Processes for the production of bulk nonwovens

Abstract

Method for producing a nonwoven fabric comprising a bulk-providing material, namely fiber balls and optionally down and / or fine feathers, wherein the nonwoven fabric has a maximum tensile strength, measured according to DIN EN 29 073 at a basis weight of 50 g / m², in at least one direction of at least 0.3 N / 5 cm, in particular of 0.3 N / 5 cm to 100 N / 5 cm, wherein a nonwoven raw material comprising the bulk-providing material, namely fiber balls and optionally down and / or fine feathers, is opened and distributed in a nonwoven forming unit, and is subsequently laid down on a lay-up belt and compacted.

Description

[0001] The invention relates to a method for producing a nonwoven fabric comprising a bulky material, in particular fiber balls, down and / or fine feathers.

[0002] Filling materials for textile applications are widely known. For example, fine feathers, down, and animal hair, such as wool, have long been used to fill blankets and garments. Down fillings are very comfortable to use because they combine excellent thermal insulation with low weight. However, a disadvantage of these materials is their low cohesion.

[0003] An alternative to these filling materials is fiber balls. Fiber balls contain more or less spherically intertwined fibers, which are usually roughly spherical in shape. For example, EP 0 203 469 A1 describes fiber balls that can be used as filling or cushioning material. These fiber balls consist of spirally crimped, intertwined polyester fibers with a length of approximately 10 to 60 mm and a diameter between 1 and 15 mm. The fiber balls are elastic and thermally insulating. A disadvantage of the described fiber balls is that, like down, feather hair, or similar materials, they have only low cohesion. Consequently, such fiber balls are poorly suited as filling material for textiles in which the fiber balls are intended to lie loosely, as they can shift due to their low adhesion.To prevent slippage in the textile material, these are often quilted.

[0004] Another alternative to using down and animal hair is the use of fiber fleeces or nonwovens as filling material. Nonwovens are structures made of fibers of limited length (staple fibers), filaments (continuous fibers), or cut yarns of any kind and origin, which have been joined together in some way to form a fleece (a fibrous nap) and bonded to each other in some way.

[0005] A disadvantage of conventional nonwoven fabrics is that they have less fluffiness than voluminous filling materials like down. Furthermore, the thickness of typical nonwoven fabrics decreases over time with use.

[0006] The invention is based on the objective of providing a nonwoven fabric that combines good thermal insulation with high softness, high bulkiness, high compressive elasticity, low weight, and good conformity to the object being covered. At the same time, the nonwoven fabric should possess sufficient stability to be handled, for example, as roll material. In particular, the nonwoven fabric should be slicable and rollable. Furthermore, a method for producing this nonwoven fabric is to be provided, as well as its use as a filling material for textile materials such as blankets, garments, and / or upholstered furniture.

[0007] This problem is solved by a method for producing a nonwoven fabric with the features of claim 1. Further preferred embodiments of the method are included in the dependent claims.

[0008] The nonwoven fabric comprises a volume-giving material, namely fiber balls and, if applicable, down and / or fine feathers, wherein the nonwoven fabric has a maximum tensile strength, measured according to DIN EN 29 073-3, at a basis weight of 50 g / m², in at least one direction of at least 0.3 N / 5 cm, in particular of 0.3 N / 5 cm to 100 N / 5 cm.

[0009] According to the invention, the term "volume-providing material" is understood in the conventional sense. In particular, a volume-providing material is understood to be a material with an average density of 0.01 g / L to 500 g / L, preferably of 1 g / L to 300 g / L, and more specifically of 1.5 g / L to 200 g / L. According to the invention, fiber balls are used as the volume-providing material. However, other volume-providing materials, such as down, fine feathers, aerogels, and / or foam components, can also be used.

[0010] Unlike conventional products containing bulk-enhancing materials, this nonwoven fabric is characterized by its high tensile strength. For example, its tensile strength can be adjusted to allow for easy production, processing, and application of the nonwoven fabric in rolls. It can be cut and rolled up, and can also be washed without any loss of functionality.

[0011] Furthermore, the nonwoven fabric is characterized by high softness, high bulkiness, high compressive elasticity, good resilience, low weight, high insulation capacity and good adaptation to the body to be wrapped.

