DEVICE FOR THE MANUFACTURING OF FILAMENTS

Description

[0001] The invention relates to a device for producing filaments, in particular filaments made of thermoplastic material, wherein the device has at least one spinneret plate and wherein the filaments emerge from spinneret openings of this spinneret plate in at least one filament row. - In particular, the invention relates to a device for producing spunbonded nonwovens or nonwoven webs from filaments made of thermoplastic material. The filaments are preferably continuous filaments. Due to their quasi-continuous length, continuous filaments differ from short fibers, which have significantly shorter lengths of, for example, 1 mm to 60 mm. It is within the scope of the invention that the filaments are deposited on a conveyor device, preferably on a depositing screen belt. The width of a product deposited on such a conveyor device depends in particular on the spinning width.Spinning width refers in particular to the width of a row of filaments emerging from the spinneret openings of the spinneret plate.

[0002] Devices of the aforementioned type are generally known in practice in various embodiments. It is often desirable to variably adjust the nonwoven web width and thus the spinning width of the devices. This is possible, for example, with segmented devices in which a plurality of distribution devices are arranged in a row across the spinning width, which can be switched on or off as needed. However, this design has the disadvantage that plastic residues remain in the switched-off device segments, which can lead to contamination of the device and ultimately to malfunctions in the device's operation.In this context, EP 1 486 591 A1 describes a device in which at least one distribution device is provided for distributing a supplied plastic melt over a preliminary spinning width. A distribution plate assembly comprising distribution plates is arranged downstream of the distribution device. The individual distribution plates each have a plurality of distribution openings distributed over a distribution width. A spinneret plate is arranged downstream of the distribution plate assembly, which spinneret channels with associated spinneret openings are distributed over a final spinning width. The distribution plate assembly can be used to reduce or expand the preliminary spinning width to a final spinning width. The interchangeability of the distribution plates and the spinneret plate enables variable adjustment of the final spinning width.In this embodiment, the plastic melt flows from the distribution device through the distribution openings of the distribution plates to the spinneret plate.

[0003] These devices, which use distribution plates to reduce or expand the preliminary spinning width to a final spinning width, have generally proven effective for the production of filaments and nonwoven webs. However, these devices, due to temperature differences, result in different thermal expansions of the distribution plates of the distribution plate assembly during spinning. These temperature differences result from the fact that the plastic melt cools to a certain extent on the flow path from the distribution device to the spinneret plate, so that the upper distribution plates associated with the distribution device are hotter during spinning than the lower distribution plates associated with the spinneret plate.Due to these temperature differences and the resulting different thermal expansion of the distributor plates, it is possible that the distributor openings of the distributor plates shift, which adversely affects the flow path of the plastic melt through the distributor plate stack. For example, the different thermal expansions of the distributor plates can lead to the distributor openings of adjacent, stacked distributor plates no longer being arranged or oriented as intended, for example, no longer being aligned with each other. This can lead to an uneven distribution of the plastic melt and ultimately to spinning defects such as droplet formation and the like.Although the distributor plate package is usually screwed together all the way around the edges, the different thermal expansions of the distributor plates are nevertheless observed to a considerable extent in the known devices and often have a detrimental effect on the spinning process. Furthermore, the described different thermal expansions of the distributor plates can also occur as a result of thermal cleaning processes in the device. Further relevant information can be found in the documents DE 44 19 555 and US Pat. No. 3,460,199. This is where the invention comes in.

[0004] The invention is based on the technical problem of providing a device of the type mentioned at the outset in which the disadvantages described above can be effectively and reliably avoided and in which, in particular, adverse influences on the spinning process resulting from different thermal expansion of the distributor plates can be reduced or avoided.

[0005] To solve this technical problem, the invention teaches a device for producing filaments, in particular filaments made of thermoplastic material, wherein the device has at least one spinneret plate, wherein the filaments emerge in at least one filament row from spinneret openings of the spinneret plate, wherein at least one distribution device is provided for distributing a supplied plastic melt to a preliminary spinning width, wherein at least one filter plate is connected downstream of the distribution device,wherein a distributor plate package comprising distributor plates is arranged downstream of the filter plate, wherein the individual distributor plates each have a plurality of distributor openings distributed over a distribution width, wherein the distributor openings are provided for receiving the plastic melt emerging from the filter plate, wherein the spinneret plate is arranged downstream of the distributor plate package, wherein the spinneret plate has spinneret channels with the associated spinneret openings distributed over a final spinning width. The device according to the invention is characterized in that an outlet surface of the filter plate assigned to the distributor plate package and / or an inlet surface of the spinneret plate assigned to the distributor plate package is curved or spherical over its entire or substantially over its entire extent in the machine direction, and in that the radius of curvature R of the curved or sphericalspherically shaped section of the outlet surface of the filter plate and / or the inlet surface of the spinneret plate is constant or essentially constant over the entire extent of the curved or spherically shaped section and amounts to 10,000 mm to 55,000 mm.

[0006] Within the scope of the invention, the term "final spinning width" refers in particular to the total width of a row of filaments emerging from the device and thus to the width of the row of associated spinneret openings. Within the scope of the invention, the term "preliminary spinning width" refers in particular to the width or spinning width at the filter plate-side end of the distribution device. Here and below, the term "spinning width" is used to indicate direction instead of the terms "preliminary spinning width" and / or "final spinning width". Furthermore, within the scope of the invention, the extent or width of a row of distribution openings of a distribution plate defines a distribution width associated with this distribution plate.

[0007] The terms "downstream", "upstream", "above", "below", "one above the other" and "one below the other" refer in the context of the invention in particular to the flow direction of the plastic melt from the distribution device to the spinneret plate in the operating state of the device.

[0008] According to a preferred embodiment of the invention, only one distribution device is provided in the direction transverse to the machine direction (CD) or with respect to the spinning width, which device is expediently preceded by only one spinning pump for the plastic melt. If the device is designed or configured according to a particularly preferred embodiment for producing multi-component filaments, in particular bi-component filaments, it is expedient for the device to have at least two distribution devices arranged next to one another in the machine direction (MD). In this case, a separate spinning pump for the respective plastic melt is preferably preceded by each of these distribution devices. Additionally or alternatively, it is also within the scope of the invention for two or more distribution devices to be arranged across the spinning width orare arranged next to each other transversely to the machine direction (CD) and a separate spinning pump can be connected upstream of each distribution device.

