GB1593386A - Noise control techniques and systems - Google Patents
Noise control techniques and systems Download PDFInfo
- Publication number
- GB1593386A GB1593386A GB49299/76A GB4929976A GB1593386A GB 1593386 A GB1593386 A GB 1593386A GB 49299/76 A GB49299/76 A GB 49299/76A GB 4929976 A GB4929976 A GB 4929976A GB 1593386 A GB1593386 A GB 1593386A
- Authority
- GB
- United Kingdom
- Prior art keywords
- mat
- rubber
- thick
- plate
- polyurethane
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B27/00—Layered products comprising a layer of synthetic resin
- B32B27/40—Layered products comprising a layer of synthetic resin comprising polyurethanes
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B25/00—Layered products comprising a layer of natural or synthetic rubber
- B32B25/04—Layered products comprising a layer of natural or synthetic rubber comprising rubber as the main or only constituent of a layer, which is next to another layer of the same or of a different material
- B32B25/045—Layered products comprising a layer of natural or synthetic rubber comprising rubber as the main or only constituent of a layer, which is next to another layer of the same or of a different material of foam
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B15/00—Layered products comprising a layer of metal
- B32B15/14—Layered products comprising a layer of metal next to a fibrous or filamentary layer
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B25/00—Layered products comprising a layer of natural or synthetic rubber
- B32B25/14—Layered products comprising a layer of natural or synthetic rubber comprising synthetic rubber copolymers
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B5/00—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts
- B32B5/18—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by features of a layer of foamed material
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
- B32B7/04—Interconnection of layers
- B32B7/12—Interconnection of layers using interposed adhesives or interposed materials with bonding properties
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
- G10K11/16—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
- G10K11/162—Selection of materials
- G10K11/168—Plural layers of different materials, e.g. sandwiches
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2262/00—Composition or structural features of fibres which form a fibrous or filamentary layer or are present as additives
- B32B2262/08—Animal fibres, e.g. hair, wool, silk
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2262/00—Composition or structural features of fibres which form a fibrous or filamentary layer or are present as additives
- B32B2262/10—Inorganic fibres
- B32B2262/101—Glass fibres
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2307/00—Properties of the layers or laminate
- B32B2307/30—Properties of the layers or laminate having particular thermal properties
- B32B2307/306—Resistant to heat
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2471/00—Floor coverings
- B32B2471/04—Mats
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Acoustics & Sound (AREA)
- Multimedia (AREA)
- Laminated Bodies (AREA)
- Carpets (AREA)
Description
(54) IMPROVEMENTS IN OR RELATING TO NOISE CONTROL
TECHNIQUES AND SYSTEMS
(71) We, DELTA MATERIALS RESEARCH LIMITED, a British company of P.O.
Box 22, Hadleigh Road, Ipswich IP2 OEG, Suffolk, do hereby declare the invention for which we pray that a patent may be granted to us and the method by which it is to be performed to be particularly described in and by the following statement:
This invention relates to materials suitable for use in reducing noise generated in industrial environments by metal impacting against metal.
There are many industrial applications where it is necessary for metal bodies to impact against other metal bodies thereby generating considerable noise. The forging of metal bodies is an obvious example. There are also many examples in the manufacturing industry where noise is generated unnecessarily by unwanted impact between metal bodies. Clearly it is desirable that the level of noise in industrial environments should be reduced and this can be done to some extent by reducing the impact noise which is produced unnecessarily.
It is an object of the invention to provide means for reducing unnecessary noise due to impact between metal bodies.
According to the present invention a mat comprises a substantially flat plate of flexible foamed plastics material at least part of one face of which is protected, optimally via an intermediate layer of flexible rubber, by a plate of polyurethane rubber having a hardness within the range 65" - 95" on the Shore A Scale and which provides a surface of the mat having resistance to mechanical wear.
