WO1997039205A1

WO1997039205A1 - Composite skin panels

Info

Publication number: WO1997039205A1
Application number: PCT/US1997/006458
Authority: WO
Inventors: Bruce Harrington
Original assignee: Structural Technologies, Inc.
Priority date: 1996-04-18
Filing date: 1997-04-18
Publication date: 1997-10-23
Also published as: AU2803997A

Abstract

A building panel (100) includes a foam core and a composite structural skin (110, 720) adhered to a surface of the foam core (105, 730). The composite structural skin (110, 720) may be textured, and a colored layer (120) may be adhered to a surface of the composite strutural skin (110, 720). A second composite structural skin (725) may be adhered to a second surface of the foam core (730) opposite the first surface of the foam core (730). A rigid frame (620) may be embedded in the foam core (105, 730), and may extend from a second surface of the foam core (730) opposite the first surface of the foam core (730).

Description

COMPOSITE SKIN PANELS Background The invention relates to building panels.

It is known that significant structural integrity may be achieved by attaching a piece of thin rigid board (e.g., plywood) on each side of a foam board (e.g., polystyrene) in a sandwich form. While the individual materials may possess little, if any, load bearing strength, the panel formed by laminating them together may provide greater load bearing strength than conventional wood or metal framing.

Known building panels based on this theory include a polystyrene or polyurethane core and oriented strand board or light gauge metal skins. Panels having metal skins are used primarily in commercial and industrial construction to enclose buildings such as warehouses, manufacturing facilities, offices and retail structures. The panels with oriented strand board skins, which also are known as structural insulated panels, are used primarily to form exterior walls and roofs of residential dwellings. In addition, curtain panels for office and other buildings have been produced using foam board attached over lightweight metal framing and covered with layers of synthetic stucco and fabric mesh, or panels pre-cast from concrete and having marble or other decorative stone attached to their surfaces.

Summary In one aspect, generally, the invention features a building panel that includes a foam core and a composite structural skin adhered to a surface of the foam core.

Embodiments of the invention may include one or more of the following features. The composite structural skin may be textured to resemble, for example, decorative stone or brick, and a colored layer may be adhered to a surface of the composite structural skin. The colored layer may be colored to resemble marble or other materials. A second composite structural skin, and a second colored layer, may be adhered to a second surface of the foam core opposite the first surface of the foam core.

A rigid frame, such as a metal or wooden frame, may be embedded in the foam core. The rigid frame may extend from a second surface of the foam core opposite the first surface of the foam core.

The composite structural skin may include polyurethane or a structural polyurethane/polyurea blend, and the foam core may include expanded polyurethane. The coloring layer may be paint or a colored polyurethane gel-coat.

In another aspect, generally, the invention features producing a building panel by spraying a composite material to form a composite structural skin and spraying a foam material on the composite structural skin to form a foam core on the composite structural skin.

Embodiments of this aspect of the invention may include one or more of the following features. A colored material may be sprayed to form a colored layer, and the composite material may be sprayed on the colored layer. The composite material may be sprayed into a textured mold to provide the composite structural skin with a textured surface. A rigid frame may be positioned over the composite structural skin, and the foam material may be sprayed around the rigid frame to embed the rigid frame in the foam material.

The invention provides composite skin building panels and associated techniques for use in building structures. A composite skin panel may include a rigid foam core formed by spraying foam material or by using, for example, an expanded polystyrene or polyurethane board. Composite skins made from, for example, structural polyurethane or fiberglass then are secured to opposing surfaces of the core to form an integral panel unit. A unique connection structure permits quick and reliable attachment of the panels for the construction of walls, roofs, and other structures. The composite skins of the panels may be cast in textured molds and colored to provide the panels with decorative features (e.g., a finished appearance of slate stone, brick, cobblestone, stucco or other surface features) to enable the complete construction of building structures without time consuming and costly finishing operations. The composite skin panels promise to provide considerable cost savings over traditional construction techniques. At the same time, the panels include structural grade polyurethane foam cores that provide insulation values far exceeding those of conventional methods. Moreover, since the panels are produced in finished or near-finished form, use of the panels promises to substantially reduce construction times. Other advantages of the composite skin panels over conventional construction techniques include increased sound and thermal insulation, increased durability, improved quality control, reduced waste and cleanup, fewer joints, and resistance to termites and dry rot.

