refixed for further processing of the nonwoven fabric according to the invention or adhesives are added for further processing which stabilize the nonwoven fabric in its new form. Also, a variety of cross-sections of the filaments are possible to produce various properties, such as stability or thermal or acoustic insulation of the nonwoven fabric.

Preferably, the filaments are spunbond fibers or meltblown fibers or filaments. The production of the nonwoven fabric is very fast and inexpensive possible with these known fibers or filaments.

When the filaments are made of thermoplastic material combinations such as PET, PBT, PP, PE or PA as a structural component and CoPET, CoPBT, PBT, PP or PE as an adhesive component of the filaments (5), they exhibit different reflow and / or melting temperature ranges on, so the fusing together of the filaments can be particularly targeted. By a more or less high temperature in the region of the component with the lower melting temperature, the type and amount of joints can be influenced, without the strength of the other Reduce component. The lower melting component serves, so to speak, as an adhesive for the connection of the higher melting component. Due to the relationship of the materials of the components good recyclability is still present.

If the filaments used have a diameter with a value of less than 40 μm, preferably between 7 and 38 μm, depending on the requirement profile of an article to be produced therefrom, they are, on the one hand, readily processable and, on the other hand, give a particularly stable and sound-absorbing product. The filaments all have the same thickness in the nonwoven fabric. Different filaments are not used, although of course other filaments may be additionally applied in particular embodiments. The choice of filament diameter used may be dependent on the required mechanical and acoustic properties of the article to be made from the nonwoven fabric.

In order to produce a particularly strong nonwoven with a low weight per unit area, it is advantageous if, in a spatial element of the intermediate layer, the number of contact points which are connected to one another is lower than in the outer layers. As a result, more stable outer layers are produced, which counteract forces acting on these outer layers, which are oriented in particular in the x-y direction. If, however, a nonwoven fabric is expected, which is particularly pressure-resistant, it will be attempted to increase the number of interconnected contact points in a spatial element of the intermediate layer, and their number may be equal to or greater than to create in the outer layers.

It is to influence the properties of the article, for example, to further increase the stability of the nonwoven fabric or to adapt the appearance of the nonwoven fabric to the required conditions of the end article advantageous if at least one of the two outer layers is covered with other materials, such as fibers, nonwovens, textiles, leather, paper or films. The compound can be done, for example, by gluing, bonding, laminating, welding, laminating or laminating. As a result, a visually appealing visible side of the nonwoven fabric can be created. It is also possible to obtain properties of the nonwoven material such as a scarf or odor absorption, haptics, water repellency or the like. Often, however, it is not necessary to prove the surface of the article with additional materials, since the surface quality of the nonwoven fabric according to the invention and the article produced therefrom is already sufficient, since the alignment of the outer layers, the entanglement of the filaments and the good bonding a very good Surface finish is achieved.

In particular, for reasons of cost-effective recycling of the nonwoven fabric, it is particularly advantageous if the nonwoven fabric and / or the material with which the nonwoven fabric is coated is made of a uniform material. The connection of the individual filament sections at the points of contact is thereby not provided by foreign materials, but advantageously by the filament material itself or by materials which are at least related to the material of the filament. Thus, in the case of a bicomponent filament, a polyester may be used as the core and a co-polyester may be used as the sheath.

If the nonwoven fabric and / or the material with which the nonwoven fabric is coated are provided with additives for improving the product properties, for example with regard to flammability, abrasion resistance, media resistance, eg with respect to oil or water or acoustics, then the article produced from the nonwoven fabric can be applied very individually. As additives, for example, dyes or flame retardants may be added which allow particular uses of the nonwoven fabric. The fire resistance of the article can be demonstrated according to FMVSS 302, for example. Advantageously, the compounds of the contact points for the further processing of the nonwoven fabric are releasable and then in the same or changed number, size, strength and / or angle of the interconnected filaments recoverable. The compounds can be numerically low in the semifinished product to ensure the basic strength of the nonwoven fabric alone. In the processed end product, the number of compounds can then be increased in order to produce a higher strength of the nonwoven fabric. The release of the compounds can be done for example by means of steam. In the course of further processing, the size of the connection point can also be changed. From one or two smaller joints, a larger joint can be created. Also, the crossing angle of two filaments can be changed during further processing by stressing the connection and fixing it in the new position.

Advantageously, the thickness of the nonwoven fabric has a value less than 40 mm, preferably between 1 and 30 mm. It thus produce a nonwoven, which can be further processed in many ways.

If the nonwoven fabric has a weight per unit area of between 50 and 2500 g / m ² , preferably between 200 and 1800 g / m ² , then it can be used particularly well in vehicle construction in which low weights are required.

In a method according to the invention for forming a nonwoven fabric having at least one, advantageously two outer layers and an intermediate layer, in which the filaments are in at least two, preferably three of the layers, the filament is deposited on a storage field. The interlayer of the nonwoven fabric is by depositing parts of the filaments in a central region of the storage field and outer layers of the nonwoven fabric by depositing other parts of the Filaments formed in respective side regions of the storage field. The filaments deposited in this way are drawn off through the central region, whereby the parts of the filaments deposited in the side regions are folded in relation to the parts of the filaments deposited in the central region, so that the parts of the filaments located in the outer region (s) lie substantially in the xy direction of the nonwoven fabric and the intermediate portions of the filaments have a more pronounced orientation in the z direction of the nonwoven fabric compared to the filaments in the outer layers. In the intermediate layer, preferably in each of the layers, a network is formed from the filaments, wherein the individual filaments touch other of the filaments and thereby form a plurality of points of contact. The filaments are joined together at many of the points of contact and thereby form the network of filaments, wherein at least the network of the intermediate layer has a pressure-stable structure at least in the z-direction. The network of the intermediate layer is formed so that it has a structure which counteracts a pressure at least in the z-direction, so that the nonwoven fabric is stabilized by a stabilization of at least one of the outer layers and rigid against buckling. As a result, the nonwoven obtains a greater intrinsic stability with respect to its deflection and its tendency to buckle than is the case with comparable nonwovens of the prior art. Comparable nonwovens are, for example, nonwovens with the same basis weight, the same thickness or the same filaments.

The nonwoven fabric is formed by peeling from the storage field, wherein the deposited in the side regions portions of the filaments are folded against the filaments deposited in the central region of the filaments. This causes the parts of the filaments located in the outer layers to be substantially parallel to one another in the z-direction and, for the most part, substantially orthogonal to the filament sections located in the intermediate layers. The farther the parts of the filaments, which are later folded, are deposited away from the central area, the longer In the x direction, the longitudinal extent of the parts of the filaments which are arranged in the outer layers.

The nonwoven fabric can be made of a uniform material and thereby ideally recycled. It is also ensured by the corresponding production that the touching filament sections connect at many points of contact. Only by this very frequent connection, whereby nodes are formed by crossing filaments and reinforcing sections by parallel abutment or structures which are reminiscent of a ladder, a very intrinsically stable web is produced.

The individual filaments may be continuous filaments or may consist of substantially continuous pieces having a length of, for example, more than 15 cm or more than one meter or a length which runs through the entire nonwoven produced. It is important in any case that the filaments are not only in one of the three layers, but from one layer at least into the adjacent, better still in all three layers rich and thus produce a certain basic stability of the nonwoven fabric. By further networking, the strength of the nonwoven fabric is finally generated. The formation of the network of each layer of the nonwoven fabric by targeted storage of the parts of the filaments in the individual layers, together with the connection of many contact points of the filaments causes a specific and predeterminable strength of the nonwoven fabric. The nonwoven fabric can thus be tailored to the particular requirement of the final product.

