Method for producing flexible sheet

0001The present invention relates to a method for producing a flexible sheet.

0002Conventionally, a processing means having a pair of rolls provided on the peripheral surface so that tooth grooves that mesh with each other are provided along the rotation axis direction is used, and the rolls are rotated to supply a sheet such as a non-woven fabric to the meshing portions. Therefore, various techniques for processing the sheet have been proposed. For example, Patent Document 1 proposes a technique for stretching a sheet such as a non-woven fabric by adjusting the degree of meshing of tooth grooves (gears).

0003However, when the stretching process is performed by passing a sheet between a pair of rolls having a tooth groove as in the stretching technique described in Patent Document 1, if the depth of the tooth groove is deepened, the processing having a high stretching ratio can be performed. However, on the other hand, there is a problem that the strength of the sheet as a whole tends to decrease.

0004Further, in Patent Document 2, in addition to adjusting the degree of engagement of the tooth groove (gear), a sheet such as a non-woven fabric is previously stretched by a stretching roll before stretching by the tooth groove (gear) to perform processing with a high stretching ratio. Techniques to apply have been proposed.

0005However, in the stretching technique described in Patent Document 2, the rotation speed of the pair of rolls having tooth grooves is set to be faster than the rotation speed of the stretching rolls located on the upstream side of the pair of rolls, so that the non-woven fabric or the like is used. Tension in the flow direction is applied to the sheet, and the width of the sheet such as non-woven fabric shrinks before stretching by the tooth groove (gear). Further, since the rotation speed of the pair of rolls having the tooth groove is high, the depth of the tooth groove cannot be set deeply, and the stretching technique described in Patent Document 2 improves the feel of the obtained elastic sheet. It's difficult.

<p num="0006"><patcit num="1"><text>Japanese Unexamined Patent Publication No. 2003-73967</text></patcit><patcit num="2"><text>Japanese Unexamined Patent Publication No. 2008-156785</text></patcit></p>

<p num="0007"> Therefore, an object of the present invention is to provide a method for producing a flexible sheet in which the width of the sheet is not easily shrunk, the sheet has high flexibility, and the sheet is excellent in touch.</p>

<p num="0008"> In the present invention, a base material sheet is supplied from a pair of first drive rolls to a meshing portion of a pair of tooth groove rolls that mesh with each other, and the base material sheet is stretched in the flow direction between the pair of tooth groove rolls. A method for manufacturing a flexible sheet including a stretching step, wherein the relationship between the peripheral speed V1 of the first drive roll and the peripheral speed V2 of the tooth groove roll is V1&gt; V2. It is to provide.</p>

<p num="0009"> According to the method for producing a flexible sheet of the present invention, it is possible to produce a sheet in which the width of the sheet does not shrink easily, the sheet has high flexibility, and is excellent in touch.</p>

0010<figref num="1">FIG. 1 is a diagram schematically showing an embodiment of a sheet processing means used in the sheet manufacturing method of the present invention and a sheet manufacturing process using the embodiment.</figref><figref num="2">FIG. 2 is a partially enlarged view of a pair of rolls in the processing means shown in FIG.</figref><figref num="3">FIG. 3 is a diagram schematically showing a state in which the base sheet is stretched between a pair of rolls in the processing means shown in FIG. 1.</figref>

0011Hereinafter, the method for producing a flexible sheet of the present invention will be described based on the preferred embodiment thereof with reference to the drawings. 1 to 3 schematically show an embodiment of a processing means (hereinafter, also simply referred to as a processing means) used in the method for producing a flexible sheet of the present invention.

0012As shown in FIG. 1, the processing means 1 of the present embodiment includes a pair of tooth groove rolls 2 and 3 provided on the peripheral surface so that the tooth grooves that mesh with each other are along the direction of the rotation axis, and the tooth groove rolls are provided. When a few are rotated, the base sheet 10 supplied to those meshing portions is stretched in the flow direction to impart flexibility. In the processing means 1 of the present embodiment, the tooth groove rolls 2 and 3 are composed of rolls of the same form. The fact that the tooth grooves that mesh with each other on the tooth groove rolls 2 and 3 are provided on the peripheral surface along the direction of the rotation axis means that the rotation axes of the tooth groove rolls 2 and 3 and the teeth 20 are provided as shown in FIG. The direction in which 30 extends on the tooth groove rolls 2 and 3 is provided on the peripheral surface so as to be parallel to each other, and a groove is formed between the tooth 20 and the tooth 20 or between the tooth 30 and the tooth 30, and the meshing portion. Means that the teeth of the tooth groove rolls are provided so as to mesh with each other's grooves.

