The present invention relates to composite articles, in particular recyclable board-like articles, methods of making such articles and products comprising such articles. Said products may include scaffold boards; and panels and posts for fences and barriers.

There is a need for a readily erectable structure to delineate areas, especially one which is capable of being demounted or provided as a permanent (or semi permanent) feature should the structure be usable as a security, flood protection or sound barrier.

It is an object of this invention to provide a solution to at least one of these needs.

A first aspect of the invention provides a barrier comprising one or more, preferably extruded, posts having at least one panel therebetween, the or each post having a first side and a second side, each side having a recess extending thereinto, wherein the first side recess extends normally from the first side and the second side recess extends at an acute angle from the second side.

Preferably, the barrier is demountable. Preferably, the or each post and/or the at least one panel is a composite article. Preferably, the or each post and/or the at least one panel comprises a mixture of a polymer, a lignocellulosic material and a plurality of fibres. Preferably, the polymer accounts for at least 40 wt% of the mixture.

Another aspect of the invention provides an elongate composite article having two continuous major surfaces, wherein the article has a composition comprising a mixture of a polymer, a lignocellulosic material and a plurality of fibres.

The lignocellulosic material may comprise fibres or particles, for example wood, preferably in the form of sawdust or wood flour.

The fibres may be glass fibres. The glass fibres may be recycled glass fibres. Other suitable fibres such as cotton, wool, hemp, carbon or aramid fibres may be used. Preferably, the fibres have strand lengths of less than 3mm, for example around 1.5mm.

The polymer may be high density polyethylene (HDPE).

The polymer may account for at least 40 wt%, preferably from 40 to 70 wt%, more preferably between 50 and 60 wt%, of the mixture.

In a preferred embodiment, the mixture may comprise 60 wt% HDPE, 20 wt% wood and 20 wt% glass fibres. Articles having this composition have been found to be suitable for use as scaffold boards. Optionally, a minor amount of additives may be included within the composition, typically in an overall amount of no more than 10 wt%, preferably 5 wt% or less. Suitable additives may include: lubricants such as stearic acid; coupling agents such as HDPE-g-MAH; colourants, e.g., Fe ₂ O ₃ if it is desired to produce red or reddish articles; antioxidants; and ultra violet stabilisers.

In a preferred composition, the mixture may comprise 50-55 wt% of plastic, 35 wt% wood, 10 wt% of glass fibres and up to 5 wt% of additives. Articles having this composition may be particularly well suited for use as part of a sound or security barrier.

In another preferred composition, the mixture may comprise 50-55 wt% of glass fibres and up to 5 wt% of additives. Articles having this composition may be particularly well suited for use as part of a flood barrier.

In another preferred composition, the mixture may comprise 40-45 wt% of plastics, 50 wt% wood, 4-5 wt% fibres and up to 2 wt% of additives. Articles having this composition may be particularly well suited to formation by extrusion.

Advantageously, mixtures comprising relatively low percentages of fibres, e.g. glass fibres, are useful so as to not significantly wear the extrusion tools used to form such articles. It will be appreciated therefore that the extrusion tools used to extrude compositions having a relatively low percentage of fibres have a greater lifetime than extrusion tools used to extrude compositions having a relatively high percentage of fibres. The composite article may be hollow. Preferably, there may be one or more open-ended cavities extending through the article. Preferably, the article may comprise at least one open-ended cavity which extends through the article along its principal axis.

The article may be used as part of a flood barrier, e.g. a panel or a post thereof.

The article may comprise engagement means adapted to engage with a portion of a neighbouring article when two or more articles according to the invention are brought together in a stack. The engagement means may comprise protruding formations such as bumps or ridges and/or depressed formations adapted to receive said protruding formations. For instance, the engagement means may comprise tongue-and-groove means.

Preferably, the panel is up to 3 m in length, e.g. up to 2.5 m in length, e.g. up to 2 m in length, e.g. 1.5 m in length.

