Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
  • B27D—WORKING VENEER OR PLYWOOD
  • B27D1/00—Joining wood veneer with any material; Forming articles thereby; Preparatory processing of surfaces to be joined, e.g. scoring
  • B27D1/04—Joining wood veneer with any material; Forming articles thereby; Preparatory processing of surfaces to be joined, e.g. scoring to produce plywood or articles made therefrom; Plywood sheets
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
  • B27M—WORKING OF WOOD NOT PROVIDED FOR IN SUBCLASSES B27B - B27L; MANUFACTURE OF SPECIFIC WOODEN ARTICLES
  • B27M3/00—Manufacture or reconditioning of specific semi-finished or finished articles
  • B27M3/0013—Manufacture or reconditioning of specific semi-finished or finished articles of composite or compound articles
  • B27M3/006—Manufacture or reconditioning of specific semi-finished or finished articles of composite or compound articles characterised by oblong elements connected both laterally and at their ends
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B21/00—Layered products comprising a layer of wood, e.g. wood board, veneer, wood particle board
  • B32B21/04—Layered products comprising a layer of wood, e.g. wood board, veneer, wood particle board comprising wood as the main or only constituent of a layer, which is next to another layer of the same or of a different material
  • B32B21/042—Layered products comprising a layer of wood, e.g. wood board, veneer, wood particle board comprising wood as the main or only constituent of a layer, which is next to another layer of the same or of a different material of wood
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B21/00—Layered products comprising a layer of wood, e.g. wood board, veneer, wood particle board
  • B32B21/13—Layered products comprising a layer of wood, e.g. wood board, veneer, wood particle board all layers being exclusively wood
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B21/00—Layered products comprising a layer of wood, e.g. wood board, veneer, wood particle board
  • B32B21/14—Layered products comprising a layer of wood, e.g. wood board, veneer, wood particle board comprising wood board or veneer
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
  • B32B7/02—Physical, chemical or physicochemical properties
  • B32B7/022—Mechanical properties
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
  • B32B7/03—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers with respect to the orientation of features
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
  • B32B7/04—Interconnection of layers
  • B32B7/12—Interconnection of layers using interposed adhesives or interposed materials with bonding properties
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B9/00—Layered products comprising a layer of a particular substance not covered by groups B32B11/00 - B32B29/00
  • B32B9/02—Layered products comprising a layer of a particular substance not covered by groups B32B11/00 - B32B29/00 comprising animal or vegetable substances, e.g. cork, bamboo, starch
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B9/00—Layered products comprising a layer of a particular substance not covered by groups B32B11/00 - B32B29/00
  • B32B9/04—Layered products comprising a layer of a particular substance not covered by groups B32B11/00 - B32B29/00 comprising such particular substance as the main or only constituent of a layer, which is next to another layer of the same or of a different material
  • B32B9/042—Layered products comprising a layer of a particular substance not covered by groups B32B11/00 - B32B29/00 comprising such particular substance as the main or only constituent of a layer, which is next to another layer of the same or of a different material of wood
• • E—FIXED CONSTRUCTIONS
  • E04—BUILDING
  • E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
  • E04C3/00—Structural elongated elements designed for load-supporting
  • E04C3/02—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces
  • E04C3/12—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces of wood, e.g. with reinforcements, with tensioning members
  • E04C3/122—Laminated
• • E—FIXED CONSTRUCTIONS
  • E04—BUILDING
  • E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
  • E04C3/00—Structural elongated elements designed for load-supporting
  • E04C3/02—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces
  • E04C3/12—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces of wood, e.g. with reinforcements, with tensioning members
  • E04C3/14—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces of wood, e.g. with reinforcements, with tensioning members with substantially solid, i.e. unapertured, web
• • E—FIXED CONSTRUCTIONS
  • E04—BUILDING
  • E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
  • E04C3/00—Structural elongated elements designed for load-supporting
  • E04C3/02—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces
  • E04C3/12—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces of wood, e.g. with reinforcements, with tensioning members
  • E04C3/16—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces of wood, e.g. with reinforcements, with tensioning members with apertured web, e.g. trusses
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/70—Other properties
  • B32B2307/72—Density

Definitions

• the present disclosure relates generally to engineered structural materials, and more particularly, to strength-enhanced structures employing plant materials (e.g., wood, bamboo, etc.), such as, but not limited to, cross-laminated timber (CLT), glued laminated timber (glulam), laminated veneer lumber (LVL), oriented strand board (OSB), and/or oriented structural straw board (OSSB).
• plant materials e.g., wood, bamboo, etc.
• CLT cross-laminated timber
• glulam glued laminated timber
• LDL laminated veneer lumber
• OSB oriented strand board
• OSSB oriented structural straw board
• CLT Cross -laminated timber
• the engineered structural material comprises multiple plant material layers (e.g., comprising one or more plant material pieces) glued, adhered, joined, or otherwise coupled together to form a laminate.
• At least one of the plant material layers within the laminate can be a densified plant material layer (e.g., comprising one or more densified plant material pieces), for example, compressed to collapse lumina of its native cellulose-based micro structure so as to have an increased density of at least 1.15 g/cm 3 .
• the densified plant material layer can be formed from lignin- compromised material, for example, in situ lignin-modified plant material or partially delignified plant material.
• the densified plant material layer can reinforce the overall structure, thereby allowing the other plant material layers to have a lower strength, allowing the laminate to be used in a more demanding application, and/or allowing the laminate to have a smaller cross-section.
• an engineered structure can comprise a first laminate.
• the first laminate can comprise a plurality of constituent plant material layers.
• the plurality of constituent plant material layers can comprise one or more first layers and one or more second layers.
