AU2019232946A1

AU2019232946A1 - Composite panels

Info

Publication number: AU2019232946A1
Application number: AU2019232946A
Authority: AU
Inventors: Daniel Charles Underwood
Original assignee: Underwood Cos Holdings Pty Ltd
Current assignee: Underwood Cos Holdings Pty Ltd
Priority date: 2018-09-21
Filing date: 2019-09-20
Publication date: 2020-04-09
Also published as: WO2020056450A1

Abstract

Abstract with Fig 1 A composite panel assembly 10 comprising a sandwich structure using a structural grid frame 11 between an underside of heat shrink plastic sheet 12 and an upper side moisture impervious sheet 13. The edges of the sheet 12 at 14 form a congealed mass where respective edges of the sheets 12 and 13 have been welded together during a heating process and also along each 15 and 16 noting that the sheet has been fed into a heater and that the relative shrinkage is such that the edge of sheet 12 has started on the upper side and has pulled the sheet 13 around the frame to the opposite side so that margin of the sheet 12 is on the underside. I-~

Description

COMPOSITE PANELS

TECHNICAL FIELD [0001] THIS INVENTION relates to composite panels and in particular but not limited to composite panels forming lost formwork for inhibiting moisture passage across the formwork.

BACKGROUND [0002] Concrete construction often employs formwork that is stripped after concrete has sufficiently cured. In other cases lost formwork is left in-situ. Moisture at any time can be detrimental to the finished concrete. It is an object of the present invention to provide a panel which may be used in concrete formwork, especially lost formwork, to inhibit the passage of moisture across the formwork.

[0003] The International Search Report conducted by the Patent Office in respect of Provisional Application 2018903563 revealed the following patent documents EP2857605A1;

EP1837164A2; US4150186; US5023143; US5676894. In that report EP2857605A1 is considered relevant but according to the report lacks perforated heat securement layer but according to the report that feature may be provided by US4150186. However, upon close examination the perforations in US4150186 are used to draw hot melt adhesive by suction as part of the particular and quite different process described in that patent.

OUTLINE [0004] In one broad aspect there is provided a composite panel assembly having a structural grid frame supporting at least two layers of thin plastics film, the first layer being a securement layer and the second layer being a moisture impermeable layer, the layers being secured to the frame.

2019232946 20 Sep 2019

Preferably, the layers are secured together and thereby being secured to the frame. The layers may be a tight fit and secured about a peripheral edge of the frame as an envelope or across mating surfaces or through the frame or be independently secured to the frame.

[0005] In a preferred embodiment the composite panel assembly comprises a sandwich structure where the frame is between the securement layer and the moisture impermeable layer. Typically, in this embodiment the layers are secured to each other through spaces in the frame.

[0006] The securement layer may be used to secure the assembly by being heated to shrink about the frame and/or heated to weld itself to the other layer without affecting the moisture impermeability characteristic of that layer. In this regard there is preferably a temperature differential between the melting points of the plastics employed so that during a process heating phase, heat is applied to effect the securement layer to a greater degree that the moisture impermeable layer. As part of this process it is preferable that a margin of at least a portion of the securement layer be wrapped around and over the frame and a corresponding margin of the other layer so that upon a heating and rolling stage the wrapped over portion adheres to the other sheet and by reason of its shrinkage pulls both sheets drum tight over the frame. The heating and rolling stage preferably includes the use of one or more blowers to aid adhesion of the overlapping marginal edge portions of the layers.

[0007] The frame may be of a metal grid frame and may be a rigid frame or may be bendable or otherwise deformable so that it may be fashioned into different formwork shapes as in for example a trench like shape for footings and so on. The plastics layers may be applied so that in a finished flat assembly the whole assembly may be deformed as may be required.

[0008] Preferably, in use marginal end portions of adjacent assemblies may overlap or a tape may be employed with the tape overlapping abutting edges. Where the frames have a grid of wires, typically welded together at the junctures of the wires in one embodiment at least the first wire running along the line of the intended overlap is located on the opposite side of the frame so that the wires extending across the overlap of the overlapping panels are in contact across the full width of the overlap by reason of the wire being on the opposite side.

2019232946 20 Sep 2019 [0009] The marginal edge regions of the moisture impermeable layer may extend out and around onto the opposite side of the frame.

[0010] In another aspect the present invention resides in a method of producing a composite panel assembly as described above, the method including the following steps:- (1) providing a supporting frame;

(2) applying the said two layers to the frame;

(3) subsequently heating the frame and the layers applied thereto to complete securement of the layers to the frame.

