A COMPOSITION

This invention relates to a composition, and particularly, but not exclusively to a composition for forming a surface such as a riding surface. The invention relates particularly to a composition forming an all weather natural surface such as a riding surface, and to a surface such as a riding surface formed from such a composition.

Riding surfaces are required to form all weather surfaces in riding arenas for example. Such surfaces may be constructed using mixes of various components. It is known that such riding surfaces may comprise a petroleum based product such as grease or oil, or synthetic materials such as synthetic rubbers.

It is becoming undesirable to use petroleum based products due to the potential damage that such products may have on the environment. In addition, synthetic and natural rubbers are also undesirable components of such surfaces due to the difficulty in recycling these components. Further, composition using petroleum based products is not able to withstand high temperatures for example 35°C and above. In such temperature conditions, the petroleum based product may dry out and/or melt. When the composition is being used as a riding surface, this is undesirable since it may result in the hooves of horses becoming clogged with the melting composition. In addition, the composition may stick to the horses' legs.

According to a first aspect of the present invention there is provided a composition comprising a mixture of wood fibres, silica sand, and a binder comprising chalk.

According to a second aspect of the present invention there is provided a riding surface comprising a composition comprising a mixture of wood fibre, silica sand and a binder comprising chalk.

The composition according to the first aspect of the present invention is suitable for use in all equestrian disciplines, and provides an all weather surface which is adaptable to climate change. This is because the components of the mixture are poor conductors of heat. The composition is particularly adapted for use at high temperatures above, for example, 35°C.

The binder serves to enable the sand and wood to knit and root together to form a homogenous mixture.

Because the binder is made from chalk, a natural ingredient, the composition is environmentally friendly.

The binder further ensures that, during use of the riding surface, the composition and the surface formed from the composition provide a secure and firm footing with a minimum of kick back. At the same time the surface provides a user with a natural feel for performance.

Since all the components of the composition according to the first aspect of the present invention are natural, the composition is recyclable and causes minimum damage to the environment. Further, the composition may be used to form a riding surface according to the second aspect of the present invention which, to a user, behaves in substantially the same way as turf. A riding surface formed from the composition according to the first aspect of the present invention emulates the qualities of "good quality turf as defined by the Racing Authority Standards.

A further advantage of the composition according to the first aspect of the present invention is that it provides a riding surface which is adapted to drain freely. The riding surface may thus be used after even heavy and prolonged rain fall.

A riding surface according to the invention, is suitable for national and international venues for racing, show jumping, dressage, eventing, polo and training, among other uses.

Because the composition does not include any petroleum based products it may be used in countries where the temperature may be high, such as Asia and the Middle East.

The chalk may be any suitable chalk, but preferably the chalk is a limestone chalk, composed of mineral calcite. Such a binder is adapted to improve the adhesion of the silica sand and wood fibres forming the composition.

In addition, such a binder is stable, has a melting point of 825°C, has negligible water stability, and has a specific gravity of 2.83.

Preferably, the chalk is in the form of a fine powder. Such a chalk is usually used for paints and emulsions and baking, for example. Set out below in Table 1 is a chemical analysis of a suitable chalk.

TABLE 1

Chalk: A very fine whiting of good brightness and purity.

The inventors have found that using such a chalk, which is usually used for domestic purposes, rather than an agricultural course grade chalk, the ingredients of the composition may be mixed more consistently. The properties of the composition according to the first aspect of the invention are more consistent if the components are consistently mixed.

Wood fibres facilitate free drainage of, for example, water through the riding surface, since the wood fibres form drainage channels, preventing the surface becoming compacted.

The wood fibres may be formed from any type of wood but preferably comprise a mixture of seasoned hard and soft wood.

The ratio of hard to soft wood may be varied depending on the particular use to which the composition is to be put. Preferably however the ratio of hard to soft wood is substantially 1 :4.

The overall performance of the riding surface is not significantly affected by the ratio of hard to soft wood used. However, the ratio will affect the durability of the riding surface.

In one embodiment of the invention the wood comprises 70% softwood and 30% hardwood. Such a mixture has a water retention of 15%.

The wood fibres may be of any suitable size, and in one embodiment, the maximum size of the wood fibres is substantially 20mm. Wood fibres of this size are particularly useful

for forming a composition which is to be used to form a riding surface in an area in which polo is to be played.

A typical range of wood fibre size in such an embodiment is from 1 to 20mm.

In an alternative embodiment, the maximum size of the wood fibres is substantially 35mm. Wood fibres of this size may be used to form a composition that may be used to form a riding surface suitable for the majority of equine uses.

A typical range of wood fibres of such an embodiment is from 1 to 35mm.

In another embodiment of the invention, the maximum size of wood fibres is substantially 15mm. In such an embodiment the wood fibre size may range from less than 5mm (which wood fibres are defined as a fines) to 15mm. A typical wood composition would be as follows:

30% of the wood fibres having a length of approximately 15mm; 45% of wood fibres having a length of approximately 10mm; 20% of wood fibres having a length of approximately 5mm; and 5% of wood fibres comprising fines.

Advantageously, the sand comprises unwashed silica sand.

If silica sand is used in an unwashed state, it contains other ingredients in addition to the silica as set out below in Table 2. These additional ingredients have surprisingly been found by the inventors to increase the adherence of the wood fibre with the sand.

