KR101915810B1 - Non-woven Fabric Of Cross-section For High-efficiency Filter - Google Patents

Abstract

The present invention relates to a composite non-woven fabric with a modified cross-section for a high-efficiency filter, and specifically, to a composite non-woven fabric with a modified cross-section for a high-efficiency filter, wherein the composite fabric is composed of a sheath core part, the sheath part is 40 to 60 wt% of a polyolefin resin having a flow index of 10 to 30 g/10 min, the core part is formed with 40 to 60 wt% of a polyester resin or polypropylene resin having an intrinsic viscosity of 0.50 to 0.70 dl/g and the release ratio of the cross section of the composite fiber is 1.5 or more.

Description

TECHNICAL FIELD [0001] The present invention relates to a non-woven Fabric Of Cross-section For High-efficiency Filter for High-

The present invention relates to a nonwoven fabric having a cross section of a high-efficiency filter, and more particularly to a nonwoven fabric having a cross-section of a high-density nonwoven fabric having a cross- .

Polyester spunbond nonwovens are widely used as industrial raw materials due to their thinness and high strength.

Polyester spunbonded nonwoven fabrics are produced by spinning continuous polyester filament yarns at a high speed of 5,000 m / min or more, integrating filaments spun by suitable means onto a moving wire net or a plastic net, Is manufactured by applying a suitable adhesive force using a thermal bonding method (calender roll, emboss roll, hot air method) or needle punching method. The spunbond nonwoven fabric thus produced is made of continuous filaments and has high strength.

Therefore, polyester spunbond nonwoven fabrics are widely used on civil engineering and construction roads. Recently, the use thereof as a filter material for industrial, automobile or domestic air filters has been increasing, but generally, a short fibrous nonwoven fabric including a spunbonded nonwoven fabric is widely used as a filter material of an air filter.

However, unlike the long-fiber nonwoven fabric, the short-staple nonwoven fabric has a soft and flexible characteristic and is not suitable for the air filter of the present invention. That is, the air filter nonwoven fabric is used by being pleated in order to ensure a maximum filter area in use. However, the monofilament nonwoven fabric has poor shape stability after bending due to its flexible characteristics. In other words, since the bending process can not be maintained after bending, it tends to return to its original shape. Therefore, it is unsuitable as an air filter material which is exposed to a constant wind pressure and air volume for a long time.

Japanese Patent Application Laid-Open No. 2001-54706 is characterized in that the fibers constituting the nonwoven fabric are composed of circular cross-sectional fibers having a diameter of about 10 to 15 占 퐉 (about 2 to 3 denier), and as a high-weight product of 120 g / Melting polyester to a level of 10 to 20% by weight in order to improve bending workability. Further, in order to further improve the peeling property and the bending property, heat and pressure were applied using an M-source roll having a predetermined pattern on the surface thereof.

Such a spunbond nonwoven fabric product exhibits the characteristics of high strength and low toughness specific to spunbond, and has an advantage of excellent bending workability and peeling performance. However, since circular fiber is used and emboss heat bonding is performed, In order to improve the filter performance, it is necessary to produce and apply a high-weight product of 120 g / m < 2 > or more, thereby causing pressure loss and cost increase.

In order to solve such problems, commercially available spunbonded nonwoven fabrics made of low-grade polypropylene can be used, but polypropylene spunbonded nonwoven fabrics are more flexible and less strong than polyester materials and have poor bending property and form stability, It is unsuitable as a filter material.

 An object of the present invention is to provide a nonwoven fabric for a high-efficiency filter by using morphological characteristics of a mold release ratio and a cross section by using a cross-section conjugated conjugate fiber.

In order to solve the above-mentioned problems, the present invention provides a high-efficiency filter having a cross-section of a composite fiber nonwoven fabric, wherein the composite fiber is composed of a cisco fisher, wherein the sheath is a polyolefin resin having a flow flow index of 10 to 30 g / And the core portion is formed of 60 to 40 wt% of a polyester resin or polypropylene resin having an intrinsic viscosity of 0.50 to 0.70 dl / g, and the core portion has a mold release ratio of 1.5 or more, Sectional composite fiber nonwoven fabric.

The present invention also provides a polyolefin-based resin of the sheath having a melting point lower than that of the core resin by 20 占 폚 or more.

The present invention also provides a modified cross-section conjugated nonwoven fabric for a high-efficiency filter, characterized in that the modified cross-section conjugate fiber has an elliptical shape, a rectangular shape, and a cross-section of two to four circles.

In addition, the present invention provides a modified cross-section composite fiber nonwoven fabric for a high-efficiency filter, characterized in that the cross-section and core cross-sections of the composite fibers are the same or different.

In addition, the present invention provides a non-woven fabric having a cross-section composite filament nonwoven fabric for a high-efficiency filter having a collecting efficiency of 80% or more.

