WO2008130329A1

WO2008130329A1 - Composite board

Info

Publication number: WO2008130329A1
Application number: PCT/SG2008/000122
Authority: WO
Inventors: Wei Fern Choo
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-04-18
Filing date: 2008-04-15
Publication date: 2008-10-30
Anticipated expiration: 2009-10-18
Also published as: SG147328A1

Abstract

A composite board comprising a first layer of material consisting of one material from a first hard plastic material set; a second layer consisting of a metal having at least a substantially high strength to weight ratio; a third layer of material consisting of a second hard plastic material; a fourth layer consisting of a metal having at least a substantially high strength to weight ratio; a fifth layer of material consisting of one material from the first hard plastic material set, where the layers are bonded in a sequential fashion and the resulting board is laminated.

Description

COMPOSITE BOARD

FIELD OF THE INVENTION

The invention relates to a composite board. The invention is particularly suitable for use as a shuttering board and it is in this context that the invention will be described.

BACKGROUND TO THE INVENTION

The following discussion of the background to the invention is intended to facilitate an understanding of the present invention. However, it should be appreciated that the discussion is not an acknowledgment or admission that any of the material referred to was published, known or part of the common general knowledge in any jurisdiction as at the priority date of the application.

Shuttering boards are commonly used at construction sites to maintain poured concrete in a desired shape. It is particularly used in maintaining poured concrete that, when set, forms a vertical pylon or the like. This process of maintaining the poured concrete in predefined shapes is also known as formwork.

There are essentially three types of shuttering boards that can be used:

Plywood shuttering boards. Such shuttering boards are cheap. But subject to degradation with each use. As a result, plywood shuttering boards are often re-used somewhere between 8 to 10 times before they need to be changed. Changing such shuttering boards consumes additional labour and material costs. Furthermore, the used plywood shuttering boards must be disposed of in some manner, often by incineration, which creates further environmental problems.

Steel shuttering boards. Being made of a more durable material, steel shuttering boards may be re-used up to 100 times before needing to be changed. However, this durability is also a disadvantage as such shuttering boards are difficult to handle and shape at the construction site. Plastic shuttering boards. Plastic shuttering boards have been introduced to the market with limited success. The main reasons for this lack of success has been their low strength to weight ratio. While some attempts to improve the strength to weight ratio of plastic shuttering boards have been technically successful, it has been done at such a high production cost that the commercial viability of such boards has been significantly compromised.

It is therefore an object of the present invention to produce a composite shuttering board which has significant durability that can be recycled.

SUMMARY OF THE INVENTION

Throughout this document, unless otherwise indicated to the contrary, the terms "comprising", "consisting of, and the like, are to be construed as non-exhaustive, or in other words, as meaning "including, but not limited to".

In accordance with a first aspect of the invention there is a composite board comprising five layers of material, the first layer of material consisting of one material from a first hard plastic material set, the second layer consisting of a metal having at least a substantially high strength to weight ratio, a third layer of material consisting of a second hard plastic material, a fourth layer consisting of a metal having at least a substantially high strength to weight ratio, a fifth layer of material consisting of one material from a first hard plastic material set, where the layers are bonded in a sequential fashion and the resulting board being laminated.

Ideally, the material used in the first layer is also used in the fifth layer. It is further preferred that that same material be used in the third layer. In its most preferred embodiment, the composite board is further constructed in a manner that the material used in the second layer is also used in the fourth layer. This allows ease of manufacturing as the number of materials needed for manufacturing to be significantly reduced.

The first hard plastic material set, preferably, includes polyethylene, polyvinyl chlorate or polypropylene. Similarly, the second hard plastic material is preferred to be one of polyethylene, polyvinyl chlorate or polypropylene, the second hard plastic material being in either a solid or foam state. The second hard plastic material may be a recycled or virgin material.

The third layer is ideally made up of aluminium sheeting. This provides the necessary strength to weight ratio, while at the same time having good durability properties.

For most building sites it is preferred that the composite board have a thickness between 9 and 30mm.with the ideal thickness of the composite board being between 10 and 18mm Composite boards of a smaller thickness do not have the strength for general usage on a construction site. Composite boards of greater thickness have limited durability (and may require additional strengthening structures), which further limits the advantages of the current invention, not to mention the attendant manufacturing difficulties.

Boards in the range 10 to 18mm provide the best overall performance and are relatively easy to manufacture compared to boards of other sizes.

The proportions between the differing layers may vary, but ideally the size of the first and fifth layers do not exceed 2mm in thickness. It is also preferred that the thickness of the third layer, as a proportion of the total thickness of the composite board, remains at substantially 80%. The size of the second and fourth layers can vary depending on the overall strength desired for the composite board.

Thermal bonding may be used to sequentially bind each layer to its next layer. It is further preferred that any such bond be waterproof.

In accordance with a second aspect of the present invention there is a method of producing a composite board comprising the steps of:

bonding a first layer made of a material from a first hard plastic material set to a second layer made of a metal having at least a substantially high strength to weight ratio;

bonding the second layer to a third layer made of a second hard plastic material; bonding the third layer to a fourth layer made of a metal having at least a substantially high strength to weight ratio; and

bonding the fourth layer to a fifth layer made of a material from a first hard plastic material set; and

laminating the bonded board.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 is an exploded view of a composite board according to the present invention.

