Fire resistant door and access panel system

Abstract

A fire-resistant composite (1) comprising: hemp hurd filler (3); blended resin mixture (11), wherein the blended resin mixture comprises at least a resin (13) and a fire retardant (15), wherein the blended resin mixture (11) binds the hemp hurd filler (3). The hemp hurd filler (3) may comprise charred hemp hurd (5).

Description

"Fire resistant door and access panel system"Technical Field

[0001] The present disclosure is directed to a fire resistant door and access panel system. This can include doors, door frames, access panels in walls, ceilings, etc.Background

[0002] Door systems and access panels in walls and ceilings function to selectively partition areas, such as between rooms, corridors, attics, etc. Wood is a common material door systems as they are renewable, abundant, easy to work, and cost effective. Metal, or metal components, have also been used for door systems and access panels. However, metal is heavy, relatively expensive, and may require more specialised tools to shape and form.

[0003] In some applications, the spread of fire, heat, smoke and gasses is a consideration. Thus some door systems and access panels require ratings. In particular, fire-resistance rating indicative of reducing spread and the effects of fire in a building or other structure. To that end, the use of known timber can be a hazard as wood is flammable and may not sufficient slow or stop the effects of fire.

[0004] Throughout this specification the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

[0005] Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present disclosure as it existed before the priority date of each claim of this application.Summary

[0006] According to one form of the present invention there is provided a fire-resistant composite comprising hemp h rd filler; blended resin mixture, wherein the blended resin mixture comprises at least a resin and a fire retardant, wherein the blended resin mixture binds the hemp hurd filler.

[0007] According to another form of the present invention there is provided a method of forming a fire-resistant composite material comprising blending a resin with a fire retardant to form a blended resin mixture; combining the blended resin mixture with a hemp hurd filler; moulding, in a mould, the combined blended resin mixture and hemp hurd filler to form the fire-resistant composite material.Brief Description of Drawings

[0008] Fig. 1 illustrates a fire-resistant composite in accordance with one example;

[0009] Fig. 2 illustrates a schematic illustrating components of a fire-resistant composite;

[0010] Fig. 3 illustrates a fire-resistant door in accordance with one example;

[0011] Fig. 4 illustrates a flow diagram of a method of forming a fire-resistant composite material;

[0012] Fig. 5 is a flow diagram of steps of a method of preparing hemp hurd filler for the fire-resistant composite material;

[0013] Fig. 6 is a flow diagram of steps of a method of preparing a blended resin mixture for the fire-resistant composite material;

[0014] Fig. 7 is a flow diagram of steps of a method of moulding the hemp hurd filler and blended resin mixture to form the fire-resistant composite material;

[0015] Fig. 8 is a flow diagram of steps of a method of bonding a skin layer to a fire- resistant composite material;

[0016] Fig. 9 is a flow diagram of additional steps of a method of bonding a skin layer to a fire-resistant composite material;

[0017] Fig. 10. illustrates a fire-resistant door system including a door and a door frame in accordance with one example; and

[0018] Fig. 11. Illustrates a fire-resistant access panel in accordance with one example.Description of Embodiments

[0019] Overview

[0020] The present disclosure provides a fire-resistant composite 1 for door systems 101 and access panels 201 and a method 300 for manufacturing the fire-resistant composite 1. The present disclosure includes a fire-resistant composite that includes components from the hemp plant whilst providing fire-resistant properties.

[0021] In general, bast crops such as hemp have stalks that includes an inner woody component and an outer layer of fibrous material (bast) layer. The inner component, when separated, provides to the hurd. The hurd has been used to make paper, particleboards, etc. The outer layer of bast is useful in textiles, ropes, bags, and industrial fabrics.

[0022] Fig. 1 illustrates an example of a fire-resistant composite 1 and Fig. 2 illustrates a schematic of an example of components of the fire-resistant composite 1. The fire-resistant composite 1 includes a hemp hurd filler 3 that is bonded together with a blended resin mixture 11.

[0023] The hemp hurd filler 3 includes hemp-based material such as hemp hurd (also called shives, shoves, boon). In some examples, at least some of the filler 3 is charred hemp hurd 5. In further examples, the hemp hurd filler 3 may include a combination of charred hemp hurd 5 and uncharred hemp hurd 7.

[0024] The blended resin mixture 11 includes a resin 13 and a fire retardant 15. When cured, the blended resin mixture 11 functions to bind the hemp hurd filler 3 together to form the fire resistant composite 1. The fire retardant 15 aids in increasing the fire-resistant properties of the material 1.

