Mycelia-based loose-fill insulation material and methods for production thereof

Abstract

The present invention concerns methods for making mycelium-based loose filling insulation units. The method comprises suspending a solid substrate in a mycelium-based liquid inoculum in the presence of a liquid medium to obtain a suspension; removing liquid from the suspension to obtain a mycelium-grafted solid substrate; incubating the mycelium-grafted solid substrate; recovering the solid substrate once it's covered with mycelial skin; and drying it to obtain the loose filling insulation units. The present invention also concerns the loose filling insulation units, products and arrangements produced thereof.

Description

[0001] Insulation material

[0002] Field of the Invention

[0003] The present invention concerns insulation materials. More particularly, but not exclusively, this invention concerns mycelium based insulation materials and methods of making the same.

[0004] Background of the Invention

[0005] Insulation materials are widely used in, for example, the construction and building industry to reduce the rate of heat transfer from a structure. When used in building structures, insulation materials play an important role in maintaining optimal indoor temperatures, keeping spaces warm during winter and cool during summer. This not only enhances the comfort of occupants but also improves the energy efficiency of the building, leading to significant savings on heating and cooling costs.

[0006] Insulation materials may be used to form various insulation products, which may come in various forms, including for example rolls and batts, loose fill, rigid foam boards, and foam-in-place. The choice of insulation product depends on several factors, including the climate, the type of building, the part of the building to be insulated, and local building regulations.

[0007] Among the various types of insulation material, loose fill insulation is particularly noteworthy for its versatility and effectiveness. Loose fill insulation, as the name suggests, is a type of insulation that is not structured or formed into specific shapes or slabs. Instead, it consists of small particles of fibrous materials or granules. Common materials used for loose fill insulation include cellulose, fiberglass, and mineral wool. These materials are chosen for their high thermal resistance properties, and their ability to fill irregular spaces, cavities, and around obstructions where other types of insulation might struggle.

[0008] In terms of application, loose fill insulation is often blown into spaces using special equipment, allowing it to conform to the space's shape and size. This makes it an excellent choice for retrofitting older buildings that lack insulation, as well as for insulating irregularly shaped areas and around obstructions in new constructions. Loose fill insulation is also commonly used in attic spaces, wall cavities, and other hard-to- reach areas. Professional installation is typically recommended to ensure optimal performance and safety.

[0009] Mycelium of fungi has been proposed as a potentially promising source of insulation material. Mycelium is the root structure of fungi. It is a naturally occurring, self-assembling, and renewable resource. It grows by consuming organic waste materials, for example agricultural byproducts, and forms a dense, interwoven network of fibers. This network, when dried, exhibits excellent thermal and acoustic insulation properties, making it suitable for use in building structures.

[0010] One of the key advantages of mycelium-based insulation is its sustainability. It is biodegradable, compostable, and does not rely on petrochemicals, unlike many conventional insulation materials.

[0011] The production process of mycelium-based insulation usually involves inoculating a substrate, usually organic waste, with mycelium containing medium such as grain spawn. The mycelium then grows through the substrate, consuming it and binding it together. After a certain growth period, the mycelium and substrate mixture is dried, stopping the growth and creating a lightweight, durable, and insulating material. However, while mycelium-based insulation holds great promise, problems still remain. There are issues associated with existing processes for making myceliumbased insulation products. For example, these processes may be difficult to scale up due to, for example, long growth cycles, high sterilisation / storage requirements. Moreover, these processes may often rely on grain as a nutrient, and the substrate used may also have a great impact on not only the efficiency of the production method but also the final properties of the insulation product produced.

[0012] The present invention thus seeks to provide improved methods for producing mycelium-based insulation materials. Summary of the Invention

[0013] According to a first aspect, the present invention provides a method for making a mycelium-based loose filling insulation unit. The method may be considered a liquidbased sediment process. The inventors of the present invention found that, surprisingly, the liquid-based process removes reliance on grain of previous solid-based methods, and facilitates the use of a wider range of material for the production of myceliumbased insulation product. The method of the present invention may also be easier to scale up as it can be performed in large volume ferment tanks or bioreactors, whilst previous solid-based methods typically suffered from gas transfer and / or heat issues on scale up. The substrates may be dispersed more easily and thoroughly in a liquid system, thus creating more inoculation points. In this way, by using methods of the present invention, mycelium growth time may be significantly reduced.

[0014] The terms “mycelium-based insulation product” or “mycelium-based insulation unit” are well-understood in the art. The exact percentage of mycelium in these products can vary depending on the specific formulation and manufacturing process. Generally, the majority of the product is typically the substrate that the mycelium grows through and binds together. Mycelium-based insulation products / units typically comprise more than 10 vol% or 5 wt% mycelium. The mycelium-based insulation products / units of the present invention may comprise 10-50 vol%, preferably 10-30 vol%, for example 10- 20 vol%, mycelium. Alternatively, the mycelium-based insulation products / units of the present invention may comprise 5-30 wt%, preferably 5-20 wt%, for example 5-10 wt%, mycelium. The percentage, however, can vary depend on the specific manufacturing process and formulation used in producing the insulation.

