KR101894725B1 - Heat-resistant Nonwoven Fabric Sheet - Google Patents

Abstract

The present invention relates to a high heat-resistant nonwoven fabric sheet comprising an outer layer formed through a wet process (Wet-laid) containing polyphenyl sulfide (PPS) undrawn filaments and an inner layer formed by needle punching a polyphenyl sulfide (PPS) Heat-resistant nonwoven fabric sheet laminated and then formed by molding.

Description

[0001] Heat-resistant Nonwoven Fabric Sheet [0002]

TECHNICAL FIELD The present invention relates to a high heat-resistance nonwoven fabric sheet, and more particularly, to a high heat-resistance nonwoven fabric sheet composed of a nonwoven fabric partially formed of polyphenylsulfide (PPS) undrawn fibers in a wet process.

When driving a car, there are various noises. Automobile noise is mainly transmitted from the engine to the interior of the automobile through air and noise generated from the exhaust system.

The engine of an automobile is an internal combustion engine that generates power by burning fuel. The exhaust gas discharged from each combustion chamber is discharged to the outside of the vehicle through the exhaust system and the silencer at a high temperature of about 800 ° C to 1000 ° C. The temperature in the tunnel front of the car body is usually raised to 400 ° C.

In order to reduce the noise transmitted from the engine and the exhaust system to the room, a sound absorbing material for automobiles is used. A vehicle insulation dash, a dash isolation pad and the like are used to block the engine radiation noise from entering the room. A tunnel pad, a floor carpet, And to prevent noise from the floor from entering the room.

Korean Patent Laid-Open Publication No. 2004-0013840 discloses a technique for inserting a synthetic resin film layer having a thickness of 40 to 100 占 퐉 in the longitudinal direction at an intermediate position of a PET fiber fiber layer as a sound absorbing material having a thickness of 20 mm Korean Patent Laid-Open Publication No. 2002-0089277 discloses a method in which a polyester fiber and an acrylic fiber are cut and then mixed with a low-melting-point polyester fiber at a certain ratio, and then molded and heated to produce a nonwoven fabric- And the like. Korean Patent Laid-Open Publication No. 2006-0043576 discloses a method in which at least one layer of an upper layer and a lower layer is made of resin by using polyester (PET) felt in which low melting point fibers (LMF) and regular fibers are mixed Coating technique.

To date, the sound absorbing materials for automobiles have to be increased in weight in order to reduce the engine radiation noise and the emission noise of the exhaust system. In order to overcome these limitations, it is most effective to apply a sound absorbing material to a portion nearest to the noise source of the engine and the exhaust system. In order to apply the noise absorbing material to a portion closest to the noise source of the engine and the exhaust system, It is impossible to use the material that is used as a sound absorbing material for automobiles until now.

An object of the present invention is to provide a high heat-resistant nonwoven fabric sheet composed of a polyphenylene sulfide (PPS) nonwoven fabric by a wet process in order to effectively prevent the noise generated from the road surface and the exhaust system from being transmitted to the interior of the vehicle.

It is another object of the present invention to provide a high heat-resistant nonwoven fabric sheet comprising a polyphenylene sulfide (PPS) nonwoven fabric formed by a dry process in order to improve durability.

It is another object of the present invention to provide a high heat-resistance nonwoven fabric sheet that adds a flame retarding function to a dry nonwoven fabric through a flame retardant impregnation process.

In order to solve the above problems, the present invention provides a high heat-resistance non-woven fabric sheet comprising an outer layer formed by a wet process (Wet-laid) containing polyphenyl sulfide (PPS) undrawn filament fibers and a polyphenyl sulfide Heat-resistant nonwoven fabric sheet in which fibers are laminated by an inner layer formed through a needle punching process and then formed by molding.

Further, the present invention provides a high heat-resistant nonwoven fabric sheet characterized in that the outer layer has a thickness of 0.5 to 5 mm and the inner layer has a thickness of 1 to 10 mm, and the weight of the laminated high heat-resistant nonwoven fabric is 200 to 1000 gsm.

