WO2024159182A1

WO2024159182A1 - Building construction compsotions and methods

Info

Publication number: WO2024159182A1
Application number: PCT/US2024/013240
Authority: WO
Inventors: Stephen Turner
Original assignee: Individual
Current assignee: Individual
Priority date: 2023-01-26
Filing date: 2024-01-26
Publication date: 2024-08-02
Anticipated expiration: 2025-07-26

Abstract

A method of manufacturing a structure is described. The method includes the steps of breaking hemp stalk into a plurality of pieces, mixing the hemp stalk pieces with an expanding foam, pouring or spraying the mixture into a mold, allowing the mixture to expand and harden; and separating the mold from the hardened mixture. A static mixing nozzle is also described. The nozzle has an inlet for hemp stalk pieces located downstream from the inlets for the expanding foam components. A spray can having a mixture of an expanding foam, a gaseous propellant, and a plurality of hemp stalk pieces is also described. An expanding foam comprising a plurality of hemp stalk pieces is also described.

Description

BUILDING CONSTRUCTION COMPSOTIONS AND METHODS

Field of the Invention

[0001] The field of the invention is building construction compositions and methods.

Background

[0002] The following description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.

[0003] It is known to mix hemp hurd with concrete to make walls for building structures (e.g., “hempcrete”). Hemp hurd has many beneficial characteristics as a building material. For example, hemp hurd is strong, light weight, fire resistant, economical, and has a high insulation value. Hemp hurd also absorbs carbon dioxide, which is good for the environment, and has natural antimicrobial properties that help prevent mildew and mold. Hempcrete can be cast in place at the construction site, or alternatively, it can be manufactured as blocks off-site and then transported to the construction site for assembly. See, for example,

sZ1950.htm.

[0004] While advantageous in many aspects, hempcrete is still relatively heavy and takes a lot of time to manufacture due to the amount of tamping required to strengthen the concrete. Hempcrete is also thick and does not fill in small cracks or small spaces very well.

[0005] It is also known to use hemp hurd to make particleboard and fiberboard. The hemp hurd particles are typically bound together using a veneer glue. The hemp hurd particleboard advantageously reduces the consumption of tree forests and reduces costs. However, even hemp hurd particleboard can still be expensive due to the cost of the veneer glue.

[0006] Thus, there is still a need for improved building construction compositions and methods that take advantage of the beneficial characteristic of hemp material. [0007] All publications identified herein are incorporated by reference to the same extent as if each individual publication or patent application were specifically and individually indicated to be incorporated by reference. Where a definition or use of a term in an incorporated reference is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply.

Summary of The Invention

[0008] The inventive subject matter provides apparatus, systems and methods for building structures, such as walls and buildings, using hemp stalk pieces and expanding foam. The method comprises (i) breaking hemp stalk into a plurality of hemp stalk pieces, (ii) mixing the plurality of hemp stalk pieces with the expanding foam to create a mixture, (iii) pouring or spraying the mixture into a mold, (iv) allowing the mixture to expand and harden, and (iv) separating the mold from the hardened mixture.

[0009] In some embodiments, the step of breaking the hemp stalk into a plurality of hemp stalk pieces comprises processing the hemp stalk in a wood chipper. The method can further include the step of processing the hemp stalk in a pulverizer or grinder after being processed by the wood chipper to further reduce the size of the pieces. In other aspects, the step of breaking the hemp stalk into a plurality of pieces can comprise processing the hemp stalk in a fiber classifier. The fiber classifier can separate the hurd from the fiber and reduce break the hurd and fiber into smaller pieces. See for example, the hemp fiber classifier at https://www.agprocessingsolutions.com/hemp-processing-hemp-fiber-classifier. Separation of the hurd and fiber advantageously allows for control of the ratio of hurd-to-fiber in the expanding foam. Hemp hurd is beneficial because it is a relatively inexpensive, carbon absorbent, insulative, fire resistant, renewable, and environmentally friendly. Hemp fiber is beneficial because it is durable, renewable, environmentally friendly, and has a high tensile strength. The ratio of hurd-to-fiber can be selected based on the needs and conditions of the application, and based on the environment where the material will be used. It is contemplated that the plurality of hemp stalk pieces that end up on the expanded and hardened foam can include both hemp hurd and hemp fiber. However, in some embodiments it may be beneficial to remove all of either the hemp hurd or the hemp fiber prior to mixing. The ratio of hemp hurd to hemp fiber can be selected based on the needs and conditions of the structure or building material.

