JP2002069822A - Stretchable bulky filament nonwoven fabric and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a filament nonwoven fabric excellent in stretchability and in bulkiness. SOLUTION: This stretchable and bulky long fiber nonwoven fabric comprises a long fiber having a latent crimping ability and actualized its latent crimping ability and partly has heat pressed parts. The nonwoven fabric has a waved shape and has <=0.1 g/cm3 bulky density.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a long-fiber nonwoven fabric having excellent bulkiness and elasticity.

[0002]

2. Description of the Related Art Conventionally, nonwoven fabrics have been used for various purposes such as clothing, industrial materials, civil engineering construction, agricultural and horticultural materials, living-related materials, and medical hygiene materials. In particular, in recent years, various properties have been required for nonwoven fabrics with the expansion of these uses. As one of them, a nonwoven fabric excellent in elasticity and bulkiness is desired.

As a nonwoven fabric having both elasticity and bulkiness, there is a nonwoven fabric made of short fibers having three-dimensional crimps. The short fiber non-woven fabric can be appropriately selected in the arrangement of the fibers, and can have good stretchability in both the vertical and horizontal directions. However, depending on the application, there is a problem that the fiber strength is limited due to a short fiber length, and the fiber is liable to fall off and lint is generated.

On the other hand, there is a long-fiber nonwoven fabric having a three-dimensional crimp manufactured by a spun bond method. The long-fiber nonwoven fabric has a moderate elasticity and a long fiber length, so that it has high strength and excellent lint-free property. In addition, according to the spun bond method, the web can be directly spun to obtain a web and formed into a nonwoven fabric without going through a manufacturing process such as a short fiber forming process, a carding process, etc. as in the production of a short fiber nonwoven fabric. It has excellent properties.

[0005]

DISCLOSURE OF THE INVENTION The present invention provides a more stretchable nonwoven fabric having a three-dimensional crimp or a three-dimensional nonwoven fabric having a three-dimensional crimp produced by a spunbond method. It is an object of the present invention to provide a nonwoven fabric having excellent bulkiness and improved bulkiness.

[0006]

Means for Solving the Problems The present inventors have made intensive studies to solve the above problems, and as a result, have reached the present invention. That is, the present invention is a long-fiber nonwoven fabric comprising a long fiber having latent crimping ability and having the latent crimp revealed, and the nonwoven fabric has a corrugated shape and a bulk density of 0. 1 g / cm ³
The gist of the present invention is a stretchable bulky long-fiber nonwoven fabric characterized by the following.

[0007] The present invention also relates to a method of melt-spinning a parallel type composite long fiber or an eccentric core-sheath type composite long fiber comprising two kinds of fiber-forming polymers having different heat shrinkages from each other, and taking it up using an air sucker. The fiber is spread and deposited on a movable collecting surface such as a screen conveyor to obtain a long fiber web, and the long fiber web is partially thermocompressed using a partial thermocompression bonding apparatus to obtain a long fiber web. Is subjected to buckling by a buckling machine, and then subjected to a heat treatment at a temperature lower than the melting point of the low melting point polymer among the fiber-forming polymers constituting the long fibers, and is imparted by buckling. It is another object of the present invention to provide a method for producing a stretchable bulky long-fiber nonwoven fabric, which heat-fixes the wavy shape and makes the latent crimping ability of the long fiber obvious.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
First, the stretchable bulky long-fiber nonwoven fabric of the present invention is made of long fibers having latent crimping ability and having the latent crimps manifested.
In the long fibers, latent crimps are revealed by the relaxation heat treatment, and a three-dimensional spiral crimp is developed.
In consideration of the bulkiness of the long-fiber nonwoven fabric, the average number of crimps of the long fibers in which latent crimps become apparent is preferably 15 pieces / 25 mm or more, and more preferably 20 pieces / 25 m.
m or more. The upper limit is not particularly limited.
What is necessary is just about 0 pieces / 25 mm.