In use, the mat is positioned between two metal bodies which would, in the absence of the mat, come into contact with each other and the mat serves to prevent impact of the metal bodies. When a metal body impacts against foamed plastics material, the relatively low bulk modulus of the material permits it to move and cushion the blow thereby reducing the noise which is produced. Unfortunately foamed plastics materials do not have much resistance to mechanical wear such as abrasion or scuffing by a metal body. Furthermore, the materials are readily cut by an edge of a metal body impacting against them. To protect the foamed plastics materials, the surface of the mat which is impacted by the metal body is provided with a layer of polyurethane rubber having a hardness of at least 65" and not greater than 95" on the Shore A Scale.Such materials have considerable resistance to mechanical wear brought about by metal scuffing against it and impacting it.
The mat is suitable for application to a metal body which would otherwise be impacted by a further metal body. The mat is arranged so that the impacting metal body impacts the mat rather than the metal and the mat reduces the energy transfer from a sharp peak which occurs on metal-to-metal contact, to a longer, more gentle energy transfer and this results in a very much lower level of sound being generated.
The foamed plastics material may take the form of a plate supporting one one face thereof said layer of polyurethane. Alternatively, a plate of a flexible rubber and a plate of foamed plastics material may be arranged one upon the other and a face of one of said plates supports the layer of polyurethane rubber. In such an arrangement the plates of flexible rubber and/or foamed plastics material may be secured together by an adhesive.
Where such a plate or rubber is employed, one face of it may be profiled in order to reduce the effective bulk modulus of the rubber plate so that there is more movement of the rubber on impact.
In order that the invention may be more readily understood it will now be described, by way of example only, with reference to the accompanying drawing, in which:
Figure I is a diagrammatic side elevation of a mat in accordance with the present invention, as applied to a draw bench, and
Figures 2, and 3 are diagrammatic side elevations of mats according to alternative embodiments of the invention.
A draw bench used in the drawing of rod and wire includes a massive metal chain 1 which is arranged above a metal base plate 3. In use, the chain is dragged horizontally above the level of the base plate but periodically the chain is allowed to drop on to the base plate and this causes considerable noise to be generated.
To bring about a reduction in noise level which occurs when the chain is allowed to drop, a mat 5 is mounted on the upper surface of the base plate 3 to prevent the falling chain 1 from impacting against the base plate. The mat consists of foamed plastics material with its upper surface covered by a layer of hard polyurethane rubber. In Figure 1, reference numeral 7 indicates a plate of closed cell polyethylene foam which rests on the base plate 3 and on its upper surface it supports a plate 9 of polyurethane rubber which has a hardness of between 65 and 95" on the Shore A Scale.
In use, when the chain 1 is allowed to fall it impacts against the mat and this isolates the impact shock from the base plate 3. The impact of the chain against the plate 9 causes a certain amount of noise to be generated but, because the plate 7 is flexible, it allows the plate 9 to move relative to the chain 1 and consequently the energy transfer between the chain and the mat 5 is spread over a longer period of time than is the case when the chain impacts against the non-movable metal plate 3. The plate 9 provides resistance to mechanical wear due to the abrasion and impacting of the chain against the plate.
In the arrangement shown in Figure 2, provision is made for use of the material in a hot environment. If for example the base plate 3 is at a fairly high temperature, then the mat 5 is spaced from the plate 3 by a layer of fibrous material 11. The layer is conveniently of wire wool, glass fibre or mineral wool. Otherwise the mat 5 is the same as that shown in Figure 1 but as the mat is in use in a hot environment, it is sensible to choose for the plate 9 a polyurethane rubber which has a melting point sufficiently high for it not to be affected by the environment in which it is placed.
In an alternative embodiment, shown in Figure 3, the mat 13 comprises a plate of foamed plastics material 15, on one face of which there is a rubber plate 17 and the plate of polyurethane rubber 9 is supported on the upper face of the plate 17. The plate 15 is conveniently of closed cell polyethylene foam and the plate 17 is of polysulphide rubber which is profiled on the face which is in contact with the plate 15 in order to reduce the bulk modulus of the material. The polyurethane layer 9 is supported on the non-profiled face of the layer 17.
