AU727384B2 - A building panel - Google Patents

Description

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AUSTRALIA

Patents Act COMPLETE SPECIFICATION

(ORIGINAL)

Class Int. Class Application Number: Lodged: Complete Specification Lodged: Accepted: Published: Priority *w* a a.

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a Related Art: Name of Applicant: Unipanel Pty Ltd Actual Inventor(s): ROBERT KROIE Address for Service: PHILLIPS ORMONDE FITZPATRICK Patent and Trade Mark Attorneys 367 Collins Street Melbourne 3000 AUSTRALIA Invention Title: A BUILDING PANEL Our Ref: 617223 POF Code: 333734/333734 The following statement is a full description of this invention, including the best method of performing it known to applicant(s): -1- 6006q A BUILDING PANEL This application is a divisional application of Australian Patent Application No 33218/99, the contents of which are herein incorporated by cross reference.

The present invention relates to a building panel. One aspect of the invention has been developed especially, but not exclusively for use in interior wall or ceiling panelling, and the invention is herein described in that context. However it is to be appreciated that the invention has broader application and is not limited to these uses. In particular, another aspect of the invention is especially suited for use in flooring or the like.

In the building industry, panels are widely used in interior walls, partitions and ceilings. One of the most common type of panelling used is plasterboard, .which traditionally is formed from a core of gypsum or anhydrite plaster, faced with two sheets of heavy paper. Plasterboard has gained widespread acceptance because it is inexpensive, relatively light weight, can be easily cut and provides a good surface finish.

However, there are significant problems with plasterboard. Traditional plasterboard panels are not self supporting and need to be fixed to a supporting frame such as a stud wall or the like. This substantially increases the cost of o .oo installation. Furthermore, plasterboard has relatively poor thermal and acoustic insulation properties as compared to block walls, and is relatively inflexible thereby making it difficult to form into complex shapes.

An aim of the present invention is to provide a building system which is inexpensive, easier to install and has improved performance characteritics as compared to traditional plasterboard wall systems.

Accordingly, the present invention provides a building system including a building panel and a reinforcing element, the building panel having spaced metal sheets interconnected by a core, said metal sheets defining opposite major surfaces of said panel, each of said metal sheets including opposite edge regions which form longitudinal edge regions of the panel, wherein at least one of the edge regions of the metal sheets on both opposite sides of the panel is profiled to form connecting elements, the connecting element of the longitudinal edge regions of divisonal of pd264e.doc:5/18/00 3 the panel being adapted to interfit with the connecting element of a respective one of the longitudinal edge regions of a like panel, the panel being configured such that the major surfaces of the interconnected panels are aligned and in substantially abutting relationship to form a substantially continuos surface and wherein the reinforcing element is operative to be installed at the join formed on connection of the panel with a like panel and. is secured in place by locating between the interfitting connecting elements to form a concealed reinforcing member which is operative to improve the load bearing characteristics of the interconnected panels.

The system of the present invention has been designed especially, but not exclusively, to use a building panel, the subject of the Applicant's co-pending .application 33218/99, where the sheet structures are formed of metal and at least one of the sheet structures incorporate a paper covering. Alternatively, the metal sheet structures may be fully exposed such as if a stainless steel surface is required, or other finishes or composite materials may be used.

The advantage of the present invention is that it provides a building panel with enhanced load bearing properties as compared to simple sandwich panels.

Further, fully concealing the reinforcing member enables continuous smooth surfaces on both sides of the panels to be obtained.

A panel in accordance with this aspect of the invention is suitable for use both as wall panels or ceiling or floor paneling.

S" In a particularly preferred form, the sheet structure includes longitudinal edge regions which are profiled to enable the panels to be connected in abutting relationship with a like panel in edge to edge relationship and the reinforcing member is locatable within the join formed at the abutting panels.