0013The tooth groove rolls 2 and 3 have an improving effect such as high flexibility on the base sheet 10, and the base sheet 10 is stretched to a stretching ratio of 1.1 to 5.0 times from the viewpoint of maintaining the strength of the base sheet 11 after stretching. It is preferable to process it, and it is more preferable to stretch it 1.5 to 3.0 times. The draw ratio of the stretching process is calculated by the following mathematical formula 1 from the pitch P between the adjacent teeth 20 and 30 and the meshing depth D of the teeth 20 and 30 of the tooth groove rolls 2 and 3 shown in FIG.

0014<maths num="1"><img id="000002" he="16" wi="159" file="JP5268854B2_D0001.tif" img-format="tif" img-content="drawing" /></maths>

0015In order to keep the draw ratio within the above range, as shown in FIG. 2, the pitch P between the adjacent teeth 20 and 30 in the tooth groove rolls 2 and 3 is preferably 1.0 mm to 5.0 mm, and each tooth 20 and 30 It is preferable that the width T1 at the root of the tooth is less than 0.5 times the pitch and the heights H of the teeth 20 and 30 are equal to or larger than the pitch of the adjacent teeth. Here, the pitch P between adjacent teeth in the tooth groove roll means the distance between the center line of one tooth and the center line of adjacent teeth. The tooth width of the tooth groove roll means the width of one tooth. The width of the tooth is not uniform, and it may be a trapezoidal tooth that narrows from the root of the tooth toward the tip of the tooth. Width at the root The tooth height of the tooth groove roll is the length from the root to the tip of the tooth.

0016The pitch P between adjacent teeth in each of the tooth groove rolls 2 and 3 is more preferably 1.5 to 3.5 mm and particularly preferably 2.0 to 3.0 mm in consideration of uniform elongation. In addition, the width T1 at the root of the tooth in each tooth groove roll 2 or 3 is preferably 0.25 times or more and less than 0.5 times, and 0.3 times or more and 0.4 times or less the pitch P between the teeth in consideration of the strength of the tooth. More preferred. Further, the tooth height H of each tooth groove roll is preferably 1.0 to 2.0 times or more, preferably 1.25 times or more of the tooth pitch P, in consideration of increasing the draw ratio in order to give flexibility to the material. ~ 1.75 times or less is more preferable. In the case of a trapezoidal tooth, the width T1 at the root of the tooth in each of the tooth groove rolls 2 and 3 is preferably in the above range, and the width T2 at the tip of the tooth in each of the tooth groove rolls 2 and 3 is Considering the strength of the teeth, the pitch P between the teeth is preferably 0.2 times or more and 0.45 times or less.

0017In addition, as shown in FIG. 2, the corners of the tips of the teeth 20 and 30 in the tooth groove rolls 2 and 3 should be chamfered so that the base sheet 10 is not damaged at the corners. preferable. The radius of curvature of the chamfer is preferably 0.1 to 0.3 mm. The values of the widths T2 of the tooth groove rolls 2 and 3 described above are the values before chamfering.

0018The meshing depth D of the teeth 20, 30 of the tooth groove rolls 2 and 3 shown in FIG. 2 is preferably 1.0 mm or more, preferably 2.0 mm or more, when the pitch P is in the above range, considering that it gives excellent flexibility to the material. More preferably mm or more. From the same viewpoint, the meshing depth D is preferably equal to or greater than the tooth pitch P. Here, the tooth meshing depth D means the overlapping length of the adjacent teeth 20, 30 when the tooth groove rolls 2 and 3 are meshed and rotated.

0019The tooth groove rolls 2 and 3 rotate in a so-called rotating state in which they mesh with each other and rotate by transmitting a driving force from a driving means (not shown) to one of the rotating shafts. In addition to the teeth 20 and 30, a general gear specified in JIS B 1701 may be attached to each shaft of the tooth groove rolls 2 and 3 as a gear for drive transmission. As a result, the teeth 20 and 30 of the tooth groove rolls 2 and 3 do not mesh with each other, but the gears mesh with each other to transmit the drive to the tooth groove rolls 2 and 3 to rotate the tooth groove rolls 2 and 3. Can be done. In this case, the teeth 20 and 30 of the tooth groove rolls 2 and 3 do not come into contact with each other.

