KR20080061283A - Topsheet for absorbent article and method for manufacturing the same - Google Patents

Abstract

A top sheet for an absorbent article and a method for manufacturing the same are provided to separate a high adhesive material such as menstrual blood or loose feces from a wearer's skin rapidly by improving absorptiveness. A top sheet for an absorbent article includes: a first non-woven fabric(1) and a second non-woven fabric(2) mutually laminated; plural heat-fusion parts(4) formed by partial heat-fusion of the first and second non-woven fabrics; and plural convex parts(5) formed on a part except for the heat-fusion part of the first non-woven fabric to be protruded toward a wearer's skin. The convex parts and the heat-fusion parts are alternately arranged in plural lines. The surface of the second non-woven fabric is nearly flat, and the inside of the convex part comprises the first non-woven fabric or an aggregate of filament different from the first non-woven fabric.

Description

Surface sheet for absorbent article and its manufacturing method {TOPSHEET FOR ABSORBENT ARTICLE AND METHOD FOR MANUFACTURING THE SAME}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface sheet (laminated nonwoven fabric) suitably used for skin contact surfaces of absorbent articles such as disposable diapers, sanitary napkins, panty liners, incontinence pads and the like and a method of manufacturing the same.

BACKGROUND ART Surface sheets, such as disposable diapers and sanitary napkins, are generally used in which irregularities are formed on the surfaces of the wearer's skin. According to the surface sheet having the unevenness, the contact area with the wearer's skin is reduced by the presence of the unevenness, so that stickiness and tightness can be reduced.

As a surface sheet having irregularities, for example, a surface sheet in which a thick sheet material is integrated into another sheet material by embossing, and a compression part by embossing is used as a concave portion and other portions are convex portions are known. have.

In addition, Patent Document 1 describes a surface sheet in which two nonwoven fabrics are partially heat-sealed and a discontinuous convex portion is formed on one nonwoven fabric other than the heat-sealed portion.

As a surface sheet having irregularities on the surface, for example, Patent Document 2 discloses that the first nonwoven fabric and the second nonwoven fabric are partially heat-sealed to form a heat-sealed portion, and the first non-woven fabric has a portion other than the heat-sealed portion of the wearer's skin. There is proposed a surface sheet which has a convex portion protruding toward the side and is filled with short fibers inside the convex portion.

In addition, Patent Document 3 proposes a surface sheet in which a loop-shaped continuous filament layer is formed on one side of a water-permeable substrate.

[Patent Document 1] Japanese Patent Application Laid-Open No. 2004-174234

[Patent Document 2] Japanese Patent Application Laid-Open No. 2006-115974

[Patent Document 3] Japanese Patent Application Laid-Open No. 2002-065736

In the surface sheet in which the embossed compression portion described above is a concave portion and other portions are convex portions, the performance of the convex portion that can be designed is limited depending on the properties of the sheet material.

In addition, since the surface sheet described in Patent Document 1 has a cavity inside the convex portion, improvement in liquid ingress is desired, and it causes the high viscosity material such as menstrual blood and thin stools to move away from the wearer's skin quickly. There was room for improvement.

Moreover, in the surface sheet of patent document 2, the fiber filled in the inside of the convex part was short fiber, and the compressive repulsion property of the convex part was inferior, and there existed room for improvement in cushioning point.

In the surface sheet described in Patent Document 3, since the surface directly contacting the wearer's skin is formed of a continuous filament layer having less inter-fiber entanglement between fibers, when the force is applied to the filament layer in a direction orthogonal to the orientation direction of the fiber, the fiber Is scattered and is twisted, and it is easy to become a fluff shape. Since the fluff-shaped part is easy to hold | maintain a liquid, liquid remained in the surface vicinity of the surface sheet, and the external appearance after liquid absorption may worsen, or it may become sticky. Moreover, since it has a cavity with a height between a filament layer and the base material layer below, it is inferior to the drawability of a liquid.

The present invention relates to a surface sheet for use in the skin abutment surface of an absorbent article.

In the surface sheet of this invention, the 1st nonwoven fabric and the 2nd nonwoven fabric laminated | stacked mutually were partially heat-sealed, and the heat-sealing part is formed. In the first nonwoven fabric, portions other than the heat-sealed portion protrude toward the wearer's skin to form a plurality of convex portions. The convex portions and the heat-sealed portions are alternately arranged in one row, and the rows are arranged in multiple rows.

The surface on the second nonwoven fabric side of the surface sheet is almost flat, and the inside of the convex portion is composed of a first nonwoven fabric or an aggregate of long fibers different from the first nonwoven fabric.

In a preferred embodiment of the surface sheet, at least a portion of the convex portion is a sparse fiber having a fiber density lower than the fiber density in the central portion of the fiber orientation direction at one or both ends thereof in the fiber orientation direction of the first nonwoven fabric. Has a part The surface sheet having such a configuration is excellent in the drawability of the liquid and can quickly separate high-viscosity such as menstrual blood or thin stools from the wearer's skin.

In another preferred embodiment of the surface sheet, an aggregate of long fibers is disposed inside the convex portion, and a plurality of long fibers constituting the aggregate are curved in the convex direction of the convex portion. The surface sheet of such a structure is excellent in cushioning property and the drawability of liquid.

Moreover, this invention is a method of manufacturing the said surface sheet | seat in which the cavity is not formed between the 1st nonwoven fabric and the 2nd nonwoven fabric in the part which has a convex part, Comprising: The core-sheath crimped. type) Volume recovery treatment by hot air is applied to the first nonwoven fabric containing the composite fiber, and the circumferential surface is roughly concave and convex in shape to engage with the concave-convex shape of the first roll and the first roll. After embossing by engaging the engaging portion with the second roll on the surface, the second roll is joined with the second nonwoven fabric while being held on the circumferential surface of the first roll to convex the first roll together with the second nonwoven fabric. It is to provide a method for producing a surface sheet to form the heat-sealed portion by heating and pressing between the portion and another roll.

In addition, the present invention provides a method for producing the surface sheet in which the cavity is not formed between the first nonwoven fabric and the second nonwoven fabric in a portion having a convex portion, the first nonwoven fabric comprising crimped eccentric core sheath composite fibers. The volume recovery process by hot air is performed, it adsorb | sucks to the circumferential surface of the roll which has a circumferential surface concave-convex shape, and has a suction hole in a recess, and it joins with a 2nd nonwoven fabric in the state maintained on the circumferential surface of the said roll, It is to provide a method for producing a surface sheet to form the thermal fusion by pressing and heating between the convex portion of the roll and the other roll with the second nonwoven fabric.

Moreover, this invention is a method of manufacturing the said surface sheet | seat in which the cavity is not formed between the 1st nonwoven fabric and the 2nd nonwoven fabric in the part which has a convex part, Comprising: The 1st nonwoven fabric containing a thermoextension fiber is a circumferential surface. The concave-convex shape of the first roll having the concave-convex shape and the concave-convex shape of the concave-convex shape of the first roll and the second roll having the concave-convex shape on the circumferential surface thereof is engaged. The second nonwoven fabric is joined with the second nonwoven fabric in a state of being held in the state of the above, and is heated and pressurized between the convex portion of the first roll and the other roll together with the second nonwoven fabric to form the thermal fusion portion, and then subjected to heat treatment to perform the thermal extension. It is to provide a method for producing a surface sheet to extend the sex.

In addition, the present invention provides a method for producing the surface sheet in which the cavity is not formed between the first nonwoven fabric and the second nonwoven fabric in the portion having the convex portion, wherein the first nonwoven fabric containing the thermostretchable fiber has a circumferential surface. It adsorb | sucks to the circumferential surface of the roll which has an uneven shape, and has a suction hole in a recessed part, and joins with a 2nd nonwoven fabric in the state hold | maintained at the circumferential surface of the said roll, and it is different from the convex part of the said roll with said 2nd nonwoven fabric. The present invention provides a method for producing a surface sheet, which is heated and pressurized with a roll to form the heat-sealed portion, and then subjected to heat treatment to extend the thermal stretchability.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated, referring drawings based on the preferable embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS The perspective view which shows one Embodiment of the surface sheet for absorbent articles of this invention.

