KR20230085638A - Apparatus for manufacturing of single layer sound adsorbing material randomly mixed with meltblown fiber and nano fiber for reducing noise in audio frequency band and sound adsorbing material manufactured using the same - Google Patents

Abstract

The present invention relates to an apparatus for manufacturing a sound absorbing material for reducing noise in an audible frequency band of a single layer in which meltblown fibers and nanofibers are randomly mixed, and a sound absorbing material manufactured thereby, wherein a base sound absorbing pad, a fastener, and a hybrid sound absorbing pad are sequentially A porous support on which a sound-absorbing material for reducing noise in the audible frequency band is seated, characterized in that it is composed of a thermoplastic melt-type adhesive material of a thin film having a structure in which fasteners are breathable; a heater that provides heat for melting the adhesive material provided on the fastener to one side of the sound absorbing material seated on the pedestal; and a suction for absorbing heat from the heater together with air from the other side of the sound absorbing material and transmitting the heat in the thickness direction of the sound absorbing material, wherein the base sound absorbing pad and the hybrid sound absorbing pad of the sound absorbing material are formed by an adhesive material provided on a fastener melted by the heat of the heater. A sound absorbing material for sound absorbing noise may be manufactured by combining the pads.

Description

Sound-absorbing material manufacturing apparatus for reducing noise in audible frequency band of a single layer in which meltblown fibers and nanofibers are randomly mixed and sound-absorbing material manufactured thereby REDUCING NOISE IN AUDIO FREQUENCY BAND AND SOUND ADSORBING MATERIAL MANUFACTURED USING THE SAME}

The present invention relates to a sound absorbing material manufacturing apparatus, and more particularly, to a sound absorbing material manufacturing apparatus for absorbing noise and a sound absorbing material manufactured thereby.

In general, as a sound absorbing material used for the purpose of absorbing sound in order to reduce noise, a sound absorbing material in the form of a non-woven fabric is used. These non-woven fabric-type sound absorbing materials are mainly used in the automobile field or the construction field. As a number of fibers intersect on the surface and inside of the non-woven fabric, small bubbles or tubular holes are formed, and the air in the holes vibrates by sound waves, resulting in friction. As the sound energy is absorbed, the noise is reduced.

Conventionally, in order to manufacture such a sound-absorbing material in the form of a non-woven fabric, a device for manufacturing a sound-absorbing material in the form of a non-woven fabric by forming a fibrous web using a melt blown method has been used.

A nonwoven fabric composed of a single layer of a melt-blown web by the melt-blown method has been used. The meltblown spinning apparatus for producing such a single-layer meltblown web-type nonwoven fabric can produce microfibers with a diameter of from submicron to several microns, but there are restrictions on applicable polymers and for high-performance filter materials. There was a limit to the miniaturization of the fiberscope.

Accordingly, a fiber web was formed with nanofibers using an electrospinning method to manufacture a sound-absorbing material in the form of a non-woven fabric made of nanofibers. However, the production of nanofibers using the electrospinning method is one of the methods for obtaining the fineness of the fiber diameter and the high performance of the filter material, but the electrospinning method is a solution spinning method, and the process yield is low in the case of the spinning solution used in the manufacture of nanofibers. It is only less than 30%, and the manufacturing cost of the product is high because the process cost is high, such as recovering or treating the used solvent. In addition, since the mechanical strength is low, it has a disadvantage that the nanofiber web product cannot be used alone.

In addition, in the case of a sound absorbing material manufactured by the conventional melt blown method, fibers with a single component or a small difference in fiber diameter constitute a fiber web. The sound absorption performance for the is somewhat insufficient, so there was a disadvantage that it is difficult to use it for devices or equipment in which frequencies in a specific range are used. For example, a vehicle equipped with an internal combustion engine shows sufficient sound absorption characteristics due to a non-woven sound absorbing material manufactured by a melt blown method, but an electric vehicle equipped with an electric motor generating noise in a low frequency band has sound absorption performance for the corresponding band. Since it is measured below this standard value, there was a problem that it was difficult to use.

Republic of Korea Patent Registration No. 10-1665895

The present invention has been made to solve the above-mentioned problems, and a single-layer sound absorbing material for reducing noise in the audible frequency band in which meltblown fibers and nanofibers are randomly mixed, which can laminate laminated pads by non-contact processing without compression processing It is to provide a manufacturing apparatus and a sound absorbing material produced thereby.

In particular, to provide an apparatus for manufacturing a sound absorbing material for reducing noise in an audible frequency band of a single layer in which meltblown fibers and nanofibers that can effectively remove noise in a low frequency band are randomly mixed, and a sound absorbing material manufactured thereby.

In addition, an apparatus for manufacturing a sound absorbing material for reducing noise in the audible frequency band of a single layer in which meltblown fibers and nanofibers are randomly mixed, which can prevent the sound absorbing material from deteriorating during processing, and a sound absorbing material manufactured by the same are provided is to do

In addition, the present invention can remove noise generated in a vehicle so that it can be used as a sound absorbing material for a vehicle, and in particular, it can be used as a sound absorbing material for an electric vehicle by effectively removing noise caused by a motor that generates noise in a low frequency band. To provide an apparatus for manufacturing a sound absorbing material for reducing noise in an audible frequency band of a single layer in which blown fibers and nanofibers are randomly mixed, and a sound absorbing material manufactured thereby.

In order to achieve the above object, the sound absorbing material manufacturing apparatus for reducing noise in the audible frequency band of a single layer in which meltblown fibers and nanofibers are randomly mixed according to the present invention has a base of a foam material or non-woven fabric material having a predetermined thickness sound absorbing pad; A hybrid sound-absorbing pad made of non-woven fabric that is made of a thickness smaller than the thickness of the base sound-absorbing pad, microfibers and nanofibers are randomly mixed by a spinning method to form a single layer, and is bonded to the base sound-absorbing pad in a laminated state; and a fastener for attaching and fixing the hybrid sound-absorbing pad to the base sound-absorbing pad in a breathable manner, wherein the base sound-absorbing pad, the fastener, and the hybrid sound-absorbing pad are sequentially laminated, and the fastener is bonded by thermoplastic melt type having a breathable structure. A porous support on which a sound absorbing material for reducing noise in the audible frequency band is seated, characterized in that composed of a material; A heater that provides heat for melting the adhesive material provided on the fastener to one side of the sound absorbing material seated on the pedestal; and the base sound absorbing pad and the hybrid sound absorbing pad of the sound absorbing material are formed by the adhesive material provided on the fastener melted by the heat of the heater. combine

And, the pedestal is composed of a mesh conveyor belt for moving the sound absorbing material and is circulated by a drive motor of the conveyor.

In addition, the heater, a heat source for dissipating heat for melting the adhesive material; A blower for blowing heat from a heat source to a sound absorbing material; and a guide chamber for isolating the hot air blown from the blower and guiding it to one side of the sound absorbing material in a diffused state.

In addition, it may further include; a suction for absorbing heat from a heater together with air on the other side of the sound absorbing material and transmitting the heat in the thickness direction of the sound absorbing material, and the suction is installed on the other side of the sound absorbing material to collect hot air passing through the sound absorbing material. collector; and an intake fan providing negative pressure to the collector.

On the other hand, it is manufactured by the above-described manufacturing apparatus, and on one side of the base sound-absorbing pad made of a foam material or non-woven fabric material having a predetermined thickness, it is made of a thickness smaller than the thickness of the base sound-absorbing pad, and microfibers and nanofibers are spun. The hybrid sound-absorbing pad made of non-woven fabric, which is randomly mixed to form a single layer and bonded to the base sound-absorbing pad in a laminated state, and the sound-absorbing material integrally laminated by a thin-film fastener having a plastic melt-type adhesive material having a breathable structure Provided.

Here, the fastener is interposed between the hybrid sound-absorbing pad and the base sound-absorbing pad so that the hybrid sound-absorbing pad and the base sound-absorbing pad are closely adhered to each other on both sides, and the hot melt constituting the adhesive material is meltably applied to both sides, and the hybrid sound-absorbing pad and the base sound-absorbing pad are meltably applied to both sides through the hot melt. As the sound absorbing pad and the base sound absorbing pad are attached, the hybrid sound absorbing pad is attached to the base sound absorbing pad, and is composed of a thin film of nonwoven fabric to ventilate the hybrid sound absorbing pad and the base sound absorbing pad.

