KR101488320B1 - Sound absorbing material, sound absorbing and sound blocking material and method for manufacturing the same - Google Patents

Abstract

(TPU), polyethylene terephthalate (PET), polyurethane foam, low melting point polyethylene terephthalate (LMPET), polypropylene (PP), and fumed silica. The present invention relates to a sound absorbing material, a sound absorbing material and a manufacturing method thereof. a sound absorbing material and a method for manufacturing the same, which are not only reduced in weight and cost, but also have an effect of improving the recycling rate of scrapped vehicles and protecting the environment.

Description

TECHNICAL FIELD The present invention relates to a sound absorbing material, a sound absorbing material and a method for manufacturing the same,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sound absorbing material, a sound absorbing material and a manufacturing method thereof, and more particularly, to a sound absorbing material, a sound absorbing material and a method of manufacturing the same, which include thermoplastic polyurethane (TPU) .

Generally, it is important to absorb and block sound for a driver's comfortable driving environment, so it is necessary to develop a material that absorbs and blocks sound. Therefore, in order to prevent the noise generated during the running of the vehicle from entering the interior of the vehicle, a sound absorbing material excellent in sound absorption and sound insulation has been developed and applied to automobiles.

The above-mentioned sound absorbing property is a property of absorbing sound coming into an object, and a porous material having a lot of small holes such as glass fiber or rock surface is rich in sound absorption. In addition, the sound insulation (sound insulation property) is a property of not blocking the sound coming in from any object, and the object without holes in the interior is rich in car sound.

Recently, as interest in the environment has increased and regulations on the environment have been strengthened, there is a continuing demand for the development of technologies that can reduce the emission of environmental pollutants by recycling resources in all industries.

Particularly, a crash pad of an automobile is installed on a front surface of a driver's seat and a front passenger's seat, and various operating mechanisms, convenience devices, a grill, and a glove box are mounted. FIG. 1 is a view showing a crash pad, and FIG. 2 is a view showing a triple structure of a crash pad.

As shown in FIG. 2, the crash pad has a three-layer structure composed of an upper layer (TPU skin) and an intermediate layer in which a thermosetting polyurethane foam is foamed between a lower layer (PC / ABS alloy or PP-GF) There is no commercial method for recycling the TPU skin layer, which is the upper layer of the crash pad, and a case where it is applied to both the domestic and foreign countries.

On the other hand, the sound absorbing materials used in automobiles in the past are polyethylene terephthalate (PET) fibers and low melting point polyethylene terephthalate (LM PET) serving as a binder, polypropylene (PP) fibers for stiffness or moldability, and jute fibers However, since the constituent components are in the form of fibers, there is a problem in that it is not easy to disperse during mixing, and since the low melting point polyethylene terephthalate (LM PET) fiber serving as a binder is not uniformly dispersed, There is a problem that a deviation occurs in the bonding force.

Accordingly, the present inventor intends to provide a recycling technique in which thermoplastic polyurethane (TPU) is obtained from an automobile crash pad to be discarded and applied to a sound absorbing material.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems and to provide a thermoplastic polyurethane resin composition which can be used for thermoplastic polyurethane (TPU), polyethylene terephthalate (PET), polyurethane foam, low melting point polyethylene terephthalate (LMPET), polypropylene The present invention is to provide a sound absorbing material, a sound absorbing material, and a manufacturing method thereof using a recycled material having an effect of improving the recycling rate of a scrapped vehicle and protecting the environment as well as reducing weight and cost.

In order to achieve the above object, the sound absorbing material and the sound absorbing material include thermoplastic polyurethane (TPU) and polyethylene terephthalate (PET).

The sound absorbing material may further include at least one member selected from the group consisting of polyurethane foam, low melting point polyethylene terephthalate (LM PET), polypropylene (PP), and jute.

