KR20170074289A - Floor carpet impoved noise absorbent for vehicle - Google Patents

Abstract

The present invention relates to a floor carpet for automobiles with improved sound absorption performance, and more particularly to a floor carpet comprising a carpet layer, a breathable adhesive layer, and a double-layered nonwoven sound absorbing layer. The nonwoven fabric comprises a hexaflower- The present invention relates to a floor carpet for an automobile having improved sound absorption performance, which is capable of improving the sound absorption performance and reducing the weight of a product by showing the same sound absorption performance even with a nonwoven fabric having a small area density compared to an existing circular cross section .

Description

[0001] The present invention relates to a floor carpet impersonating noise absorbent for vehicle,

The present invention relates to an automotive sound absorbing floor carpet, and more particularly, to an automotive sound absorbing floor carpet which is made of a carpet layer, an air permeable adhesive layer, a nonwoven sound absorbing layer using fibers of a deformed cross section yarn (helium hollow fiber), and a porous elastic layer .

External noise is introduced into the interior of the vehicle through various routes while the vehicle is traveling. Particularly, noise caused by 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. It is an element that hinders sense.

Accordingly, in order to prevent noise from entering a passenger room from a car, a sound absorbing material of various materials and weights is used. Such a sound absorbing material is widely used for floor carpets of automobiles or the like as an automobile interior or exterior material. Examples of typical materials for use are glass fiber, urethane foam, hand woven felt, and general polyethylene terephthalate (PET) fiber. However, the regulations on the environment-friendly and recyclability are gradually strengthening, and the use ratio of fiber-absorbing materials based on thermoplastic resin such as PET or PP (polypropylene) is increasing. In order to reduce carbon dioxide, the regulation of fuel efficiency of the vehicle is gradually increasing. The improvement of fuel efficiency can be attained through the weight reduction of parts, so it is necessary to develop lightweight sound absorbing material with improved performance.

Generally, the sound absorption and sound insulation performance of a fiber-based sound absorbing material depends on the thickness of the fiber aggregate (mainly nonwoven fabric), the area density of the fiber aggregate, the thickness of the fiber aggregate, and the like.

If the thickness of the fiber is reduced, more fibers can be put in a certain volume, which can improve the sound absorption performance by increasing the porosity. Also, increasing the area density and thickness of the fibrous aggregate increases the porosity and the sound dissipation path, thereby improving the sound absorption performance and sound insulation performance.

In order to improve the NVH (Noise, Vibration & Harshness) performance of vehicles in accordance with such acoustic characteristics, a heavy-weight sound-deadening soundproofing material is mainly used in medium-sized and luxury vehicles. However, when such a sound insulating material is used, the noise is reduced and the quietness of the vehicle is improved. However, since the weight of the vehicle is increased, it acts as an obstacle to the fuel efficiency.

In order to overcome the problems of conventional heavy weight and high sound insulation materials, studies have been made on a sound absorption structure in which a ventilation is formed, and examples of application to other parts are disclosed. However, as consumers' standards for improving the quietness and fuel economy of vehicles have increased, research has been actively conducted.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a floor carpet for an automobile having improved sound absorption performance, which has excellent sound absorption properties against noise from the interior of the automobile and external noise, and which can reduce product weight.

In order to achieve the above object, the present invention provides a sound absorbing carpet for an automobile,

A yarn made of one selected from the group consisting of polyester, nylon, polypropylene, acrylic, cotton, hemp and wool is tufted or bonded by needling on a nonwoven fabric base made of polypropylene or polyester, At least one kind selected from the group consisting of polyester, polyamide, polyolefin, polyethylene and polystyrene is formed into a nonwoven fabric by carpet layer which is back coated with at least one kind selected from the group consisting of ethylene vinyl acetate, styrene butadiene rubber, natural latex and polyethylene A nonwoven fabric layer, and a porous elastic layer made of polyurethane,

Wherein the nonwoven fabric layer is produced by using modified cross-section fibers.

In addition, the present invention provides a floor carpet for an automobile having improved sound absorption performance, wherein the modified section fibers have a hexagonal cross-sectional shape.