As described above, since the present invention can laminate the laminated pads by non-contact processing without compression processing through hot melt thermal bonding, it is possible to prevent a decrease in sound absorption characteristics during processing.

Further, since the present invention has a mixture of micro-diameter meltblown fibers and nano-diameter nanofibers, it is possible to effectively remove noise in a low frequency band caused by the nanofibers. That is, according to the present invention, due to the structure in which a base sound-absorbing pad excellent in sound-absorbing characteristics of high-frequency noise and a hybrid sound-absorbing pad excellent in sound-absorbing characteristics of low-frequency noise are combined, the sound-absorbing characteristics in the low-frequency and high-frequency regions are improved in a complementary manner. It can be.

In addition, according to the present invention, by laminating the base sound absorbing pad and the hybrid sound absorbing pad through fasteners to form a single sound absorbing material, it is possible to overcome difficulties in handling and post-processing of the hybrid sound absorbing pad in which nanofibers are composited. In addition, according to the present invention, since the nanofibers are dispersed and present inside the hybrid sound-absorbing pad and are not exposed on the surface, processing operations such as laminating, bending, or cutting are easy and the nanofibers are not damaged during post-processing. can be minimized.

In particular, according to the present invention, a base sound-absorbing pad and a hybrid sound-absorbing pad made of a foam material or non-woven fabric having a predetermined thickness, and a fastener having a breathable structure are laminated, and when heat is applied during manufacturing, the laminate is heated. can pass through, so that the thermal melting of the fasteners interposed between the base sound-absorbing pad and the hybrid sound-absorbing pad is smoothly performed, and the base sound-absorbing pad and the hybrid sound-absorbing pad are laminated. And to improve the sound absorption performance by not affecting the processing shape of the hybrid sound absorption pad.

In addition, according to the present invention, the base sound-absorbing pad and the hybrid sound-absorbing pad are hot-air-fused and laminated by means of a fastener made of hot melt instead of the conventional thermal compression lamination process that reduces sound-absorbing properties, so that the sound-absorbing properties can be prevented from deteriorating. .

Furthermore, according to the present invention, the overall thickness of the sound absorbing material can be provided at a desired level by adjusting the thickness of the base sound absorbing pad, which is easy to process.

In addition, according to the present invention, since the water-based polymer PVA is crosslinked during the hot melt melting process through hot air heating, the molecular structure of the polymer is changed through the crosslinking reaction and the shape stability of maintaining the shape of the nanofibers against moisture exposure can increase

In addition, as the hot air is sucked from the lower side of the base sound absorbing pad and the hybrid sound absorbing pad when heated with hot air, the movement of heat is rapidly circulated, so that the hot air completely passes through the laminated pad, and a crosslinking reaction occurs in the process of passing the hot air can proceed smoothly.

In addition, since the heat applied to the laminated pad can be discharged while passing through it completely, generation of carbide in the laminated pad due to high temperature can be prevented.

1 is a perspective view showing a sound absorbing material for reducing noise in an audible frequency band of a single layer in which meltblown fibers and nanofibers are randomly mixed according to the present invention;
Figure 2 is a cross-sectional view showing the sound absorbing material of Figure 1;
3 is a SEM image of a fiber web of a base sound-absorbing pad having a weight of 80 g/m2 made of meltblown microfiber;
Figure 4 is a SEM image of a fiber web of a hybrid sound-absorbing pad having a weight of 80 g / m 2 in which electrospun PVA nanofibers and meltblown microfibers are mixed;
5 is an SEM image of a fiber web of a nanofiber pad made of electrospun PVA nanofibers;
6 is a cross-sectional view showing a sound absorbing material for reducing noise in an audible frequency band of a single layer in which meltblown fibers and nanofibers are randomly mixed according to another embodiment of the present invention;
Figure 7 is a schematic diagram showing the overall configuration of a manufacturing apparatus for a sound absorbing material for reducing noise in the audio frequency band of a single layer in which meltblown fibers and nanofibers are randomly mixed according to the present invention;
Figure 8 is a partial perspective view schematically showing a part of the manufacturing apparatus of Figure 7;
9 is a flow chart showing a method for manufacturing a sound absorbing material for reducing noise in an audible frequency band of a single layer in which meltblown fibers and nanofibers are randomly mixed according to the present invention;
10 is a flowchart illustrating a method of manufacturing a sound absorbing material for reducing noise in an audible frequency band of a single layer in which meltblown fibers and nanofibers are randomly mixed according to the present invention;
Figure 11 is a graph image showing the cross-linking evaluation measurement result, which is a measurement of the water-insoluble item of the nanofiber PVA; and
12 to 16 show graph images showing the sound absorbing characteristics measurement results of the Alpha cabin equipment for the sound absorbing materials according to each Example and Comparative Example.

Advantages and features of the present invention, and methods for achieving them, will become clear with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and will be implemented in various different forms.

Hereinafter, technical features of the present invention will be described in detail with reference to the accompanying drawings.

1 and 2 show a sound absorbing material for reducing noise in an audible frequency band of a single layer in which meltblown fibers and nanofibers are randomly mixed according to the present invention.

As shown in FIGS. 1 and 2, the sound absorbing material for reducing noise in the audio frequency band of a single layer in which meltblown fibers and nanofibers are randomly mixed according to an embodiment of the present invention is a base sound absorbing pad (1), a hybrid It includes a sound absorbing pad (2) and a fastener (3).

The base sound-absorbing pad 1 may be formed of a foam material or a non-woven fabric material having a predetermined thickness. For example, the base sound-absorbing pad 1 may be formed of a porous foam material manufactured by foam molding or a nonwoven fabric manufactured by melt blown spinning, and in an embodiment of the present invention, it is manufactured by a melt blown spinning method. It should be explained that the non-woven fabric was used. According to this embodiment, the base sound-absorbing pad 1 may be formed of a non-woven fabric material made of polymer fibers, PP (Poly Propylene), PE (Polyethylene), PET (Polyethylene Terephthalate), Nylon (Nylon) or PLA (Poly Staple fibers are manufactured by melting polymers such as lactic acid and extruding and spraying through a nozzle, or by melting these polymers and extruding and spinning through a nozzle. It can be manufactured using various nonwoven fabric manufacturing methods such as Laid method or needle punching method. Unlike the above-described base sound-absorbing pad 1, it may be composed of porous foam formed with porous or microporous. Such a porous foam can be made of, for example, synthetic resins or polymers (polymers) such as urethane or EVA.

Here, the spinning solution used to manufacture the base sound-absorbing pad 1 using melt blown spinning, air-laid or needle punching, etc. may be used without limitation as long as it is a polymer resin. Such a polymer resin is, for example, any one selected from the group consisting of polypropylene, polyethylene, polyethylene terephthalate, polypropylene copolymer, nylon, polylactic acid, polyester, polyurethane, polyacrylonitrile, polyolefin, pitch and cellulose. may be ideal

The base sound-absorbing pad 1 is made of micro-sized fibers, and preferably has a diameter of 1 to 15 μm. According to an embodiment of the present invention, the size of the fibers constituting the base sound-absorbing pad 1 may be formed to an average size of 3 μm and as small as 1 μm. The base sound-absorbing pad 1 may have a weight of 80 to 1,000 g/m 2 .

In the hybrid sound-absorbing pad 2, micro fibers and nano fibers are randomly mixed to form a single layer. That is, the hybrid sound-absorbing pad 2 has a structure in which microfibers of microdiameter manufactured by the meltblown method and nanofibers of nanodiameter manufactured by the electrospinning method are randomly mixed, and the microfibers are discharged by the meltblowing method. And as the nanofibers discharged by the electrospinning method are mixed and collected in the collector, it is formed in the form of a nonwoven fabric sheet having a composite fiber structure layer. That is, the hybrid sound-absorbing pad 2 may be made of a non-woven fabric of mixed fibers prepared by mixing two types of spinning solutions, and since microfibers advantageous to high-frequency sound absorption properties and nanofibers advantageous to low-frequency sound absorption properties are mixed, sound absorption properties are improved. It can be.

