Patent Application
20140366348
The invention relates to a crimping apparatus for crimping a multifilament bundle in a melt spinning process.
In the manufacturing of crimped threads in a melt spinning process crimping of the threads is caused by stuffing the filament bundles to form in each case a thread plug. In this known process, on account of stuffing the filament bundles, the filaments are deposited as loops and arcs and compressed to form the thread plugs, such that, after disintegration of the thread plug, a thread having crimped filaments is produced. The shape of the crimp contained in the filaments here essentially depends on the thermal processing of the thread plug. In order to enable dwelling times for temperature-control of the thread plug that are as long as possible, processing units in which the thread plug produced after stuffing is guided with multiple enlacements on a processing drum have been successful in the prior art.
A crimping apparatus of such type is known from DE 26 32 082, for example. In the known crimping apparatus, a conveyor nozzle, a stuffer box and a processing unit with a processing drum are disposed below one another. In principle, two different positions of the processing drum for receiving and guiding a thread plug guided out of the stuffer box are known here. In a first variant, the axis of the processing drum is oriented substantially horizontally, such that, in the case of multiple enlacements on the circumference of the processing drum, the thread plug has to be guided substantially in the horizontal direction. In this arrangement of the processing drum the windings of the thread plug on the circumference of the drum wall have to be displaced in order to obtain a helical profile of the thread plug on the circumference of the processing drum. Depending on the properties of the drum wall, entanglements of adjacent windings of the thread plug that are more or less intense may arise here. In addition, indexing means are used. In order to axially displace the windings of the thread plug.
In a second variant of the arrangement of the processing drum, the latter, with its axis, is substantially vertically oriented, such that the helically guided thread plugs on the circumference of the processing drum experience natural support of their indexing movement on the circumference of the drum wall. To this extent, comparatively slight indexing forces are required in order to guide the helical profile of the thread plug from the upper end of the processing drum to a lower end of the processing drum. Here, infeeding of the thread plug takes place by an upstream deflection between the stuffer box and the processing chamber. Deflections of this type typically represent a zone which, for temperature control of the thread plug, is uncontrolled and, wherever possible, they should be implemented as short as possible.
It is an object of the invention to provide a crimping apparatus for crimping a multifilament bundle in a melt spinning process of the generic type in which the thread plug, for thermal treatment, is guidable with multiple enlacements in a gentle manner on the circumference of a processing drum.
A further object of the invention lies in refining the crimping apparatus of the generic type in such a manner that guiding of the thread plug on the circumference of the processing drum can substantially take place without an indexing unit.
This object is achieved according to the invention in that the stuffer box is disposed axially parallel to the processing drum in such a manner that the thread plug can be infed in a straight run from a plug outlet of the stuffer box to the circumference of the drum wall.
The invention is distinguished in that the natural weight force of the thread plug may be used to infeed the thread plug, without deflection, to the processing drum. The change of direction of the thread plug on the circumference of the processing drum is caused only by the relative speeds of the thread plug and the drum wall. The processing drum which, with its axis, is vertically oriented here ensures indexing of the individual windings of the thread plug without any comparatively large indexing forces.
Guiding of the thread plug on the circumference of the processing drum may still be improved in that, according to an advantageous refinement of the invention, the drum wall, at a short distance therefrom, is associated with an outer cylinder which encompasses the cooling drum in a sleeve-like manner and in that, for guiding the thread plug, an encircling annular chamber is configured between the outer cylinder and the drum wall. Here, the thread plug may be guided immediately from the plug outlet directly to the annular chamber, such that dynamic friction existing between the thread plug and the drum wall can be reduced to a minimum.
