WO2016104422A1 - Elastic nonwoven fabric manufacturing method - Google Patents

Abstract

This elastic nonwoven fabric manufacturing method involves: a conveyance step for conveying, in a conveyance direction, a nonwoven fabric that contains elastic fibers which are elastic, and extensible fibers which are less elastic than the elastic fibers; a first processing step in which the nonwoven fabric is extended by being passed through a pair of first gear rollers and in which at least some of the extensible fibers are stretched; a stretching step in which, after the first processing step, the nonwoven fabric is stretched in the conveyance direction; and a second processing step in which, after the stretching step, the nonwoven fabric is stretched by being passed through a pair of second gear rollers that include an area where teeth are formed on the peripheral surface and an area where no teeth are formed, and at least some of the elastic fibers are cut.

Description

Method for producing elastic nonwoven fabric

The present invention relates to a method for producing a stretchable nonwoven fabric.

Conventionally, non-woven fabrics are used in a wide range of fields, such as absorbent articles such as disposable diapers and sanitary napkins, cleaning articles such as wipers, and medical articles such as masks. In this way, non-woven fabrics are used in various different fields, but when actually used in products in each field, they must be manufactured to have properties and structures suitable for the use of each product. It is.
For example, Patent Document 1 discloses a technique for improving stretchability by stretching a non-woven fabric by interposing a belt-shaped non-woven fabric sheet between a pair of tooth-gap rolls having mutually engaging tooth grooves. Moreover, in the said patent document 1, when extending | stretching a nonwoven fabric, the technique which manufactures the nonwoven fabric from which a stretching property differs partially is disclosed by using a tooth gap roll from which a draw ratio differs partially.

Japanese Patent No. 479285

Since the stretchable nonwoven fabric that can be produced by the method described in Patent Document 1 has strong shrinkability, when used for an exterior member such as a diaper, it becomes easy to bite into the user's skin or is provided in the diaper. Problems such as shrinking the absorber may occur. Therefore, an elastic nonwoven fabric in which the contraction force is appropriately adjusted by providing not only a region having a high contraction force but also a region having a low contraction force is desired.
The present invention has been made in view of the above problems, and the object of the present invention is to provide a stretchable region having a high shrinkage force region and a low shrinkage force region while having good stretchability. It is in providing a non-woven fabric.

A main invention for achieving the above object is to provide a transporting process for transporting a nonwoven fabric containing stretchable fibers having stretchability and an extensible fiber having lower shrinkage than the stretchable fibers in the transport direction, and the nonwoven fabric. A non-woven fabric is stretched in the transport direction after the first processing step of extending at least a part of the extensible fibers by passing between a pair of first gear rolls, and after the first processing step. After the stretching step and after the stretching step, the non-woven fabric is stretched by passing between a pair of second gear rolls having a portion where teeth are formed on the peripheral surface and a portion where teeth are not formed, and at least And a second processing step of cutting some of the stretchable fibers.
Other features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

According to the present invention, it is possible to provide a stretchable nonwoven fabric having a region having a high shrinkage force and a region having a low shrinkage force while having good stretchability.

1 is a schematic perspective view of a stretchable nonwoven fabric 1. FIG. It is a figure explaining the structure of the manufacturing apparatus 100 which manufactures the elastic nonwoven fabric 1. FIG. 4 is a schematic side view showing the configuration of a first gear machining unit 120. FIG. FIG. 4 is an enlarged view showing a region α in FIG. 3. FIG. 5 is a schematic side view showing a configuration of a second gear machining unit 140. It is the schematic diagram expanded and represented about the state of the elastic fiber 2 in the high shrinkage area | region HS. It is the schematic diagram expanded and represented about the state of the elastic fiber 2 in the low shrinkage | contraction area | region LS. It is the graph showing the relationship between the draw ratio of a nonwoven fabric, and the return stress of MD direction. It is a graph showing the relationship between the draw ratio of a nonwoven fabric and MD / CD ratio. It is a schematic perspective view of the disposable diaper 5. FIG. It is a schematic plan view of the disposable diaper 5 in the unfolded state. It is a figure explaining the structure of the manufacturing apparatus 200 which manufactures the elastic nonwoven fabric 1. FIG. It is the schematic explaining the structure of the gear roll 245. FIG. FIG. 5 is a schematic diagram illustrating the configuration of a gear roll 246. It is a figure represented about the area | region X in FIG. It is a figure represented about the area | region Y in FIG. It is the schematic explaining the relationship of the width | variety of the CD direction of the 2nd gear process part 240. FIG. It is a figure explaining extending | stretching of the elastic fiber 2 performed at a 2nd process process.

At least the following matters will become apparent from the description of the present specification and the accompanying drawings.
A transporting step of transporting a non-woven fabric including stretchable fibers having stretchability and an extensible fiber having lower contractibility than the stretchable fibers in a transport direction; and passing the non-woven fabric between a pair of first gear rolls. A first processing step for stretching at least a part of the extensible fibers, a stretching step for stretching the nonwoven fabric in the transport direction after the first processing step, and after the stretching step, The non-woven fabric is stretched by passing between a pair of second gear rolls having a portion where teeth are formed on a peripheral surface and a portion where teeth are not formed, and at least a part of the stretchable fibers is cut. A method for producing a stretchable nonwoven fabric, comprising: 2 processing steps.

According to such a method for producing a stretchable nonwoven fabric, a stretchable nonwoven fabric in which the strength of the shrinkage force in the low shrinkage region is weaker than the strength of the shrinkage force in the high shrinkage region can be produced. Accordingly, it is possible to provide a stretchable nonwoven fabric having a region having a high shrinkage force and a region having a low shrinkage force while having good stretchability.

In this stretchable nonwoven fabric manufacturing method, it is desirable that at least one of the pair of second gear rolls is heated to a temperature lower than the melting point of the extensible fibers.

According to such a method for producing a stretchable nonwoven fabric, the stretchable fiber is easily stretched by being heated and is not easily cut in the second processing step. On the other hand, when the stretchable fiber is heated, it is distorted or deteriorated, and is easily cut. This makes it possible to efficiently cut some stretchable fibers without cutting the extensible fibers, and accurately produce a stretchable nonwoven fabric having a region having a high shrinkage force and a region having a low shrinkage force. It becomes possible.

In this stretchable nonwoven fabric manufacturing method, the teeth of the pair of second gear rolls are preferably formed so as to be convex toward the outside of the peripheral surface.

According to such a method for producing a stretchable nonwoven fabric, the nonwoven fabric is deformed into a three-point bend by the peak portions of teeth adjacent to each other in one gear roll and the peak portion of the other gear roll entering the valley portion therebetween. The stretchable fiber can be stretched in the stretching and conveying direction. Also, according to the type of stretchable fibers that make up the nonwoven fabric, the tension can be adjusted so that the nonwoven fabric does not break by changing the shallowness of gear engagement or changing the tooth shape or pitch. This makes it easy to produce a high-quality stretchable nonwoven fabric.

In such a method for producing a stretchable nonwoven fabric, of the pair of second gear rolls, teeth of one side of the gear roll are formed to be convex toward the outer side of the peripheral surface, and the pair of second gear rolls. Of the two gear rolls, it is desirable that the teeth of the gear roll on the other side are formed to be concave toward the outer side of the peripheral surface.

According to such a method for producing a stretchable nonwoven fabric, the nonwoven fabric is bent in a three-point bend shape by the crest portions of the teeth adjacent to each other in the gear roll on one side and the crest portion of the gear roll on the other side entering the trough portion therebetween. It is deformed and the stretchable fiber can be stretched in the stretching and conveying direction. Moreover, since the tooth | gear of the other side gear roll does not protrude from an outer peripheral surface, it becomes possible to wind and convey a nonwoven fabric around the said other side gear roll. Thereby, the non-woven fabric can be conveyed and stretched by the gear roll on the other side, and the configuration of the apparatus is simplified.

In this stretchable nonwoven fabric manufacturing method, the nonwoven fabric is predetermined by a pair of drive rolls provided between the pair of first gear rolls and the pair of second gear rolls in the conveying direction. The nonwoven fabric is transferred to the other side of the pair of second gear rolls by a press roll that is transported in the transport direction at a speed and provided downstream of the pair of drive rolls in the transport direction. It is desirable to stretch the nonwoven fabric in the transport direction by transporting the nonwoven fabric in the transport direction at a speed faster than the predetermined speed while pressing against the outer peripheral surface.

According to such a method for producing a stretchable nonwoven fabric, since only one press roll is provided, no separate stretching means is required, and therefore the transport distance between the first processing step and the second processing step is further increased. It becomes possible to make it short. Thereby, it is suppressed that a nonwoven fabric is extended too much in a conveyance direction, and it becomes easy to suppress that the said nonwoven fabric shrinks in the width direction. Moreover, since the 2nd process process using a 2nd gear roll is performed immediately after extending | stretching using a press roll, it seems that a part of elastic fiber can be efficiently cut | disconnected by a 2nd process process. become.

In this stretchable nonwoven fabric manufacturing method, it is desirable to heat the one side gear roll of the pair of second gear rolls to a temperature lower than the melting point of the extensible fibers.

According to such a method for producing a stretchable nonwoven fabric, when the nonwoven fabric is heated in the second processing step, the stretchable fibers are easily stretched and are not easily cut, and the stretchable fibers are easily cut. Further, by heating the nonwoven fabric with a gear roll having teeth convex toward the outside of the circumferential surface of the pair of second gear rolls, the contact area between the circumferential surface of the gear roll and the nonwoven fabric does not become too large, and the nonwoven fabric is not woven. It is suppressed that the whole is heated. Therefore, problems such as excessive strain in the stretchable fiber are less likely to occur in the second processing step.

In this stretchable nonwoven fabric manufacturing method, the other-side gear roll of the pair of second gear rolls conveys the nonwoven fabric by rotating the nonwoven fabric around at least a part of its peripheral surface. It is desirable to convey in the direction.

According to such a method for producing a stretchable nonwoven fabric, the nonwoven fabric is wound around a part of the outer peripheral surface of a gear roll having teeth that are concave toward the outside of the outer peripheral surface of the pair of second gear rolls and rotated. The nonwoven fabric can be transported smoothly. Moreover, since a nonwoven fabric can be pinched | interposed firmly between press rolls, it can extend | stretch, conveying a nonwoven fabric stably.

