TWI711437B - Hot-air non-woven fabric for absorbent article and its manufacturing method, and absorbent article - Google Patents

Abstract

The present invention is a hot-air nonwoven fabric for absorbent articles, which is formed by laminating two or more fiber layers, and has at least one fiber layer containing thermoplastic fibers and having a fiber block portion.

Description

Hot-air non-woven fabric for absorbent article and its manufacturing method, and absorbent article

The present invention relates to a hot-air non-woven fabric for absorbent articles.

The hot-air non-woven fabric is formed by blowing hot air with hot air to thermally weld the intersections of the fibers, so it is easy to be formed relatively thick, and the skin feels good. Therefore, it is mostly used as a component of absorbent articles. There have been various proposals for the hot-air nonwoven fabric for absorbent articles.

For example, in Patent Document 1, there is described a hot-air non-woven fabric that does not damage the touch of the skin, and from the point of view of imparting aesthetics by a pattern, the thickness of a part with a small fiber mass under a pressure of 7.64 kPa The difference between the thickness of the part where there is no small fiber block is set to 1 mm or less. As a method of manufacturing the hot-air nonwoven fabric, it is described that the preliminary non-woven fabric obtained by the hot-air blowing process is calendered. In addition, Patent Document 2 describes an absorbent article containing a non-woven fabric of synthetic fibers having thermoplasticity and organic cotton fibers. In the non-woven fabric described above, organic cotton fibers are arranged in plural fiber blocks. The organic cotton fiber is not thermally welded, but is retained in the non-woven fabric by the mutual entanglement of the fibers.

In Patent Document 3, it is described that from the viewpoint of improving the texture of the non-woven fabric, the completed non-woven fabric is arranged between a pair of rollers and subjected to pressure treatment at a specific linear pressure and temperature.

Patent Document 4 describes the following processing method: unwinding a fiber sheet wound into a roll The material is blown with hot air and calendered with a specific line pressure.

[Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2013-151774

[Patent Document 2] Japanese Patent Laid-Open No. 2017-202265

[Patent Document 3] Japanese Patent Laid-Open No. 60-126365

[Patent Document 4] Japanese Patent Laid-Open No. 2006-299480

The present invention provides a hot-air nonwoven fabric for absorbent articles, which is formed by laminating two or more fiber layers, and has at least one fiber layer containing thermoplastic fibers and having a fiber block portion.

In addition, the present invention provides a method for manufacturing a hot-air nonwoven fabric for absorbent articles, which includes: a fiber opening step of performing multiple opening treatments on thermoplastic fibers to form a fiber web; and a hot-air nonwoven fabric forming step, which will be described above A plurality of single-layer fiber webs obtained in the fiber opening step are laminated to form a laminated fiber web, and hot air is applied to the laminated fiber web using hot air to obtain a hot-air nonwoven fabric; and the calendering step uses a pair of calender rolls, Processing is performed on one or more selected from the single-layer fiber web, the laminated fiber web, and the hot-air nonwoven fabric.

The above and other features and advantages of the present invention can be understood from the following description with appropriate reference to the accompanying drawings.

1: Fiber layer

2: Fiber layer

7: Fiber block

8: Fiber block layer (layer with fiber block part)

9: Non-fiber block layer (layer without fiber block part)

10: Hot air non-woven fabric for absorbent articles

10A: Hot air non-woven fabric

10B: Hot-air non-woven fabric

71: raw fiber

72: raw fiber

81: Single-layer fiber mesh (or fiber mesh)

82: Single-layer fiber mesh (or fiber mesh)

90: Laminated fiber mesh

95: Laminated fiber web obtained from fiber web calendering

100: Manufacturing device of hot-air non-woven fabric for absorbent articles

101: Fiber Opening Department

102: Fiber Opening Department

103: Carding Department

103A: Take out the belt

104: Carding Department

104A: Take out the belt

105: Laminated fiber web forming part

105A: Conveying belt

106: Fiber web calendering department

106A: Calender roller

106B: Calender roller

107: Heat treatment department (hot air processing department)

107A: Filter cover

107B: Conveyor belt

107C: Filter cover

107D: Filter cover

108: Cutting/Opening Department

117: The first hot air treatment department

127: The second hot air treatment section

171: Arrow

172: Arrow

173: Arrow

174: Arrow

181: Arrow

182: Arrow

183: Arrow

184: Arrow

501: Step

502: Step

503: Step

F: Arrow

F1: Arrow

F2: Arrow

Fig. 1 is a cross-sectional view schematically showing a preferred embodiment of the hot-air nonwoven fabric for absorbent articles of the present invention.

Fig. 2 is a schematic configuration diagram showing a preferred embodiment of the nonwoven fabric manufacturing method and manufacturing apparatus of the present invention.

Fig. 3 is a schematic configuration diagram showing another preferred embodiment of the heat treatment section that implements the hot air step in this embodiment.

The present invention relates to the provision of a hot-air non-woven fabric for absorbent articles with excellent bulkiness and soft skin touch and a pattern.

In the manufacturing step of the hot-air nonwoven fabric, when the fibers are opened to form a fiber network, the fibers may be entangled with each other to partially form fiber blocks. In particular, the smaller the fiber diameter, the easier it is to produce the aforementioned fiber clumps. If the fiber block is directly subjected to the hot air processing step by the hot air, it will be hardened by the thermal welding of the fibers.

In contrast to this, previously, as described in the aforementioned Patent Documents 1, 3, and 4, the finished non-woven fabric was calendered to reduce the hardness. However, the calendering process is a process in which the hot-air non-woven fabric is held between a pair of rollers and pressed. The thickness of the hot-air non-woven fabric after pressing becomes thinner, so there is room for improvement in the bulkiness. Even if the non-woven fabrics described in Patent Documents 1, 3, and 4 are calendered and subjected to hot air treatment, there is still a limit to the thickness of the non-woven fabric once squashed, and there is room for further improvement. Regarding this point, the above-mentioned Patent Document 3 has no enlightenment regarding the response to the bulkiness.

In the hot-air nonwoven fabric for absorbent articles, from the viewpoints of absorbency and cushioning properties of absorbent articles, it is strongly desired to have both bulkiness and soft skin touch, and to make both more excellent.

In contrast, the hot-air nonwoven fabric for absorbent articles of the present invention has excellent bulkiness and soft skin touch, and has a pattern. Furthermore, according to the manufacturing method of the present invention, the above-mentioned hot-air nonwoven fabric for absorbent articles can be manufactured accurately.

Hereinafter, the hot-air nonwoven fabric for absorbent articles of the present invention will be described with reference to the drawings.

The hot-air nonwoven fabric for absorbent articles of the present invention can be applied to various absorbent articles worn on the body to absorb body fluids, and can be applied to various constituent members such as front sheets in the absorbent articles.

In the present invention, unless otherwise specified, the side in contact with the human body is referred to as the skin surface side or the skin contact surface side or the front side, and the opposite side is referred to as the non-skin surface side or the non-skin contact surface side or The back side.

In addition, in the present invention, the "hot-air nonwoven fabric" refers to a product obtained by thermally fusing and integrating thermally fusible fibers at the intersection. The hot air method is used in the manufacture of the non-woven fabric. The hot air method refers to a method in which hot air is blown through a fiber web containing thermally fusible fibers to fuse the intersections of the fiber webs to form a non-woven fabric.

The hot-air non-woven fabric for absorbent articles of the present invention is a hot-air non-woven fabric formed by laminating two or more fiber layers. The laminated fiber layer may be two layers or three or more layers. The hot-air nonwoven fabric for absorbent articles of the present invention has two or more layers, and can form a bulky nonwoven fabric without manufacturing constraints compared with the case where the nonwoven fabric is formed with one layer.

Fig. 1 shows a hot-air nonwoven fabric 10 for absorbent articles (hereinafter referred to as non-woven fabric 10) formed by laminating two fiber layers (fiber layer 1 and fiber layer 2), which is preferred as the hot-air nonwoven fabric for absorbent articles of the present invention Implementation form. The fiber layer 1 and the fiber layer 2 contain thermally fusible fibers, and by the fusion of the thermally fusible fibers, the contact surfaces of the two layers are joined over the entire area. Therefore, the non-woven fabric 10 does not have a region where the fiber layer 1 and the fiber layer 2 are separated. That is, the nonwoven fabric 10 is a sheet body formed by integrating the above-mentioned two layers.

The non-woven fabric of the present invention may have various surface shapes such as uneven surfaces, but it is preferably the non-woven fabric 10 of the present embodiment shown in FIG. 1, and both sides 10A and 10B (the surface of the fiber layer 1 and the surface of the fiber layer 2) are flat The shape. Since the nonwoven fabric 10 is a laminate of a plurality of fiber layers and has a flat shape on both sides, it has both a smooth surface and a cushioning feeling, and both are excellent. The so-called flat shape means that the thickness difference between the concave portion and the convex portion on the surface of the non-woven fabric is within 1 mm. Specifically, a razor blade was used to cut the non-woven fabric along the thickness direction, and a microscope (manufactured by Keyence Corporation, VHX-900) was used to take a picture of the cross section. In the photograph, the thickness of the convex portion, which is the uppermost surface of the nonwoven fabric, and the thickness of the concave portion, which is the bottom surface of the nonwoven fabric, were measured, and the difference in thickness was calculated. Take the average of 3 points.

The nonwoven fabric 10 has at least one fiber layer 8 having a fiber block portion 7. Hereinafter, the fiber layer 8 having the fiber block portion 7 is referred to as the fiber block layer 8. In FIG. 1, the fiber block layer 8 is arranged on the fiber layer 1.

In the present invention, the so-called "fiber block portion" refers to the section (cluster) formed by intertwining fibers in the fiber layer. In the fiber block, the density of the fiber is higher than that of the periphery in the same fiber layer The part is high, and it can be visually recognized as a block (granular) with a higher concentration (brightness) of the color (mainly white) of the fiber than the surrounding part. The shape of the fiber block is not particularly limited. In the present invention, the fiber block portion has a flat shape squashed in the thickness direction of the nonwoven fabric in a cross section in the thickness direction of the nonwoven fabric, and preferably has a structure with a smooth surface of the fiber block portion on the front side of the nonwoven fabric. Thereby, the surface of the non-woven fabric corresponding to the position where the fiber block portion 7 exists becomes smooth, and it can be felt that the surface of the non-woven fabric 10 is more excellent in touch.

The aforementioned "fiber block layer 8" refers to a layer having one or more fiber block parts. In the fiber block layer 8, the fiber block portion 7 does not need to be full, and it is preferable to disperse and arrange.

