Joiner panel system

Abstract

A composite panel system has a plurality of planar joiner panels joined along longitudinal side edges arranged to interlock when axial tensile and compressive forces are exerted in the plane of the joiner panels and when out-of-plane bending stresses are exerted on the joiner panels. In a method of forming the joiner panels, a phenolic resin core material is fed into a hopper and pushed out onto a moving conveyor formed by a layer of material that forms a bottom face skin. The core material is covered with an upper face skin and fed into a pultrusion die.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit under 35 U.S.C. § 119(e) of U.S. Provisional Patent Application No. 60/676,357, filed on Apr. 29, 2005, the disclosure of which is incorporated by reference herein.

This application is related to U.S. patent application Ser. No. 10/947,977, filed on Sep. 23, 2004, entitled Joiner Panel System, the disclosure of which is incorporated by reference herein.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

The work leading to this invention received support from the United States federal government under SBIR Grant, Contract No. N00024-0-C-4152. The federal government may have certain rights in this invention.

BACKGROUND OF THE INVENTION

Joiner panels are nonstructural partitions used to subdivide areas within a structure such as a building or ship. For example, joiner panels subdivide the area between major structural bulkheads of a ship into smaller public and private cabins, passageways and other spaces. While not part of the ship's primary structure, joiner panels are required to provide some level of structural performance, because items are frequently mounted to their faces. Therefore, the joiner panels must not only be able to statically support the weight of attached hardware, but also must be able to withstand shock loads associated with the attached equipment. Other important characteristics of joiner panels include corrosion resistance, puncture and impact damage resistance associated with routine encounters with people and their equipment, ability to repair or replace damaged sections, rodent proofing, and acceptable flame, smoke and toxicity performance. Weight and installed cost of the joiner panel system are also important parameters.

A conventional joiner panel system has three primary hardware components: a flat panel, a shoe or coaming at the bottom of the panel, and a curtain plate at the top of the panel. The panels are usually fabricated as either sandwich panels, made with two thin fiberglass, aluminum or steel face sheets surfacing a core of foam or honeycomb, or integrally-stiffened panels, usually welded from aluminum or steel.

The shoe or coaming is used to connect the bottom of the panel to the support surface, such as the deck of a ship. The shoe is typically made of two elongated pieces of steel. The upper edge of the larger piece is bent into a Z-section with its upper edge some distance, for example, at least 6 inches, above the support surface. A smaller piece is welded to the side of the Z-section, forming a U-shaped channel along the upper edge of the shoe. The lower end of the joiner panel sits in the U-shaped channel of the shoe. Commonly, the joiner panel is attached to the shoe with occasional fasteners through both sides of the U-shaped channel and the panel. The lower edge of the larger piece of the shoe is sculpted to fit the contours of the supporting surface, such as an out-of-flat deck, and either welded continuously along the length of the shoe or spot welded.

The curtain plate provides the overhead connection for the upper edge of the joiner panel. A downwardly-opening U-shaped channel is formed along the lower edge of the curtain plate. In applications subject to movements, such as on a ship, the upper edge of the joiner panel can slide vertically in the U-shaped channel.

SUMMARY OF THE INVENTION

A composite panel system according to the present invention includes a plurality of planar joiner panels, each joiner panel comprising two planar faces, a top edge, a bottom edge, and two longitudinal side edges. The longitudinal side edges are arranged to interlock when axial tensile and compressive forces are exerted in the plane of the joiner panels and when out-of-plane bending stresses are exerted on the joiner panels.

A cover may be disposed over the joint between adjacent interlocked joiner panels. A structural load bearing beam may be embedded longitudinally within the joiner panels. A longitudinally extending groove may be arranged over the reinforcing beam portion or the cover of the joiner panels. The groove indicates where other items, such as cabinetry can be mounted to the joiner panels.

In a method of producing the joiner panels as a sandwich structure having a core covered with face skins, a core material comprising a phenolic resin mixture is fed into a hopper. The core material is pushed out of the hopper onto a moving conveyor formed of a layer of material to form the bottom face skin. A layer of material to form the top face skin is laid over the core material. The core material and covering face skins are fed into a pultrusion die.