The nonwoven fabric thus produced can then be cut to size and fed to its intended use. In addition to cutting it is also possible that the nonwoven fabric is subjected to a further shaping and thus to the special requirements of End product, for which the nonwoven fabric according to the invention is used as a semi-finished is received.

It is particularly advantageous if the filaments are deposited in an oscillating manner on the storage field. As a result, the parts of the filaments are distributed back and forth on the side areas and the central area of the storage field. The filaments are thus fed to the storage field and thus sequentially form the supply of material for the outer layers and the intermediate layer of the later nonwoven fabric. In order to produce the flatly extended nonwoven fabric, a plurality of filaments are fed side by side in the manner of a curtain to the storage field. The area on which the filaments impinge on the storage field essentially corresponds in each case to an oval, which can overlap. As a result, a crosslinking of adjacent filaments is produced, which contributes to a further stability of the nonwoven fabric.

Advantageously, the thickness potential of the nonwoven fabric, the outer layers and the intermediate layer is determined inter alia by the width and shape of the central region and the respective side regions of the deposition field. This means that, depending on the central area and side areas, it can be determined which thickness the semifinished product and thus also the end product can receive. The storage field determines in which way the filaments strike and are deflected off and removed during removal. Through a wide central area in relation to the side areas, a nonwoven fabric will be produced, which will receive relatively thin outer layers and a wide intermediate layer. By in relation to the central area wider side areas of the storage field thicker outer layers are produced in comparison to the intermediate layer. In essence, it can be stated that the parts of the filaments impinging in the central region or in the vicinity of the central region are more likely to be fed to the intermediate layer of the nonwoven fabric and the parts of the filaments striking in the lateral regions of the deposition field tend to be folded over and orthogonal to the parts of the filaments of the intermediate layer are assigned to the outer layers.

Advantageously, the production of the nonwoven fabric is also determined by the amplitude of the oscillating filament deposition. If the storage of the filament sections swings far beyond the central region of the storage field, a thicker outer layer of the nonwoven fabric is produced. In contrast, the nonwoven fabric gets a thinner outer layer when the filament tray swings only slightly beyond the central area. The longitudinal extent of the filaments in the outer layers is also significantly determined by the amplitude. The further the filaments swing into the side area, the longer becomes the loop of the filament, which is folded into the outer layer.

The amplitude is determined inter alia by the delivery speed of the filaments and the withdrawal speed of the nonwoven fabric. The slower the nonwoven fabric is pulled off, the more and longer parts of the filament will be placed in the side area.

The filaments can be applied to the deposition field by the meltblown or spunlaying process. These application methods are known per se. In the meltblown process, the endless filaments are swirled together by a stream of air and then applied to the deposition field. The filaments can be torn into pieces. In the spunlaying process, the endless filaments are retained in their endless form and continuously fed onto the storage field. Each of these application methods produces a more or less different character of the nonwoven fabric. In each of these methods, however, a stable nonwoven fabric is produced by the subsequent bonding, that is, the fixing of contact points of the filaments, which has a highly networked and mutually supporting structure. A particularly good cross-linking of the filament sections is achieved when the filament is deposited on the storage field such that the probability of depositing a portion of the filament in the side area of the storage field is less than the probability of depositing in the central area or in its vicinity. As a result, a particularly large number of filament sections are supplied to the central region and thus to the intermediate layer of the nonwoven fabric. In the nonwoven fabric, this has the effect that, even with a greater thickness of the intermediate layer, a sufficient number of filament parts is contained, which is ensured for crosslinking and thus the support of the individual filament sections over short lengths.

In order to adapt the nonwoven fabric for further processing in particular to the requirements of the end product, it is advantageously provided that the nonwoven fabric is bonded, in particular glued, bonded, welded or laminated, following the production of the outer layers and the intermediate layer with at least one further material layer. As a result, for example, the visual appearance of the nonwoven fabric can be adapted to the respective requirements of the construction of the end product.

One way of applying the further layer is that the nonwoven is covered with other fibers, for example by the meltblown process. This is a very economical process for producing a suitable composite nonwoven fabric.

As a further layer and fibers can be applied by other methods, textile, nonwovens, leather, paper or film materials, in particular by gluing, bonding, thermally bonding or laminating applied to the visual appearance or other requirements of the final product can. The nonwoven fabric produced according to the invention essentially serves as semi-finished product for the production of end products. Accordingly, the nonwoven fabric may be deformed following the production of the outer layers and the intermediate layer. By the deformation, an additional stability of the nonwoven fabric can be obtained.

It is particularly advantageous if the deformation of the network of the nonwoven fabric is changed. Among other things, the deformation can act on the existing connections at the points of contact of the filament sections by eliminating these connections, that is, releasing them again and / or creating new connections. Thus, it is possible to give the nonwoven fabric in the new shape, in turn, an inherent stability already by the inner network structure of the outer layers and the intermediate layer. The release of the compounds can be done for example by means of steam. By changing the number of connections, the strength of the nonwoven fabric can be changed in particular for the respective intended use of the end product compared to the nonwoven fabric as a semi-finished product. Also, deformation can permanently change the network by altering existing angles of the filaments crossing each other in a connection and / or the sizes of the connections. For example, the crossing angles may be reduced to reduce the thickness of the nonwoven fabric.

To obtain the new shape of the nonwoven fabric for the end product, it may also be advantageous if, following the production of the outer layers and the intermediate layer, the density of the respective layer is changed. By compression or by expansion, for example, the intermediate layer, the characteristic and the shape of the nonwoven fabric is changed. This form can also be supported or even generated by dissolution and / or new formation of connections of the contact points. The shaping by changing the layers can be uniform over the Entire nonwoven fabric or locally but to produce different shapes of the nonwoven fabric.

The newly created nonwoven fabric is particularly well suited for use as a semi-finished product for technical components. Thus, the nonwoven material is particularly suitable for use in the insulation of objects, since the nonwoven fabric has a plurality of cavities, which provide both a heat and a sound insulation. Of course, the use of the nonwoven fabric for absorption, filtration, shaping or reinforcement, in aerospace engineering or in vehicle construction is suitable. Thus, the nonwovens, for example, as a headliner, but also as laminations of linings of interior trim parts to produce particularly good haptic properties of the panels find use. Due to the inherent stability of the nonwoven fabric according to the invention, large self-supporting surfaces can also be produced. The nonwoven fabric according to the invention is also suitable, for example, for use in construction. It can be used for the production of intermediate layers in road construction or landfill construction. It can also be suitable for reinforcing concrete components. In addition, the use of the nonwoven fabric in medical technology is conceivable. Here it can be used, for example, for stabilizing components or also for dressings or tubes. The illustration of the possible uses of the nonwoven fabric according to the invention described here is not exhaustive. This results in many other applications for this new stable nonwoven.

