Improved layer for footfall sound insulation

Abstract

A layer (1) for impact sound insulation consists of an elastomer. The layer (1) has a bottom surface (2) and a top surface (3). The bottom surface (2) has waves with troughs (4) and crests (5). The layer (1) has a minimum thickness (d1) in the region of a trough (4) and a maximum thickness (d2) in the region of a crest (5). The thickness (d) is defined as the local distance from the bottom surface (2) to the top surface (3) of the layer (1). The maximum thickness (d2) is less than 25 mm. The ratio of the amplitude (A) of a wave formation to the maximum thickness (d2) is at least 0.27. The amplitude (A) of the wave formation is defined as half the difference between the maximum and minimum thicknesses (d2, d1).

Description

1. Field of the invention

[0001] The present invention relates to a layer for impact sound insulation, wherein the layer consists of an elastomer, the layer has a bottom and a top surface, and the bottom surface has waves with troughs and crests, wherein the layer has a minimum thickness in the area of ​​a trough and a maximum thickness in the area of ​​a crest, wherein the thickness is defined as the local distance from the bottom to the top surface of the layer, and wherein the maximum thickness is less than 25 mm. 2. State of the art

[0002] Such layers for impact sound insulation are generally known. By way of example, the material Mat-W25x from CDM Stravitec and the materials sound 10, sound 12 and comfort 12 from the applicant can be mentioned.

[0003] Impact sound insulation layers are known from practical experience in a wide variety of designs. The maximum layer thickness of the respective material ranges—depending on the material—from a few millimeters, for example 4 mm or 6 mm, to considerably greater values ​​of up to 25 mm. Materials used include cork, polyurethane, rubber, sponge rubber, and other materials and mixtures thereof. However, the dynamic stiffness, which in turn influences impact sound insulation, is not optimal. 3. Object of the invention

[0004] The object of the present invention is to further develop a layer for impact sound insulation of the type mentioned above in such a way that, with the same material expenditure, the dynamic stiffness can be reduced or the dynamic stiffness can be maintained despite a lower material expenditure.

[0005] This problem is solved according to the invention by a layer for impact sound insulation with the features of claim 1. Advantageous embodiments of the layer for impact sound insulation are the subject of dependent claims 2 to 5 and are set out in the appended description. 4. Summary of the invention

[0006] The invention relates to a layer for impact sound insulation, wherein the layer consists of an elastomer, the layer has a bottom and a top surface, and the bottom surface has waves with troughs and crests, wherein the layer has a minimum thickness in the region of a trough and a maximum thickness in the region of a crest, the layer thickness being defined as the local distance from the bottom to the top surface of the layer, and wherein the maximum layer thickness is less than 25 mm. According to the invention, this impact sound insulation layer is designed such that the ratio of the amplitude of a wave formation to the maximum layer thickness is at least 0.27, wherein the amplitude of the wave formation is defined as half the difference between the maximum and the minimum layer thickness.

[0007] The invention thus provides a layer for impact sound insulation which, by adhering to certain parameters of wave formation and maximum layer thickness, and taking into account the ratio of these parameters, is able to guarantee optimal dynamic stiffness and thus impact sound insulation. This result is achieved using comparatively simple means and is easily reworkable without the need for complex material tests or the development of new, untested materials. The present invention offers significant advantages. Firstly, it provides high impact sound insulation or – essentially equivalent – ​​high vibration isolation. Secondly, it requires comparatively little material.

[0008] In particular, experimental investigations have shown that, with otherwise unchanged parameters of the impact sound insulation layer, a significant reduction in dynamic stiffness occurs when the aforementioned quotient is 0.27 or above.

[0009] The effect is greater the larger the aforementioned quotient. In a preferred embodiment of the invention, the quotient of the amplitude and the maximum layer thickness is therefore provided to be at least 0.30, particularly preferably at least 0.34, and most preferably at least 0.36, at least 0.37, or at least 0.40. In individual cases, the aforementioned quotient may preferably be above 0.40. Currently, it is particularly preferred if the quotient of the amplitude and the maximum layer thickness is in the range between 0.37 and 0.40, for example, at approximately 0.39, preferably at exactly 0.39.

[0010] The specific wave shape can be selected as required. For example, the waves in the cross-section through the impact sound insulation layer according to the invention can be sinusoidal, rectangular, meandering, triangular, or sawtooth-shaped. Hybrid shapes or superpositions of different wave shapes are also encompassed by the invention. A key characteristic of the wave shape is a certain, preferably precisely defined, periodicity, i.e., a repeating sequence of wave crests and troughs, which is preferably uniform across the entire surface of the impact sound insulation layer according to the invention. This results in a product that is easy to manufacture and provides consistent properties with regard to impact sound insulation and dynamic stiffness across the entire surface of the layer.

[0011] In a preferred embodiment of the invention, the maximum layer thickness is provided to be a maximum of 20 mm, preferably a maximum of 18 mm, and particularly preferably a maximum of 17 mm. This allows the material consumption per square meter of the layer to be kept within limits. Furthermore, it is preferably provided that the maximum layer thickness is a minimum of 12 mm, preferably a minimum of 15 mm. This ensures a comparatively high mechanical stability of the layer as a whole.

[0012] According to the invention, the underside of the layer is formed with the described waveform. The top side can be corrugated or smooth, as required. It is preferred that the top side be smooth and do not have a waveform comparable to the waveform on the underside, or whose amplitude mirrors or even exceeds that of the waveform on the underside. 5. Brief description of the characters

[0013] Further advantages and details will become apparent from the following description of an exemplary embodiment in conjunction with the drawings. These show, in schematic principle representation: Fig. 1 a top view from below of a layer for impact sound insulation, Fig. 2 the layer for impact sound insulation of Fig. 1 in the perspective from a low angle, and Fig. 3 a section through the layer for impact sound insulation along a line III-III from Fig. 1 . 6. Detailed description of the figures

[0014] The characters are explained together below.

