JP2010133071A - 3-d shaped sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a 3-D shaped sheet having good liquid permeability and high strength. <P>SOLUTION: There is provided a 3-D shaped sheet 10 comprising a first fiber sheet 11 and a second fiber sheet 12 and provided by connecting both the sheets 11 and 12 at the plurality of connecting parts 15. The second fiber sheet 12 is practically flat. The first fiber sheet 11 forms a convex/concave shape having a plurality of concave parts 14 containing the connecting part 15 and hollow convex parts 13. The connecting part 15 forms a shape having an angle 15a of an acute angle. At a position near the angle 15a, the convex part 13 has on its side part 13b, a hole part 16 formed by moving fibers to divide and making the inside communicate with the outside of the convex part 13. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a three-dimensional shaped sheet made of a fiber material and a method for producing the same. The three-dimensional shaped sheet of the present invention is particularly useful as a constituent material for absorbent articles such as disposable diapers and sanitary napkins.

  Various proposals have been made to use a three-dimensionally shaped nonwoven fabric as a surface sheet of an absorbent article. For example, it is composed of a non-woven fabric fused with thermoplastic fibers, and has a liquid introduction recess having an opening and a bottom surface and extending downward and arranged, and a skin contact area continuous to the periphery of the opening of the liquid introduction recess There has been proposed a surface sheet of the absorbent article (see Patent Document 1). In this surface sheet, a plurality of liquid guide tears are provided on the bottom and side surfaces of the liquid guide recess. The liquid tear is provided for the purpose of allowing the body fluid to be absorbed into the absorbent article through the liquid tear when flowing into the liquid recess.

  Patent Document 1 describes that the liquid introduction tear is formed by the following method. The molten polymer is discharged from the melt blower, and is made into ultrafine fibers with a high-speed and high-temperature air stream, and is deposited on the upper surface of a conveyor having a group of molding elements having the same shape, size, and arrangement as the liquid introduction recesses to form a nonwoven fabric. At the same time, the suction placed on the lower surface of the conveyor applies pressure to a given area of the nonwoven fabric in which the fibers are softened, and sucks the nonwoven fabric portion located in the conveyor opening group in the area where this pressure is applied downward. Stretch. By this suction stretching, a liquid introduction recess is formed in which the stretched portion of the nonwoven fabric is suspended in a tubular shape having an opening and a bottom surface. And the fiber density of the bottom face and side face of a liquid introduction recessed part becomes lower than that of a skin contact area by suction drawing, and the cloth of these parts partly ruptures and a tear is formed.

  According to the above method, since the liquid introduction tear is formed by the elongation and breakage of the fiber, the strength of the surface sheet to be obtained is likely to decrease as much as the fiber is broken. Moreover, with the above method, it is extremely difficult to make the formation position of the liquid introduction tear constant.

JP-A-4-58951

  An object of the present invention is to provide a three-dimensional shaped sheet that can eliminate the disadvantages of the above-described conventional technology.

The present invention includes a first fiber sheet and a second fiber sheet laminated thereunder, and both sheets are joined at a plurality of joints,
While the second fiber sheet is substantially flat, the first fiber sheet has a concave-convex shape having a plurality of concave portions including the joint portion and hollow convex portions located between the concave portions,
The joint has a shape with acute corners;
In the position in the vicinity of the corner portion, the convex portion is provided with a three-dimensional shaped sheet having a hole portion formed on the side portion thereof by separating fibers and communicating the inside and outside of the convex portion. is there.

Further, the present invention provides a suitable method for producing the three-dimensional shaped sheet,
The first and second concavo-convex rolls that are in mesh with each other, and at least the first roll is heated and the first roll includes heat-extensible fibers that are stretched by applying heat between the two rolls. Pushing the fiber sheet to give the first fiber sheet an uneven shape corresponding to the shape of the uneven roll,
While transporting the first fiber sheet provided with the concavo-convex shape on the peripheral surface of the first concavo-convex roll while holding the first fiber sheet, the second fiber sheet that has been separately transported and The two fiber sheets are joined at positions corresponding to the convex portions of the first concavo-convex roll by a sandwiching pressure using the first concavo-convex roll and the smooth roll disposed opposite to the first concavo-convex roll. Including the step of forming a joint,
As the first concavo-convex roll, the top surface of the convex portion has a shape having acute corners,
The three-dimensional structure that forms the hole in the first fiber sheet by separating the fibers constituting the portion to be pushed by the corner of the first fiber sheet by the corner without cutting and thermally expanding the fiber. A method for producing a shaped sheet is provided.