The composite skin panels may be used, for example, as exterior wall panels for warehouses, retail buildings, and manufacturing facilities, or as curtain panels to enclose high-rise office buildings and hotels. The composite skin panels also may be used to enclose climate-controlled rooms such as freezers or meat cutting rooms for food processing facilities. The composite skin panels also may provide graffiti-proof walls for school buildings and other public facilities; privacy walls around commercial and residential projects; and sound barrier wall along highways. In yet another application, the composite skin panels may be used to generate high- production residential buildings.

Composite roof panels may have a variety of roof tile designs molded into their exterior skins. This will result in a completed roof panel that gives the appearance of slate, standing seam or other desired roof finishes.

Advantages of the composite skin panels include reduced construction time and construction costs because the panels are complete with finished texture and color. Textures such as those resembling marble or slate may be provided at costs that are substantially less than costs associated with actually using marble or slate. The panels also have improved durability because the composite materials are impervious to essentially all environmental conditions, as well as superior energy efficiency resulting from the foam core.

Other features and advantages of the invention will be apparent from the following detailed description, including the drawings, and from the claims.

Brief Description of the Drawings Fig. 1 is a perspective view of a building panel. Figs. 2A-2D are perspective views of building panels.

Figs. 3A and 3B are perspective views of an apparatus for producing the building panel of Fig. 1. Fig. 4 is a flow chart of a method for producing the building panel of Fig. 1.

Fig. 5 is a side schematic view of an automated apparatus for producing the building panel of Fig. 1. Figs. 6A and 6B are back and side views of a building panel.

Fig. 7 is a side view illustrating use of building panels in the construction of a building having a wall and roof.

Fig. 8 is an enlarged side view of attachment of the wall panel of Fig. 7 to a foundation structure.

Fig. 9 is an enlarged side view of attachment of the wall panel of Fig. 7 to the roof panel of Fig. 7. Figs. 10 and 11 are top views illustrating, respectively, straight and corner connections between adjacent panels.

Fig. 12 is a side view showing a connection between a panel and a truss. Fig. 13 is a side view illustrating use of the panel system to construct a fence.

Fig. 14 is a top view of the fence of Fig. 13.

Fig. 15 is a top view of a fence using a post facade. Fig. 16 is a side view illustrating a panel cap.

Figs. 17A and 17B are top and perspective views illustrating corner facades.

Fig. 18 is a perspective view illustrating a window.

Description

Referring to Fig. 1, a composite skin building panel 100 includes an insulative core 105. An outer composite structural skin 110 and an inner composite structural skin 115 are adhered, respectively, to outer and inner surfaces of the insulative core 105. A coloring layer 120 is adhered to the outer surface of the outer skin 110.

The foam core, which may have a thickness of three inches, may be made, for example, from polyurethane, such as UCT 5070 polyurethane foam available from Urethane Technology Co. of New Burgh, New York. The structural skins, which may have thicknesses of 125 to 250 mils, may be made, for example, from a structural polyurethane/polyurea blend, such as Ultrathane 5440 available from Futura Coatings of St. Louis, Missouri. The coloring layer 120, which may have a thickness of 15 to 25 mils, may be made, for example, from polyurethane gel-coat 4005 available from Futura Coatings. In addition to providing coloring, the layer 120 provides resistance to ultra-violet energy that otherwise could degrade the outer skin 110.

The panel 100 is textured and colored to resemble a rough stone wall, with the texture being formed in the outer skin 110 and the color being provided by the coloring layer 120. As illustrated, for example, in Figs. 2A-2D, other textures, colors and sizes may be provided. Fig. 2A illustrates a panel 200 that looks like a wall made from finished stone. Fig. 2B illustrates a panel 205 that looks like a sheet of granite. Fig. 2C illustrates a panel 210 that looks like marble, a panel 215 that looks like a capped section of rough stone blocks, and a panel 220 that looks like a sheet of dark granite. Fig. 2D illustrates a panel 225 having a smooth, partially reflective surface, a panel 230 that looks like a piece of marble, a panel 235 that looks like a piece of granite, and a panel 240 that looks like a plaster wall.

