EP0062643A1

EP0062643A1 - Method for producing spun yarns.

Info

Publication number: EP0062643A1
Application number: EP81901813A
Authority: EP
Inventors: Fritjof Maag
Original assignee: Individual
Current assignee: Individual
Priority date: 1980-07-16
Filing date: 1981-06-22
Publication date: 1982-10-20
Also published as: WO1982000304A1; JPS57501290A; EP0062643B1; DE3167588D1; JPH0229468U; US4484435A

Abstract

Une bande de fibres textiles (2) est etiree dans un banc d'etirage (3), est transformee dans un dispositif a guiper (4) en une meche (5) en la guipant d'un fil continu fin; la meche ainsi obtenue est etiree ensuite dans un banc d'etirage (11, 12) d'un metier a filer jusqu'au titre de fil desire. Afin d'eviter des defauts lors de l'etirage de la meche et afin d'eviter l'utilisation exclusive de fils continus speciaux a allongement reduit pour le guipage, les fils continus seront dechires non pas dans la zone d'etirage preparatoire (11) du banc d'etirage, mais dans la zone d'etirage principal (12). Pour que ces operations se deroulent impeccablement, le fil continu qui est utilise pour le guipage, doit presenter une force a la traction d'au moins 10 cN pour une elongation de 4% et une resistance a la traction d'au plus 100 cN; de plus, le rapport entre l'allongement elastique et l'allongement total ne doit pas etre inferieur a 80% lors de l'application d'une force de 15 cN. Le dispositif a guiper (4) est entoure d'une protection basculante permettant d'enlever en bloc la broche creuse, le support et la bobine avec le fil continu. Les meches (5) sont bobinees sur une bobine (7) au moyen d'un cylindre entraine (6) et transferees dans un ratelier mobile (9) qui peut etre transporte dans le metier a filer ou il sera fixe en position de travail.A strip of textile fibers (2) is drawn in a drawing bench (3), is transformed in a gimping device (4) into a wick (5) by wrapping it with a fine continuous thread; the sliver thus obtained is then drawn in a drawing bench (11, 12) of a spinning machine until the desired yarn count. In order to avoid defects during the drawing of the roving and in order to avoid the exclusive use of special continuous yarns with reduced elongation for the wrapping, the continuous yarns will be torn not in the preparatory drawing zone (11 ) of the draw bench, but in the main draw area (12). For these operations to run smoothly, the continuous yarn which is used for the wrapping must have a tensile force of at least 10 cN for an elongation of 4% and a tensile strength of at most 100 cN; in addition, the ratio of elastic elongation to total elongation should not be less than 80% when applying a force of 15 cN. The guiper device (4) is surrounded by a tilting protection allowing the hollow spindle, the support and the spool with the continuous wire to be removed en bloc. The bits (5) are wound on a spool (7) by means of a driven cylinder (6) and transferred to a mobile rack (9) which can be transported into the spinning machine where it will be fixed in the working position.

Description

Method and device for producing spinning

fiber yarn

The invention relates to a process for the production of yarns from spun fiber tapes and their refinement to roving, which is consolidated by winding with a fine filament yarn, warping the yarn in the drafting unit of a spinning machine to the desired thread thickness and solidifying the resulting sliver, e.g. by granting rotation, and an apparatus for performing the method.

A draftable roving made by winding with a filament yarn is; described in DE-P 24 47 715. As a prerequisite for good warping properties, it is mentioned that the hot elongation of the wrapping filament yarns should be exceptionally low and that a certain geometric arrangement of the filament yarns in the roving is also necessary.

It makes sense to tear the filament portion in the pre-drafting zone, since then a completely unimpeded stretchable sliver is fed to the main drafting zone. The accessibility of this path is confirmed by the examples given in the patent specification. If the elongation at break of the wrapping filament yarn is higher than specified in the examples of DS-P 24 47 715, a change in the geometrical arrangement of the wrapping filament yarn in the roving, such as is caused, for example, by a change in the balloon tension when wrapping, can be uniform Prevent the same from tearing. This then leads to delays in the main delay field. In this case, a higher advance could lead to a more even tearing of the filament yarns. However, it has been found that this worsens yarn uniformity. The production of filament yarns with the low elongation at break necessary for such rovings is described in DE-OS 26 14 523. This route is not technically easy and, above all, is burdened with additional costs, which make economical use of rovings wrapped with filament yarn difficult.

