AU2003200885A1 - Insulating sheet material - Google Patents

Description

Regulation 3.2

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

(ORIGINAL)

Name of Applicant: Actual Inventor(s): Address for Service: Invention Title: Boral Australian Gypsum Limited Andrew Close William Poynter DAVIES COLLISON CAVE, Patent Attorneys, 1 Little Collins Street, Melbourne, Victoria 3000.

"Insulating Sheet Material" Details of Associated Provisional Application(s): No(s): PS0956 dated 7 March 2002 The following statement is a full description of this invention, including the best method of performing it known to me/us: P:OPER\Axd\2021(I omPlcc.do4h'&3/03 -1- INSULATING SHEET MATERIAL The present invention relates to an insulating sheet material. Particularly, the invention relates to a sheet material for building, such as a plasterboard sheet material, which includes an insulating core substrate between opposed faces of the sheet material.

The core substrate advantageously acts as an insulator and may act as a sound attenuating substrate.

Building materials such as plasterboard are known. Such sheet materials are conventionally used in the production of walls, partitions and ceilings in the building and construction industries. In some instances, it is advantageous to provide temperature and/or sound insulation to such sheet materials. This may be achieved by a number of means, including for example lamination of a foam substrate to an outer face of the sheet material.

The present invention advantageously provides an alternate means for providing insulation and sound attenuation to a sheet material, such as a plasterboard material.

Thus, according to one aspect of the invention, there is provided an insulating sheet material including first and second opposed faces; a core material disposed between the first and second opposed faces; and an insulating core substrate substantially encased by the core material.

The core substrate may include any suitable substrate but preferably includes a substrate having a plurality of air voids within the core substrate or includes a layer of fabric. Furthermore, the core substrate must be able to be substantially encased by the core material of the sheet material without the core material entering air voids within the body of the core substrate if they are present.

In one embodiment, the said insulating core substrate includes at least two film layers, a plurality of air voids being entrapped between the film layers thereby imparting insulating and sound attenuating characteristics to the core substrate.

In this regard, in one embodiment the insulating core substrate includes two polymeric film layers with a plurality of evenly spaced air voids entrapped between the film layers.

In another embodiment the core substrate includes two polymeric film layers with a P:\OPER,A2d 22IO compcte.doc4)i03A)3 -2plurality of randomly spaced air voids entrapped between the film layers.

In some instances, it may be desirable to provide insulation or sound attenuation to certain regions or zones of the sheet material. As such, in one embodiment the core substrate includes at least one insulating or sound attenuating zone which includes the plurality of spaced air voids entrapped between the film layers of the core substrate, and at least one other zone which is free of air voids.

The above discussion has referred to the inclusion of a plurality of air voids between at least two film layers, such as is provided by bubble-wrap sheet material. It should be realised, however, that the present invention also envisages situations where a multi-layer structure is provided with more than one layer of air voids. This may be provided, for example, by a double layer of bubble-wrap sheet material or multiple layers of such material. In these cases, the layers may be directly adjacent on another or may have core material disposed between them.

In an alternative embodiment to that described above, the core substrate includes a sheet of foam material, preferably polyurethane foam material. Such foam material should preferably include a multiple of air voids throughout the body of the material, those voids forming closed cells within the foam material.

The core substrate may alternatively include a sheet of fabric or material that will impart good insulating or sound attenuating characteristics to the sheet material. In this case, the core substrate preferably includes one or more layers of felt material. The layers may be adjacent one another or may have core material disposed between them.

As will be appreciated from the above discussion, the sheet material advantageously consists of a simple structure of a core substrate which provides insulating and sound attenuating characteristics to the sheet material encased by a core material disposed between first and second opposed faces of the sheet material. However, the sheet material may have a more complex structure. In particular, the sheet material may additionally include corrugated cardboard, or any plastic or cellulose products having air voids within.

The core material of the sheet material may include any suitable material. For example, the core material may include concrete, calcium silicate or fibre cement.

Preferably, the core material includes plaster as used in conventional plasterboard sheeting.

P:\OPERAxd\2I2 I0 omplctc.doC-) 6 03/0 3 -3- Similarly, although the first and second opposed faces may be formed from materials such as plasterglass or foil laminate. Preferably, the first and second faces are formed from a paper sheeting conventionally used in plasterboard sheeting.