In order to facilitate filling of the annular chamber on the circumference of the processing drum, on the one hand, and to obtain setting of the thread plug on the circumference of the drum prior to disintegration of the thread plug, on the other hand, the refinement of the invention is preferably implemented in which the annular chamber includes an inlet opening to an upper end of the outer cylinder and, between the drum wall and the outer cylinder, includes an outlet opening to a lower end of the outer cylinder, and in that the annular chamber includes a chamber cross section which tapers off in the axial direction toward the outlet opening. In this manner, the chamber cross section may be implemented so as to be preferably larger in the inlet region of the annular chamber than a diameter of the thread plug. This enables the thread plug to be directly deposited in the annular chamber immediately after stuffing and without any compression. On account of the subsequent tapering of the chamber cross section it is achieved that positive setting of the thread plug is possible in the lower region of the annular chamber. To this end, the chamber cross section, in the region of the outlet opening, includes a size that is substantially smaller than the diameter of the thread plug.
In order to obtain secure guiding within the annular chamber in the case of fine counts and correspondingly low thread weights, it is furthermore provided that the inlet opening of the annular chamber is associated with a segment-shaped holding-down element which partially covers the inlet opening. In this manner, secure guiding of the plug layers within the annular chamber is achieved even in the case of a tapering chamber cross section.
In order to obtain slight relative speeds of the processing drum and the outer cylinder, a particularly advantageous embodiment is one in which the outer cylinder is configured so as to be rotatable and is coupled to a rotational drive which drives the cylinder wall in the same direction of rotation as the drum wall of the processing drum. In this manner, the cylinder wall can be driven in the same direction of rotation as the drum wall at a circumferential speed in such a manner that no speed differential exists between the walls of the annular chamber. In order to produce special effects when guiding the thread plug, there is, in principle, however also the possibility of setting desired speed differentials between the cylinder wall and the drum wall.
In the case of a synchronous drive of the processing drum and of the outer cylinder the refinement of the invention in which the processing drum is driven by an electric motor which is coupled to the rotational drive of the outer cylinder has proven successful. In this manner, both walls can be collectively driven in the same direction of rotation by way of one electric motor.
For temperature control of the thread plug on the circumference of the processing chamber the invention offers high flexibility in the choice and implementation of the temperature-control means. In a first variant, the drum wall of the processing chamber is configured so as to be gas-permeable, wherein the processing drum is coupled to a blower for generating a flow of cooling air. In this manner, the blower in the interior of the processing drum could produce negative pressure, for example, such that the available ambient air is sucked in via the drum wall and may be used for cooling the thread plug. Alternatively, however, there is also the possibility for the blower in the interior of the processing chamber to produce positive pressure, such that a flow of cooling air from the inside to the outside is established.
Irrespective of the properties of the blower, the thread plug may also be advantageously cooled within the annular chamber, in that the outer cylinder includes a gas-permeable cylinder wall.
However, in principle there is also the possibility for a fluid to be used as a temperature-control means which, for temperature control of the drum wall, is guided through fluid ducts within the processing chamber. Cold as well as hot fluids may be used here in order to implement temperature control of the thread plug.
The invention will be explained in more detail in the following with reference to the appended figures and by means of a plurality of exemplary embodiments.
In
The exemplary embodiment as shown in
A processing unit 7 is disposed below the plug outlet 4. The processing unit 7 includes a rotatable processing drum 8 which, via a drive shaft 16, is connected to a rotational drive (not illustrated here).
As can be understood from the illustration in
The processing drum 8 is vertically oriented in relation to the drum axis, such that the drum wall 9 extends in the vertical direction from an upper end down to a lower end. The upper end of the drum wall 9, at a short distance therefrom, is associated with the plug outlet 4 of the stuffer box 3. The stuffer box 3 here is disposed axially parallel to the processing drum 8 in such a manner that a thread plug 6 is guided in a straight run between the plug outlet 4 of the stuffer box 3 and the circumference of the drum wall.
