JP2005154953A - Nonwoven fabric excellent in stretchability in one direction and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To readily produce a nonwoven fabric having excellent stretchability in one direction without using an elastomer material. <P>SOLUTION: The nonwoven fabric has a structure in which filaments spun from a thermoplastic resin are arranged and stretched in one direction and elongation of the filaments in the arranging direction is ≤50% and 50% recovery factor of elongation in the direction perpendicular to the filament arranging direction is ≤80%. The thermoplastic resin has ≤110°C crystallization temperature measured by DSC, ≥35 Shore D hardness and ≤95 (R) Rockwell hardness. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a nonwoven fabric excellent in stretchability in a specific direction without using an elastic body such as an elastomer, and a method for producing the same.

  Conventionally, as a nonwoven fabric having stretchability, a material using a urethane-based resin or a styrene-based resin, which is a stretchable material, is known as the material constituting the nonwoven fabric itself. However, this type of non-woven fabric cannot regulate the direction of stretching, and stretches in any direction.

  On the other hand, a nonwoven fabric spun and stretched using polyester resin, polyamide resin, or the like is capable of arranging fibers in the machine direction, so that the elongation in the machine direction can be regulated, but the direction is orthogonal to the machine direction. When a tensile stress is applied in the width direction, the fiber spacing only widens and does not recover even after the tensile stress is removed. That is, in the width direction, it shows elongation but does not show stretchability.

Therefore, as a non-woven fabric having high stretchability only in one direction and showing little stretch in the direction perpendicular thereto, the web composed of inelastic fibers arranged in one direction and stretched, and the arrangement direction of the inelastic fibers and A non-woven fabric obtained by joining elastomer materials joined in a direction perpendicular to each other has been proposed by the present applicants (see, for example, Patent Document 1). Patent Document 2 discloses a nonwoven fabric having stretchability in one direction by specifying a ratio of elongation stress between the longitudinal direction and the transverse direction with a 10% elongation recovery rate in the longitudinal direction and the transverse direction of 60 to 90%. Is disclosed.
JP 2001-32160 A JP-A-9-279453

  However, the nonwoven fabric disclosed in Patent Document 1 requires a relatively expensive elastomer material in order to develop stretchability. Moreover, in order to produce the nonwoven fabric disclosed in Patent Document 1, a process of joining the elastomer material to the web is required. Further, in order to have elasticity in only one direction, the elastomer material is formed in a specific pattern. A device for joining is required. Therefore, it is desirable not to use an elastomer material in order to produce a nonwoven fabric excellent in stretchability in only one direction at a low cost. On the other hand, the nonwoven fabric disclosed in Patent Document 2 is premised on stretchability with respect to elongation of about 10%, and improvement of stretchability with respect to larger elongation is desired.

  This invention is made | formed in view of the said problem, and is manufacturing easily the nonwoven fabric which has the stretching property excellent in one direction, without using an elastomer material.

  As a result of intensive studies to solve the above problems, the present inventors have found that the conventional nonwoven fabric does not have a large stretchability in the width direction, and the crystallization measured by DSC (differential scanning calorimeter) of the resin used. The temperature is higher than 110 ° C., and the surface of the fiber spun from the die in the spinning process is solidified before being collected by the conveyor, thereby resulting in insufficient network structure due to fusion between the fibers, resulting in the width direction It was found that when the fiber was spread out, the fiber spacing simply widened, and the stretchability in the width direction would not be manifested. The present invention has been made based on this finding.

  That is, in the nonwoven fabric of the present invention, filaments spun from a thermoplastic resin having a crystallization temperature measured by DSC of 110 ° C. or lower, a Shore D hardness of 35 or higher, and a Rockwell hardness of R95 or lower are aligned and stretched in one direction. Thus, the nonwoven fabric has an elongation in the filament arrangement direction of 50% or less and a 50% elongation recovery rate in the direction orthogonal to the filament arrangement direction of 80% or more.

  Thereby, the elongation in the arrangement direction of the filaments is regulated, but in the direction orthogonal to the arrangement direction of the filaments, a network structure is constructed by partial heat fusion between the filaments and exhibits excellent stretchability. Moreover, since an elastomer material is not used, its manufacture is also simple.

