EP0162787A1 - Process for manufacturing a spun cored yarn - Google Patents

Abstract

Process for obtaining a core fiber yarn. Fibers are subjected to a temporary false twist and elementary fibers (12) are projected onto the yarn (11) in the area of torsional rise by means of a mobile surface (4). According to the invention, all of the fibers (core and cover) are subjected to the action of a common drawing system (1) and, at the outlet of the drawing system (1), part of the fibers are delivered to the guide surface (4) while another part is moved away from said surface and then brought back into contact with the latter downstream of the projection zone of the first part of fibers. This process makes it possible to obtain, from a single supply, various threads whose core and covering can be of the same nature or composed of fibers of different nature.

Description

The present invention relates to an improvement made to spinning techniques making it possible to produce fiber yarns and, more particularly, fiber yarns obtained by the implementation of French patent applications filed by the Applicant under the numbers 82/01 382 and 82/15 830.

They relate more specifically to an improvement which makes it possible to obtain yarns of fibers having a structure such that they comprise a central core made up of staple fibers, this core being covered with an external sheath also made up of staple fibers, these fibers being able to be of the same or different nature.

As described in the aforementioned patent applications, the fibers to be formed form the internal core to a false twist and on this yarn is projected, upstream of the false twist spindle, elementary fibers, the projection of said fibers elementary on the core in the torsion rise zone being produced 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 being moved tangentially relative to the aforementioned guide surface in a direction concurrent with the direction of supply of fibers.

Preferably, a rotating condenser guide disposed at the outlet of the fiber drawing system is used as the movable guide surface.

In the case where the core is also constituted by a spun of fibers produced directly on the same machine, a second drawing system is provided for bringing the fibers intended to form this core.

Now we have found, and this is what is the subject of the present invention, that it was possible to obtain a spun yarn. of fibers of the aforementioned type, that is to say in which the core and the covering are based on staple fibers, using a single drawing system. Such a procedure significantly increases the possibilities of exploitation and makes it possible to obtain various threads, the core and the covering of which can either be composed of fibers of the same nature or composed of fibers of different nature, without particular adaptation of the equipment.

Furthermore, the method according to the invention makes it possible to reduce fiber losses as well as to obtain finer and more regular yarns.

• - que l'ensemble des fibres (âme et couverture) sont soumises à l'action d'un système d'étirage commun ;
• - qu'à la sortie du système d'étirage commun, une partie des fibres seront délivrées progressivement sur une surface de guidage mobile, sur laquelle elles sont maintenues à plat, cette surface tendant à exercer une force de traction sur l'extrémité libre desdites fibres alors que l'autre partie des fibres est maintenue écartée par rapport à ladite surface pour être amenée en-contact tangentiel avec celle-ci en aval de la zone de projection de la première partie de fibres sur ladite surface.

In general, the invention therefore relates to an improvement to the process for obtaining a spun of fibers of the type in which the internal core is also made up of staple fibers, the process according to the invention being characterized by the fact :

• - that all of the fibers (core and cover) are subjected to the action of a common drawing system;
• - that at the outlet of the common drawing system, part of the fibers will be delivered progressively to a movable guide surface, on which they are held flat, this surface tending to exert a tensile force on the free end of said fibers while the other part of the fibers is kept apart with respect to said surface to be brought into tangential contact with the latter downstream of the projection zone of the first part of fibers on said surface.

For the purposes of the present invention, "common drawing system" means either a single drawing system for all of the fibers or two systems operating simultaneously in parallel.

Thanks to such a process, it is possible to produce core yarns in which the core and the covering may be based on different or similar materials.

Advantageously, the fibers will however have different lengths, the fibers intended to form the core having a length greater than those intended to form the covering.

The material or materials allowing the production of a yarn according to the invention can be brought to the drawing system either in the form of an intimate mixture or in the form of separate rovings and / or ribbons.

In addition, the method according to the invention makes it possible to easily vary the percentage of each of the materials.