DE-AS 24 23 483 describes a process for the production of wrapping yarns, which is in principle also suitable for the production of wrapped rovings. To improve the process flow with regard to yarn quality and thread breaks, but also to save energy, various versions of the winding unit are described in the patent literature.

Thus, it is proposed in DE-OS 28 33 326 to surround the hollow spindle and bobbin with surrounding filament yarn by a rotating pot, which is provided with a removable cover, in the center of which an axially adjustable, rotating thread guide tube is attached.

DE-OS 29 02 404 describes a hollow spindle which is surrounded by a fixed cylinder which is closed with a cover and in the interior of which there is increased air pressure.

DE-OS 29 13 762 describes a hollow spindle, which is also surrounded by a fixed cylinder and the bobbin with the wrapping yarn is closed by a domed cover.

To ensure that the process runs smoothly, the wrapping point must be as close as possible to the delivery plant for to lay the sliver. In the case of the spindle designs mentioned, however, this is only possible if the axis of the hollow spindle for inserting or removing the bobbin is shifted with the wrapping yarn to such an extent that it does not come into contact with the delivery mechanism.

The removal of the bobbin with the wrapping yarn from the hollow spindle is also made difficult by the various proposed sheathings, which may only be a short distance from the bobbin. The removable covers make it even more difficult to replace the bobbin.

When spinning or breaking the wrapping yarn, the bobbin with the wrapping yarn must be removed from the hollow spindle, the end of the yarn searched, the bobbin put back on and the end of the thread threaded into the hollow spindle. Even if the number of thread breaks when winding is very low, the effort involved in doing so has a considerable impact on labor costs. For the production of wrapping yarns, it is advisable to use a very fine filament yarn as the wrapping yarn. Finding the end of the yarn on the bobbin and threading this very fine filament yarn into the hollow spindle is not easy. The handling of such fine filament yarns is unusual for the operating personnel and therefore requires special qualifications.

The state of the art is to place the wound roving bobbins in boxes on the roving machine, to transport them to the spinning machine, to remove them from the boxes there and to place them in a drainage gate above the drafting units. The roving bobbins are then rolled off. This procedure is very labor-intensive and also very tiring for machine operation, since the position of the roving bobbins in the drain creel is ergonomically extremely unfavorable. Because of this unfavorable position of the roving bobbins and also because of the dimensions of the roving bobbins limited by the spindle division and the machine width, their weight cannot be increased as would be desirable to rationalize the process.

The precision winding is ideal for the good and tight construction of a spool, as well as for optimal running properties. This applies in particular to the soft and less stable rovings.

To wind up material fed at a constant speed, the spool speed is controlled in known precision winders so that the peripheral speed of the spool remains constant. The continuously recorded thread tension before winding is used as the control variable. The technical effort for this is considerable and the stress on the roving through the continuous recording of its tensile force is also problematic.

The object of the present invention is to avoid the disadvantages mentioned in the production of spun fiber yarns from wrapped rovings.

This object is achieved according to the invention by methods and devices as described in the characterizing parts of the claims.

Depending on the spinning process, the amount of distortion in the main drafting zone is approximately 15 to 40 times. This is now prevented by means of correspondingly low distortions in the pre-draft zone and greater stretching of the wrapping Fila ment yarns tearing them in the pre-drafting zone, they tear safely in the main drafting zone, provided that the filament yarns are securely clamped between the cylinders of the drafting system. By tensioning the filament yarn in the pre-draft zone, the pre-yarn is evenly combined when it enters the main draft zone. This gives good preconditions for an even delay.

