JP5931131B2 - Non-woven - Google Patents

Description

  The present invention relates to a nonwoven fabric, particularly a nonwoven fabric in which the fiber density of the nonwoven fabric is biased.

  Patent Document 1 includes a first protruding portion that protrudes toward the first surface on the side of the sheet-like nonwoven fabric in plan view, and a second protruding portion that protrudes toward the second surface opposite to the first surface. The first protrusion and the second protrusion are non-woven fabrics that alternately spread in two directions of the first direction and the second direction in a plan view of the non-woven fabric, and at the top of the first protrusion A nonwoven fabric in which the fiber density on the first surface side is lower than the fiber density on the second surface side is disclosed.

JP 2012-144835 A

  However, the nonwoven fabric according to the invention disclosed in Patent Document 1 is formed so that the fiber density of the fibers constituting the nonwoven fabric is substantially uniform in a plan view of the nonwoven fabric. I can't control the direction. Therefore, for example, when such a nonwoven fabric is used for the top sheet of the absorbent article, body fluids excreted on the nonwoven fabric, such as urine and menstrual blood, are directed from the position where the body fluids are excreted to the periphery thereof. Penetrate so that it spreads out. As a result, the body fluid permeates toward the outside of the absorbent article, so that the body fluid may reach the outside of the absorbent article and leakage may occur.

  Accordingly, an object of the present invention is to provide a nonwoven fabric that allows the absorbed liquid to permeate in a desired direction.

In order to solve the above problems, according to the present invention,
A non-woven fabric formed from a base extending in a planar shape and a plurality of convex portions protruding in the thickness direction from the base,
Each said convex part has a convex part,
Each convex surface portion is configured such that the fiber density of the convex surface portion is biased in a predetermined direction in the planar direction of the nonwoven fabric.
A nonwoven fabric can be provided.

  According to the nonwoven fabric of this invention, since the fiber density of the convex part of a convex part is biased in the predetermined direction, the absorbed liquid can be osmose | permeated in a desired direction.

The top view of the nonwoven fabric which concerns on 1st embodiment of this invention. The II-II line | wire partial end elevation of FIG. The figure for demonstrating distribution of the fiber density of the convex part of the convex part in the nonwoven fabric 1 of FIG. The photograph which image | photographed the nonwoven fabric of FIG. 1 by planar view of the nonwoven fabric. The photograph of the cross section which expanded the V section of FIG. The figure for demonstrating distribution of the fiber density of the convex part of the convex part in the nonwoven fabric which concerns on 2nd embodiment. The figure for demonstrating distribution of the fiber density of the convex part of the convex part in the nonwoven fabric which concerns on 3rd embodiment, and the base part located around a convex part. The figure for demonstrating distribution of the fiber density of the convex part of the convex part in the nonwoven fabric which concerns on 4th embodiment, and the base part located around a convex part. Schematic which shows the outline | summary of the manufacturing equipment for manufacturing the nonwoven fabric which concerns on embodiment of this invention. The X section enlarged view of FIG. The figure explaining the measurement point which measures the fiber density of the convex part of the convex part of the nonwoven fabric which concerns on Examples 1-3.

(First embodiment)
Hereafter, the nonwoven fabric 1 which concerns on 1st embodiment of this invention is demonstrated, referring FIGS.

  FIG. 1 is a plan view of the nonwoven fabric according to the first embodiment of the present invention, and FIG. 2 is a partial end view taken along line II-II in FIG. The nonwoven fabric 1 according to the first embodiment extends on the plane of the nonwoven fabric 1 defined by the longitudinal direction Lo and the transverse direction Tr, and is opposite to the first surface FF that can be seen in plan view in FIG. And a second surface FS located on the side.

  As shown in FIGS. 1 and 2, the nonwoven fabric 1 includes a base 10 that expands in a substantially planar shape, and a plurality of protrusions that protrude from the base 10 in the thickness direction Th toward the first surface FF in the first embodiment. It is formed from the convex part 12. Each convex portion 12 includes a convex surface portion 12T that is separated from the base portion 10 in the thickness direction Th of the nonwoven fabric 1. Here, the convex surface portion 12T is positioned on the top side of the convex portion 12 with respect to the intermediate point in the thickness direction Th between the base portion 10 and the top portion of the convex portion 12 farthest from the base portion 10 in the thickness direction Th. This is a portion of the convex portion 12 that forms a certain surface facing the protruding direction from the base portion 10 of the convex portion 12.

  In the first embodiment, the convex surface portion 12T is substantially flat. However, the convex surface portion 12T does not have to be a completely flat surface, and may include a certain inclined surface or curved surface.

