ARTIFICIAL TURF MAT AND METHOD FOR MANUFACTURE THEREOF

Abstract

An artificial turf mat includes a woven backing and a number of artificial grass blades connected thereto. The woven backing includes a leno weave of warp and weft threads where at least some of the warp threads and/or some of the weft threads are formed by melting threads. The artificial grass blades are woven into the woven backing. Each melting thread can include a temperature-resistant thread core and a meltable coating surrounding the thread core. A method for manufacturing an artificial turf mat includes weaving a backing and connecting a number of artificial grass blades thereto. The backing is woven by interweaving a number of warp and weft threads by means of leno weaving, at least some of the interwoven threads are formed by melting threads, and artificial grass blades are woven into the woven backing.

Claims

1-28. (canceled)

29. An artificial turf mat, comprising: a woven backing and a number of artificial grass blades connected thereto; wherein the woven backing comprises a leno weave of warp and weft threads; wherein at least some of the threads are formed by melting threads, and wherein the artificial grass blades are woven into the woven backing.

30. The artificial turf mat of claim 29, wherein the artificial grass blades protrude from the backing on both sides.

31. The artificial turf mat of claim 29, wherein at least some of the warp threads and/or weft threads are formed by melting threads.

32. The artificial turf mat of claim 29, wherein each melting thread comprises a temperature-resistant thread core and a meltable coating surrounding the thread core.

33. The artificial turf mat of claim 32, wherein the thread core comprises a plastic with a relatively high melting temperature; and/or wherein the coating comprises a plastic with a relatively low melting temperature.

34. The artificial turf mat of claim 29, wherein at least some of the warp and/or weft threads are formed by shrinking yarns and/or spiral yarns.

35. The artificial turf mat of claim 29, wherein at least some of the warp and/or weft threads are biodegradable; and/or wherein at least some of the artificial grass blades are manufactured from biodegradable material.

36. The artificial turf mat of claim 29, wherein only a part of the backing is woven as leno weave.

37. The artificial turf mat of claim 36, wherein arranged between two pairs of leno-woven warp threads is a larger number of conventionally woven warp threads.

38. The artificial turf mat of claim 29, further comprising at least one secondary backing connected to the woven backing.

39. The artificial turf mat of claim 38, wherein the at least one secondary backing is manufactured from a natural fibre material; and/or wherein the artificial turf mat further comprises a plurality of secondary backings which are manufactured from different materials.

40. A method for manufacturing an artificial turf mat, comprising: weaving a backing; and connecting a number of artificial grass blades to the backing; wherein at least a part of the backing is woven by interweaving a number of warp and weft threads by means of leno weaving, and wherein at least some of the interwoven threads are formed by melting threads and wherein the artificial grass blades are woven into the woven backing.

41. The method of claim 40, wherein artificial grass fibres are woven into the backing and are locally cut in order to form the artificial grass blades.

42. The method of claim 40, wherein the artificial grass blades are woven into the backing such that they protrude therefrom on both sides.

43. The method of claim 40, wherein melting threads are interwoven as warp threads with the weft threads by leno weaving; and/or wherein the warp threads are interwoven with the weft threads embodied as melting threads by leno weaving.

44. The method of claim 40, wherein shrinking yarns and/or spiral yarns are interwoven with the warp and/or weft threads by leno weaving.

45. The method of claim 40, wherein at least some of the artificial grass blades are manufactured from biodegradable material.

46. The method of claim 40, wherein between two pairs of leno-woven warp threads a larger number of warp threads is interwoven in conventional manner with the weft threads.

47. The method of claim 40, wherein at least one secondary backing is connected to the woven backing.

48. The method of claim 47, wherein the at least one secondary backing is manufactured from a natural fibre material; and/or wherein a plurality of secondary backings is connected to the woven backing, and wherein the secondary backings are manufactured from different materials.

