GB2622567A

GB2622567A - A method of manufacturing a composite material

Info

Publication number: GB2622567A
Application number: GB2211073.8A
Authority: GB
Inventors: John Taylor Conor
Original assignee: Solomon & Wu Ltd
Current assignee: Solomon & Wu Ltd
Priority date: 2022-07-28
Filing date: 2022-07-28
Publication date: 2024-03-27
Also published as: GB202211073D0

Abstract

Method of manufacturing composite material, comprising producing a mixture by mixing wet ingredients and dry ingredients in a ratio from 1:1.2 to 1:1.95 by weight, the wet ingredients comprise a resin, a hardener and an air-release agent, the dry ingredients comprise a mineral powder and a wood product; and curing the mixture. The wet ingredients may be mixed together to produce a wet ingredient mixture and the dry ingredients are subsequently added to the wet ingredients mixture. Prior to curing the mixture the mixture may be placed into a vacuum chamber and the pressure in the vacuum chamber may be reduced. The wet ingredients may comprise a pigment. The dry ingredients may comprise a filler. The wood product may be one or a combination of woodchips, wood shavings or wood dust. The woodchips may be produced by cutting a piece of wood substantially perpendicularly to the face of the grain of the piece of wood to produce slices of end grain wood, breaking the slices of end grain wood using a hammer mill, and selecting woodchips from the broken slices of end grain wood.

Description

A method of manufacturing a composite material The present invention relates to a method of manufacturing a composite material, particularly a composite material which may be applied onto a substrate to form surfaces such as counter tops, work tops, table tops, bench tops, stool tops, flooring, and the like. Such surfaces typically comprise mined materials which may only be made available by importing from overseas. For example, counter tops typically comprise materials such as granite, quartz, glass and marble. Alternative materials, such as plastic, laminate, wood and concrete, do not require mining and may be available without having to import products from overseas, but may be equally as environmentally unfriendly either due to the way in which they are produced (for example, by emitting fumes or felling trees) or their content. Therefore, it is desirable to produce a composite material for use in such surfaces which is more environmentally friendly in its content and/or production.

The claimed invention is a method of manufacturing a composite material, wherein the method comprises producing a mixture by mixing wet ingredients and dry ingredients in a ratio from 1:1.20 to 1:1.95 by weight, wherein the wet ingredients comprise a resin, a hardener, and an air-release agent, and wherein the dry ingredients comprise a mineral powder, and a wood product; and curing the mixture.

This range of ratios of wet ingredients to dry ingredients-in particular a range of ratios of 1:1.25 to 1:1.70 wet to dry ingredients by weight-provides a mixture having a viscosity that is low enough to allow the mixture to be worked, for example poured and spread onto a substrate to form a mixture layer, for example, on a substrate, yet high enough that, once mixed, the distribution of the components remains relatively consistent throughout such that, for example, after forming the mixture layer on a substrate, the wood product does not migrate to a surface, for example, an upper or lower surface of the mixture layer, which may be undesirable.

A surface of the mixture layer may be further processed by, for example, sanding, smoothing or planing, to remove a portion of the mixture layer. In some examples, if the wood product migrates to the surface and that surface were to be subsequently processed in this way, this may lead to loss of all, or a substantial proportion, of the wood product.

The wood product may be one, or a combination, of wood chips, wood shavings and wood dust-which are visually apparent in the mixture layer, at least at a surface thereof, and may therefore provide a desirable aesthetic. For example, wood chips may provide the composite material with an aesthetic similar to that of terrazzo, and wood shavings and wood dust may provide visually-appealing flecks throughout the composite material. The wood product may include visual defects or irregularities, which can result in the composite material having an appealing aesthetic. The wood product may be locally sourced wood waste from, for example, trees which have been felled in order to make way for planned developments or have fallen as part of the natural life cycle of non-commercial forests. Therefore, the composite material can make use of wood waste which would otherwise be disregarded because of its visual defects. The wood product may comprise at least 1% by weight of the mixture, may comprise at least 5% by weight of the mixture or at least 10% by weight of the mixture.

