KR102239778B1 - Composite nonwoven fabric with improved tear strength and method for manufacturing thereof - Google Patents

Abstract

The present invention relates to a composite non-woven fabric with improved tearing strength and a method for manufacturing the same. More specifically, the present invention relates to: a composite non-woven fabric characterized by having excellent tear strength and excellent tensile strength at the same time by preventing the non-woven fabric from being easily torn by filming, and thus has excellent durability and abrasion resistance; and a method for manufacturing the same.

Description

Composite nonwoven fabric with improved tear strength and its manufacturing method {COMPOSITE NONWOVEN FABRIC WITH IMPROVED TEAR STRENGTH AND METHOD FOR MANUFACTURING THEREOF}

The present invention relates to a composite nonwoven fabric with improved tear strength and a method for manufacturing the same, specifically, the nonwoven fabric is formed into a film to prevent tearing, so that the tear strength is excellent and at the same time, the tensile strength is also excellent, and durability and abrasion resistance It relates to a composite nonwoven fabric characterized in that it is excellent and a method of manufacturing the same.

According to the prior art, when a nonwoven fabric is used for civil engineering and construction, such as a Housewrap, it is common to fix the nonwoven fabric to the wall of the building with nails or tackles when constructing the nonwoven fabric. In this case, when the tear strength of the nonwoven fabric is not sufficient, and the wind blows strongly after such construction, the nonwoven fabric sheet is often cracked and torn.

Non-woven fabric refers to bonding and fixing a web of fibers arranged randomly by heat or resin.In particular, in the case of a heat-sealed nonwoven fabric in which fibers are mutually bonded by heat-sealing, a high heat-sealing temperature is applied. In order for the fibers constituting the nonwoven fabric to be fused to each other through a heat fusion process to form a nonwoven fabric, the heat fusion process had to be performed at a temperature near the melting point of the fibers. Therefore, the energy cost for heating for the heat fusion process has been a problem, and the heat applied to the web during the heat fusion process causes damage to the fiber structure, resulting in the generation of a filmed region in the nonwoven fabric. The occurrence of such a filmed region causes a problem of lowering the tensile strength of the nonwoven fabric.

In addition, the final nonwoven fabric obtained by heat treatment of the fibers constituting the nonwoven fabric by a high heat fusion temperature has a hard touch due to the presence of such a filmed region, and thus the tear strength, which is regarded as an important physical property in addition to the tensile strength, deteriorates. There is this.

Accordingly, there is an urgent need to develop a technology capable of improving tear strength and tensile strength by preventing film formation of the manufactured nonwoven fabric while reducing energy consumption during heat fusion for bonding between fibers in the nonwoven fabric.

KR No. 10-1735959 (2017.05.08.)

The first problem to be solved of the present invention is to provide a polyester nonwoven fabric having a soft touch and improved tear and tensile strength.

A second problem to be solved of the present invention is to provide a method of manufacturing a polyester nonwoven fabric having improved tearing and tensile strength as described above by partially controlling only the process conditions without changing, omitting, and adding processes.

In order to solve the above-described first problem, the present invention includes a core component comprising polyester having a melting point of 250° C. or higher; And a sheath component surrounding the core component and comprising a polyester that is 20° C. or more lower than that of the polyester of the core component. It includes a core-sheath type polyester composite fiber comprising a,

Tear strength is 2.5 to 5kgf in the machine direction (Machine Direction), and provides a composite nonwoven fabric of 3 to 7kgf in the cross-machine direction.

In addition, according to a preferred embodiment of the present invention, the composite nonwoven fabric may not ^{have a filmed area having an area of 0.05mm 2 or more in the nonwoven fabric.}

In addition, according to another preferred embodiment of the present invention, in the composite nonwoven fabric, the total area of the filmed region in the nonwoven fabric may be 5% or less with respect to the total area of the nonwoven fabric.

