WO2015199179A1

WO2015199179A1 - Non-woven fabric

Info

Publication number: WO2015199179A1
Application number: PCT/JP2015/068353
Authority: WO
Inventors: 明寛木村; 耕出谷
Original assignee: ユニ・チャーム株式会社
Priority date: 2014-06-26
Filing date: 2015-06-25
Publication date: 2015-12-30
Also published as: EP3162939A4; KR102294225B1; AU2015281112A1; KR20170021791A; JP5931131B2; CN106661791B; AU2015281112B2; US20170226672A1; BR112016029946A2; CN106661791A; EP3162939A1; PH12016502606A1; JP2016008368A

Abstract

The present invention relates to a non-woven fabric (1) that is formed from a base part (10) that spreads out in a planar shape and from a plurality of projecting parts (12) that protrude in a thickness direction (Th) from the base part. Each of the projecting parts has a projecting surface part (12T). Each of the projecting surface parts is configured such that the fiber density of the projecting surface part increases toward one side in a prescribed direction that is a surface direction of the non-woven fabric.

Description

Non-woven

The present invention relates to nonwoven fabrics, and in particular to nonwoven fabrics in which the fiber density of the nonwoven fabric is biased.

In Patent Document 1, a first projecting portion that protrudes to the first surface side of a sheet-like non-woven fabric in plan view and a second projecting portion that protrudes to the second surface side opposite to the first surface And the plurality of first protrusions and the plurality of second protrusions are non-woven fabrics alternately extended in two directions, i.e., the first direction and the second direction in plan view of the non-woven fabric, in the top of the first protrusions A non-woven fabric is disclosed in which the fiber density on the first side is lower than the fiber density on the second side.

JP 2012-144835 A

However, in the non-woven fabric according to the invention disclosed in Patent Document 1, the absorbed liquid permeates because the fiber density of the fibers constituting the non-woven fabric is substantially uniform in a plan view of the non-woven fabric. Direction can not be controlled. Therefore, for example, when such a non-woven fabric is used for the top sheet of an absorbent article, body fluids excreted on the non-woven fabric, such as urine and menstrual blood, are directional from the position where the body fluid is excreted to its periphery Penetrate as if to spread. As a result, since the body fluid also penetrates to the outside of the absorbent article, the body fluid may reach the outside of the absorbent article, and leakage may occur.

Therefore, an object of the present invention is to provide a non-woven fabric that allows absorbed liquid to penetrate in a desired direction.

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

According to the nonwoven fabric of the present invention, since the fiber density of the convex portion of the convex portion is biased in the predetermined direction, the absorbed liquid can be permeated in the desired direction.

BRIEF DESCRIPTION OF THE DRAWINGS The top view of the nonwoven fabric which concerns on 1st embodiment of this invention. The partial end elevation figure of the II-II line 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 the planar view of the nonwoven fabric. 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 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 located around a convex part. BRIEF DESCRIPTION OF THE DRAWINGS 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. FIG. 6 is a view for explaining measurement points at which the fiber density of the convex portion of the convex portion of the nonwoven fabric according to Examples 1 to 3 is measured.

(First embodiment)
The nonwoven fabric 1 according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 5.

FIG. 1 is a plan view of a non-woven fabric according to a first embodiment of the present invention, and FIG. 2 is a partial end view taken along line II-II of FIG. The non-woven fabric 1 according to the first embodiment extends on the plane of the non-woven fabric 1 defined by the longitudinal direction Lo and the transverse direction Tr, and 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 non-woven fabric 1 has a base 10 that spreads in a substantially planar shape, and a plurality of protruding from the base 10 in the thickness direction Th to the side of the first surface FF in the first embodiment. It is formed of the convex portion 12. Each convex portion 12 includes a convex portion 12T which is separated from the base 10 in the thickness direction Th of the nonwoven fabric 1. Here, the convex portion 12T is positioned closer to the top of the convex portion 12 than the middle point of the thickness direction Th between the base 10 and the top of the convex portion 12 most distant from the base 10 in the thickness direction Th. This is a portion of the convex portion 12 that forms a constant surface that faces in the direction in which the convex portion 12 protrudes from the base 10.