[0009] In the context of the invention, machine direction (MD) or MD direction means in particular the conveying direction of a conveying device for the filaments or the nonwoven web and thus the direction transverse to the preliminary or final spinning width. In contrast, CD or CD direction means in particular the direction transverse to the machine direction or the direction along the spinning width. Expediently, several rows of filaments are produced next to one another in the machine direction (MD) or transverse to the spinning width, each across the final spinning width. For this purpose, rows of spinneret openings arranged next to one another in the machine direction are recommended. The spinneret openings of adjacent rows are preferably offset from one another.

[0010] It is within the scope of the invention that the at least one distribution device is designed as a coat hanger distributor. In such a coat hanger distributor, the plastic melt is initially fed through a feed channel that is narrow relative to the spinning width and gradually increases in width to the preliminary spinning width, taking into account a uniform flow profile at the outlet of the plastic melt from the coat hanger distributor, in particular by ensuring the same counterpressure at each exit point of the plastic melt.

[0011] According to the invention, at least one filter plate is provided downstream of the distribution device. The filter plate preferably has perforated channels for the plastic melt. The perforated channels expediently extend transversely, in particular perpendicularly, to the flat dimension of the filter plate. The perforated channels of the filter plate are recommended to be arranged in at least one row extending in the direction of the preliminary spinning width. In principle, however, the filter plate can also have other configurations within the scope of the invention.

[0012] According to the invention, a distributor plate pack of distributor plates is arranged downstream of the filter plate. A distributor plate pack here means a pack of at least two, preferably at least three, more preferably at least four, most preferably at least five, for example at least six, distributor plates arranged one above the other. It is preferred that the device has no further distributor plates apart from the distributor plates of the distributor plate pack. The distributor plate pack is then arranged directly downstream of the filter plate and directly upstream of the spinneret plate. In principle, at least one further distributor plate could be provided upstream and / or downstream of the distributor plate pack.

[0013] The term "exit surface of the filter plate" in the context of the invention refers in particular to the exit surface of the filter plate associated with the distributor plate stack or the uppermost distributor plate. The "exit surface of the filter plate" therefore expediently also refers to the exit side of the filter plate. According to a preferred embodiment, the exit surface of the filter plate is in direct contact with the distributor plate stack or the uppermost distributor plate. The term "inlet surface of the spinneret plate" in the context of the invention refers in particular to the surface of the spinneret plate associated with the distributor plate stack or the last distributor plate. In this respect, the "inlet surface of the spinneret plate" expediently also refers to the inlet side of the spinneret plate. According to a preferred embodiment, the inlet surface of the spinneret plate is in direct contact with the distributor plate stack or the lowermost distributor plate.

[0014] According to the invention, the outlet surface of the filter plate associated with the distributor plate pack and / or the inlet surface of the spinneret plate associated with the distributor plate pack is curved or spherical in design, at least in sections. It is preferred that at least the outlet surface of the filter plate, in particular the outlet surface of the filter plate, is curved or spherical in design, at least in sections. In the context of the invention, curved or spherical means curved or spherical in particular in the direction of the distributor plate pack and thus preferably convexly curved. The outlet surface of the filter plate and / or the inlet surface of the spinneret plate is expediently ground to be curved or spherical.The outlet surface of the filter plate and / or the inlet surface of the spinneret plate is thus not flat, but rounded, resulting in a convex configuration of the outlet surface of the filter plate and / or the inlet surface of the spinneret plate oriented toward the distributor plate stack within the scope of the invention. This creates additional bracing of the distributor plates of the distributor plate stack, reliably counteracting adverse effects on the spinning process caused by the different thermal expansion of the distributor plates. In addition, manufacturing tolerances, such as the flatness of the individual components of the device, can be compensated.

[0015] It is very preferred that the outlet surface of the filter plate and / or the inlet surface of the spinneret plate is curved or spherical in relation to its extension in the machine direction (MD), at least in a middle section or central section. Very particularly preferably, the outlet surface of the filter plate and / or the inlet surface of the spinneret plate is curved or spherical over its entire or substantially over its entire extension in the machine direction (MD). The above-described curvature or spherical shape is thus realized within the scope of the invention according to a preferred embodiment over the entire or substantially over the entire extension of the outlet surface of the filter plate and / or the inlet surface of the spinneret plate in the machine direction (MD). The curved, in particular the convexly curved orThe spherical design of the filter plate and / or the spinneret plate thus expediently extends, with regard to the conveying direction or the machine direction (MD), from the inlet side to the outlet side of the filter plate and / or the spinneret plate. This allows the distributor plates of the distributor plate package to be screwed simply and reliably to the filter plate and / or the spinneret plate in their outer regions, wherein, with regard to the extension of the distributor plates in the machine direction (MD), additional bracing of the distributor plate package between the filter plate and the spinneret plate is achieved, in particular at least in a central section or middle section. This will be explained in more detail below. This design has the further advantage that, in this central section orIn the middle section, additional screwing can be avoided, which would otherwise counteract the realization of a homogeneous spinning field.

[0016] According to a preferred embodiment of the invention, a plurality of screws is provided for connecting the distributor plates of the distributor plate package and / or for connecting the assembly comprising the distributor plate package and the spinneret plate and / or filter plate, which screws preferably pass through this assembly and are arranged at least in the outer edge regions of the assembly extending in the CD direction, and particularly preferably are arranged circumferentially around the edge of the assembly. Due to the curved or spherical design of the filter plate and / or the spinneret plate, the contact pressure of these screws is preferably shifted from the outer edge regions of the assembly, in particular from the outer edge regions of the assembly extending in the CD direction, along the machine direction (MD) to the center of the assembly. In this case, point loads in the area of ​​the screws are expediently converted into a line load.Due to the large number of screws, the integral of the line loads advantageously forms a uniform surface pressure within the area enclosed by the screws, which are preferably arranged circumferentially along the edges. This pressure ensures, in particular, that the surface pressure acts largely evenly on the assembly consisting of the distributor plate pack and spinneret plate and / or filter plate. Due to the surface pressure, the interfaces of the individual planes between the distributor plates of the distributor plate pack and between the distributor plate pack and the spinneret plate and / or between the distributor plate pack and the filter plate are preferably evenly compressed.In order to reliably shift the surface pressure, preferably in the area between two adjacent screws, along the machine direction (MD) to the center of the assembly consisting of the distributor plate package and spinneret plate and / or filter plate, the spacing between adjacent screws is preferably selected accordingly. This applies in particular to the width of the assembly or spinneret plate in the machine direction (MD). For example, the wider the spinneret plate is in the MD direction, the smaller the screw spacing should preferably be in the CD direction. In this context, the screw diameter and flange thickness of the screws are also preferably selected accordingly and adapted to the surface pressure.

