Composite structural material and method of making same

A method of making an elongated, composite, structural material, comprising the following steps:

• (a) supplying a substantially continuous length of a porous web material selected from the group consisting of paper and cloth;
• (b) laying substantially continuous, parallel strands of reinforcing cords on at least one side of the web material, with the cords running in the lengthwise direction of the web material;
• (c) applying a thermosetting-resin-precursor mixture to each of the cords and the web material;
• (d) forming the web material into a sleeve-like configuration having the desired cross-sectional shape of the structural material, with the cord-carrying side of the web material facing the interior of the configuration;
• (e) depositing on the cord-carrying side of the web material a fluid matrix-resin-precursor composition that is compatible with the thermosetting-resin-precursor mixture applied to each of the web material and the cords in step (c) and which, when reacted, yields a rigid matrix resin;
• and
• (f) holding the sleeve-like configuration together under conditions that are conducive to the setting of (i) the matrix resin in the core space and (ii) the thermosetting resin applied to each of the web material and the cords, and for a length of time sufficient for all of the resins to set, whereby the cords are bonded to the web material, a core space within the sleeve-like configuration is substantially filled with the matrix resin, and the matrix resin is bonded to the sleeve-like configuration.

A method of making an elongated, composite, structural material, comprising the following steps:

• (a) forming a foldable laminate of two strips of porous web material selected from the group consisting of paper and cloth, with at least one strip of a band of reinforcing cords sandwiched therebetween, with the cords running in the lengthwise direction and with the strips of porous web material and all materials lying between those strips being impregnated with a thermosetting-resin-precursor mixture;
• (b) folding the laminate into a trough shape and orienting it horizontally, with one of the strips of porous web material on the top and the other strip of porous web material on the bottom;
• (c) depositing in the trough of the laminate, while still foldable, a fluid matrix-resin-precursor composition that is compatible with the thermosetting-resin-precursor mixture in the laminate and which, when fully reacted, yields a thermoset matrix resin that is at least semi-rigid;
• (d) folding closed and sealing shut the laminate so that it surrounds and defines a core space containing said matrix resin precursor composition;
• and
• (e) holding the closed laminate and its contents in a mold under conditions conducive to the setting of both the thermosetting resin in the laminate and the matrix resin in the core space, for a time sufficient for both resins to set, whereby (i) the laminate and the matrix resin are both made at least semi-rigid, (ii) the matrix resin, together with any filler solid it may contain, fills the core space, and (iii) the laminate and matrix resin are bonded together.

A method of making an elongated, composite, structural material, comprising the following steps:

• (a) obtaining a first elongated C channel of a porous web material selected from the group consisting of paper and cloth that is impregnated with a thermosetting resin precursor mixture and orienting the channel with the C facing up;
• (b) impregnating a strip of cloth with a thermosetting resin precursor mixture that is compatible with the resin precursor mixture in the web material;
• (c) laying said strip of cloth on the inside bottom of the first C channel, with the warp running in the lengthwise direction of the channel, so as to extend the length of the channel;
• (d) depositing on the top of said strip of cloth a fluid matrix resin precursor composition that is compatible with both the resin precursor mixture in the web material and the resin precursor mixture in the cloth and which, when reacted, yields a matrix resin that is at least semi-rigid;
• (e) covering the first C channel with a second C channel of a porous web material that is impregnated with a thermosetting resin precursor mixture that is oriented with the C facing down, so that the vertical sides of the two channels overlap and touch each other and the two C channels define a core space between them;
• and
• (f) holding the two C channels together under conditions that are conducive to the setting of (i) the matrix resin in the core space, (ii) the thermosetting resin in the porous web material, and (iii) the thermosetting resin in the cloth, and for a length of time sufficient for all three resins to set, whereby the two C channels are bonded together where they overlap, the cloth strip is bonded to the first C channel, the core space is filled with the matrix resin, and the matrix resin is bonded to the cloth and the web material.

An elongated, four-sided composite structural material having a substantially uniform, rectangular cross section throughout its length, the material comprising:

• a core comprised of rubber-tire fragments embedded in a foamed polyether polyurethane resin, having a free-rise density of about 4 to about 35 pounds per cubic foot, the rubber-tire fragments constituting about 45 to 75 volume percent of the core and having a longest dimension that is no more than about 50 percent of the thickness of the composite structural material;
• and
• a one-piece laminar covering that ensheaths the core and is bonded to the core, the laminar covering including a plurality of layers of substantially parallel fiberglass cords, each cord layer being bonded, by an unfoamed epoxy resin, to at least one of a plurality of layers of rigidified kraft paper having a basis weight of about 65 to 100 pounds per thousand square feet, wherein the cord layers and the paper layers are impregnated with the same unfoamed epoxy resin that is used to bond the cord layers to the paper layers, the amount of the unfoamed epoxy resin being sufficient to render the laminar covering dimensionally stable, and wherein the cords are oriented in the longitudinal direction of the structural material and extend substantially the entire length thereof, each cord layer comprises at least 10 cords per lateral inch, and at least one paper layer is exterior to the cord layers.

An elongated, four-sided composite structural material having a substantially uniform, rectangular cross section throughout its length, the material comprising:

• a core comprised of pieces of expanded perlite embedded in a foamed polyether polyurethane resin, having a free-rise density of about 15 to 21 pounds per cubic foot, the expanded perlite constituting about 10 to 80 volume percent of the core and having a longest dimension that is no more than about 50 percent of the thickness of the composite structural material;
• and
• a one-piece laminar covering that ensheaths the core and is bonded to the core, the laminar covering including a plurality of layers of substantially parallel fiberglass cords, each cord layer being bonded, by an unfoamed epoxy resin, to at least one of a plurality of layers of rigidified kraft paper having a basis weight of about 65 to 100 pounds per thousand square feet, wherein the cord layers and the paper layers are impregnated with the same unfoamed epoxy resin that is used to bond the cord layers to the paper layers, the amount of the unfoamed epoxy resin being sufficient to render the laminar covering dimensionally stable, and wherein the cords are oriented in the longitudinal direction of the structural material, and extend substantially the entire length thereof, each cord layer comprises at least 10 cords per lateral inch, and at least one paper layer is exterior to the cord layers.