NZ578075A - Mesh reinforced foam plastics building panel - Google Patents

Abstract

A moulded foam building board 2 is reinforced by a mesh 11 embedded into the foam of the board. The mesh is formed of a resilient material that is stretched whilst being embedded within the foamed material and whilst the foamed material sets. During manufacture mesh 11 may be embedded in a first portion of the board and then the mesh is tensioned as it is dispensed from roller 19 and as it is laid into the unset foam material sprayed through top and bottom layer nozzles 18, 20 and setting as the board progresses down a conveyor 13 away from the dispensing roller.

Description

James & Wells Ref: 130113/62 PATENTS FORM NO. 5 Fee No. 4: $250.00 PATENTS ACT 1953 COMPLETE SPECIFICATION After Provisional No: 578075 Dated: 29 June 2009 A BOARD We, Lite Building Systems Ltd, a New Zealand registered company c/- Young Read Woudberg Ltd, 13 McLean Street, Tauranga, New Zealand, hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed to be particularly described in and by the following statement: 1 James & Wells Ref: 130113/62 A BOARD STATEMENT OF CORRESPONDING APPLICATIONS This application is based on the Provisional Specification filed in relation to New Zealand Patent Application Number 578075, the entire contents of which are 5 incorporated herein by reference.

TECHNICAL FIELD The present invention relates to a board for use in construction. In particular, the invention relates to a board suitable for use as an internal wall lining board, although this should not be seen as limiting as other uses are also envisaged.

BACKGROUND ART The use of liner board attached to a frame to provide an internal surface, such as a wall or ceiling, is ubiquitous in modern buildings. Typically, in New Zealand for example, homes are constructed using a timber framing. Liner boards are attached to the frame to provide the interior surfaces, such as walls.

Conventional liner boards used in New Zealand are known as Gib™ boards, which is a trade name for Gibraltar board. Gib™ boards are typically formed from a gypsum plaster core sandwiched between two thick paper liners which form the external surface. Variations on Gib™ board are well known throughout the World under various names, such as drywall, wallboard, plasterboard (US, UK and 20 Australia), gyproc (Canada, UK and Australia), rigips (Germany) and placoplatre (France), among others.

Despite their very wide use, Gib™ boards do have a number of disadvantages when used in construction. A standard board of dimension 1200 mm x 2400 mm x 2 James & Wells Ref: 130113/62 mm weighs around 20 kg. At this weight it can require two people, or a builder with considerable strength, to repetitively lift and move the boards into position for fixing to a frame. This weight also limits the number of boards that can be carried on a vehicle before the tare rating of the vehicle is exceeded, even though there 5 may be space for additional boards.

The gypsum core of Gib™ board is typically brittle, making it difficult to cut and to form a clean edge. As a consequence additional work can be required to plaster over cut joins between two sheets of Gib™ board in order to provide a smooth finish. Further, the gypsum tends to flake away from an edge as it is cut, which 10 can create a film of plaster around the work area which adds cost due to the extra cleaning required as well as providing a potential hazard for those breathing in the powder in the work area.

Furthermore, drilling into the gypsum core commonly results in a fractured internal surface rather than a neat hole. This, and the general lack of structural integrity of 15 the core under load, means that it is usually not practical to attach a fastener, such as a screw, nail, staple etc, directly into Gib™ board. This limits the usefulness of the board as special fasteners need to be used which can add to the cost and may be generally inconvenient.

Another disadvantage of Gib™ board as a building material is that it is a poor 20 thermal and acoustical insulator. Hence, in general additional insulation is required in the wall frame behind the Gib™ board to provide the level of insulation generally required in modern buildings.

It is an object of the present invention to address the foregoing problems or at least to provide the public with a useful choice.

All references, including any patents or patent applications cited in this 3 James & Wells Ref: 130113/62 specification are hereby incorporated by reference. No admission is made that any reference constitutes prior art. The discussion of the references states what their authors assert, and the applicants reserve the right to challenge the accuracy and pertinency of the cited documents. It will be clearly understood that, although a 5 number of prior art publications are referred to herein, this reference does not constitute an admission that any of these documents form part of the common general knowledge in the art, in New Zealand or in any other country.