[0017] It has proven useful for the distance between two screws arranged adjacently in the outer edge regions of the unit comprising the distributor plate package and the spinneret plate and / or filter plate to be between 20 mm and 70 mm, preferably between 25 mm and 60 mm, particularly preferably between 30 mm and 55 mm. Distance between two adjacent screws refers in particular to the center-to-center distance or flange-to-center distance of the screws. According to one embodiment, the distance between any two adjacent screws is identical or essentially identical along the entire extension in the CD direction. In principle, however, the distance between any two adjacent screws can also be partially different along the extension in the CD direction.

[0018] Advantageously, the above-described curved or spherical configuration of the filter plate and / or spinneret plate in the machine direction (MD) is realized along the entire extent or essentially along the entire extent of the filter plate and / or spinneret plate transverse to the machine direction (CD), i.e., in the direction of the spinning width. In this way, the additional bracing of the distributor plates achieved by the curved or spherical configuration of the filter plate and / or spinneret plate in the machine direction (MD) can be achieved along the entire extent of the device transverse to the machine direction (CD) or along the entire spinning width.

[0019] The radius of curvature of the curved or spherical section of the filter plate outlet surface and / or the spinneret plate inlet surface is constant or substantially constant over the entire extent of the curved or spherical section. If the filter plate outlet surface and / or the spinneret plate inlet surface is curved or spherical over its entire or substantially entire extent in the machine direction (MD), the radius of curvature of this curved or spherical exit surface of the filter plate and / or spinneret plate inlet surface is constant or substantially constant over the entire extent in the machine direction (MD). The radius of curvature of the curved or spherical section of the outlet surface of the filter plate and / or the inlet surface of the spinneret plate is 10,000 mm to 55,000 mm, preferably 12,000 mm to 45.000 mm, particularly preferably 14,000 mm to 40,000 mm, very particularly preferably 16,000 mm to 36,000 mm, for example 17,000 mm to 19,000 mm.

[0020] With a constant radius of curvature, the contact pressure for a spinneret plate with an exemplary width of 240 mm in the machine direction (MD) is advantageously significantly higher than for a spinneret plate with an exemplary width of 120 mm in the machine direction (MD).

[0021] It is preferred that the device according to the invention has at least one form-locking element that penetrates the filter plate and / or the distributor plate stack and / or the spinneret plate in the flow direction of the plastic melt, in particular completely penetrates the distributor plate stack. For this purpose, the distributor plates expediently each have at least one corresponding form-locking opening assigned to the at least one form-locking element. Preferably, at least two, particularly preferably at least three, and very particularly preferably a plurality of such form-locking elements and form-locking openings are provided for the device according to the invention or for the distributor plate stack. Expediently, the at least one form-locking element is a dowel pin.This embodiment of the device according to the invention with form-locking elements and form-locking openings is based on the finding that a different thermal expansion of the distributor plates is additionally counteracted by form-locking, so that in particular a combination of force-locking - due to the curved or spherical design of the filter plate and / or the spinneret plate according to the invention - and form-locking is realized.

[0022] It has already been explained that the invention relates in particular to a device for producing spunbonded nonwovens from filaments of thermoplastic material. According to a preferred embodiment, the device according to the invention is designed as a spunbond device, and then spunbond nonwovens or nonwoven webs are expediently produced using the device according to the invention. With the device according to the invention, monocomponent filaments and / or mixed filaments and / or multicomponent filaments, in particular bicomponent filaments, can be produced as continuous filaments. The term "mixed filament" in the context of the invention means in particular a filament which, with regard to its cross-sectional configuration, is designed as a mono-type filament, but consists of a mixture of at least two plastics or plastic melts.It has proven useful to provide a cooling device for cooling the produced filaments downstream of the spinneret plate, which cooling device preferably has a cooling chamber through which the produced filaments or continuous filaments are guided for cooling. It is preferred that air supply cabins for supplying the cooling air are arranged on two opposite sides of the cooling chamber. According to a preferred embodiment, air supply cabins arranged one above the other are present on two opposite sides of the cooling chamber, in particular two air supply cabins arranged one above the other, from which air of preferably different temperatures is introduced into the cooling chamber. It has also proven useful to provide a monomer extraction device between the spinneret plate and the cooling device, with which interfering gases that arise during the spinning process can be removed from the device or the spunbond device.

[0023] Advantageously, a drawing device for drawing the produced filaments is arranged downstream of the cooling device in the filament flow direction. According to a particularly recommended embodiment of the device according to the invention, the unit comprising the cooling device and the drawing device is designed as a closed unit, in which, apart from the supply of cooling air in the cooling device, no further air is supplied to the closed unit.

[0024] It is also preferred that at least one diffuser is arranged between the drawing device and the conveying device, in particular the deposition screen belt. The continuous filaments emerging from the drawing device are guided through the diffuser and then deposited on the conveying device. According to one embodiment of the invention, two diffusers arranged one behind the other are provided. The conveying device is preferably designed as a continuously rotating conveying device or as a continuously rotating deposition screen belt. Most preferably, the conveying device, in particular the deposition screen belt, is designed to be permeable to air, so that process air can be extracted from below through the conveying device.

