CN104884015B - Pants-type disposable diaper and manufacturing method thereof - Google Patents

Abstract

A diaper (50B) of the present invention comprises an absorbent body (2) and an outer covering body (3) disposed on the non-skin contact surface side of the absorbent body (2) and fixing the absorbent body (2), and the pants-type disposable diaper joins the left and right side edges of the outer covering body (3) of a front body (F) and the left and right side edges of the outer covering body (3) of a rear body (R) to form a pair of side seals (4, 4), a waist opening (8), and a pair of leg openings (9, 9). The side seal (4) has low visibility when the diaper (50B) is worn, and side seal visibility-improving means (step (53)) for improving the visibility of the side seal (4) is provided in the vicinity of the side seal (4).

Description

Pants-type disposable diaper and manufacturing method thereof

technical field

This invention relates to the underpants type disposable diaper which has a side seal part.

Background technique

At present, as underpants-type disposable diapers, diapers including an absorbent main body and an outer body arranged on the non-skin-contacting side of the absorbent main body to fix the absorbent main body and joined to the front body are widely used. The left and right side edges of the body and the left and right side edges of the back body form a pair of side seals, a waist opening and a pair of leg openings.

Usually, when taking off the shorts-type disposable diaper from the wearer's body, the diaper is torn into a front body and a back body at the side seal portion, and when the diaper is replaced after use, it is necessary to prevent dirt such as excrement from adhering to the wearer's body. It is necessary to quickly remove the used diaper from the body, so it is preferable that the side seals can be easily torn in the longitudinal direction. Regarding the tearability of the side seal, for example, it is described in Patent Document 1 that, from the viewpoint of both sufficient joint strength and improved tearability of the degree that the diaper does not fall off during wearing, the side seal is made to have 3 levels of bonding strength.

In addition, conventionally, in the manufacturing process of absorbent articles such as disposable diapers and sanitary napkins, heat rollers have been widely used when overlapping sheets are bonded together. Usually, side seals are formed using heat rollers as described later. In addition, as another bonding method, a method of welding using a laser is also known. For example, in Patent Document 2, it is described that a sheet laminate in which a plurality of sheets are stacked is deformed so as to be conveyed along the shape of the peripheral surface of a rotating roller having a laser-transmitting portion on the peripheral surface, and the A method of irradiating the sheet laminate with laser light to weld the sheets in the sheet laminate to each other.

Underpants-type disposable diapers are usually manufactured through the following steps. That is, manufacture a diaper continuous body (for example, the diaper continuous body shown in the symbol 10 of FIG. The front body (the exterior body forming the front body) and the back body (the exterior body forming the back body) in which the predetermined parts of the seal portion overlap each other are joined together, and then the joint portion is cut off by a cutting device such as a cutter to cut into individual diapers, The said underpants type disposable diaper was manufactured through the said process. The side seal portion of the conventional underpants-type disposable diaper produced in this way (the cut edge portion of the above-mentioned joining portion produced by cutting with the above-mentioned cutting device), the left and right side edges of the front body and the left and right side edges of the back body The overlapping is formed in a herringbone shape (joined palm shape), and the top of the herringbone part protrudes outward compared with the peripheral part, so it can be easily recognized visually.

In the manufacturing process of the above-mentioned underpants-type disposable diaper, when a heat source such as a laser or a thermocompression method is used to cut the diaper continuous body, the diaper continuous body is cut (fused) into individual units, and at the same time, a The cutting edges of the plurality of exterior bodies are welded together to continuously manufacture a pants-type disposable diaper having a pair of side seals. The side seal obtained by performing such cutting and welding processes at the same time, compared with the herringbone-shaped side seal obtained through the above-mentioned manufacturing process, has a narrower joint width between the outer bodies, so the wearing of the diaper is improved. On the other hand, the herringbone-shaped side seals are formed without protruding to the outside of the diaper, so the visibility of the diaper is low in the wearing state or the natural state (contracted state), and it is difficult to pass through the diaper. depending on the circumstances in which it is identified. Especially when the diaper is worn, if the visual visibility of the side seal is low, for example, after the diaper is used, when the protector (such as a mother) of the wearer's infant takes off the diaper from the infant, it is difficult to find the side seal. It may take time for the sealing part to take off the diaper. Patent Documents 1 and 2 do not describe the side seal portion obtained through the simultaneous cutting and welding steps and the inherent problems therein.

prior art literature

patent documents

Patent Document 1: Japanese Patent Laid-Open No. 2001-120595

Patent Document 2: Japanese Patent Laid-Open No. 2010-188629

Contents of the invention

The present invention provides a pants-type disposable diaper comprising an absorbent main body and an exterior body disposed on a non-skin-contacting side of the absorbent main body and fixing the absorbent main body. The left and right side edges of the exterior body are joined to the left and right side edges of the exterior body of the back body to form a pair of side seals, a waist opening, and a pair of leg openings. The side seal part has a side seal part visibility improving mechanism which can improve the visual visibility of the side seal part when the visibility of the diaper is low when the side seal part is worn. .

In addition, the present invention provides a method for manufacturing the underpants-type disposable diaper, the method including: a main body fixing step of fixing the absorbent main body to the strip-shaped outer body; The front body side and the back body side of the strip-shaped outer body of the absorbent main body are overlapped, and the predetermined portion of the overlapped outer body to form a side seal is in a pressurized state; The side seal portion is formed by welding the cut edge portions of the plurality of outer casings in a pressurized state generated by the cutting to each other to form the side seal portion in the pressurized state. The side seal portion visibility improvement mechanism is provided on the exterior body after the main body fixing step is completed and before the side seal portion forming step is completed.

Description of drawings

FIG. 1 : is a schematic perspective view of an example of the manufacturing method of the underpants type disposable diaper using the laser type joining apparatus applicable to the manufacturing method of the underpants type disposable diaper of this invention.

Fig. 2 is a perspective view schematically showing an underpants-type disposable diaper (an underpants-type disposable diaper outside the scope of the present invention) manufactured by implementing the manufacturing method shown in Fig. 1 .

FIG. 3 is a cross-sectional view schematically showing a cross-section taken along line II of FIG. 2 .

Fig. 4 is a plan view schematically showing the unfolded and stretched state of the diaper shown in Fig. 2 .

Fig. 5 is a perspective view schematically showing a manufacturing process of the diaper continuous body shown in Fig. 1 .

Fig. 6 is a planar development and schematically shows the state in which the diaper continuous body is introduced into the laser type joining device shown in Fig. 1, Fig. 6 (a) is a bottom view showing a part of the pressing member in section, Fig. 6 (b) It is a sectional view taken along line II-II of FIG. 6( a ).

Fig. 7(a) to Fig. 7(c) respectively illustrate the case where the side seal portion (sealing edge portion) is formed while cutting the diaper continuous body (belt-shaped sheet laminate) using the laser joining device shown in Fig. 1 An explanatory diagram of .

Fig. 8 is a cross-sectional view of one side seal and its vicinity in a state in which the waist opening of the diaper shown in Fig. 3 is enlarged.

Fig. 9 (a) and Fig. 9 (b) respectively schematically show the main part of the first embodiment of the underpants type disposable diaper of the present invention, that is, the junction part and the protruding part (side seal part visibility improvement mechanism) and their Figure 9 (a) is a perspective view of the natural state (contracted state) of the diaper of the first embodiment, and Fig. 9 (b) is a perspective view of the state (wearing state) of the waist opening of the diaper enlarged .

Fig. 10 is a view corresponding to Fig. 2 of the second embodiment of the underpants-type disposable diaper of the present invention (a perspective view schematically showing a state in which the diaper is viewed from the front side of the diaper).

Fig. 11 (a) ~ Fig. 11 (c) are explanatory diagrams of the manufacturing process of the diaper shown in Fig. 10 respectively, show a process (method a) with Fig. 11 (a) and Fig. 11 (c), use Fig. 11 ( b) and Fig. 11(c) show another process (method b).

Fig. 12 is a schematic front view of a mark (side seal part visibility improvement mechanism) which is a main part of a third embodiment of the underpants type disposable diaper of the present invention, and its vicinity.

Fig. 13 is a perspective view schematically showing a part of a composite elastic member used as an exterior body in the diaper shown in Fig. 12 .

FIG. 14 is an explanatory diagram of a step of forming the mark shown in FIG. 12 .

FIGS. 15( a ) to 15 ( d ) are equivalent to FIG. 12 , respectively showing other examples of markings (side seal portion visibility improvement mechanism) which are main parts of the third embodiment of the underpants-type disposable diaper of the present invention. diagram.

Detailed ways

This invention relates to the underpants type disposable diaper which has high visual visibility of a side seal part, and its manufacturing method.

One of the main features of the present invention is that the underpants-type disposable diaper includes an absorbent main body and an exterior body that is arranged on the non-skin-contacting surface side of the absorbent main body and fixes the absorbent main body, and the left and right side edges of the front body are A pair of side seals, a waist opening, and a pair of leg openings are formed by joining the left and right side edges of the back body. Among them, the visibility of the side seals is adopted to improve the visibility of the side seals. Improve the body. The adoption of the side seal portion visibility improvement mechanism is particularly effective in the following cases, that is, as described above, in the manufacturing process of the underpants type disposable diaper, in the predetermined position (formation) of the diaper continuous body (belt-shaped outer body) The predetermined position of the side seal portion) is irradiated with laser light, etc., and the diaper continuous body (belt-shaped outer body) is cut into individual units, and at the same time, the cut edges of the plurality of outer bodies generated by the cutting are welded to each other to form A pair of side seals. This "side seal part obtained through the process of simultaneously cutting and welding the outer body" has low visibility when the diaper is worn (wearing state), and in particular, it is difficult to tear the side seal for taking off the diaper. From the viewpoint of the side seal portion, it is effective to adopt a side seal portion visibility improvement mechanism to improve the visual visibility of the side seal portion when the diaper is worn. In addition, such a side seal is also a side seal with low visual visibility in the natural state (contracted state) of the diaper, so in order to clearly see the front, rear, left and right of the diaper when wearing it, the visibility of the side seal is adopted. It is effective to improve the visibility of the side seal portion in the natural state (contracted state before wearing) of the diaper by improving the mechanism. Hereinafter, first, the basic technology to which the side seal portion visibility improvement mechanism of the present invention can be applied will be described, and then the side seal portion visibility improvement mechanism will be described. The diaper 1 mentioned later which demonstrates as a basic technique does not have the side seal part visibility improvement mechanism of this invention, and is a diaper outside the range of this invention.

(basic technology)

FIG. 1 shows the outline of the manufacturing method of the underpants type disposable diaper using the laser type joining apparatus which can be applied to the manufacturing method of the underpants type disposable diaper of this invention. As shown in FIGS. 2 to 4 , a diaper 1 to be manufactured by the manufacturing method using this laser-type bonding device includes an absorbent main body 2 and a non-skin-contacting surface side of the absorbent main body 2 that is arranged and fixed. The outer body 3 of the absorbent main body 2 includes the left and right side edges A1 and A1 of the front body F (abdominal part 1A) along the longitudinal direction X of the outer body 3 and the edge of the back body R (back side part 1B). A pair of side seals 4, 4, a waist opening 8, and a pair of leg openings 9, 9 are formed by joining the left and right side edges B1, B1 in the longitudinal direction X of the outer body 3. The side seal portion 4 is formed by welding the edges of a plurality of exterior bodies 3 in a state where they are overlapped. The width of the side seal is 5 mm or less, or 3 mm or less, or 2 mm or less.

The diaper 1 has a longitudinal direction X corresponding to the front-back direction of the wearer and a transverse direction Y perpendicular thereto in a plan view in an unfolded and stretched state as shown in FIG. 4 . The diaper 1 can be divided into a crotch portion 1C arranged in the crotch portion when worn, and an abdominal portion 1A and a back portion 1B positioned in front and rear of the longitudinal direction X described above. The crotch portion 1C is a region in which notches for forming the leg openings 9 , 9 are formed on the left and right side edges along the longitudinal direction X. As shown in FIG. In addition, as shown in FIG. 4 , the diaper 1 can be divided into a front body F and a rear body R on the boundary of a virtual center line CL that divides the diaper 1 into two in the longitudinal direction X.