The surface sheet 10 shown in FIG. 1 is used for the skin contact surface of absorbent articles, such as a disposable diaper, a sanitary napkin, a panty liner (a lower sheet), and an incontinence pad.

The surface sheet 10 is composed of a first nonwoven fabric 1 and a second nonwoven fabric 2 stacked on each other. The first nonwoven fabric 1 forms a surface (skin contact surface) facing the wearer's skin side in the surface sheet 10, and the second nonwoven fabric 2 faces the absorber side in the surface sheet 10. The facing surface (non-skin contact surface) is formed.

The first nonwoven fabric 1 and the second nonwoven fabric 2 are partially heat-sealed, whereby a plurality of heat-sealed portions 4 are formed on the surface sheet 10. In the first nonwoven fabric 1, portions other than the heat-sealed portion 4 protrude toward the skin side of the user to form a plurality of convex portions 5.

As shown in FIG. 1, the convex portions 5 and the heat-sealed portions 4 are arranged so as to form a single row alternately in the X direction, which is parallel to the surface of the surface sheet 10. It is formed in multiple rows in the Y direction orthogonal to the X direction. The convex part 5 and the heat-sealed part 4 in the mutually adjacent row are shift | deviated and arrange | positioned in the X direction, respectively, More specifically, the half pitch shift is arrange | positioned.

The X direction in the surface sheet 10 of this embodiment is the same direction as the orientation direction (fiber orientation direction) of the constituent fiber of the 1st nonwoven fabric 1. Usually, a nonwoven fabric has the fiber generally oriented in the flow direction (machine direction) of a wave and a nonwoven fabric at the time of manufacture. The fiber orientation direction of the first nonwoven fabric 1 and the like is the same direction as the flow direction (machine direction) of the wave or nonwoven fabric at the time of its manufacture, but when the flow direction at the time of manufacture is unclear, the convex portion 5 and The direction in which more fibers are oriented among the direction in which the heat formed by the heat-sealed portion 4 extends and the direction orthogonal thereto is set as the fiber orientation direction.

In the surface sheet 10 of the present embodiment, the orientation direction (fiber orientation direction) of the constituent fibers of the second nonwoven fabric 2 is also the X direction, and the fiber orientation direction (X direction) of the first nonwoven fabric is the surface sheet 10 ) And the flow direction (refer FIG. 5) of each of the 1st nonwoven fabric 1 and the 2nd nonwoven fabric 2 in the manufacturing process of the same. In addition, it is preferable that the fiber orientation direction (X direction) of the first nonwoven fabric coincides with either the longitudinal direction (front and rear direction) of the absorbent article and the direction orthogonal thereto when the surface sheet 10 is embedded in the absorbent article. It is particularly desirable to match the longitudinal direction of the absorbent article.

As for the surface sheet 10 of this embodiment, as a whole, the surface by the side of the 2nd nonwoven fabric 2 is substantially flat, and the unevenness | corrugation with large ups and downs is formed in the surface by the side of the 1st nonwoven fabric 1 side.

The inside of the convex part 5 in the surface sheet 10 is filled with the constituent fiber of the 1st nonwoven fabric 1, as shown in FIG. That is, the cavity is not formed between the 1st nonwoven fabric 1 and the 2nd nonwoven fabric 2 in the part which has the convex part 5 of the surface sheet 10. FIG. The cavity mentioned here is a cavity which arises between the 1st nonwoven fabric 1 and the 2nd nonwoven fabric 2, For example, the space | gap which cannot be easily confirmed when visually observing the cross section of the surface sheet 10, or a 1st The voids about the same or several times as the voids between the fibers present in the nonwoven fabric 1 and the second nonwoven fabric 2 are not included in the voids herein.

In the surface sheet 10 of the present embodiment, the cavity is not formed between the first nonwoven fabric 1 and the second nonwoven fabric 2 in the portion having the convex portion 5, so that the first nonwoven fabric 1 The transfer of the liquid from the second nonwoven fabric 2 to the second nonwoven fabric 2 is more excellent.

As for the surface sheet 10, at least one convex part 5 shows one end part XE or both ends XE and XE in the fiber orientation direction (X direction) of the 1st nonwoven fabric 1, as shown in FIG. ) Has a small fiber portion 5b having a lower fiber density than the fiber density of the central portion 5a in the fiber orientation direction (X direction).

The convex part 5 has the coarse fiber part 5b, and the gradient of a large fiber density between the small fiber part 5b with low fiber density and the part located in the heat-sealing part 4 or its vicinity is shown. Is formed, and the liquid supplied on the surface sheet 10, in particular, the liquid flowing into the concave portion between the convex portions 5, flows into the first nonwoven fabric 1 in a path as shown in FIG. 4 (a). Transition smoothly to the heat-sealed portion 4 or a portion located in the vicinity thereof. Then, the liquid transferred to the heat-sealed portion 4 or a portion located in the vicinity thereof smoothly moves to the second nonwoven fabric 2 and further to an absorber (not shown) disposed thereunder. In particular, by matching the fiber orientation direction (X direction) of the first nonwoven fabric 1 with the longitudinal direction of the absorbent article, menstrual blood flowing along the width direction of the product can be quickly absorbed in the small fiber portion 5b, thereby producing the product. Lateral glands from the side can be prevented.

In addition, highly viscous substances such as menstrual blood and thin stools, which are relatively high in viscosity, are blown into the small fiber portion 5b having a low fiber density and can be quickly separated from the wearer's skin.

Further, since the fiber density of the central portion 5a in the X direction of the convex portion 5 is relatively high, the parietal portion of the convex portion 5 is relatively smooth, so that the coefficient of friction with the skin is relatively low. It has a smooth texture.

The convex part 5 which has the small fiber part 5b in the one end part XE or the both ends XE and XE in the fiber orientation direction (X direction) of the 1st nonwoven fabric 1 has the effect as mentioned above. It is preferable that it is 10% or more of the total number of the convex parts 5 of the surface sheet 10 from a viewpoint to make it appear reliably, It is more preferable that it is 20-50%, More preferably, it is 30-50%.

FIG. 3: is a figure which shows the cross section along the Y direction in the convex part same as the convex part 5 shown in FIG.

The convex part 5 shown to FIG. 2 and FIG. 3 is the center part 5a and the small fiber part of the fiber orientation direction (X direction) of the 1st nonwoven fabric 1 as can be seen from the contrast of FIG. The difference in fiber density of (5b) is larger than the difference in fiber density between the center portion 5c and the both ends YE and YE in the direction (Y direction) perpendicular to the fiber orientation direction.

For this reason, the liquid supplied on the surface sheet 10 is blown into the surface sheet 10 also by the path | route as shown in FIG.4 (b), and the 1st nonwoven fabric 1 is located in the vicinity of the crown of the convex part 5. By the gradient of the fiber density toward the heat-sealed portion 4 or the portion located in the vicinity, the transition to the heat-sealed portion 4 or the portion located in the vicinity thereof is smoothly performed. Then, the liquid transferred to the heat-sealed portion 4 or a portion located in the vicinity thereof smoothly moves to the second nonwoven fabric 2 and further to an absorber (not shown) disposed thereunder.

Whether the first nonwoven fabric 1 has the small fiber portion 5b at one end XE or both ends XE, XE of the convex portion 5 in the fiber orientation direction (X direction), and the first nonwoven fabric The difference in fiber density between the central portion 5a and the small fiber portion 5b in the fiber orientation direction (X direction) of (1) is the central portion 5c and both ends in the direction (Y direction) orthogonal to the fiber orientation direction. Whether or not the difference in fiber density from (YE, YE) is greater than that is observed in the X and Y directions by observing the cross section in the X and Y directions through the center point of the convex portion in the planar view of the surface sheet. It can be determined by looking at the state of the center and the end of the fiber is filled. In the state in which the fibers at the center and the end in the X and Y directions are respectively filled, a portion up to about 2/3 from the height direction in the convex portion is divided into three or five portions in the X or Y direction, and the center and both ends thereof. It is preferable to look at and determine the state in which the fiber at the part located in the whole is filled.

