KR20150103943A - Noise absorption material and producing method - Google Patents

Abstract

The present invention relates to a sound absorption material for a vehicle which comprises polyurethane foam foamed on the top of a fabric and a meltblown fiber web, and a manufacturing method thereof. According to the present invention, a sound absorption material for a vehicle can be manufactured with a lightweight, low manufacturing costs, and excellent sound absorption capacity in a broad region.

Description

TECHNICAL FIELD [0001] The present invention relates to a sound absorbing material for a vehicle,

The present invention relates to a sound absorbing material for a vehicle and a method of manufacturing the same, and more particularly, to a sound absorbing material for a vehicle including a meltblown fiber web and a polyurethane foam foamed on a base paper and a method of manufacturing the same.

Generally, during running of a vehicle, noise and vibration sounds generated by the engine, and noise and vibrations during running through the door, the headliner, and the floor of the vehicle enter the interior space of the vehicle. Accordingly, a sound absorbing material has been installed in the interior of a vehicle so as to prevent noise from being transmitted to the engine, to suppress vibration, to absorb noise, and to transmit the combined energy of low frequency and high frequency generated during traveling to the interior space of the vehicle.

In the case of a sound absorbing material for a vehicle in which a urethane foam is foamed, there is a problem that a urethane foam is penetrated into the sound absorbing material when foaming the urethane foam directly to a PET felt sound absorbing material. Therefore, . When manufactured in this manner, it exhibits a sound insulation function and is characterized by low sound absorption function. There is a problem that a wire forming process is required to include a separate layer, and the weight is heavy and the manufacturing cost is high.

Korean Utility Model No. 20-0251584 not only simplified the structure of the material so that the polyester needle punch and the polypropylene binder felt are bonded with the adhesive film to achieve the noise acceleration target value. To a material for which the process is simple in the order of material preheating and shaping (Forming / Trimming), thereby reducing defective rate and excellent moldability so that airtightness and adhesion can be maintained in any shape.

Disclosure of Invention Technical Problem [8] Accordingly, the present invention has been made to solve the above-mentioned problems occurring in the prior art, and it is an object of the present invention to provide a sound absorbing material for automobiles including a meltblown fiber web and a polyurethane foam foamed on a base paper and a method of manufacturing the same. According to the present invention, it is an object of the present invention to provide a sound absorbing material for a vehicle which is light in weight, low in manufacturing cost, and excellent in sound absorption ability, and a method for manufacturing the same.

A method of manufacturing a sound absorbing material for a vehicle, comprising the steps of: preparing a meltblown fiber web including bubbles on one side or both sides; Placing the meltblown fibrous web in the foam mold so that the foam is upward; Injecting a polyurethane foam liquid into the foam mold; And trimming to the desired shape.

Preferably, the foam is SMS or SMMS.

Preferably, the foam has a weight per unit area of 8 to 500 g / m < 2 >.

Preferably, the meltblown fibrous web is a meltblown fibrous web consisting of a single resin, or a meltblown fibrous web comprising a mixture of meltblown fibers and at least one staple fiber.

Preferably, the meltblown fibrous web has a weight per unit area of 20 to 1000 g / m < 2 >.

Preferably, the polyurethane foamed liquid is prepared by kneading polypropylene glycol (PPG) and methylene diphenyl diisocyanate (MDI) at a weight mixing ratio within the range of 6: 4 to 8: 2.

Further, the present invention provides a sound absorbing material for a vehicle, comprising: a meltblown fiber web layer; A support layer positioned on top of the meltblown fibrous web layer; And a polyurethane foam layer located on top of the base paper layer.

Preferably, the meltblown fibrous web layer is a layer comprising a meltblown fibrous web consisting of a single resin or a meltblown fibrous web in which one or more staple fibers are mixed with the meltblown fibers.

Preferably, the meltblown fibrous web layer has a weight per unit area of 20 to 1000 g / m < 2 >.

Preferably, the sound absorbing material for a vehicle has a weight per unit area of 50 to 5,000 g / m < 2 >.

