KR102420023B1 - Sound absorbing material and method for fabricating the same - Google Patents

Abstract

The present invention relates to a melt-blown nonwoven fabric comprising a hollow fiber and a thermoplastic resin microfiber; and a compressed cotton containing polyester fiber and polyester hollow fiber; to a sound-absorbing material that is a laminated body. Thereby, it is applied to various home appliances that cause vibration and noise, such as transportation means such as automobiles, washing machines, dryers, air conditioners, and air purifiers. In addition, it is possible to extend the life of the product by minimizing damage to the product due to vibration.

Description

Sound absorbing material and manufacturing method thereof {Sound absorbing material and method for fabricating the same}

The present invention relates to a sound absorbing material and a method for manufacturing the same, and to a sound absorbing material that can be applied to various products that cause noise, such as automobiles and home appliances, and a method for manufacturing the same.

BACKGROUND ART In general, external noise is introduced into the interior of the vehicle through various routes in a driving vehicle. Friction noise between the tire and the ground, noise generated by the flow of high temperature and high pressure combustion gas in the exhaust system, and engine transmission noise generated from the engine and transmitted through the vehicle body or air are transmitted to the passenger's ears and impair the quietness of the vehicle. . In order to suppress engine transmission noise, in general, an engine cover or hood insulator is used, but there is some limitation in removing engine transmission noise to a desired level by itself.

Therefore, a sound-absorbing material is installed on the front, left side, and floor of a vehicle. For example, in order to block noise generated from the engine room, the sound-absorbing material is installed on the dash panel that separates the engine room and the vehicle room, and the noise introduced through the side of the vehicle body A sound-absorbing material is also attached to the side panel to block the noise.

Conventionally, glass fiber, urethane foam, and miscellaneous felt are used as a material used as such a sound absorbing material. In the case of urethane foam, which is mainly used, there is a toxic smell, there is a possibility that toxic gas may be generated in an accident due to flammability, and when the foam thickness is thin when manufactured as a sound absorbing material, there was a problem that molding was difficult.

Meanwhile, in a washing machine, which is one of the essential home appliances, a drum mounted therein is driven by a motor to rotate and thus inevitably generate vibration due to rotation. Moreover, the laundry accommodated in the drum and washed is not fixed at a certain position and is not evenly distributed. Accordingly, vibration is further generated due to the unbalanced mass of the laundry. Excessive vibration may cause play or malfunction in various devices installed inside the washing machine, and thus significantly affect the lifespan of the washing machine, and also become the main cause of noise generated by the washing machine.

In addition, during operation of household appliances including a compressor, such as a clothes dryer and an air conditioner, vibration and noise are generated while the compressor compresses and circulates the refrigerant. Since the home appliance is used inside the home, a device for suppressing such vibration or noise is essential. For this purpose, a sound absorbing material is installed outside the compressor in the manufacturing process of a clothes dryer or an air conditioner.

In the existing sound absorbing material installation, an asphalt sheet or an ethylene-vinyl acetate copolymer (EVA) sheet is placed on the outer surface of the dishwasher, leaving only the external panel installation, and the dishwasher is heated by passing it through a hot air fan to apply heat to the asphalt sheet or EVA. It is made by attaching a non-woven fabric having sound-absorbing properties after the sheet has adhesiveness.

Therefore, the development of a sound absorbing material that can be applied to various products that cause noise, such as automobiles and home appliances, can be firmly attached to a curved part, and has improved sound absorption performance is required.

Korean Patent Registration No. 10-1919855

It is an object of the present invention to provide a sound absorbing material with improved performance, which can be applied to various products that cause noise, such as automobiles and home appliances, and a method for manufacturing the same.

According to one aspect of the present invention,

Melt-blown nonwoven fabric comprising a hollow fiber and a thermoplastic resin microfiber with a deformed cross-section; And compression cotton comprising a polyester fiber and a polyester hollow fiber; A sound absorbing material is provided as a laminated laminate.

The laminate may be bonded by needle punching.

The cross-section hollow fiber may be made of any one selected from polypropylene, polyethylene, polymethylpentene, polylactic acid (PLA), and polytrimethylene terephthalate.

