WO1994000978A1

WO1994000978A1 - Resilient sheet materials

Info

Publication number: WO1994000978A1
Application number: PCT/GB1993/001373
Authority: WO
Inventors: Robert Crause Baden-Powell; Timothy Nicholas Moss
Original assignee: Fieldguard Limited; The Pelters Co Limited
Priority date: 1992-07-01
Filing date: 1993-06-30
Publication date: 1994-01-20
Also published as: GB9213948D0; EP0647094A1; AU4507393A

Abstract

A water-impermeable, resilient and compressible sheet material suitable for use as animal bedding, preferably for horses, is formed from a natural or synthetic rubber or plastics material. It has grooves (54) in its upper surface ans columns (58) to space it above a stable floor. The sheets are linked by plates (see figure 7) engaging the columns adjacent the sheet edges. The linking plates leave spaces between the mats so that urine and other liquids run between the mats. If the stable floor slopes the liquid runsbeneath the mats down the slope. The grooves (54) help prevent splashing and conduction liquids to the mat edges. Other composite materials are shown in figures 1 to 4 and can be used as bedding or for protective purposes.

Description

RESILIENT SHEET MATERIALS

Thi s invention rel ate s t o re s ilient sheet materials . Materials according to the invention can be used as floor coverings to provide bedding for animals , particularly hors es , and al so f or covering other surfaces , particularly where a shock-absorbing property is required.

Various materials have been proposed for use as f loor coverings in animal hous ing , particularly stables , in addition to traditional bedding materials such as straw . These materials have been developed with a view to reducing the cleanliness problems and labour which traditional materials involve . The materials include hard rubber mats with ribbed upper surf aces and substantially smooth lower surfaces ; compositions which are coated onto a stable floor and consist of prevulcanised rubber granules supported in a matrix of a material which is solidified in situ after having been applied to the floor as a liquid containing the granules ; and a matting material composed of prevulcanised rubber granules or crumbs which are moulded into a solid material by use of a binding agent . All these materials have disadvantages ; the rubber matting having a smooth lower surface is not suf f iciently compres sible to provide comf ortable bedding and its smooth lower surface means urine and other liquids must drain away over its upper surface ; the coated compositions also have these disadvantages and in addition that of being permanently secured to the floor or other surface; the last material mentioned has the disadvantage of being insuf f iciently compressible and is also porous so tends to absorb animal urine and lead to cleanliness problems .

The present invention aims to overcome at least some of the disadvantages of the known materials . The invention provides a water-impermeable, resilient and compressible sheet, with two major outer surfaces, the first of which comprises means on said first outer surface to allow run-off of liquid therefrom and the second of which comprises means on said second outer surface for spacing the main body of the sheet from a support surface to allow flow of liquid between the second surface and the support surface.

The sheet may comprise a single solid material. Conveniently such a material is an elastomer such as natural or synthetic rubber, or a suitable durable synthetic plastics material.

Alternatively, the sheet comprises a composite resilient material having first and second layers of water-impermeable resilient material and, therebetween, an intermediate resilient layer of greater compressibility than the first and second layers, wherein the first layer provides the first outer surface, the second layer provides the second outer surface and the material is sealed around its periphery to prevent ingress of liquid to the intermediate layer.

Preferably the sheet is sealed around its periphery by further water-impermeable resilient material, conveniently forming an integral part of at least one of the first and second layers.

Advantageously, each of the first and second layers has a peripheral skirt portion and the two skirt portions are dimensioned to be an interference fit one within the other. The upper and lower layers thus fit together in the manner of a box and lid to enclose the intermediate layer.

Preferably the profile formed by the sheet in plan view is a shape that is tessellated, more preferably is rectangular, most preferably is a rectangle with its major sides twice the length of its minor sides.

The run-off means of the first outer surface are conveniently formed by ribs on the outer surface of the layer providing grooves for run-off of liquid. The spacing means of the second outer surface may be formed by ribs on the second outer surface of the layer, or by an array of projections, such as short pillars or studs, or by any other suitable formations.