• Each plant material layer can be adhered to an adjacent plant material layer via one or more respective glues.
• Each first plant material layer can be a densified plant material layer having a density greater than or equal to 1.15 g/cm 3 and a mechanical strength greater than or equal to a first value.
• Each second plant material layer can be a plant material layer having a density less than 1.15 g/cm 3 and a mechanical strength less than the first value.
• an engineered structural material can comprise one or more laminate structures.
• Each laminate structure can have a plurality of constituent plant material layers.
• Each plant material layer can be coupled to an adjacent plant material layer via one or more respective glues.
• At least one of the plurality of constituent plant material layers can be a densified plant material layer having a density greater than or equal to 1.15 g/cm 3 .
• a method can comprise providing one or more first layers. Each first layer can comprise a densified plant material having a density greater than or equal to 1.15 g/cm 3 and a mechanical strength greater than or equal to a first value. The method can further comprise providing one or more second layers. Each second layer can comprise a plant material having a density less than 1.15 g/cm 3 and a mechanical strength less than the first value. The method can also comprise coupling the one or more first layers to the one or more second layers via one or more respective glues so as to form a laminate.
• FIGS. 1A-1G are simplified schematic diagrams of various strength-enhanced engineered structures formed from one or more plant materials, according to one or more embodiments of the disclosed subject matter.
• FIGS. 2A-2B are partial isometric views of strength-enhanced cross -laminated timber (CLT) structures, according to one or more embodiments of the disclosed subject matter.
• FIGS. 3A-3D are partial isometric views of various strength-enhanced glued laminated timber (glulam) structures, according to one or more embodiments of the disclosed subject matter.
• FIG. 6 is a simplified process-flow diagram for fabricating a strength-enhanced engineered structure from one or more plant materials, according to one or more embodiments of the disclosed subject matter.
• the natural wood can be any type of hardwood (e.g., having a native lignin content in a range of 18-25 wt%) or softwood (e.g., having a native lignin content in a range of 25-35 wt%), such as, but not limited to, basswood, oak, poplar, ash, alder, aspen, balsa wood, beech, birch, cherry, butternut, chestnut, cocobolo, elm, hickory, maple, oak.
• Engineered Structure or Engineered Structural Material' A structure formed from a plurality of pieces or layers of natural or modified plant materials coupled together using glue or other adhesive to form a structure with improved strength and/or durability.
• Examples of such structures/materials include, but are not limited to, cross -laminated timber (CLT), glued laminated timber (glulam), laminated veneer lumber (LVL), oriented strand board (OSB), and/or oriented structural straw board (OSSB).
• Lignin-compromised plant material Plant material that has been modified by one or more chemical treatments to (a) in situ modify the native lignin therein, (b) partially remove the native lignin therein (i.e., partial delignification), or (c) fully remove the native lignin therein (i.e., full delignification).
• the lignin-compromised plant material can substantially retain the native micro structure of the natural plant material formed by cellulose- based cell walls.
• Partial Delignification The removal of some (e.g., at least 1%) but not all (e.g., less than or equal 90%) of native lignin (e.g., on a weight percent basis) from the naturally-occurring plant material.
• the partial delignification can be performed by subjecting the natural plant material to one or more chemical treatments.
• the lignin content after partial delignification can be in a range of 0.9-23.8 wt% for hardwood or in a range of 1.25-33.25 wt% for softwood.
• Lignin content within the plant material before and after the partial delignification can be assessed using known techniques in the art, for example, Laboratory Analytical Procedure (LAP) TP-510-42618 for “Determination of Structural Carbohydrates and Lignin in Biomass,” Version 08-03-2012, published by National Renewable Energy Laboratory (NREL), and ASTM E1758-01(2020) for “Standard Test Method for Determination of Carbohydrates in Biomass by High Performance Liquid Chromatography,” published by ASTM International, both of which are incorporated herein by reference.
• LAP Laboratory Analytical Procedure
• TP-510-42618 for “Determination of Structural Carbohydrates and Lignin in Biomass”
• NREL National Renewable Energy Laboratory
• ASTM E1758-01(2020) Standard Test Method for Determination of Carbohydrates in Biomass by High Performance Liquid Chromatography
• Full Delignification- The removal of substantially all (e.g., 90-100%) of native lignin from the naturally-occurring plant material.
• the full delignification can be performed by subjecting the natural plant material to one or more chemical treatments. Lignin content within the plant material before and after the full delignification can be assessed using the same or similar techniques as those noted above for partial delignification.
• the full delignification process can be, for example, as described in U.S. Publication No. 20200238565, published July 30, 2020 and entitled “Delignified Wood Materials, and Methods for Fabricating and Use Thereof,” which delignification processes are incorporated herein by reference.
• the lignin modification process can be, for example, as described in International Publication No. WO 2023/028356, published March 2, 2023, and entitled “Waste-free Processing for Lignin Modification of Fibrous Plant Materials, and Lignin-modified Fibrous Plant Materials,” which lignin modification processes are incorporated herein by reference.
• Non-densified Plant Material or N on-densified Wood' A plant material (e.g., wood) that substantially retains its native density.
• the non-densified plant material e.g., wood
• the non-densified plant material can have a density of, for example, less than 1.15 g/cm 3 , such as less than or equal to 1.0 g/cm 3 or even less than or equal to 0.9 g/cm 3 (e.g., 0.1-0.9 g/cm 3 ).
• the lumina of the cellulose-based microstructure of the non-densified plant material can remain substantially open, at least prior to inclusion within the engineered structure.
• Longitudinal growth direction' A direction along which a plant grows from its roots or from a trunk thereof, with cellulose fibers forming cell walls of the plant being generally aligned with the longitudinal growth direction.