In this method of manufacturing a stretchable nonwoven fabric, the thickness of the tip of the tooth of the other side of the pair of second gear rolls is the thickness of the one side of the pair of second gear rolls. It is desirable that it is thicker than the thickness of the tooth tip.

According to such a method for producing a stretchable nonwoven fabric, when the press roll is pressed against the outer peripheral surface of the other gear roll having teeth that are concave toward the outer side of the outer peripheral surface, the tips of the teeth are formed sharply. As a result, there is no trace of teeth on the surface of the press roll. Thereby, it becomes easy to suppress that the conveyance accuracy of a press roll deteriorates.

In this stretchable nonwoven fabric manufacturing method, it is desirable that the teeth of the pair of second gear rolls are continuously formed in the CD direction, which is a direction perpendicular to the transport direction.

According to such a method for producing a stretchable nonwoven fabric, all stretchable fibers existing in the region between the teeth of two gear rolls provided adjacent to each other in the transport direction are easily stretched in the transport direction. Thereby, among the plurality of stretchable fibers constituting the nonwoven fabric, stretched fibers and unstretched fibers are generated, and it becomes easy to suppress problems such as the inability to obtain a uniform stretching effect. Thereby, an elastic nonwoven fabric with little bias in elasticity in the CD direction can be produced.

In this stretchable nonwoven fabric manufacturing method, it is preferable that the teeth of the pair of second gear rolls are arranged along a direction parallel to the CD direction.

According to such a method for producing a stretchable nonwoven fabric, the nonwoven fabric transported in the transport direction is easily stretched with a uniform force between the teeth of two gear rolls adjacent to each other in the transport direction. It becomes difficult to occur.

In this stretchable nonwoven fabric manufacturing method, it is desirable that the fibers constituting the stretchable nonwoven fabric are long fibers, and two or more of the long fibers are bonded to each other by a plurality of pressure bonding points.

According to such a method for producing a stretchable nonwoven fabric, since the stretchable fibers are long fibers, at least a part of the stretchable fabric is easily arranged along the transport direction, and the nonwoven fabric is easily stretched in the transport direction. Moreover, since several long fibers are mutually crimped | bonded by the some crimping | compression-bonding point, mutually exert elasticity and it becomes easy for the whole nonwoven fabric to express favorable elasticity.

In this stretchable nonwoven fabric manufacturing method, the second processing step includes the pair of second gear rolls having teeth having a pitch wider than the shortest distance between the two crimping points adjacent in the transport direction. It is desirable to be performed using.

According to such a method for producing a stretchable nonwoven fabric, there is a high probability that at least one or more crimping points for crimping stretchable fibers are included between the pitches of the gear roll teeth. Thereby, in the 2nd processing process, since the crimping point included between the pitches of the teeth of the gear roll is easily removed, the stretchability in the conveyance direction of the nonwoven fabric becomes weaker, and the low-shrinkage region is efficiently formed in the stretchable nonwoven fabric. Can be formed.

=== First Embodiment ===
<Outline of stretchable nonwoven fabric>
First, an outline of the stretchable nonwoven fabric 1 will be described as a stretchable nonwoven fabric according to this embodiment. The stretchable nonwoven fabric 1 is a fabric that exhibits stretchability in a predetermined direction by subjecting the nonwoven fabric sheet S to a stretching process described later. In the nonwoven fabric sheet S, the stretchable fibers 2 having stretchability and the extensible fibers 3 having lower shrinkage than the stretchable fibers 2 are mixed, and the stretchable fibers 2 and the stretchable fibers 3 are constant. It is a latent stretchable nonwoven fabric joined by self-bonding by softening or melting at a number of spaced-apart crimp points.

FIG. 1 is a schematic perspective view of the stretchable nonwoven fabric 1. As shown in FIG. 1, the stretchable nonwoven fabric 1 is a flat strip-shaped sheet member having a longitudinal direction and a transverse direction that intersects the longitudinal direction, and is long in the longitudinal direction. Moreover, let the direction which each cross | intersects the vertical direction and the horizontal direction of the elastic nonwoven fabric 1 be a thickness direction. The stretchable fibers 2 constituting the stretchable nonwoven fabric 1 (nonwoven fabric sheet S) are elastically stretchable thermoplastic elastomer fibers, such as urethane elastomer, polystyrene elastomer, polyolefin elastomer, polyamide elastomer, and polyester. Fibers such as elastomers can be used. Specifically, a polyurethane elastomer can be used. The extensible fiber 3 is a fiber made of a thermoplastic resin that has extensibility but is substantially inelastic and hardly shrinks. For example, a single fiber such as polypropylene fiber or polyethylene fiber, or a composite of a core-sheath structure made of polypropylene or polyethylene Fiber etc. can be used. Specifically, polypropylene which is a polyolefin resin can be used. The nonwoven fabric sheet S is comprised by these fibers being intertwined at random.

And if the extensible fiber 3 contained in the nonwoven fabric sheet S is plastically deformed, or the crimping point (joining point) between the fibers is destroyed, the elastic deformation of the stretchable fiber 2 is hardly hindered. The nonwoven fabric sheet S can be changed, whereby the stretchability of the nonwoven fabric sheet S is expressed and the nonwoven fabric sheet 1 can be used. A specific method for expressing the stretchability of the nonwoven fabric sheet S will be described later.

The stretchable nonwoven fabric 1 of this embodiment has stretchability in the vertical direction and the horizontal direction. The stretchable nonwoven fabric 1 has a high shrinkage region HS that expresses a strong shrinkage force when stretched in the longitudinal direction, and a low shrinkage that has a weak shrinkage force when stretched in the longitudinal direction compared to the high shrinkage region HS. The regions LS are alternately provided along the vertical direction (see FIG. 1). Since the high shrinkage region HS and the low shrinkage region LS are arranged side by side in this way, when the nonwoven fabric sheet S is stretched in the vertical direction, there are portions that are likely to shrink and portions that are difficult to shrink. Will do. Therefore, by appropriately changing the size of the high shrinkage region HS and the low shrinkage region LS and the range to be formed, it is possible to adjust the magnitude of the shrinkage force when the stretchable nonwoven fabric 1 is in the stretched state.

<Method for producing stretchable nonwoven fabric 1>
The direction in which stretchability is imparted to the nonwoven fabric sheet S to produce the stretchable nonwoven fabric 1 will be described. FIG. 2 is a diagram illustrating the configuration of the manufacturing apparatus 100 that manufactures the stretchable nonwoven fabric 1. The manufacturing apparatus 100 according to the present embodiment includes a transport mechanism CV, a heating unit 110, a first gear processing unit 120, a stretching processing unit 130, a second gear processing unit 140, and a sheet member bonding unit 150. .

The transport mechanism CV is a transport unit that continuously transports the nonwoven fabric sheet S along a predetermined transport path. As the transport mechanism CV, for example, a transport roller, a suction belt conveyor having a suction holding function on a belt surface as a placement surface, or the like is used. In the conveyance mechanism CV of the present embodiment, the nonwoven fabric sheet S is conveyed in a predetermined conveyance direction as a continuous sheet continuous in the vertical direction. And in the process in which the nonwoven fabric sheet S is conveyed in a conveyance direction (longitudinal direction), the elastic nonwoven fabric 1 is manufactured by performing various processes mentioned later, such as a heat processing and an extending | stretching process. In the following description, the continuous sheet of the nonwoven fabric sheet S to be conveyed is referred to as a nonwoven fabric continuous sheet Sa.

In the following description, the conveyance direction set on the manufacturing apparatus 100 is also referred to as “MD direction”. As shown in FIG. 1, the MD direction changes depending on the location. That is, the direction in which the nonwoven fabric continuous sheet Sa is conveyed is not necessarily a fixed direction. Further, one of the two directions intersecting (orthogonal) with the MD direction is referred to as “CD direction”, and the other is referred to as “Z direction”. The CD direction is a direction parallel to the width direction of the nonwoven fabric continuous sheet Sa, and in FIG. The Z direction is a direction parallel to the thickness direction of the nonwoven fabric continuous sheet Sa.

When the nonwoven fabric 1 is manufactured, first, the nonwoven fabric continuous sheet Sa is fed out from a raw fabric roll in which the nonwoven fabric continuous sheet Sa is wound in a roll shape. The fed nonwoven fabric continuous sheet Sa is transported from the upstream side to the downstream side in the MD direction by the transport mechanism CV at a predetermined transport speed V1, and reaches the position where the heating unit 110 is disposed.

The heating unit 110 heats the conveyed nonwoven fabric continuous sheet Sa with a plurality of heating rollers (heating process). As shown in FIG. 2, the heating unit 110 of the present embodiment has four heating rollers 111 to 114. The heating rollers 111 to 114 are cylindrical transport rollers having a smooth outer peripheral surface, and a heater is provided on the outer peripheral surface. The nonwoven fabric continuous sheet Sa is conveyed from the heating roller 111 on the upstream side in the MD direction to the heating roller 114 on the downstream side in the MD direction while being wound in a substantially S shape around the outer peripheral surface of each of the heating rollers 111 to 114 in the sheet state. In the process of transporting the heating unit 110, while being in contact with the outer peripheral surface of each of the heating rollers 111 to 114, the heater is heated by the heater provided on the outer peripheral surface.

The heaters provided on the outer peripheral surfaces of the heating rollers 111 to 114 can adjust the heating temperature of the nonwoven fabric continuous sheet Sa by adjusting the amount of heat generated. The temperature at which the nonwoven fabric continuous sheet Sa is heated varies depending on the fiber configuration of the nonwoven fabric continuous sheet Sa, but when the above-described thermoplastic polypropylene is used, the temperature is equal to or lower than the melting point based on the melting point of the polypropylene fiber. Adjusted. For example, the temperature of the nonwoven fabric continuous sheet Sa is preferably equal to or lower than the melting point of the polypropylene fiber and 40 ° C. or higher. Below 40 ° C., the extensibility of the fibers is poor and the strength tends to decrease. When the melting point of the polypropylene fibers is exceeded, the fibers of the nonwoven fabric continuous sheet Sa may stick to the heating rollers 111 to 114, etc. This is because there is a risk of being cut during processing. In the present embodiment, the temperature is adjusted so that the heating temperature by the heating unit 110 is 50 ° C. to 60 ° C. The heating process is not an essential process, and the stretchable nonwoven fabric 1 can be manufactured even when heating is not performed.