[0011] Preferably step (2) includes the further step of applying the moisture impermeable layer to the frame with an edge region or otherwise accumulated marginal edge region and step (3) includes the further step of applying the securement layer over the marginal edge region and then securing them together. In use, the panel assemblies may be joined together along edges, at least to juxtaposed panel assemblies, the use of a tape, a first panel assembly having a vertical edge, the tape secured to the first panel assembly along a margin and having a fold which extends along the edge, the tape having a releasable layer adapted to be peeled away to expose about half of an adhesive layer and in use being peeled away the full vertical length of the first panel assembly, at the same time or subsequently upon a second panel assembly having a matching vertical edge being brought into abutment or overlaying the edge of the first panel assembly, a further release sheet being progressively peeled away to expose more of the adhesive layer and as it is peeled away the tape may be manually applied to the second panel assembly, thus the two panel assemblies a sealed together.

BRIEF DESCRIPTION OF THE DRAWINGS [0012] In order that the present improvements may be more readily understood and put into practical effect reference will now be made to the accompanying drawings and wherein:Figure 1 is an underside view of a composite panel assembly according to a preferred

2019232946 20 Sep 2019 embodiment of the present invention;

Figures 2 and 3 are a details 2 and 3 from Figure 1;

Figure 4 is a schematic section through a panel just prior to entering an oven, the section being across the direction of travel;

Figures 5A and 5B are drawings showing the passage of a panel assembly through a heating process;

Figure 6 is detail of the process by which the sheets are heated and welded together in accordance with Figures 5A and 5B; and

Figures 7 through 9 are drawings showing how two adjacent panel assemblies may be joined or connected along adjacent vertical edges.

METHOD OF PERFORMANCE [0013] Referring to the drawings and initially to Figures 1 through 3 there is illustrated a composite panel assembly 10 comprising a sandwich structure using a structural grid frame 11 between an underside of heat shrink plastic sheet 12 and an upper side moisture impervious sheet 13. The view in Figures 1 and 3 is from an underside and along the edges of the sheet 12 at 14 there is shown a congealed mass where respective edges of the sheets 12 and 13 have been welded together during a heating process and also along each 15 and 16 noting that the sheet has been fed into a heater in the direction of arrow 17. It will be appreciated that the relative shrinkage is such that the edge of sheet 12 has started on the upper side and has pulled the sheet 13 around the frame to the opposite side so that margin of the sheet 12 is on the underside.

[0014] The sheet 12 is perforated to allow air to be expelled as the composite panel is being formed in an oven while passing through upper and lower rollers as depicted more clearly in Figure 6. This process results in the spaces between the grid like frame being occupied by the plastics sheets and the plastic sheets therein being welded together across the surface at 18.

[0015] Referring now to Figure 4 there is illustrated the arrangement of the sheets 12 and 13 as they reach the rollers. This is a schematic only it being appreciated that in a dynamic process blowers are used to lift the margin 19 and as the assembly moves through an oven at an

2019232946 20 Sep 2019 appropriate temperature and speed, the sheets soften, the margins 19 will sag onto the sheet 13 and the welding process and shrinking process will begin, the press rollers will then push the sheets together along the edges and inside the frame. Air will also be expelled by the rollers, through the perforated heat shrinkable sheet 12. The marginal edge section 19 is wrapped around and overlapping the vapour impermeable sheet 13 at its marginal edge 20 on each side so that as the panel passes through the rollers 21 and 22 and pressure is duly applied as illustrated in Figure 6 the marginal edge section 19 adheres to the marginal edge section 20. The heat shrinkable sheet pulls the other sheet around the edge 23 of the grid frame to the position illustrated in Figure 1 thus both sheets of plastic have become taught while at the same time being welded together along the side edges and in the spaces 18.

[0016] Referring now to Figures 5A and 5B a roller conveyor not shown carries the frame 11 which draws the plastic sheets off rollers 24 and 25, the roller 25 being marginally wider as shown in Figure 4, a heated cutter 26 at the entrance to oven cuts and welds what becomes the trailing edge of one panel 27 from the leading edge of the next panel 28. Leading edge 28 is shown just about to enter the rollers 21 and 22.

[0017] Before entering the oven the bottom sheet 12 lays flat along its side edges. In the oven blowers are used to lift the side edges and as it softens it will approximate the arrangement of Figure 4 so that as it passes through the rollers 21 and 22 and combined with the relative shrinkage properties as the whole assembly cools it is transformed to the arrangement of Figures 1-3.