• the longitudinal growth direction may be generally vertical or correspond to a direction of its water transpiration stream. This is in contrast to the radial direction, which extends from a center portion of the plant outward and may be generally horizontal.
• the engineered structural materials can have enhanced mechanical strength, for example, as compared to existing engineered structural materials (e.g., formed with native or non-densified wood alone).
• the engineered structural material can be made with a smaller cross-section (e.g., as compared to existing engineered structural materials) for a particular application (e.g., requiring a particular strength rating).
• the engineered structural material with a same cross-section can be used in a more demanding application (e.g., as compared to existing engineered structural materials), for example, by spanning a longer distance.
• the size and/or strength of the engineered structural material can be custom designed to a particular application by including an appropriate number and/or arrangement of densified plant material layers in the engineered structural material.
• the engineered structural materials comprises a laminate structure having a plurality of constituent plant material layers joined, adhered, or otherwise coupled to each other via a glue, with at least one of the layers being a densified plant material layer, for example, having a density of at least 1.15 g/cm 3 (e.g., > 1.2 g/cm 3 or > 1.3 g/cm 3 , for example, in a range of 1.4- 1.5 g/cm 3 ).
• one, some, or all of other layers of the laminate structure can be non-densified plant material layers, for example, having a density less than 1.15 g/cm 3 (e.g., ⁇ 1.0 g/cm 3 or ⁇ 0.9 g/cm 3 , for example, in a range of 0.1-0.9 g/cm 3 ).
• the non-densified plant material layers can be formed of the native plant material (e.g., without compression).
• one, some or all of the other layers of the laminate structure can be plant material layers that have been densified (e.g., prior to inclusion in the laminate or after inclusion in the laminate), but to a lesser degree than the densified plant material layers, for example, such that the densified density remains less than 1.15 g/cm 3 .
• references to non-densified plant material layers are intended to include such lesser-densified plant material layers.
• the densified plant material layers can have a mechanical strength greater than that of the other plant material layers (e.g. non-densified or lesser-densified).
• each densified plant material layer can have a strength of at least 100 MPa (e.g., 100-600 MPa), while each non-densified plant material layer can have a strength less than 100 MPa (e.g., 15-65 MPa).
• the laminate structure can have any number of plant material layers.
• FIG. 1A illustrates a laminate structure 100 having a pair of plant material layers, in particular, a densified plant material layer 102 coupled to a non-densified plant material layer 106 via an intervening glue layer 104.
• the glue layer 104 can comprise any type of adhesive, such as but not limited to epoxy, polyurethane adhesive, polyvinyl acetate-isocyanate adhesive, resorcinol formaldehyde resin adhesive, phenolic resin, and/or sodium carboxymethyl cellulose (CMC).
• one, some, or all of the plant material layers constituting the laminate structure can be formed of multiple plant material pieces.
• densified plant material layers can be disposed at a location within the laminate structure that would be subject to stresses that exceed a predetermined threshold and/or a maximum stress.
• densified plant material layers can be used as outermost layers of the laminate structure in a cross-sectional view, for example, as shown in FIG. IB.
• laminate structure 110 has three plant material layers - a pair of densified plant material layers 102a, 102b coupled to opposite sides of a centrally-disposed non-densified plant material layer 106 via respective intervening glue layers 104a, 104b.
• the densified plant material layer can be disposed at any location within the laminate structure.
• densified plant material layers can be used as interior or central layers of the laminate structure in a cross-sectional view.
• laminate structure 120 has three plant material layers - a pair of non-densified plant material layers 106a, 106b coupled to a centrally-disposed densified plant material layer 102 via respective intervening glue layers 104a, 104b.
• lateral side surfaces of the non-densified plant material layers can be exposed.
• densified plant material layers can also be provided over one, some, or all of these exposed surfaces, for example, to contain, bound, or otherwise enclose the non-densified plant material layers within a surrounding structure formed by the densified plant material layers.
• the provision of densified plant material layers to enclose the non-densified plant material layers can form a post or beam that has improved aesthetics (e.g., more desirable appearance due to the densified layer as compared to the non-densified layers), improved durability (e.g., due to greater fire resistance and/or weatherability of the densified layer as compared to the non-densified layers), and/or installation flexibility (e.g., to provide enhanced strength regardless of orientation).
• aesthetics e.g., more desirable appearance due to the densified layer as compared to the non-densified layers
• improved durability e.g., due to greater fire resistance and/or weatherability of the densified layer as compared to the non-densified layers
• installation flexibility e.g., to provide enhanced strength regardless of orientation.
• FIG. 2A illustrates a strength-enhanced cross-laminated timber (CLT) structure 200 having a laminate structure, with a stack 202 in between outer layers of densified wood panels 204a, 204b (e.g., having a thickness, tl or t2, of 3/16-inch to 1/4-inch (4.76 mm to 6.35 mm), such as 3/8-inch (9.35 mm)).
• the stack 202 can be a conventional CLT structure, for example, having three layers (or five, or seven) of lumber boards.
• each lumber board of the stack 202 can have a thickness of 5/8-inch to 2-inches (15.88 mm to 50.8 mm) and/or a width of 2.4-inches to 9.5-inches (60.96 mm to 241.3 mm).
• the strength-enhanced CLT structure 200 can have a length, L, of at least 6-feet (1.83 m), for example, about 8-feet (2.43 m).
• the strength-enhanced CLT structure 200 can have a width, W, of at least 1-foot (0.30 m), for example, about 2-feet (0.61 m).
• the strength-enhanced CLT structure 200 can have a height, H, of at least 6-inches (15.2 cm), for example, about 8-inches (20.3 cm).
• the lumber boards in each layer can be connected together via joining, for example, finger joints and/or structural adhesive.
