GB2405569A

GB2405569A - Soiless turf on fibrous material

Info

Publication number: GB2405569A
Application number: GB0320574A
Authority: GB
Inventors: Stephen Charles Rudstone Fell
Original assignee: LINDUM SEEDED TURF Ltd
Current assignee: LINDUM SEEDED TURF Ltd
Priority date: 2003-09-03
Filing date: 2003-09-03
Publication date: 2005-03-09
Anticipated expiration: 2023-09-03
Also published as: GB0320574D0; GB2405569B

Abstract

A turf product comprising a first layer 1 of soilless turf, the roots 4 thereof having been grown into a second layer 2 which comprises a sheet of fibrous water absorbent material; a method of fabrication thereof comprising preparing a base layer 2 comprising a sheet of fibrous water absorbent material, preparing a soilless turf layer, and growing the soilless turf layer onto the base layer until the roots thereof penetrate into the base layer and a method of temporary or permanent application thereof to any surface which is required to be covered. Fibrous sheet material fibres include cotton, polyester, jute, hair, polypropylene, wool, soft fabric waste and acrylic and combinations thereof. The sheet material may comprise at least 75% cellulosic fibres. The product may have a water impermeable sheet 3 deployed between the turf product and the substrate in use. The sheet material may comprise a felt mat.

Description

TURF PRODUCT

The invention relates to a turf product suitable for being laid as a surface covering incorporating living grass, to a method of manufacture of such a turf product, and to a method of providing such a covering for a surface. The invention relates both to a turf product suitable as a temporary removable covering for a surface and to a turf product suitable for permanent surfing of an area for landscaping. The invention in particular relates to a turf product which is susceptible to being laid on any surface and not merely on the surface of a substrate which constitutes a suitable growing medium for the turf.

Turf products are well known. At their simplest, turf products comprise areas of grass removed entire with the root structure intact and with the soil or other growing substrate retained within the root structure to give support. The turf product is intended to be laid on the surface of a substrate consisting of a suitable growing medium, for example on a soil surface, in the desired growing position where it will in due course establish itself by growing into the substrate.

Various refinements of this basic product are known. For example, it is known to supply washed turf products, comprising a layer of leaf and root structure from which the soil or other growing medium has been removed.

Such a washed product can be easier to deal with and transport and easier to lay in some situations. However, the absence of the moisture providing soil layer at the roots can mean that it requires more care and attention before it is laid and as it establishes. In particular, such a product can require much more care than a soiled turf product as it establishes when it has been laid on dry or otherwise difficult surfaces and/or in hot and dry conditions if excessive drying out or shrinkage is to be avoided.

It is also known to incorporate reinforcement into turf products, whether or not the soil has been first removed, in the form of structural synthetic meshing material and the like to give increased strength to the basic turf layer. Such reinforcements are primarily intended where it is desired to establish the turf on a more difficult growing substrate, such as for example on a sloping surface. As the turf establishes on the sloping surface, the synthetic mesh material assists in maintaining the structural integrity. Again, with all of these products, it is the ultimate desire that the turf product should become lO established permanently growing on the substrate.

However, the invention relates to the provision of a deployable grass covering which is suitable for laying on any substrate, rather than merely one intended to establish itself by growth on a suitable growth substrate. Indeed, in one embodiment it is envisaged that the invention will serve as a temporary deployable grass covering suitable for any surface. This presents a number of different problems. In particular, there is no requirement, nor even desire, for the roots of the turf product to grow through into the substrate. The turf product itself needs to provide a water supply and reservoir for the roots since the substrate is not intended to provide this. It is the intention that the turf product should be simply deployed at any angle, and be suitable for easy removal to be taken away and subsequently reused at another location.

No conventional turf product lends itself satisfactorily to this sort of use. In consequence, where a temporary grass-like carpet has been required, it has been the practice hitherto to use artificial turf for such a purpose. The artificial turf consists for example of blades of polymeric material, shaped and coloured to carry the appearance of grass, on a suitable backing layer to form a carpet or the like for deployment on the desired surface. Such artificial turf can have satisfactory appearance, but cannot match the feel and look of living grass turf.

