EP1896637A2

EP1896637A2 - Unravelable knit fabric

Info

Publication number: EP1896637A2
Application number: EP06755444A
Authority: EP
Inventors: Alfredo Meneghin; Michel Therin
Original assignee: Sofradim Production SAS
Current assignee: Sofradim Production SAS
Priority date: 2005-04-22
Filing date: 2006-04-21
Publication date: 2008-03-12
Anticipated expiration: 2026-04-21
Also published as: FR2884835B1; WO2006111665A2; EP1896637B1; JP2008537027A; WO2006111665A3; FR2884835A1

Abstract

The invention relates to a knit fabric (1) made of a single piece based on an arrangement constituted of at least two thread laps having at least one first lap defining a first pillar stitch weave and at least one or more unmeshed inlay laps, each of these unmeshed laps defining a weave, characterized in that it comprises at least one free pillar stitch thread (A1, A11, A12), one free pillar stitch thread being defined by a pillar stitch thread for which, over the longitudinal dimension of the knit fabric, every thread of these unmeshed laps approaching said free pillar stitch thread effects a half-turn at this free pillar stitch thread. The invention also relates to a medical textile device (2) obtained by unraveling at least two free pillar stitch threads of this knit fabric. The invention additionally relates to a method for producing this knit fabric.

Description

Removable knit

The present invention relates to a prosthetic knit having demountable areas allowing the easy separation of strips or knit strips in the direction of knitting. These strips or strips can be used as textile medical devices, implantable in the human body or not.

For example, as non-implantable textile devices, mention may be made of compresses, textile holding tapes, etc. As implantable devices in the human body, mention may be made of textile prostheses in general, such as wall reinforcements for example in surgery parietal, urethral support strips in the treatment of stress incontinence in women, as well as in the treatment of disorders of pelvic statics mainly in women in general, also called prolapse.

These textile devices must generally have a particular behavior according to their application. This is particularly the case of textile prostheses implanted in the human body. Thus, parietal wall reinforcements are required to replace and / or strengthen and / or support the abdominal wall, at least temporarily. Similarly, the suburethral retaining strips should support the middle urethra, preferably permanently and permanently. The same is true of supportive implants used in the treatment of prolapse.

These textile prostheses must therefore have a certain dimensional stability. To do this, these textile prostheses are usually subjected to a heat-setting step which increases their dimensional stability. Prostheses are then more easily manipulated.

However, the handling, especially for a heat-setting operation, of small strips for example strips is particularly difficult and can lead to many wasted strips become unusable due to poor heat-setting. Furthermore, the fact of heat setting each strip unitarily does not lead to a homogeneous and reproducible heat setting of the strips.

It has been proposed to produce knits in wide width having the desired properties of breaking strength, elasticity and porosity for these products. implants, and then cut the strips or implants into these knits.

However, these support implants must be able to be cut into narrow strips of the order of 1 cm in long lengths, for example of the order of 50 cm, without disbanding or tiling. By "tiling" is meant, in the sense of the present application, the spontaneous winding of the strip on itself, around its longitudinal axis, under tension stress along its length. These implants must retain in this form mechanical properties, including resistance, sufficient, while minimizing the release of particles, that is to say son ends, when they are under stress. Preferably, these implants must also allow mechanically stable tissue anchoring.

Thus, a problem posed by the cutting process lies in the fact that the edges of the implants are frayed. There is then a release of particles especially in the case of stress elongation and thus the loss of son. Furthermore, the cut macroporous elastic implants are difficult to use without protective sheath. Indeed, because of their elasticity and their non-smooth edges, these implants cling to the patient's tissue at the risk of forming a rasp in case of a sharp turn, they deform, tile and release particles. This is why they are generally proposed in a protective sheath, which complicates and increases the surgical operation.

