KR20180121030A - Under Cover For Automobile, and the Process Of Producing Thereof - Google Patents

Abstract

The present invention relates to an undercover for an automobile with excellent sound absorption and rigidity and a method for manufacturing the same and, more specifically, to an undercover for an automobile with excellent mechanical properties capable of effectively absorbing sound since air permeability of a laminated structure is ensured. According to the present invention, the undercover for an automobile can ensure air permeability of a laminated structure so that the undercover can effectively absorb engine and exhaust noise and effectively prevent moisture permeation to a substrate since the device has a smaller pore size than an ordinary perforated air permeable film and has a low water absorption rate. In addition, compared to the perforated air-permeable film, the processing cost is reduced and the price is low. Air permeability and mechanical properties are secured at the same time, thereby improving the durability of parts.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a vehicle under cover which is excellent in sound absorption properties and rigidity,

The present invention relates to a vehicle under cover excellent in sound absorption properties and rigidity, and a method of manufacturing the under cover. More particularly, the present invention relates to a method for manufacturing a vehicle under cover which has excellent air permeability and can absorb noise effectively, It is about excellent car undercover.

External noise is introduced into the interior of the vehicle through various routes while the vehicle is traveling. Particularly, noise due to friction between the tire and the ground, noise generated by the high temperature and high pressure combustion gas flow of the exhaust system, mechanical noise due to driving of the engine system, etc. are introduced into the vehicle interior and transmitted to the passenger's ears. . ≪ / RTI >

For the quietness of the vehicle, the undercarriage has been equipped with parts such as undercovers and wheel guards to protect the lower part of the vehicle body from road noise interruption and scattering impacts such as earth and stone.

Conventional undercovers are formed by laminating a polycarbonate (PC) film and a polypropylene film on both sides of a polypropylene (PP) powder and a glass short fiber (GF) composite substrate for the purpose of reinforcing the bending strength on both sides, and a chemical nonwoven fabric (Fig. 1).

However, in the conventional under-cover laminated structure, the PC film and the PP film used for bending strength reinforcement purposes are non-breathable, so that penetration of sound waves into the base material is not smooth, resulting in insufficient sound absorption performance and poor impact resistance.

In order to solve the above-mentioned problem, Korean Patent No. 10-1626320 discloses a technique of laminating a vent film on one side.

 However, the general purpose general ventilation film is manufactured by mechanically perforating a general film, and this additional perforation process has a disadvantage in that the product ratio is increased. Also, there is a limit to the air permeability of the film due to the perforation size of the perforating machine, .

Korean Patent No. 10-1626320

The present invention provides an automotive under cover which is capable of effectively absorbing noise, ensuring air permeability in a laminated structure, excellent in mechanical properties, and excellent in sound absorption properties and rigidity.

(EN) Disclosed is an automotive undercover excellent in sound absorption properties and rigidity according to one aspect of the present invention, which comprises: (a) a polypropylene (PP) powder and a glass short fiber (GF) composite base layer; (b) a film layer integrally formed on the upper surface of the composite substrate layer; (c) a nonwoven fabric layer integrally formed on the upper surface of the film layer of (b); (d) a film layer integrally formed on the lower surface of the composite substrate layer; And (e) a nonwoven fabric layer integrally formed on the lower surface of the film layer of (d), wherein the film layer of (b) or the film layer of (d) is a microporous film layer.

The film layer of (b) and the film layer of (d) may be a microporous film layer.

The material of the microporous film layer may be selected from the group consisting of PC, PET, PA6, ABS, and PP.

The microporous film layer may be a film layer in which micron-sized pores are formed on the surface by mixing the film material with an inorganic filler, followed by extrusion and stretching.

The diameter of the pores of the microporous film layer may be 0.05 to 25 탆.

In addition, the porosity of the microporous film layer may be 50 to 80%.