  Moreover, you may laminate | stack two or more said nonwoven fabrics of this invention by making the arrangement direction of a filament correspond. Thus, a texture improves by laminating | stacking a some nonwoven fabric.

  In the method for producing a nonwoven fabric of the present invention, a thermoplastic resin having a crystallization temperature measured by DSC of 110 ° C. or lower, a Shore D hardness of 35 or higher, and a Rockwell hardness of R95 or lower is spun as a filament, and the filament is unidirectional. A step of producing an aligned web and a step of drawing the web in the filament arrangement direction, and in the step of producing the web, the spinning temperature is set to 60 ° C. or more higher than the crystallization temperature of the thermoplastic resin. .

  According to this manufacturing method, since the progress of surface solidification of the spun filament is delayed, the above-described filament network structure is easily constructed, and the stretchability in the direction orthogonal to the filament arrangement direction is further improved.

  According to the present invention, it is suitably used as an elastic member for clothing, sanitary goods, etc., in which elongation is restricted in the filament arrangement direction and excellent stretchability is exhibited in the direction orthogonal to the filament arrangement direction. It is possible to easily obtain a non-woven fabric excellent in stretchability in one direction without using an elastomer material.

  Hereinafter, embodiments of the present invention will be described in detail.

  The nonwoven fabric of the present embodiment has a stretched unidirectional array structure in which filaments made of a thermoplastic resin are arrayed in almost one direction and stretched in the filament array direction as a filament array structure, and mechanical properties The elongation in the filament arrangement direction is 50% or less, and the 50% elongation recovery rate in the direction perpendicular to the filament arrangement direction is 80% or more.

  As the thermoplastic resin, a resin having a crystallization temperature of 110 ° C. or less measured by DSC (differential scanning calorimeter) is used. As a result, the progress of surface solidification of the filament during spinning becomes slower than in the past, and partial filament fusion occurs due to contact between adjacent filaments before completion of surface solidification of the filament. It becomes easy to construct a network structure.

  The thermoplastic resin constituting the nonwoven fabric has not only a crystallization temperature of 110 ° C. or lower, but also the nonwoven fabric cannot exhibit excellent stretchability unless it is soft to some extent and has no resilience. From such a viewpoint, the thermoplastic resin used for the nonwoven fabric of the present invention has a Shore D hardness of 35 or more and a Rockwell hardness of R95 or less. If the Shore D hardness is less than 35, the film is soft and excessively stretched. Therefore, even if the filaments are arranged by stretching, the elongation cannot be regulated. On the other hand, if it exceeds Rockwell hardness R95, the resin is too hard and the deformation resilience is low, so that it is difficult to obtain good stretchability.

  As described above, a non-woven fabric in which filaments are arranged and stretched in one direction using a thermoplastic resin having a crystallization temperature measured by DSC of 110 ° C. or lower, a Shore D hardness of 35 or more and a Rockwell hardness of R95 or less. Thus, the obtained non-woven fabric has a high tensile strength due to stretching in the filament arrangement direction and hardly exhibits elongation. On the other hand, in the direction orthogonal to the arrangement direction of the filaments, the filaments themselves are moderately soft and the network structure of the filaments is moderately constructed during spinning, so that excellent stretchability is exhibited. That is, a nonwoven fabric that does not require an elastomer material, and as a result does not perform a bonding step with the elastomer material, and hardly stretches in the filament arrangement direction, but exhibits excellent stretchability only in the direction perpendicular to the filament arrangement direction. It becomes.

  Examples of the resin suitably used in the present invention include a block copolymer of propylene and ethylene, a random copolymer of propylene and α-olefin, LDPE, LLDPE, EVA and the like. Further, these resins may be used alone or may be a compound product obtained by mechanically melting and kneading two or more kinds of resins. Furthermore, additives such as antioxidants, weathering agents, lubricants, antiblocking agents, flame retardants, nucleating agents, antistatic agents, pigments and inorganic fillers can be added as necessary.

  In order to produce the nonwoven fabric of the present invention, the above-mentioned thermoplastic resin is spun as a filament, a step of producing a web in which the filament is arranged in one direction, and a step of stretching the web in the arrangement direction of the filament, Have at least. As described above, according to the present invention, it is not necessary to use an elastomer material only by specifying a resin to be used. Therefore, it is possible to easily manufacture a nonwoven fabric excellent in stretchability in one direction.