Thus, there is the need for a knitwear, in particular a macroporous prosthetic knit, which would make it possible to produce textile medical devices, in particular supportive implants, for example in the form of strips, which are easy to produce and to handle and having no frayed edges and which would provide homoformed strips homogeneously.

The present invention aims to remedy this need by proposing a knit fabric having demountable zones allowing easy separation, in the direction of manufacture of the knit fabric, of strips or strips of knit fabric, in particular macroporous, and made from monofilament of biocompatible material. , in particular by eliminating one or more specific catenary yarns, the elimination of said one or more yarns enabling the separation of said knit into strips with smooth edges and without risk of fraying. The present invention relates to a knit, preferably prosthetic and perforated, made in one piece, based on an arrangement consisting of at least two plies son, preferably a biocompatible polymer material, comprising at least a first web defining a first warp armor and at least one or more non-meshing webs of partial weft, each of these non-mesh webs defining armor, characterized in that it comprises at least one so-called free warp thread, a warp thread free being defined by a chain yarn for which, over the entire longitudinal dimension of the knit, any yarn of said non-meshing plies approaching said free warp thread performs a half-turn at this free chain yarn.

The present invention also relates to the use of a knit as above to obtain a textile medical device, in particular a prosthetic product for surgical use, in particular to obtain a support implant for the treatment of urinary incontinence. effort and / or prolapse.

Another object of the invention is a textile medical device, characterized in that it is obtained by demisting at least two free, preferably consecutive, chain yarns of a knit such as above, preferably on the length of the longitudinal dimension of said knit. The present invention also relates to a process for manufacturing a knit, preferably a prosthetic and openwork knit, made in one piece, based on an arrangement consisting of at least two sheets of yarns, preferably of a polymer material biocompatible, characterized in that it comprises the following step: manufacture of a knit on a warp or Rachel loom according to a first ply and one or more non-meshing plies, said first ply being threaded continuously or at disposal and being obtained from a guide bar, the scale followed for knitting the yarns of said first ply leading to the formation of a chain, said non-meshing plies being threaded continuously or at disposal, each of said non-meshing plies being obtained at from a guide bar, the scale followed for the knitting of the threads of each non-meshing sheet being such that for at least one thread of the chain armor, di t yarn of free chain, taken in the direction of manufacture of the knit, any thread of said non-meshing plies approaching said free chain thread performs a half-turn at the level of this free chain thread. The knit according to the invention makes it possible to produce a large number of homogeneous strips, in particular thermofixed homogeneously. The knit according to the invention, preferably made in large width, for example over a width ranging from 1.2 to 1.5 meters, is easily manipulated and therefore thermofixable. In addition, the thermofixation performed on a piece of large width, as an example for a knit according to the invention of 1.2 to 1.5 m wide, is particularly homogeneous, and textile medical devices, in particular implants, obtained from this knit, in the form of strips separated by unraveling free warp threads, are also homogeneous and reproducible.

The textile medical device, in particular the support implant, according to the invention has excellent tensile strength, may be inelastic, and is thus quite suitable for the manufacture of a support implant for the treatment of urinary stress incontinence and prolapse, without the need for a protective sheath.

Moreover, because of its manufacturing process, the textile medical device according to the invention has atraumatic and stable smooth edges, that is to say without risk of fraying or release of particles. Finally, all textile medical devices, in particular all strips or implants, obtained from the same knit according to the invention have a homogeneous thermofixation and are easily manipulated.

In the present application, "prosthetic knit" means a knit intended to be implanted in the human or animal body in the form of a prosthesis or of any other piece shaped at least in part with said knit.

In the present application, "openwork knit" means a knit whose armor or armor determine cells or voids in the thickness of the knit, these cells or voids may constitute channels opening on either side knitting. Such openwork knit, also called macroporous, allows better tissue integration.