[0012] Surprisingly, it was discovered that a nonwoven fabric can be obtained by producing a bulk-forming nonwoven raw material, in particular comprising fiber balls, down, fine feathers, and / or foam particles, using a carding process. It was unexpectedly found that carding such a raw material, especially when using a carding machine comprising at least one pair of spiked rollers, allows for efficient opening, mixing, and alignment of this material—without destroying it. This was surprising because, for example, fiber balls, down, and / or fine feathers used as raw materials are extremely delicate, so it was assumed that they would be destroyed during carding, which would compromise the stability and function of the final product.

[0013] However, it was found that carding allows for a very even distribution of the raw material on the lay-up belt, resulting in a very homogeneous nonwoven fabric in which the bulking material is evenly distributed. This homogeneous distribution of the bulking material is particularly advantageous with regard to the thermal insulation and softness of the nonwoven fabric.

[0014] As already explained above, the nonwoven fabric is characterized by surprisingly well-adjustable stability. For many applications, it has proven advantageous if the nonwoven fabric has a maximum tensile strength, measured according to DIN EN 29 073-3, at a basis weight of 50 g / m², in at least one direction of at least 0.3 N / 5 cm, and in particular from 0.3 N / 5 cm to 100 N / 5 cm. Furthermore, the nonwoven fabric advantageously exhibits high resilience. Thus, the nonwoven fabric preferably has a recovery of more than 50, 60, 70, 80 and / or more than 90%, whereby the recovery is measured as follows: 1.) Six samples are stacked on top of each other (10x10cm) 2.) The height is measured with a measuring stick. 3.) The samples are weighted down with an iron plate (1300g) 4.) After one minute of exertion, the height is measured with a measuring stick. 5.) The weight is removed. 6.) After 10 seconds, the height of the samples is measured with a measuring stick. 7.) After one minute, the height of the samples is measured with a measuring stick. 8.) The repetition is calculated by relating the values ​​from points 7 and 2.

[0015] Due to its high stability, the nonwoven fabric, for example as sheet material, can easily be rolled up and further processed.

[0016] Furthermore, the nonwoven fabric is characterized by excellent thermal insulation combined with high softness, large bulkiness, pressure elasticity, low weight and very good adaptation to the body to be wrapped.

[0017] When fiber balls are used as the bulk-providing raw material for nonwoven fabrics, their structure and shape can vary depending on the materials used and the desired properties of the nonwoven. In particular, the term "fiber balls" should be understood to encompass both spherical and near-spherical shapes, for example, irregular and / or deformed, such as flattened, spherical shapes. It has been found that spherical and near-spherical shapes exhibit particularly good properties with regard to fluffiness and thermal insulation.

[0018] Furthermore, the fibers in the aggregates can be arranged essentially within a spherical shell, while relatively few fibers are located in the center of the fiber spheres. However, it is also conceivable that, for example, there is a uniform distribution of fibers within the fiber spheres and / or a fiber gradient.

[0019] It is also conceivable that the fiber balls contained in the nonwoven fabric are spherically wound and / or downy fibers. To ensure good cohesion of the aggregate, it is advantageous if the fibers are crimped. The fibers can be disordered or exhibit a certain degree of order.

[0020] According to one embodiment of the invention, the fibers inside the individual fiber balls are arranged randomly, while those in an outer layer of the fiber balls are arranged spherically. In this embodiment, the outer layer is comparatively small relative to the diameter of the fiber balls. This further increases the softness of the fiber balls.

[0021] The type of fibers present in the fiber balls is generally uncritical, provided they are suitable for forming fiber balls, for example, through a suitable surface structure and fiber length. Preferably, the fibers of the fiber balls are selected from the group consisting of staple fibers, threads, and / or yarns. Here, staple fibers, in contrast to filaments which have a theoretically unlimited length, are understood to be fibers with a limited length, preferably from 20 mm to 200 mm. The threads and / or yarns also preferably have a limited length, in particular from 20 mm to 200 mm. The fibers can be in the form of monocomponent filaments and / or composite filaments. The fiber titer can also vary. Preferably, the average fiber titer is in the range of 0.1 to 10 dtex, more preferably from 0.5 to 7 dtex.