The sound absorbing material for a vehicle according to the present invention does not require a separate layer for preventing penetration of the polyurethane into the sound-absorbing layer, so that there is no need for a pre-forming step for manufacturing the same and the manufacturing cost is reduced. In addition, since the weight is light, the fuel consumption can be reduced. Further, since the meltblown fiber is a material having softness, it has a good matching with the mold and a gap filling property. In addition, by using a meltblown fiber web made of microfibers, the sound absorption performance is maximized and high sound absorption performance is exhibited, which is effective in reducing noise.

1 shows a flow chart of a method of manufacturing a sound absorbing material for a vehicle according to the present invention.
2 is a schematic view showing a method of manufacturing a sound absorbing material for a vehicle according to the present invention.
3 shows a sound absorbing material for a vehicle manufactured according to the present invention.
Fig. 4 shows a sound absorbing material for a vehicle when foamed without using the film of Comparative Example 4. Fig.
Fig. 5 shows a graph of sound absorption ratios of Example 1 and Comparative Examples 1 and 2. Fig.
Fig. 6 shows a graph of sound absorption ratios of Example 1 and Comparative Examples 1, 3 and 4. Fig.

Unless defined otherwise, all technical terms used in the present invention have the following definitions and are consistent with the meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Also, preferred methods or samples are described in this specification, but similar or equivalent ones are also included in the scope of the present invention.

As used herein, the term "meltblown fibers" refers to fibers or microfibers formed by extruding a molten processable polymer through a plurality of fine capillaries with a high temperature, high speed compressed gas. Here, the capillary may be variously changed, such as a polygon including a circle, a triangle and a rectangle, and a star. As an example, high temperature and high speed compressed gas can finely thin the molten thermoplastic polymer material and reduce the diameter to about 0.3 to 10 mu m. The meltblown fibers may be discontinuous fibers or continuous fibers. 70 to 80%, or 70 to 90% of the meltblown fibers may have a diameter of 10 [mu] m or less. 10, 20, 30% of the meltblown fibers may have a diameter of 3 탆 or less.

The terms "SMS " and" SMMS "used in the present specification refer to a mixture of any one of polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), polyurethane (PU) Means a nonwoven fabric having a composite structure of a spunbonded web and a meltblown web formed from a raw material base. SMS has a structure of spunbond / meltblown fiber / spunbond, and SMMS has a structure of spunbond / meltblown fiber / meltblown fiber / spunbond.

The term "spunbond" fiber, as used herein, refers to a fibrous web produced by a method of drawing a plurality of fine diameter filaments extruded through a capillary tube using a hot tube. The spunbond fibers are continuous in the length direction of the filaments and the average diameter of the filaments is greater than about 5 占 퐉. The spunbond nonwoven web or nonwoven web is formed by irregularly arranging the spunbond on a collecting surface such as a porous screen or belt.

As used herein, the term "nonwoven and fibrous web" refers to a structure composed of individual fibers, filaments, or yarns that forms a planar material by disposing the individual fibers, filaments, or yarns in an irregular manner in a patternless manner as opposed to a knitted fabric.

The sound absorbing material for a vehicle according to the present invention can be manufactured by the following method. 1 and 2 show a flowchart and a schematic diagram of a method of manufacturing a sound absorbing material for a vehicle according to the present invention.

(S11) preparing a meltblown fibrous web 101 comprising bubbles on one or both sides; (S12) placing the meltblown fibrous web 101 on the foam metal mold 200 so that the foam paper faces upward; (S13) injecting the polyurethane foamed liquid 300 into the foam metal mold 200; And trimming (S14) to the desired shape.

First, step (S11) of preparing a meltblown fiber web 101 including bubbles on one surface or both surfaces. In order to produce a meltblown fibrous web, the thermoplastic resin composition is caused to collide with a high-temperature and high-velocity gas at the same time as melt-extrusion spinning. Next, in the case of producing a meltblown mixed with staple fibers, a meltblown fiber web can be prepared by air blending the meltblown microfine fibers and the staple fibers.