[0025] A particularly preferred embodiment of the invention is characterized in that the at least one spinneret plate is designed as an exchangeable spinneret plate. More preferably, the distributor plates are also designed to be exchangeable. In this way, the desired final spinning width can be set by suitable selection and replacement of the distributor plates and the spinneret plate. In this context, it is within the scope of the invention that the distribution width formed by the distributor openings of at least one distributor plate, preferably a plurality of distributor plates, preferably each distributor plate of the distributor plate package, is in each case smaller or larger than the provisional spinning width, so that with the aid of the distributor plate package the provisional spinning width is reduced or expanded to the final spinning width and preferably by replacing the distributor plates orThe desired final spinning width can be adjusted by adjusting the width of the distributor plate pack. The distributor openings of the distributor plates are expediently arranged vertically or perpendicularly to the distributor plate surface. It is further preferred that, in at least some of the distributor plates of the distributor plate pack, the distributor openings open into distribution channels, which lead to an expansion or reduction of the inlet-side distribution width. The extent or width of a row of distributor openings defines the distribution width for the respective distributor plate.

[0026] It is within the scope of the invention that the distribution widths formed by the distribution openings of the individual distribution plates decrease or increase from the filter plate to the spinneret plate, so that the preliminary spinning width is thus reduced or expanded to the final spinning width. It is also within the scope of the invention for a distribution plate to have several rows of distribution openings arranged next to one another. Each row of distribution openings expediently extends across the distribution width of the respective distribution plate. The distribution openings of two rows of distribution openings arranged next to one another in the conveying direction or machine direction (MD) are preferably offset from one another.

[0027] A particularly preferred embodiment of the invention is characterized in that at least one of the distributor plates has at least one distributor channel extending over at least part of the distribution width, which distributor channel connects at least part of the distributor openings to one another. It is within the scope of the invention for the distributor channel to connect the distributor openings arranged in a row with regard to the distribution width. The distributor channel expediently extends over the entire distribution width of the distributor plate and preferably connects all of the distributor openings arranged in a row of this distributor plate. According to a very preferred embodiment of the invention, in at least one distributor plate, the distributor openings of each row are connected to one another by a distributor channel. A distribution channel is preferably arranged horizontally or perpendicularly to the distributor openings.It has also proven advantageous for a distribution channel of a distribution plate to be directly adjacent to an adjacent distribution plate. A distribution channel adjacent to an adjacent distribution plate expediently connects at least some of the distribution openings arranged in a row of the adjacent distribution plate, and preferably all of the distribution openings arranged in a row of this adjacent distribution plate.

[0028] The above-described configuration of a distributor plate with distributor openings and distributor channels is preferably implemented in at least one of the distributor plates of the distributor plate stack and preferably in at least some, particularly preferably in at least a majority, of the distributor plates of the distributor plate stack. The distributor channels serve, in particular, to distribute the plastic melt in the direction of or along the distribution widths to expand or reduce the preliminary spinning width.

[0029] A further preferred embodiment of the invention is characterized in that at least one of the distributor plates of the distributor plate pack, preferably some of the distributor plates of the distributor plate pack, has no distribution channels. This is preferably at least one distributor plate of the distributor plate pack assigned to the spinneret plate and thus at least one lower distributor plate of the distributor plate pack, for example the last distributor plate of the distributor plate pack assigned to the spinneret plate. Within the scope of such an embodiment, the preliminary spinning width is adjusted to the desired distribution width orThe final spinning width is reduced or expanded, and the distributor plates arranged downstream in the flow direction of the plastic melt can be used to further influence the plastic melt, for example to combine at least two plastic melts to produce multi-component filaments or to reduce the diameter of the distributor openings, etc., particularly without significantly influencing the final spinning width. It has also proven useful for at least some of the distributor plates of the distributor plate pack to have the distributor openings of adjacent distributor plates arranged one above the other offset from one another with respect to the distribution width. This is particularly the case for the distributor plates of the distributor plate pack that have distribution channels.

[0030] Within the scope of the invention, the at least one plastic melt preferably flows through the flow paths formed by the distributor plates or by the distributor plate package from distributor openings and distributor channels and exits above the spinneret plate, in particular directly above the spinneret plate, from the distributor openings of a distributor plate or the last distributor plate of the distributor plate package and into associated spinneret channels of the spinneret plate. It is preferred that the flow paths for the at least one plastic melt - in particular with regard to the flow path length and / or the cross-sectional geometry of the distributor channels or the distributor openings and / or with regard to the cross-sectional area of ​​the distributor channels or the distributor openings - are designed with the proviso that at the outlet of the plastic melt from the distributor plate package orAt the inlet to the spinneret channels of the spinneret plate, the same or essentially the same counterpressure is present at each distribution opening and / or at each spinneret channel. The counterpressure is thus preferably adjusted by the design of the flow paths associated with the individual spinneret channels and, in particular, with the filaments produced.

[0031] Within the scope of the invention, the filter plate according to the invention is preferably designed to support a filter. The filter is expediently arranged between the at least one distribution device and the filter plate and thus downstream of the distribution device in the flow direction of the plastic melt. A close-meshed filtration sieve is preferably used as the filter. It is also within the scope of the invention that a plurality of heating zones for the distribution device is provided across the width of the at least one distribution device. These heating zones can each be heated separately, and for this purpose, each heating zone is preferably assigned a heating device that can be separately set to a specific heating temperature. With the help of the heating zones or heating devices, the viscosity or flow rate of the plastic melt in the device according to the invention or in the distribution device can be influenced.

[0032] According to a preferred embodiment of the invention, the final spinning width is at least 1,600 mm, preferably at least 1,800 mm, more preferably at least 2,000 mm. For final spinning widths of this magnitude, the curved or spherical design of the outlet surface of the filter plate and / or the inlet surface of the spinneret plate according to the invention has proven particularly successful. It is within the scope of the invention that the ratio of the preliminary spinning width to the final spinning width (B v :B e ) in the case of a reduction in the preliminary spinning width is 1.01 to 1.5, preferably 1.02 to 1.3, particularly preferably 1.05 to 1.15, and in the case of an expansion of the preliminary spinning width is 0.7 to 0.98, preferably 0.8 to 0.97, particularly preferably 0.85 to 0.95. Such a ratio of the preliminary spinning width to the final spinning width has proven particularly useful in the context of the invention.

