KR101637644B1 - Noise prevention materials - Google Patents

Abstract

The noise preventing member according to the present invention is a noise preventing member adapted to sound and absorb noise transmitted through a medium. The noise preventing member includes a first member formed by compression molding sawdust, a first foamed member joined to one side of the first member, . At this time, porous ceramic is included in the first member and the first foam layer. Accordingly, a plurality of kinds of pores having different sizes exist in the noise preventing member according to the present invention. The sound waves transmitted through the noise preventing member are reflected or resonated according to the resonance frequency of the pores. Therefore, the sound insulating function and the sound absorbing function of the noise preventing member are improved.

Description

{NOISE PREVENTION MATERIALS}

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a noise preventive material that can be used in buildings and other structures.

Recently, multi - layered houses and apartments have been exposed to interstory noise problems, and there have been active discussions on ways to solve these problems and legal institutionalization.

1 is a cross-sectional view showing an example of a building construction standard that is currently standardized. 1, the lightweight foamed concrete layer 2 and the finish mortar layer 3 are sequentially laminated on the upper side of the concrete slab layer 1. A sound insulating mat (4) is provided between the concrete slab layer (1) and the lightweight foamed concrete layer (2) for noise shielding, and a side buffer material (5) is provided between the laminate and the side wall.

The sound insulating mat 4 is for blocking the noise generated in the upper layer from being transmitted to the lower layer through the medium of the building, and it is mainly composed of a material capable of absorbing sounds.

In the current construction standard shown in the drawing, the noise generated in the upper layer is absorbed through the sound-insulating mat 4, and the shock absorbing material 5 is installed on the inner side wall of the side wall so that the impact applied to the closed mortar layer 3 To the neighboring space.

Korean Utility Model Registration No. 20-0379075 discloses a noise preventing member having a sound absorbing and sound insulating effect by using first and second foam layers having different densities, respectively. This is constructed by stacking foamed porous layers having different densities to disperse vibration to prevent noise.

BACKGROUND OF THE INVENTION [0002] As a conventional noise preventive material, a foam sheet mainly foamed with organic material is used. However, such a noise-proofing material has a disadvantage in that it can not provide a good sound-absorbing function and a sound-absorbing function for a low-frequency sound range, which is a problem in the interlayer noise, because it has sound insulation and sound absorption function mainly for noise in a high frequency range.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is a technical object to provide a noise preventing member capable of effectively reducing noise or vibration transmitted through a structural medium of a building.

The noise preventing member according to the first aspect of the present invention for realizing the above object is characterized in that the noise preventing member is made of sawdust so that the noise transmitted through the medium is sounded and absorbed.

The noise preventing member may be provided with pores having two or more sizes.

The noise preventing member according to the second aspect of the present invention is characterized in that the noise preventing member includes sawdust and porous ceramics so that the noise transmitted through the medium is sounded and absorbed.

A noise preventing member according to a third aspect of the present invention is a noise preventing member adapted to sound and absorb noise transmitted through a medium, comprising: a first member formed by compression molding sawdust; And a first foam layer.

A noise preventing member according to a fourth aspect of the present invention is a noise preventing member adapted to sound and absorb noise transmitted through a medium, comprising: a first member formed by compression molding sawdust and porous ceramics; And a first foam layer bonded to the first foam layer.

The first foam layer may include an organic material.

Further, the first foam layer is characterized by having pores having two or more kinds of sizes.

The first foamed layer may further include a porous ceramic.

The first foamed layer may further include a porous ceramic.

The first foamed layer may further include a ferroelectric material.

The first foamed layer may further include a metal powder.

And the ferroelectric material is polarized.

And a second foam layer is further provided on the other side of the first member.

The noise preventing member according to the present invention is formed by compression molding sawdust, and the porous ceramic is included therein. Accordingly, a plurality of kinds of pores having different sizes exist in the noise preventing member. The sound waves transmitted through the noise preventing member are reflected or resonated according to the resonance frequency of the pores. Therefore, the sound insulating function and the sound absorbing function of the noise preventing member are improved.

1 is a sectional view showing an example of a building construction standard to which the present invention is applied.
2 is a diagram for explaining a basic concept of the present invention;
3 is a perspective view showing an outer shape of the noise preventing member according to the first embodiment of the present invention.
4 is a perspective view showing an outer shape of the noise preventing member according to the second embodiment of the present invention.
5 is a perspective view showing an outer shape of a noise preventing member according to a third embodiment of the present invention.