[0025] In the example illustrate in Fig. 1, the fire-resistant composite 1 further includes a core 3 with the hemp hurd filler 3 and have skin layers 19, 21 on opposite surfaces 21, 25 of the core 3.

[0026] The fire-resistant composite material 1 can be used as a primary material for a fire- resistant door 103 as illustrated in Fig. 3.

[0027] The present disclosure also provides a method 300 of forming a fire-resistant material 1 as illustrated in Fig. 4. This includes the steps of blending 310 the resin 13 with a fire retardant 15 to form a blended resin mixture 11. The blended resin mixture 11 is then combined 320 with the hemp hurd filler 3. The method 300 further includes moulding 330, in a mould, the combined blended resin mixture 11 and hemp hurd filler to form the fire- resistant composite material 1.

[0028] Composite material 1

[0029] A detailed example of the composite material 1 will now be described with reference to Fig. 1. This includes the components of the composite material that improve the fire-resistant qualities. Although this example illustrates the composite material 1 having a substantially flat planar structure and having outwardly facing skins 19, 23, it is to be appreciated that other examples are not limited to such features.

[0030] Hemp hurd filler 3 and core 17

[0031] The hemp hurd filler 3, that forms the core 17 of the example composite material 1, comprises hemp hurd which is the inner component of hemp stalk. Loose hemp hurd typically includes fragments that are between 5mm to 20mm. In some examples, the hemp hurd is selected to be between 10mm to 15mm in size. In some examples, having at least some relatively larger hemp hurd particles can improve strength of the finished core 17.

[0032] In some examples, the core 17 is formed of compressed hemp hurd. This can include moulding 330 the hurd in a mould. This will be described in the method 300 below with reference Fig. 4.

[0033] The hemp hurd filler 3 can include charred hemp hurd 5. The charred hemp hurd can improve the fire resistant properties of the hemp hurd filler 3. This can include heating to breakdown at least part of the cellulose components in the hemp hurd and maintaining the lignin components. In some examples, this includes altering the proportion of cellulose to lignin.

[0034] In some examples, the charred hemp hurd 5 is formed by exposing hemp hurd to elevated temperatures. In some examples, this can be between 300 to 500 degrees Celsius. In some examples, this can include exposing the hemp hurd to high temperatures while in a low oxygen environment to reduce burning.

[0035] The hemp hurd filler 3 can include a mix of charred hemp hurd 5 and uncharred hemp hurd 7. The uncharred hemp hurd 7 may provide other desirable qualities such as strength and insulation qualities.

[0036] In some examples, the hemp hurd filler 3 can include a mixture of charred hemp hurd 5 and uncharred hemp hurd 7 in one of the following ratios:• Between 10 and 50% by mass of charred hemp hurd 5 in the hemp hurd filler 3;• Between 20% to 40% by mass of charred hemp hurd 5 in the hemp hurd filler; and• Approximately 33% by mass of charred hemp hurd 5 in the hemp hurd filler.

[0037] The particles of the hemp hurd filler 3 are bonded together by a blended resin mixture 11. In some examples, this combination forms the composite material. However, in the example illustrated in Fig. 1, this combination of bonded hemp hurd filler 3 forms a core 17 sandwiched between two skin layers 19, 23, to form a planar panel or door.

[0038] In this form, the core 17 is typically thicker than the individual skin layers 19, 23 but it need not be. The thickness of the core 17 may be determined by a number of factors including: thermal insulation requirements, rigidity and strength for the door system / access panel, and desired fire rating and (fire-resistance) performance. Additional factors can include dimensions to fit the application and use, such as a standardised door sizes, or thickness to suit the passage and door structure for a particular situation.

[0039] In some examples, the core 17 has a thickness of between 15 to 60mm. The skin layers 1, 23, described in further detail below, may each have thicknesses of between 5mm to 20mm .

[0040] In a particular example, such as a door with approximately 38mm thickness, the core 17 may have a thickness of approximately 18mm and the skin each having a thickness of approximately 10mm.

[0041] Blended resin mixture 11, resin 13

[0042] The blended resin mixture 11 includes a resin 13 and fire retardant 15. The resin 13, when set, functions as a matrix to hold the hemp hurd filler 3 together. In some examples, the resin 13, or a similar compound, may also be used as a binder 29 for the skin layers 7, 15. Thus the resin may have the additional function to bond the skin layer(s) 19, 29 to the core 17.

