JP2018100457A - Method for producing extensible sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress trouble that can occur when a sheet is stretched between a pair of grooved rolls while sheets are jointed.SOLUTION: A method for producing an extensible sheet comprises a stretch step of stretching a base material sheet 10 between a pair of grooved rolls 2 and 3 in the conveyance direction Y and a pulling-out step of pulling out the base material sheet from the pair of grooved rolls 2 and 3 while tensile force is applied on the stretched base material sheet 10 in the conveyance direction Y. Before the stretch step, the method for producing an extensible sheet has a sheet jointing step of jointing a base material sheet 10A to another base material sheet 10B. In the sheet jointing step, an adhesive material 60 with extensibility is placed between the base material sheet 10A and another base material sheet 10B along the conveyance direction Y so as to join the base material sheets 10A and 10B.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a method for producing an extensible sheet. The extensible sheet produced by the method of the present invention is suitably used as a constituent member of various articles that require extensibility.

  Using processing means provided with a pair of rolls provided on the peripheral surface portion so that the tooth grooves that mesh with each other along the rotational axis direction, rotate the rolls to supply a sheet of nonwoven fabric or the like to the meshed portions, Various techniques for processing the sheet have been proposed. For example, in Patent Document 1, the nonwoven fabric previously stretched in the upstream stretching step is passed through a gap between a pair of rolls that rotate while meshing a plurality of teeth formed on the outer peripheral surface. Techniques have been proposed for further stretching a nonwoven fabric in the longitudinal direction.

  In addition, as a technique for processing the above-described sheet, the applicant first supplies a base sheet from a pair of driving rolls to a meshing portion of a pair of tooth groove rolls that mesh with each other. In the manufacturing method of the flexible sheet that stretches the base sheet, the technique for stretching the base sheet is proposed by adjusting the relationship between the peripheral speed of the drive roll and the peripheral speed of the tooth gap roll ( Patent Document 2).

  By the way, in the prior art mentioned above, the sheet | seat used as the object of an extending | stretching process is generally drawn | rolled out from the wound body of the state wound by roll shape to a processing line, and is continuously attached to an extending | stretching process. Therefore, in order to prevent the processing line from being stopped, an operation of joining with another sheet fed from another winding body, that is, a so-called sheet splicing operation before all the feeding of the sheet from the winding body is completed. Is required.

  As a conventional technique related to a sheet joint of a sheet to be subjected to stretching processing, for example, the one described in Patent Document 3 is known. In this document, joint portions formed on two sheets joined together are intermittently provided in a direction orthogonal to the sheet conveying direction.

JP 2008-156785 A JP 2011-80172 A JP 2012-207336 A

  In the technique described in Patent Document 3, when the sheet is pulled along the stretching direction, the sheet is not divided in a direction orthogonal to the stretching direction. However, since the sheet joint portion is a portion where two sheets are overlapped, it is harder to be stretched than other portions, and when the strength of the stretch portion of the sheet is low, the boundary between the sheet joint portion and the stretch portion Troubles such as breakage often occur.

  Accordingly, an object of the present invention is to improve the sheet stretching method, and more specifically, to suppress troubles that may occur when the sheet is stretched between a pair of tooth gap rolls while joining the sheets.

The present invention supplies a base sheet from an infeed roll to a meshing portion of a pair of tooth groove rolls that mesh with each other, and stretches the base sheet in a conveying direction between the pair of tooth groove rolls; ,
The base sheet stretched by the pair of tooth groove rolls is supplied to an outfeed roll, and the base sheet is pulled by the outfeed roll from the pair of tooth groove rolls while applying a tension in the conveying direction. A method for producing an extensible sheet comprising a drawing step,
Prior to the stretching step, further comprising a sheet joining step for joining the base sheet to another base sheet,
In the sheet splicing step, an extensible sheet manufacturing method in which an adhesive material having extensibility along the conveying direction is applied between the base sheet and the another base sheet to join both sheets. It is to provide.

  According to the present invention, even when the sheet is joined before the sheet is stretched between the pair of tooth gap rolls, troubles are less likely to occur when the sheet is stretched.