As can be seen from the illustration in
In the exemplary embodiment illustrated in
In the exemplary embodiment illustrated in
For guiding the thread plug on the circumference of the drum wall 9, the processing drum 8 is associated with an outer cylinder 10. The outer cylinder 10 includes a gas-permeable cylinder wall 11 which is implemented in an enclosing manner, having a small spacing in relation to the drum wall 9. An annular chamber 12 for receiving the thread plug 6 is formed between the drum wall 9 and the cylinder wall 11. The annular chamber 12, on the upper end of the processing drum 8, includes an inlet opening 13 and, on the lower end of the processing drum 8, includes an outlet opening 14. The inlet opening 13 is associated with a segment-shaped holding-down element 15 which acts on the windings of the thread plug 6 that have been deposited in the annular chamber 12. The outer cylinder 10 is rotatably held by way of a bearing unit 19 on an upper support 20.
The processing drum 8 and the stuffer box 3 and the conveyor nozzle 1 are implemented in an identical manner to the aforementioned exemplary embodiment as shown in
In the exemplary embodiment illustrated in
In the exemplary embodiment illustrated in
The exemplary embodiment in
The processing unit 7 in this exemplary embodiment is disposed between an upper support 20 and a lower support 21. The lower support 21 supports a processing drum 8 which has a cup-shaped drum wall 9. The drum wall 9 is associated with an inner annulet 22 which, on the circumference, has a plurality of fluid ducts 23. The fluid ducts 23 may be helically configured so as to be one groove or so as to be a plurality of grooves having connecting grooves. The fluid ducts 23 are coupled to a fluid infeed (not illustrated here). A temperature-controlled fluid, preferably a liquid, is guided within the fluid ducts 23, such that the inside of the drum wall 9 is directly temperature controlled by way of the fluid.
The inner annulet 22 and the drum wall 9 are connected to the drive shaft 16. The drive shaft 16, on one free end, is coupled to an electric motor 27 via a rotational drive 25.
On the upper support 20, an outer cylinder 10 is rotatably held by way of a bearing unit 19. The outer cylinder 10, with one cylinder wall 11, extends sleeve-like toward the drum wall 9 and, with the drum wall 9, forms an annular chamber 12. The annular chamber 12 includes an upper inlet opening 13 and a lower outlet opening 14. The inlet opening 13, over part of the circumference, is covered by a holding-down element 15. To this end, the holding-down element 15 is held in the upper region of the annular chamber 12.
A rotational drive 24 which is coupled to the electric motor 27 acts on the circumference of the outer cylinder 10. In this exemplary embodiment, the rotational drive 24 is formed by an encircling crown gear 33 and a gear wheel 34 which is held on a motor shaft 26.
The rotational drive 25 of the processing drum 8 is formed by a gear pair 35 which connects the drive shaft 11 with the motor shaft 26. To this end, the motor shaft 26 extends axially parallel to the processing drum 8. The electric motor 27 is disposed on the upper support 20 and directly coupled to the motor shaft 26.
The rotational drives 24 and 25 are adapted in such a manner that, when rotating the motor shaft 26, the cylinder wall 11 of the outer cylinder 10 and the drum wall 9 of the processing drum 8 can be operated without any speed differential. In this manner slippage-free guiding of the windings of the thread plug within the annular chamber 12 is possible.
For temperature control, a heating radiator 28 which enables temperature control, in this case being heating of the thread plug, in the region of the outlet opening 14 of the annular chamber 12 is associated with the lower end of the cylinder wall 11 on the lower support 21. Thermal post-processing of this type may facilitate in particular setting of the crimp in the filaments.
The function of the exemplary embodiment as shown in
The exemplary embodiments illustrated in
A further exemplary embodiment of the crimping apparatus according to the invention is shown schematically in
It may be furthermore derived from the illustration in
The exemplary embodiment illustrated in
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2012 004 747.9 | Mar 2012 | DE | national |
This application is a continuation-in-part of PCT/EP2013/054126 filed Mar. 1, 2013, which claims priority to German Application No. 10 2012 004 747.9 filed Mar. 8, 2012; the entire contents of each are incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/EP2013/054126 | Mar 2013 | US |
| Child | 14476015 | US |
