EP1857593A1

EP1857593A1 - Artificial grass system, artificial grass mat and method of preparing an artificial grass mat

Info

Publication number: EP1857593A1
Application number: EP07108339A
Authority: EP
Inventors: Abraham Wilhelmus Brandon
Original assignee: Inventress BV
Current assignee: DOMO Zele NV
Priority date: 2006-05-19
Filing date: 2007-05-16
Publication date: 2007-11-21
Anticipated expiration: 2027-05-16
Also published as: PL1857593T3; ES2376689T3; PT1857593E; ATE530709T1; DK1857593T3; EP1857593B1; NL1031837C2

Abstract

An artificial grass system (1) comprises artificial grass elements (4), which protrude on a main surface (7) and are distributed thereover. The artificial grass elements (4) comprise at least one capillary channel (5) which is in open communication on a first side with a liquid delivery system (2, 3) located under the main surface (7) and debouches above the main surface (7) on an opposite side. The artificial grass system (1) comprises anti-microbiological means (12) which prevent the growth of micro-organisms in the capillary channels (5) of the artificial grass elements (4). An artificial grass system (1) is thus provided in which the growth of micro-organisms is avoided, or at least inhibited to a significant extent. The capillary channels (5) hereby remain open during operation so that they continue to carry sufficient liquid for the artificial grass system (1) to remain sufficiently moist on the surface (7).

