JP3611761B2 - Absorbent articles - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to absorbent articles such as sanitary napkins, disposable diapers, incontinence pads, panty liners, pet sheets, and the like. More specifically, the seal portion is less likely to cause adhesion failure or damage, and has excellent appearance and leakage prevention. The present invention relates to an absorbent article.
[0002]
[Prior art and problems to be solved by the invention]
As an absorbent article such as a sanitary napkin, a surface material that has a liquid-retaining absorbent layer and a liquid-impermeable leak-proof layer, and that forms a skin contact surface and a back material that forms a non-skin contact surface Is widely known in which a seal portion is formed by bonding.
Conventionally, since such a seal portion has been formed by joining the front surface material and the back surface material at the same pitch and in the same pattern, particularly when there is a thickness difference or a basis weight difference at the site to be sealed. Is likely to cause poor bonding such as floating or peeling in the seal part or damage such as cuts or holes, and such poor bonding or damage may deteriorate the appearance of the absorbent article or cause leakage. .
Moreover, since the rigidity of the seal portion is increased, the wearing feeling may be deteriorated.
[0003]
Accordingly, a first object of the present invention is to provide an absorbent article excellent in appearance and leak-proof property, and a method for producing the same, in which there is no adhesion failure or damage in the seal portion.
The second object of the present invention is to provide an absorbent article excellent in wearing feeling and a method for producing the same.
[0004]
[Means for Solving the Problems]
The present invention has a liquid-retaining absorbent layer and a liquid-impervious leak-proof layer, and is formed substantially vertically to form a surface material that forms a skin contact surface and a non-skin contact surface In the absorbent article in which a heat seal part is formed by being joined to the back material, the heat seal part has irregularities, and the irregularities are in the longitudinal direction or the width direction of the absorbent article, The first and / or second objects described above are achieved by providing an absorbent article having different pitches or areas of recesses or projections.
[0005]
Further, the present invention is a method for producing the above absorbent article, which has a large number of protrusions, and the pitch between the protrusions or the area of the protrusion front end surface is the flow direction of the surface material and the back surface material or the flow. Using a joining device having a pressing part with a protrusion different in a direction orthogonal to the direction and a smooth pressing part with a smooth surface, between the pressing member with the protrusion and the smooth pressing part between the surface material and the back surface material. The first and / or second object is achieved by providing a method for manufacturing an absorbent article that is pressed and bonded together to form the heat seal portion.
[0006]
Further, the present invention is a method for producing the above-described absorbent article, which has a large number of protrusions, and the pitch between the protrusions or the area of the protrusion front end surface is the flow direction of the front surface material and the back surface material or the A joining device having a pressing portion with a first protrusion that is different in a direction orthogonal to the flow direction and a pressing portion with a second protrusion having a plurality of protrusions that mesh with the protrusion of the pressing portion with the first protrusion, By providing the manufacturing method of the absorbent article which press-joins between the back surface material between the pressing part with the first protrusion and the pressing part with the second protrusion and forms the heat seal part, / Or achieved the second objective.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail based on preferred embodiments thereof.
[0008]
First, points common to the sanitary napkins of the first and second embodiments will be described. The sanitary napkin 1 (1 ′) of the first and second embodiments includes a liquid-retaining absorbent layer 2 and a liquid-impermeable leak-proof layer 3. The absorbent layer 2 is composed of a liquid-permeable top sheet 21, a liquid-retaining absorbent 22 and a leak-proof sheet 23, and the leak-proof layer 3 is composed of a liquid-impermeable back sheet 31.
[0009]
The absorber 22 has a vertically long shape in which both end portions in the longitudinal direction are formed in a substantially arc shape. The topsheet 21 has an outer dimension larger than that of the absorbent body 22, and the left and right side edges in the longitudinal direction cover the left and right sides of the absorbent body 22 and the non-skin contact surface side of the absorbent body 22. The both ends of the longitudinal direction are located outward from the front and rear ends 22a, 22a of the absorber. The back sheet 31 has a width substantially equal to the width of the top sheet 21 in a state where the left and right side edges are folded, and both end portions in the longitudinal direction are outward from the end portions 22 a and 22 a of the absorber 22. It is extended. Moreover, the leak-proof sheet 23 is disposed between the absorbent body 22 and the back sheet 31, and the right and left side edges are rolled up and positioned on the skin contact surface side of the absorbent body 22, and the longitudinal direction Both end portions extend outward from the end portions 22 a and 22 a of the absorber 22.