The fiber block layer 8 is not limited to the case where only the fiber layer 1 is located as shown in FIG. 1, and it can also be located in the fiber layer 2 instead of the fiber layer 1, or can be located in two layers. From the viewpoint of soft skin touch, it is preferably located on any layer. From the viewpoint of improving the visual effect obtained by the pattern of the fiber block portion 7 when the nonwoven fabric 10 is viewed from above, it is preferable to have the fiber block layer 8 in two layers. Thereby, the pattern formed by the fiber block portion 7 is not only visible in the plane direction of the nonwoven fabric 10, but also scattered in the thickness direction, and the density of the fiber block portion 7 seen in the thickness direction is thinner as the lower layer side is. It is visible in a state of change, so that you can see patterns with depth. When the fiber layer 1 and the fiber layer 2 have the fiber block layer 8, it is preferable that the fiber block portion 7 of the fiber layer 1 and the fiber block portion 7 of the fiber layer 2 do not overlap in the thickness direction. In addition, the fiber block layer 8 may be disposed in the entire fiber layer (fiber layer 1 or fiber layer 2) where the fiber block layer 8 is disposed, or may be disposed in a part.

As described above, the nonwoven fabric 10 is obtained by fusing the fibers at the interface of the layers to integrate the fibers in the entire area where the fiber layer 1 and the fiber layer 2 abut. Therefore, although the non-woven fabric 10 contains fiber The fiber block layer 8 of the block portion 7 can also feel that the nonwoven fabric 10 obtained by integrating multiple fiber layers on the layer interface as a whole has a thickness, and has excellent bulkiness and soft skin touch. In addition, when the nonwoven fabric 10 is viewed from above, the pattern is provided by the difference in color between the part having the fiber block part and the part without the fiber block part. The pattern formed by the fiber block portion 7, especially the pattern formed by the fiber block portion 7 with a flat thickness, makes the non-woven fabric 10 aesthetic.

The non-woven fabric 10 of the present embodiment preferably has fine fibers and thick fibers having a larger fiber diameter than the fine fibers, and the fine fibers have a fiber diameter of 1 dtex or more and 2.2 dtex or less. Thereby, the soft skin touch of the non-woven fabric can be improved by the fine fiber, and the bulkiness can be improved by the thick fiber. In addition, by having thick fibers, it also helps to improve the thickness repeatability of the nonwoven fabric after pressing, which is preferable.

In addition, it is preferable that the fiber block layer 8 contains the above-mentioned fine fibers. In this case, the above-mentioned fine fibers may be included in the fiber block portion 7 or may be included in parts other than the fiber block portion 7. Thereby, the stiffness around the fiber block portion 7 felt when the nonwoven fabric 10 is touched is alleviated by the presence of the above-mentioned fine fibers. In this case, it is preferable that the nonwoven fabric 10 has the fiber layer 1 which has the fiber block layer 8 containing the said fine fiber facing the skin contact surface side of an absorbent article.

From the viewpoint of improving the soft skin touch of the nonwoven fabric 10, the fiber diameter of the above-mentioned fine fibers is preferably 2 dtex or less, and more preferably 1.5 dtex or less. In addition, from the viewpoint of the spinnability of a carding machine in the production of nonwoven fabrics, the fiber diameter of the fine fibers is preferably 1 dtex or more, more preferably 1.2 dtex or more. Specifically, the fiber diameter of the above-mentioned fine fibers is preferably 1 dtex or more and 2 dtex or less, more preferably 1.2 dtex or more and 1.5 dtex or less.

From the viewpoint of improving the soft skin touch of the nonwoven fabric 10, the content of the above-mentioned fine fibers in the fibrous block layer 8 is calculated as a mass ratio, preferably 50% by mass or more, more preferably 80% by mass or more, and even more preferably It is 100% by mass.

In addition, the non-woven fabric 10 of this embodiment preferably has at least one fiber layer 9 (hereinafter referred to as non-fiber block layer 9) that does not have the fiber block portion 7 in addition to the fiber block layer 8 described above. For example, the following forms can be cited: as shown in FIG. 1, the fiber layer 1 is a fiber block layer 8, and the fiber layer 2 is a non-fiber block layer 9.

When the non-woven fabric 10 has a fibrous block layer 8 and a non-fiber block layer 9, it preferably has thick fibers and fine fibers with a smaller fiber diameter than the thick fibers. The fiber diameter of the thick fibers is more than 2.2 dtex and less than 7 dtex. . The fiber diameter of the fine fiber is preferably within the above range. Specifically, the fiber diameter of the fine fiber is preferably 1 dtex or more and 2.2 dtex or less. Thereby, the soft skin touch of the non-woven fabric can be improved by the fine fiber, and the bulkiness of the thick fiber can be improved, which also helps to improve the thickness reproducibility of the non-woven fabric after pressure, which is preferable.

In addition, it is preferable that the non-fiber block layer 9 contains the aforementioned thick fibers. By making the non-fiber block layer 9 contain the above-mentioned thick fibers, the bulkiness can be improved and a cushioning feeling can be provided. In this case, it is preferable that the nonwoven fabric 10 has the fiber layer 2 which has the non-fiber block layer 9 containing a thick fiber facing the non-skin contact surface side of an absorbent article.

From the viewpoint of improving the bulkiness and compression recovery of the non-woven fabric 10, the fiber diameter of the above-mentioned thick fibers is preferably more than 2.2 dtex, more preferably 4.4 dtex or more. Also, from the side of the fiber block layer From the viewpoint of texture, the fiber diameter of the above thick fibers is preferably 5.5 dtex or less, and more preferably 5 dtex or less. Specifically, the fiber diameter of the above-mentioned thick fiber is preferably more than 2.2 dtex and 5.5 dtex or less, more preferably 4.4 dtex or more and 5 dtex or less.

From the viewpoint of improving the bulkiness and compression recovery properties of the non-woven fabric 10, the content of the thick fibers in the non-fiber block layer 9 is calculated by mass ratio, preferably 50% by mass or more, more preferably 80% by mass or more, and further More preferably, it is 100% by mass.

In addition, from the viewpoint of improving the soft skin feel of the nonwoven fabric 10, the content of the above-mentioned crude fibers in the fibrous block layer 8 is, in terms of mass ratio, preferably 50% by mass or less, more preferably 30% by mass or less, and further More preferably, it is 10% by mass or less.

(Method for measuring the fiber diameter of fine fibers and thick fibers, method for measuring the content of fine fibers in the fiber block layer 8, and method for measuring the content of thick fibers in the non-fiber block layer 9)

A scanning electron microscope (JCM-5100 manufactured by JEOL Ltd.) was used to magnify and observe 3 positions on the fiber block layer side and the front side of the non-fiber block layer from any part of the non-woven fabric at a magnification of 100.

Fiber diameter: measure the fiber diameter within an area of 1mm ² . Regarding the measurement of fiber diameter, 20 points of different fibers are measured at each position, and the average value is taken as the fiber diameter. Furthermore, the deviation width of the fiber diameter of the nonwoven fabric for absorbent articles is usually a slight difference to the extent that it is difficult to confirm even if it is observed with the scanning electron microscope described above. For example, generally speaking, the deviation width of the fiber diameter is about 6% from the fiber specification. Therefore, the average value obtained after measuring 20 points as described above can be used as the diameter of each fiber.

Fiber content rate: Place OHP (Over Head Projector) film on the photo within 1mm ² of the previously magnified observation, and blacken it according to the fiber diameter. Use image analysis software (Nexus New Qube) to perform image analysis processing on the sheet. Perform binarization processing to find the area. The area of each fiber was measured, and the ratio was used as the content rate of each fiber.

(Sampling method for measuring components)

When performing the above-mentioned measurement, when the constituent member (for example, surface material) of the measurement object is to be taken out from the absorbent article for evaluation and measurement, it can be obtained by the following method. That is, when the constituent member is fixed to another constituent member by an adhesive or the like, the adhesive is cooled using liquid nitrogen to make the constituent member easy to peel off. When the structural member is fixed to another structural member by welding or the like, the structural member is peeled off by hand, or the welded part is cut off with a cutter etc. and then the structural member is peeled off. This method can also be used for other measurement methods.

In the non-woven fabric 10, it is preferable that the average fiber diameter of the non-fiber block layer 9 is larger than that of the fiber block layer 8. Thereby, the fiber block layer 8 becomes a layer that improves the soft skin touch of the non-woven fabric 10, and the non-fiber block layer 9 becomes a layer that improves the bulkiness and thickness reversibility of the non-woven fabric 10. As a result, with respect to the non-woven fabric 10, the fiber block layer 8 and the non-fiber block layer 9 can share functions in units of layers, and the two layers can cooperate in the thickness direction to make the overall texture of the non-woven fabric 10 better. In this regard, the non-woven fabric 10 has the above-mentioned fine fibers and the above-mentioned thick fibers, and the fiber block layer 8 includes the above-mentioned fine fibers in a form that enables the above-mentioned effects to be more clearly exhibited, so it is preferable. Moreover, from the same viewpoint, it is more preferable that the non-fiber block layer 9 contains the aforementioned thick fibers.

From the viewpoint of the above-mentioned function sharing of the non-woven fabric, the average fiber diameter of the non-fiber block layer 9 The difference V3 (=V1-V2) between V1 and the average fiber diameter V2 of the fiber block layer 8 is preferably more than 0 dtex, more preferably more than 2.2 dtex, and still more preferably more than 3 dtex. In addition, from the same viewpoint as described above, the difference V3 is preferably 5.6 dtex or less, more preferably 4 dtex or less, and still more preferably 3.5 dtex or less. Specifically, the difference V3 is preferably more than 0 dtex and 5.6 dtex or less, more preferably 2.2 dtex or more and 4 dtex or less, and still more preferably 3 dtex or more and 3.5 dtex or less.

(Measurement method of average fiber diameter of fiber block layer 8 and non-fiber block layer 9)

The fiber calculated based on the above (method for measuring the fiber diameter of fine fibers and thick fibers, the method for measuring the content of fine fibers in the fibrous block layer 8, and the method for measuring the content of thick fibers in the non-fiber block layer 9) The diameter is multiplied by the content rate, and the sum of the same is used as the average fiber diameter of each layer.

Furthermore, in the non-woven fabric 10, it is preferable that the basis weight of the non-fiber block layer 9 is larger than that of the fiber block layer 8. Thereby, the non-fiber block layer 9 is bulkier than the fiber block layer 8, and it is harder to perceive the hard feeling brought by the fiber block portion 7. In addition, the bulkiness of the non-fiber block layer 9 can play a role in improving the cushioning properties of the entire nonwoven fabric 10, thereby further reducing the stress that the fiber block portion 7 exerts on the skin when the fiber block layer 8 is squeezed in the thickness direction. Further improve the good texture. The non-woven fabric 10 has the above-mentioned fine fibers and the above-mentioned thick fibers, and the fiber block layer 8 includes the above-mentioned fine fibers, and the shape with the difference in basis weight can make the above-mentioned effects more clearly displayed, which is preferable. In addition, from the same viewpoint, it is more preferable that the non-fiber block layer 9 contains the above-mentioned thick fibers. Furthermore, it is preferable that the non-woven fabric 10 has a larger average fiber diameter of the non-fiber block layer 9 than the fiber block layer 8.

