FILAMENT-MAKING APPARATUS

Abstract

An apparatus for making filaments has a spinneret plate having a row of holes from which emerge filaments. A manifold distributes a supplied plastic melt over a starting spinning width. A filter plate is downstream of the manifold. A pack of distributor plates is downstream of the filter plate. The distributor plates each have a plurality of distributor holes distributed over a manifold width. The distributor holes receive the plastic melt emerging from the filter plate. The spinneret plate is downstream of the distributor-plate pack and has a row of spinneret passages extending over a final spinning width aligned with the spinneret holes. An output face of the filter plate turned toward the distributor-plate pack and/or an inlet face of the spinneret plate turned toward the distributor-plate pack is curved or crowned at least in sections.

Claims

1. An apparatus for making thermoplastic filaments, the apparatus comprising a spinneret plate having a row of holes from which filaments emerge in a filament-travel direction, a manifold for distributing a supplied plastic melt over a starting spinning width, a filter plate downstream of the manifold, a pack of distributor plates downstream of the filter plate, the distributor plates each having a plurality of distributor holes distributed over a manifold width B.sub.i, the distributor holes receiving the plastic melt emerging from the filter plate, the spinneret plate being downstream of the distributor-plate pack and having a row of spinneret passages extending over a final spinning width and aligned with the spinneret holes, the filter plate having an output face turned toward the distributor-plate pack and the spinneret plate having an inlet face, at least one of the faces being curved or crowned in the filament-travel direction at least in sections.

2. The apparatus according to claim 1, further comprising: a conveyor downstream in the filament-travel direction from the pack of distributor plates for receiving the filaments therefrom and transporting them in a machine direction transverse to the row of spinneret passages, the output face of the filter plate and/or the inlet face of the spinneret plate being curved or crowned over its entire or substantially its entire extension in the machine direction.

3. The apparatus according to claim 1, wherein a radius of curvature R of the curved or crowned section of the output face of the filter plate and/or the inlet face of the spinneret plate is constant or substantially constant over the entire extent of the curved or crowned section and measures 10,000 mm to 55,000 mm.

4. The apparatus according to claim 1, wherein the manifold width formed by the row of distributor holes of each distributor plate is smaller or larger than a starting spinning width, so that the starting spinning width is decreased or increased to the final spinning width by the distributor-plate pack, whereby exchanging the distributor plates of the distributor-plate pack changes the final spinning width.

5. The apparatus according to claim 1, wherein the manifold width formed by the rows of distributor holes of the individual distributor plates decreases or increases from the filter plate toward the spinneret plate, so that the preliminary spinning width is decreased or increased in this way to the final spinning width.

6. The apparatus according to claim 1, wherein at least one of the distributor plates has a distributor passage extending along at least a part of the distributor width, the distributor passage connecting at least some of the distributor holes to one another with the distributor holes of at least some of the distributor plates of the distributor-plate pack being offset relative to the distributor holes of adjacent distributor plates along the manifold width.

7. The apparatus according to claim 1, wherein the final spinning width is at least 1,600 mm.

8. The apparatus according to claim 1, wherein the ratio of the starting spinning width to the final spinning width is 1.01 to 1.5 in the case of a reduction in the starting spinning width and is 0.7 to 0.98 in the case of an increase in the starting spinning width.

9. The apparatus according to claim 1, wherein the apparatus makes multicomponent filaments and/or mixed filaments, and the apparatus for this purpose has at least two of the manifolds arranged next to one another in a machine direction for distributing at least two plastic melts.

10. The apparatus according to claim 9, wherein the distributor plates are provided such that at least two plastic melts initially flow separately from one another through the distributor-plate pack and can then be brought together directly above the spinneret plate to produce multicomponent filaments or bicomponent filaments.

11. The apparatus according to claim 1, wherein diameters of some of the distributor holes of at least one of distributor plates of the distributor-plate pack differs from the diameters of the remaining distributor holes of this one distributor plate.

12. The apparatus according to claim 1, wherein diameters diameter d.sub.1 of the distributor holes in at least one lateral region of at least one of the distributor plates of the distributor-plate pack differ from the diameters d.sub.2 of the distributor holes in the center of this one distributor plate, and the diameter d.sub.1 is greater than the diameter d.sub.2.

13. The apparatus according to claim 1, wherein the manifold is designed of at least one material with a thermal conductivity at 20 E C of 30 to 42 W/mk.

14. The apparatus according to claim 1, wherein the manifold is formed of at least one hot-worked tool steel.

15. The apparatus according to claim 1, wherein the filter plate and/or the spinneret plate is formed of at least one material with a thermal conductivity at 20 EC of 15 to 35 W/mk.

16. The apparatus according to claim 1, wherein the filter plate and/or the spinneret plate are formed of a martensitic X17CrNi16-2 steel.

