EP0085635B1 - Method and device for manufacturing a coreyarn - Google Patents

Description

The present invention relates to an improvement in spinning techniques making it possible to produce fiber yarns comprising an internal core, spun yarns which, in the following description, will be designated by the expression "core yarns".

Many techniques have been proposed for making core threads. The most common is to introduce a multifilament core inside a wick, during the last spinning operation, that is to say on the continuous spinning, said core being introduced upstream of the last pair of wick stretching rollers. This solution gives good results but has the drawback of being limited in speed given that the reception of the thread obtained is carried out by a system communicating a twist to the thread, for example a winding device with ring and slider.

It has also been proposed, in particular in United States patent No. 4033102, to produce self-twisted yarns, at least one of the constituents of which has a core in its central part, said core also being incorporated upstream of the last pair of rollers in the strand of a fiber wick. This technique makes it possible to increase the production speeds taking into account the fact that the reception of the wires formed does not require a twist to be communicated to it. On the other hand, in the zones of change of torsion, the wire can sometimes present defects. In addition, given that the wire formed has at least two components, twisted one on the other, it is relatively difficult to obtain very fine son.

Many solutions which, to date, have not experienced great industrial development, have also been proposed for making fiber yarns. Thus, it has been envisaged to project elementary fibers onto a continuous wire subjected to a temporary false twist, and this upstream of the false twist spindle.

It has also been proposed to project the fibers onto a core previously glued or coated with a heat-bonding material. These solutions are relatively complex to implement and do not lead to yarns having properties comparable to conventional fiber yarns having a true twist.

Now we have found, and this is what is the subject of the present invention, an improved process, of great flexibility of implementation and allowing a high production, which overcomes the drawbacks of the previous solutions while allowing '' obtaining a core yarn which, after winding, has a true twist along its length, the fibers being perfectly linked to the internal core.

• - à délivrer positivement un fil destiné à former l'âme interne,
• - à soumettre ledit fil à une fausse torsion passagère,
• - à projeter sur ce fil, en amont de la broche de fausse torsion, des fibres élémentaires, et il se caractérise par le fait que:
• - la projection des fibres élémentaires sur l'âme dans la zone de remontée de torsion est réalisée au moyen d'une surface de guidage mobile sur laquelle lesdites fibres sont délivrées tangentiellement et qui tend à exercer une force de traction sur l'extrémité libre desdites fibres,
• - l'âme est déplacée tangentiellement par rapport à la surface de guidage précitée selon une direction concourante avec la direction d'amenée des fibres.

The invention therefore relates to a method for producing a yarn of fibers comprising an internal core, method which consists in:

• - to positively deliver a wire intended to form the internal core,
• - subjecting said wire to a temporary false twist,
• - to project on this wire, upstream of the false twist spindle, elementary fibers, and it is characterized by the fact that:
• - The projection of the elementary fibers onto the core in the torsion rise zone is carried out by means of a movable guide surface on which said fibers are delivered tangentially and which tends to exert a tensile force on the free end of said fibers,
• - The core is moved tangentially relative to the aforementioned guide surface in a direction concurrent with the direction of supply of the fibers.

In a preferred embodiment of the method according to the invention, the movable guide surface is subjected to the action of a stream of fluid, air for example, the flow of which is such that it promotes, in cooperation with said guide surface, transport and condensation of the fibers. This flow of fluid can, for example, be obtained by subjecting the guide surface to a vacuum. Furthermore, the action of the fluid current, for example the vacuum effect, is advantageously eliminated in the vicinity of the junction point between the fibers and the core with which they must be associated.

As guide surface allowing the implementation of the invention, one can use, for example, a rotary guide, having at its periphery a groove for guiding the core wire and fibers. The shape of this groove will preferably have a V-shaped section, the branches of which can be more or less spaced from one another. The bottom of this groove is subjected to a vacuum, the core wire passing inside tangentially, the fibers intended to be projected onto the core also being delivered substantially tangentially to the bottom of the groove but upstream from the point. tangency of the core thread. The vacuum inside the groove can be obtained by providing an internal suction source, the air flowing through orifices provided at the bottom of this groove. These orifices can be arranged in different configurations, for example being aligned or, preferably, having substantially the shape of a sinusoid.

