EP3356587A1

EP3356587A1 - Method and device for producing a tubular knitted textile structure

Info

Publication number: EP3356587A1
Application number: EP16787488.2A
Authority: EP
Inventors: Jacques Tankere; Eric Mignot; Clément PRUDHOMME
Original assignee: MDB Texinov SA; Deltaval SARL
Current assignee: MDB Texinov SA; Deltaval SARL
Priority date: 2015-09-28
Filing date: 2016-09-26
Publication date: 2018-08-08
Also published as: FR3041663B1; WO2017055722A1; FR3041663A1

Abstract

The invention relates to a method for producing a tubular knitted textile structure, consisting in: firstly producing, by warp knitting on a double-bed knitting machine, two layers joined together which will eventually define a tubular or multi-tubular structure; and inserting a continuous weft in the double bed, which then inserts into the loops on said two layers, staggered in the direction of production, the continuous weft being guided on the beds by rotation around said beds.

Description

METHOD AND DEVICE FOR REALIZING A TUBULAR KNIT TEXTILE STRUCTURE

FIELD OF THE INVENTION

The present invention is in the field of the realization of tubular textile structures, made by knitting, using the so-called "pier stitch" technology. It also relates to a device implementing this method. PRIOR STATE OF THE ART

The need for tubular textile structures has existed for a long time already, and moreover, is constantly increasing, particularly in the areas of fluid circulation whatsoever.

Traditionally, most tubular textile structures that exist to date are made on braiding or braiding. Such braids have the advantage of having some cohesion and significant mechanical strength. The textiles obtained, by the diagonal arrangement of the son, have a certain extensibility and a diameter not perfectly defined.

This diameter is, in addition, determined by that of the trade. The change of diameter requires the choice of another machine, without allowing the realization of intermediate adjustments.

Moreover, it is practically impossible to combine different materials for the construction of the tubular textiles in question. It is also known to produce tubular textile structures on mesh looms picked cellular or trades hooks.

Whatever the techniques used, the diameter of the resulting tubular structure is controlled only in an approximate manner, and moreover, there is always a greater or lesser possibility of radial extension of said structure. In addition, the mechanical properties are still limited in this radial direction. In addition, the braiding technique imposes a choice of constituents of materials of the same nature, effectively limiting the possible combinations, and consequently, the applications likely to result from such tubular structures. The objective sought by the present invention is to allow the realization of such a tubular textile structure developing a controlled extensibility of its diameter, so in radial direction, and may further develop mechanical properties impossible to achieve with the techniques of the invention. prior art. SUMMARY OF THE INVENTION

For this purpose, the invention proposes a method for producing a tubular knitted textile structure which consists of:

firstly to make by knitting jersey knit on a double needle loom two webs joined together to eventually define a tubular or multi-tubular structure;

and inserting a continuous weft at the level of the double needle, being inserted into the meshes on said two plies with shift in the production direction, the weft being fed to the needle beds by rotation around them.

In other words, the method of the invention is to achieve a 3D structure through the implementation of a double needle knitting machine, typically a Rachel machine, implementing in known manner the so-called jetty mesh technology and then to continue by weaving the resulting 3D structure by means of a continuous frame, the continuity of the weft yarn making it possible in particular to effectively control the resistance and elongation properties of the tubular structure. The properties are thus directly identical or in any case very close to the characteristics of the weft yarn, the filling being almost zero. In fact, because of the insertion of a continuous weft, concomitantly with the knitting on the double needle loom, it generates in fact at the level of the tubular or multi-tubular structure a continuous helical weft, whose pitch, obviously, can be variable and adjusted to the desired performance, and which can come block and limit the circumference of the textile structure in the transverse direction relative to the production direction. In addition, this method makes it possible to vary the choice of the materials used and in particular to differentiate the constituent son of the structure obtained on the Rachel double needle bed and the weft thread, thus making it possible to multiply the conceivable applications of the tubular structure and as a corollary, its physical or mechanical properties.