[0015] The term “loose-fill” is well-understood in the art. Loose-fill insulation is capable of conforming to any space without disturbing structures or finishes. They are particularly effective for retro-fitting insulation to existing finished areas, irregular shaped areas and / or spaces, and around obstructions.

[0016] In the method of the present invention, a mycelium-based liquid inoculum is prepared. The mycelium-based liquid inoculum may be prepared from a liquid broth comprising fungus spores and, optionally, agar squares and / or grain. The fungus suitable for use in the present invention is capable of generating mycelium. The mycelium-based liquid inoculum may also be prepared by propagating a liquid culture to a larger volume.

[0017] Preferably, the mycelium-based liquid inoculum already contains mycelium prior to use. Nevertheless, the present invention also covers methods using a liquid inoculum comprising, or consisting essentially of, just fungus spores, provided that the liquid inoculum is suitable for mycelium to grow from the fungus spores during the method of the present invention, for example after the fungus spores are suspended to the surface of the substrate. Using a liquid inoculum comprising, essentially, only spores may be desirable when individual colonies are required, for example when a genetically similar group is being selected for beneficial mutations. Preferably, the liquid inoculum comprising the fungus spores is conditioned for a day or two prior to being used in the method of the present invention.

[0018] Preferably, the liquid inoculum comprises fragmented mycelium. A fragmented liquid culture contains mycelium which has undergone a sheer stress sufficient to break its cells into smaller “fragmented” units. This typically refers to a fungal stock which was originally grown in a pelletised form before being blended to fragment the mycelium clumps into smaller units. Homogenous or disperse liquid cultures can also be fragmented in this method to reduce their size and increase the counts of inoculation sites. This also typically involves a conditioning step to allow the mycelium to repair and recover prior to inoculation. The term “fragmented mycelium” is well-understood by the skilled person in the art. Using a liquid inoculum comprising fragmented mycelium helps to increase the points of inoculation for that liquid culture without destroying the cells activity. Optionally, the liquid inoculum may be a solution comprising at least one nutrient useful for encouraging the growth of fungi and / or mycelium and at least one piece of agar with fungus cultivated thereon.

[0019] Preferably, the mycelium is of a fungus that is of a fungus subdivision selected from Agaricomycetes, Agaricostilbomycetes, Atractiellomycetes, Bartheletiomycetes, Classiculomycetes, Cryptomycocolacomycetes, Cystobasidiomycetes, Dacrymycetes, Exobasidiomycetes, Malasseziomycetes, Microbotryomycetes, Mixiomycetes, Moniliellomycetes, Pucciniomycetes, Spiculogloeomycetes, Tremellomycetes, Tritirachiomycetes, Ustilaginomycetes, Wallemiomycetes Taphrinomycotina, Pezizomycotina, and genetic mutates thereof. Genetic mutants of a fungus are strains of the fungus that have undergone changes in their genetic material, or DNA. These changes can occur naturally through processes such as DNA replication errors, exposure to radiation, or interaction with certain chemicals. Alternatively, they can be induced in a laboratory setting through techniques like gene editing or mutagenesis.

[0020] In the method of the present invention, the fungus may be selected from a single subdivision, or co-cultivated with other fungal specifies or bacterial species. In a preferred embodiment of the present invention, the fungus is Dikarya.

[0021] Once the liquid inoculum is prepared, a solid substrate is suspended in the liquid inoculum in the presence of a liquid medium to obtain a suspension. Optionally above a filter. In a non-limiting embodiment of the present invention, 1 kilo of solid substrate with 200 mL of liquid inoculum are suspended in 5 L liquid medium, which may be water. Optionally, the solid substrate takes up between around 1 vol% to around 50 vol%, preferably between about 5 vol% to about 20 vol%, of the liquid medium.

[0022] In the context of this application, the terms “substrate” and “substrates” are used indistinguishably. The solid substrate may be in one piece, or may be a collection of multiple pieces of the same or different shapes, materials and / or sizes. Optionally, the solid substrate may be a composite.

