EP0098230A1 - Method and device for manufacturing core yarns of staple fibres - Google Patents

Abstract

Method for producing a core spun according to which elementary fibers (11) are projected onto a wire (3), the wire (3) being subjected to the action of a false twist spindle. The projection of the fibers (11) is obtained by means of a movable guide surface (10) on which the fibers (11) are delivered tangentially and are held parallel and flat. Furthermore, the core (3) is brought tangentially to the fibers (11) parallelized at an angle and in the direction of movement of said fibers.

Description

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

It relates more particularly to an improvement made to the technique which is the subject of the French patent published under the number 497 481.

• - à délivrer un fil destiné à former l'âme interne,
• - à faire passer ce fil en contact tangentiel avec une surface mobile (tambour de carde) sur laquelle des fibres élémentaires sont maintenues parallélisées et à plat, ledit fil passant transversalement par rapport à ladite surface ;
• - à communiquer audit fil d'âme une torsion qui tend à remonter sur la surface mobile supportant les fibres élémentaires, cette torsion étant communiquée par un organe agissant de manière intermittente de telle sorte que le fil formé puisse se détordre automatiquement et instantanément, cette rapide rotation du fil en sens inverse n'ayant pas d'effet sur les fibres déjà enroulées sur lui.

The aforementioned document describes a technique which, in general, consists of:

• - to deliver a wire intended to form the internal core,
• - Passing this wire in tangential contact with a movable surface (carding drum) on which elementary fibers are kept parallel and flat, said wire passing transversely relative to said surface;
• to communicate to said core wire a twist which tends to go up on the mobile surface supporting the elementary fibers, this twist being communicated by a member acting intermittently so that the formed wire can untwist automatically and instantaneously, this rapid rotation of the thread in the opposite direction having no effect on the fibers already wound on it.

It is easily understood that such a process, if it can make it possible to obtain a spun of fibers comprising a core, does not make it possible to have high production speeds and above all does not lead to good quality threads given that these fibers are not really linked to the core but form in some way a felt around the latter as indicated on page 3 lines 80 to 95 of the description of this patent. These disadvantages may explain the fact that at the to the knowledge of the Applicant, such a technique has not been used industrially.

Now we have found, and this is what is the subject of the present invention, an improvement to the aforementioned process, which not only simplifies the implementation thereof and makes it possible to have very high production speeds but which, moreover, it makes it possible to treat any type of fiber indifferently, and in particular wool fibers (where fibers having similar hook properties), materials which are difficult to use to date. Finally, the method according to the invention makes it possible to obtain very good cohesion of the fibrous surface with the internal core as well as core yarns having very regular textile characteristics.

• - le passage du fil d'âme sur les fibres parallélisées est réalisé en biais par rapport à la surface supportant lesdites fibres et ce, dans leur sens de déplacement ;
• - la torsion communiquée au fil est donnée par une broche de fausse torsion, agissant en permanence sur ledit fil et qui est disposée en aval de la surface mobile supportant les fibres.

In general, the invention therefore relates to an improvement to the process which is the subject of French patent 497 481, a process mentioned above, an improvement which is characterized by the fact that:

• - The passage of the core wire on the parallelized fibers is made at an angle relative to the surface supporting said fibers and this, in their direction of movement;
• - The twist imparted to the wire is given by a false twist pin, permanently acting on said wire and which is arranged downstream of the mobile surface supporting the fibers.

In the following description, the movable surface on which the elementary fibers are kept parallel and flat will be designated by the expression "movable guide surface".

According to the invention, the maintenance of the fibers in parallelized form, flat on the movable guide surface, can be achieved either by subjecting said surface to a suction or, preferably, by using a surface which has a surface state which maintains the fibers by simple contact, or even by combining these two possibilities.

Several types of devices can be used for implementing the method according to the invention.

Thus, the guide surface can be in the form of a cylindrical drum, a hyperboloid-shaped drum, an endless belt or any other equivalent member.

In the case where the retention of the fibers on this guide surface is obtained under the action of a suction phenomenon, the surface will be perforated or porous and will appear either in the form of a drum or in the form of an endless belt.

According to the preferred embodiment of the invention, according to which the maintenance of the fibers on the guide surface is ensured by simple mutual contact, the surface will preferably be covered with a material facilitating the adhesion of the fibers, for example of a material similar to velvet. It could possibly be envisaged to use a surface having the structure of a brush.