Referring to Figs. 3A and 3B, building panels may be formed using a molding apparatus 300 that includes an open mold platform 305 that is twelve feet wide and forty eight feet long. The mold platform may be built from conventional framing lumber and floor decking that is covered with a layer of epoxy to make it level and seamless for the production of building panels having smooth surfaces.

The mold platform 305 includes hinged side plates 310 that contain the materials within the mold during casting, but may be opened to permit removal of a finished panel. Textured silicone mold liners 315 may be positioned in the base of the mold platform 305. The mold liners 315 can have any desired texture (e.g., brick, stone, or slate) , and may be replaced as desired. A panel production carriage 320 is used to fill the mold 305 with the materials needed to produce a panel. The carriage 320 moves along the length of the mold platform 305 on tracks 325. A spray gun 330 is mounted on a gun track 335 that permits movement of the spray gun 330 along the width of the mold.

Supply hoses 340 carried by a supply line carriage 345 supply air and materials to the spray gun 330. Electricity is supplied to the apparatus 300 by a ceiling-mounted electrical supply line 350. A band-saw 355 extends across the width of the mold 305 and is used to remove excess polyurethane foam. The apparatus 300 is controlled by a user-operated control center 360.

The apparatus 300 may be used to generate one or more panels according to the procedure 400 illustrated in Fig. 4. First, a polyurethane based gel-coat or quick¬ set in-mold paint is sprayed onto the surface of the textured mold liner to form the coloring layer for the outer half of the panel (step 405) . Next, a structural polyurethane layer is sprayed onto the coloring layer to form the outer skin of the panel (step 410) . An insulating polyurethane foam is then sprayed onto the structural polyurethane layer to form the insulative core (step 415) . Next, the band saw 355 is used to plane off any excess foam (step 420) . Steps 410-420 then are repeated in another section of the mold to form the inner half of the panel (step 425) . If desired, step 405 may be repeated to color the inner surface of the panel . The outer and inner surfaces of the panel may have different colors and textures.

One half of the panel is then demolded (step 430) by attaching a panel clamp to the edge of the panel half and lifting the panel half out with a gantry crane. The panel half is lifted to a completely vertical position and then moved to a position over the second panel half (step 435) . An adhesive coating is then applied to the surface of the second panel half (step 440) . The first panel half then is lowered onto the second panel half to connect the insulation foam layers of the two halves together with the adhesive (step 445) . After the adhesive cures, the completed panel is demolded using the gantry crane and a panel clamp as described above (step 450) .

Referring to Fig. 5, building panels also may be generated using a high pressure conveyor mold 500. The mold 500, which is approximately sixty feet long and twelve feet wide, includes an upper belt 505 and a lower belt 510. Each of these belts may be textured to provide suitable textures to the panels produced by the mold. The belts also may be replaced to change the texture produced. The belts 505 and 510 are motor driven at rates suitable to permit the mold 500 to extrude panels at rates on the order of sixty square feet per minute.

Five high pressure spray guns are mounted to spray materials onto the belts 505, 510. A first spray gun 515 is positioned adjacent to the lower belt 510 and is configured to spray material for an outer colored layer of the building panel onto the belt 510. For example, the spray gun 515 may be positioned to spray the outer- colored-layer material on a vertical portion 520 at an upstream end 525 of the lower belt 510.

A second spray gun 530 is positioned downstream of the spray gun 515 and is configured to spray material for an outer structural skin on the outer-colored-layer material coating the belt 510. For example, the spray gun 530 may be positioned to spray the outer-structural- skin material on a horizontal edge 535 at the upstream end 525 of the lower belt 510. A third spray gun 540 is positioned downstream of the spray gun 530 and is configured to spray insulative foam material on the outer-structural-skin materials coating the belt 510. For example, the spray gun 540 may be positioned to spray the foam material on a horizontal surface 545 of the lower belt 510.

A fourth spray gun 550 is positioned adjacent to the upper belt 505 and is configured to spray material for an inner colored layer of the building panel onto the belt 505. For example, the spray gun 550 may be positioned to spray the inner-colored-layer material on a horizontal upper surface 555 near an upstream end 560 of the upper belt 505.