From the viewpoint of improving the overall cushioning and good texture of the non-woven fabric, the difference Y3 (=Y1-Y2) between the basis weight Y1 of the non-fiber block layer 9 and the basis weight Y2 of the fiber block layer 8 is preferably more than 0 g /m ² , more preferably 3 g/m ² or more, still more preferably 5 g/m ² or more. Moreover, from the viewpoint of improving the texture, the difference Y3 is preferably 20 g/m ² or less, more preferably 15 g/m ² or less, and still more preferably 10 g/m ² or less. Specifically, the above-mentioned difference Y3 is preferably more than 0 g/m ² and 20 g/m ² or less, more preferably 3 g/m ² or more and 15 g/m ² or less, and still more preferably 5 g/m ² or more and 10 g/m ² or less .

(Method for measuring the basis weight of fiber block layer 8 and non-fiber block layer 9)

1) The value obtained by converting the mass of the non-woven fabric of the measuring object per 1 m ² as the overall basis weight.

The mass (w) of the non-woven fabric of the measurement object is measured, and the value calculated by the following formula is used as the overall basis weight (W).

W=(1000000/LMD/LCD)w=25w

LMD: The length of the non-woven fabric to be measured in the MD direction is 250mm

LCD: The length of the non-woven fabric to be measured in the CD direction is 160mm

If the sample cannot be taken in the above-mentioned size when the self-made product is taken, it shall be cut within the acceptable range and converted per 1m ² .

2) Basis weight of each layer: carefully peel off each layer of the non-woven fabric to be measured, and use the value obtained by converting its mass per 1 m ² as the basis weight of each layer.

[Unit: digits] g/m ² : round to the second decimal place and reserve to the first decimal place.

[Number of Measurements] Measurements were performed on 3 points, and the average value was used as each basis weight.

From the point of view that the non-woven fabric 10 has excellent bulkiness, soft skin touch, and good texture in a structure in which two or more fiber layers are laminated and integrated, the basis weight of the entire non-woven fabric 10 is preferably 15 g/m ² or more, more preferably 18 g/m ² or more, and still more preferably 20/m ² or more. In addition, from the viewpoint of spinning ability in non-woven fabric production, the basis weight of the entire non-woven fabric 10 is preferably 40 g/m ² or less, more preferably 30 g/m ² or less, and even more preferably 25 g/m ² or less. Specifically, the basis weight of the entire nonwoven fabric 10 is preferably 15 g/m ² or more and 40 g/m ² or less, more preferably 18 g/m ² or more and 30 g/m ² or less, and still more preferably 20/m ² or more and 25 g/m ^{2 2} or less. In addition, the basis weight of the entire nonwoven fabric 10 is measured in accordance with the above (Method for Measuring the Basis Weight of the Fiber Block Layer 8 and the Non-Fiber Block Layer 9).

Regarding this kind of non-woven fabric 10, the thickness of the non-woven fabric 10 measured under a pressure of 7.64 kpa at the position where the fiber block part 7 is arranged is set as T1, and the position where the fiber block part 7 is not arranged will be measured under the same pressure When the thickness of the non-woven fabric 10 is set to T2, the smaller the difference T3 between the thicknesses defined by T3=T1-T2, the harder it is to feel the rigidity caused by the fiber block portion 7. As a result, it is easy to feel the cushioning sensation accompanying the bulkiness achieved by laminating a plurality of fibers, and it is easy to feel the soft touch of the skin. From this viewpoint, the above-mentioned difference in thickness T3 is preferably 0.4 mm or less, more preferably 0.3 mm or less, still more preferably 0.2 mm or less, and most preferably 0 (zero) mm.

In addition, the "position where the fiber block portion is arranged" here means that when viewed from the pressure side of the front and back of the nonwoven fabric 10, the fiber block portion 7 can be visually confirmed in the top view. The location of existence (hereinafter, in this specification, the meaning is the same). In addition, the "position where the fiber block portion is not arranged" refers to a position where the fiber block portion 7 cannot be visually confirmed in the above-mentioned plan view (hereinafter, in this specification, the meaning is the same).

(Method for measuring the thickness of non-woven fabric under 7.64kPa pressure)

Use dial gauge type thickness gauge (JIS B 7503 (1997), manufactured by PEACOCK UPRIGHT DIAL GAUGE, the pressure is 7.64kPa, the tip of the probe is a flat disc with Φ5mm), measure the thickness T1 of the non-woven fabric where the fiber block is arranged, and the non-woven fabric under the same pressure For thickness T2, find the difference in thickness defined by T3=T1-T2. Regarding T1 and T2, measurement was performed at 5 or more points, respectively. Then, the average value of T1 and the average value of T2 are calculated, and the difference between them is calculated as T3. In addition, the load of 7.64 kpa is a measurement condition set in order to clarify the existence of the fiber mass.

In addition, the soft skin touch of the non-woven fabric 10 is represented by the value of the average friction coefficient, and the smaller the value, the better the skin touch. Generally speaking, the value of the average friction coefficient of the part where the fiber block part 7 is not arranged is smaller than the value of the part where the fiber block part 7 is arranged. However, the nonwoven fabric 10 of the present embodiment is obtained by laminating a plurality of fiber layers in the thickness direction to be integrated, and therefore, the average friction coefficient is small at the position where the fiber block portion 7 is arranged. From the viewpoint of maintaining a soft skin touch, the average friction coefficient (Q1) of the position where the fiber block portion 7 of the non-woven fabric 10 is arranged is preferably 2.5 or less, more preferably 2.4 or less, and even more preferably 2.3 or less, and , 1.6 is more realistic. Specifically, the average coefficient of friction (Q1) of the position where the fiber block portion 7 of the nonwoven fabric 10 is arranged is preferably 1.6 or more and 2.5 or less, more preferably 1.6 or more and 2.4 or less, and still more preferably 1.6 or more and 2.3 or less.

In addition, from the viewpoint of maintaining a soft skin touch, the difference Q3 between the average friction coefficient Q1 of the position where the fiber block portion 7 of the nonwoven fabric 10 is arranged and the average friction coefficient Q2 of the position where the fiber block portion 7 is not arranged of the nonwoven fabric 10 (=Q1-Q2) is preferably 0.7 or less, more preferably 0.5 or less, still more preferably 0.32 or less, particularly preferably 0.3 or less, and most preferably 0 (zero).

(Measurement method of average friction coefficient)

Using KES-FB4 surface testing machine manufactured by Jiaduo Technology Co., Ltd., The non-woven fabric of the elephant is cut into 15cm squares. For its measuring surface, under the conditions of SENS: 2×5, load: 4.9kPa, measure the MIU values of the position where the fiber block is arranged and the position where the fiber block is not arranged. Measure at least 5 points each in two orthogonal directions (typically MD direction and CD direction), and calculate their average value. The MIU value is the average friction coefficient. According to the evaluation, the larger the value, the rougher the surface and the worse the texture. The smaller the value, the smoother the surface and the better the texture.

The fiber block layer 8 is preferably the outermost layer of the non-woven fabric 10. In this case, the fiber block layer 8 exists only on one of the front and back surfaces of the nonwoven fabric 10, or the fiber block layer 8 exists on both the front and back surfaces of the nonwoven fabric 10. By making the fiber block layer 8 the outermost layer of the non-woven fabric 10, the visual effect is maximized.

From the viewpoint of maintaining the soft skin touch of the non-woven fabric 10, the number of the fiber block portions 7 arranged on the non-woven fabric 10 is per 10 cm when viewed from the top view (a top view in the state where each fiber layer is laminated) of the non-woven fabric 10 The average of the square area is preferably 50 or less, more preferably 40 or less, and even more preferably 30 or less. On the other hand, from the point of view of patterning, the number of fiber blocks 7 arranged on the non-woven fabric 10 is the area per 10 cm square when the front and back sides of the non-woven fabric 10 are in a plan view (a plan view in a state where each fiber layer is laminated) The average is preferably 5 or more, more preferably 10 or more, and even more preferably 20 or more. Specifically, the number of fiber block portions 7 is calculated as the average of the area per 10 cm square of the front and back of the non-woven fabric 10 in a plan view (a plan view in a state where each fiber layer is laminated), preferably 5 or more and 50 or less, more preferably It is 10 or more and 40 or less, and more preferably 20 or more and 30 or less.

In addition, from the viewpoint of reducing the chance of skin contacting the fiber block portion 7, the number of fiber block portions 7 in the fiber layer on the skin side of the absorbent article among the laminated fiber layers is expressed as a plan view It is the average per 10 cm square area of the fiber layer on the skin surface side, and is preferably 30 or less, more preferably 20 or less, and still more preferably 10 or less. The number of fiber block portions 7 in the fiber layer on the skin side of the absorbent article is preferably 1 or more. Specifically, the number of fiber block portions 7 in the fiber layer on the skin side of the absorbent article is calculated as an average of 10 cm square area when viewed from the top of the fiber layer on the skin side, preferably 1 or more and 30 or less , More preferably 1 or more and 20 or less, and still more preferably 1 or more and 10 or less.

Furthermore, from the viewpoint of forming a deep pattern, the number of fiber block portions 7 arranged on the fiber layer on the non-skin surface side of the absorbent article among the two laminated layers is the fiber on the non-skin surface side in a plan view. The average per 10 cm square area at the time of layering is preferably 3 or more, more preferably 8 or more, and still more preferably 15 or more.

From the viewpoint of maintaining the soft skin touch of the non-woven fabric 10, the size (area) of the non-woven fabric 10 when viewed from the top of each fiber block portion 7 is preferably 10 mm ² or less, more preferably 8 mm ² or less, and still more preferably 6 mm ² the following. On the other hand, from the viewpoint of patterning, the size of the nonwoven fabric 10 of each fiber block portion 7 in plan view is preferably 1 mm ² or more, more preferably 2.5 mm ² or more, and still more preferably 4 mm ² or more. Specifically, the size (area) of the nonwoven fabric 10 in plan view of each fiber block portion 7 is preferably 1 mm ² or more and 10 mm ² or less, more preferably 2.5 mm ² or more and 8 mm ² or less, and still more preferably 4 mm ² or more and 6 mm ² or less .

In addition, the size of the nonwoven fabric 10 arranged on the fiber block portion 7 of the fiber layer on the skin surface side of the absorbent article is preferably 9 mm ² or less in plan view, more preferably 7 mm ² or less, and still more preferably 5 mm ² or less.

Furthermore, from the viewpoint of forming a deep pattern, the size of the non-woven fabric 10 in plan view of the fibrous block portion 7 arranged on the fiber layer on the non-skin surface side of the absorbent article among the two laminated layers is preferably 2 mm ² or more, more preferably 3 mm ² or more, still more preferably 5 mm ² or more.

From the viewpoint of maintaining the soft skin touch of the non-woven fabric 10, the size (thickness) of the non-woven fabric 10 of each fiber block portion 7 in the thickness direction is preferably 50% or less in relation to the thickness of the non-woven fabric 10. It is more preferably 40% or less, and still more preferably 30% or less. On the other hand, from the point of view of texture, the size (thickness) in the thickness direction of the non-woven fabric 10 of each fiber block portion 7 is calculated as a ratio to the thickness of the non-woven fabric 10, and the smaller the better within the range of more than 0% . Specifically, the size (thickness) in the thickness direction of the non-woven fabric 10 of each fiber block portion 7 is calculated as a ratio to the thickness of the non-woven fabric 10, preferably more than 0% and 50% or less, more preferably more than 0% And 40% or less, more preferably more than 0% and 30% or less.