The nonwoven fabric continuous sheet Sa is heated by the heating unit 110 and then subjected to the first gear stretching by the first gear processing unit 120 (first processing step). FIG. 3 is a schematic side view illustrating the configuration of the first gear machining unit 120. FIG. 4 is an enlarged view showing a region α in FIG.

The first gear processing unit 120 includes a guide roller 121 and a pair of gear rolls 125 and 126 (first gear roll) (see FIG. 1). The guide roller 121 is provided between the heating unit 110 and the pair of gear rolls 125 and 126 in the MD direction, and includes a plurality of transport rollers that rotate around a rotation axis along the CD direction. The circumferential speed value V121 of the guide roller 121 is substantially the same as the transport speed value V1 of the nonwoven fabric continuous sheet Sa transported from the upstream process. Accordingly, the guide roller 121 can guide the nonwoven fabric continuous sheet Sa to the gear rolls 125 and 126 in a state where the nonwoven fabric continuous sheet Sa is not stretched and is not loosened.

The gear rolls 125 and 126 are a pair of upper and lower roll mechanisms that rotate around a rotation axis along the CD direction with their outer peripheral surfaces facing each other. On the outer peripheral surface of the gear roll 125, crests 125m and troughs 125v are alternately formed along the rotation direction, and the crests 125m and the troughs 125v are formed to extend in the CD direction. Has been. In addition, the peak part 125m and the trough part 125v do not need to be formed in the whole CD direction of the gear roll 125, and a part area | region (for example, area | region contact | abutted with the nonwoven fabric continuous sheet Sa) in the CD direction in the outer peripheral surface of the gear roll 125. It may be formed only in the CD direction or intermittently in the CD direction. In addition, similar mountain portions 126m and valley portions 126v are alternately formed on the outer peripheral surface of the gear roll 126. When the gear rolls 125 and 126 are rotating, the crest portions 125m and the trough portions 126v are engaged with each other with a slight gap so that the crest portion 125m of one gear roll 125 enters the trough portion 126v of the other gear roll 126. It has become. During the rotation, the nonwoven fabric continuous sheet Sa passes between the pair of gear rolls 125 and 126 along the MD direction.

The nonwoven fabric continuous sheet Sa that is passing between the pair of gear rolls 125 and 126 is adjacent to each other in the one gear roll 126, and the peak portion 125m of the other gear roll 125 that enters the trough portion 126v. And is deformed into a three-point bending shape (see FIG. 4). At this time, in the nonwoven fabric continuous sheet Sa, the portion Sa12 that comes into contact with the top surface of the mountain portion 126m of the one gear roll 126 is in contact with the top surface so as not to be relatively movable, and thus is not easily stretched. On the other hand, a portion Sa11 between two adjacent Sa12 and Sa12 is extended based on the intrusion of the mountain portion 125m. As a result, as shown in FIG. 4, the nonwoven fabric continuous sheet Sa has the stretched first portions Sa11 and the second portions Sa12 that are not stretched more than the first portions Sa11 arranged alternately in the MD direction. Processed. And in the area | region of 1st part Sa11, the extensible fiber 3 which comprises the nonwoven fabric continuous sheet Sa is partially extended. That is, by passing between the pair of gear rolls 125 and 126, at least a part of the extensible fibers 3 is stretched in the nonwoven fabric continuous sheet Sa. Thereby, the extensible fiber 3 becomes a state in which the elastic deformation of the stretchable fiber 2 cannot be inhibited, and the nonwoven fabric continuous sheet Sa exhibits stretchability based on the elastic deformation of the stretchable fiber 2.

In the gear roll 125, the formation pitch Pv in the rotation direction of the valley portion 125v (pitch Pv at a position corresponding to the top surface of the valley portion 125v) is the formation pitch Pm in the rotation direction of the mountain portion 125m (the peak of the mountain portion 125m). It is equivalent to the pitch Pm) on the surface. Further, the pitches Pv and Pm of the gear rolls 125 and 126 have the same value. The formation pitch Pm in the rotational direction of the mountain portions 125m (126m) is preferably in the range of 1.0 mm to 5.0 mm, for example. In this embodiment, Pm = 2.72 mm. Further, the height of each tooth (the height from the top surface of the mountain portion 125m to the top surface of the valley portion 125v) is preferably equal to or greater than the pitch Pm, and is 5.0 mm in this embodiment. Further, the meshing height between the mountain portion 125m and the mountain portion 126m is 4.0 mm.

In this embodiment, since the nonwoven fabric continuous sheet Sa is heated in advance and the temperature is increased in the heating step described above, the extensible fibers 3 are easily deformed and easily stretched. Thereby, the fracture | rupture of the nonwoven fabric continuous sheet Sa in a 1st process process can be prevented. In addition, you may change suitably the draw ratio in a 1st process process according to other conditions.

After exhibiting stretchability by the first processing step, the nonwoven fabric continuous sheet Sa is conveyed downstream in the MD direction and stretched in the MD direction (longitudinal direction) by the stretching unit 130 (stretching step). The stretch processing unit 130 includes an upstream nip roll 131 and a downstream nip roll 132 (see FIG. 2). The upstream nip roll 131 is a pair of upper and lower rollers capable of adjusting the peripheral speed value, and is continuously driven by a predetermined peripheral speed value V131 while sandwiching the nonwoven fabric continuous sheet Sa between the outer peripheral surfaces of the nonwoven fabric continuous sheet Sa. The sheet Sa is conveyed downstream in the MD direction at the conveyance speed of V131. The downstream nip roll 132 is a pair of upper and lower rollers similar to the upstream nip roll 131, and is driven and rotated at a predetermined peripheral speed value V132 to move the nonwoven fabric continuous sheet Sa downstream in the MD direction at the conveyance speed of V132. Transport.

In this embodiment, the peripheral speed value of each nip roll is adjusted so that the conveyance speed V132 of the nonwoven fabric continuous sheet Sa by the downstream nip roll 132 is faster than the conveyance speed V131 of the nonwoven fabric continuous sheet Sa by the upstream nip roll 131. ing. Thereby, the nonwoven fabric continuous sheet Sa after passing through the stretched portion 130 is stretched in the MD direction at a predetermined magnification. This draw ratio is determined according to the elastic limit of the stretchable fiber 2 constituting the nonwoven fabric continuous sheet Sa. Specifically, the draw ratio is determined so that the stretchable fiber 2 is stretched to such an extent that plastic deformation does not occur. For example, in the case where polyurethane is used as the stretchable fiber 2 in this embodiment, when the length in the MD direction of the nonwoven fabric continuous sheet Sa in the no-load state is 1.0, the MD is about 2.5 times longer. Stretched in the direction. Thereby, the elastic fiber 2 will be in the state fully extended to the extent which does not fracture | rupture.

After being stretched by the stretching process, the nonwoven fabric continuous sheet Sa is conveyed downstream in the MD direction, and subjected to the second gear stretching process by the second gear processing unit 140 (second processing process). FIG. 5 is a schematic side view illustrating the configuration of the second gear machining unit 140. The second gear machining unit 140 has a pair of gear rolls 145 and 146 (second gear roll). The pair of gear rolls 145 and 146 is a pair of upper and lower roll mechanisms that rotate about the rotation axis along the CD direction while facing each other's outer peripheral surfaces in substantially the same manner as the gear rolls 125 and 126 of the first gear processing unit 120. is there. However, the gear rolls 145 and 146 of the second gear machining unit 140 are different from the gear rolls 125 and 126 of the first gear machining unit 120 in that they have a portion where teeth are formed on the outer peripheral surface and a portion where teeth are not formed. .

As shown in FIG. 5, on the outer peripheral surface of the gear roll 145, tooth surfaces 145ts that are regions where teeth are formed and smooth surfaces 145fs that are regions where teeth are not formed are alternately arranged. Then, on the tooth surface 145ts, crests 145m and troughs 145v are alternately formed along the rotation direction. Similarly, on the outer peripheral surface of the gear roll 146, tooth surfaces 146ts which are regions where teeth are formed and smooth surfaces 146fs which are regions where teeth are not formed are alternately formed. And the tooth | gear surface 146ts is alternately formed with the peak part 146m and the trough part 146v along the rotation direction.

In the second gear machining unit 140, the tooth surface 145ts of the gear roll 145 and the tooth surface 146ts of the gear roll 146 are arranged at positions facing each other. Thereby, when the gear rolls 145 and 146 rotate, the teeth of each other mesh with each other. Further, the smooth surface 145fs of the gear roll 145 and the smooth surface 146fs of the gear roll 146 are also arranged at positions facing each other. The nonwoven fabric continuous sheet Sa passes between the pair of gear rolls 145 and 146 along the MD direction.

When the nonwoven fabric continuous sheet Sa passes between the smooth surfaces 145fs and 146fs, since the teeth are not formed in the region, the nonwoven fabric continuous sheet Sa passes directly downstream in the MD direction without being stretched. That is, the area | region which passed between smooth surface 145fs and 146fs of nonwoven fabric continuous sheet Sa is an area | region which is not extended | stretched by the 2nd gear process part 140. FIG. This region becomes the high shrinkage region HS of FIG.

On the other hand, when the nonwoven fabric continuous sheet Sa passes between the tooth surfaces 145ts and 146ts,
The non-woven fabric continuous sheet Sa has three ridges 146m, 146m adjacent to each other in one gear roll 146 and the ridge 145m of the other gear roll 145 entering the valley 146v therebetween, as described in FIG. It is deformed into a point bend. As a result, the stretchable fibers 2 that have been stretched to the vicinity of the elastic limit in the stretching step are further stretched until they are 4.0 times or more the length of the unwoven continuous sheet Sa in an unloaded state. Thereby, at least a part of the stretchable fibers 2 is cut, and the low shrinkage region LS of FIG. 1 is formed. In the low shrinkage region LS, since a part of the stretchable fiber 2 is cut, the shrinkage force due to the stretchable fiber 2 is less likely to be generated, and the shrinkage force in the MD direction is weaker than that in the high shrinkage region HS. .

