AU2015271912B2 - Method of manufacturing a stiff engineered composite - Google Patents

Abstract

of the Disclosure The method of making a compressed biocomposite body includes compressing a mass of biocomposite material comprised of discrete particles and a network of interconnected glucan-containing mycelia cells in the presence of heat and moisture 5 into a compressed body having a density in excess of 18 pcf. Compression may take place batch wise in a press or continuously in a path of narrowing cross-section defined by a series of heated rollers. 27 Fig, I Step Fungallnculun + Pa ts + utrets Water Step 2 Mix substrate corponerts and inoculum vohnetrically or gravimetrically Step 3 Place growth media inamolded enllosure, a flat enclosurc, or series ofcenclosures. or or Step 4 Mycelia is growa matching the geometryof the enclosure Step 4a Mycelia Eandparticles and'or tibers are intermied L or 10 Step 5 Mycea s grown out in Steps I - 3, ground, and played in a new enclosure to complete grOwth Step Sa Mycelin colonized particles nd/or fiber are pressed n a heated platen pres /6 33 124

Description

Fig, I

Step Fungallnculun + Pa ts + utrets Water

Step 2 Mix substrate corponerts and inoculum vohnetrically or gravimetrically

Step 3 Place growth media inamolded enllosure, a flat enclosurc, or series ofcenclosures.

or or

Mycelia is growa matching the geometryof the enclosure Step 4a Mycelia Eandparticles and'or tibers are intermied Step 4

or L

10

Step 5 Mycea s grown out in Steps I - 3, ground, and played in a new enclosure to complete grOwth

Step Sa Mycelin colonized particles nd/or fiber are pressed n a heated platen pres

/6 33

Method of Manufacturing a Stiff Engineered Composite

This invention relates to a method of manufacturing a stiff engineered composite.

More particularly, this invention relates to a method of producing stiff mycelium bound

parts.

As is known, conventional methods for producing nonstructural boards rely on

compressing wood veneer sheets, fibers, or particles and binding them together with

resin to form composites like hardwood plywood and medium density fiberboard, which

are used for applications such as furniture and fixtures, cabinetry, paneling, molding and

athletic equipment. The ingredients for these typical non-structural boards require

considerable pre-processing, and the feedstocks, especially timber and resins, are

subject to considerable price volatility. Additionally, many of the resins used to produce

non-structural boards are carcinogenic and can emit volatile organic compounds

(VOCs).

Much like nonstructural boards, structural boards are produced by compressing

wood veneer sheets, fibers, or particles and binding them together with resin to form

composites like oriented strand board (OSB) and softwood plywood. OSB and softwood

plywood are used for applications such as wall sheathing, floor sheathing, and concrete

framework. These structural boards face the same concerns that nonstructural boards

face because they use similar feedstocks and resins.

Many structural and nonstructural boards are used for applications in furniture,

cabinetry, and fixtures where they must be cut, milled, and sanded to form the desired

shape. Such post processing is expensive and time consuming and creates material waste as the products are shaped. Plastics are also used for these applications and require expensive tools and machines for molding in their production processes.

US Published Patent Application 2008/0145577 describes various techniques for

making self-supporting composite bodies comprised of discrete particles and a network

of interconnected mycelium cells bonding the particles together. As described therein,

the composite bodies may be formed into panels as well as into panel systems with a

composite core.

It is an object of this invention to provide an improved process for the

manufacture of a compressed composite body of particle/mycelium and/or to provide

the public with a useful choice.

Briefly, the invention provides a method of achieving adhesion between a matrix

of fungal mycelium and a slurry of particles and/or fibers (natural or synthetic) through a

heated compression process.

More specifically, in a first aspect the present invention provides a method of making a

composite body comprising the steps of

obtaining a mass of material comprised of discrete particles, glucan

containing mycelia cells and a moisture content of from 45% to 70%;

placing the mass of material in a compression fixture;

heating the mass of material in the compression fixture while compressing

the material into a compressed body of a desired density and shape within said

compression fixture; maintaining the compressed body under heat and compression for a time sufficient to allow cross-linking between the glucans in said mycelia cells to bind the discrete particles together in the compressed body; and removing the compressed body from the compression fixture.

In a second aspect the present invention provides a method of making a

composite body comprising the steps of

obtaining a mass of biocomposite material comprised of discrete

particles, a network of interconnected glucan-containing mycelia cells extending

around the discrete particles and a moisture content of greater than 10% by

weight;

molding said mass into a plurality of tiles of rectangular shape;

stacking said tiles in alternating manner with a plurality of wooden veneers

and with a plate of porous plastic on an underside thereof to from a stack;

compressing said stack to compress said tiles to approximately three

times density while drying the compressed tiles to obtain a pre-compressed

biocomposite body;

thereafter compressing said pre-compressed biocomposite body at a

force of 20 tons and at a temperature of 600°F for a time of two minutes while

reducing the moisture content to less than 10% to obtain a compressed

composite body.