In addition, in this specification, the skin-contacting surface is the surface of a disposable diaper or its constituent parts (for example, the absorbent main body 2) facing the wearer's skin side when the disposable diaper is worn, and the non-skin-contacting surface is a disposable diaper. The surface of the diaper or its constituent parts facing the side opposite to the skin side (wearing side) when the disposable diaper is worn. In addition, the longitudinal direction X corresponds to the direction (longitudinal direction) along the long side of the disposable diaper or the absorbent main body 2 as its component, and the horizontal direction Y corresponds to the width direction of the disposable diaper or the absorbent main body 2 as its component. unanimous.

As shown in FIG. 4, the absorbent main body 2 has a relatively elongated shape in one direction (longitudinal direction X), and includes: a front sheet (not shown) forming a skin-contacting surface; and a back surface forming a non-skin-contacting surface. a sheet (not shown); and a liquid-retaining absorbent body (not shown) disposed between the two sheets, the absorbent body having a shape elongated in the same direction as the longitudinal direction X. The absorbent main body 2 has its longitudinal direction aligned with the longitudinal direction X of the diaper 1 in the unfolded and stretched state (state shown in FIG. 4 ), and is bonded to the center of the exterior body 3 by known bonding means (adhesive, etc.). department. Here, the unfolded and stretched state means that the side seals are peeled off to make the diaper in the unfolded state, and the diaper in the unfolded state is expanded so that the elastic parts of each part are stretched to become the design size (with the influence of all elastic parts excluded. In the state in which the dimensions are the same after being expanded planarly).

As shown in FIGS. 2 to 4 , the exterior body 3 includes: an outer layer sheet 35 forming the outer surface of the diaper 1 (the non-skin-contacting surface of the exterior body 3 ); The inner layer sheet 36 on the inner surface of the diaper 1 (the skin-contacting surface of the exterior body 3 ); and a plurality of thread-shaped or belt-shaped elastic members fixed between the two sheets 35 and 36 by an adhesive (not shown) 5, 6, 7. The two sheets 35 and 36 are bonded at predetermined locations with an adhesive or heat seal or the like (not shown).

The exterior body 3 (outer-layer sheet 35, inner-layer sheet 36) includes a resin material, and is formed using the resin material as a main component. As an example of the exterior body 3 (the outer layer sheet 35, the inner layer sheet 36), the resin material includes heat-sealable synthetic resins such as polyethylene, polyethylene terephthalate, and polypropylene, and is made of a non-woven fabric. , film, non-woven fabric and film laminate, etc. Examples of the nonwoven fabric include an air-through nonwoven fabric, a heated roll nonwoven fabric, a spunlace nonwoven fabric, a spunbonded nonwoven fabric, a melt blown nonwoven fabric, and the like.

The manufacturing method of the diaper 1 includes: the main body fixing process, the absorbent main body 2 is fixed on the belt-shaped outer body 3 (outer layer sheet 35, inner layer sheet 36); The front body side and the back body side of the shape outer casing 3 are overlapped (one edge side and the other side edge side are overlapped along the longitudinal direction of the strip-shaped outer casing 3 ), so that the overlapping outer casing 3 forms a side seal. The predetermined part of the part becomes a pressurized state; and the side seal part forming step cuts off the predetermined part of the side seal part in the pressurized state, and at the same time cuts off a plurality of outer casings 3 in a pressurized state generated by the cutting The edge portions are welded together to form the side seal portion 4 . That is, the side seal portion 4 is both exterior bodies 3, 3 formed by irradiating a laminated body of the strip-shaped exterior body 3 for the front body F and the strip-shaped exterior body 3 for the back body R with laser light and cutting the stacked body. cut edge.

More specifically, in the manufacturing method of the diaper 1, as shown in FIG. , the front body side and the back body side of the strip-shaped outer body 3 fixed with the absorbent main body 2 are overlapped, thereby manufacturing "the precursor of the underpants-type disposable diaper without forming the side seal portion is connected in one direction. The Diaper Continuum 10". And, in the above-mentioned side seal portion forming step, as shown in FIG. Cut edges of the plurality of outer casings 3 (outer layer sheet 35, inner layer sheet 36) in the resulting pressurized state are welded to each other, and pants including the outer casing body 3 having a pair of side seal portions 4, 4 are continuously manufactured. Type Disposable Diaper1.

First, as shown in FIG. 5, a belt-shaped outer layer sheet 35 continuously supplied from a blank roll (not shown) and a belt-shaped inner layer sheet 36 continuously supplied from a blank roll (not shown) are formed. A plurality of waist elastic members 5 for waist gathers, waist elastic members 6 for forming waist gathers, and leg elastic members 7 for forming leg gathers are arranged in a stretched state at a predetermined elongation rate. At this time, the leg elastic members 7 form and arrange predetermined leg circumference patterns via known swing guides (not shown) that reciprocate perpendicularly to the conveying direction of the sheet. In addition, before overlapping the belt-shaped outer layer sheet 35 and the belt-shaped inner layer sheet 36, an adhesive coater is used to apply an adhesive agent to a predetermined position on the opposing surface of either one or both of the two sheets 35, 36. (not shown) Apply a hot-melt adhesive. In addition, in the elastic members such as the waist elastic member 5 and the waist elastic member 6, the part (the predetermined part to form the side seal part 4) (shown by symbol 10C in FIG. In the case where the portion to be cut) is arranged in an extended state, in order to avoid problems such as large shrinkage of the elastic member after cutting and falling off of the elastic member, it is preferable to apply adhesive to this portion and its vicinity. agent. A hot-melt adhesive may be intermittently applied to the waist elastic member 5 and the waist elastic member 6 with an adhesive applicator (not shown) before being placed between the two sheets 35 and 36 .

And, as shown in FIG. 5 , between a pair of nip rollers 11, 11, the belt-shaped outer layer sandwiching the waist elastic member 5 in the stretched state, the waist elastic member 6 and the leg elastic member 7 is fed. The sheet 35 and the strip-shaped inner-layer sheet 36 are pressurized together to form the strip-shaped exterior body 3 in which a plurality of elastic members 5 , 6 , 7 are arranged in an extended state between the strip-shaped sheets 35 , 36 . In the forming process of the exterior body 3, a joint belt-shaped outer layer sheet 35 is formed between two adjacent waist elastic members 6, 6 using a joint device (not shown) such as a convex roll and an anvil roll corresponding thereto. and a plurality of joining portions (not shown) of the strip-shaped inner layer sheet 36 . Afterwards, if necessary, use an elastic member pre-cutting device (not shown) to press the plurality of waist elastic members 6 and the plurality of leg elastic members 7 corresponding to the positions where the absorbent main body 2 described later is arranged, and cut into multiple parts. individual so as not to exhibit systolic function. As said elastic member pre-cutting apparatus, the elastic member cutting part etc. which are used for the manufacturing method of the composite elastic member described in Unexamined-Japanese-Patent No. 2002-253605 are mentioned, for example.

Next, as shown in FIG. 5 , an adhesive such as a hot-melt adhesive is applied in advance on the absorbent main body 2 produced in another process, and the absorbent main body 2 is rotated 90 degrees to supply and fix it intermittently (main body Fixing process) on the inner layer sheet 36 constituting the strip-shaped outer body 3 . In addition, the adhesive for fixing the absorbent main body may not be applied to the absorbent main body 2, but may be pre-applied to a predetermined position of the inner layer sheet 36 where the absorbent main body 2 is to be arranged.

Next, as shown in FIG. 5 , leg holes LO' are formed inside the annular portion annularly surrounded by the leg elastic members 7 of the strip-shaped exterior body 3 on which the absorbent main body 2 is disposed. This leg hole forming step can be carried out using conventional technologies such as a rotary cutting machine and a laser cutting machine, which are the same as those used in the manufacturing method of such an article. In addition, in the illustrated form, the leg holes are formed after the absorbent main body 2 is arranged in the strip-shaped exterior body 3 , but the leg holes may be formed before the absorbent main body 2 is arranged.

Next, the strip-shaped exterior body 3 is folded in its width direction (the direction perpendicular to the conveyance direction of the exterior body 3 ). More specifically, as shown in FIG. 5, the both sides 3a, 3a of the belt-shaped outer covering body 3 along the conveying direction are covered with both ends in the longitudinal direction of the absorbent main body 2 (absorbent body shown in FIG. 4). The two ends of the longitudinal direction X of the main body 2) are folded back, and the two ends of the longitudinal direction of the absorbent main body 2 are fixed, and then the exterior body 3 and the absorbent main body 2 are folded in two in the width direction (overlapped and pressed). process). In this way, the diaper continuous body 10 is obtained.

Next, as shown in FIG. 1, the diaper continuum 10 produced in another way is irradiated with laser light using a laser type bonding device 20 to form a pair of side seals 4, 4 (side seal forming process), and continuously manufacture the diaper continuum 10 including The underpants type disposable diaper 1 which has the exterior body 3 of a pair of side seal part 4.

The laser type bonding device 20 is described. As shown in FIG. The pressing device 26 has an endless pressing belt 24 (pressing member). The laser type bonding device 20 includes a gap adjustment mechanism (not shown) capable of increasing or decreasing the gap between the support member 21 (the peripheral surface portion of the cylindrical roller 23) and the pressure belt 24. By adjusting the gap, the support member 21 and the pressure belt 24 can properly adjust the pressure applied to the continuous body 10 of the diaper.

The support member 21 forms the peripheral surface of the cylindrical roller 23 (contact portion with the workpiece), and is sandwiched and fixed between a pair of annular frames 22 and 22 forming the left and right side edges of the cylindrical roller 23 . between. The support member 21 is composed of a single ring-shaped member having the same length as the circumference of the ring-shaped frame body 22, and is made of a metal material such as iron, aluminum, stainless steel, copper, or a heat-resistant material such as ceramics.

The support member 21 has a light passing portion through which laser light can pass. As shown in FIGS. 1 and 6 , the support member 21 has a slit-shaped opening 27 penetrating the support member 21 in the thickness direction as a light passing portion. The opening 27 has a rectangular shape when viewed from above, and its longitudinal direction coincides with the width direction of the supporting member 21 (the direction indicated by symbol X in FIG. A plurality of cylindrical support members 21 are formed at predetermined intervals in the circumferential direction. The supporting member 21 allows the laser beam to pass through the opening 27 , while the laser beam cannot pass through (transmits) through the opening 27 . As a method of forming the opening 27 in the support member 21, in addition to 1) a method of forming the opening 27 at a predetermined position of the support member 21 by etching, punching, laser processing, etc., 2) as a method of forming the opening 27 in the support member 21, can also be mentioned. A method of using a plurality of bent rectangular members instead of a single annular member, and arranging these plural members at predetermined intervals in the circumferential direction of the frame body 22 between the pair of frame bodies 22 , 22 . In the method of 2) above, the interval between two adjacent members is the slit-shaped opening 27 . In addition, the part (the through-hole for forming a junction part) shown by the code|symbol 27A in FIG.

As shown in FIG. 6( b ), the support member 21 has a concave portion 28 on its outer surface (contact surface with the workpiece). A plurality of recesses 28 are formed at predetermined intervals in the circumferential direction of the cylindrical support member 21 , and a slit-shaped opening 27 is formed in a region (convex portion) between two adjacent recesses 28 . The opening part 27 is formed in the center of the circumferential direction of the cylindrical support member 21 of the said convex part.