In the second gear machining unit 140, the meshing height between the mountain part 125m and the mountain part 126m is 1.5 mm, and the meshing height (4. 0 mm), the meshing is shallower. Thereby, the tension is adjusted so that the nonwoven fabric continuous sheet Sa itself is not broken while the elastic fiber 2 is broken. The height, shape, and pitch of the mountain portion 125m (126m) are appropriately changed according to the type of fiber that constitutes the nonwoven fabric continuous sheet Sa. In FIG. 5, tooth surfaces 145ts (146ts) and smooth surfaces 145fs (146fs) are alternately formed on the outer peripheral surface of the gear roll 145 (146). In addition, the number and arrangement of the smooth surfaces can be changed as appropriate.

The nonwoven fabric continuous sheet Sa from which a part of the stretchable fibers 2 has been cut by the second gear processing section 140 is pasted and joined to another sheet member Sb in the thickness direction by the sheet member pasting section 150 on the downstream side in the MD direction. (Bonding process). The sheet member laminating unit 150 includes an adhesive application unit 151 and a pair of upper and lower laminating rolls 152. The adhesive application unit 151 applies an adhesive such as a hot-melt adhesive to the surface of the conveyed nonwoven fabric continuous sheet Sa. The laminating roll 152 is driven and rotated at a predetermined peripheral speed value V152 to convey the non-woven fabric continuous sheet Sa to the downstream side in the MD direction at the conveying speed of V152, and another sheet member Sb supplied separately to the non-woven fabric. The continuous sheet Sa is bonded and bonded to the surface on which the adhesive is applied.

In the sheet member laminating portion 150, the peripheral speed value V152 of the laminating roll 152 is the same value as the peripheral speed value V132 of the downstream nip roll 132 of the stretching unit 130. That is, the nonwoven fabric continuous sheet Sa is conveyed downstream in the MD direction at a constant speed after being stretched in the stretching process. Thereby, the timing at the time of bonding other sheet | seat member Sb with respect to the nonwoven fabric continuous sheet Sa in the bonding roll 152 can be made easy to match. In addition, this bonding process is not an essential process, and the nonwoven fabric continuous sheet Sa and the other sheet member Sb may not be bonded.

In the present embodiment, the stretchable nonwoven fabric 1 is manufactured by sequentially executing the above-described steps using the manufacturing apparatus 100.

<Shrinkage characteristics of stretchable nonwoven fabric 1>
In the conventional stretchable nonwoven fabric, only the high shrinkage region HS is formed by the gear stretching process corresponding to the first processing step described above. On the other hand, in the stretchable nonwoven fabric 1 of the present embodiment, a portion having a strong contraction force and a portion having a weak contraction force are formed by having the low contraction region LS having a contraction force lower than that of the high contraction region HS. Moreover, compared with the conventional elastic nonwoven fabric, the contraction force can be weakened as a whole. Therefore, when it uses for products, such as an absorptive article (for example, disposable diaper mentioned below), an appropriate contraction force can be given to a required part. Hereinafter, the shrinkage | contraction characteristic of the elastic nonwoven fabric 1 is demonstrated concretely.

First, the difference in structure between the high shrinkage region HS and the low shrinkage region LS of the stretchable nonwoven fabric 1 will be described. In the stretchable nonwoven fabric 1, when the stretchable fiber 2 is stretched, stretchability is expressed by the contraction force when the stretchable fiber 2 tries to return to its original state. In the present embodiment, the state of the stretchable fiber 2 is different between the high shrinkage region HS and the low shrinkage region LS. FIG. 6 is an enlarged schematic view showing the state of the stretchable fiber 2 in the high shrinkage region HS. FIG. 7 is an enlarged schematic view showing the state of the stretchable fiber 2 in the low shrinkage region LS. In addition, the extensible fiber 1 is the state extended | stretched by extending | stretching in the above-mentioned 1st process process among the fibers which comprise the elastic nonwoven fabric 1. FIG. And since the extensible fiber 1 itself hardly shrinks, there is a low possibility that the extensible fiber 1 in the stretched state affects the shrinkage of the stretchable fiber 2. Accordingly, in FIG. 6 and FIG. 7, the extensible fiber 1 is not shown for simplification of description.

In the high shrinkage region HS, the stretchable fibers 2 in an uncut state are bonded to each other at a plurality of locations, thereby forming a network structure as shown in FIG. For example, in FIG. 6, the stretchable fibers 2a and 2b have three crimping points WP along the longitudinal direction (MD direction) and are joined to each other at the crimping points. In addition, this crimping | compression-bonding point WP is formed by embossing etc. with respect to the nonwoven fabric continuous sheet Sa.

When the stretchable fibers 2a and 2b are stretched in the longitudinal direction in FIG. 6, when the stretchable fibers 2a and 2b contract by themselves by the mutual contraction force acting while maintaining the network structure. A stronger contraction force is generated compared to. Then, by forming such a network structure over the entire region of the high shrinkage region HS, a large shrinkage force is generated in the vertical direction in the high shrinkage region HS. Moreover, since the stretchable fiber 2 in the high shrinkage region HS generates a shrinkage force in the lateral direction by the network structure, the stretchable nonwoven fabric 1 can be stretched in the lateral direction. Thereby, the use of the elastic nonwoven fabric 1 becomes wide.

On the other hand, in the low shrinkage region LS shown in FIG. 7, since some of the stretchable fibers 2 are cut by the above-described second processing step, the number of stretchable fibers 2 that can develop shrinkage force is reduced. Yes. Therefore, the contraction force generated as a whole of the low contraction region LS is relatively weak. Furthermore, when the stretchable fiber 2 is cut at a plurality of locations in the longitudinal direction, the contractile force is less likely to be transmitted in the longitudinal direction, so that the contractile force generated in the low contraction region LS tends to be weaker. That is, in the low shrinkage region LS, there are a plurality of cut end portions CE formed by cutting the stretchable fiber 2. And the contraction force in the said low contraction area | region LS becomes weak, so that there are many cutting | disconnection edge parts CE contained in the low contraction area | region LS.

In the stretchable nonwoven fabric 1 of the present embodiment, the cut end portion CE is easily formed in the low shrinkage region LS, whereas the cut end portion CE is hardly formed in the high shrinkage region HS. That is, the ratio of the cut end portion CE existing per unit volume of the low contraction region LS is higher than the ratio of the cut end portion CE existing per unit volume of the high contraction region HS. Thereby, the contraction force generated in the low contraction region LS is weaker than the contraction force generated in the high contraction region HS.

In addition, since the stretchable nonwoven fabric 1 contains the stretchable fiber 1 and the stretchable fiber 2, when measuring the number of the cut ends CE of the stretchable fiber 2, only the stretchable fiber 2 is dyed. Then, after making the cut end CE conspicuous, observation may be performed using a microscope or the like. As a dye for dyeing the stretchable fiber 2, for example, Katsuya Fine Goods Co., Ltd., Koji Daiall can be used. The dye has a property that it is difficult to dye polypropylene (extensible fiber 1) while dyeing polyurethane (stretchable fiber 2). By dyeing only the stretchable fiber 2 using such a dye, the number of cut end portions CE of the stretchable fiber 2 can be efficiently measured as necessary.

Moreover, in the low shrinkage | contraction area | region LS, the crimping | compression-bonding point WP of the elastic fibers 2 comes off, and it has the structure where the elastic fiber 2 which is not cut | disconnected is arrange | positioned along the vertical direction, as FIG. 7 shows. . That is, the stretchable fiber 2 is longitudinally oriented (MD orientation). For example, in FIG. 7, the stretchable fibers 2c and 2d are arranged in a substantially straight line along the longitudinal direction (MD direction). In this case, since the stretchable fibers 2c and 2d cannot maintain the network structure as shown in FIG. 6, the contraction force does not act between the plurality of fibers. Therefore, as compared with the high shrinkage region HS in which the stretchable fibers 2 maintain a network structure, the shrinkage force generated in the low shrinkage region LS tends to be relatively weak.

That is, in the stretchable nonwoven fabric 1 of the present embodiment, the proportion of the crimping points WP existing per unit volume of the low shrinkage region LS is lower than the proportion of the crimping points WP present per unit volume of the high shrinkage region HS. ing. Thereby, the contraction force generated in the low contraction region LS is weaker than the contraction force generated in the high contraction region HS.

Next, the magnitude of the contraction force actually generated in the high contraction region HS and the low contraction region LS will be described. The magnitude of the “contraction force” can be represented by “return stress”. The “return stress” is a value obtained by measuring the magnitude of a force (ie, contraction force) for returning to the original state when the sheet member to be measured is stretched under a predetermined condition.

The measurement of “return stress” in the present embodiment was performed using a low-speed extension type tensile tester (for example, SHIMADZU autograph AG-1, hereinafter also simply referred to as “tester”). First, for each of the MD direction and the CD direction of the stretchable nonwoven fabric 1, a predetermined number of sample pieces having a length of 70 mm and a width of 50 mm are collected. The testing machine is provided with a pair of chuck portions (not shown) having a predetermined interval, and while holding the sample pieces with the pair of chuck portions, the sample pieces are pulled in the direction of increasing the interval between the chuck portions. Thus, the sample piece can be extended.

First, the sample piece collected from the stretchable nonwoven fabric 1 is gripped by the chuck portion of the testing machine so that the lengthwise interval is 50 mm. In this state, the sample piece is pulled at a pulling speed of 100 mm / min until the interval between the chuck portions reaches 100 mm. That is, the sample piece is extended to twice the length. Subsequently, the sample pieces are returned so that the interval between the chuck portions becomes 50 mm, and pulled to 100 mm again. And it returns until the space | interval of a chuck | zipper part will be in the state of 87.5 mm. That is, after the pulling operation is repeated twice, the sample piece is fixed in a state where the length of the sample piece is 1.75 times the original length. At this time, the force with which the sample piece attempts to return is measured and recorded as a return stress (unit is expressed as N / 50 mm). In addition, when the size of the sample piece that can be collected is less than 70 mm × 50 mm, measurement is performed using a sample piece having a smaller size, and conversion is performed so that the width of the sample piece corresponds to 50 mm. Calculate the return stress.