0020In the present embodiment, as shown in FIG. 1, the feeding roll 41, which feeds out the base sheet 10 to which the original fabric (base sheet roll) of the base sheet 10 is attached, is located on the upstream side of the tooth groove rolls 2 and 3. , On the transport path between the pair of first drive rolls 42,43 arranged between the feeding rolls 41 and the tooth groove rolls 2, 3 and the tooth groove rolls 2, 3 and the first drive rolls 42, 43. It is provided with a tension detector (not shown) arranged in the above and a control unit (not shown) that controls the peripheral speed V1 of the first drive rolls 42 and 43 based on the detection output of the tension detector. Based on the detection output of the tension detector, the peripheral speeds V1 of the first drive rolls 42 and 43 are adjusted to a predetermined speed with respect to the peripheral speeds V2 of the tooth groove rolls 2 and 3 in a state where they are meshed with each other, and the base sheet 10 Is given the desired tension. As a specific control method by the control unit, when a tension larger than the desired tension is detected, the peripheral speed V1 of the first drive rolls 42 and 43 is slightly increased from the peripheral speed V2 of the tooth groove rolls 2 and 3. To reduce the tension in this section and adjust it to approach the desired tension. On the other hand, when a tension smaller than the desired tension is detected, the tension in this section is increased by slightly reducing the peripheral speed V1 of the first drive rolls 42 and 43 from the peripheral speed V2 of the tooth groove rolls 2 and 3, and the desired tension is increased. Adjust to approach the tension of.

0021It is also possible to adjust the peripheral speed V1 of the first drive rolls 42 and 43 to a predetermined speed with respect to the feeding speed V4 of the base sheet 10 fed from the feeding roll 41 to apply a desired tension to the base sheet 10. it can.

0022In the present embodiment, as shown in FIG. 1, the base sheet 11 stretched between the tooth groove rolls 2 and 3 is pulled out from the tooth groove rolls 2 and 3 on the downstream side of the tooth groove rolls 2 and 3. A pair of second drive rolls 51, 52 to be conveyed to the next step, and a tension detector (not shown) arranged on the transfer path between the second drive rolls 51, 52 and the tooth groove rolls 2 and 3. A control unit (not shown) that controls the peripheral speed of the second drive rolls 51 and 52 based on the detection output of the tension detector is provided, and the second drive roll 51 is provided based on the detection output of the tension detector. The peripheral speed V3 of 52 is adjusted to a predetermined speed with respect to the peripheral speed V2 of the tooth groove rolls 2 and 3, and the stretched base sheet 11 is pulled out from the tooth groove rolls 2 and 3 and desired for the base sheet 11. Tension is applied. As a specific control method by the control unit, when a tension larger than the desired tension is detected, the peripheral speed V3 of the second drive rolls 51 and 52 is slightly reduced from the peripheral speed V2 of the tooth groove rolls 2 and 3. By reducing the tension in this section, the tension is adjusted to approach the desired tension. On the other hand, when a tension smaller than the desired tension is detected, the tension in this section is increased by slightly increasing the peripheral speed V3 of the second drive rolls 51 and 52 from the peripheral speed V2 of the tooth groove rolls 2 and 3. , Adjust to approach the desired tension.

0023Here, the peripheral speed V1 of the first drive rolls 42, 43 is the speed on the surface of each roll 42, 43, and the feeding speed V4 of the base sheet 10 fed from the feeding roll 41 is fed out. It is the speed on the surface of the base sheet 10. Further, the peripheral speed V3 of the second drive rolls 51 and 52 is the speed on the surface of each roll 51 and 52, similarly to the peripheral speed V1 of the first drive rolls 42 and 43. The peripheral speed V2 of the tooth groove rolls 2 and 3 is not the tip of the teeth 20 and 30, but as shown in FIG. 2, inward from the tip of the teeth 20 and 30 to half of the meshing depth D of the teeth 20 and 30. It is the velocity at the entered position D1 (half the length of overlapping adjacent teeth).

