JP2018144314A - Method for producing elastic nonwoven fabric sheet, and elastic nonwoven fabric sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing an elastic nonwoven fabric sheet that has high elongation and also resists perforation.SOLUTION: A method for producing an elastic nonwoven fabric sheet includes the steps of forming a napped fiber on the surface of a filament nonwoven fabric, passing the filament nonwoven fabric and an elastic resin material extruded in molten state through a nip roll, and fusing together the napped fiber of the filament nonwoven fabric and the elastic resin material, to form a composite sheet, and drawing the composite sheet.SELECTED DRAWING: Figure 2

Description

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

A technique relating to a sheet material having elasticity is known.
For example, Patent Documents 1 and 2 describe a stretchable nonwoven fabric sheet in which a molten resin material extruded from a die and a base sheet are bonded together by a nip roll nip pressure. The stretchable nonwoven fabric sheet is stretchable by applying a tooth gap extension process after the bonding.
In this stretchable nonwoven fabric sheet, the elastic resin is fused and solidified with the base sheet when in a molten state, and the integrity between the members is high. In addition, unlike the three-dimensional gathers of Patent Document 1, the elastic resin is substantially non-stretched and fused to the base sheet over the entire length, so that the peel strength is high and the stretchability is not easily lowered. . In such a stretchable nonwoven fabric sheet, in the natural state, there is little shrinkage of the elastic resin and it is difficult for the base sheet to float or wrinkle. Therefore, it becomes a thin sheet with reduced bulk in the natural state.
From the viewpoint of improving the touch, the absorbent article described in Patent Document 3 describes that a raised sheet is used for a three-dimensional gather with an elastic member. The elastic member is fixed to the sheet in a stretched state by an adhesive or a heat seal distributed in a dot shape.

JP 2009-190235 A Japanese Patent Application Laid-Open No. 2015-113547 JP 2013-5879 A

In the stretchable nonwoven fabric sheet described in Patent Documents 1 and 2, in the manufacturing process, a fused portion 93 between the elastic resin material 91 and the fiber 92 of the base sheet is formed by bonding with a nip pressure. (See FIG. 9A). If the nonwoven fabric sheet is stretched too much in the subsequent tooth gap stretching process, the fiber 92 may break between the fused portions 93, 93 as the elastic resin material 91 is stretched (see FIG. 9B). . Breaking increases as the tooth gap stretch ratio is increased, which can cause perforation of the stretchable nonwoven sheet. An increase in perforation causes deterioration in the appearance of the sheet surface and a decrease in sheet strength. Therefore, it has been difficult in the past to enhance the stretchability of the stretchable nonwoven fabric sheet while maintaining the appearance and sheet strength.
On the other hand, the fusion strength between the elastic resin material and the base sheet fiber is necessary from the viewpoints of integrity when using the stretchable nonwoven fabric sheet and the ability to transmit the elongation force of the elastic resin material to the base sheet. However, if the fusion strength is increased too much, elongation of the elastic resin material and fiber is restricted at the fusion point, and there is a possibility that breakage occurs during the tooth gap extension processing. Forcibly increasing the tooth gap stretch ratio in order to overcome the restraint due to fusion and obtain higher extensibility results in a further increase in perforation.
As described above, it is necessary to control the fusion strength between the elastic resin material and the fibers of the base sheet in order to achieve both high extensibility of the stretchable nonwoven fabric sheet and suppression of perforation. In this regard, in the three-dimensional gather of Patent Document 3, since the elastic member is not welded, the above problem cannot occur, and there is no description about the problem.

  In view of the above problems, the present invention relates to a stretchable nonwoven fabric sheet that achieves both high extensibility and perforation suppression and a method for producing the same.

  The present invention includes a step of forming a raised fiber on the surface of a long-fiber nonwoven fabric, the long-fiber nonwoven fabric, and an elastic resin material extruded in a molten state through a nip roll, and the raised fiber of the long-fiber nonwoven fabric and the elastic fiber Provided is a method for producing a stretchable nonwoven fabric sheet, which comprises a step of fusing a resin material to form a composite sheet and a step of stretching the composite sheet.

  The present invention also relates to a stretchable nonwoven fabric sheet in which an elastic resin material is disposed and bonded between a pair of long fiber nonwoven fabrics, wherein the perforated area ratio is 5% or less, the bulk softness value is 8 cN or less, and the maximum elongation is An elastic nonwoven fabric sheet having a 100% to 500% and 50% return stress value of 0.3 N / 25 mm to 3 N / 25 mm is provided.

According to the method for producing a stretchable nonwoven fabric sheet of the present invention, a stretchable nonwoven fabric sheet having both high extensibility and perforation suppression can be obtained.
The stretchable nonwoven sheet of the present invention has high extensibility and little perforation.

It is a partially notched perspective view which shows an example of the elastic nonwoven fabric sheet manufactured by the method of this invention. It is process drawing which shows the 1st process (formation process of raising fiber) in preferable one Embodiment of the manufacturing method of the elastic nonwoven fabric sheet of this invention, (A) is explanatory drawing which shows a partial extending | stretching process, (B) It is sectional drawing which expands and shows the meshing state of a pair of uneven | corrugated roll in a partial extending | stretching process partially, (C) is explanatory drawing which shows a raising process, (D) is code | symbol d1 of (C) It is a schematic diagram which shows the state by which the raising fiber was formed in the long-fiber nonwoven fabric about the part shown by a circle. It is explanatory drawing which showed typically the method of measuring the number of the raising fiber in a long-fiber nonwoven fabric, (A) is a figure which shows the state which folded the long-fiber nonwoven fabric, (B) is the length of (A) It is a figure which shows the state which piled up the black mount with a window on the fiber nonwoven fabric, and (C) is a figure which shows an example of the state of the raising fiber observed from the window of a black mount. It is process drawing which shows the 2nd process (formation process of a composite sheet) in preferable one Embodiment of the manufacturing method of the elastic nonwoven fabric sheet of this invention. It is sectional drawing which partially expands and shows typically the composite sheet obtained in the 2nd process, (A) is sectional drawing along a conveyance direction (MD), (B) is a width direction (CD) FIG. In a 2nd process, it is explanatory drawing which shows typically the process of making the surrounding surface of the main roll and sub roll which comprise a nip roll uneven | corrugated shape, and fusing the long-fiber nonwoven fabric and elastic resin material of front and back. It is process drawing which shows the 3rd process (tooth gap extending | stretching process process) in preferable one Embodiment of the manufacturing method of the elastic nonwoven fabric sheet of this invention. It is explanatory drawing which shows typically the process of extending | stretching a composite sheet | seat by mesh | engaging a pair of tooth space roll in a 3rd process. In the manufacturing method of the conventional elastic nonwoven fabric sheet, it is explanatory drawing which shows typically the fusion | melting relationship of the elastic resin material and nonwoven fabric fiber before and behind tooth space extending | stretching process, (A) shows before tooth space extending | stretching, ( B) shows after tooth space extension.

  Hereinafter, the present invention will be described based on preferred embodiments with reference to the drawings. In addition, the elastic nonwoven fabric sheet which concerns on this invention can be used for the site | part which needs the elasticity of absorbent articles, such as a diaper, for example. For example, the member etc. which comprise the waist of a diaper are mention | raise | lifted.