[0010]
The surface sheet 21 as the surface material that forms the skin contact surface and the back sheet 31 as the back material that forms the non-skin contact surface are portions extending from the end portions 22a and 22a of the absorber. A pair of heat seal portions ( hereinafter referred to as “seal portions”) which are heat-sealed with each other in a state where a leak-proof sheet 23 is interposed therebetween, and which are substantially symmetrical with each other at both ends in the longitudinal direction of the napkin 1. In this case, it means “heat seal part” ) S and S are formed.
[0011]
Each of the seal portions S, S has a first area E having a large basis weight and a second area F having a relatively small basis weight as compared to the first area E. That is, as shown in FIG. 2B, each seal portion S has a different number of stacked sheets in the width direction of the napkin, and the sheets are stacked in five layers at both ends in the width direction of the napkin 1. It has first areas E and E with a high basis weight, sheets are laminated in three layers in the center in the width direction, and a second area F with a low basis weight is smaller than the first area E. doing. Moreover, between the area | region E and the area | region F, it has the 3rd area | region G which has the basic weight of the intermediate | middle of the 1st area | region E and the 2nd area | region F by which the sheet | seat was laminated | stacked by 4 layers. In addition, the basic weight difference of the 1st area | region E and the 2nd area | region F is 15 g / m < ² > or more.
[0012]
As shown in FIG. 3, each seal portion S is formed by pressing and joining between the top sheet 21 and the back sheet 31 using a joining device including a pair of seal members 4 and 5. Specifically, each of the continuous sheets of the top sheet 21, the leak-proof sheet 23, and the back sheet 31 has a plurality of absorbers 22 and 22 held therein at a predetermined interval and the absorber 22 does not exist. 2 is introduced into a heat seal device including the first seal member 4 and the second seal member 5, and the continuous laminate sheet 10 laminated so that the laminated structure of the sheet becomes the structure shown in FIG. The front and back sheets 21 and 31 in the continuous laminated sheet 10 are pressed from both sides at a portion where the absorbent body 22 is not disposed, and sealed across the width direction. And the continuous lamination sheet 10 in which seal part S 'was formed is cut | disconnected in each seal part S', and the sanitary napkin which has a pair of seal part S and S at both ends is obtained.
[0013]
Next, the characteristic part in the sanitary napkin of 1st Embodiment is demonstrated.
As shown in FIG. 4B, the sanitary napkin 1 of the first embodiment has a large number of protrusions 45, and the area of the front end surface of the protrusion 45 is the flow direction of the top sheet 21 and the back sheet 31 (continuous lamination). A first seal roll 41 having a pressing portion 42 with protrusions different in a direction orthogonal to the conveying direction of the sheet 10 and a second seal roll 51 having a smooth pressing portion 52 having a smooth surface are used. The continuous laminated sheet 10 is inserted between the seal rolls 41 and 51 to form seal portions S and S.
And the unevenness | corrugation formed in the seal part S differs in the area of a recessed part in the width direction of the sanitary napkin 1 as shown to Fig.4 (a).
[0014]
More specifically, as shown in FIG. 4B, the first seal roll 41 has protrusions with large tip surfaces at both end portions 43 and 43 in the axial length direction, and the center in the axial length direction. The portion 44 has a protrusion whose tip end surface area is relatively smaller than the protrusions of both end portions 43 and 43.
[0015]
And the area of the recessed part Sa corresponding to the said protrusion 45 formed in the 1st area | regions E and E of the seal | sticker part S is larger than the area of the recessed part Sb corresponding to the said protrusion 45 formed in the 2nd area | region F. It is getting bigger.
That is, in the heat sealing apparatus provided with the first and second seal rolls 41, 51, the first regions E, E existing at both ends in the width direction of the continuous laminated sheet 10 are the both ends of the first seal roll 41. The second region F, which is pressed between the front end surface of the protrusion 45 in the portions 43 and 43 and the smooth pressing portion 52 of the second seal roll 51 and exists in the center in the width direction, is the center of the first seal roll 41. By introducing the projection 44 so as to be pressed between the front end surface of the protrusion in the portion 44 and the smooth pressing portion 52 of the seal roll 51, the front end surface of the protrusion 45 of the both end portions 43, 43 is provided in the first regions E, E. The second area F is formed with a recess Sb having a smaller area than the recess Sa, which is substantially equal to the area of the tip surface of the protrusion 45 of the central portion 44. ing. In addition, the boundary between the both end portions 43 and 43 and the central portion 44 of the roll 41 is located in the third region G, and a large-area concave portion Sa is formed in approximately half of the third region G, and in the remaining half. A small-area recess Sb is formed.