By "mesh tablecloth" is meant according to the present application, a sheet of son for which the scale followed for the knitting son leads to the formation of meshes. In known manner, a chain-weave web is a mesh web, while partial weft webs are non-mesh webs. In the present application, the term "free warp thread" means a warp thread completely traversed by any weft yarn, in other words a warp yarn for which any weft yarn approaching and interacting with this warp yarn, for example by bonding with it, then performs a half-turn at the level of this string, and this over the entire longitudinal dimension of the knit.

In this application,

the weight per unit area of a knit is measured according to ISO 3801,

the breaking force of a knit in the longitudinal direction and in the transverse direction is measured according to ISO 13934-1,

the elongation under 2 daN in the longitudinal direction is measured according to ISO 13934-1.

In a preferred embodiment of the invention, the knit comprises at least one percent of free warp threads spaced regularly or not according to the transverse dimension of the knit.

More preferably, the knit comprises at least ten percent of free warp threads spaced evenly along the transverse dimension of the knit.

Advantageously, the knit according to the invention comprises a non-meshing tablecloth having the following scale: 0-0 / 2-2 //.

In a preferred embodiment of the invention, the knit according to the invention comprises at least two non-meshing plies. Indeed, the presence of two non-meshing plies, in particular two non-meshing plies crossing one another, that is to say whose respective guide bars move symmetrically with respect to one another, shifted one by relationship to the other in the direction of the manufacture of knitting on the knitting machine, allows to obtain strips and / or implants having a very good resistance to lateral compression. Thus, when compressing, for example between two fingers, the two opposite longitudinal edges of a textile medical device, in particular a strip and / or implant, obtained from the knit according to the invention, this textile medical device , in particular this strip and / or implant, keeps significantly the same width. Preferably, the width loss of a medical device, in particular a strip and / or implant, according to the invention under the effect of the compression of its two opposite longitudinal edges between two fingers is less than 10%. The medical devices, in particular the strips and / or implants, according to the invention are therefore particularly stable in handling, in passing in possible ancillaries (needle eye, cannula ...) and in the tissues of the patient (limitation of the rope effect).

In a preferred embodiment of the invention, the knit comprises a first non-meshing web and a second non-meshing web, said first non-meshing web having the table 1-1 / 3-3 / 2-

2 / 0-0 //, said second non-meshing ply having the scale 3-3 / 2-2 / 0-

0 / 1-1 //.

Preferably, the distance between said free warp threads, depending on the transverse dimension of the knit, is from 0.5 cm to 2 cm, preferably from 0.5 cm to 1.5 cm.

Preferably, the knit according to the invention is a prosthetic knit.

Thus, preferably, the knit is made based son, monofilaments or multifilament, a biocompatible polymer material selected from polypropylene, polyester, polyamide and mixtures thereof. Advantageously, said biocompatible polymer material is polypropylene.

In another embodiment, the knit according to the invention is made from yarns, monofilaments or multifilaments, of a biocompatible and bioabsorbable polymer material. In yet another embodiment, the knit according to the invention is made from a mixture of bioabsorbable biocompatible yarns and nonabsorbable biocompatible yarns.

Preferably, the knit according to the invention is made from monofilament yarns having a diameter ranging from 0.05 mm to 0.15 mm, preferably from approximately 0.10 mm.

Preferably, the knit according to the invention has a thickness ranging from 0.20 mm to 0.40 mm, preferably around 0.30 mm.

Preferably, the knit according to the invention is a perforated knit. Thus, in a preferred embodiment of the invention, the knit according to the invention comprises cells having a diameter ranging from 0.3 to 1.5 mm, preferably from 0.3 to 0.9 mm. Such a knit makes it possible to manufacture a support implant having good tissue anchoring.

Preferably, the knit according to the invention is heat set.

Preferably, the textile medical device according to the invention has a width ranging from 0.5 cm to 2 cm, preferably ranging from 0.5 cm to 1.5 cm. Advantageously, the weight per unit area of the textile medical device according to the invention ranges from 40 to 100 g / m ² , preferably from 50 to 75 g / m ² , and more preferably from 50 to 60 g / m ² .