[0009] As such a long fiber, a parallel type composite fiber in which two kinds of fiber-forming polymers having different heat shrinkages are juxtaposed along the length direction of the fiber, or a heat shrinkability different from each other. An eccentric core-sheath type composite fiber in which two types of fiber-forming polymers are arranged in an eccentric core-sheath structure is exemplified.

As the combination of the fiber-forming polymers having different heat shrinkages, different or similar polymers may be selected according to the purpose. As a combination of thermoplastic polymers having different heat shrinkage, for example, polyester-based and polyamide-based,
Examples include polyester-based and polyolefin-based, polyamide-based and polyolefin-based, and the like. As the combination of the same type of thermoplastic polymer, a combination of different viscosities or a combination of different melting point polymers (combination of a homopolymer and a copolymer) in a polyester, polyamide, or polyolefin polymer is used. No.

When a parallel type is adopted as a composite form of long fibers, two types of polymers having compatibility with each other are used. When incompatible materials are used, peeling occurs at the interface of the composite cross section formed by both polymers in the yarn production / reversing process, causing serious trouble. On the other hand, when adopting the eccentric core-sheath type as the composite form of the long fiber,
The species polymers may be compatible or incompatible with each other.

The fiber-forming polyolefin polymer used in the present invention is preferably an aliphatic α-olefin having 2 to 16 carbon atoms.
Monoolefins, for example ethylene, propylene, 1-
There are homopolyolefins or copolymerized polyolefins of butene, 1-pentene, 3-methyl 1-butene, 1-hexene, 1-octene, 1-dodecene, and 1-octadecene. Aliphatic α-monoolefins are other olefins and / or small amounts (up to about 10% by weight of polymer weight) of other ethylenically unsaturated monomers such as butadiene, isoprene, pentadiene-1,3, styrene, α-methyl It may be copolymerized with a similar ethylenically unsaturated monomer such as styrene. In particular, in the case of polyethylene, a copolymer obtained by copolymerizing propylene, butene-1, hexene-1, octene-1 or a similar higher α-olefin up to about 10% by mass of the polymer is preferable because the spinning property is improved.

As the fiber-forming polyamide polymer,
Nylon-4, Nylon-46, Nylon-6, Nylon-66, Nylon-610, Nylon-11, Nylon-12 and polymetaxylene adipamide (MXD-
6), polyparaxylenedecaneamide (PXD-1)
2), polybiscyclohexylmethanedecaneamide (P
CM-12) or copolymerized polyamides containing these monomers as constituent units.

As the fiber-forming polyester polymer, an aromatic dicarboxylic acid such as terephthalic acid, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid or an aliphatic acid such as adipic acid or sebacic acid is used as an acid component. Homopolyester or copolyester synthesized from dicarboxylic acids or their esters and diol compounds such as ethylene glycol, diethylene glycol, 1,4-butanediol, neopentyl glycol, 1,4-cyclohexanedimethanol as alcohol components Paraoxybenzoic acid, 5-sodium sulfoisophthalic acid, polyalkylene glycol, pentaerythritol, bisphenol A or the like may be added to or copolymerized with the above polyester.

As the fiber-forming polymer other than the above, for example, a vinyl polymer is used. Specifically, polyvinyl alcohol, polyvinyl acetate, polyacrylate, ethylene-vinyl acetate copolymer, polyvinyl chloride , Polyvinylidene chloride, or a copolymer thereof. Further, a polyphenylene-based polymer or a copolymer thereof can also be used.

The fiber-forming polymer may be added, if necessary, to a matting agent, a pigment, a flame retardant, a deodorant, a light stabilizer, a heat stabilizer, an antioxidant, an antibacterial agent, etc. Can be added within a range that does not impair the effects of the present invention.

The fiber cross section of the long fibers constituting the long fiber web used in the present invention is not limited to a circular shape, but may be a triangular cross section or other irregular shapes, or may be a hollow cross section having a hollow portion.