• - la figure 1 est une vue en perspective schématique d'une installation permettant la mise en oeuvre du procédé selon l'invention, installation dans laquelle le système d'étirage commun est constitué par un seul train d'étirage de système conventionnel à manchons ;
• - la figure 2 est une vue de détail, de côté, montrant la manière dont est réalisée la séparation des fibres et l'amenée des fibres de couverture sur l'âme formée ;
• - les figures 3-4, 5-6, 7-8, 9-10, illustrent schématiquement quatre possibilités de mise en oeuvre du procédé selon l'invention ;
• - la figure 11 est une vue partielle, en perspective, d'une'forme de mise en oeuvre de l'invention selon laquelle les fibres sont amenées au moyen d'un système d'étirage commun constitué de deux trains d'étirage à manchons fonctionnant en parallèle ;
• - les figures 12 et 13 sont des vues respectivement de côté et de dessus montrant plus en détail la structure de la surface de guidage utilisée pour la mise en oeuvre de cette variante et la manière dont les fibres sont distribuées sur cette surface de guidage.

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 is a schematic perspective view of an installation allowing the implementation of the method according to the invention, installation in which the common drawing system is constituted by a single drawing train of conventional sleeve system;
• - Figure 2 is a detail view, from the side, showing the manner in which the separation of the fibers and the supply of the covering fibers are carried out on the formed core;
• - Figures 3-4, 5-6, 7-8, 9-10, schematically illustrate four possibilities of implementing the method according to the invention;
• - Figure 11 is a partial perspective view of a form of implementation of the invention according to which the fibers are fed by means of a common drawing system consisting of two drawing sleeved trains operating in parallel;
• - Figures 12 and 13 are respectively side and top views showing in more detail the structure of the guide surface used for the implementation of this variant and the manner in which the fibers are distributed on this guide surface.

If reference is made to the appended diagrams, FIGS. 1, 3, 5, 7 and 9 illustrate, schematically, a working position of a machine allowing the implementation of the method according to the invention, ie -dire allowing to realize in a single step, a core yarn comprising a core formed of staple fibers and a cover also of staple fibers. FIG. 2 shows in more detail the manner in which the core / covering fiber junction is produced, FIGS. 4, 6, 8 and 10 showing different possibilities on the manner in which the fibers are brought to the common drawing system.

Referring to these figures, the installation for implementing the method according to the invention essentially comprises a conventional stretching system, one for each working position, designated by the general reference (1) and which , in this case, is a conventional sleeve system, well known to technicians and which will therefore not be described in detail. Of course, any other equivalent stretching system could be used.

Downstream of the last pair of stretching cylinders (2-3) of the stretching system (1) is arranged a guide surface (4) constituted by a rotating disc, surface which has a peripheral groove (5), in the form of V and the bottom of which is pierced with orifices (6) allowing a depression to be created there. In this embodiment of the invention, the rotary guide surface is arranged so that the bottom of the groove is substantially arranged in the extension of the axis of the drawing train (1).

A friction false-twist spindle (7), with crossed belts for example, is arranged downstream of the rotary condenser guide (4). A call system (8) is provided before the winding means (9) which, in the present case, will be constituted by a winding system with tangential drive which does not impart torsion additional to the yarn formed. Of course, any other winding system which possibly makes it possible to communicate an additional twist could be used.

In summary, such an installation has a structure similar to that which is the subject of the French patent applications cited in the preamble to the present description, except that it does not include additional means making it possible to deliver a wire. 'soul.

Indeed, in accordance with the method according to the invention, the core of the yarn is obtained directly from the fibers introduced into the common drawing system (1) that this installation comprises.

The only adaptation resides, as is apparent from FIG. 2, in the installation of a guide element (10), constituted for example by a ceramic diabolo, guide arranged so that the path of the fibers to the exit of the stretching rollers (2-3) is such that a part of the fibers comes to wrap said guide surface while another part is moved away from said guide surface (4) to then be brought substantially tangentially to said surface in the extension of the zone of action of the false twist spindle (7), downstream from the point where the first part of the fibers is distributed on said guide surface.