[0010] The plurality of hemp stalk pieces can include a plurality of fine hemp stalk pieces and a plurality of coarse hemp stalk pieces. For example, the fine hemp stalk pieces can be the size of milled powder and can have an average particle size or diameter between 10 to 500 pm. The coarse hemp stalk pieces can be chunks the size of mulch pieces and can have an average width between 1/16 inches to 1/2 inches and an average length between 1/2 inches to 2 inches.

However, other average particle sizes and diameters are contemplated for the fine and coarse pieces, based on the needs and conditions of the application, and based on the environment where the material will be used. The ratio of fine hemp stalk pieces to coarse hemp stalk pieces can also be selected based on the needs and conditions of the structure. In some embodiments, the ratio of fine hemp stalk pieces to coarse hemp stalk pieces is between 1 :2 and 2: 1. However, other ratios are also contemplated based on the needs and conditions of the structure. Fine hemp stalk pieces are beneficial for filling in cracks and small spaces but do not provide stability or strength. In contrast, coarse hemp stalk pieces provide stability and strength, but do not fill in small cracks. The ratio of fine and coarse hemp stalk pieces is preferably optimized to reduce the amount of expanding foam required to reduce cost of the product.

[0011] The expanding foam can comprise a first component and a second component. For example, the first component can be an isocyanate component and the second component can be a polyol resin component, wherein the two components chemically react to expand and harden. See for example, htt£S //ww .^^

The polyol resin component can include catalysts, blowing agents, flame retardants, and/or surfactants. In some embodiments, the first and second components of the expanding foam are liquids prior to the chemical reaction and a solid after the chemical reaction. The expanded and hardened foam can be either closed-cell or open cell.

[0012] The step of mixing the plurality of hemp stalk pieces with an expanding foam comprises mixing the plurality of hemp stalk pieces with the isocyanate component and the polyol resin component. The mixing can take place all at once, or in stages. For example, the plurality of hemp stalk pieces can be mixed with one of the components of the expanding foam first and then mixed with the second component at a different time. Alternatively, the two components of the expanding foam can be mixed together first, and then the hemp stalk pieces can be mixed with the two mixed components of the expanding foam.

[0013] In some embodiments, once the chemical reaction between the isocyanate component and polyol resin component has completed and the mixture has expanded and hardened, the hardened mixture can comprise about 85%-90% by volume of hemp stalk pieces and 10%- 15% by volume of the expanding foam. However, other volumetric ratios are contemplated depending on the application and environment. It is contemplated that a construction material can comprise an expanded foam containing 50%-87% hemp stalk pieces. The volumetric ratio is determined in large part by calculated expansion rates of the expanding foam, as provided by the expanding foam manufactures, as well as the temperature/pressure/humidity in the manufacturing environment. It is contemplated that the manufacturing environment could be indoors or outdoors. When indoors, it is contemplated that the temperature could be maintained between 70 and 75 degrees Fahrenheit and the humidity could be maintained at around 35% or between 30% and 40%. If the temperature is too hot, it could result in an unstable product that is very brittle. If the temperature is too cold, the expanding foam does not expand very well and a greater volumetric percentage of expansion foam is required, thereby increasing material costs. A preferred humidity is determined in large pail on the chemistry of the expanding foam and the optimal humidity is often recommended by the manufacturer of the expansion foam.

