Improved noise resistant gasket and further improved noise resistant gasket and method of producing same

Abstract

The present application describes an anti-noise gasket 100 comprising at least one layer of damping material comprising fibers selected from organic natural and / or artificial and / or synthetic fibers or inorganic fibers, fillers and binders. The present application also describes an anti-noise gasket (200) or (300) comprising a structurally discontinuous or non-uniform support layer in the form of a perforated metal foil or made of fibers, respectively, embedded / clamped / inserted between two layers of damping material, which are identical or different from each other, and coupled to each other and to the support layer by chemical binders and / or by the application of pressure and / or temperature, each layer of damping material comprising fibers selected from organic natural and / or artificial and / or synthetic fibers or inorganic fibers, fillers and binders.

Description

Technical Field

[0001] This application relates to an improved noise-canceling pad. More specifically, this application relates to an improved noise-canceling pad comprising at least one damping material layer, more preferably, comprising a structurally discontinuous or non-uniform support layer. The support layer is selected from the group consisting of: perforated metal foil support layers or support layers made of fibers, continuous or discontinuous long, medium or short fibers, organic fibers or inorganic fibers. The support layer has different structures: fibers randomly distributed to form a dense but non-uniform support layer; fibers in the form of a woven “mesh” support layer; and fibers arranged in a network. The fibers are fused together at overlapping points to provide a network structure support layer, the support layer being embedded / clamped / inserted between two damping material layers that are identical or different from each other, and bonded together by chemical adhesives and / or by applying pressure and / or temperature. Background Technology

[0002] Gaskets are widely used in the automotive industry to reduce noise, vibration, and harshness (NVH). This makes the use of gaskets particularly significant for braking systems. Gaskets are used in braking systems for brake pads to reduce NVH during braking events.

[0003] Typical gaskets are functional multilayer compounds. The numerous gaskets available on the market vary in the number of layers, layer thickness, and chemical composition of each layer. The composition, thickness, and design of multilayer gaskets significantly affect their NVH-related properties.

[0004] Typically, shims are used for damping purposes. Shims are bonded to the backing plate of the brake pads via an adhesive layer. This is crucial for maximizing the damping effect of the shims. Due to their excellent damping properties and elasticity, different types of rubber can be used.

[0005] Another type of gasket includes a supporting metal layer, which typically serves both as a carrier for the rubber and increases the product's strength in the XY plane. Furthermore, different types of supporting metal layers can be used depending on the target application requirements and cost constraints (see Patent No. 102020000011902, granted in the name of the applicant).

[0006] In order to improve the performance of existing noise-canceling pads, the applicant has developed a new, cost-competitive noise-canceling pad whose improved characteristics are comparable to existing, higher-quality and more expensive noise-canceling pads on the market. Summary of the Invention

[0007] This application relates to a novel noise-reducing pad, which represents a further improvement over existing noise-reducing pads.

[0008] This improvement is achieved through a noise-damping pad comprising at least one damping material layer comprising organic, natural, and / or artificial and / or synthetic fibers or inorganic fibers, fillers, and adhesives. More preferably, it further comprises a structurally discontinuous or non-uniform support layer selected from the group consisting of: Perforated metal foil support layer or A support layer made of fibers, continuous or discontinuous long, medium or short fibers, organic fibers or inorganic fibers; the support layer has the following different structures: The fibers are randomly distributed to form a dense but uneven support layer; Fibers woven into a "mesh" support layer; and Fibers arranged in a network, wherein the fibers are fused together at overlapping points to provide a support layer for the network structure.

[0009] The support layer is embedded / clipped / inserted between two damping material layers, which may be the same or different from each other, and are bonded to each other by chemical adhesive and / or by applying pressure and / or temperature, as well as the relevant methods for its production as defined in the appended independent claims. Attached Figure Description

[0010] Figure 1 This application illustrates a structurally discontinuous or non-uniform support layer, wherein fibers are randomly distributed to form a dense but non-uniform support layer.

[0011] Figure 2a and Figure 2b The present application illustrates a structurally discontinuous or non-uniform support layer, wherein the fibers are in the form of a woven "net" support layer.

[0012] Figure 3 This application illustrates a structurally discontinuous or non-uniform support layer, wherein fibers (arranged in a network with different mesh sizes (w) that remain constant or vary in the same structure) and fibers having the same diameter (φ) or even different diameters) are fused together at overlapping points to provide a network structure forming the support layer.