The fineness of single filaments of the long fibers constituting the long-fiber nonwoven fabric may be appropriately selected according to the intended use.
It is preferably decitex. Single yarn fineness is 1.5
If it is less than the decitex, the mechanical properties of the obtained composite nonwoven fabric tend to decrease, and the spinning properties tend to decrease in the melt spinning step. On the other hand, if the single-fiber fineness exceeds 13 decitex, the texture of the obtained web becomes hard, and it becomes difficult to obtain a long-fiber nonwoven fabric with high flexibility. Because it is not suitable, its use is limited. When it is desired to obtain a low-weight one, the formation tends to be inferior.

The long-fiber nonwoven fabric of the present invention partially has a thermocompression-bonded portion. The shape of each thermocompression bonding portion is not necessarily required to be circular, and may be any of an ellipse, a square, a cross, and the like, and each thermocompression bonding portion is 0.1 to 1.2 m.
m ² , and its density, that is, the crimping point density is 4
-80 points / cm ² , preferably 10-60 points / cm ² . Further, the ratio of the area of the entire thermocompression bonding area to the total surface area of the long fiber web, that is, the thermocompression bonding area ratio is 5-5.
0%, preferably 10-20%. When the compression area ratio is less than 5%, the mechanical properties and dimensional stability of the long-fiber nonwoven fabric are inferior. On the other hand, if the compression area ratio exceeds 50%, most of the fibers constituting the long-fiber nonwoven fabric are heat-sealed, and the portion where latent crimps become apparent becomes small. In this case, a long-fiber nonwoven fabric having excellent elasticity tends not to be obtained.

The long-fiber nonwoven fabric of the present invention has a corrugated shape. The wavy shape may be either the longitudinal direction or the width direction of the nonwoven fabric. However, in order to obtain the long-fiber nonwoven fabric of the present invention by the method described later, peaks and valleys alternate in the longitudinal direction (machine direction). It is preferable that the shape is a wave shape expressed in

In the wavy shape of the long-fiber nonwoven fabric, the amplitude (the height of the wave, ie, the difference between the valley and the peak) is 1
It is preferably about 3 mm. When the amplitude is less than 1 mm, the wave shape is too fine, and the fibers constituting the wave-shaped peaks and valleys are easily cut, and fiber breakage occurs in that portion, resulting in poor quality and bulkiness. And a long-fiber nonwoven fabric having poor elasticity. If the amplitude exceeds 3 mm, it is difficult to obtain a long-fiber nonwoven fabric having excellent stretch recovery properties, and the object of the present invention tends to not be achieved.

The wave number of the wave shape of the long-fiber nonwoven fabric is 5
It is preferable that it is ３０30/25 mm. 5/25
When the length is less than 30 mm, it is difficult to obtain a material having an excellent elongation recovery property which is the object of the present invention. Since the shape is too fine, the fibers constituting the wave-shaped peaks and valleys are easily cut, and fiber breakage occurs at those portions, resulting in a long-fiber nonwoven fabric of inferior quality.

The amplitude and wave number of the corrugated shape of the long-fiber nonwoven fabric can be controlled by the gap between the rolls, the roll temperature, the relative angle of the letterer, and the surface roughness of the letterer during the buckling process described later. .

The bulk density of the long-fiber nonwoven fabric of the present invention is 0.1
g / cm ³ or less. Those having a bulk density of more than 0.1 g / cm ³ are not the object of the present invention and cannot be said to be excellent in bulkiness.

The basis weight of the long-fiber nonwoven fabric may be appropriately selected according to the application, but is generally 10 to 130 g / m ^2.
Degree. Relatively low weight non-woven fabric is bed sheet,
It can be suitably used for beddings such as pillow covers, sanitary napkins, various members of sanitary materials such as disposable diapers, and household / industrial wipers. In addition, nonwoven fabrics with a relatively high basis weight are used for various purposes such as cotton filling in bedding and sleeping bags, bulking materials, fertilizer absorbing materials for horticulture and nurseries, heat insulating materials in buildings, filter base materials for home use and industry, etc. Can be suitably used.

