Title of Invention

"APPARATUS FOR SPINNING FILAMENTS"

Abstract The apparatus (2) according to the invention for spinning filaments (56) has a heating box (8), a plurality of spinnerets (12) arranged in the heating box (8) and at least one spinning pump (10) arranged on the outside of the heating box (8). A plurality of distributing lines (52) lead from the spinning pump (10) to the spinnerets (12). The spinning pump (10) is surrounded by a heating jacket (14) which is detachably fastened to the heating box (8). The heating jacket (14) is preferably screwed, bolted or welded to the heating box (8). The heating jacket (14) which is detachably fastened to the heating box (8) can be taken off in the event of a failure, thus making the spinning pump (10) and the mating surface (sealing surface) easily accessible. The spinning apparatus (2) according to the invention is also of advantage in the event of a leak, which mat occur in particular at the transitions between the spinning pump (10) and the distributing lines (52). Fig. 1
Full Text Apparatus for spinning filaments
The present invention relates to an apparatus for spinning filaments, having a heating box, a plurality of spinnerets arranged in the heating box and at least one spinning pump arranged on the outside of the heating box, there being provided a. melt line leading to the spinning pump, a plurality of distributing lines leading from the spinning pump to the spinnerets, and a heating jacket surrounding the spinning pump.
Known from the prior art are pieces of apparatus for spinning filaments which comprise essentially an extruder or other unit for producing melt, such as directly from a reaction vessel for example, one or more spinning bars, an air-blast duct, a preparing means and a stretching unit. The spinning bar generally comprises a heating box, a spinning pump and a plurality of spinnerets arranged in a row. The extruder feeds the melted thermoplastic material to the spinning pump via a melt line. The spinning pump distributes the melted material via distributing lines to the spinnerets, from which the material emerges in the form of filaments. In the air-blast duct which follows, the filaments are cooled and are prepared with a preparing liquid, which makes the subsequent processing
easier. The filaments are then guided through a stretching unit, which comprises a plurality of stretching rollers for example, in order finally to be wound up into a reel.
When thermoplastic filaments are being spun, things that have a crucial influence on the quality of the filaments are the uniform temperature of the melt and the dwell time of the melt m the apparatus. It has proved advantageous for the temperature of the melt to be kept as near constant as possible during its passage. For this purpose, it is necessary for the components of the apparatus through which the melt passes to be heated to counteract any loss of heat through the components into the surroundings. As a rule, this is done by arranging the components through which the melt passes in the heating box.
In this way, DE 19g 24 946 Al proposes a spinning bar having a heating box, the heating box comprising essentially two elongated heating chambers into which a heating medium, such as diphyl vapour for example, is introduced. The spinnerets, which are arranged in a row, and the spinning pump are arranged between those surfaces of the two heating chambers which face one another. There is also a thermally insulating cover provided above the spinning pump. Both the spinning pump and the spinnerets are thus heated up laterally by the two
heating chambers. Furthermore, there is arranged between the spinning pump and the spinnerets what is termed a pump block, which is of gas-tight design and which is filled with a heating medium. The pump block produces an equalisation of temperature between all the adjacent components, thus enabling the aim of a uniform temperature of the melt during its passage through the components to be achieved.
A piece of apparatus for spinning filaments is also known from DE 198 09 495 Al and in this case the heating box simply forms a chamber, with the melt line, the distributing lines and the spinnerets being arranged in the heating box. The heating box is heated by a medium in vapour form. In contrast to the prior art described above, the spinning pump is not arranged inside the heating box but on the outside of the heating box. This enables the spinning pump to be serviced or repaired more easily in the event of a fault in its operation. The heating of the spinning pump is accomplished in this case by the transmission of heat through the wall of the heating box. This however produces inadequate heating of the spinning pump, which means that a constant temperature is not obtained for the melt during its passage.
To overcome this problem, DE 199 24 83 8 Al proposes a spinning apparatus for spinning melted polymers in which a spinning
pump, which is connected to the heating box via a supporting structure, is surrounded by a heating jacket which is solidly connected to the supporting structure. The purpose served by the supporting structure in this case is to space the spinning pump away from the heating box so that the two regions are decoupled thermally. The intention is for the spinning pump to be heated solely by the heating jacket which surrounds it. The heating box and heating jacket may be heated both in unison and by mectns of separate heating circuits.
The prior art described above has the disadvantage either that there is no guarantee of a constant temperature for the melt during its passage through the components or that it is more difficult for the spinning pump to be repaired or stripped out in the event of a failure. What is meant by a failure is, in particular, a leak at the spinning pump itself or at the transitions between the spinning pump and the melt line or the distributing lines, or a fault in the spinning pump.
The object underlying the present invention is thus to provide an apparatus for spinning filaments which ensures a constant temperature for the melt during the passage of the melt through the components and which simplifies the repair of the mating surface with the spinning arrangement and the pump and
the stripping out of the spinning pump in the event of a failure.
This object is achieved in accordance with the invention by virtue of the features specified in claim 1. Advantageous embodiments of the invention form the subject matter of the sub-claims.
The apparatus according to the invention for spinning filaments has a heating box. What may be introduced into a heating box of this kind is for example a heating medium in vapour form which is -fed out of the heating box again within a circuit. Arranged in the heating box are a plurality of spinnerets, what is to be understood by this being that the spinnerets may be inset both directly into the heating box and also into a depression in the wall of the heating box. Also, there is a spinning pump arranged on the outside of the heating box. This may for example be a planetary-geared pump having one inlet and a plurality of outlets. Provided in addition to this are a melt line leading to the spinning pump, a plurality of distributing lines leading from the spinning pump to the spinnerets, and a heating jacket surrounding the spinning pump. In accordance with the invention, the heating jacket is detachably mounted on the heating box and fastened thereto.