[0023] The solid substrate may be of any form provided that there is an internal structure through which the mycelium can grow. For example, the solid substrate may be in the form beads, balls, foams, chips, or combinations thereof. It should be noted that the substrates can be any shape (regular or irregular) and the terms such as “bead”, “ball”, “foam”, “chip” used herein are not intended to suggest any specific geometric shape. Examples of regular shapes which could be used are cylinders, shapes, spheres, cones, cubes, prisms, tetrahedron, cuboid, pyramidal, dodecahedron, icosahedron or octahedron (this list should not be considered exhaustive). Preferably, the solid substrate of the present invention is of a form capable of maintaining its structure (when dried) with the growth of a mycelial skin, for example a mycelial skin about 1 -500mm thick. Solid substrates of suitable shape / form may be useful in making insulation products suitable for loose filling. Preferably, the substrate may be in the form of beads, for example beads that are substantially spherical. The present invention is suitable for making loose fill insulation units from substrates of various size ranges, for example small substrates, medium-sized substrates, or large substrates. In a preferred embodiment of the present invention, the substrate is a small substrate, for example in the form of beads having a (largest) diameter of from about 0.5 to 10 cm, more preferably from about 0.5 to 5 cm, most preferably from about 0.5 to 4 cm; or in the form of chips having a (largest) length of from about 0.5 to 10 cm, more preferably from about 0.5 to 5 cm, most preferably from about 0.5 to 2 cm; or in the form of foam pieces with a length from 1 to 10 cm and a width from 2 to 5 cm. In another preferred embodiment of the present invention, the substrate is a medium-sized substrate, for example in the form of beads having a (largest) diameter of from about 20 to 50 cm, more preferably from about 20 to 40 cm, most preferably from about 30 to 35 cm; or in the form of chips having a (largest) length of from about 20 to 50 cm, more preferably from about 20 to 40 cm, most preferably from about 30 to 40 cm; or in the form of foam pieces with a length from 20 to 150 cm and a width from 20 to 100 cm. In yet another preferred embodiment of the present invention, the substrate is a large substrate, for example in the form of beads having a (largest) diameter of from about 50 to 100 cm, more preferably from about 50 to 80 cm, most preferably from about 55 to 65 cm; or in the form of chips having a (largest) length of from about 60 to 100 cm, more preferably from about 60 to 80 cm, most preferably from about 60 to 70 cm; or in the form of foam pieces with a length from 200 to 300 cm and a width from 100 to 150 cm, for example a foam piece of 240><140cm. The substrate can, of course, also be a combination of substrates of different sizes.

[0024] The substrate may be of any suitable material on which or through which the mycelium can grow, such as a functional material with catalytic properties that can facilitate biological processes in symbiosis with mycelium. For example, the substrate may be of an organic material, such as lignocellulosic material, refined cellulose foams, gels (including calcium alginate, gelatin, xanthium gum, gellan gum, guar gum and pectin), fructose, glucose, saccharose, maltose, dextrose, pectin, lactose, xylose, starch, dextrin, hemicellulose, and derivatives and / or combinations thereof. Alternatively, the substrate may be of an inorganic material, such as alumina, silica, quartz, hafinia, zirconia, functional materials, such as titania and cerium (IV) oxide, ceramic blends, silicon, and combinations thereof. Preferably, the substrate may be made from lignocellulosic organic matter. The use of organic material may help to reduce dusts that may be created during a subsequent incubation step. Preferably, the substrate may be lignocellulosic beads having a (largest) diameter of about 0.5 to 4 cm, or 30 to 40 cm, or 50 to 65 cm. Also preferably, the substrate may be cellulose foam beads having a (largest) diameter of about 0.5 to 4 cm, or 10 to 50 cm, or 60 to 100 cm. In preferred embodiments of the present invention, the substrate may be a lignocellulosic foam panel of 240><140cm. Different material and different sizes (or size ranges) of the substrate can be combined.

[0025] Advantageously, it may not be necessary to functionalise the substrate, e.g. with a functional group via silanization, or to attach a linker molecule to such a functional group, or to attach a carbohydrate and / or amino acid to such a functional group or linker molecule. In a preferred embodiment of the present invention, the solid substrate is not subject to such a separate functionalisation step.

[0026] The liquid medium may be water, or water with one or more additives, for example a pest-control additive and / or a nutrient. In one embodiment of the present invention, the liquid medium is water. In yet another embodiment of the present invention, the liquid medium is a nutrient broth.

[0027] Once mixed in the liquid medium, the substrate may be brought into contact with a fungus in the liquid inoculum. The liquid from the suspension is subsequently removed to obtain a mycelium-grafted solid substrate. The removal of liquid may be done by any means deemed suitable by the person skilled in the art, for example by draining the liquid of the suspension, or by removing the substrates from the suspension. Typically, the removal of liquid is performed through filtration.

[0028] Optionally, the solid substrate is suspended in the liquid inoculum in the presence of a liquid medium, above a filter. Preferably, the filter comprises one or more separators configured to cut the substrate into smaller, pre-defined pieces.

[0029] The mycelium-grafted substrate, when dried, typically has a density from 40 to 120 kg / m3, preferably from 50 to 100 kg / m3.

[0030] The term “mycelium-grafted substrate” also covers substrates grafted by fungus spores or substantially fungus spores. Methods in which the growth of mycelium only starts after the suspension step are also covered within the scope of the present invention.

[0031] The mycelium-grafted substrate is then incubated in a container, for example a reactor, preferably in a fermenter or a bioreactor, to allow the growth of mycelial skin on the substrates. The incubation time may be about 2 to 10 days, preferably about 2 to 7 days. The exact time required for sufficient mycelium growth will depend upon the fungus chosen and the conditions of the environment and the skilled person will be aware and / or be able to determine a suitable growth time accordingly. The incubation temperature is typically 15 to 30 °C, preferably from 18 to 25 °C, depending on the fungal strain selected.