A fifth spray gun 565 is positioned downstream of the spray gun 550 and is configured to spray material for an inner structural skin on the inner-colored-layer material coating the belt 505. For example, the spray gun 565 may be positioned to spray the inner-struetural- skin material on a vertical surface 570 at the upstream end 560 of the upper belt 505. The upstream end 560 of the upper belt 505 is positioned downstream of the upstream end 525 of the lower belt 510. This positioning exposes the horizontal surface 545 of the lower belt 510 on which the insulative foam material is sprayed. The downstream ends 575, 580 of the upper and lower belts 505, 510 include peel off rollers 585 that serve to separate the completed building panels from the belts.

At the upstream end 560 of the upper belt, the inner-structural-skin material is joined under pressure with the insulative-foam material to form a building panel. The upper belt 505 is of a length sufficient to permit the building panel materials to cure before the building panel is separated from the mold. In general, the coloring materials and the structural skin materials are "quick set" materials that cure in a matter of seconds. By contrast, the insulative foam generally requires several minutes to expand and cure. Heaters or other devices may be positioned along the length of the belt 505 to hasten the curing process. Referring to Figs. 6A and 6B, an open-framed building panel 600 includes a polyurethane insulative core 605, an outer polyurethane structural skin 610 adhered to an outer surface of the insulative core 605, and a polyurethane coloring layer 615 adhered to the outer surface of the outer skin 610. However, the panel 600 does not include an inner structural skin. Instead, a metal frame 620 is positioned within the insulative core 605. When the panel 600 is used, drywall or similar materials may be attached to the frame 620 to finish an interior surface of the panel 600.

Figs. 7-9 show use of a wall panel 700 and a roof panel 705 to construct a building 710 having a wall and a roof. The wall panel 700 includes a foam core 715, an outer composite skin 720 and an inner composite skin 725. As desired, the foam core may be routed out around the perimeter of the panel to produce recesses relative to the composite skins at the perimeter of the panel. As discussed below, these recesses may be filled with composite plates configured for different purposes. The roof panel 705 includes a foam core 730, an outer composite skin 735, an inner composite skin 740, and an end composite skin 745. The outer composite skin 735 is textured to resemble roof tiles.

Fig. 8 illustrates connection of the wall panel 700 to a foundation 750 of the building 710. Initially, a composite base plate 805 is secured to the foundation 750 by screws 810 positioned at appropriate intervals along the length of the base plate 805. Next, a composite fusing material, such as a fusion monomer or other adhesive, is applied in a bead along side surfaces 815 of the base plate. Finally, the bottom 820 of the panel 700, where the foam is recessed, is placed over a composite base plate 805 with the composite skins 720 and 725 saddling the base plate 805 so that the fusing material chemically fuses the composite panel skins to the base plate. If desired, screws 825 may be used to further secure the composite skin 725 to the base plate 805.

As shown in Fig. 9, the roof panel 705 may be attached to the wall panel 700 in a similar manner. First, a composite top plate 900 is attached to the composite skin 740 of the roof panel using a fusion monomer or similar material to chemically fuse the pieces together. Next, a fusion monomer is applied along the inside surfaces of the composite skins 720 and 725 at the top 905 of the wall panel 700. The roof panel is then attached to the wall panel by placing the composite top plate 900 into the open top 905 of the wall panel so that the fusion monomer chemically fuses the top plate 900 to the skins 720 and 725. If desired, screws 910 may be used to further secure the composite skin 725 to the base plate 805.

Fig. 10 illustrates connection of an adjacent wall panel 1000 to the wall panel 700. Before attaching the wall panel 700 to the foundation, a composite connection spline 1005 is attached to what will be the vertical end of the wall panel 700 by applying the fusion monomer along the inside edges of the panel skins 720, 725 and then placing the connection spline into the recessed area between the skins. The panel 1000 then is attached to the panel 700 by applying the fusion monomer to the inside surfaces of the panel skins 720, 725 of the panel 700 and sliding the inside surfaces over the connection spline 1005. Fig. 11 illustrates connection of a corner wall panel 1100 to the wall panel 700. First, a vertical connection plate 1105 is secured between the skins 720, 725 of the wall panel 700 using a fusion monomer as discussed above. The vertical connection plate 1105 is similar to the composite connection spline 1005.

However, unlike the composite connection spline 1105, the vertical connection plate does not extend substantially beyond the ends of the skins 720, 725. Next, the vertical connection plate is secured to the inner composite skin 1110 of the corner wall panel 1100 using the fusion monomer as discussed above. Lag screws 1115 are then used to further secure the corner wall panel 1100 to the wall panel 700. A corner cap 1120 then may be applied to cover the lag screws 1115 and enhance the appearance of the corner.

