Method of manufacturing a molded composite urethane foam structural panel
First Claim
1. PROCESS FOR MANUFACTURING A HIGH QUALITY MOLDED URETHANE FOAM STRUCTURAL PANEL WHICH COMPRISES CONTINUOUSLY APPLYING A THIN PLASTIC FILM TO A BELT WHICH CONTINUOUSLY MOVES ALONG A MOLD, INTRODUCING A RELATIVELY HIGH DENSITY FOAMABLE URETHANE MIXTURE ONTO SAID FILM FROM A FIRST SPRAY APPLICATOR, SUBSEQUENTLY CONTINUOUSLY INTRODUCING ADDITIONAL RELATIVELY LOW DENSITY FOAMABLE URETHANE MIXTURE ONTO SAID PLASTIC FILM FROM A SECOND SPRAY APPLICATOR IN A MANNER THAT THE SPRAY FROM SAID SECOND APPLICATOR SLIGHTLY OVERLAPS THE SPRAY FROM SAID FIRST APPLICATOR, AND IN A MANNER THAT THE FOAMABLE URETHANE MIXTURE FROM SAID FIRST APPLICATOR COMPLETELY COVERS THE FOAMABLE URETHANE MIXTURE FROM SAID FIRST APPLICATOR, CONFORMING SAID FILM TO THE MOLD CONFIGURATION BY MEANS OF A VACUUM, AND FORMING A URETHANE FOAM SUBSTRATE ON SAID PLASTIC FILM, AND THEN SEPARATING SAID BELT FROM SAID PLASTIC FILM SUPPORTED BY SAID URETHANE FOAM SUBSTRATE.
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Accused Products
Abstract
The invention covers a high quality structural building panel comprising a unique construction of high density and low density urethane foam faced with a weather resistant plastic film or sheet material surface, and with the method of manufacture wherein the supporting urethane foam is molded onto the film instead of laminating the film onto the supporting substrate.
48 Citations
20 Claims
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1. PROCESS FOR MANUFACTURING A HIGH QUALITY MOLDED URETHANE FOAM STRUCTURAL PANEL WHICH COMPRISES CONTINUOUSLY APPLYING A THIN PLASTIC FILM TO A BELT WHICH CONTINUOUSLY MOVES ALONG A MOLD, INTRODUCING A RELATIVELY HIGH DENSITY FOAMABLE URETHANE MIXTURE ONTO SAID FILM FROM A FIRST SPRAY APPLICATOR, SUBSEQUENTLY CONTINUOUSLY INTRODUCING ADDITIONAL RELATIVELY LOW DENSITY FOAMABLE URETHANE MIXTURE ONTO SAID PLASTIC FILM FROM A SECOND SPRAY APPLICATOR IN A MANNER THAT THE SPRAY FROM SAID SECOND APPLICATOR SLIGHTLY OVERLAPS THE SPRAY FROM SAID FIRST APPLICATOR, AND IN A MANNER THAT THE FOAMABLE URETHANE MIXTURE FROM SAID FIRST APPLICATOR COMPLETELY COVERS THE FOAMABLE URETHANE MIXTURE FROM SAID FIRST APPLICATOR, CONFORMING SAID FILM TO THE MOLD CONFIGURATION BY MEANS OF A VACUUM, AND FORMING A URETHANE FOAM SUBSTRATE ON SAID PLASTIC FILM, AND THEN SEPARATING SAID BELT FROM SAID PLASTIC FILM SUPPORTED BY SAID URETHANE FOAM SUBSTRATE.
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2. Process as defined by claim 1 wherein said structural product comprises a siding member characterized by having one or more courses.
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3. Process as defined by claim 1 wherein said film is heated to a temperature in the range of about 110*F. to 120*F. before being applied to said belt and then heated to a temperature in the range of about 260*F. to 290*F. before forming said foam substrate thereon.
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4. Process as defined by claim 3 wherein said vacuum is 2 to 4 inches of water.
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5. Process as defined by claim 1 wherein the relatively high density foamable urethane mixture from said first applicator has a final density in the range from about 10 to 30 lbs/ft3.
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6. Process as defined by claim 5 wherein the average thickness of the applied relatively high density foamable urethane mixture is about 1/16 to 1/2 inch, and wherein the average thickness of the applied relatively low density foamable urethane mixture is about 1/4 to 1 inch.
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7. Process as defined by claim 1 wherein the spray from said second applicator overlaps the spray from said first applicator by about 1/4 to 1 inch.
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8. Process as defined by claim 1 wherein said structural member comprises a siding member characterized by having two to four courses.
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9. Process as defined by claim 1 wherein said plastic film has a thickness of about 1 to 5 mils, wherein said relatively high density foamable urethane mixture is about 10 to 20 lbs ft3, and wherein said relatively low density foamable urethane mixture is about 1 to 3 lbs ft3.
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10. Process for manufacturing a high quality molded urethane foam structural product comprising the steps of continuously applying a thin weather resistant plastic film from a roller to an open weave belt which continuously moves along a mold, conforming said belt and said film to the mold configuration by means of a vacuum, introducing a relatively high density foamable urethane mixture onto said film from a first spray applicator, subsequently introducing additional relatively low density foamable urethane mixture onto said film from a second spray applicator in a manner that the spray from said second applicator slightly overlaps the spray from said first applicator, and in a manner that the foamable urethane mixture from said second applicator completely covers the foamable urethane mixture from said first applicator, and finally separating said belt from said film supported by said urethane foam substrate.
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11. Process as defined by claim 10 wherein said plastic film has a thickness in the range of about 1 to 5 mils.
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12. Process as defined by claim 10 wherein said plastic film is heated to a temperature in the range of about 105*F to about 130*F before being applied to said belt.
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13. Process as defined by claim 12 wherein said film is heated to a temperature in the range of about 260* to about 290*F before forming a urethane foam substrate upon said film.
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14. Process as defined by claim 10 wherein said relatively high density foamable urethane mixture is about 1 to 3 lbs ft3.
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15. Process as defined by claim 14 wherein conditions are adjusted to secure an expansion of said relatively high density foamable urethane mixture of about 15 percent to 20 percent of its original volume, and expansion of said relatively low density foamable urethane mixture is about 20 to 50 fold of its original volume.
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16. Process as defined by claim 10 wherein said urethane foam substrate on said film is subjected to a hot air blast prior to separating said belt from said film supported by said urethane foam substrate.
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17. Process as defined by claim 16 wherein the intensity of said hot air blast decreases in the direction of movement of said film.
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18. Process as defined by claim 14 wherein said urethane foam substrate on said film is subjected to a hot air blast prior to separating said belt from said film supported by said urethane foam substrate.
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19. Process as defined by claim 18 wherein the intensity of said hot air blast decreases in the direction of movement of said film.
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20. Process as defined by claim 19 wherein the intensity of said hot air blast decreases to about 10 to 40 percent of its original intensity.
Specification