Patent Description:
Natural stone is a popular decorative surface for dwellings and the like. However, the cost of using skilled stonemasons to lay the stone is often prohibitive.

One proposed solution has been to provide moulded panels which are shaped and coloured to give the appearance of natural stone. However, many people dislike the use of artificial materials.

Another solution has been to use epoxy to join pieces of stone together. This has the advantage that the stones are pre-formatted, but typically still requires expensive pre-cladding supply and installation, mortar adhesive, and the use of a stonemason or tiler to install the stone. The preformatted stone is typically sold in relatively small units, which means that a large number of joins between the courses can be seen.

<CIT> discloses a mold-in fastening member which is composed of a strip of substrate, engaging elements formed on one surface of the substrate, and an elastomer layer completely surrounding the engaging elements, the substrate having slits or notches which extend from a widthwise central portion of the substrate to a widthwise end portion of the substrate.

<CIT> discloses a process and device for manufacturing a composite building panel of the type comprising a facing layer made from a plurality of facing elements, such as brick slices or stone slices for example, retained in a spaced apart relationship, and a magnetically attractable particulate material disposed between the facing elements to imitate mortar.

The reference to any prior art in the specification is not, and should not be taken as, an acknowledgement or any form of suggestion that the prior art forms part of the common general knowledge in any country.

It is an object of a preferred embodiment of the invention to provide a building panel and/or a method of manufacturing the panel and/or a method manufacturing a moulded product which will overcome or ameliorate problems with such panels or methods at present, or which will at least provide a useful choice.

Other objects of the present invention may become apparent from the following description, which is given by way of example only.

According to one aspect of the present invention there is provided a method of manufacturing a moulded product comprising at least one article set into a polymeric layer, the method comprising the steps of:.

Preferably the step of introducing the polymeric material into the container comprises placing the container into a mould tool.

Preferably the container comprises a mould tool.

Preferably the container is placed into a mould tool prior to introducing the polymeric material.

Preferably the container can be transferred or inverted into a mould tool prior to introducing the polymeric material.

Preferably the method comprises the step of laying the at least one article in a desired pattern or position on a template prior to the step of placing the at least one article in the container.

Preferably the step of introducing particulate ferrous material into the container comprises the step of locating or activating a magnetic source beneath the container to embed the decorative elements into the particulate ferrous material.

Preferably the step of introducing particulate ferrous material into the container comprises the step of vibrating the container.

Preferably the method comprises positioning a plurality of articles in the container, the method further comprising the step of positioning a spacing material between at least two adjacent articles prior to the step of introducing the polymeric material into the container.

Preferably the method comprises the step of positioning a tension member over the articles prior to the step of introducing the polymeric material into the container.

Preferably the tension member is adhered to the articles.

Preferably the tension member comprises a plurality of cables and/or a mesh.

Preferably the method comprises heating the at least one article to between <NUM>-<NUM> between the step of introducing the particulate ferrous material into the container and the step of introducing the polymeric material into the container.

Preferably mesh comprises at least one fixing means.

Preferably the moulded product is a building panel.

Preferably the article is a decorative element.

Preferably the particulate ferrous material comprises iron sand.

Preferably the step of locating or activating a magnetic source beneath the mould comprises the step of activating an electromagnet. Alternatively the step of locating or activating a magnetic source beneath the mould comprises the step of moving magnetic material beneath the mould.

Preferably the step of introducing the polymeric material into the mould comprises the step of injecting the polymeric material into the mould. Alternatively the step of introducing the polymeric material into the mould comprises the step of pouring or spraying the polymeric material into the mould.

Preferably the polymeric material comprises polyurethane.

Preferably the filler material comprises one or more of glass fibres, glass flake, chopped roving, mica, quartz, calcium carbonate, silica sand, sand or aluminum oxide.

According to a further aspect of the present invention there is provided a method of manufacturing a moulded product comprising at least one article set into a polymeric layer, the method comprising the steps of:.

the method further comprising the steps of:.

According to a further aspect of the present invention there is provided a method manufacturing a moulded product comprising at least one article set into a polymeric layer, the method comprising the steps of:.

Preferably the filler material comprises silica sand.

Preferably the filler material comprises glass fibres.

In one embodiment the method comprises the step of positioning a backing layer above the at least one decorative element, and the method comprises filling a void space between the backing layer and the at least one decorative element with the polymeric material.

Preferably the backing layer is provided with a tension member, and at least one fixing means is connected to the tension member.

Preferably a first portion of the tension member is connected to the backing layer and a second portion is not connected to the backing layer.

Preferably the method comprises the step, prior to the step of introducing the polymeric material into the mould, of locating the second portion of the tension member and the at least one fixing means such that the second portion of the tension member is embedded in the polymeric material when the material has set or cured.

Preferably the tension member comprises a mesh.