First, an example of the stretchable nonwoven fabric sheet produced by the method of the present invention will be described. In the stretchable nonwoven fabric sheet 10 shown in FIG. 1, a plurality of elastic resin materials 3 do not cross each other between the front and back long fiber nonwoven fabrics 1 and 2 (the longitudinal direction of the stretchable nonwoven fabric sheet 10. Y). Direction). The plurality of elastic resin materials 3 are juxtaposed in the width direction (X direction) orthogonal to the longitudinal direction of the stretchable nonwoven fabric sheet 10 at intervals.
The long-fiber nonwoven fabrics 1 and 2 may be of the same type or different types. “Same type” as used herein means that the manufacturing process of nonwoven fabric, the types of constituent fibers, thickness, basis weight, etc. are all the same, and “different” means that at least one of the above matters is different. .
The elastic resin 3 has a fiber (filament) shape, and is fused to the base sheet 1 and 2 over the entire length in a substantially non-stretched state. “Elasticity” of the elastic resin material 3 means that the elastic resin 3 has elasticity in a state where the elastic resin 3 is taken out from the stretchable nonwoven fabric sheet 10. “Having elasticity” means that it can be stretched and returns to a length of 1.1 times or less of the original length when the force is released from a state of 1.3 times the original length. Refers to nature. The “substantially non-stretched state” of the elastic resin material 3 is a state in which the elastic resin material 3 does not contract when the external force is removed. The elastic resin material 3 having a fiber (filament) shape means that the diameter is 500 μm or less, more preferably 300 μm or less, and still more preferably 100 μm.

  In the production method of the present invention, raised fibers are formed on the opposing surfaces of the long-fiber nonwoven fabrics 1 and 2 on the front and back sides, and the elastic resin material 3 is fused to the raised fibers. By forming such a fusion, it is possible to suppress perforation of the long-fiber nonwoven fabrics 1 and 2 even if the draw ratio is increased in the tooth gap drawing process. That is, according to the production method of the present invention, a stretchable nonwoven fabric sheet having both high extensibility and perforation suppression can be obtained.

In the present invention, the term “perforated” refers to a fiber on at least one surface of the front and back long fiber nonwoven fabrics 1 and 2 when the stretchable nonwoven fabric sheet 10 is stretched twice in the extending direction of the elastic resin material 3. It means that a region having no is generated with a size of 1 mm ² or more. In this case, the “perforated” does not include a gap between the fibers of the long-fiber nonwoven fabrics 1 and 2 and does not include a portion where the fiber density is lowered due to the above-described tooth gap drawing process and is transparent.

  Hereinafter, the manufacturing method of the said elastic nonwoven fabric sheet 10 is demonstrated as preferable embodiment of the manufacturing method of the elastic nonwoven fabric sheet of this invention.

The manufacturing method of the elastic nonwoven fabric sheet 10 of this embodiment is as follows.
(1) a step of forming the raised fibers 4 on the surfaces of the long-fiber nonwoven fabrics 1 and 2 (first step 7);
(2) The long fiber nonwoven fabrics 1 and 2 and the elastic resin material 3 extruded in a molten state are passed through a nip roll, and the raised fibers 4 and the elastic resin material 3 of the respective long fiber nonwoven fabrics 1 and 2 are fused. A step of forming the composite sheet 6 (second step 8);
(3) a step (third step 9) of subjecting the composite sheet 6 to stretching.

  The 1st process 7 has the raising process 72 of Drawing 2 (C). As the raising process 72, a method similar to the method described in Patent Document 3 can be used. Specifically, the 1st process 7 may consist only of raising process 72, and as shown in Drawing 2 (A) and (C), partial extension processing (pre-processing) 71 and raising process 72 may be a two-step raising process in which the steps 72 and 52 are performed in this order. From the viewpoint of facilitating the formation of the raised fibers 3 on the surfaces of the long-fiber nonwoven fabrics 1 and 2, reducing the surface density and reducing the fusion point with the elastic resin material 3, it is more preferable to perform the two-stage raising process. . Hereinafter, in this embodiment, the 1st process 7 is demonstrated as what is performed by this two-step raising process.

First, in the partial stretch processing 71, the long fiber nonwoven fabrics 1 and 2 are damaged. In the first step 7, the long fiber nonwoven fabrics 1 and 2 to be processed are collectively referred to as a raw material long fiber nonwoven fabric 19.
Specifically, the strip-shaped raw long fiber nonwoven fabric 19 is fed out from a raw fabric roll (not shown) and continuously supplied between the concave and convex rolls 74 and 75 as shown in FIG. This supply can be performed by, for example, transport rolls 73 and 73 provided on the upstream side and the downstream side of the rolls 74 and 75. Between the rolls 74 and 75 having irregularities on the surface, the raw material long-fiber nonwoven fabric 19 is sandwiched and partially stretched by meshing the irregularities with each other. More specifically, the meshing is performed as shown in FIG. That is, the roll 74 rotates in the direction of the arrow F1, the roll 75 rotates in the direction of the arrow F2, and the convex portion 74A and the concave portion 75A mesh with the raw material long-fiber nonwoven fabric 19 interposed therebetween. Thereby, the raw material long fiber nonwoven fabric 19 is extended | stretched partially in the width direction (CD: Cross Direction) orthogonal to a conveyance direction (MD: Machine Direction) and a conveyance direction. In addition, MD direction corresponds to the longitudinal direction (Y direction) in the elastic nonwoven fabric sheet 10 shown in FIG. 1 mentioned above, and CD direction corresponds to the width direction (X direction) in the elastic nonwoven fabric sheet 10.

  The partial stretching process 71 damages the surface of the raw long-fiber nonwoven fabric 19, and the starting points of the raising are formed by loosening the entanglement of the fibers in the raw long-fiber nonwoven fabric 19. Thereby, in the raising process 72 mentioned later, only the fiber which received the damage in the surface of the raw material long-fiber nonwoven fabric 19 can be raised efficiently, without damaging to a base fiber. Thereby, the excessive strength fall by raising can be suppressed.

Next, raising processing 72 is performed.
In the raising process 72, as shown in FIG. 2C, the raw long-fiber nonwoven fabric 19 subjected to the partial stretching process is conveyed to the raising roll 77 by the conveying rolls 76 and 76. The raised surface of the raised roll 77 is provided with a projection area 78 having a projection. Although it is preferable that the entire surface of the long-fiber non-woven fabric is a raised region, in the case where a non-raised region is provided, both end portions of the projection region 78 in the roll axis direction may be smooth regions 79 and 79 having no projection.
The raising roll 77 rotates while contacting one surface 101 of the raw material long fiber nonwoven fabric 19 to be conveyed. Due to the rotation of the raising roll 77, a part of the long fibers on the surface is cut off and released from the sheet base 5 on the surface 101 of the raw long-fiber nonwoven fabric 19 subjected to the partial stretching process, and the raised fibers 4 are formed. In the present embodiment, the raised fibers 4 are formed only on one surface (surface 101) of the raw long fiber nonwoven fabric 19. That is, the raised long fiber nonwoven fabrics 1 and 2 are both formed with the raised fibers 4 only on one side (surface 101). However, it is not limited to this form, You may make it the raising fiber 4 be formed in both surfaces (surface 101 and 102).

