JPWO2016103435A1 - Laminated sheet, manufacturing apparatus and manufacturing method thereof - Google Patents

Abstract

On the discharge side of the embossed part (immediately after the embossing step), when the convex part 12a of the second convex roll 12 is withdrawn from the concave part 11a of the first concave roll 11, it is embossed and overlapped inside the concave part 11a. The first bulging portion 1a and the second bulging portion 2a immediately after being accommodated in the above are released from the pressing force and tension, respectively. At this time, since the contraction amount in the moving direction of the second sheet 2 is larger than the contraction amount of the first sheet 1, the second bulge portion 2a is further smaller than the first bulge portion 1a, A gap 4 is formed between the first bulge portion 1a and the second bulge portion 2a on the tip top side. Thereby, the laminated sheet which is excellent in buffer performance and heat retention performance and has good tactile sensation is provided. Moreover, the manufacturing apparatus and manufacturing method for manufacturing such a lamination sheet easily and cheaply are provided.

Description

  The present invention relates to a laminated sheet composed of two stretchable sheets, a production apparatus and a production method for the laminated sheet. Specifically, for example, in a body fluid absorbing article such as a disposable diaper or a sanitary napkin, the laminated sheet of the present invention is suitably used for a portion that comes into contact with the human body, and the present invention is suitable for the production of such a laminated sheet. .

  For example, in an article for absorbing body fluid such as a disposable diaper, an absorbent body including superabsorbent polymer particles is covered with a plurality of sheets. Generally, a top sheet (also referred to as a top sheet or an upper layer sheet), a second sheet (intermediate sheet, or intermediate sheet) from the side closer to the skin on the human body side than the absorbent body (which may itself be covered with a packaging sheet) A lower sheet is also provided, and an exterior sheet (also referred to as a back sheet or a main body sheet) is provided on the side opposite to the human body. Among these, the top sheet and the second sheet are required to be liquid-permeable, and the exterior sheet is required to be non-liquid-permeable. The second sheet also has a backflow prevention function. In particular, in order to improve the absorbability and the touch, a large number of bulging portions (protruding portions) are formed on the top sheet on the contact side with the human body (skin).

  At that time, as in Patent Documents 1 to 3, for example, in the first stage, an embossing roll comprising a concave roll having a plurality of concave portions on the peripheral surface and a convex roll having a plurality of convex portions corresponding to the concave portions on the peripheral surface. By embossing (embossing) a plurality of bulging parts that bulge on the surface of the first sheet (top sheet) on one side (contact side with the skin), and then using a smooth roll in the second stage A second sheet (second sheet) is supplied to the other side (flat surface side) of the sheet, and the two sheets are bonded (bonded) together. As a result, the surface area of the top sheet is increased and the absorbability is improved, and the contact area with the skin is decreased and the touch is improved.

  However, during the transition (movement) from the first stage to the second stage, the top sheet contracts when released from the pressing force (pressing force) between the embossing rolls and the tension (tensile load) at the time of supply. The plurality of bulges formed on the top sheet in one step contracts (deforms) individually in the recesses of the embossing roll, so that they may be crushed (that is, abnormally deformed) or dropped from the recesses. It tends to be easier. As a result, there is a possibility that the second sheet may be stuck in the second stage, and the absorptivity and touch uniformity may be impaired. Therefore, as in Patent Document 3, in order to prevent the embossing roll from falling off from the concave portion, a structure in which the bulging portion of the top sheet is brought into close contact with the concave portion of the embossing roll by air suction must be added.

  Further, in Patent Documents 4 and 5, the first sheet (top sheet) and the second sheet (second sheet) are overlapped and simultaneously embossed so that the second sheet bulge is located inside the bulge of the top sheet. Fits in without gaps. In this manner, by integrating both the bulging portions and thus both the sheets, it is possible to prevent the bulging portions from falling off (separation), simplify the process, and the like. However, when the bulging part of the top sheet and the bulging part of the second sheet are integrated, the thickness increases, and the absorbability and the touch may be deteriorated.

JP 2014-188129 A Japanese Patent No. 5329806 Japanese Patent No. 4711943 Japanese Patent No. 5524792 Japanese Patent No. 5065037

  An object of the present invention is to provide a laminated sheet having excellent buffering performance and heat retention performance and good tactile sensation. Moreover, the other subject of this invention is providing the manufacturing apparatus and manufacturing method for manufacturing such a lamination sheet easily and cheaply.

Means for Solving the Problems and Effects of the Invention

In order to solve the above problems, the laminated sheet of the present invention is
A laminate sheet composed of two (for example, non-woven fabric) sheets having elasticity,
Among these two sheets, the first sheet located on one side in the stacking direction is formed with a plurality of first bulging portions that bulge in a hollow shape only on one side, and on the other side in the stacking direction. A plurality of second bulge portions that bulge in a hollow shape only on one side are formed in the second sheet positioned, and the first flat portion of the first sheet is around the first bulge portion and A plurality of spot joints that join the two sheets in a dotted, linear, or planar manner around the second bulging portion and an overlapping area with the second flat portion of the second sheet Formed,
The first bulge portion formed on the first sheet and the second bulge portion formed on the second sheet (for example, having a similar shape to each other) are arranged on the base end side of the first bulge portion. The second bulging portion is fitted inside, and a predetermined gap is provided between the first bulging portion and the second bulging portion at least on the tip top side.

  Such a laminated sheet is a double air layer between a gap formed between the first bulging portion and the second bulging portion of the two sheets and a hollow second bulging portion of the second sheet. It has excellent cushioning performance (double cushion function) and heat retention performance (double blanket function), and the tactile sensation is also improved.