Preferably the backing layer comprises keying portions which are shaped to provide a mechanical connection between the polymeric material and the backing layer when the polymeric material has set or cured.

Preferably the backing layer has a density which is greater than a density of the polymeric material.

Preferably the density of the backing layer is substantially twice the density of the polymeric material.

Preferably the backing layer comprises a second polymeric material.

Preferably the second polymeric material comprises polyurethane.

Preferably the method comprises the step of forming the backing layer by introducing the second polymeric material into a backing layer mould and setting the second polymeric material.

Preferably the step of forming the backing layer comprises the step of embedding the first portion of the tension member in the backing layer.

Preferably the at least one decorative element comprises a stone or rock.

Preferably the method further comprises moulding an edge formation into one or more edges of the moulded product.

Preferably the edge formation comprises a tongue or a groove.

According to another aspect of the present invention there is provided a building panel produced by the method of the first or second aspects of the invention.

The invention may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, in any or all combinations of two or more of said parts, elements or features, and where specific integers are mentioned herein which have known equivalents in the art to which the invention relates, such known equivalents are deemed to be incorporated herein as if individually set forth.

According to a still further aspect of the present invention, a building panel and/or a method of manufacturing a building panel is substantially as herein described, with reference to the accompanying drawings.

Further aspects of the invention, which should be considered in all its novel aspects, will become apparent from the following description given by way of example of possible embodiments of the invention.

Referring first to <FIG>, a building panel made in accordance with a method of the present invention is generally referenced by arrow <NUM>. The panel <NUM> comprises at least one, and more preferably a plurality of decorative elements <NUM> set into a backing layer <NUM>, as is described further below.

One embodiment of the method of manufacturing the building panel <NUM> is described below.

Referring first to <FIG>, in a first step the decorative elements <NUM> are set out in a required pattern on a template <NUM>. The decorative elements <NUM> are preferably set out face up.

In a preferred embodiment the decorative elements <NUM> are simply placed on the template <NUM>, and are not secured to the template <NUM> in any way.

Referring next to <FIG>, a container <NUM> is shown. The container <NUM> has recess <NUM> which has an outline which is a mirror image of the template <NUM>. The container <NUM> is preferably also provided with flanges <NUM> on opposite sides of the container.

Once the decorative elements <NUM> have been laid out in a suitable pattern, the container <NUM> is placed over the template <NUM> such that the recess <NUM> fits over the decorative elements <NUM>. The depth of the recess <NUM> is less than the depth of the decorative articles <NUM>, and so the container <NUM> can be held tightly against the decorative elements <NUM>. The template <NUM> and container <NUM> are then inverted so that the decorative elements <NUM> are lying inside the container <NUM> and the template <NUM> is removed. The arrangement of the decorative elements <NUM> is generally maintained during this process, although small realignments of the decorative elements may be required.

Referring next to <FIG>, a particulate magnetic material, such as a particulate ferrous material, for example iron sand, is brushed into the spaces between adjacent decorative elements <NUM>, and between the decorative elements <NUM> and the sides of the container <NUM>. In one embodiment the container <NUM> is then positioned adjacent to or over a magnet <NUM> prior to particulate ferrous material being added, although in other embodiments this step may be omitted.

The container <NUM> (and magnet <NUM> if used) may be vibrated during this process. By this process the decorative elements <NUM> are embedded in the particulate ferrous material <NUM> to a predetermined depth, corresponding to the amount of the decorative element which is to protrude from the backing layer <NUM> in the finished panel <NUM>. A spacing material such as a settable or mouldable material, for example a putty <NUM> may also be placed between adjacent decorative articles <NUM> in order to maintain their relative spacing. This may assist in maintaining the relative spacing between the decorative elements <NUM> before they are set into the polymer matrix, and may also assist in reducing "creep" when the panels are in use.

Referring next to <FIG>, a tension member, which in one example is provided in the form of a mesh <NUM>, is laid over or about the decorative elements <NUM>. In one embodiment a removable frame (not shown) may be placed over the container to assist in aligning the mesh. The tension member may alternatively comprise one or more lengths of material such as strips or cables or wires. In a preferred embodiment a plurality of substantially "L" shaped fixing means <NUM> are attached to the mesh <NUM> and are spaced so as to fit in spaces between the decorative elements <NUM>. The mesh <NUM> may be connected to the back of the decorative elements <NUM> with a suitable adhesive or putty, in order to keep it in position until the polymer matrix is formed. The removable frame (if used) may now be removed. In this state the assembly may be referred to as a pre-form. A cross-section side view including the decorative elements shown in <FIG> is provided in more detail in <FIG>.