The foam used in the present invention may be SMS or SMMS. The weight per unit area of the base paper may be 8 to 500 g / m 2. Since the foam has a partial membrane characteristic, the air passes but does not allow the polyurethane foam liquid to pass, so that the polyurethane foam liquid can be prevented from being absorbed into the meltblown fiber web layer. Further, since SMS and SMMS having a high content of meltblown fibers are used, the property of meltblown to control viscous materials can be utilized.

The meltblown fibrous web used in the present invention may be a meltblown fibrous web made of a single resin or a meltblown fibrous web having a mixture of meltblown fibers and one or more staple fibers. The weight per unit area of the meltblown fibrous web may be 20 to 1000 g / m < 2 >. Since the meltblown fiber web is light in weight, it is convenient to move and work during operation, and has softness, so that it has an advantage of excellent matching property with a mold and gap filling property.

Next, step (S12) of placing the meltblown fibrous web 101 on the foam metal mold 200 with the foam paper facing upward. The partial membrane property of the foam paper and the property of controlling the viscous material of the meltblown fibers contained in the foam paper, etc., the desired effect can be obtained by not infiltrating the meltblown layer when the polyurethane foam is foamed thereafter.

Next, a polyurethane foam liquid is injected into the foam metal mold (S13). The polyurethane foamed solution may be prepared by kneading polypropylene glycol (PPG) and methylene diphenyl diisocyanate (MDI) at a weight mixing ratio within the range of 6: 4 to 8: 2. If it is more than or less than the above range, the rigidity (density) of the product may be too strong or too soft for the product to use. However, this indicates an optimum ratio, but is not limited thereto.

Next, step S14 is performed to trim the product into a desired shape to manufacture the product.

The sound absorbing material for a vehicle according to the present invention comprises a meltblown fiber web layer (101); A support layer positioned on top of the meltblown fibrous web layer; And a polyurethane foam layer 202 located on top of the base layer. 3 shows a sound absorber for a vehicle according to the present invention.

The meltblown fibrous web layer 101 may comprise a meltblown fibrous web of a single resin or a meltblown fibrous web comprising a mixture of meltblown fibers and one or more staple fibers. Also, the meltblown fibrous web may have a weight per unit area of 20 to 1000 g / m < 2 >.

The sound absorbing material 400 for a vehicle according to the present invention may have a weight per unit area of 50 to 5,000 g / m 2. Therefore, it is easy to carry and work, and the fuel consumption of the vehicle can be improved.

Hereinafter, the present invention will be described in detail with reference to examples and comparative examples. These examples are for illustrating the present invention specifically, and thus the scope of the present invention is not limited thereto.

Example  One

In the extruder, 99.8 wt% of homopolyethylene H7914 polymer resin of LG Chemical Co. with a melt index (230 ° C) of 1400 g / 10 min, 0.01 wt% of Tinuvin 622, an ultraviolet stabilizer of Ciba special chemical, And 0.01 wt% of a stabilizer Irganox 1010 (Irganox 1010). A single extruder with L / D of 1/28 was rotated 80 times per minute to knead, heat and extrude the thermoplastic resin composition. The kneaded composition was then transferred to a spinneret and the fibers were spun in the direction of the collector through an orifice having a diameter of 0.2 mm and a number per inch of 32. The fibers collide with the high-temperature and high-velocity gas injected from the high-temperature and high-velocity gas ejection holes provided in the spinning die during spinning to form meltblown microfibers made of polypropylene having an average fiber thickness of 3 μm.

The meltblown microfibers and the staple fibers were fed through a staple fiber feeder to an area having an average thickness of 6 denier and an average length of 40 mm and to which the meltblown microfibers were radiated, Blended. At this time, the meltblown microfibers and the staple fibers were mixed at a weight ratio of 60:40.

The meltblown fiber web thus prepared was wound on a winding machine so that the web was 300 g / m 2, the width was 1,800 mm, and the length was 100 m. The twisted fiber web was prepared by laminating 15 g / m < 2 > of SMMS nonwoven fabric on both sides to produce a meltblown fibrous web having a total weight of 330 g / m < 2 > and a thickness of 35 mm.