In addition, in order to solve the above problems, the laminated sheet of the present invention is
It consists of two sheets (for example, made of nonwoven fabric) having stretchability and liquid permeability, and is a laminated sheet used for an article for absorbing body fluid,
Among these two sheets, the first sheet that is located on one side in the laminating direction and contacts the human body is formed with a plurality of first bulging portions that bulge in a hollow shape only on one side, The second sheet located on the other side of the direction is also formed with a plurality of second bulging portions that bulge in a hollow shape only on one side, and is around the first bulging portion, Two sheets are joined in a dotted, linear, or planar shape to the overlapping area between the first flat portion and the second bulging portion and the second flat portion of the second sheet. A plurality of spot joints are formed,
The first bulge portion formed on the first sheet and the second bulge portion formed on the second sheet (for example, having a similar shape to each other) are arranged on the base end side of the first bulge portion. The second bulging portion is fitted inside, and a predetermined gap is provided between the first bulging portion and the second bulging portion at least on the tip top side.

  Such a laminated sheet is a double air layer between a gap formed between the first bulging portion and the second bulging portion of the two sheets and a hollow second bulging portion of the second sheet. And exhibits excellent buffer performance (double cushion function) and heat retention performance (double blanket function) to improve the tactile sensation. Further, since the first bulging portion and the second bulging portion are not overlapped by forming the gap, the absorbability of the body fluid absorbing article is also improved.

  Therefore, when the laminated sheet of the present invention is used for an article for absorbing body fluids such as disposable diapers and sanitary napkins, the first sheet is applied as a top sheet and the second sheet is applied as a second sheet. In addition, as a sheet | seat which has a stretching property, or a sheet | seat which has a stretching property and liquid permeability, the porous or non-porous nonwoven fabric mainly comprised by an elastomer fiber, a porous plastic sheet, etc. can be used, for example.

  Further, in these laminated sheets, the gap is such that the minimum dimension CL in the laminating direction is equal to or greater than the total thickness t of the first sheet and the second sheet, and the average bulge of the first bulge and the second bulge. It can be in the range of height H or less (t ≦ CL ≦ H).

  This keeps the gap between the bulging parts and the size of the second bulging part appropriate for a long time, and the double air layer is not damaged by folding, packaging, packing, transportation, storage, etc. It can be used in a state in which the heat retention performance (particularly the touch and absorbency in the body fluid absorbing article) is suitable. When the gap dimension CL is less than the total thickness t (t> CL), the gap becomes excessively small, and when the gap dimension CL exceeds the average bulge height H (CL> H) In addition, the second bulging portion becomes excessively small, and there is a possibility that a sufficient double air layer cannot be obtained in any use.

Furthermore, in order to solve the said subject, the manufacturing apparatus of the lamination sheet of this invention is the following.
An apparatus for producing a laminated sheet composed of two (for example, non-woven fabric) sheets having elasticity,
A first concave roll having a plurality of concave portions on the peripheral surface and a second convex roll having a plurality of convex portions corresponding to the concave portions on the peripheral surface are arranged to be rotatable and supplied between both rolls. Embossed molding parts for embossing each of a plurality of bulging parts that bulge in a hollow shape inside the recesses with respect to two sheets;
A point-like shape with respect to the overlap region of the supplied two sheets disposed opposite the first concave roll at a position a predetermined distance away from the second convex roll on the downstream side in the rotation direction of the first concave roll A fixing portion for forming a plurality of spot joint portions that are joined in a linear or planar manner,
In the embossed molded part, a predetermined radial force (i.e., pressing force) is applied to each of the predetermined tensions (i.e., pressing force) when the convex part of the second convex roll enters the concave part of the first concave roll. A first bulging portion formed on the first sheet that comes into contact with the concave portion of the two sheets simultaneously supplied between the two rolls in a superposed state, and a convex portion; The second bulging portion formed on the second sheet to be in contact with each other has a similar shape, and is simultaneously and integrally molded in a form in which the latter is fitted inside the former,
On the discharge side of the embossed forming part, the convex part of the second convex roll is retracted from the concave part of the first concave roll. The protruding portions are released from the pressing force and the tension, respectively, and are deformed by contraction in the moving direction while rotating together with the first concave roll. At this time, the amount of contraction in the moving direction of the second sheet is the first amount. By being larger than that of the sheet, a predetermined gap is formed at least on the tip top side between the first bulge portion and the second bulge portion,
In the fixing portion, the first bulging portion being contracted and deformed while forming the gap, the first flat portion of the first sheet, and the second bulging portion. A plurality of the spot joints for fixing two sheets are formed in an overlapping region with the second flat portion of the second sheet.