In a similar embodiment, which is not illustrated, the polyethylene foam may be positioned between the profiled rubber and the polyurethane rubber, with the profiled face of the rubber plate being in contact with the polyethylene foam. By selecting a high hysteresis rubber for the plate which is against the base plate 3, a high degree of damping can be provided.
The performance of mats constructed according to the invention has been evaluated and compared with the performance of mats constructed with known materials by means of a simple test rig which involves the use of a 4 inch tall by 2 inch diameter steel cylinder which is dropped from a height of about 24 inches. An accelerometer is mounted on the cylinder and the shock pulse generated as the cylinder strikes the mat is monitored. A Figure of
Merit has becn determined to rate each mat under test. The Figure of Merit is the total rise and fall time of the first impulse peak divided by the peak impulse level. Clearly the longer the period of time that is required to transfer the energy from the falling cylinder to the mat, the higher the Figure of Merit and the more effective the material for shock isolation.The results of the tests are shown in Table 1 below.
TABLE 1
Mat or Pad Construction Figure of Merit
(a) 1" thick 40 Shore solid polyurethane rubber 233
(b) 1" thick 50 Shore neoprene rubber 368
(c) 1" thick felt pad 351
(d) 1" thick 85" Shore solid polyurethane rubber 15
(e) -" thick 85" Shore solid polyurethane 385
+ 2 thick foamed polyethylene 755 3/8" thick foamed polyethylene
+ 5/8" thick profiled neoprene
(g) 3/8" thick foamed polyethylene 780
+ 3/8" thick profiled polysulphide
+ 1/4" thick solid polyurethane wear surface (70 Shore)
(h) 3/8" thick foamed polyethylene 770
+ 3/8" thick profiled polyurethane
+ 1/4" solid polyurethane wear surface (70 Shore)
It can be seen from tests (a) and (d) that by employing polyurethane rubber alone, a not very satisfactory Figure of Merit is obtained, particularly when the harder grade of polyurethane rubber is employed. The reason for this is that the bulk modulus of the material is so high that it is hardly flexible. An improved Figure of Merit is obtained when 50 Shore profiled neoprene rubber or a felt pad is employed, but as these materials have very little resistance to mechanical wear, they could not be used on their own. Test (e) shows that a reasonable Figure of Merit is obtained if a hard solid polyurethane material is used to cover a -" thick plate of foamed polyethylene.By providing a plate of foamed polyethylene and a plate of profiled neoprene rubber, a very satisfactory Figure of Merit is obtained, as shown by test (f), but the mat has very little resistance to wear since it is not provided with a polyurethane cover. Tests (g) and (h) show that even better Figures of
Merit can be obtained for a mat consisting of plates of foamed polyethylene and profiled rubber with the mat having a 1/4" thick solid polyurethane wear surface. Such materials have the advantage of being resistant to mechanical wear and they serve to reduce the noise generated when the material is impacted.
WHAT WE CLAIM IS:
1. A mat comprising a substantially flat plate of flexible foamed plastics material at least part of one face of which is protected by a plate of polyurethane rubber having a hardness within the range 65" - 95" on the Shore A Scale and which provides a surface of the mat having resistance to mechanical wear.
2. A mat as claimed in claim 1, in which a plate of flexible rubber is disposed between the foamed plastics material and the polyurethane rubber.
3. A mat as claimed in claim 2, in which the face of the flexible rubber plate which is against the foamed plastics material is profiled to reduce the bulk modulus of the rubber.
4. A mat as claimed in claim 1, in which the plate of foamed plastics material is disposed between the plate of polyurethane rubber and a plate of flexible rubber with the face of the flexible rubber which is against the foamed plastics material being profiled to reduce the bulk modulus of the rubber.
5. A mat as claimed in claim 2, 3 or 4, in which the plates of foamed plastics material and flexible rubber are secured together by an adhesive.