Here, the spinning solution used to manufacture the hybrid sound-absorbing pad 2 is a spinning solution for electrospinning to form nanofibers and a melt blown spinning solution for forming microfibers, and two spinning solutions may be used, nano Spinning solutions for electrospinning for fiber formation include, for example, polypropylene (PP) resin, polyethylene terephthalate (PET) resin, polyvinylidene fluoride (PVdF) resin, polyvinyl acetate (PVAc) resin, polymethyl methacrylate ( PMMA) resin, polyacrylonitrile (PAN) resin, polyurethane (PUR) resin, polybutylene terephthalate (PBT) resin, polyvinyl butyral resin, polyvinyl chloride (PVC) resin, polyolefin resin, poly Lactic acid (PLA) resin, polyethylene naphthalate (PEN) resin, polyamide (PA) resin, polyvinyl alcohol (PVA) resin, polyethyleneimide (PEI) resin, pitch resin, polycarprolactone (PCL) resin, poly It may include one or more selected from the group consisting of a lactic acid glycol acid (PLGA) resin, a silk solution, a cellulose solution, and a chitosan solution. Another melt-blown spinning solution may be a polymer resin solution used to manufacture the above-described base sound-absorbing pad (1).

On the other hand, the hybrid sound-absorbing pad 2 may be manufactured by electrospinning and meltblown spinning as described above, of which an aqueous solvent may be used in the case of a spinning solution for electrospinning for forming nanofibers. An organic solvent such as dimethylformamide (DMF) may be used, but it is preferable to use an aqueous solvent because there are disadvantages that remain even after performing a multi-step solvent removal process. As an example, polyvinyl alcohol (PVA) may be used. As a solution mixing process for producing nanofibers using 20% PVA aqueous solution, after weighing water and PVA according to the concentration selected in the concentration range of 15 to 30%, it is put into a stirring tank and heated in a water bath at a temperature of 80 ° C. By stirring for more than an hour, the solution is prepared. At this time, PVA may be used as a raw material having a degree of saponification in the range of 70% to 99%. Then, the viscosity of the prepared solution is evaluated and used, and a solution having a viscosity value of 1,000 to 5,000 cP can be used. At this time, if the viscosity is lower than this range, the formation of nanofibers is not smoothly performed, and if the viscosity is high, the solution supply is not smooth, so it is preferable to select within an appropriate range. Unlike the above, other solvents may be used instead of the PVA solvent.

In this embodiment, the hybrid sound-absorbing pad 2 uses PP or PET as a raw material, has a spinning temperature of 280 ° C, a discharge amount of 100 g / min, a side air of 6 CMM, a distance between a nozzle and a collector of 890 mm, and a line speed of 1.6 m / min. The melt blown method of the condition, PVA is used as raw material, Micro- and nano-sized fibers are mixed by the electrospinning method under the conditions of discharge amount of 1g/min (regulator: 6kgf/cm2), side air of 200LPM, distance between nozzle and melt blown spinning of 500mm, and high voltage of 45KV. It may be formed, and preferably, nanofibers having a diameter of 100 to 900 nm and micro fibers having a diameter of 1 to 15 μm are mixed. According to an embodiment of the present invention, the size of fibers constituting the hybrid sound-absorbing pad 2 may be formed to an average size of 2.5 μm and a size of 900 nm as small as possible.

This hybrid sound-absorbing pad (2) is formed with a thickness thinner than the total thickness of the base sound-absorbing pad (1). The thickness of the hybrid sound-absorbing pad 2 may be formed to a thickness of 5 to 25% of the total thickness of the base sound-absorbing pad 1, for example.

The hybrid sound-absorbing pad 2 may have a weight of 80 g/m 2 , and may be coupled to the base sound-absorbing pad 1 in a laminated state.

The fastener 3 is provided between the base sound absorbing pad 1 and the hybrid sound absorbing pad 2. That is, the base sound-absorbing pad 1, the fastener 3, and the hybrid sound-absorbing pad 2 are sequentially stacked. These fasteners 3 fix the hybrid sound-absorbing pad 2 to the base sound-absorbing pad 1 so as to be breathable. Here, the fastener 3 is interposed between the hybrid sound-absorbing pad 2 and the base sound-absorbing pad 1, the hybrid sound-absorbing pad 2 and the base sound-absorbing pad 1 are closely adhered to each other on both sides, and the hot melt adhesive is applied to both sides. The hybrid sound-absorbing pad 2 is attached to the base sound-absorbing pad 1 as the hybrid sound-absorbing pad 2 and the base sound-absorbing pad 1 are attached to both sides through a hot melt adhesive. The fastener 3 may be composed of a thin film of a non-woven fabric that allows the hybrid sound-absorbing pad 2 and the base sound-absorbing pad 1 to be ventilated. The hot melt nonwoven fabric is a commonly used thin film hot melt nonwoven fabric. Therefore, since those skilled in the art can easily understand, the detailed description is omitted.

Such a fastener 3 may be composed of a hot melt nonwoven fabric having a weight of 1.5 to 5.0 g/m 2 . At this time, when the fastener 3 is composed of a weight of 1.5 g / m 2 or less, there is a problem in that the adhesive property is lowered, and when composed of a weight of 5.0 g / m 2 or more, it does not directly affect the sound absorbing characteristics of the sound absorbing material, but the amount of use increases. Since there is a problem of increasing production cost, it is preferable to use within an appropriate weight, and as an example, it may be provided with a low weight of 3 g / m 2 .

The fastener 3 is thermally fused by a sound absorbing material manufacturing apparatus or manufacturing method for reducing noise in the audible frequency band of a single layer in which meltblown fibers and nanofibers are randomly mixed, which will be described later, to form a base sound absorbing pad 1 and a hybrid sound absorbing pad (2) can be combined. That is, the sound absorbing material of the present invention may be provided as a single sound absorbing material by laminating the base sound absorbing pad 1 and the hybrid sound absorbing pad 2 while the fastener 3 is melted.

The sound absorbing material for reducing noise in the audible frequency band of a single layer in which meltblown fibers and nanofibers of the present invention are randomly mixed as described above is a base sound absorbing pad (1) having excellent sound absorbing characteristics of high frequency noise, and sound absorbing of low frequency noise Due to the structure in which the hybrid sound-absorbing pad 2 having excellent characteristics is combined, sound absorption characteristics in the low-frequency region and the high-frequency region can be improved complementary to each other.

In addition, the sound absorbing material for reducing noise in the audio frequency band of a single layer in which meltblown fibers and nanofibers are randomly mixed according to the present invention is a base sound absorbing pad (1) and a hybrid sound absorbing pad (2) through a fastener (3). As it is laminated to form a single member, it is possible to overcome difficulties in handling and post-processing of the hybrid sound-absorbing pad 2 in which the nanofibers are composited. In addition, the sound absorbing material for reducing noise in the audio frequency band of a single layer in which the meltblown fibers and nanofibers of the present invention are randomly mixed is exposed on the surface while the nanofibers are dispersed and present inside the hybrid sound absorbing pad 20 Since it is not, it is easy to process during post-processing such as laminating, bending or cutting, and it is possible to minimize damage to nanofibers during post-processing.

In particular, the sound absorbing material for reducing noise in the audio frequency band of a single layer in which meltblown fibers and nanofibers are randomly mixed according to the present invention has a non-woven base sound absorbing pad (1) and a hybrid sound absorbing pad (2), and a breathable structure Since the fastener 3 of the laminated structure allows heat to pass through the laminate when heat is applied during manufacturing, the fastener 3 interposed between the base sound absorbing pad 1 and the hybrid sound absorbing pad 2 The base sound-absorbing pad (1) and the hybrid sound-absorbing pad (2) are laminated while the thermal melting is performed smoothly, and the processing shape of the base sound-absorbing pad (1) and the hybrid sound-absorbing pad (2) is achieved by using a low-weight hot-melt nonwoven fabric. It improves the sound absorption performance by not affecting the

In addition, the sound absorbing material for reducing noise in the audio frequency band of a single layer in which meltblown fibers and nanofibers are randomly mixed according to the present invention is a fastener (3) composed of hot melt instead of conventional thermal compression lamination processing that reduces sound absorption characteristics Since the base sound-absorbing pad 1 and the hybrid sound-absorbing pad 2 are bonded by hot air fusion, it is possible to prevent the sound absorption characteristics from deteriorating.

Furthermore, the sound absorbing material for reducing noise in the audio frequency band of a single layer in which the meltblown fibers and nanofibers of the present invention are randomly mixed is manufactured by foam molding or meltblown spinning method, or staple spun by polymer melting As the fibers are manufactured through various nonwoven fabric manufacturing methods such as an air-laid method or a needle punching method, the overall thickness of the sound-absorbing material can be provided at a desired level by adjusting the thickness of the base sound-absorbing pad 1, which is relatively easy to process.

