AU2010212281A1 - Artificial grass - Google Patents

Description

1 ARTIFICIAL GRASS FIELD OF THE INVENTION This invention relates to artificial grass which simulates the look of natural grass. 5 BACKGROUND TO THE INVENTION Artificial grass, also referred to as artificial turf or synthetic turf, is a man made surface usually manufactured from synthetic textile. It is suitable for many applications and is often used in arenas and fields for sports that were originally or are normally played on grass. However, it is now being used on residential 10 lawns and in commercial applications as well. Artificial grass has many advantages over conventional natural grass. In particular, artificial grass can be a better solution when the environment is particularly hostile to natural grass, for example an arid environment or one where there is little natural light so the natural grass does not grow. 15 Artificial grass can withstand significantly more use than natural grass and can therefore be used much more frequently. Artificial grass also requires much less maintenance than conventional grass and requires no irrigation. Therefore it is convenient for situations where maintenance of lawns is not practical. It is also a practical solution for those people who find the upkeep of lawns too much hard 20 work. Most things in nature have some imperfections. There are many different types of artificial grasses, however, none of them look like natural grass. Most of them look too perfect which makes them seem artificial and does not give the appearance of natural living grass. 25 It is therefore an object of the present invention to provide an artificial grass which has a more natural appearance. Any discussion of documents, devices, acts or knowledge in this specification is included to explain the context of the invention. It should not be taken as an admission that any of the material formed part of the prior art base or 30 the common general knowledge in the relevant art in Australia or any other country on or before the priority date of the claims herein.

2 SUMMARY OF THE INVENTION The present invention provides a mat of artificial grass including a plurality of main tufts of fibres secured to a substrate. Each of the main tufts include a plurality of base coloured fibres and at least one fibre which is dissimilar in colour 5 to the base coloured fibres. The fibres in each main tuft are substantially the same length, such that when installed the mat of artificial grass gives the appearance of natural grass. In a preferred embodiment of the present invention the base coloured fibres are coloured one or more shades of green and the at least one dissimilar 10 coloured fibre is beige, faun, tan or brown in colour to simulate a dried or dead blade of grass. It is desirable that the proportion of base coloured fibres to dissimilar coloured fibres in each main tuft is 6:1. It is also desirable that the main tufts of fibres have a pile height in the 15 range of 30-50mm, preferably 40mm, a stitch rate in the range of 12-20 stitches/1 0cm, preferably 17 stiches/1Ocm, and a row gauge in the range of 3.175 - 25.4mm (1/8" - 1"), preferably 9.525mm (3/8 "). In another embodiment of the present invention the mat of artificial grass further includes a plurality of secondary tufts of fibres and/or a plurality of root 20 zone tufts of fibres, wherein the fibres in the secondary tufts are substantially the same height as the fibres in the main tufts and the fibres in the root-zone tufts are shorter than the fibres in the main tufts. BRIEF DESCRIPTION OF THE DRAWINGS It will be convenient to further describe the invention with respect to the 25 accompanying drawings which illustrate preferred embodiments thereof. Other embodiments of the invention are possible, and consequently, the particularity of the accompanying drawings is not to be understood as superseding the generality of the preceding description of the invention. Figure 1 shows a cross section of a mat of artificial grass according to an 30 embodiment of the present invention. Figure 2 shows a cross section of a mat of artificial grass according to an embodiment of the present invention after it has been installed.

3 Figure 3 shows a cross section of a mat of artificial grass according to another embodiment of the present invention. DESCRIPTION OF PREFERRED EMBODIMENT Referring to the drawings, Figure 1 shows a mat of artificial grass 1 which 5 includes a plurality of tufts of fibres secured to a substrate 2. The fibres simulate blades of grass. Thus each tuft simulates a plurality of blades of grass. The tufts are preferably arranged in rows and threaded through or stitched into the substrate in a conventional manner, but can also be secured by glue or otherwise secured to the substrate. 10 The mat of artificial grass 1 includes a number of main tufts 3, each main tuft being made up of a number of base coloured fibres 4 and at least one dissimilar coloured fibre 5. The base coloured fibres 4 and the dissimilar coloured fibre 5 in each main tuft 3 are substantially the same height, and when installed the mat of artificial grass 1 containing the main tufts 3 gives the appearance of 15 natural looking grass because the blades of grass are not all the same or a similar colour. So that the tufts of artificial grass adequately simulate natural growing grass, the base coloured fibres 4 are preferably coloured in a plurality of green colours and more preferably two different green colours. The two different green 20 colours are preferably defined by RAL 6010 Grass Green and RAL 6011 Reseda Green. The dissimilar coloured fibre 5 is preferably a contrasting colour to the colour of the base coloured fibres 4. It may be coloured beige, faun, tan, brown or the like to simulate a dried or dead blade of grass. Preferably the dissimilar coloured fibre is defined by the colour RAL 1001 Beige. 25 In order to simulate natural growing grass, the ratio of base coloured fibres 4 to dissimilar coloured fibres 5 in the main tufts is 6:1. The preferred ratio of base coloured fibres 4 to dissimilar coloured fibres 5 in a main tuft 3 is six base coloured fibres for every dissimilar coloured fibre, and more preferably there are six base coloured fibres and one dissimilar coloured fibre in each main tuft. 30 A mat of artificial grass can be defined by particular parameters. In particular the parameters of row gauge (the distance between the rows), the stitch rate (the number of stiches per unit length of the mat), the pile height (the height of the fibres or tufts of fibres) and the pile weight are the most important.

