JP5074174B2 - Manufacturing method of three-dimensionally shaped nonwoven fabric - Google Patents

Description

  The present invention relates to a method for producing a three-dimensionally shaped nonwoven fabric that shapes a concavo-convex shape on a raw nonwoven fabric.

  A technique is known in which a single nonwoven fabric is used as a raw material, and is subjected to three-dimensional shaping to obtain a three-dimensional shaped nonwoven fabric having a large number of irregularities. For example, Patent Document 1 describes a top sheet material for absorbent articles in which uneven portions are formed on a nonwoven fabric by hot embossing. This top sheet material is manufactured using an embossing apparatus in which one embossing roll and one smooth soft roll are combined. In this case, an embossing roll is used as a heat roll, and a smooth soft roll is used as a cooling roll. Alternatively, the top sheet material is made of a male and female embossing type embossing roll, and is manufactured by using an embossing apparatus that is a combination of a high embossing roll and a low embossing roll that matches this embossing roll. In this case, an embossing roll with a high mountain is used as a heat roll, and an embossing roll with a low mountain is used as a cooling roll.

  Patent Document 2 describes a surface sheet of an absorbent article in which valleys and peaks facing the liquid receiving side extend in the longitudinal direction and are formed in a wave shape in the width direction orthogonal to the longitudinal direction. A connecting portion that connects the peak portions located on both sides of the valley portion and the peak portions is formed in a convex shape toward the liquid receiving side. The connecting portion connects the inclined surfaces of the side portions of the two mountain portions. This surface sheet is formed by sandwiching a nonwoven fabric supplied in a certain direction between the first forming means and the second forming means. The first forming means has convex ribs and grooves that extend along the supply direction of the nonwoven fabric and are alternately formed in the width direction orthogonal to the supply direction. The second forming means has convex ribs and grooves extending in the supply direction and alternately formed in the width direction. The convex rib is formed with a plurality of depressions at intervals in the supply direction. The surface sheet formed by using the first forming means and the second forming means has a crest pressed between the convex ribs of the first forming means and the grooves of the second forming means. , A trough pressed between the groove of the first forming means and the convex rib of the second forming means, and crests on both sides of the trough in the portion corresponding to the depression of the second forming means And a convex connecting portion formed so as to connect the two.

Japanese Patent Laid-Open No. 11-347062 JP 2001-95845 A

  When manufacturing a three-dimensionally shaped nonwoven fabric by each method mentioned above, if the heating temperature of an apparatus is made high, a convex part with a clear shape and high height can be formed. However, the nonwoven fabric tends to be hard due to the high heating temperature, and the touch is reduced. If the heating temperature is set to be relatively low, the good touch of the nonwoven fabric is maintained. However, the shape of the convex portion tends to be unclear, and it becomes difficult to form a convex portion having a high height. Thus, in the three-dimensionally shaped nonwoven fabric, there was a trade-off relationship between the good touch and the clarity of the convex portions and the height of the convex portions.

  The objective of this invention is providing the manufacturing method of the three-dimensional shaping nonwoven fabric which can eliminate the fault which the prior art mentioned above has.

The present invention relates to a first and second pressing molds in which a large number of irregularities are regularly arranged on the surface and are meshed with each other. In the method for producing a three-dimensionally shaped nonwoven fabric in which the raw nonwoven fabric is three-dimensionally formed,
After the original nonwoven fabric was three-dimensionally shaped, it was three-dimensionally formed by suctioning from the outer surface of the first stamping die toward the inside while the original nonwoven fabric was adhered to the surface of the first stamping die. The present invention provides a method for producing a three-dimensionally shaped non-woven fabric that allows heated air to pass through the original non-woven fabric and conveys the original non-woven fabric.

The present invention also has a large number of convex portions and concave portions located between the convex portions,
The concave portions and the convex portions are alternately arranged along one direction of the three-dimensional shaped nonwoven fabric and are alternately arranged along a direction orthogonal to the direction,
The convex portion has a pair of first wall portions positioned along the one direction and facing each other, and a pair of second wall portions positioned along the direction orthogonal to the one direction and facing each other. Furthermore, it has a top surface part connected to the upper side of each first wall part and the upper side of each second wall part,
The present invention provides a three-dimensional shaped nonwoven fabric in which the basis weight of each first wall portion and the basis weight of each second wall portion are different.

  According to the present invention, it is possible to obtain a three-dimensionally shaped nonwoven fabric that has a large apparent thickness and is bulky, and that maintains the good touch that the original nonwoven fabric originally has.

  The present invention will be described below based on preferred embodiments with reference to the drawings. First, an example of the three-dimensionally shaped nonwoven fabric manufactured based on preferable embodiment of this invention is demonstrated. The three-dimensionally shaped nonwoven fabric 1 shown in FIG. 1 has a large number of convex portions 5 on one surface and has concave portions 6 located between the convex portions 5. On the other surface of the nonwoven fabric 1, the convex portion 5 on one surface is a concave portion, and the concave portion 6 on one surface is a convex portion. That is, the one surface and the other surface of the nonwoven fabric 1 have shapes reversed from each other. The convex portions 5 and the concave portions 6 are alternately arranged along the X direction shown in FIG. At the same time, the convex portions 5 and the concave portions 6 are alternately arranged along the Y direction which is a direction orthogonal to the X direction. When the three-dimensional shaped nonwoven fabric 1 is viewed in plan, the convex portions 5 and the concave portions 6 are arranged in a staggered pattern.

  Each convex part 5 does not exist separately independently, but when paying attention to any one convex part 5, two convex parts located obliquely forward in the X direction (and Y direction) 5 and two convex portions 5 located obliquely rearward. The height of the connecting portion 7 between the convex portions 5 is lower than the height of the top portion of the convex portion 5. However, it is higher than the recess 6. On the other hand, regarding the recessed part 6, each recessed part exists separately independently. That is, when attention is paid to one recess 6, the recess 6 is surrounded by four protrusions 5 positioned around the recess 6 and is independent from each other, and the recesses 6 are not connected to each other.