Preferably, the textile medical device according to the invention has a thickness ranging from 0.20 mm to 0.40 mm, preferably about 0.30 mm.

Preferably, the textile medical device according to the invention comprises cells having a diameter ranging from 0.3 to 1.5 mm, preferably from 0.3 to 0.9 mm. Preferably, the breaking force in the longitudinal and transverse direction of the textile medical device according to the invention, measured according to the ISO 13934-1 standard, ranges from 20 to 90 N, preferably from 40 to 90 N, preferably from 55 to 75 N, more preferably 60 to 70 N.

Thus, the textile medical device according to the invention has both excellent mechanical strength, or breaking strength, and a low surface mass. Such a textile medical device is particularly advantageous as a support implant because it makes it possible to obtain effective support for the organs to be treated while minimizing the mass of implanted foreign bodies. Preferably, the elongation under 2 daN in the longitudinal direction of the textile medical device according to the invention, measured according to ISO 13934-1, is less than or equal to 15%, more preferably less than or equal to 10%. Such a textile medical device is therefore particularly dimensionally stable. Preferably, the textile medical device according to the invention is prosthetic and perforated and constitutes a support implant for the treatment of stress urinary incontinence and / or prolapse.

Moreover, the textile medical device according to the invention preferably corresponds to a zone of the knit according to the invention comprised between two consecutive loose chain yarns, it does not include free warp threads. It does not present any risk of unraveling.

Preferably, the knit according to the invention is manufactured according to a method comprising the following step manufacturing a knit on a warp or Rachel loom according to a first ply and one or more non-knit plies, said first ply being threaded continuously or available and being obtained from a guide bar, the scale followed for knitting the yarns of said first ply leading to the formation of a chain, said non-meshing plies being threaded continuously or at disposal, each of said non-meshing plies being obtained from a bar with gauges, the scale followed for the knitting of the threads of each non-meshing sheet being such that for at least one yarn of the chain armor, called free chain yarn, taken in the direction of manufacture of the knitted fabric, any yarn of said nonwovens meshing approaching said free chain thread performs a half-turn at this free chain thread.

Preferably, the scale followed for the knitting of the yarns of each non-meshing web is such that for at least one percent, preferably at least ten percent, of the warp armor threads, known as free warp threads, taken in the direction of manufacture of the knit, any thread of said non-meshing plies approaching said free warp threads performs a half-turn at these free warp threads. Thus, according to the method of manufacturing the knit according to the invention, all the warp threads, whether free or not, are knitted with the same guide bar.

In one embodiment of the method according to the invention, a single non-meshing web is used, the threads of the first ply according to a chain-weave being knitted according to a scale of 1-0 / 0-1 //, the threads of the non-meshing ply are meshing being knitted according to a scale: 0-0 / 2-2 //.

Preferably, the guide bar of the first ply is threaded continuously full and the guide bar of the non-sparing web is threaded continuously full. In a preferred embodiment of the method according to the invention, at least two non-meshing plies are used. Preferably, two non-meshing plies are used, the guide bars of said two non-meshing plies moving symmetrically with respect to each other, offset with respect to each other in the direction of knitting. .

Advantageously, a first non-meshing ply and a second non-meshing ply are used, the son of the first ply according to the chain-weave being knitted according to a scale of 1-0 / 0-1 //, the threads of the first non-knit ply being knitted. in accordance with a scale 1-1 / 3-3 / 2-2 / 0-0 //, the yarns of the second non-meshing ply being knitted according to a scale of 3-3 / 2-2 / 0-0 / 1-1 / /. Preferably, the guide bar of the first ply according to chain weave is threaded continuously solid, the guide bar of the first non-weaving ply is threaded continuously 1 full, 1 empty, 3 full, 1 empty, 1 full, 3 empty, and the guide bar of the second non-meshing web is threaded continuously 1 full, 1 empty.