  According to the present invention, a solid shaped sheet having good liquid permeability and high strength is provided.

  The present invention will be described below based on preferred embodiments with reference to the drawings. FIG. 1 shows a longitudinal sectional view of an essential part of one embodiment of the three-dimensional shaped sheet of the present invention. FIG. 2 is a plan view of the three-dimensional shaped sheet shown in FIG. 1 and shows an arrangement pattern of joint portions. The three-dimensional shaped sheet 10 shown in FIG.1 and FIG.2 is comprised from the joined body of the 1st fiber sheet 11 and the 2nd fiber sheet 12 laminated | stacked under it. The three-dimensional shaped sheet 10 has a large number of convex portions 13 formed of the first fiber sheet 11 on the substantially flat second fiber sheet 12 by the three-dimensional shaping of the first fiber sheet 11. In addition, a recess 14 is provided between the protrusions 13. The first fiber sheet 11 and the second fiber sheet 12 are partially bonded at a large number of bonding portions 15. The joining portion 15 is included in the above-described recess 14 and forms a part thereof. The inside of the convex portion 13 is hollow, that is, hollow. A concave portion 14 is formed between the adjacent convex portions 13.

  The convex portions 13 and the concave portions 14 are alternately arranged along the X direction shown in FIG. At the same time, the protrusions 13 and the recesses 14 are alternately arranged along the Y direction, which is a direction orthogonal to the X direction. The X direction coincides with the machine direction (MD) when the three-dimensional shaped sheet 10 is manufactured. The Y direction coincides with the width direction (CD). When the three-dimensional shaped sheet 10 is viewed in plan from the first fiber sheet 11 side, the convex portions 13 and the concave portions 14 are arranged in a staggered pattern. The front and rear and the left and right of the concave portion 14 are surrounded by the convex portion 13. That is, the recess 14 is closed.

  Since the convex portion 13 and the concave portion 14 are arranged in this way, when the three-dimensional shaped sheet 10 is used as, for example, a surface sheet of an absorbent article, liquid leakage is extremely effective in the absorbent article provided in the sheet. Is prevented. Specifically, when the three-dimensional shaped sheet 10 is used as, for example, a disposable diaper, particularly as a surface sheet of 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, if the three-dimensional shaped sheet 10 of this embodiment is used, since the soft stool is captured in the closed recessed part 14 enclosed and formed by the convex part 13, a cross flow becomes difficult to occur. Moreover, the downward movement (that is, the absorber direction) is promoted due to the trapping. As a result, leakage of soft stool is prevented. Moreover, since the convex part 13 has a hollow inside, there is also a concealing effect that the color of soft stool absorbed by the absorber is reduced when viewed from the top sheet side. These effects are also exhibited when the three-dimensional shaped sheet 10 of the present embodiment is used as a surface sheet of a sanitary napkin for absorbing menstrual blood, which is excrement having high viscosity as with loose stool. The

  As shown in FIG. 1, the convex portion 13 includes a top surface 13a and an inclined side portion 13b that continues to the top surface 13a. 1 shows a longitudinal sectional view of the three-dimensional shaped sheet 10 along the X direction in FIG. 2, but the state of the longitudinal section along the Y direction in FIG. 2 is the same as that in FIG.