When the spacing means comprises an array of projections, advantageously the projections comprise up to 50% of the surface area of the lower surface as seen in plan view, more advantageously between 5% and 25%, most advantageously about 15%.

When the run-off means are formed by ribs, these preferably extend in different directions, conveniently two mutually perpendicular directions, in respective different zones of a single sheet of the material. Liquid flow in different directions is thus possible in a single orientation of the sheet of material. This makes the orientation of the sheet on a sloping surface less critical than it would be if the ribs extended in a single direction only. In a preferred arrangement, a rectangular sheet of the material is divided into four equal rectangular zones and the ribs extend in a direction inclined to the edges of the sheet in two diagonally opposite zones and perpendicularly thereto in the other two zones.

Advantageously, each sheet of the material has spacing means at its periphery, whereby the sheets can be laid adjacent one another with the peripheral spacing means maintaining a predetermined spacing between the sheets to allow liquid to flow from the first, upper surface of one sheet to beneath adjacent sheets. When the spacing means of the second outer surface comprise an array of projections, then suitable peripheral spacing means may comprise movable plates containing locating means in which the projections from adjacent sheets can be received. Suitable materials for the first and second layers of the composite material, or the single layer of the solid material, include elastomers such as natural or synthetic rubber and synthetic plastics materials. Examples of suitable materials are thermoset elastomers, for example natural and synthetic rubbers, thermoplastic elastomers and synthetic plastics materials. As examples of synthetic rubbers, styrene- butadiene rubber, nitrile rubber, neoprene and ethylene-propylene rubbers generally, including copolymers and terpolymers such as ethylene-propylene terpolymer, can be mentioned. Examples of thermoplastic elastomers are styrene-butadiene-styrene, styrene-isoprene-styrene and styrene-ethylene-butylene block copolymers, as well as nylon types and olefinic, polyolef inic , polyester and polyurethane types.

Examples of synthetic plastics materials are polyvinyl chloride and polyethylene. Derivatives and mixtures of the foregoing materials can also be used. The materials preferably have a hardness on the International Rubber Hardness Scale of 45° to 75° with hardness values in the range 50° to 70° being more preferred.

The intermediate layer may be formed from closed- cell or open-cell foamed material, for example material formed from natural or synthetic rubber or synthetic plastics materials. Examples of suitable materials are as given in the preceding paragraph. Other forms of intermediate layer are also possible however, for example layers formed from interf itting elongate formations such as bristles or fingers extending from the inner surfaces of the first and second layers, or any other open structure providing appropriate compressibility.

The compressibility of the intermediate layer is preferably from 5 psi to 25 psi (about 35 kPa to about

170 kPa) , more preferably from 8 psi to 15 psi (about

55 kPa to about 105 kPa) and most preferably about 10 psi (about 70 kPa) on the ASTM D1056 scale.

The compressibility of the composite material itself is preferably from 20 psi to 60 psi (about 140 kPa to about 415 kPa) , more preferably from 30 psi to 50 psi (about 205 kPa to about 345 kPa) , again on the ASTM D1056 scale.

The overall thickness of the material is preferably from 10 mm to 150 mm, more preferably 20 mm to 100 mm.

If the sheet is made from a single piece of solid material then the thickness of the material is most preferably from 10mm to 50mm and the height of the projections from the lower surface is most preferably from 10mm to 20mm.

The intrinsic compressibility of the material of non-composite sheets is preferably from 40 psi to 70 psi (about 275 kPa to about 485 kPa) , on the ASTM D1056 scale. The compressibility of the sheet itself is however surprisingly greater and may be in the range 25 psi to 50 psi (about 170 kPa to about 345 kPa) .