Or in order to solve the above-mentioned subject, the manufacturing method of the lamination sheet of the present invention,
A method for producing a laminated sheet comprising two (for example, non-woven fabric) sheets having elasticity,
A first concave roll having a plurality of concave portions on the peripheral surface and a second convex roll having a plurality of convex portions corresponding to the concave portions on the peripheral surface are arranged to be rotatable and supplied between both rolls. Embossed molding parts for embossing each of a plurality of bulging parts that bulge in a hollow shape inside the recesses with respect to two sheets;
A point-like shape with respect to the overlap region of the supplied two sheets disposed opposite the first concave roll at a position a predetermined distance away from the second convex roll on the downstream side in the rotation direction of the first concave roll A fixing portion for forming a plurality of spot joint portions that are joined in a linear or planar manner,
In the embossing step in the embossed part, each of the first concave rolls has a predetermined radial force (that is, pressing force) while the convex part of the second convex roll enters the concave part of the first concave roll. The first bulge portion formed on the first sheet that comes into contact with the recess, out of the two sheets supplied with the tension (i.e., tensile load) at the same time between the two rolls in an overlapped state, The second bulge portion formed on the second sheet in contact with the convex portion has a similar shape to each other, and is simultaneously and integrally embossed in a form in which the latter is fitted inside the former,
In the shrinking step on the discharge side of the embossed molded part, the first bulging part accommodated inside the concave part and the convex part of the second convex roll are retracted from the concave part of the first concave roll, and Each of the second bulging portions is released from the pressing force and the tension, and is deformed by contraction in the moving direction while rotating together with the first concave roll. At this time, the contraction amount in the moving direction of the second sheet is reduced. By being larger than that of the first sheet, a predetermined gap is formed at least on the top end side between the first bulging portion and the second bulging portion,
In the joining step in the fixing unit, the first bulging part is being contracted and deformed while forming the gap, and the first flat part of the first sheet and the second bulging part. A plurality of spot joining portions for fixing two sheets are formed in an overlapping area with the second flat portion of the second sheet.

  According to such a manufacturing apparatus (or manufacturing method), the first bulge formed on the first sheet when the pressing force acting between the two rolls and the tension applied to each supply sheet are released. The second bulging portion formed on the portion and the second sheet contracts and deforms from the overlapping state in the concave portion of the first concave roll, and a gap is formed between the bulging portions. As a result, these bulging parts are not easily crushed (abnormal deformation) or fall off from the recesses, so there is no hindrance to the formation of spot joints, and buffer performance and heat retention performance (in body fluid absorbing articles) Does not particularly impair the uniformity of touch and absorbency. Furthermore, since the shrinkage amount of the second sheet is larger than the shrinkage amount of the first sheet, the gap constituting the double air layer can be easily and inexpensively formed on the laminated sheet.

The following items can be exemplified as factors for changing the sheet shrinkage after embossing (embossing) (in other words, means for providing a difference in the sheet shrinkage).
(1) Sheet material (2) Sheet thickness (3) Emboss shape = bulge shape (4) Temperature during emboss molding (5) Roll pressing force during emboss molding (6) Supply during emboss molding Sheet tension (7) Conveyance (roll rotation) speed after embossing = Time lag from embossing to joining Among these, the influence on sheet shrinkage is the strongest and the degree of freedom of change is large (that is, the variable range is wide). Is considered to be the supply sheet tension of (6).

  Therefore, in the emboss forming part, it is desirable that the tension of the second sheet is set to be larger than the tension of the first sheet among the two sheets to be supplied.

  As a result, even when the material, thickness, etc. of both sheets are the same, the amount of contraction of the second sheet is reduced when the pressing force acting between both rolls and the tension applied to the individual supply sheets are released. Since the amount of shrinkage is larger than that, stable gap formation becomes possible.

  Moreover, in the said embossing shaping | molding part, the heat generating body for shaping | molding is incorporated only in the 1st concave roll among the 1st concave roll and the 2nd convex roll.

  As a result, the shape of the first sheet (of the first bulging portion) is quickly stabilized by heating during embossing, so the contraction of the first sheet (of the first bulging portion) when the pressing force and tension are released. The amount can be made relatively small. As a result, the difference in the amount of contraction (of the bulging portion) between both sheets is enlarged, and the formation of a gap is facilitated.

  Furthermore, in the said embossing formation part, the diameter of a 1st concave roll is larger than the diameter of a 2nd convex roll.

  As a result, when the pressing force and tension are released, the first bulging portion is held on the bottom side of the concave portion of the large-diameter first concave roll, and is unlikely to move or come off from the opening side of the concave portion. On the other hand, the second bulging portion located on the opening side in the recess tends to contract in the recess when the pressing force and tension are released. As a result, the difference in the amount of contraction (of the bulging portion) between both sheets is enlarged, and the formation of a gap is facilitated. In addition, since the diameter of the first concave roll is larger than the diameter of the second convex roll, the degree of freedom of the shape, size, number of arrangement, layout, and the like of the bulging portion and the spot joint portion is increased.

On the other hand, in the fixing unit, a smooth roll having a flat peripheral surface and containing a heating element for bonding is disposed so as to be opposed to the first concave roll across the first sheet and the second sheet. On the other hand, the first concave roll is formed with a plurality of protrusions that rise in a step shape from the peripheral surface at a position corresponding to the spot joint portion around the concave portion,
A spot joint is formed by heating the first sheet and the second sheet by the first concave roll and the smooth roll.

  In this way, the first sheet and the second sheet are heated by the heating element with the first concave roll and the heating element with the smooth roll, and the overlapping region between the first flat part and the second flat part is fused. By forming a plurality of spot joint portions, both sheets can be fixed in a short time in a gap-formed state and during shrinkage deformation. One or more smooth rolls can be installed according to the sheet material, thickness, shape, size, number of arrangements, layout, etc. of the spot joints, and smooth rolls according to the formation status of the spot joints. You can also adjust the number of running.

  The fixing unit is an ultrasonic vibration unit for bonding, which is disposed to face the first concave roll with the first sheet and the second sheet interposed therebetween, and the ultrasonic wave of the second sheet by the ultrasonic vibration unit A spot junction is formed by vibration.

  As described above, the ultrasonic wave is applied to the second sheet by the heating element and the ultrasonic vibration part built in the first concave roll, and the overlapping region between the first flat part and the second flat part is fused to be plural. By forming the spot joint portion, both sheets can be fixed in a short time in a gap formation state and during shrinkage deformation.