Here, the thermoplastic polyurethane (TPU) is preferably 2 to 50 parts by weight, and the polyethylene terephthalate (PET) is preferably 10 to 80 parts by weight based on 100 parts by weight of the entire sound absorbing material.

The polyurethane foam, the low-melting polyethylene terephthalate (LM PET), the polypropylene (PP) and the low-melting polyethylene terephthalate (LM PET) are contained in an amount of 20 to 80 parts by weight, (jute) is preferably 2 to 30 parts by weight.

At this time, it is preferable that the thermoplastic polyurethane is in the form of a powder obtained from the skin material of an automobile crash pad.

The sound absorbing material of any one of claims 1 to 4 and a sound insulating material formed on one surface of the sound absorbing material and comprising thermoplastic polyurethane is preferable.

Also, a method for manufacturing a sound absorbing material and a sound absorbing material comprises the steps of: pulverizing a thermoplastic polyurethane to produce a thermoplastic polyurethane powder having a size of 20 to 800 탆; Mixing the resulting thermoplastic polyurethane powder and polyethylene terephthalate (PET) to form a mixture; Creating a sound absorbing felt from said mixture; Cutting the sound absorbing felt after cooling to manufacture a sound absorbing material; And a step of producing a sound absorbing material by forming and bonding a sound insulating material by using thermoplastic polyurethane on one side of the sound absorbing material.

Here, in the step of producing and bonding the sound insulating material, it is preferable that a sound insulating material is formed and joined by extruding a thermoplastic polyurethane on one side of the sound absorbing material with a T-DIE extruder.

In addition, in the step of producing and bonding the sound insulating material, it is preferable that a sound insulating material is formed and bonded by applying thermoplastic polyurethane to one surface of the sound absorbing material and then heat-treating the same.

The effect of the present invention having the above-described structure is that it is possible to expect the environmental protection effect by recycling the skin material which is the thermoplastic polyurethane (TPU) skin layer of the automobile crash pad which has been buried or incinerated in the past, It is possible to cope with this problem.

If the sound insulating material containing the thermoplastic elastomer (TPE) is replaced by thermoplastic polyurethane (TPU), a weight reduction of about 15 to 20% and a substitution effect of cost reduction of about 10% can be expected.

Also, by recycling the crash pad, it is expected to improve the recycling rate of the scrap car of 0.1%, and it has the effect of preventing resource depletion.

1 is a view showing a crash pad.
2 is a view showing a triple structure of a crash pad.
3 is a view illustrating a process for manufacturing the sound absorbing material according to the present invention.
4 is a view showing a manufacturing process for producing a sound absorbing material using thermoplastic polyurethane (TPU).
5 is a view showing a state of a process for manufacturing a thermoplastic polyurethane (TPU) powder through a process such as recovery, crushing, extrusion, and freezing pulverization of a thermoplastic polyurethane (TPU) skin of a crash pad.
6 is a view showing a process of producing and bonding a sound insulating material on one side of a sound absorbing material through extrusion of a T-DIE extruder after recovering and crushing a crash pad.
7 is a view showing a process for forming and bonding a sound insulating material on one surface of a sound absorbing material by applying a thermoplastic polyurethane (TPU) powder to the surface of the sound absorbing material,

The terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary terms and the inventor may appropriately define the concept of the term in order to best describe its invention It should be construed as meaning and concept consistent with the technical idea of the present invention.

Hereinafter, the present invention will be described in detail with reference to tables and drawings.

The present invention relates to a sound absorbing material, a sound absorbing material and a method of manufacturing the same.

In one aspect, the present invention relates to a sound absorbing material and a sound absorbing material. The sound absorbing material may be classified into a sound absorbing material constituting the sound absorbing layer and a sound insulating material constituting the sound insulating layer.

The sound absorbing material preferably includes thermoplastic polyurethane (TPU) and polyethylene terephthalate (PET). The sound absorbing material may further include at least one member selected from the group consisting of polyurethane foam, low melting point polyethylene terephthalate (LM PET), polypropylene (PP), and jute.