The meltblown fiber web 101 thus prepared is placed on the foam mold 200 as shown in FIG. The polyurethane foam liquid 300 is injected into the melt blown fiber 101 seated on the foam metal mold 200 into the injection port 201 to form a polyurethane foam 202 having a density of 90 K and a thickness of 20 mm. The foamed polyurethane foam 202 and the meltblown fiber web 101 were bonded to each other to produce a product 400 having a total weight of 1,930 g / m 2 and a thickness of 55 mm.

Comparative Example  One

Comparative Example 1 was prepared by laminating an SMMS nonwoven fabric of 15 g / m 2 on both sides of a meltblown fiber web produced by the same method as in Example 1 above. The total weight of the meltblown fiber web produced is 330 g / m 2 and the thickness is 35 mm.

Comparative Example  2

In Comparative Example 2, the polyurethane foam liquid 300 was injected into the foam metal mold 200 through the injection port 201 into the foam metal mold 200 to obtain a polyurethane foam having a density of 90 K, a weight of 1,600 g / .

Comparative Example  3

In Comparative Example 3, needle punched PET felt weighed 1,200 g / m < 2 > and had a thickness of 20 mm.

Comparative Example  4

In Comparative Example 4, a nylon film was adhered to PET felt used in Comparative Example 3, and the polyurethane foam was foamed by placing it on a foaming mold to produce a product having a weight of 2,800 g / m 2 and a thickness of 40 mm. In Comparative Example 4, when the urethane foam was foamed, the nylon film was adhered and the foaming operation was performed. Nylon film was used to prevent this. A photograph of the foamed film without using the film is shown in Fig. 4

Experimental Example  One

ISO 354 Reverberation method Sound absorption rate is measured using the simple reverberation method which is similar to the method of measuring the sound absorption rate. The measurement method was tested according to GMW14177 sound absorption rate measurement method. (Random incidence sound absorption evaluation test produce) Simple reverberation room sound absorption rate measurement is measured in 1/3 octave bands from 400 Hz to 10,000 Hz. The sample size should be 1.2m2. The conditions of the test room were measured after standing at room temperature (23 ± 2 ℃, 50 ± 5% RH) for 24 hours.

frequency Hz 400 500 630 800 1k 1.25k 1.6k 2k 2.5k 3.15k 4k 5k 6.3k 8k 10k Example 1 0.54 0.70 0.81 0.93 1.08 1.16 1.15 1.10 1.04 1.03 1.08 1.11 1.10 1.13 1.18 Comparative Example 1 0.45 0.61 0.72 0.88 1.03 1.08 1.07 1.05 1.01 0.98 0.98 1.00 1.04 1.09 1.05 Comparative Example 3 0.21 0.32 0.45 0.57 0.71 0.73 0.74 0.71 0.73 0.78 0.86 0.93 0.94 0.91 0.89 Comparative Example 4 0.30 0.52 0.67 0.79 0.87 0.95 0.90 0.89 0.87 0.88 0.88 0.94 0.94 0.90 0.89

5 is a graph of sound absorption ratios of Example 1 and Comparative Examples 1 and 2. Table 1 is a table showing the frequency absorption values of the respective samples according to FIG. The meltblown fibrous web prepared in Comparative Example 1 maximized the sound absorption effect in the low frequency region (400 to 2 kHz), and the polyurethane foam prepared in Comparative Example 2 had a sound absorbing effect in all the regions, It can be seen that it exhibits a low sound absorption performance. As can be seen from FIG. 5, it can be seen that Example 1, in which the meltblown fiber web and the polyurethane foam were bonded, was superior in sound absorption effect in the entire frequency range than Comparative Example 1. [ The maximum sound absorption performance can be obtained by bonding the polyurethane foam having a relatively weak sound absorption region to the meltblown fiber web.