According to another preferred embodiment of the present invention, in the composite nonwoven fabric, the tear strength in the machine direction and the tear strength in the machine direction may satisfy the following relationship.

[Relationship 1]

T _CD -T _MD ≥ 0.5 kgf

Can be satisfied.

Here, the T _CD denotes the tear strength _{in the machine direction, and the T MD} denotes the tear strength in the machine direction.

According to another preferred embodiment of the present invention, the composite nonwoven fabric may have a tensile strength of 10.0kg/5cm to 30.0kg/5cm in the machine direction, and 4.0 to 20.0kg/5cm in the machine direction.

According to another preferred embodiment of the present invention, the weight ratio of the core component and the sheath component of the core sheath type polyester composite fiber may be 90:10 to 70:30.

According to another preferred embodiment of the present invention, the composite nonwoven fabric may have a basis weight of 30 to 150 g/m ² .

In order to solve the second problem described above, the present invention includes (1) _{a polyester having a melting point (T m} ) of 250°C or higher in the core component, and a polyester having a melting point of 20°C or higher than that of the polyester of the core component in the sheath component. Preparing a core-sheath type polyester composite fiber comprising a; And

(2) heat-sealing by passing the web containing the core-sheath type polyester fiber between two smooth rolls; It provides a composite non-woven fabric manufacturing method comprising a.

In addition, according to a preferred embodiment of the present invention, in the step (2), the core-sheath type polyester composite fiber may be thermally fused by passing it between two smooth rolls at a temperature of 160°C to 200°C.

According to another preferred embodiment of the present invention, the weight ratio of the core component and the sheath component of the core sheath type polyester composite fiber may be 90:10 to 70:30.

The composite non-woven fabric according to the present invention can suppress the phenomenon that the non-woven fabric is partially filmed by point bonding, and thus, the non-woven fabric is not easily torn, and thus tear strength can be improved. In addition, while suppressing film formation, bonding between fibers can be sufficiently performed at the same time, and thus tensile strength is also excellent, so that both durability and abrasion resistance of the nonwoven fabric are excellent.

According to the method for manufacturing a composite nonwoven fabric according to the present invention, it is possible to manufacture a composite nonwoven fabric having excellent both durability and abrasion resistance by a simple process by simply adjusting the process conditions.

Other effects of the present invention will be described in more detail below along with the technical configurations related thereto.

1 is a photograph showing that the composite nonwoven fabric manufactured according to Example 1 was taken with SEM (magnification: x20).
FIG. 2 is a photograph showing that the nonwoven fabric manufactured according to Comparative Example 2 was taken with an SEM (magnification: x34).
3 is a view schematically showing the manufacturing process of the composite nonwoven fabric according to the present invention.
4 is a diagram schematically illustrating a manufacturing process of a nonwoven fabric by a conventional point bonding method.

Hereinafter, a composite nonwoven fabric having improved tear strength and a method of manufacturing the same according to the present invention will be described in more detail with reference to the drawings and examples.

First, terms used in the present specification will be described.

The term "tear strength" as used herein refers to the strength when tearing a fabric such as a nonwoven fabric in different directions as if tearing paper, and in this specification, the trapezoid method The average value of the values obtained by measuring 16 times according to the ASTM D 5733 test method was used as the tear strength.

In addition, the term "tensile strength" used in the present specification refers to the maximum load when the fabric is pulled and broken using a tensile tester. In this specification, the KS K 0521 test using a tensile tester of Instron After repeating measurements for 16 times by the method, the average value of the obtained values was used as the tensile strength.

In addition, the term "intrinsic viscosity (IV)" as used herein refers to a viscosity in which the effect of the interaction between solute particles is removed.

In addition, the term "smooth roll" as used herein refers to a roll having a smooth surface. Specifically, there are no artificially applied irregularities such as grooves, protrusions or teeth on the surface, so that the circular circumferential surface And means a roll in which only irregularities that exist due to errors in the manufacturing process exist.

