AU722832B3 - Reinforced plasterboard - Google Patents

Description

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A PETTY PATENT

ORIGINAL

Name of Applicant: Actual Inventor: Address of Service: FLETCHER CHALLENGE LIMITED Johan Theodoor Gerlich BALDWIN SHELSTON WATERS MARGARET STREET SYDNEY NSW 2000 Invention Title: REINFORCED PLASTERBOARD Associated Divisional Application No. 90094/98 dated 16 July 1998 The following statement is a full description of this invention, including the best method of performing it known to me/us:la- Field of the invention The present invention relates to reinforced plasterboard. The term "plasterboard" will, for simplicity, be used throughout the specification to refer to a building material which is formed from any cementitious slurry resulting in a panel of indefinite length which will be then cut to the required sizes. The term "panel" is intended in this specification to cover any type of wall, ceiling or floor component of any required size.

Background Numerous proposals have been put forward in the past, many of them patented, relating to the construction of such plasterboard panels.

Typically, such plasterboard panels have utilised a gypsum or Portland cement slurry. Some of the existing proposals for plasterboard have included the introduction of a reinforcement into the cementitious slurry. This reinforcement has been proposed as comprising glass fibre sheets or fibres, for example.

The proposals for reinforced plasterboard to date have all suffered from various disadvantages, and in particular, a failure to provide a plasterboard which has superior strength to resist typical impacts which can result in a building in which the panel is used. For example, in a panel used as an interior lining in commercial and domestic buildings, it would need to be able to satisfactorily resist the forces of human impact over a substantial period of time.

It is an object of the present invention to overcome or ameliorate at least one of the disadvantages of the prior art or to provide a useful alternative.

Summary of the Invention According to the invention there is provided a reinforced plasterboard including: a core of cementitious material having one side and an opposite side; a first external layer of paper adjacent to said one side; at least one internal layer of a mesh reinforcement embedded in said opposite side, said mesh reinforcement including at least one of glass fibre and plastics material; and I a second layer of paper being immediately adjacent to said mesh reinforcement -2such that said core is disposed between said first and second layers.

Preferably said second layer is in contact with said mesh reinforcement.

Preferably said cementitious material includes gypsum plaster.

Brief Description of Drawings Preferred embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings in which:.

Figure 1 is a diagrammatic representation of a production line for the continuous production of a reinforced plasterboard, according to one possible embodiment of the invention; and Figure 2 is a diagrammatic cross sectional view through a reinforced plasterboard according to one possible embodiment of the invention.

Detailed Description Referring to Figure 1, arrow 1 indicates a continuous production line for the manufacturing of a reinforced plasterboard.

The manufacturing process is seen to involve the feeding of a back paper 2 along rollers 3, 4, 5 and 6, and the feeding of a reinforcing mesh-7 from roller 8, so as to lie adjacent the back paper 2, and in this example, contacting it.

The term "paper" is used throughout this specification to refer to any suitable outer facing material which is strong and may be a cardboard such as that made from recycled fibres which may include Kraft paper, or the like. The reinforcing mesh may be of any suitable type providing a required density and strength, but a glass fibre or plastics open weave mesh may be particularly suitable such as the commercially available CRENETE (trade mark) mesh.

A cementitious slurry 15 is shown being fed from a feeder 9 which distributes the slurry 15 across the width of a face paper 11, fed via rollers 12, 13 and 14. The slurry may be of any suitable type, for example a gypsum or Portland plaster. Suitable spreading means may be provided so as to ensure that the slurry 15 is distributed evenly across the width of the paper 11. Also guide means may be provided each side of the production line so as to turn up the sides of i'the paper 11 so as to form a trough in which the slurry 15 can be accommodated. It is envisaged that in one example, the turned up sides of the paper 11 may then be folded over and adhered to the back paper 2.

The process will suitably include heating means to facilitate the setting of the slurry 15 and also cutting means, so that the resultant plasterboard can be cut into appropriate sizes.

It will be appreciated that although single layers of paper 2, 11 and reinforcing mesh 7 are shown being utilised, any number of layers can be used as appropriate.

Referring to Figure 2, a reinforced plasterboard according to one possible embodiment of the invention is shown very diagrammatically with a face paper 11, a plaster core 15 of gypsum plaster, a reinforcing mesh 7 and immediately adjacent thereto, a back paper layer 2. While in setting, some of the plaster 15 will extrude through the openings in the mesh 7 and bond with the paper 2, the mesh 7 may be positioned so as to be in substantial contact across the entire face of the back paper 2. In this way, the reinforcing mesh 7 is providing a substantial and uniform reinforcement of the plasterboard across the entire face defined by the layer of paper 2 and will thus be able to contribute substantially to the impact resistance of the plasterboard.

In other embodiments the mesh 7 is adjacent the paper 2 but not in cofitact with it.

Where in the foregoing description reference has been made to specific components or integers of the invention having known equivalents then such equivalents are herein incorporated as if individually set forth.

Although this invention has been described by way of example and with reference to possible embodiments thereof it is to be understood that modifications or improvements may be made thereto without departing from the scope of the invention as defined in the appended claims.

Claims (3)

1. A reinforced plasterboard including: a core of cementitious material having one side and an opposite side; a first external layer of paper adjacent to said one side; at least one internal layer of a mesh reinforcement embedded in said opposite side, said mesh reinforcement including at least one of glass fibre and plastics material; and a second layer of paper being immediately adjacent to said mesh reinforcement such that said core is disposed between said first and second layers.

2. A reinforced plasterboard according to claim 1 wherein said second layer is in contact with said mesh reinforcement.

3. A reinforced plasterboard according to claim 1 or claim 2 wherein said cementitious material includes gypsum plaster. DATED this 15th Day Of June, 2000 FLETCHER CHALLENGE LIMITED Attorney: JOHN B. REDFERN Fellow Institute of Patent Attorneys of Australia of BALDWIN SHELSTON WATERS