Experimental Example  2

Sound absorption ratios were measured by comparing Example 1 with Comparative Examples 1, 3 and 4 by the same experimental method as Experimental Example 1. [

frequency Hz 400 500 630 800 1k 1.25k 1.6k 2k 2.5k 3.15k 4k 5k 6.3k 8k 10k Example 1 0.54 0.70 0.81 0.93 1.08 1.16 1.15 1.10 1.04 1.03 1.08 1.11 1.10 1.13 1.18 Comparative Example 1 0.45 0.61 0.72 0.88 1.03 1.08 1.07 1.05 1.01 0.98 0.98 1.00 1.04 1.09 1.05 Comparative Example 3 0.21 0.32 0.45 0.57 0.71 0.73 0.74 0.71 0.73 0.78 0.86 0.93 0.94 0.91 0.89 Comparative Example 4 0.30 0.52 0.67 0.79 0.87 0.95 0.90 0.89 0.87 0.88 0.88 0.94 0.94 0.90 0.89

6 is a graph of sound absorption ratios of Example 1 and Comparative Examples 1, 3, and 4. Table 2 is a table showing the frequency absorption values of the respective samples according to FIG. The PET felt produced in Comparative Example 3 generally exhibits a generally low absorption rate value in the entire region from the low frequency region to the high frequency region. Compared with the comparative example 1 made of a meltblown fiber web, a difference in sound absorption performance of about twice or more occurs in a low frequency range (400 to 2 kHz). In Comparative Example 4, urethane foam was foamed on the felt to show higher performance in Comparative Example 3 than in Comparative Example 3, but exhibited lower performance than Example 1.

Experimental Example  3

The weights of Example 1 and Comparative Examples 1 to 4 were measured according to GMW 3182.

Experimental Example 3 room Example 1 ratio Curriculum 1 ratio Teaching 2 ratio Teaching 3 ratio Teaching 4 Weight (g / ㎡) 1,944 341 1,637 1,275 2,744

Experimental Example  4

The thicknesses of Example 1 and Comparative Examples 1 to 4 were measured according to ISO 9073-2.

Experimental Example 3 room Example 1 ratio Curriculum 1 ratio Teaching 2 ratio Teaching 3 ratio Teaching 4 Thickness (mm) 54.25 36.15 21.15 20.05 42.15

101: meltblown fiber web
200: foaming mold
201: inlet
202: foamed polyurethane foam
300: polyurethane foam liquid
400: Final product

Claims (10)

Preparing a meltblown fibrous web comprising foam on one or both sides;
Placing the meltblown fibrous web in the foam mold so that the foam is upward;
Injecting a polyurethane foam liquid into the foam mold; And
And trimming the sound absorbing material to a desired shape. The method according to claim 1,
Wherein said foam is SMS or SMMS. The method according to claim 1,
Wherein the foam has a weight per unit area of 8 to 500 g / m < 2 >. The method according to claim 1,
Wherein the meltblown fiber web is a meltblown fiber web made of a single resin or a meltblown fiber web in which one or more kinds of staple fibers are mixed with the meltblown fiber. The method according to claim 1,
Wherein the meltblown fibrous web has a weight per unit area of 20 to 1000 g / m < 2 >. The method according to claim 1,
Wherein the polyurethane foam solution is prepared by kneading polypropylene glycol (PPG) and methylene diphenyl diisocyanate (MDI) at a weight mixing ratio within a range of 6: 4 to 8: 2. A meltblown fibrous web layer;
A support layer positioned on top of the meltblown fibrous web layer; And
And a polyurethane foam layer disposed on the top of the base paper layer. 8. The method of claim 7,
Wherein the meltblown fibrous web layer is a layer comprising a meltblown fibrous web consisting of a single resin or a meltblown fibrous web in which one or more staple fibers are mixed with the meltblown fibers. 8. The method of claim 7,
Wherein the meltblown fibrous web layer has a weight per unit area of 20 to 1000 g / m < 2 >. 8. The method of claim 7,
Wherein the vehicle sound absorbing material has a weight per unit area of 50 to 5,000 g / m < 2 >.

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