In a third aspect the present invention provides a method of making a composite

body comprising the steps of obtaining a mass of biocomposite material comprised of discrete particles, a network of interconnected glucan-containing mycelia cells extending around the discrete particles and a moisture content of greater than 10% by weight; and thereafter compressing said mass at a pressure between 25 psi and

5000psi and at a temperature of 600°F for a time of four minutes while

reducing the moisture content to less than 10% to obtain a compressed

composite body.

In a fourth aspect the present invention provides a method of making a

composite body comprising the steps of

obtaining a mass of biocomposite material comprised of discrete

particles, a network of interconnected glucan-containing mycelia cells extending

around the discrete particles and a moisture content of greater than 10% by

weight; and

thereafter compressing said mass at a pressure between 25 psi and

5000 psi and at a temperature of 300°F for a time of one minute while

reducing the moisture content to less than 10% to obtain a compressed

composite body.

In a fifth aspect the present invention provides a method of making a composite

body comprising the steps of obtaining a mass of biocomposite material comprised of discrete particles, a network of interconnected glucan-containing mycelia cells extending around the discrete particles and a moisture content of greater than 10% by weight; forming said mass of biocomposite material into a flat blank board of 1.25" thickness with a 0.25" hemp nonwoven matt grown into at least one face of said flat blank board; thereafter compressing said flat blank board into the predetermined curved shape under a compressive force of 3000 psi and at a temperature of

340°F for a time of 10 minutes while reducing the moisture content to less than

10% to obtain a compressed composite body of curved shape.

In a sixth aspect the invention provides a method of making a composite body

comprising the steps of

cultivating mycelium into a sheet;

freeze drying said sheet;

thereafter milling said dried sheet to form a first mass of particles;

milling Kenaf pith to form a second mass of particles;

blending said first mass of particles and said second mass of particles into

a mixture;

thereafter heating and compressing said mixture in a mold cavity for a

time sufficient to form a cohesive product; and

removing said product from the mold as a self-supporting composite body.

US Published Patent Application 2008/0145577 has demonstrated that fungal

mycelium can bind natural (lignocellulosic and chitinous waste streams) and/or synthetic

(fiberglass) particles together during a controlled incubation process. The mycelium in

the latter instance serves as a grown adhesive, digesting a portion of the particles and

fibers while encapsulating the slurry in a network of a vegetative tissue.

The process described within demonstrates that the extracellular matrix of

mycelium, known as the matrix layer of the cell wall and comprised of polysaccharides

(alpha and beta glucans), polymerized amino sugars (N-glucosamine, chitin),

monoproteins, and phosopholipids, can serve as a traditional adhesive when heated

and dried concurrently. The mycelium is either grown on, or mixed with, an engineered

substrate of natural and/or synthetic particles and/or fibers and then compressed under

heat and dried to desired geometry.

The heating of the mycelium matrix actually provides value in two places, which

makes this process distinctly different from the prior art. The fungal cell wall is

comprised of chitin and glucans. The glucans, when heated and saturated with the

moisture embedded within the composite, begin to flow like a traditional resin and when

dried stick the particles together beyond the traditional mycelium matrix.

By creating sheets of material made from particles bound together with mycelium

(hereinafter "the biocomposite material") and compressing these sheets together, bio

based nonstructural boards can be created with feedstocks. The sheets of biocomposite

material can be grown together or compressed together with heat to set and dry the

final product. The sheets of biocomposite material can vary in product density, fiber content, particle size, and fiber orientation to selectively promote specific mechanical properties (screw hold strength, core shear, modulus of elasticity).

Further, a large mass of mycelium can be cultivated on particles or fibers, milled

to a consistent particle size and then pressed in a constrained heated tool.

Additionally, VOCs are not a concern for structural boards produced in this

manner because no VOC emitting resins are used in the production process, and the

cross-linking occurs between the biochemical construct of the fungal cell wall.

There are significant mechanical advantages garnered from compressing sheets

of mycelium bound particles into a single cohesive product with heightened

temperatures (200°F - 650 0F) while compressing the biocomposite material at a

pressure of from 10 to 1500 psi.. These advantages include enhanced modulus of

rupture and elasticity (stiffness), and the ability to layer sheets of varying particles size

to achieve greater stiffness or dimensional stability (squareness, flatness).

Other materials, including veneers, textiles, or laminates, that are comprised of

wood, plastics (polyester scrim), foam, natural fibers, stone, metal, or the like can be

grown and bound to the face or internal structure of the mycelium and particle sheets.