Of course, the guide surface could be made up of any other equivalent means, for example by a conveyor belt system.

As a device making it possible to bring the fibers onto the guide surface, any known device can be used for drawing a wick of fibers, such as for example sleeve drawing systems, a breaker of the type used in spinning with free fibers, devices for performing a large stretch, commonly designated by the expression "selector", for example of the type described in French patents Nos ^. 1044932,1117278 and 1503693.

According to the embodiment of the invention according to which a rotary guide (or condenser) is used as guide surface or not subjected to an internal vacuum, the core wire is moved vertically from top to bottom and the rotary guide is arranged at the outlet of a fiber drawing system conventional, the latter being arranged at an angle so that the fibers are brought to the bottom of the groove at an angle of about 45 ° C with the core wire. Of course, such an embodiment is not limiting and other paths and / or angles between the core wire and the supply of the fibers could be envisaged.

Furthermore, the distance between the point of exit of the fibers from the member enabling them to be delivered, for example between the last pair of cylinders of a drawing system, and the point of contact of said fibers with the guide surface, for example with a rotary guide, will be adapted according to the fibers treated, but it has been found that good results are obtained by having a distance at least equal to the average length of the fibers which must be associated with the core.

However, in certain particular cases resulting either from existing spinning machines which are suitable for implementing the method according to the invention, or from the very nature of the fibers treated, in particular because of their length, it may happen that it is necessary to put the rotary guide (or condenser) on which the fibers are delivered at a certain distance, of the order of several centimeters, from the point of exit of the fibers from the conventional drawing system which delivers them.

In this case, the fibers can therefore have a relatively large path in the open air which can cause difficulties in obtaining a regular thread.

In accordance with an improved variant, which is also the subject of the present invention, this drawback can be overcome by providing, between the outlet of the fiber drawing device and the guide surface, preferably consisting of a rotary condenser guide, a conveying surface, subjected to a vacuum, and which ensures the transport of the fibers from the outlet of said drawing system to the guide surface.

According to this variant, the conveyor surface is advantageously constituted by an endless belt carried, on the one hand, by one of the cylinders of the fiber drawing system and which, on the other hand, comes practically to tangent with the surface of guide on which the fibers are brought for example with a rotary guide.

As a thread-like element constituting the core of a yarn produced in accordance with the invention, any textile material of known type can be used, for example multifilament yarns, fiber yarns made either beforehand or directly during processing. of the method according to the invention, or even optionally yarns of fibers themselves comprising an internal core.

Finally, as a pin making it possible to communicate a false twist to the core, any known type of pin will be used, for example pins with internal or external friction, belt pins, or even pneumatic pins.

• - les fig. 1 et 7 illustrent schématiquement, vue de côté et en perspective, une position de travail d'une machine selon l'invention, permettant de réaliser un fil à âme;
• - la fig. 2 est une vue de détail montrant plus particulièrement un mode de réalisation d'une surface de guidage mobile pour les fibres, constituée par un guide rotatif soumis à une dépression interne ainsi que la manière dont le fil d'âme et les fibres sont amenées sur ce guide,
• - la fig. 3 est une coupe transversale d'une surface de guidage sous forme de guide rotatif permettant la mise en oeuvre de l'invention; .
• - la fig. 4 illustre schématiquement, vue de face, l'obtention d'un fil comportant deux fils à âme réalisés conformément à l'invention;
• - la fig. 5 illustre une variante conforme à l'invention, variante selon laquelle le transport des fibres entre la sortie du système d'étirage. conventionnel et la surface de guidage mobile (guide rotatif) permettant de projeter des fibres sur l'âme est obtenu en prévoyant outre ces éléments une surface transporteuse soumise à une dépression;
• - la fig. 6 est une vue de face illustrant une variante d'une surface de guidage sous forme de guide rotatif permettant la mise en oeuvre de l'invention.