However, whatever the surface used, it is essential, not only that the fibers are kept parallelized in the form of a strip but also that the wire intended to form the core is brought tangentially to said strip of fibers and this, so secant, at an angle in the direction of movement of the fibers.

• - la figure 1 illustre schématiquement, vue de côté, une position de travail d'une machine mettant en oeuvre le procédé selon l'invention afin de réaliser un fil à âme,
• - la figure 2 est une vue en perspective d'une surface de guidage mobile, sous forme de courroie, utilisée pour la mise en oeuvre du procédé selon l'invention,
• - la figure 3 est une vue de face de la surface de guidage de la figure 2 montrant de manière plus précise comment s'effectue la liaison fil d'âme/fibres sur une surface de guidage conforme à l'invention,
• - la figure 4 illustre une variante, également en perspective, d'une surface de guidage sous forme de tambour utilisable pour la mise en oeuvre de l'invention,
• - la figure 5 illustre une autre variante, également en perspective, d'une surface de guidage sous forme de courroie associée à un système d'aspiration,
• - la figure 6 est une vue schématique, partielle, en perspective montrant une surface de guidage particulière permettant d'assurer le maintien des fibres par combinaison d'une aspiration et d'un état superficiel particulier assurant le maintien par simple contact,
• - les figures 7 et 8 illustrent deux autres variantes d'un dispositif conforme à l'invention.

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

• - Figure 1 illustrates schematically, side view, a working position of a machine putting implements the method according to the invention in order to produce a core wire,
• FIG. 2 is a perspective view of a movable guide surface, in the form of a belt, used for implementing the method according to the invention,
• FIG. 3 is a front view of the guide surface of FIG. 2 showing more precisely how the core wire / fibers connection is effected on a guide surface according to the invention,
• FIG. 4 illustrates a variant, also in perspective, of a guide surface in the form of a drum usable for the implementation of the invention,
• FIG. 5 illustrates another variant, also in perspective, of a guide surface in the form of a belt associated with a suction system,
• FIG. 6 is a schematic partial view in perspective showing a particular guide surface making it possible to maintain the fibers by combining a suction and a particular surface state ensuring maintenance by simple contact,
• - Figures 7 and 8 illustrate two other variants of a device according to the invention.

Figure 1 illustrates, side view, a working position of a machine allowing the implementation of the method according to the invention, that is to say allowing to realize, in a single step, real son core .

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

This treatment zone (5) comprises a deliverer (6), a false twist spindle (7) of known type, for example a friction spindle, with crossed belts.

A third call provider (8) is arranged downstream of the spindle (7) and the formed wire is returned at (9) by means of a conventional winding system which may or may not impart an additional twist to the formed wire.

The distribution of staple fibers around the core (3) is carried out by providing, upstream of the false twist spindle (7), that is to say in the area of ascent of the twist, a guide surface mobile (10) on which the fibers (11) are delivered tangentially and which tends to exert a tensile force on the free end of said fibers. These fibers (11) come from a wick (12) which undergoes drawing for example by means of a conventional system with sleeves (13) or a large drawing of the selector type. Compared to the teachings of French patent 497481 according to the invention, the guide surface (10) has a straight generator and has a surface state ensuring the maintenance of the fibers by simple contact. Furthermore, the fibers (11) are kept parallelized, in the form of a ribbon on the surface (10). In addition, the core (3) is brought tangentially to the surface (10) in a direction not only concurrent with the direction of supply of the fibers (11) but also in a secant and tangential manner to said flat wick (11). Finally, the torsion communicated by the spindle (7) and which goes up on the guide surface has a direction such that, in combination with the direction of advance of said guide surface, the fibers are taken up by the core (3) passing under this core, that is to say that their free end is trapped between the core and said guide surface.

In the embodiment illustrated in Figures 2, 3 and 7, the guide surface (10) consists of an endless belt supported by two rollers (14-15). On the other hand, in the example illustrated in FIG. 5, the guide surface (10) is also constituted by an endless belt but this belt is directly driven by the last cylinder of the drawing train.

In the examples illustrated by FIGS. 4 and 8, the guide surface is constituted by a rotary drum which is cylindrical in shape in FIG. 4 and in the form of a hyperboloid in FIG. 8.

Preferably, as is clear from FIGS. 3,4 and 7, guides (16) and (17) are provided on each side of the guide surface (10) so that the core wire (3) is presented tangentially to said surface and comes to cut the wick of fibers (11) over its entire width and at an angle in their direction of movement.