Throughout this specification, the word "comprise", or variations thereof such as "comprises" or "comprising", will be understood to imply the inclusion of a stated 10 element, integer or step, or group of elements integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

Further aspects and advantages of the present invention will become apparent from the ensuing description which is given by way of example only.

DISCLOSURE OF THE INVENTION According to one aspect of the present invention there is provided a board including: a moulded core formed from a foamed material, and a mesh 20 characterised in that the mesh is embedded within the foamed material during formation of the board. In a preferred embodiment the board is an interior liner wall board. 4 James & Wells Ref: 130113/62 Reference to an interior liner wall board (or more generally a wall board) throughout this specification should be understood to refer to a panel typically used in conjunction with a load bearing framework to provide an interior surface, typically a wall, to a structure. However, the board may be used as a liner for structures 5 other than walls (such as ceilings for example) so reference to wall board only throughout this specification should not be seen as limiting.

In a preferred embodiment the board is in the form of a slab having a front face and a rear face.

A slab may be understood to be a relatively thin, flat block of material, having a flat 10 front face and a flat rear face, the front and rear faces being substantially parallel. In general the wall board may be in the form of a rectangular slab. The front face should be understood to be the face that is exposed to the interior of the building.

In other embodiments a board may be formed in any desired shape, including without limitation, a curved or arcuate shape or a corner board having an edge 15 separating two planar sections oriented orthogonally to one another.

In a preferred embodiment at least one edge of the board includes a rebate on the front face of the board.

Commonly wall boards used to form a wall (or other flat surface) are butted together, which typically leaves a gap that needs to be covered or filled with plaster 20 and worked to provide a smooth finish. This requires skill and takes some time, adding cost to the job of forming the wall.

A rebate in the edge of the front face of two wall boards of the present invention may be configured such that, when the rebated edges are butted together a strip of tape may be attached to the rebates across the gap between the boards, the James & Wells Ref: 130113/62 dimensions of the rebates and the tape being such that the finished joint is fully covered and substantially coplanar with the front faces of the two wall boards. This method of joining may reduce the requirement for highly skilled labour and save time and cost in providing a smooth finish to the wall.

In a preferred embodiment the board includes a liner attached to a face of the moulded core.

A liner may be any layer of material applied to the surface of the core to provide a desired finish. Typically at least the front face of the core may be covered by a liner.

In a preferred embodiment the liner is paper.

A paper liner may be a suitable liner for the board as it may provide a good substrate for further finishing, for instance by painting or wall papering over the wall board. A liner may also be patterned or otherwise decorated to provide a desired finish to the interior surface of the board.

In a preferred embodiment the moulded core is sandwiched between two liners. Having paper liners on both sides of the wall board may aid with the appearance and ease of handling, and provide a suitable surface for finishing (as with painting or applying wall paper).

In a preferred embodiment the core has a density greater than 15 kg per cubic 20 meter.

In a preferred embodiment the foamed material is a foamed plastics material.

Reference to foamed plastics material throughout this specification should be understood to refer to any material of a group of synthetic thermoplastic resins which, under appropriate conditions can be converted into foam. Plastics that are 6 James & Wells Ref: 130113/62 commonly foamed include vinyls, polystyrene, polyethylene, phenolics, silicones, cellulose acetate, urethanes and polyurethane.

In a preferred embodiment the foamed plastics material is a polyisocyanurate material.

In another preferred embodiment the foamed plastics material is high density polyurethane.

In a preferred embodiment the foamed plastics material has a density greater than 15 kg per cubic meter.

In practice the choice of foamed material used to form the core may be chosen to 10 meet specific requirements, such as rigidity, density, cost, ease of manufacture and so on, so that a preference for a polyisocyanurate (PIR) or high density polyurethane material should not be seen as limiting.

In a preferred embodiment the embedded mesh is formed from a resilient material.

Reference to a resilient material should be understood to refer to a material that, 15 following deformation, exhibits a tendency to return to its original shape and form when the forces producing the deformation are removed. Common forms of deformation include extension (stretching) and compression.

In a preferred embodiment the embedded mesh is stretched.

By extending the mesh beyond its natural form (i.e. its form when free of externally 20 applied forces) a tensional force is introduced into the mesh, the tensional force acting to restore (or try to restore) the mesh to its natural form. A stretched mesh formed inside the core applies a compression force to the core which may strengthen the core, especially against bowing. 7 James & Wells Ref: 130113/62 In a preferred embodiment the embedded mesh is stretched in at least one direction.

