KR101788705B1

KR101788705B1 - Nonwoven fabric with excellent bulkiness and manufacturing method of the same from composite filament fiber

Info

Publication number: KR101788705B1
Application number: KR1020150189905A
Authority: KR
Inventors: 곽동헌
Original assignee: 코오롱글로텍주식회사
Priority date: 2015-12-30
Filing date: 2015-12-30
Publication date: 2017-11-15
Also published as: KR20170079401A

Abstract

One example of the present invention provides a nonwoven fabric formed by thermal welding of eccentric core-sheath type composite filaments. The nonwoven fabric according to an example of the present invention has excellent bulkiness by a combination of parameters such as the eccentricity of the core-sheath type composite filament, the elongation at break of the core-sheath type composite filament, and the crimping form of the core-sheath type composite filament. Accordingly, the nonwoven fabric according to an exemplary embodiment of the present invention can be used for a variety of applications such as agricultural products, household insulation materials, thermal insulation materials, shock absorbing materials, and the like in addition to a topsheet, an absorbent dispersion layer (ADL layer), an outer layer, a backsheet, and a waist band of a disposable diaper and a sanitary napkin Absorbing materials, sound absorbing materials, and the like.

Description

TECHNICAL FIELD [0001] The present invention relates to a composite nonwoven fabric having excellent bulk properties and a method for manufacturing the nonwoven fabric,

The present invention relates to a nonwoven fabric and a method for producing the nonwoven fabric, and more particularly, to a nonwoven fabric formed from composite filaments having predetermined characteristics and having excellent bulk properties and a method for producing the nonwoven fabric.

BACKGROUND ART [0002] Heat-sealable conjugate fibers that can be molded by thermal fusion using heat energy such as hot air or heating rolls can easily obtain bulkiness. Therefore, hygienic materials such as diapers, napkins, pads, , Industrial materials such as household goods and filters, and the like. In particular, hygiene materials are required to have a liquid-absorbing property because they are in direct contact with the skin, and need to quickly absorb liquids such as touch, touch, urine, and menstrual blood, and have bulk properties A method of obtaining a fiber and a nonwoven fabric having a fiber-reinforced polypropylene fiber has been proposed. In general, the nonwoven fabric having a bulk property is produced by cutting a crimped long fiber by a melt spinning, a stretching step and a crimping step to produce a short fiber, forming a web by forming a short fiber to form a web, . When such a nonwoven fabric is produced from staple fibers, the bulkiness and mechanical strength of the nonwoven fabric are lowered and the manufacturing process is complicated.

To solve this problem, various methods for producing nonwoven fabric directly from long fibers have been studied. For example, the spunbond long fibrous nonwoven fabric is a kind of nonwoven fabric manufactured by forming a layer of long fibers on a conveyor by being blown onto a conveyor running on fibers running from a nozzle, which is advantageous in terms of manufacturing efficiency and economical advantage. In addition, Korean Patent Registration No. 10-1149594 discloses a method for producing a spunbonded nonwoven fabric by spinning a polypropylene-based polymer to form a web on a continuous belt and thermally bonding the same to the belt, Polypropylene having the first and second components is guided to each nozzle hole by using a distribution plate having a specific structure to produce composite filament yarns to produce composite filament yarns. An air jet device which is laminated on a porous continuous belt to form a web of composite filaments to facilitate separation of the fibrous web and the belt, and an air jet device which partially thermally compresses or needle punches the composite filament web Wherein the viscosity of the first component and the second component are different from each other, The second component polypropylene has a melt index difference of 5 to 30 g / 10 min, and the polypropylene contains polyethylene glycol, polyethylene oxide, polyacrylic acid or polyvinyl acetate as the basis weight of the polypropylene nonwoven fabric. And 0.3 to 30 parts by weight of a selected hydrophilic polymer and cellulose are added to the nonwoven fabric. Korean Patent Laid-Open Publication No. 10-2014-0065898 discloses a method for producing a spunbonded nonwoven fabric by spinning a polypropylene-based polymer to form a web on a continuous belt and thermally bonding the same to the belt, Polypropylene having different primary and secondary components is guided to each nozzle hole by using a distribution plate having a specific structure to produce composite filament yarn by composite spinning and separation of filament web and belt An air jet device which is laminated on an easy porous continuous belt to form a web of composite filaments to facilitate separation of the fibrous web and the belt, And a step of heat-treating the sheet form fixed by punching and bonding to a suction drum to form a sheet. A process for producing a polypropylene composite spunbonded nonwoven fabric having excellent bulky properties is disclosed. However, when the polypropylene having different physical properties such as melt index or viscosity as in the above-mentioned prior art technique is used in combination, there is little or no crimp effect and there is no difference in heat shrinkage ratio. Thus, the difference in bulk property between general spunbond long- It is hard to expect.

