Structural panel and method of making same

{
  "publication_number": "US4091142A",
  "country": "US",
  "kind": "A",
  "title": "Structural panel and method of making same",
  "abstract": "A structural panel for use in building construction and the like wherein side skin sheets of fiber-reinforced polyester are spaced to form a mold cavity to receive a foamable resin composition which, upon curing, is integrally secured to the skin sheets so as to prevent delamination of the skin sheets from the core. The methods of making the side skin sheets and introducing the foamable core composition therebetween provide a structural panel of high strength and durability independent of the size of the panel, with increased core integrity over panels heretofore available.",
  "claims": [
    "1. A structural panel for use in building construction and the like, comprising a core of cured foamed resin composition having a configuration corresponding substantially to the desired shape of the structural panel and including side surfaces, and a side skin sheet integrally secured to each side surface of said core, at least one of said side skin sheets being made of a cured fiber-reinforced resin including a first layer of resin which has reinforcing material to provide increased strength for the sheet, and a second layer of resin on said first layer having a plurality of fibers with portions thereof embedded in said second layer and other portions of the fibers projecting from a surface thereof into and integrally adhering with said foamed core.",
    "2. A structural panel as defined in claim 1 wherein said core is comprised of cured thermosetting foamed polyurethane.",
    "3. A structural stress skin panel for use in building construction, comprising a core of cured foamed thermosetting resin composition having a configuration corresponding substantially to the desired shape of the structural panel and including side surfaces, and a first side skin sheet and a second side skin sheet integrally secured respectively to a pair of opposite side surfaces of said core, at least one of said side skin sheets comprising a cured fiber-reinforced polyester body including a first layer of thermosetting resin which has fiberglass material integral therewith to provide increased strength for the sheet, and a second layer of thermosetting resin on said first layer including a plurality of fibers having portions thereof embedded in said second layer and other portions of the fibers projecting from the second layer and into the foamed core and integrally adhering to the interior of said foamed core to provide an interface between the core and the first layer which provides increased vertical columnar strength.",
    "4. A structural stress skin panel for use in building construction and the like, comprising a core of cured foamed resin composition having a configuration corresponding substantially to the desired shape of the structural panel and including at least one side skin sheet integrally secured to one side surface of said core comprising a first and a second layer of cured fiber-reinforced polyester resin, each of which layers has fiberglass material integral therewith to provide increased strength for the sheet, the second layer having a plurality of fiberglass fibers having portions embedded in said polyester resin layer and other portions of the fibers projecting into the core and integrally adhering to the foam within said core.",
    "5. A structural stress skin panel for use in building construction, comprising a core of cured foamed thermosetting resin composition having a configuration corresponding substantially to the desired shape of the structural panel and including side surfaces, and a first and a second side skin sheet integrally secured respectively to a pair of opposite side surfaces of said core, at least one of said side skin sheets comprising a cured fiber-reinforced polyester body including a first layer of thermosetting resin which has fiberglass fibers integral therewith to provide increased strength for the sheet, and a second layer of thermosetting resin polymerized with said first layer including a further plurality of fibers having portions thereof embedded in said second layer and some portion of the resin stiffened fibers projecting into the first layer and other portions of the resin stiffened fibers projecting from the second layer and into the foamed core and integrally adhering to the interior of said foamed core to provide an interface between the core and the first layer which provides increased resistance to separation of the skin from the core and thereby increased strength.",
    "6. A structural stress skin panel for use in building construction and the like, comprising a core of cured foamed resin composition having a configuration corresponding substantially to the desired shape of the structural panel and including at least one side skin sheet integrally secured to one side surface of said core, comprising a first layer of a cured fiber-reinforced polyester resin, and a second layer of polyester resin polymerized with said first layer, each of which layers has fiberglass fibers integral therewith to provide increased strength for the sheet, a plurality of resin stiffened fiberglass fibers embedded in said second polyester resin layer having certain portions which project into the first layer and other portions which project into the core and integrally adhere to the foam within said core to provide an interface between the core and the skin of increased strength.",
    "7. A laminated sandwich panel comprising: a first outer laminate resin layer; a first inner layer bonded at an outer surface thereof to said outer laminate resin layer, said first inner layer comprising a mixture of resin and a sufficient quantity of chopped fibers per unit area of said first inner layer to form a fibrillar surface of a multiplicity of said fibers extending from the inner surface of said first inner layer; and a layer of foamed synthetic resin bonded on one surface to said first inner layer with said extending fibers of said first inner layer interlocking with said layer of foamed synthetic resin.",
    "8. A panel as claimed in claim 7, further comprising: a second outer laminate resin layer; a second inner layer identical to said first inner layer and bonded to the other surface of said layer of foamed synthetic resin and to said second outer laminate resin layer, with the extending fibers of said second inner layer interlocking with said layer of foamed synthetic resin.",
    "9. A panel as claimed in claim 7 wherein said chopped fibers consist of fiberglass.",
    "10. A panel as claimed in claim 7, wherein the outer surface of said first outer laminate resin layer additionally is provided with a gel coat.",
    "11. A panel as claimed in claim 7, wherein said foamed synthetic resin is a rigid polyurethane foam having a density of approximately 2 pounds per cubic foot."
  ],
  "cpc": [
    "B29C 44/386",
    "B29C 37/0082",
    "B29C 70/00",
    "B29C 70/086",
    "B29K 2309/08",
    "B32B 5/24",
    "E04C 2/296",
    "Y10T 428/249946",
    "Y10T 428/24996"
  ],
  "assignees": [
    "DURA PLEX IND INC"
  ],
  "filing_date": "1976-01-21",
  "publication_date": "1978-05-23",
  "grant_date": "1978-05-23",
  "priority_date": "1974-04-23",
  "application_number": "US-65094176-A",
  "family_id": "23839536",
  "citations": [
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    "US3959541A"
  ]
}