When the three-dimensional shaped sheet 10 of the present embodiment is used as, for example, a surface sheet of an absorbent article, the height 13 (see FIG. 1) of the convex portion 13 is 0.3 to 10 mm, particularly 0.7 to 5 mm. It is preferable that Moreover, it is preferable that the bottom part dimension A of the convex part 13 along a X direction is 1.5-30 mm, especially 2-5 mm. The bottom dimension along the Y direction can be the same as the bottom dimension A of the protrusion 13 along the X direction. Furthermore, it is preferable that the bottom area of the projection 13 is 2.25～900Mm ^2, especially 4~50mm ^2.

  The three-dimensional shaped sheet 10 of the present embodiment is characterized by the shape of the joining portion 15 that forms part of the recess 14 in a plan view. Specifically, as shown in FIG. 3A, the joint portion 15 has a shape having acute corner portions 15a. Specifically, a plurality of triangular portions having acute apex angles are arranged radially. FIG. 3A and FIG. 2 described above show a cross-shaped joint 15 having a cross-shaped shape including four triangular portions 15b. By forming the joint portion 15 having such a shape in accordance with the manufacturing method described later, at the position near the corner portion 15a, as shown in FIG. A hole 16 is formed which is formed by shifting and communicates between the inside and outside of the projection 13. This hole 16 is also one of the features of the three-dimensional shaped sheet 10 of this embodiment. Since this hole portion 16 communicates the inside and outside of the convex portion 13, when the three-dimensional shaped sheet 10 is used as a surface sheet of an absorbent article, for example, and the first fiber sheet 11 is arranged on the skin contact surface side, The liquid excreted on the first fiber sheet 11 side quickly permeates into the convex part 13 through the hole 16, further permeates through the second fiber sheet 12, and is absorbed by the absorber located therebelow. . As a result, liquid residue hardly occurs on the surface of the first fiber sheet 11 that is the skin contact surface, and the absorbent article provided with the three-dimensional shaped sheet 10 has a high dry feeling.

  In addition, although the cross-shaped shape was shown in FIG.3 (a) as a shape of the junction part 15 which has the acute corner | angular part 15a, the shape of the junction part 15 is not restricted to this, For example, FIG.3 (b) A star-shaped polygonal shape such as a star-shaped regular pentagon shown in FIG. 3 or a star-shaped regular hexagon shown in FIG. Furthermore, the shape shown in FIG. In the joint 15 having these shapes, it is sufficient that at least one corner 15a has an acute angle, and it is not necessary that all the corners 15a have an acute angle. When the corner 15a has an angle of preferably 10 to 50 degrees, more preferably 20 to 40 degrees, a hole 16 in which fiber breakage is not substantially observed is formed more successfully. It is possible to prevent fuzz from being formed by hooking or the like after the formation, or to block the hole 16. Microscopically, the corner 15a may be rounded at the cutting edge for the accuracy of manufacturing the three-dimensional shaped sheet 10, but the fibers can be divided and macroscopically with the corner. As long as it can be called, such rounded corners are also included in the corners referred to in the present invention.

3A to 3D, the size of the joining portion 15 is the joining between the first fiber sheet 11 and the second fiber sheet 12. The strength and the formability of the hole 16 are affected. In this respect, the size of the individual joints 15, about ² 1~50mm expressed by area, and particularly preferably 4～25Mm ² about. Further, the ratio of the total area of the joints 15 to the area of the three-dimensional shaped sheet 10 in plan view (this value is referred to as “area ratio”) is preferably 5 to 50%, particularly 10 to 20%. .

The hole 16 is formed by shifting the constituent fibers of the first fiber sheet 11 which is a fiber sheet constituting the convex portion 13. The hole 16 includes a complete hole in which no fiber is present, or a hole in which fibers are present but the number is sparse and has a shape that can be referred to as a hole. To do. The size and shape of the hole 16 are not critical in the present invention, and depending on the specific use of the three-dimensional shaped sheet 10 and the size of the convex portion 13, for example, the three-dimensional shaped sheet 10 is used as an absorbent article. When it is used as a top sheet, if it is set to about 0.7 to ² mm ² , especially about 1 to ² mm ² , a sufficiently satisfactory result can be obtained.