Advantageously, the two guide bars of the two non-meshing plies move in partial weft under three needles, symmetrically relative to each other, staggered with respect to each other in the direction of knitting. . Such a knitting, with the weft bars moving symmetrically relative to each other and thus crossing between them, makes it possible to obtain a better maintenance of the chains and thus a better resistance to the lateral compression of the implants and / or strips obtained from the knit according to the invention.

Preferably, at the outlet of the trade, the knit is subjected to a heat-setting operation. The knit is thus easy to handle, in particular for the demaling step. Moreover, all the strips and implants obtained from the same heat-set knit have a homogeneous thermofixation which makes it possible to better guarantee the homogeneity of the physi-co-mechanical properties of one strip to the other after demagneting. The invention will be better understood from the description which follows with reference to the accompanying drawings.

FIG. 1 represents a simplified schematic drawing of a knit comprising a first warp armor ply and two non-knit plies; FIG. 2 represents a prosthetic knit according to the invention of which two free warp threads are partially unraveled,

FIG. 3 is the representation of a scanning electron microscope "Itashi S 800", magnification X20, of the unraveling of a free-chain thread in a knit according to the invention, FIG. 4 is a representation of FIG. 'Itashi S 800' scanning electron microscope, X20 magnification, of the heart of an implant according to the invention.

In Figure 1, for a knit according to the invention, EE 'is represented by the direction or transverse dimension of the knit, by FF' the direction or longitudinal dimension of the knit and by GG 'the direction or diagonal dimension of the knit. This figure shows the movements of the warp yarns and weft yarns for a knit according to the invention having a chain ply and two non-meshing plies. The A and A1 threads of the chain armor are shown in solid solid lines. The wire A1 is a free-chain thread within the meaning of the present invention. The A-yarns are chain yarns that are not free within the meaning of the present invention. The yarns of the first non-meshing ply are represented in fine solid lines: they are the B yarns. The yarns of the second non-meshing ply are represented by a dashed line: these are the C yarns. In this example, the first bar with shelves, corresponding to the armor chain is threaded continuously full. The second guide bar, corresponding to the first non-meshing sheet and son B, is threaded continuously 1 full, 1 empty, 3 full, 1 empty, 1 full, 3 empty. The third guide bar, corresponding to the second non-meshing web and son C, is threaded continuously 1 full, 1 empty.

The knitting scales for these three tablecloths are as follows:

- the chain ply (wires A and A1): 1-0 / 0-1 //,

the first non-meshing web (son B): 1-1 / 3-3 / 2-2 / 0-0 //.

the second non-meshing sheet (thread C): 3-3 / 2-2 / 0-0 / 1-1 //. Thus, the warp yarn A1, as it appears in FIG. 1, is completely traversed by no weft yarn, or in other words, any weft yarn, that is to say any yarn B or C, approaching said yarn. A1 chain yarn, possibly binds with said A1 chain yarn, then performs a half-turn at this A1 chain yarn. The free warp thread A1 can thus be demilled without any consequences on the neighboring warp threads A, which are not free within the meaning of the present application, and therefore without destructuring the knit on either side of this thread A1. By pulling on the warp thread A1, the part of the knit on the left of this wire A1 is separated from the part situated to the right of this wire A1 without unraveling these two parts.

On the other hand, because any weft yarn approaching the yarn A1 makes a half-turn at this yarn A1, the edges of the separated parts have only one yarn B or C making a half-turn and are therefore smooth. No fraying occurs. Such unraveling of a free warp thread A1 of a knit according to the invention is visible in FIG. 3, which is a representation of a photograph, taken with a scanning electron microscope "Itashi S 800", magnification X20, of a demagnage zone of a knit according to FIG. 1 and example 1 of the present application. In the upper part of the figure, the wire A1 is unmated and the knit portions on either side of this wire A1 are not destructured. Their edges are smooth: only a wire C performs a half-turn. No knitting yarn is cut or frayed. As it appears clearly in this Figure 3, thanks to the particular threading son of the non-meshing plies, the wire C performing a half-turn at the edge of a separate portion is consistent with the heart of this separate part. In this figure, the A1 wire is being unmaked. Thus, at the bottom of the figure, the wire A1 is still meshed with the C wires approaching him.

