JP2011125641A - Method of manufacturing stretchable sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a stretchable sheet, in which the stretchable sheet having partially no stretchability can be efficiently manufactured using laser light. <P>SOLUTION: In the method of manufacturing the stretchable sheet 1, an elastic body 6 disposed on a sheet 2 or between upper and lower sheets 4, 5 is cut by irradiation with laser light 2 to manufacture the stretchable sheet 1 having an area where stretchability due to the elastic body 1 is partially eliminated, wherein on the sheet transmitting the laser light 2 or between upper and lower sheets 4, 5, the elastic body 6 absorbing the laser light is placed in a stretched state to form a laminate body 3, and then the elastic body 6 is cut by irradiating the laminate body 3 with the laser light 2. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

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

  In wearing articles such as disposable diapers, in order to improve the fit of the wearer's waist and underbody, in particular, by attaching an elastic body such as rubber thread to a non-woven fabric or plastic sheet to make an elastic sheet It can be stretched.

  In the manufacture of such a stretchable sheet, the elastic body is disposed even in a portion that does not need to be stretched due to manufacturing convenience. Therefore, the sheet is not expanded or contracted by cutting the elastic body that does not normally need to be expanded or contracted.

  As a method of cutting the elastic body adhered to the sheet, for example, as in Patent Document 1, an elastic body is provided between the first roll and the second roll facing the first roll in which a plurality of convex portions are arranged on the surface. There is one in which only the elastic body is cut without breaking the sheet by running the arranged sheet and pressing or heating between the convex portion of the first roll and the second roll.

  It is also known to cut the constituent material using laser light in the manufacture of sanitary goods. For example, as a method of cutting an article by irradiating the article being conveyed by the conveying means with laser light, the present applicant uses a laser beam when performing a cut including a component in a direction perpendicular to the article conveying direction. A method of pattern-cutting the article by moving the focal point of the article in the conveyance direction of the article and moving in the direction orthogonal to the conveyance direction to reduce the relative speed between the laser beam and the article (see Patent Document 2), Proposed a method (see Patent Document 3) for cutting a continuous absorbent article using the above laser apparatus.

JP 2002-35029 A Japanese Patent Laid-Open No. 09-192863 JP 2001-145659 A

In the method of cutting the elastic body described above between the convex portion of the first roll and the second roll, when changing the pattern for cutting the elastic body, it is necessary to newly manufacture and replace the roll. It is disadvantageous in terms of stability. In addition, since the elastic body sandwiched between the sheets is cut, a strong pressure is applied to the sheets, so that the appearance may be deteriorated due to perforation or film formation.
On the other hand, in the technology of cutting the constituent material using laser light in the manufacture of sanitary goods, the cutting object is a sheet material, and laser light is used for cutting an elastic body arranged on a sheet or between upper and lower sheets. Not yet proposed.

  The present invention relates to a method for producing a stretchable sheet, which can produce a stretchable sheet that does not have stretchability partially and with high flexibility by using laser light.

  The present invention cuts an elastic body arranged on a sheet or between upper and lower sheets by irradiation of a laser beam, and manufactures an elastic sheet having a region in which the elasticity due to the elastic body is partially lost. The elastic body that absorbs the laser light is arranged in a stretched state on the sheet that transmits the laser light or between the upper and lower sheets to form a laminate, and then the laser light is applied to the laminate. The manufacturing method of the elastic sheet which irradiates and cut | disconnects this elastic body is provided.

  In the present invention, when an elastic body that absorbs laser light is disposed between the upper and lower sheets and the elastic body is interposed between the sheets, the sheet that sandwiches the elastic body is any one that is transparent to laser light. Use.

According to the method for producing a stretchable sheet of the present invention, a stretchable sheet having no stretchability can be efficiently produced with high flexibility by using laser light.
In addition, the elastic sheet manufacturing method of the present invention can cut the elastic body on or between the sheets while suppressing damage to the sheets, and the merit such that the cutting pattern can be easily changed. There is.