[0033] According to a particularly preferred embodiment of the invention, the device is designed or configured for producing multicomponent filaments, in particular bicomponent filaments, and / or mixed filaments, wherein the device preferably has at least two distribution devices arranged side by side in the machine direction (MD) for distributing at least two plastic melts. The at least two distribution devices expediently distribute two plastic melts separately from one another over a preliminary spinning width. It has proven useful for the two plastic melts to then be guided separately from one another through perforated channels of a filter plate arranged downstream of the at least two distribution devices.The perforated channels of the filter plate are then recommended to be arranged in at least one row extending in the direction of the preliminary spinning width per plastic melt, and the rows of perforated channels assigned to the respective plastic melts are very particularly preferably arranged next to one another in the machine direction (MD). If the device is designed or configured according to a very particularly preferred embodiment to produce bicomponent filaments, two distribution devices are recommended, which are arranged next to one another in the machine direction (MD) and are each designed, in particular, as coat hanger distributors. It is within the scope of the invention that, in a device designed or configured to produce multicomponent filaments or bicomponent filaments, only a single filter plate, a single distribution plate package, and a single spinneret plate are arranged downstream of the distribution devices.

[0034] If the device according to a preferred embodiment is designed or configured to produce multi-component filaments or bi-component filaments and / or mixed filaments, it is very particularly preferred that the distributor plate assembly or the distributor plates is / are designed with the proviso that at least two plastic melts initially flow separately through the distributor plate assembly and can then be combined above the spinneret plate, in particular directly above the spinneret plate, to produce multi-component filaments or bi-component filaments. For this purpose, the two plastic melts expediently first flow through at least two separate flow path systems formed by the distributor plates or the distributor plate assembly, consisting of distributor openings and distributor channels, and can be combined or are combined above the spinneret plate, in particular directly above the spinneret plate.In this context, it is within the scope of the invention that the two plastic melts are combined at least by the distributor plates arranged directly above the spinneret plate, in particular at least by the last distributor plate of the distributor plate stack. With the device according to the invention, for example, multicomponent filaments or bicomponent filaments with a core-shell configuration, with a side-by-side configuration, with a segmented-pie configuration, with an island-in-the-sea configuration, and the like, and / or mixed filaments, can be produced within the scope of the invention. For this purpose, the distributor plates of the distributor plate stack, and in particular the lower distributor plates of the distributor plate stack assigned to the spinneret plate, are preferably designed accordingly.

[0035] According to a very preferred embodiment, which is of particular importance within the scope of the invention, the diameter of some of the distributor openings of at least one distributor plate of the distributor plate pack - preferably at least the last distributor plate of the distributor plate pack arranged directly above the spinneret plate - differs from the diameter of the remaining distributor openings of this distributor plate. In this embodiment, not all distributor openings of at least one distributor plate of the distributor plate pack have the same diameter, but the diameter of some of the distributor openings of the distributor plate differs from the diameter of the remaining distributor openings of this distributor plate. In this way, adverse influences on the spinning process due to different thermal expansion of the distributor plates can be additionally counteracted.In particular, in combination with the curved or spherical design of the filter plate and / or the spinneret plate according to the invention, the spinning stability of the device can be ensured in a particularly effective and functionally reliable manner. It is possible for the above-described design of a distributor plate with different diameters of the distributor openings to be implemented in at least two, in particular in at least three distributor plates of the distributor plate package, and these distributor plates are then expediently assigned to the spinneret plate and, in particular, arranged one above the other above the spinneret plate. Within the scope of the invention, the distributor openings of a distributor plate are round, in particular circular, at least in some of the distributor plates. It is also within the scope of the invention for the distributor openings to be angular, in particular rectangular, at least in some of the distributor plates.The distributor openings, together with the distributor channels, preferably form flow paths for the plastic melt through the distributor plate package, wherein particularly preferably each spinneret channel or each spinneret opening of the spinneret plate and thus in particular also each filament produced is assigned a flow path consisting of distributor openings and distributor channels.

[0036] Within the scope of the invention, it is possible to create increased counterpressure at certain openings for the plastic melt, for example at certain distributor openings of a distributor plate, in particular the last distributor plate of the distributor plate pack, in order to spin thinner filaments in these areas. This makes it possible to compensate for system-related differences in the cooling air. Very particularly preferably, the diameter d 1 of the distributor openings in at least one edge-side outer region, preferably in at least one CD outer region, of at least one distributor plate of the distributor plate pack - preferably at least the last distributor plate of the distributor plate pack arranged directly above the spinneret plate - differs from the diameter d 2 of the distributor openings in the middle of this distributor plate. Very particularly preferably, the diameter d 1 is greater than the diameter d 2 .Preferably, the diameter d 1 of the distributor openings in at least one, preferably in the two CD outer regions of at least one distributor plate differs from the diameter d 2 in the middle of this distributor plate. In this case, d 1 > d 2 preferably applies. CD outer region means in particular an outer region of a distributor plate extending parallel to the CD direction. Center of the distributor plate, on the other hand, means in particular a section of the distributor plate that is arranged centrally or centrally with regard to the planar extent of a distributor plate. This diameter distribution of the distributor openings of at least one distributor plate of the distributor plate package has proven particularly successful. In principle, however, it is also possible for the diameter d 1 to be smaller than the diameter d 2 .

[0037] It is further preferred if a diameter gradient of the distributor openings results from at least one peripheral outer region, in particular from at least one, preferably from the two CD outer regions, of the respective distributor plate towards the center of this distributor plate.

[0038] Additionally or alternatively, it is possible for the diameter d 1 of the distributor openings in at least one, preferably in the two, MD outer regions of at least one distributor plate to differ from the diameter d 2 in the center of this distributor plate. Preferably, d 1 > d 2 then applies. The invention thus also encompasses an embodiment in which the diameter d 1 of the distributor openings of at least one distributor plate differs circumferentially around the edge from the diameter d 2 of the distributor openings in the center of this distributor plate, wherein d 1 > d 2 preferably applies.

[0039] According to a very preferred embodiment of the invention, the at least one distribution device is designed based on at least one material with a thermal conductivity at 20°C of 30 to 42 W / (mK), preferably 33 to 39 W / (mK), more preferably 34 to 38 W / (mK). The thermal expansion coefficients of the distributor plates are preferably matched to the thermal expansion coefficients of the distributor device and / or the filter plate and / or the spinneret plate. The larger the final spinning width or the extension of the spinneret plate in the CD direction, the smaller the differences in the thermal expansion coefficients of the distributor plates on the one hand and the distributor device and / or the filter plate and / or the spinneret plate on the other hand are expediently. The at least one distribution device is expediently designed based on at least one hot-work steel and is preferably based on 55 NiCrMoV7 steel.

