JP4749256B2 - Manufacturing method of composite sheet - Google Patents

Description

  The present invention relates to a method for producing a composite sheet and a method for producing an absorbent article using the same.

  In absorbent articles such as disposable diapers, a stretchable sheet (stretchable sheet) and a non-stretchable sheet (a sheet that does not substantially have stretchability and contractibility) are bonded as its constituent members. Some have a composite sheet. Such a composite sheet of a stretchable sheet and a non-extensible sheet is generally conveyed while applying a longitudinal tension to each of the belt-like stretchable sheet and the belt-like non-stretchable sheet, and the both sheets are joined together. Formed by joining them together. The reason why tension is applied to the sheet during conveyance is that the belt-like sheet cannot be stably conveyed when it is slackened between the conveyance rolls.

  If it is a non-extensible sheet | seat, if some tension | tensile_strength is given to a longitudinal direction, slack will be eliminated and it can convey stably (for example, refer patent document 1, 2 below). On the other hand, since the stretchable sheet is stretched when a tension is applied in the longitudinal direction, it is necessary to apply a large tension to eliminate the slack. Further, when a large tension is applied in the longitudinal direction of the stretchable sheet, the stretchable sheet is greatly reduced in width (width is reduced), while when the longitudinal tension is removed, the stretchable sheet is widened (width). Will recover). Therefore, it is necessary to convey the stretchable sheet in anticipation of the width reduction during conveyance and the widening after removing the tension.

JP-A-4-161152 JP-A-6-296638

  However, it is not easy to set the transport conditions for elastic sheets in anticipation of width reduction and widening, and to stably transport elastic sheets. In many cases, the width of the film becomes wider or narrower. For example, if the width of the stretchable sheet is wider than the designed dimensions, the stretchable sheet will be loose, which is not preferable.

  Accordingly, an object of the present invention is to provide a method for producing a composite sheet that can prevent a reduction caused by applying tension in the longitudinal direction of the stretchable sheet during conveyance, and a method for producing an absorbent article using the same. It is to provide.

  The present invention conveys a belt-like stretchable sheet having stretchability in the longitudinal direction in the longitudinal direction without substantially stretching, and converts both sheets into a belt-like non-shrinkable sheet that does not substantially shrink in the longitudinal direction. This object is achieved by providing a composite sheet manufacturing method for manufacturing a stretchable composite sheet composed of a stretchable sheet and a non-shrinkable sheet by matching the longitudinal directions of the two.

  The present invention also relates to a method for producing an absorbent article comprising a stretchable composite sheet in which a stretchable sheet having stretchability in the longitudinal direction and a non-shrinkable sheet that does not substantially shrink in the longitudinal direction are joined. A composite sheet forming step of joining a stretchable sheet and a non-shrinkable sheet to form a composite sheet using the method for manufacturing a composite sheet, and a composite sheet formed in the composite sheet forming step. The above object is achieved by providing a method for manufacturing an absorbent article comprising a composite sheet conveying step for conveying in the longitudinal direction without stretching.

  According to the method for producing a composite sheet of the present invention, it is possible to prevent a decrease in width caused by applying tension in the longitudinal direction of the stretchable sheet during conveyance. Therefore, according to the manufacturing method of the absorbent article of this invention, an elastic sheet can be conveyed stably and an absorbent article can be manufactured accurately.

Hereinafter, the manufacturing method of the composite sheet of this invention and the manufacturing method of an absorbent article using the same are demonstrated, referring drawings based on the preferable embodiment (1st embodiment).
First, the underpants type disposable diaper which is one form of the absorbent article manufactured by the manufacturing method of the absorbent article of this embodiment is demonstrated.
The perspective view of an example of the underpants type disposable diaper manufactured by the manufacturing method of this embodiment is shown by FIG. FIG. 2 shows a plan view of the deployed state of the disposable diaper shown in FIG. FIG. 3 shows an exploded perspective view of the disposable diaper shown in FIG. 4 shows a cross-sectional view taken along line II-II in FIG.

  The pants-type disposable diaper 1 shown in FIGS. 1 to 4 includes a liquid-permeable top sheet 2, a liquid-impermeable or water-repellent back sheet 3, and a liquid-retaining absorption disposed between both sheets 2 and 3. A substantially vertically long absorbent body 10 having a conductive core 4 and an outer packaging material 11 joined to the non-skin contact surface side (back surface sheet 3 side) of the absorbent body 10.