[0013] Figure 4a and Figure 4b This application illustrates a structurally discontinuous or non-uniform support layer in the form of a perforated metal foil. Detailed Implementation

[0014] The applicant has surprisingly and unexpectedly developed a novel noise-reducing pad 100 comprising at least one damping material layer, which includes organic, natural and / or artificial and / or synthetic fibers or inorganic fibers, fillers, and adhesives.

[0015] As another preferred embodiment of this application, the applicant has surprisingly and unexpectedly developed a novel noise-damping pad 200. The novel noise-damping pad 200 comprises a structurally discontinuous or non-uniform support layer in the form of a perforated metal foil. Preferably, the perforated area occupies at least 30% (more preferably at least 50%) of the entire surface of the perforated metal foil. The support layer is embedded / clipped / inserted between two damping material layers, which may be identical or different from each other, and are bonded to the support layer by a chemical adhesive and / or by applying pressure and / or temperature. Each damping material layer comprises fibers of organic natural and / or artificial and / or synthetic fibers or inorganic fibers, fillers, and adhesives.

[0016] As another preferred embodiment of this application, the applicant has surprisingly and unexpectedly developed a novel noise-reducing pad 300, comprising a structurally discontinuous or non-uniform support layer made of fibers, such as: • Fibers that are randomly distributed to form a dense but uneven support layer; • Fibers woven into a “mesh” support layer; and • Fibers arranged in a network, wherein the fibers are fused together at overlapping points to provide a support layer for the network structure.

[0017] The support layer is embedded / clipped / inserted between two damping material layers, which may be identical or different from each other, and are bonded together by a chemical adhesive and / or by the application of pressure and / or temperature. Each damping material layer comprises fibers of organic natural and / or artificial and / or synthetic or inorganic fibers, fillers, and adhesives.

[0018] According to one embodiment, the adhesive is an elastomeric adhesive, but it can also be a non-elastomeric resin-based adhesive. Compared to conventional rubber materials, fibers make the material more robust and less elastic in a planar surface without significantly affecting its compressive properties in the normal direction. Furthermore, fibers and fillers reduce the amount of elastomeric adhesive in the layer, thus making the padding material cheaper. According to one embodiment, the fiber content in the damping material layer is not less than 5%, 10%, or 14% by weight and not more than 23% or 30%. However, for some applications, the fiber content can be higher than 30% (e.g., up to 50%, up to 80%, or even up to 95%).

[0019] Depending on the specific application, the fiber is selected from organic fibers. Examples of organic natural fibers include cellulose fibers and cotton linters (typically derived from plants); examples of organic man-made or synthetic fibers include aromatic polyamide fibers, other polyamide fibers besides aromatic polyamide fibers, polyolefin fibers, polyester fibers, polyacrylonitrile fibers, polyvinyl alcohol fibers, polyvinyl chloride fibers, polyurea fibers, polyurethane fibers, polyfluorocarbon fibers, or phenolic fibers, etc. According to one embodiment, the fiber includes aromatic polyamide fibers. More preferably, the fiber is selected from inorganic fibers, such as carbon fibers, glass fibers, ceramic fibers, rock wool, mineral wool, fused silica fibers, chemically treated high-silica fibers, fused aluminosilicate fibers, continuous alumina fibers, stabilized zirconia fibers, boron nitride fibers, alkali metal titanate fibers, whiskers, boron fibers, wollastonite, basalt fibers, and aramid fibers. The filler can be an inorganic filler, such as clay, ash, talc, barium sulfate, sodium bicarbonate, graphite, lead sulfate, diatomaceous earth, wollastonite, rubber shavings, or an organic filler.

[0020] The adhesive can be a rubber-type elastomer material, such as styrene-butadiene rubber (SBR), nitrile-butadiene rubber (NBR), isoprene rubber (IR), chloroprene rubber (CR), butadiene rubber (BR), butyl rubber (IIR), ethylene propylene rubber (EPM), fluororubber (FPM), silicone rubber (Si), chlorosulfonated polyethylene (CSM), ethylene-vinyl acetate copolymer (EVA), chlorinated polyethylene (CPE), chlorinated butyl rubber (CIIR), epichlorohydrin rubber (ECO), or nitrile-isoprene rubber (NIR), etc. Other elastomers besides rubber can also be used. According to alternative embodiments, the adhesive is a resin-based material, such as rubber-modified phenolic resin, phenolic resin, or epoxy resin, etc.

