JP2014173209A - Method for manufacturing stretchable sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a stretchable sheet that can solve the problem that, after transiently stopping an elongation process during the elongation process performed by holding a sheet between a pair of rolls and then restarting, the sheet held between the pair of the rolls are broken.SOLUTION: A method for manufacturing a stretchable sheet holds a sheet 10 between a pair of rolls 2 and 3 having a concavity and a convexity on their peripheral surfaces, and rotating with each other by engaging the concavity and the convexity to elongate the sheet. A distance between the pair of rolls 2 and 3 is increased from a distance dm between the rolls at the time of operation upon elongation between the rolls 2 and 3 with a line stopping signal, and is returned to the distance dm between the rolls at the time of operation with the line operating signal during stopping of the line.

Description

  The present invention relates to a method for producing an elastic sheet.

  A technology that uses a manufacturing apparatus including a pair of rolls having tooth grooves engaged with each other on a peripheral surface, rotates the rolls to supply a sheet of nonwoven fabric or the like to the meshed portions, and stretches the sheets. It has been proposed (see, for example, Patent Documents 1 and 2).

JP 2007-177384 A JP 2012-005529 A

However, in a state where the sheet is sandwiched between a pair of rolls engaged with the tooth gap, that is, in a state where tension is applied to the sheet by the tooth groove of the roll, the rotation of the roll is stopped, and the sheet is re-started from the stopped state. When the pair of rolls is re-driven in a state where the tooth gaps are engaged to be stretched, a hole may be opened or cut depending on the basis weight or material of the sheet.
The present invention relates to a stretching process in which a sheet is sandwiched between a pair of rolls having recesses and projections (grooves and teeth) meshing with each other on the peripheral surface. The present invention relates to solving a problem that a hole is opened or cut in a sandwiched sheet.

  The present invention relates to a method for producing an elastic sheet, which has an uneven surface, and stretches the sheet between a pair of rolls rotating while the uneven surface meshes with each other. Provided is a stretch sheet manufacturing method in which the distance between rolls during operation when the rolls are stretched by a stop signal is separated from the distance between the rolls during operation and the distance between the rolls is returned to the distance between the rolls during operation by the line start signal during line stop.

  According to the method for manufacturing an elastic sheet of the present invention, it is possible to solve the problem that the sheet is perforated or cut when the roll is in operation.

It is principal part sectional drawing which showed an example of the manufacturing apparatus of a preferable elastic sheet for enforcing the manufacturing method of the elastic sheet of this invention. It is principal part sectional drawing of a pair of roll which has an uneven | corrugated shape in a surrounding surface. It is the flowchart which showed the manufacturing method of the elastic sheet of this invention. It is the principal part front view which showed the manufacturing method of the elastic sheet of 1st Embodiment typically, (a) is a principal part front view at the time of sheet processing, (b) is the principal part front view at the time of a line stop. It is. It is the principal part front view which showed typically the manufacturing method of the elastic sheet of 2nd Embodiment, (a) is a principal part front view at the time of sheet processing, (b) is a principal part front view at the time of a line stop. It is. It is the principal part front view which showed the manufacturing method of the elastic sheet of 3rd Embodiment typically, (a) is a principal part front view at the time of sheet | seat processing, (b) is the principal part front view at the time of a line stop It is.

A preferred embodiment of the method for producing an elastic sheet according to the present invention will be described below with reference to FIGS. 1 and 2.
First, the principal part of the manufacturing apparatus of an elastic sheet suitable for implementing the manufacturing method of an elastic sheet is demonstrated, referring FIG.

  As shown in FIG. 1, a stretchable sheet manufacturing apparatus (hereinafter also referred to as a manufacturing apparatus for short) 1 includes a pair of rolls 2 and 3 that rotate with a peripheral surface engaged with unevenness. Yes. Specifically, the rolls 2 and 3 have convex portions (hereinafter also referred to as teeth) in parallel along the rotation axis, and tooth traces are formed in parallel on the peripheral surface of the roll. A sheet 10 is supplied between the rolls 2 and 3, and with the rotation of the rolls 2 and 3, the sheet 10 supplied to the engaging portion of the unevenness is stretched. The rolls 2 and 3 are composed of rolls of the same form, and concave portions (hereinafter also referred to as grooves) and convex portions are alternately arranged on the peripheral surfaces of the rolls 2 and 3 along the roll axis direction. . In short, the rolls 2 and 3 are formed with teeth 20 and 30 which are convex portions along the roll axis direction. Moreover, it is preferable to provide tension applying means 5 and 6 for applying tension to the sheet 10 before and after the stretching process. The machine flow direction refers to the direction in which the sheet 10 flows during manufacturing. MD is an abbreviation for “Machine Direction”.

  The rolls 2 and 3 mesh with each other when the driving force from a driving means (not shown) is transmitted to any one of the rotation shafts, and rotate together. In addition to the teeth 20 and 30, a general gear defined in JIS B1701 may be attached to each axis of the rolls 2 and 3 as a driving gear. As a result, the teeth 20 and 30 of the rolls 2 and 3 do not rotate, but the gears mesh with each other so that the drive is transmitted to the rolls 2 and 3 and the rolls 2 and 3 can be rotated. In this case, the teeth 20 and 30 of the rolls 2 and 3 can be arranged without contact. Further, by providing driving means (not shown) for independently transmitting the driving force to the rolls 2 and 3, the respective driving means are controlled so as not to contact the teeth 20 and 30 of the rolls 2 and 3. Is also feasible. In order to make the elongation of the sheet 10 uniform as a whole, the teeth 20 and 30 of the rolls 2 and 3 are preferably rotated without contact.

  One or both of the rolls 2 and 3 may be heated from the viewpoint of sheet processability. From the viewpoint of preventing adhesion to the rolls 2 and 3 when a hot melt material is coated in the sheet, it is preferable that both the rolls 2 and 3 are heated. For example, the sheet 10 is heated to a temperature that is 20 ° C. to 30 ° C. lower than the melting point of the sheet 10. For example, when the sheet 10 is made of a nonwoven fabric having a melting point of about 120 ° C. and a hot melt material is applied, the rolls 2 and 3 are heated from 90 ° C. to 100 ° C., for example. It is preferable that the rolls 2 and 3 are heated in this manner because the hot melt material applied in the sheet 10 hardly adheres to the teeth 20 and 30 of the rolls 2 and 3. As a sheet in which a hot melt material is coated in the sheet, there is a composite sheet as disclosed in paragraph [0022] of JP2012-005529A. For example, two side sheets are joined by an adhesive. There is a sheet that has been made.

  In the present embodiment, the tension applying means 5 is arranged on a pair of nip rolls 51, 52 arranged on the upstream side of the rolls 2, 3, and on a conveyance path between the nip rolls 51, 52 and the rolls 2, 3. A tension detector (not shown), and a controller (not shown) for controlling the peripheral speed of the nip rolls 51 and 52 based on the detection output of the tension detector. Based on the detected output, the peripheral speed of the nip rolls 51 and 52 is adjusted to a predetermined speed with respect to the peripheral speed of the rolls 2 and 3, and a desired tension is applied to the sheet 10 supplied between the rolls 2 and 3. As a specific control method by the control unit, when a tension larger than a desired tension is detected, the tension in this section is decreased by slightly increasing the peripheral speed of the nip rolls 51 and 52 to obtain a desired tension. Adjust to get closer. When a tension smaller than the desired tension is detected, the peripheral speed of the nip rolls 51 and 52 is slightly reduced, thereby increasing the tension in this section and adjusting it to approach the desired tension.

