JP5885783B2 - Non-woven - Google Patents

Description

  The present invention relates to a nonwoven fabric, and more specifically to a nonwoven fabric used for a top sheet of a disposable diaper.

  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, in the nonwoven fabric according to the invention disclosed in Patent Document 1, when the liquid is injected onto the nonwoven fabric, even in the liquid once collected in the space formed between the protrusions, the nonwoven fabric In such a case, the liquid may flow due to the smooth cross-sectional corrugated shape of the nonwoven fabric. In particular, when such a nonwoven fabric is used for a disposable diaper top sheet, when the wearer moves around, the liquid injected into the nonwoven fabric is, for example, high-viscosity excretion such as soft stool of an infant of young age Even if it is a liquid having a relatively high viscosity such as an object, if it is easy to flow on the nonwoven fabric, it may leak from the disposable diaper before being absorbed by the nonwoven fabric and the absorbent body located under the nonwoven fabric.

  Accordingly, an object of the present invention is to provide a non-woven fabric in which when a liquid is injected onto the non-woven fabric, it is difficult for the liquid to flow on the non-woven fabric, whereby the liquid can be efficiently absorbed and permeated.

In order to solve the above problems, according to the present invention,
A non-woven fabric comprising a base portion that extends in a substantially planar shape and a plurality of convex portions that protrude from the base portion,
Each said convex part is located in the opposite side to the said base end of the said peripheral surface part which stands up in the thickness direction of the said nonwoven fabric from the said base, and forms a surrounding surface from the said base part side as a base end A top portion formed on the tip side of the peripheral surface portion,
The peripheral surface portion includes at least part of the peripheral surface including a protruding portion that protrudes outward from the peripheral surface from the peripheral surface.
A nonwoven fabric can be provided.

  According to the nonwoven fabric according to the present invention, when the peripheral surface portion of the convex portion is provided with a protruding portion that protrudes outward from the peripheral surface, the liquid is injected onto the nonwoven fabric. In the case where the nonwoven fabric is tilted, the protrusion can block the liquid flow. As a result, it becomes difficult for the liquid to flow on the non-woven fabric, whereby the liquid can be efficiently absorbed and permeated.

The top view of the nonwoven fabric which concerns on embodiment of this invention. The II-II line end view of FIG. The figure for demonstrating distribution of the fiber density of the convex part in the nonwoven fabric of FIG. The partial enlarged photograph of the top part of the convex part of FIG. The top view of the convex part of the nonwoven fabric which concerns on the deformation | transformation embodiment of this invention. The VB-VB line | wire end view of FIG. 5A. Schematic which shows the outline | summary of the manufacturing equipment for manufacturing the nonwoven fabric which concerns on embodiment of this invention. The VII part enlarged view of FIG. The plane photograph of the nonwoven fabric which concerns on a comparative example. The enlarged overhead view which shows the cross section of the nonwoven fabric of FIG.

(Embodiment)
The nonwoven fabric 1 which concerns on embodiment of this invention is demonstrated referring FIGS.

  The nonwoven fabric 1 which concerns on embodiment is spreading on the plane of the nonwoven fabric 1 defined by the longitudinal direction Lo and the cross direction Tr, and is the 1st surface FF which is appearing in FIG. Surface FS.

  As shown in FIGS. 1 and 2, the nonwoven fabric 1 includes a base portion 10 that expands in a substantially planar shape, and a plurality of protrusions protruding from the base portion 10 in the thickness direction Th of the nonwoven fabric 1 toward the first surface FF in this embodiment. The convex part 12 is provided. Each convex portion 12 has the base 10 side as the base end 12EB, and rises from the base 10 in the thickness direction Th of the nonwoven fabric 1 to form the peripheral surface 12SP, and is opposite to the base end 12EB of the peripheral surface 12S. And a top portion 12T formed on the tip 12ET side of the circumferential surface portion 12S located on the side. As shown in FIG. 2, the top portion 12T is substantially flat.

