JP2010089706A - Heat insulating and sound absorbing material for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sound and heat insulating material for a vehicle reducing noises or load noises that occur from a power source of a railroad vehicle or an automobile, and insulating heat of the power source or the outside. <P>SOLUTION: At least on one side of a fiber layer formed by cotton-blending fibers containing at least ≥20 wt.% of a flameproof fiber and ≥30 wt.% of a heat adhesive fiber, a water glass solution is sprayed so as to permeate in the range of at least 10% from a surface relative to the thickness of the fiber layer, and then, dried, thereby forming this heat insulating and sound absorbing material. Moreover, the bulk density of the fiber layer is set to be not more than 10 kg/m<SP>3</SP>. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a heat insulating sound-absorbing material for vehicles used in railway vehicles, automobiles, and the like.

  Various heat insulating and sound absorbing materials are used in railway vehicles, automobiles, and the like for the purpose of reducing noise generated from a power source and road noise, and cutting off heat from the power source or outside. For example, a nonwoven fabric mat mainly composed of thermoplastic organic fibers such as polyester fibers is used as the core material, a nonwoven fabric mat composed of flame-resistant acrylic fibers is used as the surface layer material, and the surface layer material is needle punched on one or both sides of the core material. A vehicle sound insulation material and its surface layer material that are joined by processing are disclosed (for example, see Patent Document 1).

Further, there is disclosed a heat insulating sound absorbing material in which inorganic fibers having a fiber diameter of 7 μm or less and a fibrous binder resin are defibrated and laminated by heating after glass fiber layers are laminated on the upper and lower surfaces of the fiber layer departed simultaneously with mixing. (For example, refer to Patent Document 2).
Japanese Patent Laid-Open No. 2005-246952 JP-A-5-318639

  The vehicle soundproofing heat insulating material shown in Patent Document 1 uses a nonwoven fabric mat mainly composed of thermoplastic organic fibers such as polyester fibers as a core material, and a nonwoven fabric mat composed of flame-resistant acrylic fibers as a surface material. However, even if the surface layer material is made of only flame retardant fibers or a mixture of flame retardant fibers and other fibers, sufficient heat insulation cannot be obtained unless the flame retardant fibers are used in an amount of 70% by weight or more. There is a problem that the material cost becomes high.

  Further, the heat insulating sound absorbing material shown in Patent Document 2 is heated and integrated after laminating glass fibers on the upper and lower surfaces of a fiber layer in which inorganic fibers having a fiber diameter of 7 μm or less and a fibrous binder resin are defibrated and departed simultaneously with mixing. It has become. However, since glass fiber is used, there is a drawback that the fiber breaks at the time of handling and adheres to the skin and clothes and tingles. Therefore, rock wool with phenol resin attached is used as the binder resin, but rock wool is weak and the fibers are weak, so that it can not express the prescribed strength when pressure molding such as hot press. In addition, due to the presence of particulates generated during the production of rock wool, there is a problem that heat insulation and sound absorption are poor as compared with glass fibers of equivalent weight.

The heat insulating sound absorbing material for vehicles of the present invention has at least one side of the fiber layer formed by blending fibers containing at least 20% by weight of flameproofing fiber and 30% by weight of heat-adhesive fiber. It is characterized in that it is formed by spraying a water glass solution so as to penetrate at least 10% from the surface to the thickness and then drying. Further, the bulk density of the fiber layer is 10 kg / m ³ or less.

  FIG. 1 is a front view of a heat insulating sound absorbing material for a vehicle according to the present invention. The heat insulating sound absorbing material for a vehicle 1 includes a fiber layer 2 and a water glass solution permeation layer 3 sprayed on one or both surfaces of the fiber layer 2. It is configured. As the flame-resistant fiber, a PAN (pan) -based oxidized fiber made from a synthetic acrylic long fiber, or a pitch-based carbon fiber made from coal tar or petroleum pitch can be used. For example, in the case of PAN-based oxidized fiber, when the raw material fiber is carefully heat-treated at 200 to 300 ° C. in the air, it becomes a flame-resistant fiber having a structure resistant to fire and heat.