Preferably, the panel is up to 50 cm wide, e.g. up to 45 cm wide, e.g. up to 40 cm wide, e.g. up to 35 cm wide, e.g. up to 30 cm wide, e.g. up to 25 cm wide, e.g. 225 mm wide.

Preferably, the panel is up to 100 mm deep, e.g. up to 80 mm deep, e.g. up to 60 mm deep, e.g. 40 mm deep. The tongue may extend around 5 to 40 mm from the panel. Preferably, the tongue may extend around 5 to 20 mm, or 5 to 10 mm, e.g. 8 mm from the panel. The groove may comprise dimensions having size and/or shape corresponding to that of the tongue.

Preferably, the panel comprises two approximately 6 mm deep sections of composite material interposed by an air pocket. Strengthening ribs may interconnect the two panels.

It is known to vertically stack panels between neighbouring pairs of posts for use as a flood protection system. In such a system the stacked panels are usually provided with flexible seals, e.g. rubber, plastics or like material, to prevent ingress of water. However, it has been demonstrated that such seals do not work or have very limited lifetimes and consequently require replacement.

The present invention utilises in some embodiments the combination of panels comprising corresponding engagement means and a clamp (which will be described below) for ensuring that the panels are tightly stacked, e.g. to preclude ingress of moisture. The present invention does not rely on rubber inter panel seals.

Further, known flood protection systems additionally comprise brace units to provide structural reinforcement. In such systems, at least one water retention unit is supported by a pair of support units. The brace units are provided to engage with the at least one retention unit to provide lateral support; i.e. to prevent the retention unit from bowing under forces such as those imparted by flood water.

It is an advantage of the present invention to provide posts and/or panels having the structural capacity to preclude the use of additional brace units.

It will be appreciated that extruded composites comprise longitudinal strength due to the orientation of the extruded fibres. Therefore, panels and/or posts according to the present invention are provided with adequate strength to support flood water without the need for additional supports. Indeed, such inherent strength and the benefit vis-a-vis the absence of further supports makes installation quicker and cheaper.

In preferred embodiments, the ratio of polymer to lignocellulosic material may be around 1 : 1.

In certain embodiments, composites may comprise higher percentages of fibre, e.g. up to 50wt%.

According to another aspect of the invention, there is provided a post comprising an elongate member having a longitudinally-extending side provided with a longitudinally-extending recess for receiving a portion of a panel, wherein the article has a composition comprising at least 40 wt% of a polymer and up to 55 wt% of a lignocellulosic material, e.g. wood, preferably in the form of sawdust or wood flour.

Preferably, the elongate member comprises a curved surface or part thereof. Preferably, the elongate member comprises radiused edges.

The elongate member may comprise a substantially circular cross section. Other shapes such as quadrilaterals are also encompassed by the present invention.

Preferably, the post is around 5 m in length, e.g. up to 4 m, e.g. up to 3 m, e.g. up to 2.5 m, e.g. up to 2 m, e.g. 1.5 m in length.

Preferably, the post is up to 30 cm wide, e.g. up to 25 cm wide, e.g. up to 20 cm wide, e.g. up to 15 cm wide, e.g. 14 cm wide.

Preferably, the longitudinally-extending recess is up to 100 mm wide, e.g. up to 80 mm wide, e.g. up to 60 mm wide, e.g. 42 mm wide.

Preferably, the longitudinally-extending recess is up to 80 mm deep, e.g. up to 60 mm deep, e.g. up to 40 mm deep, e.g. 25 mm deep.

One desired composition for a post and/or panel according to the invention comprises:

>40 wt% polymer

<25 wt% glass

<55 wt% wood flour or sawdust

<5 wt% additives.

For example: 43 wt% HDPE, 5 wt% glass fibres; 50 wt% wood flour; and 2 wt% additives. Composite articles may comprise higher percentages of fibres such as glass fibres. For example, this is particularly advantageous for articles to be used as flood defence barriers because articles comprising relatively high levels of fibres are less likely to absorb moisture.

