Method for Processing a Strand-Shaped Fiber Sliver, and Roving Frame Machine

Abstract

A method for processing a strand-type fiber bundle includes sending the fiber bundle to an air nozzle of a pre-spinning machine used to produce roving. During normal operation, a twist is imparted to the fiber bundle via a vortex air current within the air nozzle to form the roving, wherein the roving leaves the air nozzle through an outlet and is deposited in or on a receptacle. Normal operation of the pre-spinning machine is interrupted in a stop phases during which roving is not produced by the air nozzle. A start-up phase is commenced between the stop phase and subsequent normal operation wherein the roving produced during the stop phase is discarded via a roving discharge after leaving the air nozzle when quality of the roving does not meet a desired specification. The roving discharge is deactivated when the quality of the roving meets the desired specification and the roving removed by the roving discharge is separated from the roving.

Claims

1-14. (canceled)

15. A method for processing a strand-type fiber bundle, comprising: sending the fiber bundle to an air nozzle of a pre-spinning machine used to produce roving; during normal operation, imparting a twist to the fiber bundle via a vortex air current within the air nozzle to form the roving from the fiber bundle, wherein the roving leaves the air nozzle through an outlet in the air nozzle; from the outlet, depositing the roving in or on a receptacle; interrupting the normal operation in a stop phases during which roving is not produced by the air nozzle; performing a start-up phase between the stop phase and subsequent normal operation wherein the roving produced during the stop phase is discarded via a roving discharge after leaving the air nozzle when quality of the roving does not meet a desired specification; and deactivating the roving discharge when the quality of the roving meets the desired specification and separating the roving removed by the roving discharge.

16. The method according to claim 15, wherein the roving is drawn off from the air nozzle with a draw-off device and is deposited in a form of a loop in or on the receptacle.

17. The method according to claim 16, wherein the roving is captured by the deposition device after passing through the draw-off device and is deposited in or on the receptacle device via the deposition device.

18. The method according to claim 17, wherein the roving forms a curtain between the draw-off device and the deposition device, and wherein a vertical and spatial extent of the curtain is regulated by a deposition rate of the deposition device.

19. The method according to claim 15, wherein a receptacle replacement operation is carried out when the receptacle has reached a defined level of filling or when a defined quantity of roving or length of roving has been produced by the air nozzle and deposited in or on the receptacle.

20. The method according to claim 19, wherein production of the roving is not stopped during the receptacle replacement operation.

21. The method according to claim 20, wherein the roving produced by the air nozzle during the receptacle replacement operation is discarded at least in some sections by a yarn discharge mechanism.

22. The method according to claim 19, wherein production of the roving is interrupted temporarily during the receptacle replacement operation.

23. The method according to claim 22, wherein after the interruption in the roving production process, the start-up phase is performed.

24. The method according to claim 15, wherein the receptacle is moved to an air-jet spinning machine that is used to produce yarn after being partially or completely filled with the roving.

25. The method according to claim 15, wherein the receptacle is moved to a spinning/knitting machine that is used to produce a knit fabric after being partially or completely filled with the roving.

26. A pre-spinning machine for producing a roving from a strand-type fiber bundle, comprising: an air nozzle comprising air jets configured to impart a twist to the fiber bundle via a vortex air current to produce a roving from the fiber bundle; an outlet in the air nozzle through which the roving leaves the air nozzle during normal operation of the pre-spinning machine; a deposition device disposed downstream of the air nozzle and configured to deposit the roving into or on a receptacle; and wherein the pre-spinning machine is configured to operate in accordance with the method of claim 15.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Additional advantages of the invention are described in the following embodiments, in which each shows schematically:

[0031] FIG. 1 shows selected elements of a pre-spinning machine according to the invention in a side view;

[0032] FIG. 2 shows a sectional diagram of a detail of an air nozzle of a pre-spinning machine according to the invention; and

[0033] FIG. 3 shows selected elements of another pre-spinning machine according to the invention in a side view as well as a top view of a receptacle designed as a container, including the roving.

DETAILED DESCRIPTION

[0034] Reference will now be made to embodiments of the invention, one or more examples of which are shown in the drawings. Each embodiment is provided by way of explanation of the invention, and not as a limitation of the invention. For example features illustrated or described as part of one embodiment can be combined with another embodiment to yield still another embodiment. It is intended that the present invention include these and other modifications and variations to the embodiments described herein.

[0035] FIG. 1 shows a schematic side view of a pre-spinning machine according to the invention (wherein only selected elements, which are relevant for an understanding of the invention, are shown; the same thing is also true of the remaining figures).

[0036] The pre-spinning machine may comprise, if needed, a draw frame having a plurality of draw frame rollers 15, each of which can rotate about an axis of rotation (only two of the six draw frame rollers 15 are labeled with a reference numeral), wherein the draw frame is supplied with a fiber bundle 1, for example, in the form of a double draw frame sliver during spinning operation.

[0037] Furthermore, the pre-spinning machine shown here comprises one or more air nozzles 2 arranged in proximity to one another, each with an interior vortex chamber 23 (see FIG. 2), in which the fiber bundle 1 and/or at least a portion of the fibers of the fiber bundle 1 is provided with a twist (the exact mechanism of action of the nozzle is described in greater detail below).

[0038] In addition, the pre-spinning machine may comprise a draw-off device 6, preferably having a plurality of cooperating draw-off rollers 16 with the aid of which the roving 3 leaving the nozzle through its outlet 4 is captured and guided (the draw-off rollers 16 can preferably be made to rotate with the aid of a drive, not shown here). The pre-spinning machine according to the invention need not necessarily include a draw frame, as illustrated in FIGS. 1 and 3. The draw-off rollers 16 are also not absolutely necessary.