When producing the mixture, the wet ingredients and dry ingredients may be mixed in any manner suitable to achieve a substantially uniform consistency and / or distribution of ingredients. For example, the ingredients may be mixed in a vat using a paddle. When producing the mixture, the wet ingredients may be mixed together to produce a wet ingredient mixture, and the dry ingredients may be subsequently added to the wet ingredient mixture. Mixing the wet ingredients together before adding the dry ingredients may increase the uniformity of the mixture (i.e. enable each of its components to be more evenly distributed). Each of the dry ingredients may be added to the wet ingredients asynchronously (for example, the mineral powder may be added prior to the wood product), or the dry ingredients may be mixed together to produce a dry ingredient mixture and the dry ingredient mixture may subsequently be added to the wet ingredient mixture.

The method may further comprise, prior to curing the mixture, placing the mixture into a vacuum chamber and reducing the pressure within the vacuum chamber. Placing the mixture into a vacuum chamber and reducing the pressure therein enables gas which may have been introduced, trapped and/or produced during the mixing step, or otherwise, to be expelled from the mixture. This may reduce the likelihood of bubbles appearing in the cured product which may appear as a fault. This may also enable the wood product to absorb more of the resin, thereby reducing the extent by which the wood product may expand and contract when exposed to variations in humidity and/or temperature and reducing the likelihood of fractures forming in the composite material. This may increase the durability, and may also the aesthetic appeal of the composite material.

The resin may be any resin suitable for binding the components of the mixture in order to produce the composite material. The resin may be an epoxy resin (i.e. a polyepoxide). The resin may be a bio-based epoxy resin, such as Sicomin's SR GreenPoxy The hardener may be any hardener suitable for curing the resin to produce the composite material. The hardener may be an epoxy-curing agent. The epoxy-curing agent may have a relatively slow reactivity level in order to enable the mixture to achieve a substantially even consistency or allow the mixture to be worked, prior to completion of a curing process. Examples of such epoxy-curing agents include Sicomin's SD 4771' or SD 47701M.

The air-release agent may be any agent suitable for de-aerating, or facilitating the de-aeration of, the mixture to produce the composite material. The air-release agent may be a silicon-based oil, such as BASF's EFKA SI 2008TM The mineral powder may be any mineral powder which may be, for example, suitable for binding the mixture to produce the composite material. The mineral powder may increase the durability and heat-resistance of the composite material. The mineral powder may be a cement, such as Portland cement. The mineral powder may be white Portland cement which provides good durability and aesthetic appeal.

The wet ingredients may further comprise a pigment. The pigment may be any pigment able to change the colour of the composite material. The pigment may be natural (for example, iron oxide) or manmade.

The dry ingredients may further comprise a filler. The filler may be a mineral filler. The proportion of mineral filler may be selected based on a desired durability and aesthetic outcome of the composite material. For example, to increase the durability of the composite material the proportion of mineral filler may be increased, or to produce a warmer aesthetic the proportion of mineral filler may be decreased and wood dust may be increased.

The wood product may be one, or a combination, of woodchips, wood shavings, and wood dust. The use of a wood product incorporated into the material as opposed to, for example, wood veneer applied over a surface is advantageous as it soaks up the resin in the mixture, thereby minimising the likelihood of delamination.

The wood moisture content may be between 5 to 14% (for example, 7%). Higher wood moisture contents may interfere with the curing of the mixture layer, meaning the mixture layer may not harden sufficiently or may delaminate from a substrate to which it is applied.

The proportion of wood chips, wood shavings and wood dust may be selected based on a desired durability of the composite material. For example, to increase the durability and/or plasticity of the composite material the proportion of wood dust may be increased. Increasing the plasticity of the composite material is particularly advantageous as it allows the wood chips to expand and contract with changes in temperature and humidity which may be brought about due to a change in environment (for example, a change of the seasons), thereby preventing hairline cracks from forming. The proportion of wood chips, wood shavings and wood dust may be selected based on an aesthetic outcome of the composite material. For example, a greater proportion of wood chips may be selected to produce an appearance akin to terrazzo (with the wood chips replacing the conventional marble, quartz, granite or glass chips).

Alternatively, a greater proportion of wood shavings and wood dust may be selected to produce an appearance where flecks of wood shavings and wood dust can be seen within the composite material.