As described above, in the case of using the nonwoven fabric for civil engineering and construction, the nonwoven fabric is easily torn due to wind or work friction, etc., due to the decrease in tear strength and tensile strength of the nonwoven fabric due to film formation in the manufacturing process. There was a problem with poor durability and abrasion resistance.

In order to solve this problem, the present inventors have a core component comprising a polyester having a melting point of 250° C. or higher; And a sheath component surrounding the core component and comprising a polyester that is 20° C. or more lower than that of the polyester of the core component. Including a core-sheath type polyester composite fiber, the tear strength is 2.5 to 5kgf in the machine direction (Machine Direction), 3 to 7kgf in the cross-machine direction (Cross-machine Direction) to provide a composite nonwoven fabric, this The composite nonwoven fabric has improved tear strength and tensile strength by suppressing film formation as described above, thereby achieving excellent durability and abrasion resistance at the same time.

The composite nonwoven fabric of the present invention is characterized in that it comprises a core sheath type composite fiber composed of a core component and a sheath component. Specifically, the core sheath type composite fiber is characterized in that two polyester resins having different _{melting points (T m) of the sheath component and the core component are used.}

As described above, by using polyester resins with different melting points for the core component and the sheath component, bonding between fibers can be appropriately formed in the process of manufacturing a composite nonwoven fabric using such composite fibers, and at the same time, There is an advantage that physical properties such as strength and stiffness can be sufficiently maintained.

First, the core component includes a polyester resin having a melting point of 250°C or higher. When the melting point of the polyester resin having such a high melting point is included and thermally fused at a temperature lower than this, the melting phenomenon of the polyester of the core component does not occur, and thus there is an effect of suppressing the film formation of the nonwoven fabric. Accordingly, the tear strength of the nonwoven fabric can be maintained satisfactorily.

More preferably, as the core component, a polyester resin having a melting point of 260° C. or higher may be used, and most preferably, a polyester resin having a melting point of 260° C. to 270° C. may be used.

If the melting point is 250° C. or less, some or all of the core component may be melted during thermal fusion, and thus a filmed region may be generated in the nonwoven fabric, resulting in poor tear and tensile strength.

More preferably, the core component may include at least one of polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT), and polybutylene terephthalate (PBT), and more preferably polyethylene terephthalate It may contain resin. Polyethylene terephthalate resin has good stiffness and heat resistance, and satisfies the above-described high melting point, while simultaneously imparting sufficient strength to the nonwoven fabric.

These polyester resins may be included in an amount of at least 50% by weight or more in the core component, more preferably 75% by weight or more, and more preferably in an amount of 90% by weight or more.

In addition, according to a preferred embodiment of the present invention, the polyester of the core component may have an intrinsic viscosity of 0.50 to 1.00 dl/g. More preferably, the polyester of the core component may have an intrinsic viscosity of 0.60 to 0.90 dl/g, and more preferably 0.60 to 0.80 dl/g. If the intrinsic viscosity is less than 0.50dl/g, the strength of the polyester composite fiber decreases, and the tensile strength and tear strength of the nonwoven fabric as a whole may decrease. Conversely, if the intrinsic viscosity exceeds 1.00dl/g, spinning And there may be problems such as poor stretching workability.

Therefore, it is most preferable that the core component includes a polyethylene terephthalate (PET) resin having a melting point of 260 to 270°C or higher and an intrinsic viscosity of 0.60 to 0.80 dl/g.

Next, the sheath component will be described. The sheath component is formed in a form surrounding the periphery of the core component to form the outer sheath of the core sheath type composite fiber, and includes polyester having a melting point lower than that of the polyester of the core component by 20°C or more. The sheath component may be entirely or partially melted in the composite nonwoven fabric of the present invention to form a bond between the fibers. The polyester contained in the sheath component can easily form a bond between the core sheath type polyester composite fibers by using a polyester having a melting point lower than that of the polyester contained in the core component by 20℃ or higher, and the melting point difference between the core component and the sheath component Sufficient, the core component can improve the tear and tensile strength of the nonwoven fabric by maintaining the fiber shape in a state where deformation does not occur.