Also, from the viewpoint of relaxing the firmness felt when the skin is in contact with the fibrous block part 7 by the laminated and integrated plural fiber layers, the fibers on the skin side that becomes the absorbent article are arranged in the two layers of the laminated layer The size in the thickness direction of the non-woven fabric 10 of the fiber block portion 7 of the layer is preferably 50% or less, more preferably 40% or less, and still more preferably 30% or less in terms of the ratio of the thickness of the non-woven fabric 10 to the thickness of the non-woven fabric 10.

Furthermore, from the same viewpoint as described above, the size (thickness) in the thickness direction of the nonwoven fabric 10 of each fiber block portion 7 is preferably 1 mm or less, more preferably 0.8 mm or less, and still more preferably 0.5 mm or less, and , The smaller the better within the range of more than 0mm. Specifically, the size (thickness) in the thickness direction of the nonwoven fabric 10 of each fiber block portion 7 is preferably more than 0 mm and 1 mm or less, more preferably more than 0 mm and 0.8 mm or less, and still more preferably more than 0 mm and 0.5 mm or less .

(Method for measuring the number, area and thickness of the fiber block)

Using a microscope (manufactured by Keyence Co., Ltd., VHX-900), a photograph was taken from the observation target surface (for example, the surface 10A of the non-woven fabric 10) cut into a 10 cm square non-woven fabric. Use image analysis software (Nexus New Qube) to analyze the image data (jpeg) of the photo. Perform binarization processing to obtain the number and area of the fibrous part. In addition, all the blocks were cut in the thickness direction with a razor blade, and the cross section was observed using the above-mentioned microscope to measure the thickness of the nonwoven fabric and the thickness of the fiber block.

The hot-air nonwoven fabric for absorbent articles of the present invention can be used as a component of absorbent articles. Examples of absorbent articles include diapers, menstrual sanitary napkins, urine-absorbent pads, sanitary pads, etc., which have the function of absorbing and retaining human excreted liquid.

The hot-air nonwoven fabric for absorbent articles of the present invention combines its functions as various components of absorbent articles and is incorporated into absorbent articles. For example, when it has liquid permeability, it is incorporated as a front sheet, and when it has water repellency, it is incorporated as a side sheet. In addition, it is made thinner and softer, and it is incorporated as an exterior material that improves the feel of the skin on the outer side (clothing side) of absorbent articles such as diapers.

Among them, from the viewpoint that the skin can easily perceive the texture of a non-woven fabric with excellent bulkiness and soft skin touch, and the pattern of the non-woven fabric can be easily recognized visually, the hot-air non-woven fabric for absorbent articles of the present invention is preferably It is arranged on the outermost layer on the skin surface side of the absorbent article, and the fiber block layer 8 is arranged toward the skin surface side. For example, a top sheet or a side sheet can be mentioned, and it is especially preferable to arrange|position the hot air nonwoven fabric for absorbent articles of this invention as a top sheet on an absorbent article.

Next, a preferred embodiment of the method of manufacturing the hot-air nonwoven fabric for absorbent articles of the present invention will be described. Here, the manufacturing method of the nonwoven fabric 10 of the said embodiment is demonstrated. but The fiber layers to be laminated are not limited to two layers (fiber layer 1 and fiber layer 2), and three or more fiber layers may be laminated.

The manufacturing method of this embodiment includes the following steps 501 and 502.

Step 501: a fiber opening step, which is to perform multiple fiber opening treatments on the thermoplastic fiber to form a fiber web.

Step 502: Hot-air non-woven fabric forming step, which is to form a laminated fiber web by laminating a plurality of single-layer fiber webs obtained in the above-mentioned opening step, and use hot air to perform hot-air processing on the laminated fiber web to obtain a hot-air non-woven fabric.

In addition, the manufacturing method of this embodiment includes the following step 503.

Step 503: a calendering step, which uses a pair of calender rolls to process one or more selected from the single-layer fiber web, the laminated fiber web, and the hot-air nonwoven fabric.

Step 503 is performed after step 501 and before step 502, in the middle of step 502, and after step 502, one or more of them.

Fig. 2 shows a manufacturing apparatus 100 that can be preferably used in the manufacturing method of the non-woven fabric 10 of this embodiment. From the upstream side to the downstream side, the manufacturing device 100 is equipped with: opening sections 101 and 102 for the amount of fiber material used as the raw material of the non-woven fabric; carding sections 103 and 104 for forming the fiber web; conveying the carded single-layer fiber web and The laminated fiber web forming portion 105; the fiber web calendering portion 106 that pressurizes the laminated fiber web; and the heat treatment portion (hot air processing portion) 107.

In the manufacturing apparatus 100, the above-mentioned step 501 is performed in the opening parts 101 and 102 and the carding parts 103 and 104. The above step 502 is in the laminated fiber web forming part 105 and the heat treatment part 107 get on.

In the manufacturing apparatus 100, the above step 503 is performed in the fiber web calendering part 106. The fiber web calendering part 106 is arranged between the laminated fiber web forming part 105 and the heat treatment part 107, and the above step 503 is implemented as the fiber web calendering of the laminated fiber web in the middle of the above step 502.

The opening sections 101 and 102 respectively have devices for opening the thermoplastic fibers used as the raw material of the fiber layers 1 and 2 and sending them to the subsequent carding sections 103 and 104, respectively. In the case of using thin fibers and thick fibers having the above-mentioned specific fiber diameters, it is preferable to separate the thin fibers and the thick fibers into fibers. In FIG. 2, the following situation is shown: the raw fiber (thin fiber) 71 is fed into the opening section 101 to be opened (arrow 171), and the raw fiber (thin fiber) 72 is fed into the opening section 102 to It is opened (arrow 172).

As the raw material fiber (thin fiber) 71 and the raw material fiber (thick fiber) 72, various thermoplastic fibers that can be used for the hot-air nonwoven fabric can be used. For example, a composite fiber having a core-sheath structure and a resin component of the sheath having a lower melting point than the resin component of the core can be cited.

The carding parts 103 and 104 receive the fibers (arrows 173 and 174) that have been opened in the opening parts 101 and 102, respectively, to form single-layer fiber webs 81 and 82. Specifically, the assembly of fibers that have been opened in the opening parts 101 and 102 is carded and further opened to form a sheet-like fiber web. In the carding part 103, a single-layer fiber web 81 based on the raw fiber (thin fiber) 71 is formed, and in the carding portion 104, a single-layer fiber web 82 based on the raw fiber (thin fiber) 72 is formed.

In the carding sections 103 and 104, various carding machines commonly used in the manufacture of hot-air nonwoven fabrics can be used without special restrictions. For example, parallel carding machine, semi-random carding machine, random carding machine, equipment formed by combining cross layer and drafting device into parallel carding machine, etc. In addition, examples of the carding machine include those provided with three types of rollers, a main cylindrical roller covered with a serrated metal wire, a working roller, and a stripping roller. The fiber assembly can be combed and opened between the main cylindrical roller, the work roller and the stripping roller. By arranging multiple groups of work rollers and stripping rollers on the main cylindrical rollers, multiple opening treatments can be performed in the carding machines of the carding sections 103 and 104.

As described above, the fiber-opening parts 101 and 102 and the carding parts 103 and 104 are subjected to a plurality of fiber-opening treatments.

In the manufacturing method of this embodiment, a fiber opening step (step 501) is performed, which is in the fiber opening parts 101 and 102 and the carding parts 103 and 104, and the thermoplastic fiber is subjected to multiple fiber opening treatments to form a fiber web .

Then, in the laminated fiber web forming portion 105, the single-layer fiber web 82 formed in the carding portion 104 is laminated on the single-layer fiber web 81 formed in the carding portion 103 to form a laminated fiber web 90.

Specifically, the single-layer fiber web 81 is unloaded from the carding section 103 along the unloading belt 103A and placed on the conveying belt 105A. The conveying belt 105A conveys the single-layer fiber web 81 downstream. Moreover, the single-layer fiber web 82 is carried out along the carry-out belt 104A from the carding, and is guided to the conveying belt 105A, and is laminated on the single-layer fiber web 81 that is being conveyed. The laminated fiber web 90 is conveyed downstream along the conveying belt 105A. In addition, in the laminated fiber web 90, the parts corresponding to the single-layer fiber webs 81 and 82 are referred to as fiber webs 81 and 82 for short.

In the laminated fiber web 90, the fiber web 82 is formed of raw material fibers (thick fibers) 72, and the fiber web 81 is formed of raw material fibers (thin fibers) 71. Therefore, the average fiber diameter of the fiber web 82 is greater than the average fiber diameter of the fiber web 81. Furthermore, therefore, the fiber web 81 in the completed non-woven fabric 10 becomes a fiber block layer 8 containing fine fibers of the aforementioned specific fiber diameter. The fiber web 82 in the completed non-woven fabric 10 can become a non-fiber block layer 9 containing thick fibers of the aforementioned specific fiber diameter. In addition, in the finished non-woven fabric 10, the basis weight of the non-fiber block layer 9 is larger than that of the fiber block layer 8. The fiber mass supplied from the fiber opening section 102 to the carding section 104 can be more than that from the fiber opening section 101 to the carding section. 103 supplied fiber quality is achieved.

Thus, in the manufacturing method of this embodiment, it is preferable to form a laminated fiber web using a plurality of types of fibers having different fiber diameters. In particular, it is more preferable that the fiber diameters used in the fiber web 82 and the fiber web 81 are different.

Regarding fibers having different fiber diameters, it is preferable to use the above-mentioned thin fibers having a fiber diameter of 1 dtex or more and 2.2 dtex or less. Furthermore, the fiber diameter of the thin fiber is more preferably within the above-mentioned fiber diameter range.

In the fiber web calendering section 106, a fiber web calendering process is performed in which the transported laminated fiber web 90 is pinched between a pair of calender rolls 106A and 106B and pressed (hereinafter, sometimes referred to as "calendering" "). Thereby, the surface of the fiber web having the fiber block portion 7 can be made smooth, and the rigidity of the fiber block portion 7 can be reduced.

In particular, in the manufacturing method of the present embodiment, the laminated fiber web 90 before being non-woven is calendered, so the fibers have not been welded and fixed yet, and the fibers can be moved largely. That is, in the calendering process of the present embodiment, there is no possibility that the fibers in the welded part between the fibers will be peeled or broken, and the fibers concentrated in the fiber block portion 7 can be better separated under the condition of maintaining the fiber state. (Expand the space between the fibers) so that the fiber block portion 7 is well dispersed. Thereby, the effect of reducing the stiffness of the fiber block portion 7 is improved. In addition, the press in the thickness direction caused by calendering on any one of the fiber webs 81 and 82 before the non-woven fabric of the laminate makes the fibers of the fiber block part 7 easy to be separated from each other, and the laminate fiber web 90 is integrated The effect of reducing the stiffness of the fiber block portion 7 is improved (hereinafter, the laminated fiber web obtained by performing fiber web calendering may be referred to as the laminated fiber web 95). In addition, in a series of manufacturing steps, by performing the following hot-air processing after the above-mentioned calendering processing, the hot-air processing can be utilized as a non-woven thickness recovery processing. That is, in the present embodiment, the processing steps carried out in this order are beneficial for reversing the thickness of the laminated fiber web 95, making it more bulky, making the soft skin feel better, and forming a pattern.