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

In the first embodiment, the convex portion 12 has a substantially cylindrical shape with a diameter of about 10 mm in appearance. In another embodiment, the shape of the convex portion 12 is a shape including a convex portion having a certain area, such as, for example, a truncated cone shape or an elliptical or polygonal columnar shape or a truncated pyramid shape. .

FIG. 3 is a view for explaining the distribution of fiber density of the convex portion 12T of the convex portion 12 in the nonwoven fabric 1 of FIG. In addition, FIG. 3 is described paying attention to one convex part 12, and represents the distribution of the fiber density of convex part 12T by the magnitude of the density (number) of "x" mark.

As shown in FIG. 3, each convex portion 12T is configured such that the fiber density of the convex portion 12T 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 portion 12T, there is a portion where the fiber density is high on one side in the longitudinal direction Lo and the fiber density is low on the other side in the longitudinal direction Lo on a predetermined line extending in the longitudinal direction Lo.

In other words, in the non-woven fabric 1 according to the first embodiment, each convex portion 12T is formed by a virtual line VL extending in a direction orthogonal to the longitudinal direction Lo of the non-woven fabric 1 in plan view of the non-woven fabric 1. When the two

semiconvex portions

121T and 122T are bisected so as to have the same area, the fiber density of one semiconvex portion 121T is higher than the fiber density of the other semiconvex portion 122T. Here, the “fiber density of the semiconvex portion” refers to the average of the fiber density of the entire

semiconvex portions

121T and 122T, but when measuring the fiber density as described later, each

semiconvex portion

121T , 122T in a direction perpendicular to the direction in which the fibers are offset, ie in the transverse direction Tr in the case of the first embodiment, in the direction in which the fibers are offset, ie in the case of the first embodiment The fiber density is equally divided into three in the longitudinal direction Lo of 1 and the central portions in the transverse direction Tr of these cut surfaces are averaged.

FIG. 4: is the photograph which image | photographed the nonwoven fabric of FIG. 1 on the black stand by planar view of a nonwoven fabric. In the photograph of FIG. 4, the shade of color indicates the high and low of the fiber density. In other words, darker black in the photo in Fig. 4 indicates that the color of the photographing table is more easily seen through, indicating that the fiber density is lower, and darker white indicates that the color of the photographing table is less transparent, meaning that the fiber density is higher. Do. Also 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 among the planar directions of the nonwoven fabric 1 in plan view of the nonwoven fabric 1 It can be said that This is because, when the convex 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 the measurement of the “fiber density”, the number of points FC at which the fibers are cut per 1 mm ² in 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 Corporation), the magnification is adjusted to about 50 to 100 times and a fixed area (for example, about 2.0 mm ²⁾ Observe the cut surface of) and count the points FC (Fig. 5) where the fibers were cut. The cut surface to be observed includes the entire thickness direction Th from the first surface FF to the second surface FS. Then, the number of cutting points is replaced with the number per 1 mm ² , and the number is used as an index of “fiber density”.

The fibers used for the non-woven fabric 1 in the first embodiment are fibers with a core-sheath structure, and the material is a high density polyethylene (HDPE) sheath and a polyethylene terephthalate (PET) core.

Fibers used for non-woven fabrics include natural fibers, regenerated fibers (rayon, acetate, etc.), thermoplastic resin fibers (polyethylene, polypropylene, polybutylene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, Ethylene-acrylic acid copolymers, polyolefins such as ionomer resins, polyethylene terephthalate, polyesters such as polybutylene terephthalate, polytrimethylene terephthalate, polylactic acid, polyamides such as nylon, etc. or surface-modified products thereof Among these, it is preferable that they are a thermoplastic resin fiber or its surface modification body. In addition, these fibers include core-sheath fibers, composite fibers such as side-by-side fibers, island / sea fibers, hollow fibers, flat fibers, atypical fibers such as Y-type and C-type fibers, latent fibers It may be a crimped or three-dimensional crimped crimped crimped fiber, a water stream, or a split fiber split by physical load such as heat or embossing. These fibers may be hydrophilic fibers or hydrophobic fibers. However, in the case of using a hydrophobic fiber, 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 arrange | positioned linearly along each of 1st direction D1 and 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 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. Thus, for example, when the non-woven fabric 1 is used as a top sheet of an absorbent article such as disposable diapers or a sanitary napkin, the bodily fluid excreted on the non-woven fabric 1 can be absorbed when the first surface FF is used as the surface. It is possible to arrange the base 10 which penetrates into the inside where the absorbent or the like of the article is located, and the convex part 12 which penetrates the body fluid in a desired direction, in a suitable distribution.

