EP0140796A1 - Core yarn piecing method and device - Google Patents

Abstract

Method for making a piecing on a machine for producing core yarns.

• - prélèvement du fil formé (1) sur l'organe de réception (5) (bobine par exemple),
• - mise à nu de l'âme interne (2) dudit fil sur une longueur déterminée,
• - raccordement de l'âme (2) ainsi mise à nu avec l'extrémité (11) du fil d'âme alimentaire,
• - introduction de l'âme dénudée dans le système de distribution des fibres (13),
• - distribution des fibres sur l'âme en aval du point de jonction et,
• - défilement normal et renvidage.
  

This process involves the following steps:

• - removal of the wire formed (1) on the receiving member (5) (coil for example),
• - exposure of the internal core (2) of said wire over a determined length,
• - connection of the core (2) thus exposed with the end (11) of the food core wire,
• - introduction of the stripped core into the fiber distribution system (13),
• distribution of the fibers on the core downstream of the junction point, and
• - normal scrolling and rewinding.
  

Description

The present invention relates to a method for making the connection of yarns of fibers comprising an internal core, yarns which, in the following description, will be designated by the expression "core yarns".

To date, many solutions have been envisaged for producing yarns of fibers comprising an internal core.

The most widespread consists of introducing a multi-filamentary 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 drawing rollers.

It has also been proposed to project dietary fibers onto a continuous wire subjected to a temporary false twist and this, upstream of the false twist spindle. This projection of the elementary fibers onto the core in the torsion rise zone can be carried out in accordance with the teachings of European patent application No. 0085635 in the name of the Applicant, by means of a movable guide surface on which said fibers are delivered tangentially and which tend to exert a tensile force on the free ends of these fibers, the core being displaced tangentially with respect to said guide surface in a direction concurrent with the direction of supply of the fibers.

In all cases, the problem arises of making a connection, in particular following a breakage.

Among the various solutions commonly used to date for making such piecings, the simplest consists in forming a knot which therefore necessarily involves the presence of a defect (excess thickness) in the thread after the piecing.

Another solution is to make a splice.

Finally, in the case of synthetic yarns, it has been envisaged to glue or weld the filaments end to end.

As regards the core yarns, taking into account the different materials used in the composition of such an article, only a knotting operation can be envisaged.

Now we have found, and this is what is the subject of the present invention, a new process which makes it possible to carry out a piecing on core wires which makes it possible to eliminate practically any defect and which can be adapted to practically all machines for making such yarns.

• - prélèvement du fil formé sur l'organe de réception, bobine par exemple,
• - mise à nu de l'âme interne dudit fil sur une longueur déterminée,
• - raccordement de l'âme ainsi mise à nu avec l'extrémité du fil d'âme alimentaire,
• - introduction de l'âme dénudée dans le système de distribution de fibres,
• - distribution des fibres sur l'âme en aval du point de jonction et,
• - défilement normal et renvidage.

In general, the invention therefore relates to a process allowing the production of a piecing on a machine for the production of webs, a process which is characterized by the fact that it comprises the succession of the following stages:

• - removal of the wire formed on the receiving member, coil for example,
• - exposure of the internal core of said wire over a determined length,
• - connection of the core thus exposed with the end of the food core wire,
• - introduction of the stripped core into the fiber distribution system,
• distribution of the fibers on the core downstream of the junction point, and
• - normal scrolling and rewinding.

The removal of the wire, the connection of the core, the reintroduction into the distribution system will be carried out by means of devices commonly used in the textile industry which will not be described in detail in the following description by measurement of simplification. Thus, for example, the sampling can be carried out by means of a suction nozzle which can be moved and the connection can be carried out by knotting, splicing, welding or gluing.

On the other hand, the exposure of the wire will be carried out by means of a particular device which is also the subject of the present invention. Such stripping is obtained by friction against an abrasive surface so as to put the covering fibers in the form of bundles which are then recovered by any suitable means, such as for example a suction system, a second adherent surface. vis-à-vis the fibers.

Preferably, this stripping of the core is carried out by keeping the wire fixed, the abrasive surface being pushed against said wire.

• - les figures 1 à 5 illustrent les différentes phases d'une opération de nouage réalisée conformément au procédé selon l'invention,
• - la figure 6 illustre schématiquement la manière dont est mis en oeuvre le procédé sur une installation permettant de réaliser un filé à âme,
• - les figures 7 et 8 sont des schémas illustrant deux modes de réalisation de dispositifs permettant de dénuder l'âme.

The invention will however be better understood thanks to the following description and attached diagrams in which:

• FIGS. 1 to 5 illustrate the different phases of a knotting operation carried out in accordance with the method according to the invention,
• FIG. 6 schematically illustrates the manner in which the method is implemented on an installation making it possible to produce a core spun,
• - Figures 7 and 8 are diagrams illustrating two embodiments of devices for stripping the core.