  The raised fibers 4 are portions where the surface fibers of the raw long fiber nonwoven fabric 19 are separated from the sheet base 5 where the long fibers are bundled together at the bundle fusion part 5A. For example, the raised fiber 4 may be a raised fiber 4 having a fusion-fixed end 4A and a free end 4B with other fibers in the bundle fusion part 5A (FIG. 2D). Moreover, the raising fiber 4 etc. which stand up in the loop shape between bundle | flux fusion | bond part 5A, 5A are mentioned. A portion where long fibers other than the raised fibers 4 are integrated by fusion is the sheet base 5.

  The number of the raised fibers 4 (raised amount) is more reliably fused with the elastic resin material 3 in the second step 8 described later, and perforation is suppressed in the stretchable nonwoven fabric sheet 10 obtained through the third step 9. And from the viewpoint that the elongation force of the elastic resin material 3 can be sufficiently transmitted to the long-fiber nonwoven fabrics 1 and 2, it is preferably 5 / cm or more, more preferably 10 / cm or more, and 20 / cm. The above is more preferable. In addition, the number of raised fibers 4 ensures the strength of the bases of the long-fiber nonwoven fabrics 1 and 2 after raising, enables processing to impart high extensibility of the stretchable nonwoven fabric sheet 10, and prevents perforation. 100 / cm or less, more preferably 80 / cm or less, and even more preferably 50 / cm or less.

(Method for measuring the number of raised fibers 4)
The number of the raised fibers 4 can be measured by the following measuring method. Sampling and measurement are performed at 22 ° C. and 65% RH.
First, a 20 cm × 20 cm measurement piece was cut out from the long-fiber nonwoven fabrics 1 and 2 after raising with a sharp blade (razor), and the measurement piece was turned outward as shown in FIG. 3 (A). The measurement sample 104 is formed by mountain folding (in the direction of the arrow in FIG. 3A). Next, this measurement sample 104 is placed on an A4 size black mount, and as shown in FIG. 3 (B), an A4 size black mount with a 1 cm vertical by 1 cm wide window 107 is further formed thereon. Overlapping. At this time, as shown in FIG. 3B, the fold 105 of the measurement sample 104 is arranged so that it can be seen from the upper black mount window 107. For both mounts, “Kenran (black) continuous weight 265 g” of Fuji Kyowa Paper Co., Ltd. is used. Thereafter, a weight of 50 g is placed on each side of the upper mount window 107 at a position 5 cm outward along the fold line 105 to create a state in which the measurement sample 104 is completely folded.
Next, as shown in FIG. 3C, the inside of the mount window 107 is observed at a magnification of 30 times using a microscope (VHX-900 manufactured by KEYENCE Inc.), and the fold 105 of the measurement sample 104 is observed. The number of raised fibers 4 raised above the imaginary line 108 formed at a position translated 0.2 mm above is measured. In the nonwoven fabric to be measured at this time, when the width of the raised portion is 1 cm or more, three 20 cm × 20 cm measurement pieces are cut out and measured so as to include the raised portion. Moreover, when the width | variety of the site | part to which the raising process was performed is 1 cm or less, it measures by cutting out the measurement piece of 20 cm x 20 cm at random. The above operation is measured for three sheets of the nonwoven fabric to be measured, and an average of a total of nine places is taken as the number of raised fibers.

  Further, when counting the raised fibers 4, for example, when there is a fiber that crosses the imaginary line 108 twice 0.2 mm above the fold 105, such as a fiber 106 a shown in FIG. Count as two. Specifically, in the example shown in FIG. 3C, there are four fibers crossing the virtual line 108 once and one fiber 106a crossing the virtual line 108 twice, but two fibers 106a crossing the virtual line 108 twice. Counted as a book, the number of the raised fibers 4 is six.

  When the raised height of the raised fibers 4 is the length from the sheet base 5 to the highest position, the fusion between the raised fibers 4 and the elastic resin material 3 is ensured. From the viewpoint of suppressing fusion between the sheet base portion 5 and the elastic resin material 3, 0.5 mm or more is preferable, and 1 mm or more is more preferable. Further, the raised height of the raised fibers 4 is preferably 5 mm or less, preferably 3 mm or less from the viewpoint of suppressing the thickness of the stretchable nonwoven fabric sheet 10 and ensuring the integrity of the long-fiber nonwoven fabrics 1 and 2 and the elastic resin material 3. More preferred. The raised height can be measured according to the above-described (Method for measuring the number of raised constituent fibers).

In this embodiment, it has the raised fiber 4 of the long-fiber nonwoven fabric 1 and 2 before the process of forming the composite sheet 6 of the 2nd process 8 mentioned later after the process of forming the raised fiber of the 1st process 7. There is preferably a step of applying a release agent to the surface. As a result, the fused raised fibers in the tooth gap extending process in the third step 9 described later can be more effectively broken.
From the viewpoint of effective breakage of the raised fibers 4, the coating amount of the release agent is preferably 0.1 wt% or more, more preferably 0.2 wt% or more, and further preferably 0.3 wt% or more. Further, the coating amount of the release agent is preferably 1 wt% or less, more preferably 0.7 wt% or less, and further preferably 0.5 wt% or less from the viewpoint of preventing contamination of processing equipment. The release agent is preferably applied more on the raised fibers 4 than on the sheet base 5, and more preferably on the raised fibers 4 without being applied on the sheet base 5.

  Next, the second step 8 will be described.

  In the second step 8, as shown in FIG. 4, the long fiber nonwoven fabrics 1 and 2 having the raised fibers 4 and the elastic resin material 3 extruded in a molten state are passed through a nip roll 85. As a result, the raised fibers 4 of the long-fiber nonwoven fabrics 1 and 2 and the elastic resin material 3 are fused to form a composite sheet 6. At this time, the long-fiber nonwoven fabrics 1 and 2 both sandwich the elastic resin material 3 with the surfaces 101 having the raised fibers 4 facing each other.

  Specifically, first, spinning is performed by extruding a fiber (filament) -like elastic resin material 3 in a molten state from a plurality of spinning nozzles 82 provided in the spinning head 81. The spinning nozzles 82 are arranged in a row in the spinning head 81 in a direction along the width direction perpendicular to the conveying direction of the long-fiber nonwoven fabrics 1 and 2. The interval between the adjacent spinning nozzles 82 corresponds to the interval between the fiber (filament) -like elastic resin materials 3 in the composite sheet 6. The diameter of the spinning nozzle 82 is preferably 0.1 mm or more, and more preferably 0.2 mm or more. The aperture is preferably 2 mm or less and more preferably 0.6 mm or less.