  The outer packaging material 11 has an hourglass shape in which both side edges are bound inward in the central portion in the longitudinal direction, and defines the outline of the diaper. The disposable diaper 1 is divided into an abdominal side A disposed on the wearer's belly side, a back side B disposed on the back side, and a crotch C positioned therebetween in the longitudinal direction of the disposable diaper 1. . In the outer packaging material 11, both side edges A1 and A2 on the ventral side A and both side edges B1 and B2 on the back side B are joined to each other, and a pair of side seal parts are attached to the disposable diaper 1 by the joining. S, S, a waist opening 5 and a pair of leg openings 6, 6 are formed.

  The top sheet 2, the back sheet 3, and the absorbent core 4 each have a rectangular shape, and are integrated to form a vertically long absorbent body 10. As the surface sheet 2, the back surface sheet 3, and the absorbent core 4, those similar to those conventionally used in this type of disposable diaper can be used. For example, as the absorptive core 4, what is comprised from the particle | grains and fiber material of a superabsorbent polymer, and is coat | covered with the tissue paper (not shown) can be used.

  As shown in FIG. 2, side cuffs 8 and 8 made of a liquid-resistant or water-repellent and breathable material are formed on the left and right sides of the absorbent body 10 in the longitudinal direction. In the vicinity of the free end of each side cuff 8, a side cuff elastic member 81 is disposed in an extended state. When the diaper is worn, the side cuff 8 is erected by contracting the side cuff elastic member 81, and the outflow of the liquid in the width direction of the absorbent body 10 is prevented. FIG. 3 shows a sheet material 82 forming the side cuff 8. In the completed disposable diaper 1, the sheet material 82 has a portion 82 </ b> S having a predetermined width on the outer side in the width direction of the absorbent main body 10 wound down to the non-skin contact surface side of the back sheet 3. 11.

  As shown in FIGS. 3 and 4, the outer packaging material 11 is a composite in which an outer layer sheet 12 and an inner layer sheet 13 disposed on the inner surface side of the outer layer sheet 12 (on the side facing the absorbent main body 10) are laminated. It consists of a sheet. The outer layer sheet 12 forms the outer surface of the disposable diaper 1, and the inner layer sheet 13 is disposed on the inner surface side of the outer layer sheet 12 and is partially joined. Hereinafter, the outer layer sheet 12 and the inner layer sheet 13 are also simply referred to as two sheets 12 and 13 or both sheets 12 and 13.

  As shown in FIGS. 3 and 4, between the two sheets 12 and 13 on the ventral side A and the back side B, respectively, heat sealing and high frequency sealing are performed on both side edges A1, A2 and B1, B2. Alternatively, they are bonded to each other by ultrasonic sealing, and the peripheral edge 50 of the waist opening 5 and the peripheral edge 60 of each of the pair of leg openings 6 are bonded to each other by adhesives 52 and 62 such as a hot-melt adhesive. Yes.

  And between the two sheets 12 and 13 in each of the ventral part A and the back part B is not joined in most of the parts except the joined part. Specifically, between the two sheets 12 and 13, both side edges A 1, A 2 and B 1 and B 2 of the ventral side A and the back side B, the peripheral edge 50 of the waist opening 5, and a pair of leg openings It joins in the peripheral part 60 of each part 6, and is joined by the adhesive agent 14 in the diaper width direction center part of each of the abdominal part A and the back part B in addition to them, and it joins in parts other than those It has not been.

A plurality of waist elastic members 51 and 51 are arranged along the opening peripheral edge of the waist opening 5 on the peripheral edge 50 of the waist opening 5 in each of the ventral side A and the back side B. These waist elastic members 51 and 51 are joined in an extended state between the two sheets 12 and 13 via an adhesive 52.
In addition, the leg elastic members 61a are provided along the peripheral edges of the leg openings 6 along the peripheral edges 60, 60 of the leg openings 6 existing over the ventral side A, the crotch C, and the back side B. , 61b are arranged. These leg elastic members 61 a and 61 b are joined in an extended state between the two sheets 12 and 13 via an adhesive 62.
As the waist elastic member 51 and the leg elastic members 61a and 61b, elastic materials such as natural rubber, polyurethane resin, urethane foam resin, and hot melt elastic member are made into a thread (thread rubber) or a belt (flat rubber), respectively. Those formed into (rubber) are preferably used.