In the heat treatment section 107, hot air is used to perform hot air processing on the laminated fiber web 95 obtained by performing the web calendering process.

Specifically, the heat treatment unit 107 has a filter cover 107A and a conveyor belt 107B provided with an air-permeable net surrounding the filter cover 107A. In the filter cover 107A, the conveying belt 107B blows hot air from above (arrow F shown in FIG. 2). In the conveying belt 107B, the blown hot air is blown away by the above-mentioned air-permeable net. The laminated fiber web 95 obtained by performing the fiber web calendering process is extruded to the heat treatment portion 107 by the rotation of the roll of the fiber web calendering portion 106. In the heat treatment section 107, the laminated fiber web 95 is transported into the filter cover 107A by the conveyor belt 107B. Self-laminated fiber web 95 Square (that is, above the fiber web 82) along the thickness direction, blows hot air heated to a specific temperature through the laminated fiber web 95 in the filter cover 107A. That is, the laminated fiber web 95 is subjected to hot air processing. Thereby, in the laminated fiber web 95, by the above-mentioned fiber web calendering process, the space between the fibers in the fiber block portion 7 is enlarged, and under the condition of the fiber state where the rigidity of the fiber block portion 7 is relaxed, by It is blown by hot air to fuse the intersections of the fibers. Thereby, the hot-air nonwoven fabric 10 for absorbent articles of this embodiment can be obtained.

As described above, in the manufacturing method of this embodiment, the single-layer fiber web 81 obtained through the opening step of step 501 is processed by the laminated fiber web forming portion 105, the fiber web calendering portion 106, and the heat treatment portion 107. And 82 execute the above step 502 and the above step 503. Specifically, step 502 is performed by the laminated fiber web forming part 105 and the heat treatment part 107, and the calendering step is performed by the fiber web calendering part 106 in the middle (step 503).

By executing these steps 501, 502, and 503, the hot-air nonwoven fabric 10 for absorbent articles of the present embodiment described above can be manufactured accurately. That is, although the fiber layer 8 having the fiber block portion 7 is included, the hot-air nonwoven fabric 10 for absorbent articles having excellent bulkiness and soft touch and having a pattern can be manufactured accurately. The manufactured hot-air nonwoven fabric 10 for absorbent articles is taken up in a roll as needed.

In the manufacturing method of this embodiment, a calendering process is performed on the laminated fiber web 90 before hot air processing (step 503). However, it is not limited to this, and the single-layer fiber web 81 and the single-layer fiber web 82 before lamination may be individually calendered, or the hot-air non-woven fabric after the hot-air processing may be calendered. Furthermore, when calendering the hot-air nonwoven fabric, the hot-air nonwoven fabric to be processed is the raw material before the hot-air nonwoven fabric 10 for absorbent articles of this embodiment. Non-woven.

In the manufacturing method of the present embodiment, by performing the calendering step (step 503), the fiber mass 7 is spread by calendering, and the parts other than the fiber mass 7 are also smoothed and changed by calendering. Go smoothly. The non-woven fabric 10 with a smooth surface is obtained by maintaining the thickness of a plurality of fiber layers and integrating them. Therefore, it has the thickness and cushioning properties to reduce the degree of foreign body sensation (discomfort) of the fiber block portion 7 in contact with the skin.

In addition, in the manufacturing method of this embodiment, the fiber block can be scattered in a series of manufacturing steps of the nonwoven fabric. Therefore, it is not necessary to introduce the fiber block inspection device after the non-woven fabric is manufactured, so that the manufacturing cost can be reduced. Furthermore, there is no need to perform post-manufacturing inspection processing, post-production calendering processing, and hot-air recovery processing, so that the non-woven fabric manufacturing efficiency can be improved.

From the viewpoint of effectively reducing the stiffness of the fiber block portion 7, the above-mentioned calendering process is preferably a fiber web calendering process performed on one or more selected from a single-layer fiber web and a laminated fiber web.

In addition, the calendering process is not limited to only one stage among the single-layer fiber web stage, the laminated fiber web stage, and the hot-air non-woven fabric stage, and may be performed in two or more stages. Furthermore, it is not limited to the case where the calendering is performed only once in each stage, and it may be performed twice or more. For example, it is not limited to the case where the laminated fiber web 90 of this embodiment is calendered only once, and it may be performed twice or more.

The linear pressure in the calendering step is to apply the laminated fibers pressed by the calender rollers 106A and 106B The linear pressure applied by the web 90, the single-layer fiber webs 81, 82 and the hot-air nonwoven fabric (raw material hot-air non-woven fabric) is preferably applied to the single-layer fiber webs 81, 82 and the laminated fiber webs 90, 95 by all rollers in all steps. And the hot air non-woven fabric 601 has the highest linear pressure. The all rollers referred to herein refer to all rollers used in all manufacturing steps except for the above-mentioned calender rollers 106A and 106B. For example, the nip rollers used for conveying non-woven fabrics after heat treatment, the nip rollers or press rollers during winding, and the press rollers during slitting thereafter, meet this meaning.

In particular, from the viewpoint of effectively reducing the rigidity of the fiber block portion 7 before heat welding, the linear pressure (P) applied to the single-layer fiber webs 81, 82 and the laminated fiber web 90 in the calendering process is relatively low. It is preferably 20 N/cm or more, more preferably 100 N/cm or more, and even more preferably 180 N/cm or more. In addition, from the viewpoint of thickness recovery after pressing, the linear pressure (P) is preferably 700 N/cm or less, more preferably 500 N/cm or less, and even more preferably 250 N/cm or less. Specifically, the linear pressure (P) is preferably 20 N/cm or more and 700 N/cm or less, more preferably 100 N/cm or more and 500 N/cm or less, and still more preferably 180 N/cm or more and 250 N/cm or less.

One pair of calender rolls 106A and 106B used in the fiber web calendering part 106 are rolls with smooth peripheral surfaces. The raw materials can be various raw materials used in calendering. In addition, the raw material of the calender roller 106A and the raw material of the calender roller 106B may be the same or different.

Among them, from the viewpoint of further enhancing the effect of reducing the hardness of the fiber block portion 7, the calender roll used in the calendering process is preferably a combination of a resin roll and a steel body roll. In the fiber web calendering process of this embodiment, the calender roll 106A is used as a contact with the fibrous web 82 containing coarse fibers of the laminated fiber web 90, and a steel body roll is used, and the calender roll 106B is used as a contact with the laminated fiber web 90 When the fiber web 81 containing fine fibers abuts, a resin roller is used. But the configuration of resin roller and steel roller is not limited to This can also be the opposite combination.

From the viewpoint of further improving the effect of reducing the hardness of the fiber block portion 7, the hardness of the resin roller is D hardness (JIS K6253-3), preferably 20 degrees or more, more preferably 50 degrees or more, and even more preferably Above 80 degrees. In addition, from the same viewpoint as the above, the hardness of the resin roller is preferably 100 degrees or less in terms of D hardness (JIS K6253-3), more preferably 95 degrees or less, and even more preferably 90 degrees or less. Specifically, the hardness of the above-mentioned resin roller is preferably 20 degrees or more and 100 degrees or less, more preferably 50 degrees or more and 95 degrees or less, and still more preferably 80 degrees or more and 90 degrees or less.

Furthermore, the hot air processing preferably includes a plurality of hot air treatments.

FIG. 3 shows the state of the heat treatment part (hot air processing part) including the first hot air treatment part 117 and the second hot air treatment part 127. In this aspect, the hot air processing is divided into a first hot air treatment and a second hot air treatment and performed twice. However, the number of hot air treatments is not limited to the 2 times in Fig. 3, and may be 3 times or more. When the hot air processing includes more than 3 hot air treatments, the "post-stage hot air treatment" in relation to the "initial hot air treatment" means the second and subsequent hot air treatments. In the second hot air treatment in Fig. 3, the so-called "initial hot air treatment" means the first hot air treatment, and the so-called "post-stage hot air treatment" means the second hot air treatment. In the hot air step (second hot air treatment) shown in FIG. 3, hot air blowing is performed in the filter cover 107C of the first hot air treatment section 117 (arrow F1), and hot air blowing is performed in the filter cover 107D of the second hot air treatment section 127 (Arrow F2). At this time, by the conveyor belt 107B, the laminated fiber web 95 obtained by performing the fiber web calendering process is continuously conveyed from the 1st hot air processing part 117 to the 2nd hot air processing part 127. Thereby, the first hot air treatment and the second hot air treatment are continuously performed on the laminated fiber web 95.

In the above-mentioned hot air step, the wind speed of the hot air in the subsequent hot air treatment is preferably faster than that of the initial hot air treatment, that is, the initial hot air treatment is performed at a low wind speed. Thereby, it is suppressed that the inside of the hot air treatment part is not fluffy due to wind pressure, and the hot air recovery effect is exhibited to make the fiber web fluffy. In particular, when calendering the laminated fiber web 90 or the single-layer fiber webs 81 and 82 before non-woven fabric as in this embodiment, the above-mentioned treatment in the subsequent hot air treatment is effective.

Specifically, the wind speed S1 of the hot air in the initial hot air treatment is preferably 0.2 m/sec or more, more preferably 0.25 m/sec or more, and even more preferably 0.4 m/sec or more. The wind speed S1 of the hot air in the initial hot air treatment is preferably 1.2 m/sec or less, more preferably 0.8 m/sec or less, and even more preferably 0.5 m/sec or less. Specifically, the aforementioned wind speed S1 is preferably 0.2 m/sec or more and 1.2 m/sec or less, more preferably 0.25 m/sec or more and 0.8 m/sec or less, and still more preferably 0.4 m/sec or more and 0.5 m/sec or less. In this way, the fiber web is suppressed from being flattened and the thickness recovery effect is exhibited.

The wind speed S2 of the hot air in the subsequent hot air treatment is preferably 0.8 m/sec or more, more preferably 0.9 m/sec or more, and even more preferably 1.2 m/sec or more. The wind speed S2 of the hot air in the subsequent hot air treatment is preferably 1.6 m/sec or less, more preferably 1.4 m/sec or less, and even more preferably 1.3 m/sec or less. Specifically, the wind speed S2 is preferably 0.8 m/sec or more and 1.6 m/sec or less, more preferably 0.9 m/sec or more and 1.4 m/sec or less, and still more preferably 1.2 m/sec or more and 1.3 m/sec or less. Thereby, air penetrates the fiber web uniformly, and heat energy is effectively imparted, thereby forming a non-woven fabric structure.