In a particularly preferred form, the panel is arranged to interlock with a like panel at the longitudinal edge regions. Preferably the longitudinal edge regions interlock with the reinforcing element. This arrangement has the advantage that if further increases the load bearing capability of the panel as the reinforcing member and the profiled longitudinal edge regions can work together.

dMsvilonal of pdt264e.doc:518/00 The system of the preferred form of .the invention including a panel according to the arrangement disclosed in co-pending application 33218/99 provides significant advantages over the plasterboard panels. The panel with its paper covering, has a surface characteristic which can match that of plasterboard, yet offers significant improvements in structural properties because of the metal substrate. The panel is load bearing, may be formed or otherwise shaped into complex configurations, and is able to exhibit improved thermal and acoustic insulation characteristics.

A particular advantage of the panel is that the surface of a wall formed from the panels can be finished to appear continuous using standard techniques used on plasterboard walls. Such techniques include plaster rendering and the use of plaster tape.

Throughout the specification the term "paper" includes sheet material formed from any fibrous material produced from either naturally occurring or synthetic fibres. The sheet material may be of unitary or composite construction. It also includes other types of sheet material which have characteristics, in particular surface texture, which are similar to paper.

In a particularly preferred form, the paper covered metal sheets are formed :in continuous lengths using a laminating process to adhere the paper covering to the metal substrate. The production of sheets in this way provides significant cost benefit and also has the advantage of enabling sheets of indefinite length to be produced. In a particular preferred form the entire panel is made using a continuous laminating process.

Preferably the building panel includes a generally planar abutment surface at each longitudinal edge region which extends generally perpendicular to the major surface. Preferably the connecting elements are disposed inwardly of each major surface with the abutment surfaces being disposed between that major surface and the connecting elements. This arrangement is ideally suited where the paper covering gives the panel a surface characteristic which is substantially the same as a plasterboard panel. In that arrangement, the panel is operative to form a substantially continuous exposed surface by connection of the panel with a like dkvsional of pd264edoc:518/00 panel through interfitting of respective ones of the connecting elements, or through abutting of an edge of a plasterboard against a respective one of the abutment surfaces.

The profiles may be formed in the metal sheets using any known technique such as roll forming, folding or the like. However in a particularly preferred form, the metal sheets are roll formed to the desired profile. In this way this forming step can be easily included as an extension to the laminating process.

Any appropriate sheet metal may be used, such as steel, aluminium, tin or the like. In general construction, galvanised steel has wide application as the metal substrate as it is relatively inexpensive, has good structural properties and is corrosive resistant. The gauge of the metal substrate may be chosen depending the required structural properties of the panel. However it is envisaged that the S• gauge will be between 0.3 to 1mm in most applications. Metal falling within this range of thicknesses can easily be cut thereby enabling services to be easily installed in the panel on site.

In a particularly preferred form, the paper is bonded directly to the metal surface. Preferably a reactive hot melt adhesive is used to bond the paper to the metal substrate. An advantage of using a reactive hot melt adhesive is that it provides high bond strength including high initial adhesive and cohesive strength which makes it ideal for laminating the paper directly onto the bare metal substrate.

The ability to bond the paper directly onto a metal substrate again provides significant cost benefit in that it avoids the need for pretreatment of the metal such as the application of a primer coat to the metal surface. However, it is to be appreciated that intermediate layers such as paint or waterproof coatings may be included between the metal substrate and the paper covering if required.

In a preferred form, the adhesive is applied by a roller to the metal surface, as this gives good even coverage of the adhesive across the substrate surface which is important for providing an even surface finish on the panel.

In one form, the panels are installed using top and bottom rails. The rails may have a simple C-shaped cross section. In this arrangement, the depth of the rails, the distance they are spaced apart, and the height of the panel is related so divisional of pct264e.doc:5/1 8/00 that the panels may be easily installed by merely locating the upper end of the panel into the top rail and then swinging the bottom end of the panel into alignment with the bottom rail and then dropping the panel down into the bottom rail. The panel is then captured between the top and bottom rails and may be secured in place by fasteners, such as rivets or self tapping screws or the like. It is to be appreciated that other fastening arrangements may be used. For example the rails may be specially formed so that they interlock with the panels without the need for separate fasteners.

