WO2012075169A1

WO2012075169A1 - Acrylic resin composite architectural panel and system for joining of panels

Info

Publication number: WO2012075169A1
Application number: PCT/US2011/062684
Authority: WO
Inventors: Ghislain Beauregard
Original assignee: Arcoplast, Inc.
Priority date: 2010-11-30
Filing date: 2011-11-30
Publication date: 2012-06-07

Abstract

A wall and ceiling panel for use in barrier designs used in high containment facilities. The panel is comprised of a homogeneous reinforced resin core with an exterior gel coating. The homogeneity of the core ensures long-term impermeability and avoids delamination of layer problems faced by panels comprising an interior core of different material. A system for joining the panels includes a spline element designed to ensure planar alignment of the panel surfaces.

Description

ACRYLIC RESIN COMPOSITE ARCHITECTURAL PANEL AND SYSTEM

FOR JOINING OF PANELS

RELATED APPLICATIONS

[0001] The present patent application is related to and claims priority benefit to an earlier-filed provisional patent application titled ACRYLIC RESIN COMPOSITE ARCHITECTURAL PANEL, Serial No. 61/418,301 filed November 30, 2010. The identified earlier-filed application is hereby incorporated by reference into the present application as though fully set forth herein.

FIELD OF THE INVENTION

[0002] The present invention relates to wall and ceiling panel systems. In particular, the wall and ceiling panel systems of the present invention relate to barrier designs used in high containment facilities such as laboratories.

BACKGROUND OF THE INVENTION

[0003] The biosafety industry strives to develop standards and facilities that provide mechanisms and practices to lower the risk of unintentional infection from pathogens or biological materials in the laboratory or environmental release of those materials from the laboratory. The Centers for Disease Control and Prevention (CDC) and the National Institutes of Health (NIH) have established levels of biosafety (BSL-1 to BSL-4) to guide laboratory researchers in the safe handling of biological agents. Generally, the term "high containment" refers to the higher levels of biosafety wherein enhanced protective measures are employed.

[0004] While all structural and operational aspects of a laboratory facility are considered in the overall approach in ensuring high containment protocol, the walls and ceilings of a facility are one of the most dynamic areas of laboratory design. Walls and ceilings provide the main barrier in preventing the escape of biological agents from a lab facility. There presently exist a number of barrier construction systems, including gypsum board panels, concrete blocks and stainless steel panels. Each systems offers certain advantages but also suffer from disadvantages. The pursuit of the advantageous features offered by gypsum board panels, such as lower cost, lighter weight, ease of transporting materials to the lab site, is offset tremendously by their susceptibility to deterioration or mechanical damage. A bacterial agent can quite easily pass through a hole or other imperfection in the gypsum board thereby resulting in immediate failure of the high containment purpose. Furthermore, pressure decay tests have demonstrated that a negative pressure exceeding 0.5 inches water column will crack flat and corner joints allowing air and foreign agents to seep and contaminate exterior environments. BSL-3 and BSL-4 level environments must withstand a negative pressure environment up to 4 inches water column.

[0005] Concrete blocks are commonly used in barrier design and provide certain benefits in their durability and structural stability. However, the porous surface of concrete blocks unfortunately provides a haven for bacterial agents which can ultimately permeate through the concrete block and escape the lab facility. Accordingly, if concrete blocks are used in the barrier design, they must be treated with additional sealants. Concrete block walls add substantial weight to a facility while reducing its useable space. It limits the routing of utilities to the outside of a barrier (causing conduit and pipes to be exposed within the envelope), and severely decreases a facility's overall flexibility. The strength of concrete blocks, however, provides significant usefulness due to their impact-resistant qualities, offering definite advantages in that regard over gypsum board construction. Nonetheless concrete block, with its numerous joints filled with a cementeous grout, is extremely unreliable and is generally the most common failure in primary barrier function. [0006] Stainless steel panels, while having the advantage of a surface produced under exacting conditions, lacks the design flexibility of other methods. This can increase the complexity and cost of a facility. Continuous welding of stainless steel joints is an impractical task. While airtight, they are not seamless and will produce problem areas for potential contamination while being rather unsightly. Stainless steel also creates a drab environment by soaking up a room's candlelight, and it needs regular buffing and polishing to keep its finish from becoming dull. There are no means of reasonable repair, with dents and scratches becoming part of the decor - creating a surface more reminiscent of a hail-damaged car hood than a high performance barrier. The harsh disinfecting solutions used in the facilities may also adversely react with steel, furthering the lack of professional appeal and potentially causing irreparable damage to the surface. [0007] Recently, the use of fiberglass reinforced polymer panel systems has been introduced as a high containment barrier construction alternative. Such panels comprise a cement core sandwiched between layers of fiberglass impregnated resign. A gel coat finish is applied to the exterior of the fiberglass impregnated resin panel. This construction provides a panel of substantial strength conferred by the cement core, a high degree of impermeability to moisture conferred by the fiberglass/resin layer, and a durable and impermeable layer conferred by the gel coat exterior. The panel can be manufactured offsite in uniform sections and transported to the lab site for easy erection. The panels are suitable for initial construction or may be adapted for retrofitting existing lab facilities.