Hereinafter, embodiments according to the present invention will be described with reference to the drawings. However, the embodiments described below are illustrative of one preferred embodiment of the present invention, and examples of such embodiments are not intended to limit the scope of the present invention.

The basic concept of the present invention will be described.

Examples of the noise preventive material generally used for providing sound insulation and sound absorption function include an organic material including water, such as PVC, nylon, and polyester, and water-based acrylic, ethylvinyl acetate (EVA), polyvinyl alcohol A foamed foam sheet is used. Such a noise preventing member exhibits a sound insulating function and a sound absorbing function by the pores provided in the foam sheet.

If the size of the pore is adjusted in the above-described noise preventing member, the sound absorbing characteristic can be changed. That is, as the size of the pores is made smaller, the sound absorption characteristics with respect to the low frequency range are improved. However, in order to reduce the pore size of the noise-proofing material, an advanced process and a high manufacturing cost are required.

According to the study by the present inventors, when pores having different sizes are formed in a certain material, sound absorption and sound insulation functions are improved. Fig. 2 is a view for explaining such a sound absorption and sound insulation function.

2, reference numeral 20 denotes a porous material having a plurality of pores. The first pore 21 having a relatively large diameter and the second pore 22 having a small diameter are present in the porous material. When the sound wave A is drawn from the outside, the sound wave A passes through the medium 20, And the first and second pores (21, 22). However, when the sound wave A having passed through the first pore 21 enters the second pore 22, the sound wave A is reflected or refracted as indicated by a and b. This phenomenon occurs similarly when the sound wave b passing through the second pore 22 enters the first pore 21. This is because the resonance frequency of the pore varies depending on the pore size.

Generally, the sound insulation function of a material is determined by how much of the sound wave applied from the outside passes through it, and the sound absorption function is determined by how much the sound wave applied from the outside is absorbed. All materials are vibrated when they are stimulated by external sound waves. At this time, the frequency sounds that are affected by the vibration are absorbed through the process of conversion into vibrational energy.

As described above, if pores having different sizes are formed in a certain medium, the linearity of the sound waves is remarkably reduced as the sound waves are reflected and refracted in passing through the pores. That is, the sound insulation function is improved. The sound waves are resonated while passing through pores of different sizes. That is, the sound wave energy of various frequency bands is converted into the vibration energy of the pore, thereby improving the sound absorption function.

3 is a perspective view showing an outer shape of the noise preventing member according to an embodiment of the present invention. The noise preventing member according to the present embodiment is formed by compression molding sawdust. Sawdust is a by-product that is usually produced in the process of applying wood. The main raw material of sawdust is wood, which has the original pores of wood. When sawdust is compression molded, many pores are formed according to the compressive strength. As the compression ratio is increased, the pore size becomes smaller.

When the sawdust is compression molded to form the noise preventing member, a plurality of pores having various sizes are formed inside the noise preventing member. These pores, as described above, reflect or refract the sound waves passing through the noise preventing member to obstruct the progress of the sound waves, and sound waves are absorbed while being converted into vibrational energy by resonance in the pores.

Also, the noise preventing member according to the present embodiment has a very low thermal conductivity. Accordingly, if the noise preventing member is installed under the lightweight foamed concrete layer, it is possible to minimize the leakage of heat generated from the heating pipe disposed in the lightweight foamed concrete layer to the outside.

On the other hand, in order to remove the low-frequency noise, which is a main cause of the interlayer noise, it is necessary to form fine pores as described above. In order to form fine pores, very high pressure must be applied when compressing the sawdust. However, when the sawdust is compression-molded at a high pressure, it is difficult to form pores having various sizes, and the expansion / contraction ratio of the noise preventing material is remarkably lowered, so that the ability to absorb vibration is lowered.

In order to solve such a problem, sawdust and a porous material, preferably a porous ceramic, are preferably used in the compression molding of the noise preventing member. The porous ceramics can be produced by using a polymeric sponge method, a stacking method, a bubble generation method, or the like. Such porous ceramics usually have pores in the order of μm.

When the noise absorbing material is compression-molded by mixing the sawdust and the porous ceramics, the elasticity of the noise preventing member is improved firstly, thereby facilitating the vibration absorbing ability and easily setting the pore size of the noise preventing member. Particularly, since the micropores possessed by the porous ceramics improve the noise absorbing capacity in the low frequency band, the interlayer noise can be more effectively reduced.