  The width | variety of the area | region where two sheets 12 and 13 which exist in the peripheral part 50 of the waist opening part 5 are joined from the peripheral edge 50 of the waist opening part 5 about each of the ventral | abdominal side part A and the back side part B. It is preferably within 50 mm, more preferably within 30 mm. In addition, the width of the region where the two sheets 12 and 13 are joined to each other in the peripheral edge 60 of the leg opening 6 is the leg opening in each part of the abdominal part A, the crotch part C, and the dorsal part B. It is preferably within 50 mm from the peripheral edge 60 of the part 6, and more preferably within 30 mm.

In the diaper width direction in each of the ventral side A and the back side B, the total length of the portions where the two sheets 12 and 13 are not joined (L1 + L2, see FIG. 3) is the left and right side edges A1, The length La (Lb) between A2 is preferably 60% or more, more preferably 70% or more, and still more preferably 80% or more.
Moreover, the area of the part which is not joined between the two sheets 12 and 13 in each of the ventral part A and the dorsal part B is 60 to 100 with respect to the areas of the ventral part A and the dorsal part B, respectively. %, Preferably 70 to 100%. Those satisfying this numerical value shall be referred to as “the entire region or most of them are not joined”.

  As shown in FIG. 2, the dimensions and ratios of the respective parts described in the present specification are such that the diaper is stretched against the contraction force by the elastic members in the waist opening 5 and the leg opening 6 (such as a tensile force). The value measured in a state where no external force is applied) or based on it.

  In the disposable diaper 1 according to the present embodiment, the adhesives 62 and 14 are disposed between the two sheets 12 and 13 in the crotch part C at the peripheral part 60 of the leg opening 6 and the diaper width direction central part of the crotch part C. However, it is not joined in other parts. Further, as shown in FIG. 2, leg elastic members 61 a and 61 b for imparting elasticity to the peripheral edge 60 of the leg opening 6 are arranged in the center in the width direction of the crotch C from the peripheral edge 60 of the leg opening 6. In this way, the portion where the leg elastic members 61 a and 61 b for providing the leg opening 6 with circumferential stretchability are arranged at the periphery of the leg opening 6. 60.

  In the disposable diaper 1, the outer layer sheet 12 has a length that extends further than a portion where the waist elastic members 51, 51 are sandwiched and joined by the two sheets 12, 13, as shown in FIG. 3. Extending portions 12a and 12b extending from the inner layer sheet 13 are folded back toward the absorbent body 10 side. Therefore, the absorbent main body 10 is covered with the folded back extended portions 12 a and 12 b of the outer layer sheet 12 on the skin contact surface side at both ends in the longitudinal direction. The covered portions are bonded to the folded back extended portions 12a and 12b of the outer layer sheet 12 via an adhesive (not shown). Thereby, the longitudinal direction both ends of the absorptive main body 10 are firmly joined to the outer packaging material 11.

  As for the absorptive main body 10, only the center part of the width direction is joined via the outer packaging material 11 and the adhesive agent 15 in the part except the both ends of the longitudinal direction, as shown in FIG. According to such a joining form, since the expansion and contraction in the width direction of the outer packaging material 11 is not easily inhibited by the joining of the absorbent main body 10, a good fit is obtained at the waistline portion. The width U1 (see FIG. 4) of the region where the absorbent main body 10 and the outer packaging material 11 are bonded is 20 to 80% of the width U0 of the absorbent main body 10 in each of the ventral part A and the back part B. It is preferable that it is 30 to 70%.

  The outer layer sheet 12 is made of an elastic sheet. As the stretchable sheet, various sheets having stretchability in the longitudinal direction can be used. The stretchable sheet is used so that the stretch direction of the outer layer sheet 12 is oriented in the width direction of the absorbent main body 10 (left and right direction in FIG. 2).

  The stretchable sheet in the present invention is a sheet having stretchability in at least one of the in-plane directions. The stretchable sheet may have stretchability in all directions within the surface. In that case, the degree of stretchability may differ depending on the direction. The degree of stretchability in the most stretchable direction is preferably 20 to 500 cN / 25 mm, particularly preferably 40 to 150 cN / 25 mm, at 100% elongation. Further, the residual strain when contracted from the 100% stretched state is preferably 15% or less, and particularly preferably 10% or less.