If the sheet is a composite, the first layer is preferably from 2 mm to 10 mm thick and the second layer from 0.5 mm to 40 mm thick. Towards the lower ends of these ranges, the first and second layers will tend to form a surface skin which follows the profile of the water run-off and the spacing means; towards the higher ends of the ranges the first and second layers will tend to comprise portions of constant thickness extending over the entire sheet of material with the water run-of f and spacing means extending outwardly therefrom. The thickness of the intermediate layer is preferably from 10 mm to 100 mm, more preferably 10 mm to 80 mm.

Two particular combinations of dimensions are particularly preferred, according to the intended use o f the material . For use as animal bedding , a relatively thick material is preferable . Dimensions of a composite sheet suitable for such use are as follows :

Broader More

Preferred (mm) (mm)

Thickness of first layer 5 to 10 5 to 8 Thickness of intermediate layer 30 to 80 40 to 60 Thickness of second layer 10 to 40 20 to 30 Overall thickness 60 to 100 70 to 90

For use as a protective shock-absorbing material, a thinner material is to be preferred. Dimensions of a composite sheet suitable for such use are as follows:

^■*> P7

The materials of the invention preferably have a high energy absorption value on impact, according to the ASTM D1056 rating. Composite materials according to the invention can be fabricated from separate components providing the first, second and intermediate layers. This method is particularly convenient when the peripheral seal is formed as mentioned above by interfitting peripheral skirt portions of components providing the first and second layers. The method is also suited to the manufacture of the relatively thick materials mentioned above .

In another method, the three layers are formed by simultaneous moulding in a suitable mould.

Unvulcanised material without a blowing agent is introduced into the cavity of a mould to form the first and second layers, together with unvulcanised material containing a blowing agent therebetween. Upon application of heat and pressure, the material for forming the first and second layers is then vulcanised and the blowing agent causes the intermediate layer to expand thus forming a composite material with the intermediate layer bonded to the first and second layers. The peripheral seal can be formed by introducing a suitably-shaped strip of unvulcanised material around the periphery of the mould cavity.

In another aspect, the present invention provides a method of covering a support surface to provide animal bedding, in which a plurality of resilient and compressible sheets as defined in any of the preceding paragraphs are laid on the support surface in a close- fitting array which provides spaces between at least some adjacent sheets for run-off of liquid from the upper surface of the sheets.

The invention also provides such a resilient and compressible sheet, for use in providing animal bedding.

Thus, for use as an animal bedding, the material of the invention is preferably formed into mats of an area of 0.5 to 1.0 m , for example measuring 0.5 x 1 m. These mats are then laid on a floor, for example of a stable, the floor preferably having a slope, usually constant, towards one edge of the floor, the mats being orientated so that the water run-off means direct liquids down the slope of the floor and the spacing means of the second layer allow flow under the mats. The water run-off means is preferably shaped to also minimise splashing when the horse or other animal urinates on the mats. The mats preferably have peripheral spacing means as mentioned so that urine or other liquid falling on one mat will flow down to the edge of the mat and then down beneath adjacent mats to run away around the spacing means of the other mats. The water run-off means are preferably also shaped to present relatively large areas from which liquids will run to leave a relatively large dry area.

It will be appreciated that the mats just described can be very easily cleaned and disinfected.^' This is a particular advantage in stables at race courses where regulations require complete disinfection of stables between race meetings . With traditional bedding such as straw this involves removal and disposal of large volumes of straw and subsequent 5 cleaning and disinfecting of the stable areas .

Further , the mats of the invention are easily removed and replaced singly in the event of damage or excessive wear.

The thinner types of material are useful f or 0 covering floors and walkways where animals tread or stand and also surfaces likely to be kicked or scuffed by animals .

All materials according to the invention have other applications wherever their particular properties 5 are desirable .

Three embodiments of the invention will now be described by way of example with reference to the drawings , in which:

Figure 1 is a top plan view of a portion of a 0 stable mat which can be used as animal bedding.