According to another aspect of the present invention, there is provided a method of manufacturing an automotive undercover, comprising: (a) preparing a polypropylene (PP) powder and a glass short fiber (GF) composite substrate layer; (b) forming a film layer integrally on the upper surface of the composite substrate layer; (c) forming a nonwoven fabric layer so as to be integrally formed on the upper surface of the film layer of (b); (d) forming a film layer so as to be integrally formed on a lower surface of the composite substrate layer; And (e) forming a nonwoven fabric layer so as to be integrally formed on the lower surface of the film layer of (d), wherein the film layer of (b) or the film layer of (d) is a microporous film layer.

The film layer of (b) and the film layer of (d) may be a microporous film layer.

The microporous film layer may be prepared by mixing a film material with an inorganic filler, followed by extrusion and stretching.

INDUSTRIAL APPLICABILITY The automobile undercover according to the present invention can effectively absorb the noise of the engine and the exhaust system by ensuring the air permeability of the laminated structure and effectively absorb moisture penetration into the substrate because the pore size is smaller than that of the general air- .

In addition, compared to the perforated air-permeable film, the processing cost is reduced and the price is low. The air permeability and the mechanical properties are simultaneously secured, thereby improving the durability of the parts.

1 shows a stacked structure of a conventional under cover.
2 shows a laminated structure of an under cover according to an aspect of the present invention.
3 is a photograph showing pores of a microporous film according to one aspect of the present invention.
4 is a photograph showing the ventilation path of the microporous film according to one aspect of the present invention.
5 is a graph showing sound absorption ratios measured according to Experimental Example 1 of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention is capable of various modifications and various embodiments, and specific embodiments are illustrated in the drawings and described in detail in the detailed description. It is to be understood, however, that the invention is not to be limited to the specific embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

(A) a polypropylene (PP) powder and a glass short fiber (GF) composite base layer; (b) a film layer integrally formed on the upper surface of the composite substrate layer; (c) a nonwoven fabric layer integrally formed on the upper surface of the film layer of (b); (d) a film layer integrally formed on the lower surface of the composite substrate layer; And (e) a nonwoven fabric layer integrally formed on the lower surface of the film layer (d), wherein the film layer of (b) or the film layer of (d) comprises a microporous film layer Provide undercover.

According to another aspect of the present invention, there is provided a method of manufacturing a semiconductor device, comprising: (a) preparing a polypropylene (PP) powder and a glass short fiber (GF) composite base layer; (b) forming a film layer integrally on the upper surface of the composite substrate layer; (c) forming a nonwoven fabric layer so as to be integrally formed on the upper surface of the film layer of (b); (d) forming a film layer so as to be integrally formed on a lower surface of the composite substrate layer; And (e) forming a nonwoven fabric layer so as to be integrally formed on the lower surface of the film layer (d), wherein the film layer of (b) or the film layer of (d) A method for manufacturing an automotive undercover according to claim 1 is provided.

A car under cover excellent in sound absorption property and rigidity according to a specific embodiment of the present invention will be described in more detail.

Conventional under-cover laminated structures have a problem in that the penetration of sound waves into the base material is insufficient because the PC film and the PP film used for bending strength reinforcement purposes are non-breathable, insufficient sound absorption performance, and are vulnerable to impact.

Accordingly, when the microporous film layer is applied, the present inventors have found that the air permeability of the laminated structure is ensured, the noise of the engine and the exhaust system can be effectively absorbed, the breathability and the mechanical properties are secured at the same time, Through experiments, we confirmed and completed the invention.

In this technology, an undercoat material structure having excellent air permeability, excellent sound absorption, and excellent bending rigidity is proposed.

(EN) Disclosed is an automotive undercover excellent in sound absorption properties and rigidity according to one aspect of the present invention, which comprises: (a) a polypropylene (PP) powder and a glass short fiber (GF) composite base layer; (b) a film layer integrally formed on the upper surface of the composite substrate layer; (c) a nonwoven fabric layer integrally formed on the upper surface of the film layer of (b); (d) a film layer integrally formed on the lower surface of the composite substrate layer; And (e) a nonwoven fabric layer integrally formed on the lower surface of the film layer of (d), wherein the film layer of (b) or the film layer of (d) is a microporous film layer.