[0043] In some examples, the resin 13 is an epoxy resin, and in other examples, a polyester resin. In one particular example, the resin 13 is a thermoset resin that is cured, at least in part by application of elevated temperature and / or pressure. This can include thermosetting polymers that cure to form a hard polymer matrix. In some examples, the resin 13 is an epoxy resin that is cured, at least in part, by adding a hardener.

[0044] It is to be appreciated that in other examples, the resin 13 may be in the form of other adhesives, and compound that function to bind the hemp hurd filler 3 together.

[0045] The fire retardant 15, in some examples, include alumina trihydrate. This can assist in the fire-resistance of the resultant composite 1. In some examples, the alumina trihydrate is added as a powder.

[0046] In some examples, the blended resin mixture 11 includes resin 13 and fire retardant 15 in one of the following ratios:• Between 10% and 50% by mass of fire retardant 15 in the blended resin mixture 11 ;• Between 20% to 40% by mass of fire retardant 15 in the blended resin mixture 11 ;• Approximately 33% by mass of fire retardant 15 in the blended resin mixture 11; and• Approximately 23% by mass of fire retardant 15 in the blended resin mixture 11.

[0047] Ratio of hemp hurd filler 3 to blended resin mixture 11

[0048] The ratio of the hemp hurd filler 3 and the blended resin mixture may be selected based on desired strength, fire -resistance, cost, etc.

[0049] In some examples, the ratio of the blended resin mixture 11 with the hemp hurd filler 3 is in the range of 30% to 50% by mass of the blended resin mixture 11 in the composite. In further examples, the ratio is approximately 40% by mass of the blended resin mixture 11 in the composite.

[0050] In one example, the formulation can include:Resin 13, including the resin and hardener by mass of 156kg;Fire retardant 15 by mass of 78kg;Charred hemp hurd 5 by mass of 121kg;Uncharred hemp hurd 7 by mass of 243kg.

[0051] It is to be appreciated that alternative ratios can be used. In some examples, this ratio may be used for the core 17, where the materials for the skin layers 19, 23 are separately defined. In other examples, these ratios may be generally used for the complete fire-resistant composite 1.

[0052] Skin layers 19, 23

[0053] The skin layer 19, 23 forms an external facing barrier and inclusion of the binder aids moisture resistance to the composite material 1. In some examples, the skin layer 1, 23 may provide a protective layer to the core 17, and may aid in resisting pests, mould, microbes, bacteria, from degrading the hemp hurd filler 3. In further examples, the skin layer 19, 23 may resist fluids, gasses, and radiation that may degrade the hemp hurd 5, 105.

[0054] In some examples, the skin layers 19, 23 are formed of hemp bast fibres 27 and binder 29. Hemp bast fibres are typically sourced from the outer layer of fibrous material from the stalk of hemp crop.

[0055] Turning to Fig. 1, this example includes two skin layers 19, 23, where the second skin layer 23 is bonded to a second surface 25 of the core 17 that is opposite the first surface 21 with the first skin layer 19. In some examples, the skin layer 19, 23 with the hemp bast fibres 9, resist tension and, in conjunction with the core 3, provide bending strength to the composite 1.

[0056] The first skin layer 17 and the second skin layer 23 may be made of the same or similar hemp bast fibres and binder 29. However, it is to be appreciated that in alternative examples, different thicknesses, binders 29, or other additives may be used for skin layers based on desired properties. Additives may include colourant, to provide a desired colour. Other forms of additives may be selected for chemical resistance. Yet further additives to the binder 29 may affect texture (e.g. smooth or rough finish).

[0057] Additional skin layers may be provided to cover other surfaces of the core 17. In some examples, the core 17 is fully enveloped by skin layers . This may advantageously provide a complete barrier to protect to core 3.

[0058] However, it is to be appreciated that some alternative examples may have fewer skin layers, including a sing skin layer 19. This may be suitable for applications where moisture, wear, or other factors are only anticipated to substantially affect a single side (for example the external facing side).

[0059] In some examples, the skin layers 19, 23 each have a thickness of between 2mm to 25mm thick. In further examples, the skin layers 19, 23 each have a thickness of between 5mm to 20mm. I some examples, the skin layer 19, 23 is approximately 10mm thick. In yet another example, the skin layer 19, 23 is approximately 5mm thick.

[0060] Binder 29 in the skin layers 19, 23

[0061] The binder 29 may include an epoxy resin, or a polyester resin (or other resins similar to resin 13 described above). In some further examples, the binder 29 may be mixed with a fire retardant 15 similar to the blended resin mixture 11 described above.