The return stress measured in this way indicates that the larger the value, the stronger the contraction force. In the present embodiment, when three samples were taken from the stretchable nonwoven fabric 1 in the MD direction (longitudinal direction) and the CD direction (transverse direction) to measure the return stress, the MD direction in the high shrinkage region HS was measured. The average value of the return stress was 0.794 (N / 50 mm), and the average value of the return stress in the CD direction was 0.172 (N / 50 mm). Further, the average value of the MD direction return stress in the low shrinkage region LS was 0.437 (N / 50 mm), and the average value of the CD direction return stress was 0.071 (N / 50 mm). From this result, it became clear that the return stress in the high shrinkage region HS is larger than the return stress in the low shrinkage region LS. That is, it can be seen that in the MD direction (longitudinal direction) of the stretchable nonwoven fabric 1, the stretch force generated in the low shrinkage region LS is smaller than the stretch force generated in the high shrinkage region HS. Therefore, if the manufacturing apparatus 100 of this embodiment is used, it is possible to manufacture the stretchable nonwoven fabric 1 having a region having a high shrinkage force and a region having a low shrinkage force while having good stretchability.

FIG. 8 is a graph showing the relationship between the stretch ratio of the nonwoven fabric and the return stress in the MD direction. The horizontal axis in FIG. 8 represents the stretching ratio of the stretchable nonwoven fabric 1 in the MD direction when stretched by gear stretching or the like, and the vertical axis represents the actually measured return stress in the MD direction. The point A in FIG. 8 indicates a state where the stretchable nonwoven fabric 1 is not stretched (a state when the stretch ratio is 1.0), that is, a nonwoven fabric continuous sheet Sa before being stretched (a state of a raw fabric roll) Represents the magnitude of the return stress. At this time, the return stress in the MD direction is about 1 (N / 50 mm). Further, point B in FIG. 8 indicates a return stress for the high shrinkage region HS formed by the stretchable nonwoven fabric 1 being stretched about 3.3 times, that is, by being stretched by the first gear processing portion 120. Represents the size of 8 is formed by the stretchable nonwoven fabric 1 being stretched by about 4.0 times, that is, stretched by the stretched portion 130 and stretched by the second gear worked portion 140. The magnitude | size of the return stress about the made low shrinkage area | region LS is represented.

In the present embodiment, the second gear processing unit 140 further performs gear stretching processing on a partial region (low shrinkage region LS) of the nonwoven fabric stretched by the stretching processing unit 130, thereby reducing the elastic limit in the nonwoven fabric. Since the number of stretchable fibers 2 that are cut exceeding the number increases, the shrinkage force in the region can be reduced. As a result, as shown in FIG. 8, the return stress value decreases as the draw ratio increases, and the return stress value can be lowered to 0.6 (N / 50 mm) or less. The draw ratio of 3.7 when the return stress is 0.6 (N / 50 mm) is a value that can be realized by performing the gear drawing process by the second gear processing unit 140.

Next, the magnitude of the return stress in the MD direction (longitudinal direction) with respect to the return stress in the CD direction (lateral direction) (hereinafter also referred to as MD / CD ratio) will be examined. The MD / CD ratio indicates that the larger the value, the stronger the influence of the contractive force in the MD direction. That is, as the MD / CD ratio is larger, the fiber orientation of the stretchable fiber 2 is more likely to be closer to the MD direction.

FIG. 9 is a graph showing the relationship between the stretch ratio of the nonwoven fabric and the MD / CD ratio. The horizontal axis in FIG. 9 represents the stretch ratio of the stretchable nonwoven fabric 1, and the vertical axis represents the MD-direction return stress actually measured. Similarly to the case of FIG. 8 described above, the point A in FIG. 9 represents the magnitude of the return stress for the nonwoven fabric continuous sheet Sa (the state of the raw fabric roll) before being subjected to stretching. The point B in FIG. 9 represents the magnitude of the return stress for the high shrinkage region HS, and the point C represents the magnitude of the return stress for the low shrinkage region LS.

In the nonwoven fabric continuous sheet Sa (point A in FIG. 9) before being stretched, the MD / CD ratio is about 3.0, whereas in the high shrinkage region HS (point B in FIG. 9), The MD / CD ratio is 4.62, and the MD / CD ratio is 6.15 in the low-shrinkage region LS (point C in FIG. 9). Contrary to the case of FIG. 8, the MD / CD ratio increases with an increase in the draw ratio, and the MD / CD ratio in the low shrinkage region LS becomes larger than the MD / CD ratio in the high shrinkage region HS. This is because the second gear processing unit 140 further applies a gear stretching process to a partial region (low shrinkage region LS) of the non-woven fabric stretched by the stretching unit 130, so that the fibers in the low shrinkage region LS It is considered that the fiber orientation of the stretchable fiber 2 tends to be close to the MD direction. As a result, the MD / CD ratio in the contraction region LS shows a high value of 5.3 or more. The draw ratio of 3.7 times when the MD / CD ratio is 5.3 is a value that can be realized by performing the gear drawing process by the second gear processing unit 140.

In addition, the range of strain generated when the stretchable fiber 2 contracts in the low shrinkage region LS of the stretchable nonwoven fabric 1 is larger than the range of strain generated when the stretchable fiber 2 contracts in the high shrinkage region HS. For example, in the above-described return stress measurement, when the strain generated in the MD direction is measured for a sample piece released after the return stress measurement, a strain of 7 to 8% is generated in the sample piece taken from the high shrinkage region HS. On the other hand, the sample piece collected from the low contraction region LS has a strain of 15 to 20%. This is because the network structure of the stretchable fibers 2 is not maintained in the low shrinkage region LS, and the fiber orientation of the stretchable fibers 2 is closer to the MD direction (see FIG. 7). This is considered to be because when the distortion occurs, the influence of the distortion tends to appear directly in the MD direction. Since the strain in the MD direction of the stretchable fiber 2 indicates that the stretchable fiber 2 is difficult to shrink in the MD direction, the low shrinkage region LS is higher than the high shrinkage region HS. It can be seen that the contraction force is weakened.

<Usage example of stretchable nonwoven fabric 1>
As an example of a specific method for using the stretchable nonwoven fabric 1, an example in which the stretchable nonwoven fabric 1 is used as a packaging material for disposable diapers will be described. FIG. 10 is a schematic perspective view of the disposable diaper 5. FIG. 11 is a schematic plan view of the disposable diaper 5 in the unfolded state.

The disposable diaper 5 (hereinafter also simply referred to as “diaper 5”) includes an absorbent main body 51 (first component) that is applied to the crotch portion of the wearer and absorbs excrement such as urine, and the ventral side portion of the wearer. It is a so-called three-piece type disposable diaper constituted by three parts, a ventral band member 52 (second part) that covers the back and a back side band member 53 (third part) that covers the back side of the wearer. In the unfolded state of FIG. 11, the absorbent main body 51 is fixed between the ventral band member 52 and the dorsal band member 53 arranged substantially in parallel, and the external shape is substantially H in plan view. It has a shape. When the diaper 5 is worn, the absorbent main body 51 is folded in half at the center in the longitudinal direction, and the abdominal belt member 52 and the back belt member 53 facing each other are joined to each other at the widthwise short edges 52e and 53e. Thus, the diaper 5 in the wearing state is formed with the waist opening 5HB and the pair of leg openings 5HL as shown in FIG.

In this diaper 5, an elastic nonwoven fabric may be used as a material for the ventral band member 52 and the dorsal band member 53 so that the ventral band member 52 and the dorsal band member 53 can expand and contract in the width direction of the diaper 5. Thereby, stretchability (shrinkability) is provided to the waistline opening 5HB, and an appropriate fit can be given to the wearer's waistline (waistline) when the diaper 5 is worn.

By the way, as FIG.11 and FIG.10 shows, when the abdominal side band member 52 shrink | contracts inside in the width direction in the abdominal side part of the diaper 5, the absorptive main body 51 joined to the abdominal side band member 52 will also be wide. Shrink inward direction. When the absorbent main body 51 contracts, the area of the region covering the wearer's skin is reduced by the contraction. In particular, if the area of the portion that absorbs urine in the abdominal side of the absorbent main body 51 is reduced, there is a risk of problems such as urine leakage. Therefore, in the ventral belt member 52, it is necessary to adjust the strength of the contraction force to suppress the absorbent main body 51 from contracting inward in the width direction.

Therefore, the stretchable nonwoven fabric 1 of this embodiment is used as the ventral belt member 52 of the diaper 5. Specifically, the stretchable nonwoven fabric 1 is disposed on the belly side of the diaper 5 so that the longitudinal direction of the stretchable nonwoven fabric 1 is aligned with the width direction of the diaper 5. As described above, the stretchable nonwoven fabric 1 has a high shrinkage region HS and a low shrinkage region LS, while having stretchability, so that the shrinkage force can be weakened as a whole. In particular, by using the stretchable nonwoven fabric 1 as the ventral belt member 52 and arranging the low shrinkage region LS and the absorbent main body 51 so as to overlap each other, the absorbent main body 51 is effectively contracted inward in the width direction. Can be suppressed. Moreover, the stretchable nonwoven fabric 1 can adjust the strength of shrinkage by changing the range in which the high shrinkage region HS and the low shrinkage region LS are formed. Thereby, a comfortable fit can be given to the wearer by imparting appropriate stretchability to the waist opening 5HB of the diaper 5 while suppressing the shrinkage of the absorbent main body 51. In addition, if the low-shrinkage region LS is disposed in a region that is not desired to be shrunk with respect to other parts, the product can be configured so that the region that does not want to shrink is not shrunk while having elasticity as a whole.

=== Second Embodiment ===
Then, the direction which manufactures the elastic nonwoven fabric 1 is demonstrated using the manufacturing apparatus 200 of 2nd Embodiment. FIG. 12 is a diagram illustrating the configuration of the manufacturing apparatus 200 that manufactures the stretchable nonwoven fabric 1. The manufacturing apparatus 200 includes a transport mechanism CV, a heating unit 210, a first gear processing unit 220, a second gear processing unit 240, and a sheet member bonding unit 250.

