GB2445408A

GB2445408A - A composite wall sound barrier vacuum panel

Info

Publication number: GB2445408A
Application number: GB0625881A
Authority: GB
Inventors: Michael John Rickards
Original assignee: Individual
Current assignee: Individual
Priority date: 2006-12-27
Filing date: 2006-12-27
Publication date: 2008-07-09
Anticipated expiration: 2026-12-27
Also published as: GB2445408B; GB0625881D0

Abstract

A composite wall sound barrier vacuum panel comprises first 9 and second 10 panes separated by a perimeter wall 11. The perimeter wall is composed of two or more lengthwise strips of different thicknesses 14, 15. These may be in the form of two thicker strips each side of a thinner strip and may form a channel. The thicker strips may be formed from flanges on the panes. The enclosed space evacuated to less than 100 Pa.

Description

2445408

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A composite wall sound barrier vacuum panel

Sound deadening materials are available in abundance each justly claiming a particular advantage whether in acoustic efficiency, ease of use or cost economy etc. They all have a common function in that as sound passes through them a substantial reduction in the intensity of the sound is secured i .e. they provide a useful degree of sound alternation.

Attenuation is of value in reducing sound levels inside an enclosed space, such as a recording studio for example, but when it comes to controlling sound entering from outside, as in the case of traffic or aircraft noise for instance, sound deadening materials offer only limited effectiveness. A sound barrier to that incoming noise is required.

Since sound waves are not propagated through a vacuum an ideal panel,

Figure 1, comprising upper (1) and lower (2) panes separated by a perimeter wall (3) would be a very effective sound barrio\ In a real vacuum panel, Figure 2,

atmospheric compression causes the upper (4) and lower (5) panes to flex inwardly and the perimeter wall (6) must have at least the height (7) required to prevent contact between the panes. The perimeter wall must also be thick (8) enough to have sufficient strength to withstand atmospheric compression acting on the panel and yet as thin as possible to reduce the transmission of sound through it

According to the present invention there is provided a vacuum panel, illustrated in Figure 3 in cross section, comprising square upper (9) and lower (10) panes separated by a perimeter wall (11) made up of two lengthwise strips, one strip (12) making up a part of the height of the perimeter wall and thick enough (15) to provide a rigid support for a thinner (14) strip making up the rest (13) of Ifce height of the wall The enclosed space evacuated to less than 100P&. The height of the perimeter wall is made sufficient to prevent the panes (9,10) from making contact under atmospheric pressure.

The principal advantages that a composite wall sound barrier vacuum panel provides over existing sound attenuating panels are:

1. They have a very high level of sound rejection, of the order of 40dB or even greater.

2. Their high rejection level of sound is maintained unchanged over a wide frequency range, nominally 100 to 3200 Hz

3. Their simple structure enables low cost mass production from readily available materials.

4. Made from appropriate materials they are likely to have an effective life well in excess of twenty years under a wide range of ambient conditions.

5. They have a useful degree of thermal insulation in addition to their sound barrier capability.

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Tbe following drawings are used in this document

Figure 1 shows a cross section of an idealized vacuum panel

Figure 2 shows a cross section of the vacuum panel described in Example 1.

Figure 3 shows a cross section of a basic composite wall sound barrier vacuum panel.

Figure 4 shows a cross section of the composite wall sound barrier vacuum panel described in Example 2

Figure 5 shows a cross section of part of the composite wall sound hairier vacuum panel described in Example 3.

Figure 6 shows a cross section of part of the composite wall sound barrier vacuum panel described in Example 4

Figure 7 shows a cross section of part of the composite wall sound barrier vacuum panel described in Example 5

The glass reinforced plastic (GRP) used in Examples 3 and 4 consisted of glass fibre, as chopped strand mat, impregnated with polyester resin and the whole compressed to give a laminate containing not less than 40% glass by weight

The sound transmitted through the panel was measured at 100,200,400,800, 1600 and 3200Hz and was found to remain substantially unchanged Le. independent of frequency, for each of the examples quoted below.

In all the examples quoted the enclosed space of die panel was evacuated to less than lOOPa.

Example 1

This example shows the sound rejection level that can be realised when the perimeter wall of the vacuum panel is not composite. Figure 2 illustrates a cross section of the panel with upper (4) and lower (5) panes separated by a perimeter wall (6). The square panes had 400mm sides and woe made from 0.8mm mild &eel sheet and the 1.2mm thick (8) mOd steel perimeter wall had a height (7) of 35mm. This panel was found to trananit about 0.1% of incoming sound giving a sound rejection level of 25 to 30dB.

Exaiaple 2

Figure 4 illustrates a vacuum panel similar to that described in Example 1 but with the upper (16) and lower (17) panes separated by a composite p&imeter wall (18) made up of a mild steel strip (19) 12mm high and 1.2mm thick, a mild steel strip (21) 0.8mm thick andlOmm high and a mild steel strip (20) 1.2mm thick and 12mm high. This panel was found to transmit about 0.01% of incoming sound giving a rejection level of 35 to 40dB.

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Example 3

Two parts of a vacuum panel similar to that described in Example 2 is illustrated in Figure S with the upper (22) and lower (23) panes separated by a perimeter wall made up of a 15 mm high (27), 1.2 mm thick mild steel strip (24), a 0.25 mm thick, 5 mm high (28) internally flanged mild steel channel (26|), and a 1.2 mm thick and 15 mm high (29) mild steel strip (25). This panel was found to transmit about 0.001% of incoming sound giving a rejection level of 45 to 50 dB.

Example 4

A square composite wall vacuum panel, as partly illustrated in Figure 6, with 3 mm thick upper (30) and lower (34) panes made up from GRP with 250 mm sides and with edges shaped to provide a perimeter lip (31,33) approximately 7 mm high (35,37). The panes were separated by a 5 mm high (36), 1 mm thick GRP perimeter strip (32). This panel was found to transmit about 0.05% of incoming sound giving a rejection level of 30 to 35 dB.

Example 5

A vacuum panel, partly illustrated in Figure 7, similar to dimensions in Example 4 but with a 20 mm wide GRP perimeter band (40), 0.5 mm thick, made from plain weave glass fibre impregnated with polyester resin and separating the edges of the upper (38) and lower (39) panes by about 5 mm (42). This panel was found to transmit about 0.005% of incoming sound giving a rejection level of 40 to 45 dB.

Although the above examples refer to square panels, oblong, triangular, hexagonal or irregularly shaped panels are equally feasible.

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Claims

1. A sound barrier vacuum panel comprising square upper and lower panes separated by a composite perimeter wall made up of a thick lengthwise strip supporting a thinner lengthwise strip with the enclosed space evacuated to less than 100 Pa the combined height of both strips providing sufficient separation between the panes to prevent them from making contact under atmospheric compression.

2. A panel as in Claim 1 wherein the perimeter wall is composed of an upper and lower thick lengthwise strip supporting a thin lengthwise strip between them

3. A panel as in Claim 1 and Claim 2 wherein the thin strip is in the form of a channel with internal flanges.

4. A panel as in Claim 1 and Claim 2 wherein the upper and lower panes have edges formed to provide a thick perimeter lip to support a thin lengthwise strip.

5. A panel as in Claim 1 and Claim 4 wherein the edges of the upper and lower panes are separated by a thin perimeter band having a lesser width than the overall height of the panel.

6. A panel as in any of the above claims wherein the shape of the panel is triangular.

7. A panel as in any of the above claims wherein the shape of the panel is a regular hexagon.

8. A panel as in any of the above claims wherein the shape of the panel is irregular.