0024The processing means 1 includes a control means (not shown), and the control means detects the tension by the drive means and the tension detector, and the feeding roll 41, the first drive rolls 42, 43, and the teeth based on the control means. The speed control of each of the groove rolls 2, 3 and the second drive rolls 51, 52 is controlled according to a predetermined operation sequence.

0025Next, one embodiment of the method for producing a flexible sheet of the present invention will be described based on the method for producing a flexible sheet in which the base sheet is subjected to flexible processing using the processing means 1.

0026In the method for manufacturing a flexible sheet of the present invention, as shown in FIG. 1, the base sheet 10 is supplied from the base sheet rolls between the pair of first drive rolls 42 and 43, and the pair of first drive rolls 42 , 43 is provided with a stretching step of supplying the base sheet 10 to the meshing portion of the pair of tooth groove rolls 2 and 3 and stretching the base sheet 10 between the pair of tooth groove rolls 2 and 3 in the flow direction. are doing. Further, in the present embodiment, the stretched base sheet 11 is supplied between the pair of second drive rolls 51 and 52, and the flow thereof flows to the base sheet 10 between the pair of second drive rolls 51 and 52. It is provided with a pull-out process of pulling out from between a pair of tooth groove rolls 2 and 3 while applying tension in the direction. Hereinafter, the stretching step and the drawing step will be described.

0027In the pre-process of the stretching step, the base sheet 10 is supplied from the feeding roll 41 to the first driving rolls 42 and 43. In the present embodiment, the peripheral speed V1 of the first driving rolls 42 and 43 for supplying the base material sheet 10 and the feeding speed V4 of the base material sheet 10 are constant speeds (V1 = V4). In the stretching step, as shown in FIGS. 1 and 3, the base sheet 10 is formed from the pair of first drive rolls 42 and 43, and the meshing portions thereof are rotated while rotating the pair of tooth groove rolls 2 and 3 in the processing means 1. The base sheet 10 is stretched in the flow direction. By making the peripheral speed V1 of the first drive rolls 42 and 43 higher than the peripheral speed V2 of the tooth groove rolls 2 and 3, the width of the base sheet 10 is reduced before being supplied to the tooth groove rolls 2 and 3. The tensioned base sheet 10 can be supplied to the meshing portions of the tooth groove rolls 2 and 3 so as not to be present. By making the peripheral speed V1 of the first drive rolls 42 and 43 faster than the peripheral speed V2 of the tooth groove rolls 2 and 3 (V1&gt; V2), in other words, the peripheral speed V2 of the tooth groove rolls 2 and 3 is set to the first. By making the peripheral speeds of the drive rolls 42 and 43 lower than the peripheral speed V1, the tension is not applied to the tensioned base sheet 10 more than necessary, so that the meshing depths of the teeth 20 and 30 of the tooth groove rolls 2 and 3 D Can be set deeply as described above. From this point of view, the ratio of the peripheral speed V2 of the tooth groove rolls 2 and 3 to the peripheral speed V1 of the first drive rolls 42 and 43 [(V2 / V1) × 100] is 60% to 90%. It is preferably 70% to 85%, more preferably 70% to 80%. In the stretching step, the peripheral speed V2 of the tooth groove rolls 2 and 3 is made lower than the peripheral speed V1 of the first drive rolls 42 and 43, but the meshing depth of the teeth 20 and 30 of the tooth groove rolls 2 and 3 is set. Since D is deep as described above, the base sheet 10 can be supplied to the tooth groove rolls 2 and 3 without causing slack. The tension applied is preferably 10% or more and 50% or less, and more preferably 10% or more and 40% or less of the breaking load of the base sheet 10. The tension applied to the base sheet 10 is, for example, when the breaking load of the base sheet 10 is about 60 N per 100 mm width, the tension applied before the stretching process is preferably 6 to 30 N per 100 mm width, preferably per 100 mm width. 6 to 24N is more preferable. This is because when the tension is small, the stretchability may not be sufficiently exhibited even if the stretching process is performed, and conversely, when the tension is large, the material is stretched and the width shrinks in this section, which is desired after the stretching process. This is because the seat width may not be obtained.