The molten filamentary elastic resin material 3 spun from the spinning nozzle 82 merges with the long fiber nonwoven fabrics 1 and 2 drawn from the original fabric at the same speed, and is sandwiched between the long fiber nonwoven fabrics 1 and 2. And picked up at a predetermined speed. The take-up speed of the elastic resin material 3 is matched with the feed speed of the long-fiber nonwoven fabrics 1 and 2. The take-up speed of the elastic resin material 3 affects the diameter and the draw ratio of the elastic resin material 3. That is, the elastic resin material 3 is stretched by the tension due to the take-up until it is joined with the long-fiber nonwoven fabrics 1 and 2 after being spun, and the molecules are oriented in the stretching direction and the diameter is reduced. Further, the tension generated in the elastic resin material 3 prevents the elastic resin material 3 from being disturbed due to wind or static electricity. Accordingly, the filamentous elastic resin material 3 can be bonded to the long-fiber nonwoven fabrics 1 and 2 by being arranged in one direction without crossing each other.
Here, the stretching of the elastic resin material 3 is for forming a filament shape, and is cooled until the elastic resin material 3 extruded in a molten state is bonded to the long fiber nonwoven fabrics 1 and 2. While being stretched. Therefore, it may be not only stretching in a molten state (melt stretching) but also stretching in a softened state (softening stretching) in the cooling process. The molten state is a state in which the resin flows when an external force is applied.

  The elastic resin material 3 is in a state capable of being fused before solidification when joining with the long fiber nonwoven fabrics 1 and 2. Therefore, the elastic resin material 3 is fused to the plurality of raised fibers 4 formed on the opposing surfaces 101 of the long-fiber nonwoven fabrics 1 and 2 by their own fusion force. The temperature of the elastic resin material 3 is preferably equal to or higher than the melting point of the resin material used, specifically 100 ° C. or higher, from the viewpoint of ensuring fusion with the raised fibers 4 during the fusion. The temperature is preferably 120 ° C. or higher.

  When the elastic resin material 3 is fused, heat is not applied to the long fiber nonwoven fabrics 1 and 2 from the outside. Therefore, the elastic resin material 3 and the raised fibers 4 of the long-fiber nonwoven fabrics 1 and 2 are fused by the heat of fusion of the elastic resin material 3 that can be fused. As a result, only the site | part which exists in the circumference | surroundings of the elastic resin material 3 among the long-fiber nonwoven fabrics 1 and 2 fuse | melts with the elastic resin material 3, and the site | part distant from it is made not to fuse | melt.

  Further, in addition to the limitation of the fusion range as described above, by appropriately setting the nip pressure of the nip roll 85, as shown in FIGS. The fibers 4 can be fused with the elastic resin material 3 with high accuracy. That is, it is possible to suppress the fusion between the sheet base portion 5 of the long-fiber nonwoven fabrics 1 and 2 and the elastic resin material 3. Thus, the composite sheet 6 in which the fusion point between the elastic resin material 3 and the sheet base 5 of the long fiber nonwoven fabrics 1 and 2 is suitably reduced can be obtained. 5A and 5B, in order to schematically show the arrangement of the raised fibers 4 and the elastic resin material 3, the gap between the sheet base 5 of the long-fiber nonwoven fabrics 1 and 2 and the elastic resin material 3 is shown. The space is shown as being separated. Actually, the space between the sheet base 5 and the elastic resin material 3 is considered to be crushed by the nip pressure.

  By using the composite sheet 6 to perform a stretching process in a third step 9 described later, it is possible to create a situation in which the raised fibers 4 are stretched together with the elastic resin material 3 instead of the sheet base 5 to be broken. Even if the elastic resin material 3 is fused not only to the raised fibers 4 but also to the sheet base 5, the linear raised fibers 4 have a lower breaking strength than the planar sheet base 5. Is likely to occur preferentially. As a result, the fibers of the sheet base 5 are less likely to break, and perforation due to stretching can be effectively suppressed. In addition, processing at a high tooth gap stretching ratio is possible.

  In the present embodiment, the nip roll 85 includes a main roll 86 and two sub rolls 87, and performs a first nip 85A and a second nip 85B on the laminate of the long fiber nonwoven fabrics 1 and 2 and the raised fibers 4. . The main roll 86 and the sub roll 87 have smooth peripheral surfaces, and are made of, for example, metal or rubber. The sub roll 87 is arranged so that its axis is parallel to the axis of the main roll 86. The nip treatment by the nip roll 85 may be performed in two stages as in the present embodiment, may be performed in one stage, or may be performed in three or more stages. When performed in two stages of the first nip 85A and the second nip 85B as in this embodiment, the strength reduction of the long-fiber nonwoven fabrics 1 and 2 is suppressed while controlling the fusion strength between the elastic resin material 3 and the raised fibers 4. This is preferable because it is possible.

The nip pressure by the nip roll 85 is appropriately set from the viewpoint of suitably fusing the elastic resin material 3 and the raised fibers 4 as described above.
The “nip pressure” acts on the laminate by sandwiching the laminate in which the filamentous elastic resin material 3 is sandwiched between the long-fiber nonwoven fabrics 1 and 2 by the main roll 86 and the sub-rolls 87. It is a pressure. The nip pressure includes (i) clamping pressure (force for pressing the sub roll 87 against the main roll 86), (ii) clearance between rolls, (iii) roll surface hardness, (iv) roll surface shape, etc. Can be adjusted. In particular, it can be suitably adjusted by (i) the clamping pressure and (ii) the clearance between the rolls. (I) The nip pressure increases as the pinching pressure increases and (ii) the clearance between the rolls decreases.
The clamping pressure is a force for pressing the sub roll 87 against the main roll 86 regardless of the interposition and clearance of the laminated body of the fiber nonwoven fabrics 1 and 2 and the elastic resin material 3. The clamping pressure is measured by, for example, a load cell installed in a clearance setting device installed to provide clearance between the main roll and the sub roll.

  The “nip pressure” is preferably 0 (zero) N / cm or more and 150 N / cm or less, more preferably 0 (zero) N / cm or more and 120 N / cm or less, and 0 (zero) N / cm or more and 100 N / cm or less. Further preferred. Thereby, melt | fusion with the sheet | seat base 5 of the long-fiber nonwoven fabrics 1 and 2 and the elastic resin material 3 can be suppressed, and melt | fusion with the elastic resin material 3 and the raising fiber 4 can be formed in a preferable range.

  The “nip pressure” is preferably set for each of the first nip 85A and the second nip 85B within the above range. In that case, the nip pressure of the first nip 85A is preferably 1 N / cm or more, particularly preferably 2 N / cm or more, more preferably 100 N / cm or less, and particularly preferably 50 N / cm or less. The nip pressure of the second nip 85B is preferably 0 N / cm or more, more preferably 150 N / cm or less, and particularly preferably 10 N / cm or less.

(Measurement method of nip pressure)
The nip pressure can be measured by the following method.
(I) When clearance is provided:
First, in a state where there is no laminate of the long-fiber nonwoven fabrics 1 and 2 and the elastic resin material 3, the force A that tries to press the sub roll against the main roll is measured. Next, in a state where the laminate is present, a force B that attempts to press the sub roll against the main roll is measured. The nip force C acting on the laminate can be obtained from the following equation (a).
C = A−B (a)
Here, A and B are measured by, for example, a load cell installed in a clearance setting device installed to provide clearance between the main roll and the sub roll.
Based on the nip force C, the nip pressure is determined as a linear pressure from the following equation, where W is the width of the base material (the width of the long-fiber nonwoven fabrics 1 and 2).
Nip pressure = C / W (b)
(Ii) When no clearance is provided (solid nip):
It is calculated | required by the following formula | equation (c) from the force (pressing force) which presses the sub roll by a machine setting to a main roll, and the width W of the said long-fiber nonwoven fabric 1 and 2.
Nip pressure (linear pressure) = pressing force / W (c)
If the pressing force is unknown in the machine settings, it is measured by the load cell.