As previously stated, the insulating sheet material advantageously provides for heat insulation and sound attenuation. In this regard, the sheet material preferably has a thermal resistance (R value) of at least about 0.2m 2 .K/W compared with conventional plasterboard which has a resistance of from about 0.04-0.06m 2 This is because air, in the form of air voids in the core substrate, acts as a good insulator and provides for sound attenuation.

So as to facilitate the inclusion of the core substrate, the sheet material will generally have a thickness of about 16mm compared with conventional plasterboard which has a thickness of about 10mm. However, the weight of the sheet material will be substantially the same as that of conventional plasterboard.

The insulating sheet material of the invention may be prepared by any suitable means. In particular, the sheet material is manufactured using a process the same or similar to that currently employed in the manufacture of plasterboard sheets.

In the light of the above, according to another aspect of the invention there is provided a method for the manufacture of an insulating sheet material including: pouring a slurry of core material onto a facing sheet material; laying an insulating core substrate on the slurry; covering the core substrate with a slurry of core material; and laying an opposing facing sheet material on the slurry covering the core substrate.

A more detailed description of embodiments of the invention will now be described with reference to the accompanying drawings in which: Figure 1 illustrates an embodiment of the invention where the sheet material includes a single layer of bubble-wrap material as the core substrate; Figure 2 illustrates an alternative embodiment of the invention in which the core substrate includes two or more layers of bubble-wrap material; and Figure 3 is a graphical representation of the data provided in Table 1 which follows.

Referring to Figure 1 which illustrates a sectional view of an insulating sheet material according to one embodiment of the invention, the sheet material 10 is a planar PAOPERAWx d 2O21O complctc.do4)JG33 -4sheet material having a thickness X of approximately 16mm. First and second opposing faces 11, 12 encase a core material 13 such as plaster. The core material 13 in turn encases a core substrate 14, in this case bubble-wrap. The bubble-wrap core substrate 14 includes a plurality of air voids 15 which may be provided as discreet air voids, or which may be interconnecting.

As illustrated in Figure 2, in an alternative embodiment two or more bubble-wrap core layers 24 are provided, preferably so that the bubbles 25 of each layer of core substrate 24 are positioned in an alternating array so as to maximize insulation and sound attenuation of the sheet material As previously mentioned, the form of the core substrate may be bubble-wrap as illustrated in the Figures, but may also suitably be selected from a foam material, such as polyurethane foam.

Example 1 A sample board was formed as follows: a plaster slurry was poured onto the back of a sheet of facing paper positioned in a mould, bubble wrap was laid over the slurry with additional slurry being poured onto the bubble wrap. Scattered holes within the bubble wrap layer allowed the lower and upper slurries to bond creating shear connectors keeping the halves of the sheet together.

Backing paper was applied before passing through a forming head where excess slurry was removed when the dimensions of the board were established.

Testing was performed by inserting the sample in a purpose made opening in a panel over the front of a laboratory oven with the temperatures set at 40 degrees Celsius.

The temperature on the back of the sample was then recorded using a hand held infrared thermometer, which read to the nearest degree Celsius, at one minute intervals for a period of fifteen minutes. This test was loosely based on the conventional method for determining the thermal conductivity of a panel and was performed to validate whether the presence of the air voids within the core made any difference.

P:\OPER\Axd20210 complln .doc05A)3A)3 The Results are provided in Table 1 below: Table 1 ThermaStop testing, Oven Temperature 42 Ambient Temperature degrees C 23 degrees c time 10mm std core 2 layers of 1 layer bubble plain. No bubble (minutes) bubble wrap 9 wrap4 connecting wrap connecting holes holes 0 25 26 .26 25 26 26. 1 26 26 26 26 2 26 26 26 26 3 28 28 26 27 4 29 29 27 28 29 29 28 28 6 29 30 28 29 7 30 30 29 29 8 31 30 29 9 31 30 29 31 30 30 11 32 31 30 12 32 31 30 31 13 32 31 30 31 14 32 31 30 31 33 32 30 31 Board weight 605.5g 604.9g 840.6g, 856.2g P:\OPERAxd\2)210 complec.doc-5A)3A)3 -6- Example 2 Six samples were manufactured and tested. The samples were made using a plaster mix of similar proportions of stucco to water in an attempt to create samples of equivalent weight. The specimen details are listed in the table below: Table 2: Descriptions and weights of tested samples.

sample after test.