At the end of the unraveling, that is to say when the wire A1 has been peeled over the entire length of the knit, the yarn A1 is removed from the knit according to the invention and the two parts of the knitted fabric from else of this wire A1 are completely separated. By unraveling in the same way a second free warp thread, a strip of the knit is completely separated. The distribution of A1 son allows to predetermine with great precision the width of each strip.

FIG. 2 schematically shows a knit 1 according to the invention for which the free-chain yarns A1 are regularly spaced in the knit. Two of these wires, the wires A11 and A12 are partially unraveled. Thus, by completely unraveling these free warp threads A11 and A12, a textile medical device 2 according to the invention is obtained.

The heart of a textile medical device according to the invention is shown in Figure 4, which is the representation of a photograph, taken under the scanning electron microscope "Itashi S 800", magnification X20. The heart of a textile medical device according to the invention preferably corresponds to a zone of the knit according to the invention comprised between two consecutive free chain yarns. Thus, the textile medical device itself does not include free warp threads. It does not present any risk of unraveling.

EXAMPLE:

A knit according to the invention was made from a polypropylene monofilament yarn, with a diameter of 0.10 mm, on a Rachel loom, with a tablecloth chain and two non-meshing tablecloths, according to the following scales for the different tablecloths:

- the chain ply: 1-0 / 0-1 //,

the first non-meshing web: 1-1 / 3-3 / 2-2 / 0-0 //, the second non-meshing web: 3-3 / 2-2 / 0-0 / 1-1 //.

The first guide bar, corresponding to the chain armor was threaded continuously full. The second guide bar, corresponding to the first non-meshing web, of partial weft, was threaded continuously 1 full, 1 empty, 3 full, 1 empty, 1 full, 3 empty. The third guide bar, corresponding to the second non-meshing nonwoven web, was threaded continuously 1 full, 1 empty. The threading of the two partial wefts was carried out so as to move under nine warp threads, this finally obtaining strips separated by about 1 cm in width each. Thus, in this example, 1 in 10 warp thread, or ten percent, was a free warp yarn in the sense of the invention.

The gauge used was 24 needles.

The guide bars of the two non-meshing plies moved in partial weft under three needles, symmetrically relative to each other, shifted relative to each other in the direction of manufacture of the knit.

This knit corresponds to the weave shown in FIG. 1 of the present application.

On leaving the trade, the knit was subjected to a heat-setting operation. The knitting had the following characteristics:

- thickness: about 0.3 mm

diameter of the cells: approximately 1 mm.

From this knit, strips were obtained by unraveling at least two consecutive free chain yarns. The strips had the following characteristics:

- thickness: about 0.3 mm

diameter of the cells: approximately 1 mm.

- width: about 1 cm.

- mass per unit area: about 50 g / m ² . - breaking force measured according to ISO 13934-1 on a strip 1 cm wide and 20 cm long: 66 N. The strip thus obtained by demealing at least two free, preferably consecutive, chain yarns of the knit according to the invention has excellent tensile strength and is therefore entirely suitable for use as, or for the manufacture of, a supportive implant for the treatment of stress urinary incontinence and prolapse.

For example, an implant 20 cm in length, or 30 cm in length or 40 cm in length can be prepared from this strip.

Furthermore, because of its manufacturing process, this implant has edges, including longitudinal, smooth atraumatic. Finally, all the strips or implants obtained from the same knit have a homogeneous thermofixation and are easily manipulated.