  Moreover, in 1st embodiment, the convex part 12 has the substantially cylindrical shape whose diameter is about 10 mm on the external appearance. In another embodiment, the shape of the convex portion 12 is a shape including a convex surface portion having a certain area, such as a truncated cone shape, an elliptical or polygonal columnar shape, or a truncated cone shape. .

  FIG. 3 is a view for explaining the fiber density distribution of the convex surface portion 12T of the convex portion 12 in the nonwoven fabric 1 of FIG. Note that FIG. 3 is described by paying attention to one convex portion 12, and represents the fiber density distribution of the convex surface portion 12 </ b> T depending on the density (number) of “x” marks.

  As shown in FIG. 3, each convex surface portion 12 </ b> T is configured such that the fiber density of the convex surface portion 12 </ b> T is biased in the longitudinal direction Lo of the nonwoven fabric 1 in the planar direction of the nonwoven fabric 1. That is, in the convex surface part 12T, on a predetermined line extending in the longitudinal direction Lo, there is a portion where the fiber density is high on one side in the longitudinal direction Lo and low on the other side in the longitudinal direction Lo.

  In other words, in the nonwoven fabric 1 according to the first embodiment, each convex surface portion 12T is represented by a virtual line VL extending in the direction orthogonal to the longitudinal direction Lo of the nonwoven fabric 1 in a plan view of the nonwoven fabric 1, that is, in the transverse direction Tr. When the two semi-convex surface portions 121T and 122T are divided into two equal parts so as to have the same area, the fiber density of one semi-convex surface portion 121T is higher than the fiber density of the other semi-convex surface portion 122T. Here, “the fiber density of the semi-convex surface portion” means an average of the fiber densities of the entire semi-convex surface portions 121T and 122T, but in measuring the fiber density as described later, each semi-convex surface portion 121T. 122T in a direction perpendicular to the direction in which the fibers are biased, that is, in the case of the first embodiment, in the transverse direction Tr, and in a direction in which the fibers are biased, that is, in the case of the first embodiment, non-woven fabric. It is assumed that the fiber density measured in the central portion in the transverse direction Tr of these cut surfaces is averaged by being equally divided into three in the longitudinal direction Lo.

  FIG. 4 is a photograph of the nonwoven fabric of FIG. 1 taken on a black table in a plan view of the nonwoven fabric. In the photograph of FIG. 4, the shading of the color indicates the fiber density. In other words, the darker the black color in the photograph of FIG. 4, the more easily the color of the photographing stand is seen and the fiber density is low, and the darker the white color is, the harder the color of the photographing stand is and the higher the fiber density. To do. From the photograph shown in FIG. 4, in the nonwoven fabric 1 according to the first embodiment, the fiber density of the convex portion 12T of the convex portion 12 is biased in the longitudinal direction Lo in the planar direction of the nonwoven fabric 1 in the plan view of the nonwoven fabric 1. It can be said that. This is because, when the convex surface portion 12T is observed in FIG. 4, black tends to be dark on one side in the longitudinal direction Lo, and white tends to be dark on the other side.

In the present invention, in measuring the “fiber density”, the number of locations FC where fibers are cut per 1 mm ^{2 on} the cut surface of the nonwoven fabric 1 is used as an index. Specifically, using a scanning electron microscope (for example, “Real Surface View Microscope VE-7800” manufactured by KEYENCE, Inc.), the magnification is adjusted to about 50 to 100 times, and a certain area (for example, about 2.0 mm ^2). ) Is observed, and the locations FC (FIG. 5) where the fibers are cut are counted. The cut surface to be observed includes the entire thickness direction Th from the first surface FF to the second surface FS. Next, the number of cut portions is replaced with the number per 1 mm ² , and the number is used as an index of “fiber density”.

  The fiber used for the nonwoven fabric 1 in 1st embodiment is a fiber of a core sheath structure, Comprising: As for the raw material, a sheath is a high density polyethylene (HDPE) and a core is a polyethylene terephthalate (PET).

  The fibers used for the nonwoven fabric include natural fibers, recycled fibers (rayon, acetate, etc.), thermoplastic resin fibers (polyethylene, polypropylene, polybutylene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, Polyolefins such as ethylene-acrylic acid copolymers and ionomer resins, polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, polyesters such as polylactic acid, polyamides such as nylon, etc.) or surface modified products thereof Among these, among these, a thermoplastic resin fiber or a surface modification product thereof is preferable. These fibers include core-sheath fibers, side-by-side fibers, island / sea fibers, etc., hollow fibers, flat fibers, irregular fibers such as Y-type and C-type fibers, latent fibers It may be a crimped or manifested crimped three-dimensional crimped fiber, a water stream, a split fiber that is split by a physical load such as heat or embossing. These fibers may be hydrophilic fibers or hydrophobic fibers. However, when a hydrophobic fiber is used, processing such as separately applying a hydrophilic oil to the fiber is required.