[0022] In principle, the fiber balls can consist of a wide variety of fibers. These can include natural fibers, such as wool fibers, and / or synthetic fibers, such as fibers made of polyacrylic, polyacrylonitrile, pre-oxidized PAN, PPS, carbon, glass, polyvinyl alcohol, viscose, cellulose, cotton, polyaramides, polyamide-imide, polyamides, in particular polyamide 6 and polyamide 6.6, PULP, preferably polyolefins, and most preferably polyesters, in particular polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate, and / or mixtures thereof. According to a preferred embodiment, fiber balls made of wool fibers are used. This allows for the production of particularly dimensionally stable and well-insulating nonwovens.According to another preferred embodiment, polyester fiber balls are used to achieve particularly good compatibility with the usual other components within the nonwoven fabric or in a nonwoven composite.

[0023] The proportion of fiber balls in the nonwoven fabric is preferably at least 20 wt.%, more preferably 25 to 100 wt.%, in particular 30 to 90 wt.%, in each case based on the total weight of the nonwoven fabric.

[0024] If, according to the invention, down and / or fine feathers are used as a volume-giving material, their proportion in the nonwoven fabric is, for example, 0 to 90 wt.%, preferably 20 to 70% or at least 50 wt.%. The term down and / or fine feathers is understood in the conventional sense according to the invention. In particular, down and / or fine feathers are understood to mean feathers with a short quill and very soft and long, radially arranged barbs, essentially without barbs.

[0025] According to a preferred embodiment of the invention, the nonwoven fabric contains a thermally sensitive material, which is used, for example, in fiber or powder form during nonwoven fabric production. The use of binding fibers is preferred according to the invention. These can be components of the fiber balls or be present as further fiber components in the fiber pile or in the manufactured nonwoven fabric. The fibers commonly used for this purpose can be employed as binding fibers. Binding fibers can be uniform fibers or multi-component fibers. Particularly suitable binding fibers according to the invention are fibers from the following groups: • Fibers with a melting point below that of the bulking material to be bonded, preferably below 250°C, particularly between 70 and 230°C, and most preferably between 125 and 200°C. Suitable fibers are, in particular, thermoplastic polyesters and / or copolyesters, especially PBT, polyolefins, especially polypropylene, polyamides, polyvinyl alcohol, or also copolymers and their copolymers and mixtures. • Fibers that stick together, such as unstretched polyester fibers.

[0026] Particularly suitable binding fibers according to the invention are multi-component fibers, preferably bi-component fibers, especially core / sheath fibers. Core / sheath fibers contain at least two fiber materials with different softening and / or melting temperatures. Preferably, core / sheath fibers consist of these two fiber materials. The component with the lower softening and / or melting temperature is located on the fiber surface (sheath), and the component with the higher softening and / or melting temperature is found in the core.

[0027] In core / sheath fibers, the binding function can be exerted by the materials arranged on the surface of the fibers. A wide variety of materials can be used for the sheath. According to the invention, preferred sheath materials are PBT, PA, copolyamides, or copolyesters. Similarly, a wide variety of materials can be used for the core. According to the invention, preferred core materials are PET, PEN, PO, PPS, or aromatic PA and PES.

[0028] The advantage of having binding fibers is that the volume-giving material in the nonwoven fabric is held together by the binding fibers, so that a textile cover filled with the nonwoven fabric can be used without the volume-giving material shifting significantly and without cold bridges being formed due to the lack of filling material.

[0029] The binding fibers can, for example, be contained within the fiber balls. Alternatively or additionally, they can be present as a separate fiber component in the nonwoven fabric. Preferably, the binding fibers have a length of 0.5 mm to 100 mm, more preferably 1 mm to 75 mm, and / or a density of 0.5 to 10 dtex.

[0030] The proportion of binding fibers in the nonwoven fabric is adjusted depending on the type and quantity of the other components of the nonwoven and the desired stability of the fabric. If the proportion of binding fibers is too low, the stability of the nonwoven is reduced. If the proportion of binding fibers is too high, the nonwoven becomes too stiff overall, at the expense of its softness. Practical trials have shown that a good compromise between stability and softness is achieved when the proportion of binding fibers is in the range of 5 to 50 wt.%, preferably 7 to 40 wt.%, and particularly preferably 10 to 35 wt.%. This results in a nonwoven fabric that is stable enough to be rolled and / or folded. This facilitates handling and further processing of the nonwoven.

[0031] Furthermore, such a nonwoven fabric is washable. For example, it is stable enough to withstand three household washes at 40 °C without disintegration.