Thanks to this simple adaptation, it is possible, using as fibrous materials fibers of the same or different nature, to directly obtain a core spun in which the core is also based on fibers. Preferably, the fibers will have different lengths, the longest fibers being able to form either the core or the covering. In the case where the longest fibers will form the core, in normal operation, they will then be caused to pass around the deflecting guide (10) while the shortest fibers (fibers 12) will be projected onto the guide surface ( 4) and will wrap the latter to then be trapped in the wire of core, the twist communicated by the pin (7) going up along this wire.

This taking of the fibers (12) by the core is done in a manner similar to that described in the French patent application 82/01 383 mentioned in the preamble and will therefore not be described in detail for the sake of simplification.

Figures 11,12 and 13 illustrate a variant according to the invention in which the common drawing system (1) consists of two sleeve systems (la-lb), operating in parallel, a device commonly used in spinning fibers.

In this variant, one of the systems, for example the system (la) makes it possible to deliver the fibers intended to form the cover while the other system (lb) delivers the fibers intended to form the core. According to the invention, the fibers coming from the system (la) are delivered on a guide surface (4), rotary, and come to wrap this surface while the other fibers coming from the system (lb), and which are intended to form the core, will be brought vertically, tangentially to this surface in the extension of the false twist spindle (7). The twist communicated by the spindle (7) goes back as previously along the wire formed and allows to trap the fibers from the drawing system (1). Compared to the examples of implementation described above, the condenser guide (4) has a different structure and is generally in the form of a rotary drum arranged parallel to the outlet of the drawing system (1). , this rotary drum comprising a perforated part (4a) located on the side of the fiber outlet and a larger diameter part (4b) located at the rear and which makes it possible to guide the fibers. This condensing element is arranged so that the fibers intended to form the tangent core the surface (4a) while the fibers intended to form the cover envelop this surface.

• - l'exemple 1 concerne l'obtention d'un filé à âme selon l'invention à partir d'une source unique d'alimentation (rubans par exemple) ;
• - les exemples 2,3,4,5 et 6 illustrent l'obtention d'un fil selon l'invention dans lesquels les fibres alimentaires proviennent de deux alimentations séparées (mèche et/ou ruban), ces matières étant amenées en parallèle à l'intérieur d'un système d'étirage commun ;
• - l'exemple 7 illustre un mode de mise en oeuvre de l'invention tel que schématisé aux figures 11, 12 et 13 et dans lequel les fibres alimentaires proviennent égalé- ment de deux sources séparéessoumises à l'action d'un système d'étirage commun constitué de deux trains d'étirage fonctionnant en parallèle.

The examples which follow show the implementation of the process according to the invention and the advantages which this process brings:

• - Example 1 relates to obtaining a core spun according to the invention from a single source of supply (ribbons for example);
• - Examples 2,3,4,5 and 6 illustrate the production of a thread according to the invention in which the dietary fibers come from two separate feeds (wick and / or ribbon), these materials being brought in parallel to the 'inside a common drawing system;
• - Example 7 illustrates an embodiment of the invention as shown diagrammatically in FIGS. 11, 12 and 13 and in which the dietary fibers also come from two separate sources subjected to the action of a system of joint drawing consisting of two drawing trains operating in parallel.

Example 1:

This example is illustrated more particularly by FIGS. 1, 2, 3.

A core spun according to the invention is produced under the following conditions.

The food material consists of a cotton ribbon formed from a mixture comprising 15% of fibers between 2.8 cm and 4 cm and 85% of short fibers between 1.5 cm and 2.8 cm.

This ribbon R has a title of 33,000 dtex.

It is introduced, as shown in Figures 1 and 4, flat, inside a single drawing system (1), lateral guides (13-14-15-16) being provided on each side to ensure perfect guidance of the material.

The speed V 0 of the last pair of cylinders stretchers (2-3) is reduced to 200 m / min.