Different types of materials can be used for the covering material of the guide surface (10). It has been found that good results are obtained by using, as covering materials for the surface, a textile material having the structure of a pile pile. Such a material makes it possible to obtain good retention of the parallelized fibers (11) which, however, are easily detached from said surface during the passage of the core wire (3) and distributed around this element.

Of course, other types of materials can be used without departing from the scope of the invention.

For a correct implementation of the invention, it has moreover been determined that it is preferable to have a distance between the exit of the last elements of the drawing train (13) and the point where the fibers of the wick (12) come into contact with the core greater than the length of the fibers.

Furthermore, with regard to the speeds of the various members with respect to each other, it has been found that good results are obtained by having a speed (V ₂ ) greater than or equal to the speed (V 1) of feeding fibers (11) onto the guide surface (10). Preferably, (V ₂ ) is of the order of 1.3 to 1.5 times ( ^V ₁ ).

In the above examples, it can be envisaged to use an additional pressure roller, shown in dotted lines in FIGS. 2, 3 and 4, designated by the reference (20). This pressure roller is disposed substantially in the area where the fibers come into contact with the movable surface and promotes the attachment of the fibers to said surface.

Figures 5 and 7 illustrate alternative embodiments of the method according to the invention using as a guide surface a conveyor belt (10).

In these variants, the same references as those used for the example illustrated in FIGS. 2 and 3 are used to designate the same members.

In the embodiment according to FIG. 5, with respect to the example described in FIG. 2, the transport surface (10) also consists of an endless belt, but is mounted directly around one of the engine cylinders of the last pair of the stretching train (11). Consequently, the support roller (14) of FIG. 2 can be omitted. In this embodiment, the fibers are brought below the belt (10) and their maintenance on this surface is ensured by a suction system (21) arranged between the two strands of the belt. This belt must of course allow the passage of air and can be either perforated or porous.

Such a variant is particularly suitable for treating cotton fibers but of course, this is not limiting.

In the variant illustrated in Figure 8, the conveyor belt (10) is arranged vertically, so that its straight strand is opposite the output cylinders of the drawing train. In this case, the fibers are distributed on this rectilinear strand, their taking by the core (3) being carried out as previously by bringing this core tangentially to the surface, concurrently with the wick of fibers. This embodiment makes it possible to minimize the spacing between the outlet of the drawing device and the fiber transport surface.

If, in the previous examples, the fibers were maintained either by simple mutual contact of said fibers with the surface, or by the action of a suction phenomenon on this surface, it can be envisaged, as illustrated in FIG. 6, to use as a transport surface a surface making it possible to combine a phenomenon of aspiration and a latching of the fibers by simple mutual contact. In this case, it is possible, for example, to use a belt which has alternating zones (22) of velvet type similar to that which is the subject of FIG. 2 and perforated zones (23). It has been found that good results are obtained by having a length of perforated zone (23) less than the average length of the fibers intended to be treated.

Example 1:

• - fil d'âme (3) : fil polyester 167 Dtex,
• - mèche de fibres (12) : laine 3300 Dtex - deux bouts - longueur moyenne des fibres : 120 mm,
• - étirage en (l3) : 18,73 ;
• - titre du ruban à sa sortie d'étirage : 356 Dtex,
• - vitesse (V_l) de sortie de la mèche (11) : 50m/mn,
• - distance entre la sortie du train d'étirage (13) et le point de contact des fibres (11) avec l'âme (3) : 240 mm,
• - largeur de la mèche (11) sur le tambour (10) : environ 4 mm,
• - vitesse (V₂) du tambour (10) : 53 m/mn,
• - surface du tambour (10) : velours à poils ras ayant une hauteur d'environ 2 mm,
• - broche de fausse torsion (7) : broche à courroies croisées formant entre elles un angle de 48° ayant une vitesse linéaire de 185 m/mn,
• - tension du fil d'âme : 30 à 35 gr.,
• - vitesse de renvidage (V₃) : 48 m/mn.

On an installation illustrated in FIG. 1, and comprising as a guide surface a rotary drum (10) of the type illustrated in FIG. 4, a core wire is produced in accordance with the invention under the following conditions.

