EP0106830B1 - Open-end spinning method and device - Google Patents

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 known as "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 stocked, 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 later) 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 projected 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 unknown area, which will be called hereinafter "fiber deposition area". This area refers to 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 are deposited in the groove of the rotor. Under determined conditions, this zone is fixed in space.

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 shredder 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 which has become thread by the effect of the twist.

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 continuously in the rotor, with a speed such that the difference between the absolute linear speed of this wire formation zone and the peripheral speed of the rotor at 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 defibrator are deposited on the wire in formation by twisting before being able to be deposited in the groove of the rotor and having 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.

This is particularly the case of the device according to US.A. 3,620,002 where the fibers enter the rotor through four orifices and necessarily meet the wire in formation. No means is provided for adjusting the position of the fiber end points relative to the zone of formation of the yarn.

According to DE.A. 2 320 822 a ribbon of fibers is obtained which must still be twisted to achieve a false twist. The ribbon exit point is fixed. On the other hand, the zone of deposit of the fibers rotates. Consequently, this point and this zone necessarily meet in a cyclic manner, creating bundles.

The object of the present invention is to remedy this drawback, to eliminate the phenomenon of "bundling" and therefore to make possible the spinning of long fibers on an apparatus of the "open-end" type, comprising a supply device, a defibrator, a rotor, a rotary channel conveying the fibers from the output of the defibrator to the rotor, an output nozzle, a defibrator device and a winder device, apparatus in which the ribbon is first of all disaggregated in the defibrator that the rotary channel carries only individual fibers.

With a view to achieving this aim, the process which is the subject of the invention is distinguished in that the “fiber deposition zone” is given a speed equal to that of the “wire formation zone” so that the fibers coming from the shredder cannot be deposited on the wire in formation.

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

This device has the characteristics defined in claims 2 to 5.

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

In the 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.

Indeed 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. El - the can therefore be integrated into the fiber ring 12 before being taken by the twist, and this situation lasting indefinitely due to the equality of the two speeds mentioned above, the phenomenon of bundling will not appear never.

In the accompanying drawings a channel 2 is provided which conveys the fibers 10 from the outlet 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 deposit 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 of wire size ”13. This can cause excessive tension in wire 14.

A special provision avoids this excessive tension.

The element 3 is mounted so as to be able to rotate freely, for example by a ball bearing 8 on a part 7 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: part 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 enabling the bent fiber supply conduit to be driven 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 relationship, but applies to any embodiment based on the same principles.

Claims (5)

1. A method of «open-end» spinning using a device comprising a supply device, a disintegrator means (1), a rotor (4), a rotary channel (2) conveying the fibres from the disintegrator outlet to the rotor (4), an outlet end member (6), a delivery device and a winding device, in which the thread is first of all disintegrated in the disintegrator (1 ) so that the rotary channel (2) only conveys individual fibres, characterised in that the «fibre deposition zone» (11) is given a speed equal to that of the thread formation zone (13) so that the fibres (10) coming from the disintegrator (1) cannot be deposited on the thread (14) which is forming.

2. A device for working the method according to claim 1, comprising a channel (2) conveying the fibres (10) from the disintegrator (1) outlet towards the rotor (4), channel (2) being disposed along the rotor (4) axis, and a deflecting component (3) in the form of a bent duct which prolongs the supply channel (2) so as to guide or deflect the fibres (10) coming from the disintegrator towards the groove (5) in the rotor, characterised in that the deflecting component (3) is driven at the speed of rotation of the thread formation zone (13).

3. A device according to claim 2, characterised in that the speed of rotation of the component (3) can be obtained by electric or electronic means.

4. A device according to claim 2, characterised in that the component (3) is driven through a mechanical device (9) directly by the thread (14) being formed.

5. A device according to any of claims 2 to 4, characterised in that the thread formation zone (13) in the rotor (4) and the outlet of the bent duct (3) or fibre supply channel (2) are offset to one another.

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