  The tension applying means 6 includes a pair of nip rolls 61 and 62 arranged on the downstream side of the rolls 2 and 3, and a tension detector (on the conveyance path between the nip rolls 61 and 62 and the rolls 2 and 3). And a control unit (not shown) for controlling the peripheral speed of the nip rolls 61 and 62 based on the detection output of the tension detector, and the nip roll based on the detection output of the tension detector. The peripheral speeds 61 and 62 are adjusted to a predetermined speed with respect to the peripheral speeds of the rolls 2 and 3, and a desired tension is applied to the processed base sheet. Specific control by the control unit is performed similarly to the control in the tension applying means 5 described above. However, in this case, when a tension larger than the desired tension is detected, the peripheral speed of the nip rolls 61 and 62 is slightly reduced, so that the tension in this section is reduced and adjusted so as to approach the desired tension. When a tension smaller than the desired tension is detected, the tension in this section is increased by slightly increasing the peripheral speed of the nip rolls 61 and 62 so as to approach the desired tension.

  The manufacturing apparatus 1 includes control means (not shown), and the control means controls the driving means according to a predetermined operation sequence.

Next, the rolls 2 and 3 that perform stretching will be described in detail.
As shown in FIG. 2, each pitch P between adjacent teeth 20 in the roll 2 and adjacent teeth 30 in the roll 3 is preferably 1.0 mm or more and 5.0 mm or less. The tooth thickness W measured in (1) is preferably less than 1/2 of the pitch, and the total tooth depth H is preferably equal to or greater than the pitch P.
Various shapes can be used for the tooth profiles of the rolls 2 and 3. For example, a roll having the same shape as that described in JP 2007-177384 A or JP 2012-005529 A can be used. Moreover, about the main structure of the manufacturing apparatus 1 of an elastic sheet, what was described in the gazette can be used without a restriction | limiting in particular.

  The tooth pitch P in each of the rolls 2 and 3 is preferably 1.0 mm or more, and more preferably 2.0 mm or more, considering the uniform elongation of the sheet 10. Moreover, 5.0 mm or less is preferable and 3.0 mm or less is more preferable. And 1.0 mm or more and 5.0 mm or less are preferable, and 2.0 mm or more and 3.0 mm or less are more preferable. Further, the tooth thickness W of each of the rolls 2 and 3 is preferably ¼ or more and ½ or less of the pitch P, more preferably １ ／ or more and ½ or less, considering the strength of the teeth. Further, the total tooth depth H of each of the rolls 2 and 3 is 2.0 (when the pitch P is 2.0 mm, for example, 2.0 (1 of the pitch) in consideration of increasing the draw ratio in order to give the material stretchability. .0 times) mm to 4.0 (2.0 times the pitch) mm or less, preferably 2.5 (1.25 times the pitch) mm to 3.5 (1.75 times the pitch) mm or less. preferable.

  Moreover, it is preferable that the corner | angular part of the front-end | tip of the teeth 20 and 30 in each roll 2 and 3 is chamfered so that the sheet | seat 10 may not receive damage in this corner | angular part. The radius of curvature of chamfering is preferably from 0.1 mm to 0.3 mm.

  The engagement depth D of the teeth 20 and 30 of the rolls 2 and 3 is preferably 1.0 mm or more and more preferably 2.0 mm or more in consideration of increasing the draw ratio in order to impart stretchability to the material. The tooth engagement depth D refers to the maximum length in the brushing direction of the tooth portion of the other roll that enters the groove of one roll when the rolls 2 and 3 are rotated by meshing the teeth 20 and 30. . In other words, when the rolls 2 and 3 are engaged, the maximum length between the tooth tip circles in the radial direction of the roll where the tooth tip circle of one roll 2 overlaps the tooth tip circle of the other roll 3 is said.

The stretch ratio of the manufacturing apparatus 1 described above is 50% (1.5 times) or more, preferably 150% (2.5 times) or more, more preferably 200% (3.0 times) or more, and 400 % (5.0 times) or less, preferably 350% (4.5 times) or less, more preferably 300% (4.0 times) or less. More specifically, it is 50% (1.5 times) to 400% (5.0 times), preferably 150% (2.5 times) to 350% (4.5 times), and more preferably 200%. % (3.0 times) to 300% (4.0 times). Therefore, the manufacturing apparatus 1 can perform such a drawing process with a high draw ratio.
Here, the draw ratio is (the length when the material is stretched by meshing of the rolls having tooth gaps-the length of the material before stretching by meshing of the rolls) / (before stretching by meshing of the rolls) Material length) x 100 (%). The numbers in parentheses (times) are obtained by adding the length of the material before stretching to the value obtained by dividing the stretch ratio by 100 and expressing the stretch ratio in another expression.

  In the manufacturing apparatus 1, the distance between the rolls 2 and 3 can be changed. As an example of a mechanism for changing the distance between the rolls 2 and 3, it is possible to change the distance between the bearings that receive the shafts of the rolls 2 and 3 by a hydraulic cylinder or a pneumatic cylinder. For example, a mechanism for adjusting with a clearance adjusting unit or a servo motor described in paragraph [0016] of JP 2011-178124 A can be cited. Or it is good also as a mechanism which adjusts the space | interval of a roll by providing a wedge in each axis | shaft as described in the paragraph [0038] of the gazette.

  Next, an embodiment of the sheet manufacturing method of the present invention will be described below. In this manufacturing method, the sheet is stretched using the manufacturing apparatus 1 described above.

  As shown in FIG. 1, the sheet 10 is supplied to the engaging portion of the unevenness while rotating the pair of rolls 2 and 3 having the unevenness on the peripheral surface in the manufacturing apparatus 1. Then, the sheet 10 is stretched between the rolls 2 and 3.

  At that time, the rolls 2 and 3 have the same shape. Each of the rolls 2 and 3 satisfies the above-described conditions.

In this stretching process, it is preferable to supply the sheet 10 between the rolls 2 and 3 with tension applied to the unprocessed sheet 10 by the nip rolls 51 and 52 from the viewpoint of effectively imparting stretchability. The tension applied to the sheet 10 is preferably 10% or more and 80% or less, and more preferably 20% or more and 70% or less of the breaking stress of the sheet before processing.
From the same viewpoint, it is preferable that tension is applied to the processed sheet 10 by the nip rolls 61 and 62 and the sheet 10 is pulled out between the rolls 2 and 3. The tension applied to the supplied sheet 10 is preferably 5% to 80% of the breaking stress of the processed sheet, and more preferably 10% to 70%. The breaking stress of the material is smaller after processing than before processing of the tooth gap extension processing. The tooth gap stretching process refers to performing a stretching process on the sheet by meshing the convex portions and the concave portions (tooth grooves) of the rolls 2 and 3. In addition, the processed sheet 10 provided with stretchability by the tooth gap extension processing is easily extended even with a slight tension. From such a viewpoint, it is preferable to make the tension applied to the processed sheet 10 weaker than the tension applied to the unprocessed sheet 10.