[0014] It is also contemplated that mixture can be poured or sprayed into either a compression mold that has movable surfaces during the expanding and hardening phase, or a non-compression mold. In some embodiments, a compression mold having air bags could be used to increase pressure against the expanding foam during the expansion and hardening phase. Greater pressure results in a tougher material and a better/ smoother skin finish. However, it is also contemplated that a non-compression mold comprising an enclosed fixed volume can be used. The step of removing the mold from the hardened mixture could include the step of disassembling the mold, wherein the mold is made up of multiple pieces. In other embodiments, it is contemplated that the mold can have a movable bottom for punching the hardened mixture out of the mold. [0015] It is further contemplated that the mold can form the shape of a building structure, such as a wall, a roof, or a floor. In some embodiments, the mold forms the shape of an at least partially enclosed structure that has walls, a floor, and a roof. The mold can also include obstructions or shapes that form openings for doors, windows, conduits, and recessed lighting. It is also contemplated that plumbing, electrical wiring, wiring harnesses, sockets, outlets, rebar, and other structural components can be placed inside the mold and the mixture can be poured around the structural components. It is also contemplated that an inner mold can be placed inside an outer mold and the space between the inner mold and outer mold creates a shell of a structure, building, or house. The inner mold can also be comprised of a plurality of modular mold units that can be combined together to form the interior space of the structure. Once the foam expands and hardens, the modular mold units can be dissembled and removed through the openings of the structure (e.g., wall, window).

[0016] The step of mixing the plurality of hemp stalk pieces with an expanding foam can be performed by manually adding the plurality of hemp stalk pieces and one or more components of the expanding foam into a container and mixing by hand. However, it is also contemplated that the step of mixing the plurality of hemp stalk pieces with an expanding foam comprises adding the plurality of hemp stalk pieces and components of the expanding foam into a mixing machine or proportioner.

[0017] The step of mixing the plurality of hemp stalk pieces with an expanding foam can also be performed by pushing the two components of the expanding foam and the hemp stalk pieces through a static mixing nozzle. Since the hemp stalk pieces increase the viscosity of the mixture, it is contemplated that the hemp stalk material can be introduced into the static mixing nozzle downstream from the two components of the expanding foam. This allows the two components of the expanding foam to mix together at a lower viscosity before adding the hemp stalk pieces.

[0018] The inventive subject matter also includes a spray can that has a nozzle and a compartment filled with a mixture comprising an expanding foam, a gaseous propellant, and a plurality of hemp stalk pieces. The gas propellant creates a pressure inside the can that pushes the mixture through the can’s nozzle. Once the mixture exits the nozzle, the mixture reacts with oxygen in the air to initiate a chemical reaction that causes the mixture to expand and harden. In some embodiments, the mixture comprises 5%- 10% by weight of the plurality of hemp stalk pieces.

[0019] The inventive subject matter also includes an expanding foam (e.g., isocyanate component, a polyol resin component) that comprises a plurality of hemp stalk pieces. The expanding foam can be sprayed on surfaces of a structure during construction to provide insulation. The expanding foam can also be sprayed into cracks or holes and used as a filler. The expanding foam can also be sprayed or poured into a mold to create a structure such as a brick, a wall, a board, a piece of furniture, or even an entire building.

[0020] Various objects, features, aspects and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.

Brief Description of The Drawings

[0021] FIG. 1 is a diagram of a method of manufacturing a structure using an expanding foam comprised of hemp stalk pieces.

[0022] FIG. 2 is one embodiment of a spray system for dispensing an expanding foam comprising hemp stalk pieces.

[0023] FIG. 3 is another embodiment of a spray system for dispensing an expanding foam comprising hemp stalk pieces.

[0024] FIG. 4a is a top perspective view of a mold for making bricks with the lid removed.

[0025] FIG. 4b is a top perspective view of the mold of Fig. 4a with the lid closed.

[0026] FIG. 4c is a side cut-out view of the mold of Fig. 4a with the bottom pushed inward.

