KR20150122568A - Dash pad for vehicle - Google Patents

Abstract

The present invention relates to a low weight sound-absorbing type dash pad for a vehicle and, more specifically, to a low weight sound-absorbing type dash pad having a new structure wherein sound-absorbing materials made of at least three sound-insulating materials and a superfine fiber are mutually bonded. The present invention provides: the low weight sound-absorbing type dash pad for a vehicle, which optimizes sound-insulating performance by mutually bonding a sound-absorbing material made of a superfine fiber and a sound-insulating material having an air permeable multi-layered structure and simultaneously promotes weight reduction, production cost reduction, and reduction of processes; and a manufacturing method thereof.

Description

[0001] The present invention relates to a dash pad for vehicle,

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a low-weight sound-absorbing dash pad for an automobile, and more particularly, to a low-weight sound-absorbing dash pad having a new structure in which at least three layers of sound absorbing materials and micro-

Generally, a dash panel is mounted at the boundary between the engine room and the room. The dash panel is equipped with a dash pad, which is a kind of sound absorbing material that absorbs and blocks engine noise and the like from being transmitted to the room.

The dash pad functions to block, dampen, and absorb noise of the engine, and to prevent the combined energy of low frequency and high frequency generated during traveling from being transmitted to the interior space of the vehicle.

In the case of a conventional dash pad for a vehicle, as shown in Table 1 below, different materials are made of different materials in different thicknesses and weights.

As shown in FIG. 1, the dash pads shown in Table 1 are stacked in a two-layer to four-layer structure from the sound-absorbing layer (engine room side) toward the sound-insulating layer (indoor side).

In order to improve the sound absorption performance of the conventional dash pads, different materials for the dash pads are manufactured by stacking layers of two to four layers. However, the absorption layer is applied to the PU substrate and hard PET is applied to the sound insulation layer There is a problem that the weight increases and the cost increases overall.

In addition, molding, trimming mold and PU foaming mold are required for production of actual product including start mold and mass production mold for confirmation of performance verification during mass production, which causes increase in investment cost and manufacturing cost, A film (PA6) or the like is required to increase the cost and increase the number of steps.

Disclosure of the Invention The present invention has been made in order to solve the problems as described above, and it is an object of the present invention to provide a sound absorbing material having a micro structure and a breathable multi- Weight absorptive type dash pad for a vehicle and a method of manufacturing the same.

According to an aspect of the present invention, there is provided a sound absorbing article comprising: a sound absorbing layer having a multi-layer structure bonded to one side of a sound absorbing material made of microfine fibers, wherein the sound absorbing layer having a multi- Layer and the third sound-absorbing layer are sequentially bonded to each other.

Particularly, the microfiber is characterized in that the polypropylene staple fibers are laminated on the meltblown polypropylene fibers so that the fibers are 100 to 1,000 g / m3.

Preferably, the sound-absorbing layer of the multi-layered structure includes a first sound-absorbing layer made of polyethylene terephthalate (PET) and a second sound-absorbing layer made of olefin-based resin or thermoplastic elastomer (TPE) And the third sound-absorbing layer is made of polyethylene terephthalate (PET).

Preferably, the first sound-absorbing layer and the third sound-absorbing layer are selected from among a needle punching material, a dull PET obtained by thermally bonding a low melting point fiber and a polyester fiber (PET FIBER), a felt or a nonwoven fabric One of which is mutually bonded to the second sound insulating layer.

Preferably, the second sound insulating layer has a gas permeability in the thickness direction of 0.1 to 30 (cm 3 / cm 2 · seconds).

Through the above-mentioned means for solving the problems, the present invention provides the following effects.

First, by applying microfiber 100 to 330 g per unit area (m 3) as a sound absorbing material and bonding it to a breathable sound insulating material having a multi-layer structure, it is possible to maximize the sound absorbing performance and lighten the sound absorbing performance by using micro-

Second, microfiber is applied instead of the polyurethane used as a sound-absorbing layer in the prior art, so that the polyurethane foam mold can be excluded, thereby improving the productivity and reducing the cost.

Third, the PA6 film and the attaching step for laminating the sound-absorbing layer and the sound-insulating layer are not needed, and cost reduction and process water reduction can be realized.

1A and 1B are diagrams showing a conventional dash pad structure,
FIG. 2 is a view showing a structure of a low-light absorption-type dash pad for an automobile according to the present invention,
3 is a graph showing a result of a sound absorption test of a low-weight sound-absorbing type dash pad for an automobile according to the present invention,
FIG. 4 is a graph showing the results of sound insulation tests of a low-weight sound-absorbing type dash pad for an automobile according to the present invention,
FIG. 5 is a schematic view showing a method for manufacturing a sound insulating material of a low-weight sound-absorbing type dash pad for an automobile according to the present invention,
6 and 7 are graphs showing the results of sound absorption tests according to the air permeability of the sound insulating material of a low-weight sound-absorbing type dash pad for an automobile according to the present invention,
8 is a graph showing the results of a sound insulation test according to the air permeability of a sound insulating material of a low-weight sound-absorbing type dash pad for an automobile according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to the accompanying drawings.