It is an object of the present invention to mitigate some or all of the above disadvantages.

It is a further object of the present invention to provide a practical deployable product which incorporates living grass within its structure and which is readily laid on a range of surfaces, including surfaces which can serve as a growth substrate into which it can establish and surfaces which cannot so serve.

it is a particular object of the present invention to provide a living grass turf product which is suitable for temporary and removable deployment on any 1 5 surface.

It is a particular object of the present invention to provide a living grass turf product which more readily establishes as a permanent turf cover on the surface of difficult growth substrates.

It is also an object of the present invention to provide a method of covering any substrate, whether a substrate is suitable as a turf growing medium or not, with a practical living grass covering.

Thus, according to the invention in a first aspect, a turf product comprises a first layer of soilless turf, herein meaning a layer of leaves of grass or other suitable herbaceous material and associated roots, the roots thereof having been grown into a second layer which comprises a sheet of fibrous water absorbent material.

The turf is soilless, having had any soil or other growth medium on which it was initially grown removed. It is for example prepared by a conventional turf washing process. In the absence of any soil or like growing medium at the roots the water reservoir is provided by the sheet. Since the water reservoir is tle sheet the turf product can be laid on any surface whether otherwise suitable for surfing or not. Even slopes and shaped surfaces where normal turf products could be of limited practical use are suitable.

In particular, a turf product in accordance with the invention, can be laid on a dry substrate with little or no water-retention capacity which could never itself support and sustain a conventional growing turf, since it could not act as a reservoir for supply of water to the growing toots. The turf product can also be laid on poor soil surfaces and/or in especially dry conditions, and exhibit a more manageable and effective establishment phase as it establishes in situ, since the water reservoir of the mat supports initial growth and reduces reliance on the poor/ dry soil in the initial phase.

It is possible to lay the turf products in accordance with the invention very easily in a desired position. For example it can be laid in a relatively dry state and watered in situ. The turf product also makes possible its use as a temporary covering. After use, the product can be lifted from the surface on which it is laid and removed. The turf product can also be maintained in situ even on a substrate that cannot itself sustain growth for as long as desired on a permanent basis. Alternatively, on suitable growth substrates, the turf product can be allowed to establish itself conventionally by growth into the substrate.

TO sheet of fibrous water absorbent material is critical to the turf product of the invention. The fibrous material must hold sufficient water to supply the entire needs of the grass thereon, since it is the intention that there will be little or no requirement for moisture take up from the surface of the substrate on which the product is laid (at any time in the case of temporarily laid product, and at least initially in the case of product grown to establish on a soil surface). However, the fibrous material needs to give that water up readily to the roots of the grass. It also provides structural integrity for the sheet. The selection of fibrous material for the sheet is therefore very important.

The fibres themselves may be a mix of primarily absorbent and primarily structural fibres in a composite sheet material. Preferably at least 75% of the fibres are primarily absorbent. For example, the sheet of fibrous water absorbent material may comprise a fabric and/or paper sheet. In particular, at least some of the fibres are of a cellulosic material.

Suitable fibres are selected from cotton, polyester, jute, hair, polypropylene, wool, soft fabric waste and acrylic. Preferably at least 75% of the fibres are organic, and in particular at least 75% of the fibres are cellulosic. In particular, the fabric layer preferably comprises a mixture of jute, cotton and polypropylene, and for example includes at least 75% by weight in combination of jute and cotton.

The sheet making up the second layer may be provided as a single sheet or as a multilayered sheet, in which latter case different layers might be selected for different properties such as water retention and structural integnty. The sheet comprises a single integral whole serving to supply both water and structural integrity to the turf layer.

The sheet preferably comprises non-woven fibrous material, for example in the fond of a non-woven fabric such as a felt mat. The turf product conveniently comprises a single layer of this felt mat. Optionally, this felt mat may include, either within the structure or on a surface thereof, reinforcement material such as a woven reinforcement layer to ensure that the mat retains structural integrity. In particular, the sheet of absorbent material comprises a single layer non-woven mat, for example including jute, cotton and polypropylene, incorporating a single woven polymeric layer, for example a polypropylene scrim, for integrity. It is important to emphasise that this structural layer serves merely as a part of the mat to give structure to the mat itself. In particular there is no need for reinforcing geosynthetic layers such as a mesh or other structures which will be familiar from the prior art, since it is not intended that the turf product of the present invention will serve as a reinforcement for a bank or the like.