  Examples of the elastic sheet include (1) a sheet in which a stretchable fiber layer is integrated on both sides or one side of the elastic fiber layer, and (2) a fiber that can be stretched on both sides or one side of a net-like elastic sheet. A sheet in which layers are integrated, and (3) a sheet in which stretchable fiber layers are integrated on both sides or one side of an elastic sheet made of an elastic film. In addition, as an integration method of the elastic fiber layer and the extensible fiber layer, these are laminated and hydroentangled, or the fibers are entangled by air-through, etc., bonded by heat embossing, adhesive, ultrasonic waves, etc. The method of letting it be mentioned.

As the sheet of (1), for example, (a) a substantially inelastic non-elastic fiber layer is disposed on at least one surface of the elastic fiber layer, and both fiber layers have a fiber form of the constituent fibers of the elastic fiber layer. In a state where the fibers are joined together by thermal fusion at the fiber intersections, a part of the constituent fibers of the inelastic fiber layer has entered the elastic fiber layer and / or a part of the constituent fibers of the elastic fiber layer Stretchable non-woven fabric in a state where is embedded in the non-elastic fiber layer.
The sheets (1) to (3) include, for example, (b) an elastic layer having elastic stretchability and a substantially inelastic nonelastic fiber layer, and the both layers are laminated in the thickness direction. A stretchable sheet obtained by stretching a laminated sheet that is partially bonded can be preferably used.

The stretchable nonwoven fabric (a) will be described.
At the interface between the elastic fiber layer and the non-elastic fiber layer and in the vicinity thereof, the intersection of the constituent fiber of the elastic fiber layer and the constituent fiber of the non-elastic fiber layer is heat-sealed, and it is bonded substantially uniformly over the entire surface. Has been. By joining all over, it is prevented that both layers are separated and a space is formed, and a stretchable nonwoven fabric having a multi-layer structure with a sense of unity, such as a single nonwoven fabric. "The state in which the constituent fibers of the elastic fiber layer maintain the fiber form" means that even if most of the constituent fibers of the elastic fiber layer are given heat, pressure, etc., they are deformed into a film or film-fiber structure. The state that is not. Further, in the elastic fiber layer, the intersections of the constituent fibers are thermally fused in the layer. Similarly, in the non-elastic fiber layer, the intersection of the constituent fibers is thermally fused in the layer.

  When non-elastic fiber layers are arranged on both sides of the elastic fiber layer, at least one of the constituent fibers is in a state in which a part of the constituent fibers enters the elastic fiber layer and / or the constituent fibers of the elastic fiber layer A part has entered into at least one of the inelastic fiber layers. In order to allow the constituent fibers of the non-elastic fiber layer to enter the elastic fiber layer and / or to allow the constituent fibers of the elastic fiber layer to enter the non-elastic fiber layer, the constituent fibers of the non-elastic fiber layer and the non-elastic fiber layer It is preferable that at least one of the non-elastic fiber and the elastic fiber is in a web state (a state where the fiber is not heat-sealed) before the process of thermally fusing the constituent fibers.

  From the viewpoint of allowing the constituent fibers to enter into other layers, the fiber layer in the web state is preferable in that the short fibers are more flexible than the long fibers. Moreover, it is preferable to use the air-through method in order to allow the constituent fibers of the non-elastic fiber layer to enter the elastic fiber layer and / or to allow the constituent fibers of the elastic fiber layer to enter the non-elastic fiber layer. By using the air-through method, the constituent fibers can be made to enter the opposing fiber layer, and the constituent fibers can be easily made to enter from the opposing fiber layer. Further, by using the air-through method, it becomes easy to allow the constituent fibers of the inelastic fiber layer to enter the elastic fiber layer while maintaining the bulkiness of the inelastic fiber layer.

  In particular, when the constituent fibers of the inelastic fiber layer are entangled with the constituent fibers of the elastic fiber layer, it is preferable that they are entangled only by the air-through method. In order to entangle the fibers by the air-through method, the gas blowing pressure, the blowing speed, the basis weight and thickness of the fiber layer, the conveyance speed of the fiber layer, etc. may be adjusted appropriately. Preferably it is done. In the hot air treatment (particularly, the air-through method), a part of the constituent fibers of the non-elastic fiber web enters the elastic fiber web, and at the same time, the constituent fibers of the non-elastic fiber web and / or the constituent fibers of the non-elastic fiber web are elastic. The constituent fibers of the fiber web are heat-sealed at their intersections. In this case, care should be taken so that the constituent fibers of the elastic fiber web do not become a film or film-fiber structure by the hot air treatment.