The long-fiber nonwoven fabric of the present invention has an elongation recovery rate at 30% elongation of 3% in both the longitudinal and horizontal directions.
It is preferably 0% or more. In the present invention, a nonwoven fabric in which the elongation recovery rate in both the longitudinal and lateral directions of the long-fiber nonwoven fabric is 30% or more can be said to have good stretchability in the present invention.

Next, a preferred method for producing the stretchable bulky long-fiber nonwoven fabric of the present invention will be described. First, a long fiber web having latent crimpability is obtained. That is, two types of fiber-forming polymers having different heat shrinkages from each other are individually melted by a known melt composite spinning method and spun from a spinneret having a parallel composite cross section or an eccentric core-sheath composite cross section. . The spun yarn is cooled by a blowing wind using a cooling device such as a horizontal spraying or an annular spraying, and then drawn and thinned to a target fineness using an air sacker and taken up. It is preferable that the fiber is drawn at a drawing speed of 3000 m / min or more, particularly 4000 m / min or more, because the dimensional stability and latent crimpability of the obtained long-fiber nonwoven fabric are improved. In general, the composite filaments discharged from the air sacker are passed through a corona discharge zone or a frictional collision zone in a high-voltage field and charged and spread, and then spread on a moving deposition device such as a screen conveyor. It is deposited to form a long fiber web.

Next, the long fiber web is passed through a partial thermocompression bonding apparatus to partially thermocompress the long fiber web. Partial thermocompression bonding, for example, heated to a temperature equal to or lower than the melting point of the polymer having a low melting point among the fiber-forming polymers constituting long fibers, a metal roll having an engraved pattern engraved on the surface, By passing a long fiber web between an embossing roll and a metal roll heated to the temperature and having a smooth surface,
The long-fiber web contacting the engraving pattern is partially thermocompression-bonded. This thermocompression bonding temperature must be performed at a temperature equal to or lower than the melting point of the polymer having a low melting point, and when performed at a temperature higher than the melting point of the polymer having a low melting point, the long fiber web sticks to the roll and significantly. The operability will be degraded. Examples of the thermocompression bonding device used here include the above-described embossing roll and ultrasonic fusion device.

Since the shape, area, and arrangement density of the convex portion of the embossing roll determine the shape, area, and compression point density of the partial thermocompression bonding portion applied to the long-fiber nonwoven fabric, the above-described partial thermocompression bonding is used. An embossing roll is selected so as to obtain the shape, area, compression point density, and compression area ratio of the portion.

The long fiber web partially heat-compressed is subjected to a buckling process, and is subsequently subjected to a heat treatment so as to impart a wave shape in which the wave-shaped peaks and valleys are repeated in the longitudinal direction of the nonwoven fabric. At the same time, the latent crimping ability of the long fiber is made obvious.

The buckling process can be applied by pushing a nonwoven fabric into a narrow space. As such a buckling compression method, a buckling machine (microcraper) manufactured by Micrex Corporation can be effectively used.

A method of performing a process by a buckling action using a buckling machine will be specifically described with reference to FIG. The long fiber web 5 to be processed is passed between a pair of supply rollers 1 and 2 and pushed into the letterers 3 and 4 to impart a corrugated shape. At this time, by appropriately selecting the gap between the rolls, the roll temperature, the relative angle of the letterer, and the surface roughness of the letterer, the amplitude and the wave number of the wave shape given to the long-fiber nonwoven fabric can be determined. In other words, the larger the gap between the rolls, the larger the amplitude of the wave shape. On the other hand, the smaller the gap between the rolls, the smaller the amplitude of the wave shape. The gap between the rolls is preferably about 1.5 mm. In addition, since the fibers constituting the long fiber web to be treated are softened by increasing the roll temperature, a wave shape is easily provided, and the wave number tends to increase. The roll temperature is preferably from room temperature to a temperature lower by at least 20 ° C. than the melting point of the polymer having a low melting point among the polymers constituting the long fibers. With respect to the relative angle of the letter, the larger the angle, the larger the amplitude and the wave number tends to decrease, while the smaller the angle, the smaller the amplitude and the wave number tends to increase. The relative angle of the letterer is preferably about 15 to 30 degrees. Regarding the surface roughness of the letterer, as the roughness increases, the frictional resistance between the long fiber web and the letterer decreases, so that the long fiber web tends to be discharged, and the amplitude and wave number tend to decrease. On the other hand, when the roughness is small, the frictional resistance between the long fiber web and the letterer increases, so that the long fiber web is hardly discharged, and the amplitude and the wave number tend to increase.

