JP4046677B2 - Composite sheet manufacturing equipment - Google Patents

Description

  The present invention relates to an apparatus for manufacturing a composite sheet which is composed of two sheet-like materials, and one sheet-like material forms a number of convex portions. Moreover, this invention relates to the manufacturing method of the composite sheet using this manufacturing apparatus.

  A spunbond nonwoven fabric is point-bonded to at least one side of the elastic material to form a composite nonwoven fabric. After applying a load by pulling the composite nonwoven fabric in a predetermined direction, the load is removed to cause sagging in the spunbond nonwoven fabric. A bulky composite nonwoven fabric is known (see Patent Document 1). This composite nonwoven fabric is used as a side belt of a pants-type diaper. As a method of obtaining a composite sheet having a large number of convex portions, in addition to the method described in Patent Document 1, methods described in Patent Documents 2 and 3 are also known.

  However, since the nonwoven fabric described in Patent Document 1 causes sagging by utilizing plastic deformation of the spunbond nonwoven fabric, fiber fluffing occurs in the sagging portion. Therefore, when such a nonwoven fabric is used as the top sheet of the absorbent article, the fluffy fibers will irritate the skin and the feeling of wearing the absorbent article will be reduced. In the first place, since this nonwoven fabric is not designed as a top sheet for absorbent articles, a sufficient liquid leakage preventing effect cannot be expected even if it is used as a top sheet for absorbent articles. In particular, it cannot be expected to prevent leakage of loose stool or menstrual blood that is a highly viscous liquid.

  Moreover, since the sagging in the nonwoven fabric is caused by plastic deformation of the spunbonded nonwoven fabric, it is not always easy to produce sagging with a constant size and good reproducibility.

JP-A-5-59655 Japanese Patent Laid-Open No. 10-245757 JP-A-2-18036

  Accordingly, an object of the present invention is to provide a composite sheet manufacturing apparatus that eliminates the disadvantages in manufacturing the above-described conventional composite sheet.

In the present invention, the first and second sheet-like materials are partially joined to form a large number of joints, and the first sheet-like material protrudes at a portion other than the joints, An apparatus for producing a composite sheet forming a large number of convex portions that are hollow inside,
The manufacturing apparatus includes a first roll having a concavo-convex shape on the peripheral surface, and a second roll having a concavo-convex shape meshing with the concavo-convex shape of the first roll on the peripheral surface. And
At least the first roll has a roll shape in which a plurality of gears are attached to the rotary shaft so as to form uneven portions alternately along the rotation direction of the roll,
A gap of a predetermined width is formed between the gears every predetermined number of gears, and the gap communicates with a suction path formed in the first roll so as to extend in the rotation axis direction of the roll. This object is achieved by providing a composite sheet manufacturing apparatus.

Further, the present invention is a method for manufacturing a composite sheet using the manufacturing apparatus,
The first sheet and the second roll are meshed with the first sheet-like material, and the sheet-like material is shaped unevenly,
While holding the first sheet-like material in an unevenly shaped state on the peripheral surface of the roll by suction through the suction path formed on the first roll, the second sheet-like material is overlaid, The manufacturing method of the composite sheet which joins the sheet-like material of 2 with the 1st sheet | seat located on the convex part in a 1st roll is provided.

  According to the manufacturing apparatus of the present invention, it is possible to easily manufacture a composite sheet having convex portions having a desired pitch and size, particularly convex portions having a small pitch. It is also easy to reliably form a large number of small convex portions. Further, the convex portion can be formed with a constant size and good reproducibility. Furthermore, the pitch and size of the convex portions can be freely changed by a simple operation by simply changing the combination and width of the gears. The composite sheet produced by the production apparatus of the present invention is particularly suitably used as a surface sheet for absorbent articles. When used as a top sheet, the sheet has excellent liquid leakage prevention properties and high concealability of absorbed liquid.