[0008] The fiberglass reinforced polymer panel system, however, is not without its drawbacks. Practically all materials are susceptible to some degree of permeability. While the gel coat and fiberglass impregnated resin layers offer substantial impermeability qualities, those layers are subject to delamination from the cement core layer. When the interior cement core is exposed through delamination, biological agents may filter into the porous cement core causing contamination which can spread outside of the contained area.

SUMMARY OF THE INVENTION

[0009] The present invention provides a high containment barrier system comprising panels comprised of a homogeneous fiberglass reinforced resin core. The homogeneity of the panel's core provides manufacturing advantages because problems faced in bonding different layers during the molding process can be avoided. The homogeneity of the core also ensures long-term impermeability which could otherwise be adversely affected by delamination of layers or damage to the surface of the panel. The solid core nature of the panel further confers a greater rigidity to the panel to contribute to the overall stability of the barrier structure. Also, by omitting a heavy internal core material, such as cement board, the panel is made lighter in weight while maintaining its strength and rigidity.

[0010] The inventive high containment barrier system provides for economies on the manufacturing and installation process. Because the homogeneous core does not require an interior substrate material sandwiched by the fiberglass reinforced resin material, the molding process for producing the panels need not be dictated by dimensional requirements of a substrate core material. This avoids potential waste as substrate core materials, such as cement board, comes supplied in standard sheet sizes whose dimensions may exceed the panel size requirements. Another advantage of the homogeneous core is that the panels may be manufactured within tight tolerances without disrupting the structural integrity of the panel. This permits a heightened degree of uniformity of joined panels when erecting the barrier system and creates a flat, even wall surface at areas where panels are joined together. Furthermore, the homogenous core allows increased loading of aluminum trihydrate (ATH) now made possible with nano technologies resulting in substantial increase in smoke development index, critical in high people and animal occupancies, such as hospitals, universities and laboratory environments.

[0011] The homogeneous core panel of the present invention is used in providing a high containment barrier system. The high containment barrier system incorporates modular panels to allow for added design versatility, performance and ease. The inventive panels can be used with traditional steel studs and furring channels, or attached to existing walls and ceilings. The panels present a viable option for retrofit applications as their substrate can be specified to fit the dimensions of an existing wall or ceiling system for a direct-fit replacement. Alternatively, the high containment barrier system of the present invention can be a self- supported shell within a larger facility. The freestanding partitions and load-bearing panels can be engineered to meet load requirements as well as interface with lightweight or heavy duty structural members to facilitate a more effective build.

[0012] Another embodiment of the present invention comprises a system for joining the homogeneous core panels using a spline element that guides edges of the panels into alignment such that the inward facing surface of the erected wall or ceiling maintains an even surface and avoids an irregular surface at the seams where the panels are joined. The spline element helps guide the joined panels together in even alignment and provides a snug wedging fit to minimize play in the joint that may otherwise cause separation of the joined panels. [0013] The present teachings therefore include homogeneous core fiberglass reinforced resin panels for use in a high containment barrier system.

[0014] The present teachings include methods for manufacturing homogeneous core fiberglass resin panels. [0015] In accordance with a further aspect, the present teachings include a high containment barrier system comprised of homogeneous core fiberglass resin panels.

[0016] In accordance with yet another aspect, the present teachings include a spline system for joining together panels comprised of the homogeneous core fiberglass reinforced resin. [0017] In accordance with yet another aspect, the present teachings include methods for erecting a high containment barrier system.

[0018] These and other features of the present invention are described in greater detail below in the section titled DETAILED DESCRIPTION OF THE INVENTION.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

[0019] The present invention is described herein with reference to the following drawing figures, with greater emphasis being placed on clarity rather than scale:

[0020] FIG. 1 shows a cross-sectional view of a prior art fiberglass panel having a cement core.

