EP0106830A1 - Open-end spinning method and device - Google Patents

Abstract

"Open-end" spinning process using an apparatus comprising a feed device, a defibrator, a rotor, an outlet nozzle, a deliver device and a winder device characterized in that provision is made means by which the "fiber deposition zone" (11) is given a speed equal to that of the "yarn formation zone" (13) and in that these zones are arranged so that the fibers ( 10) coming from the shredder cannot be deposited on the forming wire (14).

Description

The present invention relates to an "open-end" spinning process and apparatus.

• - un dispositif d'alimentation destiné à amener une mèche de fibres ou un ruban de fibres provenant d'une machine de préparation ;
• - un organe défibreur destiné à individualiser les fibres en provoquant, grâce aux dents ou aux aiguilles dont il est garni, une extraction rapide des fibres hors de l'extrémité du ruban qui lui est présentée par le dispositif d'alimentation ;
• - un rotor qui recueille les fibres ainsi libérées et les condense dans une rainure circulaire en un anneau de fibres qui se transformera par torsion en un fil continu ;
• - une buse de sortie ou un entonnoir ou un embout (ce dernier terme sera utilisé dans la suite) par lequel le fil se détachant de la rainure du rotor peut sortir de l'enceinte dans laquelle tourne le rotor ;
• - un dispositif délivreur destiné à entraîner le fil fini et à lui donner la tension nécessaire pour l'extraction en dehors du rotor ;
• - un dispositif bobineur pour enrouler le fil fini.

As is well known, any spinning machine called "open-end (or free fibers) rotor" consists of the following elements:

• - a feeding device intended to bring a wick of fibers or a ribbon of fibers coming from a preparation machine;
• - a defibrator intended to individualize the fibers by causing, thanks to the teeth or needles with which it is provided, a rapid extraction of the fibers from the end of the ribbon which is presented to it by the supply device;
• - a rotor which collects the fibers thus released and condenses them in a circular groove into a ring of fibers which will transform by twist into a continuous wire;
• - an outlet nozzle or a funnel or a nozzle (the latter term will be used below) by which the wire detaching from the groove of the rotor can exit from the enclosure in which the rotor turns;
• - a delivery device intended to drive the finished wire and to give it the tension necessary for the extraction outside the rotor;
• - a winder device for winding the finished yarn.

The shredder constituted by a cylinder furnished with teeth or needles, may have its axis of symmetry and rotation coincident with the axis of symmetry and rotation of the rotor; in this case we say that the device is coaxial. If these axes are different, and in particular left, the device is said to be biaxial.

In a coaxial device, the defibrator partially penetrates the rotor. The fiber ribbon is brought into an area, fixed in space, where the fibers are brought into contact with the teeth of the shredder and are extracted from the ribbon. They are then conveyed on the teeth of the shredder for a certain time then, by the effect of centrifugal force, detach from the teeth and are projected into the rotor in the groove from which they gather. The exact location of the space where the fibers detach from the shredder and are thrown into the rotor is difficult to know and in fact depends on several factors, such as: speed of the shredder, type of teeth of the shredder, type of fibers, suction phenomena created by the rotation of the rotor, etc. It is therefore accepted that for a given operating regime, the fibers are deposited in the rotor in a given but not known area, which will be called hereinafter "fiber deposition area". This zone refers to the space and not to the rotor since it rotates continuously.

In a biaxial device, the fibers, when they detach from the shredder, cannot enter directly into the rotor, since the shredder and the rotor are more distant from each other. They are then conveyed, between the defibrator and the rotor in a channel by a movement of air which collects them, at the exit of the defibrator which is also the entry of the channel and leads them to the exit of the channel which is also the rotor inlet.

The exact location of the space where the fibers are projected into the rotor is therefore well known, since it is the outlet of the channel.

The fibers are therefore deposited in the rotor in a given and known area, which will also be called hereinafter "fiber deposition area". This zone refers to space and not to the rotor, since it rotates continuously.

Whether the device is coaxial or biaxial, there is therefore a "fiber deposition zone" where the fibers settle in the groove of the rotor. Under determined conditions, this zone is fixed in space.