The woodchips may be produced by cutting a piece of wood substantially perpendicularly to the face grain of the piece of wood to produce slices of end grain wood; breaking the slices of end grain wood, for example using a mill such as a hammer mill; and selecting woodchips from the broken slices of end grain wood.

The piece of wood may be cut using a saw, for example using a bandsaw. The slices of end grain wood may be from 1 to 10mm thick, for example no more than 4mm thick, and may be from 3 to 4 mm thick. Using end grain wood as opposed to face grain wood to produce the wood chips helps to avoid a 'woodchip' visual effect in the end product and the wood chips may impart extra durability to the composite material that would not be provided by wood chips produced from face grain woodchips.

The woodchips may be selected based on a desired size and/or shape; for example, woodchips which are too large, too long, too regular may be disregarded and, optionally, broken again until they are the correct size and/or shape. The woodchips may be considered too large or long if they have a length that exceeds 60mm or a length and width that when combined exceeds 110mm. If the wood chips are too large then there is a greater risk of delaminafion and water damage as well as entrapment of air, which destabilises the composite material and reduces durability over time. The selecting may be carried out using a vibrating machine and/or by eye.

The slices of end grain wood may be broken with a hammer mill. The hammer mill may be configured in order to produce a higher proportion of wood chips than wood dust. For example, any sharp edged teeth of the hammer mill may be replaced with blunt teeth so that the slices of end grain wood are broken rather than cut. This enables the production of woodchips with a gravel-like consistency which mimics stone chippings. Bearings attaching the teeth to the mill may be loosened allowing the teeth to move more freely. The position of the teeth may be altered such that they are further apart. For example, they may be spaced from 10mm to 25mm apart, and preferably about 15mm apart. The hammer mill may not include a screen preventing ejection of material from the mill. This may enable wood chips to be ejected from the hammer mill once produced, thereby preventing the wood chips from being milled to wood dust by the hammer mill. These modifications help to ensure that the chips are broken rather than shredded and are not reduced to dust as most hammer mills are designed to do. If they are shredded to fibres then they may not adhere well in the composite material and may not become fully impregnated with the resin.

The wood shavings which may be included in the dry ingredients may be produced as a by-product of producing the wood chips. For example, the wood shavings may comprise sawdust produced when cutting the piece of wood to produce slices of end grain wood and breaking the slices of end grain wood using the hammer mill to produce woodchips. Alternatively, the wood shavings may be produced by shaving, for example planing, a piece of wood. The wood shavings may have a length of 0.5cm to 2cm (for example, 1 cm) and a thickness of 0.05 to 0.25mm (for example, 0.1mm to 0.2mm).

The wood dust which may be included in the dry ingredients may be produced as a by-product of producing the wood chips and/or wood shavings. For example, the wood dust may comprise sawdust produced when cutting the piece of wood to produce slices of end grain wood, breaking the slices of end grain wood using the hammer mill to produce woodchips and/or shaving the piece of wood to produce wood shavings. The wood dust may have an average diameter of a few tens of micrometers (for example 10pm to 30pm).

A first example mixture may comprise 26.25% resin, 8.66% hardener, 0.38% air-release agent, 3.49% pigment, 46.25% mineral powder, 13.01% wood product and 1.95% filler. A second example mixture may comprise 25.98% resin, 8.57% hardener, 0.38% air-release agent, 3.46% pigment, 45.77% mineral powder, 13.9% wood chips, and 1.93% wood dust and/or wood shavings. The first and second example mixtures have a viscosity which makes it easy to work, and produces a sufficiently durable and aesthetically pleasing composite material.

A third example mixture may comprise 33.3% resin, 10.99% hardener, 0.33% air-release oil, 0.44% pigment, 53.27% mineral powder and 1.66% wood dust and/or filler. This third example mixture has a relatively small quantity of dry mixture (less than the first and second example mixtures) meaning it is less viscous and less durable, but traps a relatively small quantity of gas.

A fourth example mixture may comprise 22.98% resin, 7.58% hardener, 0.46% air-release oil, 3.06% pigment, 52.13% mineral powder, 11.49% wood product and 2.3% filler. This example mixture has a relatively large quantity of dry mixture (more than the first and second example mixtures) meaning it is more viscous and durable, but difficult to work and traps a relatively large quantity of gas.