Previously, it had been thought by those skilled in the art necessary to use washed silica sand in order to remove these additional elements which had been regarded as undesirable impurities. However, the inventors have found that unwashed silica sand has better adhering qualities than washed silica sand.

TABLE 2

Silica Sand SFSS (Screened Fine Silica Sand)

Advantageously, the ratio of wood to sand to binder in the composition is substantially 7:2:1.

The ratio of wood to sand to binder could be any convenient ratio. For example, if a riding surface is to be used in a polo arena a preferred ratio of wood to sand to binder would be 5.5 : 3 : 1.5.

Set out below in Table 3 are ratios of wood fibre to sand to binder for three different compositions according to the first aspect of the present invention suitable for polo, general riding, and racing respectively.

TABLE 3

According to a third aspect of the present invention there is provided a method of forming a composition comprising the steps of measuring predetermined amounts of wood fibre, silica sand and a binder comprising chalk; mixing the wood fibre, silica sand and binder together.

Preferably, the silica sand and the binder are added to the wood fibres.

The components should have as little moisture content as practicably possible.

Advantageously, the wood fibres, silica sand and binder are mixed in a tumble mixer to achieve an even composition. Water is added to the mixer.

Water may be added to the mixer in any desirable ratio, but is preferably added to the mixer in a ratio of 25 to 40 litres per cubic metre of materials. Most preferably, the water is added to the mixer at a ratio of 20 litres per cubic metre of materials.

Recycled timber may be used to form the wood fibre forming the composition according to the present invention. Metals contained in such recycled timber are removed before forming the wood fibres.

Wood fibre of an appropriate size may be manufactured using rotor hammer mills in a known manner.

In the composition according to the first aspect of the invention, the wood fibres, silica sand and binder work together to form a composition able to form a riding surface having the properties described hereinabove. The wood fibre provides moisture to the silica sand, and the silica sand gives weight to the wood fibre and helps to form an enduring surface.

The invention will now be further described by way of example only with reference to the accompanying drawings in which:

Figure 1 is a schematic representation of an apparatus used to form wood fibres suitable for forming a composition according to the present invention;

Figure 2 is a schematic representation of an apparatus used to mix the composition;

Figure 3 is a schematic representation of the primary shredder forming part of the apparatus of Figure 1 ; and

Figure 4 is a schematic representation of the wash plant forming part of the apparatus of Figure 1.

Referring to the figures, an apparatus for forming wood fibre is illustrated schematically by the reference numeral 2.

The apparatus 2 comprises a primary shredder 4 which is shown schematically in more detail in Figure 3. The primary shredder 4 comprises an in-feed 6 in which wood may be placed.

The wood may be of any convenient form and may for example take the form of recycled wooden pallets and/or packaging cases.

The primary shredder 4 further comprises one or more swing hammers 8 mounted on rotor 10. In this embodiment, the primary shredder comprises 72 swing hammers. The hammers are rotated by the rotor 10 and thus crush the wood against a plate known as a smash plate 12. The initial impact of a hammer on the wood scatters the wood which causes the wood to be pulled down and around the side of the rotor 10 which rotor causes the hammers to rotate. The wood then lands on a screen 14 having an appropriate screen size. In this example the screen dimensions are approximately 5 inches by 10 inches. There may be a plurality of screens. This allows wood chips of appropriate size to pass through the screen.

The primary shredder 4 is thus able to reduce wood fed into the in-feed 6 to an appropriate size. In this embodiment, wood fibres passing through the screen 14 will be up to 75 mm long.

After passing through the primary shredder 4, the wood fibre passes through a series of magnets by means of a conveyor belt 15, for example, including a head drum magnet 16 and one or more electromagnets 18. The magnets 16, 18 act to remove metal impurities from the wood fibre.

The wood fibre then enters a secondary shredder 20 which comprises one or more fixed hammers which operate in conjunction with one or more screens of dimensions approximately 2" x 2" each. The secondary shredder 20 serves to smash and roll the wood fibre against wear plates, thus fibrerising the wood. The fixed hammers in the secondary shredder 20 act in a similar manner to steak mallets which break down fibres of meat thus tenderising the meat.

After exiting the secondary shredder 20, the fibre drops onto a conveyor belt 22 which takes the fibre over a head drum magnet 24 which removes any further pieces of metallic product having a size above 25 mm.

A box screen 26 removes wood fibre having a length of 3mm or less. Such wood fibres are known as fines and are regarded as dust. The fines serve no useful purpose, but would make the finished product dusty and could therefore irritate horses' breathing if left in the composition. This leaves a required blended product suitable for mixing with sand and binder.

The wood fibre then passes into a wash plant 28 comprising a screw auger 30. The screw auger is immersed in water, and is preferably 50% immersed in water. The screw auger 30 rotates to carry the wood fibre through the wash plant 28. The wash plant further comprises trays 32 positioned below the screw auger. Any impurities remaining in the product should drop into water contained in the trays 32, and sink. The wood fibre will, however, float and will be carried by a conveyor 34 out of the apparatus 2.

The wood is then ready for mixing with sand and binder to produce a composition according to the invention.

Wood fibre exiting the apparatus 2 may then be placed into a receiving hopper 34 together with appropriate amounts of sand and binder. The components are preferably fed into the receiving hopper by for example, a loading shovel. The components are then mixed within the receiving hopper.

The mixed composition then exits the receiving hopper 34 by means of screw auger 36.