Further advantages of the invention are described in the following exemplary embodiments. It shows:

FIG. 1 shows a cross section through a nonwoven fabric according to the invention, Figure 2 shows a section of the nonwoven fabric with indicated

Joints

FIG. 3 a detail of a top view of the nonwoven fabric with indicated filament loops,

Figure 4 a-c various changes in the joints

Figure 5 shows the process for the preparation of the inventive

Nonwoven fabric with a schematically illustrated storage surface,

FIG. 6 shows the production according to FIG. 4 with a modified one

Storage space,

Figure 7 is a plan view of a storage surface with several

filaments

FIG. 8 shows a cross section through a nonwoven fabric according to the invention during the bonding,

FIG. 9a-c details of a nonwoven fabric according to the invention in the intermediate region,

FIG. 10a-c show further details of a nonwoven fabric in an edge region,

FIG. 11a-c details of a nonwoven fabric in a further edge region,

FIG. 12 shows details of a further nonwoven fabric according to the invention,

FIG. 13 shows details of a further nonwoven fabric according to the invention,

FIG. 14 a shows an opened form with a nonwoven fabric, FIG. 14b shows a closed mold with a molded article,

FIG. 14c shows the finished molded article,

FIG. 15 shows details of an article according to the invention,

FIG. 16 shows a vehicle with applications for the article according to the invention,

FIG. 17 shows a bending force deformation diagram,

FIG. 18 shows a compressive force deformation diagram,

FIG. 19 shows a tensile force-deformation diagram,

FIG. 20 shows a frequency absorption diagram,

FIG. 1 shows a cross section in a schematic representation through a nonwoven fabric 1. It can be seen that the nonwoven fabric 1 consists of a first outer layer 2 and a further outer layer 3, which are spaced apart by an intermediate layer 4. In the outer layer 2 and the outer layer 3 and in the intermediate layer 4, a plurality of filaments 5 are arranged, which from a substantially horizontal position in the outer layer 2 in a tendency vertical position in the intermediate layer 4 and then again in a horizontal position in the outer layer 3 move. Each of the filaments 5 of this embodiment is thus incorporated in both outer layers 2, 3 and in the intermediate layer 4. The nonwoven fabric 1 extends flat in the x- / y direction with a thickness dv in the z-direction, which is composed of the two individual thicknesses dA of the outer layers 2, 3 and the thickness dz of the intermediate layer 4. Due to the often occurring gradual transition of Filaments 5 from an outer layer 2 in the intermediate layer 5 and back to the other outer layer 3, the thickness dA or dz of the individual layers is not always accurate to determine, but it is in the nonwoven fabric 1 tend the orientation of the filaments 5 in the outer layers. 2 , 3 in x- / y-direction and in the intermediate layer 4 in the z-direction usually very well visible.

The individual filaments 5 are each crosslinked in the outer layers 2, 3 and the intermediate layer 4. Each layer 2, 3, 4 forms a network per se, and may also be called a matrix having a predetermined property with regard to its capacity to absorb force. The crosslinking arises because the individual filaments 5 meet at a multiplicity of contact points 7, to which they are connected to one another. This compound results in a stronger cohesion in the individual layers 2, 3, 4. The nonwoven fabric 1 is thus very resistant in terms of a compressive force D or a tensile force Z, which act on the surface of the nonwoven fabric 1. With a compressive force D on the surface of the nonwoven fabric 1, the free buckling length of the single filament 5 is reduced by the plurality of connected contact points 7. Each filament 5 is supported so to speak by adjacent filaments 5, so that in this way a space structure of individual filaments 5 is formed. The matrix of the intermediate layer 4 supports, as it were, the outer layers 2, 3. A similar effect occurs when a tensile force Z acts on the surface of the nonwoven fabric 1. Here, the extension of the individual filament 5, in particular in the intermediate layer 4, by the retention of adjacent filaments 5, which act on the contact points 7, increased.

The plurality of contact points 7 reinforce the nonwoven fabric 1 not only with respect to a compressive force D and a tensile force Z, but also with respect to a shear force S which tends to displace the individual sheets 2, 3, 4 against each other. Again, the networking of individual filaments 5 acts in the networks of the layers 2,3,4 to the effect that the individual Support filaments 5 in the Kraftauf tome and thus form a firmer fleece 1. The networks are present in each of the layers 2, 3, 4, so that an optimal power consumption is ensured. In addition, the individual layers 2, 3, 4 are supported by the connected contact points 7 from each other, so that a stable construction of the nonwoven fabric 1 is also formed thereby.

A special feature of the invention is that the filaments 5 project far into the outer layers 2, 3. They form, as shown schematically in Figures 1, 2 and 3, loops FS with a length I, which is usually a multiple of the thickness d _v advantageously more than 3 times, often even 20 times this thickness d _v of Nonwoven fabric 1 corresponds. The loops FS arise because the filaments 5 from the matrix of the intermediate layer 4 enter into the matrix of the outer layer 2 or 3, run essentially along the surface of the nonwoven fabric 1, describe a type of sheet within the outer layer 2 or 3 and themselves extend in the opposite direction. Approximately in the area of entry into the outer layer 2 or 3, the filament 5 finally leaves again the outer layer 2 or 3 and re-enters the matrix of the intermediate layer 4 and then in the opposite outer layer 3 or 2 to take there about the same course. These filament loops FS, in conjunction with the connected contact points 7, create a solid filament bond in the matrices of the outer layers 2, 3.

2 shows an enlarged section of the nonwoven fabric 1 is shown schematically. In this illustration, the course of the individual filaments 5 can be seen, which extend substantially in the illustration from the left in the outer layer 2 beginning to the right within the outer layer 2, then bent down the intermediate layer 4 and again substantially at right angles to the left in the outer layer 3 extend into it. The individual filaments 5 can take this course several times if they have a corresponding length. In short Filaments 5 but it is also conceivable that the filaments 5 extend only from one outer layer 2 on the intermediate layer 4 in the other outer layer 3.

In the illustration of Figure 2, the different networked structure of the individual layers 2, 3 and 4 of the nonwoven fabric 1 is shown. The individual filaments 5 form a multiplicity of filament sections 6, which extend between two contact points 7. The points of contact 7 designate the points at which filaments 5 touch and are connected to one another. The contact points 7 can be almost punctiform, but also extend flat, as indicated by the contact point T. In this way, in addition to the nodes at the contact points 7 also reinforced filament 6, which also contribute to the stability of the nonwoven fabric 1.

As can be seen from the illustration, the individual filament sections 6 are significantly shorter than, for example, the distance between the two outer layers 2 and 3. Without the formation of these bonded contact points 7, the free buckling length of a filament 5 would correspond to the thickness dz of the intermediate layer 4. This leads inevitably to a very soft product, which may also have advantages depending on the application, but is not desired for the present nonwoven fabric 1. The contact points 7 are not only in the intermediate layer 4, but also in the outer layers 2 and 3, so that the outer layers 2 and 3 are much more stable, as if the individual filaments 5 would be only without connected contact points 7 together. In this case, only frictional forces of the individual filaments 5 would ensure the cohesion, but the nonwoven fabric 1 is strengthened by a mechanical connection of the individual filaments.

The nonwoven fabric according to the invention is essentially a semi-finished product intended for further processing. During further processing is on the compounds of the contact points 7 influence. Figures 4a to 4c show different contact points 7 of filaments 5, as they can be changed starting from the semi-finished product to the final product. In FIG. 4 a, the crossing angle between two filaments 5 is changed. While in the left-hand representation of the semifinished product the crossing angle α is relatively large, the contact point 7 was put under stress in the further processing and the smaller angle α 'was produced. According to FIG. 4b, the connection of the contact point 7 after further processing has become a larger contact point T. It can be seen from FIG. 4c that at some points of contact 7 a consolidation to a contact point T can take place. Of course, it is also possible that connections are completely dissolved or newly formed.