In this way, by forming the concave portion 28 on the outer surface of the support member 21, when the thickness of the diaper continuous body 10 is uneven, it is possible to use the relatively thick part of the diaper continuous body 10 (for example, the arrangement of the absorbent main body 2). The diaper continuous body 10 is introduced into the outer surface of the support member 21 in such a manner that it is accommodated in the concave portion 28 . And when the diaper continuous body 10 is introduced on the support member 21 in this way, as shown in FIG. ) is substantially flat, so when the pressurizing belt 24 is pressed on the diaper continuous body 10, the portion of the diaper continuous body 10 on the above-mentioned convex portion formed with the opening 27 [cutting schedule shown by symbol 10C in FIG. Part (predetermined part forming the side seal part 4) and its vicinity) as a whole, through the diaper continuous body 10, is wound on the support member 21 and the pressure belt 24 with a predetermined tension, and is evenly distributed in the thickness direction under a predetermined pressure. Pressurize. In this way, when cutting this portion by irradiating laser light on the portion pressurized in the thickness direction from before the cutting by laser irradiation, it is possible to more reliably fuse the cut edges of the multilayer sheets constituting the cut portion. Therefore, further improvement of the weld strength of the side seal portion 4 (sealing edge portion) can be achieved.

The belt-type pressing device 26 includes an endless pressing belt 24 (pressing member) and three rollers 25 a , 25 b , and 25 c that rotate while the pressing belt 24 is stretched across. The rollers 25 a , 25 b , and 25 c may be driving rollers or driven rollers that follow and rotate with the cylindrical roller 23 . The pressure belt 24 rotationally drives any one or more of the rotating rollers 25a, 25b, and 25c, or rotates with the cylindrical roller 23, and moves at the same speed as the cylindrical roller 23 (support member 21). The temperature of the support member 21 and the pressure belt 24 is preferably maintained within a predetermined temperature range by air cooling, water cooling, or the like.

As the pressure belt 24 (pressing member), a metal or resin belt having heat resistance against heat generated during processing can be used, for example, a belt made of metal materials such as iron, aluminum, and stainless steel can be used. In addition, as the pressure belt 24, generally, a belt that does not have the transmittance of the laser light irradiated to the workpiece (continuous diaper 10) is used, but a belt having such transmittance may be used.

As shown in FIG. 1 , in a hollow portion of a hollow cylindrical roller 23 (support member 21 ), an irradiation head 31 for irradiating laser light 30 toward the support member 21 forming the peripheral surface portion of the cylindrical roller 23 is provided. The irradiation head 31 is a galvanometer scanner capable of freely scanning the laser 30 (a device with a mirror on the motor shaft), including: making the laser 30 in a direction parallel to the rotation axis of the cylindrical roller 23 (in FIG. 6( a ) The direction indicated by symbol X) advances and retreats, the position (irradiation point) where the laser beam 30 hits the diaper continuous body 10 on the support member 21 moves in the circumferential direction of the cylindrical roller 23, and the A mechanism to keep the spot diameter of the laser beam 30 constant on the peripheral surface, etc. The irradiation head 31 does not have the function of generating laser light 30 (light source). The laser light 30 is generated by a light source (not shown) arranged outside the cylindrical roller 23, and passes through an optical path (not shown) connecting the light source and the irradiation head 31. And reach the irradiation head 31 . By having such a structure, the laser irradiation mechanism can make the irradiation point of the laser beam 30 in the circumferential direction of the cylindrical roller 23 and the direction (direction shown by symbol X in FIG. 6( a) perpendicular to the circumferential direction. 23 in the direction parallel to the axis of rotation.) Any movement in two directions. In addition, the direction parallel to the rotation axis of the cylindrical roller 23 (direction perpendicular to the circumferential direction of the cylindrical roller 23) shown by the symbol X in FIG. 6 is the longitudinal direction of the diaper 1 (absorbent main body 2) in FIG. X in the same direction.

As shown in FIG. 1 , the diaper continuous body 10 is introduced into the support member 21 forming the peripheral surface of the cylindrical roller 23 that is rotationally driven in the arrow A direction by a guide roller (not shown) or the like while applying a predetermined tension. It is wound on the support member 21 on the outer surface of the cylindrical roller 23, and after being transported a predetermined distance in its circumferential direction by the rotation of the cylindrical roller 23, it is lifted from the support member 21 by unshown lead-out rollers and pinch rollers. leave. In this way, the diaper continuous body 10 is wound around the support member 21 forming the peripheral surface of the cylindrical roller 23 with a predetermined tension, and is pressed by the pressure belt 24 to be transported, whereby the supported member of the diaper continuous body 10 The portion sandwiched between 21 and the pressure belt 24 and its vicinity are in a state of being pressed (compressed) in the thickness direction from before cutting by laser irradiation. Therefore, when the diaper continuous body 10 includes a nonwoven fabric, the diaper continuous body 10 can be compressed more efficiently. The cutting edge portions of the plurality of sheets (exterior body 3 ) in the cut portion are more reliably welded to each other, and further improvement in the welding strength of the side seal portion 4 can be achieved.

The rotation angle of the support member 21 (cylindrical roller 23 ) from the introduction of the diaper continuous body 10 to the separation from the support member 21 can be, for example, 90° to 270°, preferably 120° to 270°. In addition, the range of the angle (pressure contact angle) at which the diaper continuous body 10 is pressed against the support member 21 by the pressurizing belt 24 (pressing member) extends over the circumference of the cylindrical support member 21 (cylindrical roller 23). When pressure-bonding is carried out on the entire circumference of the direction, when it is 360 degrees, it is preferably not less than 90 degrees and not more than 270 degrees, and more preferably not less than 120 degrees and not more than 270 degrees.

In the embodiment shown in FIGS. 1 and 6 , the diaper continuous body 10 is continuously conveyed, and one surface 10 a forms the peripheral surface portion of the cylindrical roll 23 and has a slit-like opening 27 through which the laser beam 30 can pass (light The outer surface of the support member 21 of the pass portion) abuts, and the diaper continuous body 10 (forming side seals) which is in a pressurized state due to the support member 21 and the pressurizing belt 24 (pressing member) is pressed from the support member 21 side through the opening 27. part 4) to irradiate the laser 30, thereby cutting the diaper continuous body 10, and at the same time, the cutting edges of the plurality of sheets (exterior body 3) in the above-mentioned pressurized state generated by the cutting are fused to each other to form a side. Seal part 4 (side seal part forming process).

Specifically, as shown in FIGS. 1 and 6 , the pressurizing belt 24 (pressing member) is pressed against the other surface 10 b of the diaper continuous body 10 abutting against the supporting member 21 (the contact surface with the supporting member 21 is the other surface 10 b). On the surface opposite to one surface 10a), the diaper continuum 10 in this state is irradiated with laser light 30 from the support member 21 side through the slit-shaped opening 27 to continuously manufacture the diaper continuum 10 having a pair of side seals 4, 4. The diaper 1 of the exterior body 3 . In this way, the irradiation of the laser light 30 is carried out to the diaper continuous body 10 which is in a pressurized state (compressed state) by being sandwiched by the support member 21 and the pressurizing belt 24, and the plurality of sheets (exterior) produced by the irradiation It is preferable from the viewpoint of improving the welding strength of the side seal portion 4 by reliably welding the cut edges of the body 3).

Fig. 7 is a diagram illustrating a situation in which a side seal portion 4 (sealing edge portion) is formed while cutting a diaper continuous body 10 (belt-shaped sheet laminate) using a laser type bonding device 20, and Fig. 7(a) schematically shows a diaper Part 10C to be cut (part where side seal portion 4 is to be formed) and its vicinity that are cut by laser 30 of continuum 10 . 10C of the part to cut of the diaper continuous body 10 of the form shown in FIG. In this part to be cut 10C, the opening end of the waist opening 8 (see FIG. 2 ) and its vicinity have an 8-layer structure in which 8 sheets are overlapped, and the other parts have a 4-layer structure in which 4 sheets are overlapped. part. The 4-layer structure part includes two sheets (outer layer sheet 35 and inner layer sheet 36) constituting the one-layer exterior body 3 of the abdominal part 1A as shown in FIG. The same two sheets 35 and 36 of the body 3 are formed by laminating these four sheets. On the other hand, the 8-layer structure part is formed as described above in such a manner that since the both sides 3a, 3a of the strip-shaped exterior body 3 cover the longitudinal ends of the absorbent main body 2 when the diaper continuous body 10 is manufactured. 4 and 5), there are 2 layers of exterior bodies 3 in each of the abdominal portion 1A and the back portion 1B, and these 4 layers of exterior bodies 3, 3 are laminated, so as a result, an 8-layer structure It is formed by laminating eight sheets 35 and 36 . In addition, in each of the 4-layer structure part and the 8-layer structure part, elastic members such as the waist elastic member 5 and the waist elastic member 6 may be arranged between the overlapping sheets 35 and 36. In FIG. , the illustration of the elastic member is omitted. Hereinafter, the 4-layer structure part will be mainly described, and unless otherwise specified, the 8-layer structure part also has the same structure as the 4-layer structure part, and forms the side seal part 4 .

In the planned cutting portion 10C of the four-layer structure of the diaper continuous body 10, the outer layer sheet 35 constituting one surface 10a (the contact surface with the support member 21) of the diaper continuous body 10 and the sheets other than the sheet constituting the one surface 10a ( Either or both of the inner layer sheets 36) are sheets that absorb the laser light 30 and generate heat. In the illustrated form, all the four sheets 35 and 36 constituting the portion to be cut 10C are sheets (nonwoven fabrics) that absorb the laser light 30 and generate heat. In addition, the overlapping outer-layer sheet 35 and inner-layer sheet 36 in the portion 10C to be cut and its vicinity may be bonded with an adhesive or not at all before irradiation with the laser beam 30 .

As shown in FIG. 7( b ), the diaper continuous body 10 is introduced in such a way that one surface 10 a abuts against the support member 21 and the planned cut portion 10C (the planned portion to form the side seal portion 4 ) is positioned on the slit-shaped opening 27. The supporting member 21 rotating in the direction of arrow A presses the pressing belt 24 (pressing member) on the other surface 10b, thereby conveying in the direction of arrow A and pressing (compressing) in the thickness direction. Then, laser light 30 is irradiated to the part to be cut 10C in the conveyed and pressurized state from the support member 21 side through the opening part 27 . As mentioned above, the irradiation point of the laser beam 30 can move arbitrarily in the circumferential direction of the cylindrical roller 23, and it is set to move along with the movement of the opening 27 along the circumferential direction, so the cutting on the opening 27 is planned. The portion 10C continuously irradiates the laser light 30 for a certain period of time during its conveyance.

When laser beam 30 is irradiated to part 10C to be cut in the four-layer structure, the forming materials (fibers, etc.) The formation material in the vicinity of the portion to be cut 10C is indirectly heated and melted by the laser light 30 . As a result, as shown in FIG. 7( c), the planned cutting portion 10C of the four-layer structure is fused, and a sheet-like sheet laminate (diaper precursor) is cut out from the diaper continuous body 10, and the diaper continuous body is cut out in the above-mentioned manner. The body 10 is cut, and at the same time, the cut edges of the four sheets 35, 36 in the sheet-like sheet laminate produced by the cutting and the four sheets 35, 36 of the cut out diaper continuous body 10 are The cut edges are welded to each other, respectively. These cut edges are in a pressurized state (compressed state) by being sandwiched by the support member 21 and the pressurizing belt 24 from before formation (before cutting of the diaper continuous body 10 irradiated by the laser beam 30 ), respectively. According to the manufacturing method of the diaper in the form shown in the figure, the cutting of the strip-shaped exterior body 3 and the cutting edge portions of the pressurized state of the exterior body 3 at two locations generated by the cutting are performed simultaneously by one laser irradiation. Therefore, compared with the method of welding two welded parts by two laser irradiations, the welding and cutting can be performed in the same process with about half the laser output, and the diaper 1 can be manufactured efficiently. In addition, since welding and cutting can be performed in the same process, there is no non-sealed edge portion in which the cut edge portions of the sheet (exterior body) are not welded, thereby reducing material.