[0021] FIG. 2 shows a cross-sectional view of a prior art spline joining system for joining adjacent reinforced fiberglass resin panels.

[0022] FIG. 3 shows a cross section of a homogeneous fiberglass reinforced resin core panel of the present invention.

[0023] FIG. 4 is a cross sectional view of the spline element of the present invention. [0024] FIG. 5 is a cross-sectional view in side elevation of the spline joining system of the present invention. [0025] FIG. 6 is another cross-sectional view in side elevation of the spline joining system of the present invention.

[0026] FIG. 7 is yet another cross-sectional view in side elevation of the spline joining system of the present invention. [0027] FIG. 8 is a view in side elevation of a first panel section being joined with a second panel section with the spline joining system.

DETAILED DESCRIPTION OF THE INVENTION

[0028] A preferred embodiment of a panel having a homogeneous fiberglass reinforced resin core of the present invention comprises a composition of 20% fiberglass strands, 40% acrylic resin and 40% aluminum trihydrate (ATH) filler. The acrylic resin best suited for the panel is the modified acrylic resin produced by Ashland Performance Materials under the MODAR® brand product number 814 A. A gel coat is applied to the exterior of the panel, the gel coat preferably comprising that manufactured by Ashland under product number WG-SRT-4323-h. The gel coat is non-shedding and nonarticulating, and is formulated to meet the levels of stain and chemical resistance required by ANSI Z124.1.2 standards.

[0029] The finished panel optimally has a thickness of 0.375 inches. The panel may also have a thickness in the range of between 0.125 inches to 1 inch. The panel can be supplied in sheets of any dimension and can be molded to specified dimensions or cut to specified dimensions after molding or at the actual job site.

[0030] The advantages of the panel of the present invention can best be appreciated when compared to a prior art panel 10 comprised of a reinforced fiberglass resin surface 12 having a cement core 14 such as shown in FIG. 1. To enable joining of adjacent panels to form a wall or ceiling, the edge 16 of panel 10 must be configured to receive a spline element 18 as shown in FIG. 2. So that spline element 18 may be received in edge 16 of panel 10, a kerf 20 must be configured into edge 16. Because it is generally not feasible to cut a kerf into the cement core 14, an insert 22 must be placed in the edge 16. The insert 22 is itself configured to have kerf 20. However, the placement of insert 22 into the edge 16 leaves that portion of panel 10 without the structural integrity present throughout the rest of panel 10 where the cement core 14 is sandwiched between the reinforced fiberglass resin surfaces 12. As such, it leaves multiple areas in the panels at the joint area subject to weakness and delamination that may adversely affect the otherwise impermeable advantages of the panel system. Specifically, the areas of adhesion between the insert 22 and the reinforced fiberglass resin surfaces 12, and also between the insert 22 and the cement core 14, are subject to delamination and disruption. Given that the joint area is the portion of the wall and ceiling system that becomes most susceptible to breach, and ultimate failure, of the high containment enclosure, the prior art panel comprised of a cement core suffers from this potential for breakdown.

[0031] A preferred embodiment of the present invention comprises a system for joining together panel edges of a homogeneous fiberglass reinforced resin core to create a continuous wall or ceiling surface of a high containment enclosure where the structural integrity of the panels at the joint area can be maintained while consistently placing the panel surfaces in a true plane. A panel 24 is formed of a solid core homogeneous fiberglass reinforced resin 26 as shown in FIG. 3. Panel 24 is cut to an appropriate dimension as one of several panels that will collectively make up the wall or ceiling section. FIG. 7 generally shows the spline system 28 by which the panels are joined together and attached to the surface substrate. As shown in FIG. 7, the panels may be secured to studs 30. Adjacent panels are joined together at their edges by spline element 32 as seen in FIG. 4 and FIG. 8. Spline element 32, which may be of aluminum, comprises an elongated leg 34 which is secured by screws or other appropriate fastener to stud 30. Spline element 32 extends perpendicularly from elongated leg 34 to terminate in dog elements 36 and 38. Each of dog elements 36 and 38 extend laterally an equal distance and have a common distal flat surface 40. Each dog element has an angled surface 42 opposing the flat surface 40 to give the dog element a wedge shape.