These laminates can be stacked and interlaid to the mycelium colonized particle sheets,

and then compressed to a desired form (flat or molded).

Structural boards can be created by compressing thick blocks of grown material

or layered sheets of grown material (particles and/or fibers bound by mycelium) while

drying with heat (radiation, conduction, or convective).

Orienting particles within an engineered substrate and then preliminarily binding

these with mycelium creates a bio-based product that does not emit VOCs.

The compressed biocomposite material can be easily and cheaply shaped during

production. The grown material can be compressed in an inexpensive mold (fiberglass,

carbon fiber, composite, wooden and/or metal, e.g. aluminum), giving the material the

desired shape and material properties without creating waste. The final product can be

dried in the tool to promote cross-linking between the natural polymers within the

mycelium, which can occur within the magnitude of minutes.

The grown material can also be compressed in a conductive tool that is heated

as well to the final shape, either with a heated platen or inserted cartridges.

These and other objects and advantages of the invention will become more

apparent from the following detailed description taken in conjunction with the

accompanying drawings wherein:

Fig. 1 schematically illustrates the steps in the method of manufacturing a stiff

engineered composite in accordance with the invention.

Referring to Fig. 1, in accordance with the method of the invention, an

engineered substrate bound with mycelium 10 is grown into a sheet of appropriate

dimensions in step 1. In this respect, the basic steps of the method include:

1. Obtain substrate constituents, including fungal inoculum, a bulking collection of

particles and/or fibers, a nutrient source or variety of nutrient sources, and

water.

2. Combine the substrate constituents by mixing together in volumetric or

mass ratios to obtain a solid media with the inoculum (cell and/or tissue

culture) added during or following the mixing process.

3. Place the growth media in an enclosure or series of enclosures of the desired geometry.

4. Allow the mycelia to grow through the substrate, creating a composite with a

geometry matching the enclosure. This may be either the final geometry or

the near net geometry of the final product.

4a. For parts that are dried in compression, the mycelium does not have to grow

on the engineered substrate but could be grown in a secondary process and

thoroughly intermixed to distribute culture just prior to compressive drying

(conduction, convection, radiation).

5. Repeat steps 1-3 for applications where materials are layered or embedded

to create the desired final composite media. Alternatively to steps 3 and 4,

the growth media may be grown as a solid mass, and then ground up for

later steps or placed in an enclosure of the desired shape and then be

allowed to regrow into that shape.

5a. Repeat steps 1-3 for applications where the materials are grown and

colonized, and then alternative to steps 3 and 4, the growth media is milled or

particlized into the uniform size. The resultant particles are then compressed into

a constrained and heated tool.

In step 2 of the method, the engineered substrate 10 containing some residual

moisture and, for example in the form of a flat rectangular plate or tile, is placed in a

compression fixture 11, for example, a pinch press 11. As illustrated, the pinch press 11

has a bottom platen 12 that can be heated and that is formed with a mold body 13 of

predetermined shape, for example, of semi-cylindrical shape. The pinch press 11 also

has a top platen 14 for engaging on the bottom platen 12 with a cavity 15 within the platen 14 for mating about the mold body 13. Typically, when the platens 12, 14 are closed together, a semi-cylindrical gap exists between the mold body 13 and the cavity

15.

Typically, the engineered substrate 10 should contain a minimum of 10%

moisture by weight. Steam may also be injected during compression to induce the

adhesion.

Since the glucans are activated by steam, the engineered substrate 10 should

contain a minimum of 40% moisture by weight so that the moisture may be transformed

into steam during the heated pressing process as otherwise live steam would be

injected into the dry mass during compression to induce the adhesion.

After positioning of the engineered substrate 10 on the mold body 13 of the pinch

press 11, the top platen 14 is lowered onto the bottom platen 12 in order to compress,

trim and dry the biocomposite material of the substrate 10.

During operation, the pinch press 11 is heated to 300°F while compressing the

biocomposite material of the substrate to between 10psi and 1500 psi. The length of

time that the biocomposite material of the substrate 10 is retained within the pinch press

11under heat and pressure is sufficient to the reduce the moisture content of the

material to less than 10% by weight and to promote cross-linking between the natural

polymers within the mycelium. The biocomposite material can also be held in the pinch

press 11 for a time sufficient to achieve a product stiffness that is sufficient to remove

the compressed material from the pinch press 11 ("tool" or "buck").

In step 3 of the method, with the pinch press 11 opened, a compressed

monolithic body 16 is removed from the pinch press 11. As illustrated, the monolithic

body 16 has a semi-cylindrical shape and is characterized as being a rigid shell.

Variations

Additional methods can also be used to produce desirable properties in the final

composite.