The apparatus according to the invention has the advantage on the one hand that the spinning pump can be heated to an adequate degree by the heating jacket, thus ensuring that the temperature of the melt is constant during the passage of the melt through the components, and on the other hand that in the event of a failure the spinning pump can be stripped out easily and the pump and the sealing surface on the heating box can be repaired easily. In this way, the heating jacket, which is detachably fastened to the heating box, can be taken off in the event of a breakdown in the operation of the spinning pump, thus making the spinning pump and the mating surface (sealing surface) easily accessible. The apparatus also affords a benefit in the event of a leak, which may occur particularly at the transitions between the spinning pump and the melt line or the distributing lines. In this case the space enclosed by the heating jacket fills with the melt that leaks out, which hardens there. To enable the hardened material to be removed together with the spinning pump, it is merely necessary for the heating jacket and the spinning pump to be detached and taken off. The removal of the hardened material from the heating jacket and from the spinning pump can then be performed elsewhere, while a new spinning pump and a new heating jacket can be fitted to the apparatus to ensure that the apparatus can go on operating and to minimise downtimes.
In an advantageous embodiment of the invention the heating jacket is fastened to the heating box by means of screws or bolts. It is particularly preferable for the heating box to be fastened to the heating box by means of point welds, because point welds on the one hand produce the requisite fastening and on the other hand allow the heating jacket to be detached easily from the heating box. The spot welds can be destroyed with simple tools.
In a particularly preferred embodiment of the apparatus according to the invention, the heating box has a carrier plate which is mounted on the outside and on which and to which the spinning pump and the heating jacket are mounted and fastened. It is particularly easy for an apparatus of this kind to be produced because the carrier plate can be produced and worked on separately from the rest of the heating box. This is an advantage in that the carrier plate, which does in fact form the mating surface for the spinning pump, needs to be produced with great accuracy to enable the spinning pump to be sealed without additional sealing materials and to stop the melt from escaping. A high standard of sealing is thus ensured for the apparatus.
In a further preferred embodiment of the invention, the carrier plate has a surrounding collar which projects outwards
radially. The surrounding collar, on which the heating jacket is mounted and to which it is fastened, is spaced away from the surface of the heating box. In this way, the heating jacket remains largely unaffected thermally by the heating box, which means that the two heating circuits are easy to control. The invention does not however rule out the possibility of the heating jacket and heating box having a common heating circuit.
In a further advantageous embodiment of the invention, there are preferably provided in the carrier plate an inlet opening for the infeed of melt to the spinning pump via the melt line and a plurality of outlet openings for the outfeed of the melt from the spinning pump into the distributing lines.
To enable not only the spinning pump and the spinneret but also the other components of the apparatus to be heated, the distributing lines and at least part of the melt line are arranged in the heating box in a particularly preferred embodiment of the apparatus according to the invention. In this way, the temperature of the melt is kept at a constant level during the entire passage of the melt, namely within the lines as well.
To enable that portion of the melt line which extends between the heating box and the melt infeed means (e.g. an extruder) to be heated as well, the heating box has a tubular, projecting extension through which the melt line extends. It is thus inside the tubular extension, which forms part of the heating box, that the melt line is run to that region of the heating box in which the spinnerets are situated. In this way the melt, on its way from the melt infeed means to the spinning pump, does not change to a temperature which is lower than in the other parts of the apparatus.
The heating jacket is preferably in the form of a twin-tube jacket and has an inlet and an outlet for a heating medium. What is meant by a twin-tube jacket is a jacket of which the inside is formed by a first tube of smaller diameter and of which the outside is formed by a second tube of larger diameter, with an intervening space being formed between the two.
To make it easier for the spinnerets to be fitted and removed, the latter are arranged, in a particularly preferred embodiment of the invention, within a row of outward facing depressions in the heating chamber, the row of depressions being enclosed by the space within the heating box. This latter fact means that, inside the heating box, the heating
medium is able to surround the depressions and is thus able to effect highly uniform heating of the spinnerets inserted therein.
In a particularly advantageous embodiment of the apparatus according to the invention, the heating box and the heating jacket each have heating circuits of their own. In this way it is possible for the components to be heated differently, thus enabling a possible difference in temperature, which arises for example due to differences in pressure in the components, to be counteracted by appropriate controlling action.
In what follows, the invention will be explained in more detail by reference to an illustrative embodiment and to the accompanying drawings .-
In the drawings:
Fig. 1 is a partial side elevation, in section, of the
apparatus according to the invention and
Fig. 2 is a perspective view of the apparatus of Fig. 1.
Fig. 1 is ci partial view of the apparatus according to the invention. To provide a better understanding, Fig. 2 is a perspective view of the apparatus of Fig.1 , certain of the
components shown in Fig. 1 having been omitted in this case from considerations of clarity.
The apparatus 2 for spinning filaments has, in essence, an extruder 4 or other melt-producing unit, such for example as a reaction vessel, a spinning bar 6 and, connected downstream, a plurality of means for applying further processing to the filaments produced, the means connected downstream not having been shown. The spinning bar 6 comprises essentially a heating box 8, one or more spinning pumps 10, only one of which is shown, a plurality of spinnerets 12, which have not been shown in Fig. 2, and a heating jacket 14 for each of the spinning pumps 10.