Description

[0025] The invention will now be elucidated on the basis of a number of embodiments, wherein reference is made to the accompanying drawings, in which:

[0026] FIG. 1 is a perspective view of an artificial turf mat according to a first embodiment of the invention on a ground surface, wherein some of the artificial grass blades have been omitted,

[0027] FIG. 2 is a schematic top view of a leno weave as applied in the backing of the artificial turf mat according to the invention,

[0028] FIG. 3 is a cross-section through a melting thread for application in the artificial turf mat according to the invention,

[0029] FIG. 4A and 4B are respectively a side view of and a cross-sectional view through a weft thread embodied as melting thread and two warp threads of the leno weave before and after melting of the melting thread,

[0030] FIG. 5A and 5B are schematic perspective views showing the connection between a weft thread and two warp threads embodied as shrinking yarns of the leno weave, before and after heating of the shrinking yarns,

[0031] FIG. 6 is a schematic perspective view of a weft thread and two warp threads twisted therearound of a leno weave, wherein a number of threads is embodied as spiral yarns,

[0032] FIG. 7 is a flow diagram with the most important steps of the method according to the invention, and

[0033] FIG. 8 is a schematic bottom view of a backing of an artificial turf mat according to a second embodiment of the invention.

[0034] An artificial turf mat 1 (FIG. 1) comprises a woven backing 2 and a large number of artificial grass blades 3 connected thereto and protruding from the backing 2 on one sidethe side forming the upper side T in use. Backing 2 is woven from threads or yarns which, just as artificial grass blades 3, can themselves be manufactured from plastic. In order to form a very stable backing 2 without use having to be made for this purpose of a coating or a layer of latex, at least a part of the weave of backing 2 is according to the invention a leno-weave. In such a leno-weave the warp threads 7a, 7b are arranged twisted in pairs round weft threads 8 (FIG. 2). Due to this pairwise twisting of warp threads 7a, 7b, the weft threads 8 are gripped tightly therebetween, whereby slippage of the threads relative to each other is prevented and a stronger connection in the weave is achieved than is possible with conventional weaving techniques.

[0035] In order to stabilize backing 2 still further the warp threads 7a, 7b and/or the weft threads 8 are in any case partially formed by melting threads. By melting these threads after the weaving the weave is in fact welded, whereby it is strengthened still further. Because the weave of backing 2 is thus intrinsically stable, and can be used without coating or stabilizing layer of latex, backing 2 is lighter and easier to handle than a conventional backing with coating, while the eventual artificial turf mat will in addition have an open structure owing to the absence of the coating or the layer of latex, and is thus for instance air-permeable and water-permeable.

[0036] Each melting thread can be formed by a temperature-resistant thread core 9 and a meltable coating 10 which encloses thread core 9 (FIG. 3). This meltable coating 10 provides for the bonding, while the thread core 9 will not melt and thus guarantees the strength and stability of the weave. A plastic with relatively high melting temperature, such as polypropylene, is for instance suitable as material for the thread core 9. A plastic with a relatively low melting temperature, such as for instance polyethylene, could be chosen for coating 10. The difference in melting temperature between thread core 9 and coating 10 need otherwise not be exceptionally great, as long as it is sufficient to ensure that the mechanical properties of thread core 9 are not affected, or hardly so, when backing 2 is heated to a degree that coating 10 of the melting thread melts. As can be seen, the melting thread here has a round cross-section, whereby the leno weaving is simplified. In the case of other cross-sections, particularly flat cross-sections, the twisting of warp threads 7a, 7b around weft thread 8 results in deformation, whereby an irregular weave is obtained.

[0037] For the purpose of heating the melting threads use can be made of any desired heating technique, such as for instance heating by irradiation with infrared radiation. It is also possible to envisage guiding the weave along a heated roller and thus heat the melting threads. In that case it can be advantageous to protect the backing 2 on the side facing toward the heated roller with an additional backing which is manufactured from a non-meltable material, for instance a natural fibre material or a biodegradable material.