  The elastic fiber layer has a property that it can be stretched and contracts when released from the stretched force. The elastic fiber layer preferably has a residual strain of 20% or less, particularly 10% or less when contracted after 100% elongation in at least one direction parallel to the surface. This value is preferably satisfied in at least one of the MD direction and the CD direction, and more preferably satisfied in both directions.

  The elastic fiber layer is an aggregate of fibers having elasticity. The elastic fiber forming method includes, for example, a melt blown method in which a molten resin is extruded from a nozzle hole, and the extruded molten resin is elongated by hot air to thin the fiber, and a semi-molten resin is cooled by cold air. And a spunbond method in which stretching is performed by a mechanical draw ratio. There is also a spinning blow method which is a kind of melt spinning method.

  The elastic fiber layer may be in the form of a web or a nonwoven fabric made of elastic fibers. For example, it may be a web or a nonwoven fabric formed by a spinning blow method, a spun bond method, or a melt blow method. Particularly preferred is a web obtained by the spinning blow method.

  As the constituent fiber of the elastic fiber layer, for example, a fiber made of thermoplastic elastomer, rubber or the like can be used. In particular, fibers made from thermoplastic elastomers can be melt-spun using an extruder in the same way as ordinary thermoplastic resins, and the fibers thus obtained are easily heat-sealed. Is suitable for stretchable nonwoven fabrics. Examples of the thermoplastic elastomer include styrene elastomers such as SBS, SIS, SEBS, and SEPS, olefin elastomers, polyester elastomers, and polyurethane elastomers. These can be used individually by 1 type or in combination of 2 or more types.

  The inelastic fiber layer is extensible but substantially inelastic. The extensibility here refers to the case where the constituent fibers themselves are stretched, and even if the constituent fibers themselves are not stretched, the two fibers that have been thermally fused at the intersection of the fibers are separated from each other, or the fibers are thermally fused. For example, the three-dimensional structure formed by a plurality of fibers may be structurally changed, the constituent fibers may be broken, and the entire fiber layer may be elongated.

  Examples of the fibers constituting the inelastic fiber layer include fibers made of polyethylene (PE), polypropylene (PP), polyester (PET or PBT), polyamide, and the like. The fibers constituting the inelastic fiber layer may be short fibers or long fibers, and may be hydrophilic or water repellent. Further, core-sheath type or side-by-side composite fibers, split fibers, irregularly shaped cross-section fibers, crimped fibers, heat-shrinkable fibers, and the like can also be used. These fibers can be used singly or in combination of two or more. The inelastic fiber layer may be a continuous filament, a short fiber web or a non-woven fabric.

The stretchable sheet (b) will be described.
In the stretchable sheet of (b), a substantially inelastic nonelastic fiber layer is laminated on both sides or one side of an elastic layer having elastic stretchability, and these are partially joined in a regular pattern. It can be obtained by stretching the laminated sheet.

  The laminated sheet used for the production of the stretchable sheet is, for example, supplying an elastic fiber on a fiber web (first inelastic fiber layer) supplied from a card machine to form an elastic layer, A fiber web (second inelastic fiber layer) is supplied from another card machine, and the obtained three-layer laminated sheet is subjected to hot air treatment by an air-through dryer. The laminated sheet after the hot air treatment is subjected to hot embossing by an embossing device including an embossing roll in which embossing convex portions are regularly arranged on the peripheral surface and an anvil roll arranged to face the embossing roll. Hot air treatment using a dryer is performed for the purpose of heat-sealing elastic fibers and non-elastic fibers and entering the fibers. Note that such hot air treatment can be omitted.

  The elastic layer preferably includes elastic fibers made of an elastic material. Examples of the elastic material include a thermoplastic elastomer, rubber, ethylene / propylene copolymer, and the like. Among these, a thermoplastic elastomer is preferable because a fibrous elastic body can be formed relatively easily. Examples of the thermoplastic elastomer include polyurethane, styrene (SBS, SIS, SEBS, SEPS, etc.), olefin (copolymers such as ethylene, propylene, butene, etc.), vinyl chloride, and polyester. These can be used individually by 1 type or in combination of 2 or more types.