[0062] The binder 29 may be pre-impregnated into the cloth or mat layers 25 before moulding and curing.

[0063] In some examples described above, the binder 29 comprises two or more compounds mixed together to form the matrix for the skin. It is to be appreciated than in further examples, additional binders may be used for additional functions, such as binding the skin layer 19, 23 to the core 17.

[0064] Thus in one alternative example, a binder 29 is used to form the skin layer 19, 23. A different binder may be used to aid bonding the skin layer 19, 23 to the core 17. In some examples, this can include first forming the skin layer 19, 23 and subsequently bonding the formed skin layer 19, 23 to the core 17. In another example, at least part of the cloth or mat of hemp bast fibres 27 are first bonded with the different binder to the core 3, and a subsequent binder is introduced to finish forming the skin layer 19, 23.

[0065] Hemp bast fibres and cloth

[0066] The hemp bast fibres are fibrous material that may (before use) be in the form similar to those with making fibre -reinforced plastics such as fibreglass. This can include the hemp bast fibres that are in the form of substantially layers, such as a cloth or mat.

[0067] In some examples loose hemp bast fibres are combined into a chopped strand mat. The chopped strand mats are then cut to size and shape for the particular application and skin layer. The mats may also be layered on top of one another to provide the specified thickness and strength. The layers may also overlap to reduce weak spots.

[0068] In other examples, the hemp bast fibres 27 are woven to form cloth layers. The cloth or mat layers are combined with the binder 29 to form the skin.

[0069] Examples of appropriate hemp bast fibres include: (but not limited to): a. Variety of hemp plant - Cannabis sativa b. Size and of fibres - 30mm to 300mm in length c. Moisture content - 8% or lower d. Size of stalks when harvested - 20mm to 40mm in diameter e. Age of crop - 80 days to 120 days

[0070] In some examples, the cloth or mat layers of hemp bast fibres are impregnated with binders 29. This may include pre-impregnating the hemp bast fibres with binder 29. This may aid the bonding of the skin layer and / or curing of the binder.

[0071] Although the above examples include the hemp bast fibres in cloth or mat forms, it is to be appreciated that alternative examples include providing the hemp bast fibres as loose fibres, or in other examples as yarn.

[0072] Mould

[0073] A heated mould is provided to provide shape to the composite material during curing. The shape can include corresponding shape of components of the door system or access panel.

[0074] The mould may be heated to assist in the curing process. In further examples, heat and pressure are applied to aid shaping and curing. One or more moulds may be used in the process, that can include pre-forming the core 17 and / or the skin layers 19, 23 before they are combined. The step of combining may include the same, or further mould.

[0075] Method of forming composite material

[0076] A detailed example method of forming a fire-resistant composite material 1 will now be described with reference to Figs. 5 to 9. It is to be appreciated that variations of this method may be performed, including methods utilising fewer steps such as the method illustrated in Fig. 4.

[0077] Preparing the hemp hurd filler 3

[0078] Referring to Fig. 5, the method 300 includes preparing charred hemp hurd 5 by heating 302 hemp hurd at an elevated temperature. This can include heating 302 in an oxygen depleted (or restricted) environment to create charred hemp hurd 5. By restricting oxygen, this can reduce burning of the hemp hurd. In some examples, the elevated temperature is in the range of 300 to 500 degrees Celsius.

[0079] The method 300 subsequently includes cooling 303 of the charred hemp hurd 5 before use in the composite 1.

[0080] The method 300 includes mixing 305 the charred hemp hurd 5 with uncharred hemp hurd 7. In some examples, the ratio of mixing includes 20% to 40 % by mass of charred hemp hurd 5. In some particular examples, this may be approximately 33% charred hemp hurd 5 in the hemp hurd filler 3.

[0081] It is to be appreciated that various forms of mixing particle of hurd 5, 7 can be used. In some example, this can include an auger to aid mixing and even distribution of charred and uncharred hemp hurd 5, 7 to create the hemp hurd filler 3.

[0082] In some examples, the hemp hurd filler 3 may be compressed to increase density. This can be important to increase compressive strength and fire-resistance properties in the completed product. Compression will aid in reducing potential air pockets in the final product. This can include feeding loose hemp hurd filler 3 into an auger to apply pressure to loose hemp hurd particles. This can include forcing hemp hurd under pressure at the output of the auger. In some examples, the auger may have a variable pitch to achieve desired pressures and flow rates. In some examples, the auger may have a decreasing pitch from the input to output with the effect of increasing pressure on the hemp hurd particles.