[0038] As can be seen by comparing FIG. 4A and FIG. 4B, when weft thread 8 is embodied as melting thread, the warp threads 7a, 7b will sink slightly into coating 10 of weft thread 8, and tightly enclose thread core 9, when coating 10 of weft thread 8 is melted. The material of meltable coating 10 will here flow around warp threads 7a, 7b so that they become wholly or partially embedded therein. When the temperature is then once again reduced and meltable coating 10 solidifies again, a very strong welded connection (shown in broken lines) will be created between weft thread 8 and warp threads 7a, 7b.

[0039] Although weft thread 8 is embodied as melting thread in this example, it is of course equally possible to envisage, in addition to or instead of weft thread 8, one of the warp threads 7a, 7b or even both of the warp threads 7a, 7b being embodied as melting thread.

[0040] It is additionally or instead possible to achieve a particularly strong connection between the warp and weft threads 7, 8 when some of these threads are formed by shrinking yarns. When warp threads 7a, 7b are for instance formed by shrinking yarns, they can in the first instance be interwoven in twisted manner with weft threads 8 in order to thus form a leno weave (FIG. 5A), after which warp threads 7a, 7b can shrink by heating and are thus pulled even more tightly around weft threads 8 (FIG. 5B). When weft threads 8 are here once again embodied as melting threads, an even stronger connection is formed.

[0041] Another way of achieving an additional strengthening of the leno weave is shown in FIG. 6, where the weft thread 8 and warp threads 7a, 7b are all embodied as spiral yarns. Owing to the spiral form of the warp and/or weft threads 7, 8 they engage even more tightly in each other than is the case with smooth yarns, since the spiral yarns as it were hook into each other. This counteracts slippage of the threads relative to each other still further.

[0042] The backing 2, which is formed as a leno weave and the warp and/or weft threads 7, 8 of which are embodied as melting threads, can be applied for the purpose of forming an artificial turf mat 1. The artificial grass blades 3 are for this purpose woven into backing 2. Some of the warp or weft threads 7, 8 are brought out of a main plane of the weave of backing 2 in loops in order to there form the artificial grass blades 3. The loops can optionally be cut through so that each loop forms two individual artificial grass blades 3. This cutting can already take place during the weaving, as described in WO 2010/120174. Because the combination of leno weave and the use of melting threads results in a very stable backing 2 with artificial grass blades 3 co-woven therein, a relatively large mesh width of the weave can be chosen. A relatively open structure is thus formed, which is very well water-permeable and thus results in an artificial turf field with good drainage properties. The structure is also air-permeable and thereby suitable for ventilation and/or heating of the artificial turf field.

[0043] It can be useful to make the leno weave of backing 2 on the basis of shrinking yarns, because the artificial grass blades 3 are thereby very tightly enclosed or gripped. In that case it can further be useful to apply a secondary backing 4 (FIG. 1) in order to prevent deformation of the primary backing 2 when the shrinking yarns shrink. The secondary backing 4 can ensure that primary backing 2 remains flat. Secondary backing 4 can be manufactured from a natural fibre material, such as jute or viscose. As stated, an additional secondary backing (not shown here), which serves mainly to protect primary backing 2 and secondary backing 4 from overheating during heating of the melting threads, can in addition also be provided. This additional backing can be manufactured from a biodegradable material so that it eventually decays once artificial turf mat 1 has been laid on a ground surface 5. The secondary backing 4 and/or the additional backing can further serve to support and fixate a filler layer (to be discussed below) when an artificial turf field 11 is installed on the basis of artificial turf mat 1.

[0044] Because the artificial turf mat 1 already has sufficient strength and stability even without coating, latex layer or secondary backing, it is also suitable to be suspended vertically, for instance in order to form a screen or partition. In that case the pile threads can be brought out of the main plane of the weave and cut on both sides, so that protruding artificial grass blades 3 are formed on both sides of backing 2. A two-sided artificial turf mat 1 is then thus in fact formed.

