CN1324171C - Spinneret assemblies for the production of rayon threads and fibers - Google Patents

Abstract

A spinning head assembly for producing synthetic threads and fibres has a housing (2) which accommodates a nozzle block (3). The nozzle group (3) comprises a nozzle block upper part (6) resting on a support part (5), and a nozzle (4) arranged below the support part and supported by the housing (2). The upper part of the spinning head assembly and the support part enclose a filtering space (25). The nozzle group is supported in the housing in such a way that, when pressure is applied to the sand reservoir (25), the seal (30) between the support part (5) and the nozzle (4) is axially compressed, the freedom of movement in the axial direction being limited by a stop (17). Thus, the filtering space can be reliably sealed from the housing both when pressure is applied to the spinning head assembly and in a pressureless state.

Description

Spinneret assemblies for the production of rayon threads and fibers

The present invention relates to a spinneret pack for the production of rayon yarns and fibers having a housing housing a nozzle block having a spinneret upper part, a support part and a nozzle.

Melt spinning equipment with at least one spinneret assembly is used for the production of rayon threads and fibers. The spinneret assembly of the known spinning device has a housing which accommodates the nozzle group. The nozzle group generally includes a spinneret pack upper part, a support part and a nozzle arranged one after the other in a flow direction.

DE 42 36 570 A1 and DE 33 24 833 A1 disclose nozzle groups with an upper part of the spinneret assembly and a nozzle arranged in a cylindrical housing.

EP 0 931 863 A2 (US-A-5,662,947) describes a spinneret assembly with such a nozzle group as described above. In this example, a conical ring seal is used to seal the nozzle block from the support plate. As the upper part of the spin pack, a peripherally layered displacement body with holes in the outer ring is located within the conical ring seal. A bowl-shaped support plate is supported on the plate-shaped nozzle inserted into the housing. Thus, an outer peripheral edge of the bowl-shaped support plate rests against the nozzle plate, and an annular seal is provided on the peripheral edge between the support plate and the nozzle plate. The upper part of the spinneret assembly and the supporting part rely on a compression ring to support each other.

The bowl-shaped support plate encloses a cylindrical filter space, which works when it is under pressure. When the pressure acts on the filter space, the above-mentioned melt will exert a radial force on the ring seal, which is pressed against the outer periphery by this pressure. As a result, although the sealing is completed between the outer peripheral surface of the annular seal and the inner peripheral surface of the outer shoulder, the passage of the melt to the outside is thereby prevented, which on the one hand still allows the melt to pass through the annular seal and the outer shoulder. The horizontal gap between the shoulders, on the other hand also passes through the horizontal gap between the ring seal and the support plate. These gaps are caused by the lack of axial support of the subsequent seal when excessive settling occurs. There are basically two cases in which the filter space/nozzle group is pressurized and unpressurized.

Furthermore, when pressure acts on the filter space, the material of the ring seal can flow into the gap. In practice, this leads to the formation of residues inside the housing that are difficult to remove.

Another disadvantage is that it is difficult to remove filter material, especially filter sand, from the bowl-shaped support part. These residues generally remain on the walls of the bowl support.

Based on this, the object of the present invention is to provide a spinneret assembly whose nozzle group can be reliably sealed to the housing both when pressure is applied to the filter space and in the non-pressurized state, thereby ensuring high product quality.

According to the invention, this object of the invention is achieved by a spinneret assembly having a housing housing a group of nozzles having an upper part of the spinneret assembly resting on a support part, and a The nozzle under the supporting part and supported on the shell, the upper part of the spinning head assembly and the supporting part enclose a filter space, and the seal is arranged between the supporting part and the nozzle, wherein the nozzle group is supported in the shell in the following way When pressure is applied to the filter space, the seals for sealing between the support part and the nozzle are pressed together axially, and the freedom of movement in the axial direction is limited by a stopper.

The nozzle block of the spin pack according to the invention is known as a self-sealing nozzle block, the supporting part being pressed against the nozzles when pressure is applied to the filter space. The nozzle group is supported in the housing in such a way that when pressure is applied to the filter space, the means for sealing between the support part and the nozzles can be pressed together axially.