Figure 2 is an underneath plan view of a portion of the mat of figure 1 ,

Figure 3 is a section on the line III-III of figure 1 , 5 Figure 4 shows schematically the arrangement of ribs on the underside of the mat of figures 1 to 3 ,

Figure 5 a view corresponding to figure 3 of a shock-absorbing material which is useful as a mat and in other ways , 0 Figure 6 is a perspective view, partially cut away , of part of a sheet acc ording to a third embodiment of the invention, constructed from a single piece of solid material , and

Figure 7 is a plan view of a joining piece for use

~ ~ w th the sheet shown in figure 6. The mat shown in figures 1 to 3 measures about 1 m by 0.5 m. Figures 1 and 2 show only a corner portion. Figure 3 is an interrupted section parallel to the longer sides. Other shapes and sizes are of course possible. The mat has upper and lower layers 1, 2 and an intermediate layer 3 (see figure 3). The upper surface of the mat has ribs 10 and troughs 12. The ribs 10 are about 30 mm wide and the troughs 12 about 12 mm wide at their tops. The sides of the troughs are inclined at about 45°. The troughs are about 4 mm deep and taper to a width of about 7 mm at their bottoms. The upper layer 1 has a thickness of about 6 mm including the height of the ribs 10. The top surface of the upper layer is speckled or flecked with a green or rust-red colour on a black background, as horses do not respond well to plain dark colours. The upper layer is made from a material resistant to wear and abrasion such as carbon-reinforced natural/SBR rubber and has a hardness of about 55° on the IRHD scale. T e lower layer 2 of the mat is made from the same material as the upper layer 1 but with a hardness of about 65° on the IRHD scale. The lower layer 2 has an overall thickness of about 24 mm and is made up of a continuous part about 12 mm thick and a part formed by rectangular-section ribs 14 which are about 10 mm wide and spaced by about 10 mm. As can be seen in figure 2, the ribs 14 extend diagonally across the mat at an angle of about 45° to its edges.

The intermediate layer 3 of the mat is formed by a block of EPDM closed cell foam rubber material which is about 55 mm in thickness and has a compressibility of about 10 psi or about 70 kPa on the ASTM D1056 scale.

The sides of the mat are formed by a continuous skirt 18 around the edges of the upper layer and a continuous upstanding wall 20 around the edges of the lower layer. The wall 20 is an interference fit within the skirt 18 so that the periphery of the mat is sealed by the interfitting wall and skirt.

The sides of the mat are formed with spaced protrusions 21 which are about 3mm thick and provide for spacing of adjacent mats by about twice this dimension when the protrusions of adjacent mats abut. Double width protrusions on only two sides of the mat could be provided instead. Figure 4 shows schematically the arrangement of the ribs 14 on the lower surface of the mat. The surface is divided into four equal rectangular zones by imaginary lines 22, 24. The ribs in the zones extend in the direction of the respective arrows A, B C and D. Thus, the ribs in two diagonally-opposed zones extend in one direction and those of the other zones in a perpendicular direction. This arrangement of ribs 14 means that when the mat is placed on an inclined surface, at least some of the channels 16 formed between the ribs will tend to lead water or other liquid to flow towards the edge of the mat regardless of its particular orientation on the surface.

Two ways of making the mat of figures 1 to 4 will now be described. In the first way the mat is fabricated from an upper layer 1 and integral skirt 18 moulded in one piece, a lower layer 2 and integral wall 20 moulded in one piece and a block of foam material. The three parts are assembled with the foam in the tray provided by the lower layer and its wall 20 and then the skirt 18 of the upper layer 1 is stretched over the wall 20 to form an interference fit.

A second way of making the mat is to mould it in one piece. This can be achieved by introducing a sheet of unvulcanised rubber into the cavity of a suitable mould to form the lower layer 2, adding material with a blowing agent to form the intermediate layer 3 and then adding a further sheet of unvulcanised rubber to form the upper layer 1. A strip of unvulcanised rubber without blowing agent is wrapped around the sides to form the skirt 18 and wall 20 integrally. Upon application of heat and pressure to the mould the mat is formed in a single piece with the blowing agent producing the desired foam structure of the intermediate layer 2 and the ribs and troughs 10, 12, 14, 16 being formed in the upper and lower layers 1, 3 by suitable formations in the mould cavity.