The core of the composite panel may be of any suitable form depending on its application or requirements. In particular, the core may be of solid construction of may be of open form including interconnecting webs to thereby form cavities within the core. These cavities may be used to reduce the weight of the integrated S panel or to provide passage for services such as wiring and the like.

In one form, the edge profiles are specifically designed to form a load bearing member at the interlock between adjacent panels. In a preferred form, the S interlock is still by virtue of a male/female coupling but the edge profiles are shaped to form a part box section. The section has inherent strength and also is convenient for use in the passage of cabling or other services. Moreover, the male Scoupling may be arranged to be drawn into tight engagement with the female coupling so that the overlapping structure of the male and female connection acts in unison thereby increasing the load bearing capability of the panels.

It is convenient to hereinafter describe embodiments of the present invention with reference to the accompanying drawings. It is to be appreciated however that the particularity of the drawings and the related description is to be understood as not limiting the preceding broad description of the invention.

In the drawings; Figure 1 is a perspective view of a panel; Figure 1A is a detailed view to an enlarged scale illustrating the construction of the panel of Figure 1; Figure 2 is a perspective view illustrating the panel of Figure 1 used as a ceiling panel when in position; dMsional of pcl264e.doc:5/18/00 Figure 3 is a perspective view of a composite panel for use in a building system according to an embodiment of the invention; Figure 3A is a detailed view to an enlarged scale illustrating the construction of the panel of Figure 3; Figure 4 is an exploded perspective view illustrating the connection of the panel of Figure 3 with a like panel; Figure 5 is a cross sectional view of the connection of the panel of Figure 3 with a like panel.

Figure 6 is a perspective view illustrating the connection of a variation of the panel of Figure 3 with a like panel and including an intermediate reinforcing member according to an embodiment of the present invention; i Figure 7 illustrates a variation of the panel of Figure 3 and its connection with a like panel; Figure 8 is a partial perspective view illustrating the connection of an end trim component to the panel of Figure 7; Figures 9A and 9B are schematic side views showing installation of the panel into top and bottom rails; Figure 10 is a perspective view illustrating the connection of a variation of the panel of Figure 3 with a like panel and including an intermediate reinforcing a member; Figure 11 illustrates a variation of the panel of Figure 3 incorporate separately formed longitudinal edge profiles; Figure 12 is a partial perspective view illustrating the panel of Figure when used as a flooring system; and Figure 13 is a line diagram of a laminating process for use in the production of a building panel.

Figure 1 illustrates a building panel 10 which is generally planar and includes opposite major surfaces 11 and 12 interconnected by edge regions 13 and 14.

The panel 10 is of composite material and formed from a laminating process which forms the panel in continuous lengths. The panel may be of any desired divisional of pd264e.doc: E8100 8 width, although if made from one sheet, the width will be limited by the width of the feed stock. In one form, the panel is formed in standard widths of 1200mm, 900mm, 600mm and 300mm.

The panel includes a metal substrate 15 and a paper covering 16 which is bonded to the substrate 15 by a reactive hot melt adhesive 17. The covering 16 constitutes a heavy plasterboard paper so that the outer face 11 of the panel has the same general appearance and surface characteristics of a plasterboard panel.

In the illustrated form, the substrate 15 is formed of galvanised steel thereby enabling the inner surface 12, which in use is concealed, to remain exposed due to its corrosive resistant properties.

The edge regions 13 and 14 of the panel are profiled so as to enable the i o panel 10 to be connected at these edge regions to a like panel. In the illustrated "":form, the profiles on the edge regions 13 and 14 are formed by roll forming the metal substrate 13. The edge regions 13 and 14 are formed with one edge region 13 forming a female coupling which is adapted to receive and contain the **.other edge region 14 which is formed as a male coupling. With this arrangement, the male edge region 14 locates in and is retained within a seat 18 formed within the female edge region 13 of a like panel so that the adjacent panels can be interconnected along their edge regions.