[0016]
The total area of the recesses Sa per unit area (1 cm ² ) in the first regions E and E is larger than the total area of the recesses Sb per unit area (1 cm ² ) in the second region F.
Further, the ratio of the area of the recess Sa to the area of the recess Sb (the former / the latter) is not particularly limited, but is preferably 1.0 to 40, particularly 1.5 to 9.0. The protrusion 45 has a truncated pyramid shape with a rectangular cross section, and has a substantially rectangular front end surface. And the shape of both recessed part Sa and Sb is a rectangular shape substantially corresponded with the front end surface of each protrusion.
[0017]
The sanitary napkin according to the first embodiment has a large area recess Sa in the first areas E, E having a large basis weight, and a small area recess Sb in the second area having a relatively small basis weight. Therefore, it is difficult to cause poor bonding such as floating or peeling or damage such as breakage or hole in the seal portion, and the appearance and leakage prevention are excellent. Moreover, since the recessed part of 2nd area | region F is a smaller area than the recessed part of 1st area | region E and E, the touch which strikes a wearer is soft and it is excellent in a feeling of wearing.
[0018]
Next, features of the sanitary napkin of the second embodiment will be described.
The sanitary napkin 1 ′ of the second embodiment has a large number of protrusions 47 as shown in FIG. 5B instead of the first seal roll 41 and the second seal roll 51 described above. A first seal roll 46 having a first protrusion-equipped pressing portion 42 in a direction orthogonal to the flow direction of the top sheet 21 and the back sheet 31 (the same direction as the conveying direction of the continuous laminated sheet 10), and the first protrusion Except that the seal portion S is formed using a second seal roll 55 having a second protrusion-equipped pressing portion 53 having a number of protrusions 54 that mesh with the protrusions 47 of the attached pressing portion 42, the same as in the first embodiment. As shown in FIG. 5 (a), the unevenness formed in each seal portion S has a different pitch of the recesses in the width direction of the sanitary napkin.
[0019]
More specifically, a large number of protrusions 47 are formed at a large pitch P ₃ at both end portions 48, 48 of the first seal roll 46 in the axial length direction, and an intermediate portion 49 of the roll 46 in the axial length direction. A large number of protrusions 47 are formed at a pitch P ₄ that is relatively smaller than both end portions 48, 48. The first region E, are formed in the E, spacing P ₁ of recess Sa corresponding to the protrusion 47 is formed in the second region F, greater than the distance P ₂ of the recess Sb corresponding to the projections 47 ing.
[0020]
That is, in the heat sealing apparatus provided with the first and second seal rolls 46 and 55, the first regions E and E existing at both ends in the width direction of the continuous laminated sheet 10 are the both ends of the first seal roll 46. The second region F, which is engaged between the protrusions 47 in the portions 48 and 48 and the protrusions 54 at both ends of the second seal roll 55 and exists in the center in the width direction, is the center of the first seal roll 46. 49, and the first region E, E is introduced into the first region E, E so that the pitch of the protrusions 47 at both end portions 48, 48 is introduced between the protrusion 47 at 49 and the protrusion 54 at the center of the second seal roll 55. Concave portions Sa are formed with a pitch P ₁ substantially equal to P ₃ , and concave portions Sb are formed in the second region F with a pitch P ₂ substantially equal to the pitch P ₄ of the protrusions 47 of the central portion 49.
[0021]
Here, the pitches P ₃ and P ₄ of the protrusions 47 mean intervals between valleys formed between the protrusions, and the pitches P ₁ and P _{2 of the} recesses Sa and Sb are between adjacent recesses. Mean interval. Note that the first and second seal rolls in each heat sealing device used in the first and second embodiments rotate in synchronization with each other, and are provided with a protrusion with a protrusion (press with a first protrusion approximately every half rotation). Part) 42 and the smooth pressing part 52 or the pressing part 53 with the second protrusion, the continuous laminated sheet 10 is sandwiched, and the sealing part S (S ′) is intermittently formed on the sheet 10. Yes. Further, in the heat sealing apparatus used in the second embodiment, the valley between the protrusions 47 of the first seal roll 46 has a V-shaped cross section, and the angle formed by the left and right wall surfaces of each valley is the axis of the roll. It is the same angle over the long direction. Each protrusion 47 has a substantially truncated pyramid shape, and each protrusion 54 is formed in the circumferential direction of the roll 54 as a protrusion having a substantially trapezoidal cross section.