Figure 5 of the drawings shows a view corresponding to figure 3 of a second composite resilient material which can be used, for example, for covering walkways and other surfaces exposed to wear by the hooves of animals such as horses. The material is produced by the second method described above although could also be made by the first method. The material has an upper layer 31 which is formed in its upper surface with ribs and troughs 34, 36 of similar dimension to those of the mat shown in figures- 1 to 4. The thickness of the upper layer is however only about 3 mm and the layer is itself corrugated and follows the contours of the ribs and troughs at a constant thickness of about 3 mm. The upper layer 31 has a hardness substantially the same as that of the upper layer 1 of the first mat. The intermediate layer 33 has a foamed structure which has a compressibility of about 10 psi (about 70 kPa) on the ASTM D1056 scale. The lower layer 32 is formed as a skin 37 of about 1 mm thickness along the lower surface of the material which is formed with ribs and troughs 38, 40 dimensioned similarly to those of the first mat. The sides of the material are sealed by a harder material 28 extending around the sides of the mat. The sides of the material are sealed by a further skin layer 42 of about 1 mm in thickness and composed of the same material as the skin 37 of the lower layer 32.

The use of the mat described with reference to figures 1 to 4 will now be described. A number of these mats are laid on a stable floor so as to cover the floor, or a portion of it, in a substantially continuous layer. Each mat is spaced from its neighbouring mats by the spacing protrusions 21 on the sides of the mat, so as to leave gaps between adjacent mats. If the floor of the stable is inclined, the mats are orientated so that the channels 12 extend in the direction of the slope. The lower surfaces of the mats are then spaced from the stable floor by the ribs 14 whilst the channels 16 between the ribs 14 extend diagonally to the ribs 10 and allow for drainage of liquids between the mats and the floor in two perpendicular directions. Any gaps around the edges of the stable floor not covered by the mats should preferably be filled with a material such as packed peat, sawdust or chopped straw.

When the stable floor has been covered by the mats in this way, the troughs 12 in the upper surfaces of the mat provide channels for flow horses' urine to the edge of each mat and then between the mat and adjacent mats. It can then flow away to a suitable drain beneath other mats towards the lowest edge of the stable floor.

It will be appreciated that the width of the ribs 10 presents a relatively large area on the upper surface of the mats. These areas will drain readily and remain dry to provide a surface on which the horse lies. The ribs 10 also have the desirable effect of preventing splashing when a horse urinates, particularly as horses tend to be disturbed by such splashing . Because of the spaces provided between adjacent mats , the wetting of the floor by urination will be substantially restricted to the particular mat on which the horse urinates . If any particular mat is damaged or requires removal or replacement such removal and replacement is possible without disturbing the remaining mats covering the floor.

It will also be appreciated that the mats are particularly easy to clean and can simply be washed down and disinfected as appropriate . This cuts down substantially the time required f or mucking out of stables and avoids any problem of disposal of used bedding which , under legislation shortly to come into ef f ect , will not be allowed to be disposed of by burning . The mats have high thermal insulation properties and are particularly warm for old horses and young foals . They are also suf ficiently soft for horses spending long hours boxed , horses with leg problems and horses injured or resting. They also are sufficiently flexible to avoid muscle problems arising from horses laying down . They further provide a non- slip surface which is long lasting and can be expected to have a surface life of several years . The mats can be used with no further bedding on sloping-f loor stables and with minimal bedding on flat floors .

The resilient material described with reference to figure 5 of the drawings may be used as a floor mat in a stable or in other areas where horses walk but is not generally suitable for use a bedding for horses or other animals . Particular applications are walkways between stables and other buildings and for covering for kicking boards which are easily damaged by horses ' hooves .