The invention and the advantages which it provides will be understood better thanks to the exemplary embodiments given below by way of indication but not limitation and which are illustrated by the attached diagrams in which:

• - figs. 1 and 7 schematically illustrate, side view and in perspective, a working position of a machine according to the invention, making it possible to produce a core wire;
• - fig. 2 is a detail view showing more particularly an embodiment of a movable guide surface for the fibers, constituted by a rotary guide subjected to an internal depression as well as the manner in which the core wire and the fibers are brought to this guide,
• - fig. 3 is a cross section of a guide surface in the form of a rotary guide allowing the implementation of the invention; .
• - fig. 4 illustrates diagrammatically, front view, obtaining a wire comprising two core wires produced in accordance with the invention;
• - fig. 5 illustrates a variant according to the invention, variant according to which the transport of the fibers between the outlet of the drawing system. conventional and the movable guide surface (rotary guide) making it possible to project fibers onto the core is obtained by providing, in addition to these elements, a conveyor surface subjected to a vacuum;
• - fig. 6 is a front view illustrating a variant of a guide surface in the form of a rotary guide allowing the implementation of the invention.

Referring to the attached diagrams, FIGS. 1 and 7 illustrate a working position of a machine allowing the implementation of the method according to the invention, that is to say making it possible to produce, in a single step, real core wires.

This machine comprises, in known manner, a storage area (1), creel for example, where are arranged coils (2) of wires (3) intended to constitute the core of the wire produced in accordance with the invention. These wires (3) are brought, via a deliverer (4), which could possibly be omitted, to the treatment zone proper, designated by the general reference (5), where they will be covered and associated with staple fibers.

Furthermore, if the implementation of the method according to the invention is preferably carried out, using as continuous core threads (3) continuous multifilament threads, it could be envisaged, as shown in dotted lines in these figures, to have a core formed itself by a yarn of fibers (3a) obtained by drawing a wick or ribbon (2a), this yarn being used either alone, or possibly by incorporating a multifilament core (3) therein.

The treatment zone (5) comprises, in a known manner, a deliverer (6), a false twist spindle (7) of known type, for example a friction spindle, with crossed belts. Of course, any other type of friction pin or not could be used.

A third call provider (8) is arranged downstream of the spindle (7) and the wire formed is returned at (9) by means of a conventional system, for example of the type with peripheral and reciprocating drive .

According to the invention, upstream of the false twist spindle (7), that is to say in the area of torsional rise, is arranged one on movable guide face, constituted in this case by a rotary guide (10), intended to distribute discontinuous fibers (11) on the core wire (3). These fibers (11) come from a wick (12) which is stretched, for example by means of a conventional system with sleeves (13). Of course, any other wicking system could be used, such as for example the breakers used for the implementation of the spinning technique known as free fibers or the systems allowing a large drawing of the type of those described in the French patents N ° ^S 1044932, 1117278 and 1503693.

In the embodiment illustrated by the appended figures, the guide surface (10) constituted by the rotary disc is arranged downstream of the last pair of stretching cylinders (14) of a stretching system (13) with sleeves . According to this embodiment, the rotary guide (10) has, as is clear from Figures 2 and 3, a peripheral groove (15). Furthermore, it comprises radial orifices (16) making it possible to create a depression inside said groove (15).

The core wire (3) is brought tangentially, or at a very short distance from the bottom of the groove (15) while the fibers (11) are also delivered tangentially to the bottom of the groove but enveloping the surface of the rotary guide ( 10). Consequently, this rotary guide serves not only as a guide and transport element for the elementary fibers (11), but also as a distribution element for said elementary fibers on the core wire (3).

Furthermore, the phenomenon of depression is preferably eliminated in the vicinity of the point of tangency A of the wire (3) and the rotary guide (10), for example by means of a fixed cover (18) which closes the orifices (16 ). In the present case, for the sake of simplification, the cover (18) is shown in a position such that it closes the orifices (16) substantially from the point of tangency A of the core wire, but it is obvious that this position could be modified, the suppression of the phenomenon of depression being able to be carried out either before or after this point of tangency A and this, according to the materials worked and / or production speeds.