[0040] It is within the scope of the invention that the filter plate and / or the spinneret plate is formed on the basis of at least one material with a thermal conductivity at 20°C of 15 to 35 W / (mK), preferably 18 to 32 W / (mK), preferably 20 to 30 W / (mK), particularly preferably 22 to 28 W / (mK). Further preferably, the filter plate and / or the spinneret plate is formed on the basis of at least one martensitic steel, preferably based on X17CrNi16-2 steel.

[0041] The above-described material selection for the at least one distribution device and / or the filter plate and / or the spinneret plate is based on the knowledge that, with such a design of these device components, the device can withstand a cleaning process, in particular a thermal cleaning process, required after a certain period of operation without significant impairment. This is particularly important in light of the special coordination of the individual device components with regard to the flow path of the plastic melt(s). The described preferred material selection for the device components ensures continued functional reliability even after the cleaning process, particularly with regard to the orientation of the openings and channels provided for guiding the plastic melt.This is particularly relevant in view of the curved or spherical design of the filter plate and / or the spinneret plate according to the invention.

[0042] The invention is based on the finding that, in the device according to the invention, adverse influences on the spinning process due to the different thermal expansion of the distributor plates can be effectively and reliably counteracted by the curved or spherical design of the outlet surface of the filter plate and / or the inlet surface of the spinneret plate. The inventive design of the filter plate and / or the spinneret plate, and in particular of the assembly comprising the filter plate, the distributor plate package, or the distributor plates, and the spinneret plate, achieves additional bracing of the distributor plates, so that adverse effects of the different thermal expansion of the individual distributor plates, particularly due to frictional engagement, are reduced or avoided.In particular, the additional bracing prevents any adverse influence on the orientation of the distribution openings and / or distribution channels of the distribution plates relative to one another. If, according to a preferred embodiment, additional form-locking elements or locating pins are used for the distribution plate assembly, a particularly advantageous combination of force-locking and form-locking results. Nevertheless, the device according to the invention can be used to achieve very simple and reliable adjustment of various final spinning widths. Thus, the device according to the invention ensures, on the one hand, the flexible applicability of the device and, on the other hand, the spinning stability and thus the product quality of the manufactured product or nonwoven web.It must also be emphasized that the advantages described above are achieved with little effort and that the device is therefore also characterized by very advantageous economic efficiency.

[0043] The invention is explained in more detail below with reference to a drawing that represents only one exemplary embodiment. The drawing shows a schematic representation: Fig. 1 a section through a device according to the invention in a first operating state Fig. 2 the object according to Fig. 1 in a second operating state Fig. 3a a distributor plate according to the invention in a first embodiment Fig. 3b a distributor plate according to the invention in a second embodiment Fig. 4 a spinneret plate according to the invention Fig. 5 a section through the aggregate comprising filter plate, distributor plate package and spinneret plate.

[0044] The figures show a device 1 for producing filaments (not shown in detail) from thermoplastic material. The filaments are in particular continuous filaments. In the exemplary embodiment according to the figures, the filaments emerge from the spinneret openings 3 of a spinneret plate 2 in several rows extending over a final spinning width B e. The plastic melt for the filaments to be spun is first fed from an extruder (not shown in detail) via a spinning pump (also not shown in detail) to a feed channel 14. This feed channel 14 opens into a distribution device 4, which in the exemplary embodiment according to the Figure 1 and 2 is designed as a coat hanger distributor. By means of the distribution device 4, the supplied plastic melt is distributed over a preliminary spinning width B v. The distribution device 4 is according to the invention and in the embodiment according to the Figure 1and 2 a filter plate 5 is arranged downstream, which preferably has, and in the exemplary embodiment, distributed perforated channels 13 for the plastic melt over the preliminary spinning width B v. The filter plate 5 is recommended and in the exemplary embodiment serves to support a filter 15. This is particularly important in the Figure 1 The filter 15 is expediently and in the exemplary embodiment downstream of the distribution device 4 in the flow direction of the plastic melt.

[0045] According to the invention and in the exemplary embodiment, the filter plate 5 is followed by a distributor plate package 6 comprising distributor plates 7. The distributor plate package 6 preferably has, and in the exemplary embodiment, a plurality of distributor plates 7. The distributor plates 7 each have a plurality of distributor openings 8 distributed over a distribution width B i, wherein the distributor openings 8 are provided for receiving the plastic melt emerging from the filter plate 5. In the Figure 1 and 2 For each distribution plate 7, a row of distribution openings 8 can be seen.

[0046] The extension or the width of a row of distribution openings 8 defines the distribution width B i for each distribution plate 7. Preferably and in the exemplary embodiment, each distribution plate 7 of the distribution plate package 6 has several rows of distribution openings 8 arranged next to one another in the direction transverse to the distribution width B i. This is shown, for example, in the Figures 3a and 3b to recognize.

[0047] In the Figure 3a It can also be seen that the distributor openings 8, according to a preferred embodiment, are rectangular in cross-section. According to a further preferred embodiment of a distributor plate 7, the distributor openings 8 have a round, in particular a circular, cross-section. This is shown in the Figure 3bIn particular, the distributor openings 8 of distributor plates 7, which are arranged in the lower part of the distributor plate package 6 associated with the spinneret plate 2, have, according to a preferred embodiment, a round or circular cross-section. Advantageously, and in the embodiment according to the Figure 3a the distribution openings 8 of a distribution plate 7 each have the same diameter or substantially the same diameter.

[0048] Within the scope of a further preferred embodiment of a distributor plate 7, it is preferred that the diameter of a part of the distributor openings 8 of at least one distributor plate 7 of the distributor plate package 6 differs from the diameter of the remaining distributor openings 8 of this distributor plate 7. This is in the Figure 3bAccording to one embodiment, this can be the last distributor plate 7 of the distributor plate package 6, which is arranged directly above the spinneret plate 2. Expediently and in the embodiment according to the Figure 3b the distributor openings 8 are then round, in particular circular, and the diameter of the distributor openings then means in particular the diameter of the circular distributor openings.