  The present invention will be described below based on preferred embodiments with reference to the drawings. First, an example of a composite sheet manufactured using the manufacturing apparatus of the present invention will be described. FIG. 1 is an enlarged view of a main part of an example of a composite sheet manufactured using the manufacturing apparatus of the present invention. The composite sheet manufactured according to the present embodiment is suitably used as the top sheet 1 disposed on the skin contact surface of an absorbent article such as a sanitary napkin or a disposable diaper. The surface sheet 1 shown in FIG. 1 is composed of two sheet-like objects. The topsheet 1 has an upper layer 2 as a first sheet-like material directed to the skin side of the wearer and a lower layer 3 as a second sheet-like material arranged on the absorber side. The upper layer 2 and the lower layer 3 are typically composed of various nonwoven fabrics and films. As a nonwoven fabric, the nonwoven fabric manufactured by the card | curd method, the spun bond nonwoven fabric, the melt blown nonwoven fabric, the spunlace nonwoven fabric, the needle punch nonwoven fabric etc. are mentioned, for example. When a film is used, it is preferable to perforate the film to provide a large number of holes so that the liquid can be permeated.

  The upper layer 2 and the lower layer 3 are partially joined at a number of joints 4. The upper layer 2 protrudes toward the wearer's skin side at a portion other than the joint portion 4 to form a convex portion 5. The inside of the convex part 5 is hollow.

  In the present embodiment, the bottom surface of the convex portion 5 is rectangular. Further, the convex portion 5 is a flat rectangular parallelepiped or truncated quadrangular pyramid having rounded ridge lines as a whole. On the other hand, the joint 4 is also rectangular.

  The convex portions 5 and the joint portions 4 are arranged alternately and in a row in one direction. In the present embodiment, as shown in FIG. 1, the convex portions 5 and the joint portions 4 are alternately arranged along the X direction in the figure to form a row. This direction coincides with the flow direction in the manufacturing process of the topsheet 1 and also coincides with the longitudinal direction of the absorbent article when the topsheet 1 is incorporated into the absorbent article or a direction perpendicular thereto. The row | line | column which consists of the convex part 5 and the junction part 4 is arrange | positioned at multiple rows over the Y direction in FIG.

  In the topsheet 1, when attention is paid to any one convex portion in one row, no convex portion is located at a position adjacent to the one convex portion in the left and right rows adjacent to the row. . “No convex part is located adjacent to one convex part” means that when one convex part is focused, the convex part is not located at the same position in the adjacent row. I mean. That is, in the Y direction in FIG. 1, it means that the convex portions are not arranged so that the convex portions between adjacent rows are completely connected. Therefore, both a part of a convex part and a part of junction part may exist in the position adjacent to one convex part, or only a junction part may exist. If the convex portions are arranged so as to be completely connected in the Y direction, a convex portion that apparently extends in the Y direction is formed, and in this case, the liquid flows out along the long convex portion. It becomes easy to cause liquid leakage.

  In the present embodiment, in two adjacent rows, the joint portions are arranged so as to be shifted by a half pitch. Therefore, when attention is paid to any one joint portion in one row, the one joint portion is a closed concave portion formed by being surrounded by convex portions on the front and rear sides and the right and left sides. That is, the joints are arranged in a staggered pattern. Accordingly, the convex portions are similarly arranged in a staggered pattern.

  By arranging the convex portion 5 and the joint portion 4 in this manner, liquid leakage is prevented extremely effectively in the absorbent article including the topsheet 1. In detail, when the top sheet 1 is used as a top sheet of a disposable diaper, for example, a diaper for a low-age infant who excretes loose stool, which is a highly viscous excrement, the following effects are exhibited. Since soft stool has a high viscosity, it is generally difficult to permeate the surface sheet quickly and stays on the surface sheet and tends to cause a lateral flow. On the other hand, according to the surface sheet of the present embodiment, the soft stool is trapped in the closed recess formed by being surrounded by the protrusion 5, so that the lateral flow is less likely to occur and is captured. As a result, the downward movement (that is, the absorber direction) is promoted. As a result, leakage of soft stool is prevented. Moreover, since the convex part 5 has a hollow inside, it has a concealing effect that the color of soft stool absorbed by the absorbent body is reduced when viewed from the surface sheet side. These effects are also exhibited when the topsheet 1 of the present embodiment is used as a topsheet for a sanitary napkin for absorbing menstrual blood, which is excrement having high viscosity, as with loose stool.