According to yet another aspect of the invention there is provided a post comprising an elongate member having a first longitudinally-extending side provided with a first longitudinally-extending recess for receiving a portion of a panel, the recess extending into the elongate member, from the first side, at an acute angle.

Preferably, the post is formed by extrusion. Preferably, the post is formed from a composite material.

The post preferably having a second longitudinally-extending side provided with a second longitudinally-extending recess for receiving a portion of a second panel. The second recess may extend at right angles from the second side.

Preferably, the first and second longitudinally extending recesses are arranged such that panels extending therefrom are antiparallel and/or antiorthogonal.

Preferably, the composition further comprises up to 25 wt% of inorganic fibres, e.g. glass fibres. The composition may further comprise one or more additives, typically in an overall amount of no more than 10 wt%, preferably 5 wt% or less.

Suitable additives may include: lubricants such as stearic acid; coupling agents such as HDPE-g-MAH; colourants, e.g., Fe2θ3 if it is desired to produce red articles; antioxidants; and ultra violet stabilisers.

Typically, the post may comprise two, three, four, five, six, seven or eight longitudinally extending sides.

A longitudinally-extending recess may be provided in each longitudinally- extending side.

One or more of the or each of the longitudinally-extending recesses may be adapted such that a panel, a portion of which is received therein, extends from the post, in use, in a direction which is non-perpendicular to the longitudinally-extending side or a tangent thereto in which the recess is located.

The post may further comprise attachment means for fixing sections of wire thereto. Alternatively, or additionally, the post may comprise one or more transverse apertures therethrough, for receiving a section of wire and/or a portion of a clamping means, in use.

The post may further comprise lock receiving means for engagement with a locking means such as a locking pin operable to fix securely and releasably the post to another article, e.g. a supporting member. Preferably, the post may comprise an internal channel extending therethrough in a direction substantially parallel to the longitudinal axis of the post.

A barrier such as a fence, sound barrier or flood barrier may comprise one or more board-like or panel-shaped articles according to the invention located between a pair of posts.

In a preferred embodiment, metal wires pass from post-to-post through the articles, in order to provide additional strength to the barrier.

Where the barrier comprises a plurality of board-like articles, the articles may be arranged in a stack such that adjacent articles engage with one another, e.g. by virtue of making tongue-and-groove formations.

The ends of the board-like articles may be provided with sealing members, e.g. rubberised sealing members, to seal the ends within the receiving slots of the posts.

Within a fence or barrier, there may be free space or spacer components between articles according to the invention.

Advantageously, composite articles according to the present invention comprising HDPE have been found to be suitable for use as structural elements, e.g. posts for fences or flood barriers. Known structural composite articles typically comprise PVC rather than HDPE. This is because composite articles comprising PVC are less likely to creep deform than composite articles that comprising HDPE. However, it has been discovered that structural elements of the present invention comprising HDPE have been found to resist creep deformation.

Without being bound to any theory, it is believed that articles comprising HDPE, lignocellulosic material and fibres in preferred proportions can greatly reduce the tendency of the extruded article to move or creep deform when under the influence of stress.

In another aspect of the invention, there is provided a method of manufacture of composite structural element comprising the steps of: obtaining the following components: (i) a polymer, preferably in the form of pellets, (ii) a lignocellulosic material; and (iii) fibres: melting a mixture of the components; forming pellets comprising the mixture; and using the pellets as feedstock for extrusion into a finished product, wherein the polymer is HDPE.

Typically, the finished product may be a post or any of the articles described or illustrated herein.

Advantageously, finished articles according to the invention may be recycled back into the manufacturing process once they have reached the end of their useful life. Such used products may be melted down and pelletised, which pellets may then form part of the feedstock for extrusion into new finished articles.