1. The substrate of engineered particles and/or fibers ("biocomposite material"),

either colonized with mycelium (bioactive) or intermixed with mycelium (inactive), can

also include cation salts (divalent Na2+ and the like) that can assist with cross-linking

between the polysaccharides and amino sugars. Acids (hydrochloric, acetic, lactic) can

be provided as well to ensure the substrate stays protonated.

a. The cation salts can be applied during initial substrate preparation and

sterilization.

b. The cations can be applied in a solution by either vacuum infusing the solution

into the substrate or immersing the substrate in a cation solution for a certain period of

time.

2. Surface treatments, such as laminates, veneers, or supplemental fibers, can

be bound to the engineered substrate. For example, a laminate can be placed on the

face of the engineered substrate during the initial growth step. This is "colonization".

Alternatively, a laminate may be applied to the engineered substrate just before

pressing and bound with only the glucans.

The laminate treatments are applied to the surfaces, or in between tiles if multiple

colonized blocks are used, and pressed with a heated platen until the biocomposite

material is < 10% moisture.

Laminations and inserts can also be pressed into the surface of a colonized

engineered substrate, again using the adhesion from the glucans. The laminations can

include non-woven textiles, woven products (jute, fiberglass), and Kraft paper, which

become an integrated component of the final part.

Inserts can be positioned in either the lower or upper platens of the compression

tooling, and can be pressed into the biological composite during the setting process.

3. The biocomposite material can also be dried to a particular moisture content

with conduction, convection, and/or radiation at atmospheric pressure, and then

compression dried to complete the process.

4. The biocomposite material can be dried to a moisture content of between 6%

and 30% during the heated compression stage to retain enough moisture to impart

electrical conductivity such that the resultant compressed monolithic body can be

powder coated since a powder coating process requires the material to be electrically

conductive and moisture, rather than metals salts, is used to impart this characteristic.

a. The heated compression tool, which forms the final product geometry, can

include surface finishes that translate to the final part.

5. The colonized biocomposite material can be compressed and dried with a

series of heated rollers that narrow in cross-section as the material is conveyed through

the process.

Sheets of biocomposite material can be grown together or compressed together

with heat to set and dry the final product. The sheets of biocomposite material can vary

in product density, fiber content, particle size, and fiber orientation to selectively

promote specific mechanical properties (screw hold strength, core shear, modulus of

elasticity). Additionally, VOCs are not a concern for structural boards produced in this

manner because no VOC emitting resins are used in the production process, and the

cross-linking occurs between the biochemical construct of the fungal cell wall.

There are significant mechanical advantages garnered from compressing sheets

of mycelium bound particles into a single cohesive product with heightened

temperatures (200°F - 650 0F). These advantages include enhanced modulus of rupture

and elasticity (stiffness), and the ability to layer sheets of varying particles size to

achieve greater stiffness or dimensional stability (squareness, flatness). Other

materials, including veneers, textiles, or laminates, that are comprised of wood, plastics

(polyester scrim), foam, natural fibers, stone, metal, or the like can be grown and bound

to the face or internal structure of the mycelium and particle sheets. These laminates

can be stacked and interlaid to the mycelium colonized particle sheets, and then

compressed to a desired form (flat or molded).

The methods described herein allow a final part to have a density between 18

and 60 lbs/ft3 , an elastic modulus up to 440 ksi and a modulus of rupture as high as

2500 psi.

Further Variations

Where the growth media is grown as a solid mass and then ground up to

produce particles or pellets with mycelium therein, the particles may be poured into an enclosure of the desired shape and then heated and pressed with the process parameters described above. In this embodiment, the final product has a Modulus of

Rupture of 111 psi and a Modulus of Elasticity of 2840 psi.

The method provides for crosslinking to occur between the glucans in the

mycelia that are solubilized during the compression and moisture release process. This

can be further mediated with mild acids that assist in protonating and cross-linking.

Example 1:

1. Kenaf pith (screened over a 0.375" screen, 42% of mass), maltodextrin (1.6% of

mass), calcium sulfate (0.4% of mass), and water (56% of mass) are mixed in an

autoclavable bag to form the substrate for fungal growth. For five liters of

substrate, the amount of Kenaf pith is 670 grams (g).

2. The bag is sterilized in a pressure cooker at 15 psi and 240°F for 60 minutes.

3. Millet grain spawn containing fungal tissue is mixed into the substrate (10%

[m:m].

4. Plastic tool molds that are 6 inches long, 6 inches wide, and 1 inch deep are filled

with inoculated substrate.

5. The substrate is allowed to colonize in the tools for 7 days at ambient laboratory

conditions (75 0F, 20% relative humidity, 2000 ppm C02)

6. Wooden veneers that are 6 inches wide by 6 inches long and a square of porous

plastic with the same dimensions are soaked in 10% hydrogen peroxide for 30

minutes. This is a chemical disinfection method that also imparts the correct

amount of water, since hydrogen peroxide oxidizes to water.