In the convex part 5 shown to FIG. 2 and FIG. 3, the fiber density of the both ends YE and YE in the direction (Y direction) orthogonal to the fiber orientation direction of the 1st nonwoven fabric 1 is the center part 5c of the said direction. It is more than the fiber density of. Therefore, the drawability of the liquid by the path | route as shown in FIG.4 (b) improves further.

The both ends YE, YE of the fiber density of the both ends YE and YE in the direction (Y direction) orthogonal to the fiber orientation direction of the 1st nonwoven fabric 1 is more than the fiber density of the center part 5a of the said direction. It is meant that the fiber density of) and the fiber density of the center portion 5a are equal, or the fiber density of the both ends YE and YE is larger than the fiber density of the center portion 5a. From the viewpoint of the blowing ability of the liquid, it is preferable that the fiber density of the one end or both ends YE and YE is larger than the fiber density of the central part 5c.

Various well-known nonwoven fabrics can be used as the 1st and 2nd nonwoven fabrics 1 and 2, For example, the air which formed the heat-fusion point of fibers between the fiber waves obtained by the card method by the air through method. Heat-roll nonwoven fabric, heat-embossed nonwoven fabric, spunbond nonwoven fabric, meltblown nonwoven fabric, spunlace nonwoven fabric, needle punch nonwoven fabric, airlaid, through which the heat-sealing points of fibers are formed by the heat-roll method on the fiber wave obtained by the card method Various nonwoven fabrics, such as a nonwoven fabric and resin bond nonwoven fabric, can be used. In the surface sheet 10 of this embodiment, the nonwoven fabric which does not expand and contract substantially is used as a 1st and 2nd nonwoven fabric.

As the 1st nonwoven fabric 1, the said air through nonwoven fabric, the spunlace nonwoven fabric, the needle punch nonwoven fabric, the airlaid nonwoven fabric, resin bond which are comparatively bulky from the viewpoint of the formation of the convex part 5 which does not have a cavity inside. It is preferable to use a nonwoven fabric, and it is particularly preferable to use the air-through nonwoven fabric from the viewpoint of good skin feel and excellent heat sealing property with the second nonwoven fabric.

The second nonwoven fabric is particularly preferably the heat-roll nonwoven fabric, the heat embossed nonwoven fabric, the spunbond nonwoven fabric, the meltblown nonwoven fabric, the spunlace nonwoven fabric and the like from the viewpoint of increasing the fiber density to facilitate the movement of the liquid from the first nonwoven fabric 1. Used.

As the constituent fibers of the first and second nonwoven fabrics, heat-sealable fibers, particularly fibers made of a thermoplastic polymer material, are preferably used. Examples of the thermoplastic polymer material include polyolefins such as polyethylene and polypropylene, polyesters such as polyethylene terephthalate, polytrimethylene terephthalate and polybutylene terephthalate, and polyamides. Moreover, the sheath type | mold composite fiber and side-by-side composite fiber which consist of a combination of these thermoplastic polymer materials can also be used suitably. The first and second nonwoven fabrics may include, as constituent fibers, fibers which do not have heat sealability (for example, cotton fibers, etc.) in addition to the heat sealable fibers.

The first nonwoven fabric 1 is preferably bulky in view of the formability of the convex portion 5 having no cavity therein and from the viewpoint of rapidly absorbing the liquid and rapidly transferring the liquid to the second nonwoven fabric 2. It is preferable that the fiber density is less than 0.075 g / cm <2>, and it is more preferable that it is 0.05 g / cm <2> or less.

In addition, the first nonwoven fabric 1 is soft and rich in cushioning properties, and forms a convex portion 5 that is easily deformed in accordance with the movement of the skin, from the viewpoint of reducing friction with the skin and reducing irritation to the skin. The average fineness of the constituent fibers is preferably 4.4 dtex or less, more preferably 3.3 dtex or less.

The second nonwoven fabric 2 needs to have a fiber density higher than the fiber density of the first nonwoven fabric 1 from the viewpoint of extracting the liquid from the first nonwoven fabric 1 by capillary force. More specifically, the fiber density is preferably 0.075 g / cm 2 or more, and more preferably 0.1 g / cm 2 or more.

Moreover, since the 2nd nonwoven fabric 2 needs to provide cushioning property to a surface sheet, and to make fiber density higher than the 1st nonwoven fabric 1, it is preferable that the average fineness of the constituent fiber is less than 3.3 dtex, and it is 2.2 dtex. It is more preferable that it is the following.

In view of more reliably expressing one or two or more of the effects described above, the surface sheet 10 preferably has the following configuration.

The thickness H (see FIG. 2) of the portion having the convex portion 5 of the surface sheet 10 is preferably 0.6 mm or more, in particular 1.0 mm or more, and the thickness h of the heat-sealed portion 4 (FIG. It is preferable that it is 0.3 mm or less, especially 0.2 mm or less, and it is preferable that ratio (H / h) of these thickness is 2 or more, especially 3 or more.

The number of the convex portions 5 (with or without the small fiber portion 5b) per 100 cm 2 of the surface sheet 10 is preferably 250 to 2000, particularly 500 to 1500. It is also preferable that the convex portions having the small fiber portions 5b are dispersed and present in the surface sheet 10, and the number per 100 cm 2 is preferably 250 or more, particularly 500 or more.

The bottom dimension A (see FIG. 1) in the X direction of the convex portion 5 is preferably 0.5 to 5.0 mm, particularly 1.0 to 4.0 mm. The bottom dimension B (refer FIG. 1) of the convex part 5 in the Y direction is 1.0-10 mm, It is preferable that it is especially 2.0-7.0 mm.

The ratio of the bottom dimension (A) in the X direction to the bottom dimension (B) in the Y direction (bottom dimension (A): bottom dimension (B)) is 1: 1 to 1:10, especially 1: 2 to It is preferable that it is 2: 5. The bottom area (bottom dimension (A) X bottom dimension (B)) of the convex part 5 is 0.5-50 mm <2>, It is preferable that it is 2-20 mm <2> especially.

The heat-sealed portion 4 preferably has a dimension C in the X direction (see FIG. 1) of 0.1 to 2 mm, particularly 0.2 to 1.0 mm, and a dimension D in the Y direction (see FIG. 1) of 0.2 to 5.0. It is preferable that it is mm, especially 0.5-3.0 mm.

Next, the preferable manufacturing method of the surface sheet 10 mentioned above is demonstrated with reference to FIG.

In the method of the first embodiment, as the first nonwoven fabric 1, a nonwoven fabric containing an eccentric core sheath type composite fiber is used. The eccentric core sheath-type composite fiber has a core material biased in the cross section of the fiber, and when heat is applied, crimp is generated due to a difference in shrinkage rate between the core material and the sheath material. Since the crimped eccentric core sheath-type composite fiber has a three-dimensional structure, the probability of mutual contact between fibers in the fiber wave formed after the card process decreases, and since the base material, which is a heat-sealing component, is biased, the cross-sectional direction of the fiber As a result, it is possible to reduce the heat fusion point because a cotton containing a lot of vinegar components that are easy to be thermally fused with other fibers and a surface having a small amount of vinegar that is difficult to be heat-sealed is formed, and exhibits excellent volume recoverability due to volume recovery treatment by hot air. . Therefore, it is suitable for formation of the convex part 5 which does not have a cavity.

As the nonwoven fabric containing the eccentric core sheath composite fiber, the air through nonwoven fabric, the heatroll nonwoven fabric, the heat embossing nonwoven fabric, the airlaid nonwoven fabric, the resin bond nonwoven fabric, and the like are preferably used.

As the eccentric core sheath composite fiber, a composite fiber composed of two kinds of thermoplastic polymer materials is suitably used. Examples of the thermoplastic polymer material include polyolefins such as polyethylene and polypropylene, polyesters such as polyethylene terephthalate, polytrimethylene terephthalate and polybutylene terephthalate, and polyamides.