The polyester included in the sheath component according to the present invention may include at least one of polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT), and polybutylene terephthalate (PBT), and more preferably It may contain polyethylene terephthalate (PET) resin. Polyethylene terephthalate resin has good rigidity and can impart sufficient strength to nonwoven fabrics.

The polyester contained in the sheath component may control the melting point by controlling the content between isomers. More specifically, when it contains at least one of the polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT), and polybutylene terephthalate (PBT), meta-para (meta-) in the polyester resin ( The melting point can be lowered by increasing the content of the para-) isomer. For example, when the above-listed polyester resin is included in the sheath component, the melting point may be lowered when a mixture of isophthalic acid and terephthalic acid is used instead of terephthalic acid as an acid component monomer.

More specifically, when using at least one of the aforementioned PET, PTT, and PBT resins for the polyester included in the sheath component, a mixture of terephthalic acid and isophthalic acid may be used as an acid component monomer, and in this case, isophthalic acid The weight ratio of and terephthalic acid can be adjusted within 1:9 to 4:6.

If isophthalic acid is contained in an excessively small amount, the melting point of the sheath component is too high, and energy consumption increases during the manufacture of the nonwoven fabric, or the difference between the melting point between the core component and the sheath component decreases, so that most of the nonwoven fabric may be filmed. . Conversely, when isophthalic acid is contained too much, there may be a problem in that physical properties such as rigidity of the nonwoven fabric are rather deteriorated.

In addition, according to a preferred embodiment of the present invention, the core-sheath type polyester composite fiber may be one in which the above-described core component and sheath component are mixed in the fiber in a weight ratio of 9:1 to 7:3. More preferably, the weight ratio of the core component and the sheath component may be 85:15 to 75:25.

If the weight ratio of the core component is greater than 9, there may be a problem in that the physical properties of the nonwoven fabric are deteriorated due to insufficient bonding between the fibers during manufacture of the nonwoven fabric. On the contrary, when the weight ratio of the core component is less than 7, the ratio of film formation during the production of the nonwoven fabric by heat fusion increases, resulting in a decrease in the tear strength of the nonwoven fabric, and other physical properties may be deteriorated.

In addition, according to a preferred embodiment of the present invention, the core-sheath type polyester composite fiber may have an average diameter of 10 to 30 μm. More preferably, those having an average diameter of 15 to 25 μm may be used, and most preferably those having an average diameter of 15 to 20 μm may be used.

If the average diameter of the core-sheath type polyester conjugate fiber is less than 10 μm and the composite fiber is manufactured, there may be a problem that the spinning property of the fiber and the productivity of the non-woven fabric are lowered, and if it exceeds 30 μm, it is manufactured as a non-woven fabric. When the adhesive strength is uneven, there may be a problem that the physical properties are deteriorated.

Hereinafter, a nonwoven fabric including the core sheath type polyester composite fiber will be described.

The nonwoven fabric of the present invention corresponds to the composite nonwoven fabric as comprising the above-described core sheath type composite fiber. In addition, the nonwoven fabric of the present invention may be a resin bonded or heat-sealed nonwoven fabric. Preferably, it may be a heat-sealed nonwoven fabric. The heat-sealed nonwoven fabric is more preferable because the heat-sealed nonwoven fabric is more excellent in physical properties than the resin-bonded nonwoven fabric.

Nonwoven fabric according to a preferred embodiment of the present invention has a tear strength of 2.5kgf to 5.0kgf in the machine direction (Machine Direction, MD), and 3kgf to 7kgf in the cross-machine direction (CD). By having such a range of tear strength, the composite nonwoven fabric according to the present invention has excellent durability, abrasion resistance and is not easily torn due to high tear strength compared to conventional nonwoven fabrics. When used on the back, it can significantly reduce the phenomenon of being torn by the wind.