Description

The present invention relates to an artificial grass system comprising artificial grass elements, which protrude on a main surface and are distributed thereover, and a liquid delivery system under the main surface, wherein the artificial grass elements comprise at least one capillary channel which is in open communication with the liquid delivery system on a first side and debouches above the main surface on an opposite side. The invention also relates to an artificial grass mat and to a method for preparing an artificial grass mat, wherein artificial grass elements are formed from a hollow artificial grass fibre and are connected to a backing layer.
An artificial grass system of the type stated in the preamble is known from the international patent application W02005/003463 . The artificial grass system described therein makes use of capillary artificial grass elements protruding on a main surface. Capillary channels in the artificial grass elements lie on a first side in a liquid delivery system in the form of a liquid-containing substrate and debouch on an opposite side on the surface of the system. The capillary action of the channels ensures that the liquid is carried upward in the channels and is released on the surface. This known artificial grass system thus provides a continuous, autonomous, controlled irrigation of the surface.
Although the known artificial grass system provides a significant improvement for the laying and acceptance of artificial grass fields in general and for sporting purposes in particular, the capillary channels of the grass elements could in time become clogged with micro-organisms, which can thrive in a mainly moist environment. This impedes the liquid delivery via these channels and may eventually result in an insufficient moistness of the artificial grass system as a whole, whereby injuries resulting from a fall or sliding tackle cannot be precluded. In addition, the growth of micro-organisms can mar the appearance of the artificial grass system.
The present invention has for its object, among others, to provide an artificial grass system of the type stated in the preamble which obviates these drawbacks to at least a significant extent.
In order to achieve the intended object, an artificial grass system of the type stated in the preamble has the feature according to the invention that the artificial grass system comprises anti-microbiological means which prevent the growth of micro-organisms in the capillary channels of the artificial grass elements. Because the growth of micro-organisms is avoided, or at least inhibited to a significant extent, by the anti-microbiological means, the capillary channels remain open during operation so that they continue to carry sufficient liquid for the artificial grass system to remain sufficiently moist on the surface. The artificial grass system according to the present invention thus provides for a reliable and sustained irrigation on the surface, which enhances the quality and lifespan of the artificial grass.
A preferred embodiment of the artificial grass system according to the invention has the feature that the liquid delivery system comprises a buffer layer and a delivery layer which are mutually stacked, wherein the buffer layer is able and adapted to at least temporarily contain and store a liquid and the delivery layer is able and adapted to relinquish the liquid obtained from the buffer layer to the capillary channels. The buffer layer ensures that a liquid fed to the artificial grass system, such as rainwater or irrigating water, does not flow directly into a ground layer but is taken up and held in the buffer layer. Because the liquid thus remains in the liquid delivery system for a long time, and is therein always available to the liquid delivery layer, the delivery layer can provide the capillary channels with liquid and moisten the main surface for a long period of time. The main surface of the artificial grass system thus remains moist continuously.
A further preferred embodiment of the artificial grass system according to the invention has the feature that the buffer layer lies between the delivery layer and the main surface. The artificial grass elements herein protrude through the buffer layer and are in open communication with the delivery layer. The buffer layer thus provides for an improved anchoring of the artificial grass elements. An individual support layer on which to anchor the artificial grass elements can hereby be omitted. Under the influence of the force of gravity, liquid thus also sinks out of the buffer layer and into the delivery layer and rises therefrom in the capillary channels.
A further preferred embodiment of the artificial grass system according to the invention has the feature that the liquid delivery system comprises the anti-microbiological means and that the anti-microbiological means are at least partly soluble in the liquid. The anti-microbiological means are thus able to dissolve in the liquid during operation and can thereby be entrained through the whole system. The liquid thus provided with anti-microbiological means prevents, or at least inhibits, the growth of micro-organisms in all parts of the system which are accessible by the liquid. These are precisely the parts in which, because of the moist environment, growth of micro-organisms is most likely.
A further preferred embodiment of the artificial grass system has the feature according to the invention that the capillary channels of the grass elements comprise the anti-microbiological means. Possible growth of micro-organisms in the capillary parts of the artificial grass system is thus nipped in the bud.
A further preferred embodiment of the artificial grass system according to the invention has the feature that the anti-microbiological means comprise an electrical conductor. In the presence of a liquid, the electrical conductor will be surrounded with an electric potential field which repels micro-organisms. Micro-organisms are thus effectively combatted.