Suitable weight percentages in the mixture for each of the components may be: Resin: Between about 20% to 35% Hardener: Between about 7% to 12% Air-release oil: Between about 0.3% to 0.5% Pigment: Up to about 5% Mineral powder: Between about 40% to 60% Wood product: At least 1%, up to about 15% Filler: Up to about 5% filler As briefly mentioned above, the method may further comprise, prior to curing the mixture, pouring, or otherwise applying, the mixture onto a substrate to form a mixture layer over the substrate. The substrate may be placed on a flat surface-for example, a curing rack-prior to pouring the mixture onto the substrate.

A mould may be placed on or around the substrate to allow a layer of mixture to be built up on the substrate. The mould may prevent the mixture from running off the substrate. The mould may be formed from any suitable means. For example the mould may comprise walls which may be secured to the substrate. In one example the mould is made from from masking tape-for example, three layers of masking tape-and/or vinyl tape stuck to the edge of the substrate. The mixture layer may have a thickness of between from 2mm to 8mm, and the substrate may have a thickness of between from 12mm to 30mm. The combination of the mixture layer and the substrate may have a thickness of 24mm. An even thickness of the mixture layer may be encouraged by trowelling the surface of the mixture layer. Mixing the wood product into the mixture prior to pouring the mixture onto the substrate is advantageous as it means the wood product is fully immersed in the mixture prior to sanding. If the wood product were not fully immersed in the mixture (for example, if the wood product were scattered on top of the mixture once it was layered onto the substrate) a substantial portion of the wood product could be lost to the sanding process.

The resin and hardener may be heat-activated, and the method may comprise, after pouring the mixture onto the substrate and prior to curing the mixture, applying a hot press to the mixture layer such that the wood product is submerged within the mixture layer. The hot press may be at a temperature of from 80°C to 200°C and apply a pressure of from 60N to 110N for 3 minutes to 15 minutes.

The substrate may be made of any material. The substrate may be made of, for example, MDF, chipboard, honeycomb core materials, plywood and the like. Plywood is a preferred choice of material over, for example, MDF, chipboard, honeycomb core materials, as plywood is stronger and more rigid in comparison, which can reduce the likelihood of irregularities forming in the mixture layer. Plywood is also a popular choice for furniture as it machines well. The plywood may have a moisture content of 5 to 8 % (preferably 6%).

The substrate and mixture layer may form a sheet, and the substrate in the sheet may be made of plywood. The mixture may be produced in a batch process. For example, only half the required quantity of mixture may be produced at one time (to cover, for example, approximately 1.44sqm of substrate to the desired depth) in order to reduce the likelihood of irregularities being introduced during curing. The sheet may form a counter top, work top, table top, bench top, stool top, flooring, or the like.

The method may further comprise, after pouring the mixture onto the substrate and, prior to curing the mixture layer, applying a roller to the mixture layer. Applying a roller to the mixture layer ensures the wood product is submerged within the mixture layer, particularly the wood chips, and encourages the mixture layer to spread substantially evenly.

The step of applying a roller to the mixture may be conducted using a spiked roller. The use of a spiked roller is particularly advantageous as it encourages air to be expelled from the mixture (for example, by popping air bubbles) prior to curing. Furthermore, it may encourage the mixture layer to spread substantially evenly without disturbing the overall distribution of the wood product within the mixture.

The step of curing the mixture may be conducted for a length of time, and at a temperature and humidity to enable the wood product-in particular, the wood chips-to be impregnated with resin, and the mixture layer to adhere to the substrate. For example, the step of curing the mixture may be carried out on a horizontal surface for at least 1.5 days at a temperature of from 15 to 100°C and a humidity of from 35 to 65%. For example, the step of curing the mixture may be conducted for two days at a temperature of from 18 to 25 °C-for example, a temperature of 20°C-and a humidity of 40%. The curing time temperature may be selected based on the viscosity of the mixture and/or the ambient temperature at the time of curing.