0028In the drawing step, while rotating the pair of second drive rolls 51 and 52 in the processing means 1, the base sheet 11 stretched between the tooth groove rolls 2 and 3 is supplied between them, and the base sheet 11 is supplied. Pull out from between the pair of tooth groove rolls 2 and 3 while applying tension in the flow direction of the base sheet 11. Specifically, the peripheral speed V3 of the second drive rolls 51 and 52 can be made faster than the peripheral speed V2 of the tooth groove rolls 2 and 3 (V3&gt; V2), and a desired tension can be applied to the base sheet 11. preferable. Tension is applied to the base sheet 11 by the peripheral speed difference ΔV (= V3-V2) between the peripheral speed V3 of the second drive rolls 51 and 52 and the peripheral speed V2 of the tooth groove rolls 2 and 3. From the viewpoint of pulling out the base sheet 11 from between the pair of tooth groove rolls 2 and 3 while applying tension to the base sheet 11, the peripheral speed V2 of the tooth groove rolls 2 and 3 with respect to the peripheral speed V3 of the second drive rolls 51 and 52. The ratio [(V2 / V3) × 100] is preferably 10% to 90%, more preferably 30% to 70%, and even more preferably 30% to 50%. Further, it is preferable that the peripheral speed V3 of the second drive rolls 51 and 52 is set higher than the peripheral speed V1 of the first drive rolls 42 and 43 (V3&gt; V1). The ratio of the peripheral speed V1 of the first drive rolls 42 and 43 to the peripheral speed V3 of the second drive rolls 51 and 52 [(V1 / V3) × 100] is preferably 30% to 80%, preferably 40% to 40%. It is more preferably 60%. The tension applied is preferably 5% or more and 50% or less, and more preferably 5% or more and 20% or less of the breaking load of the base sheet 11 after the stretching process.

0029As described above, when the base sheet 11 is transported after the stretching step, the breaking load of the base sheet 11 after the stretching process can be used as a reference in consideration of the strength reduced by the upstream stretching. It is preferable from the viewpoint of preventing breakage of the base sheet 11 after the process. That is, it is preferable that the tension when supplying the first drive rolls 42 and 43 on the upstream side of the stretching step is smaller than the tension when supplying the second drive rolls 51 and 52 on the downstream side of the stretching step.

0030The base sheet 10 to be processed is not particularly limited, and examples thereof include paper, a single-layer non-woven fabric, a resin film, a laminate of two or more types of non-woven fabric, a laminate of a resin film and a non-woven fabric, and the like. Examples thereof include thermoplastic polymer non-woven fabrics of polypropylene fibers, fibers composed of a composition of polypropylene and polyethylene, and polyolefin fibers selected from bicomponent fibers of polypropylene and polyethylene. Further, a non-woven fabric containing elastic fibers is preferable from the viewpoint of imparting flexibility to the base sheet 10 by stretching by the processing means 1 and further imparting elasticity. As the non-woven fabric containing elastic fibers, an inelastic fiber layer composed of substantially inelastic fibers is arranged on at least one surface of the elastic fiber layer containing the elastic fibers, and both fiber layers are constituent fibers of the elastic fiber layer. Stretchable non-woven fabrics (hereinafter referred to as stretchable composite non-woven fabrics) joined by heat fusion while maintaining the fiber morphology, and a large number of elastic filaments arranged so as to extend in one direction without intersecting each other. Examples thereof include stretchable non-woven fabrics that are bonded to stretchable non-woven fabrics over their entire length in a substantially non-stretchable state.

0031As the elastic fiber, a fiber made from an elastic resin such as a styrene elastomer, a polyolefin elastomer, a thermoplastic elastomer such as a polyester elastomer or a polyurethane elastomer, or a rubber is used. Further, as the inelastic fiber, a fiber made of polyethylene (PE), polypropylene (PP), polyester (PET or PBT), polyamide or the like is used.

0032As the stretchable composite non-woven fabric, various known ones can be used. For example, the stretchable sheet described in JP-A-2008-179128, the stretchable sheet described in JP-A-2007-22066, and JP-A-2007- A stretchable nonwoven fabric manufactured by the method for producing a stretchable nonwoven fabric described in Japanese Patent No. 22066, Japanese Patent No. 3054930, and the like can also be used.