4 The main tufts of fibres in mats of artificial grass manufactured in accordance with preferred embodiments of the present invention preferably have a pile height in the range of 30-50mm, more preferably 40mm, a stitch rate in the range of 12-20 stitches/1 0cm, preferably 17 stiches/1Ocm, and a row gauge in the 5 range of 3.175 - 25.4mm (1/8" - 1"), preferably 9.525mm (3/8"). In addition, the pile weight is preferably 1470g/m 2 assuming the optimum pile height, stich rate and row gauge (as detailed above) are used. The mat of artificial grass is installed in the conventional way and is usually installed as shown in Figure 2. A layer of compacted crushed rock or soil 7 10 usually 50-100mm deep is placed on top of a natural base layer 6 such as hard soil or concrete. The compacted crushed rock or soil layer 7 is used to make a level surface upon which the artificial grass can be installed. It is necessary to install the artificial grass on this type of layer to allow for drainage of water, such as when it rains, so that the artificial grass does not retain excess water or 15 moisture, thereby giving it a more natural appearance. The mat of artificial grass 1 and main tufts 3 are infilled to approximately 25mm with granulated rubber 9 to provide some support for the artificial grass. Alternatively, the infill layer 8 can be made up of a layer of sand (not shown) as well as a layer of granulated rubber. Mats of artificial grass may be considered to have two zones. The root 20 zone 10 is the area directly above the substrate of the mat of artificial grass 1. That is, the zone just above the ground. The root zone 10 could also be referred to as a sub pile yarn layer or a thatch layer. The infilled layer 8 is within the root zone 10. Above the root-zone 10 is the cut-zone 11. The cut-zone 11 is the area 25 where the tallest blades of grass or fibres have a free end. That is, the zone at which the blades of grass would normally be cut. The fibres of the main tufts in Figure 1 extend into the cut-zone. A mat of artificial grass according to another embodiment of the present invention may also include other tufts of artificial grass fibres. As shown in Figure 30 3, such a mat of artificial grass includes a plurality of main tufts 3 and may further include a plurality of root-zone tufts of fibres 12. The main tufts 3 are made up of cut-zone fibres (fibres which extend into the cut-zone 11), they are the longer fibres. Root zone fibres 12 are shorter fibres 5 which extend to the root zone 10 but do not extend into the cut zone 11. That is, the root-zone fibres are shorter than the fibres in the main tufts 3. Alternatively, a mat of artificial grass includes a plurality of main tufts and may further include a plurality of secondary tufts of fibres (not shown). The fibres 5 in the secondary tufts are substantially the same height as the fibres in the main tufts (ie the fibres of the secondary tufts extend into the cut-zone). Furthermore, a mat of artificial grass (not shown) including a plurality of main tufts may further include a plurality of secondary tufts of fibres and a plurality of root-zone tufts of fibres. 10 The following are examples which describe various configurations of tufts of fibres which can make up the mat of artificial grass: Example I The mat of artificial grass as shown in Figure 1 is made up of continuous rows of main tufts. Therefore all the tufts in this example and figure extend into 15 the cut zone and have a plurality of base coloured fibres which are preferably two different shades of green and at least one dissimilar coloured fibre which is contrasting in colour and preferably beige, faun or brown in colour. Example 2 Alternatively, the mat of artificial grass could include a row of main tufts 20 and a row of secondary tufts. This arrangement may be referred to as A/B stitching; that is, one row is the "A" row, in this example the main tuft row, and the other row is the "B" row, in this example the secondary tuft row. The main tufts have a plurality of base coloured fibres and at least one dissimilar coloured fibre. All the fibres of the secondary tufts may be base coloured fibres and are the 25 same or similar height to the main tufts, that is, they extend to the cut-zone. Example 3 Figure 3 shows a mat of artificial grass with a plurality of main tufts 3, containing base coloured fibres 4 and at least one dissimilar coloured fibre 5, and a plurality of root-zone tufts 12. The tufts are configured such that there are 30 alternating rows of main tufts 3 and root-zone tufts 12. Example 4 Described in Example 3 and shown in Figure 3 is a mat of artificial grass which has a row of main tufts and a row of root-zone tufts. Alternatively, every 6 second (or third, fourth etc.) row of main tufts could be replaced with a row of secondary tufts. Therefore, a mat of artificial grass (viewed in cross-section and described from left to right) may have a pattern of tufts as follows: a row of main tufts, a row of root-zone tufts, a row of secondary tufts, and then another row of 5 root-zone tufts. This pattern would then repeat. The patterns for each example are summarised below in Table 1. In each of the tuft type columns labelled "Main", "Secondary" and "Root Zone" in Table 1, a "Y" indicates that that particular tuft type is present in an example and an "N" indicates that a particular tuft type is not present in an 10 example. The letters "M", "S" and "R" in the column labelled Tuft Configuration represent Main tufts, Secondary tufts and Root-zone tufts, respectively. The position of those letters in the Tuft Configuration column details the configuration or pattern of those tufts present in a cross section of the mat. Referring to Table 1, the mat of artificial grass described in Example 1 is 15 made up of only main tufts. Therefore, the tuft configuration would be continuous rows of main tufts of fibres, denoted by "MMMMMMM" in the Tuft Configuration column. The mat of artificial grass in Example 4 has main tufts, secondary tufts and root-zone tufts. These tufts are arranged so that the mat in Example 4 has a row 20 of main tufts, next to which is a row of root-zone tufts, which is next to a row of secondary tufts, which is then next to another row of root-zone tufts. This is denoted in the Tuft Configuration column as "MRSR". Two iterations of this pattern are indicated as "MRSRMRSR". 25 Table 1 - combinations of tufts in the mat of artificial grass Tuft type Main (M) Secondary (S) Root Cross-Section (cut zone) (cut-zone) Zone (R) Tuft Configuration Example 1 Y N N MMMMMMM Example 2 Y Y N MSMSMSMS Example 3 Y N Y MRMRMRMR Example 4 Y Y Y MRSRMRSR 7 In each of the above examples, the main tufts and secondary tufts are preferably bundled tufts (wherein all the fibres in the tuft are brought together, ie bundled together) and both tuft types extend to the cut zone. The fibres which extend to the cut-zone may also have a stiff central spine which makes them look 5 more like natural grass as well as assisting the fibres to remain upright with little assistance from the infill layer. The fibres in each of the root zone tufts (which are shorter than the main and secondary tufts and which only extend to the root-zone) may be fribulated fibres (that is, the fibres may be "wavy" or of matted appearance forming a mesh 10 like or thatch-like tuft) or twisted monofibres. In addition, the fibres in the root zone tufts are preferably one or more shades of green. Alternatively the root zone tufts could be made up of green coloured fibres and one or more dissimilar coloured fibres. Yarn used for the fibres of the mat of artificial grass can be manufactured 15 in the conventional way. The yarn used for the fibres in the mat of artificial grass has a PE/PE composition and is UV resistant, made of polyethylene and is metal free. The Dtex of the yarn is preferably 9700 and the blades of artificial grass used in the main or secondary tufts can be of a monofilament straight structure, whereas the blades of grass in the root-zone may be either monofilament straight 20 or KDK curled structure. The substrate used for the mat of artificial grass is made in a conventional way and has a primary and a secondary backing. The primary backing is preferably made up of three layers being PP / PP / non-woven PET and the secondary backing is preferably a hybrid emulsion. 25 The construction and manufacture of the mats of artificial grass is performed by conventional methods and need not be described in detail. When manufactured, the mat of artificial grass conveniently has a width of 3.68m a length of 20m and weighs 2385g/m 2 (assuming the optimum pile height, stitch rate and row gauge is used). Once the mat of artificial grass is manufactured it is 30 formed into a roll for easy installation, the weight of each roll is 175kg. The mat of artificial grass can be used in various applications such as: residential and commercial landscaping, park and play areas to allow for soft-fall, school multi-purpose activity areas and, recreational and training areas.