There is no restriction | limiting in particular in the material of the sheet | seat 10 which performs an extending | stretching process, For example, the sheet | seat of the material similar to the sheet | seat disclosed by Unexamined-Japanese-Patent No. 2007-177384 can be used.
The sheet suitable for the stretching process is a sheet that can be sufficiently stretched by being subjected to the stretching process, but can ensure the strength of the sheet itself. As such a sheet, (1) a sheet that does not have stretchability before stretching (that is, is non-stretchable) and exhibits stretchability or stretchability by stretching, or (2) before stretching Also, a sheet that has some extensibility (low extensibility) and whose extensibility or stretchability is improved by the stretching process (having high extensibility) is preferably used, for example, non-woven fabric, resin sheet, elastomer material, elastomer A sheet composite material containing In particular, the sheet is preferably a non-woven fabric from the viewpoints of extensibility, flexibility, and touch. Nonwoven fabrics that can be used as sheets include, for example, spunbond nonwoven fabrics, meltblown nonwoven fabrics, SMS nonwoven fabrics that combine spunbond and meltblown, air-through nonwoven fabrics, heat roll nonwoven fabrics, spunlace nonwoven fabrics, and airlaid nonwoven fabrics. And various methods such as resin-bonded nonwoven fabric. The basis weight of these nonwoven fabrics requires a certain amount of basis weight and strength to prevent tearing, and the basis weight of the sheet is preferably 5 g / m ² or more and 50 g / m ² or less from the viewpoint of fit and flexibility. 8 g / m ² or more and 30 g / m ² or less is more preferable.

  Examples of the material of the fibers constituting the nonwoven fabric that can be used as the sheet 10 include synthetic resins such as polyethylene, polypropylene, polyester, and acrylic. The fiber constituting the nonwoven fabric may be subjected to a hydrophilic treatment or a water repellent treatment, or may be a so-called core-sheath composite fiber having a heat-fusible sheath material on the surface of the core material. In a nonwoven fabric, it is preferable to use the fiber which is easy to express extensibility by a drawing process.

Examples of the resin sheet that can be used as the sheet 10 include films made of polyethylene, polypropylene, polyester, polyurethane, and the like. The resin sheet may be foamed. The thickness of the resin sheet is preferably 5 μm or more and 100 μm or less, particularly preferably 8 μm or more and 30 μm or less, from the viewpoints of softness and strength. From the same viewpoint, the basis weight of the resin sheet is preferably 5 g / m ² or more and 50 g / m ² or less, more preferably 8 g / m ² or more and 30 g / m ² or less.

  Furthermore, the sheet 10 may be a single layer, a sheet folded in two or more layers, or a laminated sheet.

  Further, as the sheet 10, it is preferable to use a composite sheet in which a plurality of elastic members are arranged between the above-described sheets in an expanded state or a non-extended state along a direction in which the sheet is transported or intersects the transport direction. In the composite sheet, an elastic member may be disposed between two sheets, or the sheet may be bent along the conveyance direction and the elastic member may be sandwiched therebetween. When two sheets are used, the same type of sheet or a combination of different sheets may be used.

Moreover, as an elastic member used with the sheet | seat 10, the thing of the well-known material conventionally used for the diaper and the sanitary napkin can be especially used without a restriction | limiting.
Examples of the material of the elastic member include synthetic rubber such as styrene-butadiene, butadiene, isoprene, and neoprene, natural rubber, EVA (ethylene vinyl acetate copolymer), SIS (styrene-isoprene-styrene), and SEBS (styrene-ethylene-butylene). -Styrene), SEPS (styrene-ethylene-propylene-styrene), stretchable polyolefin, polyurethane and the like. Further, the form of the elastic member 15 can be appropriately selected from a thread shape, a belt shape, a ribbon shape, a film shape, a net shape, and the like. In particular, it is inexpensive, has excellent adhesiveness, has excellent stretch response, and facilitates stress design. Therefore, a thread-like or ribbon-like elastic member is preferable.

  The elastic member is preferably bonded to the sheet by an adhesive, and examples of the adhesive used for bonding the sheet and the elastic member include hot melt adhesives such as SIS, SBS, SEBS, and polyolefin. .

  In the method of manufacturing the stretchable sheet, the line may be stopped at various adjustments, trouble checks, line maintenance, closed days, holidays, etc. In the method for producing the stretchable sheet, the pair of rolls 2 and 3 are separated from the distance between the rolls when the rolls are stretched by the line stop signal, and the rolls are separated by the line start signal during the line stop. Returned to the distance between rolls during operation. The embodiment described below relates to the operation of the rolls 2 and 3 from line operation to line stop and line restart.

A preferred embodiment of the method for producing an elastic sheet according to the present invention will be described below with reference to FIGS. 3 and 4. This embodiment is performed using the manufacturing apparatus 1 (see FIG. 1) described above.
First, the first embodiment will be described below as a preferred embodiment.

  As shown in FIG. 3, the elastic sheet manufacturing method is performed after the elastic sheet manufacturing apparatus 1 is operated, that is, after the elastic sheet manufacturing line is operated (also referred to as line operation), the sheet processing step S11, the line stop Step S12, line stoppage S13, and line activation step S14 are performed in this order, and each of these steps (in this specification, “line stoppage” S13 is also treated as “step”) is repeated. For convenience, the sheet processing step S11 (see FIG. 3) in which the conveyed sheet is stretched will be described. However, the steps may be performed in any order as described above.

In the sheet processing step S <b> 11, the sheet processing is performed on the sheet 10 conveyed between the pair of rotating rolls 2 and 3 in a state where the distance between the rolls during operation is dm. Sheet processing is stretching.
In the sheet processing step S11, as shown in FIG. 4A, a pair of rolls 2 and 3 having irregularities (grooves and teeth) on the peripheral surface sandwich the sheet 10 when the line to be stretched is in operation. Between 2 and 3, it is the distance dm between the rolls during operation. The distance dm between the rolls during operation is defined by the distance between the rotating shafts 2c and 3c of the rolls 2 and 3 when being stretched. The same applies hereinafter.

  In the line stop step S12, the sheet conveyance is stopped by a line stop signal. “Line stop” refers to a state where at least the sheet conveyance is stopped, and preferably refers to a state where the rotation of the rolls 2 and 3 is stopped. The line stop step S12 is performed in the “line stop” state. This is a step of performing the operation up to S13 while the line is stopped. The state in which the sheet conveyance is stopped refers to a state in which the driving of the conveying unit that contributes to the conveyance of the sheet 10 in the conveyance path of the sheet 10 is stopped. The conveying means contributing to the conveyance refers to all the units related to the feed roll, the conveyor, and the sheet conveyance, although not illustrated, as well as the rolls 2 and 3 and the tension applying means 5 and 6 described above. Note that the rotation of the roll having no drive source is also stopped. As described above, if the rotation of all the rolls that contribute to the conveyance of the sheet 10 is stopped, the tension of the sheet 10 does not change depending on the position of the roll or the like. If the sheet 10 is separated from the roll, there is no problem because the conveyance tension does not change even if the roll is rotating.