  In order for the nonwoven fabric to exhibit excellent stretchability in the direction orthogonal to the filament arrangement direction, it is important that the filaments are appropriately heat-sealed as described above. In order to realize this moderate heat fusion, in addition to using a resin having a crystallization temperature measured by DSC of 110 ° C. or lower, the spinning temperature at the time of producing the nonwoven fabric is set to 60 ° C. or higher from the crystallization temperature of the resin. It is desirable to raise it. When this temperature difference is less than 60 ° C., the filaments are solidified too quickly, and thermal fusion between the filaments may be insufficient. If this temperature difference is too large, the melt viscosity of the resin may decrease too much or the resin may deteriorate, so the upper limit of the spinning temperature does not affect the properties of the nonwoven fabric due to these reasons. It is decided. This is not limited to the present invention, but is general for the production of nonwoven fabrics using thermoplastic resins.

  As described above, the nonwoven fabric of the present invention has a stretched unidirectional array structure of filaments. Nonwoven fabrics having such a structure include longitudinally stretched nonwoven fabrics and laterally stretched nonwoven fabrics, and any of these can be used in the present invention. The longitudinally stretched nonwoven fabric is a nonwoven fabric in which filaments are arranged and stretched in the longitudinal direction, which is the feed direction when producing the nonwoven fabric, and the transversely stretched nonwoven fabric is a direction perpendicular to the feed direction when producing the nonwoven fabric. It is a nonwoven fabric in which filaments are arranged in the transverse direction, that is, the width direction.

  A longitudinally stretched nonwoven fabric is made by drawing draft tension to a spun filament and then reducing the filament diameter, and then accumulating it on a conveyor to form a web in which the filaments are aligned in the longitudinal direction. Can be obtained.

  Examples of a method for giving draft tension to the filament include a melt blow method (MB method) and a narrowly defined spunbond method (SB method). In any method, hot air is sprayed onto the filament in order to minimize molecular orientation when reducing the diameter of the filament. In addition, in order to improve the arrangement of the filaments on the conveyor, the filament is spun while being inclined with respect to the conveyor conveying surface, or a rod member is arranged in the hot air flow area, and the rod member is rotated or moved. It is preferable to vibrate the filament in the longitudinal direction using the Coanda effect generated by the above.

  The web accumulated on the conveyor is stretched in the longitudinal direction, and the stretchability of the filaments in the longitudinal direction is further improved by stretching the web in the longitudinal direction. The longitudinal stretching of the web may be fully stretched in one stage, but multistage stretching is mainly used. In multistage stretching, the first stage of stretching is performed as preliminary stretching immediately after spinning, and the second and subsequent stages of stretching are performed as main stretching.

  Next, the transversely stretched nonwoven fabric will be described. In order to produce a transversely stretched nonwoven fabric, first, a web in which filaments are arranged in the transverse direction is formed. The web in which the filaments are arranged in the horizontal direction is obtained by shaking the filaments spun from the spinning nozzles in the horizontal direction by directly ejecting air from the air ejection holes arranged around the spinning nozzles and collecting them on the conveyor. Can be formed. As another method, there is a method in which the filaments are vibrated in the lateral direction using the Coanda effect described above and accumulated on a conveyor. In this way, the filaments are accumulated on the conveyor in a state where there are many arrangement components in the lateral direction.

  A laterally stretched nonwoven fabric is obtained by stretching the web thus obtained in the transverse direction. Examples of the method of stretching the web in the transverse direction include a tenter method and a pulley method. The tenter method is generally used as a method for widening a film or the like, but requires a large floor area for installation of equipment, and it is difficult to change the product width and the magnification ratio. The width of the nonwoven fabric needs to be freely changed according to the use, and the draw ratio must be changed according to the thickness of the raw material. Therefore, it is preferable to use a pulley system in which these changes can be easily performed even during operation.

  The filament constituting the nonwoven fabric having a stretched unidirectional array structure is a long fiber filament. The long fiber filament referred to here may be a substantially long fiber and has an average length exceeding 100 mm. When the diameter of the filament is 50 μm or more, it is rigid and entanglement becomes insufficient. Therefore, it is desirably 30 μm or less, and more desirably 25 μm or less. In particular, when a non-woven fabric with high strength is intended, the filament diameter is desirably 5 μm or more. The length and diameter of the filament are measured by a micrograph.