Furthermore, as shown in FIG. 1, in the non-woven fabric 1 according to the first embodiment, the convex portions 12 adjacent to the first direction D1 and the second direction D2 are intermittently provided to separate the base 10. ing. As a result, the body fluid excreted on the first surface FF can be made to permeate in the direction in which the fiber density is biased, and transferred from the convex portion 12T of the convex portion 12 to the adjacent base portion 10. Thus, for example, when the non-woven fabric 1 is used for the top sheet of the absorbent article, the liquid can be efficiently permeated from the base 10 into the interior of the absorbent article.

The operation of the non-woven fabric according to the first embodiment will now be described. In the nonwoven fabric 1 according to the first embodiment, as described above, the convex portions 12T are configured such that the fiber density of the convex portions 12T is biased in the longitudinal direction Lo among the planar directions of the nonwoven fabric 1. Therefore, the liquid absorbed by the fibers forming the convex portion 12 easily penetrates from the low fiber density to the high fiber density by capillary action, and thus tends to move to the high fiber density side in the longitudinal direction Lo. Therefore, by disposing 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, the absorbed liquid can be infiltrated in the desired direction. In the present specification, "the liquid can be permeated in the desired direction" does not mean that the liquid penetrates only in the desired direction, but the amount of liquid that penetrates in the desired direction is increased. It should be noted that the meaning of

The fiber density of the convex portion 12T is biased in the longitudinal direction Lo in the nonwoven fabric 1 according to the first embodiment, but may be biased in any direction in the planar direction of the nonwoven fabric 1. That is, the convex portion 12T may be configured so that the fiber density of the convex portion 12T is biased in a predetermined direction in the plane direction of the nonwoven fabric 1. Then, the liquid can be made to penetrate in a desired direction by arranging the side with high fiber density to be in the direction in which the liquid is desired to permeate.

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

Further, the degree of the deviation of the fiber density of the convex portion 12T may be a degree that allows the liquid absorbed in the non-woven fabric 1 to penetrate in a desired direction.

In the nonwoven fabric 1 according to the first embodiment, as described above, the convex portion 12 is linear along the first direction D1 and the second direction D2 inclined 60 ° from the first direction D1. Are located in In another embodiment, the second direction D2 is inclined at an angle other than 60 ° from the first direction D1. In yet another embodiment, the protrusions 12 are disposed linearly along only one direction. In the other embodiment, the convex portion 12 is not disposed along any direction but disposed at an arbitrary position.

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 as mentioned above. In another embodiment, the distance between the protrusions 12 is not constant.

In another embodiment, the convex portion 12 is linearly disposed in either the first direction D1 or the second direction D2, and in still another embodiment, disposed along any direction. It is not set up and is irregularly placed.

Second Embodiment
From this, the nonwoven fabric 1 according to the second embodiment of the present invention will be described with reference to FIG. The second embodiment will be mainly described in terms of differences from the first embodiment.

FIG. 6 is a diagram for explaining the fiber density distribution of the convex portion 12T of the convex portion 12 in the nonwoven fabric 1 according to the second embodiment. As shown in FIG. 6, in each convex portion 12, the edge 12TE of the convex portion 12T has a higher fiber density than the central portion 12TC of the convex portion 12T. As described above, when the fiber density of the edge 12TE of the convex portion 12T is high, the rigidity of the edge 12TE becomes high, whereby the shape of the convex portion 12 is maintained even when an external force is applied to the convex portion 12 can do. Therefore, for example, when packaging the nonwoven fabric 1 for sale, external force can be applied to the convex portions 12 and the shape of the nonwoven fabric 1 can be suppressed from being broken. As a result, the nonwoven fabric 1 is packaged, and even after the package is opened, it is possible to exert the effect of being excellent in moldability, which is preferable. Furthermore, the nonwoven fabric 1 according to the second embodiment is preferable also in appearance (appearance) because the shape of the convex portion 12 of the nonwoven fabric 1 at the time of production can be maintained even after packaging and opening.