  The manufacturing method of this surface sheet 1 is demonstrated referring the manufacturing apparatus shown in FIGS. As shown in FIG. 2, the manufacturing apparatus according to the present embodiment surrounds the first roll 11 having a concavo-convex shape on the peripheral surface, and the concavo-convex shape having a mesh shape with the concavo-convex shape of the first roll 11. A second roll 12 on the surface and an anvil roll 14 are provided. The 1st roll 11 and the 2nd roll 12 are arrange | positioned so that the uneven | corrugated | grooved part of each roll peripheral surface may mesh | engage. The first roll 11 and the anvil roll 14 are arranged such that the top of the convex portion of the peripheral surface of the first roll 11 is in contact with the peripheral surface of the anvil roll 14.

  FIG. 3 shows a perspective view of a main part of the first roll 11, and FIG. 4 shows an exploded perspective view of a part thereof. The first roll 11 is formed by combining a plurality of first gears 11 a and second gears 11 b made of spur gears of the same module and attaching these gears concentrically to the rotary shaft 15 to form a roll. is there. Each gear 11a, 11b has the same tooth width. Each gear 11a, 11b has an opening at its center, and a rotating shaft 15 is inserted into the opening. Each gear 11a, 11b and the rotary shaft 15 are each formed with a notch (not shown), and a key (not shown) is inserted into the notch. This prevents idle rotation of the gears 11a and 11b.

  The first gear 11a and the second gear 11b have the same tip diameter. The number of teeth of the first gear 11a is an integral multiple of the number of teeth of the second gear 11b. Specifically, the number of teeth of the second gear 11b used in the present embodiment is 7, whereas the number of teeth of the first gear 11a is 21, which is an integer multiple thereof.

  In the first roll 11, one first gear 11 a is arranged on each side of one second gear 11 b, and a gear group that includes these three gears as a set. A plurality of 16 are arranged. In each gear group 16, the first gear 11a and the second gear 11b are arranged such that the teeth of the gears 11a and 11b are arranged in parallel in the direction of the rotation axis of the roll. As a result, in each gear group 16, convex portions 17 and concave portions 18 are alternately formed along the rotation direction of the roll 11. Whether the convex portion 17 is formed by teeth of the three gears (that is, the two first gears 11 a and the one second gear 11 b) arranged in parallel in the rotation axis direction of the roll 11. (Indicated by reference numeral 17a in FIG. 3), or the teeth of the two first gears 11a are formed in parallel in the rotation axis direction of the roll (indicated by reference numeral 17b in FIG. 3). On the other hand, the recess 18 is formed between the teeth of the two first gears 11a. The width of the convex portion 17 determines the dimension in the Y direction of the convex portion 5 of the topsheet 1.

  Two or more sets of gear groups 16 are used. Each gear group 16 is arranged so that the pitches of the concave and convex portions in the adjacent gear groups 16 and 16 are different from each other. In the present embodiment, the adjacent gear groups 16 and 16 have uneven portions shifted by a half pitch.

  In each gear group 16, a plurality of gap portions 19 are formed between the two first gears 11 a along the rotation direction of the roll 11 with a constant interval. Each gap 19 is formed by two first gears 11a and a second gear 11b located between them. More specifically, each gap portion 19 is defined by opposing side surfaces of the two first gears 11a and two adjacent teeth on the second gear 11b. Accordingly, the number of the gaps 19 is the same as the number of teeth of the second gear 11b. The gap portion 19 opens toward the outside in the recess 18 described above.

  A plurality of openings 20 are formed in the first gear 11a so as to surround a central opening into which the rotating shaft 15 is inserted. Each opening 20 has the same diameter, and is formed at a position equidistant from the center of the gear. The angles formed by the adjacent openings 20 and 20 and the center of the gear are all equal. The number of openings 20 in each gear 11a is the same as the number of teeth of the second gear 11b. And when each gear group 16 is assembled | attached, the 1st and 2nd gearwheels 11a and 11b are arrange | positioned so that each opening part 20 may each be located between the adjacent teeth in the 2nd gearwheel 11b. In this state where the gear groups 16 are assembled and the gear groups 16 are arranged so that the pitches of the concavo-convex portions are different from each other, the opening 20 of each first gear 11 a is in the direction of the rotation axis of the roll 11. A plurality of suction paths 21 extending in the direction of the rotation axis are formed inside the roll 11. Each suction path 21 communicates with the gap 19 described above.