[0032] During the incubation, the mycelium (contained in the mycelium-based liquid inoculum) extends its network from each inoculation site. These networks wrap and bind particles together. They form a denser network of hyphae at the surface of the substrate, which is often referred to as a mycelium skin or a hyphal skin. Preferably, the incubation is performed under high humidity and elevated CO2 levels. For example, the relative humidity (RH%) during the incubation step is at least 70, at least 80, preferably 90. Preferably, the CO2 level during the incubation step is at least 2000, at least 5000, at least 10000, at least 15000, preferably 20000, ppm. High humidity and CO2 level encourages mycelium to grow and inhibits fruiting. The solid substrate (with mycelium grafted or mycelial skin already formed) may be flipped or otherwise reshuffled to promote uniform mycelian growth on as much of the surface area as possible. For example, when the solid substrate is in the form of a panel, it may be turned over at least once, preferably more than once, during incubation. Alternatively, when the solid substrate comprises beads or chips, the container may be shaked or vibrated to shuffle the substrate. The container may optionally comprise one or more smaller sections, for example using a separating grid or one or more dividers, to allow incubation of different solid substrates at the same time. For example, one section may be used to incubate solid substrate comprising beads whilst another section may be used to incubate solid substrate which is in the form of a panel. Alternatively or in addition, the one or more sections may allow different incubation time and / or conditions. For example, the solid substrate in one section can be shuffled, flipped, or removed, without disturbing the solid substrate in other section(s).

[0033] Once the desired growth is reached, the incubation can be terminated. This can be done by any means deemed suitable by the skilled person, for example by removing the substrate from the container and heating the solid substrate. For example, the solid substrate may be dry pasteurised at a temperature of up to 70 °C, preferably up to 60 °C. Alternatively or in addition, chemical agents may be used to, to inactivate / inhibit further mycelium growth. Radiation is another possible way of terminating the incubation process.

[0034] With the desired mycelium growth, the solid substrate is able to hold its shape and / or is held together by the fungus hyphae, thereby avoiding dusting and / or lose of material. The desired growth may be monitored, tracked, and / or characterised by visual means or image analysis software. For example, the mycelium growth on the surface of the substrate may be accompanied by a color contrast (change of surface color), a visible mycelium skin growing on the surface of the substrate and / or a volume increase of the substrate. Preferably, the desired growth may be characterised by a volume gain of at least 5%, at least 10%, at least 15%, preferably 20%, of the substrate. The volume change may be monitored or measured with the assistance of image analysis apparatus and / or software. Alternatively or additionally, the desired mycelium growth may be charactered by a total surface mycelium coverage of at least 95%, preferably at least 95%. The hyphae form a skin (mycelium skin) on the surface of the substrate. The thickness of the mycelium skin ranges from a few microns to several millimeters. For example, the mycelium skin on the solid substrate is from 5 pm to 20 mm, preferably from 20 pm to 20 mm, more preferably at least 50 pm. The desired growth may further be characterised by a critical diameter of the substrate. Alternatively, the critical diameter is at least 5%, at least 10%, at least 15%, preferably 20%, larger than the original diameter of the substrate.

[0035] The weight change during the incubation process may be monitored to control moisture and / or CO2 loss, for example in the digestion of the substrate.

[0036] The substrate (with the grown mycelial skin on the surface), once recovered, may undergo different treatments in accordance with the requirements of individual applications.

[0037] For example, the mycelium coated substrate may be dried. Preferably the water content of the (mycelium-coated substrate) is reduced to not more than about 6%, not more than about 5%, preferably not more than 4%, most preferably not more than 3%. The drying step may render the mycelium inactive, prior to being used in as an insulation product for, for example, building cavities. Drying can be done by, for example, using a dehydrator at a temperature of at least 40 °C, preferably at least 50 °C. Other possible drying process may be using microwave-assisted dehydrating apparatus, using desiccants, and / or using vacuum. Suitable means and apparatus for the drying step of the present invention are well-known to the skilled person. Once dried, the substrate, for example in the form of beads, balls, and / or chips, may be blown or poured into the hollow or open space in a building for insulation in interior thereof.

[0038] Alternatively or preferably, the mycelium coated substrate obtained, for example in the form of beads, balls, and / or chips, may be further configured. In a nonlimiting example of the present invention, the mycelium coated substrate, for example in the form of beads, balls, and / or chips, may be stacked into different three- dimensional configurations. Preferably a mould or a dynamic scaffold is used to assist the making and / or maintaining of the configuration / structure. The configuration is subsequently subject to a further incubation step to bio-adhere the substrate. The further incubation step is a short incubation step of about 2-4 days. The further incubation step may be performed under a temperature from 10 °C to 35 °C, preferably from 15 °C to 30 °C, and / or under a relative humidity (RH%) of at least 60, preferably at least 70.