Drawing 1 is a mimetic diagram showing one embodiment of a drawing device used suitably for a manufacturing method of an extensible sheet of the present invention. FIG. 2 is a schematic view showing an embodiment of a sheet splicing device suitably used in the method for producing an extensible sheet of the present invention. FIGS. 3A and 3B are schematic views showing a state in which two base material sheets are joined together. 4 (a) to 4 (d) are plan views each showing a pattern of an adhesive material disposed on the base sheet.

  The present invention will be described below based on preferred embodiments with reference to the drawings. FIG. 1 schematically shows an embodiment of an apparatus suitably used in the method for producing an extensible sheet of the present invention. In the following description, the direction in which the base sheet 10 is transported is described as the Y direction, the direction orthogonal to the transport direction, and the width direction of the transported base sheet 10 as the X direction. The rotation direction R of the tooth gap rolls 2 and 3, which will be described later, coincides with the conveyance direction (Y direction) of the base sheet 10.

  As shown in FIG. 1, the manufacturing apparatus 1 according to the present embodiment includes a pair of tooth groove rolls 2 and 3 provided on a peripheral surface portion so that tooth grooves engaged with each other are along the rotation axis direction (X direction). When the tooth gap rolls 2 and 3 are rotated, the base sheet 10 supplied to the meshing portions thereof is stretched in the transport direction (Y direction) to impart extensibility along the transport direction. Device. In the manufacturing apparatus 1 of the present embodiment, the tooth gap rolls 2 and 3 are configured by rolls having the same form. As shown in FIG. 1, the tooth groove that meshes with the tooth groove rolls 2 and 3 is provided on the peripheral surface portion along the rotation axis direction (X direction). The teeth 20 and 30 are provided on the peripheral surface so that the directions in which the teeth 20 and 30 extend on the tooth gap rolls 2 and 3 are parallel to each other, and a groove is formed between the teeth 20 and 20 or between the teeth 30 and 30. Thus, in the meshing portion, the teeth of the tooth gap rolls are provided so as to mesh with each other.

  In the pair of tooth gap rolls 2 and 3, either one of the tooth groove rolls is a drive roll and the other tooth groove roll is a follower roll. In the manufacturing apparatus 1 of the present embodiment, the tooth gap roll 2 is a drive roll and the tooth gap roll 3 is a follower roll. Each of the tooth gap rolls 2 and 3 is adapted to rotate in the direction indicated by the arrow R in FIG.

  As shown in FIG. 1, the manufacturing apparatus 1 has a feeding roll 41 that feeds out a base sheet 10 to which an original fabric (base sheet roll) of the base sheet 10 is attached on the upstream side of the tooth gap rolls 2 and 3. A pair of infeed rolls 42 and 43 are provided between the feed roll 41 and the tooth gap rolls 2 and 3. The infeed rolls 42 and 43 are rolls that play a role of supplying the base sheet 10 between the pair of tooth gap rolls 2 and 3. In the manufacturing apparatus 1 of the present embodiment, the peripheral speed V1 of the infeed rolls 42 and 43 is set to a predetermined speed with respect to the peripheral speed V2 of the tooth gap rolls 2 and 3 in a state of being engaged with each other, and the base sheet 10 A desired tension is applied to the. In addition, the peripheral speed V1 of the infeed rolls 42 and 43 can be set to a predetermined speed with respect to the feeding speed V4 of the base sheet 10 fed from the feeding roll 41, and desired tension can be applied to the base sheet 10. .

  As shown in FIG. 1, the manufacturing apparatus 1 of the present embodiment forms a base sheet 10 a stretched between the tooth gap rolls 2, 3 on the downstream side of the tooth gap rolls 2, 3. A pair of outfeed rolls 44 and 45 are provided that are pulled out from the sheet and conveyed to the next process. In the manufacturing apparatus 1, the peripheral speed V3 of the outfeed rolls 44 and 45 is set to a predetermined speed with respect to the peripheral speed V2 of the tooth gap rolls 2 and 3, and the stretched base sheet 10a is pulled out from the tooth groove rolls 2 and 3. At the same time, the extensible sheet 11 in which a desired tension is applied to the base sheet 10a is manufactured.