After the buckling treatment, the long-fiber nonwoven fabric having the corrugated shape is subsequently subjected to a heat treatment by the heat treatment device 6. By this heat treatment, the corrugated shape imparted by the buckling process is fixed by heat, and the latent crimping ability of the long fiber is manifested, so that the stretchable bulky long-fiber nonwoven fabric 7 of the present invention can be obtained. This heat treatment is performed without applying pressure and tension, that is, in a relaxed state. The heat treatment temperature at this time is lower than the melting point of the low melting point polymer in the polymer constituting the long fiber. At this time, if the treatment is performed at a temperature equal to or higher than the melting point of the low-melting polymer, the low-melting polymer melts and the fibers are fused to each other, so that the latent crimp cannot be sufficiently manifested and the flexible long-fiber nonwoven fabric is flexible. Not only can not be obtained,
Workability will be significantly impaired.

In the present invention, the latent crimp of the long fiber may be made more apparent by performing a further heat treatment (depending on the relaxed state) after the heat treatment.

[0035]

Next, the present invention will be described in detail with reference to examples. The methods for measuring physical properties shown in the examples are as follows. (1) Melting point (° C.): The temperature giving the extreme value of the melting endothermic curve measured at a heating rate of 20 ° C./min using a Perkin-Elmer City Differential Scanning Calorimeter DSC-2 was defined as the melting point.

(2) Melt flow rate of polypropylene (hereinafter referred to as MFR): ASTM-D1238
It was measured by the method described in (L).

(3) Melt index of polyethylene (hereinafter referred to as MI): ASTM-D1238
It was measured by the method described in (E).

(4) Relative viscosity of polyester: A mixed solution of an equal mass of phenol and ethane tetrachloride is used as a solvent,
It was adjusted to a concentration of 0.5 g / 100 cc and measured at a temperature of 20 ° C.

(5) Tensile strength (N / 5 cm width): Tensileon UTM4-1-100 manufactured by Orientec Co., Ltd. was used and a sample piece having a sample width of 5 cm and a sample length of 10 cm was prepared according to the strip method described in JIS L 1096. Individual pieces were prepared, the maximum tensile strength was individually measured under the condition of a tensile speed of 10 cm / min, and the average value was defined as the tensile strength. The tensile strength was measured in the mechanical direction (MD direction) and the direction perpendicular to the mechanical direction (CD direction) of the nonwoven fabric.

(6) Tensile elongation (%): In measuring the tensile strength, the average value of the elongation at the maximum tensile strength was defined as the tensile elongation.

(7) Elongation recovery rate (%) at 30% elongation: Tensilon UTM4-1 manufactured by Orientec
Using 100, a tensile test was performed on a sample piece having a sample width of 5 cm and a sample length of 10 cm at a tensile speed of 10 cm / min according to the strip method described in JIS L 1096A, and an elongation of 3 was obtained.
A strength-elongation curve at 0% was drawn (line E in FIG. 2), and then the tension was released from the sample to draw a strength-elongation curve of the sample (line R in FIG. 2). Then, the area (X) of the dotted portion and the area (Y) of the hatched portion shown in FIG. 2 were measured and determined by the following equation. Elongation recovery rate (%) at 30% elongation = 100Y / (X +
Y) The elongation recovery rate was measured in the MD and CD directions of the nonwoven fabric.

(8) Compression softness (N): sample width 5c
m, five sample pieces each having a sample length of 10 cm were prepared, and each sample piece was bent in the lateral direction into a cylindrical shape, and its ends were joined to obtain a sample. Tensilon UTM-4 manufactured by Orientec Co., Ltd.
Using -100, the sample was compressed in the longitudinal direction at a compression rate of 5 cm / min, and the stress at the maximum load was measured.