The guide surface is constituted by a condenser guide (4), rotary, subjected to an internal suction, and rotating at a speed of 260 m / min. The surface of this guide has a V-shaped groove inclined at 120 °. This guide is arranged immediately at the outlet of the last pair of stretching cylinders (2-3), so that the bottom of the groove is arranged substantially in the axis of the stretching system.

Downstream of this guide, a false twist spindle (7) is arranged which is constituted by a friction spindle with crossed belts, inclined at 45 °, the linear speed of the belts being adjusted to 550 m / min.

The call cylinders (8) have a speed V ₂ substantially equal to the speed V ₀ of the cylinders (2-3) and the winding is carried out at this same speed.

The implementation for obtaining a yarn according to the invention is as follows.

After having formed a thread leader, all of the fibers are passed around the deflecting guide (10). As a result, the shortest fibers continue to be delivered to the guide surface (4) while the longest fibers are twisted by the action of the spindle (7), the twist rising almost to the level of the last pair of stretching cylinders (2-3). The short fibers which envelop the guide surface are projected onto the core thus formed and are taken up by twisting.

At the outlet of the spindle (7), a core yarn is obtained, the core of which itself is made up of fibers, the peripheral fibers being perfectly bonded to this core. This yarn has a titer of 330 dtex and has very good textile characteristics both from the resistance point of view and from a regularity point of view. It can be used as it is as well as in weaving as in knitting.

Example 2:

This example is illustrated by Figures 5 and 6.

In this example, the food material consists of two cotton wicks (Rl-R2), the cotton wick R1 being a combed cotton having a count of 3300 Dtex and the cotton wick R2 also being a combed cotton wick having a titer of 3200 dtex, but the fibers of which are slightly shorter than those of the Rl wick.

As before, the two wicks R1 and R2 are introduced simultaneously inside a drawing system (1) but are, in this case, kept separate from each other inside the system d drawing as shown in Figure 6.

When launching, we start by launching the wick R1 by passing it around the diverter guide (10). This Rl wick forms the core of the yarn. The initiation of the yarn being thus produced, the wick R2 is introduced inside the drawing system, the two wicks R1 and R2 being parallel. The fibers of the wick R2 shorter than the wick R1 are projected onto the guide surface (4) to then be brought into contact with the core (11) and this, as illustrated in FIG. 2.

In this embodiment, compared to the previous example, the adjustment of the installation is as follows:

A core yarn is obtained having a tite of 200 dtex, the core and the cover of which are made of cotton fibers.

Such a yarn can be used indifferently in weaving or hosiery.

Example 3:

This example is illustrated by Figures 9 and 10.

In this embodiment, two ribbons R1 and R2 are used as food material.

The ribbon R1 is a polyester ribbon of 33,000 dtex, the cut of the polyester being 40 mm.

The ribbon R2 is a cotton ribbon, also of 33,000 dtex, the average cotton length being 30 mm.

In this embodiment, the polyester fibers are, at the outlet of the stretching cylinder (2) and (3), deflected around the guide (10) while the cotton fibers are projected onto the guide surface (4).

The setting of the machine is as follows:

A core yarn is obtained having a count of 280 dtex, the core of which is made of polyester fibers and the cover of cotton fibers.

Example 4:

This example is illustrated by Figures 7 and 8.

In this example, the food material consists on the one hand, of a polyester wick R1 and on the other hand, of a cotton ribbon R2.

The polyester wick is a 4800 Dtex wick and consists of fibers 40 mm long.

The cotton ribbon has a count of 33,000 dtex, the cotton fibers having an average length of 30 mm.

The two food materials R1 and R2 are brought in parallel inside the stretching system (1) as illustrated in FIG. 8. They are kept separate by means of lateral guides.

In this embodiment, the cotton fibers are deflected around the guide (10) while the polyester fibers are projected onto the guide surface (4) to then be delivered onto the cotton-based core (11).

The operating conditions are as follows:

A core yarn is obtained, the core of which consists essentially of cotton fibers and is covered with polyester fibers.

