DE10060300A1 - Drafting of textile fibers, e.g. on drawframe, comprises use of fluids to accelerate fibers and apply the required drafting forces - Google Patents

Abstract

Textile fibers (6), e.g. slivers, are drafted by applying the necessary drafting forces by means of a fluid (7), e.g. water or air. The fluid and sliver are accelerated in a draw chamber (1), e.g. with gradually reducing cross-section (2, 3, 4). Additional force can be applied upstream by directing the fluid flow against the direction of fiber movement. An Independent claim is also included for drafting equipment incorporating a feed (11), e.g. an injector, for the fluid (7) to a draw chamber (1) of reducing cross-section (2, 3, 4). A fiber container (20) is attached to a transfer section (10) through a seal (15, 25).

Description

The invention relates to a method for stretching textile fibers like a device for stretching textile fibers with a stretch chamber in which the fibers are drawn.

Such methods have been used for a long time in drafting systems in Verstrec direction of the rollers arranged one behind the other, whereby a pair of rollers is formed by a so-called cylinder and a pressure roller det, which are arranged axially parallel and rotate in opposite directions. The respective cylinders and pressure rollers from each other in the stretching direction other following pairs of rollers rotate with increasing speed. The fibers trapped between the cylinder and the pressure roller (in the form of a or several fiber slivers) are supported by the respective pair of rollers its peripheral speed entrained, which ultimately a Stretching of the fibers among themselves is achieved. The well-known and Established processes are technically almost in many respects irritates.

The object of the invention is a method and a Vorrich device of the type mentioned in such a way that introduct new technologies are the prerequisites for parameter optimization be created in the default process.

This is achieved in the process of the type mentioned at the outset solved that at least one fluid supplied to the fibers to be drawn in such a way  is that it attacks the fibers and at least part of the applies the necessary drafting forces for stretching.

The object is achieved in a device of the type mentioned solved that a supply device for supplying at least one fluid the fibers conveyed into the drawing chamber is provided and together is designed with the stretching chamber such that the supplied fluid to at least part of the warping forces required to stretch the fibers applies.

The advantages of the invention are in particular that at least one Fluid is fed to the fibers to be drawn to either complete to carry out the stretching process or to act as a support. To generate a relative movement of the fibers with each other, the one fibers are braked and the others are accelerated relative to them be inclined. Braking and acceleration is in conventional stretch work by clamping each fiber in each other Stretching direction apart, with different order pairs of rollers rotating at the initial speeds. With one with The fibers become flat at least in one fluid-working drafting system if actually clamped by the fluid attacking the fibers and these holds back or accelerates. There must be one where appropriate other existing static friction of the fibers to be drawn is overcome become. According to the invention for the acceleration process and / or used a fluid medium at least to support the braking process.

The fluid expediently exercises to accelerate a fiber portion a force in the stretching direction to accelerate it. Dude natively or additionally, the at least one or another fluid attacks the desired slower fibers and clamps or brakes them in the Compared to the faster fibers. To achieve this clamping or Braking effect, the at least one fluid, on the one hand, a flow  and thus have a force component in the direction of stretching that however, it must be smaller than that of the faster fibers gripping default forces. This is similar to the situation in conventional ones Drafting systems in which the upstream roller pairs have a lower order trapping speeds than the downstream roller pairs. On the other hand, the at least one fluid can also be a flow and thus have a force component against the direction of stretching and in this way brake the fibers in question. For acceleration part of the fibers and braking of another part different fluids can also be used.

The at least one fluid can be complete or supportive in Ge accelerating the speed gradient faster fibers and / or the - in Compared to these - slow slower fibers. As an example of a supportive effect can be in addition to the use of mechanical Drafting rollers at least one fluid are used, which the Stretching fibers or helping to stretch them. The fluid can be very take on a flexible role. For example, by changing the pressure of the Fluids quickly and precisely changed the force acting on the fibers become. Also, when a sliver is stretched, penetration is in fibers of the sliver lying further to the inside to a greater extent possible than with a purely mechanical drafting system.

