WANSBROUGH LEITH EVAN (NZ)
FULLERTON JONES PAUL ROBERT (NZ)
| WHAT WE CLAIM IS: 1 . A roto-moulded hollow cuboid noise panel which includes: three pairs of opposed surfaces, each pair of opposed surfaces connected via an adjacent pair of opposed surfaces which collectively define a hollow-interior; wherein a pair of opposed surfaces defining the largest surface areas of the cuboid are further connected via Kiss-Offs located in at least two spatially distinct regions; wherein said Kiss-Offs extend in from one surface of the opposed pair of surfaces a distance sufficient to contact the other opposed surface. 2. A plurality of roto-moulded hollow cuboid noise panels including Kiss-Offs as claimed in claim 1 which are located within an enclosed space and which form a cuboid arrangement in which the cuboids: - are placed side-by-side; and - are supported above the enclosed area in which noise will be generated; wherein in said cuboid arrangement absorbs any noise transmitted thereto, in order to dampen and/or help prevent the reflection of noise, from the panel arrangement back down to the enclosed area. 3. A roto-moulded hollow cuboid noise panel as claimed in claim 1 wherein the one of the largest surface areas is substantially planar in nature and the other of the largest surface areas is defined by at least two inclined or declined surfaces. 4. A plurality of roto-moulded hollow cuboid noise panels as claimed in claim 1 which collectively form a panel arrangement in which panels: are placed to adjacently overlap or abut one another; and are supported above a partitioned area in which noise is generated so as to contact the top of said partitions; wherein in said panel arrangement absorbs said noise transmitted thereto, in order to help prevent any transmission of noise above the partitions occurring. 5. A roto-moulded hollow panel substantially as substantially as claimed in claims 1 or 3 wherein the Kiss-Off is located in two spatially distinct regions of the panel and/ or are spaced along the length of the panel. 6. A roto-moulded hollow panel substantially as claimed in claims 1 , 3 or 5 wherein the Kiss- Offs are also located in mid-section of the panel and are spaced along the length of the panel. 7. A roto-moulded hollow panel substantially as claimed in claims 1 , 3, 5 or 6 wherein the Kiss-Offs are located over substantially the entire surface of the panel. 8. A roto-moulded hollow panel as claimed in claim 1 wherein the hollow interior of the Kiss- Offs is a substantially truncated cone comprising a closed truncated end on the front wall- surface and an open end at the base on the rear wall-surface. 9. A noise wall which includes a plurality of roto-moulded hollow panels as claimed in any one of claims 1 ,3,5,6,7 or 8. |
TECHNICAL FIELD
The present invention relates to improvements in and relating to panels. In particular, the present invention related to improvements in relation to noise panels
BACKGROUND ART
Motorway noise panels, used in noise walls, or noise barriers, are commonly erected on the side of roads - to provide a level of road noise reduction for houses, buildings and people nearby a motorway or road.
Many different designs and construction materials exist for manufacturing noise walls, including :
- concrete panels fixed to upright I-beams
- timber (plywood) panels on posts; - aluminium-perforated panels filled with absorptive material such as fiberglass.
However, all the aforementioned existing systems suffer from one or more of the following drawbacks:
- being heavy; and
- requiring cranes to lift and install; The above drawbacks all increasing the cost and time required to install panels.
There are also a plastic panel systems such as those developed by AR Moulding. However, plastic panel noise walls to date are acoustically inferior to those made concrete and timber.
It is an object of the present invention to address the foregoing problems or at least to provide the public with a useful choice. All references, including any patents or patent applications cited in this specification are hereby incorporated by reference. No admission is made that any reference constitutes prior art. The discussion of the references states what their authors assert, and the applicants reserve the right to challenge the accuracy and pertinency of the cited documents. It will be clearly understood that, although a number of prior art publications are referred to herein, this reference does not constitute an admission that any of these documents form part of the common general knowledge in the art, in New Zealand or in any other country.
Throughout this specification, the word "comprise", or variations thereof such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element, integer or step, or group of elements integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.