  At least one end of the suction path 21 communicates with a suction source (not shown) such as a blower or a vacuum pump. Therefore, when a suction operation is performed by operating the suction source, air is sucked from the gap portion 19 through the suction path 21.

  A method for manufacturing a composite sheet using the manufacturing apparatus having the above configuration will be described. First, as shown in FIG. 2, the upper layer 2 is fed out from the original fabric 2 ′ of the upper layer 2. Separately, the lower layer 3 is fed out from the raw material 3 ′ of the lower layer 3. The upper layer 2 that has been fed out is engaged with the meshing portion of the first roll 11 and the second roll 12 to form the irregularities on the upper layer 2. In this case, the first roll 11 is sucked as described above. The suction is controlled so as to be performed between the meshing part of the first roll 11 and the second roll 12 and the joining part of the upper layer 2 and the lower layer 3. Therefore, the upper layer 2 formed with unevenness by the meshing of the first roll 11 and the second roll 12 is applied to the roll as shown in FIG. 5 by the suction force by the gap portion 19 formed in the first roll 11. It adheres closely to the peripheral surface of the surface, and the unevenly shaped state is maintained. When suction is not performed, the upper layer 2 is lifted from the peripheral surface of the first roll 11, and as a result, a sheet having a desired uneven shape cannot be obtained.

  Next, under the condition that the upper layer 2 is kept in close contact with the peripheral surface of the first roll 11 (see FIG. 5), as shown in FIG. Is pressed between the first roll 11 and the anvil roll 14. At this time, both the first roll 11 and the anvil roll 14 or only the anvil roll 14 are heated to a predetermined temperature. As a result, the upper layer 2 located on the convex portion of the first roll 11, that is, on the gear teeth, is joined to the lower layer 3 by heat fusion.

  Instead of joining the upper layer 2 and the lower layer 3 by heat fusion, these layers may be joined by bonding with an adhesive or ultrasonic bonding.

  The top sheet 1 shown in FIG. 1 is obtained by the above method. According to the manufacturing apparatus of this embodiment, unlike the technique described in Patent Document 1 described in the section of the prior art, there is an advantage that the convex portions can be formed with a desired pitch and a constant size with good reproducibility. Moreover, since the peripheral surface shape of the uneven | corrugated roll to be used is not impaired by providing the space | gap part 19 between gears, there also exists an advantage that many small convex parts can be reliably formed especially by a small pitch. Furthermore, the pitch and size of the convex portions can be freely changed by a simple operation by simply changing the combination and width of the gears. The ability to form a large number of small protrusions with a small pitch is advantageous from the viewpoint of obtaining a surface sheet that has a good touch, a high cushion feeling, and a good visual impression.

  The surface sheet 1 thus obtained is used for absorbent articles such as disposable diapers, sanitary napkins, and incontinence pads. Absorbent articles generally have a liquid-permeable top sheet, a liquid-impermeable back sheet, and a liquid-retaining absorbent disposed between both sheets. Further, the obtained sheet is used for applications other than the top sheet of the absorbent article, for example, the back sheet of the absorbent article, the base material sheet of the fastening tape in the disposable diaper provided with the fastening tape, and the landing tape with which the fastening tape is engaged. It can also be used as a base sheet for the wing in a sanitary napkin equipped with a wing, a panel material for a loop member of a mechanical fastener, a cleaning sheet, a wiping sheet, and the like.

  The present invention is not limited to the embodiment. For example, in the above-described embodiment, the gear groups 16 in the first roll 11 are arranged so that the pitches of the uneven portions in the gear group are shifted from each other by a half pitch, but are arranged at a pitch other than the half pitch. Also good. Alternatively, in the first roll 11, the teeth of the first gear 11a and the second gear 11b are arranged in parallel to the rotation axis direction of the roll, and the uneven portions along the rotation direction of the roll are alternately arranged in the entire width direction of the roll. It may be formed continuously. In this case, a composite sheet in which convex portions and concave portions extending in the same direction are alternately formed is obtained.

  In the above-described embodiment, a pair of gear groups is configured by the two first gears 11a and the one second gear 11b positioned between them, but the configuration of the gear group is as follows. However, the present invention is not limited to this, and at least one first gear 11a can be arranged on at least one side of at least one second gear 11b to form a set of gear groups.