By choosing a suitable flow of the fluid, Reini can also be Realization effects by z. B. very short and therefore unsung desired fibers due to relatively low flow pressures from the fiber flow Have them removed, additionally longer threads with a corresponding height ren flow pressure. The direction of flow of the fluid can also be here be chosen according to needs.

All possible fluid media are in the method according to the invention usable, i.e. a liquid, a liquid mixture, a gas, a gas mixture  or a combination of at least two of the aforementioned Me serve. Depending on the type of fiber and length and thickness to be stretched the appropriate fluid can be selected, which of course in addition Model calculations require a certain amount of empiricism.

The use of water and air in particular is inexpensive and simple or a combination of water and air.

In order to efficiently use the flow pressure of the fluid, the inventor device according to the invention a substantially sealed stretching chamber on. Fiber and fluid inlets and outlets are conveniently featured see and also formed sealing.

In an advantageous embodiment of the invention, the stretch cam mer several gradually or continuously in the direction of stretching tapering drafting system sections so that the fluid is stretched direction due to the geometric design of the stretching chamber gets faster and pulls the fibers with it. Which are still in the upstream tiger sections of the stretching fibers are corre sponding accelerated slower. In this way the higher Ge speeds of part of the fibers towards the exit of the drawing chamber will be realized. In this embodiment of the invention, the fluid Attack the fibers along the entire stretching chamber. The fibers can ge over the full length of the drafting chamber stuck, d. H. are braked or accelerated relative to each other.

Those fibers that a relatively ge during the stretching process rings should experience acceleration, can not only by a relative slow fluid flow in the direction of stretching or even through a Counterflow against the faster fibers are retained. Additionally or alternatively, the necessary restraining force can at least partly by mechanical, pneumatic and / or electrostatic action  to be exerted on those fibers which during the ver stretching process compared to the more accelerated fibers. For example, a pinch roller holds back some of the fibers other part of the fibers by means of a flowing in the drawing direction Fluids and possibly an additional mechanical stretching device tion - for example also a roller - who moves in the stretching direction that can to achieve the stretching.

If a counterflow or a relatively slow in the stretching direction flowing fluid the slower or clamped fibers on the mitbe movement with the faster accelerated fibers prevents this fluid expediently from the same fluid as that in the stretching direction acting fluid formed, for example by water and / or air. The Countercurrent can, for example, just as the fiber accelerating Fluid are guided to its operative position via guide elements. Alternatively or in addition, appropriately aligned nozzles are used. This are then expediently arranged and aligned such that they can efficiently attack the fibers and these - in relation to each other the - accelerate and / or brake. For example, there are several nozzles around the one or more slivers or the relatively loose fibers in one Level arranged perpendicular to the direction of stretching and in the we oriented in or against this direction.

Individual fibers can be counteracted by means of the method according to the invention stretch each other, fiber flakes or slivers. In the well-known Drafting devices, on the other hand, are used almost exclusively for fiber slivers stretches so that the method according to the invention a further application development area.

Advantageously, the fluid can be suitably ge by means of an injector selected pressure are applied, preferably by direct introduction into the stretching chamber. For example, an injector consists of one  double-walled tube with a concentric tube in cross section walls. The fluid can pass through the outer tube at high pressure while the inner tube is being loaded with fibers. At the outlet of the Double tube, the fluid pulls the fibers in the form of a thin strand, so that z. B. from individual fibers a fibrous web can be produced can. In this way it is also possible to use an injector to make fibers to aspirate a fiber storage container and to trans in the stretching chamber port. The shape of the injector and its nozzle can vary depending on the one can be adapted to the relevant circumstances.

For efficient reuse of the fluid after a single flow men of the stretching chamber, it is appropriate to in a fluid in a circuit or outside the stretching chamber. There may be filters necessary to prevent fiber residues from running around and from pressure fluctuations or, in the worst case, blockages in the fluid guide tubes to lead.