The difference S3 (=S2-S1) between the hot air speed S1 in the initial hot air treatment and the hot air speed S2 in the later hot air treatment is preferably more than 0m/sec, more preferably more than 0.4m/sec, and then More preferably, it is 0.8 m/sec or more. The difference S3 (=S2-S1) between the hot air speed S1 in the initial hot air treatment and the hot air speed S2 in the subsequent hot air treatment is preferably 1.4m/sec or less, more preferably 1.2m/sec or less, and more Preferably, it is 1m/sec or less. Specifically, the difference S3 (=S2-S1) between the wind speed S1 of the hot air in the initial hot air treatment and the wind speed S2 of the hot air in the subsequent hot air treatment is preferably more than 0m/sec and less than 1.4m/sec, more preferably It is 0.4 m/sec or more and 1.2 m/sec or less, and more preferably 0.8 m/sec or more and 1 m/sec or less. In this way, it is possible to effectively achieve both the fluffy response and the non-woven fabric.

Furthermore, in the above-mentioned hot air step, it is preferable that the temperature of the hot air in the subsequent hot air treatment is higher than that of the initial hot air treatment. In this way, the fusion of the fibers is promoted in stages, thereby effectively showing the response of the fiber web in the hot air treatment section. In particular, when calendering the laminated fiber web 90 or the single-layer fiber webs 81, 82 before non-woven fabric as in the present embodiment, the above-mentioned effect in the subsequent hot air treatment is higher.

Specifically, the temperature P1 of the hot air in the initial hot air treatment is preferably 85°C or higher, more preferably 90°C or higher, and still more preferably 100°C or higher. The temperature P1 of the hot air in the initial hot air treatment is preferably 134°C or lower, more preferably 115°C or lower, and even more preferably 105°C or lower. Specifically, the temperature P1 of the hot air in the first hot air treatment is preferably 85°C or more and 134°C or less, more preferably 90°C or more and 115°C or less, and still more preferably 100°C or more and 105°C or less. In this way, the responsiveness of the fiber web in the hot air treatment section can be effectively demonstrated.

The temperature P2 of the hot air in the subsequent hot air treatment is above the melting point of the components of the fiber surface (for example, the sheath of the core-sheath composite fiber), preferably 145°C or less, more preferably 137°C Hereinafter, it is more preferably 134°C or lower. Specifically, the temperature P2 of the hot air in the subsequent hot air treatment is preferably not less than the melting point of the fiber surface component used at 145°C, more preferably the melting point of the fiber surface component used at least 137°C, and still more Preferably, the melting point of the surface component of the fiber used is above 134°C. By this, the manufacture of non-woven fabrics with good texture and tactile skin can be realized.

The difference P3 (=P2-P1) between the temperature P1 of the hot air in the initial hot air treatment and the temperature P2 of the hot air in the subsequent hot air treatment is preferably more than 0°C, more preferably 20°C or more, and even more preferably 30°C the above. The difference P3 (=P2-P1) between the temperature P1 of the hot air in the first hot air treatment and the temperature P2 of the hot air in the subsequent hot air treatment is preferably 60°C or less, more preferably 40°C or less, and even more preferably 35°C the following. Specifically, the difference P3 (=P2-P1) between the temperature P1 of the hot air in the first hot air treatment and the temperature P2 of the hot air in the subsequent hot air treatment is preferably more than 0°C and below 60°C, more preferably 20°C Above 40°C, more preferably 30°C or higher and 35°C or lower. In this way, the manufacture of a fluffy non-woven fabric with good texture can be realized.

Furthermore, in the manufacturing method of the hot-air nonwoven fabric for absorbent articles of this embodiment, it is preferable to temporarily recover waste parts such as leftovers generated in the manufacturing step and return it to the opening step (step 504) as described below .

In this step 504, one or both of the following steps are included: recovering the widthwise ends of the fiber web in the carding machine used in the above-mentioned opening step; and partially recovering the above-mentioned hot air non-woven fabric, and the recovered hot air Part of the non-woven fabric is cut and opened. The recycled fiber web and parts of the cut and opened hot-air nonwoven fabric are supplied to the opening step. Furthermore, the so-called cut and opened hot air non-woven fabric includes but is not limited to the leftover material at the end in the width direction, Refers to non-woven fabric manufacturing process adjustment products or unqualified products, etc.

FIG. 2 shows a specific example of step 504 described above. The single-layer fiber webs 81 and 82 formed in the carding machines of the carding parts 103 and 104 are sucked and recovered (arrows 181 and 182) at the ends (not shown) in the width direction. In addition, the hot-air nonwoven fabric 10 obtained by performing hot-air processing in the heat treatment section 107 is partially recovered (arrow 183). In this case, the recycled hot-air non-woven fabric cannot be directly reused, so it needs to be cut and opened in the cutting/opening part 108 to restore it to a fibrous shape.

The recycled fiber web and the part of the cut and opened hot-air nonwoven fabric are returned to the opening section 101, and then opened again, and used as a material for forming the fiber web (arrow 184). At this time, it can be sent back to either the spreading part 101 and the spreading part 102. FIG. 2 shows the state of returning to the spreading section 101. In the case of returning to the opening section 101, it is preferable to appropriately adjust the input amount of the new raw material fibers (fine fibers) 71 so that the ratio of the fine fibers in the formed fiber web 81 is maintained at a certain level or higher, and the thick The fiber content is suppressed to within a few% (for example, within 5%). Thereby, while forming the fibrous block portion 7 on the fiber web 81, it is possible to include a large amount of fine fibers on the other side, thereby realizing a soft skin touch on the surface 10A side of the nonwoven fabric 10.

In addition, the return of the aforementioned materials is not limited to the aspect shown in FIG. 2. For example, it may also be the following aspect: the material recovered from the carding part 103 is returned to the opening part 101, and the material recovered from the carding 104 is returned to the opening part 102. At this time, it is preferable that the part of the cut and opened hot-air nonwoven fabric is returned to the opening section 102.

As described above, according to the manufacturing method of the present embodiment, the non-woven fabric 10 with excellent bulkiness and softness on the skin and having a pattern can be manufactured preferably. In particular, it can be better manufactured with The non-woven fabric 10 has physical properties shown in the thickness T1, T2 and the difference T3 (=T1-T2) and the average friction coefficient Q1, Q2 and the difference Q3 (=Q1-Q2) under the pressure of 7.64 kPa. In addition, the pattern formed by the fiber block portion 7, especially the pattern formed by the fiber block portion 7 having a flat thickness, makes the non-woven fabric 10 aesthetic.

The obtained hot-air nonwoven fabric for absorbent articles of the present invention is incorporated in the manufacturing step of the absorbent article as a specific constituent member of the absorbent article according to its purpose (assembly step). The integration step is preferably the following step, for example. That is, the obtained absorbent article of the present invention is prepared by cutting the hot-air nonwoven fabric into a target size or shape, and placing it in a specific position relative to other constituent members. Then, if necessary, it is rotated and folded together with other members, and the two are joined to be incorporated into an absorbent article. In this way, in the manufacturing step of the absorbent article, through the step of incorporating the hot-air nonwoven fabric for the absorbent article of the present invention, the target absorbent article is manufactured.

Among them, in terms of achieving both bulkiness and soft skin touch, and having a pattern that can visually attract users, the above-mentioned assembling step of the hot-air non-woven fabric for absorbent articles of the present invention is preferably assembling Step into the outermost member (for example, the front sheet or the side sheet) on the skin side of the absorbent article. It is particularly preferable to incorporate into an absorbent article as the most conspicuous front sheet in contact with the skin. At this time, the hot-air nonwoven fabric for absorbent articles of the present invention preferably has a configuration in which the fiber layer having the fiber block portion is the outermost layer of the nonwoven fabric. More preferably, the hot-air nonwoven fabric for absorbent articles of the present invention is arranged on the outermost layer of the absorbent article on the skin surface side, and the fiber layer having the above-mentioned fiber block portion is arranged toward the skin surface side of the absorbent article.

Regarding the above embodiment, the present invention further discloses the following hot-air nonwoven fabric for absorbent articles And a method for manufacturing hot-air nonwoven fabric for absorbent articles.

<1>

A hot air nonwoven fabric for absorbent articles, which is formed by laminating two or more fiber layers, and has at least one fiber layer containing thermoplastic fibers and having a fiber block portion.

<2>

The hot-air nonwoven fabric for absorbent articles as described in the above item <1>, wherein the hot-air nonwoven fabric for absorbent articles has fine fibers and thick fibers with a fiber diameter thicker than the fine fibers, and the fine fibers have a fiber diameter of 1 dtex or more and 2.2 dtex Hereinafter, it is preferably 1 dtex or more, more preferably 1.2 dtex or more, preferably 2 dtex or less, and more preferably 1.5 dtex or less; and the fiber layer having the fiber block portion includes the above fine fiber.

<3>

The hot-air nonwoven fabric for absorbent articles as described in the above item <2>, wherein the content of the fine fibers in the fiber layer having the fiber block portion is 50% by mass or more, preferably 80% by mass or more, and more preferably 100% by mass %.

<4>

The hot-air nonwoven fabric for absorbent articles as described in any one of the above <1> to <3>, which has at least one fiber layer that does not have the fiber block portion.

<5>

The hot-air nonwoven fabric for absorbent articles as described in the above <4>, wherein the hot-air nonwoven fabric for absorbent articles has thick fibers and fine fibers with a fiber diameter smaller than the thick fibers, and the thick fibers The fiber diameter of Weizhi is more than 2.2 dtex and less than 7 dtex, preferably more than 2.2 dtex, more preferably more than 4.4 dtex, preferably less than 5.5 dtex, and more preferably less than 5 dtex; and the fiber layer without the above-mentioned fiber block includes The above crude fiber.

<6>

The hot-air nonwoven fabric for absorbent articles as described in the above item <5>, wherein the content of the thick fiber in the fiber layer without the fiber block portion is 50% by mass or more, preferably 80% by mass or more, more preferably 100 quality%.

<7>

The hot-air nonwoven fabric for absorbent articles as described in the above <5> or <6>, wherein the content of the thick fiber in the layer having the fiber block portion is 50% by mass or less, preferably 30% by mass or less, more preferably It is 10% by mass or less.

<8>

The hot-air nonwoven fabric for absorbent articles as described in any one of the above <4> to <7>, wherein the average fiber diameter of the fiber layer without the fiber block portion is larger than the fiber layer with the fiber block portion.

<9>

The hot-air nonwoven fabric for absorbent articles as described in the above <8>, wherein the difference between the average fiber diameter of the fiber layer without the fiber block portion and the average fiber diameter of the fiber layer with the fiber block portion is more than 0 dtex and 5.6 dtex Hereinafter, it is preferably 2.2 dtex or more, more preferably 3 dtex or more, preferably 4 dtex or less, and more preferably 3.5 dtex or less.

<10>

The hot-air nonwoven fabric for absorbent articles as described in any one of the above <4> to <9>, wherein the basis weight of the fiber layer without the fiber block portion is higher than that of the fiber layer with the fiber block portion Big.