  As the heat-adhesive fiber, a polyester-based heat-adhesive fiber is used. Thermal adhesive fibers made of polyester are excellent in weather resistance, mechanical properties, durability, and the like, and are used by being mixed with main fibers in a wide range of fields such as nonwoven fabrics, stuffed cotton, spun yarn, and fabrics. Polyester-based heat-bonding fibers are generally those having a core having a high melting point polyester and a sheath having a low melting point polyester, but in the present invention, the core has a normal polyester and a sheath. It is desirable to use a core-sheath composite heat-bonded short fiber made of low-melting copolymer polyester or polyethylene. Then, after mixing with the main high melting point short fibers to form a fiber assembly, heat treatment is performed at such a temperature that only the sheath part melts to bond the fibers together, giving the fiber assembly strength and rigidity. Mold into the desired shape.

After blending flameproof fiber, heat-adhesive fiber, and polyethylene terephthalate (PET) as the main fiber, a fiber layer is formed with a non-woven roller card and a cross layer. The bulk density of the fiber layer is 10 kg / m ³ or less. The heat insulating sound absorbing material for vehicles has a feature that it has a low density and has a high tensile strength in the thickness direction even though the fiber layers are laminated in the thickness direction. The bulk density of the heat insulating sound-absorbing material for vehicles is generally 5 to 20 kg / m ³ , but in the present invention, the bulk density is set to 10 kg / m ³ or less in order to particularly reduce the weight.

  The heat insulating sound-absorbing material for vehicles according to the present invention has a low bulk density and is therefore light in weight, and has a high resilience and cushioning resilience and a high tensile strength in the thickness direction. Easily adheres to a heat insulating part. Therefore, the workability at the site can be improved, high adhesion to the heat-insulated part can be maintained even when vibrations are applied from the outside, position displacement and bias can be prevented, and vibration durability is high. Moreover, since the said cotton-like fiber sheet is laminated | stacked in the thickness direction when a heat insulating material is arrange | positioned in a to-be-insulated part, each fiber sheet is extended in the direction orthogonal to a heat-transfer direction. Therefore, the heat shielding effect and heat insulation are high.

In the heat insulating sound absorbing material for vehicles of the present invention, a water glass solution is sprayed on one side or both sides of the fiber layer with a spray gun or the like so as to penetrate at least 10% from the surface with respect to the thickness of the fiber layer. ing. The component of the water glass is sodium silicate, and the amount is 50 g / m ² or more on one side even if the amount of water glass attached is small. Next, the fiber layer sprayed with water glass is characterized by air drying, hot air drying, high-frequency heat drying, or a combination thereof. Thereby, the heat shielding effect and heat insulation can be enhanced.

  The heat insulating sound-absorbing material for vehicles according to the present invention is characterized in that the fiber layer is formed by zigzag folding in the surface direction, and the fiber direction is oriented with a degree of orientation of 80% or more in the thickness direction. It is a heat insulation sound-absorbing material for vehicles. That is, as shown in FIG. 2, it has a shape that is folded zigzag in the surface direction, and since it is integrally molded as a whole, delamination does not occur. Further, the folding direction has compressibility in the surface direction, and therefore, even when the thickness of the heat insulating sound absorbing material is thicker than the thickness (space) of the installation place, it can be installed by compressing in that direction. Furthermore, since it shows excellent flexibility in the folded surface direction, even when the installation place is curved, it can be easily attached along this curve.