  About the typical manufacturing method of the nonwoven fabric which has an extending | stretching unidirectional array structure, the longitudinally stretched nonwoven fabric and the laterally stretched nonwoven fabric were mentioned as an example, However, The manufacturing method of an extending | stretching unidirectional array nonwoven fabric is not limited to the method mentioned above. Any method can be used as long as the filaments are arranged in almost one direction and the arranged filaments can be drawn in the arrangement direction.

  The basis weight of the nonwoven fabric is not particularly limited, and can be appropriately set from a low basis weight to a high basis weight within a range that does not impair the properties of the nonwoven fabric.

  You may give secondary processing to the nonwoven fabric of this invention in the range which does not impair the characteristic. Examples of secondary processing include laminating with other materials having excellent stretchability. Examples of the material to be bonded include, but are not limited to, a urethane resin film, a styrene resin film, an olefin resin film, a stretchable net, and a rubber band. Moreover, as secondary processing, laminating | stacking two or more nonwoven fabrics of this invention is also mentioned. In this case, in order not to impair the stretchability of each nonwoven fabric, a plurality of nonwoven fabrics are laminated with the filaments arranged in the same direction.

For example, depending on the use of the nonwoven fabric, a texture may be required in addition to an appropriate expansion / contraction load. The demand for texture can be improved to some extent by increasing the basis weight of the nonwoven fabric. However, if the amount of resin extruded from the die (nozzle) is increased in order to increase the basis weight, the thickness of the filament tends to increase and the nonwoven fabric tends to become harder, and the spinning speed can be lowered without changing the amount of extrusion. Then, the connection between filaments becomes insufficient, and it becomes difficult to obtain good stretchability and stretch load. Thus, by laminating a plurality of nonwoven fabrics according to the present invention, it is possible to give a texture without impairing good stretchability and stretch load. In order to obtain a good stretchability and stretch load by laminating a plurality of nonwoven fabrics, the basis weight of one nonwoven fabric is preferably 50 g / m ² or less.

  The lamination method of the nonwoven fabrics of the present invention or the nonwoven fabric of the present invention and other materials is not particularly limited. For example, a thermocompression bonding method, an extrusion lamination method, a dry lamination method, a method of applying or spraying an adhesive and bonding them Examples thereof include a method of spray-coating a low melting point resin and thermocompression bonding, a method of physically tangling filaments, and the like, but is not limited thereto.

  The nonwoven fabric and processed product thereof of the present invention can be used for various applications. Examples include paper diapers, sanitary napkins, incontinence pads, skin care wipers, kitchen wipers, cleaning wipers, poultice bases, bandages, gauze, medical supporters, disposable towels, sweat pads, face masks, filters, training Examples include, but are not limited to, pants, medical drape gowns and drapes, interlining, underwear, disposable underwear and apparel, tape base fabrics, transdermal drug base fabrics, and the like.

  For example, in a conventional paper diaper, a nonwoven fabric is used as an elastic member, but since the nonwoven fabric does not have elasticity in only one direction, a highly elastic material is used as the nonwoven fabric in order to impart such elasticity. They are pasted together. Moreover, since the conventional nonwoven fabric does not have elasticity, it must be a structure in which the nonwoven fabric is shrunk in the initial state, and a wasteful amount of nonwoven fabric is required. On the other hand, since the nonwoven fabric of the present invention itself has excellent stretchability in only one direction, it is not necessary to make a composite with other materials exhibiting stretchability and use a useless nonwoven fabric. Nor. Therefore, the nonwoven fabric of the present invention greatly contributes to resource saving and energy saving. In addition, since the conventional elastic members in paper diapers and the like are used in a state in which the nonwoven fabric is contracted into a pleated shape, the appearance and feel when touched are not always good, but the present invention This non-woven fabric can be used as it is without shrinking into a pleated shape, and since it uses a relatively soft resin, it is excellent in appearance and touch. In particular, if the nonwoven fabric is composed of thin filaments having a diameter of about 10 μm, there is no discomfort even when touching the skin, and the skin is not damaged.

  Next, the present invention will be described together with comparative examples by specific examples.