Finally, the method of the invention makes it possible to obtain a tubular structure whose mechanical properties are controlled in two directions. By multitubular structure is meant the production of structures having not one but several tubes extending substantially parallel to one another. said tubes being capable of being detached from each other after their production. According to the invention, the joining of the two sheets can take place at their lateral edges, in order to eventually form a tubular structure. But this connection can also intervene in intermediate zone, so as to achieve a multi-tubular structure. This joining is carried out using son named in the field considered by "son of hair". These are the usual connecting threads distributed on one or more bars of a double needle job. These son pass alternately by the movement of the craft from one needle to another to create a textile having a thickness. The skilled person will be able to apply without difficulty, the various possible connections to stiffen as necessary this connection and keep it possibly completely homogeneous with the armor of each of the two faces. It is also possible to choose a different title wire or even of different nature to obtain the appropriate resistance.

By eliminating most of the securing son of the two plies, that is to say, by maintaining them in threading only on certain portions of the craft, one is likely to obtain different configurations:

• a regular tube if the connecting threads are held in the armor only on 1 to 3 threads at both ends. ;

• a tube provided with a lateral tongue, or two lateral tongues when the securing son of the webs are maintained on lateral areas, more important;

• a multitube, if the son of securing layers are held in several places along the needle bed. The invention also relates to the device for producing such a tabular knitted structure according to the aforementioned method.

This device comprises:

- A Rachel double needle craft fed son, so as to generate a 3D textile structure,

a supply reel of the 3D structure in weft yarn made on the Rachel double needle needle loom, said reel being subjected to a rotary movement around the double needle bed, concomitantly with the production of the 3D textile structure, so as to come cooperate with the knitting organs of both needle beds.

In other words, the device according to the invention implements a rotary framer describing rotations around the double needle, in order to insert a helical weft thread on the 3D structure, continuously.

The nature of the constituent wires of the 3D structure is identical or different from that of the weft yarn.

According to a first embodiment of the device of the invention, the weft feed reel is mounted on a circular ring in the center of which is mounted the double needle bed, the circular ring being rotated by any means, such as that in particular gear with pinion gears on a toothing provided at the outer periphery of the ring gear. According to another embodiment of the invention, the weft feed reel is mounted on a carriage guided on guiding means surrounding the double needle bed, said carriage being moved on said guiding means by any means such as toothed belt or rack and pinions. The invention also relates to any tubular knitted textile structure obtained by means of the method and device according to the invention.

BRIEF DESCRIPTION OF THE FIGURES The manner in which the invention may be implemented and the advantages that result therefrom will emerge more clearly from the following exemplary embodiments, given as an indication and not by way of limitation, in support of the appended figures. Figure 1 is a schematic perspective representation illustrating a tubular knitted structure obtained by the method and the device of the invention.

Figure 2 is a view similar to Figure 1, in which one can observe a variation in the diameter of the tubular structure.

Figure 3a is a schematic representation in section of a tubular structure according to the invention, in this case provided with two lateral tongues.

Figure 3b is a diagrammatic representation in section of a multi-tubular structure according to another embodiment of the invention.

Figure 4 is a schematic representation seen from above of the principle of the method and the device of the invention.

FIG. 5 is a schematic representation seen from above of a double needle bed with representation of the circular and continuous weft thread according to the method and the device of the invention.

Figure 6 is a schematic perspective representation of a first embodiment of the device of the invention.

Figure 7 is a schematic perspective representation of a second embodiment of the device of the invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 therefore shows a knitted textile tubular structure 1 obtained by implementing the method and the device of the invention. As indicated, this tubular structure results from a 3D structure 2 obtained by the technology knit throw on a loom Rachel double needle, made from bonding based on chains combined with sectional frames or bonding type simple knitting, double knitting or other , according to the desired texture and mechanical performance (strength, elongation), and in a known manner.

According to the invention, the tubular structure also comprises a helical continuous weft 3, here represented in a constant pitch 4. Both the pitch and the inclination or obliquity of the helix of the frame can be programmed to vary along the textile structure depending on the intended applications.