• the stack 202 can be formed by stacking the lumber boards crosswise at 90-degree angles and glued in place.
• the outermost lumber boards 208a, 208b can have orientations 210a, 210b that are substantially aligned with each other
• the central lumber board 212 can have an orientation 214 orthogonal to orientations 210a, 210b.
• densified wood panels 204a, 204b can have orientations 206a, 206b that are substantially aligned with each other as well as with orientation 214 of central lumber board 212.
• the orientation 206a, 206b of one or both densified wood panels 204a, 204b can be substantially aligned with the orientations 210a, 210b of the outer lumber boards 208a, 208b, or with none of the orientations 210a, 210b, 214 of stack 202.
• additional densified wood can be provided as side layers 204c, 204d (e.g., with orientations 206d that are substantially aligned with each other as well as with orientation 214 of central lumber board 212) so as to enclose stack 202 (e.g., along a circumferential direction), for example, as shown for CLT structure 220 in FIG. 2B.
• the densified wood as the top and bottom tension layers, the flatwise bending stiffness of the stack 202 can be improved (e.g., doubled), and/or the spanning capacity of the stack 202 can be increased.
• Strength-enhanced CLTs such as CLT structure 200 and/or CLT structure 220, can be used in a broad range of applications, such as but not limited to flooring, walls, and roofing, for example, to replace steel-reinforced concrete in residential and commercial buildings.
• FIG. 3A illustrates a strength-enhanced glued laminated timber (glulam) structure 300 having a laminate structure, with a lateral array 302 of wood layers 308 in between outer layers of densified wood panels 304a, 304b (e.g., having a thickness of 3/16-inch to 1/4-inch (4.76 mm to 6.35 mm)).
• the array 302 can be a conventional glulam structure.
• each wood panel of the array 302 in a cross-sectional plane perpendicular to the respective longitudinal growth direction, each wood panel of the array 302 can have a thickness of 1-inch to 6-inches (2.5 cm to 15.2 cm) and/or a width of 2-inches to 12-inches (5.1 cm to 30.5 cm).
• wood segments in each layer can be connected together via joining, for example, finger joints and/or structural adhesive.
• the array 302 can be formed by arranging individual wood layers 308 (and/or constituent segments thereof) with substantially aligned orientations 310 (e.g., substantially parallel wood fibers) and gluing together.
• additional densified wood can be provided as side layers 304c, 304d to enclose stack 302 (e.g., along a circumferential direction), for example, as shown for glulam structure 350 in FIG. 3D.
• densified wood panels 304a-304d can have orientations 306a-306d that are substantially aligned with each other as well as with orientation 310 of the wood layers 308.
• the orientations 306a-306d of one, some, or all of densified wood panels 304a-304d can be substantially orthogonal to, or at least crossing with, orientation 310 of the wood layers 308.
• FIG. 3B illustrates another strength-enhanced glulam structure 320 that employs a vertical array 322 of wood layers 328 in between outer layers of densified wood panels 324a, 324b (e.g., having a thickness of 3/16-inch to 1/4-inch (4.76 mm to 6.35 mm)).
• the array 322 can be a conventional glulam structure, for example, with each wood panel of the array 322 having a thickness of 1-inch to 6-inches (2.5 cm to 15.2 cm) and/or a width of 2-inches to 12-inches (5.1 cm to 30.5 cm). Other dimensions are also possible, according to one or more contemplated embodiments.
• wood segments in each layer can be connected together via joining, for example, finger joints and/or structural adhesive.
• the array 322 can be formed by arranging individual wood layers 328 (and/or constituent segments thereof) with substantially aligned orientations 330 (e.g., substantially parallel wood fibers) and gluing together.
• densified wood panels 324a, 324b can have orientations 326a, 326b that are substantially aligned with each other as well as with orientation 330 of the wood layers 328.
• the orientations 326a, 326b of one or both densified wood panels 324a, 324b can be substantially orthogonal to, or at least crossing with, orientation 330 of the wood layers 328.
• wood segments in each layer 324a, 324b, 328 can be connected together via joining, for example, finger joints and/or structural adhesive.
• the use of multiple wood segments in each layer can allow the glulam structure 340 to be formed of any length without restriction.
• each top densified wood segment 342a-342c can be substantially aligned (e.g., along the length direction, L, and/or width direction, W) with a corresponding one of the bottom densified wood segments 344a-344c.
• the top and bottom densified wood segments can be offset from each other (e.g., in a manner similar to wood segments 346a-346d constituting the wood layers 328 of array 322), for example, to further enhance mechanical stiffness.
• FIG. 4A illustrates a strength-enhanced laminated veneer lumber (LVL) structure 400 having a laminate structure, with a stack 402 of wood veneers 408 in between outer layers of densified wood panels 404a, 404b (e.g., having a thickness of 3/16-inch to 1/4-inch (4.76 mm to 6.35 mm)).
• one or more densified wood panels can be provided as part of stack 402, for example, in place of, or in addition to, one or more of densified wood panels 404a, 404b.
• the stack 402 can be a conventional LVL structure.
• each wood veneer 408 of the stack 402 can have a thickness of 2.5-4.8 mm.
• Other dimensions are also possible according to one or more contemplated embodiments.
• the LVL stack 402 can be fabricated, for example, by gluing together (e.g., while pressing) veneers from rotary peeling (e.g., using a peeling lathe).
• the veneers can be assembled along their longitudinal directions (e.g., with orientations 410 substantially aligned).
• densified wood panels 404a, 404b can have orientations 406a, 406b that are substantially aligned with each other as well as with orientation 410 of wood veneers 408.
• the orientations 406a, 406b of one or both densified wood panels 404a, 404b can be substantially orthogonal to, or at least crossing with, orientation 410 of the wood veneers 408.