The edge 12TE is a region of the convex portion 12T having a constant width in the direction of the central portion 12TC along the edge 12TEE of the convex portion 12T to the extent that the fiber density can be confirmed. Also, the central portion 12TC is a portion farther from the edge 12TEE than the edge 12TE. When it is difficult to distinguish between the edge 12TE and the central portion 12TC, a certain range around the center of gravity of the geometric shape of the convex portion 12T in plan view of the nonwoven fabric 1 is defined as the central portion 12TC. Further, in the case of the second embodiment, the width of the edge 12TE is about 1 mm with respect to the convex part 12T having a diameter of about 10 mm, that is, about 10% of the diameter (or the length of the convex part 12T). The length of

Also in the second embodiment, as in the nonwoven fabric 1 according to the first embodiment, in each convex surface portion 12T, the fiber density of the convex surface portion 12T is the longitudinal direction Lo of the nonwoven fabric 1 among the planar directions of the nonwoven fabric 1. It is configured to be biased. That is, in the second embodiment, on a line extending in the predetermined longitudinal direction Lo at the central portion 12TC of the convex portion 12T, the fiber density is high at a position on one side in the longitudinal direction Lo and the other side in the longitudinal direction Lo There is a portion with low fiber density in the portion.

Third Embodiment
The nonwoven fabric 1 according to the third embodiment of the present invention will be described with reference to FIG. 7. The third embodiment will be mainly described in terms of differences from the first embodiment.

FIG. 7 is a view for explaining the fiber density distribution of the convex 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, the fiber density of the fibers constituting the convex portion 12T of the convex portion 12, which is one end of the convex portion 12T in the longitudinal direction Lo, in plan view of the nonwoven fabric 1 In the portion 10 L of the base 10 adjacent to the high portion 12 TH, the fiber density is lower than the other portions of the base 10. That is, in the base 10, the fiber density becomes lower as the fiber density of the convex portion 12 approaches the portion 12TH where the fiber density of the convex portion 12 is higher.

As a result, in the base 10, there will be a portion where the fiber density is lower than the 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 which has moved to the portion 12TH where the fiber density of the convex portion 12T is high as described above In the low fiber density portion 10L of the base 10 located at the position of the base 10, it is possible to rapidly permeate. As a result, the body fluid excreted on the non-woven fabric 1 can be rapidly transferred to the inside of the absorbent article provided with an absorbent or the like, which is preferable.

Fourth Embodiment
From this, the nonwoven fabric 1 according to the fourth embodiment of the present invention will be described with reference to FIG. The fourth embodiment will be mainly described in terms of differences from the third embodiment.

FIG. 8 is a view for explaining the fiber density distribution of the convex 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 non-woven fabric according to the fourth embodiment, as in the non-woven fabric according to the second embodiment, as shown in FIG. 8, in each of the convex portions 12, the edge 12TE of the convex portion 12T is the center of the convex portion 12T. Fiber density is higher than 12 TC. That is, the nonwoven fabric 1 which concerns on 4th embodiment is a nonwoven fabric which has both the effect of the nonwoven fabric 1 which concerns on 2nd and 3rd embodiment. These effects are the same as the effects of the nonwoven fabric 1 according to the second and third embodiments, and thus the description thereof is omitted.

(Method of manufacturing non-woven fabric)
From this, the manufacturing method of nonwoven fabric 1 concerning a fourth embodiment is explained. FIG. 9 is a schematic view showing an outline of a production facility 3 for producing the non-woven 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 forms a carding machine 20 for opening the fiber F1 and adjusting the fabric weight, a suction drum 22 and an air jet nozzle 26 for forming the fiber F2 so as to be in the shape of the nonwoven fabric 1, and a fiber F3. The heat processing machine 28 heat-processes the fiber F3 so that fixed shape may be fixed. In FIG. 9, the fibers F1 to F3 and the non-woven 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 non-woven fabric 1.