In the manufacturing apparatus 200, the structure of the 2nd gear process part 240 differs compared with the manufacturing apparatus 100 of 1st Embodiment. Further, the manufacturing apparatus 200 is not provided with the stretching unit 130. Other basic configurations and functions are substantially the same as those of the manufacturing apparatus 100, and thus description thereof is omitted here. Hereinafter, the 2nd gear process part 240 is demonstrated.

The 2nd gear process part 240 of the manufacturing apparatus 200 is a mechanism which performs the process corresponded to the extending | stretching process and 2nd process process in 1st Embodiment. The second gear machining unit 240 includes a drive roll 241, a press roll 242, and a pair of gear rolls 245 and 246 (second gear roll).

The drive roll 241 is a pair of upper and lower rollers capable of adjusting the peripheral speed value, and is driven and rotated at a predetermined peripheral speed value V241 while sandwiching the nonwoven fabric continuous sheet Sa between the outer peripheral surfaces of the nonwoven fabric continuous sheet. Sa is transported downstream in the MD direction at a transport speed of V241. The magnitude | size of the conveyance speed V241 is more than the conveyance speed V221 of the nonwoven fabric continuous sheet Sa by the 1st gear process part 220, for example, the magnitude | size of about 115% of V221 is desirable. By making the conveyance speed V241 greater than the conveyance speed V221, the nonwoven fabric continuous sheet Sa is slightly extended in the MD direction between the first gear processing unit 220 and the drive roll 241. Since the nonwoven fabric continuous sheet Sa expresses stretchability in the MD direction in the first processing step in the first gear processing section 220, there is a risk that the web will be distorted during conveyance. On the other hand, the nonwoven fabric continuous sheet Sa is conveyed in the state stretched in MD direction by adjusting the conveyance speed by the drive roll 241 and applying the tension in the MD direction to the nonwoven fabric continuous sheet Sa. It is possible to suppress the occurrence of kinking during the transport of. However, the magnitude of the conveyance speed V241 is not limited to the above, and may be equal to V221 or may be greater than 115% of V221.

Note that such a relationship of the conveyance speed also applies to the first embodiment. That is, the conveyance speed V131 in the upstream nip roll 131 of the first embodiment may be equal to or higher than the conveyance speed V121 in the first gear machining unit 120. By transporting the nonwoven fabric continuous sheet Sa while applying tension in the MD direction, it becomes easy to suppress the occurrence of warp during transportation of the nonwoven fabric continuous sheet Sa exhibiting stretchability.

The press roll 242 is provided downstream of the drive roll 241 in the MD direction, and rotates while pressing the nonwoven fabric continuous sheet Sa against the outer peripheral surface of the gear roll 246 described later. The gear roll 246 rotates at a predetermined peripheral speed value V242, and the nonwoven fabric continuous sheet Sa is conveyed downstream in the MD direction at a conveyance speed of V242 while being sandwiched between the rolls 242. The conveyance speed V242 in the press roll 242 is faster than the conveyance speed V241 in the drive roll 241 and is adjusted to be about 255% of the conveyance speed V221 by the first gear processing unit 220 in this embodiment. Therefore, the nonwoven fabric continuous sheet Sa is stretched in the MD direction based on the peripheral speed difference between the transport speed V241 by the drive roll 241 and the transport speed V242 by the press roll 242 (stretching process), and the stretchable fiber 2 undergoes plastic deformation. It is in a state where it has been stretched to such an extent that it does not occur (not to break).

By providing such a press roll 242, it is possible to stretch the nonwoven fabric continuous sheet Sa without providing the stretching portion 130 (see FIG. 2) in the first embodiment, and the first processing step and the second processing are performed. The conveyance distance between processes can be made shorter than in the first embodiment. Thereby, the manufacturing apparatus 200 can be comprised compactly. Moreover, when a conveyance distance becomes short, it is suppressed that the nonwoven fabric continuous sheet Sa is extended too much in MD direction, and nonwoven fabric continuous sheet Sa becomes difficult to shrink | contract in CD direction (width direction). Furthermore, immediately after the stretching process is performed using the press roll 242, the second processing process using the gear rolls 245 and 246 is performed (see FIG. 12), so that the stretchability stretched to near the elastic limit in the stretching process. A part of the fiber 2 can be efficiently cut in the second processing step.

In this embodiment, the width W242 of the press roll 242 in the CD direction is wider than the width WSa of the nonwoven fabric continuous sheet Sa in the CD direction (W242> WSa, see FIG. 17 described later). Further, the outer peripheral surface of the press roll 242 is formed of a non-slip material such as silicone rubber, and the second gear roll 246 has a constant force in the direction of the central axis in the radial direction (that is, in the direction perpendicular to the tangential direction of the outer peripheral surface). Pressed. Thereby, it can convey, without pressing the full width of the nonwoven fabric continuous sheet Sa, without sliding on the outer peripheral surface of the 2nd gear roll 246, and can extend the nonwoven fabric continuous sheet Sa correctly.

The pair of gear rolls 245 and 246 are a pair of upper and lower roll mechanisms that rotate around a rotation axis along the CD direction with their outer peripheral surfaces facing each other. FIG. 13 is a schematic diagram illustrating the configuration of the gear roll 245. FIG. 14 is a schematic diagram illustrating the configuration of the gear roll 246. FIG. 15 is a diagram illustrating a region X in FIG. FIG. 16 is a diagram illustrating a region Y in FIG.

Of the pair of second gear rolls, the one side gear roll 245 is a tooth surface that is a region in which a plurality of teeth are formed so as to protrude outwardly from the outer peripheral surface, similar to the gear roll 145 of the first embodiment. 245ts and smooth surfaces 245fs which are regions where teeth are not formed are alternately arranged. The width W245 in the CD direction of the gear roll 245 is wider than the width WSa in the CD direction of the nonwoven fabric continuous sheet Sa (W245> WSa). As shown in FIG. 15, the tooth surface 245ts is alternately formed with ridges 245m and valleys 245v along the rotation direction. The plurality of teeth (crest portion 245m and trough portion 245v) of the gear roll 245 are continuously formed along the CD direction, and the width W245m of the crest portion 245m (valley portion 245v) in the CD direction is the nonwoven fabric continuous sheet Sa. Is narrower than the width WSa in the CD direction (WSa> W245m). Further, the thickness t245m (the width in the MD direction of the tip portion of the peak portion 245m) of the tooth tip portion of the gear roll 245 is about 0.2 mm. The gear roll 245 can heat the tooth surface 245ts to a predetermined temperature (for example, about 120 ° C.) by a heating device such as a heater. The reason for heating the teeth of the gear roll 245 will be described later.

Of the pair of second gear rolls, the other gear roll 246 includes a tooth surface 246ts, which is a region where a plurality of teeth are formed so as to be recessed outside the outer peripheral surface, and a region where no teeth are formed. The smooth surfaces 246 fs are alternately arranged. In the present embodiment, the state where the teeth formed on the tooth surface 246ts are recessed outside the outer peripheral surface means that the bottom of the tooth valley 246v is inside the outer peripheral surface of the gear roll 246 as shown in FIG. This is a state in which the tip of the tooth crest 246m is formed at the same position as the outer peripheral surface of the gear roll 246. In other words, the distance from the center of the gear roll 246 to the bottom of the tooth valley 246v is smaller than the radius of the gear roll 246, and the distance from the center of the gear roll 246 to the tip of the tooth peak 246m is substantially equal to the radius of the gear roll 246. .

The tooth surface 245ts of the gear roll 245 and the tooth surface 246ts of the gear roll 246 are formed at an equal pitch Pm and arranged at positions facing each other. The nonwoven fabric continuous sheet Sa passes between the surfaces 246ts along the MD direction. The non-woven fabric continuous sheet Sa is deformed and stretched in a three-point bend shape as described with reference to FIG. 4 in the portion that has passed between the tooth surfaces 245ts and 246ts (second processing step). That is, the stretchable fibers 2 that have been stretched to near the elastic limit are further stretched, whereby at least some of the stretchable fibers 2 of the plurality of stretchable fibers 2 constituting the nonwoven fabric continuous sheet Sa are cut, The low-shrinkage region LS in FIG. 1 is formed by removing the pressure-bonding point where the elastic fibers 2 are pressure-bonded.

In the manufacturing apparatus 200, the gear roll 246 has a function of conveying the nonwoven fabric continuous sheet Sa in the MD direction. That is, as shown in FIG. 12, the nonwoven fabric continuous sheet Sa is wound around a part of the outer peripheral surface of the gear roll 246 and rotated to convey the nonwoven fabric continuous sheet Sa in the rotation direction. Therefore, the teeth of the gear roll 246 in the second embodiment are recessed outside the outer peripheral surface, and the tip portion of the peak portion 246m of the teeth is configured not to protrude outward from the outer peripheral surface of the gear roll 246. . With such a configuration, the nonwoven fabric continuous sheet Sa wound around the outer peripheral surface can be smoothly conveyed. Further, since the teeth of the gear roll 246 do not protrude to the outside of the outer peripheral surface, the nonwoven fabric continuous sheet Sa can be sandwiched between the press roll 242 and sufficiently stretched. If the nonwoven fabric continuous sheet Sa is sandwiched and conveyed between the press roll 242 and the gear roll 245 having convex teeth on the outside of the outer peripheral surface, the outer peripheral surface of the gear roll 245 is rotated when the press roll 242 rotates. The state which contacts only with the front-end | tip part of a tooth | gear (peak part 245m) generate | occur | produces. In this case, the behavior of the press roll 242 bouncing between the teeth of the tooth surface 246ts of the gear roll 245 (between two adjacent ridges 245m) is exhibited, and the nonwoven fabric continuous sheet Sa becomes slippery. On the other hand, if the nonwoven fabric continuous sheet Sa is sandwiched and conveyed between the press roll 242 and the gear roll 246 having concave teeth on the outside of the outer peripheral surface, the outer peripheral surface of the press roll 242 becomes the teeth (mountains) of the gear roll 246. The state where only the tip of the portion 246m) is in contact does not occur. That is, since the outer peripheral surface of the press roll 242 is always pressed against at least a part of the outer peripheral surface of the gear roll 246, the nonwoven fabric continuous sheet Sa becomes less slippery and is stretched while stably transporting the nonwoven fabric continuous sheet Sa in the MD direction. can do.