[0032] The binding fibers can be bonded to each other and / or to the other components of the nonwoven fabric by thermal fusion. Hot calendering with heated, smooth or engraved rollers, by drawing through a hot-air tunnel oven, a hot-air double-belt oven, and / or by drawing onto a drum through which hot air flows, has proven particularly suitable. The advantage of using a double-belt hot-air oven is that it allows for particularly effective activation of the binding fibers while simultaneously smoothing the surface and maintaining the fabric's volume.

[0033] Alternatively, the nonwoven fabric can also be strengthened by subjecting the possibly pre-strengthened fiber pile to fluid jets, preferably water jets, at least once on each side.

[0034] According to a further embodiment of the invention, the nonwoven fabric contains additional fibers that are not in the form of fiber balls and modify the properties of the nonwoven fabric in a desired manner. Since these fibers are not in the form of fiber balls, they can have a wide variety of surface textures and, in particular, can also be smooth fibers. As already mentioned above, bonding fibers can be used as additional fibers. However, the use of non-bonding fibers is also conceivable. For example, silk fibers can be used as additional fibers to give the nonwoven fabric a special sheen. The use of polyacrylic, polyacrylonitrile, pre-oxidized PAN, PPS, carbon, glass, polyaramids, polymanimide, melamine resin, phenolic resin, polyvinyl alcohol, and polyamides, in particular polyamide 6, is also conceivable.6, Polyolefins viscose, cellulose, and preferably polyesters, in particular polyethylene terephthalate polyethylene naphthalate and polybutylene terephthalate, and / or mixtures thereof.

[0035] Advantageously, the proportion of additional fibers in the nonwoven fabric is 5 to 80 wt.%, particularly 20 to 70 wt.%. Preferably, the additional fibers have a length of 1 to 200 mm, more preferably 5 to 100 mm, and / or a density of 0.5 to 20 dtex.

[0036] According to a further preferred embodiment of the invention, the nonwoven fabric contains a phase change material. Phase change materials (PCMs) are materials whose latent heat of fusion, heat of solution, or heat of absorption is significantly greater than the heat they can store due to their normal specific heat capacity (without the phase change effect). The phase change material can be present in particle and / or fibrous form within the material composite and can be connected to the other components of the nonwoven fabric, for example, via the binding fibers. The presence of the phase change material can enhance the insulating effect of the nonwoven fabric.

[0037] The polymers used to manufacture the fibers of the nonwoven fabric may contain at least one additive selected from the group consisting of color pigments, antistatic agents, antimicrobials such as copper, silver, gold, or hydrophilizing or hydrophobizing additives in an amount of 150 ppm to 10 wt.%. The use of these additives in the polymers allows for adaptation to customer-specific requirements.

[0038] The nonwoven fabric can also contain additional layers. These additional layers could be designed as reinforcing layers, for example in the form of a scrim, and / or they could comprise reinforcing filaments, nonwovens, woven fabrics, knitted fabrics, and / or laid fabrics. Preferred materials for forming these additional layers are plastics, for example polyester, and / or metals. Advantageously, these additional layers can be arranged on the surface of the nonwoven fabric.

[0039] The thickness of the nonwoven fabric is preferably selected depending on the desired insulation effect and the materials used. Good results are typically achieved with thicknesses measured according to test standard EN 29073-T2, in the range of 2 mm to 100 mm.

[0040] The basis weight of the nonwoven fabric is adjusted depending on the intended application. For many applications, basis weights measured according to DIN EN 29073 in the range of 15 to 1500 g / m², preferably from 20 to 1200 g / m², and especially from 30 to 1000 g / m², have proven suitable.

[0041] Furthermore, after consolidation, the nonwoven fabric can be subjected to chemical bonding or finishing, such as anti-pilling treatment, hydrophilization or hydrophobization, antistatic treatment, treatment to improve fire resistance and / or to change tactile properties or gloss, mechanical treatment such as roughening, sanforizing, sanding or tumble drying, and / or treatment to change appearance such as dyeing or printing.

[0042] The nonwoven fabric is ideally suited for the production of a wide variety of textile products, especially those that are intended to be thermophysiologically comfortable and lightweight. Therefore, a further aspect of the present disclosure includes the use of the nonwoven fabric as a molding material, for example, as padding and / or filling material in clothing, seating and reclining furniture, blankets, mattresses, as a filter and / or absorbent mat, as a spacer, foam substitute, wound dressing, and fire-retardant material.