As the resin combination of the core part and the core part, a combination in which the core part is polyester such as polyethylene terephthalate, polytrimethylene terephthalate and polybutylene terephthalate and the super part polyethylene, or the combination in which the core part is polypropylene and the super part polyethylene is Is a ethylene-propylene random copolymer, and a combination in which the hyperaddition polyethylene is mentioned. It is preferable that the ratio of the eccentric cardiac composite fiber in a 1st nonwoven fabric is 50-100%, 75-100% is more preferable, It is further more preferable that it is 100%. As fibers other than the eccentric core sheath type composite fiber, the heat-sealable resin, cotton, etc. which consist of a single thermoplastic polymer material can be mixed.

In the method of the first embodiment, as shown in FIG. 5, the first nonwoven fabric 1 extracted from the roll-shaped fabric (not shown) is subjected to hot air using a heat-treating heat treatment apparatus 6 of the air through type. Perform volume recovery. In the heat treatment apparatus 6 shown in FIG. 5, heat treatment by hot air is performed on the nonwoven fabric conveyed on the circumferential surface of the drum 61. The circumferential surface of the drum 61 is made of a breathable material such as punching metal and wire mesh, and the upper portion of the drum 61 is covered with a hood 62. In the heat treatment apparatus 6, hot air is blown from the hood 62 toward the drum 61, and the injected hot air is sucked into the drum 61 through the nonwoven fabric 1. The volume recovery treatment by the hot air is preferably carried out by spraying the hot air having a melting point of -50 ° C or more at a temperature less than the melting point of the eccentric core sheath-type composite fiber to the nonwoven fabric by an air through method for 0.3 to 3 seconds. Melting | fusing point of the eccentric core sheath type composite fiber here is melting | fusing point of supercomponent resin among the polymer which comprises a core part and a sheath part. For example, when the constituent of the eccentric core sheath-type composite fiber is polyethylene, it is preferable to perform a recovery process with hot air of 90 to 110 ° C with respect to the melting point of the polyethylene of about 125 ° C.

Subsequently, the first nonwoven fabric 1 whose volume has been increased (recovered) by the volume recovery process is engaged with the uneven shape of the first roll 11 and the first roll 11 whose circumferential surface is in the uneven shape. The nonwoven fabric 1 is concave-convex by putting the concave-convex shape in the shape into engagement with the second roll 12 having the circumferential surface.

6, the enlarged view of the main part of the 1st roll 11 is shown. The first roll 11 is formed in a roll shape by combining a plurality of spur gears 11a, 11b, ... having a predetermined tooth width. The tooth width of each gear determines the dimension of the Y direction in the convex part 5 of the surface sheet 10. Neighboring gears are combined so that the pitches of the teeth are shifted by half pitch. As a result, the circumferential surface of the first roll 11 has an uneven shape.

A suction hole 13 is formed in the tooth groove portion of each gear in the first roll 11. This tooth groove part corresponds to a recessed part among uneven | corrugated shapes in the peripheral surface of the 1st roll 11. The suction hole 13 passes through a suction source (not shown) such as a blower or a vacuum pump, and suction is performed between the engaging portion of the first roll and the second roll to the confluence portion of the second nonwoven fabric 2. To be controlled. Therefore, the nonwoven fabric 1 which is uneven | corrugated by the engagement of the 1st roll 11 and the 2nd roll 12 adheres to the 1st roll circumferential surface by the suction force by the suction hole 13, and the uneven | corrugated molded part The state is maintained. As shown in FIG. 6, since the convex parts of the gears adjacent to each other of the roll 11 are shifted by half pitch, the shear force which tears the 1st nonwoven fabric 1 in the width direction between each gear is produced, One small fiber part 5b becomes easy to produce. By forming the space | gap G between the convex parts, and setting the width | variety of the said space | gap G suitably, control of the fiber density of the small fiber part mentioned above is possible. In other words, if the void G is smaller, a larger shear force is generated, and thus, the fiber density of the small fiber portion 5b is smaller, and if the larger gap is generated, the shear force generated is smaller, so that the fiber density of the small fiber portion 5b is larger.

And as shown in FIG. 5, the 2nd nonwoven fabric 2 is joined to the 1st nonwoven fabric 1 in the state which hold | maintained and hold | maintained the 1st nonwoven fabric 1 to the circumferential surface of the 1st roll 11, The overlap is pressed between the first roll 11 and the anvil roll 15. At this time, both the first roll 11 and the anvil roll 15 or only the anvil roll 15 are heated to a predetermined temperature. For this reason, it is located on the convex part in the 1st roll 11, ie, on the tooth of each gear. The 1st nonwoven fabric 1 and the 2nd nonwoven fabric 2 are heated and pressurized, the heat-sealed part 4 is formed, and the surface sheet 10 of the structure mentioned above is obtained.

According to the manufacturing method of this embodiment, a cavity is formed between the 1st nonwoven fabric 1 and the 2nd nonwoven fabric 2 in the part which has the convex part 5 by volume recovery of a 1st nonwoven fabric by hot air, The surface sheet 1 which is not present can be manufactured efficiently. When the first nonwoven fabric 1 is unevenly shaped, the first nonwoven fabric 1 extends in the fiber orientation direction (flow direction) and in a direction orthogonal thereto. The convex part formed in the nonwoven fabric 1 has a sparse fiber density in one or both parts on the left and right sides in the flow direction of the nonwoven fabric 1. Thus, the surface sheet 10 having the small fiber portion 5b having a low fiber density is obtained.

Next, another method (method of the second embodiment) of manufacturing the above-described surface sheet 10 will be described with reference to FIG.

The method of 2nd Embodiment demonstrates a different point from the method of 1st Embodiment, and attaches | subjects the same code | symbol about the same point and abbreviate | omits the description. The point which is not specifically described is the same as that of the method of 1st Embodiment, and the description about the method of 1st Embodiment applies suitably.

In the method of the second embodiment, the first nonwoven fabric 1 after the volume recovery treatment by hot air is adsorbed onto the peripheral surface of the roll 11 having a circumferential surface and having suction holes in the recess. The first nonwoven fabric 1 and the second nonwoven fabric 2 are joined to each other while the first nonwoven fabric 1 is suction-held on the circumferential surface of the roll 11. The overlap is pressurized and heated between the convex portion of the roll 11 and the anvil roll 15 to form the heat-sealed portion 4. In this manner, the surface sheet 10 having the above-described configuration is obtained. As the roll 11 in the method of the second embodiment, the same rolls as the first roll 11 in the method of the first embodiment can be used.

Next, another method (method of the third embodiment) of manufacturing the surface sheet 10 described above will be described with reference to FIG. 8.

About the method of 3rd Embodiment, the point different from the method of 1st Embodiment is demonstrated, and the same code | symbol is attached | subjected about the same point and the description is abbreviate | omitted. The point which is not specifically described is the same as that of the method of 1st Embodiment, and the description about the method of 1st Embodiment applies suitably.

In the method of 3rd Embodiment, the nonwoven fabric which consists of a thermotensile fiber is used as a 1st nonwoven fabric.

As the thermally stretchable fiber, a fiber composed of the first resin component and the second resin component having different orientation indices can be used. Among these, the first resin component is a component that maintains the strength of the composite fiber, and the second resin component is a component that exhibits heat sealability. The orientation index of the first resin component is preferably 40% or more, more preferably 50% or more. On the other hand, the orientation index of the second resin component is preferably 25% or less, more preferably 20% or less. An orientation index becomes an index of the degree of orientation of the polymer chain of resin which comprises a fiber. Therefore, when the orientation indexes of the first resin component and the second resin component are each of the above values, the thermally stretchable composite fiber is elongated by heating. In particular, it is preferable that the thermally stretchable composite fiber is manufactured by a high speed melt spinning method.