EXAMPLES [0018] Set out in the table below are examples of two applications of the above invention where a first perforated sheet is used with a similar characteristic sheet and in the second column a relatively thin high shrink film or films are used with a thicker non-permeable sheet.

TECHNICAL SPECIFICATION

PRODUCT

Same plastic heat shrink sheet both sides

Addition of thicker layer lower shrink sheet on one side or

2019232946 20 Sep 2019

		between high shrink sheets
Mesh	VR 6 Standard	VR 6 Standard
Main Wire Size [Nominal]	5.5 mm Diameter	5.5 mm Diameter
Main Wire Spacing	150 mm c/c	150 mm c/c
Cross Wire Size [Nominal]	4.0 mm Diameter	4.0 mm Diameter
Cross wire Spacing	100 mm c/c	100 mm c/c
Wire Specification	High tensile steel of strength 485 Nmm2. Non Galvanised	High tensile steel of strength 485 Nmm2. Non Galvanised
Polyethylene Colour	Green both side	Green on Bottom , Yellow or clear on Top
Polyethylene Film [Green]	0.12 mm thick - one layer each side	0.12 mm thick - One layer on bottom side
LDPE Film [Yellow or clear]		0.25 mm thick - One layer on Top side
Oven Temperature	200 - 220 Degree C	180 - 190 Degree C
Conveyor Speed	9 meter / minute	6 meter / minute
Weight [ m2 ]	2.64 kg	2.8 kg
Standard Size	PCS / Hr	PCS / Hr
600 mm x 2250 mm	150 pcs	100 pcs
900 mm x 2250 mm	100 pcs	80 pcs
1200 mm x 2250 mm	80 pcs	60 pcs
1500 mm x 2250 mm	65 pcs	50 pcs

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1800 mm x 2250 mm	50 pcs	40 pcs
Standard Plastic — TOP	2370 mm	2300 mm
Bottom	2370 mm	2370 mm

[0019] The present invention results in a composite panel that has plastics sheet drawn tight around a frame. In order to use the panels in an assembly of the panels applicant has devised the use of a tape. One example is shown in Figures 7 through 9. A first panel 30 has a vertical edge 31, a tape 32 is secured to the panel along a margin 33 and has a fold 34 which extends parallel with edge 31. This can be made up at the factory or it can be added on-site. A release sheet 35 may be peeled away as shown in Figure 8 to expose about half of an adhesive layer 36, this is peeled away the full vertical length of the panel 30. At the same time or subsequently upon a second panel 39 (in phantom in Figure 9) with its vertical edge 38 brought into abutment with edge 31 a release sheet 39 may be progressively peeled away to expose more of the adhesive layer 36 and as it is peeled away the tape may be manually applied to panel 37. This the two panels a sealed together. This may be repeated with more panels to make a line of panels. In the case where panels are to overlap then as shown in Figure 9 the panel assembly shown in solid on the right would have its first wire wended on the opposite side to that shown so that the next panel may slide into overlap without the wire interfering. This means the edge of the panel shown in phantom would slide up and abut with the next wire. If the overlap is more than than more wires would be welded onto the opposite side. It follows that frames could be made with one wire on each edge welded onto the opposite side and it is just a matter of flipping alternative panels.

[0020] Whilst the above has been given by way of illustrative example many variations and modifications will be apparent to those skilled in the art without departing from the broad ambit and scope of the invention as set out in the appended claims.

Claims

1 A composite panel assembly having a structural grid frame supporting at least two layers of thin plastics film, the first layer being on one side of the frame and the second layer being a moisture impermeable layer on the other side of the frame, the layers being secured to the frame, a margin of at least a portion of one layer be wrapped around and over a periphery of the frame so the layers are secured together just inside the periphery of the frame.

(2) applying the said two layers to the frame;

2. A composite panel assembly having a structural grid frame supporting at least two layers of thin plastics film, the first layer being a securement layer and the second layer being a moisture impermeable layer, the layers being secured to the frame.

3. A composite panel assembly having a structural grid frame supporting at least two layers of thin plastics film on opposite sides of the frame, the grid frame having spaces where the layers touch, the first layer being a perforated heat shrink securement layer and the second layer being a moisture impermeable layer, the layers being secured to each other along overlapping edges and thereby to the frame by a heating process whereby the layers weld together along the overlapping edges and in the spaces between the frames.

4. The invention according to any one of the preceding claims wherein the layers are secured together and thereby being secured to the frame.