In the line stop step S12 (see FIG. 3), the pair of rolls 2 and 3 are separated from the operating roll distance dm by a line stop signal. The distance between the pair of rolls 2 and 3 is set to the distance ds between the rolls when stopped (see FIG. 4B). In order to increase the inter-roll distance between the pair of rolls 2 and 3 to the position of the inter-roll distance ds when stopped, for example, the roll 3 is raised or the roll 2 is lowered. Alternatively, the roll 3 is raised and the roll 2 is lowered.
Specifically, in the line stop step S12, a line stop signal is received, and the separation between the rotating pair of rolls 2 and 3 from the operating roll distance dm to the stopped roll distance ds is started. The separation start may be performed simultaneously with the line stop signal, may be performed after the sheet conveyance is completely stopped, or may be performed after the sheet conveyance speed is lowered. Therefore, the conveyance stop of the sheet 10 may be performed after the rolls 2 and 3 are separated from each other, may be performed before the separation, or may be performed simultaneously with the separation of the rolls 2 and 3.
When the rolls 2 and 3 are separated during conveyance of the sheet 10, the sheet conveyance speed at the start of separation is determined by the sheet conveyance in the sheet processing step S <b> 11 from the viewpoint of providing durability of the apparatus and a non-stretching portion of the sheet. It is preferably 50% or less, more preferably 30% or less, and preferably 3% or more, and more preferably 5% or more with respect to the speed. And it is preferably 3% to 50%, more preferably 5% to 30%.

When the rotation of the rolls 2 and 3 is stopped, the timing of the conveyance stop of the sheet 10 and the stop of the rotation of the rolls 2 and 3 in the line stop step S12 is the rotation of the rolls 2 and 3 after the conveyance of the sheet 10 is stopped. After the rotation of the rolls 2 and 3 is stopped, the conveyance of the sheet 10 may be stopped, and the conveyance of the sheet 10 and the rotation of the rolls 2 and 3 may be stopped simultaneously.
Stopping the conveyance of the sheet 10 here means that the conveyance operation of all the conveyance units that contribute to the conveyance of the sheet 10 in the conveyance path of the sheet 10 is stopped. When the rotation of the rolls 2 and 3 is stopped after the conveyance of the sheet 10 is stopped, the rotation of the rolls 2 and 3 is already stopped before the conveyance of the sheet 10 is stopped.
To stop the conveyance of the sheet 10, specifically, the rolls 2 and 3, the nip rolls 51, 52, 61, and 62 of the tension applying means 5 and 6, feed rolls, conveyors, and all units related to sheet conveyance (not shown). Stop.
Note that the rolls 2 and 3 have a short stop time of the line, and as shown in FIG. 5B described later, if the teeth 20 and 30 do not mesh with the sheet 10, the rolls 2 and 3 may rotate at a low speed. There is no problem. The low speed here is preferably a speed of 1% or more and 10% or less with respect to the sheet conveying speed in the sheet processing step S11.

  The line stop signal in the line stop process S12 described above is generated by operating a normal stop switch or an emergency stop switch when the line is stopped at various adjustments, trouble inspections, line maintenance, closed days, holidays, etc. The

As described above, after the line stop process S12, the line is stopped S13 (see FIG. 3). During line stop S13, the conveyance of the sheet 10 is stopped, and preferably the rotation of the pair of rolls 2 and 3 is also stopped. Further, during the line stop S13, the distance between rolls ds is maintained between the rolls 2 and 3.
The time to stop the line varies depending on various adjustments, trouble inspections, line maintenance, closed days, holidays, etc.

Then, a line activation process S14 (see FIG. 3) for starting conveyance of the sheet 10 is performed by a line activation signal during the line stoppage S13 in which the sheet conveyance is stopped. When the rotation of the pair of rolls 2 and 3 is also stopped, the pair of rolls 2 and 3 are rotated again at the same time when the sheet conveyance starts or when the distance between the pair of rolls reaches a predetermined length. . The distance between the rolls 2 and 3 is detected by a displacement sensor or a proximity sensor. Here, the predetermined length refers to the distance between the rolls where the teeth 20 and 30 mesh with each other to the distance dm between the rolls during operation.
In the line starting step S14, when the line starting signal is received, or after the line starting signal is received, the sheet conveying speed becomes equal to or higher than the predetermined sheet conveying speed, and then the distance between the rolls 2 and 3 is restarted from the distance ds between the stopped rolls. The distance between the rolls is returned to dm (see FIG. 4A). In the line activation step S14, the conveyance of the sheet 10 is started at the same time as the line activation signal or after the distance between the pair of rolls 2 and 3 is returned to the operating roll distance dm.
When returning the distance between the rolls 2 and 3 to the operating roll distance dm after the conveyance of the sheet 10 is started, from the viewpoint of reducing the durability of the apparatus and the non-stretched portion of the sheet, the sheet at the start of movement between the rolls The conveyance speed is preferably 3% or more, more preferably 5% or more, and preferably 50% or less, and 30% or less with respect to the sheet conveyance speed in the sheet processing step S11. More preferably. And it is preferably 3% to 50%, more preferably 5% to 30%.

In the line starting step S14, from the viewpoint of further preventing damage to the sheet 10 with regard to the timing of returning the distance between the rolls 2 and 3 to the operation distance dm during operation by the procedure of the line stopping step S12. It is preferable to carry out as follows.
In the line stop step S12, when the conveyance of the sheet 10 is stopped after the rolls 2 and 3 are separated from each other, the portion where the rolls 2 and 3 of the sheet 10 are deeply engaged with each other has already passed between the rolls 2 and 3. Therefore, in the line activation step S14, upon receiving the line activation signal, the separation distance between the rolls 2 and 3 (distance between the rolls when stopped) ds begins to return to the original sheet processing step 11S state (distance between the rolls during operation dm). Alternatively, the conveyance of the sheet 10 may be started first, and before the conveyance of the sheet 10 may be started, the distance ds between the rolls at the time of stopping may be returned to the distance dm between the rolls during the operation, or the conveyance of the sheet 10 is started. At the same time, the separation distance between the rolls 2 and 3 may be returned to the distance dm between the rolls during operation. However, as shown in FIG. 4B, when the rolls 2 and 3 are in contact with or engaged with the sheet 10, the separation distance between the rolls 2 and 3 is returned to the inter-roll distance dm during operation. It is preferable to start the conveyance of the sheet 10 first. In particular, when the rolls 2 and 3 are heated, it is better to start the conveyance of the sheet 10 first.
In the line stop step S12, when the rolls 2 and 3 are separated after the conveyance of the sheet 10 is stopped, the portion where the rolls 2 and 3 of the sheet 10 are deeply engaged is positioned between the rolls 2 and 3. ing. For this reason, in the line activation process S14, after receiving the line activation signal and starting the conveyance of the sheet 10 first, the state between the rolls 2 and 3 is the state of the sheet processing process 11S, that is, the distance between the rolls is the roll distance during operation. It is preferable to return to dm.
In the line stop step S12, when the separation of the rolls 2 and 3 and the conveyance of the sheet 10 are stopped at the same time, the portion where the rolls 2 and 3 are deeply engaged is located between the rolls 2 and 3. Therefore, in the line activation step S14, it is preferable that the line activation signal is received and the conveyance of the sheet 10 is started first, and then the space between the rolls 2 and 3 is returned to the state of the sheet processing step 11S.

The start of conveyance of the sheet 10 and the start of rotation of the rolls 2 and 3 in the line activation step S14 may start rotation of the rolls 2 and 3 after starting conveyance of the sheet 10, and start rotation of the rolls 2 and 3 Then, the conveyance of the sheet 10 may be started, and the conveyance of the sheet 10 and the rotation of the rolls 2 and 3 may be started simultaneously. When the line is stopped, the rolls 2 and 3 are in contact with or shallowly engaged with the sheet 10 as shown in FIG. 4B, or when the roll 2 or roll 3 is in the sheet 10 as shown in FIG. From the viewpoint of further preventing damage to the sheet 10, it is preferable to start the rotation of the rolls 2 and 3 while maintaining the distance ds between the rolls when stopped, simultaneously with the start of conveyance of the sheet 10.
The start of conveyance of the sheet 10 here means that the sheet 10 in the sheet conveyance path starts to move in the conveyance direction when at least a part of the driving means starts driving, and all that contributes to the conveyance of the sheet 10. However, it is preferable that all the conveying means that contribute to the conveyance of the sheet 10 start the operation.
In order to start conveying the sheet 10, specifically, the rolls 2 and 3, the nip rolls 51, 52, 61 and 62 of the tension applying means 5 and 6, a feed roll not shown, a conveyor, and a unit related to sheet conveyance Operate everything. The rotation of the roll having no drive source is also operated.