  The surface temperature of the main roll 86 and the sub roll 87 constituting the nip roll 85 is preferably adjusted to a temperature of 10 ° C. or higher, preferably adjusted to 30 ° C. or lower, and adjusted to a temperature of 25 ° C. or lower. More preferred. By setting it as said temperature range, in the nip process, the elastic resin material 3 in a molten state can be gradually cooled to reduce the melt strength. The “melt strength” here refers to the tension in the molten state of the elastic resin material. This cooling is preferable because fusion between the elastic resin material and the raised fibers can be suppressed.

The peripheral surfaces of the main roll 86 and the sub roll 87 constituting the nip roll 85 are not limited to a smooth aspect as in this embodiment. The peripheral surface is preferably shaped so that the nip pressure can be appropriately set as described above.
For example, as shown in the cross-sectional view of FIG. This makes it easier to adjust the nip pressure between the main roll 86 and the sub roll 87 than when smooth, suppresses fusion to the sheet base material 5, and favors the number of fusion to the raised fibers 4. Can be controlled. For example, the clearance between the main roll 86 and the sub roll 87 is adjusted so that the nip pressure is brought close to 0 N / cm while applying a conveying force to the laminate of the long fiber nonwoven fabrics 1 and 2 and the elastic resin material 3. Can be performed with higher accuracy. Moreover, since the long fiber nonwoven fabrics 1 and 2 become uneven | corrugated shape along the surrounding surface of the main roll 86 and the subroll 87, as shown in FIG. Therefore, it is possible to accurately fuse the raised fibers 4 and the elastic resin material 3 instead of the sheet base 5. In addition, as shown in FIG. 6, by adjusting the clearance, the long fiber nonwoven fabrics 1 and 2 can be alternately fused with the elastic resin material 3 instead of the same position in the transport direction (MD). Become. Thereby, the non-bonding area | regions 11 and 12 are formed in the long-fiber nonwoven fabrics 1 and 2, and this part becomes a ventilation path and improves the air permeability of the elastic nonwoven fabric sheet 10. FIG. Further, the stretchable nonwoven fabric sheet 10 can be finely wrinkled by the irregular long fiber nonwoven fabrics 1 and 2, whereby the stretchable nonwoven fabric sheet 10 can be softened and thinned.

  In the 2nd process 8, the elongate strip-shaped composite sheet 6 formed by bonding the filament-shaped elastic resin material 3 and the long fiber nonwoven fabrics 1 and 2 as mentioned above is obtained. The composite sheet 6 is peeled from the peripheral surface of the main roll 86 and moves to the third step 9 which is the next step. In this embodiment, the composite sheet 6 is once wound up in a roll shape and then unwound again in the third step 9. However, it is not limited to this form, and after peeling from the peripheral surface of the main roll 86, it may be moved to the third step 9 as it is.

  Next, the third step 9 will be described.

  In the third step 9, as shown in FIG. 7, the elongated strip-shaped composite sheet 6 formed in the second step 8 is stretched by meshing the pair of tooth groove rolls 91 and 92. In addition, this extending process is also called a tooth gap extending process. As the tooth gap extension processing, a method similar to the method described in Patent Document 1 can be used.

  The tooth gap rolls 91 and 92 have a plurality of teeth 91 </ b> A and 92 </ b> A each having a length in the rotation axis direction at equal intervals in the roll circumferential direction. As shown in FIG. 8, the tooth gap rolls 91 and 92 are grooves between the teeth 91A and the teeth 91A, and between the teeth 92A and the teeth 92A, and the teeth of one roll are the grooves of the other roll. It is arranged so as to mesh. That is, the tooth gap roll 91 is such that the teeth 91A of the tooth gap roll 91 are loosely inserted between the teeth 92A of the tooth gap roll 92, and the teeth 92A of the tooth gap roll 92 are loosely inserted between the teeth 91A of the tooth gap roll 91. And the tooth gap roll 92 are combined.

  A pair of infeed rolls 93 and 94 is disposed on the upstream side of the tooth gap rolls 91 and 92. By adjusting the rotation speed V3 of the infeed rolls 93 and 94, the supply speed of the composite sheet 6 between the tooth gap rolls 91 and 92 can be adjusted. Further, a pair of outfeed rolls 95 and 96 are disposed on the downstream side of the tooth gap rolls 91 and 92. By adjusting the rotation speed V4 of the outfeed rolls 95 and 96, the feeding speed from between the tooth gap rolls 91 and 92 of the stretchable nonwoven fabric sheet 10 that is stretched can be adjusted.

Specifically, the tooth gap extending process is performed as follows.
As shown in FIG. 8, when the tooth gap roll 91 is rotated in the direction of the arrow F1 and the tooth gap roll 92 is rotated in the direction of the arrow F2, the teeth 91A and 92A are sequentially engaged with the grooves facing in the circumferential direction. At this time, the tips of the teeth 91 </ b> A and the teeth 92 </ b> A push the composite sheet 6 in directions opposite to each other to partially stretch the composite sheet 6. In particular, the region (93-94) and the region (95-96) have a strong force of deeply entering and extending into the grooves facing the teeth 91A and 92A. In the region (93-94), the depths by which the teeth 91A and the teeth 92A bite into the grooves are gradually increased, and the pushing force against the composite sheet 6 is gradually increased. In the region (95-96), the teeth 91A and the teeth 92A are gradually pulled away from each other groove, and a force for pulling the composite sheet 6 is generated. Thereby, the long strip-shaped composite sheet 6 inserted between the tooth gap rolls 91 and 92 is stretched along the extending direction of the elastic resin material 3.

The elastic resin material 3 is stretched by exhibiting its extensibility in the stretched portion of the composite sheet 6 by the tooth gap stretching process. The long fiber nonwoven fabrics 1 and 2 on the front and back sides follow this, and the raised fibers 4 fused to the elastic resin material 3 are appropriately broken. When the raised fibers 4 are broken, the breakage of the sheet base 5 is suppressed. At this time, even if the elastic resin material 3 is fused not only to the raised fibers 4 but also to the sheet base 5, the linear raised fibers 4 have a lower breaking strength than the planar sheet base 5. Rupture tends to occur preferentially. Therefore, the sheet base portion 5 is difficult to break.
Thereby, in the 3rd process 9, with respect to the composite sheet 6 formed at the 2nd process 8, the perforation of the long-fiber nonwoven fabrics 1 and 2 is suppressed, and the stretchable nonwoven fabric sheet 10 to which the extensibility is given is formed. The Since perforation is suppressed, processing with a high tooth gap stretching ratio is possible, and the stretchable nonwoven fabric sheet 10 that achieves both high extensibility and perforation suppression can be formed.

  As described above, according to the manufacturing method of the present embodiment, it is possible to perform processing in which the fusion strength is controlled and the tooth gap stretching ratio is further increased while suppressing perforation. This is because, in the stretched composite sheet 6, the plurality of raised fibers 4 released from the sheet base 5 form a plurality of fusion points with the elastic resin material 3 independently of each other. That is, since the raised fiber fused to the elastic resin material 3 and a plurality of individual pieces can be used as an adjustment valve for the number of breaks in preference to the sheet base 5, the sheet base 5 can be adjusted while suitably controlling the fusion strength. Enables processing with a high tooth gap extension ratio without damaging.