4 is a cross-sectional view showing the structure of a noise preventing member according to another embodiment of the present invention.

In Fig. 4, a foamed layer 32 is formed as a first member made of sawdust or a mixture of sawdust and porous ceramic, that is, a second member on one side of the noise preventing member 31 in Fig. At this time, the second member 32 is formed separately from the first member 31, and then joined using an adhesive or the like.

The foam layer 32 is formed by mixing foaming agents with organic materials including, for example, PVC, nylon, polyester, and water-based acrylic, ethylvinyl acetate (EVA), polyvinyl alcohol (PVA), and the like, followed by foaming. Preferably, at least two kinds of pores having different sizes are formed in the foam layer 32 by suitably setting the foaming conditions when the foam layer 32 is formed.

More preferably, when forming the foam layer 32, the porous ceramic is mixed with the organic material and the foaming agent to form a foam.

In the present embodiment, the foam layer 32 absorbs external impact applied to the first member 31, and the foam layer 32 also acts as a noise preventing material, And exhibits an absorption function.

In still another embodiment of the present invention, the ferroelectric material may be mixed when forming the foam layer 32.

According to the study of the present inventors, it is possible to control the resonance frequency of the medium using the ferroelectric substance. That is, in forming the foam layer 32, a ferroelectric substance is mixed with a mixture of an organic substance and a foaming agent or a mixture of an organic substance, a foaming agent and a ceramic to form a foam layer. When a certain voltage is applied thereto to polarize the ferroelectric substance, The resonant frequency of layer 32 varies. The resonance frequency can be appropriately adjusted depending on the particle size or the amount of the ferroelectric material to be mixed with the organic material or the kind of the ferroelectric material.

At this time, as the ferroelectric material, an inorganic material such as PZT, an organic material such as PVDF, a mixture of an inorganic ferroelectric material and an organic material or an organic ferroelectric material may be used, and preferably a metal powder or a conductive organic material may be mixed.

The noise preventing member according to the present embodiment can be effectively used in the foam layer 32 because the foam layer 32 is not absorbed by the first member 31 or the sound generated by the external impact generated from the first member 31 Thereby enabling absorption and removal.

The embodiments according to the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications may be made without departing from the scope of the present invention.

For example, in the above-described embodiment, the second member 32, that is, the foam layer is formed on only one side of the first member 31. However, as shown in Fig. 5, It is also possible to form the foam layers 32 and 61 on both sides.

1: concrete slab layer, 2: lightweight foam concrete layer,
3: Finishing mortar layer, 4: Soundproofing material.

Claims (21)

delete delete delete In a noise preventing member adapted to sound and absorb sound transmitted through a medium,
A first member formed by compression molding sawdust; And
And a first foam layer coupled to one side of the first member,
Wherein the first foam layer comprises an organic material,
The first foam layer is provided with pores having two or more sizes,
Wherein the first foam layer further comprises a porous ceramic,
Wherein the first foam layer further comprises a ferroelectric material,
Wherein the first foam layer further comprises a metal powder,
The ferroelectric material is polarized,
And a second foam layer on the other side of the first member,
The sound waves of the noise passing through the noise preventing member are absorbed while the sound waves are converted into vibrational energy by at least one of the pores of the first foamed layer,
Wherein the noise of the low frequency band is sounded and absorbed as the size of the pores of the first foamed layer is smaller.
delete delete delete delete delete delete delete delete In a noise preventing member adapted to sound and absorb sound transmitted through a medium,
A first member formed by compression molding sawdust and porous ceramic; And
And a first foam layer coupled to one side of the first member,
Wherein the first foam layer comprises an organic material,
The first foam layer is provided with pores having two or more sizes,
Wherein the first foam layer further comprises a porous ceramic,
Wherein the first foam layer further comprises a ferroelectric material,
Wherein the first foam layer further comprises a metal powder,
The ferroelectric material is polarized,
And a second foam layer on the other side of the first member,
The sound waves of the noise passing through the noise preventing member are absorbed while the sound waves are converted into vibrational energy by at least one of the pores of the first foamed layer,
Wherein the noise of the low frequency band is sounded and absorbed as the size of the pores of the first foamed layer is smaller.
delete delete delete delete delete delete delete delete

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