  As schematically shown in FIG. 1, the hole 16 is formed at a position lower than ½ of the height H of the convex portion 13. Further, when the three-dimensional shaped sheet 10 is viewed in plan, the hole portions 16 correspond to the corner portions 15a on a one-to-one basis so as to include the corner portions 15a at positions near the corner portions 15a in the joint portion 15. Is formed. As described above, in the present embodiment, since the cross-shaped shape has four corners 15a, the projection 13 has four holes every 90 degrees when viewed in plan. 16 will be located. For reference, FIG. 2 schematically shows the positions where the holes 16 are formed.

  It is preferable that the fiber existing around the hole 16 (this fiber is a constituent fiber of the first fiber sheet 11) does not substantially have an end portion due to cutting. Thereby, although it has the hole 16, the strength of the three-dimensional shaped sheet 10 can be made sufficiently high. When a large number of ends due to cutting are observed in the fibers existing around the hole 16, the shape of the hole 16 and the protrusion 13 tends to be easily deformed when an external force is applied to the protrusion 13. is there. Further, the strength of the three-dimensional shaped sheet 10 tends to decrease. Whether the fiber is cut or not can be determined by observing the hole 16 and its surroundings with a microscope. When many ends of the fiber are observed, it can be determined that the fiber is cut. On the contrary, if the end of the fiber is not observed at all or only a few small ends are observed, it can be determined that the fiber is not substantially cut. In order to form the hole 16 without substantially cutting the fiber, a heat-extensible fiber whose length is extended by application of heat is used as a raw fiber of the first fiber sheet 11, and manufacturing described later The method should be adopted. Therefore, as will be apparent from the manufacturing method described later, in the three-dimensional shaped sheet 10 of the present embodiment, as a constituent fiber of the first fiber sheet 11, a heat-extensible fiber in a state where the length is extended by application of heat. It is included.

  When the first fiber sheet 11 includes a heat-extensible fiber whose length is extended by application of heat, the fiber sheet 11 includes a lower layer located on the side close to the second fiber sheet, A multilayer structure having an upper layer located on the lower layer is preferable. In the fiber sheet 11 having a multilayer structure, it is preferable that the upper layer contains heat-extensible fibers whose length is extended by application of heat. On the other hand, the lower layer preferably contains heat-fusible fibers. The lower layer may or may not contain heat-extensible fibers whose length has been extended by application of heat. Preferably, the lower layer does not contain heat-extensible fibers whose length is extended by application of heat. By using the fiber sheet 11 having a multilayer structure and adopting the above-described fibers as the fibers contained in the upper layer and the lower layer, the bonding strength between the first fiber sheet 11 and the second fiber sheet 12 in the bonding portion 15 is sufficient. It becomes possible to make it high. At the same time, the holes 16 can be successfully formed without causing fiber breakage.

  Both the 1st fiber sheet 11 and the 2nd fiber sheet 12 consist of a sheet | seat which uses a fiber as a raw material. These fiber sheets 11 and 12 are composed of a nonwoven fabric, a woven fabric, a knitted fabric, a web or the like. When the fiber sheets 11 and 12 are comprised from a nonwoven fabric, as this nonwoven fabric, various nonwoven fabrics, such as the nonwoven fabric manufactured by the card method, a spun bond nonwoven fabric, a melt blown nonwoven fabric, a spunlace nonwoven fabric, and a needle punch nonwoven fabric, are mentioned. When the fiber sheets 11 and 12 are made of a web, the web may have a low entanglement degree such that the constituent fibers are gently entangled and cannot maintain a sheet-like shape by itself, In other words, those having a certain degree of shape retention are included, even if they have a certain fiber bonding point such as a non-woven fabric. In view of a suitable manufacturing method of the three-dimensional shaped sheet 10 to be described later, the first fiber sheet 11 is preferably made of a web or a nonwoven fabric, and the second fiber sheet 12 is preferably made of a nonwoven fabric.