[0027] FIG. 5 is one embodiment of a unitary structure made from expanding foam comprising hemp stalk pieces.

[0028] FIG. 6 is a spray can comprising expanding foam and hemp stalk pieces. Detailed Description of The Invention

[0029] The following discussion provides many example embodiments of the inventive subject matter. Although each embodiment represents a single combination of inventive elements, the inventive subject matter is considered to include all possible combinations of the disclosed elements. Thus, if one embodiment comprises elements A, B, and C, and a second embodiment comprises elements B and D, then the inventive subject matter is also considered to include other remaining combinations of A, B, C, or D, even if not explicitly disclosed.

[0030] Figure 1 shows a method 100 of manufacturing a structure using an expanding foam comprised of hemp stalk pieces. Step 110 comprises breaking hemp stalk into a plurality of hemp stalk pieces. Step 120 comprises mixing the plurality of hemp stalk pieces with an expanding foam to create a mixture. Step 130 comprises pouring or spraying the mixture into a mold and allowing the mixture to expand and harden. Step 140 comprises separating the mold from the hardened mixture.

[0031] Step 110 can comprise processing the hemp stalk in at least one of a wood chipper, a pulverizer, a grinder, and a fiber declassifier. If it is desirable to separate hurd from fiber to control the ratio of hurd-to-fiber, then a hemp fiber declassifier is preferred. The hemp fiber declassifier not only separates hurd from fiber but also reduces the size of the hurd and fiber. The settings of the fiber declassifier can be adjusted to control the particle sizes of the hurd and fiber. If separation of hurd and fiber is not necessary, then the hemp stalk is preferably processed using a wood chipper and grinder or pulverizer since the cost of a wood chipper, grinder, and/or pulverizer can be significantly less than the cost of a fiber declassifier.

[0032] Step 110 can also comprise breaking the hemp stalk pieces into difference sizes, ranging from coarse to fine. In some applications, it may be beneficial to include both coarse pieces and fine particles in the expanding foam. In some applications, the average particle size of the hemp pieces can range between 100 pm and 2 inches. It is also contemplated that the ratio of fine hemp stalk pieces to coarse hemp stalk pieces ranges between 1:2 and 2:1.

[0033] In one embodiment, the expanding foam can comprise a first component and a second component that chemically react to expand and harden. For example, the first component can comprise an isocyanate component and the second component can comprise a polyol resin component. The polyol resin component can include a catalyst, a blowing agent, a flame retardant, surfactant, and other ingredients suitable for the application.

[0034] Step 120 can comprise manually mixing the ingredients, using a mixing device, using a static mixing nozzle, or any other suitable mixing process. A mixing device can comprise a container coupled with a first inlet for adding the first component of the expanding foam, a second inlet for adding the second component of the expanding foam, and a third inlet for adding the plurality hemp stalk pieces. Inside the container is a mixer configured to mix all the ingredients together and a pump for pushing, dispensing, or spraying the mixture out through an outlet or nozzle. However, it is also contemplated that the mixture can be poured out of the container. The mixing device can also include one or more flow regulators coupled with the first inlet, second inlet, and third inlet for controlling a ratio or proportion of the mixture.

[0035] It is also contemplated that step 120 can be performed in stages. For example the first and second components of the expanding foam can be mixed together first, then the hemp stalk pieces can be added. Alternatively, the hemp stalk pieces can be mixed with either the first component or the second component, then the remaining component can be added.

[0036] In step 130, the mixture can completely or partially fill the mold. The mold is preferably a fixed enclosure such that expansion of the mixture creates pressure inside the foam as it hardens to create a stronger structure. The amount of mixture that is poured or sprayed into the mold depends on the application and environment that the structure will be used. The mold can be the shape of a brick, a wall, a board, a piece of furniture, or any other structure. In some applications, the mold can form the shape of an entire building having walls, a floor, and a roof, such that the expanded foam creates one unitary complete building structure.