The present invention relates to a nonwoven fabric comprising a sheath portion for a binder, a shape retaining portion and a core portion for controlling a space between the fibers, There is an excellent feature of efficiency.

1 is a cross-sectional view showing a conventional composite fiber.
FIGS. 2 to 4 are cross-sectional views illustrating various types of conjugate fibers of different cross-sectional shapes according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. First, it should be noted that, in the drawings, the same components or parts have the same reference numerals as much as possible. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted so as to avoid obscuring the subject matter of the present invention.

As used herein, the terms "substantially", "substantially", and the like are used herein to refer to a value in or near the numerical value when presenting manufacturing and material tolerances inherent in the meanings mentioned, Absolute numbers are used to prevent unauthorized exploitation by unauthorized intruders of the mentioned disclosure.

The 'release ratio' disclosed in the present invention is a value defined by the following formula of the cross section of a fiber. When the long axis is viewed as a transverse axis as shown in Figs. 2 to 4, the short axis (A) And the long axis means the longest length of the transverse axis of the fiber cross section.

◈ Deformation ratio = long axis (B) / short axis (A)

The mold release ratio is determined based on the long axis (B) and the short axis (A) on the basis of the cross section before heat bonding of the conjugate fiber. In the nonwoven fabric formed by thermal bonding of the sheath, the sheath portion may be partially or completely lost by adhesion, but as can be seen from the drawing, the thickness of the sheath portion is constant, When present, the mold release ratio can be maintained.

FIGS. 2 to 4 are cross-sectional views showing various types of conjugate fibers of different cross-sectional shapes in the cross-section composite fiber non-woven fabric for a high-efficiency filter of the present invention.

2 to 4, the sheath is 40 to 60 wt% of a polyester resin having a flow flow index of 10 to 30 g / 10 min,

The core portion is formed of 60 to 40 wt% of a polyester resin or polypropylene resin having an intrinsic viscosity of 0.50 to 0.70 dl / g, a deformation ratio of the cross section of the core portion is 1.5 or more, and the nonwoven fabric is manufactured by a heat bonding method.

As the aromatic dicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, naphthalene dicarboxylic acid and the like can be used. As the glycol, there can be used ethylene glycol, 1,3- Propanediol, 1,4-butanediol and the like can be used

The polyester resin may be a condensation product of an aromatic dicarboxylic acid and glycol, and may be one or two or more selected from polyethylene terephthalate, polyethylene 2,6-dinaphthalate, polypropylene terephthalate, polybutylene terephthalate and polyethylene isophthalate Mixtures may be used.

Preferably, polyethylene terephthalate can be used, and it is preferable to use a polyester resin having an intrinsic viscosity (IV) of 0.50 to 0.70 dL / g as measured according to ASTM 02857.

As the polypropylene resin, a general polypropylene resin may be used.

The polyolefin-based resin having a melting point of 20 占 폚 or more lower than that of the polyester-based resin may be one or two or more selected from among high density polyethylene (HDPE), medium density polyethylene (MDPE), low density polyethylene (LDPE), polypropylene and ethylene- Mixtures may be used.

Preferably, the high density polyethylene (HDPE) can be used. The flow index (MI) of the olefin resin is not particularly limited, but the flow index is preferably 1 to 100 g / 10 min, more preferably 10 30 g / 10 min.

The polyolefin-based resin of the sheath is characterized by a melting point lower than that of the core-part resin by 20 ° C or more. The sheath portion is characterized by a visor fiber and can be bonded between the composite fibers by thermal bonding, and the core portion functions as a filter substrate by the shape retaining portion.

In addition, it is preferable that the composite fiber is formed to have a weight ratio of core portion and sheath resin of 60:40 to 40:60.

The mold release ratio of the cross section of the composite fiber is preferably 1.5 or more to maintain the structural characteristics of the high density nonwoven fabric. If the mold release ratio is less than 1.5, the mold release ratio may not have a function as a filter.

The modified cross-section of the composite fiber is an elliptical shape as shown in Fig. 2 (a), or a rectangular cross-section as shown in Fig. 2 (b) or a cross-section in which two to four circles are lined up as shown in Figs. And if it is formed as the above-mentioned modified cross-section, the condition of the release ratio can be satisfied.

As shown in FIG. 2, FIG. 3 (a), and FIG. 4, the modified cross-linked thermally adhesive composite fiber of the present invention may have the same cross- The core section may be formed in a different shape.

Generally, the sheath of the heat-bondable composite fiber is often thermally adhered to the nonwoven fabric during its manufacture, but the core is not melted in the heat treatment and the initial shape is maintained.

In order to function as a high-efficiency filter as a non-woven fabric of a cross-section composite fiber nonwoven fabric as in the present invention, the voids between fibers must be considerably small. Therefore, in a heat-bonding nonwoven fabric using a low- The cross section is more efficient than the general filter.