The basis weight of the first fiber sheet 11 and the second fiber sheet 12 can be appropriately set according to the ease of manufacturing the three-dimensional shaped sheet 10 and the specific application of the three-dimensional shaped sheet 10. When the three-dimensional shaped sheet 10 is used as a top sheet of an absorbent article, for example, the basis weight of the first fiber sheet 11 is preferably set to 15 to 30 g / m ² , and the basis weight of the second fiber sheet 12 is set. it is preferable to set the amount of 10 to 30 g / m ^2.

  As described above, the first fiber sheet 11 preferably includes heat-extensible fibers whose length is increased by application of heat. The first fiber sheet 11 preferably contains heat-fusible fibers. When the first fiber sheet 11 includes these fibers, the fiber sheet 11 may be a single-layer sheet in which these fibers are uniformly mixed, or may be a multilayer structure sheet that includes each fiber separately. . In the latter case, as described above, the upper layer in the multilayer structure includes heat-extensible fibers whose length is extended by application of heat, and the lower layer includes heat-fusible fibers. Is preferred.

  On the other hand, the constituent fibers of the second fiber sheet 12 are not particularly limited. Considering the bonding strength between the sheet 12 and the first fiber sheet 11, it is preferable that the second fiber sheet 12 contains a heat-fusible fiber.

  In the heat-extensible fiber that is a raw material of the first fiber sheet 11 and is elongated by application of heat, when the resin is stretched by crystallization of a resin that is randomly folded by heating, the fiber itself is stretched. The apparent length is increased by releasing the crimp of the crimped fiber. In particular, as a heat-extensible fiber, a fiber outer surface is formed of a heat-fusible component, for example, a polyethylene resin, and a softening point of the fiber outer surface resin is a resin (for example, polypropylene resin or polyester resin) having a higher melting point than that inside the fiber. It is preferable to use a core-sheath structure fiber or a side-by-side structure fiber made of a low crystallinity resin whose crystallization is controlled so that crystallization proceeds by heat in the range from the melting point to the melting point. By using such a fiber, it is difficult to suppress elongation due to the progress of crystallization, and the fiber itself is not easily broken. From the viewpoint of further enhancing extensibility and maintaining the shape of the hole portion 16, a fiber having a core-sheath structure in which no new crimp is formed is preferable.

  As the heat-extensible conjugate fiber, for example, those described in Japanese Patent Application Laid-Open No. 2005-350836 and Japanese Patent Application Laid-Open No. 2007-130800 related to the previous application of the present applicant can be used without particular limitation. The heat-extensible conjugate fibers described in these documents are multicomponent conjugate fibers (core-sheath conjugate fibers, side-by-side conjugate fibers, etc.), and are also heat-fusible fibers. The heat-extensible conjugate fiber has a thermal elongation rate of 8% to 40%, particularly 10% to 10% higher than the melting point of the resin having the lowest melting point among the multicomponent resins constituting the heat-extensible conjugate fiber. It is preferable that it is 30% from the viewpoint that a nonwoven fabric with a high bulkiness can be easily obtained and that an appropriate rigidity can be imparted to the nonwoven fabric. The thermal elongation rate can be measured according to the method described in JP-A-2005-350836.

  On the other hand, as the heat-fusible fiber, those usually used in the technical field can be used without particular limitation. Typical examples of such fibers include core-sheath type or side-by-side type composite fibers composed of a low melting point component and a high melting point component.

  About the thickness of the constituent fiber of the 1st fiber sheet 11 and the 2nd fiber sheet 12, a suitable range is selected according to the specific use of the three-dimensional shaped sheet | seat 10. FIG. When the three-dimensional shaped sheet 10 is used as, for example, a top sheet of an absorbent article, the thickness of the constituent fibers of the first fiber sheet 11 is 0.5 to 6.6 dtex, more preferably 1.0 to 4.4 dtex. The thickness of the constituent fibers of the second fiber sheet 12 is preferably 0.5 to 6.6 dtex, more preferably 1.0 to 3.3 dtex. This thickness is the thickness after extension when the fiber is a heat-extensible fiber.