DESCRIPTION OF THE DRAWINGS

The invention will be more fully understood by reference to the following detailed description when considered in conjunction with the accompanying drawings, in which:

FIG. 1 illustrates a joiner panel system of the present invention;

FIG. 2 is a cross sectional view through two interlocked joiner panels of FIG. 1;

FIG. 3 is an isometric view of the two interlocked joiner panels of FIG. 2;

FIG. 4 is an isometric view of a reinforcing beam in a joiner panel;

FIG. 5A is an isometric view of an embodiment of a composite material shoe according to the present invention;

FIG. 5B is an isometric view of a further embodiment of a composite material shoe according to the present invention;

FIG. 6 is an isometric view of an embodiment of an extruded metal shoe according to the present invention;

FIG. 7 is an isometric view of an embodiment of a feed system for the core material according to the present invention;

FIG. 8 is an isometric view of the bottom of the feed system of FIG. 7;

FIG. 9 is a partial view of the feed system of FIG. 7 illustrating adjustable hopper walls;

FIG. 10 is a front view of the feed system of FIG. 7;

FIG. 11 is a schematic view of a pultrusion process incorporating the feed system of FIG. 7;

FIG. 12 is an isometric view of the first roller of FIG. 11;

FIG. 13 is an isometric view of the second roller of FIG. 11;

FIG. 14 is an isometric view of a further embodiment of a feed system incorporating vertical augers according to the present invention;

FIG. 15 is an isometric view of a still further embodiment of a feed system incorporating vertical augers;

FIG. 16 is an isometric view of a still further embodiment of a feed system incorporating vertical augers;

FIG. 17 is an isometric view of a still further embodiment of a feed system according to the present invention;

FIG. 18 is an isometric view of a still further embodiment of a feed system incorporating a horizontal pusher mechanism according to the present invention;

FIG. 19 is an isometric view of a still further embodiment of a feed system incorporating a horizontal auger according to the present invention;

FIG. 20 is an isometric view of the feed system of FIG. 19 without a narrowing neck region;

FIG. 21 is an isometric illustration of a corner joint; and

FIG. 22 is an isometric illustration of a flexible angled joint.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 illustrates a joiner panel system of the present invention. The system includes a joiner panel 12 attached at its lower edge to a deck 14 by a coaming or shoe 16 and attached at its upper edge to a curtain plate 18. The curtain plate is formed from a number of curtain plate sections 18a, 18b, 18c that have been cut to fit around overhead obstructions, such as pipes 20a, 20b, 20c. A joint section 22 is provided to join the upper edge of the joiner panel to the curtain plate.

The joiner panel 12 can be formed in any width, for example, from one foot wide to twelve feet wide. Multiple joiner panels are joined together along their vertical edges 30 to achieve the desired length of wall. Referring to FIGS. 2 and 3, the longitudinal vertical edges of the panels are formed with an interlocking joint that increases mechanical locking forces with axial and out-of-plane loading. The joint includes a flange having a lip on each panel's longitudinal edge. The lips interlock in the assembled configuration. Rounded faces 46 allow the lips to snap together during assembly.

The lips include opposed faces 48, preferably at a small angle to a transverse plane through the joint, that abut when the joint is subjected to axial tensile loading. In this manner, the joint mechanically interlocks under tensile loading, rather than pulls apart. In compression, faces 52 of the flanges and angled faces 54 of the lips abut, again mechanically locking the joint together. Similarly, under bending, various ones of the faces 48, 52, 54 abut and the joint mechanically locks together rather than shears apart. Assembly of the panels is also improved, because one person working on one side of the joiner panel bulkhead can assemble the panels.

The panel is preferably formed of a core material covered with face skins. The core can be any suitable material. In one preferred embodiment, the core material is a phenolic resin syntactic foam. The face skins may be formed of any suitable material, such as glass or carbon fibers in a suitable resin material. A fiberglass material wet out with a suitable resin provides good mechanical properties and reduced weight. Preferably, the same resin used for the foam core, a phenolic resin, is used to wet out the face skins. Other materials, such as stainless steel, can, however, be used for the face skins, depending on the application. The flange and lip of the joint are preferably made from the same reinforcing resin and matrix material as the face skins. The panels can be readily formed with the longitudinal edge configuration by a pultrusion process. Alternatively, any other suitable process to from the panels may be used.

A cover 60 is provided over the joint to further limit out-of-plane movement. The cover includes tabs that snap into complementary recesses on adjacent joiner panels. The cover is preferably formed of a same or similar composite material as the panels.

In one embodiment, the joiner panel incorporates a structural load bearing beam 64, formed of, for example, glass or carbon fibers. See FIG. 4. The beams are located at suitable intervals, such as every twelve inches. A pultrusion process allows ready incorporation of the beam within the panel.

A groove 72 may be formed along the joint and/or along the reinforcing beams. The groove provides an indication of where items, such as cabinetry, should be attached to the panels, for best structural support.

FIG. 21 illustrates an embodiment of a joint for two joiner panels at right angles. FIG. 22 illustrates an embodiment of a flexible joint for joining two joiner panels at variable angles.