0033As described above, according to the method for manufacturing a flexible sheet of the present embodiment in which the base sheet is flexibly processed by using the processing means 1, the peripheral speed V1 of the first drive rolls 42 and 43 is set to the tooth groove roll 2. By making the peripheral speed V2 of the tooth groove rolls 2 and 3 faster than the peripheral speed V2 of the first drive rolls 42 and 43 (V1&gt; V2), in other words, by making the peripheral speed V2 of the tooth groove rolls 2 and 3 lower than the peripheral speed V1 of the first drive rolls 42 and 43. Since the tensioned base sheet is not unnecessarily tensioned, the width W1 of the base sheet 10 immediately before being supplied to the tooth groove rolls 2 and 3 is unlikely to be unnecessarily narrowed, and the beginning of the base sheet 10 The ratio of the width W2 of the flexible sheet after processing to the width W0 [(W2 / W0) × 100] can be 80% or more (see Fig. 1). As described above, since there is almost no loss due to width shrinkage from the initial width of the base sheet 10, economic efficiency is improved.

0034Further, according to the method for manufacturing a flexible sheet of the present embodiment, tension is applied by making the peripheral speed V2 of the tooth groove rolls 2 and 3 lower than the peripheral speed V1 of the first drive rolls 42 and 43. Since the tension applied to the base sheet can be lowered, tearing, damage, and strength reduction are less likely to occur in the tooth groove rolls 2 and 3 in the stretching process, and the meshing depth of the teeth 20 and 30 of the tooth groove rolls 2 and 3 is low. D can be set deeply. Therefore, the flexible sheet obtained by the method for producing a flexible sheet of the present embodiment has high cushioning property, improves flexibility, and improves touch.

0035The manufacturing method of the flexible sheet of the present invention is not limited to the manufacturing method of the above-described embodiment, and can be appropriately changed.

0036For example, as shown in FIG. 1, the processing means 1 used in the method for manufacturing the flexible sheet of the present embodiment described above is provided with a pair of tooth groove rolls 2 and 3 in the stretching step, but the base sheet 10 By providing a plurality of pairs in series in the flow direction and repeatedly performing the stretching step on the base sheet 10, it is possible to impart even higher flexibility to the base sheet 10.

0037Further, in the method for manufacturing the flexible sheet of the present embodiment described above, the peripheral speed V1 of the first driving rolls 42 and 43 for supplying the base sheet 10 and the feeding speed V4 of the base sheet 10 are constant speeds ( Although V1 = V4), the peripheral speed V1 of the first drive rolls 42 and 43 is made faster than the feeding speed V4 of the base sheet 10, and the base sheet 10 is pre-stretched before the stretching process of the next work. May be good. That is, the base sheet 10 is pre-stretched by the peripheral speed difference ΔV (= V1-V4) between the peripheral speeds V1 of the first drive rolls 42 and 43 and the feeding speed V4 of the base material sheet 10. The ratio of the feeding speed V4 of the base sheet 10 to the peripheral speed V1 of the first driving rolls 42 and 43 [(V4 / V1) × 100] is preferably 80% to 100%, preferably 90% to 98%. It is more preferable to have. The tension applied is preferably 10% or more and 50% or less, and more preferably 10% or more and 20% or less of the breaking load of the base sheet 10. The tension applied to the base sheet 10 is, for example, when the breaking load of the base sheet 10 is about 60 N per 100 mm width, the tension applied before the stretching process is preferably 6 to 30 N per 100 mm width, preferably per 100 mm width. 6 to 12N is more preferable.

0038Further, the processing means 1 used in the method for manufacturing the flexible sheet of the present embodiment described above may be provided with a heater, if necessary. Specifically, heaters may be provided on the first drive rolls 42, 43, the second drive rolls 51, 52, and the tooth groove rolls 2 and 3 shown in FIG. By providing heaters on the 1st drive rolls 42,43, 2nd drive rolls 51,52, or tooth groove rolls 2 and 3, the sheet is easily deformed by applying heat to the sheet and stretches without damaging it. It has the effect of making it easier to stretch and easier to stretch.

0039Further, the processing means 1 used in the method for manufacturing the flexible sheet of the present embodiment described above may be provided with a suction means, if necessary. Specifically, a suction path is formed by providing a plurality of holes on the peripheral surfaces of the first drive rolls 42, 43 and the second drive rolls 51, 52 shown in FIG. However, by connecting to a suction device outside the roll, a suction force may be applied to the peripheral surface of the roll through the suction path so that the processed sheet can be conveyed.