[0043] The invention relates to the production of a nonwoven fabric as described above using a carding process.

[0044] It was found that the nonwoven fabric can be produced particularly efficiently when the opening and distribution of the nonwoven raw material is carried out using spiked rollers and / or spiked belts. This allows for a very uniform deposition of the nonwoven raw material, for example, on a lay-up belt, and results in a very homogeneous nonwoven fabric in which the bulk-providing fiber material is very homogeneously and evenly distributed. This was surprising, as it was assumed that, for example, the delicate fiber balls or down would be destroyed when treated with spiked rollers and / or spiked belts.

[0045] Practical trials have shown that the process according to the invention yields particularly good results when it includes one or more of the following steps. The raw material, comprising bulking materials and optionally other components, is fed as uniformly as possible into at least one carding machine comprising at least one pair of spiked rollers, in which the fiber raw materials are opened and mixed together. Subsequently, the fibers can be laid down for nonwoven formation in a conventional manner, for example on a wire belt, a drum, and / or a conveyor belt. The resulting nonwoven can then be consolidated in a conventional manner. According to the invention, thermal consolidation, for example with a belt furnace, has proven particularly suitable, since this avoids undesirable compaction of the nonwoven fabric, such as would occur with water jet consolidation.The use of a double-belt hot air oven has proven particularly suitable. The advantage of using such a hot air oven is that it allows for particularly effective activation of the binding fibers while simultaneously smoothing the surface and preserving volume.

[0046] According to a preferred embodiment of the invention, the fibers and fiber balls are treated in a nonwoven forming unit with at least two spiked rollers to achieve good opening and mixing of the fibers and fiber balls. According to an advantageous embodiment of the invention, the spiked rollers are arranged in rows. The rows can also be arranged in pairs (double rows) to achieve particularly good opening and mixing of the fibers and fiber balls. It is also conceivable that at least a portion of the fiber material is passed through the same spiked rollers multiple times by means of a recirculation system. For example, a continuous belt can be used for recirculation. This is advantageously arranged between two rows of spiked rollers. Furthermore, the continuous belt can also be passed through several double rows of spiked rollers arranged one behind the other or one above the other.

[0047] According to a particularly preferred embodiment of the invention, the method comprises an aerodynamic nonwoven formation process, i.e., the nonwoven formation preferably takes place with the aid of air. Methods based on the airlaid or airlay process have proven particularly suitable. The basic principle of this method consists of transferring the fiber material into an airflow, which enables a mechanical distribution of the fibers in the longitudinal and / or transverse direction within the machine and ultimately a homogeneous fiber deposition on a vacuum-assisted conveyor belt.

[0048] Air can be used in a wide variety of process steps. According to a particularly preferred embodiment of the invention, the entire transport of the fiber material during nonwoven formation takes place aerodynamically, for example by means of an installed air system. However, it is also conceivable that only specific process steps, such as the removal of the fibers from the spiked rollers, are supported by additional air.

[0049] Practical trials have shown that when carrying out the process based on the Airlaid and / or Airlay process, one or more of the following steps are preferably performed: Advantageously, the processes of nonwoven raw material preparation and / or dissolution are directly upstream of the nonwoven fabric formation process. Mixing with non-fiber materials, such as down and / or foam components, preferably takes place immediately during the distribution of the fiber material within the nonwoven fabric formation system.

[0050] Using air as a transport medium, the material can be conveyed via a feed and distribution system into the nonwoven forming unit, where controlled opening, turbulence, and simultaneous homogeneous mixing and distribution of the individual components of the nonwoven raw material take place. To easily control the material feed, each material component is advantageously fed separately.

[0051] The nonwoven raw material is then preferably treated with at least two spiked rollers, which prepare or break down the fiber material. Particularly good results are achieved when the nonwoven raw material is passed through a series of rotating shafts equipped with metal spokes (the so-called spikes) as a spiked roller. The interlocking of the metal spokes creates a dynamic screen that allows for high throughput rates.

[0052] Advantageously, the nonwoven fabric is formed on a submerged screen belt. A randomly oriented nonwoven structure without pronounced fiber orientation can be produced on the screen belt, the density of which is related to the intensity of the submersion. A layered structure can be achieved by arranging several nonwoven fabric forming units in a line.