In addition, the sound absorbing material for reducing noise in the audio frequency band of a single layer in which the meltblown fibers and nanofibers of the present invention are randomly mixed is crosslinked with PVA, a water-based polymer, during the hot melt melting process through hot air heating, so crosslinking Through the reaction, the molecular structure of the polymer is changed, and the shape stability of maintaining the shape of the nanofiber against moisture exposure can be increased.

Table 1 below shows the radiation conditions and filter performance of the sound absorbing material composed of only a single meltblown fiber, and Table 2 shows noise reduction in the audible frequency band of a single layer in which the meltblown fibers and nanofibers of the present invention are randomly mixed This is a table showing the radiation conditions and filter performance of the sound-absorbing material for use.

Sample
Name. spin beam
temperature
(℃) Feeder discharge amount
(g/min) Line Speed
(m/min) g/㎡ Side Air DCD(mm) efficiency(%) differential pressure (Pa) note Meltblown Fiber Sound Absorbing Material 280 100 1.6 80 6CMM,
300℃ 890 37.22 42.5

Sample
Name. radiation
method Feeder discharge amount
(g/min) Line Speed
(m/min) g/㎡ Side Air DCD(mm) efficiency(%) differential pressure (Pa) spin beam
temperature
(℃) mixed fibers
sound absorbing material Mlet
Blown 100 1.6 80 6CMM,
300℃ 890 64.88 36 280 electricity One - 200LPM 500

Referring to Tables 1 and 2, the mixing weight of the nanofibers by electrospinning of the sound absorbing material for reducing noise in the audible frequency band of a single layer in which the meltblown fibers and nanofibers of the present invention are randomly mixed is not clearly measured. However, in the efficiency (%) item representing filter performance by mixing meltblown fibers and nanofibers, it was confirmed that it was improved by nearly two times from 37.22% to 64.88%, and through this, it was found that it was effective in sound absorption characteristics. .

In this regard, FIG. 3 is a SEM image of a fiber web of a base sound-absorbing pad having a weight of 80 g/m2 made of meltblown microfibers, and FIG. 4 is an electrospinning PVA nanofiber and meltblown. This is a SEM image of a fiber web of a hybrid sound-absorbing pad with a weight of 80 g / ㎡ in which microfibers of a new method are mixed, and FIG. 5 is a photograph of a fiber web of a nanofiber pad made of electrospinning PVA nanofibers. It is a drawing showing the SEM image.

Referring to FIG. 3, in the fiber web of the base sound-absorbing pad 1 manufactured by the melt blown method, only microfibers having an average diameter of 3 μm and a minimum diameter of 1 μm were observed.

Referring to FIG. 4 , microfibers and nanofibers having an average diameter of 2.5 μm and a minimum diameter of 800 nm were observed in the fiber web of the hybrid sound-absorbing pad 2 manufactured by the melt blown and electrospinning method.

Referring to FIG. 5, it was confirmed that nanofibers having an average diameter of 300 nm and a minimum diameter of 170 nm were observed in the fiber web of the nanofiber pad prepared by the electrospinning method.

In this way, in the hybrid sound-absorbing pad 2 manufactured by the melt blown and electrospinning method, a nanometer-scale fiber diameter that can be confirmed with the naked eye was detected. Referring again to Tables 1 and 2 above, when comparing the base sound-absorbing pad 1 and the hybrid sound-absorbing pad 2, it can be seen that the filter efficiency is increased in the hybrid sound-absorbing pad 2, which is It can be judged by the effect of mixing. The basis for determining these nanofibers is through observation of fine nanofibers and visual confirmation of nanofibers, as shown in the drawing as a result of SEM image analysis.

Although, in the fiber web (FIG. 4) of the hybrid sound-absorbing pad (2), fibers of 300 nm, which is the fiber diameter size observed in the nanofiber pad (FIG. 5), could not be found, but meltblown in the process of mixing PVA nanofibers. Since the nanofibers penetrate into the fibers and form a layer, it is difficult to observe the fibers of the corresponding size when observing the SEM on a plane.

Therefore, when the base sound-absorbing pad 1 and the hybrid sound-absorbing pad 2 are laminated by the fastener 3, the sound-absorbing performance can be improved.

On the other hand, the sound absorbing material for reducing noise in the audio frequency band of a single layer in which meltblown fibers and nanofibers are randomly mixed according to the present invention is, as shown in FIG. 6, a hybrid sound absorbing pad (2) and a fastener (3) It may further include a second hybrid sound-absorbing pad 4 and a second fastener 5 laminated with the base sound-absorbing pad 1 on the opposite side of the. That is, the sound absorbing material according to the present embodiment has a structure in which pads of composite fibers are attached to both sides. The sound absorbing material according to this embodiment has the same configuration as that of the above-described embodiment described with reference to FIGS. 1 and 2 . Accordingly, a detailed description of the same configuration will be omitted.

Therefore, the sound absorbing material according to the present embodiment, as shown in FIG. 6, has a structure in which hybrid sound absorbing pads 2 and 4 of composite fibers are laminated to both sides of the base sound absorbing pad 1 through fasteners 3 and 5. Therefore, the sound absorption performance by the composite fibers can be further improved.

7 is a view showing the overall configuration of a manufacturing apparatus for a sound absorbing material for reducing noise in an audible frequency band of a single layer in which meltblown fibers and nanofibers are randomly mixed according to the present invention, and FIG. 8 is a view showing the meltblown according to the present invention It is a partial perspective view schematically showing a part of a manufacturing apparatus for a sound absorbing material for reducing noise in audible frequency band of a single layer in which raw fibers and nanofibers are randomly mixed.

An apparatus for manufacturing a sound absorbing material for reducing noise in the audio frequency band of a single layer in which meltblown fibers and nanofibers are randomly mixed according to an embodiment of the present invention is a base sound absorbing pad made of a foam material or nonwoven fabric material having a predetermined thickness (1) and is made of a thickness thinner than the thickness of the base sound-absorbing pad (1), and the microfibers and nanofibers are randomly mixed by a spinning method to form a single layer, and are bonded to the base sound-absorbing pad (1) in a laminated state. A hybrid sound-absorbing pad (2) made of a non-woven fabric and a fastener (3) for attaching and fixing the hybrid sound-absorbing pad (2) to the base sound-absorbing pad (1) in a breathable manner, the base sound-absorbing pad (1) and the fastener (3) ) And the hybrid sound-absorbing pad (2) are sequentially laminated, and the fastener (3) is composed of a thin film thermoplastic melt-type adhesive material having a breathable structure. To manufacture a sound-absorbing material for reducing noise in the audible frequency band As shown in FIG. 7, it includes a pedestal 20 on which the sound absorbing material 10, which is a laminated pad, is seated, a heater 30, and a suction 40.

The pedestal 20 is for transporting the sound absorbing material 10 in one direction, and the sound absorbing material 10 in which the base sound absorbing pad 1, the fastener 3, and the hybrid sound absorbing pad 2 are sequentially stacked is seated. It may be configured as a conveyor for moving the sound absorbing material 10.

As shown in FIG. 7 , the pedestal 20 includes a drive motor 21 , rollers 22 and a conveyor belt 23 . That is, the pedestal 20 is a conveyor belt 23 in which rollers 22 rotated by a driving motor 21 are disposed on both sides, and are wound around the rollers 22 and circulated and rotated by the operation of the driving motor 21 consists of As shown in FIG. 5 , the conveyor belt 23 of the pedestal 20 may be provided as a mesh conveyor belt composed of a porous wire mesh in which a plurality of air connectors 23a are formed. The pedestal 20 may be configured to transfer the sound absorbing material 10 at a speed of 0.5 m/min.

The heater 30 is for providing heat to the sound absorbing material 10, is installed on the upper side of the pedestal 20 to which the sound absorbing material 10 is transported, and provides heat to one side of the sound absorbing material 10, so that the sound absorbing material 10 ) so that the adhesive material included in the melt can be melted. As shown in FIG. 7 , the heater 30 includes a heat source 31 , a blower 32 and a guide chamber 33 .

The heat source 31 is disposed to be spaced apart from the pedestal 20 and dissipates heat for melting the adhesive material included in the sound absorbing material 10 . The heat source 31 may be composed of a coil or a hot wire, and dissipates heat.