The thermoplastic polyurethane binds the constituents of the sound absorbing material to serve as a binder and is preferably obtained from a crash pad of an automobile, more preferably a fine powder form.

Further, the sound insulating material is laminated to a thickness of about 1.0 to 3.0 mm on one side of the sound absorbing material through a T-DIE extruder to form a sound insulating layer for improving sound insulation performance, excellent moldability and mechanical properties, etc. .

Alternatively, the sound insulating material is preferably formed by applying a thermoplastic polyurethane powder uniformly to a thickness of about 0.5 to 2.0 mm on one side of the sound absorbing material, and then heating the same to form a coating layer.

More specifically, constituent components and contents of the sound absorbing material and the sound absorbing material according to the present invention will be described.

1. Components and contents of a sound absorbing material constituting the sound absorbing layer according to the present invention

1.1. Thermoplastic polyurethane (TPU)

The thermoplastic polyurethane (TPU) is basically excellent in adhesion, maintains a uniform dispersibility in a sound-absorbing material, and acts as a binder to increase the bonding force between the constituent components. The thermoplastic polyurethane is used in a crash pad It is preferable to separate them.

In detail, the crash pad is composed of a thermoplastic polyurethane (TPU) skin layer, a polyurethane foam layer and a PP-GF (or PC / ABS) layer and the thermoplastic polyurethane (TPU) is a thermoplastic polyurethane (TPU) skin layer is preferably a powder produced through a process such as crushing, extrusion, and freezing pulverization.

The thermoplastic polyurethane is preferably 2 to 50 parts by weight based on 100 parts by weight of the entire sound absorbing material. When the amount of the thermoplastic polyurethane is less than 2 parts by weight, it is difficult to sufficiently bind the components of the sound absorbing material, , The properties of the sound absorbing material may be deteriorated due to the ratio with other constituents.

1.2. Polyethylene terephthalate (PET)

The polyethylene terephthalate serves to improve the mechanical strength, moldability and shape retention of the sound absorbing material. The polyethylene terephthalate preferably has a melting point of 250 to 260 ° C and a thickness of 2 to 10 denier.

The polyethylene terephthalate is preferably 10 to 80 parts by weight based on 100 parts by weight of the entire sound absorbing material. If the content of the polyethylene terephthalate is less than 10 parts by weight, the mechanical strength of the sound absorbing material may be deteriorated. If the amount of the polyethylene terephthalate is more than 80 parts by weight, the binding between the components of the sound absorbing material may be deteriorated.

1.3. Polyurethane foam

It is preferable that the polyurethane foam is pulverized into a size of about 3 mm by recycling the waste sheet separated from a waste automobile through a recycling process and then applied to a sound absorbing material. Since the polyurethane foam is a center material of the sound absorbing material, .

The polyurethane foam is preferably 20 to 80 parts by weight based on 100 parts by weight of the entire sound absorbing material. When the polyurethane foam is less than 20 parts by weight, the sound absorption ratio of the sound absorption material may be insufficient. If the polyurethane foam is more than 80 parts by weight, physical properties of the sound absorption material may be deteriorated due to unevenness of the composition ratio.

1.4. Low melting point polyethylene terephthalate (LM PET)

The low-melting polyethylene terephthalate serves as a binder for binding components contained in the sound-absorbing material, and preferably has a melting point of 130 to 180 ° C and a thickness of about 3 to 8 denier.

The low melting point polyethylene terephthalate is preferably 5 to 50 parts by weight based on 100 parts by weight of the entire sound absorbing material. If the low melting point polyethylene terephthalate is less than 5 parts by weight, the components of the sound absorbing material may be insufficiently bound to each other. If the amount of the low melting point polyethylene terephthalate is more than 50 parts by weight, the bond may be saturated and the production cost may increase.