[0083] Preparing the blended resin mixture

[0084] Referring to Fig. 6, the method 300 further includes bending 310 the blended resin mixture 11. This can include mixing 312 the resin 13 with a hardener 14. In other examples, this can include other steps to aid or assist the preparation and curing of the resin 13. This may include exposure to heat, light (or other radiation), gasses and / or chemicals.

[0085] The method 300 may include subsequently mixing 313 the fire retardant 15 with the mixed resin 13 and hardener 14. This may include mixing with alumina trihydrate as the fire retardant 15. It is to be appreciated that other examples can use other fire retardants as described herein.

[0086] In some examples, the ratio of mixing 313 includes 20% to 40 % by mass of the fire retardant 15. In some particular examples, this may be approximately 33% by mass of the fire retardant 15 in the blended resin mixture 11.

[0087] Combining 320 the blended resin mixture 11 with the hemp hurd filler 3

[0088] The prepared blended resin mixture 11 is then combined 320 with the hemp hurd filler 3. This can include adding the hemp hurd filler 3 whilst agitating the blended resinmixture 11 to ensure thorough mixing. This can include an auger, or other mixer, to stir and distribute the components.

[0089] In some examples, this can include gradually adding the hemp hurd filler 3 to the blended resin mixture 11 until the desired ratio is achieved. Examples of ratios, as noted above, include blended resin mixture 11 in the order of 30% to 50% by mass, and with the corresponding hemp hurd filler 3 forming the balance with between 50% to 70% by mass. In one particular, example, the blended resin mixture is approximately 40% by mass and the hemp hurd filler is approximately 60% by mass.

[0090] Moulding 330 the combined blended resin mixture and hemp hurd filler 3

[0091] In the illustrated example of Fig. 7, the method further includes laying 331 the combined blended resin mixture and hemp hurd filler 3 into a mould. The mould may be used to apply further pressure, moulding 330 the hurd to form the composite material 1 or core 17 for the composite material 17. In some examples, this core 17 may be a substantially flat layer. However, it is to be appreciate that other forms of the composite material 1 or core 17 can be made such as a cylindrical core, tubular core , elongated element, rectangular frame, etc.

[0092] The method includes curing the combined blended resin mixture in the mould, which can include application of heat so the that an elevated temperature aids curing of the resin. In some examples, this elevated temperature may be between 60 degrees to 140 degrees. It is to be appreciated that the specified elevated temperature may be based on design specification of the resin and may include temperatures outside of this range.

[0093] In some examples, moulding 330 includes a combination of heat and pressure so that the resin 3 cures to bind with the hemp hurd filler 3, and forming the composite material 1 or core 17 of the composite material 1.

[0094] In some examples, the composite material 1 comprises the above mentioned hemp hurd filler 3 and blended resin mixture 11 moulded to a final form. In alternative examples, one or more skin layers 19, 23 are also provided which will be described below.

[0095] Preparing the skin layers 19, 23

[0096] Examples of preparing and bonding 342 skin layers 19, 23 to the core 17 will now be described with reference to Fig. 8 and 9.

[0097] In some specific examples, the skin layers 19, 23 comprise a composite of hemp bast fibres 27 and a binder 29. Preparation of such skin layers 19, 23 my include impregnating 340 the hemp bast fibres 27 with the binder 29. This can optionally include at least partially shaping the hemp bast fibres 27 to match the shape of the core 17, or match the shape of the finished composite material, and / or a shape to aid bonding to the core 17. In some examples, this can be achieved by preforming 345 one or more cloth or mat layers of hemp bast fibre 27 at a preforming tool. Examples of a preforming tool includes a mould or a mandrel configured to support and shape the hemp bast fibre.

[0098] The method 300 further includes soaking 346 the one or more cloth or mat layers with the binder 29. The binder 29 is then partially cured 347. In some examples, partially curing 347 the binder 29 includes application of heat (or other radiation), and / or pressure. In other examples, partially curing 347 the binder 29 is (at least in part) based on time and allowing the binder 29 to building chemical bonds.

[0099] The partial curing 347 of the binder 11 aids in shaping the hemp bast fibre 9, 109. In some examples this can be the shape of the skin 17, 23, in the final form, or be in a shape or configuration to enable ease of combining and bonding 342, 343 with the core 17. In some example, partial curing 347 may be performed in a mould.

