KR20040081520A - Acoustic absorber of automobile floor carpet - Google Patents

Abstract

PURPOSE: A sound absorbing material of a floor carpet for a vehicle is provided to absorb and insulate sound efficiently and to cut down manufacturing cost by stacking the polyester sound absorbing materials with the multiple structure, and to reduce the weight by removing the heavy layer. CONSTITUTION: A sound absorbing material for a floor carpet of a vehicle is formed of two-stage polyester sound absorbing materials or more, and composed of low melting point polyester fiber and high melting point polyester fiber with different apparent density. The transmission loss below 2500 Hz is more than 10 dB, and the transmission loss less than 2500 to 5000 Hz is more than 30 dB. The apparent density of the first stage of the polyester sound absorbing material is 60 to 140 Kg/m3, and the apparent density of the second stage is 160 to 280 Kg/m3.

Description

Acoustic absorber of automobile floor carpet

The present invention relates to a sound absorbing material for an automobile flow carpet, and more specifically, a low melting point polyester binder and a high melting point polyester fiber are mixed by a predetermined weight ratio, and manufactured by needle punching and general plush processes to have different apparent densities. Later, by stacking it to complicate the transmission path of noise, and relates to a flow carpet substrate that maximizes the sound absorption and sound insulation performance.

In general, the noise introduced by the vehicle flow carpet is roughly classified into the noise generated from the engine through the vehicle body and the noise generated from the contact between the tire and the road surface. There are two ways to improve the noise, which is to improve the sound absorption performance and sound insulation performance. Sound absorption means that the generated sound energy is converted into heat energy as it passes through the internal path of the material and is extinguished. It is reflected and blocked by the shield.

Sound absorption performance is mainly related to the internal shape of the material, and sound insulation performance is closely related to the density and structure of the material. That is, in order to satisfy the sound absorbing performance, many fine open cell particles such as urethane foam should be present, and it is already well known that fibers having low fineness should be used for felt. In order to improve sound insulation performance, it is a general technique to use a heavy insulation material, which is a separate sound insulation material.

Polyurethane foam has been used as a sound absorbing material conventionally used to suppress noise. However, in the case of urethane foam, sound absorption is excellent, but sound insulation material is inserted into the carpet fabric because of its sound insulation deterioration. I use it. However, in this case, the sound insulation is improved to some extent, but the overall assembly weight is increased due to the insertion of a high density heavy layer layer, thereby deteriorating automobile fuel economy and increasing manufacturing costs due to the need to prepare a separate mold for urethane foam. . In addition, since the heavy layer layer is not recycled after use, problems such as environmental problems and separate disposal costs occur.

Therefore, in recent years, many products have been used that have lowered weight and improved sound absorption and sound insulation performance by using a polyester in which a heavy layer layer has been removed. However, these products are superior to the conventional resin felt or needle felt, but compared to the products using the urethane foam, sound absorption and sound insulation performance is somewhat lower, and the consumer's continuous noise improvement is somewhat lacking.

Accordingly, the present inventors have come to invent a polyester flow carpet with excellent sound absorbing and insulating performance compared to the existing urethane foam.

Therefore, the present invention has been made a technical problem to lower the weight while improving the sound absorption and sound insulation performance of the conventional products. We tried to improve the sound absorption and sound insulation performance by eliminating the heavy layer that has been used in the existing flow carpets and instead, the structure of the sound absorbing material is multi-layered into the sound absorption area and sound insulation area.

1 is a cross-sectional view of a flow carpet sound absorbing material for automobiles according to the present invention.

2 is a cross-sectional view of a conventional flow carpet sound absorbing material for automobiles.

Therefore, according to the present invention, in the automotive carpet carpet sound absorbing material,

It consists of two or more stages of polyester sound-absorbing materials with different apparent densities of low-melting polyester fibers and high-melting polyester fibers, and has a sound insulation (transmission loss) of less than 2500 dB and a difference between 2500 and 5000 dB. An automotive flow carpet sound absorbing material is provided, wherein the voice (transmission loss) is 30 dB or more. In this case, the sound insulation is expressed as a sound pressure value called transmission loss (dB). That is, the sound pressure lost by the object when the initial sound source passes through the object is called transmission loss, and is a representative term for expressing sound insulation. .