Description

BRIEF DESCRIPTION OF THE DRAWING

[0046] The invention will be described in detail hereinafter with reference to a drawing showing merely one embodiment. In the drawing in schematic view:

[0047] FIG. 1 shows a sectional view through an apparatus according to the invention in a first operating state

[0048] FIG. 2 shows the subject matter according to FIG. 1 in a second operating state

[0049] FIG. 3a shows a distributor plate according to the invention in a first embodiment

[0050] FIG. 3b shows a distributor plate according to the invention in a second embodiment

[0051] FIG. 4 shows a spinneret plate according to the invention

[0052] FIG. 5 shows a sectional view through the assembly of filter plate, distributor plate package and spinneret plate.

SPECIFIC DESCRIPTION OF THE INVENTION

[0053] The drawings show an apparatus 1 for producing filaments of thermoplastic material not shown in detail. The filaments are in particular continuous filaments. In the embodiment according to the drawing the filaments emerge in several rows extending over a final spinning width B.sub.e from the spinneret holes 3 of a spinneret plate 2. The plastic melt for the filaments to be spun is initially supplied from an extruder not shown in detail via a spinning pump also not shown in detail to a feed passage 14. This feed passage 14 opens into a manifold 4 which in the embodiment according to FIGS. 1 and 2 is configured as a coat-hanger distributor. By means of the manifold 4 the supplied plastic melt is distributed to a preliminary spinning width B.sub.v. According to the invention and in this embodiment a filter plate 5 is arranged downstream of the manifold 4 which preferably and in this embodiment has perforated passages 13 for the plastic melt distributed over the preliminary spinning width B.sub.v. It is recommend that and in this embodiment the filter plate 5 is used to support a filter 15. This can be seen in particular in FIG. 1. Expediently the filter 15 is located downstream of the manifold 4 in the flow direction of the plastic melt.

[0054] Again according to the invention and in this embodiment a distributor plate package 6 of distributor plates 7 is located downstream of the filter plate 5. Preferably and in this embodiment the distributor plate package 6 comprises a plurality of distributor plates 7. The distributor plates 7 each have a plurality of distributor holes 8 distributed over a distribution width B.sub.i, wherein the distributor holes 8 are provided for receiving the plastic melt emerging from the filter plate 5. In FIGS. 1 and 2 a row of distributor holes 8 can be seen for each distributor plate 7.

[0055] The extension or the width of a row of distributor holes 8 defines the distribution width B.sub.i for each distributor plate 7. Preferably and in this embodiment each distributor plate 7 of the distributor plate package 6 has a plurality of adjacently arranged rows of distributor holes 8 in the direction transverse to the distribution width B.sub.i. This can be seen for example in FIGS. 3a and 3b.

[0056] In FIG. 3a it can additionally be seen that the distributor holes 8 according to a preferred embodiment are rectangular in cross-section. According to a further preferred embodiment of a distributor plate 7, the distributor holes 8 have a round, in particular circular cross-section. This is shown in FIG. 3b. In particular, the distributor holes 8 of distributor plates 7 which are arranged in the lower part f the distributor plate package 6 have a round or circular cross-section according to a preferred embodiment. Expediently and in the embodiment according to FIG. 3a, the distributor holes 8 of a distributor plate 7 each have the same diameter or substantially the same diameter.

[0057] Within the scope of a further preferred embodiment of the distributor plate 7, it is preferred that the diameter of a part of the distributor holes 8 of at least one distributor plate 7 of the distributor plate package 6 differs from the diameter of the remaining distributor holes 8 of this distributor plate 7. This is shown in FIG. 3b. According to one embodiment, this can be the last distributor plate 7 of the distributor plate package 6 arranged above the spinneret plate 2. Expediently and in the embodiment according to FIG. 3b, the distributor holes 8 are then round, in particular circular and the diameter of the distributor holes then means in particular the diameter of the circular distributor holes.

[0058] It can also be seen in FIG. 3b that particularly preferably the diameter d.sub.1 of the distributor holes 8 in at least one, preferably in the two CD outer regions 16 of the distributor plate 7 differs from the diameter d.sub.2 of the distributor holes 8 in the center of this distributor plate 7 and that preferably and in this embodiment the diameter d.sub.1 is greater than the diameter d.sub.2. CD outer region 16 of the distributor plate 7 means in this case in particular an outer region of the distributor plate 7 extending parallel to the CD direction, i.e. along the distribution width or spinning width.