[0021] In one embodiment of this application, the structurally discontinuous or non-uniform support layer is made of fibers, either continuous or discontinuous long, medium, or short fibers, organic or inorganic fibers; for example, carbon fibers, metal fibers, glass fibers, and polymer fibers. These fibers provide different structures for the support layer: fibers randomly distributed to form a dense but non-uniform support layer (…). Figure 1 Examples from the text); fibers in the form of a woven "mesh" support layer ( Figure 2a and Figure 2b Examples in the text); and fibers arranged in a network ( Figure 3 (Examples in the text) The mesh size (w) of this network varies (either remaining constant or variable within the same structure), and the fibers have the same diameter (φ) or even different diameters. These fibers are fused together at their overlap points to provide the network structure that forms the support layer.

[0022] As another implementation, the structurally discontinuous or non-uniform support layer provided in this application is in the form of a perforated metal foil. Figure 4a and Figure 4b (as in the example), preferably, wherein the perforated area accounts for at least 30% (more preferably at least 50%) of the entire surface of the perforated metal foil.

[0023] Preferably, the thickness of the support layer made of metal foil is not higher than 1000 μm (preferably not higher than 400 to 500 μm, more preferably not higher than 250 μm).

[0024] Preferably, the thickness of the support layer, which is made of fibers that form a dense but uneven support layer by random distribution, is not higher than 1000 μm (preferably not higher than 400 to 500 μm, more preferably not higher than 250 μm).

[0025] Preferably, the thickness of the support layer made of fibers in the form of a woven "mesh" support layer is not higher than 1000 μm (preferably not higher than 400 to 500 μm, more preferably not higher than 250 μm).

[0026] More preferably, as another embodiment of the damping material layer provided in this application, the damping material layer includes at least a filler, organic fibers (more preferably cellulose fibers), and an adhesive. The adhesive includes NBR and / or SBR. The filler content is 30 to 70% by mass (preferably 45 to 55% by mass), the organic fiber (more preferably cellulose fiber) content is 15 to 30% by mass (preferably 20 to 25% by mass), and the adhesive comprising NBR and / or SBR content is 15 to 30% by mass (preferably 20 to 25% by mass), the percentages being based on a combination of 100 parts by weight of filler, organic fibers, and adhesive selected from NBR and / or SBR.

[0027] Preferably, when NBR and SBR are present simultaneously, their relative weight percentage (NBR / SBR) is 35 / 65% to 65 / 35% by weight, and the sum of NBR and SBR is 100% by weight.

[0028] In addition to the cost savings due to reducing the amount of more expensive materials, the technical advantage of the damping material layer provided in this application lies in achieving a damping effect through the ability of the fiber material to generate internal frictional work and the deformation of rubber. Rubber typically generates damping only through deformation. When the fiber bundle is deformed, most of the internal work can be represented by the friction between the strains of individual fibers. Furthermore, the excitation energy is converted into heat, thereby enhancing the damping effect. Since the damping material layer provided in this application uses both fibers and rubber, the resulting damping is a combination of both effects.

[0029] In view of the advantages of the above combination, the applicant has developed another noise-damping pad technology, which includes connecting the damping material layer provided in this application to a structurally discontinuous or non-uniform support layer selected from the group consisting of: - Perforated metal foil support layer, or - A support layer made of fibers, continuous or discontinuous long, medium or short fibers, organic fibers or inorganic fibers; the support layer has the following different structures: • Fibers that are randomly distributed to form a dense but uneven support layer; • Fibers woven into a “mesh” support layer; and • Fibers arranged in a network, wherein the fibers are fused together at overlapping points to provide a support layer for the network structure.

[0030] Among all the support layers, the damping material layer is firmly attached to the support layer because the support layer has a discontinuous or non-uniform structure (with holes, meshes or irregular textures), for example, randomly distributed fibers or fibers forming a woven mesh.

[0031] According to this application, the noise-reducing pad includes a support layer made of fibers with different structures embedded in two damping material layers. Therefore, its technical advantage lies in that the support layer improves the strength of the noise-reducing pad under piston action in the radial (XY) direction.

[0032] According to this application, the noise-absorbing pad includes a support layer made of perforated metal foil embedded in two layers of damping material. Therefore, its technical advantage lies in the fact that the support layer absorbs vibration waves better than solid metal (i.e., all-metal foil).