1.5. Polypropylene (PP)

The polypropylene has a low melting point and improves the formability of the sound absorbing material and binds the components contained in the sound absorbing material. The polypropylene has a melting point of 130 to 150 ° C and a thickness of 2 to 10 denier desirable.

The polypropylene is preferably 2 to 30 parts by weight based on 100 parts by weight of the entire sound absorbing material. If the amount of the polypropylene is less than 2 parts by weight, the formability of the sound absorbing material may be insufficient. If the amount is more than 30 parts by weight, the physical properties of the sound absorbing material may be deteriorated.

1.6. Jute

The hemp is a fiber type which improves the mechanical rigidity of the sound absorbing material. It is preferable that the water content is 2 to 30 parts by weight based on 100 parts by weight of the entire sound absorbing material. If the mark is less than 2 parts by weight, the rigidity of the sound absorbing material may deteriorate, and if it exceeds 30 parts by weight, the moldability of the sound absorbing material may be deteriorated.

2. Usage

The sound absorbing material and the sound absorbing material according to the present invention are preferably used for parts requiring sound absorption and sound insulation characteristics, and are particularly preferably applied to an automobile dash insulation pad, a floor carpet, or a luggage trims such as a built-in part.

3. Manufacturing Method

In another aspect, the present invention relates to a sound absorbing material and a method of manufacturing the sound absorbing material.

The sound absorbing material according to the present invention can be classified into a sound absorbing material and a sound insulating material. Preferably, the sound absorbing material constitutes a sound absorbing layer, and the sound insulating material constitutes a sound insulating layer. Preferably, the sound absorbing material and the sound insulating material include thermoplastic polyurethane (TPU) or the like obtained from a crash pad of an automobile or the like. 3 is a view illustrating a process for manufacturing the sound absorbing material according to the present invention. Hereinafter, a method of manufacturing the sound absorbing material will be described in detail.

4 is a view showing a manufacturing process for producing a sound absorbing material using thermoplastic polyurethane (TPU). More specifically, a method for manufacturing a sound absorbing material and a sound absorbing material according to the present invention comprises: milling a thermoplastic polyurethane to produce a thermoplastic polyurethane powder having a size of about 20 to 800 μm; Mixing the resulting thermoplastic polyurethane powder and polyethylene terephthalate (PET) in a mixer to produce a mixture; Creating a sound absorbing felt from said mixture; Cutting the sound absorbing felt after cooling to manufacture a sound absorbing material; And producing and adhering a sound insulating material by using thermoplastic polyurethane on one surface of the sound absorbing material to produce a sound absorbing material. At this time, it is preferable that the step of manufacturing the sound absorbing felt is carried out through processes such as conveying, carding, laminating, needle punching, heat oven and heat roller.

It is preferable that a sound insulating material is formed and bonded by extruding a thermoplastic polyurethane on one side of the sound absorbing material by a T-DIE extruder, and the thermoplastic polyurethane is coated on one surface of the sound absorbing material and then heat- It is preferable to bond them.

5 is a view showing a state of a process for manufacturing a thermoplastic polyurethane (TPU) powder through a process such as recovery, crushing, extrusion, and freezing pulverization of a thermoplastic polyurethane (TPU) skin of a crash pad.

The manufacturing process will be described in more detail with reference to the above drawings. In the step of producing the polyurethane powder, the thermoplastic polyurethane (TPU) layer among the various layers of the thermoplastic crash pad is subjected to washing, crushing, extrusion, and then freezing and pulverization to obtain a powder of a thermoplastic polyurethane (TPU) powder is preferably prepared.

The crushing is preferably carried out using a knife-type crusher at a size of about 0.5 to 10 mm, and the extrusion is preferably performed at about 140 to 180 DEG C with a single screw extruder to produce pellets. The speed is 50 to 500 rpm, the extrusion temperature is 140 to 170 캜, and the cooling bath temperature is 30 to 50 캜. In addition, it is preferable to crush the pellet produced by the extrusion at -190 캜, which is the cryogenic temperature.