Claims

1. A method of manufacturing a knit (1) made of a single piece, based on an arrangement constituted by at least two plies of son, characterized in that it comprises the following step: manufacturing a knitting on a chain loom or Rachel according to a first web and one or more non-meshing webs, said first web being threaded continuously or at disposal and being obtained from a guide bar, the scale followed for the knitting of the threads of said first ply leading to the formation of a chain, said non-meshing plies being threaded continuously or at disposal, each of said non-meshing plies being obtained from a guide bar, the scale followed for the knitting of the yarns of each non-meshing sheet being such that for at least one thread (A1, A11, A12) of the chain armor, said free chain thread, taken in the direction of manufacture of the knit, any thread of said non-meshing plies approaching said free warp thread makes a half-turn at this free warp thread.

2. Method according to claim 1, characterized in that the scale followed for the knitting son of each non-meshing web is such that for at least one percent, preferably for at least ten percent, the son of the armor chain, called free chain yarn (A1, A11, A12), taken in the direction of manufacture of the knitted fabric, any thread of said non-meshing plies approaching said free warp threads makes a half-turn at the level of these free warp threads ( A1, A11, A12).

3. Method according to claim 1 or 2, characterized in that a single non-meshing web is used, the son of the first tablecloth in chain weave being knitted according to a scale 1-0 / 0-1 //, the son of the non-meshing ply being knitted according to a scale: 0-0 / 2-2 //.

4. Method according to claim 3, characterized in that the guide bar of the first web is threaded continuously full and the guide bar of the non-meshing web is threaded continuously full.

5. Method according to claim 1 or 2, characterized in that at least two non-meshing plies are used.

6. Method according to claim 5, characterized in that two non-meshing plies are used, the guide bars of said two non-meshing plies moving symmetrically relative to each other, offset relative to each other in the direction of knitting.

7. A method according to claim 5 or 6, characterized in that a first non-meshing web and a second non-meshing web are used, the son of the first web armor chain being knitted according to a scale 1-0 / 0-1 //, the yarns of the first non-meshing ply being knitted according to a 1-1 / 3-3 / 2-2 / 0-0 // scale, the yarns of the second non-knitting ply being knitted according to a scale of 3-3 / 2-2 / 0-0 / 1-1 //.

8. A method according to claim 7, characterized in that the guide bar of the first ply in chain weave is threaded continuously full, the guide bar of the first non-meshing ply is threaded continuously 1 full, 1 empty, 3 full, 1 empty, 1 full, 3 empty, and the guide bar of the second non-meshing web is threaded continuously 1 full, 1 empty.

9. A method according to claim 8, characterized in that the two guide bars of the two non-meshing plies move in partial frame under three needles, symmetrically relative to each other, offset with respect to the other in the direction of knitting.

10. Method according to any one of claims 1 to 9, characterized in that, at the end of the craft, the knit is subjected to a heat-setting operation.

11. Knit (1) obtained according to the method of one of claims 1 to 10.

12. Knit (1) made of a single piece, based on an arrangement constituted by at least two plies of son, comprising at least a first ply defining a first chain armor and at least one or more non-meshing plies, of partial weft, each of these non-mesh mats defining an armor, characterized in that it comprises at least one so-called free-chain thread (A1, A11, A12), a free-chain thread being defined by a chain thread for which over the entire longitudinal dimension of the knit, any yarn of said non-meshing plies approaching said free warp thread performs a half-turn at this free warp thread.

13. Knit (1) according to claim 12, characterized in that it comprises at least one percent of free warp threads spaced regularly or not according to the transverse dimension of the knit.

14. Knit (1) according to claim 12 or 13, characterized in that it comprises at least ten percent of free warp threads regularly spaced along the transverse dimension of the knit.

15. Knit (1) according to any one of claims 12 to 14, characterized in that it comprises a non-meshing web having the following scale: 0-0 / 2-2 //.