PREFERRED EMBODIMENTS OF THE INVENTION

In accordance with a first embodiment of the invention there is a composite board 10 of 18mm thickness (T). The composite board 10 comprises five layers of various material compositions. The first layer 12 and the fifth layer 14 are made of virgin polyethylene to a thickness of 1.5mm. The second layer 16 and fourth layer 18 are made of aluminium sheeting of 3mm thickness. The third, middle, layer 20 is made of recycled polyethylene. In this embodiment, the polyethylene of the third layer 20 is solid state polyethylene. The third layer has a thickness of 14.4mm

Each layer is thermally bonded to the layer below by adhesives to provide additional strength to the composite board 10 and to make the resulting composite board 10 waterproof. In this manner, first layer 12 is thermally bonded by adhesive to second layer 16, which is in turn thermally bonded by adhesive to third layer 20 and so on. The whole composite board is then laminated using conventional laminating techniques.

The applicant has found that the re-use cycle of composite boards made in accordance with the invention, and used as shuttering boards, ranges from 200 to 500 uses. Furthermore, such composite shuttering boards are completely recyclable. The inherent strength of the composite boards also makes them suitable for other uses such as non-load bearing walls, scaffolding boards, floor decking, roofing shelters and truck cabins.

It should be appreciated by the person skilled in the art that the above invention is not limited to the embodiment described. In particular, the following modifications and improvements may be made without departing from the scope of the present invention:

• The polyethylene material used in the first, third and fifth layers may be replaced with other hard plastic materials such as polyvinyl chloride or polypropylene.

• The material used in the third layer may be of virgin or recycled origin. In this manner, new composite boards may be made by recycling the material used in older composite boards.

• The material used in the third layer may take the form of a foam of such material.

• The thickness of the composite board may vary from the 18mm described above. While the preferred thickness range identified by the applicant is from 9mm to 30mm thickness, boards of other sizes may just as easily be created.

• The thickness of the first and fifth layers should be limited to a maximum of 2mm for any composite board less than or equal to 30mm in thickness (total).

• The thickness of the third layer, as a proportion of the total thickness of the composite board, should be roughly 80%.

• The composite board may have a groove cut along each edge adapted to receive an edge bander made of a plastic material. By edge-banding the board in this manner, the edges of the board are protected during handling and usage - thereby also further prolonging the lifespan of the board. The plastic material that may be used for the edge bander includes polyvinyl chlorate, polyethylene, polypropylene and rubber.

It should be further appreciated by the person skilled in the art that the features described above, where not mutually exclusive, can be combined to form yet further embodiments of the invention.

Claims

Claims:

1. A composite board comprising:

a first layer of material consisting of one material from a first hard plastic material set;

a second layer consisting of a metal having at least a substantially high strength to weight ratio;

a third layer of material consisting of a second hard plastic material;

a fourth layer consisting of a metal having at least a substantially high strength to weight ratio;

a fifth layer of material consisting of one material from the first hard plastic material set,

where the layers are bonded in a sequential fashion and the resulting board is laminated.

2. A composite board according to claim 1 , where the first hard plastic material set comprises the materials: polyethylene; polypropylene; polyvinyl chlorate.

3. A composite board according to either claim 1 or claim 2, where the second hard plastic material is one of: polyethylene; polyvinyl chlorate or polypropylene.

4. A composite board according to any preceding claim, where the second hard plastic material is formed in either a solid or foam state.

5. A composite board according to any preceding claim, where the second hard plastic material is made from recycled material.

6. A composite board according to any preceding claim, where the third layer is made up of aluminium sheeting.

7. A composite board according to any preceding claim where the total thickness of the composite board is between 9 and 30mm.

8. A composite board according to claim 7, where the total thickness of the composite board is between 10 and 18mm.

9. A composite board according to claim 7 or claim 8, where the thickness of the first and fifth layers does not exceed 2 mm.

10. A composite board according to any preceding claim, where the thickness of the third layer represents substantially 80% of the total thickness of the composite board.

11. A composite board according to any preceding claim where each layer is thermally bonded to the next layer in sequence.

12. A composite board according to claim 11 , where the bonding agent used is waterproof.

13. A composite board according to any preceding claim, where the material used in the first layer is the same as the material used in the fifth layer.

14. A composite board according to any preceding claim, where the material used in the third layer is the same as the material used in the first layer.

15. A composite board according to any one of claims 1 to 12, where the material used in the fifth layer is the same as the material used in the third layer.

16. A composite board according to any preceding claim, where the metal used in the second layer is the same as the metal used in the fourth layer.

17. A method of producing a composite board comprising the steps of:

bonding a first layer made of a material from a first hard plastic material set to a second layer made of a metal having at least a substantially high strength to weight ratio; bonding the second layer to a third layer made of a second hard plastic material;

bonding the third layer to a fourth layer made of a metal having at least a substantially high strength to weight ratio; and

laminating the bonded board.

18. A composite board substantially as described herein with reference to the drawings.

19. A method of producing a composite board substantially as described herein with reference to the drawings.