  Moreover, as shown in FIG. 1, in the nonwoven fabric 1 which concerns on 1st embodiment, the convex part 12 is linearly arrange | positioned along each of the 1st direction D1 and the 2nd direction D2. Here, the first direction D1 is the same as the transverse direction Tr, and the second direction D2 is a direction inclined by 60 ° from the first direction D1. Moreover, in the nonwoven fabric 1 which concerns on 1st embodiment, the base 10 and the convex part 12 are arrange | positioned equally by arrange | positioning the convex part 12 at equal intervals. Thereby, for example, when the nonwoven fabric 1 is used as a top sheet of an absorbent article such as a disposable diaper or a sanitary napkin and the first surface FF is used as a surface, the body fluid excreted on the nonwoven fabric 1 is absorbed. The base 10 that permeates the interior where the absorbent body or the like of the article is located and the convex portion 12 that permeates the body fluid in a desired direction can be arranged in a suitable distribution.

  Furthermore, as shown in FIG. 1, in the nonwoven fabric 1 which concerns on 1st embodiment, the convex part 12 adjacent to the 1st direction D1 and the 2nd direction D2 is provided intermittently through the base 10, respectively. ing. As a result, the bodily fluid excreted on the first surface FF can be permeated in the direction in which the fiber density is biased and transferred from the convex surface portion 12T of the convex portion 12 to the adjacent base portion 10. Thereby, for example, when the nonwoven fabric 1 is used for the top sheet of the absorbent article, the liquid can be efficiently penetrated from the base 10 into the absorbent article.

  From this, the effect | action of the nonwoven fabric which concerns on 1st embodiment is demonstrated. In the nonwoven fabric 1 which concerns on 1st embodiment, as above-mentioned, each convex-surface part 12T is comprised so that the fiber density of the convex-surface part 12T may be biased to the longitudinal direction Lo in the plane direction of the nonwoven fabric 1. FIG. Accordingly, the liquid absorbed by the fibers forming the convex portion 12 easily penetrates from the lower fiber density to the higher fiber due to the capillary phenomenon, and therefore easily moves to the higher fiber density side in the longitudinal direction Lo. Therefore, the absorbed liquid can be infiltrated in a desired direction by installing the non-woven fabric so that the side with the higher fiber density is disposed in the direction in which the liquid is to be infiltrated. In the present specification, “the liquid can permeate in a desired direction” does not mean that the liquid permeates only in the desired direction, but the liquid permeating in the desired direction increases. It should be noted that

  In addition, although the fiber density of the convex surface part 12T is biased in the longitudinal direction Lo in the nonwoven fabric 1 according to the first embodiment, it may be biased in any direction among the planar directions of the nonwoven fabric 1. That is, the convex surface portion 12 </ b> T only needs to be configured such that the fiber density of the convex surface portion 12 </ b> T is biased in a predetermined direction in the planar direction of the nonwoven fabric 1. And a liquid can be osmose | permeated to a desired direction by arrange | positioning the side with a high fiber density so that it may face in the direction which wants to infiltrate a liquid.

  Moreover, in FIG. 3, although the fiber distribution of the convex part 12T of one convex part 12 was demonstrated, in the nonwoven fabric 1 which concerns on 1st embodiment, the convex part 12T of each convex part 12 is the same as that of FIG. Has fiber distribution. However, the fiber density of the convex surface portions 12T of all the convex portions 12 does not need to be biased, and the nonwoven fabric 1 in which the fiber density of the convex surface portions 12T of the convex portions 12 is biased is at least part of the convex portions 12. It can be said that it is a nonwoven fabric within the scope of the invention. This is because there is no change in the effect of the nonwoven fabric 1 of the present invention that the liquid absorbed by the nonwoven fabric 1 can permeate in a desired direction.

  Further, the degree of unevenness of the fiber density of the convex surface portion 12T only needs to be biased to such an extent that the liquid absorbed by the nonwoven fabric 1 can permeate in a desired direction.

  In the nonwoven fabric 1 which concerns on 1st embodiment, as above-mentioned, the convex part 12 is linear along each of the 2nd direction D2 inclined 60 degrees from the 1st direction D1 and the 1st direction D1. It is arranged. In another embodiment, the second direction D2 is tilted at an angle other than 60 ° from the first direction D1. In yet another embodiment, the protrusions 12 are linearly arranged along only one direction. In other embodiment, the convex part 12 is not arrange | positioned along any direction, but is arrange | positioned in arbitrary positions.

  Moreover, in the nonwoven fabric 1 which concerns on 1st embodiment, as mentioned above, the base 10 and the convex part 12 are arrange | positioned equally by arrange | positioning the convex part 12 at equal intervals. In another embodiment, the space | interval of the convex parts 12 is not constant.