SUMMARY OF THE INVENTION The present invention has been made under the background of the prior art, and an object of the present invention is to provide a composite long-fiber nonwoven fabric excellent in bulk property by combination of various parameters such as the material and structure of the composite long- And a method of manufacturing the same.

The inventors of the present invention have found that when the nonwoven fabric is formed by thermal welding of the core-sheath type composite filament fibers, parameters such as the eccentricity of the core-sheath type composite filament, the elongation at break of the core-sheath type composite filament, The bulkiness of the nonwoven fabric is remarkably improved, and the present invention has been completed.

In order to achieve the above object, an embodiment of the present invention is a nonwoven fabric formed by thermal fusion of eccentric core-sheath type composite filaments, wherein the core part of the eccentric core-sheath type composite filaments includes a polyester resin or a polypropylene resin Wherein the core part comprises a polyolefin resin having a melting point lower than the resin constituting the core part by 20 DEG C or more, the elongation at break of the eccentric core-sheath type composite filament is 60% or less, and the eccentric core- Of the total length of the nonwoven fabric.

In order to achieve the above object, one example of the present invention is a method for manufacturing a polyolefin-based resin, wherein a polyolefin-based resin having a melting point lower than that of the resin disposed in the core portion by a polyester- Forming a unstretched eccentric core-sheath type composite filament yarn by melt spinning after supplying to a spinning head of a core-sheath type; Cooling the unstretched eccentric core-sheath type composite long fibers; Stretching the cooled eccentric unoriented core-sheath type composite long fibers to have a elongation at break of 60% or less to form a spiral or Ω-type crimp; Forming a web by laminating the crimped elongated eccentric core-sheath type composite long fibers; And forming a nonwoven fabric by thermally fusing a web comprising the stretched eccentric core-sheath type composite filament fibers.

The nonwoven fabric according to an example of the present invention has excellent bulkiness by a combination of parameters such as the eccentricity of the core-sheath type composite filament, the elongation at break of the core-sheath type composite filament, and the crimping form of the core-sheath type composite filament. Accordingly, the nonwoven fabric according to an exemplary embodiment of the present invention can be used for a variety of applications such as agricultural products, household insulation materials, thermal insulation materials, shock absorbing materials, and the like in addition to a topsheet, an absorbent dispersion layer (ADL layer), an outer layer, a backsheet, and a waist band of a disposable diaper and a sanitary napkin Absorbing materials, sound absorbing materials, and the like.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 schematically shows longitudinal cross-sections of eccentric core-sheath type composite long fibers.
Fig. 2 is a photograph of the core-sheath type composite long fiber prepared in Preparation Example 1 of the present invention, and Fig. 3 is a photograph of the core-sheath type composite long fiber prepared in Production Example 2 of the present invention after stretching.
Fig. 4 is a photograph of the core-sheath type composite long fiber prepared in Comparative Production Example 1 of the present invention, and Fig. 5 is a photograph of the core-sheath type composite long fiber prepared in Comparative Production Example 3 of the present invention after stretching.

Hereinafter, the present invention will be described in detail.

One aspect of the present invention relates to a composite long fibrous nonwoven fabric having excellent bulk properties, and the nonwoven fabric according to an example of the present invention is formed by heat fusion of eccentric core-sheath type composite long fibers.

The eccentricity of the eccentric core-sheath type composite filament yarns is preferably 50% or more, more preferably 60% or more, in consideration of ease of self-crimping in the drawing process of the eccentric core-sheath type filament yarns and bulkiness of the nonwoven fabric.

