Method of Manufacturing a Stiff Engineered Composite

Abstract

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 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.

What is claimed is: 
     
         1 . 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 from 45% to 70%;   placing the biocomposite material in a compression fixture;   heating the biocomposite material in the compression fixture while compressing the biocomposite 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;   removing the compressed body from the compression fixture; and   heating the removed compressed body to dehydrate the compressed body to reduce said moisture content to less than 30% and to deactivate the mycelia cells.   
     
     
         2 . A method as set forth in  claim 1  wherein said step of heating 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 reduces said moisture content of less than 10%. 
     
     
         4 . A method as set forth in  claim 1  wherein said step of heating includes heating the biocomposite material to a temperature of from 250° F. to and 650° F. while compressing the biocomposite material at a pressure of from 10 to 1500 psi. 
     
     
         5 . A method as set forth in  claim 4  wherein said step of heating includes heating the biocomposite material to 300° F. 
     
     
         6 . A method as set forth in  claim 4  wherein the biocomposite 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 biocomposite material in the compression fixture prior to said step of heating the biocomposite 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 biocomposite material during said step of heating the biocomposite material. 
     
     
         9 . A method as set forth in  claim 1  wherein said compression fixture is a pinch press for compressing the biocomposite 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 biocomposite material into a compressed body in a continuous manner. 
     
     
         11 . 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.   
     
     
         12 . A method as set forth in  claim 11  wherein said compressed composite body has a density of 20 lbs/ft 3 , a modulus of elasticity around 80 ksi, a modulus of rupture around 800 psi, and a screw hold strength around 100 lbf. 
     
     
         13 . 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 600° F. for a time of four minutes while reducing the moisture content to less than 10% to obtain a compressed composite body.   
     
     
         14 . A method as set forth in  claim 13  wherein said compressed composite body has a density of 34 lbs/ft 3 , 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. 
     
     
         15 . A method as set forth in  claim 13  wherein said compressed composite body has a density of 29 lbs/ft 3 , 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. 
     
     
         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; 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.   
     
     
         17 . A method as set forth in  claim 16  wherein said mass is molded into a sheet prior to said step of compressing and pressed into a deformed geometric shape. 
     
     
         18 . A method as set forth in  claim 17  wherein said sheet has dimensions of 18 inches by 18 inches by 1 inch and said deformed geometric shape is a semi-cylindrical shape. 
     
     
         19 . 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.   
     
     
         20 . A method as set forth in  claim 19  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. 
     
     
         21 . 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.   
     
     
         22 . A method as set forth in  claim 21  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 75° F., 20% relative humidity and 2000 ppm C0 2  until said sheet of mycelium is formed. 
     
     
         23 . A method as set forth in  claim 21  wherein said step of milling said dried sheet includes hammer milling through a 0.0625″ screen. 
     
     
         24 . A method as set forth in  claim 21  wherein said step of milling Kenaf pith includes hammer milling through a 22 mesh and over a 38 mesh screen. 
     
     
         25 . A method as set forth in  claim 21  wherein said step of blending blends said kenaf pith and said mycelium together at a 9:1 ratio. 
     
     
         26 . A method as set forth in  claim 21  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. 
     
     
         27 . A self-supporting composite body comprising a substrate of discrete particles and a network of interconnected mycelia cells extending through and around the discrete particles and bonding the discrete particles together, said composite body being characterized in being stiff and in having a density between 18 and 60 pounds per cubic foot (pcf), a modulus of elasticity of up to 250 ksi and a modulus of rupture of up to 2500 psi. 
     
     
         28 . A self-supporting composite body comprising a substrate of discrete fibers and a network of interconnected mycelia cells extending through and around the discrete fibers and bonding the discrete fibers together, said composite body being characterized in being stiff and in having a density between 18 and 60 pounds per cubic foot (pcf), a modulus of elasticity greater than 250 ksi and a modulus of rupture of up to 2500 psi.