<11>

The hot-air nonwoven fabric for absorbent articles as described in the above <10>, wherein the difference between the basis weight of the fiber layer without the fiber block portion and the basis weight of the fiber layer with the fiber block portion is more than 0 g/m ² and 20 g /m ² or less, preferably 3 g/m ² or more, more preferably 5 g/m ² or more, preferably 15 g/m ² or less, and more preferably 10 g/m ² or less.

<12>

The hot-air nonwoven fabric for absorbent articles as described in any one of the above <1>~<11>, wherein the whole basis weight of the hot-air nonwoven fabric for absorbent articles is 15g/m ² or more and 40g/m ² or less, preferably 18 g/m ² or more, more preferably 20/m ² or more, preferably 30 g/m ² or less, more preferably 25 g/m ² or less.

<13>

The hot-air non-woven fabric for absorbent articles as described in any one of the above <1>~<12>, wherein the position where the fiber block part is arranged is measured at a pressure of 7.64 kPa. The thickness is set to T1. When the thickness of the hot-air nonwoven fabric for absorbent articles measured under the same pressure at the position where the fiber block is not arranged is set to T2, the thickness difference T3 defined by T3=T1-T2 is 0.4mm Hereinafter, it is preferably 0.3 mm or less, more preferably 0.2 mm or less, and still more preferably 0 (zero) mm.

<14>

The hot-air nonwoven fabric for absorbent articles as described in any one of the above <1> to <13>, wherein the average coefficient of friction of the position where the fiber block portion is arranged in the hot-air nonwoven fabric for absorbent articles is 1.6 or more and 2.5 or less, Preferably it is 1.6 or more, preferably 2.4 or less, more preferably 2.3 or less under.

<15>

The hot-air nonwoven fabric for absorbent articles as described in <14> above, wherein the average coefficient of friction of the position where the fiber block portion is arranged and the average friction coefficient of the position where the fiber block portion is not arranged in the hot-air nonwoven fabric for absorbent article The difference is 0.7 or less, preferably 0.5 or less, more preferably 0.32 or less, still more preferably 0.3 or less, and particularly preferably 0 (zero).

<16>

The hot-air non-woven fabric for absorbent articles as described in any one of the above <1> to <15>, wherein the fiber block portion is a flat shape squashed in the thickness direction of the non-woven fabric in a cross section in the thickness direction of the non-woven fabric, It has a smooth structure on the surface of the fiber block on the front side of the non-woven fabric.

<17>

The hot-air nonwoven fabric for absorbent articles as described in any one of the above <1> to <16>, wherein the fiber layer having the fiber block portion is the outermost layer of the hot-air nonwoven fabric for absorbent articles.

<18>

An absorbent article comprising the hot-air nonwoven fabric for absorbent articles as described in any one of the above <1> to <17>.

<19>

An absorbent article in which the hot-air nonwoven fabric for absorbent articles as described in the above <17> is arranged on the outermost layer of the skin side of the absorbent article, and the fiber layer having the fiber block portion is arranged toward the skin side Assume.

<20>

The absorbent article as described in the above <18> or <19>, which has the above-mentioned hot-air nonwoven fabric for the absorbent article as a front sheet.

<21>

A method for manufacturing a hot-air nonwoven fabric for absorbent articles, comprising: a fiber opening step, which is to perform multiple opening treatments on thermoplastic fibers to form a fiber web; a hot-air nonwoven fabric forming step, which will be obtained in the above-mentioned fiber opening step A plurality of single-layer fiber webs are laminated to form a laminated fiber web, and hot air is used to perform hot air processing on the laminated fiber web to obtain a hot-air non-woven fabric; and a calendering step, which uses a pair of calender rolls, is selected from the single One or more of the laminated fiber web, the laminated fiber web and the hot-air nonwoven fabric are processed.

<22>

The method for manufacturing the hot-air nonwoven fabric for absorbent articles as described in the above <21>, wherein in all steps of the method for manufacturing the hot-air nonwoven fabric for absorbent articles, the single-layer fiber web, the laminated fiber web and the hot-air nonwoven fabric are applied Among the line pressures, the line pressure in the above-mentioned calendering step is the highest.

<23>

The method for producing hot-air nonwoven fabric for absorbent articles as described in the above <21> or <22>, wherein the calendering step is performed on one or more selected from the single-layer fiber web and the laminated fiber web The fiber mesh calendering processing steps.

<24> The method for manufacturing the hot-air nonwoven fabric for absorbent articles as described in the above <23>, wherein in the fiber web calendering step, the linear pressure applied to the single-layer fiber web or the laminated fiber web is 20N/cm or more and 700N /cm or less, preferably 100 N/cm or more, more preferably 180 N/cm or more, preferably 500 N/cm or less, and more preferably 250 N/cm or less.

<25>

The method for manufacturing a hot-air nonwoven fabric for absorbent articles as described in any one of the above <21> to <24>, wherein the calendering step uses a combination of a pair of calender roll-based resin rolls and steel body rolls.

<26>

The method for manufacturing the hot-air nonwoven fabric for absorbent articles as described in the above <25>, wherein the hardness of the resin roller is 20 or more and 100 or less in terms of D hardness, preferably 50 degrees or more, more preferably 80 degrees or more. It is preferably 95 degrees or less, more preferably 90 degrees or less.

<27>

The method for manufacturing hot-air nonwoven fabric for absorbent articles as described in any one of the above <21>~<26>, wherein the hot air processing includes a plurality of hot air treatments, and the speed of the hot air in the subsequent hot air treatment is higher than that of the initial hot air treatment fast.

<28>

The method for manufacturing the hot-air nonwoven fabric for absorbent articles as described in the above item <27>, wherein the wind speed of the hot air in the first hot air treatment is 0.2m/sec or more and 1.2m/sec or less, preferably 0.25m/sec or more, More preferably, it is 0.4 m/sec or more, preferably 0.8 m/sec or less, and even more preferably 0.5 m/sec or less.

<29>

The method for manufacturing hot-air nonwoven fabric for absorbent articles as described in the above <27> or <28>, wherein the wind speed of the hot air in the latter stage of the hot air treatment is 0.8m/sec or more and 1.6m/sec or less, preferably 0.9m /sec or more, more preferably 1.2 m/sec or more, preferably 1.4 m/sec or less, and more preferably 1.3 m/sec or less.

<30>

The method of manufacturing hot-air nonwoven fabric for absorbent articles as described in any one of the above <27>~<29>, wherein the difference between the wind speed of the hot air in the first hot air treatment and the speed of the hot air in the later hot air treatment It is more than 0 m/sec and 1.4 m/sec or less, preferably 0.4 m/sec or more, more preferably 0.8 m/sec or more, preferably 1.2 m/sec or less, and more preferably 1 m/sec or less.

<31>

The method for manufacturing hot-air nonwoven fabric for absorbent articles as described in any one of the above <21>~<30>, wherein the hot air processing includes a plurality of hot air treatments, and the temperature of the hot air in the subsequent hot air treatment is higher than that of the initial hot air treatment high.

<32>

The method for manufacturing hot-air nonwoven fabric for absorbent articles as described in the above <31>, wherein the temperature of the hot air in the initial hot air treatment is 85°C or more and 134°C or less, preferably 90°C or more, more preferably 100°C or more , Preferably 115°C or less, more preferably 105°C or less.

<33>

The method for manufacturing hot-air nonwoven fabric for absorbent articles as described in the above <31> or <32>, wherein the temperature of the hot air in the subsequent hot air treatment is above the melting point of the fiber surface component used and below 145°C, preferably It is above the melting point of the components on the fiber surface to be used, preferably 137°C or lower, more preferably 134°C or lower.

<34>

The method of manufacturing hot-air nonwoven fabric for absorbent articles as described in any one of the above <31>~<33>, wherein the difference between the temperature of the hot air in the first hot air treatment and the temperature of the hot air in the subsequent hot air treatment is It exceeds 0°C and 60°C or lower, preferably 20°C or higher, more preferably 30°C or higher, preferably 40°C or lower, and more preferably 35°C or lower.

<35>

The method of manufacturing hot-air nonwoven fabric for absorbent articles as described in any one of the above <21>~<34>, which includes one or both of the following steps: in the carding machine used in the above-mentioned opening step, Recycling the ends of the fiber web in the width direction; and partially recycling the hot-air non-woven fabric, cutting and opening the recycled hot-air non-woven fabric; and The recycled fiber web and the cut and opened part of the hot-air nonwoven fabric are supplied to the opening step.

<36>

The manufacturing method of the hot-air nonwoven fabric for absorbent articles as described in any one of the above <21> to <35>, wherein the laminated fiber web has a plurality of fibers with different fiber diameters.

<37>

The method for producing the hot-air nonwoven fabric for absorbent articles as described in any one of the above <21> to <36>, wherein the laminated fiber web has fine fibers, and the fiber diameter of the fine fibers is 1 dtex or more and 2.2 dtex or less, preferably It is 1 dtex or more, more preferably 1.2 dtex or more, preferably 2 dtex or less, and more preferably 1.5 dtex or less.

<38>

A manufacturing method of an absorbent article, comprising the steps of incorporating the absorbent article manufactured by the manufacturing method described in any one of <21> to <37> above into the absorbent article with a hot-air nonwoven fabric.

<39>

The method for manufacturing an absorbent article as described in the above <38>, which includes the step of incorporating the above-mentioned hot-air nonwoven fabric for absorbent articles into the absorbent article as a front sheet.

[Example]

Hereinafter, the present invention will be described in more detail based on examples, but the present invention should not be limited and interpreted by this. "←" in the following table means the same as the content on the left.

(Example 1)

Using the manufacturing device shown in Fig. 2, at a processing speed of 10 m/min, the non-woven fabric sample of Example 1 was produced as described below.

First, a core-sheath type (the core is polyethylene terephthalate resin and the sheath is polyethylene resin) thermoplastic fibers with a fiber diameter of 1.4 dtex are used as the raw fibers (thin fibers) 71 for forming the fiber layer 1. Using this raw fiber 71, the fiber-opening part 101 and the carding part 103 were subjected to a fiber-opening treatment several times to produce a single-layer fiber web 81 with a basis weight of 10 g/m ² .

In addition, a core-sheath type (core is polyethylene terephthalate resin, sheath is polyethylene resin) thermoplastic fiber with a fiber diameter of 4.4 dtex is used as the raw fiber (crude fiber) 72 for forming the fiber layer 2. Using this raw fiber 72, the fiber-opening part 102 and the carding part 104 were subjected to a fiber-opening treatment several times to produce a single-layer fiber web 82 with a basis weight of 15 g/m ² .

Then, in the laminated fiber web forming portion 105, the single-layer fiber web 82 is laminated on the single-layer fiber web 81 to form the laminated fiber web 90. In the fiber web calendering part 106, a fiber web calendering process is performed on the laminated fiber web 90. In the fiber web calendering part 106, the steel body calender roll 106A on the upper layer side and the resin roll 106B (D hardness: 90 degrees) on the lower layer side were used to make the linear pressure 200 N/cm.

In the heat treatment section 107, the laminated fiber web 95 obtained by the fiber web calendering process is subjected to hot air processing in which the second hot air treatment shown in FIG. 3 is performed. The wind speed and temperature of the first hot air treatment and the second hot air treatment are shown in Table 1. In this way, a nonwoven fabric sample of Example 1 was produced.