The cut edges of the sheets 35 and 36 are heated during and after the irradiation of the laser 30 and become molten, but the sheet-shaped diaper precursor cut out from the diaper continuous body 10 by the irradiation of the laser 30 and the diaper continuous body 10 each maintains the pressurized state formed by the supporting member 21 and the pressurizing belt 24, and after the end of the irradiation, it is rapidly cooled and solidified by the outside air, and becomes a welded part in which the forming material (fiber, etc.) of the cut edge is melted and integrated 40. Thus, by forming the welded part 40, one of a pair of side seal parts 4 and 4 of one diaper 1 is formed. In addition, if necessary, the cut edges of the fins 35 and 36 can be forcibly cooled using a known cooling mechanism such as a suction device or an exhaust device, thereby promoting the formation of the welded portion 40 .

In this way, when one part to be cut 10C (the part where the side seal 4 is to be formed) is cut, the irradiation point of the laser beam 30 moves so as to touch another adjacent opening 27 in the direction opposite to the conveying direction A, The other portion to be cut 10C positioned thereon is irradiated through the other opening 27 . Thereby, 10 C of other part to cut|disconnect is cut|disconnected and welded similarly to the above, and the other side seal part 4 (weld part 40) paired with the side seal part 4 formed previously is formed. Thereafter, by repeating the same operation, the underpants-type disposable diaper 1 including the exterior body 3 having a pair of side seal portions 4 and 4 is continuously manufactured.

The side seal part 4 can be mentioned as one of the main characteristic parts of the diaper 1 manufactured in this way. As shown in FIG. 7( c), in the direction in which the side seal portion 4 extends (the direction indicated by the symbol X in FIG. 1. It is the same direction as the longitudinal direction X of the diaper 1 shown in FIG. 4.) The direction perpendicular to In the cross-sectional view (the same direction as the transverse direction Y of the diaper 1 shown in FIG. 4 ), the outer edge 4a of the side seal portion 4 produced by the above-mentioned cutting is formed in an arc shape convex to the inside of the outer body 3, and includes the outer edge 4a. Edge 4a and a position closer to the inside of the outer body 3 than the welded portion 40 between the four sheets 35, 36 constituting the outer body 3 is formed, and the welded portion 40 is formed in the thickness direction of the outer body 3 (Fig. ) in the up-and-down direction) has a wider width than both ends (upper end and lower end). That is, in the cross-sectional view of the welded portion 40 along the transverse direction Y of the diaper 1 (the direction perpendicular to the cutting direction generated by the laser), the width of the welded portion 40 gradually becomes wider toward the center in the thickness direction, forming a so-called crescent or crescent shape. Half-moon shape [the welding portion 40 shown in FIG. 7(c) is crescent-shaped].

The presence of the welded portion 40 formed by melting and solidifying the forming material of the sheet in the side seal portion 4 is hardened compared with other portions of the diaper 1, and the skin feel is deteriorated, which is a portion that causes the wearing feeling of the diaper 1 to decrease. In this way, when the welded portion 40 is formed in a crescent shape or a half-moon shape in the cross-sectional view of the width direction of the diaper 1, it is the same as the welded portion of the conventional side seal portion (for example, the position indicated by the symbol 9 described in FIG. 1 of Patent Document 1). Compared with the case of forming a rectangle in the same cross-sectional view, the ratio of the welded portion 40 existing in the corner portion 3S of the side edge portion of the exterior body 3 constituting the side seal portion 4 is reduced, thereby making it difficult to damage the original corner portion 3S. Compared with existing products, the wearing feeling of diapers is improved due to the softness and touch of the skin. On the other hand, at the portion that greatly affects the weld strength of the side seal portion 4, that is, the center portion in the thickness direction of the side edge portion of the exterior body 3 (the corner portion 3S on one side of the exterior body 3 and the corner portion on the other side 3S sandwiched), there is a sufficient amount of welded portion 40, so the side seal portion 4 has sufficient weld strength practically, and troubles such as damage to the side seal 4 are difficult to occur when the diaper 1 is worn.

In addition, in particular, when the outer edge 4a of the side seal portion 4 is formed into an arc shape protruding inwardly of the exterior body 3, as shown in FIG. The corner portion 3S of the side edge portion of the exterior body 3 and the corner portion 3S of the side edge portion of the exterior body 3 on the back side 1B side are close, and the separation distance between the two corner portions 3S and 3S is reduced, so it is located at the two corner portions 3S. The welded portion 40 between , 3S is located on the outside of the diaper 1 than the welded portion 40 , and the two corners 3S, 3S that are close to each other are in a state that is difficult to touch by hand and difficult to see from the outside, so that the diaper 1 Not only the feeling of wearing but also the appearance is improved.

In this way, the reason why the welded portion 40 of the side seal portion 4 is formed in a crescent or half-moon shape in the cross-sectional view of the width direction of the diaper 1 is presumed to be because, as shown in FIGS. During and after the irradiation of the portion 10C to be cut of the diaper continuous body 10, the continuous diaper 10 including the nonwoven fabric [the portion 10C to be cut (the part where the side seal portion 4 is to be formed)] is placed on the supporting member 21 made of a metal material. and between the pressing member 24. That is, the metal material as the main forming material of the support member 21 and the pressing member 24 sandwiching the diaper continuous body 10 (outer layer sheet 35 and inner layer sheet 36) from up and down, and the main forming material of the sheets 35, 36 Compared with the non-woven fabric, the thermal conductivity is higher, so by the irradiation of the laser 30, the heat generated in the sheet 35, 36 is easily and quickly absorbed by the support member 21 or the pressing member 24 in contact with the sheet 35, 36, and the heat generated by the laser 30 The corner portion 3S of the side edge portion of the exterior body 3 constituting the side seal portion 4 formed by irradiating and cutting the diaper continuous body 10 is in contact with the support member 21 or the pressing member 24 whose thermal conductivity is higher than the corner portion 3S. The heat generated at the corner 3S is rapidly absorbed by both members 21 and 24 , and as a result, the corner 3S is less likely to become high enough to form the welded portion 40 , so the ratio of the welded portion 40 is extremely small. On the other hand, the central portion in the thickness direction of the side edge portion of the exterior body 3 (the portion sandwiched by the corner portion 3S on one side of the exterior body 3 and the corner portion 3S on the other side of the exterior body 3 ) is not separated from the two members 21 with high thermal conductivity, 24 are in contact with each other, so the heat generated in the central part by the irradiation of the laser beam 30 stays in the central part and melts the central part. As a result, the welded part 40 is often unevenly distributed in the central part.

Therefore, in order to form the welded portion 40 into a crescent or half-moon shape in the cross-sectional view of the width direction of the diaper 1 to achieve the above-mentioned effects, the supporting member 21 and the pressing member 24 include metal materials such as iron, aluminum, stainless steel, copper, or Ceramics, and at least a part of the plurality of sheets constituting the exterior body 3 (in particular, the outer layer sheet 35 forming the outer surface of the diaper 1), a part thereof includes a resin material, specifically, preferably includes a nonwoven fabric, for example. In addition, it is preferable to include a resin material in all of the plurality of sheets 35 and 36 . As the nonwoven fabric, nonwoven fabrics generally used in this technical field can be used without particular limitation.

The laser light will be described. As the laser light irradiated on the diaper continuous body 10 (belt-shaped outer casing 3), a wavelength that can be absorbed by the sheets (the outer layer sheet 35 and the inner layer sheet 36) constituting the outer casing 3 and cause the sheets to generate heat is used. laser. Here, the "sheet constituting the exterior body" is not limited to a sheet constituting one surface of the exterior body (the contact surface with the support member 21) (for example, the outer layer sheet 35 in the above-mentioned form), as long as it is a sheet constituting the exterior body. Any kind will do. Whether or not the laser beam irradiated on the exterior body has a wavelength that is absorbed by the sheet constituting the exterior body to cause the sheet to generate heat is determined by the relationship between the material of the sheet and the wavelength of the laser light used. When the sheet constituting the exterior body is a synthetic resin nonwoven fabric or film widely used in the manufacture of absorbent articles (sanitary products) such as disposable diapers and sanitary napkins, it is preferable to use a _CO2 laser or a YAG laser as the laser. Laser, LD laser (semiconductor laser), YVO ₄ laser, fiber laser, etc. In addition, when the sheet constituting the exterior body includes polyethylene, polyethylene terephthalate, polypropylene, etc. as a synthetic resin, it is preferable to use, for example, a wavelength of 8.0 μm or more as a wavelength that is absorbed by the sheet to make the sheet heat well. 15.0 μm or less, particularly preferably a CO ₂ laser oscillation wavelength of 9.0 μm or more and 11.0 μm or less using a high-output laser device. The laser spot diameter, laser output, and the like can be appropriately selected in consideration of the material, thickness, and the like of the sheet constituting the exterior body.

(Side seal part visibility improvement mechanism)

The diaper 1, which is the manufacturing object of the above-mentioned manufacturing method using the laser type bonding device, includes a pair of side seals 4, 4 obtained by simultaneously cutting and welding the exterior body 3, and the softness of the side seals 4 Sex and skin feel were excellent, and the wearing feeling of the diaper 1 was good. On the other hand, from the description of Fig. 2 and Fig. 8, etc., it can be known that the side seal portion 4 protrudes outward from the peripheral portion of the side seal portion 4 at least on either the outer surface or the inner surface of the diaper 1 when worn, and the diaper Since the state of the outer surface and the inner surface of 1 does not substantially change across the side seal portion 4, it is difficult to recognize the side seal portion 4 from the outside, and the visual visibility of the side seal portion 4 is low.

Moreover, if the visual visibility of the side seal portion 4 is low, for example, after the diaper 1 is used, when the protector (for example, mother) of the infant as the wearer takes off the diaper 1 from the wearer, it is difficult to see the side seal. Part 4, the diaper 1 will take trouble when taking it off. Therefore, in this invention, the side seal part visibility improvement mechanism is provided in the diaper 1 for the purpose of improving the visibility of the side seal part 4. As shown in FIG. The side seal portion visibility improvement mechanism is preferably located in the vicinity of the side seal portion 4 and at or near the opening end of the waist opening 8 as in the first, second, and third embodiments described later. In addition, in the side seal portion visibility improving mechanism, in the above-mentioned manufacturing method of the underpants-type disposable diaper including the main body fixing step, the overlapping pressurization step, and the side seal portion forming step, from the end of the main body fixing step to the side seal It is installed on the exterior body 3 before the part forming process is completed. Hereinafter, the side seal part visibility improvement mechanism of this invention, the underpants type disposable diaper of this invention which has it, and its manufacturing method are demonstrated based on the preferable embodiment, referring drawings. In addition, in the embodiment described later, the description will mainly be given to components different from the above-mentioned "basic technology", and the same components will be assigned the same reference numerals and their descriptions will be omitted. The description of the above-mentioned "basic technology" is appropriately applied to the components that are not particularly described.

Fig. 9 shows the main parts of the first embodiment (pants-type disposable diaper 50A) of the underpants-type disposable diaper of the present invention, that is, the joint part 51 and the protruding part 52 (side seal part visibility improvement mechanism) and their vicinity. The diaper 50A of 1st Embodiment is comprised similarly to the diaper 1 except having the protrusion part 52 as a side seal part visibility improvement mechanism in the said diaper 1, and the junction part 51 required for forming it. The protrusion part 52 is located in the part which forms the opening end part of the waist opening part 8 each of a pair of side seal parts 4 and 4, and is formed in the part surrounded by the circle of a dotted line in the diaper 1 shown in FIG.