  The content of elastic fibers made of an elastic material in the elastic layer is preferably 50 to 100% by weight, and more preferably 75 to 100% by weight. As an elastic layer, it can replace with what consists of a fiber layer, and a film-like thing, a net-like thing, etc. can also be used. As the film or net forming material, the above-mentioned various elastic materials can be used.

  Various known materials can be used as the elastic sheet. For example, a nonwoven fabric made of a mixed fiber containing fibers made of a thermoplastic polyurethane elastomer described in JP-A-2004-244791 can be used. The stretchable composite non-woven fabric described in JP-A-3-269145, the sheet described as “Extensible Satellite Supplies Surface Sheet” in JP-A-3-269145, the elastic-stretchable composite sheet described in JP-A-2001-18315, and JP-A-2001 A stretchable composite nonwoven fabric described in JP-A No. 140158, a composite elastic nonwoven fabric described in JP-T 9-500936, a laminated sheet described in JP-A-10-29259, and the like can also be used.

  The inner layer sheet 13 is made of a non-shrinkable sheet. A non-shrinkable sheet is a sheet that does not have shrinkability, and may have stretchability, but preferably it hardly stretches to the extent that it is pulled by hand, or stretches slightly when stretched. It is a non-extensible sheet. The non-extensible sheet has an elongation rate (elongation rate at the time of 1.0 N / 25 mm) of 20% or less when the sheet is stretched in the longitudinal direction until the tensile load per 25 mm width becomes 1.0 N, preferably 0 10% sheet. As the non-extensible sheet, for example, a nonwoven fabric, a laminated material of a nonwoven fabric and a resin film, or a porous film is preferably used. As a nonwoven fabric which comprises a non-extensible sheet | seat, the nonwoven fabric by various manufacturing methods, such as an air through nonwoven fabric, a heat roll nonwoven fabric, a spunlace nonwoven fabric, a spun bond nonwoven fabric, a melt blown nonwoven fabric, are mentioned, for example.

The elongation percentage is measured as follows using a tensile tester.
A sheet sample having a width of 25 mm and a length of 50 mm is prepared. The sample is pulled between 50 mm with a load of 1.0 N / 25 mm width, and the length of the sample after elongation is A. And the expansion rate at that time is defined as follows. “(A-50) / 50 × 100”. That is, (length of sample after stretching at 1.0 N−length of sample before stretching) / (length of sample before stretching) × 100. For example, when the length of the sample after extension is 100 mm, the extension rate is 100%, and when the sample length after extension is 150 mm, the extension rate is 200%.

The outer packaging material 11 made of a composite sheet of the outer layer sheet 12 made of an elastic sheet and the inner layer sheet 13 made of a non-shrinkable sheet has elasticity as the entire outer packaging material 11 based on the elasticity of the outer layer sheet 12. Yes. The preferable expansion / contraction performance of the outer packaging material 11 is as follows.
The outer packaging material 11 preferably has a load at 100% elongation of 25 to 1875 cN / 25 mm, particularly 50 to 500 cN / 25 mm. Further, it is preferable that the outer packaging material 11 has a residual strain of 30% or less, particularly 15% or less when contracted from an extended state of 100%.

  Next, a method for continuously producing the above-described pants-type disposable diaper 1 using one embodiment of the method for producing an absorbent article of the present invention will be described with reference to the drawings. In addition, since the manufacturing method of the composite sheet of this invention comprises the one part process of the manufacturing method of the absorbent article of this invention, it combines in description of one embodiment of the manufacturing method of the absorbent article of this invention. explain.