0040The flexible sheet produced by the production method of the present invention is suitable for constituent materials such as top sheets, back sheets, three-dimensional gathers, and exterior materials of absorbent articles such as disposable diapers, sanitary napkins, and body fluid absorption pads. Can be used for.

<p num="0041"> Hereinafter, the present invention will be described in more detail with reference to Examples. However, the scope of the present invention is not limited to such examples.</p><p num="0042"> A flexible sheet was obtained using the processing means shown in FIG. The flexible sheets of Examples 1 to 5 below are sheets formed by using an apparatus provided with the following tooth groove rolls and processing the following base sheet between the rolls only once under the following processing conditions. is there. The obtained flexibility sheet was evaluated as follows. The results are shown in Table 1.</p><p num="0043">[Example 1] &lt;Form of tooth groove roll and tooth meshing depth&gt; Same specifications for tooth groove rolls 2 and 3 Tooth pitch of tooth groove roll P: 2.0mm Roll tooth width T1: 0.7mm (root), width T2: 0.5mm (tip) Roll tooth height H: 3.5mm Roll tooth PCD (Pitch Circle Diameter): 150mm Roll tooth meshing depth D: 3.0mm (There is tooth contact and it rotates with it)</p><p num="0044">&lt;Material of base sheet&gt; On the base sheet to be processed, a large number of the following elastic filaments arranged so as to extend in one direction without intersecting each other are bonded to the following non-woven fabric which can be stretched over their entire length in a substantially non-stretched state. The stretchable composite non-woven fabric used was used. Elastic filament: Styrene-based thermoplastic elastomer fiber, fiber diameter 30 μm Basis weight of elastic filament layer: 40 g / m²Stretchable non-woven fabric: PET / PE core / sheath structure fiber, fiber thickness 2dtex Stretchable non-woven fabric basis weight: 10 g / m²Composite sheet basis weight: 50 g / m²Width of base sheet before processing: 250 mm</p><p num="0045"> The ratio of the peripheral speed and the tension applied to the base sheet were set under the conditions shown in Table 1, and the base sheet was processed. As is clear from Table 1, the first embodiment is characterized in that the peripheral speed V1 of the first drive roll is set to be higher than the peripheral speed V2 of the tooth groove roll.</p><p num="0046">[Example 2] A tooth groove roll having the same conditions as in Example 1 was used except that the meshing depth D of the teeth of the roll was changed to 2.8 mm. Moreover, the same material as in Example 1 was used as the material of the base material sheet. The ratio of the peripheral speed and the tension applied to the base sheet were set under the conditions shown in Table 1, and the base sheet was processed.</p><p num="0047">[Example 3] A tooth groove roll having the same conditions as in Example 1 was used except that the meshing depth D of the teeth of the roll was changed to 2.6 mm. Moreover, the same material as in Example 1 was used as the material of the base material sheet. The ratio of the peripheral speed and the tension applied to the base sheet were set under the conditions shown in Table 1, and the base sheet was processed.</p><p num="0048">[Example 4] A tooth groove roll having the same conditions as in Example 1 was used except that the meshing depth D of the teeth of the roll was changed to 2.4 mm. Moreover, the same material as in Example 1 was used as the material of the base material sheet. The ratio of the peripheral speed and the tension applied to the base sheet were set under the conditions shown in Table 1, and the base sheet was processed.</p><p num="0049">[Example 5] A tooth groove roll having the same conditions as in Example 1 was used except that the meshing depth D of the teeth of the roll was changed to 2.2 mm. Moreover, the same material as in Example 1 was used as the material of the base material sheet. The ratio of the peripheral speed and the tension applied to the base sheet were set under the conditions shown in Table 1, and the base sheet was processed.</p><p num="0050">[Comparative Example 1] A tooth groove roll having the same conditions as in Example 1 was used except that the meshing depth D of the teeth of the roll was changed to 2.0 mm. Moreover, the same material as in Example 1 was used as the material of the base material sheet. The ratio of the peripheral speed and the tension applied to the base sheet were set under the conditions shown in Table 1, and the base sheet was processed. As is clear from Table 1, in Comparative Example 1, unlike the Example, the peripheral speed V2 of the tooth groove roll is set to be higher than the peripheral speed V1 of the first drive roll.