FIG. 1 is a perspective view showing an outline of the production process of the stretchable sheet of the present invention. FIG. 2 is a schematic diagram showing a cross section perpendicular to the flow direction of the laminate. FIG. 3 is a diagram illustrating an example of control of the irradiation direction of laser light. FIG. 4 is a view showing a preferable cooling range of the cooling means and the sheet.

Hereinafter, the present invention will be described based on preferred embodiments with reference to the drawings.
In the manufacturing method of the elastic sheet 1 which is one embodiment of the present invention, as shown in FIG. 1, the elastic body 6 disposed between the upper and lower sheets 4, 5 is cut by irradiation with the laser beam 2. Thus, the stretchable sheet 1 having a region where the stretchability by the elastic body 6 is partially lost is manufactured.
Hereinafter, the manufacturing method of this embodiment will be described in more detail.

[Laminate manufacturing process]
An adhesive 7 such as a hot-melt adhesive is intermittently applied by an adhesive application machine 71 on a long (strip-shaped) sheet 4 that has been fed from a raw roll (not shown) and conveyed. By the intermittent application of the adhesive, the sheet 4 includes an adhesive coating portion 4S coated with the adhesive 7 and an adhesive non-coated portion 4N not coated with the adhesive 7. They are alternately formed in the flow direction (X direction). The adhesive coating portion 4S in the illustrated example is formed in a rectangular shape, and the adhesive coating portion 4S covers the entire range in which the elastic body 6 is disposed in the width direction (Y direction) of the sheet 4. It is formed as follows. And the sheet | seat 4 after adhesive agent coating is conveyed to the elastic body arrangement | positioning part 61. FIG.

  The elastic body 6 is stretched by a known tension control means, and is conveyed to the elastic body arrangement portion 61 in a state where a certain tension is applied, and is arranged on the sheet 4. In the elastic body 6, an elastic body guide roll 62 is disposed in the vicinity of the elastic body placement portion 61. The elastic body guide roll 62 is provided with elastic body guide grooves 63 at predetermined intervals in the width direction (Y direction) and along the circumferential direction. The elastic body 6 is arranged at a predetermined position on the sheet 4 after the conveyance direction is changed by the elastic body guide groove 63.

In the present embodiment, almost the same time that the elastic body 6 is arranged on the sheet 4, another sheet 5 joins the elastic body 6 arrangement surface side of the sheet 4. That is, in the embodiment shown in FIG. 1, the elastic body arranging portion 61 and the sheet joining portion 51 where the sheets 5 join are substantially at the same position in the transport direction of the sheet 4. Note that the elastic body arranging portion 61 and the sheet joining portion 51 may be separated in the conveyance direction of the sheet 4.
In the sheet joining portion 51, the sheet 5 is disposed by being guided by the upper roller 52 on the sheet 4 on which the elastic body 6 is disposed (see FIGS. 1 and 2). Further, a lower roller 53 is disposed on the surface of the sheet 4 where the adhesive is not applied so as to face the upper roller 52, and the upper and lower sheets 4 are pressed by the upper and lower rollers 52, 53. , 5 is fixed between both sheets 4 and 5 to form a laminate 3.
In the laminated body 3 obtained, the elastic body 6 is bonded to the sheets 4 and 5 via the adhesive 7 and the elastic body bonded portion 1S is not bonded to the sheets 4 and 5. The bonded portions 1N are alternately generated in the flow direction (X direction) of the sheet 4 and the laminate 5.

[Elastic body cutting process]
The elastic body cutting step is a step of irradiating the laminated body 3 with the laser beam 2 to cut the elastic body 6 in the laminated body 3.
In the present embodiment, as shown in FIG. 1, the elastic body 6 is cut by irradiating the elastic body non-bonding portion 1 </ b> N in the laminated body 3 with a laser beam 2.