[0015] A layer 1 for impact sound insulation consists of an elastomer. In particular, layer 1 contains no cork or only a small amount of cork, preferably a maximum of 10%. The elastomer can, for example, consist of recycled styrene-butadiene rubber fibers bonded with polyurethane. Alternatively, it can be, for example, a polyurethane foam, either virgin or recycled.

[0016] Layer 1 has a bottom surface 2 and a top surface 3. The bottom surface 2 is the side of layer 1 that, when layer 1 is used as intended, is at the bottom, i.e., rests on another substrate (not shown), for example, a concrete slab. Conversely, the top surface 3 is the side of layer 1 on which, when layer 1 is used as intended, another substrate (also not shown), for example, a screed, in particular a dry screed, rests or can rest.

[0017] The upper surface 3 is preferably smooth. The lower surface 2, on the other hand, has waves with troughs 4 and crests 5. In the figures, only a single trough 4 and a single crest 5 are shown with their respective reference symbols. The surface is characterized in particular by Fig. 3 The apparent shape of the wave crests 5, namely a more or less vertical rise that is then terminated by a domed crest, is shown only as an example; the wave crests 5 can also have a different shape. Likewise, the Fig. 3 The visible shape of the wave troughs 4, namely a flat plateau, is shown only as an example; the wave troughs 4 can also have a different shape. A wavelength λ is usually in the double-digit millimeter range, for example between 30 mm and 50 mm.

[0018] The thickness d of layer 1 – defined as the local distance from the bottom surface 2 to the top surface 3 of layer 1 – varies between a minimum value d1 (minimum layer thickness d1) and a maximum value d2 (maximum layer thickness d2). Specifically, layer 1 has a minimum thickness d1 in the region of a wave trough 4 and a maximum thickness d2 in the region of a wave crest 5.

[0019] Due to the wave formation, i.e., the presence of wave troughs 4 and wave crests 5, an (absolute) amplitude A of the wave formation results. The amplitude A of the wave formation is defined as half the difference between the maximum and minimum layer thicknesses d2, d1: A = d 2 − d 1 / 2

[0020] This refers to the amplitude A of the fluctuations in layer thickness d around a mean value of the layer thickness d. The amplitude A is an absolute, dimensionless quantity. Its unit is (in the SI system) meters or (in general practical use) millimeters.

[0021] When the quotient of the amplitude A and the maximum layer thickness d2 is formed, a relative amplitude a results: a = A / d 2 .

[0022] The relative amplitude a is therefore referenced to the maximum layer thickness d2. The relative amplitude a is a dimensionless quantity.

[0023] According to the invention, the maximum layer thickness d2 is less than 25 mm. However, it can also be smaller, for example, a maximum of 20 mm. It is particularly preferred that the maximum layer thickness d2 be a maximum of 18 mm, and especially a maximum of 17 mm. On the other hand, the maximum layer thickness d2 should preferably not be too small. The minimum maximum layer thickness d2 should be 12 mm, preferably a minimum of 15 mm.

[0024] According to the invention, the relative amplitude a – in effect, the quotient of the (absolute) amplitude A and the maximum layer thickness d2 – is at least 0.27. Preferably, the relative amplitude a is even larger, for example, at least 0.30. Values ​​of at least 0.34, at least 0.36, and most preferably at least 0.37 are particularly preferred. In individual cases, a value of 0.40 or even higher is also possible. Currently, a value between 0.37 and 0.40 is considered optimal, particularly approximately or even exactly 0.39.

[0025] The above description serves solely to explain the present invention. The scope of protection of the present invention, however, shall be determined exclusively by the accompanying claims. Reference symbol list

[0026] 1 Layer 2 Bottom 3 Top 4 Wave troughs 5 Wave crests AAmplitude d, d1, d2layer thicknesses λwavelength

Claims

1. Layer (1) for impact sound insulation, wherein the layer (1) consists of an elastomer, the layer (1) has a bottom (2) and a top (3), wherein the bottom (2) has waves with wave troughs (4) and wave crests (5), and the layer (1) has a minimum layer thickness (d1) in the region of a wave trough (4) and a maximum layer thickness (d2) in the region of a wave crest (5), wherein the layer thickness (d) is defined as the local distance from the bottom (2) to the top (3) of the layer (1), and the maximum layer thickness (d2) is less than 25 mm. characterized by the fact that a quotient of an amplitude (A) of a wave formation and the maximum layer thickness (d2) is at least 0.27, where the amplitude (A) of the wave formation is defined as half the difference between the maximum and the minimum layer thickness (d2, d1). 2nd layer (1) according to claim 1, characterized by the fact thatthe quotient of the amplitude (A) and the maximum layer thickness (d2) is at least 0.30, preferably at least 0.34, particularly preferably at least 0.36, at least 0.37 or particularly preferably at least 0.

40.

3. Layer (1) according to claim 1 or 2, characterized by the fact that the maximum layer thickness (d2) is a maximum of 20 mm, preferably a maximum of 18 mm and particularly preferably a maximum of 17 mm.

4. Layer (1) according to any one of the preceding claims, characterized by the fact that the maximum layer thickness (d2) is at least 12 mm, preferably at least 15 mm.

5. Layer (1) according to any one of the preceding claims, characterized by the fact that the upper surface (3) is smooth.

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