Also, the polyphenylene sulfide (PPS) unstretched fiber of the outer layer has a fiber length of 3 to 12 mm, a fineness of 1 to 2 denier and 20 to 80% of fineness, a fineness of 2 to 5 De and a fineness of 100 to 300% Heat-resistant nonwoven fabric sheet characterized in that the fibers are mixed at a weight ratio of 2: 8 to 8: 2.

Further, the present invention provides a high heat-resistant nonwoven fabric sheet characterized in that the polyphenyl sulfide (PPS) staple fiber of the inner layer has a fiber length of 22 to 76 mm, a fineness of 2 to 5 De and an elongation of 20 to 100%.

In another aspect, the present invention the molding is laminated an outer layer, and put the inner non-woven fabric in the mold and which is characterized in that press molding in the pre-heated state of 200 ~ 240 ℃ in the 100 ~ 200 kgf / cm ² pressure for heat-resistant non-woven fabric sheet to provide.

The present invention solves the above-mentioned problems by providing a polyphenylene sulfide (PPS) nonwoven fabric by a wet process as an outer layer of a high heat-resistant nonwoven fabric, and preventing the noise generated in the road surface and the exhaust system from being transmitted to the interior of the vehicle.

In addition, the present invention can improve the durability of the polyphenylene sulfide (PPS) nonwoven fabric by the dry process in the case of using a polyphenylene sulfide (PPS) nonwoven fabric alone by wet process through a laminate as a constitution of a high heat- There are features.

Further, the present invention is characterized by adding a flame retarding function through a process of impregnating a dry nonwoven fabric with a flame retardant.

1 is a schematic sectional view of a high heat-resistance nonwoven fabric sheet according to a preferred embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted so as to avoid obscuring the subject matter of the present invention.

As used herein, the terms " about, " " substantially, " " etc. ", when used to refer to a manufacturing or material tolerance inherent in the stated sense, Accurate or absolute numbers are used to help prevent unauthorized exploitation by unauthorized intruders of the referenced disclosure.

The present invention relates to a high heat-resistant nonwoven fabric sheet, which comprises an outer layer (100) formed through a wet process (Wet-laid) containing a part of polyphenyl sulfide (PPS) undrawn filaments and a polyphenyl sulfide Resistant nonwoven fabric sheet laminated with an inner layer (200) formed through a needle punching process and then formed by molding.

1 is a schematic sectional view of a high heat-resistance nonwoven fabric sheet according to a preferred embodiment of the present invention. The outer layer 100 nonwoven fabric and the inner layer 200 nonwoven fabric are laminated together. The nonwoven fabric layer is generally flat. However, when the high heat-resistance nonwoven fabric sheet is attached to the curved surface of an automobile part, it may have a curved shape as shown in FIG.

The outer layer 100 has a thickness of 0.5 to 5 mm, the inner layer 200 has a thickness of 1 to 10 mm, and the weight of the laminated high heat-resistant nonwoven fabric sheet is 200 to 1000 gsm.

In order to satisfy the thicknesses of the outer layer 100 and the inner layer 200 and the above conditions of the laminated high heat-resistant nonwoven fabric sheet, the outer layer and the inner layer may be formed of a plurality of nonwoven fabrics.

In the case of nonwoven fabrics made of unstretched fibers having a low degree of crystallinity at the initial stage of the melt extrusion produced by extruding the melt and having a non-oriented or low-oriented state, the surface rigidity generally increases. However, There is a problem of falling, so that it is laminated with the inner layer 200 which has undergone a dry process such as needle punching.

