TEXTILE SUBSTRATE FOR TUFTED PRODUCT

Abstract

This textile support is intended for the preparation of a tufted product such as an artificial grass or a carpet. It comprises at least one woven or non-woven lay. Technical yarns extend in one or two directions and are joined to the said lay for reinforcing it by knitting on a warp knitting machine, the said technical yams extending on the one hand in the warp direction and on the other in the weft direction on all or part of the width of the said lay.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a National Stage filing under 35 U.S.C. §371 of PCT Application No. PCT/FR2007/052366, filed Nov. 20, 2007. This application also claims the benefit of French Application No. 0655016, filed Nov. 21, 2006. The entirety of both applications is incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to a textile support intended for the preparation of a tufted product such as an artificial grass or a carpet. The subject matter of the present invention thereby serves to prepare a tufted product having improved mechanical strength properties.

The technique concerned above is commonly referred to as “tufting”. In the context of the present invention, tufted product means any textile product whereof the surface is covered with a multitude of “hairs”, that is more or less short strands joined to a textile support by mechanical means and optionally by glueing.

Furthermore, the present invention also relates to a method for preparing such a support.

BACKGROUND OF THE INVENTION

Tufted products are known from the prior art, such as artificial grasses and carpets, prepared by “tufting” fibres in and through a textile support, the said support being a woven, a non-woven, or other type of fabric. The fibres employed for forming the tufting strands or hairs generally consist of polymer plastics, such as polypropylene, polyethylene or a polyamide. The choice of these materials depends on the performance and functions which the tufted product is expected to perform, hence on its end use. For example, in the case of an artificial grass used to cover a sports field, it is quite clear that it must have a relatively low elongation or deformation to constitute an appropriate sports field.

Among these performance requirements, the mechanical strength upon elongation in the two main directions of the tufted product, and also in its diagonal directions, is particularly important for guaranteeing the strength, stability and longevity of the product. In general, the main directions of the tufted product are defined on the one hand by the travel direction of the production machine and, on the other, by the direction perpendicular to the said travel direction.

Furthermore, the mechanical stresses resulting from the tufting operation require the use of a textile support that strongly withstands the tensile loads, but also has low perforation resistance, so as to be easily penetrated by the needles carrying out the tufting, that is, guiding the fibres or strands through the support.

Accordingly, the woven or non-woven supports used today result from this compromise between their mechanical tensile strength and their ability to be readily perforated during tufting. However, such a compromise significantly restricts the performance of the end product and hence its field of application, because it limits the choice of materials used to prepare the tufted product.

In fact, these products are generally made from relatively fine, numerous and “tight” fibres, giving rise to tufted products with relatively high linear mass.

Furthermore, the tufted products of the prior art may have a relatively high deformation under the loads generated by sudden accelerations or stopping of a user of the sports field, owing to the inherent structure of the textile support thereof.

The present invention therefore relates to a textile support whereof the choice does not depend on the compromise described above, and whose application performance is not limited by such a compromise.

SUMMARY OF THE INVENTION

The present invention relates to a textile support whereof the mechanical strength properties are improved, while having a high aptitude for perforation during tufting.

The invention relates to a textile support intended for the preparation of a tufted product such as an artificial grass or a carpet, the said support comprising at least one woven lay. According to the invention, technical yams extending in one or two directions are joined to the said lay for reinforcing it, this joining being realised by binding threads, serving to maintain the cohesion between the lay and the technical yams.

According to the invention, the binding threads are assembled with the lay by knitting on a warp knitting machine, the said technical yams extending on the one hand in the warp direction and on the other in the weft direction on all or part of the width of the lay.

In other words, the textile support covered by the present invention comprises one or more lays of different characteristics, reinforced by technical yams in one or two dimensions.

Such a structure guarantees an effective maintenance and reliable positioning of these technical yams. Moreover, such an assembly method serves to produce the textile support at low cost and high production rate, while ensuring good cohesion of the technical yams appropriate for the end use.

