KR101012401B1 - Air filter comprising a staple fiber non-woven support with high an air-permeability and Method of preparing the same - Google Patents

Abstract

The present invention relates to an air filter comprising a painless short fiber nonwoven support and a method of manufacturing the same. The air filter of the present invention comprises a nonwoven fabric support, a nonwoven fabric cover and a melt blown nonwoven fabric interposed between the nonwoven fabric support and the nonwoven fabric cover, wherein the nonwoven fabric support is a first thermoplastic polymer having a predetermined melting point and the first It is characterized in that the non-woven fabric support formed of a heat-sealing two-component composite spun short fibers made of a second thermoplastic polymer having a lower melting point than the thermoplastic polymer. The air filter of the present invention has a non-woven fabric support having excellent uniformity, thereby extending its life and improving filtration efficiency and breathability.

Air filter, nonwoven support, heat fusion

Description

Air filter comprising a staple short fiber nonwoven support and a method of manufacturing the same {Air filter comprising a staple fiber non-woven support with high an air-permeability and Method of preparing the same}

The present invention relates to an air filter comprising a painless short fiber nonwoven support and a method of manufacturing the same. More particularly, the present invention relates to an air filter including a high-performance painless short-fiber nonwoven support that can be used in automobiles, buildings, air conditioners, clean rooms, and the like, and a method of manufacturing the same.

With the recent development of the industry, various machinery and work sites are increasing, and dust and smoke emitted therefrom are emerging as a threat to human health. Therefore, the use of the air filter in the place where the human dwelling, such as the inside of the building and the transportation means such as cars, etc. is now almost generalized. In addition, the use of a high performance air filter is essential in the semiconductor manufacturing process requiring high precision, since the presence of fine dust itself can increase the defective rate of the product.

Such an air filter generally uses a melt blown nonwoven fabric as a filter material and has a nonwoven support for supporting the melt blown nonwoven on one side thereof and a nonwoven cover for protecting the melt blown nonwoven on the other side thereof. do.

Typically, the air filter is used to increase the contact area with air by pleating the filter in order to ensure the efficiency and long life of the filter. At this time, if the folded filter is not maintained in the folded state and recovered flat, the contact ability between the air and the filter decreases, the filter efficiency falls, and the pressure loss increases.

However, since the melt blown nonwoven fabric commonly used as a filter material is formed of microfiber, the shape stability is low and the bendability is not effectively exhibited. Therefore, the shape stability of the filter support for supporting the filter is essential, and in particular, in the cabin filter for automobiles in which a large amount of air flows into the small filter area and in the medium filter of high efficiency, the shape stability is necessary.

For this purpose, polyester spunbond nonwoven fabric has been conventionally used as a nonwoven support. However, spunbond nonwoven fabrics have good morphological stability, but due to their process characteristics, they have poor homogeneity and are impossible to mix with other fibers to impart additional functionality.

Therefore, it is urgent to develop a nonwoven fabric support having excellent morphological stability and improved uniformity.

Therefore, the problem to be solved by the present invention is to provide an air filter having a non-woven fabric support excellent in uniformity, and to improve the life and improve the filtration efficiency, and a method of manufacturing the same.

In order to solve the above problems, the air filter of the present invention, the air filter comprising a nonwoven fabric support, a nonwoven fabric cover and a melt blown nonwoven fabric interposed between the nonwoven fabric support and the nonwoven fabric cover, the nonwoven fabric support has a predetermined melting point It is characterized in that the non-woven fabric support formed of a heat-sealable bicomponent composite spun short fibers made of a first thermoplastic polymer and a second thermoplastic polymer having a lower melting point than the first thermoplastic polymer.

The nonwoven support according to the present invention may further include non-fused fibers in addition to the heat-sealed short fibers. As the non-fused fiber, one or more polyester fibers, polypropylene fibers, hemp, cotton, and rayon may be used in combination. The non-fused fiber according to the present invention may be included in an amount of 0.01 to 50% by weight based on the total weight of the nonwoven support, if necessary, but is not limited thereto.