  Then, in the line starting step S14, the rolls 2 and 3 that have received the line starting signal and returned to the operating roll distance dm start the stretching process of the sheet 10 and perform the sheet processing step S11.

Next, the features of the first embodiment will be described in more detail with reference to FIG.
According to the line stop signal, in the line stop process S12, the pair of rolls 2 and 3 are separated from the operating roll distance dm. The distance between the rolls dm during operation of the pair of rolls 2 and 3 increases the distance between the rolls 2 and 3 so that the rolls 2 and 3 are in contact with both surfaces of the sheet 10 with the sheet 10 in between. . The distance between the rolls 2 and 3 is increased due to the separation from the distance dm between the rolls during operation, but the rolls 2 and 3 are in contact with both surfaces of the sheet 10 and the sheet tension is relieved. ing.
After the line stop process S12, in the line stoppage S13, the conveyance of the sheet 10 is stopped, and the rolls 2 and 3 are stopped at the distance ds between the rolls at the stop when one of the pair of rolls 2 and 3 is in contact with both surfaces of the sheet 10. Is stopped (see FIG. 4B). In the illustrated example, the teeth 20 of the roll 2 are stopped while being in contact with the lower surface of the sheet 10, and the teeth 30 of the roll 3 are being stopped while being in contact with the upper surface of the sheet 10. Specifically, the sheet 10 is pushed by the teeth 20, 30, and the sheet 10 is shallowly engaged by the teeth 20 of the roll 2 and the teeth 30 of the roll 3. This stop-to-roll distance ds is defined by the distance between the rotating shafts 2c and 3c of the rolls 2 and 3 when the rolls 2 and 3 are stopped. The same applies to other embodiments described later.

That is, when the above-described meshing depth D of the rolls 2 and 3 is set, the rolls 2 and 3 are separated in a range satisfying ds−dm ≦ D. Preferably, 0.1D <ds-dm ≦ D, and more preferably 0.5D <ds-dm ≦ D.
Although not shown, when ds−dm = D, the tooth tip surface of the tooth 20 of the roll 2 comes into contact with the lower surface of the sheet 10 without the sheet 10 being pushed by the teeth 20, 30, and the sheet 10 is in a state where the top surface of the tooth 30 of the roll 3 is in contact with the top surface of the roll 10.
When setting the distance ds between the rolls when stopped so that ds−dm ≦ D, if the tooth tips of the teeth 20 and 30 are separated as shown in FIG. Since the sheet tension is relaxed compared to the distance dm, the sheet is hardly cut.

  In the first embodiment, in order to further prevent damage to the sheet 10 in the line activation step S <b> 14, it is preferable that the rolls 2 and 3 also start rotating at the same timing as the conveyance start of the sheet 10. Similarly, in the line activation step S <b> 14, it is preferable to start transporting the sheet 10 first before starting to return the rolls 2 and 3 to the operating roll distance dm.

In the manufacturing method of the present invention, when the line is stopped, the distance ds between the rolls when stopped is longer than the distance dm between the rolls during operation, so the load applied to the sheet 10 is lower than when the distance dm between the rolls during operation. Thus, damage to the sheet 10 is prevented, and the problem that the sheet 10 is opened or cut when the rolls 2 and 3 are operated can be solved.
Further, when the rolls 2 and 3 or the rolls 2 and 3 are heated, the rolls 2 and 3 stop when the rolls 2 and 3 are stopped in a state where tension for stretching the sheet 10 is applied. The sheet 10 may be affected by heat. However, in the production method of the present invention, in the stopped state, since the tension for stretching the sheet 10 by the rolls 2 and 3 is weakened, the influence on the sheet 10 is alleviated even if the rolls 2 and 3 are heated. can do.

  In the manufacturing method according to the first embodiment, while the line is stopped, a pair of rolls 2 and 3 are in contact with each other on both sides of the sheet 10 or are in shallow contact with each other. The distance ds between the rolls when stopped is longer than the distance dm between the rolls during operation, and the load applied to the sheet 10 is lower than when the distance dm between the rolls during operation. In this state, according to the line activation signal, the rolls 2 and 3 are rotated at the same time as the sheet 10 is conveyed, so that the damage of the sheet 10 is further reduced, and the occurrence of holes and cuts can be prevented. And while the rolls 2 and 3 are moved from the distance ds between the rolls when stopped to the distance dm between the rolls during operation, the position where the load is applied to the sheet 10 at the distance dm between the rolls during operation is the roll 2, The position of the sheet 10 that is not applied with tension is moved between the rolls 2 and 3 by moving from between the three. For this reason, even if the rolls 2 and 3 are moved from the distance ds between the rolls when stopped to the distance dm between the rolls during operation, the tension applied by the rolls 2 and 3 causes less damage to the sheet 10 and prevents the occurrence of holes and breaks. To do. That is, even during re-operation, since the load of stretching by the pair of rolls 2 and 3 is not applied to the same location of the sheet 10, damage to the sheet 10 is further reduced, and generation of holes and cuts is prevented. Can do.

  Next, the characteristic part of 2nd Embodiment is demonstrated below, referring FIG. 5 in detail. 2nd Embodiment is performed using the manufacturing apparatus 1 (refer FIG. 1) mentioned above.

  According to the line stop signal, in the line stop process S12, the pair of rolls 2 and 3 are separated from the operating roll distance dm. The distance from the inter-roll distance dm when the pair of rolls 2 and 3 is in operation increases the distance between the rolls 2 and 3 from a state where the sheet 10 is sandwiched to a position where the rolls 2 and 3 do not contact the sheet 10. After the line stop process S12, in the line stoppage S13, the conveyance of the sheet 10 is stopped, and the distance between the rolls at the time of stop ds in which the pair of rolls 2 and 3 are separated from both surfaces of the sheet 10 is set (FIG. 5). (See (b).) The rolls 2 and 3 are preferably stopped, that is, the roll 2 is stopped in a state of being separated from the lower surface of the sheet 10, and the roll 3 is stopped in a state of being separated from the upper surface of the sheet 10.

That is, when the above-described meshing depth D of the rolls 2 and 3 is set, the rolls 2 and 3 are separated in a range satisfying ds−dm> D. Although the upper limit of ds-dm is not particularly defined, it is sufficient that the rolls 2 and 3 are separated from the sheet 10.
Moreover, it is preferable that the conveyance stop of the sheet 10 is performed after the rotation of the rolls 2 and 3 is stopped and the processing portion of the sheet 10 is sent in the conveyance direction.

Then, a line activation step S14 (see FIG. 3) for starting conveyance of the sheet 10 is performed by a line activation signal at the time of line stop S13.
In the line activation step S14, the distance between the rolls 2 and 3 is again determined from the distance ds during operation from the distance ds between the rolls again after the line activation signal is received or after the line activation signal is received and the predetermined sheet conveying speed is exceeded. The distance is returned to dm (see FIG. 5A).