This continuous frame 3 makes it possible to limit or even to prohibit, depending on the nature of the wire which constitutes it, any extensibility of the structure in the radial direction, that is to say any expansion of the diameter of the tube. Moreover, and because of the technology used, namely the mesh technology double needle bed, it is also possible to vary the diameter of said structure along its length (that is to say in production direction) , typically from a few tenths of a millimeter to a few millimeters,

In addition, the Rachel looms can be equipped with different gauges, that is to say, with a greater or lesser number of needles and knitting elements, allowing a great variability of adjustment of the performances, but also permeabilities by the rate of openings of the meshes.

One of the essential elements of the invention resides in the continuous nature of the weft yarn, which is therefore inserted over the entire circumference of the 3D textile structure manufactured on the Rachel double needle type loom and thus making it possible to reinforce its mechanical strength because free from any interruption resulting from the cutting weft son observed in the technologies of the prior art.

The variability of the diameter has been illustrated in FIG. 2, in which three distinct zones A, B and C, of respective programmable length, have been represented. Thus, the two areas A and C, each have a constant diameter, but different, by acting on the binding and control of the wire rates of the 3D structure or the weft and their voltage. These two zones are connected to each other continuously by zone B. Within the latter, the weft yarn is also present but can be programmed with a different "step" if necessary.

Moreover, the pitch of the helix constituted by the weft thread 3 can vary from zone A to zone C, so as to give these two zones different mechanical properties, for example. Figures 3a and 3b illustrate different variants of the tubular structure of the invention. Thus, FIG. 3a illustrates a tubular structure, provided with two lateral tongues 25, 26, resulting from the joining of the two textile faces obtained by the Rachel double needle needle loom. These tongues are likely to constitute reinforced areas suitable for fixing the tubular structure depending on the intended applications.

The continuous weft then traverses the entire circumference of the textile structure, including at these tabs. FIG. 3b shows another variant, comprising in this case three tubular structures, separated from one another by two by a junction zone 27. The realization of such a structure rests on the same principle. Again, the continuous weft yarn travels the entire circumference of the structure, both in the tubular areas themselves as junction areas and tongues.

FIG. 4 shows the principle of the method of the invention. Basically and as already indicated, it is generated a 3D structure using a Rachel double needle job 5 (for which, for the sake of simplification of understanding, it has not shown son feed modules).

Around this double needle bed, turns (arrow G) a feed reel 7 in weft thread 3, mounted on a support 6, 6 '. In fact, the weft yarn is therefore woven at the level of the needles and pencils mounted on the bedbugs RACHEL craft as the realization of the 3D structure at this level.

For this purpose, the supply reel 7 of weft thread 3 is disposed in a plane s' registering perpendicularly to that receiving the double needle and passing at the level of the cooperation zone of the needles and sets of said needle beds.

The rotational movement of the coil 7 around the two needle beds is obtained by any means, and in any event, by a mechanism synchronized with the cycle of formation of the meshes on the double needle bed. This coil 7 delivers the weft thread 3 after passing through a braking device 8, to ensure a correct tension of the weft yarn. This braking is done either directly on the weft thread or on the spool itself. Such braking systems are known in themselves. They can be in particular of mechanical, electrical, even electromagnetic nature.

The programming of the pitch of the helix resulting from the insertion of this weft yarn can in particular be a direct consequence of the introduction sequences of the weft in question in the knitting program of the 3D background structure.

It is indeed possible to program to stop the unfolding of the frame and leave it waiting on one side, then drive it again when desired. This double needle has also been schematically represented in plan view in FIG. 5. Thus, the front and rear needle beds 11 have been materialized, at which the knitting yarns 9 of the 3D support structure appear, as well as the schematic arrangement. weft thread 3 inserted by means of the device object of the present invention.