Figure 6 shows an alternative embodiment of a mat according to the invention , in which the mat is made from a single solid piece of material, such as vulcanised rubber.

The mat described below can be scaled up or down as required, or any other suitable dimensions can be chosen. The dimensions given below are by way of example only.

The mat is rectangular in plan view and comprises a solid main body 50 with an upper surface 52 containing 24 regularly spaced grooves 54 parallel to the minor sides of the mat. The grooves are tapered internally, and are 12mm wide at the top, 6mm wide at the bottom and 2mm deep. The major sides of the mat are twice the length of the minor sides. In this case the mat is approximately 50cm x 100cm. Projecting from the underside 56 of the main body is a regular, rectangular array of short cylindrical pillars 58. The thickness of the main body is 12mm and the height of the pillars is 14mm. The pillar array has the same rectangular symmetry as the mat. The diameter of each pillar is 16mm, there are 14 rows of pillars parallel to the major axis of the mat, and 26 rows of pillars parallel to the minor axis of the mat. Therefore the bottom of the pillars form about 15% of the surface area of the underside of the mat as seen in plan view from below. The rows of pillars parallel to the minor axis of the mat lie under each groove and at each edge of the mat. At the four vertices of the mat are four corresponding sets 60 of nine pillars which are screw-threaded for a purpose to be described later. Similarly half way along the major sides of the mat are two sets of six pillars (not shown) also screw- threaded. The four sets of nine pillars each form a square array with three pillars on each side with a vertex and two sides of the array corresponding to a vertex and two sides of the mat. The two sets of six pillars each form a rectangular array two pillars by three, one of the sides with two pillars forming part of the major edge of the mat, at about its mid-point.

Figure 7 shows one type of movable plate which can be used to join the mats shown in figure 6. The plate 62 can be made from any resilient material. It is convenient for the plate to be made from the same material as the solid sheet. The plate is about 10 mm thick and about 200 mm square. It has 36 screw- threaded holes 64 in a six-by-six array. Another type of plate comprises a rectangle containing 12 screw- threaded holes arranged in a two by six array.

The square plate 62 is used to join four mats together at their vertices; the rectangular plate joins the middle of the major sides of two adjacent mats. The screw-threaded holes 64 in the plates are dimensioned to receive the corresponding, screw- threaded pillars from adjacent mats in an interference fit, to join the mats. Mating between the holes and pillars can also be achieved by means other than screw threads, for example by circular ribs or grooves. It is readily apparent that the connection between plate and pillar is achieved by deformation of the resilient material, it is not necessary (or even possible) to screw the pillars into the holes. As both plate and pillar are constructed from resilient compressible material, separation of them can be achieved manually simply by pulling the mat up from the plate. However when placed on the stable floor the plate and adjacent mats are linked together in a manner which prevents horizontal separation of adjacent mats by normal movement of animals on the upper surface of the mats.

The holes in the plates are positioned to provide gaps between adjacent mats joined by the plates. These gaps act as drainage channels for liquid to reach the stable floor. Such channels may be filled with absorbent material, such as those mentioned above, which permits drainage yet provides a continuous upper surface for an assembly of these mats. The 2 to 1 ratio of the major and minor sides of the mat allows these mats to tessellate with the surface grooves of adjacent mats orientated perpendicularly to one another, whilst still being joined at their vertices and sides by the plates. This is achieved by placing the minor sides of two mats to abut the major side of a third mat, so the assembly of three mats thus formed has a rectangular plan view.

Of course square mats could also be connected through the plates so that the surface grooves of adjacent mats are mutually perpendicular. However an array of identical square mats can be arranged less flexibly than an array of identical rectangular mats of the type described above, and therefore these rectangular mats are to be preferred as a greater variety of floor shapes can be covered.

It will be appreciated that features of the embodiment shown in figure 6 can be transferred to the embodiments of figures 1 to 5. For example, the mat of figure 1 or 5 could be made with pillars as shown in figure 6 replacing the ribs on its underneath side.