The core portion of the eccentric core-sheath type composite long fiber is made of or comprises a polyester-based resin or a polypropylene-based resin. The polyester-based resin constituting the core of the eccentric core-sheath type composite long fiber is generally obtained by polycondensation reaction of diol and dicarboxylic acid. Examples of the dicarboxylic acid used in the polycondensation reaction of the polyester resin include terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, adipic acid and sebacic acid. Examples of the diol used in the polycondensation reaction of the polyester resin include ethylene glycol, diethylene glycol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,4-cyclohexanedimethanol, . As the polyester-based resin used in the present invention, polyethylene terephthalate, polypropylene terephthalate and polybutylene terephthalate can be preferably used. In addition to the above aromatic polyester, aliphatic polyesters can also be used, and preferable resins include polylactic acid and polybutylene adipate terephthalate. Fig. 1 shows kinds and chemical structures of aliphatic polyester-based resins usable in the present invention. These polyester resins may be homopolymeric polyesters as well as copolymerized polyesters (copolyesters). Examples of the copolymerization component include dicarboxylic acid components such as adipic acid, sebacic acid, phthalic acid, isophthalic acid and 2,6-naphthalenedicarboxylic acid, diol components such as diethylene glycol and neopentyl glycol, and optical isomers such as L- Can be used. Two or more of these polyester resins may be used in combination. The polyester resin constituting the core part of the various polyester resins mentioned above is preferably selected from the group consisting of polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), polyethylene naphthalate At least one selected from the group consisting of polyethylene terephthalate (PEN), polyethylene terephthalate glycol (PETG) and polycyclohexanedimethylene terephthalate (PCT), and at least one selected from the group consisting of polyethylene terephthalate or polytrimethylene terephthalate ), And most preferably polyethylene terephthalate having an intrinsic viscosity (Iv) of 0.6 to 0.7 dl / g. The melting point of the polyester-based resin constituting the core of the eccentric core-sheath type composite long fiber is preferably 220 to 280 ° C. The MFI (230 ° C, 2.16 kg load) of the polypropylene resin constituting the core of the eccentric core-sheath type composite long fiber is preferably about 10 g / 10 min to 40 g / 10 min, more preferably 20 g / 10 min Min to 40 g / 10 min. The melting point of the polypropylene resin constituting the core part of the eccentric core-sheath type composite long fiber is preferably 150 to 200 占 폚, more preferably 160 to 180 占 폚.

The initial portion of the eccentric core-sheath type composite long fiber is made of or comprises a polyolefin resin having a melting point lower than the resin constituting the core portion by 20 ° C or more, preferably 30 ° C or more. Self-crimping (wrinkling) is easily formed in the elongation process of the eccentric core-sheath type composite filament yarns as the difference in melting point between the resin constituting the core part and the core part of the eccentric core-sheath type composite filament becomes greater. The polyolefin-based resin constituting the beginning of the eccentric core-sheath type composite long fiber is preferably a high-density polyethylene, a linear low density polyethylene, a low density polyethylene, a polypropylene (propylene homopolymer), an ethylene-propylene copolymer containing propylene as a main component, 1, polybutene-1, polyhexene-1, polyhexene-1, poly 4-methylpentene-1, polymethylpentene, 1,2-polybutadiene, 1,4-polybutadiene , A maleic anhydride-modified product of an ethylene-based polymer, a maleic anhydride-modified product of a propylene-based polymer, and the like. In addition, these homopolymers may contain a small amount of an? -Olefin such as ethylene, butene-1, hexene-1, octene-1 or 4-methylpentene-1 other than the monomer constituting the homopolymer as a copolymerization component. In addition, other ethylenically unsaturated monomers such as butadiene, isoprene, 1,3-pentadiene, styrene and? -Methylstyrene may be contained in small amounts as copolymerizable components. These polyolefin resins may be used in combination of two or more. These may be preferably used not only polyolefin resins polymerized from a conventional Ziegler-Natta catalyst but also polyolefin resins polymerized from a metallocene catalyst and copolymers thereof. The melt flow index (MFI) of the polyolefin-based resin that can be used as the superfine component of the present invention is not particularly limited as long as it is in a spinning range, and is preferably 1 to 100 g / 10 min, more preferably 10 to 40 g / 10 min desirable. Considering various physical properties such as a melting point difference with a polyester resin or a polypropylene resin constituting a core part and a melt flow index (MFI), the polyolefin resin constituting the initial part of the above various polyolefin resins has a melting point of 110 - 150 ° C, and may be selected from high-density polyethylene and linear low-density polyethylene, and more preferably high-density polyethylene.