[0053] The advantage of aerodynamic nonwoven fabric formation is that the fibers and any other components present in the nonwoven raw material can be arranged in a random arrangement, enabling very high property isotropy. In addition to the structural aspects, this embodiment offers economic advantages resulting from the reduced investment volume and operating costs for the production facilities.

[0054] According to one embodiment of the invention, the nonwoven formation takes place in several nonwoven forming units arranged one after the other. For example, a lay-up belt, such as a vacuum-impregnated screen belt, is guided successively through several nonwoven forming units, in each of which a layer of nonwoven fabric is laid down. This allows a multilayered nonwoven fabric to be produced.

[0055] Nonwoven fabric consolidation can take place in conventional ways, for example chemically by spraying with binder, thermally by melting previously added adhesive fibers or adhesive powder and / or mechanically, e.g. by needling and / or water jet consolidation.

[0056] Practical trials have shown that the formation of nonwovens can be carried out with good results, for example, using a device for producing a fiber nonwoven, as described in publication WO 2005 / 044 529 A1.

[0057] The nonwoven fabric is ideally suited as a molding and / or filling material for the production of textile materials such as blankets, clothing and / or upholstered furniture, duvets, mattresses, filter and / or absorbent mats, spacers, foam substitutes, wound dressings and / or fire protection material.

[0058] The invention will be described in more detail below using several examples. Example 1:

[0059] 150 g / m² 2 The material consists of 50 wt.% siliconized 7 dtex / 32 mm PES fiber balls (Advansa 732), 30 wt.% CoPES binding fiber fiber balls, and 55 wt.% down and / or fine feathers and feathers from Minardi. It was laid on a carrier belt in a Form Fiber air-laid system, which uses spiked rollers to open the fiber raw material. The material was then solidified in a double-belt oven with a belt spacing of 12 mm at 155 °C. The residence time was 36 seconds. A rollable web material was obtained. Example 2:

[0060] 120 g / m² 2The material consists of 35 wt.% siliconized PES fiber balls (Advansa 732), treated with 40% mPCM at 28°C PC temperature enthalpy, 30 wt.% CoPES binding fiber fiber balls, and 35 wt.% down and / or fine feathers and feathers from Minardi. It was processed in a Form Fiber air-laid system, which uses spiked rollers to open the fiber raw material. The material was laid on a carrier belt and solidified in a double-belt oven with a belt spacing of 10 mm at 155°C. The residence time was 36 seconds. A rollable web material was obtained. Example 3:

[0061] 150 g / m² 2The fibers, consisting of 50% by weight wool fiber balls and 50% by weight CoPES binding fiber balls, were laid on a carrier belt in a Form Fiber air-laid system, which uses spiked rollers to open the fiber raw material, and solidified in a double-belt oven with a belt spacing of 12 mm at 155 °C. The residence time was 36 seconds. A rollable web material was obtained. Example 4:

[0062] 150 g / m² 2 The fibers, consisting of 50 wt.% silk fiber balls and 50 wt.% CoPES binding fiber, were laid on a carrier belt in a Form Fiber air-laid system, which uses spiked rollers to open the raw fiber material. They were then solidified in a double-belt oven with a belt spacing of 12 mm at 155 °C. The residence time was 36 seconds. A rollable web material was obtained. Example 5:

[0063] It will be 56 g / m² 2Made from 80 wt.% fiber balls and 20 wt.% CoPES binding fiber, the material was laid on a carrier belt in an air-laid system from Form Fiber, which uses spiked rollers to open the fiber raw material. It was then solidified in a double-belt oven with a belt gap of 1 mm at 170 °C. A rollable web material with a thickness of 6.1 mm was obtained. Example 6:

[0064] It will be 128 g / m² 2 Made from 80 wt.% fiber balls and 20 wt.% CoPES binding fiber, the material was laid on a carrier belt in an air-laid system from Form Fiber, which uses spiked rollers to open the fiber raw material. It was then solidified in a double-belt oven with a belt spacing of 4 mm at 170 °C. A rollable web material with a thickness of 7.5 mm was obtained. Example 7:

[0065] It will be 128 g / m² 2Made from 80 wt.% fiber balls and 20 wt.% CoPES binding fiber, the material was laid on a carrier belt in an air-laid kiln from Form Fiber, which features spiked rollers to open the fiber raw material. It was then solidified in a double-belt kiln with a belt spacing of 30 mm, i.e., without stress on the fiber nap, at 170 °C. A soft, rollable web material with a thickness of 25 mm was obtained. Example 8:

[0066] It will be 723 g / m² 2 Made from 80 wt.% fiber balls and 20 wt.% CoPES binding fiber, the material was laid on a carrier belt in an air-laid system from Form Fiber, which uses spiked rollers to open the fiber raw material. It was then solidified in a double-belt oven with a belt spacing of 50 mm at 170 °C. The result was a rollable, stable web material with a thickness of 50 mm.

Claims

[1] Process for producing a nonwoven fabric comprising a volume-giving material, namely fiber balls and optionally down and / or fine feathers, wherein the nonwoven fabric has a maximum tensile strength, measured according to DIN EN 29 073 at a basis weight of 50 g / m², in at least one direction of at least 0.3 N / 5 cm, in particular from 0.3 N / 5 cm to 100 N / 5 cm, wherein a nonwoven raw material comprising the volume-giving material, namely fiber balls and optionally down and / or fine feathers, is opened and distributed in a nonwoven forming unit, and is then deposited on a deposit belt and consolidated. [2] Method according to claim 1, characterized by that the proportion of fiber balls is at least 20% by weight, more preferably from 25 to 100%, in particular from 30 to 90%, and / or the proportion of down and / or fine feathers is 20 to 70%, in each case based on the total weight of the nonwoven fabric. [3] Method according to one or more of claims 1-2, characterized by that the fiber balls contain fibers selected from the group consisting of fibers made of polyester, in particular polyethylene terephthalate, polyethylene naphthalate and polybutylene terephthalate, and / or mixtures thereof and / or mixtures with other fibers. [4] Method according to one or more of claims 1-3, characterized by that the fiber balls are made of wool. [5] Method according to one or more of claims 1-4, characterized by that the fiber balls contain binding fibers that have a length of 0.5 mm to 100 mm. [6] Method according to one or more of claims 1-5, characterized by that the binding fibers are designed as core / sheath fibers, wherein the sheath comprises PBT, PA, copolyamides or copolyesters and / or the core comprises PET, PEN, PO, PPS; aromatic PA and / or PES. [7] Method according to one or more of claims 1-6, characterized by that the proportion of binding fibers in the nonwoven fabric is 5 to 50 wt.%, preferably 7 to 40 wt.% and particularly preferably 10 to 35 wt.%, in each case based on the total weight of the nonwoven fabric. [8] Method according to one or more of claims 1-7, characterized by that the nonwoven fabric contains a phase change material. [9] Method according to one or more of claims 1-8, wherein the fibers of the nonwoven fabric contain at least one additive selected from the group consisting of color pigments, antistatic agents, antimicrobials such as copper, silver, gold, or hydrophilizing or hydrophobizing additives in an amount of 150 ppm to 10 wt.%. [10] Method according to at least one of the preceding claims, characterized by that the material is deposited on a screening belt, a screening drum and / or a conveyor belt. [11] Method according to at least one of the preceding claims, characterized bythat the solidification is a thermal solidification, for example with a belt furnace. [12] Method according to at least one of the preceding claims, characterized by that the process includes an aerodynamic nonwoven formation process. [13] Method according to claim 12, characterized by that the aerodynamic nonwoven formation process comprises the transfer of the nonwoven raw material into an air stream which enables a mechanical distribution of the fibres in machines in the longitudinal and / or transverse direction and finally a homogeneous fibre deposition on a vacuum-assisted conveyor belt. [14] Method according to claim 12 and / or 13, characterized bythat the nonwoven raw material is transported with the aid of air as a transport medium via a feed and distribution system into a nonwoven forming unit, where a targeted opening, swirling and, at the same time, homogeneous mixing and distribution of the individual components of the nonwoven raw material takes place. [15] Method according to at least one of the preceding claims, characterized by that a very homogeneous nonwoven fabric is obtained in which the volume-giving fiber material is very homogeneous and evenly distributed. [16] Method according to at least one of the preceding claims, characterized by that the volume-giving material is opened by means of spiked rollers and / or spiked belts. [17] Method according to at least one of the preceding claims, characterized by that the volume-giving material is opened by carding.