Further aspects and advantages of the present invention will become apparent from the ensuing description which is given by way of example only.
DEFINITIONS
The term "roto-moulded" as used herein refers to rotationally moulded and relates to a well- known plastic forming technique which uses a mould which is rotated in an oven.
The term "Kiss-Off" as used herein refers to hollow internal reinforcing structural points that formed via a well-known rotational moulding techniques.
SUMMARY OF THE INVENTION
The present invention is founded upon the surprising discovery that Kiss-Offs conventionally used for strengthening roto-moulded products can also increase the acoustic absorption characteristics of a roto-moulded sound panel.
According to one aspect of the present invention there is provided a roto-moulded hollow cuboid noise panel which includes: three pairs of opposed surfaces, each pair of opposed surfaces connected via an adjacent pair of opposed surfaces which collectively define a hollow-interior; wherein a pair of opposed surfaces defining the largest surface areas of the cuboid are further connected via Kiss-Offs located in at least two spatially distinct regions; wherein said Kiss-Offs extend in from one surface of the opposed pair of surfaces a distance sufficient to contact the other opposed surface.
According to the second aspect of the present invention there is provided a roto-moulded hollow noise panel substantially as described above wherein a walled-hollow-passageway is formed via a Kiss-Off which extends from the rear surface and connects to an interior region of the front wall-surface. For ease of reference only the walled-hollow-passageway will now generally be referred to as a Kiss-Off to aid understanding.
According to the third aspect of the present invention there is provided a roto-moulded hollow noise panel substantially as described above wherein the Kiss-Offs are located in at least upper and lower sections of the panel and are spaced along the length of the panel.
According to the fourth aspect of the present invention there is provided a roto-moulded hollow noise panel substantially as described above wherein the Kiss-Offs are also located in midsection of the panel and are spaced along the length of the panel.
According to the fifth aspect of the present invention there is provided a roto-moulded hollow noise panel substantially as described above wherein the Kiss-Offs are located over the entire outer wall-surface of the panel.
According to the sixth aspect of the present invention there is provided a roto-moulded hollow noise panel substantially as described above wherein the panel is substantially 4 metres in length and adjacent Kiss-Offs are spaced substantially 1 m apart vertically and substantially 1 m apart along the length of the panel, each Kiss-Off comprising an open end on the rear surface of the panel and having external cross sectional dimensions on the rear surface of
approximately 400mm 2 .
According to the seventh aspect of the present invention there is provided a roto-moulded hollow noise panel as above wherein the hollow interior of the Kiss-Offs is a substantially truncated cone comprising a closed truncated end on the front wall-surface and an open end at the base on the rear wall-surface.
According to the eighth aspect of the present invention there is provided a use of a roto- moulded hollow panel which includes a plurality of Kiss-offs connecting front and rear wall- surfaces of the panel - to reduce noise transmission from the front of the panel to the rear of the panel - wherein the Kiss-Off extends from the rear wall-surface of the panel.
According to the ninth aspect of the present invention there is provided a use as above wherein the Kiss-Offs are in upper and lower sections of the panel and are spaced apart along the length of the panel.
According to the tenth aspect of the present invention there is provided a use as above wherein the front wall of the panel including the integrally sealed end of the Kiss-Offs face the noise pollution to which the panel is to absorb.
According to an eleventh aspect of the present invention there is provided a noise wall which includes a plurality of roto-moulded hollow panels substantially as described above. BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 shows a perspective view of a panel according to one preferred embodiment of the present invention; Figure 2 shows a cross-sectional view of the panel shown in Figure 1 along line C-C;
Figure 3 shows a roto-moulded (plastic) noise wall system consisting of either filled or unfilled modular (roto-moulded noise panels) that were independently evaluated by The University of Canterbury(UoC);
Figure 4 shows an individual roto-moulded noise panel that was used in the testing by
UoC); and
Figure 5 is a graph which shows the inclusion of Kiss-Offs makes a significant
contribution to the sound transmission loss rating of the n o i s e wall system.