  The heat insulating sound-absorbing material for vehicles according to the present invention has a low bulk density and is therefore light in weight, and has a high resilience and cushioning resilience and a high tensile strength in the thickness direction. Easily adheres to a heat insulating part. Therefore, the workability at the site can be improved, high adhesion to the heat-insulated part can be maintained even when vibrations are applied from the outside, position displacement and bias can be prevented, and vibration durability is high. Further, when the heat insulating material is disposed in the heat-insulated part, the cotton-like fiber sheets are laminated in the thickness direction, and each fiber sheet extends in a direction perpendicular to the heat transfer direction, thereby shielding heat. High effect and heat insulation.

  The fiber layer is formed by zigzag folding in the surface direction, and the fiber direction is oriented in the thickness direction with an orientation degree of 80% or more. In the folding direction, there is compressibility in the surface direction. Therefore, even when the thickness of the heat insulating sound absorbing material is thicker than the thickness (space) of the installation place, it can be installed by compressing in that direction. Furthermore, since it shows excellent flexibility in the folded surface direction, even when the installation place is curved, it can be easily attached along this curve.

The heat insulating sound-absorbing material for vehicles of the present invention forms a fiber layer by blending at least 20% by weight of a flameproof fiber and 30% by weight or more of a heat-adhesive fiber. One side or both sides of the fiber layer is dried by spraying a water glass solution so as to penetrate at least 10% from the surface with respect to the thickness of the fiber layer. In order to deal with vehicle weight reduction, the fiber layer has a bulk density of 10 kg / m ³ or less. Further, in order to improve compression resistance and sound absorption, the fiber layer is formed in a zigzag manner in the plane direction, and the fiber direction is oriented with an orientation degree of 80% or more in the thickness direction. . The component of the water glass is sodium silicate, and the amount of water glass attached is at least 50 g / m ² on one side even if it is small. The drying is performed by air drying, hot air drying, high-frequency heat drying, or a combination thereof.

A fiber layer is formed by blending 20% by weight of flame-resistant fiber, 40% by weight of heat-bonding fiber, and 40% by weight of polyethylene terephthalate (PET) fiber, and the amount of water glass attached to this fiber layer is changed. As a result, the results shown in Table 1 were obtained. As a non-flammability criterion, the heat propagation coefficient is 25 or less, which is acceptable, but it has been found that this can be achieved by setting the water glass adhesion amount to 50 g / m ² or more. Although not shown, when the flameproof fiber is 0% by weight, the heat propagation coefficient is 300 and the nonflammability is rejected even when sprayed with water glass at 100 g / m ² . However, practically, the water glass adhesion amount is desirably 75 to 125 g / m ² .

FIG. 3 shows the result of a combustion test based on ASTM and E162 on eight test pieces. In FIG. 3, the adhesion amount of water glass is 100 g / m ^{2 on} both sides. The flame-resistant fiber used was Toho Tenax Pyromex, the heat-adhesive polyester fiber used was Unitika Melty, and regular PET used Teijin polyethylene terephthalate. As shown in FIG. 3, the test pieces 1 and 2 to which no water glass was attached had heat transfer coefficients of 483.72 and 271.45, which were not acceptable. Further, even in the test piece 7 to which water glass was adhered, when the flame resistant fiber was 0% by weight, the heat transfer coefficient was 235.05, which was rejected.

Example 1
Flame-resistant fiber (Toho Tenax Pyromex, 2D × 76) 20%, heat-adhesive polyester fiber (Unitika Melty, 4D × 51) 40%, regular PET (polyethylene terephthalate) (Teijin 10D × 51) was mixed. Thereafter, a fiber layer having a basis weight of 150 g / m ^{2 was formed} with a nonwoven fabric roller card and a cross layer. Further, a nonwoven fabric having a thickness of 50 mm and a basis weight of 500 g / m ² was obtained using a VLAP forming apparatus. Water glass was adhered to both surfaces of this nonwoven fabric by spraying at a rate of 100 g / m ² (NET) and dried with hot air to obtain a heat insulating sound absorbing material. The heat propagation coefficient shown in Table 1 was 2.56, and the nonflammability was acceptable.