The cross-sectional shape of the irregular cross-section hollow fiber may be in the form of a cogwheel having a hollow.

The cogwheel shape may be a form in which 3 to 10 teeth are formed on the outside.

The cross-section hollow fiber may be a hexa-flower (Hexa-Flower) (Huvis).

The melt blown nonwoven fabric may contain 20 to 60 wt% of a hollow fiber with a deformed cross-section based on the total weight.

The deformed cross-section hollow fiber may have a single fineness of 1 to 50 denier.

The hollow fiber cross-section may have a hollow ratio of 10 to 70%.

The thermoplastic resin microfiber may be any one selected from polyethylene, polypropylene, polyvinyl chloride, and polystyrene.

The polyester fibers of the compressed cotton may include general polyester fibers and low-melting polyester fibers.

The polyester fibers of the compressed shoulder may be 1 to 20 denier.

The diameter of the polyester hollow fiber of the compression shoulder may be 20 to 100㎛.

The hollow ratio of the polyester hollow fiber of the compression shoulder may be 10 to 60%.

The thickness of the compressed shoulder may be 5 to 20 mm, and the areal density may be 500 to 1500 g/m ² .

The sound absorbing material may be for home appliances or automobiles.

According to another aspect of the present invention,

(a) extruding the thermoplastic resin composition into an extruder;

(b) melt-blown spinning the extruded thermoplastic resin composition into microfibers to form thermoplastic resin microfibers;

(c) forming a blended filament fiber web by air-blending with the thermoplastic resin microfiber by supplying a hollow fiber with a deformed cross-section during the melt blown spinning;

(d) producing a melt-blown nonwoven fabric comprising a hollow fiber with a different cross-section and a thermoplastic resin microfiber by pressing the blended filament fiber web; and

(e) laminating the melt-blown nonwoven fabric and the compressed cotton surface and then bonding; is provided.

The bonding in step (e) may be performed by needle punching.

The compression cotton, comprising the steps of: producing a web (web) laminate comprising a polyester fiber and a polyester hollow fiber; and needle punching the web laminate.

After the needle punching step, the compressed face may be further dried at a temperature of 200 to 240° C. for 3 to 20 minutes.

The sound absorbing material of the present invention is a melt-blown nonwoven fabric containing a hollow fiber with a deformable cross section and a thermoplastic resin microfiber, and a sound absorbing material in which a compressed cotton containing a polyester fiber and a polyester hollow fiber is laminated. It is applied to various home appliances that cause vibration and noise, such as transportation means, washing machines, dryers, air conditioners, and air purifiers. It has the effect of extending the life of the product by minimizing damage to the product.

1 is a cross-sectional SEM image of a hexa-flower.
2 is a flowchart sequentially illustrating a method for manufacturing a sound absorbing material of the present invention.
3 is an SEM image of the melt blown nonwoven fabric used in Example 1.
4 is an SEM image of a nonwoven fabric prepared by needle punching Hexa-Flower 06 used in Comparative Example 1.

Since the present invention can apply various transformations and can have various embodiments, specific embodiments are illustrated in the drawings and described in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, and it should be understood that all modifications, equivalents and substitutes included in the spirit and scope of the present invention are included. In describing the present invention, if it is determined that a detailed description of a related known technology may obscure the gist of the present invention, the detailed description thereof will be omitted.

The terms used in the present application are only used to describe specific embodiments, and are not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. In the present application, terms such as “comprise” or “have” are intended to designate that a feature, number, step, operation, component, part, or combination thereof described in the specification exists, but one or more other features It should be understood that this does not preclude the existence or addition of numbers, steps, operations, components, parts, or combinations thereof.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, and in the description with reference to the accompanying drawings, the same or corresponding components are given the same reference numerals, and the overlapping description thereof will be omitted. do.

Hereinafter, the sound absorbing material of the present invention will be described.

The sound absorbing material of the present invention includes a melt-blown nonwoven fabric comprising a hollow fiber and a thermoplastic resin microfiber with a deformed cross-section; And it is characterized in that it is a laminated body; and a polyester fiber and a compressed cotton containing a polyester hollow fiber.