  In another embodiment, the convex portion 12 is linearly arranged in one of the first direction D1 and the second direction D2, and in yet another embodiment, the convex portion 12 is arranged along any direction. It is not installed and is arranged irregularly.

(Second embodiment)
Hereafter, the nonwoven fabric 1 which concerns on 2nd embodiment of this invention is demonstrated, referring FIG. Regarding the second embodiment, differences from the first embodiment will be mainly described.

  Drawing 6 is a figure for explaining distribution of the fiber density of convex part 12T of convex part 12 in nonwoven fabric 1 concerning a second embodiment. As shown in FIG. 6, in each convex part 12, the edge part 12TE of the convex surface part 12T has a fiber density higher than the center part 12TC of the convex surface part 12T. As described above, when the fiber density of the edge portion 12TE of the convex surface portion 12T is high, the rigidity of the edge portion 12TE is increased, thereby maintaining the shape of the convex portion 12 even when an external force is applied to the convex portion 12. can do. Therefore, for example, when packaging for selling the nonwoven fabric 1, it is possible to prevent the external force from being applied to the convex portion 12 and the shape of the nonwoven fabric 1 from collapsing. As a result, the non-woven fabric 1 is packaged, and even after the package is opened, it is possible to achieve the effect of excellent moldability, which is preferable. Furthermore, since the nonwoven fabric 1 which concerns on 2nd embodiment can maintain the shape of the convex part 12 of the nonwoven fabric 1 at the time of manufacture after packaging and opening, it is preferable also on an appearance (appearance).

  The edge portion 12TE is a region of the convex surface portion 12T having a certain width along the end edge 12TEE of the convex surface portion 12T and in the central portion 12TC direction so that the fiber density can be confirmed. Further, the central portion 12TC is a portion further away from the end edge 12TEE than the edge portion 12TE. In addition, when it is difficult to distinguish the edge portion 12TE and the central portion 12TC, a certain range around the center of gravity of the geometric shape of the convex portion 12T in the plan view of the nonwoven fabric 1 is defined as the central portion 12TC. In the case of the second embodiment, the width of the edge portion 12TE is about 1 mm with respect to the convex surface portion 12T having a diameter of about 10 mm, that is, about 10% of the diameter (or the length of the difference between the convex surface portions 12T). Is the length of

  In addition, also in 2nd embodiment, similarly to the nonwoven fabric 1 which concerns on 1st embodiment, each convex surface part 12T is the longitudinal direction Lo of the nonwoven fabric 1 among the planar directions of the nonwoven fabric 1 in the fiber density of the convex surface part 12T. It is comprised so that it may be biased to. That is, in the second embodiment, on the line extending in the predetermined longitudinal direction Lo at the central portion 12TC of the convex surface portion 12T, the fiber density is high at a location on one side in the longitudinal direction Lo, and the other side in the longitudinal direction Lo. There are portions where the fiber density is low at the locations.

(Third embodiment)
Hereafter, the nonwoven fabric 1 which concerns on 3rd embodiment of this invention is demonstrated, referring FIG. In the third embodiment, differences from the first embodiment will be mainly described.

  FIG. 7 is a view for explaining the fiber density distribution between the convex surface portion 12T of the convex portion 12 and the base portion 10 located around the convex portion 12 in the nonwoven fabric 1 according to the third embodiment. Referring to FIG. 7, in the third embodiment, in the plan view of the nonwoven fabric 1, the fiber density of the fibers constituting the convex surface portion 12 </ b> T of the convex portion 12, which is one end portion of the convex surface portion 12 </ b> T in the longitudinal direction Lo. In the portion 10L of the base 10 close to the high portion 12TH, the fiber density is lower than the other portions of the base 10. In other words, the fiber density of the base portion 10 decreases as it approaches the portion 12TH where the fiber density of the protrusion 12 is high around the protrusion 12.

  As a result, the base 10 has a portion where the fiber density is lower than other portions. Thereby, for example, when the nonwoven fabric 1 according to the third embodiment is used for the top sheet of the absorbent article, the liquid that has moved to the portion 12TH where the fiber density of the convex portion 12T is high as described above, In the portion 10L where the fiber density of the base portion 10 located in the lower portion 10L is low, it can be quickly transmitted. As a result, it is preferable because the body fluid excreted on the nonwoven fabric 1 can be quickly transferred into the absorbent article provided with the absorbent body and the like.

(Fourth embodiment)
Hereafter, the nonwoven fabric 1 which concerns on 4th embodiment of this invention is demonstrated, referring FIG. In the fourth embodiment, differences from the third embodiment will be mainly described.