[0059] It can be seen in FIGS. 1 and 2 that the distributor holes 8 of the rows arranged one above the other of adjacent distributor plates 7 arranged one above the other are arranged offset with respect to one another in relation to the distribution width B.sub.i. In the embodiment according to FIGS. 1, 2 and 3 it can be seen in this context that the distributor plates 7 of the distributor plate package 6 preferably have distributor passages 12 preferably extending over the spinning width B.sub.i wherein each distributor passage 12 interconnects the distributor holes 8 of one row. According to a preferred embodiment and in the embodiment according to FIGS. 1 and 2, at least in the majority of the distributor plates 7, a distributor passage 12 directly adjoins an adjacent distributor plate 7. In other words, this neighboring distributor plate 7 forms a wall of the adjacent distributor passage 12. Expediently and in this embodiment this distributor passage 12 connects distributor holes 8 of the neighboring distributor plate 7 arranged in a row. As a result, in the preferred embodiment according to FIGS. 1 and 2, it is achieved that the distributor holes 8 and the distributor passages 12 of the distributor plates 7 are connected to one another. Located downstream of the distributor plate package 6 or the distributor plates 7 is an exchangeable spinneret plate 2 which has spinneret passages 9 with the associated spinneret holes 3 distributed over the final spinning width B.sub.e. FIG. 4 shows a spinneret plate 2 with spinneret passages 9 or spinneret holes 3. A plurality of rows of spinneret passages 9 or spinneret holes 3 are arranged next to one another transversely to the final spinning width B.sub.e, in particular in a machine direction MD (FIG. 3a). Within the scope of the invention the distributor holes 8 together with the distributor passages 12 preferably form flow paths for the plastic melt through the distributor plate package 6. Expediently each spinneret passage 9 or each spinneret hole 3 of the spinneret plate 2 and therefore in particular each filament produced is assigned a flow path of distributor holes 8 and distributor passages 12.

[0060] Expediently and in this 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 is curved or crowned over its entire or substantially over its entire extension in the machine direction MD. This can be seen in particular in FIG. 5. In FIG. 5 the perforated passages of the filter plate 5, the distributor holes and the distributor passages of the distributor plates 7 and the spinneret passages and spinneret holes of the spinneret plate 2 are not shown in detail. Preferably and in the embodiment according to FIG. 5, the outlet surface 10 of the filter plate 5 and the inlet surface 11 of the spinneret plate 2 is ground curved or crowned. Thus, the outlet surface 10 and the inlet surface 11 are not planar but rounded or rounded in toward the distributor plate package 6. Expediently and in this embodiment a convex curvature or crowning of the outlet surface 10 of the filter plate 5 and of the inlet surface 11 of the spinneret plate 2 oriented in the direction of the distributor plate package 6 is obtained. As a result, an additional bracing of the distributor plates 7 of the distributor plate package 6 is achieved in particular in a central section or middle section in relation to the machine direction MD. Machine direction MD means within the scope of the invention in particular the conveying direction of a conveyor for the filaments or the nonwoven web produced therefrom and therefore the direction transverse to the spinning width or distribution width. Within the scope of the invention and in this embodiment the curvature or crowning of the filter plate 5 or the spinneret plate 2 is therefore achieved over the entire extension of the outlet surface 10 of the filter plate and the inlet surface 11 of the filter plate in the machine direction MD. Quite particularly preferably and in this 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 substantially constant over the entire extension in the machine direction MD. In the embodiment according to the drawing, the radius of curvature R may be 17,000 mm to 19,000 mm.

[0061] In the operating state of the apparatus 1 according to FIG. 1 a distributor plate package 6 comprising a plurality of exchangeable distributor plates 7 is located downstream of the manifold 4 or the filter plate 5. The distribution widths B.sub.i formed by the distributor holes 8 of the individual distributor plates 7 expediently and in the embodiment according to FIG. 1 increase from the filter plate 5 to the spinneret plate 2. In this way the preliminary spinning width B.sub.v is expanded or increased to the final spinning width B.sub.e. The distribution width B.sub.i therefore increases from distributor plate 7 to distributor plate 7 to the spinneret plate 2. In the operating state of the apparatus according to FIG. 2, a distributor plate package 6 comprising a plurality of exchangeable distributor plates 7 is also located downstream of the manifold 4 or the filter plate 5. Expediently and in the embodiment according to FIG. 2, the distribution widths B.sub.i formed by the distributor holes 8 of the individual distributor plates 7 decrease from the filter plate 5 to the spinneret plate 2. The preliminary spinning width B.sub.v is reduced in this way to the final spinning width B.sub.e. The distribution width B.sub.i therefore decreases here from distributor plate 7 to distributor plate 7 to 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 distributor passages 12. According to an embodiment not shown in detail in the drawing, it is possible that the lower distributor plates 7 of the distributor plate package 6 which are assigned to the spinneret plate 2 have no distributor passages 12 and that the final distribution width B.sub.e is already achieved above this distributor plate 7.

[0062] According to a preferred embodiment of the invention, the final spinning width B.sub.e is at least 1,600 mm, preferably at least 1,800 mm. In the embodiment according to the drawing, the final spinning width may be at least 2,000 mm, for example. It has proved successful that the ratio of the preliminary spinning width B.sub.v to the final spinning width B.sub.e (B.sub.v:B.sub.e) in the case of a reduction of the preliminary spinning width is 1.02 to 1.3 and in the case of an expansion of the preliminary spinning width B.sub.v is 0.8 to 0.97. In the embodiment according to FIG. 1 in which the preliminary spinning width B.sub.v is expanded, the ratio B.sub.v:B.sub.e may be between 0.85 and 0.95. In the embodiment according to FIG. 2 in which the preliminary spinning width B.sub.v is reduced, the ratio B.sub.v:B.sub.e may be 1.05 to 1.15.