[0037] Figure 2 shows a spray system 200 for spraying foam comprising hemp stalk pieces. System 200 comprises a container 210 that has a first component of an expanding foam, a container 220 that has a second component of an expanding foam, and a container 230 that has a plurality of hemp stalk pieces. Container 210 has a pump 205 and container 220 has a pump 215 for pushing the first component and second component of the expanding foam, respectively, through hose 208 and 218. The first and second components of the expanding foam are typically in liquid form. In contrast, the hemp stalk pieces are in sold form. Container 230 is a pressured container, however it is also contemplated that container 230 could include pump. The pressure inside container 230 pushes the hemp stalk pieces through hose 228.

[0038] Hose 208 and 218 removably couple with a spray gun 240 via couplings 241 and 243. Hose 228 removably couples with nozzle 250 via coupling 252. Spray gun 240 has a handle 242 and a trigger 244. When trigger 244 is pressed with a force 280, a valve mechanism inside spray gun 240 (not show) allows the first and second components of the expanding foam to flow through spray gun 240 and into nozzle 250 via inlet 246 and 248. At the same time, trigger 244 presses a valve 226 in hose 228 that opens and allows the hemp stalk pieces to flow into nozzle 250 via coupling 252. Coupling 252 is located downstream of inlet 246 and 248, thus allowing the first and second components of the expanding foam to mix together before the hemp stalk pieces are added to the flow.

[0039] Nozzle 250 removably couples with spray gun 240 via removably coupling 254. Nozzle 250 has a non-linear pathway 258 inside its lumen that mixes the first component, the second component, and the hemp stalk pieces into a homogenous mixture 275. Mixture 275 is sprayed out of nozzle 250 via outlet 256.

[0040] Spray system 200 allows for a spray gun 240, which has only two passages for two mixing ingredients (e.g., first and second components of an expanding foam) to be retrofitted for use with a third passage and a third mixing ingredient (e.g., hemp stalk pieces).

[0041] Figure 3 shows a spray system 300. Spray system 300 is similar to spray system 200 in may aspects and like components share similar reference numbers. Spray system 300 is different from spray system 200 in that spray gun 340 is specifically designed for use with three passages and three mixing ingredients. Spray gun 340 couples with hose 328 via a removable coupling 345 located at the bottom of handle 342. It is also contemplated that coupling 345 could be located next to couplings 341 and 343. Pressing trigger 344 with force 380 opens a valve (not shown) in the pathways of the first and second components of the expanding foam e.g., between 341 and 348, and between 343 and 346). Pressing trigger 344 also simultaneously opens valve 326 in the pathway of the hemp stalk pieces. In this manner, all three ingredients are introduced into the non-linear pathway 358 of nozzle 350 to create a homogenous mixture 375. [0042] Mixtures 275 and 375 can be sprayed onto a surface to provide insulation. It is also contemplated that mixtures 275 and 375 can be sprayed into a mold to form a desired shape. The mold can be a compression mold or a non-compression mold. As used herein, compression mold means the surfaces or sides of the mold move to create pressure against the foam as it expands and hardens. Even when the mold is a non-compression mold, it can still provide pressure by providing a fixed enclosure. The pressure helps to strengthen the foam as it expands and hardens.

[0043] Figure 4a shows a mold 400 in the shape of a brick. Mold 400 has a lid 405, side walls 410, and a movable bottom 415. Figure 4b shows lids 405 closed and screwed tight to form a fixed enclosure. When an expanding mixture is sprayed or poured into mold 400 and lid 405 is locked closed, the mixture expands and hardens under pressure. The hardened foam can then be separated from mold 400 by punching bottom 415 inward to eject the hardened foam outward. It is also contemplated that the hardened foam can be removed from a mold by disassembling the mold, or by shaking, knocking, and/or prying the hardened foam out of the mold.