• - core thread (3): 167 Dtex polyester thread,
• - fiber wick (12): 3300 Dtex wool - two ends - average fiber length: 120 mm,
• - stretching in (13): 18.73;
• - title of the ribbon at its stretching outlet: 356 Dtex,
• - output speed (V _l ) of the wick (11): 50m / min,
• - distance between the exit of the drawing train (13) and the point of contact of the fibers (11) with the core (3): 240 mm,
• - width of the drill bit (11) on the drum (10): about 4 mm,
• - speed (V ₂ ) of the drum (10): 53 m / min,
• - drum surface (10): short pile velvet having a height of around 2 mm,
• - false twist spindle (7): spindle with crossed belts forming between them an angle of 48 ° having a linear speed of 185 m / min,
• - tension of the core thread: 30 to 35 gr.,
• - winding speed (V ₃ ): 48 m / min.

By proceeding in the aforementioned manner, a core thread is obtained having a final titer of 534 Dtex in which the wool fibers are perfectly distributed around the core (3) and which has a very great regularity.

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

Example 2:

Example 1 is repeated but the guide surface constituted by a drum is replaced by a guide surface constituted by a flat belt as illustrated in FIGS. 2 and 3. As for example 1, the belt is coated with a layer of short pile velvet.

A wire similar to that of Example 1 is obtained.

Example 3:

Repeat example 1, but replace the surface guide surface constituted by a drum by a guide surface constituted by a flat belt as illustrated in FIG. 5. This guide surface is mounted on the upper drive cylinder of the last pair of stretch cylinders of the stretching system (13 ).

As a belt (10), a perforated belt is used between the strands of which a suction box (21) is arranged.

The wick (11) consists of a cotton wick of 30,000 Dtex stretched 200 times in the system (13).

• - vitesse (V_I) = 75 m/mn,
• - vitesse linéaire de la courroie (10) = 100m/mn,
• - vitesse de passage de l'âme (3) : 150 m/mn,
• - âme (3) : filé de polyester de 100 Dtex.

The operating conditions are as follows.

• - speed (V _I ) = 75 m / min,
• - linear speed of the belt (10) = 100m / min,
• - speed of passage of the core (3): 150 m / min,
• - core (3): 100 Dtex polyester spun.

A core yarn is obtained in which the cotton fibers perfectly surround the internal core, this yarn having a count of 250 Dtex.

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 may be possible not only to produce single wires but also to produce assembled wires.

Likewise, the guide surfaces (10) may consist of elements other than drums or belts coated with velvet.

Claims (11)

1 / Process for the production of a fiber yarn comprising a core which consists of: - positively delivering a wire (3) intended to form the internal core, - passing this wire (3) in tangential contact with a movable guide surface on which elementary fibers (11) are held parallel and flat, the wire (3) passing transversely relative to said surface, - to communicate to said core wire (3) a twist which tends to rise on the movable surface (10) supporting the elementary fibers (11), characterized in that: the passage of the core wire (3) over the parallelized fibers (11) is made at an angle with respect to the surface and in the direction of movement of the fibers, - The twist communicated to the wire (3) is given by a false twist spindle, acting permanently on said wire (3) and which is arranged downstream of the mobile surface supporting the fibers. 2 / A method according to claim 1, characterized in that the maintenance of the fibers (11) on the surface (10) is ensured by simple mutual contact of the fibers with said surface. 3 / A method according to claim 1, characterized in that the maintenance of the fibers (11) on the movable guide surface (10) is ensured by creating a depression under said surface. 4 / Method according to one of claims 1 to 3, characterized in that the false twist communicated to the wire (3) is such that the fibers (11) tend to wrap around the core (3) in passing under this soul. 5 / Device for implementing the process according to claim 1, characterized in that the guide surface (10) is in the form of a drum. 6 / Device according to claim 5, characterized in that the drum is cylindrical. 7 / Device according to claim 5, characterized in that the drum has the shape of a hyperboloid. 8 / Device for implementing the method according to one of claims 1 to 4, characterized in that the guide surface (10) is in the form of an endless belt. 9 / Device according to one of claims 5 to 8, characterized in that the guide surface (10) is covered with a material similar to a velvet. 10 / Device according to one of claims 5 to 8, characterized in that the guide surface (10) consists of a perforated surface subjected to a vacuum. 11 / Device according to one of claims 8 to 10, characterized in that the surface (10) consists of an endless belt mounted directly around one of the engine cylinders of the last pair of cylinders of the drawing train (11), the fibers being brought below said belt (10) and their maintenance on this surface being ensured by a suction system (21) disposed between the two strands of the belt.

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