For example, if water is used as the fluid, they adhere fibers closer together than when dry. Therefore be preferably provided to reduce the adhesion between the fibers Add additive to the fibers. For example, an oil is among these Usable purposes, which can be used at the same time, the Pretreat fibers for subsequent processing. So can z. B. winding oils are fed to the fibers in this process step. In this way he can reduce the number of work steps aim.

The method of stretching according to the invention is in all spinning dimensions machine types can be used in which fibers are to be stretched for example in cards and draw frames. The procedure is in one route used, the drafting system is arranged in the drawing chamber mentioned.  

If the method according to the invention is used in routes, it can are extended on the stretching in the stretch before and / or after switched process steps. For example, pass through the fibers Carding device before entering the line, the carding process - d. H. Exposure of individual fibers and the order to a fleece or pile - advantageously also supported at least by means of a fluid the. The fibers can also be cleaned at least in part by means of the Fluids are carried out. Carding and cleaning if necessary is advantageously by correspondingly supplying the fluid with appropriate pressure distributed over the fiber volume to be carded taken. The same fluid is expediently used for the carding process used as for stretching in the route. Here the Kar The fluid leaving the device is then ready for stretching used in the route and then the carding process again direction are fed. Filters for Besei are expedient here Provided contamination of the fluid flow.

A spinning device can also be connected downstream of the line. Here at can from the drafting chamber - or from a pre switched carding device - escaping fluid for swirling the company dens can be used in the spinning device. Such a vortex is known for example from air spinning.

If a liquid is used to stretch the fibers, the Fibers after drawing in suitable cases advantageously ge dries, for example to put them in jugs or to continue to process. Otherwise, quality could be achieved with densely laid fibers deterioration due to excessive humidity.

The fiber storage container and the feed device are advantageous device for feeding the fibers to the drawing chamber largely sealed, so as a series of essentially sealed devices  to realize, all of which can be acted upon by the fluid. The fluid can then take on various functions: On the one hand, it can run the fibers from the fiber storage container serve by at for example a nozzle on the top layers of the fibers in the fore is directed to the stretching chamber. If the fiber storage container contains single fibers or fiber flakes and not already a nonwoven fabric, is advantageously a device in front of the stretching chamber provided for fleece formation to ver this fleece in the stretching chamber stretch. A new and inventive possibility is the Ver using an injector as described above.

The stretching method and / or is particularly preferred the carding and spinning processes described using minde least a fluid by a control and / or regulating device controls or regulates. In particular, such a control and / or Re Gelung preferred for the supply of the fluid to the stretching chamber see. By means of suitable sensors, whose function is essentially analog to the known sensors on conventional drafting systems, can Input and output of the drafting system fiber parameters like the fiber strip thickness and its uniformity determined and corresponding signals be passed on to the control device. This controls then expediently also the feed device (s) for the fluid in order to to apply the appropriate pressures or distortion forces. Advantageously in particular the flow cross-section of the fluid, its pressure and / or its application duration controlled.

Advantageous developments of the invention are due to the features of Subclaims marked.

The invention is explained in more detail below with reference to the drawings. It demonstrate:  

Fig. 1 is a schematic representation of a first game Ausführungsbei the stretching device according to the invention;

Figure 2 is a schematic representation of a sliver with two clamping sections due to a fluid flowing in the stretching direction.

Fig. 3 is a schematic representation of a sliver with two clamping sections due to a fluid flowing both in and against the stretching direction, and

Fig. 4 is a schematic representation of a second game Ausführungsbei the stretching device according to the invention.

In Fig. 1, a stretching chamber 1 for stretching fibers 6 of a sliver is shown schematically with an inlet 9 , three adjoining, telescopically tapering in the stretching direction V stretch sections 2 , 3 , 4 and an outlet 8 through which the stretchers to each other ten fibers 6 are passed from the stretching chamber 1 . With the Streckkam mer 1 , a fiber storage container 20 is connected, from which the not yet drawn fiber sliver is guided via a transition section 10 to the inlet 9 of the stretching chamber 1 . In order to guide the sliver in the direction of stretching V, which runs parallel to the longitudinal axis of the stretching chamber 1 , a deflection roller 5 is provided at the entrance of the stretching chamber 1 . In the transition section 10 , a channel-like feed device 11 opens through the top, through which a fluid 7 is conducted into the stretching chamber 1 . For this purpose, an inclined deflection device 13 - in the simplest embodiment, a simple baffle - which is arranged in the transition section 10 opposite the inlet 12 of the feed device 11 and directs at least part of the fluid 7 into the stretching chamber 1 .