The fibrous water absorbent sheet needs to be thick enough to act as a sufficient reservoir for the grass growing thereon in situ, but should not be so thick as to hind easy deployment, removal and transportation of the turf product or to contribute excessively to the weight of the product. Preferably, the sheet has a thickness of between 1 and 5 cm, and in particular around 2 to 3 cm.

The sheet needs to be capable of providing the sole supply of water to the roots of the grass. This is necessary to ensure that the grass in situ may be kept alive and in good condition. Preferably therefore, the sheet is able to absorb at least 2 litres per my, and more preferably yet 3 litres per my.

The overall turf product is sized and shaped to be readily deployable in situ.

Deployment may be on a temporary removable basis or a permanent basis. In the first case it is envisaged in particular that the turf product might serve a role currently often served by carpets, whether of a conventional woven fabric type or of an artificial turf type, where a natural grass surface would have an appeal. In this case the product serves as a temporary, for example carpet-like, covering to be easily deployable in situ and removable after use. With these purposes in mind the turf product in accordance with the invention is conveniently supplied as a roll of suitable width to be suitable for deployment by rolling out, and for removal after use and transport by rolling up into roll form. However, it is a particular advantage of the invention that the deployment of the turf product need not be limited to the sort of flat surface where grass turf is conventionally grown, but can be applied temporarily to a l O range of surfaces on a range of substrates and objects to create a desired effect.

The turf product is designed to be laid such that its water reservoir is provided by the second layer of fibrous material. No water is required from the surface on which it is laid. Indeed water transference between the surface on which it is laid and the second layer of the turf product might in some instances be undesirable (for example in the case of temporary installation on a surface susceptible to moisture damage). In those circumstances, a water impermeable sheet, for example a substantially continuous sheet of polymeric material, may be deployed between the turf product and the substrate in use.

Similarly, where temporary deployment is envisaged it might be desirable to prevent root penetration from the product into the surface on which it is laid, and a sheet resistant to root penetration might therefore be laid between the turf product and the substrate. Conveniently a single sheet provides both functions. This might be provided with the turf product as a backing layer on an opposite side of the second layer to the turf layer, but is more conveniently provided and deployed separately from the turf product.

Reference herein to the first layer of turf material is to any suitable grass or like herbaceous living material which forms a short, carpet-like layer of leaves above the ground surface and a network of roots below the ground surface suitable for growing into the said second layer. It will be understood that references to "grass" herein are to be construed accordingly. Preferred grass species will be well known and will be selected with the intended use in mind, for example for wear, light conditions etc. A selected species or mix of species is not material to the invention.

In accordance with the invention a further aspect, a method for the fabrication of a turf product suitable for being laid as a covering for a surface incorporating living grass comprises preparing a base layer comprising a sheet of fibrous water absorbent material; preparing a soilless turf layer, for example comprising washed turf; growing the soilless turf layer on to the base layer until the roots thereof penetrate into the base layer.

The product of the above method is then ready for deployment as described above oil either a temporary or permanent basis and on any surface whether it would support grass growth or not. The grass is kept alive through periodic watering to supply the base layer.

The base layer is preferably prepared by a non-woven method from suitable fibrous materials, preferably including at least some cellulosic fibres and for example comprising a mix of jute, cotton and polypropylene. In particular, the base layer is prepared as a carded felt, wherein the fibres are carded, a web is made on a cross folder, and the fibres are needled to a scrim.

In accordance with the invention a further aspect, a method of temporarily or permanently covering a surface comprises the laying of the turf product as above described over any surface which is required to be covered.