A hollow fiber with a different cross-section refers to a fiber in which a thermoplastic resin is extruded through a capillary to form a plurality of fine diameter filaments, which are stretched using a high-temperature tube to form a hollow.

The laminate may be joined by needle punching.

The cross-sectional hollow fiber may be made of any one selected from polypropylene, polyethylene, polymethylpentene, polylactic acid (PLA), and polytrimethylene terephthalate.

The cross-sectional shape of the irregular cross-section hollow fiber may be in the form of a cogwheel having a hollow. Accordingly, it is excellent in sound absorption performance compared to microfibers, hollow fibers that are not of a different cross-section, or fibers of a different cross-section without a hollow, and the deformation of the deformed cross-section after formation of the nonwoven fabric is minimized, thereby maximizing the sound-absorbing effect.

The cogwheel shape may have 3 to 10 teeth formed on the outside, more preferably 5 to 8 teeth, and most preferably 6 to 7 teeth. If fewer than three teeth are formed, the sound absorption effect may be reduced, and if there are more than 10 teeth, the result may be similar to that of not developed teeth, and the sound absorption effect may be reduced as well. Most preferably, the hollow fiber with a different cross-section may be a hexa-flower (Hexa-Flower) (Huvis). For reference, a cross-sectional SEM image of the hexa-flower is shown in FIG. 1 .

The melt blown nonwoven fabric may contain 20 to 60 wt% of the hollow fiber with a deformed cross-section based on the total weight, and more preferably 30 to 50 wt%. If the cross-sectional hollow fiber is less than 20 wt%, the sound absorption performance may be lowered, and if it exceeds 60 wt%, it may be difficult to form a nonwoven fabric according to air blending with the melt blown microfiber.

The deformed cross-section hollow fiber may have a single fineness of 1 to 50 denier, more preferably 3 to 30 denier, and even more preferably 5 to 15 denier.

It is preferable that the hollow fiber of the deformed cross-section has a hollowness of 10 to 70%, more preferably 15 to 60%, and still more preferably 20 to 50%. If it is less than 10%, the sound absorption performance may be reduced, and if it exceeds 70%, the hollow fiber shape is deformed after the nonwoven fabric is manufactured, and the sound absorption performance may be reduced.

The thermoplastic resin microfiber may be any one selected from polyethylene, polypropylene, polyvinyl chloride, and polystyrene.

The polyester fibers may include general polyester fibers and low-melting polyester fibers.

Here, the general polyester fiber means a polyester fiber having a melting point of 260 to 300°C, and the low-melting polyester fiber means a melting point of 110 to 180°C.

The polyester fiber is preferably 1 to 20 denier (denier), more preferably 2 to 10 denier, even more preferably 3 to 8 denier.

The polyester hollow fiber may have a diameter of preferably 20 to 100 μm, more preferably 30 to 80 μm, and still more preferably 40 to 60 μm. When the diameter of the polyester hollow fiber is less than 20㎛, the sound-absorbing performance may be reduced, and if it exceeds 100㎛, the durability of the compressed cotton itself may be reduced.

The length of the polyester fiber is preferably a short fiber of 10 to 150mm, more preferably 20 to 100mm, even more preferably 30 to 70mm. If the length of the polyester fiber is less than 10mm, the sound absorption performance may be lowered, and if it exceeds 150nm, the flexibility of the compression face may be lowered and it may be difficult to apply to a curved surface.

The length of the polyester hollow fiber is preferably a short fiber of 20 to 200 mm, more preferably 30 to 150 mm, more preferably 50 to 100 mm. If the length of the polyester hollow fiber is less than 20mm, the sound absorption performance may be lowered, and if it exceeds 200mm, the flexibility of the compressed shoulder may be lowered and it may be difficult to apply to a curved surface.

The hollow ratio of the polyester hollow fiber is preferably 10 to 60%, more preferably 20 to 60%, even more preferably 40 to 60%. If the hollow ratio is less than 10%, the sound absorption performance may be reduced, and if it exceeds 60%, the durability of the compression face may be reduced.