An embodiment of a deck shoe 16 is illustrated in FIG. 5A. The deck shoe extends in a longitudinal direction for any desired length. The deck shoe includes two upstanding legs or webs 82 connected by a floor plate 83 that form a recess 84 therebetween for seating the bottom edge of the joiner panels. The webs are comprised of upper web sections 86 and lower web sections 88. The lower web sections are thicker toward the interior of the recess than the upper web sections, providing a pair of shoulders. The panel fits between the upper web sections and rests on the shoulders of the lower web sections. The shoe can be connected to a deck in any suitable manner, such as by bolts or rivets through the floor plate 83 or by adhesive.

The deck shoe is preferably formed of a composite material, such as layers of E glass fabric impregnated with a suitable resin. The layers of fabric can be laid at varying angles to provide strength in different directions. For example, one suitable orientation is a layer at 0°, a layer at +45°, a layer at −45°, and a layer at 90°. The upstanding legs can be of any suitable height. In one embodiment, the overall leg height is 2 inches, and the gap between the upper leg sections allows for insertion of a panel that is 0.75 inch thick. The thickness of the upper leg sections is 0.06 inch, and the thickness of the lower leg sections is 0.13 inch.

Another embodiment of a composite material deck shoe is illustrated in FIG. 5B. The upstanding webs 82 include inwardly facing lips 94 on which the joiner panel is supported.

FIG. 6 illustrates an embodiment of a deck shoe formed by an extrusion of a suitable metal such as aluminum. The shoe includes upstanding webs 102 that form a recess 104. A plate 106 is attached to the deck in any suitable manner, such as with bolts or rivets.

A panel suitable for the joiner panel system of the present invention is fabricated from a phenolic resin syntactic foam core covered with face skins on the upper and lower faces. See U.S. patent application Ser. No. 10/947,977. Phenolic resins provide good fire, smoke and toxicity properties. They are, however, more brittle than other resins, and thus, in prior art panels, have inferior mechanical properties. The present invention provides a panel incorporating a phenolic resin matrix material for the panel core having improved mechanical properties, including greater strength and ductility.

The syntactic foam core material is made from a mixture of a phenolic resin foam, hollow micro-balloons, and fibers. Borden Durite SC1008 laminating phenolic resin is a suitable resin to provide good fire performance. Other suitable commercially available phenolic resins include GP 5236 from Georgia-Pacific and Shea Technologies Fireban room temperature cure phenolic resin. Other additives can be included in the mixture for other purposes. For example, carbon nanotubes can be added to enhance static dissipation. Fire resistant additives can be incorporated to increase fire resistance.

The phenolic resin is selected for good fire, smoke, and toxicity properties. Phenolic resins typically are available commercially with a catalyst system. The catalyst system can affect the acidity or pH of the resin, which in turn can affect the other components of the core, such as the glass fibers and glass micro-balloons. The Dow Accelacure resin system has been found to be suitable and provides an improvement in strength of the cured core material. It will be appreciated that other phenolic resins may be suitable for other core mixtures that use different additives for the mechanical properties.

The foam porosity provides increased surface area to aid in face sheet adhesion. The face skins may be formed of any suitable material, such as glass or carbon fibers in a suitable resin material. A fiberglass material wet out with a suitable resin provides good mechanical properties and reduced weight. Preferably, the same resin used for the form core, a phenolic resin, is used to wet out the face skins. Other materials, such as stainless steel, can, however, be used for the face skins, depending on the application. For example, stainless steel may be a preferred choice in areas, such as kitchens, where a sterile environment is important.

The phenolic resin core material used for the panel has traditionally been difficult to form into panels by a pultrusion process. The present invention provides a feed system for a pultrusion process that allows the phenolic resin to be formed into a panel.

In one embodiment, referring to FIGS. 7-10, the uncured core material, the phenolic resin mixture discussed above, is placed into a hopper 202 and pushed through a mesh 204, such as a wire mesh grate, to achieve a desired density, which varies depending on the application. The core material is then wrapped in wet-out reinforcing fabric, such as glass fabric, and pulled through a die. See FIG. 11.

The feed system pushes the core material through the mesh, for example, using a piston mechanism 206 (illustrated schematically in FIG. 10). A scraping mechanism 208 can also be included to scrape the core material off the mesh. For example, a wire 210 actuated by a linkage system 212 moves along the bottom of the grate, scraping the core material off as it travels.