  Since the convex portion 5 and the concave portion 6 are arranged as described above, when the three-dimensional shaped nonwoven fabric 1 is used as, for example, a surface sheet of an absorbent article, liquid leakage is extremely effective in the absorbent article provided with the sheet. To be prevented. Specifically, when the three-dimensional shaped non-woven fabric 1 is used as, for example, a disposable diaper, particularly as a surface sheet of a diaper for a low-age child 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-dimensionally shaped nonwoven fabric according to the present embodiment is used, the soft stool is trapped in the closed concave portion 6 formed by being surrounded by the convex portion 5, so that it is difficult for the lateral flow 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 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 three-dimensionally shaped nonwoven fabric 1 of the present embodiment is used as a surface sheet of a sanitary napkin for absorbing menstrual blood, which is a highly viscous excrement as with loose stool. The

  The convex portion 5 is a flat rectangular parallelepiped or truncated quadrangular pyramid with rounded ridgelines as a whole. The convex part 5 has a pair of 1st wall part 51 located along the X direction shown in FIG. Moreover, the convex part 5 has a pair of 2nd wall part 52 located along Y which is a direction orthogonal to X direction, and mutually opposing. Furthermore, the convex portion 5 has a top surface portion 53 that is continuous with the upper side of each first wall portion 51 and the upper side of each second wall portion 52.

  In the three-dimensional shaped nonwoven fabric 1 of this embodiment, the X direction shown in FIG. 1 corresponds to the machine direction (MD) at the time of manufacturing the three-dimensional shaped nonwoven fabric described later. And the Y direction corresponds to the width direction (CD) at the time of three-dimensional shaping nonwoven fabric manufacture.

When the three-dimensionally shaped nonwoven fabric 1 of the present embodiment is used as, for example, a surface sheet of an absorbent article, the height 5 (see FIG. 1) of the convex portion 5 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 5 along a X direction (MD) is 1.5-30 mm, especially 2-5 mm. The bottom dimension B of the convex portion 5 along the Y direction (CD) is preferably 1.5 to 30 mm, particularly preferably 2 to 10 mm. Further, it is preferable that the bottom area of the projection 5 is 2.25～900Mm ^2, especially 4~50mm ^2. The dimension of the recess 6 along the X direction (MD) and the dimension B of the recess 6 along the Y direction (CD) can be the same as those of the protrusion 5.

  The nonwoven fabric which is the raw material of the three-dimensional shaped nonwoven fabric 1 is substantially non-stretchable. By using such a nonwoven fabric as a raw fabric, in forming a concavo-convex shape having a desired dimension, the three-dimensional shaped non-woven fabric 1 substantially conforming to the concavo-convex shape of the first and second concavo-convex rolls described later is stably provided. And it can be manufactured with good reproducibility. The nonwoven fabric that is substantially non-stretchable has, for example, an elongation rate of 5% or less (elongation of 5% with respect to the original length), and elongation exceeding this causes material destruction or permanent distortion. What happens.

As a raw fabric nonwoven fabric, various nonwoven fabrics, such as the nonwoven fabric manufactured by the card | curd method, a spun bond nonwoven fabric, a melt blown nonwoven fabric, a spunlace nonwoven fabric, a needle punch nonwoven fabric, can be used, for example. Of these, it is desirable to use an air-through nonwoven fabric, which is a nonwoven fabric that tends to recover its thickness due to penetration of heated air. The constituent fibers of the raw nonwoven fabric are made of a thermoplastic resin. The fineness of the constituent fibers is preferably 1 to 20 dtex, particularly 1.5 to 4 dtex, from the viewpoint of ensuring the strength of the composite sheet 1 and improving the touch. The basis weight of the raw fabric nonwoven fabric and the three-dimensional shaped nonwoven fabric 1 is preferably 10 to 100 g / m ² , particularly preferably 10 to 30 g / m ² .

  Next, the suitable manufacturing method of the three-dimensional shaping nonwoven fabric 1 shown in FIG. 1 is demonstrated, referring FIG. The manufacturing apparatus of the three-dimensionally shaped nonwoven fabric 1 shown in FIG. 2 includes a first roll 11 and a second roll 12 having an uneven shape meshing with the uneven shape of the first roll 11 on the peripheral surface. ing. Both rolls 11 and 12 are arranged so as to be engaged with each other. The first roll 11 rotates in the counterclockwise direction as shown in FIG. The second roll 12 rotates in the clockwise direction at the same peripheral speed as the first roll 11. Under the meshed state of both rolls 11 and 12, the nonwoven fabric 2 is interposed between them to form the nonwoven fabric 2 three-dimensionally.

  The apparatus for manufacturing the three-dimensional shaped nonwoven fabric 1 further includes an anvil roll 13. The anvil roll 13 is disposed at a position downstream of the meshing portions of the rolls 11 and 12 so that the peripheral surface of the anvil roll 13 is in contact with the top of the convex portion of the first roll 11. The anvil roll 13 is made of a soft material such as metal or rubber.

  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 a combination of a plurality of first members 11a and second members 11b, and these gears are concentrically attached to the rotary shaft 15 and accumulated in a roll shape. The first member 11a is constituted by a spur gear. The second member 11 b includes a substantially annular center portion 100 and a large number of arm portions 101 extending radially from the periphery of the center portion 100. The center of the first member 11a composed of a spur gear is open. Similarly, the central portion 100 of the second member 11b is also open. And the rotating shaft 15 is inserted in those opening parts. Each of the members 11a and 11b and the rotary shaft 15 has a notch (not shown), and a key (not shown) is inserted into the notch. This prevents idling of the members 11a and 11b.