In another preferred embodiment the embedded mesh is stretched in at least two substantially orthogonal directions.

Stretching the mesh both lengthwise and transversely to the slab core may increase structural integrity and strength of the composite core in both directions.

In a preferred embodiment the mesh is a fibre network.

In a preferred embodiment the mesh is located within the core between a face of the board and the centre of the moulded core.

In this embodiment the mesh is located within the core so that it is closer to one face of the board than the other. In particular the mesh may be located closer to the front face of the board than to the rear face. This may provide additional resistance to impact to the front face of the board, while retaining the overall strengthening of the board as provided by the tensioned mesh. In this way the 15 front face may be more resilient to impacts, which may improve the usable lifetime of the board and reduce maintenance costs.

According to another aspect of the present invention there is provided a method of forming a board, the board including a moulded core and an embedded mesh, the method characterised by the steps of: a) forming a first layer of foam material in a mould; b) placing a mesh over the first foam layer; c) adding a second layer of foam over the mesh; and 8 James & Wells Ref: 130113/62 d) allowing the foam material to set.

In a preferred embodiment the method includes the step of placing a liner in the mould prior to adding the foam material.

In a preferred embodiment the method includes the step of placing a second liner 5 over the second layer of foam.

In a preferred embodiment the method includes the step of holding the mesh in a stretched condition until the foam material sets.

According to another aspect of the present invention there is provided a method of forming a board, the board including a moulded core and an embedded mesh, the 10 method characterised by the steps of: a) placing a liner into the base of a mould; b) adding a first layer of foam over the liner; c) placing a mesh over the first layer of foam; d) adding a second layer of foam over the mesh; e) placing a second liner over the second layer of foam; and f) allowing the foam layers to set.

According to another aspect of the present invention there is provided a method of forming a board, the board including a moulded core and an embedded mesh, the method characterised by the steps of: g) forming a first section of wall board using steps a) to f) above; 9 James & Wells Ref: 130113/62 h) repeating steps a) to f) above with the additional step of tensioning the mesh by pulling it away from the mesh held in the first section of wall board as the mesh is placed over the first layer of foam.

The above method may be used to advantage when initiating a production run of 5 the board. Initially there may be no mechanism for holding an end of the mesh so that it can be tensioned. This is achieved during production by a section of hardened board which holds the mesh and forms an anchorage against which the mesh can be pulled.

In step g) of the above method the first section of board is formed including an 10 embedded mesh, but not under tension. This first section of board is allowed to set, thus fixing (or anchoring) an end of the mesh, so that in step h) the mesh (from then on) may be tensioned by pulling against the anchored end.

According to another aspect of the present invention there is provided a machine for forming a board, the board including a moulded core and an embedded mesh, 15 the machine including: a mould for the board; a conveyor belt, at least part of which is configured to move through the mould; a first foam delivery system configured to place a first layer of foam material 20 into the mould; a second foam delivery system configured to place a second layer of foam material into the mould, characterised in that James & Wells Ref: 130113/62 the machine includes a mesh feed configured to place a mesh between the first layer of foam and the second layer of foam.

In a preferred embodiment the first foam delivery system is a foam injection nozzle.

In a preferred embodiment the second foam delivery system is a foam injection 5 nozzle.

In a preferred embodiment the mesh feed includes a roller.

In a preferred embodiment the machine includes a mesh tensioning device.

Preferably the mesh tensioning device is a control on the mesh feed which releases the mesh into the mould at a slower speed than the speed of the 10 conveyor belt.

In some embodiments the mesh tensioning device may be a spring loaded roller, the spring biased to apply tension to the mesh attached to the previously formed wall board.

In a preferred embodiment the machine includes a mesh edge tensioning device.

Preferably the mesh edge tensioning device engages with each side of the mesh and applies a force across the mesh to pull the sides of the mesh apart.

In a preferred embodiment the machine includes a cutter to cut the board into sections after the foam material has set, In a preferred embodiment the cutter is a blade.

In a preferred embodiment the machine includes a first liner feed configured to place a first sheet of liner into the mould before the first layer of foam material is added to the mould. 11 James & Wells Ref: 130113/62 Preferably the first liner feed is a roll of paper arranged such that paper is drawn or fed from the roll onto the conveyor belt.