Example 5:

This example is similar to Example 4 except that the materials are reversed and that a cotton wick R1 and a polyester ribbon R2 are used.

In this embodiment, the polyester fibers are deflected around the guide (10) while the cotton fibers are projected onto the guide surface (4) to then be delivered onto the polyester-based core (11).

The operating conditions are as follows:

A core yarn is obtained, the core of which consists essentially of polyester fibers and is covered with cotton fibers.

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

Example 6:

This example is similar to Example 2 except that a polyester wick and a cotton wick having the same titer of 3300 Dtex are used.

A core yarn is obtained, the core of which is made of polyester, the cotton fibers being a cover.

Such a yarn can also be used as it is in weaving and knitting.

Example 7:

This example is illustrated by Figures 11,12 and 13.

Compared to the previous examples, a system consisting of two stretching trains (la-lb) is used as the common drawing system (1). At the outlet of these parallel drawing trains (la-lb), there is disposed a movable guide surface (4) in the form of a rotary drum comprising a perforated cylindrical part (4a) disposed laterally with respect to a part of larger diameter (4b). This rotary guide is arranged parallel to the outlet of the drawing system (la-lb), the fibers coming from the system (la) being deflected to wrap the surface (4a) while those coming from the system (lb) pass tangentially to this surface (4a) to be brought directly to the false twist spindle (7). The torsion communicated by the spindle (7) goes up along the yarn formed substantially up to the vicinity of the outlet of the drawing system (1-2). The fibers from the system (la) are trapped in the core thus formed.

On such an installation, a core spun is produced using as food material a cotton wick R1 and a polyester wick R2 each having a count of 3300 Dtex.

Cotton fibers are introduced into the stretching system (la) and are deflected at the exit of the cylinders stretchers (2-3) to be brought to the guide surface (4) so as to envelop this surface. The polyester fibers R2 are introduced into the stretching system (lb) and are, in turn, brought vertically, parallel to the guide surface (4), downstream of the cotton fibers.

The installation is regulated as follows:

A core yarn is also obtained, the core of which consists essentially of polyester fibers covered with cotton fibers.

The preceding example clearly shows the advantages brought by the invention and in particular the fact that it is possible, without particular adaptation, to obtain a very large number of different wires from a single installation.

It was found that by proceeding in accordance with the invention, not only were yarns of fibrous core fibers of very good quality obtained, but also, the fiber losses were practically completely eliminated. In addition, the yarn obtained can be used as is without having to communicate an additional twist to it. Of course, such a twist could be given if desired.

Claims (5)

1 / Method for obtaining a yarn of fibers comprising a central core made up of staple fibers covered with an external sheath also made up of staple fibers of the type according to which fibers intended to form the inner core are subjected to a false twist transient and elementary fibers (12) are projected onto the spun yarn (11) thus formed, upstream of the false twist spindle (7), the projection of said elementary fibers (12) onto the core in the rising zone of torsion being carried out by means of a movable guide surface (4) on which said fibers are delivered tangentially and which tends to exert a tensile force on their free end, the core being displaced tangentially relative to the surface of said guide in a direction concurrent with the direction of supply of the fibers, characterized by the fact: - that all of said fibers (core and cover) are subjected to the action of a common drawing system (1), - that at the outlet of the common stretching system (1), a part of the fibers are gradually delivered to the movable guide surface (4) while the other part of the fibers are separated from said surface and are then brought back in contact with it downstream of the projection zone of the first part of fibers on said surface. 2 / A method according to claim 1, characterized in that the fibers forming the core and those forming the cover are based on similar or different materials. 3 / Method according to one of claims 1 and 2, characterized in that the fibers intended to form the core have a length greater than those intended to form the cover. 4 / Method according to one of claims 1 to 3, characterized in that the materials allowing the production of the yarn are brought to the drawing system (1) in the form of an intimate mixture. 5 / Method according to one of claims 1 to 3, characterized in that the materials intended to form the yarn are brought in the form of wicks and / or separate ribbons.

Images