  Each arm portion 101 in the second member 11b has the same length. The diameter of a circle virtually formed by connecting the tips of the arm portions 101 is the same as or smaller than the diameter of the root circle of the first member 11a. Therefore, only the tooth tips of the gears constituting the first member 11 a are located on the peripheral surface of the first roll 11. The diameter may be larger than the diameter of the root circle of the first member 11a, but is smaller than the diameter of the tip circle of the first member 11a.

  The number of teeth of the gear constituting the first member 11a is an integral multiple of the number of arm portions 101 in the second member 11b. Specifically, the number of arm portions 101 in the second member 11b used in the present embodiment is 12, whereas the number of teeth of the gear constituting the first member 11a is an integral multiple of 24. It has become.

  In the first roll 11, a plurality of member groups 16 each including a total of two members, one first member 11a and one second member 11b, are arranged. In each member group 16, the gear teeth constituting the first member 11 a and the arm portion 101 in the second member 11 b are arranged in parallel in the axial direction of the roll 11. In the first roll 11, two or more sets of member groups 16 are used according to the width of the raw fabric nonwoven fabric 2. Therefore, the first gear 11a and the second gear 11b are alternately attached to the rotary shaft 15. The first members 11a adjacent in the axial direction of the roll are arranged so as to be shifted by a half pitch.

  FIG. 5 shows a state in which the peripheral surface of the first roll 11 formed by accumulating the first member 11a and the second member 11b as described above is extended to a plane. As can be seen from the figure, in the first roll 11, the convex portion 17 is formed by the gear teeth 111 constituting the first member 11 a. The convex portions 17 are arranged in a row along the rotation direction R of the roll 11. This row is arranged in multiple rows in the axial direction A of the roll 11. When viewed along the rotation direction R of the roll 11, the arrangement of the protrusions 17 is shifted by a half pitch in the row of adjacent protrusions 17.

  As shown in FIG. 5, among the large number of convex portions 17 formed on the peripheral surface of the first roll 11, the region surrounded by the four convex portions 17 a, 17 b, 17 c, and 17 d that are the four corners of the rhombus is A recess 18 is formed. The recesses 18 are arranged in a row along the rotation direction R of the roll 11. This row is arranged in multiple rows in the axial direction A of the roll 11. When viewed along the rotation direction R of the roll 11, the arrangement of the recesses 18 is shifted by a half pitch in the row of adjacent recesses 18.

  When the concave portion 18 of the first roll 11 is viewed along the axial direction A of the roll 11, the pair of end regions located at both end portions in the axial direction A at the bottom of the concave portion 18 include gap portions 18 a and 18 a. Are formed respectively. As shown in FIG. 2, the gaps 18 a and 18 a are for sucking and adhering the raw nonwoven fabric 2 to the peripheral surface of the first roll 11. Each gap 18a is defined by the opposing side surfaces of the two first members 11a and the adjacent arm portion 101 and the central portion 100 of the one second member 11b located between the two members 11a. And a substantially V-shaped portion. Accordingly, the number of the gaps 18a is the same as the number of the arm parts 101 of the second member 11b, and the gaps 18a have a width corresponding to the width of the second member 11b. The gap 18a is open to the outside in the recess 18 described above.

  The details of the structure of the gaps 18a and 18a described above will be described. As shown in FIGS. 4 and 5, the first member 11a includes a plurality of openings so as to surround a central opening into which the rotary shaft 15 is inserted. An opening 20 is formed. 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 arms 101 in the second member 11b. And when assembling each member group 16, the 1st and 2nd members 11a and 11b are arrange | positioned so that each opening part 20 may be located in the adjacent arm part 101 in the 2nd member 11b, respectively. That is, the opening 20 is positioned in a substantially V-shaped portion defined by the two adjacent arm portions 101 and the central portion 100. This part becomes a partition part which partitions each opening part 20 provided in the 1st member 11a independently. The substantially V-shaped portion described above communicates with the gaps 18a and 18a. 3 and 4, the entire area of the opening 20 is included in the substantially V-shaped region. Instead, a part of the opening 20 is included in the V-shaped region. Only may be included.

  Thus, in the state which assembled | attached each member group 16, and also arrange | positioned each member group 16 so that the pitch of the uneven | corrugated | grooved parts 17 and 18 may be shifted by a half pitch, the opening part 20 of each 1st member 11a is a roll. 11, a plurality of suction paths 21 extending in the axial direction are formed inside the roll 11. Each suction path 21 communicates with the gaps 18a and 18a described above via the above-described substantially V-shaped portion. The gaps 18 a and 18 a constitute a part of the suction path 21.

  As is apparent from the above description, the second member 11 b is used to form independent compartments in the roll 11. This compartment communicates with the above-described gaps 18a and 18a. Moreover, it leads also to the suction path 21 described above. At least one end of the suction path 21 communicates with a suction source (not shown) such as a blower or a pump. Therefore, when the suction operation is performed by operating the suction source, air is sucked from the peripheral surface of the roll 11 toward the inside of the roll 11 through the suction path 21 from the gaps 18a and 18a.

  Moreover, the 2nd member 11b is used also in order to support the 1st member 11a which consists of gears from the side surface in addition to formation of a compartment, and to give intensity | strength to the 1st roll 11. FIG. In particular, when it is desired to reduce the size of the convex portion 5 formed on the target three-dimensionally shaped nonwoven fabric 1, it is necessary to reduce the thickness of the first member 11a. It causes a decrease in strength. In such a case, the arm portion 101 of the second member 11b becomes a beam, and the usefulness of the first member 11a for preventing distortion becomes remarkable.