It is to be appreciated that the profiles formed in the edge regions 13 and 14 may take different embodiments as will be appreciated to those skilled in the art of :roll forming techniques. Specifically, the profiles can be matched to suit the particular requirements of the panel and the mode of connection required between adjacent panels. For instance, the profiles may be designed such as those illustrated, to not require the addition of any mechanical fasteners to interconnect like panels together. Alternatively the edge regions could be formed so as to provide formations to receive specific mechanical fasteners such as rivets or screws or the like.

Figure 2 illustrates the panel 10 in place as part of a ceiling with the panel 10 aligned, and fixed to, the underside of parallel roof batons 60. In the illustrated form, the batons incorporate clips which are adapted to engage and hold divisional of pd264e.doc:5/18/O 9 the edge regions 13 and 14 of the panels. In this arrangement, the ceiling panels are installed progressively across the baton. A first panel 10' is installed and fastened to the clips 61. A second panel 10" is then installed by locating the male edge region 14" within the female edge region 13' of the affixed panel 10' whilst the panel 10" is inclined relative to the fixed panel 10'. Once located in place, the panel 10" is then swung up into alignment with the panel 10' wherein its female edge region 13' engages with associated clips 61 attached to the batons. The process then continues until all the panels are in place.

With this arrangement, the fixed panels 10 have respective outer faces which incorporate the plasterboard paper covering and thereby have a general appearance of plasterboard. If required, edge trim (not shown) can be inserted !°'"•between the adjacent panels. Typically the panels would include a bead or similar protrusion which locates within an associated groove (not shown) formed in the edge regions 13 and 14 of the respective panels. Alternatively, the join between the panels could be concealed so that the ceiling surface is continuous using standard finishing techniques such as plaster rendering or the like.

**-Figure 3 illustrates a building panel 20 according to a second embodiment of the invention. The panel 20 is of sandwich construction incorporating first and second spaced structures 21 and 22 respectively, which are interconnected by a core 23. The panel 20 further includes edge regions 24 and 25 which are profiled to enable the panel 20 to be interconnected to a like panel.

As best illustrated in Figure 3A, each of the sheet structures 21 and 22 incorporate a structure which is similar to the panel 10 illustrated above.

Specifically the panels 21 and 22 incorporate a metal sheet substrate 26 which includes a covering 27 formed from heavy plasterboard paper which is bonded to an outer surface 28 of the metal substrate 26 by a reactive hot melt adhesive 29.

Similarly, an inner face 30 of the metal substrate 26 is bonded to the core 23 by a similar adhesive 31. The longitudinal edge regions 24 and 25 are profiled by roll forming the respective edge regions of the metal substrates 26 of the respective sheet structures 22 and 21.

divisional of pct264e.doc:5/1 8/00 The core 23 of the panel is illustrated as a foam block. However it is to be appreciated that the core may be formed of any suitable structure depending on the application of the panel 20. For example, the core may be formed from a composite construction and/or may include cavities or channels if desired.

In a similar manner to the earlier described embodiment, the panel 20 is formed from a laminating process. Typically the sheet structures 21 and 22 are formed in a first laminating process. The sheet structures then form part of a second laminating process where they are bonded to the core. If desired, additional layers can be bonded to the panels to further improve the structural properties of the panel 20. For example additional layers may be incorporated to further increase the thermal or acoustic insulation properties of the panel. By virtue of the laminating process, the panels 20 are formed in continuous lengths and are typically formed in a range of standard widths such as 1200mm, 900mm, 600mm and 300mm.

The panel 20 has the general appearance and surface characteristics of plasterboard by virtue of the heavy paper covering 27. However because of its sandwich construction and sheet metal substrate, the panel 20 is lightweight, yet is self supporting and capable of acting as a load bearing.member.