  The peripheral speed V1 of the infeed rolls 42 and 43 is the speed on the surface of each roll 42 and 43. The feeding speed V4 of the base sheet 10 fed from the feeding roll 41 is a speed on the surface of the fed base sheet 10. The peripheral speed V3 of the outfeed rolls 44 and 45 is the speed on the surfaces of the rolls 44 and 45, similarly to the peripheral speed V1 of the infeed rolls 42 and 43. The circumferential speed V2 of the tooth gap rolls 2 and 3 is the speed at the tips of the teeth 20 and 30.

  As shown in FIG. 1, the manufacturing method of the extensible sheet using the manufacturing apparatus 1 shown in FIG. 1 includes a pair of tooth groove rolls 2 and 3 that engage the base sheet 10 from a pair of infeed rolls 42 and 43. A stretching step is provided in which the base sheet 10 is stretched in the conveying direction (Y direction) between the pair of tooth gap rolls 2 and 3 by being supplied to the meshing portion. Furthermore, the manufacturing method of the extensible sheet | seat of this embodiment supplies the base material sheet | seat 10a extended | stretched with a pair of tooth gap rolls 2 and 3 to a pair of outfeed rolls 44 and 45, and a pair of outfeed rolls. 44 and 45, the base sheet 10a is pulled out from the pair of tooth space rolls 2 and 3 while applying tension in the conveying direction (Y direction). In the present embodiment, the relationship between the peripheral speed V3 of the outfeed rolls 44 and 45 and the peripheral speed V1 of the infeed rolls 42 and 43 is set to V3> V1.

  In the pre-process of the stretching process, the base sheet 10 is fed out from the feed roll 41 to which the roll-shaped base sheet 10 is attached, and the fed base sheet 10 is supplied to the infeed rolls 42 and 43. In the present embodiment, the peripheral speed V1 of the infeed rolls 42 and 43 and the feeding speed V4 of the base sheet 10 at the time of supplying the base sheet 10 are constant speed (V1 = V4). In the stretching step, the base sheet 10 is supplied from the pair of infeed rolls 42 and 43 to the meshing portion of the pair of tooth groove rolls 2 and 3 that rotate in the R direction, and the base sheet 10 is conveyed in the conveying direction ( Stretching along (Y direction).

  As described above, in this manufacturing method, the peripheral speed V3 of the outfeed rolls 44 and 45 is set to be higher than the peripheral speed V1 of the infeed rolls 42 and 43 (V3> V1). By setting in this way, the stretched base sheet 10a can be transported to the subsequent process without causing slack. The ratio [(V1 / V3) × 100] of the peripheral speed V1 of the infeed rolls 42 and 43 to the peripheral speed V3 of the outfeed rolls 44 and 45 is preferably 30% or more and 80% or less, and 40% or more and 60 % Or less is more preferable. The applied tension is preferably 5% or more and 50% or less, more preferably 5% or more and 20% or less, of the breaking load of the base sheet 10a after the stretching process.

  There is no restriction | limiting in particular as the base material sheet 10 which processes, For example, paper, a single layer nonwoven fabric, a resin film, the laminated body of 2 or more types of nonwoven fabrics, the laminated body of a resin film and a nonwoven fabric, etc. are mentioned. . Specifically, the base sheet 10 may be a thermoplastic polymer nonwoven fabric of polyolefin fibers selected from polypropylene fibers, fibers composed of polypropylene and polyethylene, and bicomponent fibers of polypropylene and polyethylene. Moreover, the nonwoven fabric containing an elastic fiber is preferable from a viewpoint which provides a softness | flexibility while providing the base material sheet 10 by the extending | stretching process by the manufacturing apparatus 1. FIG. As a nonwoven fabric containing elastic fibers, a non-elastic fiber layer composed of substantially non-elastic fibers is disposed on at least one surface of an elastic fiber layer containing elastic fibers, and both fiber layers are constituent fibers of the elastic fiber layer. While maintaining the fiber form, a stretchable nonwoven fabric joined by thermal fusion (hereinafter referred to as a stretchable composite nonwoven fabric) and a large number of elastic filaments arranged to extend in one direction without crossing each other, Examples include stretchable nonwoven fabrics bonded to stretchable nonwoven fabrics over their entire length in a substantially non-stretched state. When the base material sheet 10 has elasticity, the sheet 10 after the stretching process exhibits stretchability along the stretching direction.