According to a particular embodiment of the invention, the support may comprise at least two superimposed lays, one of these lays being intended for supporting the tufting, the other lay being intended to provide a multidirectional reinforcement.

Thus, the technical support may perform various functions as required, these functions being performed by one and/or the other of the lays thereof.

According to a particular embodiment of the preceding embodiment, one of the superimposed lays is made from a non-woven fabric suitable for drainage.

This serves for example to drain the rain water in the case in which the textile support serves to prepare a tufted artificial grass.

In practice, the technical yarns may have a certain mobility at their points of joining to the said lay, in order to facilitate the tufting operation without the risk of weakening the technical reinforcement yams.

In other words, the technical yarns may have a relatively loose fastening to the lay, thereby serving to avoid their damage by the needles carrying out the tufting. In fact, this mobility or oscillation enables the technical yarn to escape when pushed by a needle.

According to another embodiment of the invention, the technical yarns may be made from glass fibres or high temperature polyethylene terephthalate (HT PET), or from polypropylene.

Technical yams made from such materials have mechanical properties which confer the desired mechanical strength on the textile support.

According to a particular embodiment of the invention, the said technical yarns may have gauges or counts of between 300 and 2,400 tex.

Thus for example, such technical yams may have an appropriate elongation at break for specific applications such as artificial grass.

In practice, the lay may consist of a woven fabric having a proof stress of 12 to 20%, and technical reinforcement yarns with an elongation at break of about 2.5%.

Thus, such a lay confers on the textile support the mechanical strength properties combining flexibility of the upper side of the material and overall mechanical strength.

According to the invention, the support may comprise two or more continuous superimposed lays, so as to confirm thereto other mechanical properties in a plurality of directions, the said layers being reinforced by technical fibres for strength.

According to another particular embodiment of the present invention, the binding threads may be densely distributed throughout the lay, in order to form numerous reliefs for the adhesion of a coating layer applied during the tufting operation.

In other words, the numerous binding threads represent as many adhesion points for the coating layer, thereby increasing the cohesion of this layer to the textile support and hence the longevity of the tufted product.

According to the invention, the reinforcement yams may be placed on either side of one of the lays.

Furthermore, the present invention relates to a method for preparing a textile support as described above.

Moreover, the present invention relates to a tufted product, such as an artificial grass or a carpet, composed of a textile support according to the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments of the invention and the advantages issuing therefrom also appear from the following exemplary embodiments, provided for information and non-limiting, in support of the figures appended hereto in which:

FIG. 1 is a schematic perspective representation of a textile support according to a first embodiment of the invention;

FIG. 2 is a schematic cross section representation of the textile support shown in FIG. 1;

FIG. 3 represents a diagram showing a comparison between the mechanical properties of a textile support according to the present invention and those of a textile support of the prior art;

FIG. 4 is a schematic cross section representation of a textile support according to a second embodiment of the invention;

FIG. 5 is a schematic plan view representation of a third embodiment of the invention;

FIG. 6 is a schematic cross section representation of the textile support shown in FIG. 5.

DETAILED DESCRIPTION OF THE INVENTION

According to the invention, the textile support shown in FIG. 1 comprises a lay 101 consisting of a woven product. On the lay 101, technical yarns 102 and 103 are combined by means of binding threads 104.

The yarns 102 extend in the production or warp direction, while the yams 103 are perpendicular thereto. In the present case, the assembly of the technical yarns 102 and 103 to the lay 101 by means of the binding threads 104 is carried out using a warp knitting machine, for example of the Karl Mayer® or Liba® make. The yams 102 are arranged in the warp direction and the yarns 103 in the weft direction.

Furthermore, to illustrate the end use of the textile support, part of the lay 101 is covered by strands or fibres 105. These strands 105 are tufted through the lay 101 as shown in greater detail in FIG. 2.

The assembly of the technical yams 102 and 103 to the lay 101 using the binding threads 104 is carried out using a warp knitting machine of the Rachel winder type with insertion of lays of multiple materials. In the present case, the yarns 102 and 103 are yams of the technical type, that is consisting of glass fibres having a very high deformation modulus.