The method may further comprise, after curing the mixture, sanding the composite material to produce a substantially flat, smooth surface. The step of sanding the composite material may be conducted using a steel roller comprising a sanding material, for example a sand paper, with a first grit size, followed by a rubber roller comprising a sanding material with a second grit size, wherein the second grit size is finer than the first grit size. Different sanding material with increasingly finer grit size may be used. For example, firstly a sanding material having a grit size P24 may be used and the sanding material may be replaced with finer and finer sandpapers until finally a sanding material having a grit size P180 may be used. For example, sanding material with the following grit sizes may be used in sequence: P24, P40, P80, P120, P180 and P240. Furthermore, different rollers being formed of different material may be used.

For example, firstly a steel roller may be used and the steel roller may be replaced with a rubber roller at a later sanding stage. Furthermore, the hardness of the rubber roller may vary; for example, firstly a relatively hard rubber roller may be used and replaced with increasingly soft rollers as the sanding process continues. For example, rubber rollers with the following hardness may be used in sequence: hard rubber roller, medium rubber roller and soft rubber roller. The harder rollers may be used in conjunction with sand papers which are more coarse; for example a steel roller may be used with P24 and/or P40 sandpaper, a hard rubber roller may be used with P80 and/or P120 sanding material, a medium rubber roller may be used with P180 sanding material, and a soft rubber roller may be used with a P240 sanding material.

The roller may form part of a wide belt sanding machine.

The filler may comprise one, or a combination, of wood, cement and resin produced as a byproduct of sanding the composite material. For example, the filler may be one, or a combination, of wood, cement and resin collected by an extraction system. The diameter of each component of the filler (i.e. each piece of dust) may be a few hundred nanometres-for example, 100nm to 300nm.

The method may further comprise, after sanding the composite material, filling in any hollows and/or bubbles at the surface of the mixture layer with a secondary mixture. The secondary mixture may comprise a resin and a hardener. The secondary mixture may also comprise at least one of mineral powder, wood dust, filler, and pigment, depending on, in order to, for example, blend with the mixture layer. Hollows and/or bubbles may be inspected by eye using, for example, a handheld light.

The secondary mixture may be further cured using an ultra-fast catalyst such as Sicomin SD4777TM. The mixture may then be further sanded, for example, by hand using a sanding paper with a fine grit, such as P240 and/or P320 sand paper. A treatment may then be applied to the mixture layer to protect the surface. The treatment may be an oil, such as a food-safe hardwax oil which functions to protect the surface from water and stains.

The invention will now be further described, by way of example only, with reference to the following figures in which: Figure 1 is a flow chart illustrating the method of manufacturing a composite material according to the claimed invention; Figure 2a illustrates a step of mixing the ingredients to produce a mixture; Figure 2b illustrates a step of placing the mixture in a vacuum chamber; Figure 2c illustrates a step of pouring the mixture onto a substrate to form a mixture layer, Figure 2d illustrates a step of applying a hot press to the mixture layer; Figure 2e illustrates a step of applying a roller to the mixture layer; Figure 2g illustrates a step of filling in any remaining hollows and/or bubbles with resin; Figure 3 is a flowchart illustrating a method of producing woodchips; and Figure 4 is a schematic illustration of a hammer mill for producing woodchips.

Figure 1 shows a method 2 of manufacturing a composite material according to the claimed invention. The method comprises a step 4 of producing a mixture by mixing wet ingredients and dry ingredients in a ratio from 1:1.20 to 1:1.95 by weight, wherein the wet ingredients comprise a resin, a hardener, and an air-release agent, and wherein the dry ingredients comprise a mineral powder, and a wood product; and a step 6 of curing the mixture.

Figures 2a to 2h each show a step in a method of manufacturing a composite material according to the claimed invention.

Figure 2a shows a first step 8 of mixing the ingredients. The weight percentage of the ingredients may be as set out in the examples mixtures presented above, for example the first or second example mixtures presented above. The wet ingredients comprising a resin 10, a hardener 12, an air-release agent 14 and, optionally, a pigment 16 are added to a first container 18 and mixed to form a wet ingredient mixture 20. The dry ingredients comprising a mineral powder 22, a wood product 24 and, optionally, a filler 26 are added to a second container 28 and mixed to form a dry ingredient mixture 30.