The container <NUM> may next be preheated to <NUM>-<NUM> then moved straight to the plastic injection stage described below, or it may be stored while the process described above is used to fill one or more further containers. In one embodiment a plurality of containers <NUM> are stored in a suitable rack <NUM> prior to the plastic injection stage, as shown in <FIG>. Alternatively, the plurality of containers can be placed in compression on a conveyor belt (not shown) to control the production speed/ flexibility of the process, if required. In a preferred embodiment the pre-forms are heated by storing them at a temperature of around <NUM> - <NUM> overnight, or for a minimum of <NUM> hours, prior to the injection step.

Referring next to <FIG>, a mould tool is generally referenced by arrow <NUM>. The tool <NUM> has at least one, and more preferably a plurality, of recesses <NUM>, each of which is shaped to receive a container <NUM>.

The mould tool <NUM> is arranged such that a suitably shaped magnet (or electromagnet) is provided beneath each recess <NUM>, or at least so that one can be placed there when required.

In some embodiments the side edges of the panel <NUM> are shaped with an undercut. The tool <NUM> may be provided with sliding side portions <NUM> which form the undercut, and which can be withdrawn into the walls of the tool to allow the panel <NUM>, once formed, to be removed from the tool. Alternatively, separate inserts (not shown) may be used to form the undercut, if required.

Prior to injection of the polymeric material into the mould, the inside of the lid <NUM> and the inserts (if provided) may be waxed.

With the magnets <NUM> in position and energised, the polymer (typically Reaction Injection Moulding (RIM) or Reinforced Reaction Injection Moulding (RRIM) polyurethane) is injected into the mould cavity. The presence of the magnetic field generated by the magnets <NUM> ensures that the particulate material stays in position, and that it is not disturbed by the injection of the polymer.

Once the polymer has set or cured to a sufficient degree, the sliding portions <NUM> (if provided) are withdrawn and the lid opened. A lifting means, for example a hydraulic ram (not shown), lifts the container <NUM> and panel <NUM> from the recess <NUM>.

The panel <NUM> is then removed from the container <NUM>, preferably with the magnets <NUM> still in position/activated. Leaving the magnets activated during this stage ensures that the particulate material falls from the face of the panel <NUM> into the container <NUM>.

The magnets <NUM> may then be de-energised/removed and the finished panel may be moved to a heat controlled environment (for example at around <NUM>-<NUM>) for a required period until the setting or curing process is complete.

In embodiments in which separate inserts are used to shape an undercut, a slightly different process may be used to remove the panel from the tool.

Here, the lid <NUM> is opened only a small amount, for example <NUM>, and the particulate material is vibrated from the face of the panel. The lid is then fully opened and the insert removed, before the panel is moved to the heat controlled environment.

In another embodiment (not shown) the decorative elements may be laid directly into the container <NUM>, rather than first being laid out on the template. The particulate ferrous material may be introduced into the container either before or after the decorative elements. In this embodiment the mould tool may define the container, rather than the container being removable from the mould tool.

Referring first to <FIG>, a building panel according to a second embodiment of the present invention is generally indicated by arrow <NUM>.

The panel <NUM> comprises a backing layer <NUM> connected to a second layer <NUM>. A plurality of decorative elements <NUM> are embedded in the second layer <NUM>.

A tension member, typically a mesh <NUM>, is connected to the backing layer <NUM>. The mesh <NUM> is provided with at least one fixing means <NUM>, more preferably a plurality of fixing means <NUM>.

In a preferred embodiment the backing layer and second layer are formed from a polymeric material, preferably a polyurethane foam. In the embodiment shown a first portion <NUM> of the mesh <NUM> is embedded in the backing layer <NUM>, and a second portion <NUM> of the mesh is embedded in the second layer <NUM>, as is described further below. The fixing means <NUM> are also preferably also embedded in the second layer <NUM>.

The first portion <NUM> of the mesh <NUM> is preferably embedded in the backing layer <NUM> at or adjacent the top of the backing layer <NUM>.

The second layer <NUM> is preferably provided with at least one keying portion <NUM> which assists to prevent relative movement between the backing layer <NUM> and the second layer <NUM> in the plane of the panel <NUM> and preferably also assists in preventing separation of the backing layer <NUM> from the second layer <NUM>. In a preferred embodiment each keying formation <NUM> may engage an inwardly tapered portion of an aperture <NUM> provided in the backing layer <NUM>.

Referring next to <FIG> a method of manufacturing the panel <NUM> is described.

Referring first to <FIG>, the backing layer <NUM> is prepared by injecting a suitable polymeric material into a mould <NUM>. The mould <NUM> is preferably proved with suitable void formers <NUM> to form the apertures <NUM> referred to above. A cross-section side view of second mould <NUM> with decorative elements <NUM> laid in bed of iron sand <NUM> is shown in <FIG>.

The mesh <NUM> is preferably located such that a first portion <NUM> is within the material of the backing layer, and a second portion <NUM> is held clear of the polymeric material.