The different phases of the joining process according to the invention are illustrated in FIGS. 1 to 5.

FIG. 1 represents the end of a core yarn designated by the general reference (1) consisting of a core (2) surrounded by a fibrous sheath (3). This wire has a free end (4) and is stored on a winding means (5) (see Figures 6, 7, 8).

Following a breakage, the installation, such as that shown diagrammatically in FIG. 6, is stopped.

In a first phase, the wire (1) formed on the receiving member (5) is withdrawn by its free end, for example by means of a suction nozzle (6) and a certain length is eliminated, which can go up to 50m, to eliminate potential faults. This being done, the core (2) is stripped over a determined length L in an area close to its free end (4). This exposure of the core is obtained by friction (abrasion) so as to assemble the peripheral fibers (3) in packages without damaging the core (2). Figures 7 and 8 illustrate two devices for carrying out this exposure.

In the embodiment illustrated in FIG. 7, such a device consists of an assembly, driven in a reciprocating motion and comprising, on the one hand, an abrasive surface (7) as well as a surface (8) similar to a felt or velvet on which are deposited the peripheral fibers detached from the core (2) by the abrasive surface (7).

In the example illustrated in FIG. 8, the device allowing the exposure to be made up consists of a rotary drum (9) comprising a succession of abrasive surfaces (7) and surfaces (8) making it possible to recover the loose fibers.

Thanks to such devices, it has been found that it is possible to obtain a stripping of the core wire (2) without deteriorating its properties. In addition, the end (10) of the covering fibers (3) is in a bevelled shape.

This stripping operation being carried out, the end (4) of the bare core wire is brought in the vicinity of the free end (11) of the food core wire (2) (FIG. 3), this operational phase being represented in dotted lines in FIG. 6. Then, by means of a conventional knotter (or by any other equivalent system, such as gluing, welding, splicing system), the connection (12) of the two portions of son of core (4-11) between them (fig. 4).

The reattachment being carried out, the core thread is reintroduced into the actual spinning system (13). This operation is carried out so that, when restarting, the fibers (3) intended to cover the core (2) are delivered to this core thus attached downstream of the node (12) (or any other means of junction) to come to rest against the bevelled part (10) of the covering fibers of the previously formed wire.

Such a piecing process, adaptable to practically all machines allowing the production of core yarns, makes it possible to eliminate practically any defect in the piecing zone. Indeed, the connection being made only on the core, it is hidden by the covering fibers (3).

Furthermore, the method according to the invention can be applied both to core yarns whose core consists of continuous multifilaments as well as yarns in which the core itself is constituted by a yarn of fibers which, of course must have sufficient cohesion to allow it to be exposed. In the latter case, it is obvious that following a breakage, the reattachment is carried out after having reformed a given length of said core.

In addition, it is obvious that the dimensions of the means enabling the internal core to be exposed will depend on the nature and / or the length of the fibers.

Claims (6)

1 / Method allowing the production of a piecing on a machine for producing core yarns, characterized in that it comprises the succession of the following stages: - removal of the wire formed (1) on the receiving member (5) (coil for example), - exposure of the internal core (2) of said wire over a determined length, - connection of the core (2) thus exposed with the end (11) of the food core wire, - introduction of the stripped core into the fiber distribution system (13), distribution of the fibers on the core downstream of the junction point (12) and, - normal scrolling and rewinding. 2 / A method according to claim 1, characterized in that the removal of the wire formed on the receiving member is carried out by means of a suction nozzle which can be moved and the connection is carried out by knotting, splicing, welding or collage. 3 / Method according to one of claims 1 and 2, characterized in that the exposure of the core (2) is obtained by friction against an abrasive surface so as to put the covering fibers (3) in the form packets which we then retrieve. 4 / A method according to claim 3, characterized in that the baring of the core is carried out by keeping the wire fixed, the abrasive surface being pushed against said wire. 5 / Device for implementing the method according to one of claims 1 to 4, characterized in that the exposure of the core (2) over a determined length in an area close to its free end (4 ) is obtained by means of a set animated by a movement alternating and comprising, on the one hand, an abrasive surface (7) as well as a surface (8) similar to a velvet felt on which are deposited the peripheral fibers detached from the core (2) by the abrasive surface (7 ). 6 / Device for implementing the method according to one of claims 1 to 4, characterized in that the member allowing the exposure of the core (2) over a determined length in an area close to its free end (A) consists of a rotary drum (9) comprising a succession of abrasive surfaces (7) and surfaces (8) for recovering the loose fibers.

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