For solid mats of the type shown in figure 6 the desired compressibility is achieved by the combination of the choice of material used, and the spacing between the pillars of the bottom surface. The compressibility of solid mats constructed as above is surprisingly greater than the compressibility of the material alone. For example, a mat having a compressibility of about 30 psi (205 kPa) can be produced from material having a compressibility of about 50 psi (about 345 kPa) . Generally, the material itself can have a compressibility in the range 40 to 70 psi (about 275 to about 485 kPa) and the mat a value correspondingly in the range 25 to 50 psi (about 170 to about 345 kPa) . All these figures are on the ASTM D1056 scale. Other advantages of making mats from a solid material are that they can be constructed from a single mould and the production is much simpler, cheaper and quicker than for composite mats.

Solid mats may also be more resistant to wear than some composite mats. Solid mats can be made with a speckled or flecked upper surface, by adding small amounts of appropriately coloured matter to the solid precursor ingredients before moulding the mat. Solid mats according to the invention also possess similar advantages in use to those described above for the composite mats of the invention. Features common to both types of mat have of course the same advantages as described previously.

Therefore it will be appreciated that the choice between either solid or composite mats, both according to the present invention, is dependent largely on the circumstances in which the mats are to be used.

The types of mat described can find other applications, both as bedding for animals and also as matting and other protective purposes. The materials from which the mats are made are also impervious and sufficiently resistant both to chemicals such as ammonia and nitric acid to which they are exposed during use and to the cleaning chemicals to which they would be exposed when being cleaned.

Claims

CLAIMS :

1. A water-impermeable, resilient and compressible sheet suitable for use for animal bedding and/or to absorb animal impacts, the sheet having two major outer surfaces, the first of which has means thereon to allow run-off of liquid therefrom and the second of which has means thereon for spacing the second surface from a support surface to allow liquid to flow between the second surface and the support surface.

2. A sheet according to claim 1, formed from a single material.

3. A sheet according to claim 2, in which the said material has an intrinsic compressibility of from 40 psi to 70 psi (about 275 kPa to about 485 kPa) on the ASTM D1056 scale.

4. A sheet according to claim 2 or 3 , having of compressibility of from 25 psi to 50 psi (about 170 kPa to about 345 kPa) on the ASTM D1056 scale.

5. A sheet according to any of claims 2 to 4 , having a hardness of 45° to 75° on the International Rubber Hardness Scale.

6. A sheet according to claim 5, having a hardness of 50° to 70° on the International Rubber Hardness Scale.

7. A sheet according to any of claim 2 to 6, having an overall thickness of from 10mm to 50mm.

8. A sheet according to claim 1, comprising a composite resilient material having first and second layers of water-impermeable resilient material and, therebetween, an intermediate resilient layer of greater compressibility than the first and second layers, wherein the first layer provides the first outer surface, the second layer provides the second outer surface and the material is sealed around its periphery t o preve nt ingre s s o f l iquid t o the intermediate layer .

9. A sheet according to claim 8 , sealed around its periphery by further water-impermeable resilient material .

10. A sheet according to claim 9, in which the peripheral seal comprises a portion which is an integral part with at least one of the first and second layers.

11. A sheet according to claim 10, in which each of the first and second layers has a peripheral skirt portion and the two skirt portions are dimensioned to be an interference fit one within the other.

12. A sheet according to any of claims 8 to 11, having a hardness of 45° to 75° on the International

Rubber Hardness Scale.

13. A sheet according to claim 12, having a hardness of 50° to 70° on the International Rubber Hardness Scale.

14. A sheet according to any of claims 8 to 13, in which the intermediate layer comprises closed- or open-cell foam material.

15. A sheet according to any of claims 8 to 14, in which the compressibility of the intermediate layer i_s from 5 psi to 25 psi (about 35 kPa to about 170 kPa) on the ASTM D1056 scale.