The wood product 24 comprises at least one of woodchips 30, wood shavings 32 and wood dust 34. The filler comprises at least one of by-product wood dust 36, by-product mineral powder 38 and by-product resin 40 produced as a by-product of the method 8.

The wet ingredient mixture 20 and dry ingredient mixture 30 are then added to a third container 42 to produce mixture 44. As explained above, the wet ingredient mixture 20 may be added to the third container 42 prior to the dry ingredient mixture 30. Alternatively, the wet ingredient mixture may be added to the third container 42 and each of the dry ingredients-mineral powder 22, wood product 24 and, optionally, filler 26-may be added to the wet ingredient mixture separately; for example, the mineral powder 22 may be added, optionally, followed by the filler 26, followed by the wood product 24. A combination of these approaches may also be used with some ingredients pre-mixed together and others added separately. The wet ingredient mixture 20 may be added directly to the third container 42 and mixed therein prior to adding the dry ingredient mixture 30 or each of the dry ingredients separately.

Figure 2b shows a second step 46 of placing the mixture 44 into a vacuum chamber 48. The mixture 44 remains in third container 42 when it is placed into the vacuum chamber 48. However, it may be transferred into a different container before being placed in the vacuum chamber. The pressure in the vacuum chamber is then reduced in order to remove gas from the mixture 44 Figure 2c shows a third step 50 of pouring the mixture 44 onto a substrate 54 in order to form a mixture layer 52 over the substrate 54. As explained above, the substrate 54 may be positioned on a flat surface in order to encourage the mixture layer 52 to have a substantially constant thickness. Furthermore, a mould may be positioned around or on top of the substrate 54 in order prevent the mixture 44 from running off the substrate 54. In this example, the substrate 54 is a flat rectangular sheet, but the substrate may be any shape and/or configuration. The substrate may 54 may be made of plywood.

Figure 2d shows a fourth step 56 of applying a hot press 58 to the mixture layer 52. This step 56 may be carried out when the resin 10 and hardener 12 are heat-activated, and may encourage the wood product to remain submerged within the mixture layer 52 and reduce the time required to cure the mixture layer 52. The hot press 58 may be at a temperature of from 80°C to 200°C and apply a pressure of from 60N to 110N, for 3 minutes to 15 minutes.

Figure 2e shows a fifth step 60 of applying a roller 62 to the mixture layer 52 to ensure the wood product is submerged within the mixture layer 52 prior to curing. The roller 62 has a plurality of spikes 64 which encourage the wood product to be submerged within the mixture layer 52 and pops gas bubbles which may have formed, for example, when producing the mixture 44 or pouring the mixture 44 onto the substrate 54. The roller 62 may be placed in contact with the mixture layer 52 and rolled over substantially the entire surface area of the mixture layer 52. The step 60 of applying the roller 62 to the mixture layer 52 may be carried out before and/or after the step 56 of applying a hot press 58 to the mixture layer 52.

Figure 2f shows a sixth step 66 of curing the mixture layer 52. The step 66 of curing the mixture layer 52 is carried out for at least 1.5 days at a temperature of from 15 to 100°C and a humidity of from 35 to 65%; for example, two days at a temperature of 20°C and a humidity of 40%.

The substrate 54 may remain on a flat surface or be moved to a flat surface (for example, provided by a curing rack) to cure.

Figure 2g shows a seventh step 68 of sanding the mixture layer 52 to produce a substantially flat, smooth surface. The step 68 of sanding the mixture layer 52 is carried out using a roller with a sanding layer 72. The step 68 of sanding the mixture layer 52 may first be carried out using a roller 70 made of steel and a sanding layer 72 comprising a sanding material having a first grit size, followed by a roller 70 made of rubber and a sanding layer 72 comprising a sanding material having a second grit size, wherein the second grit size is finer than the first.

By-product wood dust 36, by-product mineral powder 38 and by-product resin 40 produced as a result of sanding the mixture layer 52 may be used to form the filler 26.

Figure 2h shows an eighth step 74 of filling in any hollows and/or bubbles in the mixture layer 52. This may be carried out by applying using resin 10 using a brush and/or injector. The mixture layer 52 may then be left to cure further.