The blower 32 may be disposed on the front or rear side of the heat source 31 to blow heat from the heat source 31 to the sound absorbing material 10 . That is, the blower 32 is disposed on the front side of the heat source 31 to transfer rear-side heat to the front, or is disposed on the rear side of the heat source 31 to provide wind toward the front to transfer heat as hot air. .

The guide chamber 33 accommodates a heat source 31 and a blower 32 therein. The guide chamber 33 guides the hot air by the heat source 31 and the blower 32 so that the hot air is smoothly supplied to the surface of the sound absorbing material 10 moving on the pedestal 20 . The guide chamber 33 is composed of a fixing part 33a where the heat source 31 and the blower 32 are installed, and a diffusion part 33b extending radially from the fixing part 33a to spread hot air. can The guide chamber 33 guides the hot air generated inside to be smoothly supplied to the entire surface of the sound absorbing material 10 while being diffused through the diffusion part 33b.

As such, the heater 30 generates hot air from the heat source 31 through the blower 32 and transfers it to the sound absorbing material 10 through the guide chamber 33 . The heater 30 may provide hot air set at a temperature of approximately 110°C.

In addition, in the heater 30, it is preferable that the thermal fusion section H directly facing the sound absorbing material 10 transferred from the pedestal 20 is formed to a length of 50 cm to 120 cm. In the heater 30, the length of the heat welding section may be determined by the size of the guide chamber 33 in which the heat source 31 is installed. At this time, when the length of the heat-sealed section by the heater 30 is formed shorter than 50 cm, there is a problem that the lamination by heat-sealing of the adhesive material included in the sound-absorbing material 10 is insufficiently achieved, and the heat-sealed section When the length is formed longer than 120 cm, there is a problem in that carbide is generated in the sound absorbing material 10 as the hot air applied to the sound absorbing material 10 is exposed for a long time, so it is preferable to set it within an appropriate length. As an example, the length of the thermal fusion section by the heater 30 of the present invention may be configured to be 90 cm.

The suction 40 is for absorbing heat applied to the sound absorbing material 10, and is installed below the pedestal 20 to which the sound absorbing material 10 is transported, as shown in FIGS. 7 and 8 . The suction 40 absorbs air and heat from the heater 30 on the other side of the sound absorbing material 10 so that the heat is transmitted and moved in the thickness direction of the sound absorbing material 10 . in other words. The suction 40 induces hot air provided from the heater 30 to the sound absorbing material 10 to pass through the sound absorbing material 10 and apply heat to the sound absorbing material 10 . As shown in FIG. 7 , the suction 40 includes a collector 41 and an intake fan 42 installed on the other side of the sound absorbing material 10 .

The collector 41 collects hot air from the heater 30 passing through the sound absorbing material 10 . The collector 41 may be installed adjacent to or in close contact with the lower side of the pedestal 20, and may be disposed over the heat fusion section where the heater 30 is installed. The collector 41 collects heat provided by the heater 30 .

The intake fan 42 is connected to the collector 41 and provides negative pressure to the collector 41 so that the heat supplied from the heater 30 is collected through the collector 41 .

The hot air collected through the collector 41 is discharged to the outside through an exhaust pipe 43 connected to the outside.

At this time, the suction 40 may be configured to have a length corresponding to that of the heat-sealing section formed by the heater 30, but in contrast to the heat-sealing section formed by the heater 30, the sound absorbing material 10 passes through cooling. It may also be configured with a longer length than the length of the heater 30 to apply continuous heat discharge for.

The configuration of the suction 40 may be composed of a commonly used air intake device or heat exhaust device. Therefore, since those skilled in the art can easily understand, the detailed description is omitted.

The operation of the apparatus for manufacturing a sound absorbing material for reducing noise in the audio frequency band of a single layer in which meltblown fibers and nanofibers are randomly mixed according to the present invention configured as described above will be described.

First, the pedestal 20 transfers the sound absorbing material 10 mounted on the conveyor belt 23 in one direction. As an example, the pedestal 20 may transfer the sound absorbing material 10 at a transfer speed of 0.5 m/min.

The sound absorbing material 10 transported by the pedestal 20 passes through the heat-sealing section where the heater 30 and the suction 40 are located.

Then, the heater 30 applies hot air to the sound absorbing material 10 . As an example, the heater 30 applies hot air to the surface of the sound absorbing material 10 at a high temperature of 110° C., and induces the adhesive material included in the sound absorbing material 10 to be heat-sealed. The heater 30 applies hot air for about 100 seconds to the sound absorbing material 10 being transported at a transport speed of 0.5 m/min by the pedestal 20 described above.

At this time, while the heater 30 applies hot air to the sound absorbing material 10, the suction 40 absorbs air and heat from the heater 30 from the bottom of the pedestal 20 in the thickness direction of the sound absorbing material 10. allow heat to pass through.

Thus, the heated air applied on the surface of the sound absorbing material 10 easily passes through the sound absorbing material 10, and the adhesive material of the fastener 3 interposed between the base sound absorbing pad 1 and the hybrid sound absorbing pad 2 it melts

In addition, the suction 40 causes the hybrid sound-absorbing pad 2 of the upper layer of the sound absorbing material 10 and the base sound-absorbing pad 1 of the lower layer to come into close contact with each other with the differential pressure formed by the intake and exhaust, and the molten fastener 3 of the middle layer While being attached to each of the upper and lower layers, lamination is performed.

That is, the base sound-absorbing pad 1 and the hybrid sound-absorbing pad 2 of the sound absorbing material 10 are laminated by the adhesive material of the fastener 3 that is heat-sealed through hot air heating.

Here, as the pedestal 20 is constructed in the form of a mesh with a perforated conveyor belt 23 for moving the sound absorbing material 10, the discharge of hot air by the heater 30 and the suction by the suction 40 are performed smoothly. It can be.

In addition, the heater 30 guides the hot air generated inside through the guide chamber 33 to be smoothly supplied to the entire surface of the sound absorbing material 10, so that the adhesive material of the fastener 3 can be evenly fused, and some It is possible to prevent carbide from being generated in the sound absorbing material 10 by preventing heat from being concentrated in the region.

In addition, the suction 40 is disposed close to the pedestal 20 so that the hot air provided from the heater 30 can be completely discharged through the sound absorbing material 10 transported on the pedestal 20 to perform an intake operation. .

In addition, the suction 40 induces the heat generated from the heater 30 to be smoothly transmitted through the sound absorbing material 10. As the heat of the sound absorbing material 10 whose temperature has risen by heat is absorbed, after melting of the adhesive material During the bonding action, the sound absorbing material 10 is rapidly cooled. In addition, the suction 40 rapidly circulates the movement of heat, and it is possible to prevent generation of carbide in the sound absorbing material 10 due to high temperature.

In addition, the suction 40 is extended beyond the installation section of the heater 30, and it is possible to prevent generation of carbide and decrease in cooling rate due to residual heat after the supply of heat by the heater 30 is stopped.

9 is a flowchart schematically illustrating a manufacturing method using a manufacturing apparatus for a single-layered sound absorbing material for reducing noise in an audible frequency band in which meltblown fibers and nanofibers are randomly mixed according to the present invention.

A manufacturing method using a manufacturing apparatus for a sound absorbing material for reducing noise in the audio frequency band of a single layer in which meltblown fibers and nanofibers are randomly mixed according to an embodiment of the present invention is a foam material or non-woven fabric material having a predetermined thickness of the base sound-absorbing pad (1) and a thickness smaller than the thickness of the base sound-absorbing pad (1), and the microfibers and nanofibers are randomly mixed by a spinning method to form a single layer, and the base sound-absorbing pad (1) A hybrid sound-absorbing pad (2) made of non-woven fabric coupled in a laminated state and a fastener (3) for attaching and fixing the hybrid sound-absorbing pad (2) to the base sound-absorbing pad (1) in a breathable manner, the base sound-absorbing pad (1) The fastener 3 and the hybrid sound-absorbing pad 2 are sequentially laminated, and the fastener 3 is composed of a thin film thermoplastic melt-type adhesive material having a breathable structure. A sound absorbing material for reducing noise in the audible frequency band is for manufacturing.