[0022]
The first region E, the pitch _{P 1} of the concave portion Sa in E, ratio pitch _{P 2} of the recess Sb in the second region F (the former / the latter) is, is not particularly limited, 1.0 to 8. 0, especially 1.5 to 4.0 is preferred.
[0023]
According to the sanitary napkin of the second embodiment, the basis weight of greater first region E, a plurality of recesses Sa to E is formed with a large pitch P _1, the basis weight of the relatively small plurality of the second region F Since the recesses Sb are formed with a pitch P ₂ smaller than P ₁ , the same operational effects as in the first embodiment can be obtained.
[0024]
Next, sanitary napkins according to third and fourth embodiments of the present invention will be described.
As shown in FIG. 6, the sanitary napkins of the third and fourth embodiments each have a pair of flap portions 12 formed by extending the top sheet 21 and the back sheet 31 on the left and right sides in the longitudinal direction. 12 and the peripheral edge thereof is sealed over the entire circumference to form an annular seal portion S.
[0025]
A vertically long absorbent body 22 is sandwiched and fixed between the top sheet 21 and the back sheet 3, and a leakproof sheet 23 wider than the absorbent body 22 is provided on the non-skin contact surface side of the absorbent body 22. The both side edge portions are disposed so as to cover both side portions of the absorbent body 22 and to be located on the skin contact surface side of the absorbent body 22.
As shown in FIGS. 6 and 7, the seal portion S is a first area E having a large basis weight, in which the portion where the leak-proof sheet 23 is arranged is composed of a three-layer or four-layer sheet. The portions located on the left and right outer sides of the region E are second regions F in which the basis weight made of the two-layer sheets is relatively smaller than that of the first region E.
[0026]
And the sanitary napkin of 3rd Embodiment has many protrusions similarly to 1st Embodiment, and the area | region of this protrusion front end surface differs in the direction orthogonal to the flow direction of the surface sheet 21 and the back surface sheet 31 In a heat seal device having a pressing portion and a smooth pressing portion having a smooth surface, a plurality of absorbers 22, 22. It is manufactured by introducing a continuous laminated sheet that is laminated so that the laminated structure of the sheet in the portion that is opened and held and does not have the absorber 22 is the structure shown in FIG. Formed in the first region E by forming a seal portion S by pressing and joining between the pressing portion with projection and the smooth pressing portion between the top sheet 21 and the back sheet 31 in the continuous laminated sheet Area of the recess of the irregularities is made larger than the area of the concave portions of the concavo-convex formed in the second region F.
[0027]
Further, in the sanitary napkin of the fourth embodiment, similarly to the second embodiment, the sanitary napkin has a plurality of protrusions and the pitch between the protrusions is different in the direction orthogonal to the flow direction of the top sheet 21 and the back sheet 31. A continuous laminated sheet having the same configuration as that of the third embodiment is introduced into a heat seal device having a pressing portion with one protrusion and a pressing portion with a second protrusion having a number of protrusions meshing with the protrusions of the pressing portion with the first protrusion. The seal portion S is manufactured by pressing and joining the top sheet 21 and the back sheet 31 of the continuous laminated sheet between the first protrusion-equipped pressing portion and the second protrusion-equipped pressing portion. By forming, the space | interval between the uneven | corrugated recessed parts formed in the 1st area | region E is made larger than the space | interval between the uneven | corrugated recessed parts formed in the 2nd area | region F. FIG.
According to the sanitary napkin of 3rd and 4th embodiment, there can exist an effect similar to 1st and 2nd embodiment.
[0028]
As materials for forming the topsheet 21, the absorber 22 and the backsheet 31 in the first to fourth embodiments, various conventionally known materials can be used. For example, as the surface sheet as the surface material, a non-woven sheet made of thermoplastic synthetic fibers is preferably used. The back sheet 31 as the back material may be a single sheet or a laminated sheet bonded to a nonwoven fabric or the like. Moreover, as the leak-proof sheet | seat 23, the nonwoven fabric which gave the water-repellent process, the film of a thermoplastic resin, etc. are used preferably.
[0029]
The present invention is not limited to the above-described embodiments, and various modifications can be made. For example, the seal portion has a first region having a large thickness and a second region having a relatively small thickness as compared to the first region, and the unevenness in the first region is a recess or an unevenness compared to the unevenness in the second region. The pitch or area of the convex portions may be large. Moreover, the unevenness | corrugation formed in the seal | sticker part may differ in the pitch or area of a recessed part or a convex part in the longitudinal direction of an absorbent article.