020726a Plain, no addition to core 862g 851g 020726b Thick wool felt in core 872g 860g 020726c Big bubbles with 9 holes through 853g 839g 020726d 2 layers little bubbles with 5 holes 836g 811g through.

020726e 3 layers of felt material stapled together 889g 871g with holes through.

020726f Big bubbles with 5 holes through 885g 865g The samples were first weighed as they had been made and then weighed a second time after they had been trimmed down to fit within the aperture in the panel over the mouth of the oven.

Thermocouples with pads were attached to the specimen and an airborne thermocouple was placed approximately 100mm from the cold face of the specimen and a thermocouple was placed on the hot face of the plasterboard frame supporting the specimen.

The temperatures were recorded using the Yokogawa chart recorder, stored on a memory card and downloaded to an excel spreadsheet. The chart recorder was set up to record the temperatures every minute for thirty minutes.

A cover plate was set over the aperture while the temperature was raised to 40 0

C.

Once the oven temperature was reached the cover plate was replaced with a sample with thermocouples attached and the 30-minute timer commenced. Once 30 minutes had expired the sample was removed and the cover plate inserted while the next sample was prepared.

The test duration of 30 minutes was selected after previous testing with duration of minutes provided no clear indication of comparative performance.

P:\OPER\Axd\02 10 omplcIc.do-04SA)3i03 -7- Results: The samples having the felt through the middle of the core were the best performers with the temperature differential between the oven and the cold face of the sample being over 3 degrees more than the sample without any addition to the core.

The samples with the bubble wrap through the core also performed better than the sample without any addition to the core with an increase in temperature differential between the oven and the cold face of 1.6 to 1.8 degrees (18-20%).

Table 3: Ranking of the samples: Ranking Specimen No. Specimen Description 1 020726e 3 layers of felt material stapled together with 5 holes through.

2 020726b Thick wool felt in core 3 020726d 2 layers little bubbles with 5 holes through.

4 020726f Big bubbles with 5 holes through 020726c Big bubbles with 9 holes through 6 020726a Plain, no addition to core The samples were ranked on the basis on the magnitude of change experienced in the average temperature difference between the oven and the cold face which was derived by subtracting the temperature difference at t30 from the temperature difference at either to or tl, whichever was the larger. Refer to Table 4 for summary of temperature difference for each specimen and tables 5 to 10 for the results for each test.

Conclusion: On the basis of the testing completed thus far it is evident that the presence of bubble wrap or felt within the core of the plasterboard reduces the thermal conductivity through the plasterboard sheet.

P:OPER\A.2021I) coImplc.doc4-/)3A)3 -8- Table 4: Summary of Average temperature difference between oven and cold face of sample.

Time 020726a 020726b 020726c 020726d 020726e 020726f (minutes) Plain, no hick woolBig bubbles wo layers little3 layers felt materialBig bubbles with addition t felt in core with 9 holes ubbles with 9 stapled together with holes through.