Since both the fiber storage container 20 and the transition section 10 have the same cross-section, they can be coupled to one another by means of circumferential seals 15 , 25 and possibly additional clamps without, for example, any appreciable amounts of air from outside into the overall arrangement of the stretching chamber 1 , transition section 10 and fiber storage container 20 would penetrate or fluid 7 could escape.

The sliver or fibers 6 can be transported in different ways from the fiber storage container 20 to the stretching chamber 1 . One embodiment (not shown) provides mechanical transport, for example by means of a combing roller or a milling device. Al alternatively, a flowing fluid 7 can be used; The same fluid 7 , which is used for stretching, advantageously serves this purpose. Especially when filled with single fibers and fiber flakes fiber storage container 20 can, for. B. a laterally protruding into this and directed obliquely upward nozzle (not shown), which is vertically movable at or slightly below the fiber surface, entraining fibers 6 upwards through the fluid flow and transporting them to the stretching chamber 1 . A suction device for the fibers 6 from the fiber storage container 20 can be used. In order to avoid a possible negative pressure in the fiber storage container 20 by the flow in the drawing chamber 1 , a valve 21 is provided at the lower region of the container 20 , which can be operated manually or electrically.

Due to the telescopic design of the stretching chamber 1 , the fluid 7 is accelerated more from section to section 2 , 3 , 4 in the direction of stretching V and can cut the fibers 6 located there in section 4 (or 3) with the smaller cross by entrainment or clamping Accelerate faster than in sections 3 , 2 (or 2) with a larger cross-section. This situation is shown schematically in FIG. 2. For the sake of simplicity, only two clamping sections 30 , 31 are shown in this figure, which correspond to two sections of sections 2 , 3 , 4 of FIG. 1. In Fig. 2 correspond to the fibers 6 in the region of the respective terminal points 30, 31 acting delay forces in direction and magnitude to the fluid 7 to ordered arrows. Different fluids 7 can also be used at the respective clamping points 30 , 31 .

As shown in FIG. 3, a part of the fibers 6 can alternatively be braked or clamped at at least one clamping point or a clamping section 40 by a fluid counterflow 7 . Here, the same fluid 7 can be used which - for the purpose of stretching - has acceleration components in the stretching direction V and clamps and accelerates fibers 6 at the clamping point 41 . In this variant (not shown) additional funding is necessary to transport the fibers 6 in the direction of stretching V. Such funds are appropriate if necessary also in the other described embodiments or necessary.

If only one fluid 7 is used for the variants of FIGS. 2 and 3, a single inlet 12 into the stretching chamber 1 for the fluid 7 may be sufficient to design in the stretching chamber 1 - in addition to the design shown in FIG. 1 - by a suitable choice of deflection devices or several appropriately aligned nozzles to divide the fluid flow 7 to reach it. Here, a sub-fluid flow takes over a greater acceleration of part of the fibers 6 , while the other sub-fluid flow provides for a lower acceleration or a braking of another part of the fibers 6 . It is to be ensured, for example, by means of the other sub-flow shielding devices that eddies in the stretching chamber 1 do not interfere with the braking or acceleration effect. According to the invention, a fluid 7 can also be used either only for braking or only for accelerating fibers 6 - in each case viewed relative to one another.

As also shown in FIG. 1, it is also possible to provide more than two clamping sections 30 , 31 or 40 , 41 . This enables an even more precise stretching to be achieved.