In a preferred embodiment the machine includes a second liner feed configured to place a second sheet of liner over the second layer of foam material.

Preferably the second liner feed is another roll of paper arranged such that paper is drawn or fed from the roll onto the top of the second layer of foam.

A board of the present invention may have a number of advantages over a wall board of the prior art, such as drywall or Gib™ board, including: improved structural strength and integrity, with the pre-tensioned mesh 10 providing additional strength to the board; improved impact resistance to a face, which may increase the usable lifetime of the board and reduce maintenance costs in those embodiments where the mesh is placed close to the face; ease of handling as the foamed plastics core may be less dense than 15 gypsum (the core used in most drywall and Gib™ board), for example a standard wall board sheet of 1200 mm x 2400 mmx10 mm may weigh around 1 kg against around 20 kg for corresponding Gib™ board, so that less effort is required to lift and manoeuvre the wall board, especially when used as a liner for a ceiling, and as a consequence a job may be finished 20 more quickly, saving labour costs as well as energy; improved thermal and acoustic insulation in comparison to Gib™ board due to the foamed plastics core, which may result in lower heating costs for a dwelling and a less noisy environment; 12 James & Wells Ref: 130113/62 the board may be cut to shape easily and cleanly with a knife (such as a craft knife) leaving a stable, well formed edge. In comparison, the gypsum core of Gib™ board has a tendency to crumble and erode with time/handling and does not form a stable, well formed edge; • transport costs per sheet may be reduced as more sheets can be carried on a vehicle before reaching the vehicle's weight rating than is the case with the much heavier drywall or Gib™ board sheets of comparable size; and foamed plastic cored wall boards including a tensioned mesh may be relatively strong, impact and fire resistant and may support fasteners, such as screws, glue, staples and the like used to fix other items to the board. Typically Gib™ board will not hold a fastener of these types as the action of making a hole and inserting the fastener tends to break up the gypsum core reducing the ability of the core to hold the screw.

BRIEF DESCRIPTION OF THE DRAWINGS Further aspects of the present invention will become apparent from the ensuing description which is given by way of example only and with reference to the accompanying drawings in which: Figure 1A Figure 1B Figure 1C shows a schematic side view of a wall board according to one embodiment of the present invention; shows a schematic, expanded view of a wall board according to the embodiment shown if Figure 1A; shows a schematic side view of a portion of a wall board according 13 James & Wells Ref: 130113/62 to the embodiment shown if Figure 1A; and Figure 2 shows a schematic view of a machine for producing a wall board according to another aspect of the present invention.

BEST MODES FOR CARRYING OUT THE INVENTION A board in the form of an interior liner wall board is generally indicated by arrow 1 in Figures 1A to 1C. Figure 1B shows an expanded view of a wall board 1 so that the various components can be seen clearly.

The wall board 1 is in the form of a slab having dimensions 1200 mm x 2400 mm x 10 mm, these being standard for plaster board used in New Zealand. Other sizes 10 (generally different lengths of 1200mm wide board) can be produced as required.

The wall board 1 has a moulded foamed plastics core (2, 3) formed from polyisocyanurate (PIR) or high density polyurethane blown foam. Both materials are well known in the art. Polyisocyanurate (PIR) material may provide excellent resistance to moisture penetration. A suitably polyurethane material may be a 2-15 part mixture commonly referred to as P32.

A standard 1200 mm x 2400 mm x 10 mm wall board made from PIR or P32 core weighs around 0.9 kg, or around 5% of the weight of a Gib™ board or the same dimensions.

The core has a front face 4 and a rear face 5, the front face 4 being the face 20 normally facing into the interior of the structure.

The front face 4 includes a rebate 6 of around 50 mm x 1 mm along each side edge (7, 8) (ie, the edge where typically the board may be placed adjacent to another board to form a wall for example) as shown in Figure 1C. The dimensions of the rebate 6 are such that a commercially available joining tape 30, having cross 14 James & Wells Ref: 130113/62 section dimensions of around 80 mm x 0.5 mm, can be attached to the rebates 6 of adjacent boards so that it covers the joint between them. The joining tape may form a good bed for plaster 31 across the join so that a smooth finish may be readily obtained with relatively little additional work and plaster.