The edge region 24 of the panel 20 is roll formed to include a longitudinally extending projection 32 and recess 33 which are located intermediate the opposite faces 38, 39 of the panel 20. In the illustrated form, the projection 32 is formed from roll forming the edge of the structure 21 whereas the recess is formed from roll forming the edge region of the structure 22. An abutment face 34 is located between the face 38 and projection 32 and a similar abutment face 35 is formed between the recess 33 and the face 39.

Both the projection 32 and the recess 33 are shaped to be complementary such that the projection 32 is able to be received within the recess 33 of a like panel. To facilitate interconnection of adjacent panels, both the projections and the recesses include tapered surfaces to provide adequate lead in.

The other longitudinal edge region 25 of the panel 20 includes a similar edge profile and includes both a recess 32 and a projection 33, with the exception divisional of pcd264e.doc5/18100 11 that the projection is formed from roll forming the edge of the sheet structure 22 whereas the recess 33 is formed from roll forming the edge region 21.

The panel 20 is arranged to be self supporting and typically arranged to be installed between top and bottom rails (62 63) which are formed as C-shaped channels or the like. Figures 9A and 9B illustrate the installation of the panel between the rails 62 and 63. The panels are easily installed by merely locating the upper end 51 of the panel into the top rail 62 and then swinging the bottom end 52 into alignment with the bottom rail 63 and then dropping the bottom panel 20 into the bottom rail. The relationship of the distance between the panels to the height of the panel is such that the panel remains captured between the top and bottom rails as best illustrated in Figure 9B. Once in this position, the panels can then be interlocked with a like panel as will be described in more detail below. Once fully in S:position the panels are then secured in place to the rails merely by the use of fasteners, such as rivets or self tapping screws or the like.

S 15 Figures 4 and 5 illustrate the connection of the panel 20 with a like panel.

For ease of identification, one panel is designated 20' whereas the other panel is designated 20". Other features of the panels are distinguished in a similar manner.

As best illustrated in Figure 5, the edge regions 24' and 25" enable two panels 20' 20" to be connected in edge to edge relationship with the respective projections and recesses of the edge region 24' engaging with the respective projections and recesses of the edge region25" of adjacent Furthermore, the abutment surfaces 34' and 35" engage so as to form a simple linear join 36 between the abutting panels 20' and In the illustrated form, both the longitudinal edge regions 24 and 25 of the panel is slightly waisted to form a recessed portion 37 in the outer surface of both the structures 21 and 22. This recess is designed to enable the join 36 between adjacent panels to be easily covered over by plaster tape or plaster rendering which will be applied within this recess and create a flush surface across the join.

The profile of the edge regions 24 and 25 also enables the panel 20 to be easily used in conjunction with standard plasterboard panels. Specifically, the dMisional of pcd24e.doc:5/18/00 12 abutment surfaces 34 and 35 provide a space to enable a plasterboard panel to be located in abutting relationship with the panel 20. The abutment surfaces 34 and 35 are dimentioned to be slightly larger than a standard plasterboard panel which is typically 10mm or 13mm, so as to provide adequate clearance for the plasterboard panel to be located outside the projection 32 and the recess 33 so that the plasterboard surface can be flush with the respective faces 38 and 39 of the panel The coupling arrangement to join adjacent panels using the interfitting projections and recesses 32 and 33 provide an area of load bearing strength at the engaged edge regions. This has significant advantage as it improves the load bearing characteristics of the wall formed by the adjacent panels. In most applications, the interconnection of the panels gives the wall sufficient load bearing 4 characteristics. If, however, additional load bearing strength is required in the constructed wall using the panels 20, a metal reinforcing member40 may be incorporated at the connection. One such example is illustrated in Figure 6 where the beam is formed from roll formed metal sheet 41 and incorporates oppositely disposed channels 42 and 43 which are arranged to interfit between the engaging projections and recesses (32 and 34) of the adjacent panels 20 i and 20 i The member 40 substantially improves the load bearing characteristics of the wall as, 0 by virtue of its configuration and its engagement with the adjacent panels, it is able .to accommodate substantial compressive loading.