[0030]
Moreover, you may use a pair of non-roll-shaped blocks etc. as a 1st and 2nd sealing member. In addition, a description omitted portion of one embodiment is applied to other embodiments as appropriate, and requirements of only one embodiment can be applied to other embodiments. In addition to sanitary napkins, the present invention can also be applied to disposable diapers, incontinence pads, panty liners, pet sheets, and the like.
[0031]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, there is no adhesion defect and damage in a seal part, and it can provide the absorbent article excellent in the external appearance and leak-proof property, and its manufacturing method. The present invention is particularly useful when the part to be sealed has a plurality of regions having different basis weights or thicknesses. That is, by increasing the pitch or area of the recesses at a portion where the bonding strength is likely to be insufficient, sufficient bonding strength can be obtained at such a portion without causing inconvenience such as damage to other portions. In addition, when a particularly high bonding strength is required for a part of the seal portion, the bonding strength of only that portion can be similarly improved.
Moreover, according to the present invention, it is possible to provide an absorbent article excellent in wearing feeling and a method for producing the same by partially varying the pitch or area of the concave portions or convex portions in the concave and convex portions formed in the seal portion. it can.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a sanitary napkin according to first and second embodiments with a part cut away.
2 is a diagram schematically showing a cross-section along the width direction of the sanitary napkin in FIG. 1, FIG. 2 (a) is a cross-sectional view taken along the line AA, and FIG. FIG.
FIG. 3 is a perspective view showing one step in the manufacturing process of the sanitary napkin according to the first embodiment.
4A and 4B are schematic views for explaining a method and a configuration of a seal portion in the first embodiment, FIG. 4A is a plan view showing the seal portion, and FIG. 4B is a joining device. It is sectional drawing which shows the state which press-joins a to-be-sealed part using.
FIGS. 5A and 5B are schematic diagrams for explaining a forming method and a configuration of a seal portion in a second embodiment, FIG. 5A is a plan view showing the seal portion, and FIG. It is sectional drawing which shows the state which press-joins a to-be-sealed part using.
FIG. 6 is a perspective view showing a sanitary napkin according to third and fourth embodiments with a part cut away.
7 is a diagram schematically showing a cross-section along the width direction of the sanitary napkin of FIG. 6, FIG. 7 (a) is a cross-sectional view taken along the line CC, and FIG. FIG.
[Explanation of symbols]
1 Absorbent article (Sanitary napkin)
2 Absorbing layer 21 Top sheet 22 Absorber 23 Leak-proof sheet 3 Leak-proof layer 31 Back sheet 4 First seal member 41, 46 First seal roll 42 Pressing part with protrusion (pressing part with first protrusion)
45, 47 Protrusion 5 Second seal member 51, 55 Second seal roll 52 Smooth pressing portion 53 Press portion 54 with second protrusion Protrusion S Seal portion Sa, Sb Recess E First region F Second region

Claims (4)

A surface material that has a liquid-retaining absorbent layer and a liquid-impermeable leak-proof layer, is substantially vertically long, and forms a skin contact surface; and a back material that forms a non-skin contact surface; In the absorbent article in which a heat seal part is formed by bonding, the heat seal part has irregularities, and the irregularities are concave or convex in the longitudinal direction or the width direction of the absorbent article. Absorbent articles with different pitches or areas. The heat seal part has a first region having a large basis weight or thickness and a second region having a relatively small basis weight or thickness compared to the first region, and the unevenness in the first region is The absorptive article according to claim 1 whose pitch or area of a crevice or a convex part is large compared with the unevenness of said 2nd field. It is a manufacturing method of the absorbent article of Claim 1, Comprising: It has many protrusions, The pitch between these protrusions, or the area of the front-end | tip surface of a protrusion is orthogonal to the flow direction of the said surface material and the said back surface material, or this flow direction. Using a joining device having a pressing part with a protrusion different in direction and a smooth pressing part with a smooth surface, press bonding between the pressing part with a protrusion and the smooth pressing part between the surface material and the back surface material And the manufacturing method of the absorbent article which forms the said heat seal part. The method for manufacturing an absorbent article according to claim 1, wherein a plurality of protrusions are provided, and a pitch between the protrusions or an area of the tip end surface of the protrusion is orthogonal to the flow direction of the surface material and the back surface material or the flow direction. Using a joining device having a pressing portion with a first protrusion that is different in the direction to be pressed, and a pressing portion with a second protrusion having a plurality of protrusions that mesh with the protrusions of the pressing portion with the first protrusion. The manufacturing method of the absorbent article which press-joins between the press part with a 1st protrusion, and the press part with a 2nd protrusion, and forms the said heat seal part.

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