In addition, the present invention provides a floor carpet for an automobile having improved sound absorption performance, wherein the nonwoven fabric layer has a thickness of 0.5 to 20 mm, a surface density of 200 to 1,500 g / m 2, and a sound absorption coefficient of 0.3 to 0.8 do.

According to the present invention, a floor carpet for automobiles is manufactured by laminating a nonwoven fabric layer and a porous elastic layer having different sound absorption ratios and air permeability, and the fibers of the modified section yarns (hollow fiber hollow fibers) are used for the nonwoven fabric layer, It is possible to reduce the fuel consumption of the vehicle.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a cross-sectional view of a cross-
Fig. 2 is a graph showing a sound absorption rate of a sectioned cross-section fiber used in the present invention through a result of measurement of a sound absorption rate by the simple reverberation method; Fig.

Hereinafter, the present invention will be described.

According to a preferred embodiment of the present invention, a nonwoven fabric layer having a sound absorbing function and a shape-retaining function as a backing material in a carpet floor car for an automobile having improved sound absorption performance comprising a carpet layer, an adhesive layer, a nonwoven fabric layer and a porous elastic layer, And a porous elastic layer, and the nonwoven fabric layer is characterized in that the nonwoven fabric layer includes microfine fibers of a deformed cross-section yarn (hollow helix).

The fiber used in the nonwoven fabric layer of the present invention is not a circular cross-section yarn used in the prior art but is a heterogeneous cross-section yarn fiber having a hexaflower shape. The hexagonal shaped cross section yarns have a surface area that is 3 to 6 times wider than that of the general circular cross section fibers, thereby improving the sound absorption performance by 5% or more compared to the conventional circular cross section yarns. To provide a floor carpet.

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 physical phenomenon, the hexagonal cross-section fiber used in the present invention has an advantage that the surface of the fiber where the viscous loss of the sound wave occurs is relatively maximized, unlike the ordinary fiber, The sound absorption and sound insulation performance can be improved.

In the automotive floor carpet of the present invention using the hexagonal cross-section fiber with the large surface area as described above, sound absorption performance equal to or higher than that of the conventional automotive floor carpet is exhibited, And it is also advantageous to provide a higher sound absorption performance even in comparison with a general circular cross-sectional fiber sound absorbing material having the same area density.

In addition, the hexagonal cross-section fiber of the hexaflower type can be manufactured by conventional polymer melt spinning only by replacing the spinneret nozzle, so that the economical aspect can be kept at the same level as that of the conventional sound absorbing material.

According to a preferred embodiment of the present invention, a yarn made of one selected from the group consisting of polyester, nylon, polypropylene, acrylic, cotton, hemp, wool is tufted on a nonwoven fabric preform made of polypropylene or polyester, A yarn made of one selected from the group consisting of polyester, nylon, polypropylene, acrylic, cotton, hemp and wool is bonded by needling and the bottom surface is made of ethylene vinyl acetate, styrene butadiene rubber, natural latex, A carpet layer backcoated with at least one selected from among all known plastics or rubbers including those known in the art; A nonwoven fabric comprising at least one selected from the group consisting of polyester, polyamide, polyolefin, polyethylene and polystyrene formed from nonwoven fabric; And a porous elastic layer made of polyurethane. The nonwoven fabric layer is characterized in that the microfine fibers of the sectioned cross-section yarns (44 heavier hollow fibers) having a monofilament fineness of 4 to 6 denier are contained in an amount of 30 to 100% by weight based on the total weight of the nonwoven fabric A floor carpet for an automobile having improved sound absorption performance is provided.

According to another preferred embodiment of the present invention, at least one of a carpet layer, a heterogeneous cross-section fiber (hexahedral hollow) nonwoven fabric layer in the form of a hexaflower and an adhesive layer for bonding the porous elastic layer is formed by heating a thermoplastic resin having an irregular network structure And is formed by melting.

According to another preferred embodiment of the present invention, at least one of the adhesive layers for bonding the carpet layer, the first nonwoven fabric layer and the second nonwoven fabric layer is formed by pulverizing a mixture of the thermoplastic resin and the inorganic filler into a powder form, Wherein the amount of the inorganic filler in the mixture of the thermoplastic resin and the inorganic filler is 50 to 60 wt% of the weight of the thermoplastic resin, %.