In addition, in the 2nd gear process part 240, in order to wind and convey the nonwoven fabric continuous sheet Sa to a part of gear roll 246, the contact position (a pair of drive roll 241 is nonwoven fabric continuous sheet Sa) in the drive roll 241. The height of the contact position of the nonwoven fabric continuous sheet Sa on the gear roll 246 (position where the gear roll 245 and the gear roll 246 sandwich the nonwoven fabric continuous sheet Sa) is shifted. In FIG. 12, each roll is arrange | positioned so that the position of the drive roll 241 may be low and the position of the gear roll 246 may be high. As a result, longitudinal tension is generated in the nonwoven fabric continuous sheet Sa between the drive roll 241 and the gear roll 246, and a force directed from the outside to the inside of the outer peripheral surface of the gear roll 246 acts on the nonwoven fabric continuous sheet Sa. Therefore, the nonwoven fabric continuous sheet Sa can be conveyed while being wound around the outer peripheral surface of the gear roll 246 without deviation.

FIG. 17 is a schematic diagram for explaining the relationship of the width in the CD direction of the second gear machining section 240. The width W246 of the gear roll 246 in the CD direction is wider than the width WSa of the nonwoven fabric continuous sheet Sa in the CD direction (W246> WSa), and is approximately the same size as the width W245 of the gear roll 245 in the CD direction. The peak portion 246m and the valley portion 246v are formed continuously along the CD direction, the width W246m of the peak portion 246m of the gear roll 246 in the CD direction is narrower than the width WSa of the nonwoven fabric continuous sheet Sa in the CD direction, and The crest 245m of the gear roll 245 is wider than the width W245m in the CD direction (WSa> W246m> W245m). Thereby, the range of W245m where the teeth of the gear roll 245 are arranged in the width WSa of the nonwoven fabric continuous sheet Sa is extended in the CD direction. At this time, since WSa> W246m, both ends in the CD direction of the nonwoven fabric continuous sheet Sa (shaded portions in FIG. 17) are always sandwiched between the outer peripheral surfaces of the gear roll 245 and the gear roll 246 during conveyance. Yes. Thereby, the nonwoven fabric continuous sheet Sa becomes difficult to shift during conveyance. Then, the nonwoven fabric continuous sheet Sa passes between the tooth surface 245ts and the tooth surface 246ts without deviation, whereby the stretchable fiber 2 is firmly stretched.

In this embodiment, the thickness t246m (the width in the MD direction of the tip portion of the peak portion 246m) of the tooth tip of the gear roll 246 is about 0.5 mm. That is, the thickness t246m of the tooth tip of the gear roll 246 is thicker than the thickness t245m (0.2 mm) of the tooth tip of the gear roll 245 (t246m> t245m). This is to prevent the outer peripheral surface of the press roll 242 from being damaged when the press roll 242 is pressed against the outer peripheral surface of the gear roll 246. When the press roll 242 is pressed against the outer peripheral surface of the gear roll 246 while the nonwoven fabric continuous sheet Sa is sandwiched, the gear roll 246 is formed of silicone rubber or the like if the tip of the tooth is thin (that is, the teeth are sharp). The traces of the teeth are likely to be attached to the outer peripheral surface of the pressed roll 242 and the conveyance accuracy may gradually deteriorate. Therefore, the outer peripheral surface of the press roll 242 is made thicker than the tip end of the tooth of the gear roll 245 that is not in contact with the press roll 242, by making the tip end of the tooth of the gear roll 246 that is in contact with the press roll 242. The teeth are hard to be marked.

=== About the second machining step ===
In the second processing step, the manufacturing apparatus 100 (first embodiment) and the manufacturing apparatus 200 (second embodiment) extend the nonwoven fabric continuous sheet Sa to cut a part of the stretchable fibers 2 or remove the crimp points. In addition to the configurations described in the above embodiments, the following features are provided.

<Gear roll heating>
In the second processing step, the low-shrinkage region LS of FIG. 1 is formed by cutting a part of the stretchable fiber 2 out of the stretchable fiber 2 and the stretchable fiber 3 constituting the nonwoven fabric continuous sheet Sa. . At this time, it is desirable that only the stretchable fiber 2 can be cut without cutting the extensible fiber 3. Therefore, in the 2nd gear process part 140,240, while applying heat with respect to the nonwoven fabric continuous sheet Sa conveyed, while making the extensible fiber 3 easy to stretch and being hard to cut | disconnect, it is a part of elastic fiber 2 Deteriorate the structure and make it easier to cut.

In the manufacturing apparatus 100 of the first embodiment, the nonwoven fabric continuous sheet Sa is stretched (second processing step) while at least one of the pair of gear rolls 145 and 146 of the second gear processing unit 140 is heated to a predetermined temperature. Do. Specifically, heating is performed so that the temperature of at least one of the tooth surface 145ts of the gear roll 145 and the tooth surface 146ts of the gear roll 146 is higher than normal temperature and lower than the melting point of the extensible fiber 3. Heating may be performed by a heater provided outside, or may be performed by a heater provided on the gear rolls 145 and 146 itself.

When the nonwoven fabric continuous sheet Sa is heated when passing between the gear rolls 145 and 146, the extensible fibers 3 are easily stretched by heat and are not easily cut in the second processing step. On the other hand, since the stretchable fiber 2 is a thermoplastic elastomer (for example, TPU: thermoplastic polyurethane) fiber as described above, it has lower heat resistance than the extensible fiber 3 and may be distorted when heated. It becomes easy to be cut due to deterioration. Thereby, it becomes possible to efficiently cut some stretchable fibers 2 without cutting the extensible fibers 3 in the second gear processed portion 140. Moreover, it can suppress that nonwoven fabric continuous sheet Sa itself is cut | disconnected during conveyance. The temperature at which the gear rolls 145 and 146 are heated is preferably as high as possible among the temperatures lower than the melting point (about 200 ° C.) of the extensible fiber 3. In the first embodiment, for example, the gear roll up to about 120 ° C. Is heating up.

In the manufacturing apparatus 200 of the second embodiment, among the pair of gear rolls 245 and 246 of the second gear machining unit 240, the gear roll 245 having teeth protruding outward from the outer peripheral surface is heated to a predetermined temperature. The nonwoven fabric continuous sheet Sa is stretched (second processing step). The heating method and heating temperature conditions for the gear roll 245 are the same as in the first embodiment. Thereby, the extensible fiber 3 constituting the nonwoven fabric continuous sheet Sa is easily stretched and is not easily cut, and at least a part of the stretchable fiber 2 is easily cut.

In addition, as mentioned above, in the 2nd gear process part 240 of 2nd Embodiment, it conveys, winding the nonwoven fabric continuous sheet Sa around a part of outer peripheral surface of the gear roll 246 which has the tooth | gear which became concave on the outer side. At this time, if the gear roll 246 is heated, the contact area between the peripheral surface of the gear roll 246 and the nonwoven fabric continuous sheet Sa is large, so that the entire nonwoven fabric continuous sheet Sa is easily heated, and the stretchable fiber 2 is excessively distorted. Problems such as becoming larger are likely to occur. Therefore, in the second embodiment, only the gear roll 245 side of the pair of gear rolls 245 and 246 is heated, and the gear roll 246 is not heated.

<Arrangement of gear roll teeth>
The teeth of the gear rolls 145 and 146 (first embodiment) and the gear rolls 245 and 246 (second embodiment) used in the second processing step are each continuously formed in the CD direction. That is, the peak portions 145m, 146m, 245m, and 246m of each tooth are formed to have a predetermined width in the CD direction. Since the teeth of each gear roll are continuously formed in the CD direction, the stretchable fibers 2 can be efficiently stretched over a wide range in the CD direction (width direction) of the nonwoven fabric continuous sheet Sa (see FIG. 17). ).

FIG. 18 is a diagram for explaining stretching of the stretchable fiber 2 performed in the second processing step. FIG. 18 schematically shows an enlarged view of a state in which the plurality of stretchable fibers 2c to 2g constituting the nonwoven fabric continuous sheet Sa are crimped while being intertwined with each other. Among the plurality of stretchable fibers 2, the stretchable fiber 2c and the stretchable fiber 2d are crimped to each other at a crimping point WP1. Similarly, the stretchable fibers 2d and 2e are crimped to each other by the crimping point WP2, the stretchable fibers 2e and 2f are crimped to each other by the crimping point WP2, and the stretchable fibers 2f and 2g are crimped to each other by the crimping point WP4. To do. In addition, since the elastic fiber 2 which comprises the nonwoven fabric continuous sheet Sa is a long fiber, and at least one part is arrange | positioned along MD direction, it is easy to expand / contract to MD direction. Furthermore, since such long fibers are crimped | bonded by the crimping | compression-bonding point WP, mutually exerts a stretching property, and the nonwoven fabric continuous sheet Sa whole expresses a favorable stretching property about MD direction.

When such a nonwoven fabric continuous sheet Sa is stretched in the MD direction, if the teeth of two gear rolls provided adjacent to each other in the MD direction are continuously formed in the CD direction, the distance between the two teeth All the stretchable fibers 2 existing in the region are stretched in the MD direction. For example, the stretchable fibers 2c to 2g and the entire crimping points WP1 to WP4 are stretched in the MD direction in a region between the pitches Pm between the peak portions 145m1 and 145m2 in FIG. On the other hand, if the teeth of the gear roll are intermittently formed in the CD direction, a stretched fiber and a non-stretched fiber are generated among the plurality of stretchable fibers 2, and a uniform stretching effect is obtained. May not be obtained. For example, in FIG. 18, if the peak portions 145m1 and the peak portions 145m2 overlap with the stretchable fibers 2c and 2d in the CD direction and do not overlap with the stretchable fibers 2e and 2f, the stretchable fibers 2c and 2d are in the MD direction. The stretchable fibers 2e and 2f are not stretched. In this case, there may be a difference in stretchability of the nonwoven fabric continuous sheet Sa depending on the region in the CD direction, or the nonwoven fabric continuous sheet Sa may be distorted. Therefore, it is desirable that the teeth of the respective gear rolls 145, 146, 245, and 246 used in the second processing step are continuously formed in the CD direction.