  In the nonwoven fabric according to the embodiment, the convex portion 12 is generally cylindrical in shape, and the peripheral surface portion 12S of each convex portion 12 is a peripheral surface at the tip 12ET of the peripheral surface portion 12S over the entire circumference of the peripheral surface 12SP. A projecting portion 12P projecting from 12SP to the outer side DO of the peripheral surface 12SP is provided. In the present embodiment, the protruding portion 12P protrudes from the peripheral surface 12SP of the peripheral surface portion 12S to the outer side DO of the peripheral surface 12SP by about 0.5 to 3.0 mm.

  In the present embodiment, the circumferential surface portion 12S is tapered by being slightly reduced in diameter from the proximal end 12EB toward the distal end 12ET, and is enlarged in the protruding portion 12P. That is, in the circumferential surface portion 12S, the protruding portion 12P is located on the outer side of the circumferential surface 12SP from the innermost portion 12PI, which is the portion located on the innermost side DI of the circumferential surface 12SP, over the entire circumference of the circumferential surface 12SP. And it is located in the top part 12T side of thickness direction Th of the nonwoven fabric 1 rather than innermost part 12PI.

  In the present invention, in each convex portion 12, “the outer side DO of the circumferential surface 12SP” refers to a certain portion of the circumferential surface 12SP (for example, a portion represented by the reference symbol 12SPP in FIG. 2). In the plane direction in which the nonwoven fabric 1 defined by the longitudinal direction Lo and the transverse direction Tr spreads, it refers to the direction away from the convex portion 12, more specifically from the region surrounded by the peripheral surface 12SP. On the other hand, “inward side DI of the circumferential surface 12SP” similarly refers to the convex portion 12 on the plane of the nonwoven fabric 1 and more specifically, the circumferential surface 12SP with reference to a certain portion 12SPP of the circumferential surface 12SP. The direction toward the area surrounded by.

  In the present embodiment, as described above, the convex portion 12 has a substantially cylindrical shape in appearance. In another embodiment, the shape of the convex portion 12 is, for example, a cone shape, a truncated cone shape, an elliptical or polygonal column shape, a cone shape, a truncated cone shape, or the like. In yet another embodiment, the convex portion 12 has a hemispherical shape.

  Moreover, in the nonwoven fabric 1 which concerns on this embodiment, as shown in FIG. 3, in each convex part 12, the protrusion part 12P has a fiber density higher than the top part 12T. Note that FIG. 3 is described by paying attention to one convex portion 12, and represents the fiber density distribution of the fibers forming the top portion 12 </ b> T depending on the density (number) of “x” marks.

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 positions FC (see FIG. 4) 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”.

  In the present invention, the “fiber density” of the protruding portion 12P and the top portion 12T means an average fiber density of the protruding portion 12P and the top portion 12T. For example, the fiber density can be measured by measuring the fiber density at a plurality of locations of the protruding portion 12P and the top portion 12T and calculating the average value thereof.

  Moreover, as shown in FIG. 1, in the nonwoven fabric 1 which concerns on this embodiment, the convex part 12 is linear along each of the 1st direction D1 and the 2nd direction D2 among the plane directions of the nonwoven fabric 1. FIG. It is arranged. Here, the first direction D1 is the same direction 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 this embodiment, the base 10 and the convex part 12 are arrange | positioned equally by arrange | positioning the convex part 12 at equal intervals in the 1st direction D1 and the 2nd direction D2.

  The fiber used for the nonwoven fabric 1 in this embodiment is a fiber having a core-sheath structure, and the material of the fiber is high-density polyethylene (HDPE) and the core is polyethylene terephthalate (PET).

  The fibers used for the nonwoven fabric 1 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, polyester 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.

  From this, the effect of the nonwoven fabric 1 which concerns on this embodiment is demonstrated.