Filament yarns with force-length change properties can be used for the process, as are also common for other areas of application. However, quickly spun or partially drawn filament yarns can also be used.

The filament properties are essential for avoiding false warping, roving breaks and cracks.

To prevent false warping or roving breaks, the wrapping filament yarn must be able to build up enough frictional forces between the fibers of the roving when the roving is subjected to tension, in order to form sufficient roughness of the roving together with the strength of the filament yarn. For this purpose, the filament yarn has to develop a sufficiently high tensile force even with little stretching. It is therefore preferred if the force-length change behavior and the titer of the filament yarn are coordinated in such a way that a minimum tensile force of 10 cN is developed in the filament yarn with an elongation of A%.

It must also be ensured that the filament yarn is not stressed in the range of higher permanent expansions under the usual stress on the roving. This is the case if the ratio of elastic elongation to total elongation does not fall below 80% when it is loaded with 15 cN. Crackling or slippage of the filament yarn between the drafting cylinders can be prevented if, in particular, the delivery cylinder is loaded sufficiently high, the cylinder cover is not too hard and the tensile strength of the wrapping filament yarn is not too high. In today's drafting system designs, a maximum of 100 cN can be assumed as the limit for the tensile strength of the filament yarn.

By replacing the hollow spindle including the bobbin with the wrapping yarn and its storage with a new unit, in which the filament yarn has already been drawn into the hollow spindle, the removal of a roving break or the replacement of the filament bobbin can also be carried out by less experienced workers. The fault can also be remedied much more quickly. This also increases the machine utilization effect.

It is particularly advantageous to prepare the hollow spindle and sink with the wrapping yarn, i.e. cleaning the bobbin, locating the end of the yarn and threading it into the hollow spindle, and possibly also the precise adjustment of elements of the spindle, e.g. the thread guide tube in the case of DE-OS 23 33 326 to perform in a separate operation. This work can then be done by a few specially trained workers and for all machines together. It can thus also be avoided that the operating personnel of the roving machines come into contact with the fine filament yarn, which is so difficult to handle.

In the device according to the invention, the hollow spindle and bobbin system is firmly anchored in the machine on the one hand, with the surrounding yarn. On the other hand, there is also the exchange of the system, for example when spinning on or easy to do if the thread breaks.

To wind up yarn fed at a constant speed, it is advisable to drive the bobbin at its start with a drive roller. As a result, the spool receives practically the same peripheral speed as the drive roller, regardless of its diameter. In contrast, the speed of the coil changes depending on the coil diameter reached. To build the bobbin, the yarn to be wound is laid in the axial direction according to certain laws. As a management element for this you can e.g. use a changier thread guide. Its drive can e.g. by means of an eccentric, cam, reversing thread shaft or a threaded spindle that changes the direction of rotation.

For a precision winding, the bobbin ratio, that is, the ratio of the double stroke number of the traversing thread guide and the bobbin speed must be constant. Since the speed of the bobbin changes continuously, the drive of the traversing thread guide must be coupled with the rotation of the bobbin. A mechanical coupling requires a relatively large amount of power, which must be achieved via the drive. This can lead to excessive slippage between the drive roller and bobbin for the sensitive rovings and thus damage to the yarn.

An electrical coupling between the bobbin and traversing thread guide is therefore advantageous. There are many options available today. Mari can, for example, convert the speed of the coil into an electrical quantity using a tachometer and thus z.3. Control the speed of a DC motor using a potentiometer. This then drives the traversing thread guide. But you can also generate electrical impulses via the bobbin rotation and thus control a stepper motor, which in turn drives the traversing thread guide.

An absolute constancy of the winding ratio cannot be achieved with all control systems. However, the economically sensible control accuracy is sufficient to fully exploit all the advantages of a precision winding.

The winding ratio can be varied relatively easily by making appropriate changes to the controller. The coil structure can thus be optimally adapted to the material to be processed.