core through holes through 5 holes through 0 20.1 17.7 20.4 18.4 16.6 18.5 1 18.5 18.3 20.4 18.4 17.9 19.5 2 17.4 18.5 19.8 17.6 18.1 19.3 3 16.7 18.1 18.5 17.0 17.9 18.3 4 15.5 17.8 17.4 16.3 17.3 17.8 14.9 17.1 16.5 15.8 16.8 17.0 6 14.2 16.2 15.8 15.3 16.3 16.3 7 13.8 16.2 14.9 14.7 15.9 15.7 8 13.1 14.4 14.4 15.6 15.3 9 12.2 14.7 13.8 14.1 15.0 14.8 12.1 14.2 13.4 13.4 14.6 14.3 11 11.7 14.0 13.3 13.1 14.3 14.0 12 11.2 14.0 12.7 12.7 14.1 13.6 13 11.1 13.7 12.5 12.3 14.0 13.2 14 10.4 13.3 11.9 12.3 13.8 12.7 10.6 13.2 11.9 12.1 13.4 12.7 16 10.0 12.7 11.6 11.8 13.4 12.4 17 9.9 12.7 11.5 11.7 13.1 12.3 18 10.0 12.7 11.2 11.4 12.7 11.8 19 9.5 12.6 10.9 11.3 12.6 12.0 9.6 12.5 10.8 11.1 12.6 11.8 21 9.3 12.5 10.6 10.8 12.4 11.6 22 9.2 12.3 10.6 11.0 12.3 11.3 23 9.3 12.2 10.3 10.8 12.4 11.2 24 9.3 12.0 10.3 10.6 12.0 11.1 9.0 12.3 10.4 10.5 12.1 10.9 26 8.8 12.3 10.4 10.3 12.1 10.8 27 9.2 12.0 10.3 10.3 12.1 11.0 28 8.8 11.9 10.3 10.2 12.1 10.6 29 9.0 12.3 10.2 10.3 11.8 10.7 8.7 11.9 10.3 10.4 11.7 10.5 P:\OPERAxd202 10 complnct.doc.I-0533 -9- Table 5: Specimen No 020726a, Plain, no addition to core DATE020726 TIME105113 time Channel 2 Channel 3 Channel 4 Channel 5 Channel 6 Channel 7 minutes OC 0 C 0 C 0 C OC °C 19.6 19.4 19.6 19.3 19.4 39.5 0 19.6 19.6 19.8 19.6 19.2 39.7 1 21 21.4 21.6 21.4 19.2 39.8 2 22.1 22.6 22.7 22.5 19.4 39.9 3 22.6 23.2 23.4 23.4 19.4 39.8 4 24 24.7 24.9 24.7 19.6 40.1 24 24.9 25.2 25.4 19.4 39.8 6 24.9 25.8 26 26.2 19.4 39.9 7 25.5 26.4 26.7 27 19.5 40.2 8 26 26.9 27.4 27.6 19.5 40.1 9 27.1 27.9 28.4 28.6 19.8 40.2 27 27.8 28.2 28.6 19.3 11 27.8 28.4 28.7 29 19.5 40.2 12 28.5 29.1 29.6 29.8 19.5 40.4 13 28.5 29 29.4 29.9 19.6 40.3 14 29 29.8 30.2 30.5 19.4 40.3 28.9 29.4 29.9 30.4 19.8 40.2 16 29.4 30.1 30.6 31 19.4 40.3 17 29.5 30.5 30.8 31.3 19.8 40.4 18 29.4 30.2 30.5 31.1 19.3 40.3 19 29.8 30.8 31 31.6 19.4 40.3 30 30.8 30.9 31.4 19.8 40.4 21 30.5 31.3 31.6 32 19.6 40.6 22 30.3 31.1 31.5 32.1 19.8 40.4 23 30.5 31.2 31.4 32 19.6 40.6 24 30.3 30.9 31.2 31.9 18.9 40.4 30.6 31.5 31.9 32.4 19.8 40.6 26 31 31.8 32 32.5 19.8 40.6 27 30.5 31.2 31.6 32.3 19.9 40.6 28 30.9 31.8 32.1 32.6 19.6 40.6 29 30.6 31.4 31.8 32.5 19.3 40.6 31.4 32 32.2 32.8 19.8 40.8 P:\OPER\Axd\2210 complCtc.doc-OA13A)3 Table 6: Specimen No 020726b, Thick wool felt in core DATE020726 TIME112553 time Channel 2 Channel 3 Channel 4 Channel 5 Channel 6 Channel 7 minutes oC 0 C "C 0 C 0 C °C 0 22.4 22.6 23 23.5 19.8 40.6 1 22.6 22.4 22.7 23 19.5 41 2 22.2 22.1 22.5 23 19.4 40.9 3 22.5 22.3 22.6 23.4 19 40.8 4 23 22.7 22.9 23.8 18.9 40.9 23.6 23.5 23.6 24.6 19.3 40.9 6 24.7 24.6 24.6 25.4 19.5 41 7 24.9 24.9 24.9 25.8 19.1 41.3 8 25 24.7 24.7 25.6 19.1 43.7 9 26.2 25.8 25.8 26.6 19.6 40.8 26.6 26.3 26.2 27 19.6 40.7 11 26.6 26.3 26.3 27.4 19.8 40.6 12 26.6 26.3 26.3 27.4 19.8 40.6 13 26.9 26.6 26.4 27.6 19.5 40.6 14 27.2 27 26.9 28.2 19.6 40.6 27.5 27.2 27.2 28.3 19.8 40.7 16 28 27.8 27.5 28.6 19.6 40.7 17 27.9 27.6 27.4 28.6 19.6 40.6 18 28.3 27.8 27.5 28.6 19.8 40.7 19 28.5 28 27.8 28.9 20.1 40.9 28.3 28 27.9 29.1 19.9 40.8 21 28.3 27.8 27.6 28.9 19.6 40.6 22 28.2 27.9 27.9 29.1 19.5 40.6 23 28.7 28.2 27.9 29.2 19.6 40.7 24 28.6 28.2 28.2 29.4 19.8 40.6 28.5 27.9 27.8 29.1 19.2 40.6 26 28.6 28.2 27.9 29.2 19.8 40.8 27 28.6 28.2 28.2 29.5 19.8 40.6 28 28.7 28.4 28.2 29.6 19.8 40.6 29 28.6 28.2 27.9 29.5 19.8 40.8 29.2 28.9 28.5 29.8 20.1 41 P:\OPERlAxd20210 compcllc.doc-5)/0313 11 Table 7: Specimen No 020726c, Big bubbles with 9 holes through DATE020726 TIME133813 time Channel 2 Channel 3 Channel4 Channel 5 Channel 6 Channel 7 minutes 0 C OC 0 C 0 C 0 C "C 0 20.5 20.9 20.7 21.1 20.2 41.2 1 20.9 21.3 21 21.4 20.7 41.5 2 21.4 21.8 21.4 21.9 20.4 41.4 3 22.3 23.2 22.6 23.2 20.3 41.3 4 23.2 24.2 23.4 24.2 20.7 41.1 23.8 25 24.2 24.9 21.1 41 6 24.9 26 25 25.8 20.9 41.2 7 26.2 26.9 25.8 26.6 20.9 41.3 8 26.4 27.3 26.4 27.2 21.1 41.2 9 26.9 27.9 26.9 27.8 21 41.2 27.2 28.5 27.4 28.2 20.9 41.2 11 27.4 28.6 27.6 28.6 21 41.3 12 27.9 29.2 28.2 29 20.4 41.3 13 28 29.3 28.3 29.2 20.9 41.2 14 28.5 29.9 29 29.8 21 41.2 28.5 29.9 29 29.9 21.1 41.2 16 28.7 30.2 29.4 30.2 21.2 41.2 17 29 30.3 29.6 30.4 21.2 41.3 18 29.4 30.5 29.8 30.5 21.2 41.2 19 29.6 30.9 30.2 30.9 21 41.3 29.8 31 30.3 31 21 41.3 21 29.9 31.1 30.4 31 21.1 41.2 22 29.8 31 30.2 31 20.5 41.1 23 30.2 31.4 30.6 31.4 21.2 41.2 24 30.2 31.5 30.9 31.6 21.6 41.3 30 31.3 30.6 31.4 20.9 41.2 26 30.1 31.3 30.6 31.4 20.7 41.2 27 30.3 31.4 30.8 31.5 20.7 41.3 28 30.3 31.5 30.8 31.6 20.9 41.3 29 30.5 31.7 31 31.7 20.5 41.4 30.3 31.5 30.8 31.6 20.5 41.3 P:\OPER\Axd\20210 complclc.doc-S5A)3A)3 12- Table 8: Specimen No 020726d, 2 layers little bubbles with 5 holes through.