  In the case of the nonwoven fabric 1 according to the present embodiment, when the liquid is injected onto the first surface FF, that is, the surface where the convex portion 12 protrudes from the base portion 10, the nonwoven fabric is inclined. The liquid flows in the direction in which the nonwoven fabric is tilted. At this time, in the process in which the liquid reaches the top portion 12T from the base portion 10 through the peripheral surface portion 12S, the protruding portion 12P formed on the peripheral surface portion 12S protrudes from the peripheral surface portion 12S to the outer side DO of the peripheral surface 12SP. It acts like a breakwater that obstructs the flow of liquid. Therefore, it is difficult for the liquid flowing in the inclined direction to flow to the top portion 12T through the peripheral surface portion 12S of the convex portion 12 by such a protruding portion 12P. As a result, for example, when the nonwoven fabric 1 according to the present embodiment is used for the top sheet of the disposable diaper so that the first surface FF is on the surface side, even when the wearer moves around, The body fluid excreted on the nonwoven fabric 1 such as high-viscosity excrement such as loose stool can be prevented from staying on the first surface FF of the nonwoven fabric 1 and leaking from the disposable diaper.

  Moreover, when the fiber density of the edge part 12TE of the top part 12T is high like the nonwoven fabric 1 which concerns on this embodiment, the rigidity of edge part 12TE will become high, and also when the external force is provided to the convex part 12 by it. The shape of the convex part 12 can be maintained. 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 nonwoven fabric 1 is packaged, and after the packaging is opened, the effect of being excellent in shape retention can be obtained, which is preferable. And the shape which protrudes to the outer side of 12 A of peripheral surfaces can be maintained, without the protrusion part 12P formed in the peripheral surface part 12S being crushed by the outstanding shape retention property. Thereby, even after the nonwoven fabric 1 is packaged and the packaging is opened, there is an effect of the above-described nonwoven fabric 1 that it is difficult for the liquid injected into the nonwoven fabric 1 to flow in the tilted direction. Can do. Furthermore, since the nonwoven fabric 1 which concerns on this 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 external appearance.

  Moreover, in the nonwoven fabric which concerns on this embodiment, the convex part 12 is arrange | positioned at equal intervals in the 1st direction D1 and the 2nd direction D2 among the plane directions of the said nonwoven fabric 1, as mentioned above. Thereby, for example, when the nonwoven fabric 1 is used as a top sheet of a disposable diaper so that the first surface FF is on the surface side, an effect of suppressing the flow of body fluid in any direction can be achieved. .

  In the present embodiment, as described above, the peripheral surface portion 12S of each convex portion 12 includes the protruding portion 12P over the entire circumference of the peripheral surface 12SP, but the present invention is not limited to this aspect. In the present invention, the peripheral surface portion 12S of each convex portion 12 only needs to include the protruding portion 12P on at least a part of the peripheral surface 12SP. As an example, in the nonwoven fabric 1 according to the modified embodiment of the present invention shown in FIG. 5A and FIG. 5B, the peripheral surface portion 12S of each convex portion 12 is specifically only in a part of the peripheral surface 12SP, specifically in the transverse direction. The protrusion 12P is provided only on the Tr side. Thereby, in the part of the nonwoven fabric 1 in which the circumferential surface portion 12S does not include the protruding portion 12P, the area where the base portion 10 is exposed in a plan view of the nonwoven fabric 1 because the protruding portion 12P does not protrude to the outer side DO of the circumferential surface 12SP. Therefore, the liquid injected onto the first surface FF of the nonwoven fabric 1 can easily reach the base 10. As a result, in the case where the nonwoven fabric 1 according to this modified embodiment is used for the top sheet of the disposable diaper so that the first surface FF is on the surface side, the nonwoven fabric 1 was excreted on the first surface FF side of the nonwoven fabric 1. The body fluid permeates the base portion 10 and is easily absorbed quickly by an absorber or the like located thereunder. In addition, since the peripheral surface portion 12S of each convex portion 12 includes the protruding portion 12P as a part of the peripheral surface 12SP, the flow of the liquid can be suppressed in the portion where the protruding portion 12P is formed. Therefore, the effect that the liquid easily reaches the base portion 10 and the effect that the flow of the liquid can be suppressed can be achieved at the same time, which is preferable.