Explanatory drawing which shows schematic structure of the disposable diaper using the lamination sheet which concerns on this invention. FIG. 2 is a cross-sectional explanatory view taken along the line AA in FIG. Explanatory drawing which expands the B section of FIG. 1 and shows the planar structure of a lamination sheet. Explanatory drawing which expands the C section of FIG. 2, and shows the cross-section of a lamination sheet. The front view which shows an example of the lamination sheet manufacturing apparatus which concerns on this invention. Explanatory drawing which expands the D section of FIG. 5 and shows with the manufacturing process of a lamination sheet. Explanatory drawing which expands the E section of FIG. 5 and shows with the manufacturing process of a lamination sheet. Explanatory drawing which expands the F section of FIG. 5 and shows with the manufacturing process of a lamination sheet. The front view which shows the modification of a lamination sheet manufacturing apparatus instead of FIG. Explanatory drawing which shows the deformation | transformation cross-section of a lamination sheet instead of FIG.

(Example of laminated sheet)
Hereinafter, embodiments of the present invention will be described with reference to examples shown in the drawings. 1-4 shows the specific example at the time of using the laminated sheet which concerns on this invention for a disposable diaper. The disposable diaper 9 shown in FIG.1 and FIG.2 is an example of what is called a bodily fluid absorption article, and is also called "tape type paper diaper". The absorbent body 7 located substantially at the center of the disposable diaper 9 is formed into various shapes such as a flat plate shape containing superabsorbent polymer particles, and the periphery is covered with a plurality of sheets. For example, a top sheet (hereinafter referred to as a first sheet) 1 that is in direct contact with the skin on the human body side (that is, a body fluid absorption side) of the absorbent body 7 or a second sheet positioned between the first sheet 1 and the absorbent body 7. A sheet (hereinafter referred to as a second sheet) 2 is provided, and an exterior sheet 6 having a fastening tape 8 is provided on the side opposite to the human body (that is, the body fluid non-absorbing side). These sheets 1, 2, 6 are made of a stretchable nonwoven fabric, the first sheet 1, the second sheet 2 are liquid permeable, and the exterior sheet 6 is non-liquid permeable.

  As shown in FIGS. 3 and 4, the first sheet 1 and the second sheet 2 constitute a laminated sheet 5 and are arranged so that the first sheet 1 is located on the contact side with the human body. Among these, the 1st sheet | seat 1 is formed with many 1st bulging parts 1a which bulge in hollow shape only from one side (human body side) from the flat 1st flat part 1b. The second sheet 2 is also formed with a number of second bulging portions 2a that bulge in a hollow shape only on one side (the human body side) from the flat second flat portion 2b. In the overlapping region of the first flat portion 1b located around the first bulge portion 1a and the second flat portion 2b located around the second bulge portion 2a, the two sheets 1 and 2 are numerous. It is fused and fixed in a spot shape (shown in a dot shape in the figure) by the spot joint portion 3. The first bulging portion 1a and the second bulging portion 2a are configured such that the second bulging portion 2a is fitted inside the first bulging portion 1a on the base end side, and the first bulging portion is on the distal end top portion side. There is a gap 4 between the protruding portion 1a and the second bulging portion 2a.

  FIG. 3 shows an example of the planar structure of the laminated sheet 5, and the bulging portions 1a and 2a associated with each other overlap in a hat shape, and the overlapping structure of such bulging portions 1a and 2a is staggered (obliquely crossed) Arranged). Moreover, the spot junction part 3 is arranged in the position which divides the circumference into six equal parts with respect to the overlapping structure of the bulging parts 1a and 2a. Since the two sheets 1 and 2 are fixed only at these spot joint portions 3, the internal space of the gap 4 adjacent to each other and the second bulging portion 2a adjacent to each other is the same as that of the flat portions 1b and 2b. Communication is possible by a non-bonding overlap region or the like.

  FIG. 4 shows an example of the cross-sectional structure of the laminated sheet 5, and the outer first bulging portion 1 a has a cylindrical shape in which the tip top portion side is closed with a semi-ellipsoid that halves the rugby ball or the fruit of the insulator. In addition, the inner second bulging portion 2a is also formed in a similar shape.

In the laminated sheet 5 shown in FIG.
-The bulge height H1 of the 1st bulge part 1a = 3mm
-The bulge height H2 = 2mm of the 2nd bulge part 2a
・ Thickness t1 of the first sheet 1 = 0.1 mm
-The thickness t2 of the second sheet 2 = 0.1 mm
Then, the minimum gap dimension CL in the stacking direction is
CL = (H1-t1)-(H2-t2) = (H1-H2) + (t2-t1)
= 1.0mm
It becomes. Therefore, the minimum gap dimension CL = 1.0 mm in this case is the total thickness t = t1 + t2 = 0.2 mm or more of both sheets 1 and 2, and the average bulge height H = (H1 + H2) / 2 = within a range of 2.5 mm or less (t ≦ CL ≦ H), and a sufficient double air layer can be obtained in use.

  Thus, the lamination sheet 5 has a double air layer of the clearance gap 4 formed between the 1st bulging part 1a and the 2nd bulging part 2a, and the hollow 2nd bulging part 2a. Excellent cushioning performance (double cushion function) and thermal insulation performance (double blanket function), softer to the touch and more comfortable to wear. Moreover, since the 1st bulging part 1a and the 2nd bulging part 2a do not overlap two sheets but the clearance gap 4 interposes, the absorptivity of the disposable diaper 9 also improves.