In the undercoat material laminated structure, the microporous film may be formed to be integrally formed on the upper, lower, or both sides of the composite substrate.

In order to maximize the sound absorption property, a microporous film can be used on both sides of the composite substrate (FIG. 2), and can be laminated only on the upper or lower surface of the composite substrate depending on the position of the noise source.

The microporous film is a film in which a plastic material is mixed with an inorganic filler, followed by extrusion and stretching to form micron unit pores on the surface (FIG. 3).

These microporous films are randomly distributed with respect to the mechanical apertured film, and have high pore density per unit area.

In general, when a sound wave rubs against a specific material, a viscous loss occurs, which results in a reduction in the mechanical energy of the sound wave converted to thermal energy, resulting in a reduction in noise. Based on such a physical phenomenon, the microporous film used in the present invention has a very curved ventilation path, and has a long attenuation path of a sound wave, thereby increasing sound absorption (FIG. 4).

On the other hand, the material of the microporous film layer may be an amorphous or semi-crystalline film, preferably a material selected from the group consisting of PC, PET, PA6, ABS, and PP.

In addition, the diameter of the pores of the microporous film layer is variable depending on the frequency band of noise, and is not particularly limited, but may be preferably 0.05 to 25 탆 or less.

If the diameter of the pores of the microporous film layer is less than 0.05 mu m, the pores may be closed after forming the parts, and the sound absorption rate may be lowered. When the thickness is more than 25 mu m, the voids inside the film surface and inside may increase, Because.

On the other hand, the porosity of the microporous film layer is variable depending on the frequency band of noise and is not particularly limited, but may be preferably 50 to 80%.

 When the porosity of the microporous film layer is less than 50%, the porosity is low and sufficient sound-absorbing property is not secured. If the porosity exceeds 80%, the mechanical strength of the laminated structure may be lowered.

According to another aspect of the present invention, there is provided a method of manufacturing an automotive undercover, comprising: (a) preparing a polypropylene (PP) powder and a glass short fiber (GF) composite substrate layer; (b) forming a film layer integrally on the upper surface of the composite substrate layer; (c) forming a nonwoven fabric layer so as to be integrally formed on the upper surface of the film layer of (b); (d) forming a film layer so as to be integrally formed on a lower surface of the composite substrate layer; And (e) forming a nonwoven fabric layer so as to be integrally formed on the lower surface of the film layer of (d), wherein the film layer of (b) or the film layer of (d) is a microporous film layer.

In the undercover manufacturing method, the microporous film may be integrally formed on the upper, lower, or both sides of the composite substrate. In order to maximize the sound absorption property, a microporous film may be used on both sides of the composite substrate, and may be laminated only on the upper or lower surface of the composite substrate depending on the position of the noise source.

The microporous film may be prepared by mixing a plastic material with an inorganic filler, followed by extrusion and stretching.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be understood, however, that these examples are for illustrative purposes only and are not to be construed as limiting the scope of the present invention.

Experimental Example  One

An undercover having a structure in which a film layer as described below was formed on both sides of a polypropylene (PP) powder and a glass short staple fiber (GF) composite base layer was manufactured and the average sound absorption rate according to the frequency was measured according to ISO 354, .

Example 1: Formation of a microporous film on both sides

Example 2: One side is a microporous film, one side is a non-breathable general film formation

Comparative Example 1: Double-sided perforation type air permeable film formation

Comparative Example 2: Perforated air permeable film on one side, non-breathable general film on one side

As shown in FIG. 5, it was found that Example 1 in which a microporous film was formed on both sides and Example 2 in which a microporous film was formed on one side had better sound absorption performance than Comparative Examples.

Experimental Example  2

An under cover having a structure in which a film layer as described below is formed on both sides of a polypropylene (PP) powder and a glass short staple fiber (GF) composite base layer was prepared and an average sound absorption rate was measured according to ISO 354, The flexural modulus was measured and is shown in Table 1 below.