In a further alternative (not shown), the fibers 6 are mechanically retained or accelerated mechanically - for example by means of one or more pinch rollers - or also electrostatically. In the latter variant, the fibers 6 are electrostatically charged and a device with oppositely charged components is arranged in the immediate vicinity of the fibers 6 to be clamped or braked.

The second embodiment of the invention shown in FIG. 4 provides that, as an alternative to the stepwise tapering stretch sections 2 , 3 , 4 of FIG. 1, nozzles 52 , 53 are directed at sections 50 , 51 of the stretch chamber 1 passing through fibers 6 . To generate the acceleration effect, the nozzles 53 , which are oriented essentially in the direction of stretching V, are provided in downstream sections 51 of the stretching chamber 1 . Should be fiber 6 on the other hand rather braked, nozzles 52 are preferably disposed in the upstream portions 50 of the stretching chamber 1 and entge in the embodiment of Fig. 2 gene of the stretching direction V on the amounts to be braked fibers 6 oriented. In both cases, a plurality of nozzles 52 , 53 are advantageously provided, which are arranged around the entirety of the fibers 6 in the direction of stretching V (not shown) and thus act on the fibers 6 from as many sides as possible, so that a cross-section of the Fiber composite uniform stretching can be realized. In addition or alternatively, a plurality of nozzles 52 , 53 are arranged along the stretching path, all of which are oriented in the stretching direction V and introduce fluid 7 into the stretching chamber 1 with increasing pressures in the downstream direction in order to achieve successively greater acceleration of the fibers 6 (similarly the effect of the device shown in Fig. 1). In general, many variants of the nozzle arrangement and the pressurization of these nozzles 50 are possible. In particular, they depend on the intended use, and in particular on whether the fluid 7 should exert a braking and / or accelerating effect.

Initial calculations have shown that the fluid 7 used for fiber acceleration must have a flow pressure of approximately 12-15 atm to exert the same pressure as a drafting roller on a clamping width of half a centimeter.

The method according to the invention and the device according to the invention can be used in various areas of spinning technology zen to achieve a stretching of fibers. May be mentioned explicitly Cards and draw frames.

Claims (27)