The heating box 8 has at least one inlet and one outlet (not shown) for a heating medium, such for example as diphyl vapour, so that the heating medium can make its way into the enclosed space 16 within the heating box 8. Provided in the filament exit side of the heating box 8 is a row of cylindrical or quadrilateral depressions 18 which face outwards (Fig. 2). The spinnerets 12 are arranged in the depressions, which means that the spinnerets 12 are, in a sense, arranged in the heating box 8 without however being arranged directly in the space 16 within the heating box 8. The row of depressions 18 is surrounded by the space 16 within
the heating box 8, thus enabling the spinnerets 12 to be heated by the heating medium through the walls of the depressions 18.
The heating box 8 also has a tubular, projecting extension 20 which encloses a space 22 which is in flow-permitting connection with the space 16 within the heating box 8. The tubular extension 20 extends as far as the extruder 4, where it is sealed off at the end face to prevent the heating medium from escaping.
On the side of the heating box 8 remote from the depressions 18 is provided a carrier plate 24 which is mounted on from outside. The carrier plate 24 is circular in configuration and is fastened in place in a circular aperture 26 in the heating box 8 in such a way as to ensure that the latter is sealed., Through the carrier plate 24 extend an inlet opening 28 and a plurality of outlet openings 30. Provided on the side of the carrier plate 24 remote from the heating box 8 is a surrounding collar 3 2 which projects outwards radially. The collar 32 thus forms a sort of flange. The collar 32 is spaced away (a) from the surface of the heating box 8, as can be seen in particular in Fig. 1. Also, there is provided in the face of the carrier plate 24 which faces outwards a groove 34
extending round in a circle which surrounds a mating surface 36.
The spinning pump 10, which may for example be a planetary-geared pump, is arranged on the outside of the heating box 8. This being the case, it is fastened to the mating surface 36 of the carrier plate 24 in such a way that liquid melt can make its way through the inlet opening 28 and into the spinning pump 10 and can emerge again through the outlet openings 30. The spinning pump 10 is also surrounded laterally by the heating jacket 14, in which case there should also be a cover provided at the top but this has not been shown from considerations of greater clarity.
The heating jacket 14 is in the form of what is termed a twin-tube jacket, i.e. it: comprises in essence an inner tube 3 8 and an outer tube 40, between which is located an annular space 4 2 for a heating medium. Where the heating is electrical, use is made of only a single tube which is surrounded by heating bands. The ends of this space 42 are closed off to ensure that it is sealed. The heating jacket 14 also has an inlet 44 and an outlet 46 for the heating medium. The heating medium may be carried in a circuit, (not shown) which may be connected to the heating circuit for the heating box 8 but which preferably takes the form of a separate heating circuit.
The heating jacket 14 is detachably mounted on and fastened to the heating box 8. In the present embodiment, the heating jacket 14 is detachably mounted on and fastened to the carrier plate 24 of the heating box 8, or to be more exact on and to the collar 32 of the carrier plate 24. The detachable fastening is advantageously accomplished by means of spaced point welds 48 between the collar 32 of the carrier 24 and the heating jacket 14. On the one hand the point welds 48 ensure that the heating jacket is securely held in place and on the other hand they enable it to be detached easily with conventional tools. Detachable fastening may of course also be accomplished with screws or bolts or the like but the method shown is preferred for the reasons given above.
The apparatus 2 also has at least one melt line 50 per spinning pump 10. Starting from the extruder 4, the melt line 50 extends through the tubular extension 20 and into the space 16 within the heating box 8, where it opens into the inlet opening 28 in the carrier plate 24. Also extending through the space 16 within the heating box 8 are a plurality of distributing lines 52 which, starting from the outlet openings 30 in the carrier plate 24, run to the spinnerets 12.in the depressions 18. To enable connections to be made between
the distributing lines 52 and the spinnerets 12, suitable openings 54 are provided in the walls of the depressions 18.
The way in which the apparatus 2 operates will be described in what follows. The extruder 4 extrudes the melt into the melt line 50, which is heated by the heating medium (not shown) in the space 22 in the tubular extension 20 and in the space 16 within the heating box 8. Via the melt line 50, the melt makes its way into the spinning pump 10. The spinning pump 10 is heated by the heating jacket 14 surrounding it. Via the distributing lines 52, the melt is finally fed to the spinnerets 12, from which the melt emerges in the form of a large number of individual filaments 56 to then be subjected to further processing.
Occasionally, breakdowns in the operation of an apparatus for spinning filaments are due to a leak at the spinning pump or in the region of the point of connection between the spinning pump and heating box. In the embodiment shown, the apparatus according to the invention counteracts this possibility firstly in that a carrier plate 24 is provided which is mounted on from outside, i.e. which is first produced as a separate, individual part. Because the carrier plate 24 can first be produced as a separate individual part, it is possible for the mating surface 36 for the spinning pump 10 tobe produced with substantially greater accuracy before the carrier plate 24 is mounted on the heating box. In particular, this counteracts the possibility of a leak at the point of connection between the carrier plate 24 and the spinning pump 10.
If a leak occurs in conventional pieces of apparatus, the melt escapes in the region of the spinning pump and then hardens. It is then a very difficult matter both to strip out the spinning pump and to repair it. By contrast, the apparatus according to the invention has the advantage that the detachable heating jacket 14, together with the melt that has hardened in it and the spinning pump 10 surrounded by it, can be detached, to enable it to be removed easily and repaired elsewhere. In the meantime, a new spinning pump and a new heating jacket can straightaway be fitted onto the spinning bar 6 to enable the apparatus 2 to continue in operation. The detachment of the point welds 48 can be accomplished by applying a lever or wedge to them.
The operation of the heating box 8 and heating jacket 14 by means of mutually divorced heating circuits also enables those components which may generate different temperatures due to the ways in which they operate to be heated independently. "In this way, the temperature inside the spinning pump 10 forexample rises more sharply due to the high pressure therein, which means that a difference in temperature may arise between the melt in the melt line 50 and the melt in the spinning pump 10. Hence, by a difference in heating, it can be ensured that the temperature of the melt is constant during its passage through the components.