A further preferred embodiment of the artificial grass system according to the invention has the feature that an electrical conductor is at least practically arranged in each case in the at least one capillary channel of the artificial grass elements. The electrical conductors of the individual artificial grass elements together form an electrically conductive surface which can serve as conductor of (static) electricity. Static electricity could otherwise develop on the main surface during use of an artificial grass system and could give users an irritating or even painful sensation upon discharge. This can thus be avoided due to the electrical conductors in the artificial grass elements.
A particular embodiment of the artificial grass system according to the invention has the feature here that the electrical conductor is arranged in the form of at least one wire in the at least one capillary channel. A further particular embodiment of the artificial grass system according to the invention has the feature that the electrical conductor is applied in the form of a coating to an inner wall of the at least one capillary channel. Such a coating or wire can be arranged in the capillary channels in relatively simple manner, for instance by means of co-extrusion.
A further preferred embodiment of the artificial grass system according to the invention has the feature that the anti-microbiological means comprise a metal, in particular at least one from a group of copper and silver. Metals, and in particular copper and silver, are good conductors which generate a potential field in a liquid. In addition, copper and silver oxidize partially in water into copper oxide and silver oxide respectively, which are toxic to micro-organisms. Metals, and in particular copper and silver, are therefore particularly good anti-microbiological means for preventing the growth of micro-organisms.
A further preferred embodiment of the artificial grass system according to the invention has the feature that at least a part of the artificial grass elements comprise artificial blades of grass. Such blades give the artificial grass system a more natural appearance, which enhances the aesthetic properties of the system. With a view hereto, a further preferred embodiment of the artificial grass system according to the invention has the feature that at least some of the artificial grass elements are alternated with natural grass elements.
The artificial grass system according to the invention per se can be wholly assembled on site, in the form as indicated above. More practical however is a particular preferred embodiment of the artificial grass system according to the invention, which is characterized in that the artificial grass elements extend from an artificial grass mat comprising a backing layer to which the artificial grass elements are durably connected, and that the capillary channels of the artificial grass elements open on either side of the artificial grass mat. In this case the artificial grass mat can be prepared in the factory and arranged on site as more or less finished product. The delivery time of an artificial grass system can thus be limited to a significant extent.
The present invention therefore also relates to an artificial grass mat as can be applied in the artificial grass system according to the invention. According to the invention such an artificial grass mat has the feature that the artificial grass elements comprise a first and a second free outer end on either side of the mat, that the artificial grass elements protrude through the backing layer between the first and the second outer end, and that the artificial grass elements are adhered to the backing layer between the first and the second outer end. Such an artificial grass mat can be rolled out easily with an underside over the liquid delivery system, or at least arranged thereon, wherein the capillary channels opening on the underside can take up liquid and relinquish the liquid to the surface at the second outer end.
A particular embodiment of the artificial grass mat according to the invention has the feature that the artificial grass elements are mutually adhered by means of an adhesive or melted connection. It has been found in practice that such an adhesive or melt connection can be applied reliably and durably on industrial scale.
A method for preparing an artificial grass mat of the type stated in the preamble has the feature according to the invention that the artificial grass fibre is introduced into a shaft of a hollow needle, the needle with the fibre is inserted through the backing layer, the needle is pulled back over the artificial grass fibre, the artificial grass fibre is adhered to the backing layer and the artificial grass element is separated at a predetermined length from the fibre. An artificial grass mat is thus obtained with hollow artificial grass fibre parts as artificial grass elements with a longitudinal cavity which opens fully on either side in order to obtain the greatest possible liquid-transporting capacity.
A first particular embodiment of the method is characterized according to the invention in that the artificial grass fibre is adhered to the backing layer by means of high-frequency welding. Such a method makes the artificial grass elements fuse reliably and durably with the backing layer. A second particular embodiment of the method for preparing an artificial grass mat is characterized according to the invention in that the artificial grass fibre is adhered to the backing layer by means of chemical adhesion. By applying a chemical adhesive, such as in particular a UV-activated adhesive, a number of artificial grass elements can be inserted through the backing layer and provided with the correct adhesive before being cured in a collective processing step. This significantly enhances the process of preparing the artificial grass mat.
The invention will now be further elucidated on the basis of a number of exemplary embodiments and an associated drawing. In the drawing:

Figure 1: shows a perspective view of an exemplary embodiment of an artificial grass system according to the invention;
Figure 2: shows a cross-section of a first exemplary embodiment of an artificial grass element according to the invention;
Figure 3: shows a cross-section of a second exemplary embodiment of an artificial grass element according to the invention; and
Figure 4: shows a perspective view of an exemplary embodiment of an artificial grass mat according to the invention.

The figures are otherwise purely schematic and not drawn to scale. Some dimensions in particular may be exaggerated to a greater or lesser extent for the sake of clarity.
Corresponding parts are designated as far as possible in the figures with the same reference numeral.
An exemplary embodiment of an artificial grass system according to the invention is shown in perspective view in figure 1. Artificial grass system 1 comprises a delivery layer 2 of felt and a buffer layer 3 of rubber lying thereon. Delivery layer 2 and buffer layer 3 together form a liquid delivery system which is placed on top of a ground layer 10. A liquid such as for instance water can be fed to the liquid delivery system in various ways, such as for instance by means of spraying, but also by natural precipitation. Buffer layer 3 stores the liquid and relinquishes at least a part thereof to delivery layer 2 when this layer dries out. Rubber buffer layer 3 moreover has a certain elasticity whereby it provides a shock-absorbing action. The artificial grass system will hereby feel more comfortable and sportspeople will suffer significantly fewer injuries or wounds.
Delivery layer 2 relinquishes the liquid received from buffer layer 3 to capillary channels 5 which extend through artificial grass elements 4 up to an opening debouching above a main surface 7 of artificial grass system 1. A liquid is thus delivered continuously to main surface 7 due to the capillary action of channels 5, whereby the artificial grass system remains moist. In order to give the artificial grass system 1 a more natural appearance, artificial grass elements 4 can comprise artificial blades of grass 6 on the side located above main surface 7.
The capillary action of channels 5 can be supplemented by incorporating therein a liquid-absorbing material 11, for instance cotton of felt. The flow of the liquid from delivery layer 2 to main surface 7 is thus enhanced, whereby this surface remains continually moist.
In order to be able to guarantee the flow of liquid to the main surface for a considerably longer time, the liquid delivery layer comprises anti-microbiological means 12 in the form of copper particles. Part of the copper will oxidize into copper oxide and dissolve in the liquid. The copper oxide is toxic to micro-organisms, whereby the growth of micro-organisms in artificial grass system 1 will be inhibited. The artificial grass system 1 hereby remains free of micro-organisms to a significant extent. The liquid present in the system can hereby continue to flow unimpeded from delivery layer 2 to the opening (not shown) debouching above main surface 7 and there be delivered to main surface 7.
The present invention thus provides an artificial grass system in which a main surface is moistened in continuous and reliable manner, whereby injuries or wounds resulting from a fall or sliding tackle are prevented to a significant extent during participation in sports.
As shown further in figure 2 in a cross-section of a first exemplary embodiment of an artificial grass element according to the invention, the artificial grass element 4 comprises a capillary channel 5 in which the anti-microbiological means are incorporated in the form of an electrically conductive wire 8. In the presence of a liquid the electrically conductive wire 8 will be surrounded by an electric potential field which repels micro-organisms. The growth of micro-organisms in capillary channels 5 is hereby prevented, whereby capillary channels 5 will remain open for a long period of time. Part of the copper will also oxidize into copper oxide, whereby the growth of micro-organisms will be inhibited even further.
A liquid-absorbing material 11 in the form of a cotton wad is situated round the electrically conductive wire 8 in capillary channel 5 and supplements the capillary action thereof. The electrically conductive wire 8 further provides for conduction of static electricity, whereby users of an artificial grass field with the artificial grass system 1 of the invention do not experience any irritating or painful sensation as a result of the discharge of accumulated static charge. As further elaborated in figure 3 in a cross-section of a second exemplary embodiment of an artificial grass element according to the invention, the anti-microbiological means can also be applied in capillary channels 5 in the form of a coating 9 on an inner side of artificial grass elements 4. Such a coating 9 keeps capillary channel 5 free of micro-organisms and can be arranged in capillary channel 5 in relatively simple manner.
As further shown in figure 4 in a perspective view of an exemplary embodiment of an artificial grass mat according to the invention, artificial grass mat 20 comprises artificial grass elements 4 which are adhered to a backing layer of polypropylene (not shown). The adhesion can be realized by means of high-frequency welding or by chemical adhesion. Artificial grass mat 20 lies on a liquid delivery system which comprises both a buffer layer 3 and a delivery layer 2. Delivery layer 2 here lies on a ground layer 10. Artificial grass elements 4 comprise a capillary channel 5 which on a first side is in open communication with delivery layer 2 and debouches on an opposite side above a main surface (not shown).
A liquid 22 can thus flow from delivery layer 2 through capillary channels 5 and be delivered to the main surface at the outlet. The liquid 22 is delivered to the main surface by for instance bending of capillary channels 5, for instance as a result of being walked over. Some of the liquid 22 will also evaporate under the influence of for instance the sun or another heat source. Users of the artificial grass mat will perceive such an evaporation as cooling, which has an advantageous psychological effect.
Because a liquid is delivered continuously from the liquid delivery layer, through the capillary channels to the main surface, the artificial grass mat remains moist to a significant degree during use. Anti-microbiological means 12 in the form of metal particles are in delivery layer 2 or buffer layer 3 to prevent the growth of micro-organisms. Capillary channels 5 are hereby prevented to a significant extent from becoming clogged with micro-organisms.
Artificial grass elements 4 can comprise artificial blades of grass 6 in order to give the mat a more natural appearance. For an additionally natural appearance the artificial grass mat 20 can be provided with natural grass elements 21.
Although the invention has been further elucidated on the basis of several exemplary embodiments, it will be apparent that the invention is by no means limited thereto. On the contrary, many variations and embodiments are still possible for the person with ordinary skill in the art within the scope of the invention. The artificial grass can thus be applied on practically any substrate and for many purposes, such as a replacement for natural grass in the construction of landscapes and dikes. It is also highly suitable for playing ball games and other types of sport, and can be applied here both outdoors and indoors. The length of the artificial grass elements, and in particular the artificial blades of grass, can also be varied. Short elements herein provide a 'fast' field, while longer elements have a slowing effect.