16. A sheet according to claim 15, in which the said compressibility is from 8 psi to 15 psi (about 55 kPa to about 105 kPa) .

17. A sheet according to any of claims 8 to 16, having a compressibility of from 20 psi to 60 psi (about 140 kPa to about 415 kPa) on the ASTM D1056 scale.

18. A sheet according to claim 17, in which the said compressibility is from 30 psi to 50 psi (about 205 kPa to about 345 kPa) .

19. A sheet according to any of claims 8 to 18, in which the first layer is from 2 mm to 10 mm in thickness.

20. A sheet according to any of claims 8 to 19, in which the second layer is from 0.5 mm to 40 mm in thickness.

21. A sheet according to any of claims 8 to 20, in which the intermediate layer is from 10 mm to 100 mm in thickness.

22. A sheet according to claim 21, in which the intermediate layer is from 10 mm to 80 mm in thickness.

23. A sheet according to any preceding claim, in which the run-off means on the first outer surface comprise ribs providing grooves for run-off of liquid.

24. A sheet according to any preceding claim, in which the spacing means on the second outer surface comprise ribs providing flow passages therebetween.

25. A sheet according to any of claims 1 to 23, in which the spacing means on the second outer surface comprise an array of projections.

26. A sheet according to claim 25, in which the projections comprise pillars or studs.

27. A sheet according to claim 25 or 26, in which the projections cover 50% or less of the second surface of the sheet.

28 A sheet according to claim 27, in which the projections cover 5% to 25% of the second surface.

29. A sheet according to any of claim 25 to 28, i_n which the projections project from 10 mm to 20 mm from the second surface.

30. A sheet according to claim 24, in which the ribs extend in different directions in respective different zones of the sheet.

31. A sheet according to claim 30, in which the ribs extend in two mutually perpendicular directions .

32. A sheet according to claim 31 , the sheet being rectangular in plan and its second surface being divided into four equal rectangular zones , the ribs extending in a direction inclined to the edges of the s heet in two diagonal ly oppo s ite z one s and perpendicularly to that direction in the other two zones .

33. A sheet according to any preceding claim, having spacing means at its periphery , whereby a plurality of sheets can be laid adjacent one another with the peripheral spac ing means maintaining a predetermined spacing between the sheets to allow liquid to flow from the first , upper surface of one sheet and between adjacent sheets .

34 . A sheet according to any of claims 25 to 29 , having spacing means at its periphery , whereby a plurality of sheets can be laid adjacent one another with the peripheral spacing means maintaining a predetermined spacing between the sheets to allow liquid to flow from the first , upper surface of one sheet and between adjacent sheets , the spacing means comprising movable plates having means for receiving the projections of adjacent sheets .

35. A sheet according to any preceding claim, having an overall thickness of from 10 mm to 150 mm.

36. A sheet according to claim 35 , in which the thickness is from 20 mm to 10 mm.

37 . A sheet according to any preceding claim, having an area of from 0 .5 m² to 1. 0 m² .

38. A sheet according to claim 37 , having a square or rectangular shape in plan view.

39 . A sheet according to any preceding claim, having a dark-coloured f irst surface speckled in a contrasting colour .

40. Use of s heet material according to any preceding claim, in the formation of animal bedding.

41. A use according to claim 40 , in which the sheet material is laid on the floor of an animal house having a floor sloping in a predetermined direction, the sheet material being laid in individual pieces orientated so that the run-off means allows liquid to flow in the direction of the slope between the support surface and the lower surface of the sheets .

42. A method of making a material according to any of claims 8 to 22 , comprising providing a mould having a cavity corresponding to the sheet material to be made, introducing unvulcanised natural or synthetic rubber or plastics material into the cavity so as to form the first and second layers of the finished material and define a space therebetween, introducing unvulcanised material containing a blowing agent into the space defined between the first and second layers , applying heat and pressure to the mould cavity to cause the first and second layers to vulcanise and the intermediate layer to expand, and removing the resulting composite sheet material from the cavity.