FIG. 5 schematically shows the production of the nonwoven fabric 1 according to the invention. Accordingly, a plurality of filaments 5 fall onto a deposition field 8. The deposition field 8 consists of a central region 9 and two lateral regions 10. The filaments 5 strike in the central region 9 or the lateral regions 10 and are drawn down through the central region 9. As a result, the regions of the filaments 5 which have struck in the side regions 10 are bent back in the direction of the arrow P. This results in the loops FS, which are stored substantially parallel and relatively tight in the outer layers 2, 3. By these later-connected contact points 7, the solid nonwoven fabric 1 is formed in or behind the intermediate region 9. The filament pieces which have hit on the side portion 10, substantially form the outer layer 2 of the subsequent nonwoven fabric 1. Accordingly, by the choice of the shape and the Size of the side regions 10 and the central region 9 and the width of the filament 5 on the deposition field 8, the thickness dA of the outer layer 2 and 3 and the length I of the filament loops FS are affected. As shown in the example of FIG. 6, the side region 10 can be designed differently on both sides of the central region 9. As a result, more filament 5 is guided from the larger side region 10 into the central region 9, so that the outer layer assigned to the larger side region 10 becomes thicker and the loops FS become longer than in the outer layer of the nonwoven fabric 1 assigned to the smaller side region 10.

The supplied with the filaments 5 air can either be discharged through the storage field 8 through, if this is formed, for example, partially perforated. The air can also be sucked off the side of the storage box 8.

According to FIG. 7, a plan view of a schematically illustrated storage field 8 is sketched. Most filaments 5 are stored oscillating and usually largely randomly on the storage field 8. The result is a substantially elliptical surface on which the filaments 5 each impinge on the storage field 8. Statistically speaking, the largest amount of filament in the central region 9 occurs per unit of time. This filament is then distributed substantially uniformly on the intermediate layer 4. The incident on the side regions 10 filament pieces are incorporated essentially in the outer layers 2 and 3. The ellipses of filing the filaments 5 overlap partially, so that a networking of adjacent filaments 5 takes place with each other. This also contributes to a rigidity and strength of the nonwoven fabric 1.

The width of the central region largely determines the thickness dv of the later nonwoven fabric 1. The supplied filaments 5 are combined in the central region 9 and moved out of this downward. The nonwoven fabric 1 is then already used as a solid semi-finished product. In Figure 8, the bonding, that is, the connection or bonding of the contact points 7 is shown schematically. Before a bonding device 11, the filaments 5 are at their points of contact 7 only together. The contact points 7 are shown as white dots. The nonwoven fabric 1 passes through the bonding device 11 in the arrow direction. This can be horizontal as shown, but also vertically, immediately after the storage field 8 or spaced thereof. In the bonding device 11, the filaments are heated, whereby they partially melt at the contact points 7 and are firmly joined together with the cooling. The firmly connected contact points 7 "are here marked with a black dot.

FIGS. 9a-9c, 10a-1c and 11a-11c each show scanning electron micrographs of an article 23 according to the invention. FIG. 9a shows an intermediate layer 4 with a relatively loose filament composite. The individual filaments 5, as is clear in the photographs of FIGS. 9b and 9c, are firmly connected to one another at points of contact 7. The connection takes place, for example, by melting the individual filaments 5 together, in particular if these consist of bicomponent filaments. From the various illustrations, it can be seen that there are simple points of contact 7 at which two filaments 5 intersect. On the other hand, there are also contact points T 'at which a plurality of filaments 5 are connected to each other and thus produce a relatively thick node.

FIG. 10a shows an outer layer 2. It can be seen from this that in the outer layer 2 the individual filaments 5 are packed together much more densely. But here too, as can be seen in the images of FIGS. 10b and 10c, there are contact points 7 at which a plurality of filaments 5 are fixedly connected to one another. In particular from FIG. 9c a structure recognizable, which is reminiscent of a ladder and which gives a particularly strong bond.

Finally, in Figure 11 a, an outer layer 3 is shown. This outer layer 3 is less densely packed than the outer layer 2. But here too, as can be seen from FIGS. 11 b and 11 c, a connection of the individual filaments 5 takes place at the contact points 7.

FIGS. 12 and 13 show details of two nonwovens 1 according to the invention in comparison with article 23. It clearly shows the different orientation and the connections of the individual filaments 5 to one another in the different layers 2, 3 and 4 of the nonwoven fabric 1. The nonwovens 1 of these figures have relatively few joints. It is therefore more a semi-finished product, which is further processed by further process steps and then receives more joints as needed. The network structure can also be clearly seen in these pictures. The particular stability of the nonwoven fabric 1 is generated both by the network and by the orientation of the filaments 5. The small, bottom-mounted image of Figure 12 shows weakly bonded bonding points, as are typical in the nonwoven fabric 1 of this embodiment.

FIG. 14a shows an open mold 20 with an upper part 21 and a lower part 22 shown in outline. On the mutually facing sides of the upper part 21 and lower part 22, a respectively desired outer contour for an article 23 manufactured with the mold 20 is incorporated. In the region of the corresponding contour, the nonwoven fabric 1 is positioned as the semi-finished product to be processed. The nonwoven fabric 1 consists of a respective outer layer 2, 3 and an intermediate layer 4. It has a thickness D _v , which is sufficient for the production of the article 23. The thickness D _v can either approximately correspond to the later maximum thickness of the article 23. But it can also be thicker to the article 23 compared to the Nonwoven fabric 1 to have more compressed in the region of its thick points than the original nonwoven fabric 1. Upper part 21 and lower part 22 may be preheated in order to accelerate the subsequent deformation process in the closed mold 20 can. But it can also be the nonwoven fabric 1 outside the mold 20 brought to the appropriate temperature and then inserted into a relatively cold mold 20 for forming.

In Figure 14b, the mold 20 is shown in the closed state. Upper part 21 and lower part 22 partially contact each other. In the between the upper part 21 and lower part 22 remaining free space extending now deformed fabric 1 and forms the article 23. It is apparent from the outlined representation that the article 23 may have different thicknesses, on the one hand substantially to the thickness of the nonwoven fabric. 1 or that it can also be compressed so far that all fibers have intimate contact with each other.

In the form 20 shown in outline there is a system 24 for introducing steam into the cavity between upper part 21 and lower part 22. The hot steam dissolves or at least softens the connections of the networks in the outer layers 2 and 3 and the intermediate layer 4, so that they can be changed. At a lower temperature of the steam or a shorter exposure time less joints are dissolved or deformed than at a higher temperature of the steam or a longer exposure time. After a predetermined time, usually when the connections have consolidated, the article 23 is cooled and the compounds solidify in the new position and shape. The article 23 thereby retains the shape introduced by the mold 20. The nonwoven fabric 1 is thus largely arbitrarily shapeable. Also, the article 23 can be made to give a different sound transmission by creating more or less dense layers in the layers 2, 3 or 4. The finished article 23 according to FIG. 14 c can subsequently be removed from the mold 20 and, if appropriate, further processed. It can be provided with other attachments, can be punched or drilled or can also be covered or laminated with other materials to accept more decorative or functional properties can. In the arrangement of other materials, it is usually advantageous if the further material is placed together with the nonwoven fabric 1 in the mold 20. During the deformation of the nonwoven fabric 1, the additional material then attaches to the nonwoven fabric 1 and connects to the nonwoven fabric 1, for example by means of an adhesive introduced therebetween or by adhesive fibers.

The article 23 can be largely arbitrarily shaped in the x, y and z directions. Due to the structure of the nonwoven fabric 1 with elongated loops in the outer layers 2 and 3, however, different properties will be set in the x and y directions. In particular, the deep drawability may differ, so that the x and y direction of the nonwoven fabric 1 when inserting the nonwoven fabric 1 into the mold 20 should be considered accordingly.