According to another preferred embodiment of the present invention, the nonwoven fabric layer has a thickness of 0.5 to 20 mm, a surface density of 200 to 1,500 g / m 2, a coefficient of relaxation of 0.3 to 0.8, a hexaflower- And the porous elastic layer has a thickness of 1 to 50 mm and an air permeability of 3 to 70 (cm 3 / cm 2 / sec).

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

1 is a cross-sectional view of an automotive floor carpet 1 with improved sound absorption performance according to an embodiment of the present invention.

1, a floor carpet for an automobile having improved sound absorption performance according to the present invention includes a carpet layer 11, two adhesive layers 12, and a sound absorbing layer of a double-layered structure, i.e., a hexagonal cross- ) Nonwoven fabric layer 13 and a porous elastic layer 14.

According to the present invention, a carpet including a sound absorbing layer of a double structure composed of a nonwoven fabric material and a porous elastic layer using a hexaflower-shaped heterogeneous cross-section fiber having a sound absorption function (helium hollow) A floor carpet for a vehicle having improved sound absorption performance capable of effectively absorbing incoming noise.

In the floor carpet according to the present invention, the carpet layer 11 is not particularly limited, and a generally known carpet fabric can be used.

Synthetic fibers such as polyester fibers, nylon fibers, polypropylene fibers, and acrylic fibers, or natural fibers such as hemp, cotton, and wool, etc. in the base fabric made of polypropylene, polyester, polyester / , Or various fibers or yarns may be bound mechanically by a needling process or bound by an adhesive or the like. The bottom surface of the carpet layer may be back coated at a weight of 50 to 4250 g / m 2 using ethylene vinyl acetate (EVA), styrene butadiene rubber (SBR), natural latex, polyethylene, or a mixture thereof, if necessary.

According to an embodiment of the present invention, the primary coating layer is back coated at a weight of 100 to 800 g / m 2 of polyethylene (PE), then 700 to 4250 g / m 2 of ethylene vinyl acetate (EVA) and 50 to 200 g / A second coating layer composed of 40% of a mixture and 60% of an inorganic material may be back coated.

The hexagonal cross-section fiber (helium hollow) non-woven fabric layer 13 in the form of a hexaflower not only serves as a backing material for the shape retaining function of a carpet for a vehicle but also exhibits an effect of improving the sound absorption performance incidentally. The thickness is 0.5 to 20 mm, Nonwoven fabric having a weight of ~ 1,500 g / m 2 is suitable. If the area density is less than 200 g / m 2, the effect of contributing to the shape keeping ability and the sound absorption performance is low. If the area density exceeds 1,500 g / m 2, the excessive weight of the vehicle parts is problematic, the surface becomes too hard, and the sound absorption performance is also lowered.

The nonwoven fabric layer 13 in the form of a hexaflower in the form of a hexagonal cross section fiber is made of a nonwoven fabric made of a material such as polyester, polyamide, polyolefin, polyethylene, polystyrene or the like singly or in combination. A needle punch, a spun lace, a spun bond, or other known methods may be used.

The fibers constituting the non-woven fabric layer of the hexaflower type heterogeneous cross-section fiber (mesophile) may use one fineness fiber, and more preferably, the ultrafine fibers having a denier of 4 to 6 are used in an amount of 30 to 100 %. In this case, since the fibers of the common fineness and the microfine fibers are mixed, it is advantageous for the function as the backing material and the sound absorption performance. When the fineness of the fibers constituting the nonwoven fabric is less than 4 deniers, low frequency noises are hardly absorbed and the cushioning property is also undesirable. On the other hand, if it exceeds 6 denier, noise of high frequency is difficult to be absorbed. The fibers having 4 to 6 denier may be polyester / polyamide split microfiber, polyester direct microfiber spun-bonded microfiber, etc. These microfiber fibers can be used in the automobile room for noise in the range of 500 Hz to 2,000 Hz Sound absorption performance is high.

The air permeability of the non-woven fabric layer 13 of hexagonal cross-section fiber (hexahedral hollow) thus produced is 3 to 70 (cm3 / cm2 / sec) and the coefficient of absorption, which is a numerical value showing sound absorption performance, is 0.3 to 0.8 .