As shown in FIG. 5, the manufacturing method of the absorbent article according to the present embodiment is formed by joining a stretchable sheet 120 having stretchability in the longitudinal direction and a non-shrinkable sheet 130 that does not substantially shrink in the longitudinal direction. It is a manufacturing method of an absorptive article provided with composite sheet 110, and comprises the following processes S1-S3. In addition, the longitudinal direction of the stretchable sheet 120 and the non-shrinkable sheet 130 is the longitudinal direction as a strip-shaped material.
Elastic sheet conveying step S1: The belt-shaped elastic sheet 120 is conveyed in the longitudinal direction without substantially extending.
Stretchable sheet joining step S2: The stretchable sheet 120 and the non-shrinkable sheet 130 are joined by joining the stretchable sheet 120 transported in the stretchable sheet transporting step S1 so that the longitudinal directions of both sheets 120 and 130 coincide. A composite sheet 110 is formed.
Composite sheet transporting step S3: The composite sheet 110 formed in the stretchable sheet joining step S2 is transported in the longitudinal direction without substantially extending.
That is, the elastic sheet conveying step S1 and the elastic sheet joining step S2 constitute a composite sheet forming step in the method for manufacturing an absorbent article of the present invention.

Moreover, the following process S21 is included in a part of elastic sheet joining process S2.
Non-shrinkable sheet extension enabling step S21: The non-shrinkable sheet 130 is joined to the stretchable sheet 120 in a stretchable state so that the stretchable sheet 120 can be stretched. Specifically, after forming the ridges so that the unevenness is repeated along the longitudinal direction on the non-shrinkable sheet 130, the non-shrinkable sheet 130 is joined to the stretchable sheet 120 in a state where the folds are formed.

More specifically, the manufacturing method of the absorbent article of the present embodiment is a method of manufacturing the pants-type disposable diaper 1 shown in FIG. 1, wherein the composite sheet 110 formed in the composite sheet forming step is a continuous outer packaging material. Used as And the manufacturing method of the absorbent article of this embodiment further comprises following process S4 and S5.
Diaper continuum forming step S4: During or after the composite sheet conveying step S3, the absorbent main body 10 is intermittently joined to the outer packaging material continuum 110 to form the diaper continuum 100.
Diaper separation step S5: After the diaper continuous body 100 is folded in half in the width direction of the outer packaging material continuous body 110, the side seal portion S is formed in the outer packaging material continuous body 110, and the diaper continuous body 100 is cut by the side seal portion S. To separate individual pants-type disposable diapers 1.

The manufacturing method of the absorbent article of this embodiment will be described more specifically.
In the manufacturing method of this embodiment, a belt-like stretchable sheet 120 having stretchability in the longitudinal direction is used as the original fabric of the outer layer sheet 12, and the belt-like stretchable material that does not substantially contract in the longitudinal direction as the raw fabric of the inner layer sheet 13 is used. A non-shrinkable sheet 130 is used. The non-shrinkable sheet 130 in this embodiment does not substantially shrink in the longitudinal direction but does not substantially stretch in the longitudinal direction.

As the stretchable sheet 120, a sheet manufactured in advance as a belt-like sheet having stretchability in the longitudinal direction outside the diaper production line can be used, but in this embodiment, the stretchable sheet 120 is substantially Before the stretchable sheet transporting step S1 for transporting in the longitudinal direction without stretching, a non-stretchable belt-like sheet is processed to obtain a stretchable sheet 120 exhibiting stretchability or a low-stretch belt-like shape It has a stretchable sheet forming step S0 (not shown) to obtain a stretchable sheet 120 with improved stretchability by processing the sheet, and the stretchable sheet 120 thus obtained is stretched sheet transporting step In S1, the sheet is conveyed without substantially extending.
In addition, "improving stretchability" here is to make it easier to stretch with a small force, and specifically, to increase the elongation when a load of 1.0 N / 25 mm is applied, Or it means that the elongation at break increases.

  In the stretchable sheet forming step S0 in the present embodiment, the process of developing the stretchability of the sheet or the process of improving the stretchability is an inline process using a pair of tooth groove rolls (not shown) in which teeth and grooves are engaged. . Specifically, a belt-like sheet in which an inelastic fiber layer is integrated on both sides or one side of an elastic layer made of an elastic fiber layer, a net-like elastic sheet, an elastic film, or the like is bitten into a pair of tooth space rolls, As a result, the non-elastic fiber layer is divided, the constituent fibers are elongated, or the thermal fusion point between the fibers is broken, thereby changing the structure to prevent the elastic layer from stretching. By changing the non-elastic fiber layer into a structure that hardly inhibits the expansion and contraction of the elastic layer, the stretchable sheet 120 that exhibits stretchability or has improved stretchability is obtained.