FIG. 15 shows a strongly compressed article 23, on which a further material 30 is arranged on the outer sides at the top and bottom. In the nonwoven fabric 1 is further, although not as clearly as in the other embodiments, the structure with two outer layers 2, 3 and an intermediate layer 4 can be seen. The z-orientation of the filaments 5 in the intermediate layer 4 is largely eliminated. They now essentially have an xy orientation. However, the filaments 5 in the intermediate layer 4 still support the filaments 5 in the outer layers 2,3. The intermediate layer 4 has a multiplicity of connection points or bonding points, which form a compact network. In FIG. 16, a vehicle is sketched on which the manifold possible uses of the article according to the invention are indicated. The article 23 can be used with appropriate shaping and processing both in the passenger compartment and in the engine and luggage compartment. It can be used as a trunk floor or side cover to show decorative and soundproofing properties. In the passenger compartment, it can be used as a headliner or as a parcel shelf due to its static strength, but also as a floor covering, for example on the rear seat, it can be used for sound insulation due to its acoustic properties. In order to avoid reflections from the ground relative to the passenger compartment, the subfloor can also be clad with the article 23. Due to the fixed outer structure of the article 23 in the outer layers 2 and 3 and / or possible additional functional layers here, too, a sufficient strength of the article 23 against water, rockfall or wind currents is given. Similar properties will be required when cladding the wheel arches. Also they can be made with the appropriate article 23. The particularly good acoustic properties of Article 23 make it ideal for engine compartment encapsulation both in relation to the passenger compartment and to the exterior. The noise can be isolated and / or absorbed by the article 23. With the appropriate equipment of Article 23, it can even be used as an acoustic heat shield, on the one hand to shield noise and on the other hand heat to the passenger compartment.

FIG. 17 shows a bending-force-deformation diagram. The bending of various specimens was tested under the same conditions until failure, ie buckling of the specimen. Shown here is only the linear course without failure. The bending force and the deformation are normalized to 100% on a first specimen 171. This is a nonwoven fabric according to the invention with 8 mm thickness and 1000 g / m ² basis weight. Three other specimens are compared to in the Diagram shown. Sample body 172 is a nonwoven fabric of the prior art which is comparable with regard to its area of use and application. It also has a thickness of 8 mm and a basis weight of 1000 g / m ² . It can be seen from the diagram that the deflection is considerably stronger than in the case of the nonwoven fabric of the present invention. With the same bending force, the deflection at 190% is almost twice as large as in the case of the inventive nonwoven fabric 171. The same applies to the test specimens 173 and 174. Each 4 mm thick and 1000 g / m ² heavy nonwovens show that in a structure according to the invention about 220% and conventional structure about 430% of the deflection of the first specimen 171 are found. It therefore appears that the nonwoven fabric according to the invention is also much stiffer here. The bending behavior is also influenced by the tensile strength and the pressure stability of the nonwoven fabric. Both are shown in the following diagrams with the same sample bodies. The specimens were pressed at the same height under the same thermal conditions.

Figure 18 shows a compressive force deformation diagram. A sample body is pressed between two plates and the required force and the resulting deformation are measured. The illustrated curves are normalized to the course of the sample body 181 according to the invention, which has a thickness of 4 mm. By contrast, a material of a sample body 182 which is the same in terms of thickness and weight and intended for the same application, constructed in accordance with the prior art, presses about 200%. An 8 mm thick specimen 183 of the invention and a specimen 184 of the prior art show a similar behavior. Sample body 183 compresses more than 700% compared to the normalized sample body 181, and the sample body 184 of the prior art even weighs about 800%. The network of the nonwoven fabrics according to the invention makes the nonwoven fabric more pressure-stable. FIG. 19 shows a tension-deformation diagram with different test bodies that are comparable again with regard to their intended use. Sample body 191 is a nonwoven fabric according to the invention with a thickness of 4 mm and 1000 g / m ² basis weight. The percent elongation at the same tensile force is significantly lower in the case of sample body 191 than in comparable sample body 192, likewise with a thickness of 4 mm and 1000 g / m ² basis weight according to the prior art. The same can be seen in a sample body 193 according to the invention with 8 mm thickness and 1000 g / m ² basis weight in comparison to a sample body 194 with 8 mm thickness and 1000 g / m ² basis weight of the prior art. Here, too, it can be seen that in the case of the sample body 193 according to the invention the percentage elongation at the same tensile load is lower than for the sample body 194. The overall lower values for the sample bodies 193 and 194 compared to 191 and 192 result from the greater compression of the nonwoven fabric in the case of the sample bodies 193 Sample bodies 191 and 192 to 4 mm thickness with the same basis weight. Basically, the failure loads in the nonwoven fabric according to the invention are significantly higher than in the case of a nonwoven fabric of the prior art.

The frequency absorption diagram of Figure 20 discloses the good acoustic properties of an article 201 according to the invention, especially at medium and higher frequencies. In comparison, the absorption curves are shown by two prior art articles 202 and 203. Article 203 is not acoustically optimized while Article 202 is optimized in terms of its acoustic properties.

The following table compares similar articles used for the same application. Despite the same thickness and approximately the same basis weight, the two articles differ significantly in their tensile and flexural strengths. The article according to the invention has significantly better values in relative comparison than the article of the prior art.

The invention is not limited to the illustrated embodiments. Variations within the scope of the claims are possible. In particular, the storage box 8 need not be stationary, but it may also be moved. The side regions 10 may have shapes other than those illustrated. It is also possible to completely dispense with a side region 10 and to compress the filaments 5 only on one side to form an outer layer. The filaments may have a round or non-round, a solid or hollow cross-section. The bonding can be done with binders or by melting the filaments. An advantage of the invention may also be that the new product will replace articles made of glass fibers, which in themselves have a higher strength, but complicate the processing, handling or recycling of semi-finished products and articles, complicate. The required properties of the article can already be set in the nonwoven fabric or later in the manufacture of the article itself in the individual layers 2, 3, 4, in individual regions of the article 23 and / or in the entire article 23. This results in a variety of Predeterminable parameters that allow an individual production of the article. With the article high density differences can be achieved at least partially high thickness of the article. A peculiarity of the nonwoven fabric, in contrast to the prior art, is that, despite the individual layers, it is not a composite body, but, on account of the filaments which extend into the individual layers, a uniform nonwoven fabric with a different network structure is.

Claims

Patent claims

1. A molded article comprising a nonwoven fabric (1) having a plurality of filaments (5), characterized in that the filaments (5) in at least a first outer layer (2), preferably a second outer layer (3) and an intermediate layer ( 4) of the nonwoven fabric (1) are arranged so that the nonwoven fabric (1) in the intermediate layer (4), preferably in each one of the layers (2,3,4) forms a network of the filaments (5), wherein the individual filaments (5) contacting others of the filaments (5) thereby forming a plurality of contact points (7), the filaments (5) being joined together at at least many of the contact points (7), and the network of the intermediate layer (4) being a pressure-stable structure which counteracts a pressure at least in the z-direction, so that the nonwoven fabric (1) and thus the article (23) by a stabilization of at least one of the outer layers (2,3) is rigid.

2. Article according to the preceding claim, characterized in that each of the filaments (5) in the nonwoven fabric (1) in at least two, preferably three of the layers (2,3,4) is located.

3. Article according to one of the preceding claims, characterized in that the networks of the outer layers (2,3) have a tensile and pressure-stable structure at least in the x / y direction.