For the production of a bobbin in a parallel turn, so that the yarn is laid around its own diameter during one revolution of the bobbin and how it is often used for rovings due to the high packing density that can be achieved with it, the drive is via a threaded spindle, which in turn is driven by a stepper motor, which is particularly advantageous. The direction of rotation of the stepper motor can be reversed at the intended stroke end. The stroke of the traversing thread guide can be changed depending on the winding diameter or the number of wound thread layers. This gives conical faces of the coils and prevents individual layers from falling off.

The generation of waste can be avoided if the full roving spool is changed while the spinning station is at a standstill. Shutting down each individual spinning station is very complex in terms of design. It is therefore advisable to stop the entire machine when changing the bobbin and to start it again after changing the bobbin. This style of operation offers the additional advantage that the movement of the traversing thread guide can be controlled centrally. The speed then only has to be taken from a master bobbin to control all traversing thread guides.

The very high productivity of the process leads to short coil run times. This offers a good prerequisite for an economically sensible mechanization of the spool change. A traveling doffer, which moves from place to place during machine downtime, takes considerably more time to change all bobbins than a stationary doffer and therefore also leads to a lower efficiency. In the specified areas for the production per spinning station, the bobbin weight and the values for the number of positions per machine, which make sense because of the production per machine, a traveling doffer works cheaper than a stationary doffer.

If the roving bobbins are processed directly from the transport container in which they were brought from the roving machine to the spinning machine, then the roving bobbins can be spared on the spinning machine.

It is particularly advantageous to design the transport container as a drain gate. The creel on the roving machine can be brought into an ergonomically optimal position for loading. It is then also easily possible to attach the roving bobbins on several levels and thereby gain space for larger bobbin diameters. Because of the comparatively high strength of wound rovings, it is also possible to process bobbins with a very high weight by unrolling in a conventional manner. By winding in a precision cross winding, the pull-off is also possible overhead. As a result, the coils can be particularly cheap in the gate to be ordered. Covering the drain gate can prevent deposits of the fiber dust which is abundant on the spinning machine on the roving bobbins or can reduce them to such an extent that the blowers which are usually used to prevent these deposits can be dispensed with.

The drain creel equipped with the roving bobbins is e.g. brought to the spinning machine by means of a forklift and put into the working position there instead of the fixed drain gate. Expediently, however, the populated drain gate is suspended in a transport device which is located in the room above the machines and is brought into the intended position on the spinning machine by means of appropriately set switches. The drain gate gets stuck in the transport device and is not firmly connected to the spinning machine. This relieves the frame of the spinning machine despite the higher spool weight.

The method and the devices for carrying out the method are to be explained in more detail with reference to the following figures and exemplary embodiments.

FIG. 1 shows schematically the sequence of the method. The spun fiber strip (2) is fed from a storage container (1) to the drafting device (3) of a prespinning machine. The spun fiber strip refined in the drafting device is then passed through a winding device (4) and is wound around by a filament yarn. The resulting roving (5) is brought onto the bobbin (7) by means of the winding device (6). When the roving bobbin is full, the roving machine is stopped, the roving bobbins are changed mechanically, the full bobbins by means of a conveyor belt Brought to the end of the machine, collected there and started the roving machine again.

The roving bobbins (7) are plugged into a drain creel (9), the rovings (5) being drawn into the thread guide (93). With the Transporteinrich device (10), the drain gate (9) is brought to the spinning machine and placed there between the drafting units (11, 12) in the working position. The rovings are now passed through the draft zone (11) and the main draft zone (12) of the drafting system. Depending on the type of fiber, this drafting system can be designed as a clamping drafting system or as a pulling drafting system. In the main draft zone (12), the filament yarn surrounding the roving is torn when the roving is drawn and this is drawn to the desired fineness. The twine is twisted by means of the twisting device (13) and is thereby wound onto cops.