The core (2, 3) of the wall board 1 is sandwiched between two liners (9, 10) which are attached to the front face 4 and the rear face 5 respectively. The liners (9,10) are sheets of paper available commercially as Paperboard Corestock 220 GSM. This is a paper that weighs 220 grams per square meter. The colour of the paper is typically brown, but may be any desired colour.

The wall board 1 includes a mesh 11 that is embedded within the core (2, 3). The mesh 11 is in the form of a rectangular net, having a mesh size of 2.5mm x 2.5mm. The mesh is commercially available (for example from Polynet Products Limited) under the trade name Tenax™. It is formed from 100% fibreglass having an alkali resistant finish and weighs around 62 grams per square meter.

The mesh 11 is located within the core such that it is between the front face 4 and the centre of the moulded core (2, 3), as shown in Figure 1.

The mesh 11 is held under tension (both longitudinally and transversely) within the solid core (2, 3).

The wall board 1 is formed by moulding in a machine generally indicated by arrow 20 12 in Figure 2. The machine 12 includes a mould for forming the board 1. The mould is in two sections, a lower section 13 and an upper section 14, the two sections configured to apply pressure to the board as it moves through the mould. The mould has an internal width of 1200 mm and has a length of around 100 m to allow time for the foamed material to harden at normal conveyor belt (15,16) James & Wells Ref: 130113/62 operating speeds (this length being indicated in Figure 2 by the "break" in the length of the machine).

The upper section 14 of the mould is configured to form a rebate on each side of the front face 4 of the board as it is formed in the mould.

The machine includes two conveyor belts, a lower belt 15 and an upper belt 16, the lower conveyor belt 15 being arranged to move along the upper surface of the lower section 13 of the mould and the upper conveyor belt 16 being arranged to move along the lower surface of the upper section 14 of the mould. The conveyor belts 15,16 carry the board through the mould 13,14, the speed of the conveyor 10 belts being chosen such that the foam hardens into a strip of board within the length of the mould.

A sheet of Paperboard Corestock 220 GSM is fed from a roller 17 onto the surface of the lower conveyor belt 15 to form a liner 10 for the rear face of the board.

A first foam delivery system, in the form of an array of nozzles, 18, is configured to 15 place a first layer 3 of polyisocyanurate foam (or P32 polyurethane foam) onto the liner 10.

A mesh feed, in the form of a roller 19, is configured to apply a layer of Tenax™ mesh 11 over the first layer of foam. The speed of revolution of the roller 19 is controlled to be around 1% slower than the speed of the conveyor belts. In this 20 way the mesh is tensioned (stretched) as it is fed into the mould. In continuous production an end of the mesh distal to the roller 19 is fixed in the hardened board (which is moving away from the roller 19 at the speed of the conveyor belts 15,16), thus providing an anchoring against which the mesh 11 can be pulled.

Tension is also applied transversely across the mesh 11 by a mesh edge 25 tensioning device in the form of a set of wheels 21 arranged along each side of the 16 James & Wells Ref: 130113/62 upper surface of the lower mould 13, the alignment of the wheels being such as to stretch the mesh from side to side.

A second foam delivery system, in the form of an array of nozzles 20, is configured to place a second layer 2 of polyisocyanurate foam (or P32 polyurethane foam) 5 over the mesh 11. In this way the tensioned mesh 11 is embedded in a foam core (2, 3).

The description given here has been in terms of two layers of foam, 2 and 3, for clarity of description only. In practice while two applications of foam are made, they form a single core of foam with the mesh 11 embedded within the core.

A second sheet of Paperboard Corestock 220 GSM is fed from a roller 22 onto the top of the second layer 2 of foam to form a liner 9 for the front surface of the board.

A machine 12 as described above can produce long run, continuous strips of wall board. The board is carried through the mould 13, 14 by the conveyor belts 15, 16 15 which operate at a speed chosen such that the P32 foam has hardened before the section of board reaches the end of the machine. This process typically requires around 2 minutes.

A cutter, in the form of a blade 23, is situated at a location where the board has hardened. The blade 23 is operated to cut the board into the desired lengths 20 (typically 2400 mm).