The polyphenyl sulfide (PPS) staple fiber of the outer layer 100 has a filament length of 3 to 12 mm and a filament length of 1 to 2 D and an elongation of 20 to 80% and a filament of 2 to 5 De and a filament of 100 to 300% Short fibers are mixed in a weight ratio of 2: 8 to 8: 2. By using two kinds of unstretched yarns different in fineness, adjacent spaces can be efficiently used, and the spatial adhesion between fibers can be improved after molding. Also, the relationship between the elongation and the isothermal ratio is proportional to the use of the non-drawn elongated composition of the same composition.

The outer layer 100 is made by a conventional wet process (Wet-laid). The two types of unstretched fibers are dispersed in a water tank at a weight ratio of 20:80 to 80:20, preferably 50:50.

After the dispersing process, the suspension is formed into a wide and uniform web shape, followed by dehydration and drying, and finally, the nonwoven fabric of the outer layer (100). In this process, a laminating process, a calendering process, and an additive coating process may be added to adjust smoothness, pore and thickness, and the present invention does not limit the present invention.

The polyphenyl sulfide (PPS) staple fiber of the inner layer 200 is characterized by having a fiber length of 22 to 76 mm, a fineness of 2 to 5 De and an elongation of 20 to 100%.

The inner layer 200 and the outer layer 100 are formed into a structure in which the inner layer and the outer layer are formed into a multi-layered structure after the nonwoven fabric is manufactured. The laminating process is a press-bonding method in which the laminated inner and outer layers are passed through a heated upper and lower rolls and subjected to heat and pressure, and a plurality of inner and outer layer nonwoven fabrics can be laminated and pressed in accordance with a desired weight.

The PPS resin is partially crystalline and has a glass transition temperature (Tg) of 90 ° C and a melting point (Mp) of about 280 ° C.

Therefore, when the laminated body subjected to the lapping process by the molding process is finally press-molded at a high pressure of 100 to 200 kgf / cm ² in the preheated state at 200 to 240 ° C, the unstretched PPS staple fibers are partially melted and the adjacent The fibers can be fused to each other. Under such a high pressure, the melting point can be lowered to further facilitate fusion, and a close-coupled multi-layer board structure in which the fibers are closely contacted with each other at the time of fusion is completed.

That is, the surface is hardened in the molding process and the pores are reduced to a minimum to form a high-density structure. In addition to the function of increasing the rigidity, the pore size is small and the structure adjacent to the adjacent pores functions to increase the sound absorption rate. The detailed process conditions of the lapping and shaping process are not limited in the present invention. As a result, it is possible to provide a high heat-resistant nonwoven fabric having a sound absorbing function.

In the present invention, the inner layer 200 is characterized by using a nonwoven fabric manufactured by needle punching, wherein 100 parts by weight of the nonwoven fabric is impregnated with 10 to 90 parts by weight of a thermosetting binder.

The inner layer 200 is prepared by impregnating the inorganic fiber nonwoven fabric with a thermosetting binder to form a fibrous web by carding PPS staple fibers. The 100 parts by weight of the nonwoven fabric prepared by needle punching is coated with a thermosetting binder in an amount of 10 to 90 wt% And then impregnated into the part.

The thermosetting binder is composed of at least one selected from the group consisting of a phenol resin or an epoxy mixture, and binds the PPS undoped sheet of the inner layer 200, and at a temperature of 200 ° C, the shape of the heat- It is the role that keeps.

Generally, phenol resin is also called as the only plastic which is safe for flame because it generates little smoke or harmful gas when it is burned. Even if it is placed at a high temperature, it is softened and its strength is not lowered. Because it shows the carbonation rate, it is stronger and less deteriorated than other plastics.

In addition, compared with metals, they are also excellent in light weight, rust prevention, corrosion resistance, etc., and are required to have thermal properties such as interior and exterior materials for architectural use, mine use, and vehicle materials, which are not compatible with conventional glass-reinforced plastics such as polyester or epoxy The application of the field is expected.