Referring to FIG. 2, the present invention provides a dash pad which is a kind of sound absorbing material which is attached to a dash panel for a vehicle and which absorbs or blocks engine noises or the like from being transmitted to the room. The dash pad comprises a multi- Wherein the sound absorbing layer of the multilayer structure is formed by sequentially bonding a first sound absorbing layer made of a thermoplastic resin, a second sound insulating layer and a third sound absorbing layer to each other.

The microfiber used as the sound absorbing material (engine room side) is made by blending meltbraun polypropylene fibers and polypropylene staple fibers at 100-1,000 g / m 2.

More specifically, when the meltblown polypropylene fiber is spun downward from the die on which the meltblown polypropylene fiber is wound, the air pulsing is provided on one side toward the meltblown polypropylene fiber while the other side Polypropylene staple fibers are sprinkled on the meltblown polypropylene fibers to provide microbubbles in the range of 100 to 1,000 g / m < 2 > in which meltbraun polypropylene fibers are laminated with polypropylene staple fibers.

The sound-absorbing layer is made of a thermoplastic resin having a three-layer structure, that is, a structure in which a first sound-absorbing layer, a second sound-insulating layer and a third sound-absorbing layer are laminated in order.

According to a preferred embodiment of the present invention, the sound-absorbing layer may be formed by adopting polyethylene terephthalate (PET) as the first sound-absorbing layer and olefin-based resin, thermoplastic elastomer (TPE) , And the third sound-absorbing layer is made of polyethylene terephthalate (PET) and is bonded to each other.

For reference, a thermoplastic resin is a resin capable of deforming its shape when it is heated again after heat is applied, and it is advantageous in that it can be processed efficiently by extrusion molding or injection molding, and plastic deformation is caused by heating, And is made of a polymer material having a property of being reversibly hardened by cooling again.

The process of manufacturing the sound-absorbing layer of the present invention using the properties of the thermoplastic resin will be described with reference to FIG.

The first sound-absorbing layer constituting the sound-absorbing layer is made of a first sound insulating material sheet 11 adopted as polyethylene terephthalate (PET), and as the adhesive resin 13 of the second sound-insulating layer, olefin- The third sound-absorbing layer is adopted as at least one of thermoplastic elastomer (TPE), and the second sound-absorbing layer 12 is adopted as polyethylene terephthalate (PET).

The first sound insulating material sheet 11 is supplied from the skin material rollers 21 to the first pressing roller R1 and the second sound insulating material sheet 12 is supplied from the sound absorbing material rollers 22 to the second pressing rollers R2 And the adhesive resin 13 from the T-die 24 of the extruder 23 is supplied between the first and second pressing rollers R1 and R2.

Therefore, the first sound insulating material sheet 11 and the second sound insulating material sheet 12 are bonded to each other with the adhesive resin 13 interposed therebetween by the pressing force of the first and second pressing rollers R1 and R2, The sound absorbing layer according to one embodiment is completed.

At this time, the air permeability of the sound-absorbing layer, that is, the gas permeability can be determined according to the pressing force of the first and second pressing rollers, and preferably, the gas permeability of the second sound- (Cm 3 / cm 2 · sec) along the thickness direction.

On the other hand, the first sound-absorbing layer and the third sound-absorbing layer may be formed of one selected from a needle punching material, a plastics material thermally bonded with a low melting point fiber (LOW MELTING FIBER) and a polyester fiber (PET FIBER), a felt or a non- They may be mutually bonded to form a three-layer structure.

EXAMPLES Hereinafter, examples of the present invention will be described in detail with comparative examples, but the present invention is not limited by the following examples.

Example

A dash pad having a size of 840 mm × 840 mm in which a microfiber (D3) as a sound absorbing material and a polyethylene terephthalate (PET), a thermoplastic elastomer (TPE) and a polyethylene terephthalate (PET)

For reference, D3 represents micrographic grade, D1 represents 130 g per unit area (m2), D2 represents 230 g per unit area (m2), and D3 represents 330 g per unit area (m2).

Also, in Table 2 below, D3 (upper) of the dash pad according to the embodiment of the present invention means that the microfibers are arranged on the side where the noise is introduced.

Comparative Examples 1 to 2

Dash pads having a size of 840 mm x 840 mm in which polyethylene terephthalate (PET), thermoplastic elastomer (TPE) and polyurethane (PU) were laminated in order was prepared as Comparative Examples 1 and 2.

The PU (top) shown in Table 2 above is arranged on the side where the polyurethane (PU) is coming into noise, and the PU (bottom) means that the polyurethane (PU) is arranged on the opposite side from the side where the noise comes in.

Comparative Examples 3 to 4

As a comparative example 1, a dash pad having a size of 840 mm x 840 mm in which polyethylene terephthalate (PET), thermoplastic elastomer (TPE) and microfine fiber (D3)

D3 (phase) shown in Table 2 above means that the microfiber is arranged on the noise side, and D3 (bottom) means that the microfibers are arranged on the opposite side from the noise side.