In the step of producing the mixture, the sound absorbing material preferably further comprises at least one member selected from the group consisting of polyurethane foam, low melting point polyethylene terephthalate (LM PET), polypropylene (PP), and jute .

The thermoplastic polyurethane (TPU) may be used in an amount of 2 to 50 parts by weight, the polyethylene terephthalate (PET) may be used in an amount of 10 to 80 parts by weight, the polyurethane foam may be used in an amount of 20 to 80 parts by weight, It is preferable that the content of terephthalate (LM PET) is 2 to 50 parts by weight, that of polypropylene (PP) is 2 to 30 parts by weight, and the content of jute is 2 to 30 parts by weight.

6 is a view showing a process of producing and bonding a sound insulating material on one side of a sound absorbing material through extrusion of a T-DIE extruder after recovering and crushing a crash pad. More specifically, the method for producing and bonding the sound insulating material comprises: crushing the thermoplastic polyurethane into a size of 0.5 to 10 mm; Extruding the shredded thermoplastic polyurethane through a T-DIE extruder; And laminating the extruded thermoplastic polyurethane to a thickness of about 1.0 to 3.0 mm on one side of the sound absorbing material to form and join the sound insulating material. At this time, the extrusion speed of the T-DIE extruder is preferably 30 to 300 rpm and the extrusion temperature is preferably 140 to 180 ° C.

FIG. 7 is a view showing a process of applying and bonding a thermally conductive polyurethane (TPU) powder to the surface of a sound absorbing material and then forming and bonding a sound insulating material on one surface of the sound absorbing material through heat treatment. More specifically, Pulverizing urethane to a size of about 20 to 800 탆 to prepare a thermoplastic polyurethane powder; Uniformly spreading the thermoplastic polyurethane powder to a thickness of about 0.5 to 2.0 mm on one side of the sound absorbing material; And passing the coated thermoplastic polyurethane powder through an oven at a temperature of 150 to 190 캜 to produce and bond a sound insulating material on one side of the sound absorbing material.

[Example]

Hereinafter, the present invention will be described in more detail with reference to Examples. It is to be understood by those skilled in the art that these embodiments are merely illustrative of the present invention and that the scope of the present invention is not construed as being limited by these embodiments.

In order to confirm the physical properties of the sound absorbing material according to the present invention, test pieces including the constituents and contents as shown in Table 1 were prepared, and then the appearance, tensile strength and sound absorption property of the product were measured and summarized.

division Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Comparative Example 1 Comparative Example 2 TPU
powder Weight portion 30 30 20 20 20 40 - - Weight (g) 300 300 200 200 200 400 - - Size (㎛) 1000 400 400 400 400 400 - - PET
fiber Weight portion 70 70 20 20 15 60 60 60 Weight (g) 700 700 200 200 150 600 600 - Polyurethane foam Weight portion - - 50 50 50 - - - Weight (g) - - 500 500 500 - - - Size (mm) - - 3 3 3 - - - LM PET
fiber Weight portion - - - 10 10 - - - Weight (g) - - - 100 100 - - - PP
fiber Weight portion - - - - - 10 - - Weight (g) - - - - - 100 - - hemp Weight portion - - - - - 5 - - Weight (g) - - - - - 50 - - Sound absorbing material
TOTAL Weight portion 100 100 100 100 100 100 100 100 Weight (g) 1000 1000 1000 1000 1000 1000 1000 1000 TPU sound insulating material
(Thickness, mm) - - - 3 - - - - Conventional
TPE sound insulating material
(Thickness, mm) - - - - - - - 3 Product appearance 2 5 5 5 5 4 5 5 Seal
burglar MD 0.6 1.3 1.0 1.5 1.2 1.4 1.0 1.2 AMD 0.5 1.0 0.9 13 1.0 1.2 0.8 0.9 Sound absorption (1kHz) 0.32 0.45 0.58 0.55 0.56 0.40 0.50 0.47

Table 1 is a table comparing the constituents and contents of the test pieces for measuring the physical properties of the sound absorbing materials of Examples and Comparative Examples. Based on the above table, the test pieces of Examples and Comparative Examples were manufactured by the manufacturing method according to the present invention, About 50 mm and about 150 mm in length.