[0045] As can be seen in FIG. 8, it is not necessary to embody the whole backing 2 as leno weave, but it is possible to suffice with several zones 12 formed by leno weaving, whereby zones 13 with conventional weave are fixated and stabilized. In the shown example the backing is formed by strips 13 of conventional weave, which are finished on both sides with one or more pairs of warp threads 7a, 7b which are interwoven in twisted manner with weft threads 8 for the purpose of forming a local leno weave 12. These local leno weaves 12 hold in place the warp threads of the conventional weave 13 arranged therebetween. Otherwise also formed between woven strips 12, 13 in this example are strips 14, where no warp threads are present and the weft threads 8 thus lie loosely. A very open backing 2 is thus created.

[0046] The different steps of the method for manufacturing the artificial turf mat according to the invention are shown in FIG. 7. The method starts with providing warp threads 7 (step 100) and weft threads 8 (step 101). The warp threads (7) and/or the weft threads 8, or at least some of these threads, can here be embodied as melting threads. The warp and weft threads 7, 8 or some of these threads can also be embodied as shrinking yarns and/or spiral yarns.

[0047] In a subsequent step 102 the warp and weft threads 7, 8 are interwoven by making use of a leno weaving technique, wherein the warp threads 7 are intertwined. In step 103 the artificial grass blades 3 can then be connected to the woven backing 2. Since the artificial grass blades 3 are here connected to backing 2 by weaving, the steps 102 and 103 in fact coincide, as shown schematically by the dotted block 102a.

[0048] After artificial grass blades 3 have been woven into backing 2 a secondary backing 4 can optionally be connected to the leno weave backing 2 (step 104). This step is optional and could be skipped. Secondary backing 4 can be glued to primary backing 2, but it is also possible to envisage these backs 2, 4 being connected to each other by for instance double weaving or any other type of connecting technique. In addition to a secondary backing 4 which, as stated, could be manufactured from natural fibre material it is possible to arrange another additional backing, for instance a backing which functions as protective layer during heating and which can be manufactured from a biodegradable material. This backing can also be connected to the other backings in different ways.

[0049] In a subsequent step 105 the artificial turf mat 1 formed in the foregoing steps is fixated by being heated. The melting threads will here partially melt, whereby welded connections are formed with the surrounding threads, also including the pile threads forming the artificial grass blades 3. The heating can take place by radiation, for instance infrared radiation, or by guiding artificial turf mat 1 over a heated roller. The additional backing is especially important in this latter case.

[0050] Finally, artificial turf mat 1 is wound onto a roll (step 106) and is ready to be transported to a location where an artificial turf field 11 has to be installed.

[0051] The artificial turf field 11 formed using the above described artificial turf mat 1 comprises in conventional manner a ground surface 5 on which the backing 2 (in the shown example with the secondary backing 4 thereunder) is placed. The artificial grass blades 3 protrude above the backing 2 on the upper side T. The space between the artificial grass blades 3 can then be filled with a filler material or infill 6, which ensures on the one hand that the artificial grass blades are supported and in addition serves for resilience and damping. Rubber granules, cork and other materials, generally in combination with sand, are suitable as filler material 6. When backing 2 and/or artificial grass blades 3 are manufactured partially from a biodegradable material, and the artificial turf mat 1 is thus intended to form a hybrid field, the ground surface 5 can be seeded with grass seed (not shown here) prior to artificial turf mat 1 being laid. It is also possible to envisage the grass seed being sown in the layer of filler material 6 when this filler layer 6 comprises a natural material in which the grass can grow.

[0052] The invention thus provides an artificial turf mat which is lighter and cheaper than existing artificial turf mats, and is easier to handle. The artificial turf mat according to the invention further has greatly improved mechanical properties, while in addition enabling a better drainage and ventilation than existing artificial turf mats.

[0053] Although the invention is described above with reference to a number of embodiments, it will be apparent that it is not limited thereto but can be varied in many ways. The warp and weft threads 7, 8 can thus for instance have other cross-sectional forms than shown here. It is also possible to apply materials other than those stated here, both for the synthetic fibres and for the natural fibres. The scope of the invention is therefore defined solely by the following claims.