DATE020726 TIME141135 time Channel 2 Channel 3 Channel 4 Channel 5 Channel 6 Channel 7 minutes oC oC oC 0 C 0 C "C 24.2 23.4 23.6 25 21.6 41.6 0 22.9 22.7 22.7 23.6 21.3 41.4 1 22.9 22.9 22.7 23.5 20.7 41.4 2 23.4 23.6 23.3 24 21.1 41.2 3 24.3 24.5 24 24.6 21.1 41.3 4 24.9 25.2 24.6 25.4 20.9 41.3 25.5 25.8 25.2 26 21.2 41.4 6 26 26.2 25.6 26.4 21.1 41.3 7 26.5 26.7 26.2 26.9 20.5 41.3 8 26.9 27.1 26.6 27.4 20.1 41.4 9 27.4 27.6 27 27.8 20.6 41.5 27.8 28.2 27.4 28.2 20.9 41.3 11 28 28.4 27.8 28.6 20.6 41.3 12 28.6 28.7 28.2 28.9 20.9 41.3 13 28.9 29.3 28.6 29.3 20.7 41.3 14 28.9 29.2 28.6 29.4 20.4 41.3 29 29.4 28.9 29.6 20.1 41.3 16 29.4 29.9 29.2 29.9 20.5 41.4 17 29.5 29.9 29.3 30.1 20.9 41.4 18 30 30.5 29.8 30.4 20.6 41.6 19 29.9 30.3 29.8 30.5 20.7 41.4 30 30.5 29.8 30.5 19.8 41.3 21 30.4 30.9 30.2 30.9 20.5 41.4 22 30.2 30.6 30.1 30.8 20.6 41.4 23 30.2 30.8 30.1 30.9 20.7 41.3 24 30.4 30.9 30.3 31 20.7 41.2 30.6 31.1 30.4 31.1 20.6 41.3 26 30.8 31.4 30.6 31.4 20.7 41.3 27 30.6 31.1 30.5 31.3 20.3 41.2 28 30.8 31.3 30.5 31.4 20.4 41.2 29 30.6 31.3 30.6 31.5 19.8 41.3 30.6 31.2 30.5 31.4 20.2 41.3 P\OPER\AUd\20210 complce.doc4)5/03/03 Table 9: through.