The method of producing the non-woven fabric 1 will be briefly described. First, the fiber F1 is opened by the carding machine 20 and the coating weight is adjusted, and the opened fiber F2 is supplied to the suction drum 22. Subsequently, warm air is blown by the air jet nozzle 26 while suctioning and moving the fiber F2 on the outer peripheral surface of the suction drum 22 provided with the pattern plate 24 so that the shape of the nonwoven fabric 1 according to the above embodiment is obtained. Form the fiber F2. And the non-woven fabric 1 is completed by heat-treating the fiber F3 after shaping in the heat treatment machine 28 and fixing the shape of the fiber F3 shaped in the previous step.

The method of manufacturing the non-woven fabric 1 will now be described in detail. In the manufacturing process of the nonwoven fabric 1, first, the opened fiber F <b> 1 is supplied to the carding machine 20. In the carding machine 20, the fiber F1 is further opened, and the basis weight (weight) of the fiber F1 is adjusted to a desired value.

The fiber F2 which has passed through the card machine 20 is supplied to the suction drum 22. The inside of the suction drum 22 is hollow, and the inside of the suction drum 22 is under negative pressure by suction of air 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 suction the fiber F2 into the suction drum 22.

The outer peripheral surface of the suction drum 22 is covered by the pattern plate 24 over the entire circumference thereof. Specifically, the fibers F2 are supplied onto the pattern plate 24. In this manufacturing method, the pattern plate 24 is an apertured plate in which through holes 24 t having a shape complementary to the projections 12 of the nonwoven fabric 1 are provided with the distribution of the projections 12.

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

In this manufacturing method, the suction drum 22 has an area AS from the point SS where the fiber F2 is delivered from the upstream belt conveyor UB to the point SE where the fiber F2 is delivered to the downstream belt conveyor DB on the outer peripheral surface. The fiber F2 is designed to suck at the other area, and is configured not to suck at the other area AN. This is to improve the efficiency of the suction operation by the suction drum 22.

The fibers F 2 sucked to the outer peripheral surface of the suction drum 22 are blown with warm air by the air jet nozzle 26. Here, the air jet nozzle 26 has a mechanism that ejects a predetermined amount of warm air uniformly 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, warm air is blown substantially uniformly over the entire width of the laminate formed from the fiber F2. The fibers F2 can be shaped so as to have the shape of the nonwoven fabric 1 according to the above-described embodiment by the suction action and the spray action by the suction drum 22 and the air jet nozzle 26.

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 be too high in order to avoid the nonwoven fabric 1 becoming excessively hardened after completion. There is. Also, the wind speed of the warm air is determined so as to shape the fiber F2 into a desired shape. Generally, the temperature and the wind speed of the warm air from the air jet nozzle 26 vary depending on the material and weight of the fiber used, the shape of the non-woven fabric 1 after completion, and the like. Is preferred. 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 thereof 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 thereof is 38.9 m / sec. At this stage, by blowing warm air at a temperature higher than the melting point of the fiber F2, it is possible to fix the shaped shape to some extent while shaping the fiber F2.

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

When the fiber F2 is blown by the air jet nozzle 26, it is blown off and moves around it. As a result, the amount of fibers in the sprayed part will be reduced and thus the fiber density of the sprayed part will be lower. On the other hand, since the air jet nozzle 26 is stationary, the fiber F2 located in the through hole 24t of the pattern plate 24 is finally blown by the warm air at the portion F2tu located on the upstream side in the transport direction MD. The attachment reduces the fiber density. Thereafter, the fiber F2 moved by the blowing action by the air jet nozzle 26 is fixed at the position after the movement by the suction action of the suction drum 22. First, warm air is blown to the downstream portion F2td of the fiber F2 located in the through hole 24t in the transport direction MD, and the fibers located in the portion F2td are blown away, and the transport direction MD is generated. Move downstream of However, after that, warm air is blown to the upstream portion F2tu of the fiber F2 located in the through hole 24t in the transport direction MD, and the fiber moves to the downstream side 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 later 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 is increased, and conversely, the fiber density of the portion F2tu on the upstream side of the conveyance direction MD of the fiber F2 finally blown. Becomes lower. Thus, in the non-woven fabric 1, in each convex portion 12, the convex portion 12T is a direction in which the fiber density of the convex portion 12T is a predetermined direction, in the above-mentioned embodiment, the direction of It is configured to be biased in the longitudinal direction Lo.