The phenol resin preferably comprises at least one selected from the group consisting of resole and novolak. The epoxy mixture comprises 100 parts by weight of an epoxy resin, 1 to 20 parts by weight of a curing agent, 1 to 10 parts by weight of a catalyst and 5 parts by weight of an organic solvent 5 To 70 parts by weight.

The epoxy resin may be selected from the group consisting of bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, polyoxypropylene diglycidyl ether, At least one selected from the group consisting of phosphazene diglycidyl ether, phenol novolacepoxy, o-cresol novolac epoxy and bisphenol A novolacepoxy. .

The organic solvent may be at least one selected from the group consisting of methyl ethyl ketone (MEK) and dimethyl carbonate (DMC). The epoxy mixture may be evenly dispersed in the inorganic fibers so that the epoxy mixture can penetrate at a constant concentration. .

The thermosetting binder may further contain 10 to 40 parts by weight of a flame retardant per 100 parts by weight of the thermosetting binder. The component of the flame retardant is not particularly limited, and any component capable of imparting flame retardancy to the thermosetting binder may be used One, it is preferable to use melamincyanurate.

Hereinafter, the high heat-resistance nonwoven fabric according to the present invention will be described in detail with reference to Examples and Comparative Examples. However, the following examples and comparative examples are only illustrative examples for explaining the present invention in more detail, and the present invention is not limited by the following examples and comparative examples. The methods for measuring the physical properties of the high heat-resistant nonwoven fabric used in the following Examples and Comparative Examples are as follows.

≪ Measurement of tensile strength &

Measured according to the method specified in ASTM D638.

The size of the specimen is Type-I and the test speed is 5 mm / min.

<Measurement of Flexural Strength and Flexural Modulus>

ASTM D790. &Lt; / RTI &gt;

Test specimen size is 50mm x 150mm, SPAN length is 100mm and SPAN and test specimen are in the center. At this time, the test speed is 5 mm / min, and the compressive load is applied to the outer layer (100) of the test piece.

<Absorption rate>

To measure the sound absorption rate, three specimens were prepared for each test piece applicable to ISO R 354 and Alpha Cabin method. The absorptivity was measured after leaving at 0 ° C and 25 ° C for 30 minutes, and the average values of the measured absorption coefficients are shown in the table.

Example 1

50% by weight of polyphenylene sulfide short fibers having a fineness of 1De, a fiber length of 6 mm and an elongation of 35%, and 50% by weight of polyphenylene sulfide unstretched short fibers having a fineness of 3e, a fiber length of 6mm and an elongation of 200% ), And laminated with a surface density of 300 gsm to prepare an outer layer 100,

The web was formed through a carding process using a filament of 2De, a fiber length of 51 mm and an elongation of 100%, and the web was bonded by a needle punching method to a web of 220 gsm in a density. Then, the web was impregnated with the binder using a flame retardant resol type phenol resin, The resin is dehydrated so that 180 gsm is left, and the final inner layer (200) of 400 gsm is produced. Thereafter, the outer layer 100 and the inner layer 200 were laminated to form a composite layer. The composite layer was put into a mold and thermoformed at a pressure of 120 kgf / cm ² at a temperature of 210 ° C for 150 seconds to prepare a sheet.

Example 2

50% by weight of polyphenylene sulfide short fibers having a fineness of 2.5De, a fiber length of 6 mm and an elongation of 35% and 50% by weight of polyphenylene sulfide unstretched short fibers having a fineness of 5De, a fiber length of 6 mm and an elongation of 200% laid to form a nonwoven fabric and laminated at a surface density of 300 gsm to form an outer layer 100,

Comparative Example 1

The polyphenylene sulfide fibers having a fineness of 2De, a fiber length of 51 mm and an elongation of less than 35% were bound by a carding process and a needle punching process to a nonwoven fabric at a surface area of 400 gsm and then a nonwoven fabric was impregnated with a flame- 300gsm, so that the final 700gm nonwoven fabric is formed. Thereafter, the sheet was put into a mold and thermoformed at a pressure of 120 kgf / cm &lt; ² &gt; for 150 seconds at a temperature of 210 DEG C to prepare a nonwoven fabric sheet.