Referring next to <FIG>, a mould <NUM> is partially filled with a particulate ferrous material, preferably iron sand <NUM>. One or more decorative elements <NUM> are laid in the mould <NUM> in a desired pattern. The decorative elements <NUM> are pressed or settled in to the bed of iron sand such that a lower surface <NUM> (the front surface of the finished panel) of each decorative element <NUM> is buried below the surface of the iron sand <NUM>.

Referring next to <FIG>, with the decorative elements <NUM> in position, the backing layer <NUM> is positioned inside the mould <NUM>. The mesh <NUM> is positioned across the upper surfaces <NUM> of the decorative elements <NUM> and the fixing means <NUM> are positioned between the decorative elements <NUM>.

With the backing layer <NUM>, mesh <NUM> and fixing means <NUM> in position, a magnetic source <NUM> (typically an electromagnet) is activated below the mould <NUM>. In an alternative embodiment one or more permanent magnets are moved into position below the mould <NUM>.

With the magnetic source <NUM> activated (or moved into position, as the case may be), liquid polymeric material is injected into the void space between the backing layer <NUM> and the decorative elements <NUM> to form the second layer <NUM> of the panel (see <FIG>). Once the polymeric material has set or cured the panel <NUM> can be removed from the mould.

In another embodiment (not shown) the decorative elements <NUM> may be connected to the mesh <NUM> (for example by use of a suitable adhesive) prior to the backing layer <NUM> being positioned in the mould <NUM>. This may increase productivity by allowing the relatively time consuming process of determining the layout of the decorative elements to be performed remotely from the mould.

In preferred embodiments the polymeric material used for the second layer <NUM> may be a polyurethane foam. In a preferred embodiment the density of the foam used for the second layer <NUM> is less than that used for the backing layer <NUM>. In one embodiment the material of the backing layer is substantially twice the density of that used in the second layer. The second layer may comprise low density fillers such as silica sand and/or glass fibres to reduce its density.

Referring next to <FIG>, an enlarged cross-section view of a joint between two adjacent panels <NUM> according to an embodiment of the invention is shown. The joint formation may be used in panels formed by any of the methods described above.

Each panel <NUM> comprises an edge formation such as a tongue formation <NUM>. The tongue formation <NUM> is provided on one side of the panel <NUM>, and is preferably also provided at one end. The tongue formation <NUM> is adapted to engage another edge formation such as a complimentary groove formation <NUM> which is also provided on an opposite side of the panel <NUM> to the tongue formation <NUM>, and at the opposite end of the panel. In one embodiment the edge formation can be provided to ensure a complete overlap around the perimeter of the panel with other like panels.

The tongue formation <NUM> comprises a recessed portion <NUM>. The recessed portion <NUM> is preferably sufficiently recessed to accommodate the head of a screw fastener. In a preferred embodiment the recessed portion is recessed sufficiently deeply to act as a capillary break. In one example the recessed portion is recessed substantially <NUM>.

A nib <NUM> is provided at the end of the tongue portion <NUM>. The nib <NUM> preferably takes the form of a thin raised rib which extends along the tongue <NUM> down the edge of the panel. The thin nib <NUM> is compressible when the panel expends due to thermal expansion, and also reduces the friction between adjacent panels when the panels are being mounted, and minimises interference of particle contaminants that may otherwise bind in the joint and stop the panels from locating smoothly.

The groove <NUM> is preferably provided with an expanded mouth portion <NUM> in order to assist in engaging the tongue <NUM> of one panel with the groove portion <NUM> of another panel in use.

In preferred embodiments the tongue formation <NUM> may be provided with a shallow groove <NUM> to assist with locating the end of the fasteners when the panel is being fastened to a substrate.

This joint configuration may be used with either of the panels <NUM>, <NUM> described above.

Those skilled in the art will appreciate that the moulding methods described above may be used to manufacture products other than building panels. In addition, any suitable article, rather than purely decorative elements, may be embedded in the sand and thereby incorporated into the moulded product. The moulded product may provide a panel such as a wall panel that may be assembled with other like panels to form a covering such as a decorative cladding for a building or a similar structure.

Claim 1:
A method of manufacturing a building panel as a moulded product comprising at least one article (<NUM>), wherein the article is a decorative element (<NUM>) set into a polymeric layer, the method comprising:
partially filling a container (<NUM>) with particulate ferrous material;
placing the at least one article (<NUM>) in the container (<NUM>) so that at least a portion of the or each article (<NUM>) is embedded in the particulate ferrous material to a predetermined depth so that a surface of the or each article is buried below a surface of the particulate ferrous material,
positioning a tension member over or about the articles (<NUM>),
introducing a polymeric material into the container (<NUM>) to form the moulded product, and
removing the moulded product from the container (<NUM>).