1. A method for stretching the textile fibers (6), characterized in that at least one fluid (7) to be supplied to be stretched fibers (6) such that it engages the fibers (6) and at least part of the drawing necessary necessary pulling forces. 2. The method according to claim 1, characterized in that at least one fluid ( 7 ) the fibers ( 6 ) is fed such that it attacks the Ge in the speed gradient of the fibers to be stretched ( 6 ) faster Fa sern ( 6 ). 3. The method according to claim 2, characterized in that the at least one fluid ( 7 ) engages on the fibers ( 6 ) engaging Kraftkompo component in the direction of stretching (V), so that any existing adhesive forces of the fibers ( 6 ) to be stretched smaller among themselves are the default forces acting on them as a whole. 4. The method according to any one of the preceding claims, characterized in that at least one fluid (7) the fibers (6) leads thus supplied is that it acts on the slower the velocity gradient of about verstrec kenden fibers (6) fibers (6) . 5. The method according to claim 4, characterized in that the at least one fluid ( 7 ) on the fibers ( 6 ) engaging Kraftkompo component in or against the direction of stretching (V) applies. 6. The method according to any one of the preceding claims, characterized in that the same fluid ( 7 ) for clamping or braking the slower fibers ( 6 ) on the one hand and for accelerating the faster compared fibers ( 6 ) on the other hand is used. 7. The method according to any one of the preceding claims, characterized in that a liquid, a liquid mixture, a gas, a gas mixture or a combination of at least two of the aforementioned media is used as the fluid ( 7 ), in particular water, air or a combination of Water and air. 8. The method according to any one of the preceding claims, characterized in that at least some of the fibers ( 6 ) for generating egg nes gradient of the fibers ( 6 ) with each other is at least partially retained by mechanical, pneumatic and / or by electrostatic force. 9. The method according to any one of the preceding claims, characterized in that the drawing chamber ( 1 ) is associated with a stretch and that a carding device is arranged in front of the drawing chamber ( 1 ), in which the carding of the fibers ( 6 ) at least partially by means of a fluid ( 7 ), preferably the same fluid ( 7 ) as used in the stretching chamber ( 1 ). 10. The method according to any one of the preceding claims, characterized in that the fibers ( 6 ) are supplied as individual fibers, fiber flakes or as a sliver of the stretching chamber ( 1 ). 11. The method according to any one of the preceding claims, characterized in that the fluid ( 7 ) is introduced into the stretching chamber ( 1 ) by means of an injector. 12. The method according to any one of the preceding claims, characterized in that the fluid ( 6 ) is circulated in a circuit in or outside of the stretching chamber ( 1 ). 13. The method according to any one of the preceding claims, characterized in that a reducing the adhesion between the fibers ( 6 ) of the additive is supplied. 14. The method according to any one of the preceding claims, characterized in that the drawing chamber ( 1 ) is switched to a spinning device and that the fluid ( 7 ) led out of the drawing chamber ( 1 ) is used for swirling the thread in the spinning device. 15. The method according to any one of the preceding claims, characterized in that when using a liquid fluid ( 7 ) the fibers ( 6 ) are dried at the end of the stretching chamber ( 1 ). 16. The method according to any one of the preceding claims, characterized in that a control and / or regulating device is used which controls or regulates the supply of the fluid ( 7 ), such as in its flow cross section, pressure, type, duration of application. 17. A device for stretching textile fibers, in particular by means of a method according to one of the preceding claims, with a stretching chamber ( 1 ) in which the fibers ( 6 ) are stretched, characterized in that a feed device ( 11 ) for feeding at least least of a fluid ( 7 ) to the fibers ( 6 ) conveyed into the stretching chamber ( 1 ) is provided and, together with the stretching chamber ( 1 ), is designed such that the supplied fluid ( 7 ) at least a part of the fibers ( 6 ) applies the necessary drafting forces. 18. The apparatus according to claim 17, characterized in that the stretching chamber ( 1 ) has a plurality of tapering sections ( 2 , 3 , 4 ) tapering stepwise or continuously in the direction of stretching (V). 19. Device according to one of the preceding device claims, characterized in that the stretching chamber ( 1 ) except for an inlet ( 9 ) and an outlet ( 8 ) for the fibers ( 6 ) and optionally the at least one fluid ( 7 ) essentially sealed is. 20. Device according to one of the preceding device claims, characterized in that a fiber storage container ( 20 ) and one of the fiber storage container ( 20 ) to the stretching chamber ( 1 ) leading transition section ( 10 ) are substantially sealed. 21. Device according to one of the preceding device claims, characterized in that at least one injector for the at least one fluid ( 7 ) is provided, which preferably opens into the extension chamber ( 1 ). 22. Device according to one of the preceding device claims, characterized in that the injector is designed and aligned such that the fibers ( 6 ) are accelerated. 23. Device according to one of the preceding device claims, characterized in that one or more nozzles supplied with the at least one fluid ( 7 ) or one or more deflecting devices ( 13 ) which can be flown by a fluid ( 7 ) are provided in the stretching chamber ( 1 ) in this way that the at least one fluid ( 7 ) receives a flow component in and / or against the direction of stretching (V). 24. The device according to claim 23, characterized in that a plurality of nozzles in the stretching chamber ( 1 ) around the fibers ( 6 ) and / or ent long of the fibers ( 6 ) are arranged. 25. Device according to one of the preceding device claims, characterized in that mechanically and / or pneumatically and / or electrostatically acting devices are provided to clamp or brake fibers ( 6 ) during the drawing process compared to other fibers ( 6 ). 26. Device according to one of the preceding device claims, characterized by a drying device at the end of the stretching chamber ( 1 ) for drying the stretching chamber ( 1 ) leaving Fa sern ( 6 ). 27. Device according to one of the preceding device claims, characterized by a control and / or regulating device for controlling and / or regulating the drawing of the fibers ( 6 ) in the drawing chamber ( 1 ).