6. A mat as claimed in claim 1, in which the ratio of the thickness of the foamed plastics material and the polyurethane rubber is substantially 1:1.
7. A mat as claimed in any preceding claim, mounted on a metal base with the plate of polyurethane rubber away from the metal base.
8. A mat as claimed in claim 7, with a layer of heat resistant fibrous material interposed between the mat and said metal base.
9. A mat as claimed in claim 8, in which said fibrous material is wire wool.
10. A mat as claimed in claim 8, in which said fibrous material is glass fibre.
**WARNING** end of DESC field may overlap start of CLMS **.
Claims (12)
1. A mat comprising a substantially flat plate of flexible foamed plastics material at least part of one face of which is protected by a plate of polyurethane rubber having a hardness within the range 65" - 95" on the Shore A Scale and which provides a surface of the mat having resistance to mechanical wear.
2. A mat as claimed in claim 1, in which a plate of flexible rubber is disposed between the foamed plastics material and the polyurethane rubber.
3. A mat as claimed in claim 2, in which the face of the flexible rubber plate which is against the foamed plastics material is profiled to reduce the bulk modulus of the rubber.
4. A mat as claimed in claim 1, in which the plate of foamed plastics material is disposed between the plate of polyurethane rubber and a plate of flexible rubber with the face of the flexible rubber which is against the foamed plastics material being profiled to reduce the bulk modulus of the rubber.
5. A mat as claimed in claim 2, 3 or 4, in which the plates of foamed plastics material and flexible rubber are secured together by an adhesive.
6. A mat as claimed in claim 1, in which the ratio of the thickness of the foamed plastics material and the polyurethane rubber is substantially 1:1.
7. A mat as claimed in any preceding claim, mounted on a metal base with the plate of polyurethane rubber away from the metal base.
8. A mat as claimed in claim 7, with a layer of heat resistant fibrous material interposed between the mat and said metal base.
9. A mat as claimed in claim 8, in which said fibrous material is wire wool.
10. A mat as claimed in claim 8, in which said fibrous material is glass fibre.
11. A mat as claimed in claim 7, 8, 9 or 10, in which said metal base is a base plate of a
draw bench.
12. A mat substantially as hereinbefore described with reference to any one of Figures 1, 2 or 3 of the accompanying drawings.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB49299/76A GB1593386A (en) | 1977-12-19 | 1977-12-19 | Noise control techniques and systems |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB49299/76A GB1593386A (en) | 1977-12-19 | 1977-12-19 | Noise control techniques and systems |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB1593386A true GB1593386A (en) | 1981-07-15 |
Family
ID=10451873
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB49299/76A Expired GB1593386A (en) | 1977-12-19 | 1977-12-19 | Noise control techniques and systems |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB1593386A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20110168217A1 (en) * | 2010-01-12 | 2011-07-14 | Neff Raymond A | Appliance comprising polyurethane foam |
| CN104590154A (en) * | 2015-01-30 | 2015-05-06 | 柳州市同进汽车零部件制造有限公司 | Heat insulation device of automobile |
-
1977
- 1977-12-19 GB GB49299/76A patent/GB1593386A/en not_active Expired
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20110168217A1 (en) * | 2010-01-12 | 2011-07-14 | Neff Raymond A | Appliance comprising polyurethane foam |
| US8302280B2 (en) * | 2010-01-12 | 2012-11-06 | Basf Se | Appliance comprising polyurethane foam |
| CN104590154A (en) * | 2015-01-30 | 2015-05-06 | 柳州市同进汽车零部件制造有限公司 | Heat insulation device of automobile |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PS | Patent sealed [section 19, patents act 1949] | ||
| 732 | Registration of transactions, instruments or events in the register (sect. 32/1977) | ||
| 732 | Registration of transactions, instruments or events in the register (sect. 32/1977) | ||
| PCNP | Patent ceased through non-payment of renewal fee |