If the tear strength is less than the above range, the durability of the nonwoven fabric may be poor.

In addition, in the present invention, a filmed area having an area of 0.05 mm ² or more may not exist in the entire nonwoven fabric. When the nonwoven fabric is manufactured according to the heat fusion process, when the temperature of the fusion roll is high, the melting of the fibers occurs a lot, or there are convex projections (embossed) on the surface of the roll, so that the specific local area of the web is subjected to pressure. There may be areas where higher pressure is applied than other areas, causing significant melting of the fibers. In this case, when the degree of melting increases, the fiber may not maintain its original shape in that part and may become a polyester film. This is called filming.

Specifically, in the composite nonwoven fabric according to a preferred embodiment of the present invention, such a filming region may not exist, or ^{those having an area of 0.05 mm 2} or more among the filming regions may not exist.

1 is a photograph of a surface of a composite nonwoven fabric according to a preferred embodiment of the present invention taken with an SEM (magnification x20), and FIG. 2 is a photograph of a surface of a conventional nonwoven fabric taken with an SEM (magnification x34). Referring to FIG. 1, it can be seen that the composite nonwoven fabric of the present invention has almost completely preserved the shape of the fibers, and there is almost no filming area. On the other hand, referring to FIG. 2, it can be seen that a region in which film formation has occurred exists on the surface of a conventional nonwoven fabric.

As described above, the filmed area does not exist, or the area is 0.05mm ² or more. By not having a filmed region, the composite nonwoven fabric of the present invention can prevent the tear strength of the nonwoven fabric from decreasing due to film formation. Therefore, durability and abrasion resistance are better than that of the conventional nonwoven fabric.

In general, when the process of continuously manufacturing a nonwoven fabric using a conveyor belt is followed, the fibers are not completely randomly arranged in the nonwoven fabric because the ratio of the alignment direction of the fibers along the machine direction in the nonwoven fabric is high. Due to the characteristics of this arrangement, mechanical properties such as tear strength and tensile strength may have some differences depending on the direction.

In the case of the present invention, the tear strength in the machine direction has a lower value than the tear strength in the cross-machine direction. In particular, the difference between the tear strength in the machine direction and the tear strength in the machine direction may be greater than that of the conventional nonwoven fabric. have.

Preferably, in the composite nonwoven fabric of the present invention, the tear strength in the machine direction and the tear strength in the machine direction may satisfy the following relational formula 1.

[Relationship 1]

T _CD -T _MD ≥ 0.5 kgf

Here, the T _CD denotes the tear strength _{in the machine direction, and the T MD} denotes the tear strength in the machine direction.

When the composite nonwoven fabric of the present disease is manufactured by heat fusion, film formation is minimized, so that the fibers in the nonwoven fabric can maintain the original fiber shape as much as possible, and thus, the difference in tear strength has the same size or more.

If _{the value of T CD} -T _MD is less than 1.0kgf, the rate of film formation in the nonwoven fabric is high, so the difference in physical properties depending on the direction of the nonwoven fabric is small, but there may be a problem that the tear strength and tensile strength are lowered.

In addition, the composite nonwoven fabric according to a preferred embodiment of the present invention may have a tensile strength of 10.0kg/5cm to 15.0kg/5cm in the machine direction, and 4.0 to 8.0kg/5cm in the machine direction. If the tensile strength is less than the above range, the durability of the nonwoven fabric may be poor.

The composite nonwoven fabric according to the present invention may preferably have a basis weight of 30 to 150 g/m ³ . If the basis weight is less than that, the nonwoven fabric is too thin, so tearing and tensile strength may be poor, and if the basis weight exceeds 150 g/m ³ , there may be a problem that the usability is poor due to poor drape and workability. .