[0032] An edge 44 of panel 24 is provided with kerf 46 for receiving dog element

36 of spline element 32 as shown in FIG. 5. Because the fiberglass reinforced resin core of panel 24 is homogeneous, it is relatively simple to rout out the kerf directly into the edge 44. The kerf walls optimally are flat. The tapered end of dog element 36 enables its ready insertion into kerf 46. The inner width dimension of kerf 46 is equal to or less than the thickest portion of the wedge shape of dog element 36 so that the panel 24 can be snugly pushed and held firmly on to dog element 36. The depth of the kerf must be greater than the lateral length of dog element 36 so that the panel may fully seat on the spline element. In similar fashion, panel 48 is provided with kerf 50 for receiving dog element 38 of spline element 32. FIG. 8 shows panel 24 inserted on to dog element 36 of the spline with panel 48 being prepared for insertion on to dog element 38. As seen in FIG. 6, the distal flat surface 40 of spline element 32 keeps the outer surface 52 of panel 24 evenly aligned with outer surface 54 of panel 48 as panel 48 is pushed into seating engagement on to dog element 38. The flat walls of the kerfs maintain even alignment with flat surface 40 to ensure alignment of the external surfaces of the adjoining panels. Accordingly, the external surfaces of panels 24 and 48 are urged into planar alignment as the respective kerfs of the panels are moved along the angled surfaces of the dog elements while the distal flat surface maintain planar alignment of the joined panels.

[0033] The panels can be provided with kerfs on both lateral edges so that multiple panels in succession may be joined with the spline system. In this method, successive panels are installed in a progressive row along a wall or other surface substrate. Before the first panel 24 of the row of panels to be installed on the surface substrate, the spline element 32 is attached to panel 24 by inserting dog element 36 into kerf 46. After spline element 32 is attached to panel 24, elongated leg 34 of spline element 32 is secured to stud 30 of the surface substrate. Once spline element 32 and panel 24 are secured to stud 30, dog element 38 is in position to receive panel 48 as shown in FIG. 8. Dog element 38 is received in kerf 50 of panel 48. The flat surface 40 of spline element 32 guides the exterior surfaces 52 and 54 of panels 24 and 48, respectively, into exact even planar alignment as panels 24 and 48 are pushed together onto dog elements 36 and 38 as shown in FIG. 6. The joint seam between panels 24 and 48 may be sealed with appropriate compounds to ensure against air, moisture and gas leakage.

[0034] The opposite edge of installed panel 48, which has its other edge joined to panel 24 and secured to stud 30, is similarly configured with a kerf for receiving the dog element of another spline element. After the dog element is inserted into the kerf of the opposite edge of panel 48, elongated leg 34 of the spline element is secured to the next stud in line along the wall. Once so secured, dog element 38 is in position to be received in the kerf of the edge of the next available panel. This process is repeated as necessary to install panels along a given section of wall. [0035] The system is readily adaptable to accommodate the placement of the panel joint system around obstructions or to custom fit into irregular shapes. The homogenous fiberglass reinforced resin core may be cut into an appropriate size on the job site and the kerfs can be cut into the edges using a router. Likewise, the spline element may be cut to a certain length to fit the particular size panel. If necessary, the spline element may extend only a partial distance along the joint line and the remaining gap filled with an appropriate joint-sealing compound.

[0036] A preferred embodiment of spline element 32 comprises elongated leg 34 being 1.404 inches long to sufficiently engage stud 30 or other appropriate base substrate on the wall or ceiling to which the panels are affixed. The spline element extends 0.10 inches perpendicularly from elongated leg 34 to terminate in dog elements 36 and 38. Each of dog elements 36 and 38 extend laterally 0.252 inches from the spline element axis. The distal end of each of dog elements 36 and 38 is 0.06 inches thick tapering upwards to a thickness of 0.10 inches at their proximal end to present an upper wedge shaped surface 42.

[0037] Steps for Molding Panel

[0038] Inspect mold surfaces before gel coat spray

[0039] Any imperfections shall be documented and scheduled for maintenance and repair when warranted [0040] Clean mold and polish before gel coat spray

[0041] Run quality control check on the gel coat time and delivery - verify temperature, humidity, cure time, spray time.

[0042] Run Quality Control check on the gel coat.

[0043] Verify spray nozzle and pressure to be at 60 lbs. [0044] Spray gel coat in perpendicular motion to the length of the mold with one pass. [0045] Gel coat spray is to be done 36" of the top of the mold the spray pattern should be 30" wide at the base (mold surface).

