Structural members comprised of composite wood material and having zones of diverse density

A railroad crosstie comprised of composite wood material and including a longitudinal axis, the crosstie including

• a base portion comprised of a composite wood material including elongated planar wood flakes intermixed with a binder and compressed to form a densified product, said elongated wood flakes each having a longitudinal axis, the grain direction of said wood flakes being parallel with said longitudinal axis of said wood flakes, and said wood flakes being aligned with their longitudinal axes parallel to the longitudinal axis of the crosstie, and said planar wood flakes lying in parallel planes, and
• a densified rail supporting portion supported by said base portion and adapted to support a rail thereon, said densified rail supporting portion being integrally joined to said base portion, said rail supporting portion comprising elongated planar wood flakes intermixed with a binder and compressed to form a densified product, said densified product forming said rail supporting portion having a density greater than the density of said body portion, and said rail supporting portion being integrally formed with said body portion and being integrally bonded thereto,
• said base portion and said densified rail supporting portion being formed at the same time and by forming a loosely felted mat of said elongated planar wood flakes intermixed with said binder and said mat including a first mat portion for forming said base portion and said mat including a second portion for forming said densified rail supporting portion end by compressing said mat in a press to form said base portion and said densified rail supporting portion.

A post adapted to be supported in the ground and including a longitudinal axis, said post comprising a lower end adapted to extend into the ground and an upper end, said upper and lower ends of said post being comprised of composite wood material including elongated wood flakes intermixed with a binder and compressed to form a densified product, said elongated wood flakes each having a longitudinal axis, the grain direction of said wood flakes being aligned substantially parallel with said longitudinal axis of said wood flakes, and said wood flakes being aligned with their longitudinal axes parallel to the longitudinal axis of the post, and a post portion intermediate said upper and lower ends, said intermediate portion having a shear strength which is less than the shear strength of said upper and lower ends, and said intermediate portion being comprised of wood particles intermixed with a binder and compressed to form a composite product, and wherein said wood particles are in random orientation, said upper and lower post portions and said intermediate post portion being formed at the same time and by forming a loosely felted mat comprised of said elongated planar wood flakes intermixed with a binder, said mat including portions having aligned wood flakes and intended to form said upper and lower post portions and said mat including an intermediate portion comprised of randomly oriented flakes and intended to form said intermediate post portion, and by compressing said composite wood material mat in a press to form said upper and lower post ends and said intermediate post portion.

A post adapted to be supported in the ground and including a longitudinal axis, said post comprising a lower end adapted to extend into the ground and an upper end, said upper and lower ends of said post being comprised of composite wood material including elongated wood flakes intermixed with a binder and compressed to form a densified product, said elongated wood flakes each having a longitudinal axis, the grain direction of said wood flakes being aligned substantially parallel with said longitudinal axis of said wood flakes, and said wood flakes being aligned with their longitudinal axes parallel to the longitudinal axis of the post, and a densified post portion intermediate said upper and lower ends, and intended to be at the ground line when said post is set in the ground, said densified intermediate portion being integrally joined to said upper and lower ends and having a strength which is greater than the strength of said upper and lower ends, and said intermediate portion being comprised of elongated thin wood flakes intermixed with a binder and compressed to form a densified product, said upper and lower post portions and said intermediate post portion being formed at the same time and by forming a loosely felted mat comprised of said elongated planar wood flakes intermixed with a binder, said mat including portions intended to form said upper and lower post portions and said mat including an intermediate portion intended to form said intermediate post portion and by compressing said composite wood material mat in a press to form said upper and lower post ends and said intermediate post portions.

A method for forming an elongated solid structural member including a first structural member portion having a first density and a second structural member portion integrally joined to the first structural member portion and wherein the second structural member portion has a density greater than that of the first structural member portion, the method comprising the steps of

• providing elongated wood flakes having a grain direction extending generally parallel to the longitudinal axis thereof,
• admixing a binder with the wood flakes,
• forming a first mat of the resulting mixture with at least a majority of the wood flakes oriented such that the longitudinal axis thereof is parallel to the axis of the structural member to be formed from the mat,
• forming a second mat portion by depositing additional quantities of said resulting mixture on at least portions of said first mat with at least a majority of the wood flakes in said additional quantity being oriented such that the longitudinal axis thereof is parallel to the axis of the structural member to be formed, and
• compressing said first and second mat portions in a press applying sufficient pressure on the mat to bond the wood flakes together to form a densified integral compressed product.

A method for forming a railroad crosstie including a base portion having a first density and a the supporting portion integrally joined to the base portion and supported by the base portion, and the tie supporting portion having a density greater than that of the portion, the method comprising the steps of

• providing elongated wood flakes having a grain direction extending generally parallel to the longitudinal axis thereof,
• admixing a binder with the wood flakes,
• forming a first mat of the resulting mixture with at least a majority of the wood flakes oriented such that the longitudinal axis thereof is parallel to the axis of the structural member to be formed from the mat,
• forming a second mat portion by depositing additional quantities of said resulting mixture on at least portions of said first layered mat with at least a majority of the wood flakes in said additional quantity being oriented such that the longitudinal axis thereof is parallel to the axis of the structural member to be formed,
• compressing said first and second mat portions in a press applying sufficient pressure on the mat to bond the wood flakes together to form a densified integral compressed product.

A method for forming a highway guard post including a lower end adapted to extend into the ground and upper end, said lower and upper ends being comprised of composite wood material having a first density and a densified post portion intermediate said upper and lower ends and integrally joined to the upper and lower ends, the method comprising the steps of

• providing elongated wood flakes having a grain direction extending generally parallel to the longitudinal axis thereof,
• admixing a binder with the wood flakes,
• forming a first mat of the resulting mixture with at least a majority of the wood flakes oriented such that the longitudinal axis thereof is parallel to the axis of the structural member to be formed from the mat
• forming a second mat portion by depositing additional quantities of said resulting mixture on at least portions of said first mat with at least a majority of the wood flakes in said additional quantity being oriented such that the longitudinal axis thereof is parallel to the axis of the structural member to be formed
• compressing said first and second mat portions in a press applying sufficient pressure on the mat to bond the wood flakes together to form a densified integral compressed product.