  Although the structure of the 1st roll 11 is as above-mentioned, regarding the 2nd roll 12, the structure similar to the 1st roll 11 is employable. For example, the first member 11 a and the second member 11 b used in the first roll 11 are used, and these can be integrated to form the second roll 12. However, since the second roll 12 does not require a suction mechanism, it is not essential to use the same structure as the second member 11b used in the first roll 11. Therefore, as the second member in the second roll 12, for example, a disk having a diameter smaller than the root circle of the first member can be used. Moreover, you may comprise the 2nd roll 12 only using a 1st member, without using a 2nd member.

  As shown in FIG. 5, the first roll 11 and the second roll 12 are in a state where both the rolls 11 and 12 are engaged with each other, and the convex portion 27 of the second roll 12 is the concave portion 18 of the first roll 11. The meshing state is adjusted so as to be located in the center area of the. The central area of the recess 18 here is a central area along the axial direction of the roll and a central area along the rotation direction of the roll. By engaging the two rolls 11 and 12 so that the convex portion of the second roll 12 is located in the central region, the convex portion 5 formed on the raw nonwoven fabric 2 can be made symmetrical. As a result, the form stability of the convex part 5 can be made high.

  In the 2nd roll 12, it is preferable that the width | variety of the convex part 27 is 0.1-3.0 mm narrower than the width | variety of the recessed part 18 of the 1st roll 11, especially 0.5-1.0 mm. . The width said here is the length in the axial direction A of the roll. The width of the concave portion 18 of the first roll 11 is defined by the distance between the convex portions 17a and 17c in FIG. In other words, it is the sum of the thickness of one gear 11a and the thickness of two spacers 11b. Since the width of the convex portion 27 of the second roll 18 and the width of the concave portion 18 of the first roll 11 are in such a relationship, the convex portion and the concave portion are in the engaged state of both the rolls 11 and 12. Contact with is prevented. Moreover, it is prevented that the raw fabric nonwoven fabric 2 receives an excessive damage.

  For the same reason as described above, the first roll 11 and the second roll 12 have the top of the convex portion of the second roll 12 and the first roll 11 in a state where both the rolls 11 and 12 are engaged with each other. The meshing state of the rolls 11 and 12 is adjusted so that the bottom surface of the recess 18 does not come into contact.

  Further, in the second roll 12, the width of the convex portion 27 is such that the tip portion of the convex portion 27 is formed in the end region of the concave portion 18 of the first roll 11. It is preferable that the width is such that it faces at least a part. For example, as shown in FIG. 5 and FIG. 7 to be described later, among the tip portions of the convex portions 27 formed on the second roll 12, left and right portions in the width direction A of the roll are at least in the gap portions 18a and 18a. You may come to face a part. Thereby, the suction force through the gaps 18 a and 18 a effectively acts on the raw fabric nonwoven fabric 2, and the shape of the raw nonwoven fabric 2 that is unevenly shaped is maintained on the peripheral surface of the first roll 11. Increases effectiveness.

  The manufacturing method of the three-dimensionally shaped nonwoven fabric using the rolls 11 and 12 having the above configuration will be further described. The supply of the raw nonwoven fabric 2 to the meshing portion of the rolls 11 and 12 is faster than the peripheral speed of the rolls 11 and 12. Done at high speed. By this operation, shrinkage in the longitudinal direction when the raw nonwoven fabric 2 is three-dimensionally shaped can be prevented. Depending on the degree of three-dimensional shaping of the raw nonwoven fabric 2, the supply speed of the raw nonwoven fabric 2 is 1.01 to 2.0 times, particularly 1.05 to 1.4 times the peripheral speed of the rolls 11 and 12. It is preferable that

  When the raw nonwoven fabric 2 is three-dimensionally shaped, the first roll 11 is heated. If necessary, the second roll 12 may be heated. After the raw nonwoven fabric 2 is three-dimensionally shaped, as shown in FIG. 2, the hot air from the nozzle 14 is directed toward the peripheral surface of the first roll 11, and the anvil from the position where the raw nonwoven fabric 2 exits the meshing portion. Spray onto the transport path to the roll 13. The raw nonwoven fabric 2 comes into close contact with the peripheral surface of the first roll 11 by the wind pressure generated by this spraying. Further, due to the synergistic effect of the hot air and the heating of the first roll 11, the thermoplastic resin constituting the raw fabric nonwoven fabric 2 is softened, thereby promoting adhesion. Further, since the hot air penetrates the raw nonwoven fabric 2 in an air-through manner, the bulk of the raw nonwoven fabric 2 in the direction in which the thickness is reduced by the wind pressure of the hot air is recovered, and the original nonwoven fabric 2 has inherently good A smooth feel is maintained. The hot air is sprayed over the entire width direction of the raw nonwoven fabric 2.

  In parallel with the blowing of hot air, hot air is sucked from the outer surface of the heated first roll 11 toward the inside. Suction is performed in the suction zone 15 of the first roll 11. Specifically, the suction is started from a position slightly upstream from the meshing portion between the first roll 11 and the second roll 12 and is continued until the raw nonwoven fabric 2 comes into contact with the anvil roll 13. The suction is preferably continued to a position slightly downstream from the meshing portion. Until the raw nonwoven fabric 2 reaches the meshing portion, the raw nonwoven fabric 2 only needs to be sucked to the extent of being along the surface of the first roll 11, and the raw nonwoven fabric 2 is placed in the recess 18 of the roll 11. It is not necessary to perform the suction until it enters. By this operation, shrinkage in the width direction when three-dimensionally shaping the raw fabric nonwoven fabric 2 can be prevented. In addition, the raw fabric nonwoven fabric 2 comes to further adhere to the peripheral surface of the first roll 11 during the three-dimensional shaping.