  Moreover, in the said embodiment, although the space | gap part 19 was formed by interposing the 2nd gearwheel 11b between the two 1st gearwheels 11a, the formation method of a space | gap part is not restricted to this. For example, the gap may be formed using a gear having a shape in which the second gear 11b is integrated with the first gear 11a.

  Moreover, in the said embodiment, although demonstrated regarding the structure of the 1st roll 11, the 2nd roll 12 may also become a structure similar to the 1st roll 11. FIG. Of course, as long as it is meshed with the first roll 11, the structure may be different from that of the roll 11. However, in any case, the second roll 12 does not perform a suction operation.

  Moreover, in the said embodiment, although the 1st gearwheel 11a and the 2nd gearwheel 11b were comprised by the same tooth | gear width, a different tooth | gear width may be sufficient. Furthermore, the tooth width of the gear in one gear group may be different from the tooth width of the gear in the other gear group.

  In the above embodiment, the first gear 11a and the second gear 11b have the same tip diameter, but the tip diameter of the second gear 11b is that of the first gear 11a. May be smaller.

  Moreover, in the said embodiment, although the number of teeth of the 1st gearwheel 11a was comprised by the integer multiple of the number of teeth of the 2nd gearwheel 11b, it does not necessarily need to be an integral multiple.

It is a perspective view which expands and shows the principal part of an example of the composite sheet manufactured using the manufacturing apparatus of this invention. It is a schematic diagram which shows one Embodiment of the manufacturing apparatus of this invention. It is a perspective view which shows the principal part of the 1st roll in FIG. It is a disassembled perspective view of a part of roll shown in FIG. It is a figure which shows the state currently hold | maintained by the 1st roll with the 1st sheet-like material being unevenly shaped.

Explanation of symbols

1 Surface sheet (composite sheet)
2 Upper layer (first sheet)
3 Lower layer (second sheet)
4 joint portion 5 convex portion 11 first roll 11a first gear 11b second gear 12 second roll 15 rotating shaft 16 gear group 17 convex portion 18 concave portion 19 gap portion 20 opening portion 21 suction path

Claims (6)

The first and second sheet-like objects are partly joined to form a large number of joints, the first sheet-like substance protrudes at a part other than the joints, and the inside is a cavity. An apparatus for manufacturing a composite sheet forming a large number of convex portions,
The manufacturing apparatus includes a first roll having a concavo-convex shape on the peripheral surface, and a second roll having a concavo-convex shape meshing with the concavo-convex shape of the first roll on the peripheral surface. And
At least the first roll has a roll shape in which a plurality of gears are attached to the rotary shaft so as to form uneven portions alternately along the rotation direction of the roll,
A gap having a predetermined width is formed between the gears every predetermined number of gears, and the gap is a part of the suction path formed in the first roll so as to extend in the rotation axis direction of the roll. The composite sheet manufacturing equipment that constitutes Before Symbol a first gear gap portion is two, the composite sheet manufacturing apparatus of the second gear with claim 1, which is formed by the positioned therebetween. At least one first gear is arranged on at least one side of at least one second gear, thereby forming a set of gears;
In the gear group, teeth of each gear are formed in parallel with the rotation axis direction of the roll, and uneven portions along the rotation direction of the roll are alternately formed,
The composite sheet manufacturing apparatus according to claim 2, wherein two or more sets of gear groups are arranged such that the pitches of the concavo-convex portions in adjacent gear groups are different from each other.   The teeth of the first gear and the second gear are juxtaposed in the rotational axis direction of the roll, and uneven portions along the rotational direction of the roll are formed alternately and continuously across the entire width direction of the roll. The manufacturing apparatus of the composite sheet of description.   The composite sheet manufacturing apparatus according to claim 3 or 4, wherein an opening is formed in each of the first gears, and the suction path is formed by connecting the opening in the rotation axis direction of the roll. A composite sheet manufacturing method using the composite sheet manufacturing apparatus according to claim 1,
The first sheet and the second roll are meshed with the first sheet-like material, and the sheet-like material is shaped unevenly,
While holding the first sheet-like material in an unevenly shaped state on the peripheral surface of the roll by suction through the suction path formed on the first roll, the second sheet-like material is overlaid, The manufacturing method of the composite sheet which joins the sheet-like material of 2 with the 1st sheet | seat located on the convex part in a 1st roll.

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