The support portion is substantially not supported on the nozzle, but only on the seal so as to axially compress the seal. On the one hand, this ensures that the melt cannot pass through the horizontal gap between the support plate and the nozzle, and on the other hand, between the seal and the nozzle.

However, in the spinneret pack according to the invention, the freedom of movement of the support portion within the housing is limited by a stopper. This stop ensures that excessive deformation of the seal is excluded.

In the spinneret pack according to the invention, regardless of the pack tolerances, since the press-fit of the seal between the support part and the nozzle takes place axially, when pressure is applied to the filter space and in the unpressurized state , can ensure a reliable seal.

Furthermore, advantageously, the housing does not come into contact with the product flow, but only serves as an axial support for the nozzle group. Since the housing does not absorb any radial forces at all, only a small wall thickness is required, which in turn leads to relatively small housing dimensions.

In a particularly preferred embodiment, the support part has a shoulder which engages outwardly on the nozzle, and the stop of the support part is a collar which is located inside the housing below the shoulder of the support part. Since the shoulder of the supporting part surrounds the sealing element in an annular shape, a cavity for receiving the sealing element is formed. This cavity prevents the seal material from flowing under high pressure.

Preferably, the shoulder of the support part and the collar of the housing are designed in such a way that, after inserting the means for sealing between the support part and the nozzle, there is a gap between them when the filter space is in a depressurized state. There is always a definite gap. This gap is dimensioned such that the shoulder of the support part does not rest on the collar even after the seal is secured.

The nozzle block is preferably axially supported within the housing by means of a thrust ring screwed into the housing. Since the internal pressure in the filter space is used to generate the necessary pressure, usually only a small prestressing force is sufficient to seal the nozzle block.

The seal is preferably formed by a flat seal which is arranged between the support part and the nozzle and encloses a single or multilayer filter disc. Instead of a flat seal, it is also possible to arrange a separate filter disc, called an edged single-layer or multi-layer filter disc, between the support part and the nozzle. Such filter discs have one or more mesh layers bordered by an annular seal. The seal is suitably a ring, especially an aluminum ring, with a U-shaped or C-shaped cross-section, surrounding the mesh layer.

The separating surface between the spinneret upper part and the support part is preferably sealed with an annular seal located in a peripheral recess of the spinneret upper part and the support part, so that the filter space is free from dead spaces and voids.

In a further preferred embodiment, the upper part of the nozzle head has a cap shape, and the supporting part is a supporting plate. This embodiment has the advantage, compared to nozzle groups with a bowl-shaped support part, that the feeding and removal of the filter discs, in particular filter sand, into and out of the filter space is simplified. During the disassembly of the nozzle block, the filter residue adhering to the support plate will be loosened. When the upper part of the spinning head assembly is lifted off, the filter residue can be completely removed without any residue.

The purpose of this embodiment is to make it possible to fix a plurality of spinnerets one after the other on a spin beam. This presupposes the smallest possible outer diameter of the spinneret pack.

Therefore, in another preferred embodiment, the replaceable spinneret assembly is secured to the overall spinning system or spin beam, preferably in the form of a snap action fastener. This fastener is located on the top of the spinneret assembly. The fastener is suitably a bayonet coupling. Since the torque for closing or opening the fastening element acts on the nozzle tip upper part via the housing, the nozzle tip upper part is held against twisting in the housing.

A preferred embodiment of the spinning head assembly is described in detail below with reference to the accompanying drawings, in the figure:

Fig. 1 shows the housing and the nozzle group of the first preferred embodiment of the spinneret assembly in a perspective view,

Figure 2 shows the spinneret assembly in Figure 1 in a sectional view,

FIG. 3 shows detail A in FIG. 2 in an enlarged view,

Figure 4 shows a second preferred embodiment of the spinneret assembly in a cross-sectional view, and

FIG. 5 shows detail B from FIG. 4 in an enlarged view.

Figure 1 shows a first preferred embodiment of a spinneret pack 1 in a perspective view. The spinneret pack 1 has a substantially tubular housing 2 accommodating a nozzle array 3 . The housing 2 is constructed according to the known top-loading principle, ie the various parts comprising the nozzle set 3 described in detail below are inserted into the housing from above. Figure 1 shows the housing in the position of use, which is secured to a spinning beam. The direction of flow of the product stream is indicated by A in FIG. 1 .