[0046] Spray gel coat in parallel spray pattern to the length of the mold.

[0047] Photo gel coat spray completed.

[0048] Last spray of gel coat is also done perpendicular to the mold.

[0049] The final gel coat mil thickness should be at 20 to 22 mils .51 to .56 mm wet, this should yield a final dry gel coat thickness of 14.5 to 17 mils .37 to .45 mm

[0050] The gel coat thickness to be monitored and measured with a metal gauge at 5 different locations on the mold for uniform spray thickness.

[0051] Clean thoroughly tools and empty line of residual material.

[0052] Curing time of gel coat should be minimum of 45 minutes and not to exceed 120 minutes.

[0053] Cure time of gel coat if left in mold 3 days will pre-release.

[0054] Spray thickness verified in 5 locations and should read at 20 mils wet.

[0055] Spray of mist of resin along edge of mold to ensure surface coverage.

[0056] Mist of resin is then rolled onto the gel coat back side - back and forth motion perpendicular to the length of the mold 6 mil thickness.

[0057] A second mist of resin is then sprayed on mold again perpendicular for a wet out total thickness of 25 mils for optimal surface finish.

[0058] Total resin mist to be checked in 5 different locations on the mold with a metal gauge for ensuring consistent mils thickness application - Completed panel surface make-up.

[0059] Resin mist of 25 mils to be allowed to thermo-set and dry for a period of

45 minutes - temperature cure should not exceed 120 F. [0060] Control: Heat Measurements obtain with an Infrared Thermometer.

[0061] Control: Barcol hardness obtains with a Barcol Tester - unit measure should not be less 30.

[0062] Structural panel make-up -When the layer of 25 mils of highly filled modar resin Chopped glass and resin mix is sprayed onto the mold (ration glass content 20 approx.) 18 being good and 25 being bad.

[0063] Chopped glass is sprayed in perpendicular back and forth motion (approx.

13 passes) to equal 35 mil thickness.

[0064] The chopped glass is then rolled out with 8" aluminum x 1" diameter rollers to compress glass onto the mold.

[0065] The two applicators with the aluminum rollers wet-out the glass to ensure flatness and good adhesion throughout.

[0066] Then two applicators apply with a paint brush and a wheel roller (pizza cutter) ensure the glass is well folded in the mold along the edges. [0067] In this first layer of chopped glass the mold is left out to cure approximately 1 to 1.5 hours at 70 degrees F at 45 relative humidity - this will result in a barcol hardness of 30 degrading to low 20 at the end of the mold (exothermic process) and resin is dry to the touch nonetheless.

[0068] Note : The barcol hardness of an identical part that was left overnight to cure resulted in a barcol of 30 to 40 maximum.

[0069] A digital thermometer is also herein used to gauge the panels exothermic process and progress which will guide the applicator in deciding the appropriate time for the second layer of glass/resin application.

[0070] Once cured in place the final panel make-up can be completed with continuous highly filled modar resin and glass matrix layers completed in the same fashion. [0071] The mist of resin is a 12 to 16 mils sprayed on the back side of the first chopped glass lay-out, this will ensure perfect bond strength for the laminates and will also prevent "chattering" or called moderate print.

[0072] The multiple layers of chopped glass to meet thickness requirements are applied again in a criss cross pattern perpendicular to the length of the mold.

[0073] The mold is then set aside for a full cure of 2 hours (240 minutes) at which time the panel's back side will be verified one last time to ensure full cure which will be determined by the Infrared Thermometer and Barcol Tester.

[0074] Control: Infrared Thermometer should read a temperature with exo therm completed (70 F).

[0075] Control: Barcol Tester should read a Barcol hardness of (38-45).

[0076] The panel having been fully tested for a full cure is then unmolded.

[0077] The unmolded fiberglass panel edges are then trimmed to remove excess glass and resin fibers. [0078] The fiberglass panel is then inspected for surface coloration.

[0079] Control: By means of a control panel that is kept refrigerated and visually compared to side by side.

[0080] The panels is also visually inspected for surface smoothness and imperfections. [0081] Control: An approved surface finished panel is used as a control panel to ensure the new molded part conforms to the required surface finish.

[0082] The panel is also inspected for physical properties.

[0083] Control: Inspect the solid glass/resin matrix to ensure full integration of the glass, resin and filler matrix and to detect any voids, resin starved areas and any voids that could potentially lead to delamination issues. [0084] The fiberglass panel is then set on cutting tables and cut to required length.