Figure 7 illustrates a variation of the coupling arrangement between adjacent panels 20 i and 20 i In this arrangement both the longitudinal edge regions 24 and 25 incorporate a pair of recesses 33. As illustrated in Figure 7 in connecting the panel 20 i to like panel 20", the recesses 33 i 33 i of the respective panels are arranged to be aligned and inserts 44 are located within the cavity formed between the aligned recesses to couple the panels together.

The inserts may be of any suitable form and may include a continuous strip which extends over the majority of the length of the connected panels, or may be in the form of smaller wedges 46 which extends over only a portion of the length of the panels.

divisional of ptd24e.doc:5/18/0 Figure 8 illustrates a specially formed edge strip 50 which is arranged to be coupled to the longitudinal edge region 24 or 25 of the panel 20. The edge strip may be solely as a decorative end strip or may have a functional purpose such as form part of a door frame assembly as in the illustrated embodiment where the strip 50 is configured to form a door jamb.

Figure 10 illustrates a further variation of the panel 20. This panel includes many similar features to the earlier embodiments and accordingly like reference numerals have been given to like features. In a similar arrangement to the previous embodiments, the panel 20 includes longitudinal edge regions 24, which are profiled to enable the panel 20 to interlock with a like panel. A reinforcing member40 is also arranged to interfit at the join between adjacent ""panels.

In the illustrated form, the longitudinal edge region 24 provides a pair of recesses or female couplings 33 whereas the edge regions 25 provide a pair of male couplings or projections 32. It is to be appreciated that if desired, each edge region could include both a male and female coupling similar to that illustrated in Figure 3.

In the embodiment of Figure 10, the profiles have been specifically designed give the panel enhanced load bearing characteristics at it join with an adjacent panel. The male and female couplings are shaped to provide generally a part box section which interlocks with a snap fit action. This arrangement has the advantage that the box section provides good load bearing characteristics and the snap fit action draws the interlocking members together. This inhibits inadvertent separation of the members and also enables the interlocking panels to act as a single unit thereby enhancing the panels overall load bearing capabilities at this connection.

The male coupling 32 includes opposite walls 53 and 54 which are interconnected by a base portion 55. To provide the snap fit, the walls 53 and 54 are not linear but rather includes outwardly extending crests 56 intermediate the ends of the respective walls 53, 54. The female coupling 33 incorporates a complimentary shaped recess. Specifically, the female coupling 33 incorporates dMisional of pct264e.doc:5/18/00 14 opposite walls 57, 58 which are interconnected by base portion 59 and which incorporate re-entrant portions 64 on their inner surface. In use, on interconnecting the panels together the male and female couplings are caused to flex through engagement of the male coupling walls 53, 54 with the female coupling walls 57, 58. The flexing continues until the crests 56 begin to align with the reentrant surfaces 64 whereafter the couplings begin to return to their natural state as the crests move into alignment with the re-entrant surfaces 64. Once in alignment, the resilience of the couplings inhibits the release of the two interconnected members.

The positive or snap fit between the male and female couplings occurs S,:whether or not the reinforcing member 40 is incorporated. The profile of the reinforcing member 40 has inner surfaces 65 which matches that of the female S couplings 33 and an outer surface 66 which matches that of the male coupling 32.

a result, the reinforcing member 40 is able to snap fit into connection with the female couplings 33 of a first panel 20'. Once in place, the male couplings 32" of Sthe like panel 20 i is then able to locate into engagement with the inner surface of the connected reinforcing member Figure 11 illustrates a similar view to that illustrated in Figure 10 except that the edge profiles 24,25 are formed separately to the panel 20. In this arrangement the edge profiles 67, 68 are similar to the edge strip 50 are formed from a folded :0 metal sheet and are secured to the edge margins of the panels using any suitable S fastening arrangements such as by screw, adhesive or the like. These edge profiles 67, 68 enable the system to be used with a panel 20 having a straight edge and may be used when it is required to cut the structural panel or when the structural panel is required to interfit with conventional panels or other building materials.