4. Article according to one of the preceding claims, characterized in that the networks of the individual layers (2,3,4) depending on me- chanical and / or acoustic requirements of the semifinished product or the article are formed.

5. Article according to one of the preceding claims, characterized in that the networks counteract a deformation of the nonwoven fabric (1) from the predetermined state.

6. Article according to one of the preceding claims, characterized in that the filaments (5) in the outer layers (2,3) are oriented substantially in the x and y directions of the nonwoven fabric (1).

7. Article according to one of the preceding claims, characterized in that the filaments (5) in the intermediate layer (4) compared to the filaments (5) in the outer layers (2,3) a more pronounced orientation in the z direction of the nonwoven fabric (1).

8. Article according to one of the preceding claims, characterized in that the filaments (5) in the outer layers (2,3) in the x direction at least 1, 5 times, preferably at least 3 times the thickness (dv) of the nonwoven fabric (1) extend.

9. Article according to one of the preceding claims, characterized in that the filaments (5) between two contact points (7) filament sections (6) form and the filament sections (6) a layer (2,3,4) filament sections (6) touching an adjacent layer (2, 3, 4) and thereby forming a multiplicity of further contact points (7) which connect the filament sections (6) to one another such that the individual layers (2, 3, 4) adhere firmly to one another.

10. Article according to one of the preceding claims, characterized in that the filament sections (6) mutually support.

Article according to one of the preceding claims, characterized in that filament sections (6) resist deformation of the nonwoven fabric (1) due to reinforcement by the other filament sections (6) connected to them.

Article according to one of the preceding claims, characterized in that filament sections (6) resist deflection due to reinforcement by the other filament sections (6) connected to them.

13. Article according to one of the preceding claims, characterized in that the network counteracts a local longitudinal expansion of at least one outer layer (2, 3) which would have to occur from the predetermined state during the deflection of the nonwoven fabric (1).

14. Article according to one of the preceding claims, characterized in that the network is designed such that it counteracts a tensile force (Z) and / or a shear force (S) and thus a local longitudinal extent in any direction.

15. Article according to one of the preceding claims, characterized in that in the intermediate layer and / or in at least one outer layer (2,3) the ratio length / diameter of a plurality of filament sections (6) is selected such that these filament sections (6) can also be loaded on pressure.

16. Article according to one of the preceding claims, characterized in that the networks of the individual layers (2,3,4) of the nonwoven fabric (1) mutually support.

17. Article according to one of the preceding claims, characterized in that the network of the intermediate layer (4) is formed substantially uniformly.

18. Article according to one of the preceding claims, characterized in that the nonwoven fabric (1) in the xz or yz-cross section, in particular with respect to the two outer layers (2,3), is asymmetrical, so that the respective outer layer (2 , 3) acting different tensile and compressive forces (Z ₁ D) can be recorded.

19. Article according to one of the preceding claims, characterized in that the density of the nonwoven fabric (1) in the networks of the outer layers (2,3) is higher than in the network of the intermediate layer (4).

20. Article according to one of the preceding claims, characterized in that the filaments (5) are bicomponent filaments or bicomponent filaments.

21. Article according to one of the preceding claims, characterized in that the filaments (5) are spun-bonded fibers or melt-blown fibers or filaments.

22. An article according to one of the preceding claims, characterized in that the filaments (5) of thermoplastic material combinations, for example of PET, PBT, PP, PE or PA as a structural component and CoPET, CoPBT, PBT, PP or PE as an adhesive component of Filaments (5) are produced, which have different Aufschmelzverhalten and / or melting temperature ranges.

23. Article according to one of the preceding claims, characterized in that the diameter of the filaments (5) used depending on the requirement profile of the article (23) and the manufacturing process ge is selected and have a value of less than 40 microns, preferably between 7 and 38 microns.

24. Article according to one of the preceding claims, characterized in that in a spatial element of the intermediate layer (4), the number of contact points (7) is less than in the outer layers (2,3).

25. Article according to one of the preceding claims, characterized in that the connections of the contact points (7) for the further processing of the nonwoven fabric (1) releasably and then in the same or changed number, size, strength and / or angle of the interconnected filaments (5 ) can be restored.

26. Article according to one of the preceding claims, characterized in that the nonwoven fabric (1) on at least one outer layer (2,3) coated with other materials, such as fibers, nonwovens, textiles, leather, paper or films, in particular glued, bonded, welded, laminated or laminated to affect the properties of the article (23).

27. Article according to one of the preceding claims, characterized in that the nonwoven fabric (1) and / or the material with which the nonwoven fabric (1) is occupied, consists of a uniform material or different, but mutually related Matehalen.

28. Article according to one of the preceding claims, characterized in that the nonwoven fabric (1) and / or the material with which the nonwoven fabric (1) is covered with additives for changing the product properties is provided to the article (23), for example water-repellent, oil-repellent, flame-retardant or with improved abrasiveness.

29. Article according to one of the preceding claims, characterized in that the nonwoven fabric (1) in the article (23) has areas of different characteristics such as air flow resistance, Young's modulus, thickness, density, strength and / or acoustics.

30. Article according to one of the preceding claims, characterized in that in the article (23) different areas with different density of the connections of the contact points (7) and / or thickness of the respective layers (2,3,4) are present.

31. Article according to one of the preceding claims, characterized in that the thickness of the article (23) is substantially changeable by a change in the thickness of the intermediate layer (4).

32. Article according to one of the preceding claims, characterized in that the thickness of the article (23) is between 1, 5 and 30 mm, preferably between 2 and 15 mm.

33. Article according to one of the preceding claims, characterized in that the article (23) has a basis weight between 200 and 2500 g / m ² , preferably 500-1800 g / m ² .

34. Article according to one of the preceding claims, characterized in that the density of the connections of the contact points (7) in the intermediate layer (4) in the nonwoven fabric (1) of the starting material is less than in the outer layers (2,3) and for the article (23) of the end product (23) can be increased at least in a single area to the density of the outer layers (2,3).

35. Article according to one of the preceding claims, characterized in that the article (23) mechanical, in particular a molding Stability and / or acoustic properties, as required in particular for automotive applications.

36. Article according to one of the preceding claims, characterized in that the article (23) is to be used as a headliner, engine encapsulation, heat shield, underbody, wheel arch, engine compartment, interior or trunk lining.

37. Article according to one of the preceding claims, characterized in that the article (23) has better acoustic and / or mechanical properties compared to articles of the prior art, for example, with the same dimensions, such as the thickness and / or the same basis weight.

38. Article according to one of the preceding claims, characterized in that the acoustic properties on the thickness, density, modulus of elasticity, Poisson's number, porosity and / or air flow resistance of the filaments (5), the nonwoven fabric (1) and / or networks the layers (2,3,4) and / or additional applied materials and their single or multiple arrangement are determined.

39. Article according to one of the preceding claims, characterized in that the article (23) has a predetermined range of values of properties, which is detectable depending on the application with one or more of predetermined, in particular standardized test methods.

40. Article according to one of the preceding claims, characterized in that the individual layers (2,3,4) have different insulation, absorption and / or reflection properties.

41. Article according to one of the preceding claims, characterized in that the insulation, absorption and / or reflection behavior of the individual layers (2,3,4), starting from the nonwoven fabric used (1) and according to the requirements of the article (23 ) in the manufacture of the article (23) by changing the networks of the layers (2,3,4) can be influenced.