In addition, in order to solve the above problems, the air filter manufacturing method of the present invention, in the manufacturing method of the air filter comprising a nonwoven fabric support, a nonwoven fabric cover and a melt blown nonwoven fabric interposed between the nonwoven fabric support and the nonwoven fabric cover, The nonwoven support is a non-woven web made of a heat-sealing two-component composite yarn short fiber composed of a first thermoplastic polymer having a predetermined melting point and a second thermoplastic polymer having a lower melting point than the first thermoplastic polymer through a carding process or a wet process. Forming a; (S2) heat-treating the nonwoven web to a temperature higher than the melting points of the heat sealable fibers to melt the heat sealable fibers; And (S3) maintaining the temperature between the glass transition temperature and the melting point for the heat treated nonwoven web, and then thermally compressing the nonwoven web.

In the air filter manufacturing method of the present invention, in the step (S1) it may further comprise a non-fused fiber to form a nonwoven web.

Since the nonwoven fabric support formed from the heat-sealing bicomponent composite spun short fibers according to the present invention has an improved homogeneity, the air filter manufactured by using the same may have an extended life and exhibit consistent and improved filtration efficiency.

In addition, since the nonwoven fabric support according to the present invention may be formed including non-fused fibers, the bulkiness may be further imparted, the air permeability may be further improved, and additional functionalities may be further provided depending on the type of fiber.

Hereinafter, the present invention will be described in detail with reference to the drawings. The terms or words used in this specification and claims are not to be construed as limiting in their usual or dictionary meanings, and the inventors may appropriately define the concept of terms in order to best explain their invention in the best way possible. It should be interpreted as meaning and concept corresponding to the technical idea of the present invention based on the principle that the present invention.

1 schematically shows an embodiment of manufacturing a nonwoven support in a method of manufacturing an air filter according to the present invention. However, the configuration described in the embodiments and drawings described below are only the most preferred embodiment of the present invention and do not represent all of the technical idea of the present invention, which can be replaced at the time of the present application It should be understood that there may be various equivalents and variations.

First, a nonwoven web is formed of a heat-adhesive two-component composite spinning short fiber made of a first thermoplastic polymer having a predetermined melting point and a second thermoplastic polymer having a lower melting point than the first thermoplastic polymer through a carding process or a wet process ( S1).

The heat-sealable bicomponent composite spun short fibers according to the present invention can improve the poor uniformity, which is a disadvantage of the conventional long fiber nonwoven fabric. The heat-sealable bicomponent composite spun short fibers according to the present invention mean short fibers formed by spinning the first thermoplastic polymer and the second thermoplastic polymer through the same spinneret. Here, the second thermoplastic polymer has a lower melting point than the first thermoplastic polymer. FIG. 2 is a cross-sectional view illustrating a preferred cross section of the bicomponent composite spun fiber, FIG. 2a is a cross-sectional view of a side by side type bicomponent conjugate spun fiber 20, and FIG. 2b is a sheath-core type ( sheath-core type) A cross-section of a bicomponent conjugated spun fiber 20. As shown in FIG. 2, the two-component composite spun fiber comprises a first thermoplastic polymer 22 component having a predetermined melting point and a second thermoplastic polymer 21 component having a lower melting point than the first thermoplastic polymer 22 component. It is. The bicomponent conjugate fiber may be used as an eccentric type (not shown) in addition to the above-described side by side type and sheath-core type, but is not limited thereto.

The manufacturing method of the nonwoven fabric support of bicomponent composite spun fiber is the same except that the orifice of bicomponent composite spun fiber is used instead of the orifice of the shape normally used in the production of one component melt blown nonwoven fabric. Do. Therefore, the manufacturing method of the present invention can be easily carried out by those skilled in the art according to the known manufacturing method of the meltblown nonwoven fabric and the composite spinning fiber manufacturing method such as the manufacturing method of the meltblown nonwoven fabric disclosed in the Republic of Korea Patent Publication No. 1993-13311 Yes it will be natural.