  Conventionally, it has been considered that sucking a heated roll is disadvantageous in terms of energy efficiency. However, as a result of the study by the present inventors, surprisingly, by blowing hot air on the heated roll (that is, the first roll 11) and sucking it, the uneven shape of the roll surface becomes a raw nonwoven fabric. It was found that the material was transferred with good reproducibility, a clear uneven shape was imparted to the raw nonwoven fabric, and the good touch inherent to the raw nonwoven fabric was maintained. From this point of view, the heating temperature of the first roll 11 depends on the type of constituent resin of the raw nonwoven fabric, but is, for example, 25 to 15 ° C. lower than the melting point of the resin having the lowest melting point among the constituent resins. It is preferable that By adopting this heating temperature, melting of the resin can be prevented, and the feel of the raw nonwoven fabric due to the penetration of heated air is improved. Further, by adopting this heating temperature, it becomes easy to obtain a three-dimensional shaping effect by heat sealing. As an example, when using a core-sheath composite fiber in which the core is PET (polyethylene terephthalate) and the sheath is PE (polyethylene) resin, the heating temperature is considered in consideration of the melting point of the polyethylene resin as the sheath, It is preferable to set it as 80-120 degreeC, especially 100-110 degreeC. Also in the case where the second roll 12 is heated in addition to the first roll 11, the heating temperature is preferably 80 to 120 ° C., particularly preferably 100 to 110 ° C. It is advantageous to heat the second roll 12 so that the apparent thickness is large and bulky, and the good touch inherent to the raw nonwoven fabric is maintained.

  It is desirable that the heating temperature of the roll described above and the temperature of the hot air blown onto the raw nonwoven fabric are substantially the same. When emphasizing the bulkiness of the resulting three-dimensionally shaped non-woven fabric, setting the heating temperature of the roll higher than the temperature of the hot air makes it easy to give a sense of thickness when the raw non-woven fabric is three-dimensionally shaped. When emphasizing the touch feeling of the resulting three-dimensionally shaped nonwoven fabric, the softness of the raw nonwoven fabric can be easily maintained by setting the temperature of the hot air higher than the heating temperature of the roll.

  After the raw fabric nonwoven fabric 2 reaches the meshing portion, the concave and convex shape is formed on the raw fabric nonwoven fabric 2 by the meshing of the first roll 11 and the second roll 12. Further, the raw nonwoven fabric 2 is brought into close contact with the peripheral surface of the first roll 11 by the suction force, and the state in which the uneven shape is formed is maintained. When suction is not performed, the raw fabric nonwoven fabric 2 is lifted from the peripheral surface of the first roll 11, and as a result, a three-dimensional shaped nonwoven fabric having a desired uneven shape cannot be obtained. In this case, as described above, since the supply speed of the raw nonwoven fabric 2 is higher than the peripheral speed of the rolls 11 and 12, the three-dimensional application is hardly accompanied by the elongation of the raw nonwoven fabric 2 in the longitudinal direction of the raw nonwoven fabric 2. Shape is made. This is because the apparent length of the raw nonwoven fabric 2 due to the three-dimensional shaping is compensated by the high-speed supply of the raw nonwoven fabric 2. Accordingly, the basis weight of the second wall portion 52 that is a wall portion that is located along the direction orthogonal to the conveying direction of the raw nonwoven fabric 2 among the wall portions in the convex portion 5 generated by the uneven shape shaping is three-dimensionally applied. It is not significantly different from the basis weight of the raw nonwoven fabric 2 before shaping. On the other hand, the basic weight of the 1st wall part 51 which is a wall part located along the conveyance direction of the raw fabric nonwoven fabric 2 falls largely rather than the basic weight of the raw fabric nonwoven fabric 2 before uneven | corrugated shaping. The reason for this is that the apparent width of the raw nonwoven fabric 2 is shortened due to uneven shaping, and the width shrinkage occurs. However, as described above, the raw nonwoven fabric 2 is caught between both rolls 11 and 12. Since the suction is in a state along the peripheral surface of the first roll 11, the width shrinkage is restricted, and the raw nonwoven fabric 2 is elastically stretched in the width direction instead of the width shrinkage. Because. By this elongation, the basis weight of the first wall portion 51 is significantly lower than the basis weight of the raw fabric nonwoven fabric 2 before forming the uneven shape. With such a mechanism, the three-dimensional shaped nonwoven fabric 1 manufactured according to the present method has a basis weight of each first wall portion 51 lower than a basis weight of each second wall portion 52, as shown in FIG. It becomes the structure which became.

  6A and 6B schematically show the cross sections of the convex portions 5 and the concave portions 6 in the three-dimensional shaped nonwoven fabric 1 manufactured according to this method. FIG. 6A shows a state in which the convex portion 5 and the concave portion 6 are cut along the X direction (MD), and the top surface portion 53, the pair of second wall portions 52, and the bottom portion 61 are shown. FIG. 6B shows a state where the convex portion 5 and the concave portion 6 are cut along the Y direction (CD), and the top surface portion 53, the pair of first wall portions 51 and the bottom portion 61 are shown. 6A and 6B, the convex portion 5 is a portion formed corresponding to the concave portion 18 of the first roll 11, and the concave portion 6 corresponds to the convex portion 17 of the first roll 11 and the anvil. It is a part formed corresponding to the pinched part with the roll 13.

  As is clear from the comparison between FIG. 6A and FIG. 6B, the basis weight of each first wall portion 51 and the basis weight of each second wall portion 52 of the convex portion 5 are different. . Specifically, the basis weight of each first wall portion 51 is lower than the basis weight of each second wall portion 52. By the basis weights of the first wall 51 and the second wall 52 being different, the three-dimensional shaped nonwoven fabric 1 has the following advantages. When the three-dimensional shaped nonwoven fabric 1 is used as, for example, a surface sheet of an absorbent article, the permeability of the excreted liquid is caused by the liquid being preferentially transmitted from the first wall portion 51 having a low basis weight. It becomes higher than the conventional surface sheet. Moreover, when the three-dimensional shaped nonwoven fabric 1 is used as, for example, a surface sheet of an absorbent article, the cushioning property by the second wall portion 52 having a high basis weight is increased, and the texture of the three-dimensional shaped nonwoven fabric 1 is improved. Thus, the three-dimensionally shaped nonwoven fabric 1 has a good texture such as cushioning properties while ensuring liquid permeability.