The nozzle block 3 has a nozzle 4 , a support plate 5 and a nozzle head top 6 . The nozzle 4 is a disc with a plurality of continuous holes 7, only two of which are shown in FIG. 1 as an example. It is supported by an outer peripheral shoulder 8 on an inner peripheral shoulder 9 on the underside of the housing 2 .

The support plate 5 has a plate-shaped body 10 with a plurality of continuous distribution ducts 11 having an upwardly tapering peripheral extension 12 and a lower peripheral extension 13 . The lower extension 13 has a downwardly projecting horizontal sealing surface 14 adjoining a shoulder 15 which projects further downwardly and engages the support plate 4 ( FIG. 3 ). A vertical sealing surface 16 is formed on the inner side of the shoulder 15 with an essentially rectangular cross-section. Below the shoulder 15 the housing 2 has a collar 17 .

The support plate 5 is sealed to the nozzle 4 by means of an edged multi-layer filter sheet 18 arranged between the support plate and the nozzle. The multilayer filter 18 has mesh layers 19 bordered by an aluminum sealing ring 20 with a flat U-shaped cross-section. The sealing ring 20 is located in a cavity defined by the horizontal sealing surface 21 of the nozzle 4 and the horizontal sealing surface 14 and the vertical sealing surface 16 of the support plate 5 .

On the edged multi-layer filter sheet 18, a distribution space 22 with a height of 0.5-4 mm is formed between the support plate 5 and the nozzle 4. However, such allocation of space is not required.

The bowl-shaped nozzle head upper part 6 has a cover part 23 and a cylindrical part 24 , via which the nozzle head upper part rests on the upper peripheral shoulder 12 of the support plate 5 . The upper part 6 of the spinning head assembly and the support plate 5 enclose a cylindrical filter space 25 .

The upper part of the spin pack surrounds the filter space 25 completely, tightly and in the form of a hood. Since the filter space 25 can be filled with sand, it is also possible to design the filter space as a sand storage space. It is also possible to loosely insert the individual filter sheets 26 leaning against the support plate 10 into the sand storage space, and the number of individual filter sheets determines the degree of filtration and the pressure difference.

The separating surface 27 between the cylindrical part 24 of the spin pack upper part 6 and the upper shoulder 12 of the support part 10 is sealed by an annular seal 28 . The annular seal 28 is seated in an annular groove 29 formed in the cylindrical portion 24 and the shoulder 12 . It is flush with the wall of the sand storage space 25 .

The cover part 23 of the spinneret upper part 6 has a central groove 30 designed to receive a bayonet coupling, by means of which the spinneret 1 is placed from above on the melt supply pipe of the spinning beam, not shown. The polymer is supplied to the sand storage space 25 via a melt conduit 31 located in the middle of the tank 30 of the covering part 23 . In order to seal the spinneret package 1 from the melt supply line, a sleeve-type seal 32 is arranged in the melt line 31 .

The nozzle group 3 is supported in said housing by means of a thrust ring 33 screwed into the housing 2 . The thrust ring 33 supported on the outer collar 34 of the cover part 23 of the spinneret upper part 6 exerts an axial prestress on the nozzle group 3 which is sufficient to utilize the annular seal 20 in the depressurized state against each other. The support plate 5 is sealed to the nozzle 4 . In this case, the spin pack upper part 6 and the support plate 4 have no gaps within the housing 2 . When pressure is applied to the sand storage space 25, the support plate 5 is pressed onto the sealing ring 20, and the separation surface 27 between the upper part of the spinning head assembly and the support plate, which is sealed by the annular seal 28, is pressed radially to the seal. face. The sealing ring 20 between the support plate and the nozzle is only compressed in the axial direction, since the cavity of the edged filter disc 18 prevents the flow of material. The outer shoulder 15 of the support plate 5 and the collar 17 of the housing 2 are dimensioned such that a defined gap X ₁ remains between the shoulder and the collar in the unpressurized state. Under pressure, the gap decreases in size until the support plate abuts against the housing. The freedom of movement in the axial direction is thus limited.

The upper part 6 of the spinning head assembly is fixed in the casing 2 by pins 35, 36 against twisting.

The following is a brief description of the work of the spinneret assembly.