[0044] It is contemplated that the mold can be any desired shape. In some embodiments, the mold can be the shape of a wall, partition, or a board. It is contemplated that a foam board could be used as a lighter and cheaper substitute for particle board. It is also contemplated that outer molds and inner molds can be used together to create shells of structures. Figure 5 shows a building structure 500 made entirely of expanded foam containing hemp stalk pieces. Structure 500 can be made using an outer mold and an inner mold. The inner mold can be made of modular mold units that can be disassembled and removed from the structure through the door and window openings once the foam has finished expanding and hardening.

[0045] The inventive subject matter also includes a spray can for dispensing an expanding foam containing hemp stalk pieces. Figure 6 shows one embodiment of a spray can 600. Spray can 600 has a compartment 605 for storing a mixture. The mixture comprises a plurality of hemp stalk pieces, an expanding foam, and a gaseous propellant. The expanding foam can chemically react with oxygen to expand and harden. Compartment 605 is preferably impermeable to oxygen. A method of using spray can 600 can comprise shaking the can to agitate the gas propellant and pressing nozzle 610 to dispense a spray 615 that expands and hardens upon dispensing. In some preferred embodiments, the hemp stalk pieces can be fine particles and can comprise only 5%- 10% by weight of the mixture such that the spray 615 can be used to fill in cracks and small spaces.

[0046] One should appreciate that the inventive subject matter described herein improves building construction compositions and methods by providing a low cost, light weight, and high strength product. The product is also environmentally friendly due to its carbon dioxide absorption and antimicrobial properties. The product is also renewal, eco-friendly, and can be sourced from the waste product of the cannabis industry. The contemplated compositions and methods also provide a building material that is fire resistant, insulating, and can be used to fill in cracks or spaces that are too difficult for concrete to access. Some preferred applications of the inventive subject matter include building tiny and light weight homes in a workshop that can be economically transported to an installation site. Other applications include using the foam material as an insulator that has improved insulative properties, higher tensile strength, and less expansive than existing spray insulations.

[0047] In some embodiments, the numbers expressing quantities of ingredients, properties such as concentration, reaction conditions, and so forth, used to describe and claim certain embodiments of the invention are to be understood as being modified in some instances by the term “about.” Accordingly, in some embodiments, the numerical parameters set forth in the written description and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by a particular embodiment. In some embodiments, the numerical parameters should be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of some embodiments of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as practicable. The numerical values presented in some embodiments of the invention may contain certain errors necessarily resulting from the standard deviation found in their respective testing measurements.

[0048] As used in the description herein and throughout the claims that follow, the meaning of “a,” “an,” and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise.

[0049] Unless the context dictates the contrary, all ranges set forth herein should be interpreted as being inclusive of their endpoints, and open-ended ranges should be interpreted to include only commercially practical values. Similarly, all lists of values should be considered as inclusive of intermediate values unless the context indicates the contrary. The recitation of ranges of values herein is merely intended to serve as a shorthand method of referring individually to each separate value falling within the range. Unless otherwise indicated herein, each individual value with a range is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided with respect to certain embodiments herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention.

[0050] Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member can be re I erred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description of all Markush groups used in the appended claims.

[0051] The following discussion provides many example embodiments of the inventive subject matter. Although each embodiment represents a single combination of inventive elements, the inventive subject matter is considered to include all possible combinations of the disclosed elements. Thus, if one embodiment comprises elements A, B, and C, and a second embodiment comprises elements B and D, then the inventive subject matter is also considered to include other remaining combinations of A, B, C, or D, even if not explicitly disclosed. [0052] As used herein, and unless the context dictates otherwise, the term "coupled to" is intended to include both direct coupling (in which two elements that arc coupled to each other contact each other) and indirect coupling (in which at least one additional element is located between the two elements). Therefore, the terms "coupled to" and "coupled with" are used synonymously.

