Equilateral strand composite lumber and method of making same

Abstract

A method of forming a composite beam includes cutting an elongated piece of wood to produce strands having cross sections with a substantially symmetrical equilateral polygonal shape. Resin is then applied to the strands, and the strands are formed into a composite beam.

1 . A method of forming a composite beam comprising: 
 cutting an elongated piece of wood to produce strands having cross sections with a substantially symmetrical equilateral polygonal shape;    applying a resin to the strands;    forming the strands into a composite beam.    
   
   
       2 . The method according to  claim 1 , wherein the cross sections have a side length within the range of from about ¼ inch to about 1 inch.  
   
   
       3 . The method according to  claim 1 , wherein the substantially symmetrical equilateral polygonal shape is one of triangular, square, pentagonal, hexagonal, and diamond shaped.  
   
   
       4 . The method according to  claim 1 , wherein the elongated piece of wood is a high density hardwood.  
   
   
       5 . The method according to  claim 1 , wherein the resin is one of a liquid resin and a powered resin.  
   
   
       6 . The method according to  claim 1 , wherein the step of forming the strands into a composite beam includes vibrating the strands so as to arrange the strands longitudinally.  
   
   
       7 . The method according to  claim 1 , wherein the composite beam has transverse near-isotropic properties.  
   
   
       8 . The method according to  claim 1 , wherein the step of forming the strands into a composite beam further includes: 
 arranging the strands into a mat;    stacking a plurality of mats to define a laid-up billet;    curing the laid-up billet into a cured billet; and    cutting the cured billet to form a beam.    
   
   
       9 . The method according to  claim 8 , wherein the step of arranging the strands includes vibrating the strands so as to align the strands longitudinally, thereby minimizing void space between adjacent strands.  
   
   
       10 . The method according to  claim 8 , wherein the step of arranging the strands includes aligning the strands such that the end surfaces of at least one end of each strand are coplanar.  
   
   
       11 . The method according to  claim 8 , wherein the step of arranging the strands includes bonding the strands to one another with adhesive.  
   
   
       12 . The method according to  claim 8 , wherein the stacking step includes disposing a reinforcement material between layers of mats.  
   
   
       13 . The method according to  claim 8 , wherein the stacking step includes stacking the plurality of mats in a stepped arrangement.  
   
   
       14 . The method according to  claim 13 , wherein the stacking step includes stacking the plurality of mats in a stepped arrangement such that each mat overlaps an adjacent mat.  
   
   
       15 . The method according to  claim 8 , wherein the stacking step includes stacking at least a first mat and a second mat, wherein the first mat includes strands having a larger cross-sectional size than the strands of the second mat.  
   
   
       16 . The method according to  claim 15 , wherein at least one first mat forms a top portion of the beam, at least one first mat forms a bottom portion of the beam, and at least one second mat forms a central portion of the beam intermediate the top and bottom portions.  
   
   
       17 . The method according to  claim 8 , wherein the arranging step includes arranging a plurality of first strands and a plurality of second strands, wherein the first strands have a larger cross-sectional size than the second strands.  
   
   
       18 . The method according to  claim 17 , wherein the first and second strands are aligned longitudinally, and arranged such that the first strands define a first outside portion and a second outside portion of the mat, and the second strands define a central portion of the mat intermediate the first and second outside portions.  
   
   
       19 . The method according to  claim 8 , wherein the curing step includes applying pressure and energy to the laid-up billet.  
   
   
       20 . The method according to  claim 19 , wherein the energy is provided by a source of radio frequency energy.  
   
   
       21 . The method according to  claim 8 , wherein the curing step includes applying sufficient pressure to the laid-up billet so as to arrange the strands such that the growth rings of any one of the wood strands are oriented in an orthogonally randomized fashion relative to the growth rings of an adjacent wood strand.  
   
   
       22 . A composite beam comprising: 
 wood strands having cross sections with a substantially symmetrical equilateral polygonal shape, adhesively bonded together.    
   
   
       23 . The composite beam according to  claim 22 , wherein the cross sections have a side length within the range of from about {fraction (1/4)} inch to about 1 inch.  
   
   
       24 . The composite beam according to  claim 22 , wherein the substantially symmetrical equilateral polygonal shape is one of triangular, square, pentagonal, hexagonal, and diamond shaped.  
   
   
       25 . The composite beam according to  claim 22 , wherein the wood strands are formed from a high density hardwood.  
   
   
       26 . The composite beam according to  claim 22 , wherein the composite beam has transverse near-isotropic properties.  
   
   
       27 . The composite beam according to  claim 22 , wherein the wood strands are arranged such that the growth rings of any one of the wood strands are oriented in an orthogonally randomized fashion relative to the growth rings of an adjacent wood strand.  
   
   
       28 . The composite beam according to  claim 22 , wherein the beam comprises at least a first mat and a second mat, wherein the first mat includes strands having a larger cross-sectional size than the strands of the second mat.  
   
   
       29 . The composite beam according to  claim 28 , wherein at least one first mat forms a top portion of the beam, at least one first mat forms a bottom portion of the beam, and at least one second mat forms a central portion of the beam intermediate the top and bottom portions.  
   
   
       30 . The composite beam according to  claim 22 , wherein the beam comprises a plurality of mats, each mat comprising a plurality of first strands and a plurality of second strands, wherein the first strands have a larger cross-sectional size than the second strands.  
   
   
       31 . The composite beam according to  claim 30 , wherein the first and second strands are aligned longitudinally, and arranged such that the first strands define a first outside portion and a second outside portion of the mat, and the second strands define a central portion of the mat intermediate the first and second outside portions.  
   
   
       32 . A composite beam comprising: 
 wood strands having cross sections with a substantially triangular shape, adhesively bonded together.    
   
   
       33 . The composite beam according to  claim 32 , wherein the cross sections have a side length within the range of from about ¼ inch to about 1 inch.  
   
   
       34 . The composite beam according to  claim 32 , wherein the wood strands are formed from a high density hardwood.  
   
   
       35 . The composite beam according to  claim 32 , wherein the composite beam has transverse near-isotropic properties.  
   
   
       36 . The composite beam according to  claim 32 , wherein the wood strands are arranged such that the growth rings of any one of the wood strands are oriented in an orthogonally randomized fashion relative to the growth rings of an adjacent wood strand.  
   
   
       37 . The composite beam according to  claim 32 , wherein less than about 10 percent of the volume of the beam is void space.  
   
   
       38 . The composite beam according to  claim 32 , wherein the beam comprises at least a first mat and a second mat, wherein the first mat includes strands having a larger cross-sectional size than the strands of the second mat.  
   
   
       39 . The composite beam according to  claim 38 , wherein at least one first mat forms a top portion of the beam, at least one first mat forms a bottom portion of the beam, and at least one second mat forms a central portion of the beam intermediate the top and bottom portions.  
   
   
       40 . The composite beam according to  claim 32 , wherein the beam comprises a plurality of mats, each mat comprising a plurality of first strands and a plurality of second strands, wherein the first strands have a larger cross-sectional size than the second strands.  
   
   
       41 . The composite beam according to  claim 40 , wherein the first and second strands are aligned longitudinally, and arranged such that the first strands define a first outside portion and a second outside portion of the mat, and the second strands define a central portion of the mat intermediate the first and second outside portions.