The combination of the first thermoplastic polymer and the second thermoplastic polymer having such melting point difference is well known, for example, a combination of the first thermoplastic polymer and the second thermoplastic polymer, (polypropylene, polyethylene), (polyester, polyethylene ), (Low melting point polyester, polyester) and the like can be exemplified. The fineness of the bicomponent composite spun short fibers that can be used in the present invention may be, for example, 2 to 25 deniers, but is not limited thereto.

When preparing the nonwoven fabric support of the present invention, the heat-sealable bicomponent composite spun short fibers may be used alone.

Non-fusible fibers, which may optionally be further included in the nonwoven support of the present invention, may further impart bulkiness to the nonwoven support and may further improve breathability. It is also possible to introduce additional functionalities into the nonwoven support of the present invention, depending on the fiber type. Appropriate non-fused fibers can be adopted for this purpose, and for example, synthetic fibers such as polyester fibers and polypropylene fibers, natural fibers such as hemp and cotton, or semisynthetic fibers such as rayon can be mixed and used. It may be, but is not limited thereto.

The content of the non-fused fiber according to the present invention may be variously selected according to the type and use of the non-fused fiber, for example, 1 to 50% by weight relative to the total weight of the nonwoven support, but is not limited thereto. If the content is less than 1% by weight, the mixing effect of the non-fused fibers may not be expected, and if the content exceeds 50% by weight, heat fusion may not be efficiently performed in the subsequent heat fusion process.

The fineness of the non-fused fiber may also be appropriately selected depending on the type of fiber selected, and may be, for example, 1.4 to 20 denier, but is not limited thereto.

The process for producing the nonwoven support according to the present invention may adopt a conventional nonwoven fabric manufacturing process performed in the art. For example, a carding process or a wet process is possible, but is not limited thereto. Such fibers can be made into a nonwoven web, for example, through a carding process or a wet process.

Next, the nonwoven web is heat-treated at a temperature higher than the melting point of the heat sealable fibers to melt the heat sealable fibers (S2).

When the heat-sealed composite spun short fiber according to the present invention is heat-treated at a melting point or more, fusion is performed between the molten fibers, thereby making the bonds between the fibers. In this case, the heat treatment may adopt a heat treatment process that is commonly performed in the art, for example, hot air heat treatment is possible, but is not limited thereto. The heat treatment temperature is preferably equal to or higher than the melting points of the thermally fused bicomponent composite spun short fibers, and optionally, between the melting points of the two components of the composite spun spun fibers (ie, the predetermined melting point of the first thermoplastic polymer and Temperature between the low melting point of the second thermoplastic polymer). Specific examples of the heat treatment temperature may be 110 to 180 ° C., but are not limited thereto. In the above temperature range, heat fusion between fibers can occur effectively.

Subsequently, after maintaining the temperature between the glass transition temperature and the melting point with respect to the heat treated nonwoven web, it is thermally compressed (S3).

The heat treatment maintains the temperature atmosphere between the glass transition temperature and the melting point of the fiber without completely cooling the nonwoven web where the inter-fiber fusion has occurred. This temperature range varies depending on the type of fiber used, for example, may be 30 ~ 140 ℃, but is not limited thereto. Thereafter, the nonwoven web in which residual heat is maintained as described above may be thermocompressed to prepare a nonwoven support according to the present invention. The thermocompression process may be carried out through conventional methods in the art, for example, may be performed by a thermal calendaring process. Through this thermocompression bonding process, the non-woven fabric support having a strong bond and sufficient strength can be produced.

The conditions of the thermocompression process may be variously selected according to the type of fibers forming the nonwoven fabric support, the use of the air filter, and the like, for example, performed at a pressure of 2 to 7 kg / cm 2 at a temperature range of 70 to 180 ° C. It may be, but is not limited thereto. Thermocompression can be effectively performed under the above conditions.