The diaper 50A of the first embodiment will be further described. In the diaper 50A, as shown in FIG. Join the exterior body 3 (outer layer sheet 35 and inner layer sheet 36) of the front body F (abdominal part 1A) and the exterior body 3 (outer layer sheet 35 and inner layer sheet 36) of the back body R (back side part 1B) The joint portion 51 (refer to FIG. 9( a )), and the portion forming the opening end portion 81 of the side seal portion 4 (more specifically, the portion of the exterior body 3 ) is outward than its peripheral portion when the diaper 50A is worn. The protruding part 52 (refer FIG.9(b)) is formed protrudingly, and this protruding part 52 functions as a side seal part visibility improvement means. That is, the presence of the protrusion part 52 in 50 A of diapers improves the visibility of the side seal part 4 visually.

The joining portions 51 are formed one by one (mutually) symmetrically on both sides (the front body F side and the rear body R side) across the side seal portion 4 . In the above-mentioned side seal portion forming step, before and after the irradiation of the laser beam for cutting the portion of the pressurized exterior body 3 where the side seal portion 4 is to be formed, the joint portion 51 is formed on the exterior body 3 using the same laser light. In the above-mentioned pressurized state of the exterior body 3 (diaper continuous body 10) during laser irradiation, the joint portion 51 has a predetermined plan view shape such as a circle. 3 and the case of the structure of the through hole of the outer body 3) of each of the rear body R. Joining portion 51 is in the natural state of diaper 1 or under normal use state, because form the contraction etc. of the position of this joining portion 51, become the state that is difficult to see when visually (Fig. 9 (a) from the point of view of easy description Although the joint portion 51 is shown in the figure, it is not always visible visually). The joint part 51 is mainly formed to form the protruding part 52, and the joint part 51 itself may not function as a mechanism for improving the visibility of the side seal. Visually visible, the protruding portion 52 can be made more conspicuous, and the visual visibility of the side seal portion 4 can also be improved.

In the manufacturing method of the diaper 50A of the first embodiment, the cutting of the exterior body 3 and the formation of the joining portion 51 are performed by irradiating the exterior body 3 with the sheets that can constitute the exterior body 3 (the outer layer sheet 35 and the inner layer sheet 36). ) is performed by absorbing laser light of a wavelength that causes the sheet to generate heat. More specifically, as shown in FIG. 6( a), at a predetermined position (near the slit-shaped opening 27 ) of the supporting member 21 of the laser type bonding apparatus 20 , a bonded part forming part through which the laser beam 30 can pass is preliminarily provided. The light-transmitting portion 27A passes through the joining portion from the supporting member 21 side before or after irradiating the laser light 30 on the exterior body 3 (continuous diaper 10 ) in the pressurized state from the supporting member 21 side through the slit-shaped opening 27 . The forming light transmitting portion 27A is irradiated with laser light 30 . As a result, the forming materials (fibers, etc.) of the sheets 35 and 36 existing in the portion of the exterior body 3 corresponding to the light transmitting portion 27A are melted or vaporized due to heat generated by the direct irradiation of the laser beam 30 . When the materials for forming the sheets 35 and 36 are melted without disappearing due to the heat generated by the direct radiation of the laser beam 30, the melted portion becomes the joint portion 51, and the exterior body 3 of the predecessor F is joined by the joint portion 51 in the above-mentioned pressurized state. And the exterior body 3 of the rear body R. In addition, when the forming materials of the sheets 35 and 36 evaporate and disappear due to heat generated by direct radiation of the laser beam 30, the disappearing portion is a through-hole that penetrates the exterior body 3 of the front body F and the exterior body 3 of the rear body R in the thickness direction. , and the forming material present at the opening edge of the through hole is indirectly heated and melted by the laser 30, and the melted portion (the opening edge of the through hole) becomes the joint portion 51. The joint part 51 joins the exterior body 3 of the front body F and the exterior body 3 of the back body R. As shown in FIG. In addition, as shown in FIG. 6 , the shape of the light transmitting portion 27A in plan view is not limited to a circular shape, and can be set to various shapes such as a rectangle, for example.

In this way, the joint portion 51 is formed near the side seal portion 4 of the diaper 50A and is the opening end portion 81 of the waist opening 8 or its vicinity, and the outer body 3 of the front body F and the outer body of the back body R are joined by the joint portion 51. When the diaper 1 is worn, the part of the outer body 3 (outer layer sheet 35, inner layer sheet 36) located outside the joining portion 51 (side seal portion 4 side) is formed from the annular waist opening 8 to the outer side when the diaper 1 is worn. The outer side protrudes to form a protrusion 52 . In short, when 50 A of diapers are worn, since the protrusion part 52 does not follow the wearer's body, it can be seen visually. Therefore, even if the side seal portion 4 of the diaper 50A is a part with low visibility by visual inspection, when the diaper 50A is worn, due to the presence of the protruding portion 52 near it, when the diaper 50A in the wearing state is removed from the wearer When the body is taken off, the side seal portion 4 can be quickly confirmed, and then the diaper 50A can be torn into the front body F and the rear body R at the side seal portion 4 as usual, and the used diaper can be quickly removed from the body. Down.

From the viewpoint of more reliably forming the protruding portion 52 (side seal portion visibility improvement mechanism), the separation distance between the joining portion 51 and the side seal portion 4 is preferably 2 mm or more, more preferably 3 mm or more, and is preferably 20 mm or less. More preferably, it is 15 mm or less, more specifically, it is preferably 2 mm or more and 20 mm or less, more preferably 3 mm or more and 15 mm or less. In addition, from the same point of view, the separation distance between the joining portion 51 and the edge 82 of the opening end 81 of the waist opening 8 located directly above is preferably 1 mm or more, more preferably 3 mm or more, and preferably 20 mm or less, more preferably 20 mm or less. It is preferably 15 mm or less, more specifically, preferably 1 mm to 20 mm, more preferably 3 mm to 15 mm. In addition, the "separation distance" mentioned here is the distance measured about the diaper of the unfolded and stretched state, and it is as above-mentioned about "the stretched state".

In addition, in the present invention, the cutting of the exterior body and the formation of the joint portion in the above-mentioned side seal portion forming step are carried out by melting the exterior body using a heat source, and the formation of the protrusion portion when the diaper is worn can be performed by forming the joint portion. That is, the melting of the exterior body using a heat source is not limited to irradiating the exterior body with laser light as described above, but by other methods, such as thermocompression bonding of the exterior body using a known heat roller device or using a known method. It is also possible to apply ultrasonic vibration to the external body, such as an ultrasonic vibration device, or the like.

Fig. 10 shows a second embodiment (pants-type disposable diaper 50B) of the underpants-type disposable diaper of the present invention. The diaper 50B of 2nd Embodiment is comprised similarly to the diaper 1 except the point which provided the above-mentioned diaper 1 with the step 53 which is a side seal part visibility improvement means.

Further, the diaper 50B of the second embodiment will be described. In the diaper 50B, as shown in FIG. The end edges 82R of the diaper 50B are not at the same position in the vertical direction (the vertical direction of FIG. 10 ), but are staggered, and the height difference 53 between the two end edges 82F and 82R caused by the stagger occurs above the side seal portion 4. The difference 53 functions as side seal part visibility improvement means. That is, in the diaper 50B, the visibility of the side seal part 4 improves by the presence of the step difference 53. As shown in FIG. In addition, in the diaper 50B, the edge 82R of the back body R is positioned above the edge 82F of the front body F. Conversely, the edge 82F of the front body F may be positioned above the edge 82R of the back body R. Location.

In the manufacturing method of the diaper 50B of the second embodiment, in the manufacture of the above-mentioned diaper continuous body 10 (belt-shaped exterior body 3), the side seal portion visibility improvement mechanism (height difference) is formed before the above-mentioned side seal portion forming step. 53). Specifically, when the front body side and the rear body side of the exterior body 3 are overlapped in the above-mentioned overlapping pressurization step, that is, as shown in FIG. 11(a) or FIG. When folding in the width direction, the two end edges 82F, 82R of the exterior body 3 along the length direction (the left-right direction in FIG. 11 ) are not made to coincide with each other but intentionally staggered, thereby forming a height as shown in FIG. 11( c ). A difference of 53. This shift amount (separation distance between one end edge and the other end edge) corresponds to the height t of the step difference 53 (see FIG. 10 ). As a method of "intentionally shifting both ends of the exterior body along the longitudinal direction" when forming the step 53, for example, the following method a shown in FIG. 11(a) and the method shown in FIG. 11(b) are listed. Either method b shown below can be used.

・Method a: When the imaginary centerline CL that divides the diaper X in two in the longitudinal direction is used as the boundary line, and the length of the longitudinal X is equal to the front body F and the rear body R, the imaginary center line CL is not used as the folding line, but the Another straight line parallel to the imaginary centerline CL is used as the method of the folding line Q (see FIG. 11( a )). In the embodiment shown in FIG. 11( a ), from the viewpoint of locating the edge 82R of the rear body R above the edge 82F of the front body F as shown in FIG. The line CL is shifted toward the front body F (ventral part 1A) side. That is, in the embodiment shown in FIG. 11( a) (with the imaginary centerline CL that divides the diaper 50B in two in the longitudinal direction as the boundary line, and the length of the longitudinal X is equal to the front body F and the back body R), the strip-shaped The two end edges 82F, 82R along the longitudinal direction of the exterior body 3 (diaper continuous body 10) are intentionally shifted from each other, and this strip-shaped exterior body is formed by using another straight line parallel to the imaginary center line CL as a folding line. 3 is formed by folding at the fold line.

Method b: The length of the vertical X is different between the abdominal part 1A and the back part 1B, and the imaginary center line CL' that divides the crotch part 1C into two in the vertical X is a method of folding lines (see FIG. 11( b ) ). That is, in the embodiment shown in FIG. 11( b ), the intentional offset between the both end edges 82F, 82R along the longitudinal direction of the strip-shaped exterior body 3 (diaper continuous body 10 ) is formed as follows: That is, in the diaper 50B, the length of the longitudinal X is different between the abdominal part 1A and the back part 1B, and the imaginary centerline CL' that divides the crotch part 1C of the diaper 50B into two in the longitudinal direction X is used as a folding line. This strip-shaped exterior body 3 is folded along this folding line (virtual center line CL'). In the embodiment shown in FIG. 11( b ), from the viewpoint of locating the edge 82R of the rear body R above the edge 82F of the front body F as shown in FIG. The length of the side part 1B is shorter than the length of the longitudinal direction X. Moreover, the imaginary centerline CL' which bisects the crotch part 1C in the longitudinal direction X coincides with the imaginary centerline which bisects the diaper 1 in the longitudinal direction X.

The height of the step 53 is preferably 2 mm or more, more preferably 3 mm or more, and is preferably 20 mm or less, and is more preferably 20 mm or less, from the viewpoint of balancing the improvement of visual visibility of the side seal portion 4 and maintaining the shape of the diaper 50B. 15 mm or less, more specifically, preferably 2 mm to 20 mm, more preferably 3 mm to 15 mm. In addition, the "height of a step difference" mentioned here is the height measured about the diaper of a natural state.

FIG. 12 has shown the mark 54 (side seal part visibility improvement mechanism) which is the main part of 3rd Embodiment (pants type disposable diaper 50C) of the underpants type disposable diaper of this invention, and its vicinity. The diaper 50C of 3rd Embodiment is comprised similarly to the diaper 1 except the point which provided the above-mentioned diaper 1 with the mark 54 which is a side seal part visibility improvement means.

Further, the diaper 50C of the third embodiment will be described. In the diaper 50C, as shown in FIG. 4, and on the outer surface (non-skin contact surface) of the exterior body 3 of the back body R (back side 1B) and in the vicinity of the side seal 4, a mark 54 that can be recognized visually is formed. The mark 54 functions as side seal part visibility improvement means. That is, in 50 C of diapers, the visibility of the side seal part 4 improves by presence of the mark 54. As shown in FIG.