Figs. 2 and 3 illustrate in more detail an embodiment of such a guide surface in the form of a rotary guide. In this embodiment, the cover (18) for closing the orifices (16) is disposed inside the disc and the depression inside the groove (15) is obtained by means of a source of suction (not shown), connected to an internal conduit provided in the fixed support shaft (17) of the guide (10) and which opens into a cavity of said guide. This guide (10) is mounted on bearings and is driven in rotation, for example by means of a tangential belt not shown. Of course, other embodiments could be envisaged without departing from the scope of the invention.

In addition, as said previously, the distance L between the last pair of cylinders (14) of the drawing system (13) and the point of tangency B of the fibers (11) with the bottom of the groove (15) is adjusted by so as to be at least equal to the average length of the fibers (11).

It has been found that it was possible, thanks to such a process, to obtain core yarns in which not only the peripheral fibers are perfectly linked to the internal core, but also have a true twist around this core. In addition, the yarns thus produced have very good textile characteristics while being able to be obtained at high speeds, which can reach several hundred meters per minute, taking into account that the winding can be carried out without imparting torsion.

Not only does such a method make it possible to obtain single wires, but it can also be adapted, as illustrated in FIG. 4, to obtain doubled wires. For this, it suffices to bring in parallel two elementary wires (3) inside the false twist spindle (7) and to deliver fibers on each of these wires (3), for example, by means of a rotary guide (10) then comprising two peripheral grooves (15), each being subjected to an internal vacuum. The two core wires obtained are assembled by a simple joining guide (19), the assembled wire being brought in by means of winding (9) by a common deliverer (8).

It could also be envisaged to adapt this technique to obtaining the self-twisted threads, by providing downstream of the rotary guide a conventional system making it possible to communicate an alternating twist and by causing the self-twist in a conventional manner. One could for example use an installation of the type illustrated in FIG. 4, an intermittent deliverer being disposed between the rotary guides (10) and the false twist spindle (7).

Example 1

• - fil d'âme (3) : fil polyester 72 décitex, 33 brins,
• - vitesse d'appel du fil d'âme (3) (délivreurs 4 et 6) : 200 m/min,
• - broche de fausse torsion (7) : broche à courroies croisées formant entre elles un angle de 46° et ayant une vitesse linéaire de 540 m/min,
• - mèches de fibres (12): coton (Nm3),
• - étirage en (13): 30 fois,
• - distance L: 40 mm,
• - angle entre le fil (3) et l'amenée des fibres (11): environ 45°,
• - guide rotatif (10) : diamètre externe D 70 mm - diamètre en fond de gorge d: 50 mm,
• - orifices (16): au nombre de 72, ces orifices ayant un diamètre de 0,8 mm,
• - dépression interne: environ 200 mm d'eau.

On an installation illustrated by figs. 1,2 and 3, a core wire according to the invention is produced under the following conditions:

• - core thread (3): 72 decitex polyester thread, 33 strands,
• - call speed of the core wire (3) (deliverers 4 and 6): 200 m / min,
• - false twist spindle (7): spindle with crossed belts forming an angle of 46 ° between them and having a linear speed of 540 m / min,
• - wicks of fibers (12): cotton (Nm3),
• - stretching in (13): 30 times,
• - distance L: 40 mm,
• - angle between the wire (3) and the fiber feed (11): approximately 45 °,
• - rotary guide (10): external diameter D 70 mm - diameter at the bottom of the groove d: 50 mm,
• - holes (16): 72 in number, these holes having a diameter of 0.8 mm,
• - internal depression: approximately 200 mm of water.

By proceeding under the conditions indicated above, a core wire having a title of 185 decitex is obtained, the wool fibers being perfectly bonded to the core (14) and regularly covering the latter.

Such a thread can be used as it is in weaving or hosiery.