  Further, the top surface portion 53 and the bottom portion 61 are larger and bulky in the top surface portion 53. The reason for this is that the bottom 61 is formed by the clamping pressure between the convex portion 17 of the heated first roll 11 and the heated anvil roll 13, so that the constituent fibers are consolidated, whereas the top surface portion This is because 53 does not cause such consolidation. Therefore, when using the three-dimensionally shaped nonwoven fabric 1 as, for example, a surface sheet of an absorbent article, it is preferable to use the upper surface side as the skin facing surface side in FIGS. 6 (a) and 6 (b). Accordingly, the upper surface of the top surface portion 53 in the same figure comes into contact with the skin, which is preferable because the softness of the raw fabric nonwoven fabric is reflected. Moreover, since the bottom part 61 which is densified and the fiber density is high comes into contact with the absorbent body, it is preferable because the transferability of the liquid to the absorbent body through the bottom part 61 is improved due to the capillary gradient. When the anvil roll 13 is used without being heated, or when the anvil roll is not used at all, the bottom portion 61 is difficult to be consolidated. Therefore, the bottom portion 61 maintains the softness of the raw nonwoven fabric. Therefore, in this case, in FIGS. 6A and 6B, both of the upper and lower surfaces can be used as the skin facing surface side.

  FIG. 7A schematically shows the state of suction and three-dimensional shaping of the raw nonwoven fabric 2. FIG. 7B schematically shows the meshing state of the arm portion 101 of the second member 11b. In addition, in FIG.7 (b), the raw fabric nonwoven fabric is abbreviate | omitted. The raw nonwoven fabric 2 is pushed into the concave portion 18 of the first roll 11 by the convex portion 27 of the second roll 12. As described above, when the recess 18 is viewed along the axial direction A of the roll 11, a pair of end regions located at both ends in the axial direction A at the bottom of the recess 18 are opened at the bottom of the recess 18. The gaps 18a, 18a are formed. Therefore, the both sides of the axial direction A of the raw nonwoven fabric 2 pushed into the recess 18 are particularly strongly sucked by the gaps 18a and 18a. As a result, the raw nonwoven fabric 2 is promoted to be deformed along the shape of the recess 18, and the three-dimensional shaped nonwoven fabric 1 substantially conforming to the uneven shape of the first roll 11 can be manufactured stably and with good reproducibility. Thereby, a small convex part can be clearly formed in the raw fabric nonwoven fabric 2. In addition, it is possible to form a clear convex portion with a small pitch.

  As shown in FIGS. 7A and 7B, it is preferable that the width of the convex portion 27 of the second roll 12 gradually decreases toward the top portion. Since the convex portion 27 has such a shape, it is possible to reduce damage to the raw nonwoven fabric 2 when the raw nonwoven fabric 2 is three-dimensionally shaped.

  Next, the raw nonwoven fabric 2 is sandwiched between the first roll 11 and the anvil roll 13 as shown in FIG. 2 in a state where the raw nonwoven fabric 2 is kept in close contact with the peripheral surface of the first roll 11. Press. Thereby, the three-dimensionally shaped state is stabilized. The anvil roll 13 may be heated or may not be heated. From the viewpoint of obtaining a bulky three-dimensional shaped nonwoven fabric 1 having a large apparent thickness, it is preferable that the anvil roll 13 is not heated. In addition, since the 1st roll 11 is heated as mentioned above, even if the anvil roll 13 is not heated intentionally, since the heat of the 1st roll 11 is transmitted to the anvil roll 13, the anvil roll 13 is Usually, the temperature is higher than room temperature.

  The three-dimensional shaped non-woven fabric 1 manufactured in this way is suitably used as a top sheet of an absorbent article as described above. 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 three-dimensionally shaped nonwoven fabric 1 is used for applications other than the top sheet of the absorbent article, for example, the back sheet of the absorbent article, the base sheet of the fastening tape in the disposable diaper provided with the fastening tape, and the fastening tape. It can also be used as a landing tape sheet, a base sheet of the wing in a sanitary napkin equipped with a wing, a panel member for a loop member of a mechanical fastener, a cleaning sheet, a wiping sheet, and the like.

  When the three-dimensionally shaped nonwoven fabric 1 is used as a top sheet of an absorbent article, the X direction (MD) shown in FIG. 1 matches the longitudinal direction of the absorbent article, and the Y direction (CD) is the width direction of the absorbent article. It is preferably incorporated into the absorbent article so as to match. That is, it is preferable that the 1st wall part 51 in the convex part 5 is located along the longitudinal direction of an absorbent article, and the 2nd wall part 52 is located along the width direction of an absorbent article. By arranging the three-dimensional shaped nonwoven fabric 1 in this way, the cushion feeling of the three-dimensional shaped nonwoven fabric 1 can be easily perceived by the wearer.

  Next, another embodiment of the present invention will be described with reference to FIG. In the present embodiment, only the points different from the above-described embodiment will be described, and the description relating to the above-described embodiment will be appropriately applied to points that are not particularly described. In FIG. 8, the same members as those in FIGS. 1 to 7 are denoted by the same reference numerals.

  The main difference between this embodiment and the above-described embodiment is that hot air is blown to the meshing portions of the rolls 11 and 12 in the above-described embodiment, whereas in this embodiment, hot air is blown. Instead of spraying, the atmosphere of the manufacturing apparatus is heated air. Specifically, as shown in FIG. 8, the manufacturing apparatus is almost hermetically covered with a hood 30, and the atmosphere in the hood 30 is made into heated air. The air in the hood 30 circulates in the hood through the duct 31 by a pump (not shown). A part of the duct 31 is provided with a heating device (not shown), and the temperature of the circulating air is kept constant.