As shown in FIG. 12, the mark 54 is located near the side seal 4 and is the opening end 81 of the waist opening 8 or its vicinity, sandwiching the side seal 4 on both sides (the front body F side and the rear body R side) one by one. Symmetrically formed, having a heart shape in top view. From the viewpoint of more reliably improving the visual visibility of the side seal portion 4 realized by the mark 54, the separation distance between the mark 54 and the side seal portion 4 is preferably 1 mm or more, more preferably 5 mm or more, and preferably 5 mm or more. 30 mm or less, more preferably 25 mm or less, more specifically, preferably 1 mm or more and 30 mm or less, more preferably 5 mm or more and 25 mm or less. In addition, from the same point of view, the separation distance between the mark 54 and the edge 82 of the opening end 81 of the waist opening 8 located directly above is preferably 1 mm or more, more preferably 5 mm or more, and preferably 60 mm or less, more preferably 60 mm or less. It is preferably 50 mm or less, more specifically, preferably 1 mm to 60 mm, more preferably 5 mm to 50 mm. In addition, the "separation distance" mentioned here is the distance measured about the diaper of the unfolded and stretched state, and it is as above-mentioned about "the stretched state".

In the manufacturing method of the diaper 50C of the third embodiment, in the manufacture of the above-mentioned diaper continuous body 10 (belt-shaped exterior body 3), the side seal portion visibility improvement mechanism is formed before the above-mentioned side seal portion forming step ( mark 54). Specifically, before overlapping the front body and the rear body of the exterior body 3 in the above-mentioned overlapping and pressurizing step, that is, before folding the strip-shaped exterior body 3 in its width direction, pass through a predetermined portion of the exterior body 3 . Embossing or printing forms the indicia 54 . The embossing method and the printing method are not particularly limited, and known methods can be appropriately selected, respectively.

In the diaper 50C, the composite elastic member 3A shown in FIG. 13 is used as the exterior body 3, and the mark 54 is formed in the embossing process utilized for manufacture of this composite elastic member 3A, as shown in FIG. The composite expandable member 3A has the following configurations 1 to 3. As the composite expandable member 3A, for example, the composite expandable member described in Japanese Patent Application Laid-Open No. 2009-118986, which was previously filed by the present applicant, can be applied. In addition, the composite elastic member 3A of the following structure 1 - the structure 3 can also be used without limitation as the exterior body 3 of 1st Embodiment and 2nd Embodiment.

- Structure 1: The outer layer sheet 35 and the inner layer sheet 36 are joined to each other by a plurality of intermittent joining portions 37 in the stretching direction (horizontal direction Y) and the direction (longitudinal direction X) perpendicular thereto of the composite stretchable member 3A.

·Structure 2: The plurality of elastic members 5, 6 are arranged so as not to pass through the joint portion 37, and the portions except the both ends in the longitudinal direction of the elastic members 5, 6 (near the side seal portion 4, etc.) are not fixed to the outer layer Sheet 35 and inner sheet 36.

- Structure 3: The outer-layer sheet 35 and the inner-layer sheet 36 are respectively formed with a plurality of pleats 38 extending continuously across the plurality of elastic members 5 and 6 in the natural state of the composite elastic member 3A.

FIG. 14 shows the step of forming the mark 54 in the manufacture of the composite telescopic member 3A. This mark forming process (manufacturing process of the composite stretchable member) is carried out on the downstream side of the pair of nip rollers 11 and 11 in the conveying direction and before the absorbent main body 2 is arranged in the manufacturing process of the diaper continuous body 10 shown in FIG. 5 . implement. More specifically, as shown in FIG. 14 , using the embossing roll 12 disposed on the downstream side of the pair of nip rolls 11 and 11 in the conveying direction and the anvil roll 13 receiving it, the belt-shaped outer body 3 is introduced between the two rollers 12 and 13 to form the joining portion 37 on the exterior body 3, and to form the mark 54 near the portion to be formed (part to be cut) 10C where the side seal portion 4 is to be formed. The belt-shaped exterior body 3 is introduced between both rolls 12 and 13 so that the outer layer sheet 35 constituting the exterior body 3 is in contact with the emboss roll 12 . The peripheral surface of the anvil roll 13 in contact with the strip-shaped exterior body 3 (inner layer sheet 36) is smooth, while the surface of the emboss roll 12 in contact with the strip-shaped exterior body 3 (outer layer sheet 35) is smooth. On the peripheral surface, a plurality of embossing pins 14 are provided corresponding to the joint portion 37 of the composite telescopic member 3A, and corresponding to the mark 54, there is provided a mark forming mark having the same front end portion as the mark 54 plan view shape (heart shape). The pins 15 are formed by pressing the exterior body 3 from the outer layer sheet 35 side with the front ends of these pins 14 , 15 to form the joining portion 37 and the mark 54 . Two pins 14, 15 can be heating embossing pins, also can be ultrasonic embossing pins. Thus, by introducing the strip-shaped exterior body 3 between both rolls 12 and 13, the strip-shaped exterior body 3 comprised from the composite elastic member 3A in which the mark 54 was formed is obtained. In addition, from the viewpoint of preventing troubles such as wrinkles in the absorbent main body 2 when the diaper 50C is worn, the elastic members 5, 6, etc. can be cut thinly at the portions where the elastic members 5, 6 overlap the absorbent main body 2. To suppress the non-stretchable part of the embodiment of its stretchability. The non-elastic part of this elastic member 5,6 can use two rolls 12,13 to form simultaneously with the formation of joint portion 37 and mark 54, or also can use the cutting roll (not shown in the drawing) that is different from two rolls 12,13 after they are formed. shown) to form. In the former case, convex portions, cutter blades, and the like are formed on the peripheral surface of the emboss roll 12 as non-elastic portion forming means of the elastic members 5 and 6 .

In addition, as shown in FIG. 12 , the mark as the visibility improvement mechanism of the side seal portion of the present invention is not limited to a heart shape, and its plan view shape is not particularly limited, and can be composed of graphics, symbols, characters, patterns, or combinations thereof. For example, as shown in Figure 15 (a), when the diaper is taken off from the wearer's body after use, the position of the side seal part 4 as the part torn should be clarified, and the side seal part 4 can be sandwiched between the two sides to form a A mark 54A constituted by a mark (arrow). In addition, the mark of this invention may form plurally along the full length of the side seal part 4 like mark 54A which consists of the mark shown in FIG.15(b). As another specific example of the mark of the present invention, a mark 54B composed of characters is shown in FIG. 15(c), and a mark 54A composed of symbols (arrows) and a mark composed of characters are shown in FIG. 15(d). A combination of 54B.

As mentioned above, although this invention was demonstrated based on the embodiment, this invention is not limited to the said embodiment, In the range which does not deviate from the summary of this invention, it can change suitably. For example, although four sheets are stacked in the sheet laminate as shown in FIG. 6( a ), two, three, or five or more sheets may be stacked. In addition, the laser joining device 20 may have a mechanism for controlling the tension of the diaper continuous body 10 in order to wind the diaper continuous body 10 loosely around the cylindrical roller 23 (support member 21 ) without creases. In addition, in order to remove the gas generated by laser irradiation from the opening 27 , the laser bonding apparatus 20 may have an exhaust mechanism for the gas or a mechanism for blowing air to the opening 27 . In addition, the laser type bonding apparatus 20 may have the mechanism for removing the resin etc. which adhered to the contact surface with the diaper continuous body 10 of the pressing member 24. As shown in FIG.

In addition, as shown in FIG. 4, the exterior body 3 of the above-mentioned embodiment is not divided into the abdominal part 1A and the back part 1B, but has a continuous hourglass shape extending over the abdominal part 1A, the crotch part 1C, and the back part 1B. shape, but the exterior body of the present invention is not limited to this continuous shape, for example, it can also be divided into an abdominal side sheet member arranged on the wearer's abdomen side (front side) and a back sheet member arranged on the wearer's back side (rear side). The side panel components, the absorbent main body is bridged and fixed on these two panel components. In the above-mentioned overlapping and pressurizing step of the manufacturing method of the underpants-type disposable diaper comprising such a split-type exterior body, the front body side of the strip-shaped exterior body to which the absorbent main body is fixed (a strip-shaped abdominal sheet member) and The rear side (belt-shaped back side sheet member) is overlapped, and the portion to be formed of the side seal portion of the overlapped exterior body (two sheet members) is brought into a pressurized state.

In addition, in the above-mentioned embodiment, before the above-mentioned overlapping and pressurizing step is carried out, as shown in FIG. The inner-layer sheet 36 is folded back so as to cover both ends in the longitudinal direction of the absorbent main body 2 on both sides along the conveying direction, but as the belt-shaped outer-layer sheet 35, the width direction (orthogonal to the longitudinal direction) is used. direction) longer than the strip-shaped inner layer sheet 36, when the two sheets 35, 36 are overlapped, only the extended portion of the outer layer sheet 35 extending outward from the side edge of the inner layer sheet 36 may be It is folded back so that the longitudinal direction both ends of the absorptive main body 2 may be covered. In this case, the opening end of the waist opening 8 of the cutting plan portion 10C of the diaper continuous body 10 and its vicinity are a 6-layer structure part in which 6 sheets are overlapped, and the other parts are 4 layers in which 4 sheets are overlapped. layer structure section. In addition, both sides 3a, 3a of the belt-shaped outer casing 3 along the conveyance direction, ie, both sides of the belt-shaped outer-layer sheet 35 and belt-shaped inner-layer sheet 36 along the conveyance direction, may not be folded.

Moreover, you may use in combination the side seal part visibility improvement mechanism of said 1st - 3rd embodiment for an underpants type disposable diaper. Parts of the above-mentioned only one embodiment can be properly used mutually.

About embodiment of this invention mentioned above, the following appendix content (the manufacturing method of an underpants type disposable diaper and an underpants type disposable diaper) is also disclosed.

(1)

A shorts-type disposable diaper, characterized in that:

comprising an absorbent main body and an exterior body for fixing the absorbent main body disposed on the non-skin-contacting surface side of the absorbent main body,

In the pants-type disposable diaper, a pair of side seals, a waist opening, and a pair of leg openings are formed by joining the left and right side edges of the outer body of the front body and the left and right side edges of the outer body of the back body. department,

The side seal portion has low visibility when the diaper is worn, and a side seal portion visibility improvement mechanism capable of improving the visibility of the side seal portion is provided near the side seal portion.

(2)

In the underpants-type disposable diaper as described in said (1), the said side seal part has low visual visibility in the natural state of the said diaper.

(3)

In the underpants-type disposable diaper according to the above (1) or (2), the side seal visibility improving means is located at the opening end of the waist opening or in its vicinity.

(4)

The underpants-type disposable diaper described in any one of the above (1) to (3) is formed in the vicinity of the side seal portion, which is the opening end portion of the waist opening portion or its vicinity, and is formed with a joint in the thickness direction. The joint portion of the outer body of the front body and the outer body of the back body, and the opening end portion of the waist opening of the side seal portion is outwardly compared with its peripheral portion when the diaper is worn. The protruding part is formed by protruding, and this protruding part functions as the visibility improvement means of the side seal part.

(5)

In the underpants-type disposable diaper described in (4) above, the distance between the joining portion and the side seal portion is preferably 2 mm or more, more preferably 3 mm or more, and preferably 20 mm or less, more preferably 15 mm or less, more specifically , preferably more than 2 mm and less than 20 mm, more preferably more than 3 mm and less than 15 mm,

The separation distance between the joining portion and the edge of the opening end of the waist opening is preferably 1 mm or more, more preferably 3 mm or more, and preferably 20 mm or less, more preferably 15 mm or less, more specifically, preferably 1 mm or more 20 mm or less, more preferably 3 mm or more and 15 mm or less.

(6)

In the underpants-type disposable diaper described in any one of (1) to (5) above, the edge of the outer body of the front body and the edge of the back body that form the opening end of the waist opening The edge of the exterior body is shifted in the vertical direction of the diaper, and a height difference between both end edges is generated above the side seal due to the shift, and the height difference improves the visibility of the side seal. Institutions function.

(7)

In the underpants type disposable diaper as described in said (6), the edge of the said back body is located above the edge of the said front body.

(8)

In the underpants type disposable diaper as described in said (6), the edge of the said front body is located above the edge of the said back body.