  FIG. 8 is a diagram for explaining the fiber density distribution between the convex surface portion 12T of the convex portion 12 and the base portion 10 located around the convex portion 12 in the nonwoven fabric 1 according to the fourth embodiment. In the nonwoven fabric according to the fourth embodiment, as in the nonwoven fabric according to the second embodiment, as shown in FIG. 8, in each convex portion 12, the edge portion 12TE of the convex surface portion 12T is the center of the convex surface portion 12T. Fiber density is higher than part 12TC. That is, the nonwoven fabric 1 which concerns on 4th embodiment is a nonwoven fabric which has both the effect of both the nonwoven fabric 1 which concerns on 2nd and 3rd embodiment. Since these effects are the same as the effects of the nonwoven fabric 1 according to the second and third embodiments, description thereof is omitted.

(Nonwoven fabric manufacturing method)
From this, the manufacturing method of the nonwoven fabric 1 which concerns on 4th embodiment is demonstrated. FIG. 9 is a schematic view showing an outline of the production equipment 3 for producing the nonwoven fabric 1 according to the embodiment of the present invention, and FIG. 10 is an enlarged view of a portion X in FIG. The manufacturing equipment 3 is shaped into the card machine 20 that opens the fiber F1 and adjusts the basis weight, the suction drum 22 and the air jet nozzle 26 that shape the fiber F2 so as to form the nonwoven fabric 1, and the fiber F3. A heat treatment machine 28 for heat treating the fiber F3 so as to fix the formed shape is provided. In FIG. 9, fibers F <b> 1 to F <b> 3 and the nonwoven fabric 1 described later are transported in the direction of the arrow MD, and the transport direction MD coincides with the longitudinal direction Lo of the nonwoven fabric 1.

  The manufacturing method of the nonwoven fabric 1 will be briefly described. First, the fiber F1 is opened by the card machine 20, the basis weight is adjusted, and the fiber F2 after opening is supplied to the suction drum 22. Next, hot air is blown by the air jet nozzle 26 while sucking and moving the fibers F2 on the outer peripheral surface of the suction drum 22 on which the pattern plate 24 is provided, so that the nonwoven fabric 1 according to the above embodiment is formed. The fiber F2 is shaped. And the nonwoven fabric 1 is completed by heat-processing the fiber F3 after shaping in the heat processing machine 28, and fixing the shape of the fiber F3 shaped by the previous process.

  From this, the manufacturing method of the nonwoven fabric 1 is explained in full detail. In the manufacturing process of the nonwoven fabric 1, first, the opened fiber F <b> 1 is supplied to the card machine 20. In the card machine 20, the fiber F1 is further opened, and the basis weight (basis weight) of the fiber F1 is adjusted to a desired value.

  The fiber F2 that has passed through the card machine 20 is supplied to the suction drum 22. The inside of the suction drum 22 is formed in a hollow shape, and the inside of the suction drum 22 is in a negative pressure when air is sucked by suction means such as a blower. A large number of suction holes 22t are provided on the outer peripheral surface of the suction drum 22 so that outside air can be sucked. The diameter of the suction hole of the suction drum 22 is set small so as not to suck the fiber F2 into the suction drum 22.

  The outer peripheral surface of the suction drum 22 is covered with the pattern plate 24 over its entire periphery, and specifically, the fibers F <b> 2 are supplied onto the pattern plate 24. In this manufacturing method, the pattern plate 24 is an aperture plate in which through holes 24 t having a shape complementary to the convex portions 12 of the nonwoven fabric 1 are provided with the distribution of the convex portions 12.

  As a result, the suction holes of the suction drum 22 exposed in the through holes 24 t of the pattern plate 24 suck the fibers F <b> 2 supplied onto the pattern plate 24. In the nonwoven fabric 1 of the embodiment, the difference in the position in the thickness direction Th of the nonwoven fabric 1 between the base portion 10 and the convex portion 12T of the convex portion 12 on the first surface FF is substantially equal to the thickness of the pattern plate 24.

  In this manufacturing method, the suction drum 22 has, on its outer peripheral surface, a region AS from a point SS where the fibers F2 are delivered from the upstream belt conveyor UB to a point SE where the fibers F2 are delivered to the downstream belt conveyor DB. The fiber F2 is sucked in the other area AN, and is not sucked in the other areas AN. This is to improve the efficiency of the suction action by the suction drum 22.

  Hot air is blown by the air jet nozzle 26 on the fibers F2 sucked on the outer peripheral surface of the suction drum 22. Here, the air jet nozzle 26 has a mechanism for uniformly ejecting a predetermined amount of warm air with a uniform width in the width direction. By adjusting the width of the blowout port, the distance from the blowout port to the fiber F2, and the like, the warm air is blown substantially uniformly over the entire width of the laminate formed of the fiber F2. By the suction action and the spray action by the suction drum 22 and the air jet nozzle 26, the fibers F2 can be shaped so as to have the shape of the nonwoven fabric 1 according to the embodiment.