7. The substrates in the form of tiles are ejected from the mold and stacked in

groups of three with a wooden veneer at each surface and interface and the

porous plastic square on the side that will be next to an air inlet during

compression.

8. The stack of tiles, veneers, and porous plastic is compressed to approximately 3

times density in a compression frame with an air inlet for forced aeration on one

side and holes for passive ventilation on the other. For example, as described in

US Patent Application Serial No. 14/336,385, filed July 21 2014 and published

as US 2015/0038619, the disclosure of which is incorporated herein.

9. The compression frame is hooked up to an air pump and the compressed

substrate is subjected to forced aeration for 5 days. Alternatively, the

compressed substrate may be dried within the compression frame with

convective or conductive drying.

10. The compressed composite body is ejected from the compression frame and

placed in an aluminum collar of the same exterior dimensions that surrounds the

periphery of the compressed composite body. This collar that has the desired

features, locks and creates the features and dimensions required of the final part.

11. A heated platen press (at a force of 20 ton and 6000 F) is compressed onto the

pre-compressed body for two minutes, such that the body is dried to < 10%

moisture content.

The resulting part has a density of 20 lbs/ft3 , a modulus of elasticity around 80 ksi, a

modulus of rupture around 800 psi, and a screw hold strength around 100 lbf.

In this example, the biocomposite material is subjected to compression alone to

form a compressed monolithic body, e.g. as described in as described in US

2015/0038619, and then subjected to heat and pressure to promote cross-linking

between the natural polymers within the mycelium.

Example 2:

1. Kenaf pith (screened over a 0.375" screen, 42% of mass), maltodextrin (1.6% of

mass), calcium sulfate (0.4% of mass), and water (56% of mass) are mixed in an

autoclavable bag to form the substrate for fungal growth.

2. The bag is sterilized in a pressure cooker at 15 psi and 240°F for 60 minutes.

3. Millet grain spawn containing fungal tissue is mixed into the substrate (10%

[m:m].

4. Plastic tool molds that are 6 inches long, 6 inches wide, and 1 inch deep are filled

with inoculated substrate.

5. The substrate is allowed to colonize in the tools (molds) for 7 days at ambient

laboratory conditions (750 F, 20% relative humidity, 2000 ppm C0 2 )

6. The colonized substrate is ejected from the plastic tool that granted the growing

mass its original structure and placed in an aluminum collar that is perforated to

allow for water to escape.

7. The colonized substrate is placed in a heated platen press (20 ton, 6000 F) and is

compressed for four minutes, such that the part is dried to < 10% moisture

content. The colonized substrate requires between 25psi and 5000 psi to achieve

the maximum compression required.

The resulting part has a density of 34 Ibs/ft3 , a modulus of elasticity around 132 ksi, a

modulus of rupture around 1698 psi, and a screw hold strength around 24 lbf at half an

inch thickness. By way of comparison, a composite for packaging made in accordance

with the methods described in US Published Patent Application 2008/0145577 has a

density of from 5 to 8lbs/ft3

Example 3: .

1. Kenaf pith (screened over a 0.375" screen, 42% of mass), maltodextrin (1.6% of

mass), calcium sulfate (0.4% of mass), and water (56% of mass) are mixed in an

autoclavable bag to form the substrate for fungal growth.

2. The bag is sterilized in a pressure cooker at 15 psi and 240°F for 60 minutes.

3. Millet grain spawn containing fungal tissue is mixed into the substrate (10%)

[m:m].

4. Growth enclosure molds that are fabricated out of thermoformed polyethylene

plastic to the final product geometry or near net shape are filled with inoculated

substrate.

5. The substrate is allowed to colonize in the tools (molds) for 7 days at ambient

laboratory conditions (75 0F, 20% relative humidity, 2000 ppm C02)

6. The colonized substrate is ejected from the plastic tool that granted the growing

mass its original structure and placed in a structural enclosure of the final product

configuration. This second enclosure permits conductive heating and is designed

to allow for the installation of embedded inserts or secondary components. The

tool is perforated to allow for water to escape.

7. The colonized substrate in the second enclosure is placed in a heated platen

press (20 ton, 6000 F) and is compressed for four minutes, such that the part is

dried to < 10% moisture content.

The resulting part has a density of 29 lbs/ft3 , a modulus of elasticity around 120 ksi, a

modulus of rupture around 819 psi, and a screw hold strength around 132 lbf at an inch

thickness.

Example 4:

1. Kenaf pith (screened over a 0.375" screen, 42% of mass), maltodextrin (1.6% of

mass), calcium sulfate (0.4% of mass), and water (56% of mass) are mixed in an

autoclavable bag to form the substrate for fungal growth.