(9)

In the underpants-type disposable diaper according to any one of (6) to (8) above, the height difference is preferably 2 mm or more, more preferably 3 mm or more, and preferably 20 mm or less, more preferably 15 mm or less, more specifically , preferably not less than 2 mm and not more than 20 mm, more preferably not less than 3 mm and not more than 15 mm.

(10)

In the underpants-type disposable diaper described in any one of the above (1) to (9), the outer surface of the outer body of the front body is in the vicinity of the side seal part, or the side seal portion of the back body is formed. A visually recognizable mark is formed on the outer surface of the exterior body in the vicinity of the side seal portion, and the mark functions as means for improving the visibility of the side seal portion.

(11)

In the underpants-type disposable diaper according to the above (10), the marks are symmetrically formed on both sides (the front body side and the back body side) with the side seal part interposed therebetween.

(12)

In the underpants-type disposable diaper described in the above (10) or (11), the separation distance between the above-mentioned mark and the above-mentioned side seal portion is preferably 1 mm or more, more preferably 5 mm or more, and is preferably 30 mm or less, more preferably 25 mm or less. Specifically, it is preferably 1 mm to 30 mm, and more preferably 5 mm to 25 mm.

(13)

In the underpants-type disposable diaper according to any one of (10) to (12) above, the separation distance between the mark and the edge of the opening end of the waist opening located directly above is preferably 1 mm or more, more preferably 5 mm. More than 60 mm, more preferably 50 mm or less, more specifically, preferably 1 mm or more and 60 mm or less, more preferably 5 mm or more and 50 mm or less.

(14)

The underpants-type disposable diaper according to any one of (10) to (13) above, wherein the mark is a figure, a symbol, a character, a pattern, or a combination thereof.

(15)

The underpants type disposable diaper as described in any one of said (10)-(14) in which the said mark is formed in plural along the full length of the said side seal part.

(16)

In the underpants-type disposable diaper according to any one of the above (1) to (14), the outer edge of the side seal portion is formed in an arc shape convex toward the inside of the outer body, and the side seal portion is formed in an arc shape including the outer edge and lower than the outer edge. A welded portion between a plurality of sheets constituting the exterior body is formed near the inner side of the exterior body.

(17)

In the underpants-type disposable diaper according to the above (16), in a cross-sectional view along the transverse direction of the diaper, the width of the welded portion gradually increases toward the central portion in the thickness direction.

(18)

In the underpants-type disposable diaper according to the above (16) or (17), the welded portion is formed in a crescent shape or a half-moon shape in a cross-sectional view along the transverse direction of the diaper.

(19)

In the underpants-type disposable diaper according to any one of (16) to (18) above, in a state where the waist opening is expanded when the diaper is worn, the side edge of the outer body on the abdominal side is The corner of the corner and the corner of the side edge of the outer body on the back side are close, the separation distance between the two corners is reduced, and the welded part between the two corners is located closer to the welded part than the welded part. Both corners of the outer side of the diaper, which are close to each other, are hard to touch with hands and difficult to see from the outside.

(20)

The underpants-type disposable diaper according to any one of (1) to (19) above, wherein the exterior body includes: an outer layer sheet forming the outer surface of the diaper; An inner layer sheet on the inner surface of the diaper; and a plurality of filamentary or belt-shaped elastic members fixed between the two sheets.

(twenty one)

The underpants-type disposable diaper according to any one of (1) to (20) above, wherein the exterior body includes a fusion-bonding synthetic resin such as polyethylene, polyethylene terephthalate, or polypropylene as the resin material, and The outer body includes a non-woven fabric, a film or a laminate of a non-woven fabric and a film, and the non-woven fabric is a hot-air non-woven fabric, a hot roll non-woven fabric, a spunlace non-woven fabric, a spun-bonded non-woven fabric or Melt blown nonwovens.

(twenty two)

In the underpants-type disposable diaper described in any one of the above (1) to (21), a composite stretchable member is used as the exterior body, and the composite stretchable member includes: an outer layer sheet forming the outer surface of the diaper; The inner surface side of the layer sheet, the inner layer sheet forming the inner surface of the diaper; a plurality of filamentary or belt-shaped elastic members fixed between the two sheets, and the composite stretchable member has the following structures 1 to 3:

·Structure 1: the outer sheet and the inner sheet are joined to each other through a plurality of discontinuous joints in the stretching direction of the composite telescopic component and in a direction perpendicular thereto;

·Structure 2: The plurality of elastic members are arranged so as not to pass through the joining portion, and the parts except the both ends in the longitudinal direction of the elastic members are not fixed to the outer layer sheet and the inner layer piece;

·Structure 3: The outer layer sheet and the inner layer sheet are each formed with a plurality of pleats extending continuously over each of the plurality of elastic members in the natural state of the composite elastic member.

(twenty three)

The underpants-type disposable diaper according to any one of (1) to (22) above, wherein the outer body is not divided into the abdominal part and the back part, and has an hourglass covering the abdomen part, the crotch part, and the back part. continuous shape.

(twenty four)

The underpants-type disposable diaper according to any one of (1) to (22) above, wherein the exterior body is divided into an abdominal sheet member arranged on the abdomen side (front side) of the wearer and an abdominal sheet member arranged on the wearer's back side. The back side sheet member on the side (rear side), and the absorbent main body is bridged and fixed on these two sheet members.

(25)

The manufacturing method of the underpants-type disposable diaper is the manufacturing method of the underpants-type disposable diaper described in any one of the above (1) to (24), including:

a main body fixing step of fixing the absorbent main body to the strip-shaped outer body;

Overlapping pressurization step, overlapping the front body side and the back body side of the strip-shaped outer body to which the absorbent main body is fixed, and making the overlapping portion of the outer body where the side seal portion is to be formed into a pressurized state; and

The side seal forming step is to cut the part to be formed of the side seal in the pressurized state, and at the same time weld the cut edges of the plurality of pressurized exterior bodies generated by the cutting to each other to form the formed side seal. The side sealing part,

The side seal portion visibility improvement mechanism is provided on the exterior body after the main body fixing step is completed and before the side seal portion forming step is completed.

(26)

In the manufacturing method of the underpants type disposable diaper as described in said (25), cutting of the said exterior body in the said side seal part forming process is implemented by melting this exterior body with a heat source.

(27)

The manufacturing method of the underpants-type disposable diaper described in the above (26), wherein the melting of the outer body using the heat source is performed by irradiating the outer body with laser light, performing thermocompression bonding of the outer body, or melting the outer body Implemented by applying ultrasonic vibrations.

(28)

The manufacturing method of the underpants type disposable diaper described in any one of said (25)-(27), when manufacturing the underpants type disposable diaper described in said (4),

The cutting of the outer body and the formation of the joint portion in the side seal portion forming step are carried out by melting the outer body with a heat source, and the protrusion when the diaper is worn is made by the formation of the joint portion. Department can be formed.

(29)

The manufacturing method of the underpants type disposable diaper described in any one of said (25)-(27), when manufacturing the underpants type disposable diaper described in said (6),

In the overlapping and pressurizing step, when the front body side and the rear body side of the outer body are overlapped, both end edges along the longitudinal direction of the outer body do not coincide with each other and are intentionally shifted.

(30)

In the method for manufacturing a shorts-type disposable diaper described in (29) above, the length of the outer body in the longitudinal direction is equal to that of the front body and the rear body on the boundary of an imaginary center line CL that divides the diaper in two in the longitudinal direction. In the case of , take another straight line parallel to the imaginary center line CL as the folding line, and fold the strip-shaped outer body on the imaginary center line CL (should be "as another straight line parallel to the imaginary center line CL) Misrepresentation of the "folding line") is folded so that the two end edges along the longitudinal direction of the exterior body are intentionally staggered from each other.

(31)

The manufacturing method of the underpants type disposable diaper described in the above-mentioned (29), in which the length of the longitudinal direction of the outer body is different between the ventral part and the back part in the diaper so that the crotch part of the diaper is divided in the longitudinal direction. The imaginary centerline CL' of 2 is a folding line, and the strip-shaped exterior body is folded at the imaginary centerline CL', so that the two end edges along the length direction of the exterior body are intentionally staggered from each other .

(32)

The manufacturing method of the underpants-type disposable diaper described in any one of said (25)-(27), when manufacturing the underpants-type disposable diaper described in said (10),

In the overlapping press step, the mark is formed on a predetermined portion of the outer body by embossing or printing before overlapping the front body side and the rear body side of the outer body.

(33)

The manufacturing method of the underpants-type disposable diaper described in the above (32), using an embossing roll arranged on the downstream side in the transport direction from a pair of nip rolls for forming the outer body and an anvil roll supporting it A belt-shaped exterior body passing through a pair of nip rollers is introduced between the two rolls, and a junction between sheets (outer layer sheet and inner layer sheet) constituting the exterior body is formed on the exterior body, and The mark is formed near the portion where the side seal is to be formed (the portion to be cut).

(34)

The method for producing a pants-type disposable diaper according to any one of (25) to (33) above, wherein in the superposing and pressing step, a precursor of the pants-type disposable diaper in which the side seal is not formed is produced. The diaper continuous body connected in one direction, in the side seal part forming process, cut (fuse) the diaper continuous body (the above-mentioned strip-shaped exterior body) into individual bodies by laser irradiation, and simultaneously The cut edge portions of the plurality of outer casings in a pressurized state are welded to each other, and an underpants-type disposable diaper including the outer casing having a pair of side seal portions is continuously produced.

(35)

The manufacturing method of the underpants-type disposable diaper described in the above (34), wherein the side seal portion forming step is performed using a laser type bonding apparatus including a supporting member having a light passing portion through which laser light can pass, and a pressing member,

The diaper continuous body is continuously conveyed, and one surface of the diaper continuous body is brought into contact with the support member having the light passing portion, and the pressurized state is made by the support member and the pressing member. The diaper continuous body is irradiated with laser light from the support member side through the light passing portion, thereby cutting the diaper continuous body, and at the same time, the cutting edges of the plurality of sheets in the pressurized state generated by the cutting are welded to each other, forming the Side seal.

(36)

The manufacturing method of the underpants type disposable diaper described in the above (35), wherein the above-mentioned support member is formed in a cylindrical shape, and has a slit-shaped opening that penetrates the support member in the thickness direction as the above-mentioned light passing portion, and the opening is formed in a cylindrical shape. A plurality of the supporting members are formed at predetermined intervals in the circumferential direction.

(37)

The manufacturing method of the underpants-type disposable diaper according to the above (35) or (36), wherein the laser joining device includes a belt-type pressing device having an endless pressing belt, and the pressing member is the pressing belt.

(38)

The method for producing a pants-type disposable diaper according to any one of (34) to (37) above, wherein as the laser light, a laser beam capable of being absorbed by the sheets (outer layer sheet and inner layer sheet) constituting the outer body and used as the laser beam is used. The sheet heats up the wavelength of the laser light.

(39)

The method for producing a pants-type disposable diaper according to any one of the above (28) and the above (34) to (38), wherein, in the side seal portion forming step, after irradiating the pressurized The joining portion is formed on the exterior body using the same laser before and after cutting the portion of the exterior body where the side seal portion is to be formed.

(40)

In the manufacturing method of any one of the above (35) to (39), the underpants-type disposable diaper is formed at a predetermined portion of the support member of the laser bonding device (as the light passing portion penetrating the support in the thickness direction). The vicinity of the slit-shaped opening of the member) is preliminarily provided with a light-transmitting portion for forming a joint portion through which laser light can pass, and the pressurized exterior body is passed through the slit-shaped opening from the support member side. (Continuous diaper) Before or after irradiation with laser light, laser light is irradiated from the side of the support member through the light-transmitting portion for forming a joining portion, whereby in the pressurized state, the joint portion with the outer body is formed. The exterior body of the front body and the exterior body of the rear body are joined with a portion corresponding to the light transmission portion.