(9) Bulk density (g / cm ³ ): sample width 1
Five sample pieces each having a size of 0 cm and a sample length of 10 cm were prepared, and the basis weight (g / m ² ) was measured for each sample piece, and then 4.5 g / m ² using a thickness measuring device manufactured by Daiei Kagaku Seiki Seisaku-sho, Ltd. Was applied, and the thickness after standing for 10 seconds was measured, the bulk density was calculated by the following equation, and the average value of five samples was determined to be the bulk density of the nonwoven fabric. Bulk density (g / cm ³ ) = weight (g / m ² ) / [thickness (m
m) × 1000]

(10) Amplitude of wave shape (mm), wave number (pieces / 25 mm): Non-woven fabric is arbitrarily set to 20
Select the location, the amplitude of the wave shape given to the nonwoven fabric,
The wave number was measured, and the average value was defined as the amplitude (mm) of the wave shape and the wave number (pieces / 25 mm).

(11) Number of fiber crimps (pieces / 25 m
m): The fiber is arbitrarily selected at 20 points with a magnifying projector,
The average value of the number of crimps per 25 mm was determined, and was defined as the number of crimps.

Example 1 Polypropylene polymer (melting point: 162 ° C., MFR: 70)
g / 10 minutes, Q value (weight average molecular weight / number average molecular weight):
4.0) and a propylene copolymer obtained by random copolymerization of 4% by mass of ethylene (melting point: 137 ° C., MFR: 50
g / 10 min, Q value: 5.2) into separate extruder-type extruders, melt and weigh them to obtain a circular cross-section of a side-by-side fiber cross section [composite ratio (mass ratio) =
Composite spinning was performed using a spinneret having a ratio of 1: 1]. The spun conjugate long fibers were pulled by air soccer at a spinning speed of 4200 m / min, and deposited on a moving collecting conveyor to obtain a long fiber web. The obtained long fiber web was introduced into an embossing device including an embossing roll and a flat roll. The set temperature of the roll was 125 ° C., the linear pressure between the rolls was 30 kg / cm, and the thermocompression bonding area ratio was 17%. Subsequently, using a buckling machine (Microcreper manufactured by Mike Rex Corporation), the material was passed between a pair of rollers (roller surface temperature was set to room temperature) moving at 100 m / min. Buckling was performed using the relative angle as degrees. Next, the buckled nonwoven fabric was subjected to a relaxation heat treatment at 135 ° C. to thermally fix the corrugated shape and to make the latent crimpability of the long fiber obvious, thereby obtaining the long-fiber nonwoven fabric of the present invention.

Example 2 A long-fiber nonwoven fabric of the present invention was obtained in the same manner as in Example 1 except that the temperature of the roll was changed to 80 ° C. during the buckling process.

Example 3 A long-fiber nonwoven fabric of the present invention was prepared in the same manner as in Example 1, except that the relative angle at the time of the buckling process was set to 30 degrees and the angle was larger than that of Example 1. I got

Comparative Example 1 A long-fiber nonwoven fabric of Comparative Example was obtained in the same manner as in Example 1, except that the buckling treatment was not performed.

Table 1 shows the physical properties of the obtained Examples 1 to 3 and Comparative Example 1.

[0051]

[Table 1]

The long-fiber nonwoven fabrics of Examples 1 to 3 have a three-dimensional spiral crimp because the latent crimping ability of the fibers constituting the nonwoven fabric is evident. It had a wavy shape in the direction, and was excellent in stretchability and bulkiness. In addition, in Example 1, the buckling process was not performed (the nonwoven fabric did not have a corrugated shape).
Comparing with the long-fiber nonwoven fabric of Comparative Example 1, it is understood that the elongation recovery rate in the MD direction is improved by 20% and the bulk density is also extremely improved.