  The temperature of the air in the duct is preferably 80 to 120 ° C., particularly 100 to 110 ° C., from the viewpoint that a clear uneven shape can be imparted to the raw nonwoven fabric 2. Moreover, it is preferable also from the point by which the favorable touch which the raw fabric nonwoven fabric 2 has originally is maintained. According to this embodiment, a three-dimensionally shaped nonwoven fabric having the same performance as the above-described embodiment can be obtained. Further, according to the present embodiment, unlike the embodiment described above, since the wind pressure resulting from the blowing of hot air is not applied to the raw fabric nonwoven fabric 2, the thickness of the raw fabric nonwoven fabric 2 is not easily reduced. As a result, a thick and bulky three-dimensional shaped nonwoven fabric can be obtained.

  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-described embodiment, the first and second rolls 11 and 12 are used to form irregularities, but instead, a large number of irregularities are regularly arranged on the surface and mesh with each other. Using a flat first pressing die and a second flat pressing die that are in the shape, and a three-dimensional shaping is performed by interposing a raw nonwoven fabric between the two in the meshed state Good.

  In the embodiment, the gaps 18 and 18a are formed only in the pair of end regions located at both ends in the axial direction A of the roll 11 in the recess 18 of the first roll 11. In addition, by changing the shape of the first gear 11a, a gap may be provided in the central region of the recess 18 in the axial direction A. Specifically, a roll having a structure shown in FIG. 9 may be used.

  FIG. 9 is a view showing a state in which the peripheral surface of the first roll 11 is extended to a plane, and corresponds to FIG. 5 of the above-described embodiment. In the embodiment described above, the gaps 18a, 18a are formed only in the pair of end regions located at both ends in the axial direction A of the roll 11 in the recess 18 of the first roll 11, In the embodiment, as shown in FIG. 9, in addition to a pair of end regions located at both ends in the axial direction A, a gap is also formed in the central region located at the center in the axial direction A.

  Specifically, the first roll 11 in the present embodiment is arranged such that the first member 11a of the first roll 11 in the above-described embodiment is disposed on one second member 11b and both sides thereof. This corresponds to the one replaced with the gear group 116 composed of the three members of the first member 11a. The gear group 116 and the second member 11b arranged adjacent to the gear group 116 correspond to the gear group 16 of the above-described embodiment. In each gear group 116, the first member 11 a is arranged such that the teeth of the two first members 11 a and the arms (not shown) of the second member 11 b are aligned in the width direction A of the roll 11. And the 2nd member 11b is arrange | positioned. When viewed along the rotation direction R of the roll 11, the tooth arrangement in the gear group 116 adjacent in the axial direction A is shifted by a half pitch.

  In the 1st roll 11, the convex part 17 is formed of the tooth | gear 111 of the 1st member 11a. As shown in FIG. 9, among a large number of convex portions 17 formed on the peripheral surface of the first roll 11, it is surrounded by six convex portions indicated by reference numerals 17 a, 17 b, 17 c, 17 d, 17 e, and 17 f. The region is a recess 18. The recesses 18 are arranged in a row along the rotation direction R of the roll 11. This row is arranged in multiple rows in the axial direction A of the roll 11. When viewed along the rotation direction R of the roll 11, the arrangement of the recesses 18 is shifted by a half pitch in the row of adjacent recesses 18.

  In each recess 18, gaps 18 a and 18 a are formed in a pair of end regions located at both ends in the axial direction A of the roll 11, and also in the central region located in the center in the axial direction A. 18b is formed. By providing such a gap, the upper layer 2 can be sucked not only at both ends of the concave portion 18 but also in the central region, so that the uneven shaping of the upper layer 2 can be performed more stably and at a higher speed. Can do.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the scope of the present invention is not limited to such examples. Unless otherwise specified, “%” and “part” mean “%” and “part”, respectively.

[Example 1]
As a raw fabric nonwoven fabric, an air-through nonwoven fabric having a basis weight of 25 g / m ² was used, and the three-dimensional shaped nonwoven fabric shown in FIG. 1 was produced using the apparatus shown in FIG. The constituent fiber of this nonwoven fabric was a 2.2 dtex × 51 mm core-sheath type composite fiber having a PET core and PE sheath. Both the first roll and the second roll were heated to 110 ° C. The temperature of the hot air sprayed on the raw nonwoven fabric was also set to 110 ° C. The thickness of the raw nonwoven fabric was 0.28 mm, and the thickness of the three-dimensionally shaped nonwoven fabric was 1.16 mm. About the obtained nonwoven fabric, the thickness under 0.5 g / cm < ² > pressure was measured. For measurement, a laser displacement meter LK-080 manufactured by Keyence Corporation was used.

[Comparative Example 1]
In Example 1, the same operation as in Example 1 was performed except that hot air was not blown. The thickness of the obtained nonwoven fabric was measured in the same manner as in Example 1.

[Comparative Example 2]
In Example 1, the same operation as in Example 1 was performed except that the hot air was not blown and the first roll and the second roll were not heated. The thickness of the obtained nonwoven fabric was measured in the same manner as in Example 1.

[Evaluation]
About the nonwoven fabric obtained by the Example and the comparative example, the linearity LC of the compression characteristic and the compression energy WC were measured using the automated compression tester KES-FB3-AUTO-A made from Kato Tech. The results are shown in Table 1 below. The linearity LC of the compression characteristic means that the measurement object is softer as the value is smaller, and the compression energy WC means that the measurement object is softer as the value is larger. In Table 1, data of the raw nonwoven fabric is also shown.