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

To describe the present invention in detail, the polyester sound absorbing material that has been composed of a conventional single layer is composed of a structure of two or more stages, and then bonded by a general adhesive method using a water-soluble adhesive, and then attached to a carpet fabric with a PE film layer. The polyester sound absorbing material is preferably composed of a low density of 60 ~ 140Kg / ㎥ in the first stage, a high density of 160 ~ 280Kg / ㎥ in the second stage, the reason of using a low density sound absorbing material of 60 ~ 140Kg / ㎥ The purpose is to keep the surface soft so as to increase the adhesion with the bottom plate of a general vehicle, to prevent the material from splashing during vibration and to suppress the leakage of noise. The reason for applying high density sound absorbing material of 160 ~ 280Kg / ㎥ is to induce sound loss by making reflection and refraction when noise passing through low density material of 1st stage passes through high density materials of 2nd stage. The first and second stages also combine high density materials to ensure continuous reflection and refraction.

According to the present invention, a sound absorbing material (transmission loss) of less than 2500 dB is provided in an automotive flow carpet sound absorbing material having a sound insulation (transmission loss) of 10 dB or more and a sound absorption (transmission loss) of 2500 to 5000 dB or less. ) Has the same performance as the existing flow carpet, while reducing the total assembly weight by at least 10%.

In addition, in the present invention, as shown in FIG. 1, the polyester sound absorbing material may be configured in four stages, but the bottom portion (hereinafter referred to as one stage) has a low density material having an apparent density of 60 to 140 Kg / m 3, and the back side thereof (hereinafter referred to as two stages). ) Is composed of a material layer with an apparent density of 160 ~ 280Kg / ㎥, the back of the two-stage material can be composed of three and four-stage material having an apparent density of 60 ~ 280Kg / ㎥. The advantage of the four-stage configuration is that the sound transmission (transmission loss) can be improved while lowering the overall weight by complicating the negative transmission path than the case of the two-stage.

The difference in sound insulation performance between the configuration of the sound absorbing material of the present invention and the existing material configuration as described above will become more apparent from the following examples. However, the present invention is not limited to the following examples.

Example 1

A single-stage sound absorbing material that satisfies the apparent density of 80 Kg / ㎥ and thickness of 5mm after manufacturing a polyester sound-absorbing material that is heat-dried polyester with different pressure and temperature after mixing web of low melting point polyester fiber and high melting point polyester fiber. And two-stage sound absorbing material satisfying the apparent density of 160Kg / ㎥ and thickness of 5mm, and reinforcing the three-stage and four-stage sound absorbing material satisfying the thickness of 5mm on the two-stage sound absorbing material, and then attaching the two-stage sound absorbing material to the back of the first stage. After the combination, it was attached to a carpet fabric with a PE film layer having a surface density of 600 g / m 2 to make the total weight in an assembly state of 3.8 Kg per square meter, and the sound insulation performance was measured using the sound insulation measuring equipment.

Example 2

It was prepared in the same manner as in Example 1 except for changing the weight of the PE film layer in the carpet fabric to 800g / ㎡ to adjust the total weight of the assembly to 4.0Kg per square meter.

EXAMPLES 3-4

As shown in Table 1, while removing the three-stage and four-stage sound absorbing material on the two-stage sound absorbing material of Example 1, the thickness of the first stage 5mm and the second stage is 15mm, the total weight is increased 200gTlr, the weight of the PE film layer By setting it as 800g / m <2> like 2, it carried out similarly to Example 1 except having adjusted the total weight of the assembly to 4.2 and 4.4Kg per square meter, respectively.