(Example 2)
A fiber layer having a basis weight of 500 g / m ² is prepared with the same fiber composition as in Example 1 using the same roller card and cross layer, and a hot air penetration type thermal bond forming machine having a thickness of 50 mm and a basis weight of 500 g / m ² . A nonwoven fabric was obtained. Water glass was adhered to both surfaces of this nonwoven fabric by spraying at a rate of 100 g / m ² (NET) and dried with hot air to obtain a heat insulating sound absorbing material. The heat propagation coefficient shown in Table 1 was 2.62, and the nonflammability was acceptable.

Moreover, the result of having measured the sound absorption characteristic about Example 1, 2 is shown in FIG. The sound absorption characteristic indicates a normal incidence sound absorption coefficient (%), where the X axis is frequency (Hz) and the Y axis is sound absorption coefficient (%). In the frequency range of 500 to 6300 Hz, the first embodiment improves the sound absorption efficiency by about 5% compared to the second embodiment. The acoustic energy loss can be generally obtained from the following equation. The energy loss is proportional to the pipe friction coefficient (friction coefficient of the fiber surface), the pipe length (fiber length), and the average flow velocity squared, and inversely proportional to the pipe diameter (fiber thickness). From this formula, it can be proved that the fiber is oriented in the thickness direction in Example 1, so that the energy loss is increased and the sound absorption efficiency is improved by increasing the contact area.
Ei = η · L / D · μ 2/2
Ei: Acoustic energy loss η: Pipe friction coefficient L: Pipe length D: Pipe diameter μ: Average flow velocity

  The heat insulating sound-absorbing material for vehicles according to the present invention is mainly applied to railway vehicles and automobiles, but is not limited to these. For example, heat-insulating and sound-absorbing materials for machine rooms, cabins, mechanical devices, ducts, etc. Can be widely used as.

BRIEF DESCRIPTION OF THE DRAWINGS It is a front view of the heat insulation sound-absorbing material for vehicles of this invention, (a) provided the water glass solution osmosis | permeation layer on the single side | surface of a fiber layer, (b) provided the water glass solution osmosis | permeation layer on both surfaces of the fiber layer. It is a thing. It is a schematic diagram which shows the state which folded the heat insulation sound-absorbing material for vehicles of this invention in the surface direction zigzag. It is the table | surface which showed the combustion test result by the test piece of the heat insulation sound-absorbing material for vehicles of this invention. It is the table | surface which showed the result of having measured the sound absorption characteristic about Example 1 and 2 of the heat insulation sound-absorbing material for vehicles of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Heat insulation sound-absorbing material for vehicles 2 Fiber layer 3 Water glass solution penetration layer

Claims (6)

  At least at least one side of the fiber layer formed by blending fibers containing 20% by weight or more of flame-resistant fibers and 30% by weight or more of heat-adhesive fibers with respect to the thickness of the fiber layer. A heat insulating sound-absorbing material for vehicles, which is formed by spraying a water glass solution so that it penetrates to a range of 10% from the surface and then drying. The heat insulation sound-absorbing material for vehicles according to claim 1, wherein a bulk density of the fiber layer is 10 kg / m ³ or less.   The vehicle according to claim 1 or 2, wherein the fiber layer is formed by zigzag folding in the surface direction, and the fiber direction is oriented in the thickness direction with an orientation degree of 80% or more. Thermal insulation sound absorbing material.   The heat insulation sound-absorbing material for vehicles according to claim 1, wherein the component of the water glass is sodium silicate. The heat insulating sound-absorbing material for vehicles according to claim 1 or 4, wherein even if the amount of water glass attached is small, it is 50 g / m ² or more on one side.   The heat insulating sound-absorbing material for vehicles according to claim 1, wherein the drying is performed by air drying, hot air drying, high-frequency heat drying, or a combination thereof.

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