• a load 412 can be applied substantially parallel to a width direction of the strength-enhanced LVL structure 400 and/or substantially perpendicular to a direction in which veneers 408 are stacked (e.g., a height direction of stack 402).
• FIG. 4B illustrates another strength-enhanced LVL structure 420 that employs a stack 422 of wood veneers 408 in between outer layers 404a, 404b of densified wood segments.
• the top layer 404a can be formed by a plurality of densified wood segments 424a-424c
• the bottom layer 404b can be formed by a plurality of densified wood segments 444a-444c.
• wood segments in each layer 404a, 404b can be connected together via joining, for example, finger joints and/or structural adhesive.
• each top densified wood segment 424a-424c can be substantially aligned (e.g., along the length direction, L, and/or width direction, W) with a corresponding one of the bottom densified wood segments 444a-444c.
• the top and bottom densified wood segments can be offset from each other, for example, to further enhance mechanical stiffness.
• FIG. 4C illustrates another strength-enhanced LVL structure 430 having a laminate structure, with a stack 432 of wood veneers 408 in between outer layers of densified wood panels 404a, 404b (e.g., having a thickness of 3/16-inch to 1/4-inch (4.76 mm to 6.35 mm)).
• the densified wood panels 404a, 404b are provided on opposite sides of stack 432 along a direction substantially perpendicular to a direction in which the wood veneers 408 are stacked. Similar to the structure 400 of FIG.
• the stack 432 can be a conventional LVL structure, for example, with each wood veneer 408 of the stack 432 having a thickness of 2.5-4.8 mm in a cross-sectional plane perpendicular to longitudinal growth direction 410; however, other dimensions are also possible according to one or more contemplated embodiments.
• the LVL stack 432 can be fabricated, for example, by gluing together (e.g., while pressing) veneers from rotary peeling. The veneers can be assembled along their longitudinal directions (e.g., with orientations 410 substantially aligned).
• densified wood panels 404a-404d can have orientations 406a-406d that are substantially aligned with each other and parallel to orientation 410 of wood veneers 408.
• the orientations 406a-406d of one or both densified wood panels 404a-404d can be substantially orthogonal to, or at least crossing with, orientation 410 of the wood veneers 408.
• a load 434 can be applied substantially parallel to a width direction of the strength-enhanced LVL structure 430 or 450 and/or substantially perpendicular to a direction in which veneers 408 are stacked (e.g., a height direction of stack 432).
• the load 434 can be applied substantially perpendicular to exposed surfaces of densified wood panels 404a, 404b.
• the LVL structure 400, LVL structure 420, LVL structure 430, and/or LVL structure 440 can be employed as part of another engineered structure, for example, in place of one or both outermost layers 304a, 304b of glulam structure 300 in FIG. 3A, in place of one or both outermost layers 324a, 324b of glulam structure 320 in FIG. 3B, in place of one or both outermost layers 324a, 324b of glulam structure 340 in FIG. 3C, in place of one, some, or all of outermost layers 304a-304d of glulam structure 350 in FIG. 3D.
• the LVL structure 400, LVL structure 420, LVL structure 430, and/or LVL structure 440 can be employed as part of the flange of an I-joist.
• FIG. 5A shows a cross-section of an I-joist 500 that employs strength-enhanced LVL for flanges 502a, 502b.
• top flange 502a has an LVL stack 504a arranged between a pair of densified wood layers 506a, 508a
• bottom flange 502b has an LVL stack 504b arranged between a pair of densified wood layers 506b, 508b.
• a web 512 can be inserted into respective grooves 510a, 510b in the flanges 502a, 502b and glued thereto (which glue may be the same formulation or a different formulation than that constituting the glue layers of the flange).
• the web can be formed of plywood, LVL, oriented strand board (OSB), or other engineered wood structure.
• the I-joist 500 can be end-trimmed and heat- cured, or left at room temperature, to reach approximately equilibrium moisture content.
• FIG. 5B illustrates another I-joist 520 that employs LVL for the flanges. Similar to FIG.
• the web 512 is coupled into respective grooves 510a, 510b and extends between the top and bottom flanges 502a, 502b.
• the flanges only employ densified wood as outermost layers of the flanges.
• top flange 522a has an LVL stack 524a and a densified wood layer 506a at an end of the LVL stack 524a opposite the web 512
• bottom flange 522b has an LVL stack 524b and a densified wood layer 506b at an end of the LVL stack 524b opposite the web 512.
• the flange of the I-joist can be formed of strength-enhanced solid wood instead of LVL.
• FIG. 5C illustrates another I-joist 540 that employs strength-enhanced solid wood for flanges 542a, 542b (e.g., having a thickness of 3/16-inch to 1/4-inch (4.76 mm to 6.35 mm)).
• top flange 542a has a solid wood panel 544a and a densified wood layer 546a glued to an end of the wood panel 544a opposite the web 552
• bottom flange 542b has a solid wood panel 544b and a densified wood layer 546b glued to an end of the wood panel 544b.
• the web 552 can be inserted into respective grooves 550a, 550b in the solid wood panels 544a, 544b and glued thereto (which glue may be the same formulation or a different formulation than that constituting the glue layers of the flange).
• the web 552 can be formed of plywood, LVL, oriented strand board (OSB), or other engineered wood structure.
• OSB oriented strand board
• FIG. 5C shows strength enhancement via a single layer of densified wood for each flange of the I-joist
• embodiments of the disclosed subject matter are not limited thereto. Rather, in some embodiments, multiple densified wood layers can be combined with the solid wood in each flange.