As described above, the nonwoven fabric support having the thermocompression process may have various physical properties, for example, the weight may be 15 to 130 gsm, the thickness may be 30 μm to 1.0 mm, and the air permeability is It may be 30 to 1000 cm 3 / cm 2 / s, but is not limited thereto. In the above range, the nonwoven fabric support excellent in the desired performance of the present invention can be obtained.

The nonwoven support thus prepared is used for the manufacture of the air filter. Figure 3 shows one embodiment of the air filter 30 of the present invention after the bending process.

Referring to Figure 3, the air filter 30 of the present invention is a melt blown nonwoven fabric 32 is laminated as a filter material on the nonwoven fabric support 33 of the present invention, the filter material on the melt blown nonwoven fabric 32 The nonwoven cover 31 for reporting is laminated and formed.

The manufacturing method of the melt blown nonwoven filter material and the nonwoven cover may be performed according to a method known in the art, and the nonwoven cover may be, for example, an air through nonwoven fabric, a thermal bond nonwoven fabric, a spunbond nonwoven fabric, or the like. It is not limited to this.

The method of laminating the support 33, the filter material 32, and the cover 31 may be performed by selecting an appropriate method from among those commonly used in the art for laminating nonwoven fabrics, for example, direct fibers. While forming a non-woven fabric by spinning to form a laminate at the same time, but not limited to heat welding, needle punching, and the like. Once the laminate is formed, it may be further subjected to a molding process such as a bending process as necessary. 3 schematically shows an air filter 30 which has been subjected to a bending process.

Hereinafter, the present invention will be described in detail with reference to Examples. However, the embodiments according to the present invention can be modified into various other forms, and the scope of the present invention should not be construed as being limited to the embodiments described below. The embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art.

Example 1

The composite spun short fibers (fineness 15D) composed of a low melting polyester / polyester bicomponent were formed through a carding process to form a nonwoven web, and then heat-treated with hot air at 170 ° C. After the heat treated nonwoven web was left still, thermal calendaring was performed at a temperature of 160 ° C. and a pressure of 3.5 kg / cm 2 to prepare a nonwoven support according to the present invention.

The polyethylene melt blown nonwoven fabric filter material and the spunbond nonwoven fabric cover were laminated on the thus obtained nonwoven fabric support to obtain an air filter.

Example 2

A nonwoven fabric support and an air filter were manufactured in the same manner as in Example 1, except that the nonwoven fabric support was prepared by further including 25% by weight of the total weight of the nonwoven fabric support.

Example 3

A nonwoven fabric support and an air filter were manufactured in the same manner as in Example 1, except that the nonwoven fabric support was prepared by further including 35% by weight of the nonwoven fabric support.

Comparative example

A nonwoven fabric support and an air filter were manufactured in the same manner as in Example 1, except that the polyester spunbond nonwoven fabric was used as the support.

The properties of the nonwoven fabric support prepared according to the Examples and Comparative Examples are shown in Table 1 below.

Weight (gsm) Thickness (mm) Breathability (cm 3 / cm 2 / s) Example 1 70 0.397 472 Example 2 60 0.315 495 Example 3 60 0.323 554 Comparative example 70 0.26 312

As shown in Table 1, it can be seen that the nonwoven support prepared according to the embodiment of the present invention is thicker than the nonwoven support prepared according to the comparative example, but the breathability is better.

Experimental Example

1.Measuring ventilation according to temperature change

In the preparation of the nonwoven fabric support used in Example 3, the pressure was kept the same (3.5 kg / cm 2) in the thermal calendaring process and the temperature was varied to prepare various nonwoven fabric supports, and the thickness and air permeability of each were measured. The measurement results are shown in Table 2 below.