The thickness of the compressed shoulder is 5 to 20 mm, the areal density is preferably 500 to 1500 g/m ² , more preferably the thickness is 7 to 15 mm, the areal density is 600 to 1300 g/m ² , and more preferably the thickness is 8 to 12 mm, the areal density may be 800 to 1200 g/m ² . When the thickness is less than 5mm, the sound-absorbing performance is reduced, and when it exceeds 20mm, the volume is large when applied to a product, and it is difficult to apply to a curved surface.

The compression cotton preferably contains 10 to 100 parts by weight of polyester hollow fiber based on 100 parts by weight of polyester fiber, more preferably 30 to 90 parts by weight of polyester hollow fiber, even more preferably It may include 50 to 80 parts by weight of the polyester hollow fiber. If the content of the polyester hollow fiber is less than 10 parts by weight, the sound absorption performance may be reduced, and if it exceeds 100 parts by weight, the durability of the compressed cotton may be reduced.

The polyester fiber preferably contains 10 to 60 parts by weight of the low-melting polyester fiber based on 100 parts by weight of the general polyester fiber, more preferably 20 to 50 parts by weight, even more preferably 30 to 40 parts by weight. may include When the amount of the low-melting polyester fiber is less than 10 parts by weight, the sound-absorbing performance may be reduced, and when it exceeds 60 parts by weight, the heat resistance of the compression face may be reduced.

The sound absorbing material is preferably for home appliances or automobiles.

The home appliance may be a dryer, a dish dryer, an air conditioner, a washing machine, an air purifier, a dehumidifier, and the like, but the scope of the present invention is not limited thereto.

The vehicle may be a passenger car, a bus, a work vehicle, etc., but the scope of the present invention is not limited thereto and may include various transportation means that generate noise.

Figure 2 sequentially shows a method of manufacturing the sound-absorbing material of the present invention. Hereinafter, a method of manufacturing the sound absorbing material of the present invention will be described with reference to FIG. 2 .

First, the thermoplastic resin composition is put into an extruder and extruded (step a).

Thermoplastic resin and additives selected as the material of the thermoplastic resin microfiber are put into the extruder, kneaded and heated, and then extruded.

Since the type of the thermoplastic resin is the same as described above, the detailed contents will be referred to above.

Next, the extruded thermoplastic resin composition is melt-blown into microfibers to form thermoplastic resin microfibers (step b).

At the same time as spinning the thermoplastic resin composition, the thermoplastic resin microfiber may be formed according to melt blown spinning which collides with the fibers by spraying high-temperature and high-speed gas from a high-temperature and high-speed gas injection port installed inside the spinning die.

On the other hand, by supplying a hollow fiber with a deformed cross-section during melt blown spinning and air blending with the thermoplastic resin microfiber, a blended filament fiber web is formed (step c).

At this time, the molded cross-section hollow fiber and the thermoplastic resin microfiber can be air blended by supplying the molded cross-section hollow fiber to the portion where the thermoplastic resin microfiber is spun according to melt blown spinning through the fiber supply unit installed on one side of the spinning die. Accordingly, a blended filament fibrous web is formed.

Thereafter, the blended filament fiber web is compressed to prepare a melt-blown nonwoven fabric including a hollow fiber with a different cross-section and a thermoplastic resin microfiber (step d).

Next, the melt blown nonwoven fabric and the compressed cotton are laminated and bonded to complete the sound absorbing material (step e)

The compression cotton, comprising the steps of: producing a web (web) laminate comprising a polyester fiber and a polyester hollow fiber; and needle punching the web laminate.

The compressed cotton is preferably further dried at a temperature of 200 to 240 ° C. for 3 to 20 minutes, and more preferably dried at a temperature of 210 to 230 ° C. for 3 to 7 minutes. If the drying time and temperature are less than the lower limit or when drying under the conditions exceeding the upper limit, the sound-absorbing performance of the compressed cotton may be deteriorated or the durability may be reduced.

The drying may be performed by any one selected from a conveyor oven, a through-air system, and an infrared heater.