Moreover, the nonwoven fabric containing a thermotensile fiber is obtained by forming the heat-fusion point of fibers, etc. by the air through method in the fiber wave obtained by the card method, for example. It is preferable that the ratio of the thermally stretchable fiber in a 1st nonwoven fabric is 50 to 100%, 75 to 100% is more preferable, It is still more preferable that it is 100%.

In the method of 3rd Embodiment, the shape which engages the uneven shape of the 1st roll 11 and the 1st roll 11 in which the circumferential surface is the uneven | corrugated shape for the 1st nonwoven fabric 1 which consists of stretchable fiber is carried out. The nonwoven fabric 1 is concave-convex into the engaging portion with the second roll 12 having the concave-convex shape formed on the circumferential surface. Then, the first nonwoven fabric 1 and the second nonwoven fabric 2 are joined to each other under the condition that the first nonwoven fabric 1 after the uneven shape is continuously sucked and held on the circumferential surface of the first roll 11, and the overlapping is performed. This is pinched between the 1st roll 11 and the anvil roll 15, and the 1st nonwoven fabric 1 in which the heat-sealing part 4 was formed is obtained. In the first nonwoven fabric at this stage, a cavity is formed between the first nonwoven fabric 1 and the second nonwoven fabric 2 in the portion having the convex portion 5.

Then, the first nonwoven fabric 1 is subjected to heat treatment to elongate the thermally stretchable fibers in the first nonwoven fabric 1, and the inside of the cavity is filled with the thermally stretchable fibers. In this way, the surface sheet 10 of the above-mentioned structure is obtained.

The heat treatment apparatus 6 shown in FIG. 8 is an air through drum type heat treatment apparatus similar to the heat treatment apparatus 6 used in the first embodiment. When the heat-stretchable fiber composite fiber of the present invention is a sheath type, the core component is polypropylene, and the super-component is high density polyethylene, the heat treatment for stretching the heat-stretchable fiber has a hot air temperature of 50 to 120 ° C., especially 70 to 100 ° C. It is preferable that it is 10 to 500 second, and it is preferable that it is especially 20 to 200 second.

It is a perspective view which shows 4th embodiment of the surface sheet for absorbent articles of this invention. The surface sheet 10A of 4th Embodiment is used for the skin contact surface of absorbent articles, such as a disposable diaper, a sanitary napkin, a panty liner (a lower sheet), and an incontinence pad.

The surface sheet 10A is composed of a first nonwoven fabric 1 and a second nonwoven fabric 2 stacked on each other, and an aggregate 3 of long fibers disposed between these nonwoven fabrics 1 and 2.

The first nonwoven fabric 1 forms a surface (skin contact surface) facing the wearer's skin side in the surface sheet 10A, and the second nonwoven fabric 2 faces the absorber side in the surface sheet 10 ( Non-skin abutting surface).

The first nonwoven fabric 1 and the second nonwoven fabric 2 are partially heat-sealed, whereby a plurality of heat-sealed portions 4 are formed on the surface sheet 10A. In the first nonwoven fabric 1, portions other than the heat-sealed portion 4 protrude toward the skin side of the user to form a plurality of convex portions 5.

As shown in FIG. 9, the convex part 5 and the heat-sealing part 4 are arrange | positioned so that one row may be alternated in the X direction which is one direction parallel to the surface of the surface sheet 10A, and such rows are the said It is formed in multiple rows in the Y direction orthogonal to the X direction. The convex portions 5 and the heat-sealed portions 4 in the rows adjacent to each other are arranged to be shifted in the X direction, and more specifically, to be arranged at a half pitch shift.

In addition, the X direction in the surface sheet 10A of this embodiment is each of the 1st nonwoven fabric 1, the 2nd nonwoven fabric 2, and the aggregate 3 of long fibers in the manufacturing process of 10A of surface sheets. It coincides with the flow direction of the strip-shaped fabrics 1A to 3A (see Fig. 11), and coincides with the longitudinal direction of the absorbent article when the surface sheet 10A is embedded in the absorbent article or the direction orthogonal thereto. In addition, the X direction in the surface sheet 10A of this embodiment is consistent with the orientation of the fiber in each of the 1st nonwoven fabric 1, the 2nd nonwoven fabric 2, and the aggregate 3 of long fibers. Moreover, as for the surface sheet 10A as a whole, the surface by the side of the 2nd nonwoven fabric 2 is substantially flat, and the unevenness | corrugation with large relief is formed in the surface by the side of the 1st nonwoven fabric 1 side.

An aggregate 3 of long fibers is disposed inside the convex portion 5 of the surface sheet 10A. The aggregate of long fibers 3 is a strip-shaped fabric 3A in which the long fibers are oriented in the longitudinal direction at the time of manufacturing the surface sheet 10A, and the strip-shaped fabric 1A of the first nonwoven fabric and the second nonwoven fabric 2 are formed. The long fibers 31 constituting the aggregate 3 are oriented in the X direction in the planar view of the surface sheet 10A. The individual long fibers 31 constituting the aggregate 3 of long fibers span the entire length of the surface sheet 10A in the X direction, and the plurality of heat-sealed portions in the X direction of the surface sheet 10A. It has a length over (4). The long fiber 31 preferably has a length that spans the five or more heat-sealed portions 4 in the X direction, and more preferably has a length that spans the ten or more heat-sealed portions 4.

In the present invention, when the fiber length is measured by the average fiber length measuring method (C method) of JIS L1015, the fiber is preferably 70 mm or more, more preferably 80 mm or more, and even more preferably 100 mm or more. Say. However, when the total length of the direction (X direction) in which the heat | fever of the convex part 5 and the heat-sealed part 4 in the surface sheet 10A extends is less than 100 mm, the 1st nonwoven fabric 1 and the 2nd If most of the fibers disposed between the nonwoven fabrics 2, for example, 90% or more extend over the entire length of the surface sheet, the fibers are assumed to be long fibers. The long fibers used in the present invention are generally called continuous filaments. In addition, continuous filament bundles are generally called tow. Therefore, the long fiber in this invention is a concept containing a continuous filament. Moreover, the long fiber in this invention is also cut | disconnected in the vicinity of the heat-sealing part 4 so that the aggregate 3 of long fiber may not exist like the surface sheet 10B shown in FIG. do.

The aggregate 3 of the long fibers is fixed between the first nonwoven fabric 1 and the second nonwoven fabric 2 in the heat-sealed portion 4 in the X direction. Fastening of both ends of the aggregate 3 of long fibers is performed by heat-sealing the first nonwoven fabric 1 and the second nonwoven fabric 2 with the aggregate 3 interposed therebetween. In the heat-sealed portion 4 in which the first nonwoven fabric 1 and the second nonwoven fabric 2 are heat-sealed, the components of the constituent fibers of the first nonwoven fabric 1 and the constituent fibers of the second nonwoven fabric 2 are constructed. It is preferable that the components are in direct contact with each other and thermally fused, but the constituent fibers of the aggregate of long fibers 3 are thermally fused together, whereby the constituent fibers of the first nonwoven fabric 1 and the second nonwoven fabric 2 are constructed. The fibers may be heat-sealed respectively.

The aggregate 3 of the long fibers is the first nonwoven fabric 1 and the second nonwoven fabric 2 between the heat-sealed portions 4 and 4 adjacent to each other in the X direction of the surface sheet 10A. The long fibers 31 constituting the aggregate 3 are not bonded to each other. The plurality of long fibers 31 constituting the aggregate 3 are approximately in the space formed between the first nonwoven fabric 1 forming the outer surface of the convex portion 5 and the second nonwoven fabric 2 having a flat shape. It is spread throughout.