To this end, a manufacturing method for manufacturing a sound absorbing material using a manufacturing apparatus for a sound absorbing material for reducing noise in the audio frequency band of a single layer in which meltblown fibers and nanofibers are randomly mixed according to an embodiment of the present invention is shown in FIG. 9 As shown, a base sound-absorbing pad arrangement step (S110) of disposing a base sound-absorbing pad made of a foam material or non-woven fabric having a predetermined thickness on a pedestal, and a thin film type fastener having a melt-type adhesive material laminated on the base sound-absorbing pad. Fastener laminating step (S120), laminated pad forming step (S130) of forming a laminated pad by laminating a hybrid sound-absorbing pad made of non-woven fabric on the base sound-absorbing pad on which thin film fasteners are laminated (S130), and melting the adhesive material of the fastener to form the hybrid sound-absorbing pad on the base It may include a pad attaching step (S140) of attaching to the sound absorbing pad.

In detail, in the base sound-absorbing pad arrangement step (S110), a base sound-absorbing pad 1 made of a foam or non-woven fabric having a predetermined thickness is placed on the pedestal 20.

In the base sound-absorbing pad arrangement step (S110), the base sound-absorbing pad 1 disposed on the pedestal 20 may be manufactured using a polymer such as PP, PE, PET, Nylon or PLA, for example using a PET spinning solution. Thus, it can be produced into micro-sized fibers by a melt blown manufacturing method, and preferably has a diameter of 1 to 15 μm. For example, the size of fibers constituting the base sound-absorbing pad 1 may be formed to an average size of 3 μm and as small as 1 μm. Here, the base sound-absorbing pad 1 may have a weight of 400 g/m 2 . At this time, the pedestal 20 on which the base sound-absorbing pad 1 is placed in the base sound-absorbing pad arrangement step (S110) may be configured as a conveyor belt 23 for the movement of the base sound-absorbing pad 1, and the conveyor belt 23 ) may be provided as a mesh conveyor belt composed of a porous wire mesh. In addition, the pedestal 20 may be configured to transfer the sound absorbing material 10 at a speed of 0.5 m/min.

In the thin film fastener lamination step (S120), a thin film fastener 3 having a melt-type adhesive material having a breathable structure is laminated on the surface of the base sound absorbing pad 1.

In the thin-film fastener lamination step (S120), the adhesive material of the fastener 3 laminated on the base sound-absorbing pad 1 may be formed of an adhesive material made of a thin hot-melt non-woven fabric to which a hot-melt is meltably applied, of the hot-melt non-woven fabric. It may be provided as a single layer fastener 3 composed of a weight of 1.5 to 5.0 g/m2. As an example, fastener 3 may be formed with a weight of 3 g/m 2 .

In the laminated pad forming step (S130), the hybrid sound-absorbing pad made of a non-woven fabric material having a thickness smaller than the thickness of the base sound-absorbing pad 1 and randomly mixing micro fibers and nanofibers by a spinning method to form a single layer (2) ) is laminated on the fastener 3. That is, a laminated pad is formed in which the base sound-absorbing pad 1, the fastener 3, and the hybrid sound-absorbing pad 2 are successively laminated.

In the laminated pad forming step (S130), the hybrid sound-absorbing pad 2 laminated on the fastener 3 may be produced as a composite fiber in which microfibers and nanofibers are mixed by a melt blown method and an electrospinning method, and preferably Nanofibers with a diameter of 100 to 900 nm and micro fibers with a diameter of 1 to 15 μm may be mixed. For example, the size of fibers constituting the hybrid sound-absorbing pad 2 may be formed to an average size of 2.5 μm and a size of 900 nm as small as possible. Here, the hybrid sound-absorbing pad 2 may be formed with a thickness thinner than the total thickness of the base sound-absorbing pad 1, for example, may be formed with a thickness of 5 to 25% of the total thickness of the base sound-absorbing pad 1 . And, the hybrid sound-absorbing pad 2 may have a weight of 80 g/m 2 .

In addition, in this embodiment, the laminated hybrid sound-absorbing pad 2 uses PP or PET as a raw material, spinning temperature 280 ° C, discharge amount 100 g / min, side air 6 CMM, distance between nozzle and collector 890 mm, line speed 1.6 m/min melt blown method, using PVA as a raw material, 1 g/min discharge amount (regulator: 6 kgf/cm2), side air 200 LPM, distance between nozzle and melt blown radiation 500 mm, 45 KV A nonwoven fabric in which micro-sized fibers and nano-sized fibers are mixed and formed by electrospinning under high voltage conditions may be used.

The pad attaching step (S140) is performed by the pedestal 20, the heater 30, and the suction 40.

In the pad attaching step (S140), the hybrid sound absorbing pad 2 is attached to the base sound absorbing pad 1 by melting the adhesive material. In the pad attaching step (S140), hot air is supplied to the laminated pad transported by the pedestal 20 through the heater 30 to melt the adhesive material, and the heat is taken in by the suction 40 so that the heat is smoothly transferred. , It passes through the heater 30 and goes through a cooling process so that the curing of the adhesive material is completed.

Specifically, as shown in FIG. 10, the pad attaching step (S140) includes an adhesive material melting step (S141) of melting the adhesive material by providing heat to the laminated pad to melt the adhesive material provided on the fastener, and the melted adhesion. A cooling step (S142) of cooling and curing the material may be included.

In the adhesive material melting step (S141), the sound absorbing material 10 transported by the pedestal 20 passes through the heat fusion section in which the heater 30 is installed, and provides hot air by the heater 30 while passing through the heat fusion section. The adhesive material is melted and lamination is achieved. That is, in the melting of the adhesive material (S141), heat is applied to the laminated pad to induce melting of the adhesive material.

In the adhesive material melting step (S141), hot air from the heater 30 is provided from top to bottom, and the surface of the hybrid sound-absorbing pad 2, which is a laminated pad located on the upper side, is heated. The adhesive material melting step (S141) may provide hot air set at a temperature of about 110 ° C., and the heated air above the sound absorbing material 10 passes through the sound absorbing material 10 in the moving direction, so that the fastener 3 located between the pads to melt the adhesive material. The lower base sound-absorbing pad 1 and the upper hybrid sound-absorbing pad 2 are attached to each other by the molten adhesive material, and lamination is performed.

At this time, in the adhesive material melting step (S141), it is preferable that the exposure time by hot air is set between 80 and 130 seconds based on the temperature of 110 °C. If it is shorter than 80 seconds, there is a problem that the crosslinking reaction of the laminated pad is not sufficient and the phenomenon of melting in water occurs. There is a problem of reduced production. In addition, the hot air exposure time may vary depending on the length of the thermal fusion section determined by the size of the heater 30 and the conveying speed, for the size of the heater 30 having a 900 mm thermal fusion section, 80 to 130 seconds In order to maintain the heat treatment time, the transport speed of the pedestal 20 is preferably set to a speed of 0.42 to 0.68 m/min. Therefore, according to one embodiment of the present invention, in the adhesive material melting step (S141), the hot air by the heater 30 is provided at a temperature of 110 ° C, and the length of the heater 30 provided with the hot air is set to 900 mm. Accordingly, the transport speed of the laminated pad by the pedestal 20 is maintained at 0.5 m/min, and hot air can be supplied to the laminated pad in about 108 seconds.

In the adhesive material melting step (S141), cross-linking of the PVA nanofibers proceeds while hot air passes through the laminated pad.

Thereafter, in the cooling step (S142), the molten adhesive material is cooled to harden. That is, in the cooling step (S142), the natural cooling of the sound absorbing material 10 completely passes through the thermal fusion section by the heater 30 as it is transferred from the pedestal 20 in one direction. It provides a section, is cured by cooling, and is formed as a laminated sound absorbing material (10).

Meanwhile, as shown in FIG. 10 , the pad attaching step ( S140 ) may further include a suction step ( S143 ) of sucking heat provided to the laminated pad from the bottom of the laminated pad.

The suction step (S143) is between the adhesive material melting step (S141) and the cooling step (S142) or The adhesive material melting step (S141) and the cooling step (S142) may be performed, and the heat provided to the laminated pad from the heater 30 by the suction 40 installed at the bottom of the pedestal 20 is transferred to the lower part of the laminated pad. Inhaled from and induces the heat to completely penetrate the sound absorbing material (10).