(Example of laminated sheet manufacturing apparatus)
Next, FIG. 5 shows an example of a laminated sheet manufacturing apparatus according to the present invention. A laminated sheet manufacturing apparatus 100 shown in FIG. 5 simultaneously embosses a plurality of bulging portions 1a and 2a (see FIG. 6) on two sheets 1 and 2 supplied simultaneously (embossing). An embossing forming part 10 for fixing the two sheets 1 and 2 and a fixing part 20 for forming a plurality of spot joining parts 3 (see FIGS. 7 and 8).

  The first sheet 1 pulled out from the first sheet supply reel 101a is given a predetermined tension by the first tension adjuster 101b and is continuously supplied to the embossing forming unit 10, and is supplied from the second sheet supply reel 102a. The pulled-out second sheet 2 is given a predetermined tension by the second tension adjuster 102 b and is continuously supplied to the embossed molding unit 10. On the other hand, both the sheets 1 and 2 are joined by the fixing unit 20, and are continuously wound around the take-up reel 103 as the laminated sheet 5. Both the first sheet 1 and the second sheet 2 have stretchability and liquid permeability, and are made of, for example, a nonwoven fabric having the same material and the same thickness. The laminated sheet 5 is cut into an appropriate length and used for a disposable diaper 9 (see FIGS. 1 and 2).

  The embossing part 10 has a plurality of recesses 11a on the peripheral surface and a first concave roll 11 positioned below, and a plurality of convex portions 12a corresponding to the recesses 11a on the peripheral surface and a second protrusion positioned above. The embossing roll which consists of the roll 12 is provided, and both the rolls 11 and 12 are arrange | positioned so that rotation is possible. When the first sheet 1 and the second sheet 2 are simultaneously supplied in an overlapped state between the two rolls 11 and 12, the two sheets 1 and 2 have a plurality of bulges in a hollow shape inside the recess 11a. The first bulging portion 1a and the plurality of second bulging portions 2a are simultaneously and integrally stamped (embossed) (see FIG. 6).

  Each of the tension adjusters 101 b and 102 b is set so that the tension of the second sheet 2 out of the two sheets 1 and 2 supplied to the embossing forming unit 10 is larger than the tension of the first sheet 1. The As a result, when the pressing force acting between the two rolls 11 and 12 and the tension applied to the individual supply sheets 1 and 2 are released immediately after the embossing forming portion 10, the second sheet 2 (especially the second swelling) The shrinkage amount of the protruding portion 2a) is larger than the shrinkage amount of the first sheet 1 (particularly, the first bulging portion 1a).

  Of the two rolls 11 and 12 constituting the embossing roll, only the first concave roll 11 has a main heater 11h (a heating element for forming, a heating element for bonding) built therein. The main heater 11h mainly heats the first sheet 1 when the supply sheets 1 and 2 are pressed by the embossing rolls 11 and 12, so that the first sheet 1 (particularly the first bulging portion 1a) has an early embossed shape. To stabilize and suppress deformation. Therefore, the amount of contraction of the first sheet 1 (particularly, the first bulging portion 1a) after mold pressing (that is, when the pressing force and tension are released) is relatively small. Further, the main heater 11h cooperates with the first fusing heater 21h (or the second fusing heater 22h) incorporated in the first smoothing roll 21 (or the second smoothing roll 22), which will be described later, and both sheets 1, 2. And a plurality of spot joints 3 are formed by fusing.

  This will be described with reference to FIG. 5 and FIG. The diameter of the outer peripheral surface of the first concave roll 11 is larger than the diameter of the outer peripheral surface of the second convex roll 12. Thereby, after the die pressing (that is, when the pressing force and tension are released), the first bulging portion 1a is held on the bottom side of the concave portion 11a of the large-diameter first concave roll 11, and moves to the opening side of the concave portion 11a. It is hard to come off and come off. On the other hand, the second bulging portion 2a located on the opening side in the concave portion 11a easily contracts in the concave portion 11a when the pressing force and the tension are released. As a result, the difference in the amount of contraction between both sheets 1 and 2 (particularly the bulging portions 1a and 2a) is enlarged.

  Furthermore, since the diameter of the first concave roll 11 is larger than the diameter of the second convex roll 12, the shape, size, number of arrangement, and layout of the bulging portions 1a and 2a and the spot joint portion 3 (see FIG. 4). Etc. The degree of freedom increases. For example, since the small-diameter second convex roll 12 can be disposed above the large-diameter first concave roll 11, the bulging heights H1, H2 (see FIG. 4), etc., depending on the material and thickness of the sheets 1, 2 When changing, it may be sufficient to replace the lightweight second convex roll 12.

  The fixing unit 20 shown in FIG. 5 is the same as the first smooth roll 21 located about 90 ° away from the second convex roll 12 on the downstream side in the rotation direction of the first concave roll 11 and the second smooth roll 21 located about 180 ° apart. Each of the rolls 21 and 22 is disposed so as to be rotatable facing the first concave roll 11 with the first sheet 1 and the second sheet 2 interposed therebetween. Each of the smooth rolls 21 and 22 has a flat outer peripheral surface having substantially the same diameter, and incorporates fusion heaters 21h and 22h (joining heating elements) and has substantially the same structure.

  When the first sheet 1 and the second sheet 2 are supplied between the first concave roll 11 and the first smooth roll 21 (or the second smooth roll 22), the main heater 11h and the first fusion heater 21h (or A plurality of spot joint portions 3 are formed by fusion on both sheets 1 and 2 heated by the second fusion heater 22h) (see FIG. 7 (or FIG. 8)). In addition, the diameter of the outer peripheral surface of the first smooth roll 21 (or the second smooth roll 22) is smaller than the diameter of the outer peripheral surface of the first concave roll 11 and larger than the diameter of the outer peripheral surface of the second convex roll 12.