For example, around 30% of the pellets extruded into a finished product may originate from used articles, e.g. scaffold boards or the like.

The polymer may be virgin material or it may be recycled. A mixture of virgin and recycled material may be used.

Preferably, the article may be subjected to finishing steps post-extrusion.

For instance, one or more of the surfaces of the article may be rolled using a sinusoidal roller. Further a surface of the article may be ground at an angle to remove a surface layer, e.g. around 1 mm thickness of material. The finishing steps may imbue the article with a wood-like appearance.

A further aspect of the invention provides an article in the form of a panel for dissipating sound, the panel having two continuous major surfaces, the first major surface comprising a first pattern and the second major surface comprising a second pattern, wherein the first and second patterns are different from each other.

The patterns may be applied to the first and/or second surface by etching or by using a suitable finishing technique such as that described above.

Preferably, the first and/or second pattern is suitable for dissipating or reducing the level of sound. For example, the sound dissipating surface may comprise one or more indentations. Preferably, the or each indentation is engraved into the surface, e.g. engraved into a carved pattern, so as to dissipate, reduce or detract noise.

A further aspect of the invention provides a clamp for securing a panel and a post, the clamp having a first portion to engage a panel and a second portion to engage a post, the first portion comprising an elongate member to engage an aperture of the post, the second portion comprising a fence abutment part, the first and second portions being securable together.

A yet further aspect provides a fascia for occluding an aperture or recess on a panel or post.

An even further aspect of the invention provides a composite structural element in the form of a panel or post, the element comprising HDPE and being capable of resisting creep deformation under the influence of stress. Preferably, the element further comprises a lignocellulosic material and/or fibres, e.g. cotton, wool, glass, hemp, carbon or aramid fibres.

Preferably, the element is formed by extrusion.

A yet further aspect of the invention provides a composite element in the form of a scaffold board or decking, the board or decking comprising two major surfaces, wherein at least one major surface comprises indentations or ridges to provide grip. Advantageously, the indentations or ridges may be provided by using a finishing technique such as rolling the major surface using a sinusoidal roller. Therefore, the finishing step may have the combined effect of imbuing the article with a wood-like appearance and providing grip, i.e. a non-slip surface.

Preferably, the composite element does not expand when exposed to moisture. This is especially useful when the composite element is to be used as decking.

In known decking arrangements, decking slats are typically wooden and provided with spacers therebetween to provide gaps. Gaps are required in order to allow space for the slats to expand into when the slats absorb moisture.

Decking slats formed using composite elements according to the present invention do not absorb moisture and therefore can be laid without spacers. This is advantageous because the composite slats can be laid faster than wooden slats. Further, the appearance of composite decking may be more appealing to the eye. This may be due, for example, to the lack of gaps in the decking.

In order that the invention may be more fully understood, it will now be described by way of example only, with reference to the accompanying drawings, in which :-

Figure 1 shows an end view of a panel according to the invention; Figure 2 shows how a pair of panels of the type shown in Figure 1, engage, in use, to form a barrier.

Figure 3 shows a transverse cross section of a post for use with one or more panels according to the invention; Figure 4 shows an example of a fence comprising a plurality of panels according to the invention;

Figure 5 illustrates a way in which a post of the type shown in Figure 3 may be fitted in place;

Figure 6 shows a post fascia insert according to the invention; Figure 7 shows a post fascia insert in place;

Figures 8A-C show a locking clamp according to the invention;

Figure 9 shows an alternate locking clamp according to the invention;

Figure 10 shows an end view of a plank of the invention;

Figure 11 shows a schematic diagram of an apparatus for acoustic noise testing; and

Figures 12a and 12b show graphs of acoustic noise test data.

Referring to Figure 1, there is shown an end view of a panel 1 according to the invention. The panel 1 has a first major surface 2a and a second major surface 2b, which is on an opposite side of the panel from the first major surface 2a.

