WO2007114686A1

WO2007114686A1 - Synthetic fibre for use in an artificial lawn and artificial lawn comprising such a synthetic fibre

Info

Publication number: WO2007114686A1
Application number: PCT/NL2007/000069
Authority: WO
Inventors: Marinus Hendrikus Olde Weghuis; Frederik Jan Van Der Gaag; Geurt Bastiaan Slootweg; Robert Peter Rossing
Original assignee: Ten Cate Thiolon B.V.
Priority date: 2006-04-05
Filing date: 2007-03-13
Publication date: 2007-10-11
Also published as: NL1031515C2

Abstract

The invention relates to a synthetic fibre, in particular a synthetic fibre for use in an artificial lawn. The invention also relates to an artificial lawn comprising such a synthetic fibre. According to the invention the synthetic fibre is to that end characterised in that it is, at least partially, made of a biodegradable material. By using a 'bio-based' or biodegradable material as the raw material, the fibre thus obtained can be produced in large amounts from a biological natural project, whose availability is guaranteed also in the future. In addition, the use of a biodegradable fibre in an artificial lawn has the advantage that the fibre can be broken down over time without causing environmental pollution and contamination, unlike crude oil- based synthetic fibres, which remain present permanently, also after use, and thus burden the environment to a significant degree.

Description

SYNTHETIC FIBRE FOR USE IN AN ARTIFICIAL LAWN AND ARTIFICIAL LAWN COMPRISING SUCH A SYNTHETIC FIBRE

DESCRIPTION

The invention relates to a synthetic fibre, in particular a synthetic fibre for use in an artificial lawn.

The invention also relates to an artificial lawn comprising such a synthetic fibre.

The invention further relates to a synthetic fabric at least composed of a synthetic fibre according to the invention.

So far yarns have been made of natural fibres, such as cotton, or of a synthetic material, such as nylon, polyester or polyolefins. Especially synthetic fibres, and in particular synthetic fibres intended for use in an artificial lawn, are made from crude oil products, whose long-term availability is limited.

In view of the expected dearth of raw materials for the yarns or fibres that are currently used, in particular natural yams or synthetic fibres, it is desirable that other, additional raw materials be found and tested for manufacturing in particular synthetic fibres.

According to the invention the synthetic fibre is to that end characterised in that it is, at least partially, made of a biodegradable material. By using a "bio-based" or biodegradable material as the raw material, the fibre thus obtained can be produced in large amounts from a biological natural project, whose availability is guaranteed also in the future. In addition, the use of a biodegradable fibre in an artificial lawn has the advantage that the fibre can be broken down over time without causing environmental pollution and contamination, unlike crude oil- based synthetic fibres, which remain present permanently, also after use, and thus burden the environment to a significant degree.

More specifically, in one embodiment one of the biodegradable materials comprises a starch component, wherein the synthetic fibre in particular comprises 0-50 wt.%, more particularly 0-30 wt.%, of said starch component. Starch will be available in practically unlimited amounts also in the future and can be obtained as a residual product from the agricultural industry. Starch, too, can be processed via the known thermoplastic (extrusion) processes.

More specifically, moisture-repellent additives have been added to the starch component, whilst in another embodiment moisture-attracting additives, for example glycerol, have been added to the starch component.

In both cases the starch component is made more thermoplastic, so that the synthetic fibre thus obtained can be manufactured by means of known thermoplastic (extrusion) processes, which are currently used for manufacturing crude oil-based synthetic fibres.

In another embodiment, the synthetic fibre furthermore comprises a second biodegradable material component, which influences the biodegradability of the biodegradable material over time. Said second material component may comprise an aliphatic polyester or a mixture of aliphatic polyesters, in particular polylactic acid. Aliphatic polyesters themselves are also broken down over time. Polylactic acid itself may be made from "bio-based" raw materials, for example through fermentation of agricultural waste.

According to a second embodiment, the synthetic fibre may comprise 50-100 wt.%, more particularly 70-100 wt.%, of said second material component.

Thus it is possible to realise biodegradable synthetic fibres, and more in particular biodegradable artificial lawns, which have a finite life span (composting) whose duration can be programmed, as can the rate at which the decomposition process takes place.

The invention relates to an artificial lawn built up of a substrate provided with one ore more biodegradable synthetic fibres as described above. In a specific embodiment, said substrate may be an at least partially open substrate, so that natural grass can take root in the artificial lawn as well. The combination of a lawn consisting of an artificial lawn comprising biodegradable synthetic fibres and natural grass stalks rooting through the partially open substrate provides a possibility of supporting natural lawns during the time they are rooting and growing, for example at places where the growth of natural grass must be temporarily supported, for example on slopes or sheet-piled banks. A fully degradable artificial lawn can be obtained if, according to the invention, the substrate is at least partially made of the same biodegradable material as the material that is used for the synthetic fibre according to the invention.

The invention also relates to a synthetic fabric at least composed of a synthetic fibre according to the invention, which synthetic fabric may be a geotextile, for example. By configuring the fabric as a tubular end product in the specific embodiment, it may be used in dewatering watery substances such as sludge, wherein, after the remaining sludge has dried, the tubular fabric will be broken down in time without leaving any traces in the environment. This, too, prevents environmentally foreign material being left behind, which material may subsequently have to be removed.