In addition, as shown in FIG. 5B, even when the line is stopped in a state where the teeth 20 and 30 of the rolls 2 and 3 are not in contact with the sheet 10 and are separated from each other in S13 during the line stop, From the viewpoint of further preventing the damage 10, it is preferable to perform the following in relation to the timing of returning the sheet 10 to the distance dm during operation in the line activation step S <b> 14 and returning the distance between the rolls 2 and 3 to the distance dm between the rolls during operation.
In the line stop step S12, when the conveyance of the sheet 10 is stopped after the rolls 2 and 3 are separated from each other, the portion of the sheet 10 in which the teeth 20 and 30 of the rolls 2 and 3 are deeply caught is between the rolls 2 and 3 when the line is stopped. Is going through. Therefore, in the line activation step S14, even if the line activation signal is received and the conveyance of the sheet 10 is started first, the distance between the rolls 2 and 3 before the conveyance of the sheet 10 is started from the distance ds between the rolls when stopped. Even if it returns to the distance dm between rolls, you may return the separation distance between the rolls 2 and 3 to the distance dm between rolls at the same time as sheet conveyance is started. Considering the loss of the sheet 10 due to the disposal of the unprocessed part in the subsequent process, the rolls 2 and 3 are started to return to the operating roll distance dm before the sheet 10 starts to be transported, or the roll 2 at the same time as the sheet transport is started. It is preferable to start returning the distance between the three.
In the line stop step S12, when the rolls 2 and 3 are separated after the conveyance of the sheet 10 is stopped, the portion where the teeth 20 and 30 of the rolls 2 and 3 are deeply engaged is between the rolls 2 and 3 when the line is stopped. It remains on the sheet 10. Therefore, in the line activation step S14, the teeth 20 and 30 may bite the same portion of the sheet 10. Therefore, after receiving the line activation signal and conveying the sheet 10 first, the operation between the rolls 2 and 3 is performed. It is preferable to return to the distance dm between the rolls. During the line stoppage S13, the pair of rolls 2 and 3 are separated from both surfaces of the sheet 10, and the sheet 10 is easily conveyed forward while the distance between the rolls 2 and 3 is returned. The start of returning the distance between the three to the distance dm between the rolls during operation may be started simultaneously with the start of conveyance of the sheet 10.
Further, in the line stop step S12, when the separation of the rolls 2 and 3 and the conveyance stop of the sheet 10 are simultaneous, when the line is stopped, the portion where the teeth 20 and 30 of the rolls 1 and 2 are deeply held is between the rolls 2 and 3. The sheet 10 may remain. Therefore, in the line activation step S14, after receiving the line activation signal and starting the conveyance of the sheet 10 in the same manner as described above, the distance between the rolls 2 and 3 is returned to the in-operating roll distance dm, or The conveyance of the sheet 10 may be started simultaneously with the start of returning the rolls 2 and 3.
In summary, in the manufacturing method of the second embodiment, it is particularly preferable that the return of the distance between the rolls 2 and 3 and the start of conveyance of the sheet 10 are simultaneously performed in the line activation step S14.

  Moreover, in line starting process S14, it is preferable to return the distance between rolls 2 and 3 to predetermined length, and to start rotation of rolls 2 and 3 after the teeth 20 and 30 of rolls 2 and 3 mesh. Here, the predetermined length refers to the distance between the rolls where the teeth 20 and 30 mesh with each other to the distance dm between the rolls during operation. By returning the distance between the rolls 2 and 3 to the distance at which the meshing occurs, the rotation of the rolls 2 and 3 is started to prevent the teeth 20 and 30 of the rolls 2 and 3 from colliding with each other. What is necessary is just to detect the distance between rolls with a displacement sensor or a proximity sensor.

  In the manufacturing method of the second embodiment, when the line is stopped, the pair of rolls 2 and 3 are separated from both surfaces of the sheet 10, so the tension applied to the sheet 10 by the rolls 2 and 3 becomes 0, and the sheet 10 Can prevent damage. In this state, by the line activation signal, the distance between the rolls 2 and 3 is returned to the operating distance between the rolls dm, and the sheet 10 is conveyed without being opened or cut. And in line starting process S14, tension | tensile_strength was applied to the sheet | seat 10 with the distance dm between operation | movement rolls while the rolls 2 and 3 moved from the distance ds between rolls at the time of stop to the distance dm between operation | movement rolls. When restarting is performed so that the position moves out of the rolls 2 and 3 and the sheet position where no tension is applied is moved between the rolls 2 and 3, the pair of rolls 2 and 3 has a distance between the rolls when stopped. Even if the distance between the rolls dm during operation is from ds, damage to the sheet 10 due to the tension applied by the rolls 2 and 3 can be further prevented. That is, even during re-operation, the tension of the stretching process by the pair of rolls 2 and 3 is not applied again to the same location of the sheet 10, so that the sheet 10 does not open or break.

  In the stopped state, since the pair of rolls 2 and 3 are separated from both surfaces of the sheet 10 and are not in contact with the sheet 10, the heat of the rolls 2 and 3 is maintained even when the rolls 2 and 3 are heated. It is possible to prevent the influence on the sheet 10 due to the above. Therefore, when setting the distance ds between the rolls when stopped so that ds−dm> D, the rolls 2 and 3 are heated, or the sheet 10 that is easily affected by pressure or heat is used. In this case, this form is most preferable.

  Next, characteristic portions of the third embodiment will be described below with reference to FIG. 6 in more detail. 3rd Embodiment is performed using the manufacturing apparatus 1 (refer FIG. 1) mentioned above.

  In the sheet processing step S11 shown in FIG. 6 (a), the rolls 2 and 3 are stretched by the distance dm between the rolls during operation, as in the first embodiment. Then, according to the line stop signal, as shown in FIG. 6B, the rolls 2 and 3 are separated from the operating roll distance dm to be the stopped roll distance ds. The rolls 2 and 3 are separated from the distance dm between the pre-working rolls in such a state that the sheet 10 is sandwiched and one roll 3 is separated from one surface of the sheet 10 and the other roll 2 is the other of the sheet 19. The distance between the rolls 2 and 3 is widened so as to be in contact with the surface, and the distance ds between the rolls when stopped is set. Accordingly, during the line stoppage S <b> 13, the conveyance of the sheet 10 is stopped, the roll 3 is separated from one surface of the sheet 10, and the roll 2 is in contact with the other surface of the sheet 10. Preferably, the rotation of the rolls 2 and 3 is stopped (see FIG. 6B).

That is, when the roll 2 is in contact with the lower surface of the sheet 10 and the engagement depth D of the rolls 2 and 3 is set, the rolls 2 and 3 are stopped within a range satisfying ds−dm> D. The upper limit of ds-dm is not particularly defined, but the roll 3 only needs to be separated from the upper surface of the sheet 10.
Moreover, it is preferable that the conveyance stop of the sheet 10 is performed after the rotation of the rolls 2 and 3 is stopped and the processing portion of the sheet 10 is sent in the conveyance direction.

  Then, a line activation step S14 (see FIG. 3) for starting conveyance of the sheet 10 is performed by a line activation signal at the time of line stop S13.