In addition, the appearance of the product in the above table was visually confirmed on the surface of the test piece, and the results were shown as 5 excellent, 4 fair, 3 fair, 2 poor and 1 poor. The tensile strength was measured by a universal testing machine (UTM) at a speed of 10 mm / min. The MD was calculated from the machine direction tensile strength, And the sound absorption was measured by the reverberation method.

In Example 1, the thermoplastic polyurethane (TPU) skin layer of the crash pad was frozen and crushed to a size of about 1 mm, and then 30 parts by weight of thermoplastic polyurethane (TPU) powder and 70 parts by weight of polyethylene terephthalate (PET) By weight.

When the particle size of the thermoplastic polyurethane powder was 1 mm or more, the binder tilted to one place, and the appearance and sound absorption of the sound absorbing material were somewhat less favorable than those of Comparative Example 1.

In Example 2, the thermoplastic polyurethane (TPU) skin layer of the crash pad was frozen and pulverized to a size of about 400 mu m, and then 30 parts by weight of thermoplastic polyurethane (TPU) powder and 100 parts by weight of polyethylene terephthalate (PET) 70 parts by weight of fibers were added.

Unlike Example 1, when the thermoplastic polyurethane (TPU) was finely pulverized, the thermoplastic polyurethane (TPU) powder serving as a binder in the mixing process was evenly dispersed to appropriately bind the components of the sound absorbing material. In addition, the manufactured sound absorbing material showed good appearance and physical properties similar to those of Comparative Example 1.

In Example 3, the thermoplastic polyurethane (TPU) skin layer of the crash pad was frozen and pulverized to a size of about 400 mu m, and then 20 parts by weight of thermoplastic polyurethane (TPU) powder, polyethylene terephthalate (PET) 20 parts by weight of fibers, 50 parts by weight of a polyurethane foam and 10 parts by weight of a low melting point polyethylene terephthalate (LM PET) were added.

Example 3 was inferior in physical properties to Example 2, but comparable to Comparative Example 1, and sound-absorbing property was better than Comparative Example 1.

In Example 4, the thermoplastic polyurethane (TPU) skin layer of the crash pad was frozen and pulverized to a size of about 400 mu m, and then 20 parts by weight of thermoplastic polyurethane (TPU) powder, polyethylene terephthalate (PET) 20 parts by weight of fibers, 50 parts by weight of a polyurethane foam and 10 parts by weight of a low melting point polyethylene terephthalate (LM PET) were added. Then, a sound insulating layer was formed by extruding thermoplastic polyurethane (TPU) through one side of a sound absorbing material through a T-die (T-DIE).

In Example 4, the weight was reduced by about 25% as compared with Comparative Example 2, and sound absorption was superior to Example 3.

In Example 5, the thermoplastic polyurethane (TPU) skin layer of the crash pad was frozen and pulverized to a size of about 400 mu m, and then 20 parts by weight of thermoplastic polyurethane (TPU) powder, polyethylene terephthalate (PET) 15 parts by weight of fibers, 50 parts by weight of polyurethane foam, 10 parts by weight of polypropylene (PP) and 5 parts by weight of jute were added.

The addition of 10 parts by weight of polypropylene (PP) and jute improved the formability and rigidity of the sound absorbing material, and the sound absorbing property was also excellent.

In Example 6, the thermoplastic polyurethane (TPU) skin layer of the crash pad was frozen and pulverized to a size of about 400 mu m. Then, 40 parts by weight of thermoplastic polyurethane (TPU) powder and 100 parts by weight of polyethylene terephthalate (PET) 60 parts by weight of fibers were added.