Furthermore, in the above-mentioned manufacturing method, the operation of recovering the widthwise end of the formed fiber web and a part of the nonwoven fabric and returning it to the opening step is not performed. Therefore, the fiber diameter of the raw fiber (thin fiber) 71 is the average fiber diameter of the fiber layer 1, and the fiber diameter of the raw fiber (thick fiber) 72 is the average fiber diameter of the fiber layer 2.

(Examples 2~7)

Except that the temperature and wind speed of the first hot air treatment were set to the values shown in Table 1, the non-woven fabric samples of Examples 2 to 7 were produced in the same manner as in Example 1.

(Example 8)

The nonwoven fabric sample of Example 8 was produced in the same manner as in Example 1, except that the nonwoven fabric after the hot air process was not calendered by the fiber web and the nonwoven fabric shown in Table 1 was calendered.

(Example 9)

In addition to setting the fiber diameter of the raw fiber (thin fiber) forming the fiber layer 1 to 2.0 dtex, Except for the values shown in Table 1, the temperature and wind speed of the first hot air treatment were set in the same manner as in Example 1, and a nonwoven fabric sample of Example 9 was produced.

(Example 10)

Except that the fiber diameter of the raw fiber 72 forming the fiber layer 2 was set to 2.0 dtex, in the same manner as in Example 9, a nonwoven fabric sample of Example 10 was produced.

(Example 11)

Except that the fiber diameter of the raw material fiber (thin fiber) forming the fiber layer 1 and the fiber diameter of the raw fiber 71 forming the fiber layer 2 (lower layer) are set to 1.4 dtex, the other is the same as that of Example 10 to produce an example 11 non-woven fabric samples.

(Example 12)

Except that the temperature and wind speed of the first hot air treatment were set to the values shown in Table 2, the nonwoven fabric samples of Example 12 were produced in the same manner as in Example 11.

(Example 13)

The nonwoven fabric sample of Example 13 was produced in the same manner as in Example 12, except that the fiber web calendering was not performed and the nonwoven fabric after hot air processing was subjected to the nonwoven fabric calendering shown in Table 2.

(Comparative example 1)

Except that the calendering process was not performed, the non-woven fabric sample of Comparative Example 1 was produced in the same manner as in Example 1.

(Comparative example 2)

Except that the fiber diameter of the raw fiber 71 forming the fiber layer 2 (lower layer) was set to 1.4 dtex, in the same manner as in Comparative Example 1, a nonwoven fabric sample of Comparative Example 2 was produced.

(test) [1] Fluffy (1) The thickness of the non-woven fabric sample under a load of 0.05kPa

Use the laser sensor (model ZS-LD80) and controller (model ZS-LDC11) manufactured by Omron Co., Ltd. as the laser thickness gauge for measurement.

When measuring the thickness, the vertical (0.05kpa) is placed between the front end of the laser sensor and the non-woven fabric sample to be measured, and the thickness in the pressurized state is measured. Measure 5 points or more, and calculate the average value. Furthermore, 0.05kPa is the load obtained by assuming the apparent thickness of the non-woven fabric in such a way that the thickness is not squashed as much as possible.

(2) The thickness of the non-woven fabric sample under 7.64kPa pressure

Based on the method described in the above (Method for Measuring the Thickness of Nonwoven Fabric under 7.64kPa Pressure), measure the thickness (T1) of the position where the fiber block is arranged and the thickness of the position where the fiber block is not arranged for each nonwoven sample. (T2). Furthermore, the difference in thickness (T3=T1-T2) is calculated.

[2] Friction

Based on the method described in the above (Method for Measuring Average Friction Coefficient), measure the MIU value (Q1) of the position where the fiber block is arranged and the MIU value (Q2) of the position where the fiber block is not arranged for each nonwoven sample . Furthermore, the difference Q3 (=Q1-Q2) of the MIU value is calculated.

[3] Pattern

For each non-woven fabric sample, visually confirm the presence or absence of fiber blocks.

As shown in Tables 1 and 2, the difference between the thickness T1 of the position where the fiber block is arranged and the thickness T2 of the position where the fiber block is not arranged under the pressure of 7.64 kPa in Examples 1-13 and Comparative Examples 1 and 2 T3 is small and the overall bulkiness of the non-woven fabric is excellent. Especially, in the embodiment, the non-woven fabric obtained by heat treatment after calendering of the fiber web becomes thicker and thicker than that of the non-woven fabric after calendering. The texture of the fiber block is also a non-woven fabric.

In addition, in Examples 1-13, the pattern of the fiber block was confirmed, and compared with Comparative Examples 1 and 2, the average friction coefficient Q1 of the position where the fiber block was arranged, and the average of the position where the fiber block was not arranged The friction coefficient Q2 and the difference Q3 between the two are small, and the non-woven fabric has a soft skin touch as a whole.

As described above, in Examples 1-13, the bulkiness and soft touch of the skin are excellent, and the skin has a pattern, and thus the aesthetics is excellent.

The present invention has been described together with its embodiments and examples, but it is believed that as long as we do not specify it, we do not intend to limit our invention to any details in the description, and should not violate the attached Under the premise of the spirit and scope of the invention shown in the scope of the patent application, a broad interpretation is made.

This application claims priority based on the international application PCT/JP 2018/033325 filed on September 7, 2018, which is cited here, and its content is incorporated as part of the description of this specification.

1: Fiber layer

2: Fiber layer

7: Fiber block

8: Fiber block layer (layer with fiber block part)

9: Non-fiber block layer (layer without fiber block part)

10: Hot air non-woven fabric for absorbent articles

10A: Hot air non-woven fabric

10B: Hot-air non-woven fabric

Claims (17)

A hot-air nonwoven fabric for absorbent articles is formed by laminating two or more fiber layers, and has at least one fiber layer containing thermoplastic fibers and having a fiber block formed by thermoplastic fibers. According to claim 1, the hot-air nonwoven fabric for absorbent articles, wherein the fiber block part is thermally welded to the fiber. A hot-air non-woven fabric for absorbent articles, which is formed by laminating two or more fiber layers, and has at least one fiber layer containing thermoplastic fibers and having a fiber block portion, wherein the position where the fiber block portion is arranged is 7.64kPa The thickness of the above-mentioned hot-air nonwoven fabric for absorbent articles measured under pressure is set to T1, and when the thickness of the above-mentioned hot air non-woven fabric for absorbent articles measured under the same pressure at the position where the fiber block is not arranged is set to T2, use T3 = The thickness difference T3 defined by T1-T2 is 0.3mm or less. A hot-air nonwoven fabric for absorbent articles, which is formed by laminating two or more fiber layers, having at least one fiber layer containing thermoplastic fibers and having a fiber block portion, wherein the fiber layer having the fiber block portion is the aforementioned absorbent article The hot-air non-woven fabric is used as the outermost layer, and the hot-air non-woven fabric for the absorbent article is arranged on the outermost layer on the skin side of the absorbent article. Such as the hot-air nonwoven fabric for absorbent articles of any one of claims 1 to 4, wherein the above-mentioned absorbent The hot-air nonwoven fabric for sexual articles has fine fibers and thick fibers having a fiber diameter thicker than the fine fibers, and the fine fibers have a fiber diameter of 1 dtex or more and 2.2 dtex or less; and the fiber layer having the fiber block portion includes the thin fiber. The hot-air nonwoven fabric for absorbent articles according to claim 5, wherein the content of the fine fibers in the fiber layer having the fiber block portion is 50% by mass or more. The hot-air nonwoven fabric for absorbent articles according to any one of claims 1 to 4, which has at least one fiber layer without the fiber block portion, and the basis weight of the fiber layer without the fiber block portion is higher than that with the fiber The fiber layer of the block is large. The hot-air nonwoven fabric for absorbent articles according to claim 7, wherein the difference between the basis weight of the fiber layer without the fiber block portion and the basis weight of the fiber layer with the fiber block portion is more than 0 g/m ² and 20 g/m ² the following. The hot-air nonwoven fabric for absorbent articles according to any one of claims 1 to 4, wherein the hot-air nonwoven fabric for absorbent articles has an average friction coefficient of 1.6 or more and 2.5 or less at the position where the fiber block portion is arranged. The hot-air nonwoven fabric for absorbent articles of claim 9, wherein the difference between the average friction coefficient of the position where the fiber block portion is arranged and the average friction coefficient of the position where the fiber block portion is not arranged of the hot-air nonwoven fabric for absorbent article is 0.7 the following. An absorbent article having the hot-air nonwoven fabric for absorbent articles as claimed in any one of claims 1 to 4. A method for manufacturing a hot-air nonwoven fabric for absorbent articles, comprising: a fiber opening step, which is to perform multiple opening treatments on thermoplastic fibers to form a fiber web; the step of obtaining a hot-air nonwoven fabric is performed in the above-mentioned fiber opening step The obtained single-layer fiber webs are laminated to form a laminated fiber web, and hot air is used to perform hot-air processing on the laminated fiber web to obtain a hot-air nonwoven fabric; and the fiber web calendering process is selected from the single-layer fiber web and One or more of the above-mentioned laminated fiber webs are subjected to fiber web calendering processing. A method for manufacturing a hot-air nonwoven fabric for absorbent articles, comprising: a fiber opening step, which is to perform multiple opening treatments on thermoplastic fibers to form a fiber web; the step of obtaining a hot-air nonwoven fabric is performed in the above-mentioned fiber opening step The obtained single-layer fiber webs are laminated to form a laminated fiber web, and hot air is used to perform hot air processing on the laminated fiber web to obtain a hot air non-woven fabric; and a calendering step, which uses a pair of calender rolls, selected from the above One or more of the single-layer fiber web, the above-mentioned laminated fiber web and the above-mentioned hot-air nonwoven fabric are processed, wherein the above-mentioned hot-air processing includes a plurality of hot-air treatments. Such as claim 12 or 13, the method of manufacturing hot-air nonwoven fabric for absorbent articles, wherein the above Hot air processing includes multiple hot air treatments, and the wind speed of the hot air in the subsequent hot air treatment is faster than that of the initial hot air treatment. For example, the method for manufacturing hot-air nonwoven fabric for absorbent articles of claim 12 or 13, wherein the hot-air processing includes a plurality of hot-air treatments, and the temperature of the hot-air in the subsequent hot-air treatment is higher than that of the initial hot-air treatment. For example, the method for manufacturing hot-air nonwoven fabric for absorbent articles of claim 12 or 13, which includes one or both of the following steps: recovering the widthwise ends of the fiber web in the carding machine used in the above-mentioned opening step; And partially recovering the hot-air nonwoven fabric, cutting and opening the recycled portion of the hot-air nonwoven fabric; and supplying the recycled fiber web and the cut and opening portion of the hot-air nonwoven fabric to the opening step. According to claim 12 or 13, the method for manufacturing the hot-air nonwoven fabric for absorbent articles, wherein the laminated fiber web has a plurality of fibers with different fiber diameters.

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