“STRUCTURAL PANEL AND METHOD OF PRODUCTION”

FIELD OF THE INVENTION

[0001] This invention relates to structural panels and method of production of structural panels. In particular, the invention relates to structural wall, roof and/or floor panels that are used in construction.

BACKBROUND OF THE INVENTION

[0002] Wall panels are an important element of buildings. Wall panels have many variations in terms of structural function (i.e. load bearing or non-load bearing), exposure condition (interior or exterior), geometry (flat or curved), and materials used (concrete, steel, timber, etc.). P re-fabricated panels have become popular within the construction industry due to many advantages of pre-fabricated panels such as better construction quality, reduce on-site work, and reduced construction times. There are a large variety of pre-fabricated panel systems exist within the current construction industry. These panel systems can be used for construction of walls and/or roofs and/or floors.

[0003] Many of the load bearing pre-fabricated panels available are either made from concrete, steel or timber materials. Concrete and solid timber frames are heavy and therefor require heavy machinery on site for construction. Steel and timber stud frames are relatively light, but require more construction time. Steel and concrete panels are high C02 emission elements and therefore are considered as non- environmental friendly solutions. Steel and timber frame systems also suffer from poor performance under fire loads.

[0004] There are also many light weight panel systems available within the construction market, where the key performance considered in the design is the thermal insulation. Such panel systems include Structural Insulated Panel (SIP) systems, and many other products made using expanded polystyrene, cement or MgO board, timber products, etc. All available products contain weak performances in terms of at least one key performance aspects such as, poor structural performance, poor fire performance, poor durability, inability to manufacture in curved geometries, high C02 emissions, high resource consumption, etc.

OBJECT OF THE INVENTION

[0005] It is an object of the invention to overcome or alleviate the abovementioned problems or provide the consumer with a useful or commercial choice.

SUMMARY OF THE INVENTION

[0006] In one form, although not necessarily the only or broadest form, the invention resides in a complex laminated structural panel comprising:

a core having a thin-walled continuous hat section, the hat section being made of two thin timber veneers and a fibre reinforced plastic, the fibre reinforced plastic being sandwiched between the two thin timber veneers;

at least two connector elements, at least one connector element located adjacent each end of the core; and

two face sheets with each face sheet made using timber veneer and fibre reinforced plastic, wherein a face sheet is adhered to each side of the core.

[0007] The core may include an infill. The infill may be in the form of aerated concrete, concrete, foam, thermal insulation materials or the like material. The infill may be located between spaces of the hat section and the face sheets.

[0008] The hat section typically includes at least two hats.

[0009] The timber veneers of the hat section typically have the wood grain extending longitudinally.

[0010] The reinforced plastic of the hat section typically include fibres that run at least in the transverse direction with respect to the wood grain of the timber veneer.

[0011] The timber veneer of the face sheets and the core may be constructed from any type of wood, such as hard wood or soft wood. The selection of timber veneer is typically based on the desired properties of the panel.

[0012] The resin in the fibre reinforced plastic for both the face sheet and the core may be a polyester, vinylester, polyurethane, phenolic or epoxy resin. Preferably, the resin used is a polyurethane.

[0013] The fibres in the fibre reinforced plastic for both the face sheet and the core may be a glass, carbon, aramid, basal fibre or natural fibre. Normally glass fibre or carbon fibre is used.

[0014] The timber veneer of the face sheets and the core may be the same or may be different.

[0015] The resin in the fibre reinforced plastic for the face sheets and the core may be the same or may be different.

[0016] The fibres in the fibre reinforced plastic for the face sheets and the core may be the same or may be different.

[0017] The fibres in the fibre reinforced plastic for the face sheets and the core may run in a single direction.

[0018] Alternatively, the fibres in the fibre reinforced plastic for the face sheets and the core may run in two directions that are transverse with respect to each other. That is, the fibres may run laterally and longitudinally. The fibre may be in the form of a mesh.

[0019] A number of timber veneer sheets may be adhered together for use in both the core and the face sheets. The adhered sheets may be adhered together using an adhesive which is conducive to adhesion with the resin used for the fibre reinforced plastic. The orientation of the wood grain of the adjacent sheets of timber veneer may be oriented transversely with respect to each other when adhered.

[0020] The face sheets may contain a coating made of geo-polymer. The face sheets may contain one or more contain cladding layers. The face sheets may contain a layer of acoustic isolation material.

[0021] The connector elements may be made of timber, steel, or any other appropriate structural material. The connector elements may be shaped so that they have complementary parts. For example, one connector may have a female part whilst the other connector may have a male part.

[0022] The two connector elements maybe connected adjacent to the edges of the face sheets so that the connector elements and face sheets will act together as a single composite structural element where connector elements contribute to the structural capacity of the panel. The two connector elements may be sandwiched by the face sheets.