[0039] In another non-limiting example of the present invention, the mycelium coated substrate, for example in the form of beads, balls, and / or chips, may be heat pressed into an insulation board.

[0040] The mycelium-coated substrate may be subject to post-treatment to improve its properties. For example, the mycelium-coated substrate may be coated or impregnated with a property-improving coating or impregnation. Preferably, an improved property may be selected from the list consisting of water resistance, fire resistance, vapour permeability, acoustic insulation, thermal, mould resistance, or combinations thereof. Suitable coating / impregnating agents include coating compositions that are silica based, alumina based, hafinia based, zirconia based, titania based, cerium oxide based, and coating compositions based on any combination of the above. This list is not exhaustive. In a preferred embodiment of the present invention, the mycelium-coated substrate is coated or impregnated with silica based, and / or alumina based, and / or titania based, coating composition(s). There may be one or more same or different coatings / impregnations applied to the substrate.

[0041] It is noted that the coating / impregnation or other suitable post-treatment step may be performed before or after the configuration step. Nevertheless, the substrate (either treated or non-treated, either configured or non-configured) is dried prior to use, preferably to a moisture content of not more than about 6%, not more than about 5%, preferably not more than 4%, preferably not more than 3%, prior to application. In the case of a coated substrate, the requirement on drying may be more stringent if the coating composition contains solvent(s) and / or volatile(s). Preferably, a coated substrate is dried to a moisture content of not more than 1%.

[0042] The dried mycelium-coated substrate obtained from the process of the present invention may have unique properties which may make it particularly suitable for use as a loose fill insulation product. The density of the mycelium-based loose fitting insulation unit may be no more than 150 kg / m3, preferably no more than 100 kg / m3, more preferably no more than 90 kg / m3, typically no more than 70 kg / m3, most preferably no more than 50 kg / m3. The thermal conductivity of the unit may be no more than 0.05 W / mK, preferably no more than 0.04 W / mK, typically no more than 0.036 W / mK. In a preferred embodiment of the present invention, the mycelium-based loose fill insulation unit of the present invention may have a density of no more than 90 kg / m3and a thermal conductivity of no more than 0.04 W / mK. In another preferred embodiment of the present invention, the mycelium-based loose fill insulation unit of the present invention may have a density of no more than 60 kg / m3and a thermal conductivity of no more than 0.038 W / mK

[0043] The density described in this application is calculated by dividing the mass by the volume of the object measured. The mass and volume of the object can be measured using any method that belongs to the skilled person’s common general knowledge. The thermal conductivity values described in this application is measured using instruments which measure the energy in watts that are transferred across a distance per degree kelvin difference across this distance, expressed in W / mK. Those instruments are commercially available. Suitable instruments for measuring thermal conductivity include (but are not limited to) hotdisk apparatus, heat flow meters and guarded hot plate instruments, as well as other ISO test instruments. Other devices and methods may also be used for the determination of density and thermal conductivity, as long as they are deemed appropriate by the skilled person.

[0044] As described above, the mycelium coated substrate obtained, which is the mycelium-based loose fill insulation unit according to the present invention may be further configured, for example stacked or “built” into a certain three-dimensional arrangement with mould or dynamic scaffold. The further configuration may help to reduce the density even further, due to spaces between the unit(s). According to a further aspect, the present invention provides a mycelium-based loose fill insulation product comprising one or more mycelium-based loose fill insulation units of the present invention. The product has a density of no more than 100 kg / m3, more preferably no more than 70 kg / m3, for example 50 kg / m3, most preferably no more than 40 kg / m3. The thermal conductivity of the product is no more than 0.05 W / mK, preferably no more than 0.04 W / mK, typically no more than 0.036 W / mK. In a preferred embodiment of the present invention, the mycelium-based insulation product has a density of no more than 150 kg / m3and a thermal conductivity of no more than 0.04 W / mK.

[0045] According to a further aspect, the present invention provides an application for insulating an interior of a hollow or open space in a building structure. The application comprises blowing or pouring the mycelium-based loose-fill insulation unit of the present invention, or the mycelium-based loose-fill insulation product of the present invention, into the hollow or open space. In one embodiment of the application, the mycelium-based loose-fill insulation unit, for example a mycelium-based foam produced by the method of the present invention, may be broken down into smaller pieces prior to the application.

[0046] According to a further aspect, the present invention provides a method of producing an insulation arrangement. The method comprises: a) obtaining at least two mycelium-based loose fill insulation unit from the process of the present invention; b) stacking the mycelium-based loose fill insulation product into a configuration, preferably in a mould or a dynamic scaffold; and c) subjecting the configuration to a short incubation step to bio-adhere the loose fill insulation product into the insulation arrangement. The short incubation step may be performed under a temperature from 10 °C to 35 °C, preferably from 18 °C to 25 °C, and / or under a relative humidity (RH%) of at least 60, preferably at least 70, for a period of 2- 4 days.