[0049] In the Figure 3bIt can also be seen that the diameter d 1 of the distribution openings 8 in at least one, preferably in both, CD outer regions 16 of the distributor plate 7 particularly preferably differs from the diameter d 2 of the distribution openings 8 in the center of this distributor plate 7, and that preferably and in the exemplary embodiment the diameter d 1 is larger than the diameter d 2 . CD outer region 16 of the distributor plate 7 refers in particular to an outer region of the distributor plate 7 extending parallel to the CD direction, i.e., along the distribution width or spinning width.

[0050] In the Figure 1 and 2 It can be seen that the distributor openings 8 of the stacked rows of adjacent stacked distributor plates 7 are offset from each other with respect to the distribution width B i. In the embodiment according to the Figure 1 , 2 and 3In this context, it can be seen that the distributor plates 7 of the distributor plate package 6 preferably have distributor channels 12 extending over the spinning width B i, wherein each distributor channel 12 connects the distributor openings 8 of a row. According to a preferred embodiment and in the embodiment according to the Figure 1 and 2 At least in the majority of the distributor plates 7, a distributor channel 12 directly adjoins an adjacent distributor plate 7. In other words, this adjacent distributor plate 7 forms a wall of the adjacent distributor channel 12. This distributor channel 12 expediently connects, and in the exemplary embodiment, distributor openings 8 of the adjacent distributor plate 7 arranged in a row. As a result, in the preferred embodiment according to the Figure 1 and 2achieved that the distribution openings 8 and the distribution channels 12 of the distribution plates 7 are connected to each other. The distribution plate package 6 or the distribution plates 7 is followed by an exchangeable spinneret plate 2, which has spinneret channels 9 with the associated spinneret openings 3 distributed over the final spinning width B e. Figure 4shows a spinneret plate 2 with spinneret channels 9 or spinneret openings 3. A plurality of rows of spinneret channels 9 or spinneret openings 3 are arranged next to one another transversely to the final spinning width B e , in particular in the machine direction (MD). Within the scope of the invention, the distributor openings 8 together with the distributor channels 12 preferably form flow paths for the plastic melt through the distributor plate package 6. Expediently, a flow path consisting of distributor openings 8 and distributor channels 12 is assigned to each spinneret channel 9 or each spinneret opening 3 of the spinneret plate 2 and thus in particular also to each produced filament.

[0051] Advantageously and in the exemplary embodiment, an outlet surface 10 of the filter plate 5 assigned to the distributor plate package 6 and an inlet surface 11 of the spinneret plate 2 assigned to the distributor plate package 6 are curved or spherical over their entire or substantially entire extent in the machine direction (MD). This is particularly evident in the illustration of the Figure 5 to recognize. In the Figure 5 The hole channels of the filter plate 5, the distributor openings and the distributor channels of the distributor plates 7 and the spinneret channels and spinneret openings of the spinneret plate 2 are not shown in detail. Preferably and in the embodiment according to the Figure 5the outlet surface 10 of the filter plate 5 and the inlet surface 11 of the spinneret plate 2 are curved or spherically ground. Thus, the outlet surface 10 and the inlet surface 11 are not flat, but rounded or rounded in the direction of the distributor plate package 6. Expediently and in the exemplary embodiment, a convex curvature or spherical shape of the outlet surface 10 of the filter plate 5 and the inlet surface 11 of the spinneret plate 2 is produced, oriented in the direction of the distributor plate package 6. This results in additional bracing of the distributor plates 7 of the distributor plate package 6, in particular in a central section or middle section with respect to the machine direction (MD). Machine direction (MD) in the context of the invention furthermore means in particular the conveying direction of a conveying device for the filaments or the nonwoven web produced therefrom and thus the direction transverse to the spinning width orDistribution width. Within the scope of the invention and in the exemplary embodiment, the curvature or crowning of the filter plate 5 or the spinneret plate 2 is thus realized over the entire extent of the outlet surface 10 of the filter plate and the inlet surface 11 of the filter plate in the machine direction (MD). In the exemplary embodiment, the radius of curvature R of the curved or crowned outlet surface 10 of the filter plate 5 and the inlet surface 11 of the spinneret plate 2 is constant or essentially constant over the entire extent in the machine direction (MD). In the exemplary embodiment according to the figures, the radius of curvature R may be 17,000 mm to 19,000 mm.

[0052] In the operating state of the device 1 according to Figure 1A distribution plate package 6 comprising a plurality of exchangeable distribution plates 7 is arranged downstream of the distribution device 4 or the filter plate 5. The distribution widths B i formed by the distribution openings 8 of the individual distribution plates 7 expediently take up, and in the embodiment according to the Figure 1 from the filter plate 5 to the spinneret plate 2. The preliminary spinning width B v is thus expanded or enlarged to the final spinning width B e. The distribution width B i thus increases from distributor plate 7 to distributor plate 7 to the spinneret plate 2. In the operating state of the device according to Figure 2 The distribution device 4 or the filter plate 5 is also followed by a distribution plate package 6 comprising a plurality of replaceable distribution plates 7. Advantageously and in the embodiment according to the Figure 2the distribution widths B i formed by the distribution openings 8 of the individual distribution plates 7 decrease from the filter plate 5 to the spinneret plate 2. The preliminary spinning width B v is reduced in this way to the final spinning width B e. The distribution width B i therefore decreases here from distributor plate 7 to distributor plate 7 to the spinneret plate 2. It is also possible within the scope of the invention that not all distributor plates 7 of the distributor plate package 6 have distribution channels 12. According to an embodiment not shown in detail in the figures, it is possible that the lower distributor plates 7 of the distributor plate package 6, which are assigned to the spinneret plate 2, do not have distribution channels 12 and that the final distribution width B e is already reached above these distributor plates 7.

[0053] According to a preferred embodiment of the invention, the final spinning width B e is at least 1,600 mm, preferably at least 1,800 mm. In the embodiment according to the figures, the final spinning width may, for example, be at least 2,000 mm. It has proven useful that the ratio of the preliminary spinning width B v to the final spinning width B e (B v :B e ) is 1.02 to 1.3 in the case of a reduction of the preliminary spinning width and 0.8 to 0.97 in the case of an extension of the preliminary spinning width B v. Figure 1 , in which the preliminary spinning width B v is extended, the ratio B v :B e may be between 0.85 and 0.95. In the embodiment according to Figure 2 , in which the preliminary spinning width B v is reduced, the ratio B v :B e may be 1.05 to 1.15.