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

  As the stretchable composite nonwoven fabric, various known materials can be used. For example, the stretchable sheet described in JP2008-179128A, the stretchable sheet described in JP2007-22066A, and JP2007- An elastic nonwoven fabric produced by the method for producing an elastic nonwoven fabric described in 22066, a laminated sheet described in JP-A-10-029259, and the like can also be used.

  In the above process, since the extensible sheet is continuously manufactured, the base sheet 10 fed from the feed roll 41 is not completely fed out so as not to stop the production line. In addition, an operation of joining with another base sheet fed from another feed roll (not shown), that is, a sheet splicing operation is required. The sheet splicing operation is performed prior to the stretching process shown in FIG. Specifically, the sheet splicing operation is performed between the feeding roll 41 and the infeed rolls 42 and 43 shown in FIG.

  FIG. 2 shows an apparatus preferably used for the sheet joining operation. As shown in FIG. 2, the sheet splicing device 50 has a splicing portion 51 that splices the first base sheet 10 </ b> A with the start end portion 101 </ b> B of the second base material sheet 10 </ b> B that is another base material sheet. Yes. The joint portion 51 is provided with a steady roll 52 and a pressing portion 53. The stationary roll 52 and the pressing portion 53 are disposed to face each other.

  The steady roll 52 is a roll that rotates in a steady manner, and can apply a conveying force to the first base sheet 10 </ b> A introduced into the joint portion 51. The pressing portion 53 can move toward the steady roll 52 until the start end portion 101B of the second base sheet 10B introduced into the joint portion 51 comes into contact with the steady roll 52.

  A free roll 54 is disposed below the joint portion 51. The free roll 54 is a roll that turns the first base sheet 10 </ b> A or the second base sheet 10 </ b> B led out from the joint portion 51 toward the next stretching step.

  The first base sheet 10A is fed from the first feed roll 41A, guided to the guide rolls 55A and 56A, and introduced into the joint portion 51. In the state shown in FIG. 2, the first base sheet 10A is continuously conveyed. On the other hand, the second base sheet 10B is fed from the second feed roll 41B and guided to the guide rolls 55B and 56B, and the start end portion 101B is between the steady roll 52 and the pressing portion 53 in the joint portion 51. It is arranged to be located in. This operation is performed by, for example, a manual operation. In the state shown in FIG. 2, the second base sheet 10B is stationary. An accumulator mechanism may be installed between the guide rolls 55A and 56A and between the guide rolls 55B and 56B as necessary.

  As for the 2nd base material sheet 10B, the adhesive material 60 is arrange | positioned in the opposing surface with the stationary roll 52 in the start end part 101B. The adhesive material 60 is used to join the terminal end (not shown) of the first base sheet 10A and the start end 101B of the second base sheet 10B. The operation of placing the adhesive material 60 on the start end portion 101B may be performed mechanically or may be performed manually.

  In the joint portion 51, when a terminal portion (not shown) of the first base sheet 10 </ b> A approaches the joint portion 51, the pressing portion 53 moves toward the steady roll 52 and is conveyed by the steady roll 52. As shown in FIG. 3A, the first base sheet 10 </ b> A is joined to the start end 101 </ b> B of the second base sheet 10 </ b> B via the adhesive material 60 in the vicinity of the terminal end 101 </ b> A. The terminal part of 10 A of 1st base material sheets is detected by a sensor, for example, or it is detected by an operator's visual observation.

  When the starting end portion 101B of the second base sheet 10B is spliced in the vicinity of the end portion of the first base sheet 10A in this way, the second base sheet 10B is the next step after that. To be transported. In the meantime, the starting end portion (not shown) of the first base sheet 10A is disposed between the steady roll 52 and the pressing portion 53, and an adhesive material is provided on the surface facing the steady roll 52 at the starting end portion. 60 is applied. When the remaining second base sheet 10B is reduced, the end portion of the second base sheet 10B can be joined to the start end of the first base sheet 10A. In this way, the first base sheet 10A and the second base sheet 10B are alternately joined together.