BEST MODES FOR CARRYING OUT THE INVENTION In relation to the Figures there is shown a panel 1 which includes a plurality of walled-hollow- passageways in the form of Kiss-Offs 2 extending between the rear wall-surface 3 to the front wall-surface 4. The Kiss-Offs 2 are in the form of a truncated cone. In use, the front wall- surface 4 is situated so as to face the source of the noise pollution.
Example 1 - Accoustic Testing of Plastic Panels including Kiss-Offs. Sound Transmission Loss of ARMoulding Traffic Noise Control Barriers - Evaluation by Mechanical Engineering Dept. University of Canterbury B. Donohue
Introduction
The sound transmission loss ratings for sample 2.4 m x 2.4 m walls, constructed from ARM traffic noise control barrier modules were tested using the University of Canterbury's transmission loss facility. The walls were installed in the University's large transmission loss suite (2.4 m x 4.8 m) and the aperture was reduced using a heavyweight blank wall.
Test Conditions
Facilities
The large sound transmission loss suite in the Department of Mechanical Engineering consists of a reverberation room with a 2.4 m x 4.8 m opening to a semi- anechoic room. The aperture was reduced down to 2.4 m x 2.4 m using heavyweight blank walls. The system's construction within the opening results in a niche of approximately 150 mm on both sides of the sample. The receiving semi-anechoic room has sound absorption material covering all surfaces to reduce reflection of transmitted sound, as specified by ISO 15186'. The reverberation room has a right-angled trapezoidal plan with stationary diffusers. No two dimensions in the reverberation room are equal or in the ratio of small whole numbers. The volume of the room is 216 m 3 . A sufficiently diffuse sound field is established by the inclusion of 6 stationary diffusing panels of galvanized steel faced medium density fibreboard, each of one-sided area of 2.88 m 2 and suspended with random orientation. The total two-sided area of the diffusing elements is 0.13 of the total boundary surface area of the room. The diffusivity of the sound field in the room is considered acceptable. The total surface area of the
reverberation room boundaries and diffusing elements is 305 m 2 .
Systems Tested
Each single wall system, as shown in Figure 3 consisting of either filled or unfilled modular traffic noise barrier components was evaluated. Each sample wall consisted of five elements (panels), each of the profile as shown in Figure 4. The barrier components are rotationally moulded from high density polyethylene.
Three forms of the modules were tested:
(i) with the cross-section as shown in Figure 4 without Kiss-Offs (regional stand-offs connecting front and rear panels of the beam),
Weight: 7.3kg per module
(ii) the same cross-section but with Kiss-Offs, Weight: 12.4 kg per module
(iii) the same cross-section but with an internal closed cell foam layer approximately 10 mm thick,
Weight: 9.9 kg per module. Instrumentation and Measurement A summary of the equipment used is given in Table 1 below.
Generation of the Sound Field
The sound field in the source room was generated according to ISO 10140-4" by Bruel & Kjaer Pulse software and a Bruel & Kjaer Pulse 3560-C data acquisition unit. The signal was processed by a Bruel & Kjaer 271 6 power amplifier and transmitted to a Bruel & Kjaer 4296 omnidirectional speaker. Receipt of Signals
The sound pressure level in the source (reverberation) room was measured according to ISO 1 0140-4 using six Bruel & Kjaer 41 89 free field microphones connected to the Bruel & Kjaer Pulse 3560-C Pulse data acquisition unit in the control room. The microphones were placed at locations in accordance with ISO 10140, with distances from surrounding surfaces being a minimum of 1 metre.
In the receiving (semi-anechoic) room, the surfaces of the test samples were scanned according to the method described in ISO 1 51 86-1 , although due to the size of the sample the requirements set out in IS01 51 86-1 were not met. The sound intensity was calculated by using a Bruel & Kjaer D-Frame Pulse Unit running Bruel & Kjaer Labshop software and a Bruel & Kjaar 3595 sound intensity probe kit. A set of three separate sound intensity measurements were made for each test sample, each consisting of two scans of the surface (one horizontal and one vertical), which were time and space averaged. During scanning the probe was held at a distance of 150mm from the sample surface. The measurement data was exported in the form of pressure and intensity levels for further analysis and calculation of the sound transmission loss.