Via a melt supply pipe not shown, the polymer enters the sand storage space 25 through the melt pipe 31 of the upper part 6 of the spinneret assembly, and before the polymer passes through the distribution hole 11 of the support plate 5 into the distribution space 22, it There it is filtered by filter sand and loose individual filter layers 26 . After passing through the multi-layer filter sheet 18, the melt enters the nozzle duct 7 of the nozzle 4, so that threads or fibers are ejected from the nozzle.

In order to remove the spinning head assembly 1 , it is only necessary to loosen the thrust ring 33 and take the upper part 6 of the spinning head assembly out of the casing 2 . At the same time, the filter sand adhered to the support plate 5 is loosened from the wall of the filter space 25 without any residue. Subsequently, the filter sand is removed from the housing 2 together with the support plate 5 and the nozzle 4 . The installation of the spinning head assembly is carried out in reverse order.

Figures 4 and 5 show a second preferred embodiment of the spinneret assembly. This embodiment differs from the preferred embodiment described with reference to FIGS. 1-3 only in that, instead of an edged multilayer filter, a multilayer filter is arranged with a separate annular seal between the support plate and between nozzles. Parts of the spinneret pack in Figures 4 and 5 corresponding to those in Figures 1-3 are designated by the same reference numerals. The multilayer filter in FIGS. 4 and 5 is indicated by the reference numeral 37 and the annular seal by the numeral 38 . The annular seal 38 , which is likewise only axially compressed, consists of an elastic material and has a rectangular cross section. There are no other structural and functional differences between the two preferred embodiments.

Claims (12)

1. A spinneret assembly (1) having a housing (2) for accommodating a nozzle group (3), the nozzle group (3) having an upper part of the spinneret assembly ( 6), and a nozzle (4) arranged under the support part and supported on the shell, the upper part of the spinning head assembly and the support part surround a filter space (25), and the seals (20, 38) are arranged on Between the support part and the nozzles, wherein the nozzle group (3) is supported in the housing in such a way that when pressure is applied to the filter space, the seals (20, 38) used to seal between the support part and the nozzles are compressed axially Together, the freedom of movement in the axial direction is limited by a stop (17). 2. The spinning head assembly according to claim 1, characterized in that, the supporting part (5) has a shoulder (15) that engages outward on the nozzle (4), and the stopper is a Collar (17) on the inside, under the shoulder of the support section. 3. The spinneret assembly according to claim 2, characterized in that the shoulder (15) of the support part (5) and the collar (17) of the housing (2) are designed to seal the support part when inserted After the seals (20, 38) between the housing and the housing, there is a certain gap X ₁ between them when the filter space (25) is in a non-pressurized state. 4. The spinning head assembly according to any one of claims 1-3, characterized in that the nozzle group (3) can be axially supported on the casing (2) by utilizing a thrust ring (33) that can be screwed into the casing )Inside. 5. The spinning head assembly according to claim 1, characterized in that the seal (20, 38) consists of an annular seal (38), which is arranged between the support part (5) and the nozzle (4) , and surround a single-layer or multi-layer filter sheet (37). 6. spinning head assembly as claimed in claim 1 is characterized in that, seal (20,38) is made of a single-layer or multi-layer filter sheet (18), and it is arranged on support part (5) and nozzle ( 4) between, and be edged by a seal ring (20). 7. The spinning head assembly according to claim 1, characterized in that, the separation surface (27) between the spinning head assembly upper part (6) and the support part (5) is sealed by an annular seal (28) . 8. The spinneret pack according to claim 7, characterized in that the spinneret pack upper part (6) and the support part (5) form a peripheral recess (29) into which the annular seal (28) is inserted. 9. The spinneret assembly according to claim 1, characterized in that the nozzle head upper part (6) has a cap-like form and the supporting part is a supporting plate (5). 10. The spinneret assembly according to claim 1, characterized in that a single-layer or multi-layer filter (26) is arranged on the support part (5). 11. The spinneret pack according to claim 1, characterized in that a distribution space (22) is arranged between the support part (5) and the nozzle (4). 12. The spinning head assembly as claimed in claim 1, characterized in that, the spinning head assembly top (6) has a fixing member (30) for fixing the spinning head assembly (1) to the spinning head, The upper part of the spinning head assembly is fixed in the casing (2) against torsion.

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