[0085] The fiberglass panel is then passed through a drum sander and sanded down to required mil thicknesses. [0086] Note: before deposing any panels face down, a foam sheet needs to be applied to the table to protect the panels from surface abrasions.

[0087] The panel is then turned face up and inspected a second time thoroughly.

[0088] On every production shift one random panel is chosen in which a 1 " cross section is cut out for quality control to verify laminate, thickness, bond strength, flatness, each sample to be inventoried for reference and kept for a period of 6 months.

[0089] The cut panels are then routed (grooved 90 thousands) on both panel edges for mechanical spline insertion which will be completed in the field.

[0090] Control: A shop drawing demonstrate the groove dimension and placement. [0091] Control: An aluminum spline is made available at the (grooving station) for quick reference to its fit and placement.

[0092] The routing is accomplished with heavy duty router ½" shank with a diamond cutter. The cutter shall be no more than .90 of an inch = 2.30 mm finished groove. [0093] The groove distance will always be dictated by the panel thickness and established from the gel coat face of the panel.

[0094] A jig (guide) for the router is to be used in place, this will act as a protector from surface scratches and markings as well as provide for a consistent and true measure. [0095] Determined by the type of spline with the tolerances provided for the specific project, every project shall be accompanied with a shop drawing to demonstrate the dimensions and placement of the groove. Consistency in the groove placement is paramount as the plane of the panels must be identical.

[0096] Final inspection on the edges and the grooves and corrected or sanded for blemishes if required.

[0097] The panels are then polished with a glaze and final inspection is approved.

[0098] The panels will have an identification label on the back side for production date, dimension, class, client an project number.

[0099] The panels are then covered with a low tack adhesive protective plastic film 2 mm minimum thickness.

[00100] The panels are then placed on palette face to face, back to back and secured in the palette.

[00101] The optimal weight should not exceed 4,000 lbs/2,000 kg to ensure safe handling on job site.

[00102] The shipping crates will be constructed from ¾" plywood with edges reinforced and the crates will be banded with a 1" steel band to ensure the crates will withstand the handling and shipping by third parties.

[00103] Crate labeling with provide information on content, shipping address to and from and total quantities and weights.

[00104] Although the invention has been disclosed with reference to various particular embodiments, it is understood that equivalents may be employed and substitutions made herein without departing from the scope of the invention as recited in the claims.

[00105] Having thus described the preferred embodiment of the invention, what is claimed as new and desired to be protected by Letters Patent includes the following:

Claims

CLAIMS:

Claim 1: A system for joining panels in erecting a high containment enclosure, the system comprising:

panels comprised of a homogeneous fiberglass reinforced resin core, and spline elements, each spline element comprising a leg portion adapted for securing to a substrate surface and a pair of laterally opposing dog members spaced apart from the leg portion, each panel having a kerf disposed in a side edge thereof, the kerf being formed directly into the homogeneous fiberglass reinforced resin core, each dog member of the spline element adapted to engage the side edge of a panel by insertion into the kerf, each dog member comprising a distal flat surface and an angled surface opposing the distal flat surface to create a wedge shape, a pair of panels being joined together onto a substrate surface by first fastening the leg portion of a spline element to a substrate surface, connecting a first panel to the spline element by engaging a first dog element with the kerf in the edge of the first panel, then connecting a second panel to the spline element adjacently and opposed to the first panel by engaging the opposing second dog element of the spline element with the kerf in the second panel, the external surfaces of the first and second panels being urged into planar alignment as the respective kerfs of the panels are moved along the angled surfaces of the dog elements while the distal flat surface maintain planar alignment of the joined panels.

Claim 2: The system for joining panels according to Claim 1 in which the kerfs of the respective joined panels are secured against the dog elements of the spline as inner walls of the kerfs engage the wedge shape along the angled surfaces of the dog elements.

Claim 3: The system for joining panels according to Claim 2 in which the width of the kerf is less than the thickest portion of the wedge shape of the dog element. Claim 4: The system for joining panels according to Claim 1 in which kerfs are placed in opposing edges of the panels to permit joining of a series of panels in lateral succession.

Claim 5: The system for joining panels according to Claim 1 in which the spline element extends the entire length of the joined panel edges.

Claim 6: The system for joining panels according to Claim 1 in which the spline element extends for a portion of the length along the joined panel edges.

Claim 7: The system for joining panels according to Claim 1 in which the kerf walls are flat.