Figure 2 shows the special design of a winding device. The sliver (2) is fed to the hollow spindle (42) through the delivery cylinder pair (31) of the drafting device (3). The hollow spindle is driven by a tangential belt (46). With it, the bobbin is connected in a rotationally fixed manner to the wrapping yarn (4.3). At the entry of the hollow spindle, the wrapping yarn (4-7) is brought together with the fiber sliver and this is wound as a result of the spindle rotation. The resulting roving (5) is wound onto the spool (7). Hollow spindle (42) and filament spool (43) are surrounded by a fixed jacket (45, 45a) that can be opened. One half is firmly connected to the spindle bench, which is not shown in the figure. The bearing (44) of the hollow spindle is closed The jacket is firmly clamped between the jacket halves. By opening the casing, the hollow spindle (42) together with the bearing (44) and the spool (43) can be removed from the machine. FIG. 3 shows a special version of the winding device.

The roving (5) is wound onto the spool (7). For this purpose, the circumference of the coil is driven by the drive roller (61). The traversing thread guide is moved via a reversing thread shaft, not shown. The speed of the bobbin (7) is detected by a tachometer and converted into an electrical variable. With this variable, the speed of the reverse thread shaft and thus the stroke movement of the traversing thread guide are controlled so that the winding ratio, namely the ratio of the number of double strokes / min and the bobbin speed / min, remains constant over the bobbin build-up.

Figure 4 shows the transport container designed as a drain gate. The roving bobbins (7) are stored in fixed bobbin receptacles (91). The outflow gate (3) itself is suspended in a rail (10), which at the same time is used to transport the gate between the advance machine and

The roving (5) is from the roving bobbins (7)

Head pulled off. A drain aid can facilitate the drain from the spool. The roving is guided out of the drain creel via thread guide elements (93). On the roving machine, the wound roving bobbins are inserted into the drain creel. The rovings are inserted into the guide elements in such a way that the operators of the spinning machine can easily grasp the roving ends after positioning the drain gate and pull them into the drafting units. example 1

A fiber band made of cotton fibers with a strength of 700 dtex is wrapped with a filament yarn with a strength of 9 dtex and an elongation at break of 205 mm to the roving. This roving is drawn to a fineness of 200 dtex in a drafting system and solidified by twisting to form the yarn. The priority was 1.5 times. Most of the wrapping filament yarn tore in the pre-draft zone, but short periods of time were also observed in which the roving was only tense in the pre-draft zone. This led to distortion with thick and thin spots in the yarn.

Example 2

The roving from Example 1 is drawn to a fineness of 200 dtex in a drafting system and solidified by twisting to form the yarn. The advance was 1.16 times. The roving was only tense in the draft zone. The width of the roving when entering the main draft zone was significantly smaller than in Example 1 and very constant. The filament yarn only broke in the main draft zone. No distortion of delay was observed.

Claims

1. Process for the production of yarns from staple fiber tapes by refining them into roving, which is consolidated by winding with a fine filament, warping the roving in the drafting unit of a spinning machine to the desired yarn thickness and solidifying the resulting sliver, e.g. by granting rotation, characterized in that the amount of warpage in the draft zone of the drafting system is set so that the filament yarn with which the roving is wound cannot tear in the draft zone, but rather only in the main draft zone

2. The method according to claim 1, characterized in that a filament yarn is used to wind the roving, the tensile force at an elongation of 4% is at least 10 cN and its tensile strength is at most 100 cN and in which the ratio of elastic elongation to total elongation at one Load of 15 cN does not fall below the value of 80%.

3. The method according to claim 1 and 2, characterized in that for piecing or 3eheb a before yarn break, the hollow spindle including the bobbin with the winding filament yarn of the prespinning machine is removed, a new unit hollow spindle with wrapping yarn, in which the wrapping yarn is already threaded into the hollow spindle, in the. Machine used and the winding process is then continued.

4. The method according to any one of claims 1 to 3, characterized in that several roving bobbins after their manufacture are placed in a transport container so that it is transported to the spinning machine, presented there and the roving bobbins can be processed directly from it.

5. Apparatus for performing the method according to claim 3, characterized in that the hollow spindle is mounted in a fixed jacket, the fixed jacket can be opened and the

Hollow spindle including the bobbin with the wrapping yarn and the storage can be removed from the opened jacket.