As shown in FIG. 10, the long fiber 31 located in the inside of the convex part 5 has convex curve shape in the protrusion direction (upper part in FIG. 10) of the convex part 5, More specifically, As shown in FIG. 10, when viewed from the Y direction, it has formed the shape of the mountain shape which has an arcuate top part. The long filament 31 which forms a curved shape has a part which is furthest from the 2nd nonwoven fabric 2 in the substantially center part between the heat-sealing parts 4 and 4 in the X direction, and both heat-sealing parts 4, 4) The distance from the 2nd nonwoven fabric 2 is decreasing gradually toward each. As shown in FIG. 10, among the long fibers 31 which form a curved shape, the long fiber 31a arrange | positioned in the vicinity of the 1st nonwoven fabric 1 has a large convexity, and is arrange | positioned in the vicinity of the 2nd nonwoven fabric 2 The long fiber 31b is small in convexity, and the long fiber located in between is small in convexity toward the 2nd nonwoven fabric side from the 1st nonwoven fabric 1 side.

As the 1st and 2nd nonwoven fabric, the thing similar to the 1st and 2nd nonwoven fabric of the surface sheet 10 can be used. The same applies to preferred nonwoven fabrics. Also in the surface sheet 10A of 4th Embodiment, the nonwoven fabric which does not expand and contract substantially is used as a 1st and 2nd nonwoven fabric.

As the first nonwoven fabric 1, the air through nonwoven fabric, the heat embossed nonwoven fabric, the airlaid nonwoven fabric, the needle punch nonwoven fabric and the like are particularly preferably used from the viewpoint of the skin feel.

As the second nonwoven fabric, the heat transfer nonwoven fabric, the heat embossed nonwoven fabric, the spunbond nonwoven fabric, the meltblown nonwoven fabric from the viewpoint of increasing the fiber density to easily move the liquid from the first nonwoven fabric 1 or the aggregate of long fibers 3 And spunlace nonwoven fabrics are particularly preferably used.

The constituent fibers of the first and second nonwoven fabrics are the same as those of the surface sheet 10 of the first embodiment.

It is preferable that the surface of the first nonwoven fabric 1 is smooth from the viewpoint of softening the surface touching the skin, and is preferably composed of fibers having a low fineness. On the other hand, it is preferable that the first nonwoven fabric 1 has a coarse fiber density compared to the layer composed of the long fibers 31 from the viewpoint of quickly obtaining the liquid and preventing the excretion such as menstrual blood and urine from leaking. It is preferable that the fineness of the constituent fibers is larger than that of the long fibers 31 interposed between the first and second nonwoven fabrics 1 and 2.

From the above point of view, the fineness of the constituent fibers of the first nonwoven fabric is preferably 1.0 to 8.0 dtex, and is preferably formed of crimped fibers in view of lower volume and higher fiber density. Do. It is preferable that a weighing is 5-50 g / m <2>.

It is preferable that the fineness of the long fiber 31 is 0.3-3.0 dtex. It is preferable that the purity of the constituent fiber of the second nonwoven fabric is 1.0 to 5.0 dtex, and the weighing is preferably 5 to 30 g / m 2.

As the long fibers 31 constituting the aggregate 3 of the long fibers, any of heat-sealable fibers and non-heat-sealable fibers can be used. In the heat-sealed portion as in the surface sheet 10A of the fourth embodiment, In the case where the long fiber 31 is interposed between the first and second nonwoven fabrics, the fiber is preferably heat-sealed from the viewpoint of increasing the bonding strength of the heat-sealed portion.

The heat-sealable fiber referred to here is one whose surface is melted or softened by heating, and can be bonded to the constituent fibers of the first nonwoven fabric and / or the second nonwoven fabric by the molten or softened component.

As a fiber which can be heat-sealed, the fiber which consists of a thermoplastic polymer material is used suitably. Examples of the thermoplastic polymer material include cellulose acetate, polyolefins such as polyethylene and polypropylene, polyesters such as polyethylene terephthalate, and polyamides. Moreover, the sheath type | mold composite fiber and side-by-side composite fiber which consist of a combination of these thermoplastic polymer materials can also be used suitably.

The aggregate 3 of the long fibers preferably contains 30 to 100% by weight, more preferably 50 to 100% by weight of the heat-sealing fibers in the aggregate 3.

Moreover, it is preferable that the aggregate 3 of long fiber is comprised mainly by the long fiber 31 which was crimped potentially finely. The crimped long fiber 31 can exist in the state which filled the long fiber 31 in the inside of the convex part 5, and can improve the cushioning property and the drawability of a liquid further. The crimped long fibers 31 are tensioned in a manufacturing facility to the extent that the crimps are fully stretched, and then the potential crimps in the convex portion 5 are thermally fused to the first nonwoven fabric 1 and the second nonwoven fabric 2. The long filaments 31 which have been expanded by the contraction contract and the hollow convex part 5 is obtained by the effect of filling the aggregates 3 of the long fibers between the first nonwoven fabric 1 and the second nonwoven fabric 2. Lose.

It is preferable that the aggregate 3 of long fibers is comprised mainly by hydrophilic long fiber.

The hydrophilic long fibers include both fibers which are inherently hydrophilic and fibers which are not inherently hydrophilic but are given hydrophilicity by being subjected to hydrophilic treatment. Preferably, it is a long fiber inherently hydrophilic, and a cellulose acetate, rayon, a lyocell, a tencel etc. are mentioned, for example. Especially preferred are cellulose acetates which are hydrophilic and heat-sealable. As cellulose acetate, it is preferable to use cellulose triacetate and / or cellulose diacetate.

It is preferable that the aggregate 3 of long fiber contains 30-100 weight% of hydrophilic long fiber in the said aggregate 3, and it is more preferable that 50-100 weight% is included.

In the convex part (the part which has convex part 5) of surface sheet 10A, hydrophilicity is high in order of the 1st nonwoven fabric 1, the aggregate of long fiber 3, and the 2nd nonwoven fabric 2 in order. It is preferable that it is done. By placing a gradient of hydrophilicity, excretion such as urine and menstrual blood can be smoothly transferred from the surface of the convex portion 5 to the aggregate of long fibers 3 and smoothly transferred to the second nonwoven fabric 2. Can be.

Moreover, in the convex part (part with the convex part 5) of 10 A of surface sheets, fiber density in order of the 1st nonwoven fabric 1, the aggregate of long fiber 3, and the 2nd nonwoven fabric 2 It is preferable that is made high. The excretion of urine and menstrual blood is smoothly transferred from the surface of the convex part 5 to the aggregate of long fibers 3 by the gradient of fiber density, and it is also smoothly transferred to the second nonwoven fabric 2. You can.

According to the surface sheet 10A of the fourth embodiment, since the long fibers 31 having a curved shape convex in the protruding direction of the convex portion 5 are arranged inside the convex portion 5, The convex portion 5 exhibits excellent cushioning properties, and the convex portion repeats compression and recovery following the movement of the skin in use of the absorbent article. Therefore, it is hard to irritate skin and the texture which touches skin is soft.

Moreover, since the convex part 5 and the heat-sealing part 4 are arrange | positioned in the aspect mentioned above, compared with the conventional thing in which the crown part of the convex part is formed continuously in one direction, it is difficult for a liquid to flow through the surface, and it helps to prevent liquid leakage. At the same time, the spot absorbency is also excellent. In addition, since the surface sheet has excellent flexibility in the surface direction and flexes flexibly in both the X and Y directions, the surface sheet can be used for articles or parts requiring improved flexibility and wearability.

In addition, since the long fibers constituting the aggregate of long fibers are oriented in one direction (X direction), capillary force is increased from the vicinity of the central portion of the convex portion 5 toward each of the heat-sealed portions 4 and 4, Therefore, the liquid which permeate | transmitted the 1st nonwoven fabric 1 flows smoothly along the orientation direction of the long fiber of the aggregate 3 of long fibers, and it transfers also to the 2nd nonwoven fabric 2 smoothly. Therefore, spot absorbency is further excellent.

In view of more reliably expressing one or more of the above-described effects, the surface sheet 10A preferably has the following configuration.