Owing to the knitting assembly mode, the binding threads 104 pass through the lay 101 at regular intervals, as shown in FIG. 2. These binding threads 104 may consist of polyester or polypropylene threads. Their density and distribution on the surface of the lay 101 and the number of fastening points depend on the mechanical strength to be imparted to the assembly of the textile support.

As shown in FIG. 1, the yarns 102 are spaced at regular intervals 106, whereof the dimension is adapted according to the end use of the tufted product. Thus, in order to provide a “reactive force”, that is a resistance to deformation, that is relatively high, the length of each interval 106 can be decreased.

Similarly, the technical yams 103 are spaced at intervals 107 whereof the length can be adjusted as required. Moreover, the technical yams 103 can be selected in order to have mechanical properties (modulus of elasticity, elongation at break, linear weight, etc.) similar to or different from the mechanical properties of the technical yarns 102.

Furthermore, it is also possible to avoid incorporating the weft technical yams 103 and hence have technical yarns 102 in one direction only, in order to provide a different mechanical strength along one or the other of the main directions of the lay 101.

One of the advantages of the assembly by warp knitting machine resides in the fact that the technical yams 102 and 103 can be arranged in a perfectly straight manner on the lay 101, thereby procuring greater reactivity for the tufted product to the loads generated during its use. In fact, in the tufted products of the prior art using a woven lay in particular, the warp and weft yams are alternately crossed above and below, thereby causing a waviness and hence an additional elongation that is detrimental to certain uses of the tufted product.

Moreover, the present invention offers a substantial economic advantage insofar as it serves to prepare a textile support reinforced by large diameter yarns which are inserted discontinuously, instead of employing a continuous network of finer and therefore more costly fibres, which is also more expensive to assemble.

Thus, it is possible to obtain the same mechanical strength for a much lower total cost. In consequence, the production, transport and installation of the textile support or of the tufted product are easier and less costly. Furthermore, it is known that the spinning of coarse fibres is more economical (fibre cost/benefit ratio) than the spinning of fine fibres. In fact, the addition of technical yarns 102 and 103 by a Rachel type assembly mode serves to provide the extra mechanical strength necessary for the toughness and longevity of the textile support.

In the example in FIG. 1, the technical yams 102 and 103 consist of glass filaments or “rovings” having a linear mass of between 600 tex and 1,200 tex. The intervals 106 and 107 are about 20 mm here. In consequence, the strength in one or the other of the two main dimensions of the lay 101 is between 15 kN/m and 30 kN/m. Obviously, the parameters mentioned above can be varied in order to obtain different mechanical strength values ranging between 5 kN/m and 200 kN/m.

FIG. 3 shows a tensile strength diagram illustrating the tensile strength F as a function of the elongation at break ε of a textile support of the invention (curve 302), and the strength of a textile support of the prior art (curve 301). The curves 301 and 302 are obtained during the application of a tensile load according to international standards.

As stated above, the reinforcement of a lay by technical yarns consisting of glass and polymer plastics with a high modulus of elasticity (for example aramide) confers on the textile support elongations at break ε of between 2% and a maximum of 10%. Moreover, the original modulus of elasticity, shown by the initial slope of the curves 301 and 302, that is in the domain of low deformations of the support, is much higher in the case of the curve 302 of the support covered by the present invention, compared with that of the curve 301 of a standard product. In fact, this parameter represents a crucial performance advantage for the strength of the tufted product during its use.

For a relatively low elongation, 2% here, the curve 302 shows a much higher level of strength 304 than the level of strength 303 of the curve 301. Thus, the textile support covered by the invention is shown to be more “reactive” to the loads that it undergoes and less subject to deformation.

In consequence, even if a tufted product composed of a textile support according to the present invention has an identical break strength to that of a standard tufted product, it has a greater “immediate” reactivity as shown by the initial slopes of the curves 301 and 302. Thus, the end tufted product is capable of having a better resistance to deformation during sudden accelerations or stopping of the persons using the artificial grass or the carpet whereof it is made.