  This will be specifically described with reference to FIGS. 3, 4 and 7 (or FIG. 8). In the overlapping region of the first flat portion 1b located around the first bulge portion 1a and the second flat portion 2b located around the second bulge portion 2a, the main heater 11h and the first fusion heater 21h A plurality of spot joints 3 fused in a dot shape (for example, dot shape) by heating (or the second fusion heater 22h) are formed.

  The first concave roll 11 is formed with a plurality of protrusions 11b that rise in steps from the peripheral surface of the first concave roll 11 at a position corresponding to the spot joining portion 3 in the periphery (periphery) of the concave portion 11a. ing. When these protrusions 11b are pressed by the outer peripheral surface of the first smooth roll 21 (or the second smooth roll 22) in the fixing unit 20, they are the surfaces of the first sheet 1 (first flat portion 1b) and spot bonded. A dent 1b1 (a kind of trace) is formed at a position corresponding to the portion 3.

(Example of laminated sheet manufacturing method)
FIGS. 6-8 shows an example of the manufacturing method of the lamination sheet which concerns on this invention, and represents the process of manufacturing the lamination sheet shown in FIG. 3, FIG. 4 using the lamination sheet manufacturing apparatus shown in FIG.

<Embossing process> (See FIGS. 5 and 6)
When the convex portion 12a of the second convex roll 12 enters the concave portion 11a of the first concave roll 11, the two sheets 1 and 2 supplied simultaneously in an overlapped state are sandwiched between the concave portion 11a and the convex portion 12a. . At this time, the tensions set by the tension adjusters 101b and 102b (the second sheet 2 is larger than the first sheet 1) in the opposite direction (that is, each supply reel 101a). , 102a direction), and the radial pressing force of both rolls 11, 12 acts in the thickness direction of both sheets 1,2. And the 1st bulging part 1a is formed in the 1st sheet | seat 1 which contacts the recessed part 11a, and the 2nd bulging part 2a is formed in the 2nd sheet | seat 2 which contacts the convex part 12a. The first bulging portion 1a and the second bulging portion 2a are similar to each other (in the figure, a bottomed cylindrical shape), and the second bulging portion 2a is fitted inside the first bulging portion 1a. It is simultaneously and integrally molded inside the recess 11a.

<Shrinking process> (See FIGS. 5 and 6)
On the discharge side of embossing part 10 (immediately after the embossing step), the convex part 12a of the second convex roll 12 withdraws from the concave part 11a of the first concave roll 11, and is stamped and overlapped inside the concave part 11a. The first bulging portion 1a and the second bulging portion 2a immediately after being accommodated in the state are released from the pressing force and the tension, respectively. The bulging portions 1a and 2a immediately after the release are deformed by contraction in the moving direction (that is, the first smooth roll 21 side opposite to the tension acting direction at the time of embossing) while rotating together with the first concave roll 11. To do.

  At this time, since the contraction amount in the moving direction (that is, the contraction direction) of the second sheet 2 is larger than the contraction amount of the first sheet 1, the second bulge portion 2a is more than the first bulge portion 1a. The gap 4 is further reduced, and a gap 4 is formed between the first bulging portion 1a and the second bulging portion 2a on the top end side. Specifically, as shown in FIG. 6, the gap 4 between the bulging portions 1 a and 2 a according to the difference in shrinkage between the sheets 1 and 2 (in this embodiment, it is also the tension difference during the embossing process). Gradually expands.

<First joining step> (See FIGS. 5 and 7)
The two sheets 1 and 2 supplied between the first concave roll 11 and the first smooth roll 21 are heated by the main heater 11h and the first fusion heater 21h, and the first flat portion 1b and the second flat portion are heated. The overlapping region with the portion 2b is fused to form a plurality of spot joints 3 and dents 1b1 (see FIG. 4).

<Second joining step> (See FIGS. 5 and 8)
The two sheets 1 and 2 supplied between the first concave roll 11 and the second smooth roll 22 are heated again by the main heater 11h and the second fusing heater 22h, and the first flat portion 1b and the second flat roll 1b. Spot joints 3 and dents 1b1 (see FIG. 4) are replenished and formed in regions that are overlapped with the flat part 2b and are not joined or insufficiently joined in the first joining step. The second joining step in this embodiment complements the first joining step.

  The laminated sheet 5 shown in FIGS. 3 and 4 can be manufactured through the above-described steps. By such a manufacturing method, the laminated sheet 5 having a double air layer between the gap 4 formed between the first bulging portion 1a and the second bulging portion 2a and the hollow second bulging portion 2a. Can be manufactured easily and inexpensively.

  Note that only one of the first joining step (first smooth roll 21) and the second joining step (second smooth roll 22) may be executed (operated) as necessary. Moreover, you may form the spot joining part 3 of a different form in a 2 step | part in a different site | part by a 1st joining process (1st smooth roll 21) and a 2nd joining process (2nd smooth roll 22). Furthermore, the time during which the sheets 1 and 2 continue to contract (in other words, the time during which the gap 4 between the bulging portions 1a and 2a continues to expand) is not constant depending on various conditions. There may be a case where the process continues until after the second bonding process, or a case where the spot bonding part 3 continues until the temperature reaches room temperature.