• FIG. 5D shows a cross-section of another I-joist 560. Similar to the I-joist of FIG. 5A, the web 512 is coupled into respective grooves 510a, 510b and extends between the top and bottom flanges 562a, 562b. However, in contrast to FIG.
• the top flange 562a has a solid wood panel 564a arranged between and glued to a pair of densified wood layers 506a, 508a
• bottom flange 562b has a solid wood plane 564b arranged between and glued to a pair of densified wood layers 506b, 508b.
• densified wood is limited to the flanges of the I-joist in FIGS. 5A- 5D, embodiments of the disclosed subject matter are not limited thereto. Rather, in some embodiments, densified wood can be used as part of the web, for example, to allow an open structure for the web.
• FIG. 5E shows a side view of another I-joist 580 with a mesh 584 extending between the top and bottom flanges 582a, 582b.
• densified wood can be used to form the mesh 584, or as part of an engineered wood structure used to form the mesh 584.
• FIG. 6 illustrates aspects of a method 600 for fabricating an engineered structure from one or more plant material pieces.
• the method 600 can initiate at process block 602, where one or more pieces of natural plant material can be provided.
• the provision of process block 602 can include cutting, removing, or otherwise separating the piece from a parent plant (e.g., tree, bamboo stalk, etc.).
• the cutting can form the natural plant material into a substantially flat planar structure, with a direction of cellulose fibers extending parallel to a plane of the structure (e.g., longitudinal cut or rotary cut) or extending perpendicular to a plane of the structure (e.g., radial cut).
• the preparing can include pre-processing of the piece of natural plant material, for example, cleaning to remove any undesirable material or contamination in preparation for subsequent processing, forming the natural plant material into a particular shape in preparation for subsequent processing (e.g., slicing into strips), or any combination of the foregoing.
• the cutting can form the plant material piece(s) into any one-dimensional (e.g., an elongated structure, where a thickness and a width are both at least an order of magnitude less than its length), two-dimensional (e.g., a substantially flat planar structure, where a thickness is at least an order of magnitude less than its length and width), or three-dimensional (e.g., a block, where a thickness, width, and length are all within an order of magnitude of each other) structure.
• the provision of process block 602 can include assembling multiple plant material pieces into a single layer.
• the assembling of multiple plant material pieces into a single layer can occur after processing, for example, after the optional pre-press modification of process block 617 but before the compression of process block 618, or after the compression of process block 618 but before the coupling of process block 626.
• the provision of process block 624 can include machining, cutting, or otherwise physically manipulating, for example, to form a layer of appropriate size for a desired configuration of the engineered structure.
• the number of non-densified plant material pieces (or non-densified plant material layers) can be greater than the number of densified plant material pieces (or densified plant material layers), such as at least two times greater.
• blocks 602-628 of method 600 have been described as being performed once, in some embodiments, multiple repetitions of a particular process block may be employed before proceeding to the next decision block or process block.
• blocks 602- process blocks may be combined and performed together (simultaneously or sequentially).
• FIG. 6 illustrates a particular order for blocks 602-628, embodiments of the disclosed subject matter are not limited thereto. Indeed, in certain embodiments, the blocks may occur in a different order than illustrated or simultaneously with other blocks.
• method 600 can include steps or other aspects not specifically illustrated in FIG.
• Clause 4 The engineered structure of any clause or example herein, in particular, any one of Clauses 1-3, wherein the plant material forming one, some, or all of the one or more second layers is a native wood or native bamboo.
• Clause 5. The engineered structure of any clause or example herein, in particular, any one of Clauses 1-4, wherein the plant material forming one, some, or all of the one or more first layers is the same plant material as that of one, some, or all of the one or more second layers.
• the density of one, some, or all of the one or more first layers is greater than or equal to 1.2 g/cm 3 ;
• Clause 8 The engineered structure of any clause or example herein, in particular, any one of Clauses 1-7, wherein:
• Clause 9 The engineered structure of any clause or example herein, in particular, any one of Clauses 1-8, wherein one, some, or all of the one or more second layers comprises one or more pieces of non-densified plant material that retains a native micro structure of cellulose-based lumina of the plant material.
• Clause 12 The engineered structure of any clause or example herein, in particular, Clause 11, wherein the lignin-compromised plant material comprises modified lignin therein, and the modified lignin has shorter macromolecular chains than that of native lignin in the natural plant material.
• Clause 13 The engineered structure of any clause or example herein, in particular, Clause 12, wherein a content of the modified lignin in the one, some, or all of the one or more first layers is at least 90%, on a weight percentage basis, of a content of the native lignin in the natural plant material.
• Clause 16 The engineered structure of any clause or example herein, in particular, Clause 15, wherein the salt is substantially pH-neutral.
• Clause 19 The engineered structure of any clause or example herein, in particular, any one of Clauses 17-18, wherein: the plant material is a hardwood or bamboo, and a lignin content of the at least partially delignified plant material is between 0.9 wt% and 23.8 wt%, inclusive; or the plant material is a softwood, and a lignin content of the at least partially delignified plant material is between 1.25 wt% and 33.25 wt%, inclusive.
• Clause 20 The engineered structure of any clause or example herein, in particular, any one of Clauses 17-19, wherein a lignin content of the at least partially delignified plant material is at least 10 wt%.
• each first layer consists essentially of densified plant material
• each second layer consists essentially of non-densified wood; or both (a5) and (a6).
• Clause 22 The engineered structure of any clause or example herein, in particular, any one of Clauses 1-21, wherein the one or more respective glues comprise epoxy, polyurethane adhesive, polyvinyl acetate-isocyanate adhesive, resorcinol formaldehyde resin adhesive, phenolic resin, sodium carboxymethyl cellulose (CMC), or any combination of the foregoing.