42. Article according to one of the preceding claims, characterized in that the mechanical behavior of the article by the physical properties of the filaments (5) and / or the networks of the layers (2,3,4), in particular by modulus, area moment of inertia , Compressive strength, tensile strength, flexural strength, impact resistance is determined.

43. Article according to one of the preceding claims, characterized in that the article (23) through the networks of the layers (2,3,4) an inherent stability against sagging even at higher temperatures, for example at temperatures between 80 ⁰ C and 100 ⁰ C. having.

44. Article according to one of the preceding claims, characterized in that the article (23) has a higher thermoformability compared to articles of the prior art, for example, with the same thickness and / or the same basis weight.

45. Article according to one of the preceding claims, characterized in that in the article (23) areas, in particular beads or ribs as stiffening areas or eyes are arranged as attachment areas.

46. Article according to one of the preceding claims, characterized in that at least individual areas of the article (23) stronger are compressed as other areas, especially as areas with higher acoustic requirements.

47. Article according to one of the preceding claims, characterized in that in strongly compressed areas of the article (23) the filaments (5) in the intermediate layer (4) similar to the filaments (5) in the outer layers (2,3) a pronounced orientation in the xy direction of the nonwoven fabric (1).

48. A method for producing a shaped article (23) from a nonwoven fabric (1) with a plurality of filaments (5), wherein the nonwoven fabric (1) is inserted as a semi-finished product in a mold (20), the mold (20) closed and the nonwoven fabric (1) is subjected to a predetermined deformation force or deformation pressure at a predetermined temperature and then the mold (20) is opened to remove the molded article (23), characterized in that the filaments (5) of the nonwoven fabric (1 ) in at least a first

Outer layer (2), preferably a second outer layer (3) and a

Interlayer (4) of the nonwoven fabric (1) are arranged such that the nonwoven fabric (1) in the intermediate layer (4), preferably in each one of the layers (2,3,4) forms a network of the filaments (5), wherein the individual filaments (5) touch others of the filaments (5) and thereby form a plurality of contact points (7), that the filaments (5) are connected to each other at at least many of the contact points (7), and that the network of the intermediate layer (4) has a pressure-stable structure, which counteracts a pressure at least in the z-direction, so that the nonwoven fabric (1) by a stabilization of at least one of the outer layers (2,3) is rigid, and that the temperature, the deformation pressure or the deformation force and / or or the deformation time can be chosen so that by their Influence on the contact points (7) compounds are reformed and the nonwoven fabric (1) is fixed in the predetermined by the mold (20) shape.

49. Method according to the preceding claim, characterized in that a nonwoven fabric (1) with bicomponent filaments or bicomponent filaments, in particular of thermoplastic material combinations, for example of PET, PBT, PP, PE or PA as a structural component and CoPET, CoPBT, PBT, PP or PE is used as an adhesive component of the filaments (5).

50. The method according to any one of the preceding claims, characterized in that the compounds of the contact points (7) by the influence of the temperature of the deformation pressure or the deformation force and / or the deformation time dissolved and then in the same or changed number, size, strength and / or angles of the interconnected filaments (5) are restored.

51. The method according to any one of the preceding claims, characterized in that the temperature and / or the pressure less than 60 s on the nonwoven fabric (1) acts.

52. The method according to any one of the preceding claims, characterized in that at least one of the polymers of the filament (5) is heated to a temperature in the range of its melting temperature.

A method according to any one of the preceding claims, characterized in that hot steam is introduced into the mold (20) after it has been closed and discharged again before it is opened.

54. The method according to any one of the preceding claims, characterized in that the mold (20) is sealed gas-tight.

55. The method according to any one of the preceding claims, characterized in that the steam in the mold (20) is held at least temporarily during the forming process.

56. The method according to any one of the preceding claims, characterized in that the mold (20) is opened immediately after the discharge of the steam from the mold (20).

57. Method according to one of the preceding claims, characterized in that the article (23) is removed from the mold (20) immediately after opening the mold (20).

58. The method according to any one of the preceding claims, characterized in that in the mold (20) in particular the network of the intermediate layer (4) is compressed.

59. The method according to any one of the preceding claims, characterized in that the mold (20) is preheated before placing the nonwoven fabric (1) in the mold (20).

60. Nonwoven fabric of a plurality of filaments (5) having at least a first outer layer (2), preferably a second outer layer (3) and an intermediate layer (4), wherein each of the filaments (5) in at least two, preferably three of the layers (2,3,4) and the nonwoven fabric (1) has a planar extent in the x and y direction and a thickness (dv) in the z direction, characterized in that the nonwoven fabric (1) in the intermediate layer (4 ), preferably in each one of the layers (2, 3, 4) forms a network of the filaments (5), wherein the individual filaments (5) touch others of the filaments (5) and thereby produce a large number of (7) that the filaments (5) are connected to each other at at least many of the contact points (7), and that the network of the intermediate layer (4) has a pressure-stable structure, which counteracts a pressure at least in the z-direction, so that the nonwoven fabric (1) is resistant to bending by stabilizing at least one of the outer layers (2, 3).

61. Nonwoven fabric according to the preceding claim, characterized in that the nonwoven fabric (1) is a semi-finished, which can be processed further to form an end product.

62. Nonwoven fabric according to one of the preceding claims, characterized in that the networks of the outer layers (2,3) have a tensile and pressure stable structure at least in the x / y direction.

63. Nonwoven fabric according to one of the preceding claims, characterized in that the networks of the individual layers (2,3,4) are formed depending on the mechanical and / or acoustic requirements of the semifinished product or the final product.

64. Nonwoven fabric according to one of the preceding claims, characterized in that the networks counteract a deformation of the nonwoven fabric (1) from the predetermined state.

65. Nonwoven fabric according to one of the preceding claims, characterized in that the nonwoven fabric (1) is flat.

66. Nonwoven fabric according to one of the preceding claims, characterized in that the filaments (5) in the outer layers (2,3) are oriented substantially in the x and y direction of the nonwoven fabric (1).

67. Nonwoven fabric according to one of the preceding claims, characterized in that the filaments (5) in the intermediate layer (4) compared to the filaments (5) in the outer layers (2,3) a more pronounced orientation in the z direction of the nonwoven fabric (1).

68. Nonwoven fabric according to one of the preceding claims, characterized in that the filaments (5) in the outer layers (2,3) in the x direction at least 1, 5 times, preferably at least 3 times the thickness (dv) of the nonwoven fabric (1) extend.

69. Nonwoven fabric according to one of the preceding claims, characterized in that the filaments (5) between two contact points (7) form filament sections (6) and the filament sections (6) one layer (2,3,4) filament sections (6) of an adjacent Touch layer (2,3,4) and thereby form a plurality of other contact points (7), which connect the filament sections (6) together such that the individual layers (2,3,4) adhere firmly to each other.

70. Nonwoven fabric according to one of the preceding claims, characterized in that the filament sections (6) mutually support

71. Nonwoven fabric according to one of the preceding claims, characterized in that resist filament sections (6) deformation of the nonwoven fabric (1) due to the reinforcement by the associated with them other filament sections (6).

Nonwoven fabric according to one of the preceding claims, characterized in that filament sections (6) resist bending due to the reinforcement by the other filament sections (6) connected to them.

73. Nonwoven fabric according to one of the preceding claims, characterized in that the network of a local longitudinal extent of at least one outer layer (2,3), which would occur in the deflection of the nonwoven fabric (1) from the predetermined state, counteracts.

74. Nonwoven fabric according to one of the preceding claims, characterized in that the network is designed such that it counteracts a tensile force (Z) and / or a shearing force (S) and thus a local longitudinal extent in any direction.