[0023] In yet another form, the invention resides in a method of making a complex laminated structural element, the method including the steps of:

adhering a fibre reinforced plastic onto at least one side of a sheet of wood veneer to create a first face sheet;

adhering a fibre reinforced plastic onto at least one side of a sheet of wood veneer to create a second face sheet;

adhering two timber veneer sheets to opposite sides of a fibre reinforced plastic so that at least some of the fibres of the fibre reinforced plastic oriented transverse with respect to the direction of the wood grain of the timber veneer; shaping the combined timber veneer and fibre reinforced into a hat section having at least two hats;

locating a connector element adjacent each side of the hat section;

pressing the first face sheet and the second face sheet onto the hat section; and

fastening the two face sheets to the connector elements.

[0024] The first face sheet and/or second face sheet may also include cladding. The first face sheet and/or second face sheet may also include a geo-polymer layer. The first face sheet and/or second face sheet may also include acoustic isolation material.

[0025] Further features of the invention will become apparent from the detailed description below.

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] An embodiment of the invention will be described, by way of example only, with reference to the accompanying figures in which:

[0027] Figure 1 is a perspective view of a structural panel according to an embodiment of the invention;

[0028] Figure 2 is a cross section view of a structural panel show in Figure 1 ;

[0029] Figure 3A is an exploded cross sectional view of an upper face sheet of the structural panel shown in Figure 1 ; [0030] Figure 3B is cross section view of the upper face sheet shown in Figure 3A;

[0031] Figure 4A is an exploded cross sectional view of an lower face sheet of the structural panel shown in Figure 1 ;

[0032] Figure 4B is cross section view of the lower face sheet shown in Figure 3A;

[0033] Figure 5A is an exploded cross sectional view of the core and connector elements of the structural panel shown in Figure 1 ;

[0034] Figure 5B is cross section view of the core and connector shown in Figure 3A;

[0035] Figure 6A is an exploded cross sectional view of a hat section of the core as shown in Figures 5A and 5B; and

[0036] Figure 6B is an exploded cross sectional view of a hat section of the core as shown in Figures 5A and 5B.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0037] Figures 1 and 2 shows a complex laminated structural panel 10 that is able to be used for a variety of different construction purposes such a prefabricated wall panel for a building. The structural panel 10 is formed from an upper face sheet 20, a lower face sheet 30, a core 40 an two connector elements 50. The two face sheets 20 and 30 sandwich the core 40 and two connector elements.

[0038] Figure 3 shows the upper face 20 of the structural panel 10 in more detail. The upper face consists of a cladding 21 , acoustic isolators 22, an ultra-thin timber veneer (0.1 mm-1 mm thick) 23, a geo-polymer layer 24, another thin timber veneer 25, fibre reinforced plastic 26, and a thick timber veneer 27 (3mm-19mm thick) which are all adhered to together using polyurethane.

[0039] The cladding 21 in this embodiment is a vinyl. However, it would be appreciated that other types of cladding known in the building industry may be used such as aluminium or timber. The cladding 21 forms the exterior of the structural panel that is often exposed to the environment.

[0040] The acoustic isolators 22 are made from foam and located adjacent the edges and middle of the panel. It would be appreciated that the location, type and number of the acoustic isolators can be varied according to desired sound rating of the structural panel 10.

[0041] The grain orientation of the timber veneers 23 and 25 are in the longitudinal direction whilst fibres of the fibre-reinforced plastic 25 are oriented perpendicular to the longitudinal axis. The fibre reinforced plastic 25 is made glass fibre and epoxy.

[0042] The thick timber veneer 27 consists of multiple veneer sheets (typically 3-7 veneer sheets) with grain orientation of all the timber veneers is in the longitudinal axis direction. However, it would be appreciated that as an alternate, the thick timber veneer 27 may be produced with multiple veneer sheets with grain orientation that alternates between grains that follow the longitudinal axis and grains that follow the transverse axis. This type of thick veneer 27 may be used to provided different structural properties for specific applications.

[0043] The geo-polymer layer 24 is sandwiched between the ultra-thin timber veneer sheet 23 and a thin timber veneer sheet 25. The thin timber veneer sheet 25 separates the fibre reinforced plastic layer 26 and the geo-polymer layer 24. The acoustic isolators are attached to the ultra-thin timber veneer layer 23 and cladding 21.

[0044] Figure 4 shows the lower face 30 of the structural panel 10 in more detail. The lower face 30 includes of a thick timber veneer 31 , fibre reinforced plastic 32 and cladding 33.

[0045] The thick timber veneer 31 consists of multiple veneer sheets with grain orientation of all the veneers is in the longitudinal axis direction. However, it would be appreciated that alternate veneer sheets with grain orientation perpendicular to the longitudinal axis may be used to provided different structural properties for specific applications.