We Claim:
1. Apparatus for spinning filaments (56), having a heating box (8), a plurality of spinnerets (12) arranged in the heating box (8) and at least one spinning pump (10) arranged on the outside of the heating box (8), there being provided a melt line (50) leading to the spinning pump (10), a plurality of distributing lines (52) leading from the spinning pump (10) to the spinnerets (12), and a heating jacket (14) surrounding the spinning pump (10), characterized in that the heating jacket (14) is detachably mounted on and fastened to the heating box (8).
2. Apparatus according to claim 1, wherein said heating jacket (14) is fastened to the heating box (8) by means of screws or bolts, or preferably by means of point welds (48).
3. Apparatus according to claim 1 or 2, wherein said heating box (8) has a carrier plate (24) mounted on the outside, on which the spinning pump (10) is arranged and on which and to which the heating jacket (14) is mounted and fastened.
4. Apparatus according to claim 3, wherein said carrier plate (24) has a surrounding collar (32) which projects outwards, which is spaced away (a) from the surface of the heating box (8) and on which and to which the heating jacket (14) is mounted and fastened.
5. Apparatus according to claim 3 or 4, wherein there are provided in the said carrier plate (24) an inlet opening (28) for the infeed of melt to the spinning pump (10) via the melt line (50) and a plurality of outlet openings (30) for the outfeed of melt from the spinning pump (10) into the distributing lines (52).
6. Apparatus according to one of the foregoing claims, wherein said distributing lines (52) and also at least part of the melt line (50) are arranged in the heating box (8).
7. Apparatus according to claim 6, wherein said heating box (8) has a tubular, projecting extension (20) through which the melt line (50) extends.
8. Apparatus according to one of the foregoing claims wherein said heating jacket (14) is in the form of a twin-tube jacket and has an inlet and an outlet (44, 46) for a heating medium.
9. Apparatus according to one of the foregoing claims, wherein said spinnerets (12) are arranged within a row of outward facing depressions (18) in the heating box (8), the row of depressions (18) being surrounded by the space (16) within the heating box.
10. Apparatus according to one of the foregoing claims, wherein said heating box (8) and the heating jacket (14) each have a heating circuit of their own.

