AU3898301A

AU3898301A - Aircell reflective insulation sheeting

Info

Publication number: AU3898301A
Application number: AU38983/01A
Authority: AU
Inventors: Scott Ian Gibson; Brian Eric Tikey; John Webb
Original assignee: Kingspan Insulation Pty Ltd
Current assignee: Kingspan Insulation Pty Ltd
Priority date: 2000-05-03
Filing date: 2001-04-30
Publication date: 2001-11-08
Anticipated expiration: 2021-04-30
Also published as: AUPQ727100A0; AU784982B2; AU2010201133A1; AU2006202268A1; AU2003100663A4; AU2003100663B4

Description

P/00/011 28/5/91 Regulation 3.2

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT *r a Name of Applicant: Actual Inventors Address for service is: ASTRO-FOIL (AUST) PTY LTD JOHN WEBB and BRIAN TIKEY WRAY ASSOCIATES 239 Adelaide Terrace Perth, WA 6000 Attorney code: WR Invention Title: "Aircell Reflective Insulation Sheeting" fe Details of Associated Provisional Application No(s): PQ7271 The following statement is a full description of this invention, including the best method of performing it known to me:- -2- "Aircell Reflective Insulation Sheeting" Field of the Invention This invention relates to aircell insulation sheeting.

Background Art The invention has been devised particularly, although not solely, to provide insulation in buildings and other structures.

There are various types of insulation currently in use for building, including insulation batts which can be formed of a suitable insulating material such as fibreglass, polyester, paper or wool. Insulation batts of such construction provide useful thermal insulation insofar as conduction is concerned, but are less effective in relation to heat by convection and radiation.

oo••Another known form of insulation is reflective sheeting. Reflective sheeting provides useful insulation insofar as heat transfer by radiation and convection is concerned, but is less effective in relation to heat flow by conduction.

•oooo A still further known type of insulation is aircell reflective insulation sheeting comprising a closed air cell structure encased between two outer layers of reflective foil. Such insulation provides useful thermal insulation from the viewpoint of conduction, convection and radiation. An example of such aircell reflective insulation sheeting is manufactured and marketed by the applicant under the trade mark ASTRO-FOIL.

The closed air cell structure utilised within this known aircell reflective insulation sheeting comprises two air cell layers. The requirement for the closed cell structure to have two air cell layers complicates the manufacturing process for the insulation sheeting. The two air cell layers are also vulnerable to delamination.

-3- It is against this background, and the problems and deficiencies associated therewith, that the present invention has been developed.

Disclosure of the Invention The present invention comprises aircell insulation sheeting comprising a single layer cell structure interposed between two outer layers, the cell structure comprising a plurality of cells each of a width between about 15 and 25 mm and a depth of between about 6 to 10 mm.

Preferably, the width of each cell is about 20 mm, and the depth of each cell is about 8 mm.

Preferably, each cell is generally circular such that the diameter thereof corresponds to said width.

It has been found that the dimensions of the cell insofar as depth and width are concerned are particularly important.

With this arrangement, the cells are of a size which is sufficiently large to achieve 15 the necessary R rating for the insulation. If the cells were of a smaller size it would not be possible to achieve the necessary R rating without employing a double layer cell construction as used in the prior art.

If the width (which in the case of a circular cell corresponds to a diameter) exceeds 25 mm, it is likely that the single layered cell structure would not 20 maintain the outer layers in spaced apart relationship, so allowing the layers to touch and therefore creating a thermal bridge therebetween.

If the depth of the cell exceeds 10 mm, there can be difficulties in fixing the insulation in place using conventional fixing elements such as staples.

Additionally, where the aircell insulation sheeting is installed under tile battens, metal deck roofing and wall sheeting, a depth in excess of 10 mm would cause a floating effect and difficulties securing outer coverings.

Preferably, at least one of the outer layers is reflective and may comprise reflective foil.

Preferably, said reflective foil comprises high density polyethylene weave laminated aluminium foil. The advantage of high density polyethylene weave laminated aluminium foil is that it enhances the tensile strength of the insulation sheeting. This is advantageous in allowing the insulation sheeting to be installed over large spans in a building construction, plus provides a greater tear strength and burst strength, thus preventing tearing or damage by broken tiles, bricks or other building debris during and after construction.

In some applications, it is desirable for the other layer to also be of reflective foil such as high density weave aluminium foil. In still other applications, the other outer layer may be of some other material such as polyethylene.

Fire retardants and UV inhibitors can be incorporated into the materials used in the construction of the aircell insulation sheeting as appropriate.

15 Brief Description of the Drawings The invention will be better understood by reference to the following description of several specific embodiments as shown in the accompanying drawings in which: a Figure 1 is a schematic view of aircell reflective insulation sheeting 20 according to a first embodiment, with part of an outer layer of the sheeting removed to reveal the cellular structure; Figure 2 is a cross-section along the line 2-2 of Figure 1; Figure 3 is a schematic view of part of the cellular structure; Figure 4 is a schematic perspective view of the aircell reflective insulation sheeting, with several layers partly removed to reveal the internal construction; and Figure 5 is a fragmentary perspective view of aircell insulation sheeting according to a second embodiment.