Example 2

Example 1 is repeated with the only difference that one proceeds as illustrated in FIG. 4, that is to say that two wires are simultaneously treated which are then joined downstream of the false twist spindle (7).

An assembled yarn is obtained which, although no twist is communicated by the winding system (9), however has a certain cohesion, probably due to the attachment of the fibers to each other. Such a yarn with a total titer of 370 decitex can also be used as it is in weaving or hosiery.

Example 3

Example 1 is repeated, but the multifilament core (3) is replaced by a wick (3a) drawn directly on the machine as shown in dotted lines in FIG. 1. The wick (3a) is a cotton wick of Nm3 before stretching and which is stretched 30 times on the machine.

A yarn of fibers is thus obtained comprising an outer sheath consisting of fibers (11), which are twisted around a core also consisting of staple fibers substantially at zero twist.

Such a yarn can also be used both in weaving and in hosiery.

Of course, the invention is not limited to the exemplary embodiments given above, but it covers all the variants produced in the same spirit.

Thus, fig. 5 illustrates a variant in accordance with the invention in which the same references have been used to designate the same elements as in the previous examples.

According to this variant, the drawing system comprises two sleeves (13) at the outlet of which are arranged a selector cylinder (24) associated with a pressing cylinder (25). The wick of fibers (11) is stretched between these elements and, in accordance with this variant, the cylinder (25) is associated with a conveyor belt (26) constituted by a 'perforated belt inside which is disposed a box of suction (27). The belt (26), supported at its end by a support roller (28), comes practically to tangent with a rotary condenser guide (10), playing the role of movable guide surface and which, in the present case, is produced in accordance with the example illustrated in fig. 6. This guide (10), as before, tends to exert a tensile force on the free end of the fibers (11).

Compared to the previous examples, this rotary condenser guide has at its periphery a groove (15) having the shape of a V whose branches are widely spaced. Perforations (16) are made at the bottom of this groove and are arranged substantially in the form of a sinusoid. A suction is created inside the rotary guide by any suitable means not shown, for example in a manner similar to the example illustrated in FIGS. 2 and 3.

As before, the fibers (11) are distributed practically tangentially at the bottom of the groove (15) and, in this case, thanks to the conveyor belt (26). In this exemplary embodiment, the core wire (3) is brought, also tangentially, to the bottom of the groove (15) and downstream of the point of projection of the fibers (11), the connection of said fibers with the core ( 3) being obtained by the action of the false twist pin (7).

The wire obtained is returned in a conventional manner.

Such a variant makes it possible, with respect to the embodiments described above, to ensure better retention of the fibers at the outlet of the stretching system of the food wick (11), in particular in the case where the guide surface (10) , for example rotary condenser guide, is relatively distant from the outlet of the drawing system. In addition, in some cases, the suction conveyor belt (6) even makes it possible to improve the quality of the threads obtained by the fact that it promotes the parallelization of the fibers and even makes it possible, in certain cases, to ensure stretching. complementary. In addition, thanks to such an embodiment, the passage in the open air of the fibers can be very low, and adjusted so that it is shorter than the average length of said fibers, which can make it possible to treat very short fibers, such as carded cotton.

Of course, the invention is not limited to the embodiments described above, but it covers all the variants produced in the same spirit.

Thus, it could be envisaged to apply this method in combination with all the known methods making it possible to produce fancy yarns, for example by varying the feeding speed and / or the winding speed, by associating the yarn (s) with core formed with additional threads. Similarly, it could be envisaged to use unstretched core threads (3), the stretching being carried out between the deliverers (4) and (6), or even possibly to continuously produce a real textured core by providing between the rotary guide (10) and the deliverer (6) a conventional oven.

Of course, if the invention is particularly suitable for allowing winding without additional twisting, it could be envisaged to give the wires formed a complementary twist, for example by using a ring and slider winding system.

In addition, in the examples given above, the core wire is moved vertically, from top to bottom; it is obvious that this is not limiting and that the path of the wire could be modified, the displacement of the core wire being able to be carried out from bottom to top, or even horizontally.