6. Apparatus for carrying out the method according to claim 1, wherein the wound roving is wound in precision winding, characterized in that the roving spool is driven on its circumference by means of a drive roller and the speed of the roving spool is converted into a controlled variable with which the via a control element Movement of the chaning thread guide is controlled so that the 3 pul ratio remains constant.

7. The device for performing the method according to claim 4, characterized in that the ϊrans port container is designed as a drain gate, which consists of receiving devices for the roving bobbins and guide elements for guiding the rovings out of the drain gate. CHANGED CLAIMS

(Received at the International Bureau on December 1st, 1981 (December 1st, 1981))

Claims 1 to 7 (deleted)

8. A process for producing yarns from spun fiber tapes, the spun fiber tapes first being refined to rovings and being wound with a fine filament yarn, whereupon the rovings are drawn in a drafting device with a pre-drafting field and then solidified, eg. B. by granting rotation, characterized in that the filament yarns with which the rovings are wound are not torn in the pre-draft zone, but in the main draft zone.

9. A method according to claim 1, characterized in that, given the elongation at break of the filament yarns, the delay in the pre-draft zone is set so low that the rovings in the pre-draft zone are not stretched to the elongation at break of the filament yarn.

10. The method according to claim 1, characterized in that the filament yarns have such a high elongation at break that they are not reached in the pre-drafting zone, but only in the main drafting zone at given drafting ratios.

11. The method according to claim 2 or 3, characterized in that the elongation at break of the filament yarns is equal to or greater than the pre-warpage and less than the total warpage.

12. The method according to any one of claims 1 to 4, characterized in that the warp is subjected to a roving which is wound with a filament yarn, the tensile strength is at most 100 cN.

13. Process for the production of yarns from spun fiber tapes, the spun fiber tapes first being refined into rovings and wound with a fine filament yarn, whereupon the rovings are drawn in a drafting device with a pre-drafting field and then solidified, e.g. B. by granting rotation, in particular according to one or more of claims 1 to 5, characterized in that the warp is subjected to a roving which is covered with a filament yarn, the tensile force of which is at least 10 cN when stretched by 4% and in which the Ratio of elastic elongation to total elongation at a load of 15 cN does not fall below 80%.

14.The method according to any one of claims 1 to 6, characterized in that the cylinders of the drafting system are loaded sufficiently high and the cylinder cover is not chosen too hard, so that the filament yarns are securely clamped between the cylinders of the drafting system.

15. The method according to any one of claims 1 to 7, characterized in that the roving is summarized by tensioning in the pre-draft zone for the entry into the main draft zone.

16. Method according to one of claims 1 to 8, characterized in that the roving is withdrawn from the roving bobbins overhead and fed to the drafting system.

17. The method according to the preamble of claim 1, wherein the spun fiber band refined to a roving is passed through a hollow spindle carrying the filament yarn and thereby with the filament gam is wound, characterized in that for piecing or to fix a roving break, the hollow spindle including the bobbin with the winding filament yarn is removed from the roving machine, a new unit hollow spindle with winding yarn, in which the winding yarn is already threaded into the hollow spindle , inserted into the machine and the wrapping process is then continued.

18th Apparatus for carrying out the method according to claim 10, with a fixed jacket surrounding the hollow spindle and filament yarn bobbin, characterized in that the hollow spindle is mounted in the fixed jacket, the fixed jacket can be opened and the hollow spindle including the bobbin with the wrapping yarn and the Storage can be removed from the opened jacket.

19th Device for carrying out the method according to one or more of the preceding claims, characterized in that a transport device is designed as a transport container covering the roving bobbins (7) at least from above.

20. Apparatus for carrying out the method according to claim 1, wherein the wound around the roving e in precision winding, characterized in that the roving spool is driven on its circumference by means of a drive roller and the speed of the roving spool is converted into a controlled variable with which a control element controls the movement of the traversing thread guide so that the soul ratio remains constant.