[0033] Another object of this application is to provide a method for manufacturing a noise-reducing pad 100, 200, or 300 including a damping material layer of any preferred embodiment. The provided damping material layer is obtained according to the following manufacturing method: a) Preparation of damping material slurry, wherein organic fibers and water are mixed with inorganic and / or synthetic fillers and fibers in a pulper, mechanically dispersed by adding water and then separating the fibers (“pulping”), followed by the addition of binders and vulcanizing agents; b) Preparation of the damping material layer, including: b1) The damping material slurry is loaded into the distribution machine via a headbox. The distribution machine includes the following structure: i) Long mesh forming section ii) Pressing section iii) Drying section iv) Calendering roller assembly v) Winding section To obtain a semi-finished damping material layer; b2) Calender the semi-finished damping material layer; b3) The damping material layer of the calendered semi-finished product is vulcanized. To obtain a damping material layer.

[0034] Another object of this application is to provide a method for manufacturing a noise-damping pad 200, the noise-damping pad comprising a structurally discontinuous or non-uniform support layer in the form of a perforated metal foil in combination with a damping material layer of any preferred embodiment provided in this application, the method comprising: - Provide the perforated metal foil provided in this application; - Provide two damping material layers that are the same or different from each other, as provided in this application; - A perforated metal foil is embedded / clamped / inserted between two damping material layers that are bonded to each other and connected to the perforated metal foil by a chemical adhesive and / or by applying pressure and / or temperature.

[0035] Another object of this application is to provide a method for producing a noise-reducing pad 300, the noise-reducing pad comprising a structurally discontinuous or non-uniform support layer, the support layer being made of fibers selected from the group consisting of: • Fibers that are randomly distributed to form a dense but uneven support layer; • Fibers woven into a “mesh” support layer; and • Fibers arranged in a network, wherein the fibers are fused together at overlapping points to provide a support layer for the network structure. The support layer is combined with a damping material layer of any preferred embodiment provided in this application, by means of: - Provides a support layer made of fibers as provided in this application; - Provide two damping material layers that are the same or different from each other, as provided in this application; - A support layer made of fiber is embedded / clipped / inserted between two damping material layers, which are bonded to each other and connected to the support layer made of fiber by chemical adhesive and / or by applying pressure and / or temperature.

[0036] Embodiments of this application also provide a disc brake device including a noise-reducing pad according to any of the above embodiments, located between the brake caliper and the brake pad, and the disc brake device can be installed in suitable vehicles—for example, cars, trucks, trains, motorcycles, bicycles, etc.

[0037] In order to make full use of the noise-reducing shim provided in this application, a method for preventing noise from a disc brake is also provided, comprising the following steps: placing the noise-reducing shim according to any of the above embodiments between the brake caliper and the brake pad.

Claims

1. A noise-reducing pad (100) comprising at least one damping material layer, said damping material layer comprising fibers, fillers and adhesives selected from organic, natural and / or artificial and / or synthetic or inorganic materials.

2. A noise-reducing pad (200) or (300) comprising a structurally discontinuous or non-uniform support layer in the form of perforated metal foil or made of fiber, the support layer being embedded / clipped / inserted between two damping material layers, the two damping material layers being identical or different from each other, the two damping material layers being connected to each other and to the support layer by a chemical adhesive and / or by applying pressure and / or temperature, each damping material layer comprising fibers selected from organic natural and / or artificial and / or synthetic or inorganic fibers, fillers and adhesives.

3. The noise-reducing pad (200) according to claim 2, wherein, The perforated area of ​​the perforated metal foil accounts for at least 30% of the entire surface of the perforated metal foil, more preferably at least 50%.

4. The noise-reducing pad (300) according to claim 2, wherein, The discontinuous or non-uniform support layer made of fibers is selected from one or more of the group consisting of: The fibers are randomly distributed to form a dense but uneven support layer; Fibers woven into a "mesh" support layer; as well as Fibers arranged in a network, wherein the fibers are fused together at the overlapping points to provide a support layer for the network structure.

5. The noise-reducing pad according to any one of the preceding claims, wherein, The damping material layer comprises at least a filler, organic fibers, more preferably cellulose fibers, and an adhesive; the adhesive comprises NBR and / or SBR; wherein the filler has a mass fraction content of 30 to 70%, preferably 45 to 55%, the organic fibers, more preferably cellulose fibers, have a mass fraction content of 15 to 30%, preferably 20 to 25%, and the adhesive has a mass fraction content of 15 to 30%, preferably 20 to 25%, the percentages being based on a combination of 100 parts by weight of the filler, the organic fibers, and the adhesive.