[0100] In other examples, partial curing 347 of the binder 11 aids in handling of the cloth or mat layers. For example, if the skin layer 17, 23 requires a specified number of mat layers (say six mat layers), the above mentioned process can combine the six mat layers and have them partially cured to one another so they can be easily handled together.

[0101] Referring to Fig. 9 that illustrates steps of bonding 342, 343 the skin layers 17, 23 to the core 17, this may further comprise laying 350 the core 17 along with the hemp bast fibre into a mould. In some examples, the mould 53 may include, at least in part, the mould 53 used to form the core 17. In other examples, this may include, at least in part, thepreforming tool used to preform the cloth or mat layers. In other examples, this may include a further mould that is different to the other tools mentioned above.

[0102] In the step of laying 350, this may include laying the hemp bast fibre that has been partially cured with the binder 29 into the mould or further mould. The core 17 and further hemp bast fibres for other skin layers 23 may subsequently be laid, so that the core 17 is sandwiched between the hemp bast fibres.

[0103] The method further includes applying 352 pressure and elevated temperature to the core 17 and the hemp bast fibre impregnated with the binder in the mould (or further mould) to set the binder 29. This has the effect of bonding the binder 29 to the core 17. This also has the effect of fully curing the binder 29 in the skin layers 17, 23.

[0104] For some binders 29, elevated temperature and pressure is required for fully curing the binder. Depending on the binder selected, the elevated temperature and / or pressure at step 352 is higher than any temperature or pressure in the step of partially curing 347 the binder.

[0105] In some examples, pressure may not be a requirement to cure the binder. Nonetheless, pressure may be important for shaping the composite product in the mould and / or to remove excess air or excess binder from the moulded composite material 1.

[0106] It is to be appreciated that the method 3 of forming a composite material 1 may include additional steps. For example, when producing the composite panel 1 of Fig.1 where the core 3 is between two skin layers 17. 23, the method 300 may further include bonding 343 a second skin layer of the hemp bast fibre with the binder to the core 17. In some examples, the bonding 343 of the second layer 23 may be done as a separate step to bonding 342 of the first skin layer 17. In other examples, the first and second layers are laid 350 into the mould at the same time where the same step of applying 352 pressure and temperature bonds the two layers.

[0107] In further examples, such a method of manufacturing the composite panel 1 further includes locating at least one reinforcing element into the mould. In some examples, this is placed so that the reinforcing element 22 is embedded in the core 17 (as illustrated in theexample door 103 of Fig. 3). This can further include the first skin layer 17 that is bonded to the at least one reinforcing element 22. In further examples, the at least one reinforcing element 22 is placed in between and bonded to both the first skin layer 17 and the second layer 23. The reinforcing element 22 may be made of material with higher strength than the core 17 (or have alternative desirable properties). In some examples, this can include higher relative compressive strength. In further examples, this may include higher relative tensile strength.

[0108] Preparing door system and access panel components

[0109] The disclosed method 300 can be used to form composite material 1 that forms part of a fire-resistant door system 101, fire resistant door 103, fire resistant door frame 105, and / or access panel 201.

[0110] After moulding of the composite material 1, the composite material 1 may be worked further to provide additional features suitable for the application. This can include, for example, drilling or cutting holes and recesses for door locks, hinges, reinforcing elements, seals, etc. This can also include adding additional material, such as a kick plate to a lower portion of the door, a door handle, etc.

[0111] Advantages

[0112] The disclosed fire-resistant composite 1 can be used as a barrier to slow or stop the spread of fire and smoke. This has particular applications for door systems and access panels that, in some applications, require fire rating. This can include resistance to burning (or destruction) when exposed to heat. In other examples, this can include a rating based on factors such as heat and time (exposed to heat).

[0113] Another advantage of the present disclosure is the use of hemp based materials for components of the composite. Hemp is a renewable material and, compared to traditional timber, can be grown relatively quickly. The use of hemp hurd may, in some cases, provide an overall weight advantage compared to solid timber doors.

[0114] Other advantages of the fire-resistant composite 1 may include the insulation properties compared to a metal door. In normal scenarios, this can be advantageous to prevent thermal conduction of heat from one room to another, which can save heating and / or cooling costs. In scenarios of fire, such insulation properties can prevent or reduce thermal conduction of high temperatures from one side of the door to the other.

[0115] Furthermore, some of the components, such as the hemp hurd, may be considered an by-product in hemp production and the use of hemp hurd can reduce industrial waste.