</p><p num="0051">[Comparative Example 2] A tooth groove roll having the same conditions as in Example 1 was used except that the meshing depth D of the teeth of the roll was changed to 1.8 mm. Moreover, the same material as in Example 1 was used as the material of the base material sheet. The ratio of the peripheral speed and the tension applied to the base sheet were set under the conditions shown in Table 1, and the base sheet was processed. As is clear from Table 1, in Comparative Example 1, unlike the Example, the peripheral speed V2 of the tooth groove roll is set to be higher than the peripheral speed V1 of the first drive roll.</p><p num="0052">[Evaluation] When producing a flexible sheet under the conditions of Examples and Comparative Examples, the ratio of the width W1 of the base sheet to the initial width W0 of the base sheet immediately before being supplied to the tooth groove roll [(W1 / W0) × 100] and the ratio of the width W2 of the flexible sheet after processing to the initial width W0 of the base sheet [(W2 / W0) × 100] were measured. In addition, the thickness, cushioning property, and load (120% strength) at the time of 120% extension were measured for the flexible sheets obtained in Examples and Comparative Examples by the following methods. The results are shown in Table 1 below.</p><p num="0053">[Measurement of thickness] The thickness of the flexible sheet is 0.5cN / cm²The flexible sheet obtained in Examples and Comparative Examples was sandwiched between the flat plates under the load of the above, and the distance between the flat plates was measured by the laser displacement meter LK-G030 of KEYENCE CORPORATION. Specifically, the thickness (height) of the flat plate before sandwiching the sheet was measured, then the thickness (height) of the flat plate sandwiching the sheet was measured, and the difference was obtained as the thickness of the sheet.</p><p num="0054">[Measurement of cushioning property] Before the measurement, the flexible sheets obtained in Examples and Comparative Examples are cut to the measurement dimensions (2 cm × 2 cm or more) and left for 24 hours or more to remove the strain applied to the sheets before the measurement. Using a compression measuring instrument, the sheet is compressed at a compression rate of 0.02 mm / sec and the maximum load is 50 gf / cm.²From the compression work amount (a) when compressed until it becomes, and the recovery work amount (b) when the pressure is removed at the same speed and the load becomes 0, the compression recovery rate (%) (cushioning property) is calculated by the following equation. Was calculated. Compression recovery rate = (b / a) x 100 (%) For the compression measuring device, for example, a handy compression tester manufactured by Kato Tech Co., Ltd. is used, and the pressure plate is circular 2 cm.², Automatic inversion, amplifier feeling setting (SENS2, STROKESET5.0), and converted to data by a handy compression measurement program.</p><p num="0055">[Measurement of stress at 120% elongation] The flexible sheets obtained in Examples and Comparative Examples were cut to a size of 200 mm in the machine flow direction and 25 mm in the direction orthogonal to the machine flow direction to obtain test pieces. The test piece was mounted on the tensile tester AG-1kNIS manufactured by Shimadzu Corporation with a distance between chucks of 150 mm. The load-elongation characteristics when the test piece was pulled in the longitudinal direction at a speed of 300 mm / min were investigated. The stress at 120% elongation was measured for each of the three test pieces.</p><p num="0056"><tables num="1"><img id="000003" he="199" wi="71" file="JP5268854B2_D0001.tif" img-format="tif" img-content="drawing" /></tables></p><p num="0057"> As is clear from the results shown in Table 1, it can be seen that the flexible sheet of each example has almost no loss due to width shrinkage from the initial width of the base sheet as compared with the flexible sheet of the comparative example. Further, it can be seen that the flexible sheet of each example has a thickness comparable to that of the flexible sheet of the comparative example, has good cushioning property, and is excellent in touch.</p>

00581 Processing means 2,3 tooth groove roll 10 Base sheet before stretching with tooth groove rolls 2 and 3 11 Base sheet stretched by tooth groove rolls 2 and 3 20,30 teeth 41 Feed roll 42,43 1st drive roll 51,52 2nd drive roll Peripheral speed of V1 1st drive roll Peripheral speed of V2 tooth groove roll Peripheral speed of V3 2nd drive roll Peripheral speed of V4 feeding roll Initial width of W0 substrate sheet Width of base sheet just before supply to W1 tooth groove roll Flexibility sheet width after W2 processing