Both of the major surfaces 2a, 2b are provided with four spaced-apart elongate depressions 4 which extend along the entire length of the panel 1 {i.e. into the plane of the paper). Extending between the major surfaces 2a, 2b, along the top and bottom of the panel are a first minor surface 3a and a second minor surface 3b. Minor surface 3a comprises a groove 6, which extends along the length of the panel 1. Minor surface 3b comprises a tongue portion 7, which extends along the length of the panel 1. The tongue portion 7 is shaped so that it is receivable in the groove 6 of a successive panel 1.

The outer shape of the end of the panel is determined by the form of the major surfaces 2a, 2b and minor surfaces 3a, 3b.

Five spaced-apart passageways 5 extend through the panel 1 along its length. The passageways 5 are substantially rectangular in cross-section.

In preferred embodiments, the panel 1 has a uniform cross-section along its entire length.

As is shown in Figure 2, panels of the type shown in Figure 1 may be stacked in order to form a barrier, e.g. a fence, flood barrier or sound barrier. Further, such panels may be laid horizontally to form scaffolding or decking.

In Figure 2, a portion of a stack comprising two panels 1' and 1" is shown. As can be seen, the tongue portion 7' of panel 1' is received in the groove 6" of panel 1", thereby providing a tortuous path from one side of the stack to another. Of course, alternative tongue-and-groove arrangements may be provided. For instance, the stack may be formed such that one or more tongue portions face upwards. Other shapes may be used.

The panel 1 is typically extruded from a mixture of plastics, wood flour and glass fibres. Upon emerging from the extrusion head both major surfaces are brought into contact with a roller or other impressing means having a sinusoidal or otherwise curved pattern formed therearound or thereon to impart a corresponding elongate curved pattern along the extruded length. The depth of the pattern is typically lmm, although it may be deeper or shallower.

One or both of the major surfaces may then be brought into contact with, for example, a grinding or sanding station which abrades the panel at an angle to the longitudinal or principal axis of the panel 1. It has been surprisingly found, that abrading at an angle generates a simulated wood grain pattern on the surface. The grinding may remove all or most of the elongate curved pattern. Figure 3 shows a transverse cross-section of a post 8 for use with one or more panels 1 according to the invention.

The post 8 has a substantially square cross-section with rounded or radiused corners.

In alternative embodiments of the invention, the post 8 may comprise a substantially circular cross section. Posts 8 having this shape are generally quicker and easy to erect since it is straightforward to dig a cylindrical hole. Running through the centre of the post 8 in a lengthwise direction is a channel 9. Each side of the post 8 is provided with a recess 10a, 10b, 10c, 1Od which extends in a lengthwise direction.

Each recess 10a, 10b, 10c, 1Od has a pair of side walls a, b; a',b' and a base c, c'. As shown in Figure 3, recesses 10a, 10b and 10c are substantially identical.

Recess 1Od is different from recesses 10a, 10b and 10c, since its side walls a', b' are not perpendicular to the side of the post 8 in which the recess 1Od is formed and the base c' is not parallel to the respective side of the post 8.

In use, a plurality of posts 8 are installed at spaced-apart locations. Panels 1, or stacks of panels 1, according to the invention are located between the posts such that each end portion of each panel 1 or stack is received within a recess 10a-d of a post 8.

It will be appreciated that the orientations and configurations of the recesses may be adapted to suit the terrain and/or intended route of a fence or barrier formed in this way.

Sealing means SM, e.g. rubberised seals (see Figure 10), may be provided, typically at least partially in (e.g. to plug the end) or on the ends of the panels, to prevent or hinder fluid flow through the barrier in the region of the recesses and/or to make a tight fit of the panel 1 within the recess 10. This may be particularly advantageous in embodiments of the invention which comprise a flood barrier. A panel 1 and a successive panel 1' may have a jointing compound used at their abutment, such as silicone sealant, to further hinder the passage of fluids from one side of the stack to another.