5. The invention according to any one of the preceding claims wherein a heating process has been used to apply the layers tightly to the frame there being a temperature differential between the melting points of the plastics employed so that during a process heating phase, heat is applied to effect the securement layer to a greater degree that the moisture impermeable layer.

6. The invention according to any one of the preceding claims wherein a heating process has been used to apply the layers tightly to the frame and as part of this process a margin of at least a portion of the securement layer be wrapped around and over the frame and over a corresponding margin of the other layer so that upon a heating and rolling stage the wrapped

2019232946 20 Sep 2019 over portion adheres to the other sheet and by reason of its shrinkage pulls both sheets drum tight over the frame.

7. The invention according to any one of the preceding claims wherein a heating process has been used to apply the layers tightly to the frame, followed by a rolling stage, the heating stage being accompanied by the use of one or more blowers to aid adhesion of overlapping marginal edges portions of the layers.

8. The invention according to any one of the preceding claims wherein marginal edge regions of the moisture impermeable layer extend around onto the opposite side of the frame.

9. A method of producing a composite panel assembly as described above, the method including the following steps:- (1) providing a supporting frame;

10. The method according to claim 9 wherein step (2) includes the further step of applying the moisture impermeable layer to the frame with an edge region or otherwise accumulated marginal edge region and step (3) includes the further step of applying the securement layer over the marginal edge region and then securing them together.

11. The method according to claim 9 or claim 10 wherein there is employed a heating stage and a rolling stage, the wrapped over portions of the layers adheres to each other and by reason of differential shrinkage under heat one sheet pulls both sheets drum tight over the frame.

12. The method according to claim 9 or claim 10 or claim 11 wherein one or more blowers are employed to aid adhesion of overlapping marginal side edges of the layers.

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13. The invention according to many one of the preceding claims where, the layers and method employed are substantially in accordance with the following technical specification:

TECHNICAL SPECIFICATION

PRODUCT Same plastic heat shrink sheet both sides Addition of thicker layer lower shrink sheet on one side or between high shrink sheets Mesh VR 6 Standard VR 6 Standard Main Wire Size [Nominal] 5.5 mm Diameter 5.5 mm Diameter Main Wire Spacing 150 mm c/c 150 mm c/c Cross Wire Size [Nominal] 4.0 mm Diameter 4.0 mm Diameter Cross wire Spacing 100 mm c/c 100 mm c/c Wire Specification High tensile steel of strength 485 Nmm2. Non Galvanised High tensile steel of strength 485 Nmm2. Non Galvanised Polyethylene Colour Green both side Green on Bottom , Yellow or clear on Top Polyethylene Film [Green] 0.12 mm thick - one layer each side 0.12 mm thick - One layer on bottom side LDPE Film [Yellow or clear] 0.25 mm thick - One layer on Top side Oven Temperature 200 - 220 Degree C 180 - 190 Degree C Conveyor Speed 9 meter / minute 6 meter / minute Weight [ m2 ] 2.64 kg 2.8 kg Standard Size PCS / Hr PCS / Hr

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600 mm x 2250 mm 150 pcs 100 pcs 900 mm x 2250 mm 100 pcs 80 pcs 1200 mm x 2250 mm 80 pcs 60 pcs 1500 mm x 2250 mm 65 pcs 50 pcs 1800 mm x 2250 mm 50 pcs 40 pcs Standard Plastic — TOP 2370 mm 2300 mm Bottom 2370 mm 2370 mm

14. In use, the panel assemblies according to any one of claims 1-8 or by the method of any one of claims 9-11 or as specified in claim 13, at least ot juxtaposed panel assemblies, the use of a tape, a first panel assembly having a vertical edge, the tape secured to the first panel assembly along a margin and having a fold which extends along the edge, the tape having a releasable layer adapted to be peeled away to expose about half of an adhesive layer and in use being peeled away the full vertical length of the first panel assembly, at the same time or subsequently upon a second panel assembly having a matching vertical edge being brought into abutment or overlaying the edge of the first panel assembly, a further release sheet being progressively peeled away to expose more of the adhesive layer and as it is peeled away the tape may be manually applied to the second panel assembly, thus the two panel assemblies a sealed together.

15. The invention according to any one of the preceding claims wherein in use marginal end portions of adjacent assemblies may overlap and where the frames have a grid of wires, at least the first wire running along the line of the intended overlap is located on the opposite side of the frame so that the wires extending across the overlap of the overlapping panels are in contact across the full width of the overlap by reason of the wire being on the opposite side.

16. The invention according to any one of the preceding claims wherein edges of the layers are joined to form a congealed mass where respective edges of the sheets have been welded together during a heating and rolling process.