Claims

Artificial grass system comprising artificial grass elements, which protrude on a main surface and are distributed thereover, and a liquid delivery system under the main surface, wherein the artificial grass elements comprise at least one capillary channel which is in open communication with the liquid delivery system on a first side and debouches above the main surface on an opposite side, characterized in that the artificial grass system comprises anti-microbiological means which prevent the growth of micro-organisms in the capillary channels of the artificial grass elements.
Artificial grass system as claimed in claim 1, characterized in that the liquid delivery system comprises a buffer layer and a delivery layer which are mutually stacked, wherein the buffer layer is able and adapted to at least temporarily contain and store a liquid and the delivery layer is able and adapted to relinquish the liquid obtained from the buffer layer to the capillary channels.
Artificial grass system as claimed in claim 2, characterized in that the buffer layer lies between the delivery layer and the main surface.
Artificial grass system as claimed in one or more of the foregoing claims, characterized in that the liquid delivery system comprises the anti-microbiological means and that the anti-microbiological means are at least partly soluble in the liquid.
Artificial grass system as claimed in one or more of the foregoing claims, characterized in that the capillary channels of the grass elements comprise the anti-microbiological means.
Artificial grass system as claimed in claim 5, characterized in that the anti-microbiological means comprise an electrical conductor, and that the electrical conductor is arranged in the at least one capillary channel of the artificial grass elements.
Artificial grass system as claimed in claim 6, characterized in that the electrical conductor comprises at least one electrically conductive wire.
Artificial grass system as claimed in claim 6 or 7, characterized in that the electrical conductor comprises an electrically conductive coating on an inner wall of the at least one capillary channel.
Artificial grass system as claimed in one or more of the foregoing claims, characterized in that the anti-microbiological means comprise a metal, in particular at least one from a group of copper and silver.
Artificial grass system as claimed in one or more of the foregoing claims, characterized in that at least some of the artificial grass elements comprise artificial blades of grass.
Artificial grass system as claimed in one or more of the foregoing claims, characterized in that at least some of the artificial grass elements are alternated with natural grass elements.
Artificial grass system as claimed in one or more of the foregoing claims, characterized in that the artificial grass elements extend from an artificial grass mat comprising a backing layer to which the artificial grass elements are durably connected, and that the capillary channels of the artificial grass elements open on either side of the artificial grass mat.
Artificial grass mat as applicable in the artificial grass system as claimed in claim 12, characterized in that the artificial grass elements comprise a first and a second free outer end on either side of the mat, that the artificial grass elements protrude through the backing layer between the first and the second outer end, and that the artificial grass elements are adhered to the backing layer between the first and the second outer end.
Artificial grass mat as claimed in claim 13, characterized in that the artificial grass elements are mutually adhered by means of an adhesive or melted connection.
Method for preparing the artificial grass mat, wherein artificial grass elements are formed from a hollow artificial grass fibre and connected to a backing layer, characterized in that the artificial grass fibre is introduced into a shaft of a hollow needle, the needle with the fibre is inserted through the backing layer, the needle is pulled back over the artificial grass fibre, the artificial grass fibre is adhered to the backing layer and the artificial grass element is separated at a predetermined length from the fibre.
Method for preparing the artificial grass mat as claimed in claim 15, characterized in that the artificial grass fibre is fused to the backing layer by means of high-frequency welding.
Method for preparing the artificial grass mat as claimed in claim 15, characterized in that the artificial grass fibre is adhered to the backing layer by means of a suitable adhesive.