Furthermore, the teeth of the gear roll (mountain portion 145m1 and peak portion 145m2) are arranged in parallel to the CD direction. In other words, the nonwoven fabric continuous sheet Sa is arranged in a direction perpendicular to the conveyance direction (MD direction). If it is such arrangement | positioning, the nonwoven fabric continuous sheet Sa can be correctly extended | stretched along MD direction between the teeth of two gear rolls adjacent to MD direction. For example, the stretchable fibers 2c to 2g in FIG. 18 are stretched in the MD direction with a uniform force in the same region in the MD direction (the region between the peak portions 145m1 and 145m2). Distortion is less likely to occur. However, the gear roll teeth do not necessarily have to be arranged in a direction parallel to the CD direction. For example, the gear roll teeth can be stretched even if they are arranged at an angle with respect to the CD direction. It is.

Moreover, the interval (pitch) in the MD direction of two teeth arranged adjacent to each other in the MD direction in each gear roll is wider than the pitch in the MD direction of the crimping point WP for crimping the stretchable fibers 2 to each other. With such a configuration, in the second processing step, there is a high probability that at least one or more crimping points WP for crimping the stretchable fibers 2 are included between the tooth pitches of the second gear roll. In FIG. 18, the pitch Pm (the distance in the MD direction) between the peak part 145m1 and the peak part 145m2 is wider than the shortest distance Pwp in the MD direction between the crimping point WP1 and the crimping point WP2 (P1). > Pwp), four crimping points WP1 to WP4 are included between the teeth of the gear roll. If the Pm region is stretched in the MD direction in this state, the crimping points WP1 to WP4 that have crimped the stretchable fibers 2 are likely to come off, so that the stretchability in the MD direction becomes weak and the low shrinkage of FIG. The region LS is easily formed.

On the other hand, when the distance between the two teeth in the MD direction (Pm in FIG. 18) is equal to or smaller than the distance between the crimp points WP in the MD direction (Pwp in FIG. 18) (Pm ≦ Pwp), the stretchable fiber between the two teeth There is a possibility that the crimping point WP for crimping the two is not included. In this case, even if the Pm region is stretched in the MD direction, there is no crimp point WP in the region, so the stretchable fibers 2 remain crimped, and the stretchability in the MD direction compared to the above case. Is difficult to weaken. Therefore, in the manufacturing apparatus 100 and the manufacturing apparatus 200, the gap in the MD direction of the teeth of the gear roll is set to be wider than the pitch in the MD direction of the crimping points WP for crimping the stretchable fibers 2 to each other.

In addition, in the above-mentioned embodiment, since the crimping point WP is formed by embossing the nonwoven fabric continuous sheet Sa, the size of the shortest distance Pwp in the MD direction of the crimping point WP and the teeth of the second gear roll. It is possible to adjust the size of the pitch Pm.

=== Others ===
The above-described embodiments are for facilitating the understanding of the present invention, and are not intended to limit the present invention. The present invention can be modified and improved without departing from the gist thereof, and it goes without saying that the present invention includes equivalents thereof.

In the above-described embodiment, the pair of gear rolls provided in the first gear processing unit 120 and the second gear processing unit 140 has been described with reference to FIG. 4 and FIG. That is not the case. For example, in one pair of gear rolls, a convex portion is formed on the outer peripheral surface of one gear roll, and a groove portion (concave portion) corresponding to the convex portion is formed on the outer peripheral surface of the other gear roll. The structure may be such that the non-woven fabric sheet passing between the portions and the groove portions are stretched by meshing with each other. Moreover, you may make it adjust the draw ratio of a nonwoven fabric by changing the height of the tooth | gear currently formed in each gear roll, and the length of meshing.

In the above-described embodiment, the three-piece type diaper 5 has been described as an example of using the stretchable nonwoven fabric 1, but the use example of the stretchable nonwoven fabric 1 is not limited thereto. For example, the stretchable nonwoven fabric 1 can be used for all absorbent articles using nonwoven fabric such as pants-type disposable diapers, napkins, and cage sheets.

1 stretchable nonwoven fabric,
2 stretchable fiber, 2a-2g stretchable fiber,
3 extensible fibers,
5 disposable diapers (diapers),
51 absorbent body,
52 ventral side band member, 52e width direction short edge part,
53 back side belt member, 53e width direction short edge part,
5HB waist opening, 5HL leg opening,
100 manufacturing equipment,
110 heating section,
111-114 heating roller,
120 first gear machining section,
121 guide roller,
125 gear roll, 125m mountain, 125v valley,
126 gear roll, 126m mountain, 126v valley,
130 stretch processing section,
131 upstream nip roll, 132 downstream nip roll,
140 Second gear machining section,
145 Gear roll,
145ts tooth surface, 145m peak, 145m1 / 145m2 peak, 145v valley,
145fs smooth surface,
146 Gear roll,
146ts tooth surface, 146m mountain, 146v valley,
146fs smooth surface,
150 sheet member lamination part,
151 Adhesive application part, 152 Laminating roll,
200 manufacturing equipment,
210 heating section,
211-214 Heating roller,
220 first gear machining section,
221 guide roller,
225 gear roll,
226 gear roll,
240 Second gear machining section,
241 drive roll,
242 press roll,
245 gear roll,
245ts tooth surface, 245m mountain, 245v valley,
245fs smooth surface,
246 Gear roll,
246ts tooth surface, 246m mountain, 246v valley,
246fs smooth surface,
250 sheet material lamination part,
251 adhesive application part, 252 laminating roll,
CV transport mechanism,
HS high shrinkage area, LS low shrinkage area,
S non-woven sheet, Sa non-woven continuous sheet, Sb other sheet members,
WP crimping point, CE cutting edge

Claims (12)

1. A transporting step for transporting a nonwoven fabric comprising stretchable fibers having stretchability and extensible fibers having lower shrinkage than the stretchable fibers in the transport direction;
   A first processing step in which the nonwoven fabric is stretched by passing between a pair of first gear rolls, and at least some of the extensible fibers are stretched;
   After the first processing step, a stretching step for stretching the nonwoven fabric in the transport direction;
   After the stretching step, the nonwoven fabric is stretched by passing it between a pair of second gear rolls having a portion where teeth are formed on a peripheral surface and a portion where teeth are not formed, and at least a part of the A second processing step of cutting the elastic fiber;
   The manufacturing method of the elastic nonwoven fabric characterized by having.
2. It is a manufacturing method of the elastic nonwoven fabric according to claim 1,
   A method for producing a stretchable nonwoven fabric, wherein at least one of the pair of second gear rolls is heated to a temperature lower than the melting point of the stretchable fiber.
3. It is a manufacturing method of the elastic nonwoven fabric according to claim 1 or 2,
   The tooth | gear of a pair of said 2nd gear roll is formed so that all may become convex toward the outer side of a surrounding surface, The manufacturing method of the elastic nonwoven fabric characterized by the above-mentioned.
4. It is a manufacturing method of the elastic nonwoven fabric according to claim 1 or 2,
   Of the pair of second gear rolls, the teeth of the gear roll on one side are formed to be convex toward the outside of the peripheral surface,
   Of the pair of second gear rolls, the teeth of the other side of the gear roll are formed so as to be concave toward the outside of the peripheral surface.
5. It is a manufacturing method of the elastic nonwoven fabric according to claim 4,
   The nonwoven fabric is transported in the transport direction at a predetermined speed by a pair of drive rolls provided between the transport direction of the pair of first gear rolls and the pair of second gear rolls,
   The non-woven fabric is pressed against the outer peripheral surface of the gear roll on the other side of the pair of second gear rolls by a press roll provided downstream of the pair of drive rolls in the transport direction. By transporting in the transport direction at a speed faster than a predetermined speed,
   A method for producing a stretchable nonwoven fabric, wherein the nonwoven fabric is stretched in the transport direction.
6. It is a manufacturing method of the elastic nonwoven fabric according to claim 4 or 5,
   The method for producing a stretchable nonwoven fabric, wherein the one side of the pair of second gear rolls is heated to a temperature lower than the melting point of the stretchable fibers.
7. A method for producing a stretchable nonwoven fabric according to any one of claims 4 to 6,
   The other-side gear roll of the pair of second gear rolls conveys the nonwoven fabric in the conveyance direction by rotating the nonwoven fabric around at least a part of a circumferential surface thereof. For producing a conductive nonwoven fabric.
8. A method for producing a stretchable nonwoven fabric according to any one of claims 4 to 7,
   Of the pair of second gear rolls, the thickness of the tooth tip of the other side gear roll is:
   The manufacturing method of the elastic nonwoven fabric characterized by being thicker than the thickness of the front-end | tip part of the tooth | gear of the said one side gear roll among a pair of said 2nd gear rolls.
9. A method for producing a stretchable nonwoven fabric according to any one of claims 1 to 8,
   The method for producing a stretchable nonwoven fabric, wherein the teeth of the pair of second gear rolls are continuously formed in a CD direction which is a direction perpendicular to the transport direction.
10. It is a manufacturing method of the elastic nonwoven fabric according to claim 9,
    The method for producing a stretchable nonwoven fabric, wherein the teeth of the pair of second gear rolls are arranged along a direction parallel to the CD direction.
11. A method for producing a stretchable nonwoven fabric according to any one of claims 1 to 10,
    The fibers constituting the stretchable nonwoven fabric are long fibers,
    Two or more said long fibers are mutually crimped | bonded by the several crimping | compression-bonding point, The manufacturing method of the elastic nonwoven fabric characterized by the above-mentioned.
12. It is a manufacturing method of the elastic nonwoven fabric according to claim 11,
    The second processing step includes
    The method for producing a stretchable nonwoven fabric, wherein the pair of second gear rolls has teeth having a pitch wider than the shortest distance between two crimping points adjacent in the transport direction.

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