[0053]

According to the long-fiber nonwoven fabric of the present invention, the constituent fibers have a three-dimensional spiral crimp due to the potential crimping ability and the nonwoven fabric itself has a corrugated shape. Since the nonwoven fabric has excellent elasticity by itself having elasticity, the elasticity and bulkiness of the nonwoven fabric are further improved depending on the form of the nonwoven fabric, so that the elasticity and bulkiness are further improved as a whole. A bulky long-fiber nonwoven fabric is obtained.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an example of a buckling process and a heat treatment process according to the present invention.

FIG. 2 is a strength-elongation curve showing an elongation recovery rate at 30% elongation.

[Explanation of symbols]

 1,2 supply roll 3,4 letterer 5 long fiber web 6 heat treatment device 7 stretchable bulky long fiber non-woven fabric

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[Procedure amendment]

[Submission date] September 11, 2000 (2009.1.
1)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0046

[Correction method] Change

[Correction contents]

Example 1 Polypropylene polymer (melting point: 162 ° C., MFR: 70)
g / 10 minutes, Q value (weight average molecular weight / number average molecular weight):
4.0) and a propylene copolymer obtained by random copolymerization of 4% by mass of ethylene (melting point: 137 ° C., MFR: 50
g / 10 min, Q value: 5.2) into separate extruder-type extruders, melt and weigh them to obtain a circular cross-section of a side-by-side fiber cross section [composite ratio (mass ratio) =
Composite spinning was performed using a spinneret having a ratio of 1: 1]. The spun conjugated filaments were pulled by air soccer at a spinning speed of 4200 m / min, and deposited on a moving collecting conveyor to form filament webs. The obtained long fiber web was introduced into an embossing device including an embossing roll and a flat roll. The set temperature of the roll was 125 ° C., the linear pressure between the rolls was 30 kg / cm, and the thermocompression bonding area ratio was 17%. Subsequently, it was passed between a pair of rollers (roller surface temperature was set to room temperature) moving at 100 m / min by using a buckling machine (Microcreper manufactured by Mike Rex Co.), and the roll gap was 1.5 mm, Buckling processing was performed with a relative angle of 20 degrees. Next, the buckled nonwoven fabric was subjected to a relaxation heat treatment at 135 ° C. to thermally fix the corrugated shape and to make the latent crimpability of the long fiber obvious, thereby obtaining the long-fiber nonwoven fabric of the present invention.

Claims (4)

[Claims] Claims: 1. A long-fiber nonwoven fabric having a latent crimping ability and comprising a long fiber in which the latent crimp is revealed, and having a partially thermocompression-bonded portion, wherein the nonwoven fabric has a corrugated shape. A stretchable bulky and long fiber nonwoven fabric having a bulk density of 0.1 g / cm ³ or less. 2. The long fiber is a side-by-side conjugate fiber in which two types of fiber-forming polymers having different heat shrinkages are juxtaposed in the length direction of the fiber, or two types having different heat shrinkages. 2. The stretchable bulky and long-fiber nonwoven fabric according to claim 1, wherein the fiber-forming polymer is an eccentric core-sheath type composite fiber arranged in an eccentric core-sheath structure. 3. The stretchable bulky and long fiber according to claim 1, wherein an amplitude (wave height) of a corrugated shape of the nonwoven fabric is 1 to 3 mm and a wave number is 5 to 30/25 mm. Non-woven fabric. 4. A parallel composite filament or an eccentric core-sheath composite filament composed of two types of fiber-forming polymers having different heat shrinkages from each other, melt-spun and taken up using an air sacker. Opened and deposited on the movable collecting surface to obtain a long fiber web, and a long fiber web obtained by partially thermocompressing the long fiber web using a partial thermocompression bonding apparatus is obtained.
The long fiber web is subjected to buckling by a buckling machine, and then subjected to a heat treatment at a temperature lower than the melting point of the low melting point polymer among the fiber-forming polymers constituting the long fibers. A method for producing a stretchable bulky long-fiber nonwoven fabric, comprising heat fixing a corrugated shape imparted by processing, and manifesting the latent crimpability of long fibers.