Figure 3 shows a flowchart illustrating a method 78 of producing woodchips. The method 78 comprises a first step 80 of cutting a piece of wood substantially perpendicularly to the face grain of the piece of wood to produce slices of end grain wood; a second step 82 of breaking the slices of end grain wood using a hammer mill; and a third step 84 of selecting woodchips from the broken slices of end grain wood.

Figure 4 shows a schematic illustration of a hammer mill 86 for producing woodchips which may be used in the method 78 shown in Figure 3. The hammer mill 86 comprises blunt teeth 88

Claims

Claims 1. A method of manufacturing a composite material, wherein the method comprises producing a mixture by mixing wet ingredients and dry ingredients in a ratio from 1:1.20 to 1:1.95 by weight, wherein the wet ingredients comprise a resin, a hardener, and an air-release agent, and wherein the dry ingredients comprise a mineral powder, and a wood product; and curing the mixture.
2. A method as claimed in any one of the preceding claims, wherein, when producing the mixture, the wet ingredients are mixed together to produce a wet ingredient mixture, and the dry ingredients are subsequently added to the wet ingredient mixture.
3. A method as claimed in any one of the preceding claims, wherein the method further comprises, prior to curing the mixture, placing the mixture into a vacuum chamber and reducing the pressure within the vacuum chamber.
4. A method as claimed in any one of the preceding claims, wherein the wet ingredients further comprise a pigment.
5. A method as claimed in any one of the preceding claims, wherein the dry ingredients further comprise a filler.
6. A method as claimed in any one of the preceding claims, wherein the wood product is one, or a combination, of woodchips, wood shavings, and wood dust.
7. A method as claimed in claim 6, wherein the wood product comprises woodchips, and wherein the woodchips are produced by cutting a piece of wood substantially perpendicularly to the face grain of the piece of wood to produce slices of end grain wood; breaking the slices of end grain wood using a hammer mill; and selecting woodchips from the broken slices of end grain wood.
8. A method as claimed in claim 7, wherein the hammer mill comprises blunt teeth.
9. A method as claimed in any one of the preceding claims, the method further comprising, prior to curing the mixture, pouring the mixture onto a substrate to form a mixture layer over the substrate.
10. A method as claimed in claim 9, wherein the resin and hardener are heat-activated, and the method comprises, after pouring the mixture onto the substrate and prior to curing the mixture, applying a hot press to the mixture layer.
11. A method as claimed in claim 10, wherein the hot press is at a temperature of from 80°C to 200°C and applies a pressure of from 60N to 110N for 3 minutes to 15 minutes.
12. A method as claimed in any one of claims 9 to 11, wherein the substrate is made of plywood.
13. A method as claimed in any one of claims 9 to 12, wherein the substrate and composite material form a sheet.
14. A method as claimed in claim 13, wherein the sheet forms a counter top. work top, table top, bench top, stool top or flooring.
15. A method as claimed in any one of claims 9 to 14, wherein the method further comprises, after pouring the mixture onto the substrate and prior to curing the mixture layer, applying a roller to the mixture layer to ensure the wood product is submerged within the mixture layer.
16. A method as claimed in claim 15, wherein the step of applying a roller to the mixture is conducted using a spiked roller.
17. A method as claimed in any one of the preceding claims, wherein the step of curing the mixture is conducted for at least 1.5 days at a temperature of from 15 to 100°C and a humidity of from 35 to 65%.
18. A method as claimed in claim 17, wherein the step of curing the mixture is conducted for two days at a temperature of 20°C and a humidity of 40%.
19. A method as claimed in any one of the preceding claims, wherein the method further comprises, after curing the mixture, sanding the mixture layer to produce a substantially flat, smooth surface.
20. A method as claimed in claim 19, wherein the step of sanding the mixture layer is conducted using a steel roller comprising a sanding material with a first grit size, followed by a rubber roller comprising a sanding material with a second grit size, wherein the second grit size is finer than the first grit size.
21. A method as claimed in claim 19 or 20, wherein the filler comprises one, or a combination, of wood, mineral powder and resin produced as a by-product of sanding the mixture layer.
22. A method as claimed in any one of claims 19 to 21, wherein the method further comprises, after sanding the composite material, filling in any hollows and/or bubbles in a surface of the mixture layer with a secondary mixture.