(Modification of laminated sheet manufacturing equipment)
FIG. 9 shows a modification of the laminated sheet manufacturing apparatus. In the fixing unit 20 of the laminated sheet manufacturing apparatus 100 shown in FIG. 9, an ultrasonic vibration unit 121 for bonding is provided instead of the first smooth roll 21 in FIG. 5, and the second smooth roll 22 is not provided. . The ultrasonic vibration unit 121 is disposed to face the first concave roll 11 with the first sheet 1 and the second sheet 2 interposed therebetween, and forms the spot bonding unit 3 by ultrasonically vibrating the second sheet 2.

  As described above, the main heater 11h and the ultrasonic vibration unit 121 built in the first concave roll 11 impart ultrasonic vibration to the second sheet 2, and the overlapping region of the first flat portion 1b and the second flat portion 2b. By forming the spot joint 3 by fusing the two, the sheets 1 and 2 can be fixed in a short time in a state where the gap 4 is formed and during shrinkage deformation.

(Modification of laminated sheet)
FIG. 10 shows a modified example of the laminated sheet. In the laminated sheet 5 shown in FIG. 10, the first bulging portion 1 a has a small amount of contraction compared to FIG. On the other hand, since the second bulging portion 2a has a larger amount of contraction than that of FIG. 4, the tip top portion contracts in a hemispherical shape, and a gap 4 is also formed between the peripheral surface of the first bulging portion 1a. The

In the laminated sheet 5 shown in FIG.
-The bulge height H1 of the 1st bulge part 1a = 3mm
-The bulging height H2 of the second bulging portion 2a = 1.6 mm
・ Thickness t1 of the first sheet 1 = 0.1 mm
-The thickness t2 of the second sheet 2 = 0.1 mm
Then, the minimum gap dimension CL in the stacking direction is
CL = (H1-t1)-(H2-t2) = (H1-H2) + (t2-t1)
= 1.4mm
It becomes. Therefore, the minimum gap dimension CL = 1.4 mm in this case is the total thickness t = t1 + t2 = 0.2 mm or more of both sheets 1 and 2, and the average bulge height H of both bulge portions 1a and 2a = (H1 + H2) / 2 = in the range of 2.3 mm or less (t ≦ CL ≦ H), and a sufficient double air layer can be obtained in use.

  In the above embodiment, only the laminated sheet used for the disposable diaper and the production apparatus and production method for the laminated sheet have been described, but the laminated body used for other purposes as well as articles for absorbing body fluid other than the disposable diaper. The present invention can also be carried out on sheets.

  In each modification (FIGS. 9 and 10), parts having the same functions as those of the corresponding embodiments (FIGS. 5 and 4) are denoted by the same reference numerals, and detailed description thereof is partially omitted. . In addition, the embodiments and modifications described above can be implemented in appropriate combination within a range that does not cause technical contradiction. For example, the bulging portions 1 a and 2 a shown in FIG. 4 and the bulging portions 1 a and 2 a shown in FIG. 10 may be provided in a single laminated sheet 5.

1 First sheet (top sheet)
1a 1st bulging part 1b 1st flat part 1b1 dent 2 2nd sheet (second sheet)
2a 2nd bulging part 2b 2nd flat part 3 spot junction part 4 gap 5 lamination sheet 6 exterior sheet 7 absorber 8 fastening tape 9 disposable diaper (article for absorbing body fluid)
DESCRIPTION OF SYMBOLS 10 Embossing part 11 1st concave roll 11a Recessed part 11b Protrusion 11h Main heater (heating element for shaping | molding, heating element for joining)
12 Second convex roll 12a Convex portion 20 Fixing portion 21 First smooth roll 21h First fusion heater (heating element for joining)
22 Second smooth roll 22h Second fusion heater (heating element for joining)
DESCRIPTION OF SYMBOLS 100 Laminated sheet manufacturing apparatus 101a 1st sheet supply reel 101b 1st tension adjuster 102a 2nd sheet supply reel 102b 2nd tension adjuster 103 Take-up reel 121 Ultrasonic vibration part CL Minimum gap dimension (in a lamination direction) H1 1st The bulging height of the bulging portion H2 The bulging height of the second bulging portion H The average bulging height t1 The thickness of the first sheet t2 The thickness of the second sheet t The total thickness

Claims (10)