75. Nonwoven fabric according to one of the preceding claims, characterized in that in the intermediate layer and / or in at least one outer layer (2,3) the ratio length / diameter of a plurality of the filament sections (6) is selected such that these filament sections (6) can also be loaded on pressure.

76. Nonwoven fabric according to one of the preceding claims, characterized in that the networks of the individual layers (2,3,4) of the nonwoven fabric (1) mutually support.

77. Nonwoven fabric according to one of the preceding claims, characterized in that the network of the intermediate layer (4) is formed substantially uniformly.

78. Nonwoven fabric according to one of the preceding claims, characterized in that the nonwoven fabric (1) in cross section, in particular with respect to the two outer layers (2,3), is asymmetrical, so that on the respective outer layer (2,3) acting different train - And compressive forces (Z ₁ D) can be recorded.

79. Nonwoven fabric according to one of the preceding claims, characterized in that the density of the nonwoven fabric (1) in the networks of the outer layers (2,3) is higher than in the network of the intermediate layer (4).

80. Nonwoven fabric according to one of the preceding claims, characterized in that the filaments (5) are bicomponent filaments or bicomponent filaments.

81. Nonwoven fabric according to one of the preceding claims, characterized in that the filaments (5) are spunbonded fibers or meltblown fibers or filaments.

82. Nonwoven fabric according to one of the preceding claims, characterized in that the filaments (5) of thermoplastic material combinations, for example of PET, PBT, PP, PE or PA as a structural component and CoPET, CoPBT, PBT, PP or PE as an adhesive component of Filaments (5) are produced, which have different Aufschmelzverhalten and / or melting temperature ranges.

83. Nonwoven fabric according to one of the preceding claims, characterized in that the diameter of the filaments used (5) depending on the requirement profile of an article to be produced therefrom (23) is selected and have a value of less than 40 microns, preferably between 7 and 38 microns.

84. Nonwoven fabric according to one of the preceding claims, characterized in that in a spatial element of the intermediate layer (4), the number of contact points (7) is less than in the outer layers (2,3).

85. Nonwoven fabric according to one of the preceding claims, characterized in that the nonwoven fabric (1) on at least one outer layer (2,3) is coated with other materials, such as fibers, nonwovens, textiles, leather, paper or films, in particular glued, bonded, welded, laminated or laminated to affect the properties of the nonwoven fabric (1).

86. Nonwoven fabric according to one of the preceding claims, characterized in that the nonwoven fabric (1) and / or the material with which the nonwoven fabric is coated, consists of a uniform material or different, but mutually related materials.

87. Nonwoven fabric according to one of the preceding claims, characterized in that the nonwoven fabric (1) and / or the material with which the nonwoven fabric (1) is coated, is provided with additives for changing the product properties.

88. Nonwoven fabric according to one of the preceding claims, characterized in that the connections of the contact points (7) for the further processing of the nonwoven fabric (1) are releasably and then in the same or changed number, size and / or angle of the interconnected filaments can be restored.

89. Nonwoven fabric according to one of the preceding claims, characterized in that the thickness of the nonwoven fabric (1) is less than 40 mm, preferably between 1 and 30 mm.

90. Nonwoven fabric according to one of the preceding claims, characterized in that the nonwoven fabric (1) has a basis weight between 50 and 2500 g / m ² , preferably between 200 and 1800 g / m ² .

91. A method for forming a nonwoven fabric (1) according to one of the preceding claims, characterized in that the filament (5) is deposited on a storage field (8), an intermediate layer (4) of the nonwoven fabric (1) by depositing parts of the filaments (5) in a central region (9) of the storage field (8) and at least one outer layer (2,3) of the nonwoven fabric (1) by depositing further parts of the filaments (5) in at least a side region (10) of the deposition field (8) are formed, and the filaments (5) thus deposited are withdrawn through the central region (9), the parts of the filaments (5) deposited in the side regions (10) being opposite those in the central region (FIG. 9) deposited portions of the filaments (5) are folded, so that in the outer layer (s) (2,3) located parts of the filaments (6) substantially in the xy direction of the nonwoven fabric (1) and in the intermediate layer (4) parts of the filaments (6) compared to the filaments (5) in the outer layers (2,3) have a more pronounced orientation in the z direction of the nonwoven fabric (1) and in the intermediate layer (4), preferably in each of the layers (2, 3, 4) has a network of filaments (5) with the individual filaments (5) contacting others of the filaments (5) forming a plurality of contact points (7), the filaments (5) being joined together at many of the points of contact (7) and thereby the network of filaments (5) is formed, and that at least the network of the intermediate layer (4) is formed so that it has a pressure-stable structure, which counteracts a pressure at least in the z-direction, so that the nonwoven fabric by stabilizing at least one of the outer layers (2 , 3) becomes rigid.

92. Method according to the preceding claim, characterized in that the filaments (5) are placed in an oscillating manner on the depositing panel (8).

93. The method according to any one of the preceding claims, characterized in that the thickness potential of the nonwoven fabric (1), the outer layers (2,3) and the intermediate layer (4) inter alia by the width and Shape of the central region (9) and the respective side regions (10) of the storage field (8) is determined.

94. Method according to one of the preceding claims, characterized in that the thickness potential of the outer layers (2, 3) and the intermediate layer (4) is determined inter alia by the amplitude of the oscillating filing of the filaments (5).

95. The method according to any one of the preceding claims, characterized in that the amplitude is determined inter alia by the delivery speed of the filaments (5) and the withdrawal speed of the nonwoven fabric (1).

96. Method according to one of the preceding claims, characterized in that the filaments (5) are applied to the depositing panel (8) by the meltblown or spunlaying method.

97. Method according to one of the preceding claims, characterized in that the filing of the filament (5) on the deposition field (8) is such that the probability of depositing a part of the filament (5) in the side region (10) of the deposition field (8 ) is smaller than the probability of depositing in the central area (9) or in its vicinity.

98. The method according to any one of the preceding claims, characterized in that the nonwoven fabric (1) is bonded after the production of the outer layers (2,3) and the intermediate layer (4) for connecting the contact points (7).

99. The method according to any one of the preceding claims, characterized in that the nonwoven fabric (1) following the production of the outer layers (2,3) and the intermediate layer (4) with at least one further connected material layer, in particular glued, bonded or laminated.

100. The method according to any one of the preceding claims, characterized in that the further material layer is applied or glued by the meltblown process.

101. A method according to any one of the preceding claims, characterized in that as a further material layer fibers, nonwovens, textile, leather, paper or foil material, in particular by gluing, bonding, thermally bonding or laminating is applied.

102. The method according to any one of the preceding claims, characterized in that the nonwoven fabric (1) is deformed following the production of the outer layers (2,3) and the intermediate layer (4).

103. The method according to any one of the preceding claims, characterized in that the deformation of the network is changed by existing connections at points of contact (7) are repealed and / or new connections are created.

104. Method according to one of the preceding claims, characterized in that the deformation is used to modify the network by changing existing angles of the filaments (5) crossing each other in a connection and / or sizes of the connections.

105. The method according to any one of the preceding claims, characterized in that the nonwoven fabric (1) is changed in its density following the production of the outer layers (2,3) and the intermediate layer (4).

, Use of a nonwoven fabric (1) according to one of the preceding claims as semifinished product for technical components, in particular for insulation, absorption, filtration, shaping or reinforcement, in aerospace engineering, in vehicle construction, construction or medical technology.