  Note that it is preferable that the peripheral surface portion 12S is provided with the protruding portion 12P on the peripheral surface 12SP depending on the use conditions of the nonwoven fabric 1, but the protruding portion 12P can be appropriately provided in consideration of the above effects. .

  In the present embodiment, the protruding portion 12P is formed at the position of the tip 12ET of the circumferential surface portion 12S with respect to the thickness direction Th position of the nonwoven fabric 1. When the nonwoven fabric 1 is formed in this way, even when more liquid is injected into the nonwoven fabric 1, the distance between the base 10 and the protruding portion 12P is large, so more liquid can be damped up. preferable. However, since the protruding portion 12P has the same effect of suppressing the liquid flow, the protruding portion 12P may be formed at any position in the thickness direction Th of the nonwoven fabric 1 of the peripheral surface portion 12S of the convex portion 12.

  As described above, in the present embodiment, the protruding portion 12P protrudes from the peripheral surface 12SP of the peripheral surface portion 12S to the outer side of the peripheral surface 12SP by about 0.5 to 3.0 mm. However, the present invention is not limited to this. When the protruding portion 12P further protrudes from the peripheral surface 12SP, the effect of suppressing the flow of the liquid can be achieved at a higher level. On the other hand, if the protruding portion 12P protrudes too much, the liquid hardly reaches the base portion 10. Therefore, the degree of protrusion from the peripheral surface 12SP of the peripheral surface portion 12S of the protrusion portion 12P is determined in view of the effect that the liquid easily reaches the base portion 10 and the effect that the flow of the liquid can be suppressed by, for example, experiments. be able to.

  Moreover, in this embodiment, although the protrusion part 12P has a fiber density higher than the top part 12T in each convex part 12, this invention is not limited to this aspect. That is, in each convex part 12, the protruding part 12P may have a fiber density lower than that of the top part 12T, and the protruding part 12P and the top part 12T may have the same fiber density.

  Moreover, in the nonwoven fabric 1 which concerns on this embodiment, as above-mentioned, the convex part 12 is linearly 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 embodiments, each of the convex portions 12 is disposed at an arbitrary position.

  Moreover, in the nonwoven fabric 1 which concerns on this 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.

(Nonwoven fabric manufacturing method)
The manufacturing method of the nonwoven fabric 1 which concerns on said embodiment is demonstrated. FIG. 6 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. 7 is an enlarged view of the VII portion of 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. 6, 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.

  The manufacturing method of the nonwoven fabric 1 is explained in full detail. In the method for manufacturing 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 shape of the convex portions 12 of the nonwoven fabric 1 are provided with the distribution of the convex portions 12.

  In this manufacturing method, the suction drum 22 and the pattern plate 24 are formed such that a gap S is formed between the outer surface of the suction drum 22 and the inner peripheral surface of the pattern plate 24 at a predetermined interval. And it fixes with the volt | bolt etc. in the both ends of the width direction of the pattern plate 24. FIG.

  As a result, the suction holes 22t of the suction drum 22 exposed in the through holes 24t of the pattern plate 24 suck the fibers F2 supplied onto the pattern plate 24. In the nonwoven fabric 1 of the embodiment, the difference in the thickness direction Th of the nonwoven fabric 1 between the base portion 10 and the top portion 12T of the convex portion 12 on the first surface FF is the suction drum of the thickness of the pattern plate 24 and the gap S. Is approximately equal to the sum of 22 radial dimensions.