[0047] According to a further aspect, the present invention provides a method for producing an insulation board, the method comprising: a) obtaining at least two, preferably a multiplicity of, mycelium-based loose fill insulation units from the process of the present invention; and b) heat pressing the mycelium-based loose fill insulation units into a dense insulation board.

[0048] The mycelium-based loose fill insulation units, products and arrangements of the present invention may be used in various applications where high efficiency insulation is required. For example, they can be used as a packing material, for use as a building insulation material for example a building cavity insulation product, and for retro-fitting of insulation material to an intended location / area.

[0049] It will of course be appreciated that features described in relation to one aspect of the present invention may be incorporated into other aspects of the present invention. For example, the method of the invention may incorporate any of the features described with reference to the apparatus of the invention and vice versa.

[0050] Description of the Drawings

[0051] Embodiments of the present invention will now be described by way of example only with reference to the accompanying schematic drawings of which:

[0052] Figure 1 shows a gel layer formed on the surface of a ceramic bead in Example 1;

[0053] Figure 2 shows a mycelium-based loose filling insulation unit obtained in Example 1;

[0054] Figure 3 shows the solid substrate of Example 2 during the incubation step of the present invention;

[0055] Figure 4 shows a mycelium-based loose filling insulation unit obtained in Example 2;

[0056] Figure 5 shows a mycelium-based loose filling insulation unit obtained in Example 3;

[0057] Figure 6 shows a cross-section view of the mycelium-based loose filling insulation unit obtained in Example 3;

[0058] Figure 7 shows a solid substrate composite assembly prepared in Example 4;

[0059] Figure 8 shows a mycelium-based loose filling insulation unit obtained from the solid substrate composite assembly prepared in Example 4;

[0060] Figure 9 shows a mould prepared in Example 5 from bark;

[0061] Figure 10 shows a mycelium-based loose filling insulation unit obtained from the mould prepared in Example 5;

[0062] Figure 11 shows an insulation arrangement obtained in Example 5.

[0063] Examples

[0064] Example 1- Porous ceramic beads with gel layer and mycelium adhered

[0065] Ceramic beads, obtained from the Centre for Print Research at UWE and fabricated out of terracotta with bum-out fibres, were initially sterilised at high temperature before being inoculated using a fragmented mycelium suspension within a nutrient -rich calcium agarlginate gel. The gel was prepared by combining 1 g of sodium alginate with 2 g of potato dextrose and 2 g of yeast extract for every 100 mL of deionised water. This alginate solution was then combined with fragmented mycelium in a liquid broth and stirred vigorously. Once homogenous, the clay beads were emersed in the solution before being transferred to a 3% solution of calcium chloride, this instantly caused an ion exchange in the sodium alginate leading to the formation of a gel layer, as shown in Figure 1.

[0066] Once the beads were successfully inoculated with the gel suspension, they were incubated at 26 °C for 4-7 days. After this period a white layer of mycelium was observed covering all surface area not in contact with another surface. The beads were then dried in a dehydrator at 50 °C for 12 hours, as shown in Figure 2.

[0067] Example 2- Organic material core with gel layer and mycelium encapsulation

[0068] Similar to Example 1, a nutritional sodium alginate mycelium suspension gel was adhered to a material core. In this case, the core was a ball of woody organic matter (eucalyptus bark). The cores were hand rolled after first sterilising at high temperature and were between 0.5 and 2 cm in diameter. Once the gel of calcium alginate, potato dextrose, yeast extract and suspended fragmented mycelium was formed around the core, the balls were incubated at 26 °C for 4-7 days, as shown in Figure 3.

[0069] The bark-alginate gel balls were then dehydrated at 40 °C for 12 hrs. The dehydrated ball is shown in Figure 4.

[0070] Example 3- Cellulose foam with mycelium colonisation

[0071] Beads have also been produced by the inoculation of cellulose foams. These cellulose foam cores are first hydrated using a nutrient broth containing fragmented mycelium before incubation at 26 °C for 4-7 days, as shown in Figure 5.

[0072] The resultant myceliated beads show good coverage and cross-sectional images show the growth of mycelium throughout the interior of the bead, as shown in Figure 6.

[0073] The beads are then dried at 40 °C for 24 hrs. The beads can then if required be coated if required. The coating process consisted of a vacuum impregnation using a solgel silica sol-gel solution. The vacuum impregnation process consists of the emersion of the beads within the solution, then a dynamic vacuum step, whereby the chamber containing the solution and beads is open to the vacuum of a vacuum pump, then a static vacuum step, whereby the vacuum pump is isolated from the chamber but the pressure is not altered holding the system at reduced pressure for a curing period, finally, the chamber is repressurised and the beads are removed from the solution for drying. The drying process is also at 40 °C for 24 hrs.