6. The noise-reducing pad according to any one of the preceding claims, wherein, The fiber content in the damping material layer is 95% or less by weight, preferably 50% or less, more preferably 30% or less, and even more preferably 23% or less.

7. The noise-reducing pad according to any one of the preceding claims, wherein, The damping material layer includes fibers, which include organic natural fibers and / or synthetic organic fibers; the organic natural fibers include cellulose fibers and cotton linters (fibers derived from plants); the synthetic organic fibers include aromatic polyamide fibers, aramid fibers, other polyamide fibers besides aromatic polyamide fibers, polyolefin fibers, polyester fibers, polyacrylonitrile fibers, polyvinyl alcohol fibers, polyvinyl chloride fibers, polyurea fibers, polyurethane fibers, polyfluorocarbon fibers, and phenolic fibers; the inorganic fibers include carbon fibers, glass fibers, ceramic fibers, rock wool, mineral wool, fused silica fibers, chemically treated high-silica fibers, fused aluminosilicate fibers, continuous alumina fibers, stabilized zirconia fibers, boron nitride fibers, alkali metal titanate fibers, whiskers, boron fibers, wollastonite, and basalt fibers.

8. The noise-reducing pad according to any one of the preceding claims, wherein, The filler material includes inorganic filler material or organic filler; the inorganic filler includes clay, ash, talc, barium sulfate, sodium bicarbonate, graphite, lead sulfate, diatomaceous earth, wollastonite, and rubber shavings.

9. The noise-reducing pad according to any one of the preceding claims, wherein, The adhesive material includes an elastomer material, which includes latex / rubber, such as styrene-butadiene rubber (SBR), nitrile-butadiene rubber (NBR), isoprene rubber (IR), chloroprene rubber (CR), butadiene rubber (BR), butyl rubber (IIR), ethylene propylene rubber (EPM), fluororubber (FPM), silicone rubber (Si), chlorosulfonated polyethylene (CSM), ethylene-vinyl acetate copolymer (EVA), chlorinated polyethylene (CPE), chlorinated butyl rubber (CIIR), epichlorohydrin rubber (ECO), or nitrile-isoprene rubber (NIR), etc.; or the adhesive material includes a resin material, such as rubber-modified phenolic resin, phenolic resin, or epoxy resin.

10. A noise-reducing brake pad, comprising the noise-reducing pad according to any one of claims 1 to 9.

11. A method for preventing noise from a disc brake, comprising the following steps: The noise-reducing brake pad according to claim 10 is disposed between the brake caliper and the brake pad.

12. A disc brake device comprising a noise-reducing brake pad according to claim 10 located between the brake caliper and the brake pad.

13. A vehicle comprising a disc brake as claimed in claim 12.

14. A method for producing a noise-reducing pad (100), (200), or (300) according to any one of claims 1 to 9, wherein, The provided damping material layer is obtained according to the following production method: a) Preparation of damping material slurry, wherein organic fibers and water are mixed with said inorganic and / or synthetic fillers and fibers in a pulper, followed by mechanical dispersion and then fiber separation ("pulping"), and then binder and vulcanizing agent are added; b) Preparation of the damping material layer, including: b1) The damping material slurry is loaded into a dispensing machine via a headbox, the dispensing machine comprising the following structure: i) Long mesh forming section ii) Pressing section iii) Drying section iv) Calendering roller assembly v) Winding section To obtain a semi-finished damping material layer; b2) Calender the semi-finished damping material layer; b3) The damping material layer of the calendered semi-finished product is vulcanized. To obtain the damping material layer.

15. A method for producing a noise-reducing pad (200) according to any one of claims 2, 3, 5 to 9, the method comprising: Provide a perforated metal foil according to claim 2 or 3; Provide two damping material layers that are the same or different from each other as described in claims 2, 5 to 9; The perforated metal foil is embedded / clipped / inserted between the two damping material layers, which are connected to each other and bonded to the perforated metal foil by chemical adhesive and / or by applying pressure and / or temperature.

16. A method for producing a noise-reducing pad (300) according to any one of claims 2, 4, 5 to 9, the method comprising: Provide a support layer made of fibers as described in claim 2 or 4; Provide two damping material layers that are the same or different from each other as described in claims 2, 5 to 9; The fiber-based support layer is embedded / clipped / inserted between the two damping material layers, which are bonded to each other and connected to the fiber-based support layer by chemical adhesive and / or by applying pressure and / or temperature.

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