In the suction step (S143), the suction flow rate by the suction 40 is such that the hot air passes from the hybrid sound-absorbing pad 2, which is the upper part of the laminated pad, to the base sound-absorbing pad 1, which is the lower part, so that uniform heating and heat transfer are achieved. and since the passing flow rate must be 0.8 to 2.0 m/min, the suction flow rate can be set to 6.48 to 16.2 m/min. At this time, the supply flow rate is to supply a flow rate 20% higher than the suction flow rate for the purpose of forming a positive pressure in the chamber, and when the suction flow rate is provided at 10m3/min, the supply flow rate can be provided at 12m3/min there is.

In the suction step (S143), the hybrid sound-absorbing pad 2 of the upper layer and the base sound-absorbing pad 1 of the lower layer come into close contact with each other with the differential pressure formed by the intake and exhaust through the suction 30, and the molten fastener 3 of the middle layer While attached to each of the upper and lower layers, the laminated pads are laminated. That is, in addition to the adhesion of both adjacent pads by simply melting the fastener 3 through hot air, the adhesion between the hybrid sound-absorbing pad 2 and the base sound-absorbing pad 1 by differential pressure without a pressing process is increased.

In addition, since the heat applied to the laminated pad can be discharged while passing through it completely by the suction step (S143), generation of carbide in the laminated pad due to high temperature is prevented.

Here, during the laminating process performed by the pad attaching step (S140), when the processing temperature, heat treatment time, and hot air circulation structure are satisfied as described above, a desired performance result for crosslinking can be obtained.

11 is a view showing the measurement results of crosslinking evaluation, which is a measurement for the water-insoluble item of nanofiber PVA. The degree of crosslinking is evaluated by immersing the product in water at 90 ° C. for 1 minute and then taking it out and measuring the weight change of the nanofiber.

Referring to FIG. 11, during heat treatment of the nanofiber sound-absorbing product, a temperature of 140° C. or higher and a product transport speed of 5 m/min are required to achieve a degree of crosslinking of 93% or higher.

To this end, the present invention provides a low-weight hot-melt nonwoven fabric having a network structure with a melting point of 94 ° C and a weight of 3 g / m 2, and the processing temperature is set to 110 ° C. In addition, the feed rate of the pedestal 20 was set to 0.5 m/min, and the heat treatment time passing through the thermal fusion section H was increased to 108 seconds to ensure sufficient heat treatment. And, in the present invention, the inside of the guide chamber 33 of the heater 30 is designed with positive pressure at a supply flow rate of 12 m3/min and a suction flow rate of 10 m3/min for a hot air circulation structure, so that uncontrolled external fluid is supplied to the inside. While preventing this, the hot air by the heater 30 is evenly circulated.

Accordingly, the present invention provides hot air at a temperature lower than the conventional PVA crosslinking heat treatment temperature conditions, but provides a sufficient time while stably performing the crosslinking treatment, and can achieve a crosslinking degree of 93% or more.

In this way, according to the manufacturing method using the manufacturing apparatus according to the embodiment of the present invention, a non-contact lamination process in which adhesive materials are fused and laminated using a hot air heating method is performed. In the present invention, since the laminating process is performed in a non-contact manner without a compression process, it is advantageous to maintain the sound absorbing characteristics of the sound absorbing material.

That is, in the case of lamination by thermal compression, the structure of the sound absorbing material is made dense, so that the sound absorbing characteristics are reduced, while the lamination by hot air fusion without compression can improve the sound absorbing characteristics.

In addition, according to the manufacturing method using the manufacturing apparatus according to the embodiment of the present invention, since the cross-linking of PVA, which is a water-based polymer, proceeds during the thermal fusion process, the molecular structure of the polymer is changed through the cross-linking reaction, and the nanoparticles are resistant to moisture exposure. It is possible to increase the shape stability of maintaining the shape of the fiber. At this time, since the hot air is injected from one side and the hot air is sucked in from the other side to discharge the hot air at the same time, the movement of heat is rapidly circulated, so that the hot air passes through the laminated pad intact and the crosslinking reaction proceeds smoothly in the process of passing the hot air. can

Experimental example

Through the steps of FIGS. 9 and 10 described above, a single-layered sound absorbing material for reducing noise in an audible frequency band in which meltblown fibers and nanofibers were randomly mixed was prepared. The base sound-absorbing pad of the sound-absorbing material is formed of a non-woven fabric containing PET meltblown microfibers with a fiber diameter of 10 to 40 μm and has a weight of 400 g/m 2 . The hybrid sound-absorbing pad of the sound absorbing material is formed of a nonwoven fabric in which polypropylene meltblown microfibers with a fiber diameter of 2 to 5 μm and PVA electrospun nanofibers with a fiber diameter of 150 to 400 nm are combined into a single layer, and the weight is 80 g / m 2 . A sound absorbing material in which the base sound absorbing pad and the hybrid sound absorbing pad were laminated by a fastener was prepared using the above-described manufacturing device, and a sound absorbing performance measurement equipment commonly known as Alpha Cabin was used to compare sound absorbing properties with existing products. .

Table 3 below shows the sound absorption characteristics of the sound absorption material measured through the experimental example. Among the entire measurement range, data from 400 to 4,000 Hz were selectively used. The corresponding band is included in the group of regions classified in the human hearing test, including the low-frequency region of 400 to 1,000 Hz, the mid-frequency region of 1,000 to 3,150 Hz, and the high frequency region of 2,000 to 5,000 Hz. It can be included in, which is included in the audible frequency band.

Frequency Sound Absorption Coefficient Hz Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 400 0.513 0.480 0.000 0.190 0.460 0.410 0.240 450 0.698 0.625 0.000 0.256 0.565 0.480 0.320 500 0.896 0.773 0.030 0.325 0.683 0.550 0.400 565 0.987 0.838 0.070 0.430 0.780 0.625 0.430 630 1.082 0.905 0.120 0.545 0.878 0.700 0.460 715 1.117 0.950 0.152 0.634 0.970 0.770 0.520 800 1.157 1.010 0.184 0.716 1.065 0.840 0.580 900 1.190 1.083 0.186 0.782 1.135 0.950 0.665 1000 1.223 1.170 0.190 0.852 1.200 1.060 0.750 1125 1.211 1.230 0.200 0.942 1.230 1.130 0.790 1250 1.206 1.283 0.202 1.016 1.250 1.200 0.830 1425 1.187 1.240 0.172 1.016 1.250 1.275 0.915 1600 1.173 1.188 0.146 1.016 1.245 1.350 1.000 1800 1.160 1.153 0.130 1.078 1.230 1.270 1.015 2000 1.143 1.123 0.110 1.150 1.220 1.190 1.030 2250 1.163 1.035 0.116 1.190 1.180 1.170 1.015 2500 1.185 0.953 0.120 1.215 1.145 1.150 1.000 2825 1.085 0.908 0.084 1.146 1.105 1.200 1.050 3150 0.989 0.865 0.050 1.100 1.065 1.250 1.100 3575 0.978 0.888 0.030 1.068 1.060 1.220 1.075 4000 0.967 0.917 0.000 1.050 1.040 1.190 1.050

Experimental Example 1

12 is a graph showing the results of measuring the sound absorbing characteristics of the alpha cabin equipment for the sound absorbing material according to the present invention (Example 1) and the non-laminated general sound absorbing pad (Comparative Example 1).

Referring to FIG. 12, it can be seen that the sound absorbing material according to the present invention (Example 1) shows excellently improved sound absorbing characteristics over the entire area compared to a general sound absorbing pad (Comparative Example 1) that is not laminated. That is, it can be confirmed that the sound absorbing performance is improved in the audible frequency band including the low frequency and high frequency bands as the base sound absorbing pad and the hybrid sound absorbing pad are laminated and used as a single sound absorbing material according to the present invention.

Experimental Example 2

13 is a graph showing the results of measuring the sound absorbing characteristics of the Alpha cabin equipment for the sound absorbing material according to the present invention (Example 1) and the commercial product 3M Thinsulate sound absorbing material (Comparative Example 2).

3M's Thinsulate sound absorbing material (Comparative Example 2) is a non-woven fabric product made of 70% polypropylene MB fiber and 30% PET fiber non-woven fabric with a weight of 350 g / m 2.

Referring to FIG. 13, the conventional sound-absorbing material (Comparative Example 2) shows slightly higher sound-absorbing characteristics than the sound-absorbing material of the present invention (Example 1) in some high-frequency bands, but it is significantly lower in the low-frequency band and is measured in the low-frequency band. It can be seen that the sound absorption performance at . That is, it can be seen that the sound absorbing material according to the present invention (Example 1) shows excellent sound absorption characteristics in a low frequency band compared to the 3M Thinsulate sound absorbing material (Comparative Example 2).