[Example]

Example 1

A thermoplastic resin composition containing 99.8 wt% of a homopropylene H7914 polymer resin having a melt index (230° C.) of 1400 g/10min, 0.01 wt% of a UV stabilizer, and 0.01 wt% of a heat-resistant stabilizer was introduced into the extruder. A single extruder having an 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 spinning die and the fibers were spun in the collector direction by passing through an orifice having a diameter of 0.2 mm and having a number of 32 per inch. During spinning, the high-temperature and high-speed gas injected from the high-temperature and high-speed gas nozzle installed inside the spinning die collided with the fibers to form a melt-blown thermoplastic resin microfiber made of polypropylene having an average fiber thickness of 3 μm. At the same time, Huvis' Hexa-Flower 06, which has an average thickness of 7 denier, an average length of 40 mm, and a hollow fiber with a different cross-section, is supplied to the part where the thermoplastic resin microfiber is spun through the fiber supply device, and the Hexa-Flower 06 and the thermoplastic resin microfiber are air-conditioned. blended. At this time, the thermoplastic resin microfiber and Hexa-Flower 06 with a different cross section were blended in a weight ratio of 60:40. Thereafter, the blended fiber web was compressed to complete a melt blown nonwoven fabric. For reference, the SEM image of the melt blown nonwoven fabric prepared in FIG. 3 is shown.

On the other hand, after manufacturing a web laminate using general polyester fibers, low-melting polyester fibers, and polyester hollow fibers, needle punching is performed, and then drying in an infrared heater at about 220° C. for 5 minutes to obtain an areal density of about 1000 g/ ㎡ Phosphorus compression cotton was prepared. At this time, general polyester fibers (5 denier, short fibers of about 30-70 mm in length), low-melting polyester fibers (5 denier, short fibers of about 30-70 mm in length), and polyester hollow fibers (diameter of about 50 μm, length of about 50 μm) 80-100 mm, hollow ratio of about 50%) was used in a weight ratio of 65:35:60.

The sound absorbing material was completed by laminating the melt blown nonwoven fabric prepared according to the above method and the compressed cotton surface and then needle punching.

Example 2

A sound absorbing material was prepared in the same manner as in Example 1, except that the weight ratio of the thermoplastic resin microfiber and the hetero-section Hexa-Flower 06 was 50:50 instead of 60:40.

Comparative Example 1

A sound absorbing material was prepared in the same manner as in Example 1, except that a nonwoven fabric prepared by needle punching of Hexa-Flower 06 was used instead of the melt blown nonwoven fabric. For reference, the SEM image of the nonwoven fabric prepared by needle punching of Hexa-Flower 06 is shown in FIG. 4 .

Comparative Example 2

A sound absorbing material was prepared in the same manner as in Example 1, except that a spunbond nonwoven fabric was used instead of the melt blown nonwoven fabric.

Comparative Example 3

A sound absorbing material was prepared in the same manner as in Example 1, except that a laminate in which only two layers of melt-blown nonwoven fabric were laminated without using a compressed cotton surface was used.

Comparative Example 4

A sound absorbing material was prepared in the same manner as in Example 1, except that a laminate in which only the compressed cotton surface was laminated in two layers was used without using a melt blown nonwoven fabric.

[Experimental example]

Absorption Coefficient Measurement

In order to measure the sound absorption coefficient for each frequency of the sound absorbing materials prepared according to Examples 1 and 2 and Comparative Examples 1 to 45, respectively, the results of the measurement by mounting a specimen in Alpha Kevin (small reverberation room equipment) are shown in Table 1 below. It was.

frequency
(Hz) Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 400 0.350 0.374 0.255 0.280 0.290 0.150 500 0.402 0.451 0.340 0.348 0.326 0.280 630 0.510 0.522 0.460 0.476 0.376 0.243 800 0.803 0.822 0.692 0.754 0.738 0.394 1,000 0.812 0.830 0.690 0.789 0.720 0.498 1,250 0.754 0.756 0.541 0.635 0.590 0.292 1,600 0.450 0.440 0.349 0.345 0.328 0.218 average sound absorption 0.583 0.599 0.475 0.518 0.481 0.296

According to this, there was little difference in sound absorbing power between the sound absorbing materials of Examples 1 and 2, and showed a significantly higher value in terms of sound absorption compared to the sound absorbing materials prepared according to Comparative Examples 1 to 4.

In other words, the sound absorbing material of the present invention exhibited the highest sound absorption rate in this case, characterized in that it is a laminate of a melt-blown nonwoven fabric in which a compressed cotton and a hollow fiber with a deformed cross-section are mixed.