Hereinafter, a method of manufacturing a composite nonwoven fabric according to the present invention will be described with reference to the drawings.

In order to manufacture the composite nonwoven fabric having excellent durability and abrasion resistance, the present invention includes (1) _{polyester having a melting point (T m} ) of 250° C. or higher in the core component, and the melting point of the core component poly Preparing a core-sheath type polyester composite fiber comprising a polyester lower than the ester by 20 ℃ more; And (2) passing the fabric including the core-sheath type polyester fiber through two smooth rolls and thermally fused thereto.

By manufacturing the composite nonwoven fabric by the above method, the composite nonwoven fabric of the present invention has excellent tear strength and tensile strength, so that it can have excellent physical properties to be used for exterior construction for construction and civil engineering.

3 is a view schematically showing an apparatus for manufacturing a composite nonwoven fabric according to an embodiment of the present invention. The core sheath type composite fiber of the present invention can be formed through the composite spinneret 100, and in the composite spinneret 100, a core component including polyester having a melting point of 250° C. or higher, and a polyester of the core component A core-sheath type polyester composite fiber is formed by composite spinning a sheath component containing a polyester resin having a melting point lower than 20°C.

At this time, it is preferable to adjust the spinning speed to 4000 to 5000 m/min. When the spinning speed is out of the above range, there is a problem that the physical properties of the fiber cannot be uniformly obtained.

Matters related to the spinning conditions other than those that can be generally adopted by a skilled person in the field of manufacturing polyester composite fibers can be used without limitation, and the effects thereof are all that can be generally understood by a person skilled in the art. will be.

In addition, matters related to the physical properties of the polyester resin used in each component of the three-core-sheath type polyester composite fiber, and the matters regarding the diameter and the ratio of the core sheath properties of the core-sheath type polyester composite fiber are the same as described above, the description is omitted do.

Preferably, the spun core-sheath type polyester composite fiber may collide with a collision plate to form a web in a randomly stacked form. More preferably, the collision plate may form a web having a certain thickness using a conveyor belt, but the method of forming the web is not limited thereto.

Referring to FIG. 3, it can be seen that the web including the core-sheath type polyester composite fiber is passed through between two smooth rolls 200 to undergo heat fusion.

At this time, the smooth roll refers to a roll having a smooth side, and the roll is heated to melt the sheath of the polyester composite fiber to form a bond between the fibers in the web.

Since the smooth roll does not have artificially formed irregularities or the like on the surface of the roll, certain local portions of the web are further heated or further compressed during thermal fusion. Therefore, it is possible to minimize the occurrence of filming or the like on a specific local area of the nonwoven fabric.

On the contrary, FIG. 4 schematically illustrates a method of manufacturing a nonwoven fabric according to the prior art, in particular, a method of manufacturing a nonwoven fabric by a point bonding method. Therefore, the step corresponding to step (2) of the present invention is provided with an embo roll 210 having convex convex irregularities formed on the surface unlike the smooth roll 200 of FIG. 3. In the case of the nonwoven fabric manufactured by this, it can be seen that the region in which film formation has occurred as shown in FIG. 2 is wider than that of the present invention as a stronger pressure and a lot of heat are transferred from the embossing.

As described above, a web containing core sheath type polyester composite fibers is passed through the web between the smooth surface rolls 200 to perform heat fusion, and the smooth surface roll 200 may cause heat bonding to the core sheath type polyester composite fibers. It may be about the temperature.

Preferably, the two smooth rolls may each have a temperature of 160°C to 200°C. If the temperature of the smooth roll is less than 160°C, there is a problem in that the sheath component is not sufficiently melted to form a bond properly, and thus the strength and elasticity of the nonwoven fabric may not be sufficient. Conversely, when the temperature of the smooth surface roll is set to 200°C, there may be a problem in that the melting is excessive and the film-forming area is widened. This phenomenon can also cause the deterioration of the properties of the nonwoven fabric.

In addition, the temperatures of the two smooth rolls may be different from each other.