In the present embodiment, the tooth gap stretching ratio is a value obtained by the following formula (1). L, G, V3 and V5 are as follows.
L: Average gap (mm) between the tooth 91A of the tooth gap roll 91 and the tooth 92A of the tooth gap roll 92
G: Depth of engagement (mm)
V3: In-foot nip rolls 93 and 94 peripheral speed (m / min)
V5: Peripheral speed V5 (m / min) of the tooth gap rolls 91 and 92
The peripheral speed V5 of the tooth gap rolls 91 and 92 is a peripheral speed having a radius at a point where the amount of meshing between the teeth 91A of the tooth groove roll 91 and the teeth 92A of the tooth groove roll 92 is halved. The average gap L is an average value of the gap L1 in the area (93-94) and the gap L2 in the area (95-96).

  The tooth gap stretch ratio defined above can be set higher than the conventional one while suppressing the range of the perforated area ratio described later due to the presence of fusion between the raised fibers 4 and the elastic resin material 3. The stretchable nonwoven fabric sheet 10 thus obtained can be used, for example, in abdomen and back of children's diapers that require high extensibility, or a separate member for making it difficult to see perforations. It can be used alone without pasting.

  Further, according to the manufacturing method of the present embodiment, the raised fiber 4 is maintained in a state in which the raised fiber 4 connects the sheet base 5 and the elastic resin material 3 by leaving the raised fiber 4 that is not broken by controlling the extension ratio of the tooth gap. The stretchable nonwoven fabric sheet 10 can be integrated. By maintaining the integrity, the stretchable nonwoven fabric sheet 10 can follow the long-fiber nonwoven fabrics 1 and 2 when the elastic tree material 3 is shrunk, and can have high stretchability (extensibility and shrinkability). In addition, since the stretchable nonwoven fabric sheet 10 has a reduced number of fusion points with the elastic resin material in the sheet base portion 5, the stretchable nonwoven fabric sheet 10 is more flexible and softer than the conventional one.

  In the manufacturing method of this embodiment, in order to manufacture a stretchable nonwoven fabric sheet 10 that has high extensibility and simultaneously realizes high perforation suppression and ensures sheet strength (integration) during stretching, the tooth gap The draw ratio is preferably 4 times or more, more preferably 5.5 times or more, further preferably 6.5 times or more, more preferably 10 times or less, and more preferably 8 times or less. Thereby, the elastic nonwoven fabric sheet 10 which has the perforated area ratio, the bulk softness value, the maximum elongation, and the 50% return stress value described later can be manufactured.

  As described above, the stretchable nonwoven fabric sheet 10 obtained by the production method of the present embodiment is suppressed from being perforated, excellent in flexibility, and has high extensibility and high shrinkage after elongation.

  The degree of perforation based on the above definition in the obtained stretchable nonwoven fabric sheet 10 is indicated as “perforated area ratio”. Moreover, the softness | flexibility of the elastic nonwoven fabric sheet 10, extensibility, and the high shrinkability after an expansion | extension are each shown as the value of "bulk softness", "maximum elongation", and "50% return stress". These are obtained by the measurement method described later. Bulk softness indicates that the smaller the value, the higher the flexibility. The maximum elongation indicates that the greater the value, the higher the elongation. The larger the value of the 50% return stress, the stronger the return force and the better the shrinkage after elongation.

  According to the manufacturing method of this embodiment, the obtained stretchable sheet 10 has a perforated area ratio of 5% or less, a bulk softness value of 8 cN or less, a maximum elongation of 100% to 500%, and a 50% return. The stress value can be 0.3 N / 25 mm or more and 3 N / 25 mm or less.

  The viewpoint that the area ratio of perforated stretchable nonwoven fabric sheet 10 can be used alone as a stretchable member such as a diaper (such as an abdomen or a backside exterior material) from the viewpoint of good visual quality. Therefore, it is preferably 5% or less, more preferably 4% or less, still more preferably 3% or less. Further, the area ratio of perforations is preferably as small as possible, and is preferably 0 (zero)%. According to the manufacturing method of this embodiment, the elastic nonwoven fabric sheet 10 of said value can be manufactured.

(Measuring method of perforated area ratio of elastic nonwoven fabric sheet 10)
In a state where the stretchable nonwoven fabric sheet 10 is stretched 2.0 times in the longitudinal direction of the elastic resin material, an image is acquired at a magnification of 5 times. Based on the obtained image, the area of a hole having a size of 1 mm ² or more is calculated using image analysis software “ImagePro”. The ratio of the total area of the holes to the area of the entire sheet is the perforated area ratio.

  The bulk softness of the stretchable nonwoven fabric sheet 10 is preferably 8 cN or less, more preferably 6 cN or less, and even more preferably 5 cN or less from the viewpoint of touch. The bulk softness is measured by the following method. According to the manufacturing method of this embodiment, the elastic nonwoven fabric sheet 10 of said value can be manufactured.

(Measurement method of bulk softness of stretchable nonwoven sheet 10)
Under an environment of 22 ° C. and 65% RH, the stretchable nonwoven fabric sheet 10 is cut out by 150 mm in the stretch direction and 30 mm in the width direction (direction orthogonal to the stretch direction), and the end is vertically moved using a stapler in a ring shape of 45 mm in diameter. Stop in two places. At this time, the stapler core is elongated in the expansion and contraction direction. Using a tensile tester (for example, Tensilon tensile tester “RTA-100” manufactured by Orientec Co., Ltd.), the ring is placed in a cylindrical shape on a sample table, and the compression speed is applied from above to a flat plate substantially parallel to the table. The maximum load at the time of compressing at a speed of 10 mm / min is measured to obtain the bulk direction of the bulk direction. Next, a ring is produced by changing the expansion / contraction direction and the width direction, and the bulk softness in the expansion / contraction direction is similarly measured. Two rings are produced and measured for each of the stretch direction and the width direction, and the average value of the width direction and the stretch direction is defined as the bulk degree of the stretchable nonwoven fabric sheet 10.

  Further, the maximum elongation of the stretchable nonwoven fabric sheet 10 is preferably 100% or more, more preferably 150% or more, and still more preferably 200% or more from the viewpoint of facilitating stretching while suppressing the range of the perforated area ratio. . The maximum elongation of the stretchable nonwoven fabric sheet 10 is better, but from the viewpoint of ease of wearing and ease of wearing of the diaper when used in a diaper, 500% or less is preferable, 400% or less is more preferable, and 300% or less is preferable. Further preferred. According to the manufacturing method of this embodiment, the elastic nonwoven fabric sheet 10 of said value can be manufactured.

  In addition, the 50% return stress value of the stretchable nonwoven fabric sheet 10 is 0.3 N / 25 mm or more from the viewpoint of improving the fit of a diaper when used in a diaper while suppressing the range of the perforated area ratio. Preferably, 0.4 N / 25 mm or more is more preferable, and 0.5 N / 25 mm or more is still more preferable. Further, the 50% return stress value of the stretchable nonwoven fabric sheet 10 is preferably 3N / 25mm or less, more preferably 2N / 25mm or less, and more preferably 1N / 25mm from the viewpoint of reducing traces due to tightening of the diaper when used in a diaper. The following is more preferable. According to the manufacturing method of this embodiment, the elastic nonwoven fabric sheet 10 of said value can be manufactured.