[0074] Example 4- Low-density lignocellulosic core directly inoculated using liquid inoculum

[0075] Liquid inoculum was prepared by growth in a liquid broth for 3 days before fragmentation using a blender and allowing 1 day of growth for the mycelium to repair, at 26 °C. Once this was completed, a substrate composite assembly was first prepared and formed into the desired shape, using a sedimentation process before being sterilised, as shown in Figure 7.

[0076] The fragmented liquid culture was applied directly to the composite units which were then incubated for 3-7 days, at 26 °C and at 70-95% RH. After this period the units were completely coated in a mycelial skin. The mycelium coated composites were then dehydrated at 40 degrees for 12 hrs. The result is shown in Figure 8.

[0077] Example 5- Bound bead structure formation

[0078] A 400 g bag of bark was wetted with 400 mL of deionised water. This was sterilised and then inoculated using 80 g of spent grain and 80 g of grain spawn. The bag was sealed and incubated in the grow tent, 26 °C and at 70-95% RH. After five days, the bags were removed from the tent and homogenised. The substrate was pressed into moulds at 1 to 2 cm thickness. The moulds were wrapped with cling film and placed back in the tent and further incubated for a week, at 26 °C and at 70-95% RH, as shown in Figure 9.

[0079] The moulds were then taken out and shredded in different ways to test which is the best method. The methods included using; a pizza cutter, a scalpel, a saw, a box cutter, scissors and shredding by hand. The method that worked the best was using scissors, but this was reliant on being able to get the sample out of the mould, which was difficult for samples that were not grown enough. The shredded beads material was then placed into new moulds, spaced apart and incubated further, at 26 °C and at 70- 95% RH to achieve growth around the whole surface of the entire bead, as shown in Figure 10.

[0080] After one week, the beads were removed and dried at 40 °C for 24 hours. These beads were placed inside a 10 cm3mould and drenched in a sol-gel coating solution containing cellulose fibres as a binding agent. The combination was then dried at 40 °C for 24 hours. The resulting product is shown in Figure 11.

[0081] Another batch of beads where recombined in a mould whilst still wet and alive. These beads were allowed to grow together for 2 days, 26 °C and at 70-95% RH, before dehydrating at 40 °C for 24 hours. Whilst the present invention has been described and illustrated with reference to particular embodiments, it will be appreciated by those of ordinary skill in the art that the invention lends itself to many different variations not specifically illustrated herein. By way of example only, certain possible variations will now be described.

Claims

Claims1. A mycelium-based loose fill insulation unit having a density of no more than about 100 kg / m3and a thermal conductivity of no more than about 0.04 W / mK.

2. The mycelium-based loose-fill insulation unit according to claim 1, wherein the unit is of a material selected from the group consisting of: an organic material, such as a lignocellulosic material, fructose, glucose, saccharose, maltose, dextrose, pectin, lactose, xylose, starch, dextrin, hemicellulose or derivatives thereof; alumina; silica; quartz; hafinia; zirconia; a functional material, preferably titania oxide or cerium (IV) oxide; ceramic blends; silicon; and combinations thereof; and preferably, wherein the unit is of a lignocellulosic material.

3. The mycelium-based loose-fill insulation unit according to claim 1 or 2, wherein the mycelium is of a fungus selected from the group consisting of Agaricomycetes, Agaricostilbomycetes, Atractiellomycetes,Bartheletiomycetes, Classiculomycetes, Cryptomycocolacomycetes, Cystobasidiomycetes, Dacrymycetes, Exobasidiomycetes, Malasseziomycetes, Microbotryomycetes, Mixiomycetes, Moniliellomycetes, Pucciniomycetes, Spiculogloeomycetes, Tremellomycetes, Tritirachiomycetes,Ustilaginomycetes, Wallemiomycetes Taphrinomycotina, Pezizomycotina, and combinations thereof; and preferably, wherein the mycelium is of a single subdivision fungus, for example a Dikarya.

4. The mycelium-based loose-fill insulation unit according to any one of claims 1 to 3, wherein the unit is a bead, for example a bead with a diameter from 0.5 to 100 cm, for example from 0.5 to 5 cm or from 30 to 60 cm; a ball; a chip, for example a chip with a size of 0.5 to 10 cm, preferably from 0.5 to 5 cm; or a foam, for example a foam panel with a length up to 3m and width up to 1.5m, preferably a foam panel sized 2.4x 1 ,4m.

5. A method for making one or more mycelium-based loose filling insulation units, the method comprising: a) Preparing a mycelium-based liquid inoculum;b) Suspending a solid substrate in the liquid inoculum in the presence of a liquid medium to obtain a suspension; c) Removing liquid from the suspension to obtain a mycelium-grafted solid substrate; d) Incubating the mycelium-grafted solid substrate for a period of about 3-10 days, preferably about 3 to 7 days, to allow mycelial skin to form on the solid substrate; e) Recovering the solid substrate covered with mycelial skin and drying to obtain one or more mycelium-based loose filling insulation units.