The same applies to the portion F2su of the fibers F2 located on the outer surface 24s located between the through holes 24t of the pattern plate 24 and located upstream of the transport direction MD. That is, when the warm air is blown to the portion F2su, the fiber F2 is blown off and moves around. At this time, the fiber F2 also moves in the through hole 24t. Thereafter, warm air is blown to a portion F2tu of the fiber F2 in the through hole 24t on the upstream side in the transport direction of the fiber F2, but once the fiber F2 moves into the through hole 24t, the inside of the through hole 24t Since the fiber F2 does not return from the to the outer surface 24s, the fiber density of the portion F2su is low. On the other hand, the fiber density of the portion F2tu on the upstream side in the transport direction of the fiber F2 in the through hole 24t is high. As a result, as in the non-woven fabric 1 according to the third embodiment, the fiber density of the base 10 decreases as the fiber density of the convex portion 12 approaches the portion 12 TH where the fiber density of the convex portion 12 is high.

Further, warm air from the air jet nozzle 26 does not easily reach the corner portion Co formed at the position where the side wall 24 w forming the through hole 24 t of the pattern plate 24 and the outer peripheral surface of the suction drum 22 contact. It is difficult for fibers to move from On the other hand, the fibers are blown off from the periphery of the corner portion Co by the warm air from the air jet nozzle 26 and move to the corner portion Co. The corner portion Co is a position corresponding to the edge portion 12 TE of the convex portion 12 in the nonwoven fabric 1. As described above, in the manufacturing process, the amount of fibers at the corner Co increases, and as a result, as in the non-woven fabric 1 according to the second embodiment, the edge 12TE of the projection 12 is the central portion 12TC of the projection. The fiber density is higher than that.

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 fibers F3 shaped by the suction and spraying action are then transferred to the heat treatment machine. The fibers F3 are heat treated in the heat treatment machine 28 and the shape shaped in the previous step 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 a low temperature relatively to the melting point of the fiber, thereby fixing the shape of the fiber F3 formed in the previous step It is possible to make the nonwoven fabric 1 flexible. Generally, the temperature of the warm air in the heat treatment machine 28, the wind speed, the time of the heat treatment, etc. vary depending on the material of the fibers used, the coating weight, etc. However, it is preferable to determine the optimum temperature and wind speed by experiments, for example.

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

So far, the manufacturing method of the nonwoven fabric 1 according to the fourth embodiment has been described, but by appropriately changing the shape of the pattern plate 24, the temperature of the warm air blown from the air jet nozzle 26, etc. The nonwoven fabric 1 according to the first to third aspects can be manufactured.

In the present example, the liquid diffusion distance test was performed with the nonwoven fabric in which various conditions were set. The liquid diffusion distance test is a test to confirm that the liquid absorbed by the non-woven fabric penetrates in a directional manner.

Now, Examples 1 to 3 and a comparative example will be described.

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

(Comparative example)
In the non-woven fabric according to the comparative example, the fibers opened by the carding machine are not sucked by the suction drum and the hot air is not blown by the air jet nozzle, so that the fiber density becomes uniform by the heat treatment machine In a plane. The temperature and the 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 the present embodiment will be described. In the liquid diffusion distance test, a sample of the non-woven fabric according to the example and the comparative example cut to a width of 150 mm and a length of 300 mm was placed on a stainless plate of 250 mm width and 450 mm length, and 20 cc at the center of one convex portion The artificial artificial urine was done by dropping it in 2.5 seconds. At this time, the longitudinal direction of the sample is the direction in which the fiber density of the fibers constituting the convex portion of the convex portion is uneven, and the direction along which the fiber density of the convex portion is high is taken as the DH direction. 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 dropping position of the artificial urine, which the artificial urine penetrated and reached in the DH direction and the DL direction, were respectively measured. At this time, a value obtained by subtracting the distance dl from the distance dh was taken as the liquid diffusion distance. The liquid diffusion distance test was performed three times, and the 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 pigment (Blue No. 1) in 10 L of ion-exchanged water .