Hereinafter, the present invention will be described in more detail with reference to examples. It is to be understood, however, that these examples are provided so as to understand the scope of the present invention, and are not to be construed as limiting the scope of the present invention.

Example  One

The core part resin was melted by introducing 50 wt% of polyethylene terephthalate having an intrinsic viscosity of 0.64 dL / g and 50 wt% of high density polyethylene (HDPE) having a flow flow index of 20 g / 10 min in a separate extruder. After the molten sheath core resin was fed into a conventional core-sheath type cross-section composite spinning device, the undrawn yarn was spinnnnn at a spinning speed of 800 m / min at a draw ratio of 3.0 to a preheat temperature of 80 ° C, 2.0 denier, and the fiber length was cut to 100 mm. Staple fibers having a cross-section conjugate fiber as shown in Fig. 2a having a mold release ratio of 1.5 were obtained.

The cross-section composite short staple fibers obtained by the above-mentioned method were rubbed on a rim equipped with a metering feeder and carded at a speed of 250 mpm by a card machine to produce a nonwoven web, which was then fed to a pair of calender rollers, To obtain a nonwoven fabric having a thickness of 3.6 mm.

Example  2

And a non-woven fabric thickness of 3.0 mm. The results are shown in Table 1. < tb > < TABLE >

Example  3

Was prepared in the same manner as in Example 1 except that the mold release ratio in the form of Fig. 3a was 2.5 and the nonwoven fabric thickness was 2.5 mm.

Example  4

3b was prepared in the same manner as in Example 1, except that the mold-release ratio in the form of Fig. 3b was 2.5 and the non-woven fabric thickness was 3.0 mm.

Example  5

4 was prepared in the same manner as in Example 1 except that the mold-release ratio of the form of Fig. 4 was 2.5 and the nonwoven fabric thickness was 2.2 mm.

Comparative Example  One

1 was prepared in the same manner as in Example 1, except that the mold-release ratio in the form of Fig. 1 was 1.0 and the non-woven fabric thickness was 5.0 mm.

Comparative Example  2

Was prepared in the same manner as in Example 1, except that the mold release ratio in the form of Fig. 2a was 1.3 and the nonwoven fabric thickness was 5.0 mm.

division unit Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 1 Comparative Example 2 materials
Constituent fiber Material Sheath / Core HDPE / PET HDPE / PET HDPE / PET HDPE / PET HDPE / PET HDPE / PET HDPE / PET section Type 2A, 2A, Fig. 3A 3B 4 1 2A, Mold release ratio - 1.5 2.0 2.5 2.5 3.0 1.0 1.3 Fineness Denier 2.0 2.0 2.0 2.0 2.0 2.0 2.0 Filter configuration
materials weight g / m ³ 30 30 30 30 30 30 30 thickness mm 3.6 3.0 2.5 3.0 2.2 5.0 4.8 Filter performance Collection efficiency % 80 85 89 87 92 40.0 45.0 Pressure loss mmAq 2.5 2.8 3.0 3.1 3.0 2.2 2.3

(Collection efficiency and pressure loss) were measured in air at an air velocity of 3 m / min.

- Pressure loss (mmAq): Initial pressure loss was recorded during the measurement.

- Collecting efficiency (%): The collecting efficiency was examined in the range of particle size 0.3-10 μm when measuring. At this time, the collection efficiency of the particles of 5 mu m or less is referred to as collection efficiency.

- Sample size: 75 cm x 75 cm

In Table 1, it can be seen that the collecting efficiency of the non-woven fabrics according to Examples 1 to 5 of the present invention is 80% or more. Particularly, , And 92%, respectively. 3A and 4, in which two circular cross-sections are joined side by side in a side-by-side manner, in addition to the features having a cross-sectional deviation of 2.5 and 3.0, the curved portion between the circular cross- It is advantageous to secure.

Particularly, in Examples 3 and 4, the collection efficiency of Example 3 is higher even though they have the same type-ratio ratio.

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

Claims (5)

In a nonwoven fabric having a modified cross-section for a high-efficiency filter,
The composite fiber is composed of a Cisco fisher,
The sheath is 40 to 60 wt% of a polyolefin resin having a flow flow index of 10 to 30 g / 10 min,
Wherein the core portion is formed of 60 to 40% by weight of a polyester resin or polypropylene resin having an intrinsic viscosity of 0.50 to 0.70 dl / g, wherein a mold release ratio of the cross section of the composite fiber is 1.5 or more,
The modified cross section is characterized in that 2 to 4 circles are arranged in a line, and the sheath section and the core section have the same or different shapes.
The method according to claim 1,
Wherein the polyolefin resin of the sheath has a melting point lower than that of the core resin by 20 DEG C or more.
delete delete The method according to claim 1,
The nonwoven fabric of cross-section composite filament nonwoven fabric for high-efficiency filter has a collecting efficiency of 80% or more.

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