Best Mode(s) for Carrying out the Invention Referring now to Figures 1 to 4 of the accompanying drawings, there is shown aircell reflective insulation sheeting 10 comprising two outer layers 11 with an air cell structure 13 bonded therebetween.

Each outer layer 11 comprises reinforced highly reflective aluminium foil. More particularly, each outer layer 11 comprises 99.5% pure aluminium reflective foil S•reinforced with high density polyethylene scrim.

The closed cell structure 13 comprises first and second polyethylene membranes and 17 respectively bonded together. The first membrane 15, which is best seen in Figure 3 of the drawings, is formed by a vacuum suction process into a series of depressions 19 having open ends 20 which are closed by the second membrane 17. With the closure of the openings 20 in the first membrane 15 by the second membrane 17, the depressions 19 form closed air cells 21.

o*o° In this embodiment, the first and second membranes 15, 17 comprise fire 20 retarded modified polyethylene (LDPE).

Each closed air cell 21 in this embodiment is of generally circular cross-section, having a diameter a and a depth b, as illustrated in Figure 3 of the drawings.

The diameter a is within a range of about 15 mm to 25 mm, with the preferred value being about 20 mm. The depth b is within a range of about 6 mm to mm, with the preferred value being about 8 mm.

It has been found that the cell structure 13 with closed air cells 21 of such a size provide the necessary R rating for the insulation while retaining the integrity of the sheeting. If, for example, the diameter a is larger than about 25 mm, there is a real possibility that sections of the two outer layers 11 could deflect inwardly and contact each other to create a thermal bridge which would disrupt the thermal effectiveness of the insulation. Additionally, if the cells 21 are too deep in terms of dimension b, there may be difficulty in fastening the sheeting in position using staples or other fixing means. Additionally, where the aircell insulation sheeting is installed under tile battens, metal deck roofing and wall sheeting, a depth in excess of 10 mm would cause a floating effect and difficulties securing outer coverings.

It is, however, necessary for the closed air cells 21 to be of at least the minimum sizes specified in order to provide the necessary insulating value.

Because the cellular insulation sheeting 10 according to the embodiment is of a 15 single layer cell construction, as opposed to a double layer cell construction as in the case with prior art aircell reflective insulation sheeting, it can be manufactured more conveniently. In particular, only one pass through a machine is required in order to form the closed cell structure 13.

The exposed face of one of the layers 11 may be coloured so as to reduce glare 20 while retaining heat reflective characteristics. This can be particularly desirable on construction sites where the sheeting is used to line walls and roofs, and where it may be exposed for some time so creating a glare problem for,workers in the vicinity. One such suitable colour for the exposed surface has red or pink tones.

Referring now to Figure 5 of the drawings, the aircell insulation sheeting according to the second embodiment is similar to the first embodiment with the exception that one of the layers 11 is formed of polyethylene sheeting rather than reflective aluminium foil. The insulation sheeting according to this embodiment is particularly suitable for lining the roof of a building in situations where the aircell insulation sheeting remains exposed on the underside. The polyethylene can be -7coloured to provide an aesthetically appealing appearance, on the underside. A shade of white is particularly suitable in this regard.

From the foregoing, it is evident that the present invention provides aircell insulation sheeting which is simple in construction yet highly effective in use.

It should be appreciated that the scope of the invention is not limited to the scope of the two embodiments described.

Throughout the specification, unless the context requires otherwise, the word "comprise" or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

o

Claims

1. Aircell insulation sheeting comprising a single layer cell structure interposed between two outer layers, the cell structure comprising a plurality of cells each of a width between about 15 and 25 mm and a depth of between about 6 to 10 mm.

2. Aircell insulation sheeting according to claim 1 wherein the width of each cell is about 20 mm, and the depth of each cell is about 8 mm.

3. Aircell insulation sheeting according to claim 1 or claim 2 wherein each cell is generally circular such that the diameter thereof corresponds to said width.

4. Aircell insulation sheeting according to any one of the preceding claims wherein at least one of the outer layers is reflective.

5. Aircell insulation sheeting according to any one of the preceding claims in :which at least one of the outer layers comprises reflective foil. 15

6. Aircell insulation sheeting according to claim 5 wherein said reflective foil comprises high density polyethylene weave laminated aluminium foil.

7. Aircell insulation sheeting according to any one of claims 4 to 6 wherein the other outer layer is reflective.

8. Aircell insulation sheeting according to claim 7 wherein the other outer layer is comprised of high density weave aluminium foil.

9. Aircell insulation sheeting according to claim 7 wherein the other outer layer is comprised of polyethylene.

Aircell insulation sheeting according to any one of the preceding claims further comprising fire retardants. -9-

11. Aircell insulation sheeting according to any one of the preceding claims further comprising UV inhibitors.

12. Aircell insulation sheeting substantially as herein described with reference to the accompanying drawings. Dated this thirtieth day of April 2001. ASTRO-FOIL (AUST) PTY LTD Applicant Wray Associates Perth, Western Australia Patent Attorneys for the Applicant *C C C° *C o* o* o* oe