[Comparative Examples 1 and 2]

A heavy layer layer was attached to the carpet fabric, and the same procedure as in Example 1 was conducted except that a polyurethane foam or a polyester layer was used as the sound absorbing material. The sound insulation performance of the sound absorption material of the said Example and the comparative example was evaluated using the sound insulation performance measuring apparatus called apamat of Swiss Reuters. In short, the sound insulation performance measuring device is composed of a part generating noise called an excitation chamber, a part of a sample to be measured for sound insulation, and a sound receiving chamber measuring noise passing through the sample. The measured data is expressed as insertion loss [dB] value as shown in Table 2 below, and the larger the data value, the better the sound insulation performance. In addition, the sound absorbing materials of the Examples and Comparative Examples are mounted in a passenger car, and the overall sound insulation and weight reduction effect are shown in Table 3.

division Overall characteristic Floor carpet specifications Sound absorbing material composition Weight (Kg / ㎡) Thickness (mm) 1st stage (Kg / ㎥) 2 stage (Kg / ㎥) 3 steps (Kg / ㎥) 4 steps (Kg / ㎥) Example 1 3.8 20 9oZ + PE600 80 160 160 160 Example 2 4.0 20 9oZ + PE800 80 160 160 160 Example 3 4.2 20 9oZ + PE800 80 180 - - Example 4 4.4 20 9oZ + PE800 80 200 - - Comparative Example 1 4.3 20 9oZ + Heavy Layer PU 100 - - - Comparative Example 2 4.3 20 9oZ + Heavy Layer PET 120 - - -

-Carpet fabric used in Table 1 is 9CF of BCF.

division Sound insulation [dB] 500㎐ 630 yen 800㎐ 1000㎐ 1250 yen 1600 yen 2000㎐ 2500㎐ 3150㎐ 4000㎐ 5000 yen Example 1 12.5 16.5 20.2 24.9 27.5 27.7 28.5 30.9 33.6 34.7 35.9 Example 2 10.9 16.9 19.7 24.0 28.3 28.6 29.5 31.1 33.7 36.3 37.2 Example 3 11.0 17.5 22.5 21.1 22.9 24.5 27.6 30.7 34.1 39.5 45.4 Example 4 11.0 18.1 24.3 21.3 25.8 26.5 28.3 31.7 36.3 41.0 47.6 Comparative Example 1 10.7 15.5 17.8 22.7 26.9 28.2 28.1 32.2 33.1 37.7 40.2 Comparative Example 2 6.2 13.9 17.9 18.6 20.5 20.1 20.2 22.1 24.2 25.4 27.3

The sound insulation data is measured using Apamat-II (Reuters, Switzerland) test facility.

-The higher the data, the better the sound insulation performance.

division Total weight (Kg / set) Thickness (mm) Sound Insulation Evaluation Weight Reduction Effect (Kg / Large) Example 1 8.74 20 Great -1.15 Example 2 9.20 20 Great -0.69 Example 3 9.66 20 Great -0.23 Example 4 10.1 20 Great +0.20 Comparative Example 1 9.89 20 standard - Comparative Example 2 9.89 20 Inadequate 0

As described above, according to the present invention, it is possible to improve the fuel efficiency of the vehicle by improving the weight increase problem caused by the insertion of the heavy layer, which is a problem in the existing flow carpet sound absorbing material, and at the same time, it is possible to improve sound absorbency and sound insulation as well, thus manufacturing costs. Can be lowered relatively.

Claims (4)

In the automotive carpet carpet sound absorption material, It consists of two or more stages of polyester sound-absorbing materials with different apparent densities of low-melting polyester fibers and high-melting polyester fibers, and has a sound insulation (transmission loss) of less than 2500 dB and a difference between 2500 and 5000 dB. Voice (transmission loss) is a flow carpet sound absorbing material for automobiles, characterized in that more than 30dB. The method of claim 1, wherein the polyester sound absorbing material in the first stage, the apparent density of 60 ~ 140Kg / ㎥, the second stage of the flow carpet sound absorbing material, characterized in that 160 ~ 280Kg / ㎥. The vehicle sound absorbing material of claim 1, wherein the polyester sound absorbing material comprises four sound absorbing materials having different apparent densities. According to claim 3, wherein the polyester sound-absorbing material for the first stage, the apparent density is 60 ~ 140Kg / ㎥, the second stage 160 ~ 280Kg / ㎥, and the third and fourth stage 60 ~ 280Kg / ㎥ for automobiles Flow carpet sound absorbing material.