6. The method according to claim 5, wherein the mycelium is of a fungus selected from the group consisting of Agaricomycetes, Agaricostilbomycetes, Atractiellomycetes, Bartheletiomycetes, Classiculomycetes,Cryptomycocolacomycetes, Cystobasidiomycetes, Dacrymycetes, Exobasidiomycetes, Malasseziomycetes, Microbotryomycetes, Mixiomycetes, Moniliellomycetes, Pucciniomycetes, Spiculogloeomycetes, Tremellomycetes, Tritirachiomycetes, Ustilaginomycetes, Wallemiomycetes Taphrinomycotina, Pezizomycotina, and combinations thereof; and, preferably, wherein the mycelium is of a single subdivision fungus, for example a Dikarya7. The method according to claim 5 or 6, wherein the solid substrate is in the form of a bead with a diameter from 0.5 to 100 cm, for example from 0.5 to 5 cm or from 30 to 60 cm; a ball; a chip, for example a chip with a size of 0.5 to 10 cm, preferably from 0.5 to 5 cm; or a foam, for example a foam panel with a length up to 3m and width up to 1.5m, preferably a foam panel sized 2.4x 1 ,4m.

8. The method according to any one of claims 5 to 7, wherein the liquid inoculum comprises fragmented mycelium; and / or wherein the liquid inoculum comprises at least one nutrient useful for encouraging the growth of fungi and / or mycelium.

9. The method according to any one of claims 5 to 8, wherein the liquid inoculum is a solution comprising at least one nutrient useful for encouraging the growth of fungi and / or mycelium and at least one piece of agar with fungus cultivatedthereon, or wherein the liquid inoculum is a liquid culture comprising mycelium-containing fungus suspension.

10. The method according to any one of claims 5 to 9, wherein the liquid medium comprises one or more additives, and preferably the one or more additives has pest resilience and / or nutritional value.

11. The method according to any one of claims 5 to 10, wherein step b) is performed in a container comprising one or more smaller sections created by a grid or one or more dividers.

12. The method according to any one of claims 5 to 11, wherein the mycelium- grafted solid substrate produced after step c), when dried, has a density of from 40 to 120 kg / m3.

13. The method according to any one of claims 5 to 12, wherein during step d) the solid substrate is flipped to allow uniformed growth of the mycelia skin on the substrate; and preferably, wherein step d) is performed under a temperature of 10 to 30 °C, preferably 18 to 25 °C.

14. The method according to any one of claims 5 to 13, wherein step d) is performed until the solid substrate reaches a mycelium surface coverage of no less than 90%, preferably no less than 95%.

15. The method according to any one of claims 5 to 14, wherein step e) is performed under a temperature of 30 to 85 °C, preferably 40 to 75 °C.

16. The method according to any one of claims 5 to 15, further comprising coating the dried mycelium-covered solid substrate with a coating composition..

17. The method according to claim any one of claims 5 to 16, wherein the coating solution comprises one or more property-improving agent and wherein the improved property is selected from the list consisting of: water resistance, fire resistance, vapour permeability, acoustic insulation, thermal, mould resistance, or combinations thereof.

18. The method according to claim any one of claims 5 to 17, further comprising heat pressing the obtain one or more mycelium-based loose filling insulation units into a board or board-like product.

19. An application for insulating an interior of a hollow or open space in a building structure, the application comprises blowing or pouring the mycelium-based loose-fill insulation unit according to any one of claims 1 to 4, or the myceliumbased loose-fill insulation unit produced by the method of any one of claims 5 to 18, into the hollow or open space.

20. The application according to claim 19, wherein the mycelium-based loose-fill insulation unit is treated with a performance-enhancing coating or impregnate.

21. The application according to claim 19 or 20, wherein the mycelium-based loosefill insulation unit is broken down into smaller pieces prior to the application.

22. A method of producing an insulation arrangement, the method comprising: a) obtaining at least two mycelium-based loose fill insulation units as described in any one of claims 1 to 4; b) stacking the mycelium-based loose fill insulation units into a configuration, preferably in a mould or using a dynamic scaffold;; and c) subject the configuration to an further incubation step to bio-adhere the loose fill insulation product into the insulation arrangement, and in particular, step c) is performed under a temperature from 10 °C to 35 °C, preferably from 15 °C to 30 °C, and / or under a relative humidity (RH%) of at least 60, preferably at least 70.

23. A method for producing an insulation board, the method comprising: a) obtaining a multiplicity of mycelium-based loose fill insulation units as described in any one of claims 1 to 4; and b) heat pressing the mycelium-based loose fill insulation product into an insulation board.

24. A mycelium-based loose-fill insulation product comprising one or more mycelium-based loose-fill insulation units according to any one of claims 1 to 4, wherein the product has a density of no more than about lOOkg / m3, preferably no more than 70 kg / m3, more preferably no more than 50 kg / m3, for example from 40 to 90 kg / m3.

25. The mycelium-based loose-fill insulation product according to claim 24, wherein the product is used as a packing material or a building insulation material, for example a building cavity insulation product.

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