Temperature (℃) Breathability (cm 3 / cm 2 / s) Thickness (mm) 155 491.13 0.295 160 554.73 0.323 165 494.13 0.335 170 497.2 0.275 175 437.53 0.337

As shown in Table 2, the change in the air permeability is seen in accordance with the temperature change of the thermal calendar, it can be seen that the excellent air permeability is obtained in the temperature range of the present invention.

2. Measurement of ventilation according to pressure change

In the preparation of the nonwoven fabric support used in Example 3, in the thermal calendaring process, the temperature was kept the same (165 ° C.) and the pressure was changed to prepare various nonwoven fabric supports, and the thickness and air permeability of each were measured. The measurement results are shown in Table 3 below.

Pressure (kg / ㎠) Breathability (cm 3 / cm 2 / s) Thickness (mm) 2.5 527 0.341 3.5 494.13 0.335 4.5 472.13 0.3

As shown in Table 3, as the pressure of the thermal calendar increases, the thickness decreases and the air permeability decreases, but it can be seen that the air permeability is excellent in the pressure range of the present invention.

The following drawings, which are attached to this specification, illustrate preferred embodiments of the present invention, and together with the contents of the present invention serve to further understand the technical spirit of the present invention, the present invention is limited to the matters described in such drawings. It should not be construed as limited.

1 is a flow chart schematically showing an embodiment of the air filter manufacturing method of the present invention.

Figures 2a and 2b is a schematic cross-sectional view of the bicomponent composite spun short fibers that can be used in the present invention, respectively.

3 is a schematic cross-sectional view of the air filter of the present invention.

Claims (10)

An air filter comprising a nonwoven fabric support, a nonwoven fabric cover and a melt blown nonwoven fabric interposed between the nonwoven fabric support and the nonwoven fabric cover, The nonwoven fabric support,  A heat sealable bicomponent conjugated spun fiber made of a first thermoplastic polymer having a predetermined melting point and a second thermoplastic polymer having a lower melting point than the first thermoplastic polymer; And Non-fused fiber, which is any one or a mixture of two or more selected from the group consisting of polypropylene fibers, hemp, cotton, and rayon Formed into And a second thermoplastic polymer portion of the composite spun short fibers is a nonwoven support formed by thermally bonding the short fibers and the short fibers and the non-adhesive fibers to each other. The method of claim 1, The combination of the first thermoplastic polymer and the second thermoplastic polymer is one selected from the group consisting of (polypropylene, polyethylene), (polyester, polyethylene), and (low melting point polyester, polyester) or a mixture of two or more thereof Air filter, characterized in that the. The method of claim 1, The two-component composite spun short fibers are sheath-core type, eccentric type or side by side type air filter. The method of claim 1, The weight of the nonwoven support is an air filter, characterized in that 15 to 130 gsm. The method of claim 1, The nonwoven fabric has a thickness of 30 μm to 1.0 mm and an air permeability of 30 to 1000 cm 3 / cm 2 / s. delete delete The method of claim 1, The non-fused fiber is an air filter, characterized in that it comprises 1 to 50% by weight relative to the total weight of the nonwoven support. In the method of manufacturing an air filter comprising a nonwoven support, a nonwoven cover and a melt blown nonwoven interposed between the nonwoven support and the nonwoven cover, the nonwoven support (S1) a heat-sealable bicomponent composite spun short fiber made of a first thermoplastic polymer having a predetermined melting point and a second thermoplastic polymer having a lower melting point than the first thermoplastic polymer through a carding process or a wet process; And forming a nonwoven web from non-fused fibers, which is one or a mixture of two or more selected from the group consisting of polypropylene fibers, hemp, cotton, and rayon; (S2) heat-sealing the fibers by heat treating the nonwoven web to a temperature between respective melting points of the two components of the composite spun short fibers; And (S3) maintaining the temperature between the glass transition temperature and the melting point for the heat treated nonwoven web, and then thermocompression bonding Method of manufacturing an air filter, characterized in that it is prepared to include. delete

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