2. The bag is sterilized in a pressure cooker at 15 psi 2. and 240°F for 60 minutes.

3. Millet grain spawn containing fungal tissue is mixed into the substrate (10%

[m:m].

4. Plastic tool molds that are 18 inches long, 18 inches wide, and 1 inch deep are

filled with inoculated substrate.

5. The substrate is allowed to colonize in the tools (molds) for 7 days at ambient

laboratory conditions (75 0F, 20% relative humidity, 2000 ppm C02)

6. The colonized substrate, in the form of a sheet, is ejected from the plastic tool

and aligned in a heated pinch press of a desired geometry.

7. The colonized part is pressed and heated (300 0 F) for one minute, such that the

part is dried to < 10% moisture content, molded to the desired shape, and

excess material trimmed from the final product.

Example 5

1. Fabricate the biocomposite material into a flat blank board of 1.25" thickness with

a 0.25" hemp nonwoven matt grown into either face.

2. Press the flat blank board into the predetermined curved shape, such as a shape

for a chair back, along with surface features under a compressive force of 3000

psi and 340°F for 10 minutes to lock the surface features and get the board to

below 10% moisture.

The surface feature may be obtained by embossing at least one face of the

board with a predetermined sculptured feature using an embossing surface on the face

of the press that is pressed against the board.

When using a mold (tool), a mold release, such as a spray release or a

parchment paper, may be used on the surfaces of the mold to enable an easy ejection

of the colonized substrate from the mold.

Example 6

1. Kenaf pith (screened over a 0.375" screen, 42% of mass), maltodextrin (1.6% of

mass), calcium sulfate (0.4% of mass), and water (56% of mass) are mixed in an

autoclavable bag to form the substrate for fungal growth. For five liters of

substrate, the amount of Kenaf pith is 670 grams (g).

2. The bag is sterilized in a pressure cooker at 15 psi and 240°F for 60 minutes.

3. Millet grain spawn containing fungal tissue is mixed into the substrate (10%

[m:m].

4. The substrate is allowed to colonize in the tools for 7 days at ambient laboratory

conditions (75 0F, 20% relative humidity, 2000 ppm C0 2 )

5. The colonized substrate is dried to 30% moisture in a forced convection oven at

180°F for 12 hours.

6. The resultant mass is hammer milled through a 0.125" screen, and then passed

over a 38 mesh screen to remove fines.

7. The particles are positioned in a heated cavity at 3800 F, and then compressed

into the molded cavity with a featured platen under 30 tons of force. The

materials are held for four minutes

8. The final product is ejected and allowed to cool to room temperature before

loading.

In a further variation of the method, the mycelium can be grown out separately

and then added at a 10% moisture content to a collection of dried discrete particles as

set forth in the following examples.

Example 7:

1. Mycelium is cultivated on malt extract (32 g per liter) for 7 days at ambient

laboratory conditions (75 0F, 20% relative humidity, 2000 ppm C0 2 ) until a

sheet of mycelium is formed.

2. The harvested mycelium sheet is freeze dried.

3. The resultant mass is hammer milled through a 0.0625" screen

4. Kenaf pith is hammer milled through a 22 mesh and over a 38 mesh screen.

5. The kenaf pith and mycelium fragments are blended together at a 9:1 ratio

(m:m)

6. The blended together particles are positioned in a heated cavity at 3800 F, and

then compressed into a mold cavity with a featured platen under 30 tons of force and held for four minutes to form a cohesive product.

7. The final product is then ejected from the mold and allowed to cool to room

temperature before loading.

8. The resultant product offered a 31 lb/ft 3 density, a MoR of 206 psi, and a

MoE of 27050 psi.

Example 8:

1. Mycelium is cultivated on malt extract (32 g per liter) for 7 days at ambient

laboratory conditions (75 0F, 20% relative humidity, 2000 ppm C02) until a sheet

of mycelium is formed.

2. The harvested mycelium sheet is freeze dried.

3. The resultant mass is hammer milled through a 0.0625" screen.

4. The mycelium particles are positioned in a heated cavity at 3800 F, and then

compressed into a mold cavity with a featured platen under 30 tons of force and.

held for ten minutes to form a cohesive product.

5. The final product is ejected and allowed to cool to room temperature before

loading.

6. The resultant product (i.e. compressed mycelium) offered a 42 lb/ft 3 density, an

MoR of 507 psi, and an MoE of 48525 psi.

The methods described herein thus provides a compressed composite body of

particle/mycelium that is characterized in being a rigid body having a density in the

range of from 18 to 60 lbs/ft3 , a modulus of elasticity of up to 250 ksi (1k= 1000 psi) and

a modulus of rupture of up to 2500 psi.