Documents:

1371-del-2005-abstract.pdf

1371-DEL-2005-Assignment-(26-09-2008).pdf

1371-del-2005-claims.pdf

1371-del-2005-complete specification (granted).pdf

1371-DEL-2005-Correspondence-Others-(26-09-2008).pdf

1371-del-2005-correspondence-others.pdf

1371-del-2005-correspondence-po.pdf

1371-del-2005-description (complete).pdf

1371-del-2005-drawings.pdf

1371-DEL-2005-Form-1-(26-09-2008).pdf

1371-del-2005-form-1.pdf

1371-del-2005-form-13 -(26-09-2008).pdf

1371-del-2005-form-13-(26-09-2008).pdf

1371-del-2005-form-18.pdf

1371-DEL-2005-Form-2-(26-09-2008).pdf

1371-del-2005-form-2.pdf

1371-del-2005-form-26.pdf

1371-del-2005-form-3.pdf

1371-DEL-2005-Form-5-(26-09-2008).pdf

1371-del-2005-form-5.pdf

1371-del-2005-form-6-(26-09-2008).pdf

1371-del-2005-form-6.pdf

1371-DEL-2005-Others-Document-(26-09-2008).pdf

abstract.jpg


Patent Number 226561
Indian Patent Application Number 1371/DEL/2005
PG Journal Number 01/2009
Publication Date 02-Jan-2009
Grant Date 18-Dec-2008
Date of Filing 27-May-2005
Name of Patentee ZIMMER AG
Applicant Address BORSIGALLEE 1, 60388 FRANKFURT AM MAIN, GERMANY.
Inventors:
# Inventor's Name Inventor's Address
1 TIETZE, RAINER MOZARTSTRASSE 5, D-64569 NAUHEIM, GERMANY
2 HELMSTORFF, BERND WANDERSMANNSTRASSE 47 D-65205 WIESBADEN, GERMANY
PCT International Classification Number D01D 1/09
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 10 2004 028 918.2 2004-06-15 Germany