(Measurement method of maximum elongation of elastic nonwoven fabric sheet 10)
The elastic nonwoven fabric sheet 10 is subjected to a tensile test with a tensile tester, and the elongation is obtained when the tensile load is 600 cN / 50 mm.

(Measurement method of 50% return stress value of elastic nonwoven fabric sheet 10)
The elastic nonwoven fabric sheet 10 is subjected to a cycle test with a tensile tester, and the stress value at the time of 50% elongation after returning 100% is measured.

  The stretchable nonwoven fabric sheet 10 preferably has the above-mentioned characteristics, and the raised fibers 4 are preferably present as a layer between the sheet bases 5 and 5 of the long-fiber nonwoven fabrics 1 and 2 from the viewpoint of higher extensibility. In the stretchable nonwoven fabric sheet 10 produced by the production method of the present embodiment, the raised fiber 4 fused to the elastic resin material 3 and the raised fiber 4 not fused by the compressive force of tooth gap stretching are both The surface of the sheet base 5 is crushed. Even in such a case, if the raised fibers 4 are present as a layer between the sheet base materials 5 and 5, the raised fibers 4 are easily movable and can easily follow the fusion of the elastic resin material 3 that has been fused. The extensibility as the nonwoven fabric sheet 10 further increases.

  Next, the member used for the manufacturing method of this invention is demonstrated.

  Various materials can be used as the raw long fiber nonwoven fabric 19 without any particular limitation. For example, a spunbond nonwoven fabric, a laminated nonwoven fabric of a spunbond layer and a meltblown layer can be used, or a nonwoven fabric composed of continuous long fibers in a tow state can be used. A spunbonded nonwoven fabric is preferred from the viewpoint of being inexpensive, having high breaking strength, excellent processing suitability, and being thin and contributing to slimming of the absorbent article. In the case of the above laminated nonwoven fabric, the nonwoven fabric is preferably a nonwoven fabric in which a spunbond layer is disposed on one or both surfaces of the meltblown layer.

The raw long-fiber nonwoven fabric 19 is inexpensive and has a good touch feeling, and from the viewpoint of processing suitability, the basis weight is preferably 10 g / m ² or more, and is 100 g / m ² or less. Is preferable, and it is still more preferable that it is 25 g / m < ² > or less. The bundle fusion part for bundling long fibers that the raw material long fiber nonwoven fabric 19 has, for example, those formed intermittently by thermocompression bonding with an embossed convex roll and a flat roll, or those formed by ultrasonic fusion, Examples include those formed by intermittently applying hot air and partially fusing. Among these, those formed by thermocompression bonding are preferable in that they are easily raised.

  The raw material long-fiber nonwoven fabric 19 (for example, spunbond nonwoven fabric) is superior in terms of breaking strength as compared to an air-through nonwoven fabric using short fibers, but is inferior to the air-through nonwoven fabric in terms of touch. However, according to the production method of the present invention, it is possible to provide a stretchable nonwoven fabric sheet having a soft touch using the raw long fiber nonwoven fabric 19. Further, as described above, according to the production method of the present invention, the stretchable nonwoven fabric sheet 10 having high extensibility and suppressing perforation can be provided. Thereby, the obtained stretchable nonwoven fabric sheet 10 has an excellent texture such as elasticity and flexibility in addition to extensibility, strength and appearance suitable for abdominal and backside exterior materials such as diapers. Become.

  In the case of using a spunbond nonwoven fabric, the constituent fibers constituting the spunbond nonwoven fabric are made of a thermoplastic resin. The thermoplastic resin includes polyolefin resin, polyester resin, polyamide resin, acrylonitrile resin, vinyl resin, vinylidene. Based resins and the like. Examples of the polyolefin resin include polyethylene, polypropylene, and polybuden. Examples of the polyester resin include polyethylene terephthalate and polybutylene terephthalate. Nylon etc. are mentioned as a polyamide-type resin. Examples of the vinyl resin include polyvinyl chloride. Examples of the vinylidene resin include polyvinylidene chloride. Modified products and mixtures of these various resins can also be used.

  The raw long fiber nonwoven fabric 19 may be non-extensible or may be extensible. From the viewpoint of enhancing the extensibility of the resulting stretchable nonwoven fabric sheet 10, the raw long fiber nonwoven fabric 19 preferably has extensibility.

  As the elastic resin material 3, a material having elasticity and capable of being fused with the raised fibers 4 of the long-fiber nonwoven fabrics 1 and 2 can be used without particular limitation. For example, a thermoplastic elastomer can be used. Examples of the thermoplastic elastomer include styrene elastomers such as SBS (styrene-butadiene-styrene), SIS (styrene-isoprene-styrene), SEBS (styrene-ethylene-butadiene-styrene), SEPS (styrene-ethylene-propylene-styrene). And olefin elastomers (ethylene-based α-olefin elastomers, propylene-based elastomers copolymerized with ethylene / butene / octene), polyester-based elastomers, and polyurethane-based elastomers.

  As the release agent applied to the surfaces of the long-fiber nonwoven fabrics 1 and 2 having the raised fibers 4, those usually used in this type of article such as silicone resin, fluorine resin, or octadecyl isocyanate may be adopted. it can.

  The stretchable nonwoven fabric sheet according to the present invention can be used for various applications that require stretchability. For example, it can be used as a constituent member of absorbent articles such as the disposable diapers, sanitary napkins, panty liners, incontinence pads, urine pads, etc. described above.

  Hereinafter, the present invention will be described in more detail based on examples. The present invention is not construed as being limited by these examples. In the examples, “part” and “%” indicating the composition are based on mass unless otherwise specified.

Example 1
The manufacturing method of the elastic nonwoven fabric sheet using the apparatus shown in FIGS. 2, 4 and 7 was carried out under the following conditions. A stretchable nonwoven fabric sheet sample S1 of Example 2 was produced from the stretchable nonwoven fabric sheet thus obtained.
As the raw material long fiber nonwoven fabric 19, a spunbond nonwoven fabric having a basis weight of 18 g / m ² was used. As the elastic resin constituting the elastic resin material 3, SEPS resin was used. The elastic resin material 3 had a diameter of 0.1 mm in a fiber (filament) shape after spinning, stretching and cooling.
(1) In the first step 7, a partial stretching process 71 and a raised process 72 were performed. The amount of raising of the obtained long fiber nonwoven fabrics 1 and 2 was 8 / cm.
In the partial stretching process 71, the convex portions 74A of the concave-convex roll 74 had a height of 4.2 mm, a rotation axis direction pitch of 8.3 mm, and a circumferential direction pitch of 8.3 mm. The depth of engagement between the convex portion 74A of the roll 74 and the concave portion 75B of the roll 75 was 4 mm.
In the raising process 72, the circumferential speed of the raising roll 77 was set to 10 times in the opposite direction to the conveying speed of the raw long-fiber nonwoven fabric 19. The raising roll 77 was made of an aluminum alloy and subjected to sandblasting with alumina particles (abrasive particles). The protruding region 78 of the raised roll 77 has an arithmetic average roughness (Ra 12.7 μm, maximum roughness (Rt) 125.8 μm, and maximum height (Rz) 87 μm. The raw material long fiber nonwoven fabric 19 to be raised is the raised roll 77. The holding angle α in contact with was set to 60 °.
(2) In the second step 8, the diameter of the spinning nozzle 82 was 0.4 mm and the pitch was 1 mm. The first nip 85A has a clearance of 0.6 mm, the nip pressure is 35 N / cm, the second nip 85B has no clearance, is solid (the rubber roll is crushed), and the nip pressure is 18 N / cm. In the first nip 85B and the second nip 85B, the surface temperature of the main roll 86 and the sub roll 87 was 25 ° C.
(3) In the third step 9, the tooth gap stretching ratio was set to 4 times. The average gap L between the teeth 91A of the tooth space roll 91 and the teeth 92A of the tooth space roll 92 was 0.5 mm. The pitch P between the teeth 91A of the tooth gap roll 91 and the pitch P between the teeth 92A of the tooth gap roll 92 were 2 mm.