Aspects of the present invention have been described by way of example only and it should be appreciated that modifications and additions may be made thereto without departing from the scope thereof as defined in the appended claims. 17

Claims (30)

WHAT WE CLAIM IS:

1. A board including: a moulded core formed from a foamed material, and a mesh wherein the mesh is embedded within the foamed material during formation of the board, characterised in that the embedded mesh is formed of a resilient material that is stretched whilst being embedded within the foamed material and whilst the foam material sets.

2. A board as claimed in claim 1 wherein the board is an interior liner board.

3. A board as claimed in either one of claims 1 or 2 wherein the board is in the form of a slab having a front face and a rear face.

4. A board as claimed in claim 3 including a rebate on an edge of the front face of the board.

5. A board as claimed in any one of claims 1 to 4 including a liner attached to a face of the moulded core.

6. A board as claimed in claim 5, wherein the liner is paper.

7. A board as claimed in any one of claims 1 to 6, wherein the moulded core is sandwiched between two liners.

8. A board as claimed in any one of claims 1 to 7, wherein the moulded core has a density greater than 15 kg per cubic meter.

9. A board as claimed in any one of claims 1 to 8, wherein the foamed material is a foamed plastics material. 18

10. A board as claimed in claim 9 wherein the foamed plastics material is a polyisocyanurate material.

11. A board as claimed in claim 9, wherein the foamed plastics material is high density polyurethane.

12. A board as claimed in any one of claims 1 to 11 wherein the embedded mesh is stretched in at least two substantially orthogonal directions.

13. A board as claimed in any one of claims 1 to 12, wherein the mesh is a fibre network.

14. A board as claimed in any one of claims 1 to 13 wherein the mesh is located within the core between a face of the board and the centre of the moulded core.

15. A method of forming a board, the board including a moulded core and an embedded mesh, the method characterised by the steps of: a) forming a first layer of foam material in a mould; b) placing a mesh over the first foam layer; c) adding a second layer of foam over the mesh; d) allowing the foam material to set to form a first section of board; and e) repeating steps a) to c) above to form a subsequent section of the board with the additional step of tensioning the mesh by pulling it away from the mesh held in the first section of board as the mesh is placed over the first layer of foam, the second layer of foam is added, and the foam material sets. 19

A method of forming a board as claimed in claim 16 including the step of placing a liner in the mould prior to adding the foam material.

A method of forming a board as claimed in either one of claims 16 or 17 including the step of placing a second liner over the second layer of foam.

A machine for forming a board having a moulded core and an embedded mesh, the machine including: a mould for the board; a conveyor belt configured to move through the mould; a first foam delivery system configured to place a first layer of foam material into the mould; a second foam delivery system configured to place a second layer of foam material into the mould; and a mesh feed configured to place a mesh between the first layer of foam and the second layer of foam, characterised in that the machine includes a mesh tensioning device to hold the mesh in tension as the mesh is embedded into the foam material and whilst the foam material sets.

A machine as claimed in claim 18 wherein the mesh feed includes a roller.

A machine as claimed in claim 18 or 19 wherein the mesh tensioning device is a control on the mesh feed which releases the mesh into the mould at a slower speed than the speed of the conveyor belt.

A machine as claimed in claim 18 or 19 wherein the mesh tensioning device includes a spring loaded roller, the spring biased to apply tension to the mesh attached to a section of previously formed board. 20

22. A machine as claimed in any one of claims 18 to 21 wherein the first foam delivery system is a foam injection nozzle.

23. A machine as claimed in any one of claims 18 to 22 wherein the second foam delivery system is a foam injection nozzle.

24. A machine as claimed in any one of claims 18 to 23 including a cutter.

25. A machine as claimed in claim 24 wherein the cutter is a blade.

26. A machine as claimed in any one of claims 18 to 25 including a first liner feed configured to place a first sheet of liner into the mould before the first layer of foam material is added to the mould.

27. A machine as claimed in any one of claims 18 to 26 including a second liner feed configured to place a second sheet of liner over the second layer of foam material.

28. A board as claimed in claim 1 substantially as herein described with reference to and as illustrated by the accompanying description and drawings.

29. A method of forming a board as claimed in claim 1 substantially as herein described with reference to and as illustrated by the accompanying description and drawings.

30. A machine for forming a board as claimed in claim 1 substantially as herein described with reference to and as illustrated by the accompanying description and drawings. Lite Building Systems Ltd by its authorised agents James & Wells Intellectual Property 21