8 Variations can be made to the above-described arrangements without departing of the spirit or scope of the invention as described herein or as claimed in the appended claims. 5

Claims (6)

1. A mat of artificial grass including a plurality of main tufts of fibres secured to a substrate, wherein each main tuft includes a plurality of base coloured fibres and at least one fibre which is dissimilar in colour to the base coloured fibres, the 5 fibres in each main tuft are substantially the same length, such that when installed the mat of artificial grass gives the appearance of natural grass.

2. A mat of artificial grass according to claim 1 wherein the base coloured fibres are coloured one or more shades of green and the at least one dissimilar coloured fibre is beige, faun, tan or brown in colour to simulate a dried or dead 10 blade of grass.

3. A mat of artificial grass according to claim 1 or claim 2 wherein the proportion of base coloured fibres to dissimilar coloured fibres is 6:1.

4. A mat of artificial grass according to any one of the preceding claims wherein the tufts of fibres have a pile height in the range of 30-50mm, preferably 15 40mm, a stitch rate in the range of 12-20 stitches/10cm, preferably 17 stiches/10cm, and a row gauge in the range of 3.175 - 25.4mm (1/8" - 1"), preferably 9.525mm (3/8 ").

5. A mat of artificial grass according to any one of the preceding claims further including a plurality of secondary tufts of fibres and/or a plurality of root 20 zone tufts of fibres, wherein the fibres in the secondary tufts are substantially the same height as the fibres in the main tufts and the fibres in the root-zone tufts are shorter than the fibres in the main tufts. 10

6. A mat of artificial grass substantially as hereinbefore described with reference to the accompanying drawings and examples. BAREFOOT GRASS PTY LTD AND ADVANCED POLYMER TECHNOLOGY AUSTRALASIA PTY LIMITED WATERMARK PATENT & TRADE MARK ATTORNEYS P32221AUP1