  As is clear from the results shown in Table 1, it can be seen that the nonwoven fabric obtained in the example is thicker, softer and softer than the nonwoven fabric obtained in the comparative example.

FIG. 1 is a perspective view showing an example of a three-dimensionally shaped nonwoven fabric produced by the production method of the present invention. FIG. 2 is a schematic view showing an apparatus suitably used for carrying out the production method of the present invention. FIG. 3 is a perspective view showing a main part of the first roll in FIG. FIG. 4 is an exploded perspective view of a part of the first roll shown in FIG. FIG. 5 is a view showing a state in which the peripheral surface of the first roll shown in FIG. FIG. 6 is a schematic diagram showing a cross-sectional structure of the convex portion of the three-dimensionally shaped nonwoven fabric. Fig.7 (a) is a schematic diagram which shows the state of uneven | corrugated shaping of the raw fabric nonwoven fabric by a 1st roll and a 2nd roll, FIG.7 (b) is in the arm part 101 of the 2nd member 11b. It is a schematic diagram which shows a meshing state. FIG. 8 is a schematic view showing another apparatus suitably used for carrying out the production method of the present invention. FIG. 9 is a view showing a state in which the peripheral surface of another first roll used in the present invention is extended to a flat surface, and corresponds to FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Three-dimensional shaping 2 Original fabric nonwoven fabric 5 Convex part 6 Concave part 11 1st roll 11a 1st member 11b 2nd member 12 2nd roll 16 Member group 17 Convex part 18 Concave part 18a, 18a Cavity part 27 Convex part 51 1st wall part 52 2nd wall part 53 Top surface part

Claims (10)

A plurality of irregularities are regularly arranged on the surface, and the first pressing mold and the second pressing mold are meshed with each other, and the raw nonwoven fabric is interposed between the two in the meshed state. In the method for producing a three-dimensionally shaped nonwoven fabric that three-dimensionally shapes the raw nonwoven fabric,
As the first stamping die, a first roll having a concavo-convex shape on the peripheral surface is used.
As the second pressing die, using a second roll having an uneven shape meshing with the uneven shape of the first roll on the peripheral surface,
Furthermore, using an anvil roll arranged so as to be in contact with the top of the convex portion of the first roll at a position downstream from the meshing site of the first roll and the second roll,
After the raw-material nonwoven fabric three-dimensionally shaped under conditions of heating the first roll and a second roll, while depositing the raw-material nonwoven fabric on the surface of the first roll, the inside from the outer surface of the first roll performing the suction towards the in is passed through the heated air in the three-dimensional shaped been the raw-material nonwoven fabric, and transport the raw-material nonwoven fabric,
The heating temperature of the first roll is 25 to 15 ° C. lower than the melting point of the resin having the lowest melting point among the constituent resins of the raw nonwoven fabric,
A method for producing a three-dimensionally shaped nonwoven fabric without heating an anvil roll . While blowing hot air to the raw-material nonwoven fabric in the conveying path from the position where the raw-material nonwoven fabric exits the engagement portion between the first roll and second roll to the anvil roll, the outer surface of the first pressing die being heated The method for producing a three-dimensional shaped nonwoven fabric according to claim 1, wherein the hot air is sucked from the inside toward the inside, and the hot air is penetrated through the raw nonwoven fabric. The three-dimensional effect according to claim 1, wherein the atmosphere is set as heated air, the air is sucked from the outer surface of the heated first roll toward the inside, and the air is penetrated through the raw nonwoven fabric. A method for producing shaped nonwoven fabric. As a raw fabric non-woven fabric, using a core-sheath composite fiber having a core of polyethylene terephthalate and a sheath of polyethylene,
The manufacturing method of the three-dimensionally shaped nonwoven fabric in any one of Claim 1 thru | or 3 which sets the heating temperature of a 1st roll to 80-120 degreeC, and makes the heating temperature of a 2nd roll 80-120 degreeC. The three-dimensional effect according to any one of claims 1 to 4, wherein the second roll has a width of the convex portion that is 0.1 to 3.0 mm narrower than the width of the concave portion of the first roll. A method for producing shaped nonwoven fabric. The method for producing a three-dimensionally shaped nonwoven fabric according to any one of claims 1 to 5, wherein the second roll has a convex portion that gradually decreases in width toward the top. As a first roll, when the concave portion of the roll is viewed along the axial direction of the roll, the raw nonwoven fabric is applied to the pair of end regions located at both ends in the axial direction at the bottom of the concave portion. The manufacturing method of the three-dimensionally shaped nonwoven fabric in any one of Claim 1 thru | or 6 using what the space | gap part for making it adsorb | suck adhere to the surrounding surface of each is provided. The production of the three-dimensionally shaped nonwoven fabric according to any one of claims 1 to 7, wherein the supply of the raw nonwoven fabric to the meshing part of the first roll and the second roll is performed at a speed higher than the peripheral speed of these rolls. Method. A three-dimensional shaped nonwoven fabric produced by the method according to claim 8 ,
Having a large number of convex portions and concave portions located between the convex portions,
The concave portions and the convex portions are alternately arranged along one direction of the three-dimensional shaped nonwoven fabric and are alternately arranged along a direction orthogonal to the direction,
The convex portion has a pair of first wall portions positioned along the one direction and facing each other, and a pair of second wall portions positioned along the direction orthogonal to the one direction and facing each other. Furthermore, it has a top surface part connected to the upper side of each first wall part and the upper side of each second wall part,
A three-dimensional shaped nonwoven fabric in which the basis weight of each first wall portion is different from the basis weight of each second wall portion. The first wall portion is located along the MD direction of the three-dimensional shaped nonwoven fabric, and the second wall portion is located along the CD direction of the three-dimensional shaped nonwoven fabric,
The three-dimensional shaped nonwoven fabric according to claim 9, wherein the basis weight of each first wall portion is lower than the basis weight of each second wall portion.

Images