  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 44.4 [m / sec]. At this stage, the shaped shape can be fixed to some extent while shaping the fiber F2 by blowing warm air having a temperature higher than the melting point to 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. However, the hot air from the air jet nozzle 26 reaches the corner Co (FIG. 7) 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 adjacent to each other. It is difficult to move the fiber F2 from the corner Co. On the other hand, the fiber F2 is blown away from the periphery of the corner Co by the hot air from the air jet nozzle 26 and moves to the corner Co. As a result, the amount of fibers in the corner Co increases, and the corner Co is a position corresponding to the protruding portion 12P in the nonwoven fabric 1, and thus the protruding portion 12P as in the nonwoven fabric 1 according to the above-described embodiment. Has a fiber density higher than that of the top portion 12T.

  Further, in this manufacturing method, as shown in FIG. 7, since the gap S is formed between the outer peripheral surface of the suction drum 22 and the inner peripheral surface of the pattern plate 24, the gap S portion adjacent to the corner Co The fiber F2 enters into. As a result, the protruding portion 12P is formed on the peripheral surface portion 12S of the convex portion 12 like the nonwoven fabric 1 according to the above-described embodiment.

  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. 6, 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.

  In this example, a simulated soft stool flow test was performed using nonwoven fabrics according to examples and comparative examples in which different conditions were set. The simulated soft stool flow test is a test for measuring the time required for the simulated soft stool dropped on the surface of the tilted nonwoven fabric to flow through a certain distance.

  From this, the structure of the nonwoven fabric which concerns on an Example and a comparative example is demonstrated.

(Example)
The nonwoven fabric which concerns on an Example is a nonwoven fabric which concerns on the above-mentioned embodiment, Comprising: The convex part adjacent to a 1st direction and a 2nd direction was each provided in the space | interval of about 12.0 mm. The protrusion height from the base of the convex portion (distance in the thickness direction from the second surface of the base portion to the first surface of the convex portion) is about 1.9 mm, and the diameter of the convex portion in a circular shape in plan view is About 10.4 mm.

(Comparative example)
The nonwoven fabric which concerns on a comparative example is created using the pattern plate different from an Example, and as shown in FIG.8 and FIG.9, a convex part is like the protrusion part of the nonwoven fabric which concerns on the invention of patent document 1 This is different from the nonwoven fabric according to the example in that it is formed in a cross-sectional corrugated shape. In the nonwoven fabric according to the comparative example, the convex portions were linearly arranged along the first direction and the second direction inclined about 60 ° from the first direction, similarly to the nonwoven fabric according to the example. . The convex portions adjacent to each other in the first direction and the second direction are provided at an interval of about 8.1 mm, and the protruding height of the convex portion is about 2.8 mm. The diameter is about 5.8 mm.

  Next, the test method of the test performed in this example will be described. In the simulated soft stool flow test, a sample was first prepared when testing the nonwoven fabrics according to Examples and Comparative Examples. In preparing the sample, first, the absorbent material was exposed by removing the surface material (top sheet, etc.) of the baby paper diaper (Mooney “Air Fit” (registered trademark), Unicharm Corporation, S size). Next, the nonwoven fabrics according to Examples and Comparative Examples were bonded to the exposed absorbent body on the second surface side of the nonwoven fabric, that is, on the base side of the nonwoven fabric. The composite thus produced was used as a sample for a simulated soft stool flow test.

  Then, the sample prepared as described above is placed and fixed on a test stand having an inclination angle of 45 °, and a simulated soft stool having a viscosity of 2.4 Pa · s is placed at the center of the convex portion at 20 cc / 15 sec. It was dripped. Next, the time when the dripped simulated soft stool flowed 200 mm and 300 mm in the direction inclined from the dropping position was measured. In the test, both tests were performed when tilted in the transport direction (MD) during manufacture and in the cross direction (CD) perpendicular to the transport direction.