[0116] Variations

[0117] Door 103

[0118] Fig. 3 illustrates a door 103 that may be used in the door system 101. The door 103, in this example includes a core 17 formed of hemp hurd filler 3 and the blended resin mixture 11. The charred hemp hurd 5 and the fire retardant 15 in the door aids in fireresistance and, in some examples, be used as a fire rated door. That is, the door may be specified to resist the spread of smoke and fire for at least a specified time in accordance with one or more ratings.

[0119] The door 103 also includes outwardly facing skin layers 19, 23 that forms the exterior surfaces of the door 103. It is to be appreciated that the skin layers 19, 23 may be coated with a suitable coating, that can include paint. In other examples, the skin layers 19, 23 may have colourant added to provide a specified colour to the door 103.

[0120] In Fig. 4, this example includes an additional optional feature of a reinforcing element 22 that is in the core 17 that is between the two skin layers 19, 23. The reinforcing elements 22 may run vertically through the door 103 to provide rigidity.

[0121] In one example, the door has skin layers 19, 23 that are each approximately 10mm thick and with a core 17 that is approximately 18mm thick. It is to be appreciated that the thickness of the skin layers 19, 23 and core 17 can be adjusted based on required overall thickness of the door, strength, fire resistance, etc.

[0122] Door system 101 with door frame 105 and door 103

[0123] Fig. 10 illustrates an example of a fire-resistant door system 101 (not to scale) that includes a door frame 105, and a door 103. In this example, the door frame 105 comprises the fire-resistant composite 1 as described above, that includes a core 17 of hemp hurd filler 3 bonded with a blended resin mixture 11 with a fire retardant 15. This example further includes skin layers 19, 23 on outwardly facing surfaces of the core 17.

[0124] The door 103 can include a door as described above that also comprises the fire- resistant composite 1.

[0125] Access panel 201

[0126] Fig. 11 illustrates a fire-resistant access panel 201 that comprises fire-resistant composite 1 as described above. In this example, the fire-resistant access panel 201 includes a core 17 sandwiched between two skin layers 13, 23.

[0127] The fire-resistant access panel 201 may be used between ceiling, roof, floor, and / or wall structures in a building to provide a barrier to reduce the spread of smoke, fire, heat, and / or fluids.

[0128] It will be appreciated by persons skilled in the art that numerous variations and / or modifications may be made to the above-described embodiments, without departing from the broad general scope of the present disclosure. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1. A fire-resistant composite comprising: hemp hurd filler; blended resin mixture, wherein the blended resin mixture comprises at least a resin and a fire retardant, wherein the blended resin mixture binds the hemp hurd filler.

2. A fire-resistant composite according to claim 1 wherein the hemp hurd filler comprises at least charred hemp hurd.

3. A fire-resistant composite according to claim 2 wherein the hemp hurd filler comprises a mixture of charred hemp hurd and uncharred hemp hurd.

4. A fire-resistant composite according to claim 3 wherein the ratio of charred hemp hurd and uncharred hemp hurd is between 20% to 40% by mass of charred hemp hurd in the hemp hurd filler 3.

5. A fire-resistant composite according to claim 4 wherein the ratio is approximately 33% by mass of charred hemp hurd.

6. A fire-resistant composite according to any one of claims 2 to 5 wherein the charred hemp hurd is formed by exposing hemp hurd to an elevated temperature of between 300 to 500 degrees Celsius.

7. A fire-resistant composite according to any one of claims 1 to 6 wherein the fire retardant comprises alumina trihydrate.

8. A fire-resistant composite according to any one of the preceding claims wherein the ratio of fire retardant in the blended resin mixture is between 20% to 40% by mass of the fire retardant in the blended resin mixture.

9. A fire-resistant composite according to claim 8 wherein the ratio is approximately 33% by mass of fire retardant in the blended resin mixture.

10. A fire-resistant composite according to any one of the preceding claim wherein the resin is an epoxy resin or a polyester resin.

11. A fire-resistant composite according to any one of the preceding claims, wherein the ratio of the blended resin mixture with the hemp hurd filler is in the ratio of 30% to 50% by mass of the blended resin mixture in the fire-resistant composite.

12. A fire-resistant composite according to claim 11, wherein the ratio is approximately 40% by mass of the blended resin mixture.

13. A fire-resistant composite according to any one of the preceding claims wherein the hemp hurd filler and blended resin mixture form a core of the fire-resistant composite, and the fire-resistant composite further comprises:- a skin layer bonded to a first surface of the core.

14. A fire-resistant composite according to claim 13, wherein the fire-resistant composite further comprises: a second skin layer bonded to a second surface of the core, wherein the second surface is opposite the first surface.