(Example 1)
A web spun at a spinning temperature of 210 ° C. was stretched 5 times using a random PP having a crystallization temperature of 102 ° C. and Rockwell hardness R80 measured by DSC to obtain a nonwoven fabric having a stretched unidirectional array structure. The basis weight of the obtained nonwoven fabric was 15 g / m ² . Although Shore D hardness is not measured, Rockwell hardness R80 corresponds to Shore D hardness of 35 or more.

  In this example, the crystallization temperature, Shore D hardness, and Rockwell hardness of the resin were measured as follows. The same applies to the following examples and comparative examples.

<Shore D hardness>
Shore D hardness was measured according to ASTM D2240.

<Rockwell hardness>
Rockwell hardness was measured according to JIS K7202.

<Resin crystallization temperature>
The crystallization temperature of the resin is a temperature that gives the extreme value of the calorific curve when the temperature is first adjusted above the melting point using DSC and then cooled at 10 ° C./min.

  And the following item was measured about the obtained nonwoven fabric.

<Elongation>
Elongation is in accordance with JIS L1096. A test piece having a width of 50 mm and a length of 300 mm is subjected to a tensile test at a distance between chucks of 200 mm and a tensile speed of 200 mm / min. (%). The test specimen was collected so that the longitudinal direction substantially coincided with the arrangement direction of the filaments. That is, the elongation obtained here is the elongation in the arrangement direction of the filaments.

<50% elongation recovery rate>
The 50% elongation recovery rate is that a test piece having a width of 50 mm and a length of 100 mm or more is stretched at a distance between marked lines of 100 mm and a tensile speed of 300 mm / min, and immediately opened when the elongation reaches 50 mm. The residual elongation (Lmm) is determined. And from this residual elongation,
50% elongation recovery rate = {(50−L) / 50} × 100
Calculated as The test piece was collected so that the longitudinal direction substantially coincided with the direction orthogonal to the arrangement direction of the filaments. That is, the 50% elongation recovery rate obtained here is the 50% elongation recovery rate in the direction perpendicular to the filament arrangement direction.

(Example 2)
Using LDPE having a crystallization temperature of 96 ° C. and a Shore D hardness of 45, the web spun at a spinning temperature of 170 ° C. was stretched 4 times to obtain a nonwoven fabric having a stretched unidirectional array structure. The basis weight of the obtained nonwoven fabric was 14 g / m ² . Although Rockwell hardness was not measured, Shore D hardness 45 corresponds to Rockwell hardness R95 or less. And about the obtained nonwoven fabric, the elongation and the 50% elongation recovery rate were calculated | required similarly to Example 1. FIG.

(Example 3)
Using LLDPE having a crystallization temperature of 108 ° C. and a Shore D hardness of 57, the web spun at a spinning temperature of 180 ° C. was stretched 4 times to obtain a nonwoven fabric having a stretched unidirectional array structure. The basis weight of the obtained nonwoven fabric was 14 g / m ² . Although Rockwell hardness is not measured, Shore D hardness 57 corresponds to Rockwell hardness R95 or less. And about the obtained nonwoven fabric, the elongation and the 50% elongation recovery rate were calculated | required similarly to Example 1. FIG.

Example 4
A web spun at a spinning temperature of 170 ° C. was stretched 4 times using EVA having a crystallization temperature of 80 ° C. and a Shore D hardness of 43 to obtain a nonwoven fabric having a stretched unidirectional array structure. The basis weight of the obtained nonwoven fabric was 11 g / m ² . Although Rockwell hardness is not measured, Shore D hardness 43 corresponds to Rockwell hardness R95 or less. And about the obtained nonwoven fabric, the elongation and the 50% elongation recovery rate were calculated | required similarly to Example 1. FIG.

(Comparative Example 1)
Using a polyester resin having a crystallization temperature of 190 ° C. and a Rockwell hardness R100, a web spun at a spinning temperature of 300 ° C. was stretched 4 times to obtain a nonwoven fabric having a stretched unidirectional array structure. The basis weight of the obtained nonwoven fabric was 15 g / m ² . And about the obtained nonwoven fabric, the elongation and the 50% elongation recovery rate were calculated | required similarly to Example 1. FIG.

(Comparative Example 2)
Using a homo PP having a crystallization temperature of 116 ° C. and a Rockwell hardness R100, the web spun at a spinning temperature of 210 ° C. was stretched 4 times to obtain a nonwoven fabric having a stretched unidirectional array structure. The basis weight of the obtained nonwoven fabric was 14 g / m ² . For the obtained nonwoven fabric, the elongation and 50% elongation recovery rate were determined in the same manner as in Example 1.