Calculations and Background Theory The STL was calculated using:
Where L P is the average sound pressure level measured in the source room, and L / is the average intensity measured using in the receiving room.
Average STL values were calculated using values from three separate tests. Average values of sound pressure in the source room (5 microphones) were
used in calculating the STL. For both of these cases, logarithmic averages of the sound levels were calculated as follows:
Note that ISO 15186 states that the intensity method is reliable only in the frequency range of 100 Hz to 5000 Hz.
STC and R w were calculated in accordance with ISO 15186-1 ,2,3 and IS0717-1 '''. The bandwidths are:
• R w : 100 - 3150 Hz (sound reduction index)
• STC: 100 - 5000 Hz (sound transmission class) Pressure-Intensity Index and Repeatability Index
The pressure-intensity index and repeatability index were calculated for every pair of horizontal and vertical scans as if the calculated indices exceed the values specified in ISO 10140-1 and ISO 10140-2 then the measurement must be discarded.
The pressure intensity index is calculated using: And the repeatability index is calculated using: The PI index is required to be lower than 10 dB in all the measured one third octave frequency bands. The repeatability index is required to be less than 1 dB in all one- third octave frequency bands.
Results
The results for the traffic barrier measurements are presented below and consist of graphs of the measured sound transmission loss and the tabulated sound transmission loss.
As can be seen in Figure 5 (wherein 'blue barriers with stand off and foam' is shown as light grey; 'yellow barrier with no stand off is shown as black; and 'yellow barriers with stand off is shown as mid grey), the inclusion of stand-offs makes a significant contribution to the sound transmission loss rating of the wall system. The single number ratings are included in Table 2. There could also be a mass effect although some of the additional weight in samples type (ii) may be concentrated at the stand- offs it is expected that the wall thickness is also slightly higher than for type (i).
DISCUSSION OF THE INVENTION INCLUDING ALTERNATE WAYS TO IMPLEMENT THE INVENTION The walled-hollow-passageways may take a number of different forms without departing from the scope of the present invention.
In preferred embodiments the walled-hollow-passageways may be in the form of Kiss-Offs.
In one preferred embodiment the walled-hollow-passageways may be in the form of a truncated cone. In one alternate embodiment the walled-hollow-passageways may be in the form of cylinders.
In another alternate embodiment the walled-hollow-passageways may have a rectangular transverse cross-sectional profile.
Preferably, the walled-hollow-passageway have at least one closed end on the front-wall- surface which will be exposed to the noise pollution. In some embodiments the open end of the walled-hollow-passageway may be closed off with a plastic closure component.
In one preferred embodiment where the walled-hollow-passageway may be in the form of a Kiss-Off the open end of the Kiss-Off on the rear wall may be closed off with a circular "spin-fit" closure component. An advantage of closing off the open end of the walled-hollow-passageway is that it provides further sound retardation.
Thus preferred embodiments of the present invention may include one or more of the following advantages: • providing a lightweight alternative to heavier reflective noise barriers;
• providing an acoustically superior plastic noise panel/noise wall to currently available plastic noise panels/noise walls;
• providing a lightweight alternative to noise panels filled with an absorptive material. The invention may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, in any or all combinations of two or more of said parts, elements or features.
Aspects of the present invention have been described by way of example only and it should be appreciated that modifications and additions may be made thereto without departing from the scope thereof as defined in the appended claims.
REFERENCES
General references and citations i ISO 15186-1 :2000
Acoustics -Measurement of sound insulation in buildings and of building elements using sound intensity, Part 1 : Laboratory measurements ii
ISO 10140-4:2010
Acoustics - Laboratory measurement of sound insulation of building elements, Part 4: Measurement procedures and requirements iii ISO 717-1 :2013
Acoustics - Rating of sound insulation in buildings and of building elements, Part 1 : Airborne sound insulation