Example 3: Double-sided microporous film formation, microporous film material PC, pore size 10 μm, porosity 75%, density of skin nonwoven fabric 80 g / ㎡

Comparative Example 3: Double-sided perforated air-permeable film formation, perforation The air-permeable film material had a density of 80 g / m2

Comparative Example 4: Non-breathable PC film formation on both sides, the density of the skin nonwoven fabric was 80 g / m2

[Table 1]

As shown in Table 1, it was found that the sound-absorbing performance of Example 3 was superior to that of Comparative Example 3, and the flexural modulus was also excellent. Further, it was found that the sound-absorbing property was superior to that of Comparative Example 4, and the flexural modulus was slightly decreased, but it was merely a matter of no problem for use as an under cover.

Experimental Example  3

An under cover having a structure in which a film layer as described below is formed on both sides of a polypropylene (PP) powder and a glass short staple fiber (GF) composite base layer was prepared and an average sound absorption rate was measured according to ISO 354, The flexural modulus was measured and is shown in Table 2 below.

Example 4: Double-sided microporous film formation, microporous film material PC, pore size 10 μm, porosity 75%

Comparative Example 5: Double-sided perforation type air permeable film formation, microporous film material PC, pore size 0.02 μm, porosity 75%

Comparative Example 6: Double-sided perforation type air permeable film formation, microporous film material PC, pore size 30 μm, porosity 75%

Comparative Example 7: Formation of a double-sided microporous film. The microporous film material was PC, the pore size was 10 탆, the porosity was 30%

Comparative Example 8: Double-sided microporous film formation, microporous film material PC, pore size 10 μm, porosity 90%

[Table 2]

As can be seen from the above Table 2, the sound-absorbing performance of Example 4 is superior to that of Comparative Examples 5 to 8. It was found that the flexural modulus was slightly reduced as compared with Comparative Examples 5 and 7, but only to a degree that there was no problem in using as an under cover.

While the present invention has been particularly shown and described with reference to specific embodiments thereof, those skilled in the art will appreciate that such specific embodiments are merely preferred embodiments and that the scope of the present invention is not limited thereby. something to do. It is therefore intended that the scope of the invention be defined by the claims appended hereto and their equivalents.

Claims (9)

(a) a polypropylene (PP) powder and a glass short fiber (GF) composite base layer;
(b) a film layer integrally formed on the upper surface of the composite substrate layer;
(c) a nonwoven fabric layer integrally formed on the upper surface of the film layer of (b);
(d) a film layer integrally formed on the lower surface of the composite substrate layer; And
(e) a nonwoven fabric layer integrally formed on the lower surface of the film layer (d)
Wherein the film layer of (b) or the film layer of (d) is a microporous film layer which is excellent in sound absorption and rigidity.
The automotive undercover of claim 1, wherein the film layers of (b) and (d) are microporous film layers.
The undercoat of claim 1, wherein the material of the microporous film layer is selected from the group consisting of PC, PET, PA6, ABS, and PP.
The automotive under cover according to claim 1, wherein the microporous film layer is a film layer in which a film material is mixed with an inorganic filler, and then extruded and stretched to form micron unit pores on the surface.
The automotive under cover according to claim 4, wherein the microporous film layer has a pore diameter of 0.05 to 25 탆.
5. The automotive under cover of claim 4, wherein the porosity of the microporous film layer is 50 to 80%.
(a) preparing a polypropylene (PP) powder and a glass short fiber (GF) composite base layer;
(b) forming a film layer integrally on the upper surface of the composite substrate layer;
(c) forming a nonwoven fabric layer so as to be integrally formed on the upper surface of the film layer of (b);
(d) forming a film layer so as to be integrally formed on a lower surface of the composite substrate layer; And
(e) forming a nonwoven fabric layer so as to be integrally formed on the lower surface of the film layer of (d)
The method according to claim 1, wherein the film layer (b) or the film layer (d) is a microporous film layer.
The method according to claim 7, wherein the film layer (b) and the film layer (d) are microporous film layers.
The method according to claim 7, wherein the microporous film layer is produced by mixing a film material with an inorganic filler, followed by extrusion and stretching.

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