On the other hand, when a hollow fiber with a different cross section was introduced but a needle punched nonwoven fabric was used instead of a melt blown nonwoven fabric (Comparative Example 1), when a conventional spunbond nonwoven fabric was used instead of a melt blown nonwoven fabric (Comparative Example 2), or a different cross section When the laminate was prepared only from the melt blown nonwoven fabric mixed with the hollow fibers (Comparative Example 3), when the laminate was prepared only from the compressed cotton (Comparative Example 4), the sound absorption performance was significantly higher than that of Examples 1 or 2 of the present invention. appeared to decrease.

In the above, although embodiments of the present invention have been described, those of ordinary skill in the art can add, change, delete or add components within the scope that does not depart from the spirit of the present invention described in the claims. The present invention may be variously modified and changed by, etc., and this will also be included within the scope of the present invention.

Claims (13)

Melt-blown nonwoven fabric comprising a hollow fiber and a thermoplastic resin microfiber with a deformed cross-section; and
Compressed cotton containing polyester fibers and polyester hollow fibers; is a laminated body,
The compressed cotton contains 10 to 100 parts by weight of polyester hollow fiber based on 100 parts by weight of polyester fiber,
The polyester fiber includes a general polyester fiber and a low-melting polyester, and 10 to 60 parts by weight of the low-melting polyester fiber with respect to 100 parts by weight of the general polyester fiber,
The general polyester fiber is a polyester fiber having a melting point of 260 to 300°C,
The low-melting polyester fiber is a polyester fiber having a melting point of 110 to 180° C.,
The laminate is a sound absorbing material, characterized in that bonded by a needle punching (needle punching). delete According to claim 1,
The heterogeneous cross-section hollow fiber is a sound absorbing material, characterized in that it is made of any one selected from polypropylene, polyethylene, polymethylpentene, polylactic acid (PLA) and polytrimethylene terephthalate. . According to claim 1,
The cross-sectional shape of the cross-sectional hollow fiber is a sound-absorbing material, characterized in that the hollow cogwheel shape. 5. The method of claim 4,
The cogwheel shape is a sound absorbing material, characterized in that 3 to 10 teeth are formed on the outside. delete According to claim 1,
The melt-blown nonwoven fabric is a sound absorbing material, characterized in that it contains 20 to 60 wt% of a hollow fiber with a deformed cross-section based on the total weight. According to claim 1,
The heterogeneous cross-section hollow fiber is a sound-absorbing material, characterized in that the single fineness of 1 to 50 denier (denier). According to claim 1,
The molded cross-section hollow fiber is a sound-absorbing material, characterized in that the hollow ratio of 10 to 70%. According to claim 1,
The thermoplastic resin microfiber is a sound absorbing material, characterized in that any one selected from polyethylene, polypropylene, polyvinyl chloride and polystyrene. According to claim 1,
The sound-absorbing material is a sound-absorbing material, characterized in that for home appliances or automobiles. (a) extruding the thermoplastic resin composition into an extruder;
(b) melt-blown spinning the extruded thermoplastic resin composition into microfibers to form thermoplastic resin microfibers;
(c) forming a blended filament fiber web by air-blending with the thermoplastic resin microfiber by supplying a hollow fiber with a deformed cross-section during the melt-blown spinning;
(d) manufacturing a melt-blown nonwoven fabric comprising a hollow fiber with a deformed cross-section and a thermoplastic resin microfiber by pressing the blended filament fiber web; and
(e) laminating the melt blown nonwoven fabric and the compressed cotton surface and then bonding them together;
The compressed cotton contains 10 to 100 parts by weight of polyester hollow fiber based on 100 parts by weight of polyester fiber,
The polyester fiber includes a general polyester fiber and a low-melting polyester, and 10 to 60 parts by weight of the low-melting polyester fiber with respect to 100 parts by weight of the general polyester fiber,
The general polyester fiber is a polyester fiber having a melting point of 260 to 300°C,
The low-melting polyester fiber is a polyester fiber having a melting point of 110 to 180° C.,
The bonding is a method of manufacturing a sound absorbing material, characterized in that performed by needle punching (needle punching). delete

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