  The temperature of the hot air blown from the air jet nozzle 26 is higher than the melting point of the fiber F2, but is adjusted so as not to become too high in order to avoid the nonwoven fabric 1 from becoming excessively hard after completion. Yes. Moreover, the wind speed of this warm air is determined so that the fiber F2 may be shaped into a desired shape. Generally, the temperature and wind speed of the warm air from the air jet nozzle 26 vary depending on the material of the fiber to be used, the basis weight, the shape of the non-woven fabric 1 after completion, and the optimum temperature and wind speed are determined by, for example, experiments. It is preferable. For example, the temperature of the warm air blown from the air jet nozzle 26 is preferably 80 ° C. to 400 [° C.], and the wind speed is preferably 10 to 200 [m / sec]. In this manufacturing method, the temperature of the warm air blown from the air jet nozzle 26 is 180 [° C.], and the wind speed is 38.9 [m / sec]. At this stage, by blowing hot air having a temperature higher than the melting point to the fiber F2, the shaped shape can be fixed to some extent while shaping the fiber F2.

  In the manufacturing facility 3 according to the present embodiment, the surface of the laminate formed from the fibers F2 facing the suction drum 22 and the pattern plate 24 becomes the first surface FF of the nonwoven fabric 1 and faces the air jet nozzle 26. The surface of the laminate becomes the second surface FS of the nonwoven fabric 1.

  When the fiber F2 is blown by the air jet nozzle 26, the fiber F2 is blown off and moves to the periphery thereof. As a result, the amount of fibers in the sprayed portion decreases, and as a result, the fiber density in the sprayed portion decreases. On the other hand, since the air jet nozzle 26 is fixed, the fiber F2 located in the through hole 24t of the pattern plate 24 is finally blown by warm air in the portion F2tu located upstream in the transport direction MD. By being attached, the fiber density is lowered. Thereafter, the fibers F2 moved by the blowing action by the air jet nozzle 26 are fixed at the moved positions by the suction action of the suction drum 22. More specifically, first, warm air is blown to the portion F2td on the downstream side in the transport direction MD of the fiber F2 located in the through hole 24t, and the fiber located in the portion F2td is blown off, so that the transport direction MD. Move downstream. However, after that, hot air is blown to the upstream portion F2tu in the transport direction MD of the fiber F2 located in the through hole 24t, and the fiber moves downstream in the transport direction MD. And since the fiber F2 located in the through-hole 24t of the pattern plate 24 is continuously attracted | sucked by the suction drum 22, it is conveyed by the subsequent process, the movement of a fiber being suppressed. As a result, finally, the fiber density of the portion F2td on the downstream side in the conveyance direction MD of the fiber F2 becomes high, and conversely, the fiber density of the portion F2tu on the upstream side in the conveyance direction MD of the fiber F2 blown last. Becomes lower. Thus, in the nonwoven fabric 1, in each convex part 12, the convex surface part 12T is a direction in which the fiber density of the convex surface part 12T coincides with a predetermined direction, the conveyance direction MD in the above-described embodiment. It is configured to be biased in the longitudinal direction Lo.

  The same applies to the part F2su located on the upstream side in the transport direction MD among the fibers F2 located on the outer surface 24s located between the through holes 24t of the pattern plate 24. That is, when the warm air is blown to the portion F2su, the fiber F2 is blown off and moves to the periphery thereof. At this time, the fiber F2 also moves in the through hole 24t. Thereafter, warm air is blown to the upstream portion F2tu of the fiber F2 in the transport direction of the fiber F2 in the through hole 24t. Once the fiber F2 moves into the through hole 24t, the hot air is blown into the through hole 24t. Since the fiber F2 does not return from the outer surface 24s to the outer surface 24s, the fiber density of the portion F2su is lowered. On the other hand, the fiber density of the upstream portion F2tu in the transport direction of the fiber F2 in the through hole 24t is increased. As a result, as in the nonwoven fabric 1 according to the third embodiment, the base 10 has a fiber density that decreases as the fiber density of the convex portion 12 approaches the portion 12TH around the convex portion 12.

  Further, the corner Co formed at a position where the side wall 24w forming the through hole 24t of the pattern plate 24 and the outer peripheral surface of the suction drum 22 are in contact with each other is difficult to reach the hot air from the air jet nozzle 26. Fiber is difficult to move from. On the other hand, the fibers are blown from the periphery of the corner Co by the warm air from the air jet nozzle 26 and move to the corner Co. In the nonwoven fabric 1, the corner Co is a position corresponding to the edge 12TE of the convex portion 12. As described above, in the manufacturing process, the amount of fibers in the corner Co increases, and as a result, the edge 12TE of the protrusion 12 is the center 12TC of the protrusion as in the nonwoven fabric 1 according to the second embodiment. The fiber density becomes higher.