  When the first base sheet 10A and the second base sheet 10B are joined by the above method, as shown in FIG. 3 (b), the joining portion 61 has two base sheets 10A and 10B. Since the layers are stacked, troubles such as breakage occur frequently when the sheet is less stretched than other parts in the stretching process, and when the strength of the sheet is low. Therefore, in the present embodiment, the following device is applied to the joining of the two base material sheets 10A and 10B to be joined.

  When the inventor examined in detail the trouble that occurs when the joint portion between the first base sheet 10A and the second base sheet 10B is subjected to the stretching process, the break of the sheet is It was found that it often occurs near the boundary with the non-joined part. As a result of further investigations on the cause of the occurrence, it has been found that it is highly possible that the joining portion 61 is not sufficiently stretched even if the joining portion 61 is subjected to the stretching process, which is a cause of the breakage. Therefore, in the present embodiment, in the sheet splicing step, the adhesive material 60 is a material having extensibility along the transport direction Y, and is used between the first base sheet 10A and the second base sheet 10B. The two sheets 10A and 10B are bonded to each other. By using such an adhesive material 60, when the joint portion 61 of both sheets 10A, 10B is subjected to the stretching process by the tooth gap rolls 2, 3, the adhesive material together with the stretching of both sheets 10A, 10B. Since stretching of 60 also occurs, troubles such as breakage are less likely to occur in these sheets. In the present embodiment, the conveyance direction Y coincides with the extending direction of the base sheet 10A, 10B.

  As the adhesive material 60 having extensibility along the conveyance direction Y, for example, a double-sided tape can be used. This double-sided tape is one in which an adhesive is applied to each surface of the base tape. This double-sided tape is in a state in which each side is protected by release paper before the use. In the sheet joining step, the release paper is removed from the double-sided tape, and the double-sided tape is attached to the first base sheet 10A or the second base sheet 10B. And what has extensibility along the conveyance direction Y should just be used as a base-material tape in a double-sided tape. Examples of the material of the base tape include natural rubber, diene rubber such as isoprene rubber, butadiene rubber, and styrene butadiene rubber, non-diene rubber such as butyl rubber, ethylene propylene rubber, urethane rubber, and silicon rubber, and low Examples thereof include density polyethylene and thermoplastic elastomer. Examples of the form of the base tape include a film and a nonwoven fabric.

  As another example of the double-sided tape, one having a structure in which an adhesive is coated in a sheet shape between two release papers can be used. Unlike the double-sided tape described above, this form of double-sided tape does not include a base tape. In other words, in this form of double-sided tape, the adhesive itself is in the form of a tape.

  Even if the form of the double-sided tape is any of the cases described above, the adhesive material 60 is stretched higher than the first base sheet 10A and the second base sheet 10B when considering stretching along the transport direction Y. It is preferable to have properties. High stretchability means high elongation at break. That is, the adhesive material 60 preferably has a higher elongation at break along the conveyance direction Y than the elongation at break of the first base sheet 10A and the second base sheet 10B.

  Further, the adhesive material 60 preferably has an elongation after the stretching process at the joint portion 61 between the first base sheet 10A and the second base sheet 10B of 1.1 times or more that before the stretching process. It is also preferable from the viewpoint of preventing troubles during the stretching process that it has extensibility that is 0 times or less. The elongation value is more preferably 1.5 times or more and 5.0 times or less, and further preferably 2.0 times or more and 5.0 times or less. The elongation value is defined as L2 / L1, where L1 is the length before stretching and L2 is the length after stretching.

  In FIG. 3A, there is no particular limitation on the pattern in which the adhesive material 60 is arranged on one surface of the first base sheet 10A. For example, as shown to Fig.4 (a), the adhesive material 60 can be arrange | positioned in a rectangular shape over substantially the whole length along the width direction X of 10 A of 1st base material sheets.