Finally, if the fiber supply can be carried out from a wick, it is obvious, as is moreover shown in FIG. 7, that other types of food material could be used, for example skin ribbons.

Claims (15)

1. Process for making a spun yarn of fibres comprising an internal core, which consists in:

- positively delivering a yarn adapted to form the internal core,

- subjecting said yarn to a momentary false twist,

- projecting elementary fibres (11) onto this yarn, upstream of the false twist spindle (7), characterized by the fact that:

- the projection of the elementary fibres (11) onto the core (3) is effected by means of a mobile guide surface on which said fibres (11) are delivered tangentially and which tends to exert a pulling force on the free end of said fibres (11),

- the core is displaced tangentially with respect to the said guide surface in a direction concurrent with the direction of delivery of the fibres.

2. Process according to the claim 1 characterized by the fact that the guide surface is subjected to the action of a stream of fluid, for example air.

3. Process according to the claim 2 characterized by the fact that the stream of fluid is obtained by subjecting the guide surface to a phenomenon of depression.

4. Process according to the claim 3 characterized by the fact that the guide surface is in the form of a rotary guide (10) presenting on its periphery a groove (15) for guiding the core yarn (3) and fibres (11), the bottom of said groove being subjected to a depression, and the core yarn (3) passing tangentially to the interior of this groove, the fibres (11) intended to be projected on the core, likewise being delivered tangentially to the bottom of the groove but upstream with respect to the point of contact (A) of the core yarn, so as to envelope the rotary guide (10) over part of its periphery.

5. Process according to the claim 4 characterized by the fact that the guide surface allowing projection of the fibres on the core is contituted by a rotary dis (10) presenting on its periphery a groove (15) subjected to a depression, perforations (16) being made in the bottom of this groove and being disposed substantially in the form of a sine curve...

6. Process according to the claim 4 characterized by the fact that the effect of depression is eliminated in the vicinity of the point of contact (A) of the yarn (3) with the guide (10).

7. Process according to the claim 4 characterized by the fact that the core yarn is displaced substantially vertically, the rotary guide (10) being disposed at the outlet of a conventionnal stretching system (13), the latter being disposed oblique- lyso thatthe fibres (11 ) are delivered atthe bottom of the groove (15), forming an angle with the core yarn (3).

8. Process according to the claim 7 characterized by the fact that the angle formed by the core yarn (3) and the direction of delivery of the fibres (11 ) is about 45°.

9. Process according to the claim 1 characterized by the fact that the core yarn (3) is a multifilament continuous yarn.

10. Process according to the claim 1 characterized by the fact the core yarn is constituted by a spun yarn of fibres (3) made directly on the machine.

11. Process according to the claim 1 characterized by the fact the core yarn is constituted by a spun yarn of fibres (3) itself comprising an additional core.

12. Process according to the claim 1 characterized by the fact that after treatment, two yarns formed are joined.

13. Process according to the claim 1 characterized by the fact a conveyor surface (26) subjec- tedto a depression is disposed between the outlet of a rove stretching system (11) and the mobile guide surface (10) on which the fibres (11) are delivered tangentially.

14. Device for carrying out the process of claim 1, which comprises a storage area (1) where the bobbins (2) of core yarn (3) are disposed, yarns delivered via a delivery device (4) to the actual treatment zone (5), this zone (5) comprising a delivery device (6), a false twist spindle (7) and an intake delivery device (8) as well as winding means (9), characterized by the fact that upstream of the false twist spindle (7) is disposed a mobile guide surface (10) adapted to distribute discontinuous fibres (11) onto the core yarn (3), these fibres (11) coming from a rove (12) subjected to stretching by means of a conventional system (13) and the mobile guide surface exerting a pulling force on the free end of said fibres (11), the core (3) being displaced tangentially with respect to said guide surface in a direction concurrent with the direction of delivery of the fibres (11).

15. Device according to the claim 14 characterized by the fact that the mobile guide surface (10) is constituted by a rotary condenser guide comprising a peripheral groove (15) subjected to a depression.

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