Hereinafter, the present invention will be described in more detail through examples, but the following examples do not limit the scope of the present invention, which should be construed to aid understanding of the present invention.

[Example]

Example 1

Polyethylene terephthalate chips (hereinafter referred to as PET) with a melting point of 255°C and an intrinsic viscosity of 0.65 dl/g as the core component, and the content of isophthalic acid in the acid component monomer as 11% by weight as the initial component, with a melting point of 220 The composition for forming composite fibers in which each of the low melting point polyethylene terephthalate chips (hereinafter referred to as LM-PET) with an intrinsic viscosity of 0.66 dl/g is melted at a rate of about 5000 m/min through a composite spinneret. The core-sheath type polyester composite fiber was prepared by spinning so that the weight ratio was 8:2. The conjugate fibers spun from the detention were 18 μm in diameter.

The spun composite fibers are directly spun onto the conveyor belt, which is a collision plate, and at the same time collide with the collision plate so that they can be arranged in a random direction.The conveyor belt transports the fibers at a constant speed to keep the web thickness of the fibers constant. I made it possible to maintain it at a level. At this time, the speed of the conveyor belt was adjusted so that the basis weight of the nonwoven fabric ^{could be adjusted to 45 g/m 2.}

The web was passed between two smooth rolls at a temperature of 180° C. and the core-sheath type polyester composite fiber was thermally fused to prepare a composite nonwoven fabric.

Comparative Example 1

It was carried out in the same manner as in Example 1, except that a polyethylene terephthalate single fiber having a melting point of 255°C was used instead of the core-sheath type polyester composite fiber.

Comparative Example 2

A composite nonwoven fabric was manufactured in the same manner as in Example 1, except that one embossed roll having projections on the surface was used instead of the smooth roll as shown in FIG. 4.

Comparative Example 3

A composite nonwoven fabric was manufactured in the same manner as in Example 1, except that two smooth holes were used at a temperature of 150°C.

Comparative Example 4

A composite nonwoven fabric was manufactured in the same manner as in Example 1, except that two smooth rolls were used at a temperature of 210°C.

Comparative Example 5

A composite nonwoven fabric was manufactured in the same manner as in Example 1, except that the weight ratio between the core and the sheath was adjusted to 95:5.

Comparative Example 6

A composite nonwoven fabric was manufactured in the same manner as in Example 1, except that the weight ratio between the core and the sheath was adjusted to 65:35.

<Experimental Example>

The tensile strength and tear strength of the nonwoven fabrics prepared in the above Examples and Experimental Examples were measured, respectively, and the weight of the nonwoven fabric was measured, respectively, and are shown in Table 1 below.

Tensile strength and tear strength were measured in the machine direction and the machine direction, and as described above, the tear strength was measured according to ASTM D 5733 (trapizoide) method, and the tensile strength was 16 according to the KS K 0521 test method. It was measured twice and averaged, and the basis weight of the nonwoven fabric was measured by the WSP 130.1 method.

Tear strength and tensile strength were measured using Instron's 5966 equipment.

In addition, the basis weight of the nonwoven fabric ^{was cut into a size of 100 cm 2} and measured using an AND company GX400 electronic scale.

In addition, after repeating the nonwoven fabric prepared according to each Example and Comparative Example 32 times with a Martindale abrasion tester, it was observed whether or not fluff was generated, and the results are shown in Table 1 below.

division Basis weight
(g/m ² ) Roll form Roll temperature
(℃) Core Core Weight Ratio The tensile strength
(kg/5cm) Tear strength
(kgf) Whether fluffing occurs MD CD MD CD Example 1 45 Smooth surface 180 80:20 13.7 7.0 3.0 4.3 Comparative Example 1 45 Smooth surface 180 - 9.3 4.9 1.2 1.5 Comparative Example 2 45 Emboss 180 80:20 11.2 5.8 1.8 2.1 Comparative Example 3 45 Smooth surface 150 80:20 8.3 4.3 1.0 1.2 Fluffing Comparative Example 4 45 Smooth surface 210 80:20 20.1 11.3 0.6 0.8 Comparative Example 5 45 Smooth surface 180 95:5 10.3 5.2 1.5 1.8 Comparative Example 6 45 Smooth surface 180 65:35 14.5 7.4 2.1 2.3