  Next, the preferable manufacturing method of the three-dimensional shaped sheet | seat 10 of this embodiment is demonstrated, referring FIG. As shown in FIG. 4, first, the first fiber sheet 11 is supplied. The fiber sheet 11 in this state is not yet three-dimensionally shaped. The first fiber sheet 11 contains at least heat-extensible fibers in a state before being stretched. Separately from the first fiber sheet 11, the second fiber sheet 12 is supplied. The supplied first fiber sheet 11 has a convex portion and a concave portion on the peripheral surface and has a concave-convex shape and a concave-convex shape of the first roll 21 and a meshed shape. In addition, the upper fiber sheet 2 is unevenly shaped by being engaged with an engagement portion with the second roll 22 having a concavo-convex shape including a convex portion and a concave portion on the peripheral surface. The first roll 21 rotates in one direction as shown in FIG. The second roll 22 rotates in the opposite direction to the first roll 21 at substantially the same speed. Details of the rolls 21 and 22 having such a structure are described in Japanese Patent Application Laid-Open No. 2004-174234 and Japanese Patent Application Laid-Open No. 2005-111908 related to the earlier application of the present applicant.

  The arrangement pattern of the convex part in the state which extended the surrounding surface of the 1st roll 21 and the 2nd roll 22 to a plane corresponds with the arrangement pattern of the junction part 15 in the three-dimensional shaped sheet | seat 10 shown in FIG. Yes. In addition, among the first roll 21 and the second roll 22, at least the convex portion of the first roll 21 has a cross-section as shown in FIG. It has a shape.

Of the first and second rolls 21 and 22, at least the first roll 21 is heated to a temperature equal to or higher than the elongation start temperature of the heat-extensible fibers included in the first fiber sheet 11. In this specification, the elongation start temperature refers to a temperature at which all the constituent fibers can leave a fiber shape without exceeding the melting point of the constituent resin, although the elongation of the fibers is started. In the heat-extensible fiber used in the present embodiment, the temperature is higher than the softening point of the outer surface component and lower than the melting point, or higher than the melting point of the outer surface component but 20 degrees or more lower than the melting point of the inner component ( Also referred to as a suitable temperature for fusion).
(Hattori Memo: Please consider whether the above colored letters are technically meaningful.)

  When the first fiber sheet 11 is a web, the web may be temporarily joined prior to supplying the fiber sheet 11 between both rolls 21 and 22. For temporary joining, for example, a method of performing embossing with a wide distance between the embossed portions can be employed. This temporary joining is not intended to make the web non-woven, but allows a certain amount of tension to be applied to the web, and as shown in FIG. The object is to reduce the fiber sheet 11 from being caught by the convex portion of the first roll 21 when the irregular shape is formed by 22.

  The first fiber sheet 11 is conveyed in a state where tension is applied in the longitudinal direction thereof, inserted into the meshing portions of the first and second rolls 21 and 22, and pushed between the meshed rolls 21 and 22. It is. In pushing, it is preferable to assist the pushing by sucking the first roll 21 from its peripheral surface toward the center. Details of providing such suction means on the first roll 21 are described in Japanese Patent Application Laid-Open Nos. 2004-174234 and 2005-111908 described above.

  By the above pushing, the first fiber sheet 11 is provided with an uneven shape corresponding to the shape of the first roll 21. As described above, since the first fiber sheet 11 is pushed in with a tension applied, the pushing of the fiber sheet 11 occurs while the fiber sheet 11 is stretched. The first fiber sheet 11 is stretched by pushing the fiber sheets 11 with the tip portions of the convex portions 21a and 22a in both rolls 21 and 22, as described above. Among them, since the top surface of the convex portion 21a in the first roll 21 has a shape having acute corners, the pushing proceeds while the constituent fibers of the first fiber sheet 11 are separated by the corners. To do. The hole 16 is formed by this pushing.