Ill particular, the method of covering a surface comprises the preparation of a turf product in accordance with the method above described, the transport of the turf product to a desired location, and the deployment of the turf product oil the surface to be covered. Preferably, the turf product is transported and deployed in a relatively dry state, and is watered in situ. If the turf product is intended to be retained in situ for any length of time, it is periodically watered, and optionally may be treated to maintain condition for example by application of suitable fertiliser, pesticide or the like.

In one embodiment, the method comprises a method of temporarily covering a surface, wherein the product is deployed as above and subsequently removed.

Preferably the turf product is provided for repeated temporary deployment as above described. After each use, the turf product is undeployed from the covered surface, removed to a second location, and redeployed on a second surface thereat. Optionally, between uses as a decorative product, the turf product may be rejuvenated by being laid out under controlled growth conditions.

The invention will now be described by way of example only with reference to figure 1, which is a simple schematic representation of a cross section through a turf product in accordance with the invention.

The product in figure 1 comprises a primary base layer 2 is made up of a carded felt consisting of jute, cotton and polypropylene and incorporating a woven polypropylene scrim 3 with a density of around 80 gm2 to give structure to the whole. The scrim is shown as a backing layer, but may instead be incorporated within the felt layer.

A grass turf layer is grown on to this base layer. The roots thereof 4 penetrate the base layer 2, and the leaves 1 fore, a living grass carpet surface above the base layer. The product as a whole is readily transportable, easily stored, and can be kept alive under controlled conditions because the base layer 2 serves as a fluid reservoir for the growing grass. The product can be deployed on any surface and in one envisaged use provides a real and practical way of temporarily laying a living grass carpet or other living grass covering where the particular effect conferred by real grass rather than artificial turf or other carpeting is desired.

Claims

1. A turf product comprising a first layer of soilless turf, the roots thereof having been grown into a second layer which comprises a sheet of fibrous water absorbent material.

2. A turf product as claimed in Claim 1 wherein the fibrous sheet material fibres are selected from cotton, polyester, jute, hair, polypropylene, wool, soft fabric waste and acrylic and combinations thereof.

3. A turf product as claimed in Claim 2 wherein the fibrous sheet material comprises jute, cotton and polypropylene.

4. A turf product as claimed in Claim 2 or 3 wherein the fibrous sheet material comprises at least 75% cellulosic fibres.

5. A turf product as claimed in Claim 4 wherein the fibrous sheet material comprises at least 75% by weight in combination of jute and cotton.

6. A turf product as claimed in any of Claims 1 to 5 wherein the fibrous sheet material comprises non-woven fibrous material.

7. A turf product as claimed in Claim 6 wherein the fibrous sheet material comprises a felt mat.

8. A turf product as claimed in any of Claims 1 to 7 wherein the fibrous sheet material has a thickness of between 1 and 5 cm.

9. A turf product as claimed in any of Claims 1 to 8 wherein the fibrous sheet material is able to absorb at least 2 litres water per m2.

10. A turf product as claimed in any of Claims 1 to 9 additionally comprising a woven reinforcement layer.

11. A turf product as claimed in any of Claims 1 to 10 additionally comprising a water impermeable sheet deployed between the turf product and the substrate in use.

12. A method for the fabrication of a turf product as claimed in any of Claims 1 to 11 comprising preparing a base layer comprising a sheet of fibrous water absorbent material; preparing a soilless turf layer; and growing the soilless turf layer on to the base layer until the roots thereof penetrate into the base layer.

13. A method as claimed in Claim 12 wherein the base layer is prepared by a non-woven method from suitable fibrous materials.

14. A method as claimed in any of Claims 12 and 13 wherein the base layer is prepared as a carded felt, wherein the fibres are carded, a web is made on a cross folder, and the fibres are needled to a scrim.

15. A method of temporarily or permanently covering a surface comprising the laying the turf product as claimed in any of Claims I to 11 directly over any surface which is required to be covered.

16. A method as claimed in Claim 15 comprising the preparation of a turf product as Claimed in any of Claims 1 to 11, the transport of the turf product to a desired location, and the deployment of the turf product on the surface to be covered.

17. A method as claimed in any of Claims 15 and 16 wherein the turf product is transported and deployed in a relatively dry state, and is watered in situ.