  Or as shown in FIG.4 (b), you may arrange | position the adhesive material 60 intermittently along the width direction X of 10 A of 1st base material sheets. Furthermore, as shown in FIG. 4C, the adhesive material 60 may be arranged in a staggered pattern. Further, as shown in FIG. 4D, as the double-sided tape 62 which is an adhesive material, a double-sided tape 62 having one or more slits 63 formed so as to extend in the longitudinal direction is used, and the slit 63 is the first base material. A plurality of double-sided tapes 62 may be disposed so as to be orthogonal to the conveyance direction Y of the sheet 10 </ b> A and at intervals along the conveyance direction Y. The slit may not be continuous in the longitudinal direction, and the slit may be formed intermittently. Furthermore, when it has a plurality of slits formed intermittently, it is preferable that portions not slit in the direction perpendicular to the longitudinal direction of the double-sided tape are not adjacent to each other and are formed in a staggered arrangement.

  The extensible sheet produced in this manner is suitable as a constituent member for absorbent articles such as disposable diapers, sanitary napkins, body fluid absorption pads, and the like, such as top sheets, back sheets, three-dimensional gathers, and exterior materials. Can be used. Other than this, for example, it is suitably used as a constituent member of various articles that require extensibility.

  As mentioned above, although this invention was demonstrated based on the preferable embodiment, this invention is not restrict | limited to the said embodiment. For example, in the said embodiment, although the double-sided tape was mentioned as an example and demonstrated as the adhesive material 60 used for joining with the 1st base material sheet 10A and the 2nd base material sheet 10B, as the adhesive material 60, it is other than a double-sided tape. May be used.

  The sheet splicing device 50 may use a stationary plate and a pressing plate instead of the stationary roll 52 and the pressing portion 53. In this case, it is preferable to install the accumulator mechanism after the free roll 54 so that the processing steps after the paper splicing step can be performed continuously.

  Further, in the sheet splicing device 50, the cutting mechanism for the first base sheet 10 </ b> A may be installed on the upstream side of the splicing portion 51.

DESCRIPTION OF SYMBOLS 1 Manufacturing apparatus 2, 3 Tooth groove roll 20, 30 Tooth 41 Feeding roll 42, 43 Infeed roll 44, 45 Out feed roll 10 Base material sheet 10a before extending | stretching process by tooth groove roll 2, 3 Tooth groove roll 2, 3 Base material sheet 10A stretched by 1st base material sheet 101A terminal part 10B second base material sheet 101B start end part 60 adhesive material 61 joint part 11 extensible sheet V1 peripheral speed V2 of infeed roll Peripheral speed V3 Outfeed roll peripheral speed V4 Feed roll peripheral speed

Claims (5)

A base material sheet is supplied from an infeed roll to a meshing portion of a pair of tooth groove rolls that mesh with each other, and a stretching process for stretching the base material sheet in the conveying direction between the pair of tooth groove rolls;
The base sheet stretched by the pair of tooth groove rolls is supplied to an outfeed roll, and the base sheet is pulled by the outfeed roll from the pair of tooth groove rolls while applying a tension in the conveying direction. A method for producing an extensible sheet comprising a drawing step,
Prior to the stretching step, further comprising a sheet joining step for joining the base sheet to another base sheet,
In the sheet splicing step, an extensible sheet manufacturing method in which an adhesive material having extensibility along the conveying direction is applied between the base sheet and the another base sheet to join both sheets. The adhesive material is a double-sided tape,
The double-sided tape is protected by a release paper on each side before use.
The manufacturing method of the extensible sheet | seat of Claim 1 which removes the said release paper from the said double-sided tape in the said sheet | seat joining process, and affixes this double-sided tape on the said base material sheet or said another base material sheet.   The method for producing an extensible sheet according to claim 2, wherein the double-sided tape has a structure in which an adhesive is applied in a sheet form between two release papers. The double-sided tape has one or more slits formed so as to extend in the longitudinal direction,
The extensible sheet according to claim 2 or 3, wherein the plurality of double-sided tapes are arranged so that the slits are orthogonal to the conveying direction of the base sheet and spaced along the conveying direction. Manufacturing method.   The pressure-sensitive adhesive material is used such that the elongation after the stretching step at the joint portion between the base sheet and the another base sheet is 1.1 to 5.0 times that before the stretching step. The manufacturing method of the extensible sheet | seat as described in any one of Claims 1 thru | or 4.

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