The porous elastic layer 14 comprises a sponge layer made of synthetic rubber or polyurethane or a foamed foam cushion layer having a thickness of 1 to 50 mm and an air permeability of 3 to 70 cm3 / sec. The porous elastic layer has a function of providing a slip prevention function with a material in contact with the sound absorbing carpet, and additionally dispersing and absorbing noises.

The adhesive layer 12 is composed of a carpet layer 11, a heterogeneous cross-section fiber (helium hollow) nonwoven fabric layer 13 in the form of a hexaflower and a heterogeneous cross-section fiber (helium hollow) nonwoven fabric layer 13 in the form of hexaflower ) And the porous elastic layer 14, and may be formed in various ways. General industrial adhesives can be used, or one type of thermoplastic resin selected from the group consisting of low melting point polyester, polyethylene, ethylene vinyl acetate, polypropylene and polyvinyl chloride can be laminated while being laminated in a molten state. Alternatively, the thermoplastic resin may be applied in the form of a powder or a pellet, and the two layers may be laminated while being heated and melted, followed by passing through a compression roller.

Since the porous inorganic filler has irregular surface and many fine protrusions, it functions as a kind of reinforcing material and improves the surface adhesion between the materials. If a gap is formed between the resin and the inorganic filler, the improvement of the air permeability of the adhesive can be expected. Further, by using an inorganic filler such as mica having a plate-like crystal structure, there is an additional advantage that it can reinforce the lowering of sound insulation performance due to the absence of the sound insulating coating layer.

Another method of constructing the adhesive layer is to make the thermoplastic resin into the form of a thin nonwoven fabric or porous hotmelt film having an irregular network structure to form the carpet layer 11 and the nonwoven fabric layer 13 and between the nonwoven fabric layer 13 and the porous elastic layer 14 The two layers may be joined together by passing through a compression roller after laminating the two layers in a state of being heated and melted.

The adhesive layer of the irregular network structure can additionally absorb the noise in the frequency region that is not absorbed while passing through the nonwoven fabric layer, and the adhesive layer itself has breathability, so that the sound absorbing performance of the entire floor carpet is not hindered.

Either one of the two adhesive layers may be formed in a network structure, and the remaining adhesive layer may be formed by applying a thermosetting resin in the form of powder or pellets, or both adhesive layers may be formed in a network structure. When the adhesive layers having different structures are formed, the frequency range of the noise that can be absorbed due to the different structure is different and the noise is dispersed because of the advantage that the air permeability is ensured and the sound absorption performance is further improved.

Hexaflower type nonwoven fabric layer (hollow fiber hollow fiber) nonwoven fabric layer and porous elastic layer including microfiber fibers have different air permeability and sound absorption ratio, and additionally, by the structure of two adhesive layers, noise inside the vehicle and external noise Sound absorption is effective.

The automotive floor carpet with improved sound absorption performance of the present invention has excellent sound absorption performance as described above, and thus can be used as a floor carpet for automobiles.

Hereinafter, the present invention will be described concretely with reference to Examples. However, the following Examples and Experimental Examples are merely illustrative of one form of the present invention, and the scope of the present invention is not limited by the following Examples and Experimental Examples .

Example  One

The fabric was dyed and dyed in a flush file form so that 1300 den / 68fila nylon BCF yarn was pile height 9 mm and pile fiber per unit area was 610 g / m 2 in a polyester spun nonwoven fabric base paper having a surface density of 120 g / The first coating layer was back coated with polyethylene (PE) at a weight of 400 g / m < 2 >, followed by 40% of a mixture of ethylene vinyl acetate (EVA) weight of 80 g / The tea coating layer was back coated.

The nonwoven fabric layer was prepared by using 50% by weight of direct-spun polyester cross-section microfine fibers having a single yarn fineness of 4 denier and using 50% of polyester cross-section fibers having a single yarn fineness of 6 denier with a needle having a thickness of 2.5 mm and a surface density of 400 g / Punch nonwoven fabric was used. Here, hexaflower-shaped polyester fibers were prepared by melt spinning using spinnerets in hexaflower form as the modified cross-section fibers.