Fig. 12 illustrates attachment of a truss 1200 or other structural member to the top of the wall panel 700. First, a composite top plate 1200 is secured in the top of the wall panel 700 using the fusion monomer to bond the plate to the skins 720, 725 of the wall panel 700. Next, a truss 1205 is placed in position at the top of the wall panel 700. Following this, a top portion 1210 of a metal connection clip 1215 is attached to the side of the truss member with nails or screws 1220. A bottom portion 1225 of the connection clip then is attached to the top of the panel 700 by driving a screw 1230 through the skin 725 and into the composite top plate 1200 of the panel .

As shown in Figs. 13-16, the panels also may be used to construct a wall or fence. As shown in Figs. 13 and 14, a perimeter wall 1400 may be formed by driving corkscrew foundation pieces 1405 into the ground at appropriate places. Steel posts 1410 are then connected to steel base plates 1415 of the foundation pieces 1405 using welds or bolts. For example, square posts having sides that are four inches wide may be welded to the steel base plates. Steel connection plates 1420 are attached to each post 1410. For example, three connection plates may be welded to each post, with one plate at the bottom of the post, one plate at the top of the post, and one plate in the middle of the post. Fence panels 1425 then are positioned with their ends on top of the steel base plates and against the steel connection plates. Bolts or screws 1430 are applied through the connection plates and the panel ends to secure the panels together.

As shown in Fig. 15, post facades 1500 made from composites or other materials may be attached to the fence panels 1425 by applying fusion monomer to interior edges 1505 of the facade and then driving screws 1510 through locations in the facade edges and into the panel skin. Similarly, as shown in Fig. 16, a panel cap 1600 may be connected by applying fusion monomer along the top exterior edges of the wall panels 1425 and then positioning the cap to saddle the panels 1425.

Composite corner and window/door treatments may be attached to the wall panels using a combination of fusion monomer and screws to enhance the aesthetic appearance of structures produced using the panels. For example, Figs. 17A and 17B illustrate a corner facade 1700 while Fig. 18 illustrates a window frame 1800.

Other embodiments are within the scope of the following claims. What is claimed is:

Claims

1. A building panel, comprising: a foam core; a composite structural skin adhered to a surface of the foam core.

2. The building panel of claim 1, wherein the composite structural skin is textured.

3. The building panel of claim 2, wherein the composite structural skin is textured to resemble stone.

4. The building panel of claim 2, wherein the composite structural skin is textured to resemble brick.

5. The building panel of claim 1, further comprising a colored layer adhered to a surface of the composite structural skin.

6. The building panel of claim 5, wherein the colored layer is colored to resemble marble.

7. The building panel of claim 1, further comprising a second composite structural skin adhered to a second surface of the foam core opposite the first surface of the foam core.

8. The building panel of claim 7, wherein the first composite structural skin is textured.

9. The building panel of claim 8, further comprising a colored layer adhered to a surface of the first composite structural skin.

10. The building panel of claim 1, further comprising a rigid frame embedded in the foam core.

11. The building panel of claim 10, wherein the rigid frame extends from a second surface of the foam core opposite the first surface of the foam core.

12. The building panel of claim 10, wherein the rigid frame comprises a metal frame.

13. The building panel of claim 1, wherein the composite structural skin comprises polyurethane.

14. The building panel of claim 13, wherein the foam core comprises expanded polyurethane.

15. A method of producing a building panel, comprising: spraying a composite material to form a composite structural skin; and spraying a foam material on the composite structural skin to form a foam core on the composite structural skin.

16. The method of claim 15, further comprising spraying a colored material to form a colored layer, wherein the step of spraying the composite material comprises spraying the composite material on the colored layer.

17. The method of claim 15, wherein the step of spraying the composite material comprises spraying the composite material into a textured mold to provide the composite structural skin with a textured surface.

18. The method of claim 15, further comprising positioning a rigid frame over the composite structural skin, wherein the step of spraying a foam material comprises spraying the foam material around the rigid frame so as to embed the rigid frame in the foam material.

19. The building panel of claim 1, wherein the composite material comprises polyurethane.