In the elastic body cutting step, the laser beam 2 output by the laser oscillator 21 reaches the irradiation direction control unit 22 of the laser beam 2. The irradiation direction control unit 22 moves the irradiation point P to a pattern corresponding to the cutting pattern, and a galvanometer mirror as shown in FIG. 1 is preferably used. The galvanometer mirror is widely used for laser beam scanning and the like, and may be controlled by using a commercially available galvanometer scanner such as MIRAMOTION system manufactured by YE Data Co., Ltd., for example. In this case, a three-dimensional control system (having a mechanism capable of controlling the focal length) having a variable focal length is preferable in order to prevent focal blur due to a change in the optical path of the laser light.
Instead of the galvanometer mirror, a carriage composed of a carriage that moves back and forth only in the direction orthogonal to the conveying direction of the sheet 4 or the laminate 3, and a reflection mirror that is attached to the carriage and that can rotate around a predetermined rotation axis, etc. It can also be used.

In the present embodiment, the laser beam 2 is moved (scanned) in the width direction so as to irradiate all of the elastic bodies 6 in the elastic body non-bonding portion 1N of the laminate 3. FIG. 1 shows a state in the middle of cutting five of the eight elastic bodies to be cut. FIG. 3 is a diagram illustrating an example of laser beam irradiation direction control. A dotted line box 23 illustrated in FIG. 3 is a range in which laser beam irradiation can be performed by the irradiation direction control unit 22 used in the present embodiment. The processing range 23 in the elastic body cutting step.
At this time, as shown in FIG. 3A, the irradiation point P is moved in the width direction of the laminated body 3 while moving in the same flow direction at the same speed as the moving speed of the laminated body 3 in the processing range 23. Then, as shown in FIG. 3 (b), the irradiation point P of the laser beam 2 can be moved in the direction perpendicular to the longitudinal direction with respect to the laminated body 3, and the laminated body 3 has the same longitudinal direction. At the position, a plurality of elastic bodies 6 are cut. In FIG. 3A, P1 is an irradiation start point, and P2 is an irradiation end point.

The elastic body 6 in the elastic body non-bonding portion 1N generates heat and blows when irradiated with the laser beam 2 that has passed through the sheet 5 that covers the irradiation surface side of the elastic body 6. Moreover, since the elastic body 6 in the elastic body non-bonding portion 1N is arranged in an expanded state, it contracts when melted. As a result, the elastic body non-bonding portion 1N of the laminated body 3 is in a state in which the stretched elastic body 6 does not exist, and the stretched elastic body 6 exists only in the elastic body bonding portion 1S. Note that the elastic body non-bonding portion 1N includes the elastic body 6 that is cut and contracted and its end portion, but the sheet is not bonded and does not exhibit stretchability.
Thus, the laminate 3 obtained by cutting the elastic body 6 in the elastic body non-bonding portion 1N is the stretchable sheet 1 obtained in the present embodiment. In the stretchable sheet 1, the elastic body 6 is cut. This is a region where the elastic non-bonding portion 1N is partially lost in elasticity.

  The elastic sheet 1 manufactured as described above can be divided and used as a single elastic sheet by cutting at the center of the elastic body bonding portion 1S using a known cutting means. Moreover, it can also divide | segment by cut | disconnecting by the elastic body non-bonding part 1N, and can also be used as one elastic sheet.

  As the sheet used in the method for producing the stretchable sheet of the present invention, a woven fabric, a nonwoven fabric, a film or the like, a sheet in which these layers are laminated, and the like can be used, and a nonwoven fabric is particularly preferably used. As these constituent materials, various synthetic resins, pulp sheets, and the like can be used, and synthetic resins are particularly desirable.

The basis weight of the sheets 4 and 5 is not particularly limited and is, for example, 10 to 100 g / m ² . The basis weight of the sheets 4 and 5, particularly the basis weight of the sheet 5 covering the laser irradiation side, is 15 to 15 from the viewpoint of preventing the bleeding of the adhesive after coating the adhesive and facilitating the transmission of the laser beam. It is preferably 25 g / m ² .

As the elastic body 6, various elastomer fibers are used. For example, examples of the material of the elastic body 6 include synthetic rubbers such as styrene-butadiene, butadiene, isoprene, and neoprene, natural rubber, EVA, stretchable polyolefin, polyurethane, and the like. Rectangular, square, circular, polygonal thread-like (thread rubber, etc.) or belt-like (flat rubber, elastic film, etc.), or multifilament type thread-like structures made by twisting together a plurality of extremely thin thread-like elastic bodies A thing etc. can be used.
When the elastic body is thread-like, the thickness is generally 310 to 940 dtex, and particularly preferably 310 to 640 dtex.
Moreover, when an elastic body is strip | belt shape, it is desirable that the thickness shall be 0.1-1 mm, especially 0.1-0.5 mm.