The hopper includes four side walls 214 formed in a generally rectangular shape. The bottom of the hopper is comprised of the mesh grate 204. A cover 216 is provided that includes a center plate 218 that extends downwardly into the interior of the hopper to about one-half to two-thirds of the hopper depth. The center plate divides the upper portion of the hopper into two chambers. One side wall is hinged 220 to allow the core material to be loaded into the hopper. One or more hopper walls can be adjustable to accommodate panels of various widths. In the embodiment shown in FIG. 9, the wall 214 can be located at one of three locations, indicated by the three columns of bolts 222. The hopper walls can be heated if desired, to preheat the core material prior to entry into the heated pultrusion die for complete curing.

A pusher mechanism is located at the upper end of the hopper. The pusher mechanism preferably includes two pistons 206 located on either side of the center plate. (See FIG. 10.) The pistons preferably move in opposite directions, so that, as one piston is moving up, the other piston is moving down. In this manner, pressure is always placed down on the core material, and there is no time when core material is not exiting the hopper through the mesh. It will be appreciated that the pusher mechanism can take other forms.

As noted above, the scraping mechanism 208 includes a wire 210 that extends from one side of the mesh 204 to the other below the mesh. The linkage mechanism 212 includes levers 230 pivoted at their upper ends to opposed hopper walls. The ends of the wires are attached to the lower ends of the levers. As the levers are pivoted, manually or automatically, the wire travels along beneath the mesh, scraping material off and allowing it to drop down. It will be appreciated that the scraping mechanism can take other forms.

After the core material is forced through the mesh, it drops onto one or more layers of fabric 240 (e.g., glass) that will form one of the face skins upon curing. See FIG. 11. The fabric forms a conveyor and moves the core material along into a series of rollers 242, 244. The rollers compact the core material before it is wrapped with an upper layer of wet-out reinforcing fabric 246 (e.g., glass) and enters the die 248. In the embodiment illustrated, the first roller 242 (FIG. 12) compacts the core, and the second roller 244 (FIG. 13) forms the core into a desired shape. Following compaction and shaping, the core is wrapped with wet-out glass fabric, and enters the heated die for curing. The glass fabric is wet out with a suitable resin, preferably a phenolic resin. The glass fabric can be fed onto all surfaces if desired, such as all four sides in a core having a rectangular cross-section and/or longitudinal edge joint details. The wet-out glass fabric forms the face skins that are co-cured with the core during the pultrusion process to ensure a good bond between the face skins and the core, rather than adhering face skins to precured cores. By curing the core and face skins together, there is no hard or discrete boundary between the core and the face skins. Rather, the resin matrix forms a continuum from the core to the face skins and good bonding results. Phenolic resins typically begin cross linking at temperatures about 220° F. and reach final cure at about 400° F. The die length and pulling speed through the die can be selected to achieve a sufficient temperature and dwell time to ensure that the resin fully cures. Similarly, the core can be preheated prior to entering the die. A continuous panel exits the pultrusion die and is cut into smaller panels of any desired length.

In another embodiment, the feed system for the core material comprises an auger assembly 250 to assist in pushing the core material through a hopper 252. FIG. 14 illustrates a mechanism in which vertically arranged augers pass through a plate 254 forming the bottom floor of a hopper. The core material is pushed through openings in the plate onto a fabric conveyor 256, as described above.

FIG. 15 illustrates vertically arranged augers 260 and a pressure plate 262 operable to push down on the top surface of the core material in a hopper 264. The augers move downwardly with the pressure plate.

FIG. 16 illustrates a hopper 270 having a narrowed mouth region 272 with vertically arranged augers 274 that extend to the top of the mouth region. The augers are arranged in line perpendicular to the direction of pultrusion, indicated by arrow 276. The augers distribute the uncured core material across the width the hopper, which is the width of the panel. The hopper includes a funnel section 278 above the narrower mouth section. The augers extend within the funnel section to the top of the mouth section, to prevent compression of the material in the mouth section. The axes of the augers are spaced close together but without touching to eliminate any dead zones lacking movement of core material across the width of the panel.

FIG. 17 illustrates a hopper 280 with a constant cross section in which pre-made loaves 282 of uncured core material are placed. The loaves are formed to have the proper uncured density to achieve the desired post cured density.

In another embodiment, a hopper 290 with a constant cross section distributes core material onto a smooth horizontal surface 292. See FIG. 18. A thrusting device 294, such as a pneumatic cylinder, provides horizontal movement of the core material onto a moving fabric (not shown in FIG. 18). A vibration device 296 can be included to assist movement of the core downwardly within the hopper. The vibration device preferably has a low frequency and high amplitude and is attached to one or more of the hopper walls in any suitable location. Alternatively or in addition, a pressure plate 298 can be included to assist movement of the core material downwardly within the hopper.