15. A fire-resistant composite according to claim 14, wherein the fire resistant composite is substantially planar and where the core has a thickness of between 15mm to 60mm and the skin layers each have a thickness of between 5mm to 20mm.

16. A fire-resistant composite according to claim 15, where core has a thickness of approximately 18mm and the skin layers each have a thickness of approximately 10mm.

17. A fire-resistant composite according to any one of claims 13 to 16, wherein the skin layer comprises hemp bast fibres and a binder.

185. A fire-resistant composite according to claim 17, wherein the binder includes an epoxy resin or a polyester resin.

19. A fire-resistant composite according to either claim 17 or 18, wherein the skin layer comprises a fire retardant mixed with the binder.

20. A fire-resistant composite according to any one of claims 17 to 19, wherein the skin layer is formed of cloth or mat layers of hemp-based fibres impregnated with the binder.

21. A fire-resistant door system comprising a fire-resistant composite according to any one of claims 1 to 20.

22. A fire-resistant door comprising a fire-resistant composite according to any one of claims 1 to 20.

23. A fire-resistant door frame comprising a fire-resistant composite according to any one of claims 1 to 20.

24. A fire-resistant access panel comprising a fire-resistant composite according to any one of claims 1 to 20.

25. A method of forming a fire-resistant composite material comprising: blending a resin with a fire retardant to form a blended resin mixture; combining the blended resin mixture with a hemp hurd filler; moulding, in a mould, the combined blended resin mixture and hemp hurd filler to form the fire-resistant composite material.

26. A method according to claim 25, comprising: mixing charred hemp hurd with uncharred hemp hurd to create the hemp hurd filler 3.

27. A method according to claim 26, wherein the ratio of charred hemp h rd and uncharred hemp hurd is between 20% to 40% by mass of charred hemp hurd.

28. A method according to any one of claims 25 to 27, further comprising the steps of: heating hemp hurd at an elevated temperature in an oxygen depleted environment to create charred hemp hurd; cooling the charred hemp hurd, wherein the charred hemp hurd forms at least part of the hemp hurd filler.

29. A method according to claim 28, wherein the elevated temperature is between 300 to 500 degrees Celsius.

30. A method according to any one of claims 25 to 29, wherein blending the resin with the fire retardant comprises: mixing the resin with a hardener; subsequently, mixing the fire retardant with the resin and the hardener;31. A method according to any one of claims 25 to 30, wherein the fire retardant comprises alumina trihydrate.

32. A method according to any one of claims 25 to 31, wherein the ratio of fire retardant in the blended resin mixture is between 20% to 40% by mass of the fire retardant.

33. A method according to any one of claims 25 to 32, wherein the step of combining the blended resin mixture with a hemp hurd filler is in the ratio of 30% to 50% by mass of the blended resin mixture.

34. A method according to claim 33, wherein the ratio is approximately 40% by mass of the blended resin mixture.

35. A method according to any one of claims 25 to 34, wherein the step of moulding the combined blended resin mixture and hemp hurd filler to form the fire-resistant composite material includes: laying the combined blended resin mixture and hemp hurd filler in the mould; curing the combined blended resin mixture in the mould at an elevated temperature of between 60 to 140 degrees Celsius.

36. A method according to claim 35, wherein the hemp hurd filler and blended resin mixture form a core of the fire-resistant composite material, and the method further comprising the steps of: bonding at least one skin layer to a first surface of the core.

37. A method according to claim 36, further comprising: bonding a second skin layer to a second surface of the core, wherein the second surface is opposite the first surface.

38. A method according to either claim 36 or 37, further comprising: impregnating hemp bast fibres with a binder, wherein bonding the skin layers includes bonding at least one layer of hemp bast fibres impregnated with the binder to the core.

39. A method according to claim 38, wherein the step of impregnating the hemp bast fibres with the binder comprises:- preforming one or more cloth or mat layers of hemp bast fibres at a preforming tool; and- soaking, with the binder, the one or more cloth or mat layers of hemp bast fibres; and- partially curing the binder.

40. A method according to any one of claims 38 to 39, wherein the step of bonding the skin layers to the core comprises:- laying the core and hemp bast fibres impregnated with the binder in the mould, or a further mould; and- applying pressure and elevated temperature to the core and the hemp bast fibres impregnated with the binder to set the binder.

41. A method according to any one of claims 25 to 40, wherein the fire-resistant composite material forms part of a fire-resistant door system, fire-resistant door, fire- resistant door frame, or fire-resistant access panel.

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