Figure 4 shows an example of a barrier comprising a stack of three panels 1 between a pair of posts 8. A cap 20 is attached to the top of each post 8.

Clearly, the angle of recess 1Od can be altered. However, it is considered that 22.5° {i.e. Vi of 45°) is the optimum angle. In any case, the angle will usually be between 10 and 45°. If steeper angles are required the post 1 can be inverted. The post 1 may have more than one recess 1Od, angled with respect to its respective face.

Figure 5 illustrates a way in which a post 8 can be fixed in position to provide a removeable or demountable fence or barrier.

A hole 15 is provided in the ground for receiving a portion of a part post 8'. This portion of post has substantially the same form as the post shown in Figure 3 and may be cut to length such that, in use, it extends almost to the top of the hole, is flush with the top of the hole or does not extend very far above ground level GL. The part post 8' may be secured in place using concrete or other settable compositions.

As shown in Figure 5, towards its lower end to-be-installed post 8 is provided with a transverse aperture 11 for receiving a locking pin 12. The transverse aperture 11 communicates with the channel 9. Aperture 11 may extend from a recess 10 and thereby be occluded in use by a panel or fascia insert.

An elongate support insert 13, which is typically made from steel, is also provided. The insert 13 has at least one transverse aperture 14 therethrough. In use, the support insert 13 is partially received within the channel 9' of the post portion 8' located within the hole 15 and partially received within channel 9 of the post 8 such that apertures 11 and 14 are in alignment and the locking pin 12 can be inserted therethrough.

Advantageously, the aligned apertures 11, 14 and the locking pin 12 are located above ground. Hence, it may be relatively quick and simple to assemble and disassemble a fence or barrier.

Furthermore, because the post 8 offers structural support for the panels, e.g. via the composite material used to form the post 8 and/or via the support insert 13, there is no need to utilise additional brace units for providing barrier reinforcement making the barrier easier and/or quicker to construct and/or deconstruct. This is especially advantageous when the barrier is to be used as a flood defence barrier.

Figure 6 shows a three-dimensional view of a section of a post fascia insert 16, which is sized and dimensioned for a snug push-in fit within any recesses 10a, 10b, 10c, 1Od which are unoccupied by a panel 1 or stack of panels, in use. The post fascia insert 16 has a top surface 17, a pair of corrugated sides 18 extending downwardly from the top surface 17 and a base 19 which comprises a V-shaped formation 30 extending into the body of the insert 16.

The corrugations on each corrugated surface 18 extend along the length of the insert 16.

Figure 7 shows in cross-section an insert 16 in place within a recess 10 of a post 8. The insert 16 fits snugly within the recess 10. Advantageously, the V-shaped formation 30 of the base 19 serves to provide an enclosed channel for housing wiring, conduits, tubing or the like. In other embodiments, shapes other than V-shaped formations are envisaged.

Thus, if the barrier formed from panels 1 and posts 8 is to provide a boundary it is possible to mount facilities, e.g. lights, cameras and so on, at the top of the barrier, e.g. on the top of one or more of the posts 8. Should such facilities require connection to a utility (gas, water, electricity) the utility may be plumbed or connected to the facility along a recess 10 and the plumbing or connection can then be covered by the insert 16 so as to ensure that the plumbing or connection is safe and secure. Of course, if the barrier is to be used to secure an area, it is likely that the connection or plumbing is likely to run along a recess which faces and is within the secured area so as to limit the opportunity for interference.

Figures 8A-C show an example of a board locking clamp 200 of the type that may be required if it is desired to ensure that the barrier remains in place, e.g. if a barrier of fence is put under strain or is encouraged to rise, e.g. due to the pressure of flood water.

The clamp 200 comprises four portions. The first portion comprises a rigid elongate member 21 which terminates at a proximal end in a nut formation

23 with a threaded bore that runs transverse to the longitudinal axis of the elongate member 21.