The embodiments utilizing an auger assembly tend to compress the core material to a greater density, and so are less preferred for many sandwich panel applications. However, they can be used when a greater density is desirable.

FIG. 19 illustrates a further feed system incorporating a hopper 302 and a horizontal auger 304 at the bottom of the hopper. The auger pushes the core material into a feed pipe 306 that transitions via a narrower compression 308 to a mouth 310 or core shape changer having the desired shape of the core material. The interior of the feed pipe and mouth can be coated with a friction-reducing coating, such as a smooth gel coat surface, to ease passage of the core material therethrough. The auger blades and shaft can be similarly coated with a smooth gel coat. The hopper can also be similarly coated, for example with a PTFE tape. Upon exiting the mouth, the core material exits onto one or more layers of the face skin material moving toward the pultrusion die, as described above. FIG. 20 illustrates a feed system similar to FIG. 19 without the mouth 310.

The invention is not to be limited by what has been particularly shown and described, except as indicated by the appended claims.

Claims

1. A composite panel system comprising:

a plurality of planar joiner panels, each joiner panel comprising two planar faces, a top edge, a bottom edge, and two longitudinal side edges;

wherein the longitudinal side edges comprise longitudinally extending faces arranged to abut opposing longitudinally extending faces of an adjacent longitudinal side edge of an adjacent interlocked joiner panel when axial tensile and compressive forces are exerted in the plane of the joiner panels and to abut when out-of-plane bending stresses are exerted on the joiner panels.

2. The system of claim 1, wherein each longitudinal side edge comprises a longitudinally extending flange, the flange including a longitudinally extending lip, the flange and the lip forming the longitudinally extending faces of the side edge.

3. The system of claim 1, further comprising a cover disposed over a joint between adjacent interlocked joiner panels.

4. The system of claim 3, wherein the cover comprises a plate, tabs extending from the plate, and the adjacent interlocked joiner panels include recesses therein to receive the tabs.

5. The system of claim 3, wherein the cover comprises a longitudinally extending groove therein arranged over a reinforcing beam portion of the joiner panels.

6. The system of claim 1, further comprising a structural load bearing beam embedded and extending longitudinally within the joiner panels.

7. The system of claim 6, wherein the load bearing beam is comprises of a reinforcing fiber fabric embedded in a matrix material.

8. The system of claim 6, wherein the joiner panels comprise a longitudinally extending groove therein arranged over the load bearing beam.

9. The system of claim 1, wherein the joiner panels comprise a core material faced with skins on the opposed planar sides.

10. The system of claim 9, wherein the core material includes a phenolic resin syntactic foam.

11. The system of claim 9, wherein the face skins comprise a reinforcing fiber fabric embedded in a phenolic resin matrix.

12. The system of claim 11, wherein the reinforcing fiber fabric is comprised of glass.

13. The system of claim 11, wherein the reinforcing fiber fabric is comprised of carbon.

14. The system of claim 9, further comprising a fire resistant additive in the core material.

15. The system of claim 1, further comprising a shoe attachable to a support surface, the shoe formed of a composite material, comprising a pair of webs, a recess between the webs forming a seat for the bottom edge of the plurality of joiner panels.

16. The system of claim 15, wherein the webs include lower webs having an increased thickness forming a pair of shoulders, the bottom edge of the plurality of joiner panels supported on the pair of shoulders.

17. The system of claim 15, wherein the webs include inwardly facing lips, the bottom edge of the plurality of joiner panels supported on the inwardly facing lips.

18. The system of claim 15, wherein the shoe is formed of a composite material.

19. A method of producing a composite panel comprising a sandwich structure having a core having opposed surfaces and face skins on the opposed surfaces, comprising:

feeding a core material comprising a phenolic resin into a hopper;

pushing the core material out the hopper onto a moving conveyor, the moving conveyor comprising a layer of material to form a bottom face skin;

applying a layer of material to form a top face skin over the core material; and

feeding the core material and covering face skins into a pultrusion die.

20. The method of claim 19, wherein the core material is pushed through the hopper vertically with a pusher mechanism.

21. The method of claim 19, wherein the core material is pushed through a mesh at the bottom of the hopper.

22. The method of claim 21, wherein the core material is scraped off the mesh with a scraper mechanism arranged below the mesh.

23. The method of claim 19, wherein the hopper is vibrated.

24. The method of claim 19, wherein the hopper is heated.

25. The method of claim 19, wherein the core material is pushed through the hopper vertically with an auger mechanism.

26. The method of claim 19, wherein the core material is pushed through the hopper horizontally.

27. The method of claim 19, wherein the core material is compressed and shaped after exiting the hopper and before entering the pultrusion die.