[0039] In any case, the pre-spinning machine according to the invention operates downstream from an air-jet spinning process. To form the roving 3, the fiber bundle 1 is fed into the vortex chamber 23 of the air nozzle 2 via an inlet 13 to the air nozzle 2, in which a so-called fiber guide element 14 is preferably situated (see also FIG. 2). In the vortex chamber, the fiber bundle receives a twist, i.e., at least a portion of the free fiber ends of the fiber bundle 1 is captured by an air stream created by air jets 10 arranged accordingly in a vortex chamber wall surrounding the vortex chamber 23. Some of the fibers are pulled at least a certain distance out of the fiber bundle 1 in this way and wound around the tip of a yarn-forming element 11 protruding into the vortex chamber 23. Due to the fact that the fiber bundle 1 is drawn out of the vortex chamber 23 by means of a draw-off channel 12 arranged inside the yarn-forming element 11, ultimately the free fiber ends are also drawn in the direction of the yarn-forming element 11 and, in doing so, are wrapped as so-called winding fibers around the core fibers running centrally, resulting in a roving 3 with the desired twist.

[0040] In general, it should be pointed out here that the roving 3 that is produced is a roving with a relatively small amount of winding fibers and/or a yarn in which the winding fibers are wound relatively loosely around the inner core so that the roving 3 remains drawable. This is crucial because the roving 3 produced in this way must then be drawn again with the aid of a draw frame on a downstream textile machine (for example, a traditional air-jet spinning machine) to enable it to be processed to form a traditional yarn, which can be processed on a weaving machine to form a fabric, for example.

[0041] The basic idea of the present invention can now be explained with regard to FIGS. 1 and 3. It was previously customary to wind roving 3 onto a sleeve, regardless of whether it was produced on a traditional flyer or an air pre-spinning machine.

[0042] In contrast with that procedure, the present invention now proposes that the roving 3 can be deposited loosely in a receptacle 5 designed as a container after leaving the air nozzle 2, wherein the spinning cans, which are known to be used in spinning mills, can preferably be used here.

[0043] As can be seen in FIG. 1, among others, it is advantageous that the pre-spinning machine has a deposition device 7 for this purpose, including at least one deposition plate 18.

[0044] The deposition plate 18 can be induced to rotate with the aid of a drive (not shown) in order to be able to deposit the roving 3 coming from the air nozzle 2 in the form of loops in the receptacle 5.

[0045] Alternatively or additionally, the deposition device 7 may also have a rotating plate 19 which is shown in FIG. 3, and with the aid of which the receptacle 5 can be made to rotate.

[0046] If both the rotating plate 19 and the deposition plate 18 (which in the case of FIG. 3 is arranged with an offset from the central axis of the receptacle 5) are induced to rotate, the result is the deposition pattern of the roving 3 and/or the loops 22 shown at the lower left of FIG. 3 (FIG. 3 thus shows a detail of a pre-spinning machine and also a receptacle 5, which is partially filled with roving 3 from above; this of course does not reflect the actual position of the receptacle 5 with respect to the pre-spinning machine).

[0047] As also shown by a comparison of FIGS. 1 and 3, after leaving the draw-off device 6, the roving 3 can be sent directly either to the deposition plate 18 or to its interior deposition channel 21, which runs in a helical pattern (FIG. 1). However, it is also conceivable for the roving 3 to first form a curtain 8 and then to be sent to the deposition plate 18, wherein one or more sensors 17 and/or an additional guide 20, e.g., in the form of a guide roller, may be present between the deposition plate 18 and the draw-off device 6. The sensor(s) 17 monitor the vertical extent of the curtain 8, wherein one controller (not shown) regulates the rotational speed of the rotating plate 19 and/or of the deposition plate 18 on the basis of the measured values from the sensor(s) 17, as described above, in order to keep the vertical extent within a defined range.

[0048] Finally, FIG. 1 shows that it may be advantageous if the pre-spinning machine has a roving discharge 9, for example, in the form of a suction pipe. If roving production is begun now, there is first a start-up phase, during which the roving 3 leaving the air nozzle 2 is captured by the roving discharge 9 and discarded. If the quality of the roving 3 ultimately meets the specifications, the roving discharge 9 can be deactivated, wherein the portion of roving already discharged via the roving discharge 9 is separated from the roving portion now being produced by the air nozzle 2 via means not shown here (e.g., a cutting unit). Finally, the beginning of this portion is sent to the deposition device 7 and deposited in the receptacle 5, wherein the transfer of the roving portion produced last to the deposition device 7 can take place with the aid of a blow nozzle or mechanical means, for example. The function of the blow nozzle can also be taken over by the roving discharge 9 if the blow nozzle is exposed to an excess pressure instead of a vacuum.

[0049] Reference is made to the preceding discussion with regard to possible receptacle replacement operations.

[0050] The present invention is not limited to the embodiments illustrated and described here. Modifications within the scope of the patent claims are also possible as is any combination of the features described here even if they are illustrated and described in different parts of the description and/or claims or in different embodiments, assuming that the modifications are not in contradiction with the requirements of the independent claims.

LIST OF REFERENCE NUMERALS

[0051] 1 fiber bundle [0052] 2 air nozzle [0053] 3 roving [0054] 4 outlet [0055] 5 receptacle [0056] 6 draw-off device [0057] 7 deposition device [0058] 8 curtain [0059] 9 roving discharge [0060] 10 air jet [0061] 11 yarn-forming element [0062] 12 draw-off channel [0063] 13 inlet [0064] 14 fiber guide element [0065] 15 draw frame roller [0066] 16 draw-off roller [0067] 17 sensor [0068] 18 deposition plate [0069] 19 rotary plate [0070] 20 guide deposition [0071] 21 channel [0072] 22 loop [0073] 23 vortex chamber