When the thermoplastic polyurethane (TPU) powder serving as a binder is contained in an excessive amount, the thermoplastic polyurethane partially aggregates and the appearance of the product is lowered.

In Comparative Example 1, 60 parts by weight of polyethylene terephthalate (PET) and 40 parts by weight of low melting point polyethylene terephthalate (LM PET) were added to 100 parts by weight of the entire sound absorbing material.

In Comparative Example 2, 60 parts by weight of polyethylene terephthalate (PET) and 40 parts by weight of low melting point polyethylene terephthalate (LM PET) were added to 100 parts by weight of the entire sound absorbing material. Also, the TPE used as a conventional vehicle sound insulating material is laminated.

As a result of comparing the characteristics of the examples and the comparative examples, it was found that the examples generally have the same physical properties as those of the comparative examples, but the sound absorption properties are excellent.

The properties of the sound insulating material according to the present invention are shown in Table 2 below in comparison with the comparative examples.

division Example 7 (TPU sound insulating material) Comparative Example 3 (TPE sound insulating material) importance 1.1 1.5 Tensile Strength (MPa) 5.0 1.1

Table 2 is a table comparing specific gravity and tensile strength of Comparative Example 3 which is a sound insulating material including a thermoplastic elastomer (TPE) and Example 7 which is a sound insulating material including the thermoplastic polyurethane (TPU) according to the present invention.

As a result of the test, Example 7, in which the sound insulating layer was produced by extruding the thermoplastic polyurethane (TPU) according to the present invention through a T-DIE extruder, was lighter than Comparative Example 3 which is a sound insulating material containing a conventional thermoplastic elastomer, It is understood that the total weight of the sound absorbing material is reduced and the mechanical strength is improved.

Although the present invention has been described in connection with the specific embodiments of the present invention, it is to be understood that the present invention is not limited thereto. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims and their equivalents. Various modifications and variations are possible.

Claims (9)

2 to 50 parts by weight of a thermoplastic polyurethane (TPU) in the form of a powder obtained from the skin material of the crash pad, and 10 to 80 parts by weight of polyethylene terephthalate (PET), based on 100 parts by weight of the entire sound absorbing material,
20 to 80 parts by weight of a polyurethane foam, 2 to 50 parts by weight of a low melting point polyethylene terephthalate (LMPET), 2 to 30 parts by weight of a polypropylene (PP) and 2 to 30 parts by weight of a jute A sound absorbing material further comprising at least one kind of sound absorbing material; And
And a sound insulating material formed on one surface of the sound absorbing material and including thermoplastic polyurethane.
delete delete delete delete delete The thermoplastic polyurethane (TPU) layer among the various layers of the thermoplastic crash pad is collected, washed, crushed, extruded and then subjected to freezing pulverization to obtain a thermoplastic polyurethane powder having a size of 20 to 800 탆 in an amount of 2 to 50 A weight part producing step;
10 to 80 parts by weight of polyethylene terephthalate (PET) was added to the resulting thermoplastic polyurethane powder,
(1) selected from the group consisting of 20 to 80 parts by weight of polyurethane foam, 2 to 50 parts by weight of low melting point polyethylene terephthalate (LMPET), 2 to 30 parts by weight of polypropylene (PP) and 2 to 30 parts by weight of jute Mixing more than one species to produce a mixture;
Creating a sound absorbing felt from said mixture;
Cutting the sound absorbing felt after cooling to manufacture a sound absorbing material; And
A step of extruding a thermoplastic polyurethane with a T-DIE extruder on one side of the sound-absorbing material or applying a thermoplastic polyurethane on one side of the sound-absorbing material followed by heat treatment to produce a sound-absorbing material to produce a sound-absorbing material Wherein the sound absorbing material is made of a metal. delete delete

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