(Example 2)
In the raising process 72 in the first step 7, the circumferential speed of the raising roll 77 was set to 20 times the conveying speed of the raw long-fiber nonwoven fabric 19 and the raising amount was 23 / cm, as in Example 1. The manufacturing method of the elastic nonwoven fabric sheet was implemented. A stretchable nonwoven fabric sheet sample S1 of Example 2 was produced from the stretchable nonwoven fabric sheet thus obtained.

(Example 3)
A method for producing a stretchable nonwoven fabric sheet was carried out in the same manner as in Example 2 except that the nip pressure of the first nip in the second step 8 was 35 N / cm and the nip pressure of the second nip was 10 N / cm. A stretchable nonwoven fabric sheet sample S1 of Example 2 was produced from the stretchable nonwoven fabric sheet thus obtained.

(Comparative example)
The manufacturing method of the elastic nonwoven fabric sheet was implemented by performing the process similar to the 2nd process 8 and the 3rd process 9 in Example 1, without performing the process of forming the raising fiber of the 1st process 7. The elastic nonwoven fabric sheet sample C1 of the comparative example was produced from the elastic nonwoven fabric sheet obtained by this.

  The following tests were performed on the samples prepared in Examples 1 to 3 and Comparative Example 1. The following tests were performed with each sample having a size of (1) 10 cm × 25 cm, (2) 25 mm × 150 mm, and (3) 15 cm × 30 cm.

(1) Perforated area ratio The test was performed based on the above-mentioned (Measurement method of perforated area ratio of stretchable nonwoven fabric sheet 10).

(2) Bulk softness The test was performed based on the above-mentioned (Method for measuring bulk softness of stretchable nonwoven fabric sheet 10).

(3) Texture The sensory evaluation was performed by five monitors (adult women). Under an environment of 25 ° C. and humidity of 40%, in a dark box where the sheet sample was not visible, the monitor was touched with the composite sheet, and the texture (stiffness and suppleness) was evaluated according to the following criteria. The average score (rounded to the nearest decimal point) of five monitors was used as the texture evaluation score.
5 points: good texture 4 points: slightly good texture 3 points: normal 2 points: slightly bad texture 1 point: poor texture

  The test results of (1) to (3) were as shown in Table 1 below.

As shown in Table 1, in the comparative example, since the step of forming the raised fiber in the first step 7 was not performed, the hole perforation exceeded 8.0% and 5% by the subsequent four-fold drawing treatment. . Therefore, the stretchable nonwoven fabric sheet obtained in the comparative example is a single body and cannot be used, for example, as a member around the stomach or back of a diaper.
On the other hand, in Examples 1-3, since the elastic nonwoven fabric sheet was manufactured through the process of forming the raised fiber of the 1st process 7, even if a 4 times extending | stretching process is performed, perforation is 5%. It was suppressed to the following. At the same time, Examples 1 to 3 all showed the same performance as the comparative example with respect to the maximum elongation showing stretchability and the 50% return stress value. Therefore, the stretchable nonwoven fabric sheets obtained in Examples 1 to 3 had an appearance that can be used alone as a member around the stomach or back of the diaper. As for perforation suppression, as a conventional method, there is also a means for suppressing fusion with the nonwoven fabric by lowering the basis weight of the elastic resin (lowering the amount of heat of the elastic resin). However, as shown in Examples 1 to 3, it was found that the manufacturing method of the present invention can suppress perforation while maintaining the basis weight of the elastic resin (maintaining the return stress value).
In addition, the stretchable nonwoven fabric sheets obtained in Examples 1 to 3 had a high softness because the bulk softness value was suppressed to 68% or less of that of the comparative example. Similarly, the stretchable nonwoven fabric sheets obtained in Examples 1 to 3 were provided with a texture (stiffness and suppleness) superior to that of the comparative example.

DESCRIPTION OF SYMBOLS 1, 2 Long-fiber nonwoven fabric 19 Raw material long-fiber nonwoven fabric 3 Elastic resin material 4 Brushed fiber 5 Sheet base part 6 Composite sheet 7 1st process 71 Partial extending | stretching process 72 Brushed process 74,75 Concavity and convexity roll 77 Raised roll (partially raised roll)
78 Projection region on the circumferential surface of the raised roll 79 Smooth region on the circumferential surface of the raised roll 8 Second step 81 Spinning head 82 Spinning nozzle 85 Nip roll 85A First nip 85B Second nip 86 Main roll 87 Sub roll 9 Third step 91 92 tooth gap roll 91A, 92A tooth

Claims (8)

Forming brushed fibers on the surface of the long fiber nonwoven fabric;
Passing the long fiber nonwoven fabric and the elastic resin material extruded in a molten state through a nip roll, fusing the raised fibers of the long fiber nonwoven fabric and the elastic resin material, and forming a composite sheet;
A method for producing a stretchable nonwoven fabric sheet, comprising: stretching the composite sheet.   The method for producing a stretchable nonwoven fabric sheet according to claim 1, wherein a nip pressure of the nip roll is 0 N / cm or more and 150 N / cm or less.   The manufacturing method of the elastic nonwoven fabric sheet of Claim 1 or 2 with which the said nip roll is 10 to 30 degreeC. The manufacturing method of the elastic nonwoven fabric sheet of any one of Claims 1-3 by which the surrounding surface of the said nip roll is made uneven | corrugated shape.   The expansion and contraction according to any one of claims 1 to 4, further comprising a step of applying a release agent to the surface on which the raised fibers are formed before the step of forming the composite sheet after the step of forming the raised fibers. For producing a conductive nonwoven sheet.   The method for producing a stretchable nonwoven fabric sheet according to any one of claims 1 to 5, wherein the step of forming the raised fiber includes a partial stretching process and a raised process. An elastic nonwoven material sheet in which an elastic resin material is disposed and bonded between a pair of long fiber nonwoven fabrics,
Elastic nonwoven fabric having a perforated area ratio of 5% or less, a bulk softness value of 8 cN or less, a maximum elongation of 100% to 500%, and a 50% return stress value of 0.3 N / 25 mm to 3 N / 25 mm Sheet.   The stretchable nonwoven fabric sheet according to claim 7, wherein the surface of the base sheet on which the elastic resin material is disposed has raised fibers.

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