[0046] Fibres of the fibre reinforced plastic 32 are oriented perpendicular to the longitudinal axis and the wood grain of the thick veneer 33. The fibre reinforced plastic 32 is made glass fibre and epoxy.

[0047] The cladding 33 in this embodiment is a timber. However, it would be appreciated that other types of cladding known in the building industry may be used. The cladding 31 forms the interior of the structural panel.

[0048] Figure 5A and 5B show the core 40 and connectors 50 of the structural panel 10 in more detail. The core 40 includes a hat section 41 and core infill material 42.

[0049] The hat section 41 , shown in more details in Figure 6A and 6B, are made from layers of timber veneer 43 which are added to the both sides of a layer of fibre reinforced plastic 44. The combined timber veneer 43 and fibre reinforced plastic 44 section is bent into a continuous hat section 41 using known techniques, e.g. compression moulding. The hat section 41 has two hats 45.

[0050] In this embodiment, glass fibre and epoxy are used to produce the fibre- reinforced plastic 44. The grain direction of the timber veneers 43 of the hat-section 41 is kept along the longitudinal axis of the hat-section 41 , while the fibre direction of the fibre-reinforced plastic 44 is kept transverse to the longitudinal axis of the hat- section section 41.

[0051] The core infill material 42 is made from a thermally insulating foam and is located within spaces 46 of the hat section 41

[0052] The connector elements 50 are made of timber. However, it should be appreciated that other structural materials may be used such as the metals (eg. steel), hard plastics or fibre-reinforced plastic or any other appropriate structural material. Connector elements 50 are connected to the thick timber veneers 26 and 31 through adhesive bonding or mechanical fastening in such a manner that once the face sheets 20 and 30 are connected to the connector elements 43 and 44, they act as a single structural unit. The connector elements 50 should (a) transfer forces in shear and axial directions between adjacent panels 10, (b) add axial, flexural and shear stiffness and strength to the panel 10 as a whole and (c) seal the core 40 from outside.

[0053] The connector elements 50 have complementary parts so that adjacent panels can be connected to each other. In this embodiment, the complementary parts are a male part 51 located on one connector element and a female part 52 located on the other connector element 50. Accordingly, the male part 51 and female part 52 mate when panels 10 are located adjacent each other.

[0054] In order to make the structural panel 10, the first step is to make the two face sheets 20 and 30.

[0055] The upper face sheet 20 is produced by first creating the thick timber veneer 27 by adhering mutiple sheets of timber veneer together with the grain orientation of all the timber veneers is in the longitudinal axis direction.

[0056] The next step is to adhere fibre reinforced plastic 26 to the thick timber veneer 27, adhering a thin timber veneer 25 to the fibre reinforced plastic 26, adhering a geo-polymer layer 24 to the thin timber veneer 25, adhering an ultra-thin timber veneer 23 to the to the geo-polymer layer 24, adhering acoustic isolators 22 the ultra-thin timber veneer 23 and then fastening the cladding 21 onto the acoustic isolators 22This completes the upper face sheet.

[0057] The lower face sheet 30 is produced by again creating the thick timber veneer 31 by adhering multiple sheets of timber veneer together with the grain orientation of all the timber veneers is in the longitudinal axis direction. The fibre reinforced plastic 32 is adhered to the thick timber veneer 31 making sure that the fibres of the fibre reinforced plastic 32 are oriented perpendicular to the longitudinal axis and the wood grain of the thick veneer 33. The cladding 33 is then adhered to the fibre reinforced plastic 32 to completed the lower face sheet 30.

[0058] The hat section 41 is then produced by adhering two timber veneer sheets 43 to opposite sides of a fibre reinforced plastic 44 so that at least some of the fibres of the fibre reinforced plastic 44 oriented transverse with respect to the direction of the wood grain of the timber veneer 43. The combined timber veneer 43 and fibre reinforced plastic 44 is then shaped into a hat section 41 having at least two hats 46.

[0059] In fill material 42 is then located within the spaces of the hat section 41.

[0060] The connector element 50 are locate adjacent each side of the hat section 41. Finally, the face sheets 30 and 40 are used to sandwich the hat section 41 and the connectors 50. The face sheets are adhered to flat portions of the hat section and the ends of the connectors 50 to compete the structural panel 10

[0061] It should be noted that flat or curved panels can be produced and a person skilled in the art would use know techniques to make alt or curved panels.

[0062] In this specification, the terms “comprise”, “comprises”, “comprising” or similar terms are intended to mean a non-exclusive inclusion, such that a system, method or apparatus that comprises a list of elements does not include those elements solely, but may well include other elements not listed.

[0063] The reference to any prior art in this specification is not, and should not be taken as, an acknowledgement or any form of suggestion that the prior art forms part of the common general knowledge.

[0064] It should be appreciated that various other changes and modifications may be made to the embodiments described without departing from the spirit or scope of the invention.