The simulated loose stool used in this example is a high-viscosity liquid composed of the following composition (unit: mass%).
Ion exchange water: 77.0
Sodium chloride (NaCl): 1.0
Glycerin: 12.0
Sodium salt of carboxymethyl cellulose (NaCMC): 1.9
Triton-X: 0.05
Dye (Red No. 102): 0.05
Powdered cellulose: 8.0

  Table 1 is shown below. Table 1 shows the basis weight and thickness of the nonwoven fabrics according to Examples and Comparative Examples, the temperature and wind speed of the hot air from the air jet nozzle applied at the time of manufacture, and the simulated soft stool flow test results. In addition, "thickness" of Table 1 is an average value of the thickness measured 3 times under the pressure of 3 gf / cm <2>, and the thickness in a convex part was measured in the nonwoven fabric which concerns on Examples 1-3.

  As shown in the result of the simulated soft stool flow test in Table 1, the nonwoven fabric according to the comparative example has a protruding height from the base of the convex portion higher than that of the example, and the simulated soft stool is difficult to flow along the convex portion. In spite of this, as described above, the simulated stool flow time of the example is longer than that of the comparative example under any measurement conditions. That is, these measurement results show that the simulated soft stool dropped on the nonwoven fabric is less likely to flow in the direction in which the nonwoven fabric is tilted, as compared with the nonwoven fabric according to the comparative example. Based on these measurement results, the protrusion provided around the convex part acts as a breakwater that blocks the flow of liquid flowing from the base part to the top part of the peripheral surface part, thereby suppressing the liquid flow. Proved to be.

  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.

  The present invention is defined as follows.

(1) A non-woven fabric comprising a base portion that expands in a substantially planar shape and a plurality of convex portions that protrude from the base portion,
Each said convex part is located in the opposite side to the said base end of the said peripheral surface part which stands up in the thickness direction of the said nonwoven fabric from the said base, and forms a surrounding surface from the said base part side as a base end A top portion formed on the tip side of the peripheral surface portion,
The peripheral surface portion includes at least part of the peripheral surface including a protruding portion that protrudes outward from the peripheral surface from the peripheral surface.
Non-woven fabric.

(2) The peripheral surface portion of each of the convex portions includes the protruding portion only on a part of the peripheral surface.
The nonwoven fabric as described in (1).

(3) In each said convex part, the said protrusion part is provided in the said front-end | tip of the said surrounding surface part,
The nonwoven fabric as described in (1) or (2).

(4) The protrusion has a fiber density higher than the top,
The nonwoven fabric as described in (3).

(5) The said convex part is arrange | positioned along the 2nd direction different from the 1st direction and said 1st direction among the plane directions of the said nonwoven fabric,
The nonwoven fabric according to any one of (1) to (4).

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

DESCRIPTION OF SYMBOLS 1 Nonwoven fabric 10 Base part 12 Convex part 12EB Base end 12ET Tip 12P Protrusion part 12S Peripheral surface part 12SP Peripheral surface 12T Top part DO Outer side of peripheral surface Th Thickness direction of nonwoven

Claims (4)

A non-woven fabric comprising a base portion that extends in a substantially planar shape and a plurality of convex portions that protrude from the base portion,
Each said convex part is located in the opposite side to the said base end of the said peripheral surface part which stands up in the thickness direction of the said nonwoven fabric from the said base, and forms a surrounding surface from the said base part side as a base end A top portion formed on the tip side of the peripheral surface portion,
The peripheral surface portion is at least a portion of the peripheral surface provided with a protruding portion protruding outward of the circumferential surface from the peripheral surface,
In each of the convex portions, the protruding portion is provided at the tip of the peripheral surface portion,
The protrusion has a fiber density higher than the top,
Non-woven fabric. The peripheral surface portion of each of the convex portions includes the protruding portion only on a part of the peripheral surface.
The nonwoven fabric according to claim 1. The convex portion is disposed along a second direction different from the first direction and the first direction in the planar direction of the nonwoven fabric.
The nonwoven fabric according to claim 1 or 2 . The convex portions are provided at equal intervals in the first direction and the second direction.
The nonwoven fabric according to claim 3 .