In the eccentric core-sheath type composite long fiber, preferred combinations of the resin constituting the core portion and the resin constituting the novolak include polypropylene / polyethylene terephthalate, high density polyethylene / polyethylene terephthalate, linear low density polyethylene / polyethylene terephthalate, Polyethylene / polyethylene terephthalate. In addition to polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate and polylactic acid may also be used.

In the eccentric core-sheath type composite filament yarn, the weight ratio of the core to the weft portion is not particularly limited, and may be, for example, from 35:65 to 65:35, preferably from 45:55 to 65:35, More preferably 60:40.

The elongation at break of the eccentric core-sheath type composite filament yarn is preferably 60% or less, more preferably 30 to 60%, in consideration of the easiness of self-crimping and the bulk degree of the nonwoven fabric in the elongation of the eccentric core- , And most preferably 40 to 55%.

It is preferable that the eccentric core-sheath type composite filament yarn has a helical or Ω-type crimp (wrinkle or bending) formed by self-crimping in the drawing process in consideration of the bulkiness of the nonwoven fabric.

Preferably, the eccentric core-sheath type composite filament fibers are heat-sealed by through-air bonding. In the thermal fusion of the eccentric core-sheath type composite filament fibers, the superficial components of the eccentric core-sheath type composite filament are melted and fused and converted into a nonwoven fabric.

The nonwoven fabric according to an exemplary embodiment of the present invention preferably has a bulk density of 40 to 80 cm3 / g, more preferably 50 to 75 cm3 / g, and most preferably 55 to 70 cm3 / g.

Another aspect of the present invention relates to a method for producing a composite long-fiber nonwoven fabric excellent in bulkiness, and a method for producing a composite long-fiber nonwoven fabric according to an embodiment of the present invention is characterized in that a polyester resin or a polypropylene- Supplying a polyolefin-based resin having a melting point lower than the resin disposed in the core portion to an eccentric core-sheath type spinneret so that the polyolefin-based resin has a melting point lower than 20 ° C; Cooling the unstretched eccentric core-sheath type composite long fibers; Stretching the cooled eccentric unoriented core-sheath type composite long fibers to have a elongation at break of 60% or less to form a spiral or Ω-type crimp; Forming a web by laminating the crimped elongated eccentric core-sheath type composite long fibers; And forming a nonwoven fabric by thermally fusing a web comprising the stretched eccentric core-sheath type composite filament fibers.

In the method for manufacturing a composite long-fiber non-woven fabric according to an example of the present invention, cooling of the unstretched eccentric core-sheath type composite long fibers is performed by cooling air at 10 to 25 ° C, preferably 15 to 20 ° C, And the like.

In the method of manufacturing a composite long-fiber nonwoven fabric according to an example of the present invention, the unstretched eccentric core-sheath type composite long-fiber stretch and crimp formation is carried out at a temperature of 50 to 90 ° C, preferably 60 to 80 ° C, And in contact with the composite long fibers. In addition, in the method for manufacturing a composite long-fiber nonwoven fabric according to an example of the present invention, when the unstretched eccentric core-sheath type composite long-fiber is stretched and the crimp is formed, the wind pressure of the hot- The elongation at break and the crimp shape of the eccentric core-sheath type composite filament that can be controlled and ultimately elongated can be controlled.

In the method for manufacturing a composite long-fiber non-woven fabric according to an example of the present invention, the eccentricity of the drawn eccentric core-sheath type composite filament having the crimp is preferably 50% or more.