  In the line activation step S14, the distance between the rolls 2 and 3 is again determined from the distance ds during operation from the distance ds between the rolls again after the line activation signal is received or after the line activation signal is received and the predetermined sheet conveying speed is exceeded. Return to the distance dm (see FIG. 6A). In the line activation step S14, as in the first embodiment described above, the timing for returning the sheet 10 to the distance dm between the rolls during operation and adjusting the distance between the rolls 2 and 3 is adjusted by the procedure of the line stop step S12. .

  In the third embodiment, as in the first embodiment described above, when the rolls 2 and 3 are stopped in the line stoppage S13 in order to further prevent damage to the sheet 10 in the line start-up step S14. It is preferable that the rolls 2 and 3 also start rotating at the same timing as the start of conveyance of the sheet 10. Further, at that time, it is preferable that the rotation of the rolls 2 and 3 is started simultaneously from the state in which the rolls 2 and 3 are stopped so that the positions of the opposing teeth and the grooves coincide with each other. When the teeth 20 and 30 of the rolls 2 and 3 start to engage, that is, when ds−dm <D, the rolls 2 and 3 are rotated at a rotation speed that matches the conveyance speed of the sheet 10. Preferably it is. Since the roll 2 is only in contact with the sheet 10 at the line stop time S13, the conveyance start of the sheet 10 and the rotation start of the rolls 2 and 3 are not necessarily simultaneous. The conveyance of the sheet 10 may be started first.

  A sheet processing step S11 (see FIG. 3) is performed in which the sheet 10 between the pair of rotated rolls 2 and 3 is stretched in a state where the distance between the rolls during operation is dm.

In the manufacturing method of the third embodiment, during the line stoppage S13, as in the first embodiment and the second embodiment, the distance ds between the rolls when stopped is longer than the distance dm between the rolls during operation. The load that is applied is lower than the distance dm between the rolls during operation, damage to the sheet 10 is prevented, and the problem that holes are opened or cut when the rolls 2 and 3 are operated is solved. Can do.
And in line starting process S14, tension | tensile_strength was applied to the sheet | seat 10 with the distance dm between operation | movement rolls while the rolls 2 and 3 moved from the distance ds between rolls at the time of stop to the distance dm between operation | movement rolls. When the position is not between the rolls 2 and 3 and the sheet position to which no tension is applied is moved between the rolls 2 and 3, the pair of rolls 2 and 3 are operated from the distance ds between the rolls when stopped. Even when the distance dm between the rolls is reached, damage to the sheet 10 due to the tension applied by the rolls 2 and 3 can be further prevented.
Moreover, since the roll 3 is separated from the sheet 10 in the stopped state, even when the roll 3 is heated, the influence of the heat of the rolls 2 and 3 on the sheet 10 can be prevented. Therefore, when setting the distance ds between the rolls when stopped so that ds−dm> D, the roll 3 is heated, or the sheet 10 that is easily affected by pressure or heat is used. This form is most preferred.

In each of the embodiments described above, a specific example will be described below in which the line is started from S13 when the line is stopped to the line starting step S14 where the line is started.
First, a normal line start switch is operated to generate a line start signal. Thereby, the distance between the rolls is shortened to an arbitrary distance. At this time, the conveyance of the sheet 10 remains stopped. Next, after confirming that the distance between the rolls is shortened with a sensor (proximity sensor, laser displacement sensor, etc.), the conveyance of the sheet 10 is started by a cue that the distance has been confirmed. Then, the process returns to the sheet processing step S11.

  In the above description, the teeth 20 and 30 of the rolls 2 and 3 are arranged in a direction orthogonal to the MD direction, but the direction of the teeth 20 and 30 of the rolls 2 and 3 is the circumferential direction of the rolls 2 and 3. Even if it is a case, it can employ | adopt the manufacturing method of the elastic sheet demonstrated in said each embodiment. In this case, the sheet can be stretched in the width direction (CD direction). The CD direction is a direction orthogonal to the MD direction and is an abbreviation of “Cross Direction”.

The elastic sheet manufactured by the above-described method for manufacturing an elastic sheet of the present invention can be applied to a method for manufacturing an absorbent article such as a diaper using the elastic sheet. For example, in the manufacturing method of a diaper disclosed in Japanese Patent Application Laid-Open No. 2007-177384, the method can be applied to a process of producing an elastic sheet with a pair of rolls 2 and 3.
Further, the application range of the present invention is not limited to the diapers described above, and is suitable for, for example, panty liners, incontinence pads, absorbent articles such as sanitary articles, cleaning articles, and stretchable sheets used for masks and the like.

  In addition to the above-described embodiments and implementations, the following additional notes are disclosed.

<1>
A process for producing an elastic sheet having irregularities on a peripheral surface, and stretching the sheet by sandwiching the sheet between a pair of rolls that mesh with each other and rotate.
The pair of rolls are separated from the distance between the operating rolls when the rolls are stretched by the line stop signal, and the rolls are returned to the operating roll distance by the line start signal while the lines are stopped. Sheet manufacturing method.

<2>
A sheet processing step of performing the stretching process on the sheet conveyed between the pair of rolls rotating at a distance between the rolls during operation;
A line stop process for stopping sheet conveyance by the line stop signal,
A line activation step of receiving the line activation signal and starting the sheet conveyance during a line stop where the sheet conveyance is stopped;
In the line stopping step, the distance between the rolls is set to a distance between the rolls when stopped,
The stretch sheet manufacturing method according to <1>, wherein in the line starting step, the distance between the rolls is returned from the distance between the rolls when stopped to the distance between the rolls during operation.
<3>
The pair of rolls are separated from each other according to <1> or <2>, wherein the sheet conveyance is stopped.
<4>
The method for producing an elastic sheet according to <1> or <2>, wherein the pair of rolls are separated from each other simultaneously with a line stop signal.
<5>
Separation between the pair of rolls is the method for producing an elastic sheet according to <1> or <2>, which is performed after the sheet conveyance speed is lowered.
<6>
The sheet conveyance speed at the start of separation between the pair of rolls is preferably 50% or less, more preferably 30% or less, and more preferably 3% or more with respect to the sheet conveyance speed in the sheet processing step. Preferably, it is 5% or more, more preferably 3% or more and 50% or less, and further preferably 5% or more and 30% or less, and the method for producing an elastic sheet according to <5>.

<7>
Separation of the pair of rolls from the distance between the rolls during operation extends the distance between the rolls so that the pair of rolls is in contact with both surfaces of the sheet with the sheet interposed therebetween. To <6>. The method for producing an elastic sheet according to any one of <6>.
<8>
The pair of rolls are separated in a range satisfying ds−dm ≦ D, preferably separated in a range of 0.1D <ds−dm ≦ D, more preferably 0.5D <ds−dm ≦ D. The manufacturing method of the elastic sheet according to <7>, wherein D is a depth of meshing between teeth of a pair of rolls, dm is a distance between rolls during operation, and ds is a distance between rolls when stopped.
<9>
The distance between the pair of rolls from the distance between the rolls during operation is such that the distance between the rolls is increased to a position where the pair of rolls cannot contact the sheet with the sheet interposed therebetween. The manufacturing method of the elastic sheet of any one of these.
<10>
Separation of the pair of rolls from the distance between the operating rolls is such that one roll of the pair of rolls is separated from one surface of the sheet and the other roll is sandwiched between the sheets. The method for producing an expandable sheet according to any one of <1> to <6>, wherein the distance between the rolls is increased in a state of being in contact with the other surface of the sheet.