The second portion comprises a plate 24 which is substantially square. The plate has a centrally-located threaded bore therethrough. Two opposite sides of the plate 24 are provided with notches 27 at locations about halfway along the length of the sides.

The third portion of the clamp comprises a base plate 25 having an underside which is adapted to sit on and fit over the top of a panel within a barrier or fence. Extending upwardly in a substantially vertical direction from the base plate 25 at locations about half way along opposite sides of the base plate 25 are two prong formations 26, which terminate in inwardly depending formations.

The fourth portion of the clamp comprises a bolt 22. In the preferred embodiment, the head of the bold 22 is provided with a surface that is suitable for being gripped by hand.

In use, the base plate 25 of the third portion of the clamp 200 is placed on top of a panel 1 within the barrier, at a distance from a post 8. The plate

24 of the second portion of the clamp 200 is then put into place on top of the third portion such that the prong formations 26 and notches 27 fixedly engage.

The first portion is then put into place such that the threaded bore 23 is in alignment with the centrally-located bore through the plate 24.

The distal end of the elongate member 21 is accommodated within and engages with a complementary aperture formed in the post 8. Typically, this other end of the elongate member 21 may be received in one of the recesses 10 and/or a specially provided aperture within the post 8.

The first portion of the clamp is then secured to the second portion using the bolt 22, which preferably may be tightened manually.

In use, therefore, pressure from actuating the clamp 200 is applied from the top panel 1 downward. This is useful because it ensures that the vertically stacked panels 1 are tightly secured.

An alternative embodiment of a clamp will now be described in relation to Figure 9 which may be better suited for instances where the fence or barrier continues in the same direction on opposite sides of a post 8. In this embodiment, a nut formation is provided at each end of an elongate member. In use, the elongate member passes through the post (e.g. via a slot or passageway provided therefor) and is tightened in place against the top of a respective panel 1 using a bolt either side of the post. A fascia (not shown) can be used to obscure the clamp 200 from sight, in use.

As stated above, the panel 1 may be laid down horizontally for use as a scaffold board, i.e. supported by scaffold poles to provide an elevated platform or may be formed as a barrier. It is of particular interest to use the barrier as a flood prevention barrier which may be demountable or as a security barrier. It is also of interest to use the panels 1 and posts 8 in the formation of a sound barrier, e.g. for position along the sides of motorways or train lines.

In the formation of a sound barrier it has been surprisingly found that presenting a major face of a panel 1 (or stack thereof), that major face having an elongate curved pattern on the surface, to a source of noise can drastically reduce or dissipate the level of sound. This is particularly advantageous insofar as sound barriers are concerned as it is possible to grind an intended public facing side of a panel 1 to produce a simulated wood finish whilst presenting the side having the curved pattern to the noise source (motorway, train line and so on) to dissipate sound. It is believed that the contoured surface refracts sounds waves and the material is effective at absorbing sound waves.

Figure 11 shows a schematic diagram of an acoustic testing apparatus.

The apparatus, as shown generally at 100, comprises two enclosed spaces adjacent to one another: a first enclosed space 101 and a second enclosed space 102. Housed within the first enclosed space 101 is a pair of sound generation means 103 and a first sound detection means 104. Housed within the second space 102 is a second sound detection means 105. The second space 102 is also soundproofed with insulation 106 in order to prevent interference by external sound.

The apparatus 200 was used to investigate how effective a sound barrier panel 1 according to the present invention is at reducing levels of sound.

A 1.0m x 1.5m sample of 6mm thick sound barrier panel 1 according to the present invention was placed between the first 101 and second 102 enclosed spaces to form a barrier therebetween.

The panel 1 comprises first 2a and second 2b major surfaces. The first major surface 2a comprises and elongate curved pattern (i.e. a sound dissipation surface) and the second major surface 2b was plain.

The sound dissipation surface 2a of the panel 1 was directed towards the sound generation means 103 and the plain surface 2b was directed into the second enclosed space 102.