In the method for manufacturing a composite long-fiber nonwoven fabric according to an exemplary embodiment of the present invention, the thermal fusion of the web is preferably performed by through-air boning. At this time, the temperature of the through air bonding oven is 120 to 160 ° C, preferably 130 to 150 ° C, and the residence time of the web in the through air bonding oven is 5 to 20 seconds, preferably 8 to 15 seconds

In the method for producing a composite long-fiber nonwoven fabric according to an example of the present invention, the specific kind and physical properties of the polymer resin constituting the core portion and the weft portion, the weight ratio of the polymer resin constituting the core portion and the weft portion, The elongation at break of the elongated eccentric core-sheath type composite filament fibers, the bulk density of the nonwoven fabric, etc., refer to the above description in the composite filament nonwoven fabric portion.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the following examples are intended to clearly illustrate the technical features of the present invention and do not limit the scope of protection of the present invention.

1. Explanation of analysis method

(1) Elongation at Break of Composite Long Fiber: The tensile properties of the composite fiber were measured according to ASTM D3822.

(2) Eccentricity of Composite Long Fiber Eccentricity: The eccentricity of the core - sheath type composite filament fiber was controlled through spinning spinning in the spinning stage. After 20 randomly selected final heart - shaped multifilament samples, cross - sections were taken by scanning electron microscope (SEM) and eccentricity was verified.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 schematically shows longitudinal cross-sections of eccentric core-sheath type composite long fibers. As shown in Fig. 1, the core-sheath type composite filament fiber is composed of a core portion 1 and an initial portion 2 surrounding the core portion 1, and the eccentric core-sheath type composite filament fiber is a core portion of the core portion. Referring to Fig. 1, the eccentricity of the core-sheath type composite filament in the present invention is calculated by the following equation. In the present invention, considering the error range, the eccentricity of the continuous core-sheath type composite filament yarn located at the center of the deep part of the core is theoretically considered to be 0% do.

L ₀ represents the longest distance between the outer periphery of the deep portion and the outer periphery of the _{first portion} and L ₁ represents the shortest distance between the outer periphery of the deep portion and the outer periphery of the first portion. In the present invention, the eccentricity of the eccentric core-sheath type composite filament fibers can be controlled through the spinning-type spinning nip in the spinning step, and the cross section of the final eccentric core-sheath type filament fiber is scanned with a scanning electron microscope (SEM) The actual eccentricity and the distribution ratio of the eccentricity can be inversely estimated.

(3) Nonwoven basis weight: The basis weight of the nonwoven fabric was measured according to the ERT method (EDANA RECOMMENDED TEST METHODS) 40.3-90.

(4) Nonwoven Fabric Thickness: The thickness of the nonwoven fabric was measured according to the ERT method (EDANA RECOMMENDED TEST METHODS) 30.5-99.

(5) Bulk density of nonwoven fabric: The bulk density of nonwoven fabric was calculated by the following formula.

Non-woven fabric bulk density (cm 3 / g) = nonwoven fabric thickness / nonwoven fabric basis weight

2. Heart-shaped complex Long fiber Production of used nonwoven fabric

Production Example 1

A homo-type polypropylene having a melt flow index (MFI) of 30 g / 10 min, a specific gravity of 0.9, and a melting point of 162 DEG C measured under a load condition of 230 DEG C and 2.16 kg according to ASTM D1238 as a deep- Were prepared. A high density polyethylene having a melt flow index (MFI) of 30 g / 10 min, a specific gravity of 0.95 and a melting point of 130 占 폚 as measured at 190 占 폚 under a load of 2.16 kg according to ASTM D1238 as a superfine component, HDPE). The core component and the sheath component were melted and extruded through a separate extruder at a weight ratio of 50:50 and melt-extruded through a core-sheath type composite spinneret having a predetermined eccentricity at a discharge rate of 1 g / To prepare unbleached core-sheath type composite filament fibers. Thereafter, the non-drawn core-sheath type composite filament fibers were cooled by passing through a cooling air having a temperature of about 17 캜 and a wind speed of about 2 m / sec. Thereafter, high-temperature / high-pressure air at about 70 ° C and a predetermined pressure is discharged from the ejector to join the cooled unheated core-sheath type composite long-fiber, and the cooled un-drawn core-sheath type composite long-fiber is conveyed to a conveyor at about 4500 m / Min and laminated to form a web. At this time, the cooled unoriented core-sheath type composite filament yarn is stretched at a predetermined magnification by contact with high-temperature / high-pressure air, and self crimping is induced and converted into stretched core-sheath type filament yarn. The laminated web was then conveyed through a belt and passed through a through-air boning oven to form a non-woven fabric. The temperature of the belt-through-air-boning oven was about 140 ° C and the oven residence time of the web was about 10 seconds.