-13- Specimen No 020726e, 3 layers of felt material stapled together with 5 holes DATE020726 TIME144511 time Channel 2 Channel 3 Channel 4 Channel 5 Channel 6 Channel 7 minutes OC 0 C 0 C 0 C 0 C oC 0 23 26 24.6 25.2 20.9 41.3 1 22.6 24.2 23.5 24 20.9 41.5 2 22.9 23.8 23.3 23.8 21 41.5 3 23.1 23.6 23.1 24 20.7 41.3 4 24 24.2 23.6 24.5 20.9 41.4 24.7 24.7 24.2 25 21.3 41.4 6 25.4 25.1 24.6 25.4 21.2 41.4 7 25.8 25.6 25 25.8 20.9 41.4 8 26.2 25.8 25 26.2 20.9 41.4 9 26.7 26.4 25.8 26.7 20.9 41.4 27.3 26.7 26.2 27 21.1 41.4 11 27.8 27.1 26.5 27.4 21.2 41.5 12 27.9 27.3 26.6 27.5 21.3 41.4 13 28.2 27.4 26.7 27.8 21.2 41.5 14 28.4 27.6 27 27.9 21 41.5 28.5 27.9 27.3 28.2 21 41.4 16 28.6 27.9 27.3 28.4 21.4 41.4 17 28.7 28.2 27.5 28.6 21.3 41.3 18 29.2 28.6 27.9 28.9 21.1 41.3 19 29.4 28.7 28.2 29 21.3 41.4 29.3 28.6 27.9 28.9 21 41.3 21 29.5 28.9 28.2 29.1 21 41.3 22 29.5 29 28.2 29.3 21 41.3 23 29.5 28.9 28.2 29.2 21.1 41.3 24 29.8 29.3 28.6 29.5 21.4 41.3 29.6 29 28.4 29.5 21.4 41.2 26 29.6 29.1 28.6 29.6 21.4 41.3 27 29.6 29.1 28.5 29.5 21.3 41.3 28 29.9 29.4 28.7 29.8 21.3 41.5 29 30.1 29.6 28.9 29.9 21.5 41.4 30.1 29.6 29 29.9 21.4 41.3 P;\OPER\Axd\20210 Complele.doc-41.O05)3 -14- Table 10: Specimen No 020726f, Big bubbles with 5 holes through DATE020726 TIME 51753 time Channel 2 Channel 3 Channel 4 Channel 5 Channel 6 Channel 7 minutes OC 0 C 0 C 0 C 0 C "C 0 23.2 22.7 24.3 24.2 21.5 42.1 1 22.6 22.4 23.1 23.1 21.6 42.3 2 22.3 22.3 22.9 22.9 21.5 41.9 3 23 23.3 23.4 23.4 21 41.6 4 23.3 23.6 23.8 23.8 21 41.4 24.2 24.6 24.6 24.4 21.4 41.4 6 24.9 25.4 25.2 25 21.4 41.4 7 25.5 26.2 25.8 25.6 21.5 41.5 8 26 26.7 26.3 26.3 21.5 41.6 9 26.3 27 26.6 26.7 21.4 41.4 26.7 27.4 27 27.2 21.5 41.4 11 27 27.8 27.4 27.5 21.3 41.4 12 27.4 28.2 27.6 27.8 21.3 41.3 13 27.8 28.4 27.9 28.2 21.3 41.3 14 28.2 29 28.5 28.6 21.6 41.3 28.2 29 28.6 28.7 21.4 41.3 16 28.7 29.4 28.9 28.9 21.4 41.4 17 28.7 29.4 29 29.1 21.4 41.3 18 29.3 29.9 29.4 29.4 21.4 41.3 19 29.1 29.8 29.3 29.4 21.2 41.4 29.2 29.9 29.5 29.6 21.4 41.3 21 29.5 30.3 29.6 29.8 21 41.4 22 29.8 30.6 29.9 30.1 21.6 41.4 23 29.6 30.5 30 30.2 21.5 41.3 24 29.8 30.6 30.1 30.3 21.6 41.3 30.2 31 30.3 30.5 21.6 41.4 26 30.2 31 30.3 30.5 21.6 41.3 27 29.9 30.8 30.2 30.5 21.4 41.3 28 30.5 31.3 30.5 30.8 21.6 41.4 29 30.2 31.1 30.5 30.8 21.5 41.3 30.5 31.3 30.5 30.8 21.6 41.3 P:%OPER\AxdU(O2 10 mpltc.doc-05A)3/O3 The reference to any prior art in this specification is not, and should not be taken as, an acknowledgment or any form of suggestion that that prior art forms part of the common general knowledge in Australia.