  By the way, generally, when pushing-in of the first fiber sheet 11 proceeds while the above-mentioned separation by the corner portion occurs, the stretching force acts on the fiber sheet 11 and the fibers are stretched. If the elongation exceeds the breaking limit, the fiber will be cut. However, in the present manufacturing method, as described above, the first roll 21 is heated to a temperature equal to or higher than the elongation start temperature of the heat-extensible fibers contained in the first fiber sheet 11, so that the first fiber sheet 11 indentation occurs with the elongation of the heat-extensible fibers contained therein. Therefore, even if the pushing-in of the fiber sheet 11 is advanced, it is difficult for the stretching force to act on the constituent fibers, and the cutting hardly occurs. In short, in this manufacturing method, the fibers constituting the portion to be pushed by the corner portion of the first fiber sheet 11 are separated by the corner portion while being uncut and thermally stretched. By these actions, in the first fiber sheet 11 after the uneven shaping, a hole is formed in the convex portion 13 under non-cutting of the constituent fibers. As a result, the fiber existing around the formed hole 16 is not substantially cut.

  FIG. 5 schematically shows the protrusion 13 and the hole 16 formed as described above. The figure corresponds to a view of the three-dimensional shaped sheet 10 shown in FIG. 1 viewed from the right or left direction on the paper. As shown in FIG. 5, the convex portion 13 is composed of the first fiber sheet 11. In this fiber sheet 11, the fiber F located at the open end of the hole portion 16 and in the vicinity thereof is separated by pressing by the tip ends of the convex portions 21 a and 22 a in the rolls 21 and 22, and by heating. It is in a stretched state. The stretched fibers are present in a relatively large amount on the lower surface side (that is, on the side facing the second fiber sheet 12) than on the upper surface side in the first fiber sheet 11. This is because the heat-extensible fibers are stretched while being pushed downward by the tip portions of the convex portions 21a and 22a.

  By the above process, the three-dimensional shaping of the unevenness is performed, and the first fiber sheet 11 in which the hole portion 16 is formed in the side portion of the convex portion 13 is obtained. The first fiber sheet 11 to which the uneven shape is imparted is conveyed in a state of being held on the peripheral surface of the first roll 21. By such conveyance, the three-dimensional shaped state of the first fiber sheet 11 is successfully maintained. For this purpose, it is advantageous to suck the first roll 21 from its peripheral surface toward the center. The first fiber sheet 11 held on the peripheral surface of the first roll 21 is continuously applied with heat from the roll 21, but at this time, the heat-extensible fibers are not stretched. Since it has already been completed, there is substantially no elongation of the heat-extensible fiber at this point.

  In a state where the first fiber sheet 11 is kept in close contact with the peripheral surface of the first roll 21, as shown in FIG. 4, the fiber sheet 11 is joined with the second fiber sheet 12 which has been separately conveyed. And stack. And what laminated | stacked the 1st fiber sheet 11 and the 2nd fiber sheet 12 is heat-pressed between the 1st roll 12 and the smooth roll 23 arrange | positioned facing this. Thereby, the 1st fiber sheet 11 located on the convex-shaped part 21a in the 1st roll 12 is joined to the 2nd fiber sheet 12 by heat sealing | fusion. In the hot clamping, only the first roll 21 may be heated to a predetermined temperature, or both the first roll 21 and the anvil roll 23 may be heated as necessary. In addition, it replaces with joining the 1st fiber sheet 11 and the 2nd fiber sheet 12 by heat sealing | fusion, You may join these sheets 11 and 12 by adhesion | attachment by an adhesive agent, or ultrasonic bonding.

  The three-dimensionally shaped sheet 10 thus produced is suitably used as a top sheet for absorbent articles. Absorbent articles generally have a liquid-permeable top sheet, a liquid-impermeable back sheet, and a liquid-retaining absorbent disposed between both sheets. In this case, the three-dimensional shaped sheet 10 is incorporated into the absorbent article such that the first fiber sheet 11 side, which is the three-dimensionally shaped side, faces the wearer's skin. Further, the obtained sheet 10 is used in applications other than the top sheet of the absorbent article, for example, the back sheet of the absorbent article, the intermediate sheet disposed between the top sheet and the absorbent body, and the disposable diaper provided with the fastening tape. Tape base sheet, landing tape sheet with which the fastening tape engages, wing base sheet in sanitary napkin with wing, mechanical fastener loop member panel material, cleaning sheet, wiping sheet, etc. Can also be used.