Comparative Example 2

50 wt% of polyphenylene sulfide fibers having a fineness of 1De, a fiber length of 6 mm and an elongation of 35% and 50 wt% of polyphenylene sulfide fibers having a fineness of 3e, a fiber length of 6 mm and an elongation of 200% And laminated at a surface density of 700 g / m &lt; ^{2 &} gt ;. The sheet was put into a mold and thermoformed at a pressure of 120 kgf / cm &lt; ² &gt;

Comparative Example 3

A 700 gsm glass wool material with 1 mm of aluminum laminated on the surface of the existing one was made of a sound absorbing material sheet for automobiles.

Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 The tensile strength
(MPa) 168 164 140 87 145 Flexural strength
(N) 17 18 14 12 15 Flexural modulus
(MPa) 723 704 619 581 632

Suction
Well
Rate 1000
Hz 0.42 0.39 0.35 0.40 0.26 2000
Hz 0.73 0.74 0.68 0.71 0.24 3150
Hz 0.82 0.78 0.75 0.77 0.32 5000
Hz 0.95 0.95 0.92 0.91 0.65

As can be seen from Table 1, the first and second embodiments of the present invention are characterized in that an outer layer 100 is formed by a wet process (Wet-laid), an inner layer 200 is formed by a needle funnel layer, The strength and other properties such as strength and sound absorption ratio are superior to those of the comparative example.

On the contrary, in Comparative Example 1, the nonwoven fabric sheet formed only of the nonwoven fabric formed by needle punching had lower tensile strength, flexural strength, and the like, and the function was lowered even at some scratches. In the comparative example 2, only a wet process (wet-laid) nonwoven fabric layer is formed so that the sound absorbing effect is equivalent to that of the example 1. However, since the inner layer 200 is not lapped, the nonwoven fabric sheet formed only by the wet process may become a problem in durability . In Comparative Example 3, a conventional automobile sound absorbing material sheet is composed of a glass fiber material laminated with aluminum. Due to the glass fiber nature, tensile strength and the like are similar to those of the embodiment, but the sound absorption rate is much lower.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the inventions. It will be clear to those who have knowledge of.

100: outer layer 200: inner layer

Claims (5)

In the high heat-resistant nonwoven fabric sheet,
An outer layer formed by a wet process (Wet-laid) containing polyphenyl sulfide (PPS) unstretched staple fibers and an inner layer formed by a needle punching process of polyphenyl sulfide (PPS) ,
Wherein the inner layer is formed by impregnating 100 parts by weight of the nonwoven fabric with 10 to 90 parts by weight of the thermosetting binder, and the thermosetting binder is composed of at least one of a phenol resin and an epoxy mixture.
The method according to claim 1,
Wherein the outer layer has a thickness of 0.5 to 5 mm and the inner layer has a thickness of 1 to 10 mm and the weight of the laminated high heat-resistant nonwoven fabric is 200 to 1000 gsm.
The method according to claim 1,
The polyphenyl sulfide (PPS) staple fiber of the outer layer has a fiber length of 3 to 12 mm and a nonwoven fabric having a fineness of 1 to 2De and an elongation of 20 to 80%, a nonwoven fabric having a fineness of 2 to 5 De and an elongation of 100 to 300% 8 to 8: 2 by weight.
The method according to claim 1,
Wherein the polyphenyl sulfide (PPS) staple fiber of the inner layer has a fiber length of 22 to 76 mm, a fineness of 2 to 5 De and an elongation of 20 to 100%.
The method according to claim 1,
Characterized in that the laminated outer layer and inner layer nonwoven fabric are put into a mold and subjected to press molding at a pressure of 100 to 200 kgf / cm ² in a preheated state at 200 to 240 ° C.

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