• the one or more respective glues comprise epoxy, polyurethane adhesive, polyvinyl acetate-isocyanate adhesive, resorcinol formaldehyde resin adhesive, phenolic resin, sodium carboxymethyl cellulose (CMC), or any combination of the foregoing.
• Clause 30 The engineered structure of any clause or example herein, in particular, any one of Clauses 1-28, wherein the first laminate comprises a plurality of the second layers and a pair of first layers, each second layer comprising one or more plant material veneers, the second layers being arranged in a stack such that adjacent second layers have parallel orientations, the stack being disposed between the pair of first layers so as to form a reinforced laminated veneer lumber (LVL) structure.
• LTL reinforced laminated veneer lumber
• Clause 31 The engineered structure of any clause or example herein, in particular, any one of Clauses 1-30, further comprising: a second laminate comprising a second plurality of constituent plant material layers, the second plurality of constituent plant material layers comprising one or more third layers and one or more fourth layers, each plant material layer being adhered to an adjacent plant material layer via one or more respective glues; and a web extending between the first and second laminates, wherein each third layer is a densified plant material layer having a density greater than or equal to 1.15 g/cm 3 and a mechanical strength greater than or equal to a second value, each fourth layer is a plant material layer having a density less than 1.15 g/cm 3 and a mechanical strength less than the second value, the web and the first and second laminates together form an I-joist, and the first and second laminates form first and second flanges, respectively, of the I-joist. Clause 32. The engineered structure of any clause or example herein, in particular, Clause 31, wherein the web
• Clause 33 The engineered structure of any clause or example herein, in particular, any one of Clauses 31-32, wherein the web comprises one or more pieces of densified plant material, with cellulose-based lumina of a native microstructure of the plant material being substantially collapsed.
• Clause 34 The engineered structure of any clause or example herein, in particular, any one of Clauses 31-33, wherein the plant material forming one, some, or all of the constituent layers in the second laminate is a wood or bamboo.
• the plant material forming one, some, or all of the one or more third layers is a densified wood or densified bamboo
• Clause 37 The engineered structure of any clause or example herein, in particular, any one of Clauses 31-35, wherein:
• Clause 40 The engineered structure of any clause or example herein, in particular, any one of Clauses 1-39, wherein the first value is about 100 MPa, or the first value is in a range of 100-600 MPa, inclusive.
• An engineered structural material comprising: one or more laminate structures, each laminate structure having a plurality of constituent plant material layers, each plant material layer being coupled to an adjacent plant material layer via one or more respective glues, at least one of the plurality of constituent plant material layers being a densified plant material layer having a density greater than or equal to 1.15 g/cm 3 .
• Clause 45 The engineered structural material of any clause or example herein, in particular, any one of Clauses 43-44, wherein the densified plant material layer has a density greater than or equal to 1.2 g/cm 3 .
• Clause 46 The engineered structural material of any clause or example herein, in particular, any one of Clauses 43-45, wherein the densified plant material layer has a density greater than or equal to 1.3 g/cm 3 .
• Clause 47 The engineered structural material of any clause or example herein, in particular, any one of Clauses 43-46, wherein the densified plant material layer comprises one or more pieces of densified wood or densified bamboo, with cellulose-based lumina of a native microstructure of the wood or bamboo being substantially collapsed.
• Clause 48 The engineered structural material of any clause or example herein, in particular, any one of Clauses 43,-47 wherein the densified plant material layer comprises at least partially delignified plant material or lignin-modified plant material.
• Clause 49 The engineered structural material of any clause or example herein, in particular, any one of Clauses 43-48, wherein the one or more glues comprises epoxy, polyurethane adhesive, polyvinyl acetate-isocyanate adhesive, resorcinol formaldehyde resin adhesive, phenolic resin, sodium carboxymethyl cellulose (CMC), or any combination of the foregoing.
• the one or more glues comprises epoxy, polyurethane adhesive, polyvinyl acetate-isocyanate adhesive, resorcinol formaldehyde resin adhesive, phenolic resin, sodium carboxymethyl cellulose (CMC), or any combination of the foregoing.
• Clause 50 The engineered structural material of any clause or example herein, in particular, any one of Clauses 43-49, wherein the one or more laminate structures is formed as a cross-laminated timber (CLT) structure, a glued laminated timber (glulam) structure, a laminated veneer lumber (LVL) structure, an oriented strand board (OSB) structure, or part of an I-joist structure.
• CLT cross-laminated timber
• glulam glued laminated timber
• LDL laminated veneer lumber
• OSB oriented strand board
• each of the plurality of constituent plant material layers is either a non-densified plant material layer having a density less than 1.15 g/cm 3 or a densified plant material layer having a density of at least 1.15 g/cm 3 .
• each of the plurality of constituent plant material layers is either a native plant material layer having a density less than 1.15 g/cm 3 or a densified plant material layer having a density of at least 1.15 g/cm 3 .
• Clause 53 A method comprising: providing one or more first layers, each first layer comprising a densified plant material having a density greater than or equal to 1.15 g/cm 3 and a mechanical strength greater than or equal to a first value; providing one or more second layers, each second layer comprising a plant material having a density less than 1.15 g/cm 3 and a mechanical strength less than the first value; and coupling the one or more first layers to the one or more second layers via one or more respective glues so as to form a laminate.
• Clause 54 The method of any clause or example herein, in particular, Clause 53, wherein:
• the plant material of one, some, or all of the one or more first layers comprises densified wood or densified bamboo
• the density of one, some, or all of the one or more second layers is less than or equal to 1.0 g/cm 3 ; the density of one, some, or all of the one or more second layers is less than or equal to 0.9 g/cm 3 ; or any combination of the foregoing.