As the wavelength of the laser beam for cutting the elastic body, a wavelength having a high absorption rate can be selected from the light absorption characteristics of the elastic body.
Examples of the laser used in the present invention include YAG laser, LD laser (semiconductor laser), YVO ₄ laser, CO ₂ laser and the like.

  For example, a CO2 laser is desirable in that it is well absorbed by polyurethane widely used as an output of a laser oscillator and an elastic body of an absorbent article.

  The sheet 4 and / or 5 that transmits laser light is one that transmits the laser light in relation to the type and wavelength of the laser to be used, and more preferably has high transparency of the laser light. .

  As a combination of the type or wavelength of the laser beam 2 and the sheets 4 and 5, when using a laser beam in the near infrared wavelength region such as an LD laser or a YAG laser, a sheet made of a synthetic resin such as polypropylene or polyethylene is used. Is preferred.

The elastic body used in the present invention absorbs laser light. As such an elastic body, for example, a material that has been given or improved the absorbability of laser light by including a laser light absorber can be used.
The laser light absorber may be applied to an elastic body that does not absorb laser light or an elastic body that does not absorb laser light by a known coating means, or an elastic body is manufactured. In addition, a laser light absorbing material can be blended in the raw material composition.
The laser light absorber can be appropriately selected according to the light absorption characteristics of the sheet or elastic body. For example, when the constituent material of the sheet is a synthetic resin, it is preferable to apply or mix an infrared absorber or various color materials to the elastic body.
Further, as the laser light absorber, those having high absorbability of the laser light are preferably used in relation to the laser light to be used. For example, when an LD laser having a wavelength of 0.808 μm is used, if an infrared absorber Lumogen IR 788 manufactured by BASF is used as a laser light absorbing material, a wavelength range of 0.75 to 0.85 μm is absorbed. Laser light absorptivity can be improved.

  When the elastic body is cut by laser light, the upper and lower sheets can be melted by the heat of the elastic body that has generated heat. Therefore, more desirable results can be obtained by cooling the sheet using various cooling means. As the cooling means, it is conceivable to inject cold air onto the sheet using an air pipe, or to use a roller that transmits laser light and has good thermal conductivity.

  In the example shown in FIG. 4, in order to cool the sheets 4 and 5 that transmit the laser beam 2, irradiation with the laser beam 2 is performed while applying cold air from above and below to the laminate 3 through the pipes 8 and 8. It is carried out. As shown in FIG. 4, the range to which the cold air is applied includes the entire moving range PX of the irradiation point P of the laser beam in the flow direction (X direction) of the laminate 3 and the width direction (Y direction) of the laminate 3. It is preferable to set the entire moving range PY of the irradiation point P of the laser beam. 4A is an example of a cooling range in the flow direction (X direction) of the sheet (laminate 3), and FIG. 4B is a direction orthogonal to the flow direction of the sheet (laminate 3) (Y It is a figure which shows an example of the cooling range in (direction).

  The use of the stretchable sheet obtained in the present invention is not particularly limited, and is used for imparting stretchable parts to various articles. For example, it is preferably used as a constituent member of an absorbent article.

The absorbent article is mainly used for absorbing and holding liquid discharged from the human body such as urine and menstrual blood. Absorbent articles include, for example, disposable diapers, sanitary napkins, panty liners (downcome sheets), incontinence pads, and the like, but are not limited to these, and are used to absorb liquid discharged from the human body. Widely encompasses articles.
The absorbent article typically includes a liquid-permeable top sheet, a liquid-impermeable or water-repellent back sheet, and a liquid-retaining absorbent body interposed between the two sheets. The absorbent article may further include various members according to specific uses of the absorbent article. Such members are known to those skilled in the art. For example, when the absorbent article is a disposable diaper, a sanitary napkin, or the like, a pair or two or more pairs of three-dimensional guards can be disposed on the left and right sides of the topsheet.