  Finally, the shape of the convex portion 12 is determined by the shape of the through hole 24t of the pattern plate 24, the temperature of the warm air blown from the air jet nozzle 26, the wind speed, and the like.

  As shown in FIG. 9, the fiber F <b> 3 shaped by the suction and spraying action is then transferred to the heat treatment machine 28. The fiber F3 is heat-treated in the heat treatment machine 28, and the shape shaped in the previous stage is fixed. In the heat treatment machine 28, the fiber F3 is heat-treated for a long time with warm air at a relatively low temperature and low speed with respect to the melting point of the fiber, thereby fixing the shape of the fiber F3 formed in the previous process. The nonwoven fabric 1 can be made flexible. In general, the temperature and wind speed of the warm air in the heat treatment machine 28, the heat treatment time, and the like vary depending on the material of the fiber to be used, the basis weight, etc., but it is preferable to determine the optimum temperature and wind speed by, for example, experiments.

  When the heat treatment of the fiber F3 by the heat treatment machine 28 is completed, the nonwoven fabric 1 is completed. The completed nonwoven fabric 1 is used after being cut into a desired size.

  So far, the manufacturing method of the nonwoven fabric 1 according to the fourth embodiment has been described. However, by appropriately changing the shape of the pattern plate 24, the temperature of the hot air blown from the air jet nozzle 26, the wind speed, etc. The nonwoven fabric 1 which concerns on the 1st-3rd can be manufactured.

  In this example, a liquid diffusion distance test was performed using a nonwoven fabric in which various conditions were set. The liquid diffusion distance test is a test for confirming that the liquid absorbed by the nonwoven fabric penetrates with directivity.

  From this, Examples 1-3 and a comparative example are demonstrated.

(Examples 1-3)
The nonwoven fabrics according to Examples 1 to 3 are manufactured by the above-described manufacturing method. The temperature and wind speed of the warm air blown from the air jet nozzle 26 when manufacturing these nonwoven fabrics, and the temperature and wind speed of the heat treatment in the heat treatment machine 28 are shown in Table 1 described later. Moreover, the deviation of the fiber density of the convex part of a convex part in these nonwoven fabrics was measured by the above-mentioned fiber density measuring method around two measurement points PH and PL shown in FIG. One measurement point PH is a midpoint between the center point C of the convex surface portion 12T in the plan view of the nonwoven fabric 1 and the end edge 12TEE located on the higher fiber density side along the longitudinal direction Lo from the center point C. The other measurement point PL is the midpoint between the center point C of the convex surface portion 12T and the end edge 12TEE located on the side where the fiber density is low along the longitudinal direction Lo from the center point C. If the difference in fiber density measured at these measurement points is large, it can be said that the fiber density of the convex surface portion is biased. Referring to Table 1 to be described later, the fiber density of the convex portion of the nonwoven fabric according to Example 2 is more biased than Example 1. And the fiber density of the convex part of the nonwoven fabric which concerns on Example 3 is biased rather than Example 2. FIG.

(Comparative example)
In the nonwoven fabric according to the comparative example, the fiber density is equalized by the heat treatment machine without the fibers opened by the card machine being sucked by the suction drum and without being blown by the air jet nozzle. It is formed in a planar shape. The temperature and wind speed of the heat treatment in the heat treatment machine at this time are shown in Table 1 described later.

  Next, the test method of the test performed in this example will be described. In the liquid diffusion distance test, a nonwoven fabric sample according to Examples and Comparative Examples cut to a width of 150 mm and a length of 300 mm was placed on a stainless steel plate having a width of 250 mm and a length of 450 mm, and 20 cc in the center of one convex portion. The simulated artificial urine was dropped in 2.5 seconds. At this time, the length direction of the sample is the direction in which the fiber density of the fibers constituting the convex surface portion of the convex portion is biased, the direction along the length direction where the fiber density of the convex surface portion is high is the DH direction, and the convex surface The direction in which the fiber density of the part was low was taken as the DL direction. Then, distances dh and dl from the artificial urine dropping position where the artificial urine penetrated and reached in the DH direction and the DL direction were measured, respectively. The value obtained by subtracting the distance dl from the distance dh at this time was defined as the liquid diffusion distance. The liquid diffusion distance test was performed three times, and a value obtained by arithmetically averaging the measured values was calculated as the liquid diffusion distance.