[0053] It should be apparent to those skilled in the art that many more modifications besides those already described are possible without departing from the inventive concepts herein. The inventive subject matter, therefore, is not to be restricted except in the spirit of the appended claims. Moreover, in interpreting both the specification and the claims, all terms should be interpreted in the broadest possible manner consistent with the context. In particular, the terms “comprises” and “comprising” should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced. Where the specification or claims refer to at least one of something selected from the group consisting of A, B, C .... and N, the text should be interpreted as requiring only one element from the group, not A plus N, or B plus N, etc.

Claims

CLAIMS What is claimed is:

1. A method of manufacturing a structure comprising: breaking hemp stalk into a plurality of hemp stalk pieces; mixing the plurality of hemp stalk pieces with an expanding foam to create a mixture; pouring or spraying the mixture into a mold; allowing the mixture to expand and harden; and separating the mold from the hardened mixture.

2. The method of claim 1, wherein the step of breaking the hemp stalk into a plurality of hemp stalk pieces comprises processing the hemp stalk in at least one of a wood chipper, a pulverizer, a grinder, and a fiber declassifier.

3. The method of claim 1, wherein the plurality of hemp stalk pieces comprise a plurality of fine hemp stalk pieces and a plurality of coarse hemp stalk pieces.

4. The method of claim 3, wherein the fine hemp stalk pieces have an average particle size of 100 pm and the coarse hemp stalk pieces have an average length of 2 inches.

5. The method of claim 4, wherein the ratio of fine hemp stalk pieces to coarse hemp stalk pieces is between 1:2 and 2:1.

6. The method of claim 1, wherein the expanding foam comprises an isocyanate component and a polyol resin component that chemically react to expand and harden.

7. The method of claim 6, wherein the polyol resin component includes a catalyst, a blowing agent, a flame retardant, and surfactant.

8. The method of claim 6, wherein the step of mixing the plurality of hemp stalk pieces with an expanding foam comprises mixing the plurality of hemp stalk pieces with the isocyanate component and the polyol resin component at the same time.

9. The method of claim 1, wherein the hardened mixture comprises about 50%-87% by volume of hemp stalk pieces and 13%-50% by volume of the expanding foam.

10. The method of claim 6, further comprising the step of controlling temperature, pressure, and humidity of a work environment during the steps of mixing the plurality of hemp stalk pieces with the isocyanate component and the polyol resin component and allowing the mixture to expand and harden.

11. The method of claim 10, wherein the temperature is maintained between 70 and 75 degrees Fahrenheit.

12. The method of claim 1, wherein the humidity is maintained between 30% and 40%.

13. The method of claim 1, wherein the step of separating the mold from the hardened mixture comprises disassembling the mold or pushing a surface of the mold inward to eject the hardened mixture.

14. The method of claim 1, wherein the mold forms the shape of a brick, a wall, a board, a piece of furniture, or an at least partially enclosed structure having walls, a floor, and a roof.

15. The method of claim 1, wherein the plurality of hemp stalk pieces includes hemp hurd and hemp fiber.

16. The method of claim 15, further comprising the step of separating at least some hemp hurd from at least some hemp fiber prior to mixing the plurality of hemp stalk pieces with the expanding foam.

17. A static mixing nozzle for mixing a plurality of hemp stalk pieces with an expanding foam having a first component and a second component that chemically react to expand and harden, comprising: a lumen having a first inlet for adding the first component, a second inlet for adding the second component, and a third inlet for adding the plurality hemp stalk pieces; a non-linear pathway disposed inside the lumen and extending along a length of the lumen, wherein the non-linear pathway is configured to mix the first component, the second component, and the plurality of hemp stalk pieces; and wherein the third inlet is disposed in the non-linear pathway downstream from the second inlet and the third inlet.

18. A spray can comprising: a compartment having a mixture comprising an expanding foam, a gaseous propellant, and a plurality of hemp stalk pieces; a nozzle for spraying the mixture; and wherein the expanding foam chemically reacts in the presence of oxygen.

19. The spray can of claim 18, wherein the hemp stalk pieces comprise 5%-10% by weight of the mixture.

20. An expanding foam comprising a plurality of hemp stalk pieces.