• La technique de formation du fil est bien connue : on introduit dans le rotor, à travers l'embout, l'extrémité d'un fil. Cette extrémité, par la force centrifuge, se dirige vers la rainure du rotor et vient se mêler aux fibres constituant l'anneau de fibres engendré par les fibres en provenance du défibreur. Le fil est ensuite introduit dans le dispositif délivreur, qui l'attire alors en dehors du rotor. L'extrémité du fil qui s'est mêlée à l'anneau de fibres présent dans le rotor est entraînée en rotation par le rotor et se tord ; cette torsion est communiquée à l'anneau de fibres présent dans le rotor, avec lequel l'extrémité est en contact. L'anneau de fibres s'ouvre et une de ses extrémités se lie intimement, par l'effet de la torsion, à l'extrémité du fil et les deux se confondent.

If we now consider the formation of the wire:

• The technique for forming the wire is well known: the end of a wire is introduced into the rotor, through the end piece. This end, by centrifugal force, goes towards the groove of the rotor and comes to mix with the fibers constituting the ring of fibers generated by the fibers coming from the shredder. The wire is then introduced into the delivery device, which then attracts it outside the rotor. The end of the wire which has mixed with the ring of fibers present in the rotor is driven in rotation by the rotor and twists; this twist is communicated to the ring of fibers present in the rotor, with which the end is in contact. The ring of fibers opens and one of its ends is intimately linked, by the effect of the twist, to the end of the wire and the two merge.

As the thread is caught in the delivery device, it is drawn outside the rotor. It is then said that the thread is primed and the phenomenon becomes continuous: the defibrator constantly sends fibers into the rotor to reconstitute the ring of fibers, and the delivery device constantly extracts from the rotor this ring of fibers become thread by the effect of the torsion.

The ring of fibers, which becomes a thread by the effect of the twist, detaches from the groove of the rotor in a very precise zone of the rotor before moving towards the outlet nozzle. This zone, which will be called hereinafter "wire formation zone" is not fixed relative to the rotor. Indeed, if this area was fixed in the rotor, the wire could not be delivered. The "wire formation zone" therefore moves in a ma continuously in the rotor, with a speed such that the difference between the absolute linear speed of this zone of formation of the wire and the peripheral speed of the rotor at the level of its groove is equal to the speed of delivery (or production) of the wire .

• - une zone d'arrivée des fibres, la "zone de dépôt des fibres", fixe dans l'espace, donc ayant une vitesse de rotation absolue égale à zéro ;
• - une zone de départ du fil la "zone de formation du fil" ayant une vitesse de rotation absolue que l'on appellera Nf (légèrement supérieure à la vitesse de rotation absolue du rotor, que l'on appellera Nr).

Two important areas therefore exist in the open-end spinning process:

• - a fiber arrival zone, the "fiber deposition zone", fixed in space, therefore having an absolute rotation speed equal to zero;
• - A wire start zone the "wire formation zone" having an absolute speed of rotation which will be called Nf (slightly higher than the absolute speed of rotation of the rotor, which will be called Nr).

These two zones therefore meet with a frequency equal to Nf. However, each time the "wire formation zone" passes into the "fiber deposition zone", the fibers coming from the shredder are deposited on the wire in formation by twisting before being able to be deposited in the groove of the rotor. and to have been able to form with the other fibers the ring of fibers of which question above. These fibers which are deposited on the wire in formation are taken in the twist of the wire before being able to align with the other fibers and to be placed parallel to them: they then create a defect which is called "bundling". This bundling phenomenon is all the more important as the fibers are long, which makes open-end spinning unsuitable for long fibers.

The object of the present invention is to remedy this drawback, to eliminate the phenomenon of "bundling" and therefore to make it possible to spin long fibers on a machine of the "open-end" type.

With a view to achieving this aim, the process which is the subject of the invention is distinguished in that it provides means by which the "fiber deposition zone" is given a speed equal to that of the "wire formation zone" and in that these zones are arranged so that the fibers coming from the shredder cannot settle on the wire in formation.

This process will be explained below with reference to the drawings which represent, by way of non-limiting example, a device which can be used for practicing the process.

• La figure 1 est une vue en coupe latérale et
• la figure 2 une vue en plan et explicative du dispositif.

In these drawings:

• Figure 1 is a side sectional view and
• Figure 2 a plan and explanatory view of the device.

In this embodiment, the principle of the biaxial defibrator will be used.

This shredder is shown schematically and by way of example at 1 in FIG. 1.

The principle of the invention is to give the "fiber deposition zone" represented at 11 a speed equal to that of the "wire formation zone" represented at 13 and to arrange these zones so that the fibers 10 coming from the shredder 1 cannot be deposited on the wire in formation 14.