  The artificial urine used in the liquid diffusion distance test was prepared by dissolving 200 g of urea, 80 g of sodium chloride, 8 g of magnesium sulfate, 3 g of calcium chloride, and about 1 g of a pigment (blue No. 1) in 10 L of ion-exchanged water. .

  Table 1 is shown below. Table 1 shows the basis weight, thickness, preparation conditions, fiber density of the convex portion around the measurement points PH, PL, and the liquid diffusion distance test of the nonwoven fabrics of Examples 1 to 3 and Comparative Example. In addition, “thickness” in Table 1 is an average value of thicknesses measured three times under a pressure of 3 gf / cm 2, and in the nonwoven fabrics according to Examples 1 to 3, the thickness of the convex portion was measured. .

  As shown in the result of the liquid diffusion distance test in Table 1, the liquid diffusion distance is larger as the fiber density of the convex surface portion is biased. Therefore, it can be said that the greater the deviation of the fiber density, the more the liquid absorbed by the nonwoven fabric can permeate in the direction in which the fiber density of the fibers constituting the convex surface part is biased.

  All features that can be understood by those skilled in the art from the description, drawings, and claims are described in the specification in which these features are combined only in relation to certain other features. As long as the features are not explicitly excluded, or unless the technical aspects are impossible or meaningless combinations, independently and in addition to one or more of the other disclosed herein. It can be combined with any combination of features.

  For example, in the nonwoven fabric 1 according to another embodiment, as in the second embodiment, the edge portion 12TE of the convex surface portion 12T has a fiber density higher than the central portion 12TC of the convex surface portion 12T, and the third embodiment. As in the form, the base 10 has a lower fiber density as it approaches the portion 12TH where the fiber density of the protrusion 12 is higher around the protrusion 12.

  The present invention is defined as follows.

(1) A non-woven fabric formed from a base portion that extends in a planar shape and a plurality of convex portions that protrude in the thickness direction from the base portion
Each said convex part has a convex part,
Each convex surface portion is configured such that the fiber density of the convex surface portion is biased in a predetermined direction in the planar direction of the nonwoven fabric.
Non-woven fabric.

(2) In each said convex part, the edge part of the said convex surface part has a fiber density higher than the center part of the said convex surface part,
The nonwoven fabric as described in (1).

(3) As for the said base part, a fiber density becomes low as the fiber density of a convex part approaches the part around the said convex part,
The nonwoven fabric as described in (1) or (2).

(4) When each said convex surface part is equally divided into two semi-convex surface parts so that it may become the same area by the virtual line extended in the direction orthogonal to the said predetermined direction in planar view of the said nonwoven fabric, The fiber density of the semi-convex surface portion is higher than the fiber density of the other semi-convex surface portion,
The nonwoven fabric according to any one of (1) to (3).

(5) The convex portions are disposed along a first direction and a second direction different from the first direction.
The nonwoven fabric according to any one of (1) to (4).

(6) The convex portions are provided at equal intervals across the base in the first direction and the second direction.
The nonwoven fabric as described in (5).

(7) The predetermined direction coincides with the first direction or the second direction.
The nonwoven fabric as described in (5) or (6).

(8) The predetermined direction coincides with the transport direction when the nonwoven fabric is manufactured.
The nonwoven fabric according to any one of (1) to (7).

DESCRIPTION OF SYMBOLS 1 Nonwoven fabric 10 Base 12 Convex part 12T Convex part

Claims (7)

A non-woven fabric formed from a base extending in a planar shape and a plurality of convex portions protruding in the thickness direction from the base,
Each said convex part has a convex part,
Each convex surface portion is configured such that the fiber density of the convex surface portion is biased in a predetermined direction out of the plane direction of the nonwoven fabric.
As the base portion approaches the portion where the fiber density of the convex portion is high around the convex portion, the fiber density decreases.
Non-woven fabric. In each of the convex portions, the edge portion of the convex surface portion has a fiber density higher than the central portion of the convex surface portion.
The nonwoven fabric according to claim 1. When each said convex surface part is equally divided into two half-convex surface parts so that it may become the same area by the virtual line extended in the direction orthogonal to the said predetermined direction in planar view of the said nonwoven fabric, one said half-convex surface The fiber density of the part is higher than the fiber density of the other semi-convex surface part,
The nonwoven fabric according to claim 1 or 2. The convex portion is disposed along a first direction and a second direction different from the first direction.
The nonwoven fabric as described in any one of Claims 1-3. The convex portions are provided at equal intervals across the base in the first direction and the second direction.
The nonwoven fabric according to claim 4. The predetermined direction coincides with the first direction or the second direction;
The nonwoven fabric according to claim 4 or 5. The nonwoven has a longitudinal direction;
The predetermined direction coincides with the longitudinal direction ;
The nonwoven fabric of any one of Claims 1-6.