FIG. 4 shows a second embodiment of the invention in which a non-woven fabric 406 is inserted between a lay 401 and technical yarns 402 and 403. The overall textile support is assembled, as in the case of FIG. 1, by knitting on a warp knitting machine using binding threads 404. Strands or hairs 405 are also shown, as may be observed on completion of the tufting operation.

The non-woven fabric 406 serves to perform additional functions, such as drainage for example. Depending on the specification, this non-woven fabric 406 may be more or less dense and it may consist of glass fibres, polyester fibres, propylene fibres or other.

Moreover, the insertion of this non-woven fabric 406 confers additional stability to the textile support, particularly in the diagonal directions. It should also be observed that the warp knitting method of preparation serves to easily and economically insert several superimposed layers while keeping them tightly close together by means of binding threads 404.

FIG. 5 shows a third embodiment of the invention in which binding threads 504 are placed on the superimposition of a lay 501 and a non-woven fabric 506 more densely than the binding threads 104 and 404 of FIGS. 1 and 4. In fact, as shown in FIG. 5, the interval between two adjacent technical yams 502 also comprises two binding threads, which therefore only maintain the technical yams 503. In addition to increasing the mechanical strength of the assembly which they secure, these numerous binding threads 504 represent as many additional adhesion points for lining one of the sides of the support with a coating layer 507 designed to maintain the tufting fibres.

In consequence, the increased density of the binding threads 504 serves to assemble the support better, to confer thereto greater mechanical strength, and finally, to improve the retention of the tufting fibres by contributing to maintain the coating layer 507 shown in FIG. 6.

The binding threads 104, 404 and 504 may, for example, be prepared from polyester, a material which has a suitable affinity for the latex or polyurethane which are likely to form the coating 507.

Other embodiments are feasible without necessarily going beyond the scope of this invention. For example, it is possible to reverse the relative arrangement of the layers (or lays) and technical yarns according to the desired applications. Moreover, the reinforcing yarns may also be arranged, as required, on either side of the textile support.

Claims

1. A textile support configured for the preparation of a tufted product such as an artificial grass or a carpet, the support comprising:

at least one woven lay and

a plurality of technical yarns, the technical yarns extending in at least one of a warp direction and a weft direction, the technical yarns being joined to the lay by binding threads, and the technical yarns reinforcing the lay,

wherein the binding threads are assembled with the lay by knitting on a warp knitting machine, and

wherein the technical yarns extend in the warp direction.

2. The textile support according to claim 1, wherein it comprises at least two superimposed lays, one of these lays being configured for supporting the tufting, the other lay being configured to provide a multidirectional reinforcement.

3. The textile support according to claim 2, wherein one of the said superimposed lays is made from a non-woven fabric suitable for drainage.

4. The textile support according to claim 1, wherein the technical yarns have a certain mobility at their joining points with the lay, in order to facilitate a tufting operation without a risk of weakening the technical reinforcing yarns.

5. The textile support according to claim 1, wherein the technical yarns are made from one of glass fibres, high temperature polyethylene terephthalate, and from polypropylene.

6. The textile support according to claim 1, wherein the technical yarns have a linear mass between 300 and 2,400 tex.

7. The textile support according to claim 1, wherein the lay consists of a woven fabric having a proof stress of about 12 to 20%.

8. The textile support according to claim 1, wherein it is composed of two or more continuous superimposed lays, so as to confer thereto other mechanical properties in a plurality of directions, the layers being reinforced by technical fibres for strength.

9. The textile support according to claim 1, wherein the binding threads are densely distributed throughout the lay, in order to form numerous reliefs for an adhesion of a coating layer applied during a tufting operation.

10. The textile support according to claim 2, wherein the reinforcing yarns are placed on either side of one of the lays.

11. A tufted product such as an artificial grass or a carpet, comprising a textile support according to claim 1.

12. The textile support according to claim 1 wherein the technical yarns extend in the warp direction and in the weft direction, and wherein the technical yarns extend in the weft direction in at least a portion of a whole width of the lay.