In fact if the "fiber deposition zone" 11 and the "wire formation zone" 13 are driven at the same speed and do not overlap at any point, the fibers 10 coming from the shredder 1 will deposit in the groove 5 of the rotor 4 at a place where the forming wire 14 is not found. They can therefore be integrated into the ring of fibers 12 before being taken by the twist, and this situation lasting indefinitely as a result of the equality of the two speeds mentioned above, the phenomenon of bundling will never appear.

In the attached drawings a channel is provided 2 which conveys the fibers 10 from the output of the shredder 1 to the rotor 4; this channel 2 is located in the axis of the rotor 4.

The channel 2 is extended by an element 3 comprising a bent conduit 3 ¹ which deflects the fibers 10 coming from the channel 2 and directs them towards the groove 5 of the rotor 4; this element 3 is driven at the speed of rotation of the "wire formation zone" 13, either by synchronizing by electrical or electronic means the speed of element 3 and the speed of the "wire formation zone" 13 (Figure 2) or by forcing, by mechanical means, the wire in formation 14 to drive the bent conduit 3 ¹ for feeding the fibers.

For this purpose, a means 9 is provided, consisting, for example, of a rod in the shape of a "finger" fixed on the element 3 and extending sufficiently towards the bottom of the rotor 4 to be in the path of the wire in formation. 14, so that the latter, in its rotation, is forced to abut against this rod and consequently to cause the element 3 to rotate.

The "wire formation zone" 13 and the outlet of the bent conduit 3 ¹ for supplying the fibers are offset so that these fibers cannot be deposited on the wire in formation 14 in the "wire formation zone" 13 .

In the case where the wire 14 is forced to drive itself the element 3 for feeding and deflecting the fibers, it is obvious that the wire 14 must drive the bent conduit 3 ¹ at the speed of the "zone wire formation "13. This can cause excessive tension in wire 14.

A special provision avoids this excessive tension.

Element 3 is mounted so that it can freely rotate for example by a ball bearing 8 on a part 7 which is itself integral with the rotor 4.

When the rotor 4 is rotated, the part 7 secured to the rotor 4 is also rotated at the same speed. The wire 14 then no longer has to communicate to the element 3 for deflecting the fibers except the speed equal to the difference between the speed of the "wire formation zone" 13 and the speed of the rotor 4.

Key to Figures 1 and 2:

• 1: defibrating organ
• 2: fiber transport channel
• 3: fiber feed and deflection element
• 3 ¹ : bent duct
• 4: rotor
• 5: rotor groove
• 6: wire outlet end
• 7 piece integral with the rotor and supporting the bent fiber supply duct
• 8: means permitting the rotation of the bent fiber supply duct relative to the part 7
• 9: means for driving the bent conduit for supplying the fibers by the wire in formation
• 10: fibers from the shredder
• 11: fiber deposition area
• 12: fiber ring
• 13: wire formation area
• 14: wire in formation.

The invention is not limited to this type of embodiment, but applies to any embodiment based on the same principles.

Claims (8)

1. "Open-end" spinning process using an apparatus comprising a feed device, a defibrator, a rotor, an outlet nozzle, a deliverer device and a winder device characterized in that the means are provided by which the "fiber deposition zone" (11) is given a speed equal to that of the "wire formation zone" (13) and in that these zones are arranged so that the fibers (10) coming from the defibrator (1) cannot be deposited on the forming wire (14). 2. Apparatus for the practice of the method according to claim 1 comprising a channel (2) conveying the fibers (10) from the outlet of the shredder (1) to the rotor (4), this channel (2) being located in the 'axis of the rotor (4), characterized in that there is provided for the channel (2) an element (3) produced for example in the form of a bent conduit (3 ¹ ) which extends the supply channel ( 2) and which is made so as to direct or deflect the fibers (10) coming from the defibrator towards the groove (5) of the rotor, this element (3) being driven at the speed of rotation of the zone of formation of the wire (13). 3. Apparatus according to claim 2, characterized in that the speed of rotation of the deflection element (3) is obtained by electrical or electronic synchronization means. 4. Apparatus according to claim 2, characterized in that there is provided mechanical means by which the wire in formation (14) is forced to directly drive the element (3) deflection. 5. Apparatus according to any one of claims 2-4, characterized in that the element (3) deflection is free to rotate relative to the rotor, more particularly to an intermediate piece (7) integral with the rotor. 6. Method according to claim 1, characterized in that the zone of formation of the wire and the outlet of the element or of the fiber supply duct are offset so that the fibers cannot be deposited on the formation zone some thread.

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