Production Example 2

Polyethylene terephthalate (PET) having an intrinsic viscosity (Iv) of 0.663 dl / g, a specific gravity of 1.38 and a melting point of 256 ° C was used as the core component and the discharge amount per unit hole of the spinneret was changed to 0.6 g / And the drawn core-sheath type composite filament yarn was cooled to about 2800 m / min through the wind pressure of the air discharged from the ejector. Composite filament fabrics and nonwoven fabrics were prepared.

Comparative Production Example 1

A drawn core-sheath type composite filament fiber and a nonwoven fabric were produced under the same conditions and in the same manner as in Preparation Example 1, except that a complex spinning spinneret was used instead of the spinneret spinneret.

Comparative Preparation Example 2

The drawn core-sheath type composite filament fabrics and nonwoven fabrics were prepared under the same conditions and in the same manner as in Preparation Example 2, except that a complex spinning spinneret was used instead of the spinneret spinneret.

Comparative Preparation Example 3

The same procedure was followed as in Production Example 1, except that the uniaxial core-sheath type composite filament yarn cooled through the wind pressure of the air discharged from the ejector was adjusted to about 3500 m / And a nonwoven fabric.

Comparative Preparation Example 4

The same procedure was followed as in Production Example 2, except that the core speed of the uncoated core-sheath type composite filament yarn cooled through the wind pressure of the air discharged from the ejector was adjusted to about 2300 m / And a nonwoven fabric.

Comparative Preparation Example 5

The same procedure was followed as in Production Example 1, except that the shear core-sheath type composite filament yarn cooled through the wind pressure of the air discharged from the ejector was adjusted to about 5000 m / min. And the production of the nonwoven fabric was carried out. As a result, the cooled unstretched core - sheath type multifilament fiber was cut off during stretching and self - crimping was not stably implemented.

Comparative Preparation Example 6

The same procedure as in Production Example 2 was carried out except that the core yarns of the unheated core-sheath type composite filament yarn cooled through the wind pressure of the air discharged from the ejector were adjusted to about 4000 m / And the production of the nonwoven fabric was carried out. As a result, the cooled unstretched core - sheath type multifilament fiber was cut off during stretching and self - crimping was not stably implemented.

3. Heart-shaped complex Long fiber And measurement of physical properties of the nonwoven fabric produced therefrom

The core-sheath type composite long fibers prepared in Production Example 1, Production Example 2 and Comparative Production Examples 1 to 4 were sampled on a laminated web and their eccentricity, elongation at break and crimp type were measured. The basis weight, thickness and bulk density of the nonwoven fabric prepared in Production Example 1, Production Example 2, and Comparative Production Example 1 to Comparative Production Example 4 were measured. The measurement results are shown in Table 1 below.

Core-sheath type composite fiber and nonwoven fabric Properties of core-sheath type composite filament laminated in web form Nonwoven fabric properties Eccentricity (%) Elongation at break (%) Crimp shape Basis weight (g / ㎡) Thickness (mm) Bulk road
(Cm3 / g) Production Example 1 70 52 Ω 30 1.78 59.3 Production Example 2 70 43 Ω 30 1.93 64.3 Comparative Preparation Example 1 0 (in-depth) 56 none 30 0.82 27.3 Comparative Production Example 2 0 (in-depth) 45 none 30 0.85 28.3 Comparative Production Example 3 70 105 Irregular weak curl 30 0.98 32.7 Comparative Production Example 4 70 76 Irregular weak curl 30 0.92 30.7