Referring to Table 1, in the case of the nonwoven fabric of Comparative Example 1 using a polyester single fiber instead of the core sheath type composite fiber, the tensile strength was not bad, but the tear strength was compared to the composite nonwoven fabric of Example 1, which is the composite nonwoven fabric of the present invention. It can be seen that it is remarkably low.

In addition, in the case of Comparative Example 2 using an embossed roll instead of a smooth roll, it was confirmed that filmization occurred in several places as can be seen in FIG. 2, and accordingly, it was confirmed that the tear strength was lower than that of Example 1. .

In addition, when Comparative Examples 3 and 4 were compared with Example 1, Comparative Example 3, which had a low roll temperature, had poor tear and tensile strength due to insufficient bonding between the fibers, and fluff was generated as a result of combing, so that it was used as a nonwoven fabric. It was found that it was not suitable. In Comparative Example 4, film formation was excessive, so that the tensile strength was higher than that of Example 1, but the tear strength was not good, so it could be easily expected that the quality would be poor.

Finally, Comparative Examples 5 and 6 were different in the weight ratio of the core part and the sheath part, and both the tear strength did not reach an appropriate range, and thus it was confirmed that it was not suitable for achieving the object of the present invention.

100: compound radioactive detention
200: smooth roll
210: emboss roll

Claims (10)

A core component comprising polyester having a melting point of 250° C. or higher; And a sheath component surrounding the core component and comprising a polyester that is 20° C. or more lower than that of the polyester of the core component. It includes a core-sheath type polyester composite fiber comprising a,
Tear strength is 2.5 to 5kgf in the machine direction (Machine Direction), and as a composite nonwoven fabric of 3 to 7kgf in the cross-machine direction,
A composite nonwoven fabric, characterized in that there is no filmed region having an area of 0.05 mm 2 or more in the nonwoven fabric, and the total area of the filmed region is 5% or less of the nonwoven fabric area. delete delete The method of claim 1,
The composite nonwoven fabric, characterized in that the tear strength in the machine direction and the tear strength in the cross-machine direction satisfy the following relationship:
[Relationship 1]
T _CD -T _MD ≥ 0.5 kgf
The T _CD represents the tear strength _{in the machine direction, and the T MD} represents the tear strength in the machine direction. The method of claim 1,
A composite nonwoven fabric, characterized in that the tensile strength is 10.0kg/5cm to 30.0kg/5cm in the machine direction, and 4.0 to 20.0kg/5cm in the cross-machine direction. The method of claim 1,
The composite nonwoven fabric, characterized in that the weight ratio of the core component and the sheath component of the core sheath type polyester composite fiber is 90:10 to 70:30. The method of claim 1,
Composite nonwoven fabric, characterized in that the basis weight of 30 to 150g / m ^2. (1) To prepare a core-sheath type polyester composite fiber containing polyester having a melting point (T _m ) of 250°C or higher in the core component, and polyester having a melting point of 20°C or higher than that of the polyester of the core component. step; And
(2) Passing the web containing the core-sheath type polyester fiber between two smooth rolls at a temperature of 160°C to 200°C, and heat-sealing it; as a method for manufacturing a composite nonwoven fabric comprising,
The method of manufacturing a composite nonwoven fabric, characterized in that an embo roll is not used in the heat fusion step. delete The method of claim 8,
The method of manufacturing a composite nonwoven fabric, characterized in that the weight ratio of the core component and the sheath component of the core sheath type polyester composite fiber is 90:10 to 70:30.

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