It is a laminated sheet consisting of two sheets having elasticity,
Among these two sheets, the first sheet located on one side in the stacking direction is formed with a plurality of first bulging portions that bulge in a hollow shape only on one side, and on the other side in the stacking direction. A plurality of second bulge portions that bulge in a hollow shape only on one side are formed in the second sheet positioned, and the first flat portion of the first sheet is around the first bulge portion and A plurality of spot joints that join the two sheets in a dotted, linear, or planar manner around the second bulging portion and an overlapping area with the second flat portion of the second sheet Formed,
The first bulging portion formed on the first sheet and the second bulging portion formed on the second sheet are such that the second bulging portion is located inside the first bulging portion on the base end side. A laminated sheet that is fitted and has a predetermined gap between the first bulging portion and the second bulging portion at least on the tip top side. It consists of two sheets having stretchability and liquid permeability, and is a laminated sheet used for an article for absorbing body fluid,
Among these two sheets, the first sheet that is located on one side in the laminating direction and contacts the human body is formed with a plurality of first bulging portions that bulge in a hollow shape only on one side, The second sheet located on the other side of the direction is also formed with a plurality of second bulging portions that bulge in a hollow shape only on one side, and is around the first bulging portion, Two sheets are joined in a dotted, linear, or planar shape to the overlapping area between the first flat portion and the second bulging portion and the second flat portion of the second sheet. A plurality of spot joints are formed,
The first bulging portion formed on the first sheet and the second bulging portion formed on the second sheet are such that the second bulging portion is located inside the first bulging portion on the base end side. A laminated sheet that is fitted and has a predetermined gap between the first bulging portion and the second bulging portion at least on the tip top side.   The gap has a minimum dimension in the stacking direction that is equal to or greater than the total thickness of the first sheet and the second sheet, and is less than or equal to the average bulge height of the first bulge and the second bulge. The laminated sheet according to claim 2. An apparatus for producing a laminated sheet comprising two sheets having elasticity,
A first concave roll having a plurality of concave portions on the peripheral surface and a second convex roll having a plurality of convex portions corresponding to the concave portions on the peripheral surface are arranged to be rotatable and supplied between both rolls. Embossed molding parts for embossing each of a plurality of bulging parts that bulge in a hollow shape inside the recesses with respect to two sheets;
A point-like shape with respect to the overlap region of the supplied two sheets disposed opposite the first concave roll at a position a predetermined distance away from the second convex roll on the downstream side in the rotation direction of the first concave roll A fixing portion for forming a plurality of spot joint portions that are joined in a linear or planar manner,
In the embossed forming part, a predetermined tension is applied to each other in a superposed state while a pressing force in a predetermined radial direction is applied by the protrusion of the second convex roll entering the concave portion of the first concave roll. Of the two sheets supplied simultaneously between these two rolls, a first bulging portion formed on the first sheet that contacts the concave portion and a second sheet formed on the second sheet that contacts the convex portion. The two swollen portions are similar to each other and simultaneously and integrally molded in a form in which the latter is inserted inside the former,
On the discharge side of the embossed forming part, the convex part of the second convex roll is retracted from the concave part of the first concave roll. The protruding portions are released from the pressing force and the tension, respectively, and are deformed by contraction in the moving direction while rotating together with the first concave roll. At this time, the amount of contraction in the moving direction of the second sheet is the first amount. By being larger than that of the sheet, a predetermined gap is formed at least on the tip top side between the first bulge portion and the second bulge portion,
In the fixing portion, the first bulging portion being contracted and deformed while forming the gap, the first flat portion of the first sheet, and the second bulging portion. An apparatus for manufacturing a laminated sheet, wherein a plurality of the spot joints for fixing two sheets are formed in an overlapping area with the second flat portion of the second sheet.   5. The laminated sheet manufacturing apparatus according to claim 4, wherein, in the emboss forming unit, the tension of the second sheet is set to be larger than the tension of the first sheet among the two sheets to be supplied.   6. The laminated sheet manufacturing apparatus according to claim 5, wherein a heating element for molding is incorporated in only the first concave roll among the first concave roll and the second convex roll in the embossed molding section.   6. The laminated sheet manufacturing apparatus according to claim 5, wherein in the embossed part, the diameter of the first concave roll is larger than the diameter of the second convex roll. In the fixing unit, a smooth roll having a flat peripheral surface and containing a heating element for bonding is disposed so as to be opposed to the first concave roll across the first sheet and the second sheet. On the other hand, the first concave roll is formed with a plurality of protrusions that rise in a step shape from the peripheral surface at a position corresponding to the spot joint portion around the concave portion,
The laminated sheet manufacturing apparatus according to claim 4, wherein the spot joint is formed by heating the first sheet and the second sheet by the first concave roll and the smooth roll.   The fixing unit is an ultrasonic vibration unit for bonding, which is disposed to face the first concave roll with the first sheet and the second sheet interposed therebetween, and the second unit by the ultrasonic vibration unit. The laminated sheet manufacturing apparatus according to claim 4, wherein the spot joint is formed by ultrasonic vibration of the sheet. A method for producing a laminated sheet comprising two sheets having elasticity,
A first concave roll having a plurality of concave portions on the peripheral surface and a second convex roll having a plurality of convex portions corresponding to the concave portions on the peripheral surface are arranged to be rotatable and supplied between both rolls. Embossed molding parts for embossing each of a plurality of bulging parts that bulge in a hollow shape inside the recesses with respect to two sheets;
A point-like shape with respect to the overlap region of the supplied two sheets disposed opposite the first concave roll at a position a predetermined distance away from the second convex roll on the downstream side in the rotation direction of the first concave roll A fixing portion for forming a plurality of spot joint portions that are joined in a linear or planar manner,
In the embossing step in the embossed forming section, a predetermined tension is applied to each of the concave portions of the first concave roll while a convex portion of the second convex roll enters into the concave portion to apply a pressing force in a predetermined radial direction. Of the two sheets supplied simultaneously between these two rolls in an overlapped state, a first bulging portion formed on the first sheet that contacts the concave portion and a second sheet that contacts the convex portion The formed second bulging part is similar to each other and simultaneously and integrally molded in a form in which the latter is fitted inside the former,
In the shrinking step on the discharge side of the embossed molded part, the first bulging part accommodated inside the concave part and the convex part of the second convex roll are retracted from the concave part of the first concave roll, and Each of the second bulging portions is released from the pressing force and the tension, and is deformed by contraction in the moving direction while rotating together with the first concave roll. At this time, the contraction amount in the moving direction of the second sheet is reduced. By being larger than that of the first sheet, a predetermined gap is formed at least on the top end side between the first bulging portion and the second bulging portion,
In the joining step in the fixing unit, the first bulging part is being contracted and deformed while forming the gap, and the first flat part of the first sheet and the second bulging part. A method for manufacturing a laminated sheet, wherein a plurality of the spot joints for fixing two sheets are formed in an overlapping region with the second flat portion of the second sheet.

Images