<11>
The method for producing an elastic sheet according to <9> or <10>, in which the conveyance of the sheet is stopped after the rotation of the roll is stopped, and the processed portion of the sheet is sent in the conveyance direction.
<12>
Stopping the rotation of the pair of rolls is performed according to any one of <1> to <10>, which is performed simultaneously with stopping the conveyance of the sheet.
<13>
The stretchable sheet manufacturing method according to any one of <1> to <12>, wherein the pair of rolls starts rotating simultaneously with the start of sheet conveyance at the line activation signal.
<14>
The method for producing an elastic sheet according to any one of <1> to <13>, wherein the pair of rolls are rotated again when a distance between the pair of rolls reaches a predetermined length.
<15>
The pair of rolls are returned to the inter-roll distance during operation after the line activation signal is received, or after the line activation signal is received, and the distance between the rolls is returned to the operating roll distance <1> to <14> The manufacturing method of the elastic sheet of any one of 14.
<16>
The sheet conveyance speed at the start of movement between the rolls that returns the distance between the pair of rolls to the operating roll distance dm is preferably 3% or more with respect to the sheet conveyance speed in the sheet processing step. More preferably, it is 50% or less, and more preferably 30% or less, the method for producing an elastic sheet according to <15>.

<17>
While the line is stopped, the rotation of the pair of rolls is stopped <1> to <16> The method for producing an elastic sheet according to any one of <16>
The sheet conveying stop is the method for manufacturing an elastic sheet according to any one of <1> to <17>, which is performed after the pair of rolls are separated from each other.
<19>
The sheet conveying stop is performed according to any one of <1> to <17>, which is performed before the pair of rolls are separated from each other.
<20>
In response to a line activation signal, the sheet conveyance is started first rather than starting to return the separation distance between the pair of rolls from the stop roll distance ds to the operation roll distance dm <1> to <19 The manufacturing method of the elastic sheet of any one of>.
<21>
The method for producing an expandable sheet according to any one of <1> to <19>, in response to a line activation signal, and starting to return the stop-time inter-roll distance ds to the active-time inter-roll distance dm before starting the conveyance of the sheet.
<22>
Upon receipt of a line activation signal, the conveyance of the sheet is started, and at the same time, the separation distance ds between the pair of rolls starts to be returned to the operating roll distance dm <1> to <19> Sheet manufacturing method.
<23>
In the line stop process, when the separation of the pair of rolls and the stop of the conveyance of the sheet are performed at the same time, in the line activation process, after receiving the line activation signal and starting the conveyance of the sheet first, The method for producing an elastic sheet according to any one of <1> to <19>, wherein the distance between the pair of rolls is returned to the operating roll distance dm.
<24>
In the line stop step, when the pair of rolls are separated from both surfaces of the sheet, the line activation step simultaneously returns the distance between the pair of rolls and starts the conveyance of the sheet. <1> to <6> and the manufacturing method of the elastic sheet of any one of <9>.

<25>
One or both of said pair of rolls are heated, The manufacturing method of the elastic sheet of any one of <1> to <24>.
<26>
The method for producing an expandable sheet according to any one of <1> to <25>, wherein teeth that are convex portions are formed on the pair of rolls along a roll axis direction.
<27>
The method for producing an elastic sheet according to any one of <1> to <26>, wherein the pair of rolls has teeth that are convex portions arranged in a circumferential direction of the roll.
<28>
The roll is a method for producing an elastic sheet according to any one of <1> to <27>, wherein the roll is heated to a temperature 20 to 30 ° C. lower than the melting point of the sheet.
<29>
The distance between the pair of rolls is changed by changing between the bearings that receive each axis of the roll by a hydraulic cylinder or a pneumatic cylinder according to any one of <1> to <28>. Sheet manufacturing method.
<30>
The method for producing an elastic sheet according to any one of <1> to <29>, wherein the sheet is a nonwoven fabric, a resin sheet, an elastomer material, a sheet composite material including an elastomer, or the like.
<31>
Any one of <1> to <30>, wherein a composite sheet in which a plurality of elastic members are stretched or non-stretched along a direction crossing the sheet conveyance direction or the sheet conveyance direction is used as the sheet A method for producing the stretchable sheet according to claim 1.

<32>
The manufacturing method of an absorbent article using the sheet | seat manufactured with the manufacturing method of the elastic sheet any one of <1> to <31>.
<33>
The absorbent article manufacturing method according to <32>, wherein the absorbent article is a diaper, a panty liner, an incontinence pad, or a sanitary product.

DESCRIPTION OF SYMBOLS 1 Stretch sheet manufacturing apparatus 2, 3 Roll 5, 6 Tension applying means 10 Sheet 20, 30 Teeth 51, 52, 61, 62 Nip roll

Claims (12)

A method for producing an expandable sheet having irregularities on a peripheral surface, and stretching the sheet by sandwiching the sheet between a pair of rolls rotating while the irregularities mesh with each other,
The pair of rolls are separated from the distance between the operating rolls when the rolls are stretched by the line stop signal, and the rolls are returned to the operating roll distance by the line start signal while the lines are stopped. Sheet manufacturing method. A sheet processing step of performing the stretching process on the sheet conveyed between the pair of rolls rotating at a distance between the rolls during operation;
A line stop process for stopping sheet conveyance by the line stop signal,
A line activation step of receiving the line activation signal and starting the sheet conveyance during a line stop where the sheet conveyance is stopped;
In the line stopping step, the distance between the rolls is set to a distance between the rolls when stopped,
The stretch sheet manufacturing method according to claim 1, wherein in the line starting step, the distance between the rolls is returned from the distance between the rolls when stopped to the distance between the rolls during operation.   The method for manufacturing an elastic sheet according to claim 1 or 2, wherein the pair of rolls are separated from each other after sheet conveyance is stopped.   The method of manufacturing an elastic sheet according to claim 1 or 2, wherein the pair of rolls are separated from each other after the sheet conveyance speed is lowered.   The separation from the distance between the operating rolls of the pair of rolls increases the distance between the rolls in a state where the pair of rolls are in contact with both surfaces of the sheet with the sheet interposed therebetween. 5. The method for producing an elastic sheet according to any one of 4 above.   The separation of the pair of rolls from the distance between the rolls during operation increases the distance between the rolls to a position where the pair of rolls cannot contact the sheet across the sheet. The manufacturing method of the elastic sheet of 1 item | term.   Separation of the pair of rolls from the distance between the operating rolls is such that one roll of the pair of rolls is separated from one surface of the sheet and the other roll is sandwiched between the sheets. The manufacturing method of the elastic sheet of any one of Claim 1 to 4 which expands the distance between the said rolls in the state which contacted the other surface of the said sheet | seat.   The method for manufacturing an elastic sheet according to claim 6 or 7, wherein the conveyance of the sheet is stopped after the rotation of the roll is stopped, and the processed portion of the sheet is sent in the conveyance direction.   The method for manufacturing an elastic sheet according to any one of claims 1 to 8, wherein rotation of the pair of rolls is started simultaneously with the start of sheet conveyance at the line activation signal.   10. The pair of rolls is returned to the distance between the rolls during operation after receiving the line activation signal or after the line activation signal is received and after the predetermined sheet conveying speed is exceeded. The manufacturing method of the elastic sheet of any one of these.   The method for manufacturing an elastic sheet according to any one of claims 1 to 10, wherein one or both of the pair of rolls are heated. The manufacturing method of the absorbent article using the sheet | seat manufactured with the manufacturing method of the elastic sheet of any one of Claims 1-11.

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