Claims

1. Apparatus for the production of filaments, in particular filaments of thermoplastic material, wherein the apparatus (1) comprises at least one spinneret plate (2), wherein the filaments emerge from spinneret openings (3) of the spinneret plate (2) in at least one filament row, wherein at least one distribution device (4) is provided for distributing a supplied plastic melt to a preliminary spinning width Bv, wherein at least one filter plate (5) is located downstream of the distribution device (4), wherein a distributor plate package (6) of distributor plates (7) is located downstream of the filter plate (5), wherein the individual distributor plates (7) each have a plurality of distributor openings (8) distributed over a distribution width Bi, wherein the distributor openings (8) are provided for receiving the plastic melt emerging from the filter plate (5), wherein the spinneret plate (2) is located downstream of the distributor plate package (6), wherein the spinneret plate (2) has spinneret channels (9) with the associated spinneret openings (3) distributed over a final spinning width Be, characterized in that an outlet surface (10) of the filter plate (5) assigned to the distributor plate package (6) and / or an inlet surface (11) of the spinneret plate (2) assigned to the distributor plate package (6) is curved or crowned over its entire extension or substantially over its entire extension in the machine direction (MD) and that the radius of curvature R of the curved or crowned section of the outlet surface (10) of the filter plate (5) and / or the inlet surface (11) of the spinneret plate (2) is constant or substantially constant over the entire extension of the curved or crowned section and is 10,000 mm to 55,000 mm.

2. Apparatus according to claim 1, wherein the radius of curvature R of the curved or crowned section of the outlet surface (10) of the filter plate (5) and / or the inlet surface (11) of the spinneret plate (2) is 12,000 mm to 45,000 mm, particularly preferably 14,000 mm to 40,000 mm, quite particularly preferably 16,000 mm to 36,000 mm, for example 17,000 mm to 19,000 mm.

3. Apparatus according to one of claims 1 or 2, wherein the distribution width Bi of at least one distributor plate (7) formed by the distributor openings (8), preferably of a plurality of distributor plates (7), preferably of each distributor plate (7) of the distributor plate package (6), is in each case smaller than or larger than the preliminary spinning width Bv, so that with the aid of the distributor plate package (6) the preliminary spinning width Bv is reduced or expanded to the final spinning width Be and preferably the desired final spinning width Be can be set by replacing the distributor plates (7) or the distributor plate package (6).

4. Apparatus according to one of claims 1 to 3, wherein the distribution widths Bi formed by the distributor openings (8) of the individual distributor plates (7) decrease or increase from the filter plate (5) to the spinneret plate (2) so that the preliminary spinning width Bv is reduced or expanded to the final spinning width Be in this way.

5. Apparatus according to one of claims 1 to 4, wherein at least one of the distributor plates (7) has at least one distributor channel (12) extending over at least a part of the distribution width Bi, which distributor channel (12) interconnects at least a part of the distributor openings (8) and wherein preferably at least in a part of the distributor plates (7) of the distributor plate package (6) the distributor openings (8) of the adjacent distributor plates (7) arranged one above the other are arranged offset with respect to one another in relation to the distribution width Bi.

6. Apparatus according to one of claims 1 to 5, wherein the final spinning width Be is at least 1,600 mm, preferably at least 1,800 mm, preferably at least 2,000 mm.

7. Apparatus according to one of claims 1 to 6, wherein the ratio of the preliminary spinning width Bv to the final spinning width Be (Bv:Be) in the case of a reduction of the preliminary spinning width Bv is 1.01 to 1.5, preferably 1.02 to 1.3, particularly preferably 1.05 to 1.15 and in the case of an expansion of the preliminary spinning width Bv is 0.7 to 0.98, preferably 0.8 to 0.97, particularly preferably 0.85 to 0.95.

8. Apparatus according to one of claims 1 to 7, wherein the apparatus (1) is configured or set up for producing multicomponent filaments, in particular bicomponent filaments, and / or mixed filaments and wherein the apparatus (1) preferably has for this purpose at least two distribution devices (4) arranged adjacent to one another in the machine direction (MD) for the distribution of at least two plastic melts.

9. Apparatus according to claim 8, wherein the distributor plate package (6) or the distributor plates (7) is / are configured with the proviso that at least two plastic melts initially flow separately from one another through the distributor plate package (6) and can then be combined above the spinneret plate (2), in particular directly above the spinneret plate (2), to produce multicomponent filaments or bicomponent filaments.

10. Apparatus according to one of claims 1 to 9, wherein the diameter of a part of the distributor openings (8) of at least one distributor plate (7) of the distributor plate package (6) - preferably of at least the last distributor plate (7) of the distributor plate package (6) arranged directly above the spinneret plate (2) - differs from the diameter of the remaining distributor openings (8) of this distributor plate (7).

11. Apparatus according to one of claims 1 to 10, wherein the diameter d1 of the distributor openings (8) in at least one edge-side outer region, preferably in at least one CD outer region (16), of at least one distributor plate (7) of the distributor plate package (6) - preferably of at least the last distributor plate (7) of the distributor plate package (6) arranged directly above the spinneret plate (2) - differs from the diameter d2 of the distributor openings (8) in the center of this distributor plate (7) and wherein the diameter d1 is preferably greater than the diameter d2.

12. Apparatus according to one of claims 1 to 11, wherein the at least one distributor device (4) is formed on the basis of at least one material having a thermal conductivity at 20°C of 30 to 42 W / (mK), preferably of 33 to 39 W / (mK), preferably of 34 to 38 W / (mK).

13. Apparatus according to one of claims 1 to 12, wherein the at least one distributor device (4) is formed on the basis of at least one hot-work tool steel and is preferably formed on the basis of 55NiCrMoV7 steel.

14. Apparatus according to one of claims 1 to 13, wherein the filter plate (5) and / or the spinneret plate (2) is formed on the basis of at least one material having a thermal conductivity at 20°C of 15 to 35 W / (mK), preferably of 18 to 32 W / (mK), preferably of 20 to 30 W / (mK), particularly preferably of 22 to 28 W / (mK).

15. Apparatus according to one of claims 1 to 14, wherein the filter plate (5) and / or the spinneret plate (2) is formed on the basis of at least one martensitic steel, preferably on the basis of X17CrNi16-2 steel.