Experimental Example 3

14 is a graph showing the results of measuring the sound absorbing characteristics of the alpha cabin equipment for the sound absorbing material (Example 1) according to the present invention and Comparative Examples 3 and 4, which are conventional sound absorbing materials.

The sound absorbing materials according to Comparative Examples 3 and 4 are sound absorbing materials made of melt blown nonwoven fabric having a weight of 330 g/m 2 . The sound absorbing materials of Comparative Example 3 and Comparative Example 4 are composed of nonwoven fabrics of the same weight, but are manufactured in a manner in which the weight ratio of fibers or manufacturing process is partially different.

Referring to FIG. 14, the sound absorbing material according to the present invention (Example 1) is superior to the conventional sound absorbing materials of Comparative Examples 3 and 4 in a low frequency band (400 Hz to 1,000 Hz) and some high frequency bands (2,500 Hz). characteristics can be seen.

Experimental Example 4

15 is an image showing the results of measuring the sound absorbing characteristics of the alpha cabin equipment for the sound absorbing material according to the present invention (Example 1) and the conventional sound absorbing material (Comparative Example 5) as a graph.

The sound absorbing material according to Comparative Example 5 is a sound absorbing material made of a melt blown nonwoven fabric having a weight of 180 g/m 2 . The sound absorbing material according to Comparative Example 5 is configured to have a different weight from the sound absorbing material of Comparative Example 4.

15, the sound absorbing material according to the present invention (Example 1) has a range from 400 Hz to 2,825 Hz than the conventional sound absorbing material of Comparative Example 5, that is, from a low frequency band (400 Hz to 1,000 Hz) to some high frequency band (2,825 Hz) It can be seen that excellent sound absorption properties are exhibited in the range up to.

Experimental Example 5

16 is the alpha cabin equipment for the sound absorbing material according to the present invention (Example 1, Example 2), the general sound absorbing pad that is not laminated (Comparative Example 1), and the conventional sound absorbing material (Comparative Examples 2, 3 and 5) It is an image showing the result of measuring sound absorption characteristics as a graph.

Example 2 is an average value (cross-sectional average) of characteristic values measured for a plurality of sound-absorbing material groups manufactured by cross-section bonding a hybrid sound-absorbing pad to one side or the other side of a base sound-absorbing pad according to an embodiment of the present invention. show

Referring to FIG. 16, it can be seen that the overall average value of the sound absorbing material of Example 2 according to the present invention is slightly lower than that of the sound absorbing material of Example 1. That is, in the case of the sound absorbing material of Example 2, it can be seen that different characteristics are exhibited as the position of the attachment surface of the hybrid sound absorbing pad to the base sound absorbing pad is changed.

As a result of the experiment, it was confirmed that the performance improvement of the sound absorbing characteristics was confirmed through the lamination of the hybrid sound absorbing pad according to the present invention. That is, it was found that the sound absorbing material according to the present invention has significantly improved sound absorbing properties compared to the general sound absorbing pad to which the hybrid sound absorbing pad is not attached (Comparative Example 1). It was found that it showed high sound absorption characteristics in some high frequency bands.

After all, according to the present invention, the sound absorbing properties can be improved by laminating the hybrid sound absorbing pad including the nano-diameter fibers together with the micro fibers, and the sound absorbing properties can be improved in the overall audible frequency band across the low and high frequency bands. can

In particular, according to the present invention, due to the structure in which a base sound-absorbing pad having excellent sound-absorbing characteristics of high-frequency noise and a hybrid sound-absorbing pad having excellent sound-absorbing characteristics of low-frequency noise are combined, the sound-absorbing characteristics in the low-frequency and high-frequency regions are improved in a complementary manner. For example, it is possible to absorb high-frequency noise caused by an engine of a general internal combustion engine vehicle and at the same time absorb low-frequency noise caused by a motor mounted on a hybrid or electric vehicle. That is, according to the present invention, rather than being limited to the purpose of blocking noise of a specific band, it can be used in various fields in a general purpose.

The above description is merely an example of the technical idea of the present invention, and various modifications and variations can be made to those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are for explanation, not for limiting the technical idea of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments.

1: base sound-absorbing pad 2: hybrid sound-absorbing pad
3: fastener 10: laminated pad
20: pedestal 21: drive motor
22: roller 23: conveyor belt
30: heater 31: heat source
32: blower 33: guide chamber
40: suction 41: collector
42: intake fan 43: exhaust pipe

Claims (7)

A base sound-absorbing pad made of a foam material or non-woven fabric having a predetermined thickness; a hybrid sound-absorbing pad made of non-woven fabric that is bonded to the base sound-absorbing pad in a laminated state and randomly mixed with microfibers and nanofibers by a spinning method to form a single layer; and a fastener for attaching and fixing the hybrid sound-absorbing pad to the base sound-absorbing pad in a breathable manner, wherein the base sound-absorbing pad, the fastener, and the hybrid sound-absorbing pad are sequentially stacked, and the fastener has a breathable structure. A porous support on which a sound absorbing material for reducing noise in the audible frequency band is seated, characterized in that composed of a thin film of thermoplastic melt-type adhesive material; and
A heater providing heat for melting the adhesive material provided on the fastener to one side of the sound absorbing material seated on the pedestal;
A single layer in which meltblown fibers and nanofibers are randomly mixed, characterized in that the base sound-absorbing pad and the hybrid sound-absorbing pad of the sound-absorbing material are laminated by an adhesive material provided on the fastener melted by the heat of the heater. Sound absorbing material manufacturing apparatus for noise reduction in audible frequency band. The method of claim 1, wherein the pedestal,
It consists of a mesh conveyor belt for moving the sound absorbing material and is circulated by a drive motor of the conveyor, a sound absorbing material manufacturing apparatus for reducing noise in the audible frequency band of a single layer in which meltblown fibers and nanofibers are randomly mixed. The method of claim 1, wherein the heater,
a heat source dissipating heat for melting the adhesive material of the fastener;
a blower for blowing heat from the heat source to the sound absorbing material; and
A guide chamber for guiding the hot air blown from the blower to one side of the sound absorbing material in a diffused state; a single layer in which meltblown fibers and nanofibers are randomly mixed for noise reduction in the audible frequency band, including a manufacturing apparatus . According to claim 1,
Suction for absorbing heat from the heater together with air from the other side of the sound absorbing material and transmitting the heat in the thickness direction of the sound absorbing material; meltblown fibers and nanofibers randomly mixed single layer audio frequency band further comprising Sound absorbing material manufacturing device for noise reduction. The method of claim 4, wherein the suction,
a collector installed on the other side of the sound absorbing material to collect hot air passing through the sound absorbing material; and
A sound absorbing material manufacturing apparatus for reducing noise in an audible frequency band of a single layer in which meltblown fibers and nanofibers are randomly mixed, comprising: an intake fan for providing a negative pressure to the collector. Manufactured by the apparatus of claim 1, on one side of a base sound-absorbing pad made of a foam material or non-woven fabric having a predetermined thickness, it is bonded to the base sound-absorbing pad in a laminated state, and microfibers and nanofibers are randomly spun by a spinning method. A hybrid sound-absorbing pad made of nonwoven fabric that is mixed to form a single layer is integrally laminated by a thin-film fastener having a thermoplastic melt-type adhesive material having a breathable structure, wherein meltblown fibers and nanofibers are randomly mixed. A single-layer sound-absorbing material for reducing noise in the audible frequency band. The method of claim 6, wherein the fastener,
The hybrid sound-absorbing pad and the base sound-absorbing pad are interposed between the hybrid sound-absorbing pad and the base sound-absorbing pad, and the hybrid sound-absorbing pad and the base sound-absorbing pad are adhered to each other on both sides, and the hot melt constituting the adhesive material is meltably applied to both sides of the hybrid sound-absorbing pad and the base sound-absorbing pad. As the hybrid sound-absorbing pad and the base sound-absorbing pad are attached, the hybrid sound-absorbing pad is attached to the base sound-absorbing pad, and it is composed of a thin film of non-woven fabric to ventilate the hybrid sound-absorbing pad and the base sound-absorbing pad. Characterized in that, a sound absorbing material for reducing noise in the audible frequency band of a single layer in which meltblown fibers and nanofibers are randomly mixed.

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