The invention will now be explained in more detail with reference to the drawing, in which:

Figures 1 and 2 schematically show a few embodiments of an artificial lawn, and in particular an artificial grass sports field comprising a synthetic fibre according to the invention.

In figures 1 and 2 embodiments of an artificial lawn are shown in which a synthetic fibre according to the invention can be used. In both figures the artificial lawn comprises a substrate 1 , to which several synthetic fibres 2 are attached at the locations indicated at 3, for example by tufting. According to the invention, the synthetic fibre is made of a biodegradable material, in particular a thermal plastic material, so that it can be produced by means of known production techniques, such as extrusion. The synthetic fibre thus obtained, for example by extrusion, may be attached to the substrate 1 either individually or in the form of a bundle of individual (for example twined) monofilament fibres 2a-2c.

The substrate 1 may also be made of a similar biodegradable material.

In the embodiment that is shown in figure 1 , the synthetic fibre according to the invention may be a monofilament. In this embodiment, too, several monofilaments may be twined to form a bundle, after which each bundle is attached to the substrate 1. In figure 2, the substrate 1 has an open structure and is composed of a grid of supporting yarns 1a-1 b, to which the synthetic fibres 2 are attached.

The open structure of the substrate 1 in figure 2 makes it possible to combine the artificial lawn thus realised with natural grass, which can take root in the underlying soil as a result of said open structure. By forming the synthetic fibres 2, and optionally also the substrate 1 , of the biodegradable material (as described above) a temporary support or anchoring can be realised to enable the growth of a natural grass covering, for example on slopes or sheet-piled banks. By forming the synthetic fibre according to the invention at least partially from a starch component, a biodegradable fibre is realised. More specifically, the synthetic fibre consists of 0-50 wt.%, in particular 0-30 wt.%, of said starch component.

In addition to that, the synthetic fibre may consist of a second biodegradable material component, which, according to the invention, influences the biodegradability of the biodegradable material over time. Thus a "preprogrammed" synthetic fibre can be realised, which is slowly broken down and assimilated into the environment or the soil under the influence of the weather conditions and the presence of the second material component. Natural grass taking root in the artificial lawn can grow sufficiently during that period and will take over the function of the artificial lawn as a covering entirely. This application is in particular very suitable for use at places where natural grass will not grow easily if no auxiliary measures are taken, for example on slopes, sheet-piled banks or dikes.

Furthermore, such an artificial lawn, whether or not combined with natural grass, may be used for temporarily preventing erosion (until the natural grass can provide sufficient soil stability).

As already said before, starch may be used as the first biodegradable material component, whilst the second material component that influences the biodegradability over time may be an aliphatic polyester, for example polylactic acid.

The content in wt.% of the second material component influences the degradability of the synthetic fibre (and possibly also of the substrate 1 of the artificial lawn) over time, and preferably amounts to 50-100 wt.%, in particular 70- 100 wt.%.

See the table below for a few compositions (in wt.%) of a biodegradable synthetic fibre suitable for artificial grass mats whose functionality has been proved by experiment.

To make the starch suitable for being processed into a synthetic yarn, additives that make the material thermoplastic must be added to the starch component. Said additives may be moisture-repellent additives on the one hand and moisture-attracting additives, for example glycerol, on the other hand.

Claims

1. A synthetic fibre, in particular a synthetic fibre for use in an artificial lawn, characterised in that the synthetic fibre is at least partially made of a biodegradable material.

2. A synthetic fibre according to claim 1 , characterised in that one of the biodegradable materials comprises a starch component.

3. A synthetic fibre according to claim 2, characterised in that the synthetic fibre comprises 0-50 wt.%, in particular 0-30 wt.%, of said starch component.

4. A synthetic fibre according to claim 2 or 3, characterised in that moisture-repellent additives have been added to the starch component.

5. A synthetic fibre according to claim 2 or 3, characterised in that moisture-attracting additives, for example glycerol, have been added to the starch component.

6. A synthetic fibre according to any one or more of the preceding claims, characterised in that the synthetic fibre furthermore comprises a second biodegradable material component, which influences the biodegradability of the biodegradable material over time.

7. A synthetic fibre according to claim 6, characterised in that said second material component may comprise an aliphatic polyester.

8. A synthetic fibre according to claim 7, characterised in that said aliphatic polyester comprises polylactic acid.

9. A synthetic fibre according to any one or more of the preceding claims, characterised in that the synthetic fibre comprises 50-100 wt.%, in particular 70-100 wt.%, of said second material component.

10. An artificial grass mat comprising a substrate to which one or more synthetic fibres according to any one or more of the claims 1 -9 are attached.

11. An artificial grass mat according to claim 10, characterised in that said substrate is an at least partially open substrate, so as to enable natural grass to take root therein.

12. An artificial grass mat according to claim 10 or 11 , characterised in that the substrate is at least partially made of the same biodegradable material as the material that is used for the synthetic fibre according to the invention.

13. A synthetic fabric at least composed of a synthetic fibre according to any one or more of the claims 1 -9.

14. A synthetic fibre according to claim 13, characterised in that the fabric is configured as a tubular end product.