Those skilled in the art will appreciate that the invention described herein is susceptible to variations and modifications other than those specifically described. It is to be understood that the invention includes all such variations and modifications which fall within its spirit and scope. The invention also includes all the steps, features, compositions and compounds referred to or indicated in this specification, individually or collectively, and any and all combinations of any two or more of said steps or features.

Claims (16)

1. An insulating sheet material including: first and second opposed faces; a core material disposed between said first and second opposed faces; and an insulating core substrate substantially encased by said core material.

2. A sheet material according to claim 1, wherein the insulating core substrate includes a substrate having a plurality of air voids or includes a sheet of fabric.

3. A sheet material according to claim 2, wherein said insulating core substrate includes at least two film layers, a plurality of air voids being entrapped between said film layers thereby imparting sound attenuating and heat isolating characteristics to said core substrate.

4. A sheet material according to claim 2, wherein said insulating core substrate includes two polymeric film layers with a plurality of evenly spaced air voids entrapped between the film layers.

A sheet material according to claim 2, wherein said insulating core substrate includes two polymeric film layers with a plurality of randomly spaced air voids entrapped between the film layers.

6. A sheet material according to claim 2, wherein said insulating core substrate includes at least one sound attenuating zone which includes the plurality of spaced air voids entrapped between the film layers of the core substrate; and at least one other zone which is free of air voids.

7. A sheet material according to claim 2, wherein the insulating core substrate includes a sheet of foam material, preferably polyurethane foam material.

8. A sheet material according to claim 2, wherein the insulating core substrate includes a sheet of felt material.

9. A sheet material according to claim 1, wherein the core material includes concrete, calcium silicate, fiber cement or plaster.

10. A sheet material according to claim 1, wherein the first and second faces are formed from plasterglass, foil laminate or paper sheeting. PAOPERAsId22I(I complcte.doc4-i)AJ3)3 -17-

11. A sheet material according to claim 1, said sheet material having an energy rating (R value) of at least about 0.2.

12. A sheet material according to claim 1, said sheet material having a thickness of about 16mm.

13. A method for the manufacture of an insulating sheet material including: pouring a slurry of core material onto a facing sheet material; laying an insulating core substrate on the slurry; covering the core substrate with a slurry of core material; and laying an opposing facing sheet material on the slurry covering the core substrate.

14. An insulating sheet material substantially as hereinbefore described with reference to the drawings and/or Examples.

A method for the manufacture of an insulating sheet material substantially as hereinbefore described with reference to the drawings and/or Examples.

16. The steps, features, compositions and compounds disclosed herein or referred to or indicated in the specification and/or claims of this application, individually or collectively, and any and all combinations of any two or more of said steps or features. DATED: 5 March, 2003 by DAVIES COLLISON CAVE Patent Attorneys for the Applicant(s): BORAL AUSTRALIAN GYPSUM LIMITED