As an example of the combination of two sheets in the case of using the elastic sheet manufacturing method of the present invention or the elastic sheet obtained thereby for manufacturing an absorbent article and its constituent members, a diaper outer package is formed. An outer layer sheet and an inner layer sheet disposed on the skin contact surface side, a surface sheet forming a skin contact surface and a back sheet forming a non-skin contact surface, and being disposed between the surface sheet and the back sheet Two sheets for elastic body arrangement, a three-dimensional guard forming sheet and a top sheet, a three-dimensional guard (three-dimensional gather) forming sheet and a back sheet, a top sheet or a back sheet and a wing part forming sheet, and the like.
Further, in the present invention or the present invention, in order to form a stretchable part in a leg opening, a waist opening, a waist part between the leg opening and the waist opening in a pants-type wearing article such as a pant-type diaper, The obtained elastic sheet can also be used. It is also preferable that the non-stretchable portion formed by cutting the elastic body is disposed in a portion that overlaps the absorber in the crotch portion or the waistline portion when a diaper or a diaper exterior body is manufactured by a so-called cross flow method.

As mentioned above, although embodiment of this invention was described, this invention is not restrict | limited to embodiment mentioned above, In the range which does not deviate from the meaning of this invention, it can change suitably.
For example, in the above-described embodiment, the elastic body 6 disposed between the two sheets 4 and 5 is cut with laser light, but instead, the elastic body disposed on one side of one sheet is You may cut | disconnect with the laser beam which permeate | transmitted the said sheet | seat, and may cut | disconnect the elastic body arrange | positioned on the single side | surface of one sheet | seat with the laser beam irradiated from the surface side which has arrange | positioned the elastic body of the said sheet | seat. . One or both of the upper and lower sheets sandwiching the elastic body may be a laminate of sheets that absorb laser light.

In addition, the elastic body bonded portions 1S and the elastic body non-bonded portions 1N are alternately formed in the flow direction of the stacked body 3 in a part of the stacked body 3 in the width direction. The elastic body bonding portion 1S can be continuously formed in the flow direction of the laminated body 3 in the portion.
The elastic body 6 may be cut at the elastic body bonding portion 1S. Moreover, you may perform the cutting | disconnection of the elastic body 6 in each elastic body non-bonding part 1N so that each elastic body 6 may be cut | disconnected in multiple places, respectively. A plurality of elastic bodies can be cut using two or more laser beams.

DESCRIPTION OF SYMBOLS 1 Elastic sheet 2 Laser beam 3 Laminated body 4 Sheet (lower sheet)
5 sheets (upper sheet)
6 Elastic body 7 Adhesive 8 Piping for cooling

Claims (5)

A method for producing a stretchable sheet, which cuts an elastic body arranged on a sheet or between upper and lower sheets by irradiation of laser light, and produces a stretchable sheet having a region in which stretchability by the elastic body is partially lost. There,
An elastic body that absorbs the laser light is placed in a stretched state on the sheet that transmits the laser light or between the upper and lower sheets to form a laminated body, and then the laser light is applied to the laminated body to form the elastic body. A method for producing an elastic sheet to be cut.   The elastic body is fixed on the sheet or between the upper and lower sheets so that an elastic body bonding portion where the elastic body is bonded to the sheet and an elastic body non-bonding portion where the elastic body is not bonded to the sheet are generated. The method for producing a stretchable sheet according to claim 1, wherein the laminated body is cut and the elastic body is cut by irradiating the elastic body non-bonding portion of the laminated body with laser light.   The method for producing a stretchable sheet according to any one of claims 1 and 2, wherein an elastic body imparted or improved by absorbing a laser beam by including a laser beam absorbent is used as the elastic body.   A method for producing a stretchable sheet, wherein the laser light is irradiated while cooling the sheet that transmits the laser light.   The manufacturing method of an absorbent article including the process of manufacturing an elastic sheet with the manufacturing method of the elastic sheet in any one of Claims 1-4.

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