  As mentioned above, although this invention was demonstrated based on the preferable embodiment, this invention is not restrict | limited to the said embodiment. For example, in the above embodiment, the convex portions 13 and the concave portions 14 are arranged in a staggered pattern, and the front and rear and the left and right sides of the concave portion 14 are surrounded by the convex portions 13, but the concave portions are closed. The part may be connected with the other recessed part.

  Moreover, in the said embodiment, the row | line | column (the row | line | column of the X direction in FIG. 1) of the convex part 13 and the recessed part 14 in the three-dimensional shaped sheet | seat 10 shift | displaces by a half pitch from the adjacent row | line | column, and is arrange | positioned. However, it may be arranged with a shift other than a half pitch.

FIG. 1 is a longitudinal sectional view showing a main part of one embodiment of the three-dimensional shaped sheet of the present invention. FIG. 2 is a plan view of the three-dimensional shaped sheet shown in FIG. 1 and shows an arrangement pattern of joint portions. FIGS. 3A to 3C are diagrams showing the shape of the joint. FIG. 4 is a schematic diagram showing a preferred method for producing the three-dimensional shaped sheet shown in FIGS. 1 and 2. FIG. 5 is a schematic diagram showing convex portions and holes in the three-dimensional shaped sheet formed by the method shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Three-dimensional shaped sheet 11 1st fiber sheet 12 2nd fiber sheet 13 Convex part 14 Concave part 15 Joining part 16 Hole part 21 1st roll 22 2nd roll

Claims (7)

Including a first fiber sheet and a second fiber sheet laminated under the first fiber sheet, wherein both sheets are joined at a plurality of joints;
While the second fiber sheet is substantially flat, the first fiber sheet has a concave-convex shape having a plurality of concave portions including the joint portion and hollow convex portions located between the concave portions,
The joint has a shape with acute corners;
The three-dimensional shaped sheet which has the hole part which the said convex part formed in the side part in the position of the vicinity of the said corner | angular part, and was connected with the inside and outside of this convex part.   The three-dimensionally shaped sheet according to claim 1, wherein an end portion is not substantially present in a fiber present around the hole portion.   The three-dimensionally shaped sheet according to claim 1 or 2, wherein the first fiber sheet contains heat-extensible fibers whose length is extended by application of heat. The first fiber sheet is of a multilayer structure having a lower layer located on the side closer to the second fiber sheet and an upper layer located on the lower layer,
The three-dimensionally shaped sheet according to claim 3, wherein the upper layer includes the heat-extensible fiber in a state where the length is extended, and the lower layer includes a heat-fusible fiber.   The three-dimensional shaped sheet according to any one of claims 1 to 4, wherein the joint portion has a shape in which a plurality of triangular portions having acute apex angles are radially arranged.   The three-dimensional shaped sheet according to claim 5, wherein the joint portion has a cross-shaped shape including four triangular portions. It is a manufacturing method of the three-dimensional shaped sheet according to claim 1,
The first and second concavo-convex rolls that are in mesh with each other, and at least the first roll includes a heat-extensible fiber that is stretched by application of heat between the two rolls in a heated state. Pushing the fiber sheet to give the first fiber sheet an uneven shape corresponding to the shape of the uneven roll,
While transporting the first fiber sheet provided with the concavo-convex shape on the peripheral surface of the first concavo-convex roll while holding the first fiber sheet, the second fiber sheet that has been separately transported and The fiber sheets are joined and laminated, and both fiber sheets are joined at a position corresponding to the convex portion of the first concavo-convex roll by a sandwiching pressure using the first concavo-convex roll and the smooth roll disposed opposite thereto. Including the step of forming a joint,
As the first concavo-convex roll, the top surface of the convex portion has a shape having acute corners,
The three-dimensional structure that forms the hole in the first fiber sheet by separating the fibers constituting the portion to be pushed by the corner of the first fiber sheet by the corner without cutting and thermally expanding the fiber. Manufacturing method of shaped sheet.

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