16. Knit (1) according to any one of claims 12 to 14, characterized in that it comprises at least two non-meshing plies.

17. Knit (1) according to claim 16, characterized in that it comprises a first non-meshing web and a second non-meshing web, said first non-meshing web having the scale 1-1 / 3-3 / 2- 2 / 0-0 //, said second non-meshing web having the scale 3-3 / 2-2 / 0-0 / 1-1 //.

18. Knit (1) according to any one of claims 12 to 17, characterized in that the distance between said free warp threads, according to the transverse dimension of the knit, ranges from 0.5 cm to 2 cm, preferably from 0.5 cm to 1.5 cm.

19. Knit (1) according to any one of claims 12 to 18, characterized in that it is prosthetic.

20. Knit (1) according to claim 19, characterized in that it is made from son of a biocompatible polymer material.

21. Knit (1) according to the preceding claim, characterized in that it is made based son, monofilaments or multifilament, a biocompatible polymer material selected from polypropylene, polyester, polyamide and mixtures thereof.

22. Knit (1) according to claim 21, characterized in that said biocompatible polymer material is polypropylene.

23. Knit (1) according to claim 20, characterized in that it is made based son, monofilaments or multifilament, a biocompatible and bioresorbable polymer material.

24. Knit (1) according to claim 20, characterized in that it is made from a mixture of biocompatible son bioabsorbable and biocompatible son non-bioabsorbable.

25. Knit (1) according to any one of claims 12 to 24, characterized in that it is made of monofilament son having a diameter of 0.05 mm to 0.15 mm, preferably about 0.10 mm.

26. Knit (1) according to any one of claims 12 to 25, characterized in that it has a thickness ranging from 0.20 mm to 0.40 mm, preferably about 0.30 mm.

27. Knit (1) according to any one of claims 12 to 26, characterized in that it is perforated.

28. Knit (1) according to the preceding claim, characterized in that it comprises cells having a diameter ranging from 0.3 to 1.5 mm, preferably from 0.3 to 0.9 mm.

29. Knit (1) according to any one of claims 12 to 28, characterized in that it is heat set.

30. Use of a knit (1) according to any one of claims 11 to 29 to obtain a textile medical device, in particular a prosthetic product for surgical use, in particular to obtain a support implant for the treatment of incontinence. urinary stress and / or prolapse.

31. Textile medical device (2), characterized in that it is obtained by unraveling at least two free, preferably consecutive, chain yarns from a knit (1) according to any one of claims 11 to 29. , preferably along the length of the longitudinal dimension of said knit.

32. Textile medical device (2) according to claim 31, characterized in that it has a width ranging from 0.5 cm to 2 cm, preferably ranging from 0.5 cm to 1.5 cm.

33. Textile medical device (2) according to claim 31 or 32, characterized in that its surface mass ranges from 40 to 100 g / m ² , preferably from 50 to 75 g / m ² , and more preferably from 50 to 60 g / m ² .

34. A textile medical device (2) according to any one of claims 31 to 33, characterized in that it has a thickness ranging from 0.20 mm to 0.40 mm, preferably about 0.30 mm.

35. textile medical device (2) according to any one of claims 31 to 34, characterized in that it comprises cells having a diameter ranging from 0.3 to 1.5 mm, preferably from 0.3 to 0.9 mm.

36. Textile medical device (2) according to any one of claims 31 to 35, characterized in that its breaking force in the longitudinal and transverse direction, measured according to ISO 13934-1, from 20 to 90 N, preferably from 40 to 90 N, preferably from 55 to 75 N, more preferably from 60 to 70 N.

37. Textile medical device (2) according to any one of claims 31 to 36, characterized in that it has an elongation under 2 daN in the longitudinal direction, measured according to ISO 13934-1, less than or equal to 15%, more preferably less than or equal to 10%.

38. Textile medical device (2) according to any one of claims 31 to 37, characterized in that it is prosthetic and perforated and constitutes a support implant for the treatment of stress urinary incontinence and / or prolapse.