GB2469837A - Elongate composite article comprising a lignocellulose material - Google Patents

Abstract

An elongate composite article 1 has two major surfaces 2a, 2b, the article has a composition comprising a mixture of polymer, lignocellulosic material and a plurality of inorganic fibres. The polymer accounts for at least 45 wt% of the mixture. Preferably, the polymer is high density polyethylene, the lignocellulosic material may be wood and the inorganic fibres can be glass fibres. In another aspect, the composition comprises a mixture of polymer, lignocellulosic material and a plurality of inorganic fibres and up to 5 wt% of additives, the inorganic fibres are glass fibres accounting for 50-55 wt% of the mixture. In a third aspect, a composite article in the form of a post (8, Fig.3) comprises 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. A barrier or fence is also claimed comprising at least one composite article and one or more posts. A method of manufacturing composite articles is also claimed.

Description

Composite Articles 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 for fences and barriers.

A first 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 inorganic fibres.

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

The inorganic fibres may be glass fibres.

The polymer may be high density polyethylene (HDPE).

The polymer may account for at least 45 wt%, preferably from 45 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., Fe203 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.

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 longest dimension.

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.

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

According to another aspect of the invention, there is provided a composite article in the form of 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 composite article has a composition comprising at least 45 wt% of a polymer and up to 55 wt% of a lignocellulosic material, e.g. wood, preferably in the form of sawdust or One desired composition for a post according to the invention comprises: >45 wt% polymer <25 wt% glass �=55 wt% wood flour or sawdust �=5 wt% additives.

According to yet another aspect of the invention, there is provided a composite article in the form of 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.

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 anti orthogonal.

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., Fe203 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 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.

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

Typically, the finished product may be 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 3O% 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 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.

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

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.

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 roller having a sinusoidal pattern formed therearound to imprint an elongate curved pattern along the extruded length. The depth of the pattern is typically 1mm, although it may be deeper or shallower.

One or both of the major surfaces may then be brought into contact with 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 the entire 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.

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 lOa, lOb, lOc, lOd which extends in a lengthwise direction.

Each recess lOa, lOb, lOc, lOd has a pair of side walls a, b; a',b' and a base c, c'. As shown in Figure 3, recesses lOa, lOb and lOc are substantially identical.

Recess 10d is different from recesses 10a, lOb and lOc, since its side walls a', b' are not perpendicular to the side of the post 8 in which the recess lOd 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 lOa-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, e.g. rubberised seals (see Figure 10), may be provided, typically 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 lOd can be altered. However, it is considered that 22.5° (i.e. 1/2 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 lOd, 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.

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 and the locking pin are located above ground. Hence, it may be relatively quick and simple to assemble and disassemble a fence or 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 ba, lOb, lOc, lOd 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 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 of the base 19 serves to provide an enclosed channel for housing wiring, conduits, tubing or the like.

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 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.

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.

As stated above, the panel 1 may be laid down 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.

In agricultural or domestic use it may be that spacers are 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.

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, 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.

Claims (1)

1. CLAIMS1 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 inorganic fibres and the polymer accounts for at least 45 wt% of the mixture.

   2 An article according to Claim 1, wherein the ratio of polymer to lignocellulosic material is around 1:1.

   3 An article according to Claim 1 or Claim 2, wherein the polymer is high density polyethylene, the lignocellulosic material is wood and the inorganic fibres are glass fibres. 0)

   4 An article according to Claim 3, wherein the mixture comprise 60 wt% high density polypropylene, 20 wt% wood and 20 wt% glass fibres. Co

   An article according to Claim 1, wherein the lignocellosic material is wood and the inorganic fibres are glass fibres and the mixture comprises 50-55 wt% polymer, 35 wt% wood, 10 wt% glass fibres and up to 5 wt% of additives.

   6 An elongate composite article having two continuous major surfaces, wherein the article has a composition comprising a mixture of a polymer, a lignocellulosic material a plurality of inorganic fibres and up to 5 wt% of additives, wherein the inorganic fibres are glass fibres and account for 50-55 wt% of the mixture.

   7 An article according to any one of the preceding Claims, comprising one or more open-ended cavities extending therethrough.

   8 An article according to any one of the preceding Claims, comprising engagement means adapted to engage with a portion of a neighbouring article when two or more articles according to any one of the preceding Claims are brought together in a stack.

   9 A composite article in the form of 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.

   A post according to Claim 9 having a second longitudinally Q extending side provided with a second longitudinally-extending If) recess for receiving a portion of a second panel.

   CO 11 A composite article in the form of 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 composite article has a composition comprising at least 45 wt% of a polymer and up to 55 wt% of a lignocellulosic material.

   12 A post according to any one of Claims 9 to 11 comprising one or more transverse apertures therethrough for receiving a section of wire and/or a portion of a clamping means, in use.

   13 A barrier or fence comprising at least one article according to any one of Claims 1 to 8 and/or one or more posts according to any one of Claims 9 to 12.

   14 A method of manufacture of composite articles comprising the steps of: a) obtaining the following components: (i) a suitable polymer; (ii) a lignocellulosic material; and (iii) inorganic fibres; b) melting a mixture of the components; c) forming pellets comprising the mixture; and d) using the pellets as feedstock for extrusion into a finished product; wherein finished, used or damaged products made according to, or by-products of, the method are introduced into the mixture at one or more of steps a), b) and c), preferably after pelletising.

   If) 15 A method according to Claim 12, wherein the finished product 0 comprises an article according to any one of Claims 1 to 12. Co

   16 A composite article as described hereinbefore and with reference to the accompanying drawings.

   17 A method of manufacture of composite articles as described herein before.