The thickness H (see FIG. 10) of the portion having the convex portion 5 of the surface sheet 10A is preferably 0.6 mm or more, particularly 1.0 mm or more, and the thickness h of the heat-sealed portion 4 (FIG. 10) is preferably 0.3 mm or less, in particular 0.2 mm or less, and it is preferable that the ratio (H / h) of these thicknesses is at least 2 or more, in particular 3 or more. The upper limit of the thickness H, the upper limit of the ratio H / h, and the lower limit of the thickness h are not particularly limited, but the thickness H is 3.0 mm or less, the ratio H / h is 30 or less, and the thickness h is It is preferable to set it as 0.1 mm or more.

The number of the convex portions 5 per 100 cm 2 of the surface sheet 10A is preferably 250 or more, particularly 500 or more.

The bottom dimension A (see Fig. 9) in the X direction of the convex portion 5 is preferably 0.5 to 5.0 mm, particularly 1.0 to 4.0 mm. The bottom dimension B (see Fig. 9) in the Y direction of the convex portion 5 is preferably 1.0 to 10 mm, particularly 2.0 to 7.0 mm.

The ratio of the bottom dimension (A) in the X direction to the bottom dimension (B) in the Y direction (bottom dimension (A): bottom dimension (B)) is 1: 1 to 1:10, especially 1: 2 to It is preferable that it is 2: 5. The bottom area (bottom dimension A x bottom dimension B) of the convex part 5 is 0.5-50 mm <2>, It is preferable that it is 2-20 mm <2> especially.

The heat-sealed portion 4 preferably has a dimension C (see Fig. 9) in the X direction of 0.1 to 2 mm, particularly 0.2 to 1.0 mm. It is preferable that the dimension D (refer FIG. 9) of a Y direction is 0.2-5.0 mm, especially 0.5-3.0 mm.

A preferred manufacturing method of the above-described surface sheet 10A will be described with reference to FIGS. 11 and 12.

First, as shown in FIG. 11, the strip | belt-shaped fabric 3A of the long fiber aggregate 31 is joined to the strip | belt-shaped fabric 1A of the 1st nonwoven fabric 1 continuously conveyed, and these circumferential surfaces are uneven | corrugated. The first nonwoven fabric 1 is engaged with the engaging portion of the first roll 11 and the second roll 12 having a concave-convex shape in a shape that engages with the concave-convex shape of the first roll. Unevenness of the fabric 1A

12, the enlarged view of the principal part of the 1st roll 11 is shown. The first roll 11 is formed in a roll shape by combining a plurality of spur gears 11a, 11b, ... having a predetermined tooth width. The tooth width of each gear determines the dimension in the Y direction at the convex portion 5 of the surface sheet 10A. Neighboring gears are combined so that the pitches of the teeth are shifted by half pitch. As a result, the circumferential surface of the first roll 11 has an uneven shape.

A suction hole 13 is formed in the tooth groove portion of each gear in the first roll 11. This tooth groove part corresponds to a recessed part among uneven | corrugated shapes in the peripheral surface of the 1st roll 11. The suction hole 13 passes through a suction source (not shown) such as a blower or a vacuum pump, and suction is performed between the engaging portion of the first roll and the second roll to the confluence portion of the second nonwoven fabric 2. To be controlled. Therefore, the 1st nonwoven fabric 1 uneven | corrugated by the engagement of the 1st roll 11 and the 2nd roll 12 adheres to the 1st roll circumferential surface by the suction force by the suction hole 13, and the unevenness | corrugation The embossed state is maintained. In this case, as shown in FIG. 12, when the predetermined space | gap G is formed between gears which adjoin mutually, the 1st nonwoven fabric 1 does not apply the cutting effect by unreasonable extension | strength force or uneven | corrugated engagement of a roll, without giving a 1st. The nonwoven fabric 1 is brought into close contact with the circumferential surface of the first roll 11.

And as shown in FIG. 11, the strip | belt-shaped fabric of the 2nd nonwoven fabric 2 was carried out in the state which hold | maintained and retained the original fabric 1A of the 1st nonwoven fabric 1 to the circumferential surface of the 1st roll 11 ( 2A) is overlapped and the overlap is pinched between the 1st roll 11 and the anvil roll 15. FIG. At this time, both the first roll 11 and the anvil roll 15 or only the anvil roll 15 are heated to a predetermined temperature. Thereby, it is located on the convex part in the 1st roll 11, ie, on the tooth of each gear. The fabric 1A of the first nonwoven fabric 1, the band-like fabric 3A of the aggregate of long fibers 3, and the fabric 2A of the second nonwoven fabric 2 are joined by heat fusion.

As the strip-shaped fabric 3A of the aggregate of long fibers, crimped long fibers are used as constituent fibers, and those long fibers are oriented in the longitudinal direction. Then, when the original fabric 3A is introduced into the engaging portion between the first roll 11 and the second roll 12, the original fabric 3A is greatly extended in the longitudinal direction, and the state is maintained. The first nonwoven fabric 1 and the second nonwoven fabric 2 are joined together by thermal fusion between the first roll 11 and the anvil roll 15. The fabric 3A of the aggregate 3 of the long fibers introduced in the stretched state between the first nonwoven fabric 1 and the second nonwoven fabric 2 passes between the first roll 11 and the anvil roll 15. After that, the stretched state is alleviated, whereby the long fibers constituting the fabric 3A contract and the volume of the long fibers present in the convex portion 5 increases. Thereby, as shown in FIG. 10, 10 A of surface sheets in which the convex part 5 was filled by the aggregate 3 of long fiber are obtained.

The elongation rate of the long fiber 31 or the fabric 3A of the aggregate in fixing the long fiber between the first nonwoven fabric 1 and the second nonwoven fabric 2 is 105 to 130%, particularly 110 to 120 It is preferable that it is%.

Here, the elongation rate of the long fiber or the original fabric 3A of the aggregate is determined by the following equation.

% Elongation of fabric (3A) = L ₂ / L ₁ × 100

(Wherein L ₁ is the length before the fabric is stretched, the length of the long fiber aggregate per unit weight cut in the process before the fabric stretching equipment in the manufacturing equipment, and L ₂ is the length after the fabric stretching equipment in the manufacturing equipment) Length of the long fiber aggregate per unit weight cut out in the process of).

As described above, the surface sheet according to the present invention is preferably used as the surface sheet of absorbent articles such as disposable diapers, sanitary napkins, panty liners, incontinence pads and the like. The absorbent article generally consists of a liquid permeable absorbent body disposed between a liquid permeable surface sheet, a liquid impermeable or liquid impermeable back sheet, and both sheets.

As mentioned above, although embodiment of the surface sheet of this invention and its manufacturing method was described, each invention is not limited to the said embodiment, It can change suitably.

For example, although the convex part 5 of the surface sheet shown in FIG. 1 or FIG. 9 is a square pyramid shape, the convex part 5 may be another shape, such as hemispherical shape. In addition, the degree to which the convex part 5 and the heat-sealing part 4 in the adjacent rows mutually shift | deviate to the X direction can respectively be made into arbitrary magnitude | sizes, such as 1/3 pitch and 1/4 pitch instead of 1/2 pitch. have.

In addition, although the convex part shown to FIG. 2 and FIG. 3 had the small fiber part 5b in the both ends of the fiber orientation direction of the 1st nonwoven fabric 1, you may have the small fiber part 5b only in one end part, One surface sheet 10 may have a mixture of the small fiber portion 5b at both ends and the small fiber portion 5b only at one end thereof. Moreover, the surface sheet which concerns on this invention may be arrange | positioned only in the part which opposes a part of skin contact surface of an absorbent article, for example, an excretory part. Moreover, although it is preferable that the convex part 5 which has the small fiber part 5b is distributed in the whole surface sheet, the convex part which has the small fiber part 5b may distribute only in the opposing part of the excretion part.

Moreover, the orientation direction of the long fiber of the aggregate 3 of long fiber may be Y direction of the surface sheet 10A, and the long fiber orientated in the X direction and the long fiber orientated in the Y direction can also be mixed.

BRIEF DESCRIPTION OF THE DRAWINGS The perspective view which shows one Embodiment of the surface sheet for absorbent articles of this invention.

FIG. 2 is an enlarged cross-sectional view showing an enlarged cross section along the X direction of the convex portion having the small fiber portion in the surface sheet shown in FIG. 1. FIG.