Noise having a range of frequencies from 20 to 10,000 Hz was directed toward the intended sound dissipation surface 2a of the panel 1. Sound intensity levels were recorded at the first 104 and the second 105 sound detection means.

Table 1 (below) shows the recorded intensity (dBA) levels for the applied range of frequencies (Hz).

Table 1

Figures 12a and 12b show plots of the recorded intensity (dB/dBA) versus frequency (Hz) data.

The horizontal axes of Figures 12a and 12b relate to the applied frequency in Hertz (Hz). The vertical axis of Figure 12a relates to the recorded sound intensity (dB) referenced to the nominal threshold of human hearing - the sound pressure level (SPL). (i) is a plot showing intensity (dB) as a function of frequency (Hz) recorded at the first sound detection means 104; and (ii) is a plot showing intensity (dB) as a function of frequency (Hz) at the second sound detection means 105.

The vertical axis of Figure 12b relates to the recorded intensity (dBA) referenced to the nominal threshold of human hearing and multiplied by an A-weighting factor - sound pressure level x A (SPLA). (i') is a plot showing intensity (dBA) as a function of frequency (Hz) recorded at the first sound detection means 104; and (ii') is a plot showing intensity (dBA) as a function of frequency (Hz) at the second sound detection means 105.

As shown in Table 1 and Figure 12, the overall reduction in sound across the sound barrier panel 1 is 72.6%. As will be appreciated, this data corresponds to a 1.5m x Im x 6mm thick piece of composite material according to the present invention. In practice, and as shown in Figure 1, the sound barrier panel 1 effectively comprises two 6mm thick sections of composite material interposed by an air pocket 5. Therefore, it is conceivable to predict that a sound barrier panel 1 having two 6mm sections of composite material will reduce the level of sound by up to 92%. Clearly, this figure does not take into account the effect that the air pocket will have on insulating noise. Therefore, it is predicted that the overall reduction in sound is likely to be in the region of 95%, including sound insulation provided by the air pocket. Finally, in alternative embodiments of the invention such as use in agriculture or domestic use, it is envisaged that spacers may used to separate panels 1 so as to provide a fence which can be seen through, e.g. for paddocks or pens. Domestic uses may also benefit from spaced panels 1.

In one exemplary embodiment of the invention, a barrier having the dimensions (see Table 2) and composition (see Table 3) was erected.

Table 2

Table 3

If the panels 1 and/or posts 8 are to be used as flood barriers, it is desirable to increase their composition of glass fibre to, for example, between 40 and 50 wt%, in order to make the article less prone to absorb moisture.

In another exemplary embodiment of the invention, a flood protection barrier comprising ten panels each stacked one upon the other was erected. The barrier stood approximately 2.25m high and was used as a defence against an increasing tide. The water level increased to approximately 1.75m from ground level and the barrier did not leak nor did the panels bow. It was therefore demonstrated that the barrier was 100% effective.

If the panels 1 are to be used as a security fence, it is possible to thread steel cables along one or more passageways 5 of one or more mounted panels 1. The cables may extend through posts 8 and long further panels 1. Of course, depending on the security arrangement it may be that just the top most panel 1 in a stack is secured using cables. Alternatively, all of the panels 1 may be secured.

It is envisaged that barriers, fences, decking, scaffolds and platforms comprising one or more articles according to the invention may have utility in a wide range of industrial, agricultural and/or domestic settings. Further, such barriers, fences, scaffolds and platforms typically may be readily assembled and/or disassembled and recyclable. For example, used or damaged panels and/or posts may be ground down for use as at least a part of the feedstock for new panels and/or posts.

It will be appreciated that by providing first and second post recesses for receiving the edges of panels, which recesses extend in non parallel or anti normal directions the flexibility and versatility of the design is demonstrated. Further, the provision of one, two or more further recesses adds to the versatility. The recesses enable a huge number of shapes with different effective radii of curvature to be defined.