According to a first embodiment of the invention shown in connection with FIG. 6, the supply reel 7 in weft yarn 3 is mounted on a circular ring 15. This circular ring is thus mounted around the double needle bed 5. It is rotated by means of toothed pinions 16 whose axis of rotation 17 actuated by electric motors (not shown). These toothed gears 16 mesh with the toothed peripheral edge 18 of said ring gear 15. The management of the electric motor (s) actuating the toothed gears 16 is synchronized with the operating cycle of the double needle needle loom, so that to introduce the weft thread 3 at the appropriate time at each of the needle beds.

Thus, the weft yarn 3 performs a revolution, and in the example described a rotation, around the needle beds in the area where the 3D textile structure is obtained obtained by the play of the knitting members mounted on needle beds, respectively needles 20 and pans 21. The pucks are themselves moved on support bars 22, according to the binding program son retained.

Also shown in this figure the braking device 8 positioned at the output of the coil, for the purpose of regulating the tension of the weft yarn.

According to another embodiment of the device of the invention shown in FIG. 7, the weft feed reel 7 is mounted on a carriage 25 guided according to a guide system, in this case, in the form of a racecourse, and typically consisting of rectilinear portions 26 and curvilinear portions 27, adapted to constitute a continuous path for said carriage 25, and corollary for the coil 7. In doing so, the carriage 25 also provides revolutions around the double needle bed, as in the embodiment previously described. For this purpose, the carriage 25 is secured to a toothed belt or any other equivalent device, cooperating with a suitable roller (not shown), or any other means adapted to ensure its progression on the guide path 26, 27.

The support carriage of the weft reel is then released at the end of rectilinear stroke 26 to be supported by another means of transport on the crown 27. This embodiment is particularly advantageous for the production of tubular textile structures of large width or large diameter, particularly allowing the use of linear motors or high-speed control by appropriate electronics.

The invention also relates to the tubular textile structures obtained by the method and the device described above.

Claims

Process for producing a tabular knitted textile structure, which consists of:

first of all to make by knitting stitch knit on a double needle loom two webs joined together constituting a 3D structure to eventually define a tubular or multi-tubular structure;

and inserting a continuous weft at the level of the double needle, being inserted into the meshes on said two plies with shift in the production direction, the continuous weft being fed to the needle beds by revolution around said needle beds.

Process for the production of a tubular knitted textile structure according to claim 1, characterized in that the joining of the two plies, in order to eventually form a tubular or multi-tubular structure is carried out using connecting son intervening according to intermediate points.

Process for the production of a tubular knitted textile structure according to one of claims 1 and 2, characterized in that the weft is inserted into the 3D structure helically with respect to the production direction of said structure.

4. Process for the production of a tubular knitted textile structure according to claim 3, characterized in that the pitch of the helix is constant.

5. Process for the production of a tubular knitted textile structure according to claim 3, characterized in that the pitch of the helix is parameterizable, and is liable to vary during the production of the textile structure. 6. Process for producing a tubular knitted textile structure according to one of claims 1 to 5, characterized in that the nature of the constituent son of the 3D structure is identical to or different from that of the weft yarn. Device for producing a tabular knitted textile structure, comprising:

a loom Rachel double needle (5) fed son (9), so as to generate a 3D textile structure,

a supply reel (7) made of weft yarn (3) of the 3D structure made on the Rachel double needle loom, said reel being subjected to a revolution-like movement around the double needle loom (5), concomitantly with the realization of the 3D textile structure, so as to cooperate with the knitting members (20, 21) of the two needle beds.

Device for producing a tubular knitted textile structure according to Claim 7, characterized in that the weft thread supply spool (7) is mounted on a circular ring (15) in the center of which is mounted the double needle loom (5), the circular ring (15) being rotated by any means, such as in particular by toothed gear gear (16) meshing on a toothing (18) formed at the outer periphery of the ring.

Device for producing a tubular knitted textile structure according to Claim 7, characterized in that the weft thread supply spool (7) is mounted on a carriage (25) guided on a guide path ( 26, 27) surrounding the double needle loom (5), said carriage being moved on said guide path by any means such as toothed belt or rack and pinions.

Knitted tubular textile structure obtained according to the method of one of claims 1 to 6.