3 is an enlarged cross-sectional view showing an enlarged cross section along the Y direction of the convex portion having the small fiber portion in the surface sheet shown in FIG. 1.

(A) and (b) are each a schematic diagram explaining the effect of the surface sheet for absorbent articles of this invention, (a) is a cross section corresponding to FIG. 2, (b) is a cross section corresponding to FIG. It is a figure which shows.

Fig. 5 is a schematic view showing the first embodiment of the method for producing the surface sheet for absorbent article of the present invention.

FIG. 6 is an enlarged view of an essential part of the first roll in FIG. 5.

Fig. 7 is a schematic diagram showing a second embodiment of the method for producing the surface sheet for absorbent article of the present invention.

8 is a schematic view showing a third embodiment of the method for producing the surface sheet for absorbent article of the present invention.

It is a perspective view which shows 4th embodiment of the surface sheet for absorbent articles of this invention.

FIG. 10 is an enlarged cross-sectional view showing an enlarged cross section along the X direction of the surface sheet shown in FIG. 9.

It is a schematic diagram which shows an example of the manufacturing method of the surface sheet shown in FIG.

12 is an enlarged view of a main part of the first roll in FIG. 10.

It is sectional drawing (corresponding to FIG. 10) which shows 5th Embodiment of the surface sheet for absorbent articles of this invention.

Claims (20)

A surface sheet used for the skin abutment surface of an absorbent article, The first nonwoven fabric and the second nonwoven fabric stacked on each other are partially heat-sealed to form a heat-sealed portion, In the first nonwoven fabric, portions other than the heat-sealed portion protrude toward the wearer's skin side to form a plurality of convex portions, The convex portions and the heat-sealed portions are alternately arranged in one row, and the rows are arranged in multiple rows; The surface on the second nonwoven side of the surface sheet is substantially flat, and the inside of the convex portion is composed of a first nonwoven fabric or an aggregate of long fibers different from the first nonwoven fabric. The at least part of said convex part has a sparse fiber part of which fiber density is lower than the fiber density of the center part of the said fiber orientation direction at the one end or both ends in the fiber orientation direction of a 1st nonwoven fabric. Surface sheet, characterized in that. The said convex part which has the said small fiber part is a thing in which the difference of the fiber density of the said central part and the said small fiber part in the fiber orientation direction of a 1st nonwoven fabric is orthogonal to the said fiber orientation direction. A surface sheet, characterized by greater than the difference in fiber density at the center and both ends. The said convex part which has the said small fiber part is that the fiber density of the both ends in the direction orthogonal to the fiber orientation direction of a 1st nonwoven fabric is more than the fiber density of the center part of the said direction. Surface sheet. The surface sheet according to claim 2, wherein the first nonwoven fabric is an airthrough nonwoven fabric in which a heat fusion point of fibers is formed on the fiber wave obtained by the card method by an air through method. The first nonwoven fabric comprising the crimped eccentric sheath-type composite fiber is subjected to a volume recovery process by hot air, and conforms to the uneven shape of the first roll and the first roll having a circumferential surface. The concave-convex shape of the biting shape is engaged with the second roll having the circumferential surface to engage with the concave-convex shape, and then joins with the second non-woven fabric under the state of being held on the circumferential surface of the first roll. Surface sheet, characterized in that the heat-sealed portion formed by heating and pressing between the convex portion of the first roll and the other roll. 6. The circumferential surface of the roll according to claim 5, wherein the first nonwoven fabric containing the crimped eccentric core sheath composite fiber is subjected to a volume recovery process by hot air, and the circumferential surface is in an uneven shape and the suction hole has a suction hole. And the second nonwoven fabric is joined to the second nonwoven fabric in a state of being held on the circumferential surface of the roll, and heated and pressurized between the convex portion of the roll and another roll together with the second nonwoven fabric to form the fusion portion. Surface sheet characterized by. 6. The circumferential surface according to claim 5, wherein the circumferential surface has a first nonwoven fabric including a thermally stretchable fiber having a concave-convex shape in which a circumferential surface is engaged with a concave-convex shape of the first roll and the first roll. Concave and convex in the engagement portion with the second roll, and joined with the second nonwoven fabric while being held on the circumferential surface of the first roll, between the convex portion of the first roll and the other roll with the second nonwoven fabric. And forming the heat-sealed portion by heating and pressing at, followed by heat treatment to elongate the thermally stretchable fiber. The state according to claim 5, wherein the first nonwoven fabric containing the thermally stretchable fiber is adsorbed to the peripheral surface of the roll having a periphery in the concave-convex shape and having a suction hole in the concave portion, and held on the peripheral surface of the roll. And joining the second nonwoven fabric to form a fusion portion by heating and pressurizing the convex portion of the roll with the other roll together with the second nonwoven fabric to form the fusion portion, and then performing heat treatment to extend the thermally stretchable fiber. Surface sheet, characterized in that. As a method for producing a surface sheet according to claim 1, The first nonwoven fabric containing the crimped eccentric core fiber composite fiber is subjected to a volume recovery process by hot air, and the unevenness of the first roll having the circumferential surface and the uneven shape of the first roll is engaged. Concave and convex shape by engaging the engaging portion with the second roll having the shape on the circumferential surface, and then joined with the second non-woven fabric under the state of maintaining the circumferential surface of the first roll, the convex of the first roll with the second nonwoven Method for producing a surface sheet, characterized in that for forming the heat-sealed portion by heating and pressing between the portion and the other roll. As a method for producing a surface sheet according to claim 1, The first nonwoven fabric containing the crimped eccentric sheath-type composite fiber is subjected to a volume recovery process by hot air, adsorbed on the circumferential surface of the roll having a concave-convex shape and having a suction hole in the recess, And joining the second nonwoven fabric in a state held on the circumferential surface, and heating and pressurizing between the convex portion of the roll and another roll together with the second nonwoven fabric to form the fusion portion. . As a method for producing a surface sheet according to claim 1, Engagement of the first nonwoven fabric comprising the thermally stretchable fiber with the first roll having the circumferential surface and the second roll having the convex and convex shape on the circumferential surface of the first roll having the concave-convex shape. And the second nonwoven fabric is joined with the second nonwoven fabric in a state of being unevenly shaped and held on the circumferential surface of the first roll, and heated and pressurized with the second nonwoven fabric between the convex portion of the first roll and another roll. After forming the heat-sealed portion, the heat treatment is performed to stretch the thermally stretchable fiber manufacturing method of a surface sheet. As a method for producing a surface sheet according to claim 1, The first nonwoven fabric containing the thermally stretchable fiber is adsorbed onto the circumferential surface of the roll whose periphery has an uneven shape and has a suction hole in the concave portion, and is joined to the second nonwoven fabric while being held on the circumferential surface of the roll. To form the fusion portion by heating and pressurizing between the convex portion of the roll and another roll together with the second nonwoven fabric, and then performing heat treatment to stretch the thermally stretchable fiber. Manufacturing method. The surface sheet according to claim 1, wherein an aggregate of long fibers is arranged inside the convex portion, and a plurality of long fibers constituting the aggregate are curved in the convex direction of the convex portion. The surface sheet according to claim 14, wherein the aggregate of long fibers is composed mainly of a heat-sealable fiber. The surface sheet according to claim 14, wherein the aggregate of long fibers is substantially free of the heat-sealed portion. The surface sheet according to claim 14, wherein the aggregate of long fibers is composed mainly of long fibers that are crimped in a wavy shape. The surface sheet according to claim 15, wherein the long fiber has a convex curve in the protruding direction of the convex portion by relaxation of the stretched state after being introduced into the stretched state between the first nonwoven fabric and the second nonwoven fabric. The surface sheet according to claim 14, wherein the aggregate of long fibers is composed mainly of hydrophilic long fibers. 20. The surface sheet according to claim 19, wherein the degree of hydrophilization is high in order of the first nonwoven fabric, the long fibers, and the second nonwoven fabric.

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