Comparative Example 5

A dash pad having a size of 840 mm x 840 mm in which a microfiber D3 as a sound absorbing material, a polyethylene terephthalate (PET), a thermoplastic elastomer (TPE) and a polyethylene terephthalate (PET) The microstructure (D3) was fabricated with the inverted structure arranged on the opposite side of the noise.

For reference, D3 (bottom) in Table 2 above means that the microfiber (D3) is arranged on the opposite side of the noise.

Test Example 1

In order to investigate the sound absorbing effect on the dash pad according to the above-described embodiment and each of the comparative examples, the sound absorption rate was tested using a conventional simple reverberation method (Alpha Cabin Measurement). The results are shown in Tables 3 and 4 As shown in Fig.

As shown in the above Table 3 and FIG. 3, the dash pad according to the embodiment of the present invention, i.e., the dash pad having the PET + TPE + PET + D3 Could know.

Test Example 2

In order to investigate the sound insulation effect of the dash pad according to the above-described embodiment and each comparative example, the sound transmission loss ratio was tested using a normal small cabin method (APA MAT TEST: STL (Sound trans loss)), Are shown in Table 4 and FIG. 4 below.

As shown in Table 4 and FIG. 4, the dummy pads according to the embodiment of the present invention, i.e., dummy pads in which PET + TPE + PET + D3 , And it was found that there is a deviation according to the frequency interval, but it maintains the same level as the comparative examples.

Test Example 3

The damping performance of the dash pad according to the embodiment of the present invention, that is, the difference in gas permeability between the damping pad (PET + TPE + PET) and the damping layer (PET + TPE + PET) And the results are as shown in Table 5 below and FIG. 6 attached hereto.

At this time, the gas permeability of the sound-absorbing layer was tested by dividing the gas permeability into a large [7 to 12 (cm3 / cm2 · sec)] and a small [6 to 10 (cm3 / cm2 · sec)].

As shown in Table 5 and FIG. 6, it can be seen that the higher the gas permeability of the sound insulating material, the better the sound absorption performance is at 4 kHz or less, which is the interest range of the road noise.

Test Example 4

In the dash pad according to the embodiment of the present invention, only the sound insulating material (PET + TPE + PET) in which the sound insulating material was excluded was tested for sound absorption performance according to the gas permeability difference. The results are shown in Table 6 below As shown in Fig.

At this time, the gas permeability of the sound-absorbing layer was tested by dividing the gas permeability into a large [7 to 12 (cm3 / cm2 · sec)] and a small [6 to 10 (cm3 / cm2 · sec)].

As shown in Table 6 and attached FIG. 7, it was found that the higher the gas permeability of the sound insulating material, that is, the sound absorbing layer, the better the sound absorbing performance at a frequency of 4 kHz or less, which is the interest range of the road noise.

Test Example 5

In the dash pad according to the embodiment of the present invention, the sound insulating performance according to the gas permeability difference was tested only for the sound absorbing layer (PET + TPE + PET) in which the sound insulating material, As shown in Fig.

At this time, the gas permeability of the sound-absorbing layer was tested by dividing the gas permeability into a large [7 to 12 (cm3 / cm2 · sec)] and a small [6 to 10 (cm3 / cm2 · sec)].

As shown in Table 7 and attached FIG. 8, the sound insulating performance of the sound insulating material was found to be equal regardless of the gas permeability, that is, regardless of whether the gas permeability was high or low.

As described above, by providing the dash pad bonded to the breathable sound insulating material of a multilayer structure by applying the microfiber 100 to 1000 g per unit area (m 3) as a sound absorbing material, it is possible to maximize the sound absorbing performance And the gas permeability of the sound insulating material can be controlled to further improve the sound absorption performance.

11: First sound insulating material sheet
12: Second sound insulating material sheet
13: adhesive water
21: Surface skin rollers
22: Sound absorbing material roller
23: Extruder
24: Tie Dye
R1: first pressing roller
R2: second pressing roller

Claims (5)

The sound absorbing layer of the multi-layer structure is bonded to one side of the sound absorbing material made of microfine fibers, wherein the first sound absorbing layer, the second sound insulating layer and the third sound absorbing layer, which are made of thermoplastic resin, Weight dash-type dash pad for an automobile.
The method according to claim 1,
Wherein the microfiber is formed by blending polypropylene staple fibers in a range of 100 to 1000 g / m < 3 > in a meltblown polypropylene fiber.
The method according to claim 1,
Wherein the first sound-absorbing layer is made of polyethylene terephthalate (PET) and the second sound-absorbing layer is made of at least one of olefin-based resin and thermoplastic elastomer (TPE) And the third sound-absorbing layer is made of polyethylene terephthalate (PET).
The method according to claim 1,
The first sound-absorbing layer and the third sound-absorbing layer may be formed of a material selected from the group consisting of a needle punching material, a dull PET obtained by thermally bonding a low melt point fiber (LOW MELTING FIBER) and a polyester fiber (PET FIBER), a felt, And the sound insulating layer is bonded to the sound insulating layer.
The method according to claim 1,
Wherein the second sound insulating layer has a gas permeability in the thickness direction of 0.1 to 30 cm 3 / cm 2 · seconds.

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