The composite panel 20 incorporating the profiled edges and the internal reinforcing member 40 may be advantageously used in many aspects of building constructions including in interior as well as exterior wall structures, or in flooring or ceiling systems. Further, the choice of the surface materials used to form the outer faces 38, 39 of the panel will depend on the application of the panel. For example, divisional of pct24e.doc:5/1 8/00 if the panel is to be used as an internal partition wall, then the paper covering may be laminated to the metal substrate as described earlier so that the panel has a surface characteristic which is similar to that of plasterboard. Alternatively, the outer face of the panel may be exposed metal, such as stainless steel, which is suitable for use in operating theatres or the like. In this example, to reduce material cost, the stainless steel may be applied as a laminate to the metal substrate of the panel 20 or alternatively the substrate may be formed from solid stainless steel. It is to be appreciated that other surface configurations could be used as will be appreciated by those skilled in the art.

Figure 12 illustrates a further variation of the panel when used as part of a flooring system. In this arrangement the reinforcing member 40 acts as an internal bearer thereby providing the required loading characteristics for the flooring system. In this arrangement the upper face 38 incorporates a timber veneer so as to give the impression of a timber floor.

Figure 13 illustrates a line diagram of a laminating process used to bond the paper covering to the metal substrate for use in the building panel of the invention.

In this process, the metal feed stock 26 which is typically galvanised steel but may be any other sheet metal, is fed from an uncoiler 101 into the process line 100. The sheet metal is then correctly positioned by running through an edge guide 102 and then subsequently through a straightener 103. The sheet metal then passes through a cleaning and heating unit to remove any debris on the :metal surface and to bring the temperature up to a predetermined level. The exact temperature range used is dependent on the characteristics of the adhesive being applied but is typically in the range of 20 to 50 0 C. The sheet metal then passes through to an adhesive coater 105 which incorporates a roller 106 which comes into contact with the upper surface 28 of metal substrate 26 so as to apply a thin film to the metal sheet. The adhesive is a reactive hot melt polyurethane and is typically applied at a temperature in the range of typically 110 to 1400C with a coating being applied to the metal surface in the order of 10-20 microns in thickness.

divisional of pd2S4e.doc:5/18/00 16 After the adhesive has been applied, the metal sheet 26 then passes through a humidifier 107 which further conditi6ns the adhesive coating on the metal surface 28. The sheet then passes to a laminator 108 where the paper 27 which is stored in a coil 109 is applied under tension to the surface 28 of the metal 26. The laminated product is then fed to a recoiler wherein it is stored in rolls ready for transporting (as illustrated) or to a further production station. The station further processes the metal panel and may include a roll forming station to form the edge profiles, a sheering station to form the panel into sheet form or to slit the metal panel so as to alter the panel width. To make the integrated composite building panel 20, the laminated metal sheet is fed to a separate laminating process to form the panel 20 with its sandwich construction.

4** An advantage of the panel of the present invention is that the paper laminated metal sheet is inexpensive to manufacture as it can be made using the laminating process without requiring any pretreatment, such as painting of the S4 15 metal substrate. This has substantial practical benefit as it enables the building :::panel formed from the metal substrate to be extremely competitive in price with traditional plasterboard panels. Furthermore by making the building panel using the composite material of a metal sheet substrate and a paper covering, the panel the invention can be used in conjunction with plasterboard panels, as it has a surface characteristic which can match that of plasterboard, yet has the additional advantages in that it can be load bearing, can be formed or otherwise shaped into o :*complex configurations, including being able to have profiled edges to enable the panel to be interlocked with a like panel and can be designed to have improved thermal and acoustic insulation characteristics.