The compressed composite bodies described herein that are pressed to 0.25" or

less achieve these above metrics. The use of particles in the bodies normally obtain a

modulus of elasticity under 250 ksi, whereas the use of fibers instead of particles can

obtain a modulus of elasticity well above 250 ksi since the fibers bear more of the

tensile strength in flexure.

The compressed composite body made in accordance with the methods

described herein differs from a compressed composite body made in accordance with

the methods described in Patent Application 14/336,385, filed July 21, 2014, inter alia,

in that due to conductive drying, the glucans are cross-linked and all the water is

removed.

The composite body made in accordance with the invention may be subjected to

further processing steps to achieve a desired final product. For example, the composite

body may be die cut to a desired three-dimensional shape; drilled or cut to provide

openings therein; and the like.

Further, an assemblage of flat sheets of biocomposite material, sheets of woven

or non-woven laminations and inserts of three-dimensional contour (i.e. inserts on non

flattened shape) may be heated and pressed together.to form a desired final product

having an internal shape corresponding to the inserts.

The term "comprising" as used in this specification and claims means "consisting

at least in part of'. When interpreting statements in this specification, and claims which

include the term "comprising", it is to be understood that other features that are

additional to the features prefaced by this term in each statement or claim may also be

present. Related terms such as "comprise" and "comprised" are to be interpreted in

similar manner.

In this specification where reference has been made to patent specifications,

other external documents, or other sources of information, this is generally for the

purpose of providing a context for discussing the features of the invention. Unless

specifically stated otherwise, reference to such external documents is not to be

construed as an admission that such documents, or such sources of information, in any

jurisdiction, are prior art, or form part of the common general knowledge in the art.

In the description in this specification reference may be made to subject matter

that is not within the scope of the claims of the current application. That subject matter

should be readily identifiable by a person skilled in the art and may assist in putting into

practice the invention as defined in the claims of this application.

Claims (31)

What is claimed is:

1. A method of making a composite body comprising the steps of

obtaining a mass of material comprised of discrete particles, glucan

containing mycelia cells and a moisture content of from 45% to 70%;

placing the mass of material in a compression fixture;

heating the mass of material in the compression fixture while compressing

the material into a compressed body of a desired density and shape within said

compression fixture;

maintaining the compressed body under heat and compression for a time

sufficient to allow cross-linking between the glucans in said mycelia cells to bind

the discrete particles together in the compressed body; and

removing the compressed body from the compression fixture.

2. A method as set forth in claim 1 wherein said step of heating the mass of

material in the compression fixture reduces said moisture content to a range of

from 6% to 30% to impart electrical conductivity to the removed compressed

body.

3. A method as set forth in claim 1 wherein said step of heating the mass of

material in the compression fixture reduces said moisture content of less than

10%.

4. A method as set forth in claim 1 wherein said step of heating the mass of

material includes heating the material to a temperature of from 250°F to 650°F

while compressing the material at a pressure of from 10 to 1500 psi.

5. A method as set forth in claim 4 wherein said step of heating the mass of

material includes heating the material to 3000 F.

6. A method as set forth in claim 4 wherein the mass of material is compressed for

a time of between 4 minutes and 15 minutes.

7. A method as set forth in claim 1 further comprising the step of placing a

lamination on a surface of the material in the compression fixture prior to said

step of heating the material whereby the lamination is integrated into the

compressed body.

8. A method as set forth in claim 1 wherein said compression fixture includes at

least one insert for pressing into the material during said step of heating the

material to emboss a surface of the compressed body.

9. A method as set forth in claim 1 wherein said compression fixture is a pinch

press for compressing the material into a compressed body in a batch-like

manner.

10. A method as set forth in claim 1 wherein said compression fixture includes a

series of heated rollers defining a path of narrowing cross-section for

compressing the material into a compressed body in a continuous manner.

11. A method as set forth in claim 1 wherein said mass of material is placed in at

least one enclosure prior to said step of placing the material in the compression

fixture to allow said mycelia cells to form a network of interconnected glucan

containing mycelia cells extending around said discrete particles.

12. A method as set forth in claim 11 wherein the mass of material in the fixture is

compressed at a pressure between 25psi and 5000psi at a temperature of

300°F for a time of one minute while reducing the moisture content to less than

10% to obtain a compressed composite body.

13. A method as set forth in claim 12 wherein said mass of material is molded into a

sheet prior to said step of heating and compressing and pressed into a

deformed geometric shape during said step of heating and compressing.

14. A method as set forth in claim 1 wherein the mass of material in the fixture is

compressed at a pressure between 25psi and 5000psi at a temperature of

600°F for a time of four minutes while reducing the moisture content to less than

10% to obtain a compressed composite body.

15. A method as set forth in claim 1 wherein the removed compressed body has a

density between 18 and 60lbs/ft 3 .