• Clause 58 The method of any clause or example herein, in particular, Clause 57, wherein the compressing is in a direction crossing a longitudinal growth direction of the one or more pieces of lignin-compromised plant material.
• Clause 60 The method of any clause or example herein, in particular, any one of Clauses 57-59, wherein the compressing comprises pressing the one or more pieces of lignin- compromised plant material at a pressure in a range of 5-20 MPa, inclusive.
• Clause 61 The method of any clause or example herein, in particular, any one of Clauses 57-60, wherein the compressing comprises pressing the one or more pieces of lignin- compromised plant material while subjecting to a temperature of at least 50 °C.
• Clause 62 The method of any clause or example herein, in particular, any one of Clauses 57-61, wherein the compressing comprises pressing the one or more pieces of lignin- compromised plant material while subjecting to a temperature in a range of 80-180 °C, inclusive.
• Clause 64 The method of any clause or example herein, in particular, Clause 63, wherein the subjecting to the chemical treatment comprises: infiltrating the one or more pieces of natural plant material with one or more chemical solutions; and after the infiltrating, subjecting the one or more pieces of natural plant material with the one or more chemical solutions therein to a first temperature of at least 80 °C for a first time, so as to form the one or more pieces of lignin-compromised plant material.
• Clause 65 The method of any clause or example herein, in particular, Clause 64, wherein the one or more chemical solutions comprise p-toluenesulfonic acid, NaOH, NaOH + Na 2 SO 3 /Na 2 SO 4 , NaOH + Na 2 S, NaHSO 3 + SO 2 + H 2 O, NaHSO 3 + Na 2 SO 3 , NaOH + Na 2 SO 3 , NaOH/ NaH 2 O 3 + AQ, NaOH/Na 2 S + AQ, NaOH + Na 2 SO 3 + AQ, Na 2 SO 3 + NaOH + CH 3 OH + AQ, NaHSCh + SO2 + AQ, NaOH + Na2Sx, where AQ is Anthraquinone, any of the foregoing with NaOH replaced by LiOH or KOH, or any combination of the foregoing.
• the one or more chemical solutions comprise p-toluenesulfonic acid, NaOH, NaOH + Na 2 SO 3 /Na 2 SO 4 , NaOH + Na 2
• Clause 66 The method of any clause or example herein, in particular, any one of Clauses 64-65, wherein: the first temperature is in a range of 120-160 °C, inclusive; and/or the first time is in a range of 1-5 hours, inclusive.
• Clause 67 The method of any clause or example herein, in particular, any one of Clauses 64-66, wherein at least 90% of the one or more chemical solutions infiltrated into the one or more pieces of natural plant material is consumed by the subjecting to the first temperature for the first time.
• Clause 69 The method of any clause or example herein, in particular, any one of Clauses 64-68, wherein, after the subjecting to the first temperature for the first time:
• a content of modified lignin in the one or more pieces of lignin-compromised plant material is at least 90%, on a weight percentage basis, of a content of the native lignin in the one or more pieces of natural plant material;
• a content of modified lignin in the one or more pieces of lignin-compromised plant material is at least 20 wt%; or both (b5) and (b6).
• Clause 70 The method of any clause or example herein, in particular, any one of Clauses 64-69, wherein, after the subjecting to the first temperature for the first time, a salt of an alkaline chemical is immobilized within a cellulose-based micro structure of the one or more pieces of lignin-compromised plant material.
• Clause 74 The method of any clause or example herein, in particular, Clause 73, wherein the subjecting to the chemical treatment comprises partial or full immersion of the one or more pieces of natural plant material in one or more chemical solutions at a second temperature for a second time, so as to remove at least some lignin from the one or more pieces of natural plant material.
• Clause 75 The method of any clause or example herein, in particular, Clause 74, wherein the one or more chemical solutions comprise an alkaline solution.
• Clause 78 The method of any clause or example herein, in particular, any one of Clauses 74-77, wherein:
• the second temperature is in a range of 100-160 °C, inclusive;
• Clause 81 The method of any clause or example herein, in particular, any one of Clauses 74-80, wherein a lignin content of the lignin-compromised plant material is at least 10 wt%.
• each second layer consists essentially of non-densified or native plant material; or both (b9) and (blO).

Landscapes

• Engineering & Computer Science (AREA)
• Life Sciences & Earth Sciences (AREA)
• Architecture (AREA)
• Wood Science & Technology (AREA)
• Structural Engineering (AREA)
• Civil Engineering (AREA)
• Manufacturing & Machinery (AREA)
• Forests & Forestry (AREA)
• Mechanical Engineering (AREA)
• Ceramic Engineering (AREA)
• Dry Formation Of Fiberboard And The Like (AREA)
• Chemical And Physical Treatments For Wood And The Like (AREA)
• Veneer Processing And Manufacture Of Plywood (AREA)
• Panels For Use In Building Construction (AREA)
• Laminated Bodies (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=90013869

Family Applications (1)

Country Status (7)

Families Citing this family (2)

Family Cites Families (7)

• 2023
  • 2023-08-22 CN CN202380065201.7A patent/CN119998093A/zh active Pending
  • 2023-08-22 AU AU2023330965A patent/AU2023330965A1/en active Pending
  • 2023-08-22 WO PCT/US2023/030783 patent/WO2024044160A1/en not_active Ceased
  • 2023-08-22 KR KR1020257009433A patent/KR20250072706A/ko active Pending
  • 2023-08-22 CA CA3264961A patent/CA3264961A1/en active Pending
  • 2023-08-22 EP EP23857973.4A patent/EP4577385A1/de active Pending
  • 2023-08-22 JP JP2025511783A patent/JP2025528403A/ja active Pending

Also Published As

Similar Documents

Legal Events