Fig. 2 is a photograph of the core-sheath type composite long fiber prepared in Preparation Example 1 of the present invention, and Fig. 3 is a photograph of the core-sheath type composite long fiber prepared in Production Example 2 of the present invention after stretching. Fig. 4 is a photograph of the core-sheath type composite long fiber prepared in Comparative Production Example 1 of the present invention, and Fig. 5 is a photograph of the core-sheath type composite long fiber prepared in Comparative Production Example 3 of the present invention after stretching. The core-sheath type composite long-haul fibers prepared in Comparative Preparation Example 2 of the present invention had substantially the same crimp shape as the core-sheath type composite long-haul fibers after stretching prepared in Comparative Production Example 1, The core-sheath type composite filament yarn after stretching had almost the same crimp type as the core-sheath type composite filament yarn after stretching prepared in Comparative Production Example 3. [ As shown in FIGS. 2 to 5, when the core-sheath type composite long fibers after stretching have an eccentricity of 50% or more and a breaking elongation of 60% or less, a spiral or Ω-type crimp is formed by the self-crimping process in the stretching process . Further, as shown in Table 1, the nonwoven fabrics (Production Example 1 and Production Example 2) produced by thermal fusion of the core-sheath type composite filament yarns formed with spiral or Ω type self-crimps had comparative Production Examples 1 to 4 The bulkiness was about twice as large as that of the nonwoven fabric produced by the method of the present invention.

While the present invention has been described in connection with the exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. Therefore, the scope of the present invention should be construed as including all embodiments falling within the scope of the appended claims.

Claims

A nonwoven fabric formed by heat welding of eccentric core-sheath type composite long fibers,
Wherein the core part of the eccentric core-sheath type composite long fiber comprises a polyester-based resin or a polypropylene-based resin, and the beginning part thereof comprises a polyolefin-based resin having a melting point lower than that of the resin constituting the core part by 20 占 폚 or more,
The eccentricity of the eccentric core-sheath type composite filament fiber is 60% or more,
In the eccentric core-sheath type composite filament yarn, the weight ratio of the core to the weft portion is 45:65 to 65:45,
The elongation at break of the eccentric core-sheath type composite long fiber is 40 to 55%
The eccentric core-sheath type composite filament yarn has a spiral or Ω-type crimp,
And a bulk density of 55 to 70 cm < 3 > / g.

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The composite long-fiber nonwoven fabric according to claim 1, wherein the polyester-based resin constituting the core portion has a melting point of 220 to 280 ° C.

The composite long-fiber nonwoven fabric according to claim 1, wherein the polyolefin-based resin constituting the initial portion is a polyethylene-based resin having a melting point of 110 to 150 ° C.

The composite filament according to claim 1, wherein the eccentric core-sheath type composite filament fibers are thermally fused by through-air boning, and the superfine components of the eccentric core- Non-woven.

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A polyester resin or a polypropylene resin is disposed in the core and a polyolefin resin having a melting point lower than that of the resin disposed in the core is placed in the core, Forming an eccentric core-sheath type composite long fiber;
Cooling the unstretched eccentric core-sheath type composite long fibers;
Stretching the cooled eccentric unoriented core-sheath type composite long fiber having a breaking elongation of 40 to 55% to form a spiral or Ω-type crimp;
Forming a web by laminating the crimped elongated eccentric core-sheath type composite long fibers having the crimp formed thereon; And
And forming a nonwoven fabric by thermally fusing a web comprising the elongated eccentric core-sheath type composite filament fibers,
The eccentricity of the crimped elongated eccentric core-sheath type composite long fiber having the crimp is 60% or more,
In the crimped elongated eccentric core-sheath type composite filament yarn in which the crimp is formed, the weight ratio of the core to the weft portion is 45:65 to 65:45,
Wherein the bulk density of the nonwoven fabric is 55 to 70 cm 3 / g.

The method of manufacturing a composite long-fiber nonwoven fabric according to claim 8, wherein cooling of the unstretched eccentric core-sheath type composite long-fiber is performed by bringing cooling air at 10 to 25 ° C into contact with un-stretched core-sheath type composite long-fiber.

9. The composite nonwoven fabric according to claim 8, wherein the unstretched eccentric core-sheath type composite filament fibers are stretched and crimped are formed by bringing hot air at 50 to 90 DEG C into contact with un- Gt;

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9. The method of claim 8, wherein the web is heat bonded by through-air boning, wherein the temperature of the through-air bonding oven is 120 to 160 < 0 > C and the retention time of the web in the through- Lt; RTI ID = 0.0 > 20 seconds. &Lt; / RTI >