16. A method of making a composite body comprising the steps of

obtaining a mass of biocomposite material comprised of discrete

particles, a network of interconnected glucan-containing mycelia cells extending

around the discrete particles and a moisture content of greater than 10% by

weight;

molding said mass into a plurality of tiles of rectangular shape;

stacking said tiles in alternating manner with a plurality of wooden veneers

and with a plate of porous plastic on an underside thereof to from a stack;

compressing said stack to compress said tiles to approximately three

times density while drying the compressed tiles to obtain a pre-compressed

biocomposite body; thereafter compressing said pre-compressed biocomposite body at a force of 20 tons and at a temperature of 600°F for a time of two minutes while reducing the moisture content to less than 10% to obtain a compressed composite body.

17. A method as set forth in claim 16 wherein said compressed composite body has

a density of 20 lbs/ft3 , a modulus of elasticity around 80 ksi, a modulus of

rupture around 800 psi, and a screw hold strength around 100 lbf.

18. A method of making a composite body comprising the steps of

obtaining a mass of biocomposite material comprised of discrete

particles, a network of interconnected glucan-containing mycelia cells extending

around the discrete particles and a moisture content of greater than 10% by

weight; and

thereafter compressing said mass at a pressure between 25 psi and

5000psi and at a temperature of 600°F for a time of four minutes while

reducing the moisture content to less than 10% to obtain a compressed

composite body.

19. A method as set forth in claim 18 wherein said compressed composite body has

a density of 34 lbs/ft3 , a modulus of elasticity around 132 ksi, a modulus of

rupture around 1698 psi, and a screw hold strength around 24 lbf at half an inch

thickness.

20. A method as set forth in claim 18 wherein said compressed composite body has

a density of 29 lbs/ft3 , a modulus of elasticity around 120 ksi, a modulus of rupture around 819 psi, and a screw hold strength around 132 lbf at an inch thickness.

21. A method of making a composite body comprising the steps of

obtaining a mass of biocomposite material comprised of discrete

particles, a network of interconnected glucan-containing mycelia cells extending

around the discrete particles and a moisture content of greater than 10% by

weight; and

thereafter compressing said mass at a pressure between 25 psi and

5000 psi and at a temperature of 300°F for a time of one minute while

reducing the moisture content to less than 10% to obtain a compressed

composite body.

22. A method as set forth in claim 21 wherein said mass is molded into a sheet prior

to said step of compressing and pressed into a deformed geometric shape.

23. A method as set forth in claim 21 wherein said sheet has dimensions of 18

inches by 18 inches by 1 inch and said deformed geometric shape is a semi

cylindrical shape.

24. A method of making a composite body comprising the steps of

obtaining a mass of biocomposite material comprised of discrete

particles, a network of interconnected glucan-containing mycelia cells extending

around the discrete particles and a moisture content of greater than 10% by

weight; forming said mass of biocomposite material into a flat blank board of 1.25" thickness with a 0.25" hemp nonwoven matt grown into at least one face of said flat blank board; thereafter compressing said flat blank board into the predetermined curved shape under a compressive force of 3000 psi and at a temperature of

340°F for a time of 10 minutes while reducing the moisture content to less than

10% to obtain a compressed composite body of curved shape.

25. A method as set forth in claim 24 wherein said step of forming said mass of

biocomposite material into a flat blank board includes embossing said at least

one face with a predetermined sculptured feature.

26. A method of making a composite body comprising the steps of

cultivating mycelium into a sheet;

freeze drying said sheet;

thereafter milling said dried sheet to form a first mass of particles;

milling Kenaf pith to form a second mass of particles;

blending said first mass of particles and said second mass of particles into

a mixture;

thereafter heating and compressing said mixture in a mold cavity for a

time sufficient to form a cohesive product; and

removing said product from the mold as a self-supporting composite body.

27. A method as set forth in claim 26 wherein said step of cultivating mycelium into

a sheet includes cultivating the mycelium on malt extract at a rate of 32 g per liter for 7 days at ambient conditions of 750 F, 20% relative humidity and 2000 ppm C02 until said sheet of mycelium is formed.

28. A method as set forth in claim 26 wherein said step of milling said dried sheet

includes hammer milling through a 0.0625" screen.

29. A method as set forth in claim 26 wherein said step of milling Kenaf pith

includes hammer milling through a 22 mesh and over a 38 mesh screen.

30. A method as set forth in claim 26 wherein said step of blending blends said

kenaf pith and said mycelium together at a 9:1 ratio.

31. A method as set forth in claim 26 wherein said step of heating and compressing

said mixture includes heating the mold cavity to 380°F and compressing said

mixture under 30 tons of force for four minutes to form the cohesive product.

Editorial Note

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