The porous elastic layer of the urethane material attached to the nonwoven fabric layer had a thickness of 1.5 mm, a surface density of 50 g / m 2, and an air permeability of 60 cm 3 / cm 2 / sec. The bonding of the nonwoven fabric layer and the porous elastic layer was carried out by spreading polyethylene powder at a density of 60 g / m 2 on the nonwoven fabric layer, heating the resultant by heating at 150 캜 with hot air, melting the porous elastic layer, The adhesion of the double layered backing layer thus attached to the carpet was evaluated by spreading 150 g / m 2 of polyethylene powder on the top of the nonwoven fabric layer, melting it by heating at 150 캜 with hot air, Respectively.

Example  2

A needle punch nonwoven fabric having a thickness of 2.5 mm and a surface density of 600 g / m 2 was used in the same manner as in Example 1.

Comparative Example  One

A needle punch nonwoven fabric having a thickness of 2.5 mm and a surface density of 600 g / m 2 was used with circular cross-section polyester fibers, and the same procedure as in Example 1 was conducted.

Experimental Example

The physical properties of floor carpets for automobiles manufactured in Examples 1 and 2 and Comparative Example 1 were evaluated by the following methods, and the results are shown in Table 1 below.

≪ Evaluation of air permeability &

The air permeability of the carpet was measured by the method of JIS L1096-1999 (Method A, 8.27.1). The unit is expressed in cm 3 / cm 2 / sec, which means the amount of air (cm 3) permeating a 1 cm 2 unit area per second. Therefore, the larger the value, the better the air permeability.

≪ Evaluation of sound absorption rate &

Ei is the energy of sound incident on the surface of the sound absorbing material, and Er is the energy of the sound reflected from the surface. The absorption coefficient (α) is defined as follows.

? = 1- (Er / Ei)

The sound absorption rate was measured by the reverberation method measured in the reverberation room which realizes conditions close to random incidence according to ISO 354 standard. NRC (Noise Reduction Coefficient) is a characteristic value of the absorption coefficient value at 500 ~ 2000Hz, which is the frequency range of the air transmission noise to the automobile room. The higher the value at the center frequency 500, 1000, 2000Hz, Do.

Breathability
(Cm3 /
Cm2 / sec) Coefficient of sensitivity
(500 Hz) Coefficient of sensitivity
(1000 Hz) Coefficient of sensitivity
(2000 Hz) Example 1 (area density: 400 g / m 2, 30 0.23 0.23 0.34 Example 2 (surface density: 600 g / m 2, 30 0.21 0.25 0.38 Comparative Example 1 (area density: 600 g / m 2, circular cross section yarn) 29 0.20 0.22 0.33

As can be seen from the above Table 1, the floor carpets for automobiles (Examples 1 and 2) manufactured using the nonwoven fabric using the hexagonal cross-section fiber in accordance with the present invention were obtained by using the nonwoven fabric using the circular cross- It was found that the sound absorbing performance was remarkably improved as compared with the manufactured floor carpet for automobile (Comparative Example 1). Particularly, the area density of carpets manufactured by using a circular cross section and 600g / ㎡ nonwoven fabric and carpets manufactured by using a hexagonal cross section are used. Sound absorption of carpet made using 400g / ㎡ nonwoven fabric It is possible to reduce the product weight because the performance is almost equal or superior.

11: carpet layer 12: two adhesive layers
13: A sound absorbing layer of a double-layered structure, i.e., hexaflower-shaped non-woven fabric layer
14: Porous elastic layer

Claims (3)

In an automobile sound absorbing carpet,
A yarn made of one selected from the group consisting of polyester, nylon, polypropylene, acrylic, cotton, hemp and wool is tufted or bonded by needling on a nonwoven fabric base made of polypropylene or polyester, A carpet layer backcoated with at least one selected from plastics or rubber;
A nonwoven fabric comprising at least one selected from the group consisting of polyester, polyamide, polyolefin, polyethylene and polystyrene formed from nonwoven fabric; And
A porous elastic layer made of polyurethane; Lt; / RTI >
Wherein the nonwoven fabric layer is produced by using a cross-section fiber.
The method according to claim 1,
Wherein the modified cross-section fiber has an unshaped cross-sectional shape of a hexaflower shape.
The method according to claim 1,
Wherein the nonwoven fabric layer has a thickness of 0.5 to 20 mm, a surface density of 200 to 1,500 g / m 2, and a coefficient of sounding of 0.3 to 0.8.

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