Finally it is to be understood that modifications and or additions may be made to the parts as previously described without departing from the spirit or ambit of the invention.

divisional of pdct284e.doc:5/180O

Claims (14)

1. A building system including a building panel and a reinforcing element, the building panel having spaced metal sheets interconnected by a core, said metal sheets defining opposite major surfaces of said panel, each of said metal sheets including opposite edge regions which form longitudinal edge regions of the panel, wherein at least one of the edge regions of the metal sheets on both opposite edge regions of the panel is profiled to form connecting elements, the connecting elements of the longitudinal edge regions of the panel being adapted to interfit with the connecting element of a respective one of the longitudinal edge regions of a like panel, the panel being configured such that the major surfaces of the interconnected panels are aligned and in substantially abutting relationship to form a substantially continuous surface and wherein the reinforcing element is operative to be installed at the join formed on connection of the panel with a like panel and is secured in place by locating between the interfitting connecting elements to form a S 15 concealed reinforcing member which is operative to improve the load bearing characteristics of the interconnected panels.

2. A building system according to claim 1, wherein the edge region of each of the metal sheets of the building panel is profiled to form a said connecting element, and wherein in use, the reinforcing element locates between each pair of interfitting connecting elements at the join between the interconnected panels to thereby interconnect the opposite metal sheets of each of the connected panels.

3. A building system according to any preceding claim, wherein the connecting elements are in the form of interfitting channels and projections, the or each channel incorporating opposite walls interconnected by a substantially flat base portion, and wherein the or each projection is shaped to interfit with the channel of a like panel and includes opposite walls interconnected by a substantially flat apical portion, and wherein said reinforcing element includes at least one engagement part which is generally U-shaped and locates between a said interfitting channel and projection of the interconnected panels.

4. A building system according to claim 3 when dependent on claim 2, wherein the reinforcing element includes spaced apart engagement parts interconnected by a web. divisional of pdc264e.doc:5/1 8100 18 A building system according to either claims 3 or 4, wherein the opposite walls of each channel merges with its base portion at approximately 900 to form a part box section.

6. A building system according to any one of claims 3 to 5, wherein the opposite walls of each projection merge with its apical portion at approximately 900 to form a part box section.

7. A building system according to any one of claims 3 to 5, wherein the opposite walls of the channel include a re-entrant inner surface, and wherein the opposite walls of the projection includes a crest on its outer surface and wherein the crest portion on the projection of one panel is arranged to engage with the re- entrant inner portion of the channel like panel in a snap fit arrangement.

8. A building system according to any preceding claim, wherein the connecting @9 94O elements are adapted to interfit with the connecting elements of a like panel and lot6 with the reinforcing element in a snap fit arrangement.

9. A building system according to any one preceding claim, wherein the building panel further includes at least one abutment surface at each longitudinal 9999edge region, the abutment surfaces extending generally perpendicular to said major surface of said panel and wherein the or each abutment surface is disposed between a respective one of the major surfaces and the said connecting elements.

10. A building system according to any preceding claim, wherein at least one of said metal sheets of the building panel incorporates a paper covering along its 0. major surface.

11. A building system according to claim 10, wherein said paper is bonded to said metal sheet using a reactive hot metal adhesive.

12. A building system according to either claim 10 or 11, wherein said paper is bonded directly onto said metal sheet.

13. A building system according to any one of claims 10 to 12, wherein the metal sheet incorporating the paper covering is formed in continuous lengths using a laminating process to adhere the paper covering to said metal sheet.

14. A building panel when used in a building system according to any preceding claim. dMsional of pd264e.doc:518100 19 A reinforcing element when used in a building system according to any one of claims i to 13.

16. A building system substantially as herein described with reference to the accompanying drawings. DATED: 23 May, 2000 PHILLIPS ORMONDE FITZPATRICK Attorneys for: UNIPANEL PTY LTD s* oboe S d~isional of pd264edoc:511 8100