Table 1 is shown below. Table 1 shows the results of the fabric weight, thickness, preparation conditions, each measurement point PH, the fiber density of the convex portion around PL and the liquid diffusion distance test around each of the nonwoven fabrics of Examples 1 to 3 and Comparative Example. In addition, "thickness" of Table 1 is an average value of the thickness measured 3 times under the pressure of 3 gf / cm2, and in the nonwoven fabric concerning Example 1-3, the thickness of the convex part was measured. .

As shown in the results of the liquid diffusion distance test in Table 1, the more uneven the fiber density of the convex part, the larger the liquid diffusion distance. Therefore, it can be said that as the deviation of the fiber density is larger, the liquid absorbed in the non-woven fabric can be permeated in the direction in which the fiber density of the fibers constituting the convex portion is biased.

All features as would be understood by one of ordinary skill in the art from the present specification, drawings and claims are described herein in combination with only those particular features. As long as the features are not specifically excluded, or unless the technical aspects result in an impossible or meaningless combination, one or more of the other disclosed herein or separately. It can be combined in any combination with the features.

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

The present invention is defined as follows.

(1) A non-woven fabric formed of 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, and
Each of the convex portions is configured such that the fiber density of the convex portions is biased in a predetermined direction of the planar direction of the nonwoven fabric.
Non-woven fabric.

(2) In each of the convex portions, an edge portion of the convex portion has a higher fiber density than a central portion of the convex portion.
The nonwoven fabric as described in (1).

(3) The fiber density of the base decreases as the fiber density of the convex portion approaches the portion around the convex portion,
The nonwoven fabric as described in (1) or (2).

(4) When each of the convex portions is bisected into two semi-convex portions so as to have the same area by an imaginary line extending in a direction orthogonal to the predetermined direction in a plan view of the nonwoven fabric, The fiber density of the semiconvex part is higher than the fiber density of the other semiconvex part,
The nonwoven fabric according to any one of (1) to (3).

(5) The convex portion is 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 apart from 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 manufacturing the non-woven fabric,
The nonwoven fabric according to any one of (1) to (7).

1 Non-woven fabric 10 Base 12 Convex part 12 T Convex part

Claims

A non-woven fabric formed of a base extending in a planar manner and a plurality of projections projecting in the thickness direction from the base,
Each said convex part has a convex part, and
Each of the convex portions is configured such that the fiber density of the convex portions is biased in a predetermined direction of the planar direction of the nonwoven fabric.
Non-woven fabric.
In each of the convex portions, the edge of the convex portion has a higher fiber density than the central portion of the convex portion.
The nonwoven fabric according to claim 1.
The fiber density of the base portion decreases as the fiber density of the convex portion approaches the portion around the convex portion.
The nonwoven fabric according to claim 1 or 2.
One of the half convex surfaces when each of the convex surface portions is bisected into two semi convex surface portions so as to have the same area by an imaginary line extending in a direction orthogonal to the predetermined direction in a plan view of the nonwoven fabric The fiber density of one section is higher than the fiber density of the other half convex section,
The nonwoven fabric according to any one of claims 1 to 3.
The convex portion is disposed along a first direction and a second direction different from the first direction.
The nonwoven fabric according to any one of claims 1 to 4.
The protrusions are provided at equal intervals across the base in the first direction and the second direction.
The nonwoven fabric according to claim 5.
The predetermined direction coincides with the first direction or the second direction.
The nonwoven fabric according to claim 5 or 6.
The predetermined direction coincides with the transport direction when manufacturing the non-woven fabric,
The nonwoven fabric according to any one of claims 1 to 7.