(Comparative Example 3)
A web spun at a spinning temperature of 180 ° C. was stretched 4 times using HDPE having a crystallization temperature of 115 ° C. and a Shore D hardness of 73 to obtain a nonwoven fabric having a stretched unidirectional array structure. The basis weight of the obtained nonwoven fabric was 13 g / m ² . And about the obtained nonwoven fabric, the elongation and the 50% elongation recovery rate were calculated | required similarly to Example 1. FIG.

(Comparative Example 4)
Using LDPE having a crystallization temperature of 78 ° C. and a Shore D hardness of 34, the web spun at a spinning temperature of 170 ° C. was stretched 3 times to obtain a nonwoven fabric having a stretched unidirectional array structure. The basis weight of the obtained nonwoven fabric was 10 g / m ² . And about the obtained nonwoven fabric, the elongation and the 50% elongation recovery rate were calculated | required similarly to Example 1. FIG.

(Comparative Example 5)
Using LLDPE having a crystallization temperature of 107 ° C. and a Shore D hardness of 59, the web spun at a spinning temperature of 160 ° C. was stretched 4 times to obtain a nonwoven fabric having a stretched unidirectional array structure. The basis weight of the obtained nonwoven fabric was 13 g / m ² . And about the obtained nonwoven fabric, the elongation and the 50% elongation recovery rate were calculated | required similarly to Example 1. FIG.

  The results of Examples 1 to 4 and Comparative Examples 1 to 5 are shown in Table 1.

  From Table 1, it can be seen that Examples 1 to 4 have an excellent 50% elongation recovery rate in a direction perpendicular to the filament arrangement direction, and the elongation in the filament arrangement direction is restricted. On the other hand, Comparative Examples 1 to 5 are inferior either in the filament arrangement direction or in the 50% elongation recovery rate in the direction perpendicular to the filament arrangement direction.

  Furthermore, a composite nonwoven fabric obtained by laminating the nonwoven fabric produced in Example 1 with another material or the same nonwoven fabric was produced, and a 50% elongation recovery rate was obtained.

(Example 5)
The nonwoven fabric produced in Example 1 was laminated with a styrene resin film excellent in stretchability to produce a composite nonwoven fabric. Both layers were laminated by embossed thermocompression bonding.

(Example 6)
The nonwoven fabric produced in Example 1 was laminated with a styrene resin film excellent in stretchability to produce a composite nonwoven fabric. Both layers were laminated by adhering with an adhesive applied by spraying.

(Example 7)
Two nonwoven fabrics produced in Example 1 were laminated with their filaments aligned in the same direction to produce a composite nonwoven fabric. Both layers were laminated by embossed thermocompression bonding.

(Example 8)
Two nonwoven fabrics produced in Example 1 were laminated with their filaments aligned in the same direction to produce a composite nonwoven fabric. Both layers were laminated by adhering with an adhesive applied by spraying.

  The results of Examples 5-8 are shown in Table 2.

  From Table 2, it turns out that all of Examples 5-8 show the outstanding elasticity about the direction orthogonal to the arrangement direction of the filament of a nonwoven fabric.

Claims (3)

  Filaments spun from a thermoplastic resin having a crystallization temperature measured by DSC of 110 ° C. or lower, a Shore D hardness of 35 or higher, and a Rockwell hardness of R95 or lower are aligned and stretched in one direction, whereby the direction of filament alignment The nonwoven fabric has an elongation at 50% or less and a 50% elongation recovery rate in a direction orthogonal to the filament arrangement direction of 80% or more.   A nonwoven fabric obtained by laminating a plurality of the nonwoven fabrics according to claim 1 so that the arrangement directions of filaments coincide with each other. Spinning a thermoplastic resin having a crystallization temperature measured by DSC of 110 ° C. or less, a Shore D hardness of 35 or more and a Rockwell hardness of R95 or less as a filament, and producing a web in which the filaments are arranged in one direction; ,
Stretching the web in the direction of filament arrangement,
In the step of producing the web, a nonwoven fabric manufacturing method in which a spinning temperature is set to 60 ° C. or more higher than a crystallization temperature of the thermoplastic resin.