Industrial availability

According to this invention, the underpants type disposable diaper with high visual visibility of a side seal part is provided.

Claims (34)

1. A shorts type disposable diaper, characterized in that: comprising an absorbent main body and an exterior body disposed on the non-skin-contacting side of the absorbent main body to fix the absorbent main body, In the pants-type disposable diaper, a pair of side seals, a waist opening, and a pair of leg openings are formed by joining the left and right side edges of the outer body of the front body and the left and right side edges of the outer body of the back body. department, The side seal portion has low visual visibility when the diaper is worn, and a side seal portion visibility improvement mechanism that can improve the visual visibility of the side seal portion is provided near the side seal portion, The outer edge of the side seal portion is formed in an arc shape protruding inwardly of the outer body, and a gap between a plurality of sheets constituting the outer body is formed at a position closer to the inner side of the outer body than the outer edge. between the welds. 2. The underpants type disposable diaper according to claim 1, characterized in that: The width of the welded portion gradually increases toward the central portion in the thickness direction in a cross-sectional view along the lateral direction of the diaper. 3. The underpants type disposable diaper according to claim 1 or 2, characterized in that: The welded portion is formed in a crescent or half-moon shape in a cross-sectional view along the transverse direction of the diaper. 4. The underpants type disposable diaper according to claim 1 or 2, characterized in that: In the state where the waist opening is expanded when the diaper is worn, the corners of the side edges of the exterior body on the abdominal side and the corners of the side edges of the exterior body on the back side Closer, the separation distance between the two corners decreases, and the welded portion between the two corners is difficult to touch with hands because it is located on the outer side of the diaper than the welded portion, and the two corners are close to each other. In a state that is hard to see from the outside. 5. The underpants type disposable diaper according to claim 1 or 2, characterized in that: The said side seal part has low visual visibility in the natural state of the said diaper. 6. The underpants type disposable diaper according to claim 1 or 2, characterized in that: The side seal portion does not protrude outward from the diaper beyond the peripheral portion of the side seal portion when the diaper is worn. 7. The underpants type disposable diaper according to claim 1 or 2, characterized in that: The side seal portion is a double exterior formed by cutting the laminated body of the belt-shaped outer body for the front body and the belt-shaped outer body for the rear body with laser light. The cut edge of the body. 8. The underpants type disposable diaper according to claim 1 or 2, characterized in that: The visibility-enhancing mechanism of the side seal is located at or near the opening end of the waist opening. 9. The underpants type disposable diaper according to claim 1 or 2, characterized in that: In the vicinity of the side seal portion, which is the opening end of the waist opening or its vicinity, a joint portion joining the outer body of the front body and the outer body of the rear body in the thickness direction is formed, In addition, the opening end portion of the waist opening forming the side seal portion protrudes outward compared with the peripheral portion thereof when the diaper is worn to form a protruding portion, and the protruding portion serves as a mechanism for improving visibility of the side seal portion. Play a role. 10. The underpants type disposable diaper according to claim 1 or 2, characterized in that: The edge of the exterior body of the front body and the edge of the exterior body of the back body forming the opening end of the waist opening are shifted in the vertical direction of the diaper, and the side seal portion A height difference between the two end edges due to the shift occurs above the upper side, and this height difference functions as a means for improving the visibility of the side seal portion. 11. The underpants type disposable diaper according to claim 10, characterized in that: The edge of the rear body is located above the edge of the front body. 12. The underpants type disposable diaper according to claim 10, characterized in that: The edge of the front body is located above the edge of the rear body. 13. The underpants type disposable diaper according to claim 1 or 2, characterized in that: On the outer surface of the outer body of the front body and in the vicinity of the side seal portion, or in the outer surface of the outer body of the rear body in the vicinity of the side seal portion, there is formed a The mark for identification functions as the means for improving the visibility of the side seal portion. 14. The underpants type disposable diaper according to claim 13, characterized in that: The marks are symmetrically formed one by one on the front body side and the rear body side with the side seal portion interposed therebetween. 15. The underpants type disposable diaper according to claim 13, characterized in that: The mark is one or more selected from the group consisting of graphics, symbols, characters and patterns. 16. The underpants type disposable diaper according to claim 13, characterized in that: A plurality of the marks are formed along the entire length of the side seal. 17. The underpants type disposable diaper according to claim 1 or 2, characterized in that: The exterior body includes: an outer layer sheet forming the outer surface of the diaper; an inner layer sheet disposed on the inner surface side of the outer layer sheet and forming the inner surface of the diaper; and a plurality of filamentary sheets fixed between the two sheets. or a strip-shaped elastic member. 18. The underpants type disposable diaper according to claim 1 or 2, characterized in that: The exterior body includes one or two or more heat-sealable synthetic resins selected from the group consisting of polyethylene, polyethylene terephthalate, and polypropylene as a resin material, and the exterior body is a non-woven cloth. 19. The underpants type disposable diaper according to claim 1 or 2, characterized in that: A composite stretchable member is used as the exterior body, and the composite stretchable member includes: an outer layer sheet forming the outer surface of the diaper; an inner layer sheet disposed on the inner surface side of the outer layer sheet and forming the inner surface of the diaper; A plurality of filamentary or ribbon-shaped elastic components between the two sheets, and the composite telescopic component has the following structures 1 to 3: ·Structure 1: the outer sheet and the inner sheet are joined to each other through a plurality of discontinuous joints in the stretching direction of the composite telescopic component and in a direction perpendicular thereto; ·Structure 2: The plurality of elastic members are arranged so as not to pass through the joining portion, and the parts except the both ends in the longitudinal direction of the elastic members are not fixed to the outer layer sheet and the inner layer piece; ·Structure 3: The outer layer sheet and the inner layer sheet are each formed with a plurality of pleats extending continuously over each of the plurality of elastic members in the natural state of the composite elastic member. 20. The underpants type disposable diaper according to claim 1 or 2, characterized in that: The said exterior body is not divided into an abdominal part and a back part, but has an hourglass-shaped continuous shape extending over an abdominal part, a crotch part, and a back part. 21. The underpants type disposable diaper according to claim 1 or 2, characterized in that: The exterior body is divided into an abdominal sheet member arranged on the abdomen side of the wearer and a back sheet member arranged on the back side of the wearer, and the absorbent main body is bridged and fixed between these two sheet members. 22. A method for manufacturing a shorts-type disposable diaper, which is a method for manufacturing a shorts-type disposable diaper according to any one of claims 1 to 21, characterized in that it comprises: a main body fixing step of fixing the absorbent main body to the strip-shaped outer body; Overlapping pressurization step, overlapping the front body side and the rear body side of the strip-shaped outer body to which the absorbent main body is fixed, and making the overlapping portion of the outer body where the side seal portion is to be formed into a pressurized state; and The side seal portion forming step is to cut the part to be formed in the pressurized side seal portion, and at the same time weld the cut edges of the plurality of pressurized exterior bodies generated by the cutting to each other to form the side seal portion. The side sealing part, The side seal portion visibility improving mechanism is provided on the exterior body after the main body fixing step is completed and before the side seal portion forming step is completed, The cutting of the exterior body in the side seal portion forming step is performed by melting the exterior body with a heat source. 23. The manufacturing method of the underpants type disposable diaper according to claim 22, characterized in that: Melting of the exterior body using the heat source is carried out by irradiating the exterior body with laser light, performing thermocompression bonding of the exterior body, or applying ultrasonic vibration to the exterior body. 24. The manufacturing method of the underpants type disposable diaper according to claim 22 or 23, characterized in that: In the case of manufacturing the underpants type disposable diaper according to claim 9, The cutting of the outer body and the formation of the joint portion in the side seal portion forming step are carried out by melting the outer body with a heat source, and the protrusion when the diaper is worn is made by the formation of the joint portion. Department can be formed. 25. The manufacturing method of the underpants type disposable diaper according to claim 22 or 23, characterized in that: In the case of manufacturing the underpants type disposable diaper according to claim 10, In the overlapping and pressurizing step, when the front body side and the rear body side of the outer body are overlapped, both end edges along the longitudinal direction of the outer body do not coincide with each other and are intentionally shifted. 26. The manufacturing method of the underpants type disposable diaper according to claim 25, characterized in that: When the imaginary centerline (CL) that divides the diaper in two in the longitudinal direction is the boundary and the length of the outer body in the longitudinal direction is equal to the front body and the back body, the imaginary centerline (CL) ) is a folding line, and the strip-shaped outer casing is folded at the folding line so that both end edges along the longitudinal direction of the outer casing are intentionally shifted from each other. 27. The manufacturing method of the underpants type disposable diaper according to claim 25, characterized in that: In the diaper, the longitudinal length of the exterior body is different between the abdominal part and the back part, and the imaginary center line (CL') dividing the crotch part of the diaper into two in the longitudinal direction is the folding line, and the The strip-shaped exterior body is folded at the imaginary center line (CL') such that both end edges along the length direction of the exterior body are intentionally shifted from each other. 28. The manufacturing method of the underpants type disposable diaper according to claim 22 or 23, characterized in that: In the case of manufacturing the underpants type disposable diaper according to claim 13, In the overlapping press step, the mark is formed on a predetermined portion of the outer body by embossing or printing before overlapping the front body side and the rear body side of the outer body. 29. The manufacturing method of the underpants type disposable diaper according to claim 28, characterized in that: Using the embossing roll disposed on the downstream side of the conveying direction from the pair of nip rolls for forming the exterior body and the anvil roll supporting it, the embossed roll passing through the pair of nip rolls is introduced between the two rolls. A belt-shaped exterior body in which joints between sheets constituting the exterior body are formed, and the mark is formed near the portion where the side seal portion is to be formed. 30. The manufacturing method of the underpants type disposable diaper according to claim 22 or 23, characterized in that: In the superposing and pressurizing step, a diaper continuum in which the precursors of the underpants-type disposable diaper without the side seal formed are connected in one direction is manufactured, and in the side seal forming step, the The diaper continuous body is cut into individual bodies, and at the same time, the cut edges of the plurality of outer casings in a pressurized state produced by the cutting are welded to each other, and the diaper having a pair of side seals is continuously produced. The underpants type disposable diaper of the exterior body. 31. The manufacturing method of the underpants type disposable diaper according to claim 30, characterized in that: The side seal portion forming step is performed using a laser type bonding apparatus including a pressing member and a supporting member having a light passing portion through which laser light can pass, The diaper continuous body is continuously conveyed, and one surface of the diaper continuous body is brought into contact with the support member having the light passing portion, and the pressurized state is made by the support member and the pressing member. The diaper continuous body is irradiated with laser light from the support member side through the light passing portion, thereby cutting the diaper continuous body, and at the same time, the cutting edges of the plurality of sheets in the pressurized state generated by the cutting are welded to each other, forming the Side seal. 32. The manufacturing method of the underpants type disposable diaper according to claim 31, characterized in that: As the laser light, a laser light having a wavelength capable of being absorbed by the sheet constituting the exterior body and causing the sheet to generate heat is used. 33. The method of manufacturing the underpants type disposable diaper according to claim 31, characterized in that: In the side seal portion forming step, before and after irradiating the laser beam for cutting the part where the side seal portion is to be formed in the pressurized state of the exterior body, the same laser beam is used to form the outer body at a thickness The direction joins the outer body of the front body and the outer body of the rear body. 34. The manufacturing method of the underpants type disposable diaper according to any one of claims 31 to 33, characterized in that: A light-transmitting portion for forming a bonding portion through which laser light can pass is provided in advance through a predetermined portion of the supporting member of the laser bonding apparatus, and the pressurized state is passed through a slit-shaped opening from the supporting member side. Before or after irradiation of the exterior body with laser light, laser light is irradiated from the side of the supporting member through the light transmitting portion for joint portion formation, whereby in the pressurized state, the light for formation of joint portion with the exterior body The corresponding part of the light-transmitting part joins the exterior body of the front body and the exterior body of the rear body.