  In this way, before the elastic sheet conveying step S1 for conveying the elastic sheet 120 in the longitudinal direction without substantially extending, the non-elastic or low elastic belt-like sheet is processed inline, and the belt-like sheet It is manufactured as a belt-like sheet having stretchability in the longitudinal direction in advance of the diaper production line by providing a stretchable sheet forming step S0 that expresses stretchability or improves the stretchability of the belt-like sheet. Elasticity equivalent to that of a sheet is obtained.

  In this embodiment, the elastic sheet 120 obtained in the elastic sheet forming step S0 is conveyed in the longitudinal direction without substantially extending in the elastic sheet conveying step S1. The means for conveying the elastic sheet 120 without substantially extending in the elastic sheet conveying step S1 is not particularly limited. For example, an elastic sheet suction conveying conveyor (not shown) that conveys the elastic sheet 120 while sucking it. Is used.

  The elastic sheet suction / conveyor is disposed so as to contact only the lower surface or only the upper surface of the elastic sheet 120 or sandwich both surfaces. The stretchable sheet suction / conveyor preferably sucks the stretchable sheet 120 entirely, but is difficult to suck the stretchable sheet 120, such as immediately before the stretchable sheet 120 is introduced into the stretchable sheet joining step S2. Then, partial suction may be performed after securing the non-expanded state of the stretchable sheet 120.

  In order to convey a belt-like stretchable sheet material having stretchability in the longitudinal direction without substantially stretching, it is preferable to carry it under low tension. The term “low tension” as used herein means that the conveyance tension for conveying nonwoven fabric, paper, and film is generally at a low level, preferably 100 cN / 25 mm or less, particularly preferably 25 cN / 25 mm or less. Yes, and most preferably, it is as close as possible to 0 cN / 25 mm.

  A pair of sandwiching rolls 154a and 154b that sandwich and join the two sheets 120 and 130 in the stretchable sheet joining step S2 are disposed on the downstream side of the stretchable sheet conveying step S1. In addition, a pair of wrinkle forming rolls 154b and 151 for forming wrinkles on the non-shrinkable sheet 130 in the non-shrinkable sheet extension enabling step S21 is disposed. That is, in this embodiment, the roll 154b serves as one roll in the pair of pinching rolls 154a and 154b and one roll in the pair of ridge forming rolls 154b and 151.

  In the non-shrinkable sheet extension enabling step S21, the non-shrinkable sheet 130 is joined to the stretchable sheet 120 in a stretchable state so that the stretchable sheet 120 can be stretched. More specifically, the non-shrinkable sheet 130 is formed in a state where wrinkles are formed after the wrinkles are formed on the non-shrinkable sheet 130 by the pair of wrinkle forming rolls 154b and 151 so that the unevenness is repeated along the longitudinal direction. Is bonded to the elastic sheet. As the wrinkle forming roll, for example, a pair of rolls described in JP-A Nos. 2003-153946 and 2001-145667 can be used.

  The non-shrinkable sheet 130 in which wrinkles are formed so that unevenness is repeated along the longitudinal direction is easily stretched and extinguishes when extensible force is applied in the longitudinal direction. When the formation of the crease on the non-shrinkable sheet 130 by the crease forming rolls 154b and 151 and the joining of the stretchable sheet 120 and the non-shrinkable sheet 130 by the pair of sandwiching rolls 154a and 154b are performed continuously, The formed non-shrinkable sheet 130 can be joined to the stretchable sheet 120 with no wrinkles formed in the longitudinal direction without applying an extension force. In addition, as another method, when forming a ridge using an uneven roll, or after forming a ridge, if an engagement treatment such as heat treatment, embossing, hot embossing or the like that prevents the heel from disappearing is performed, the shape of the ridge In order to stabilize, joining processing of both sheets 120 and 130 can be performed stably.

  In the stretchable sheet joining step S2, the stretchable sheet 120 and the non-shrinkable sheet 130 are joined continuously or discontinuously and are sandwiched between the pair of sandwiching rolls 154a and 154b. Since the non-shrinkable sheet 130 in the present embodiment is formed with wrinkles, the stretchable elastic sheet 120 is joined to the stretchable non-shrinkable sheet 130 in a stretchable state. .

  As shown in FIG. 5, the elastic sheet 120 and the non-shrinkable sheet 130 are joined in a state where the leg elastic members 61 a and 61 b and the waist elastic member 51 are sandwiched between the sheets 120 and 130. . Specifically, before the sheets 120 and 130 are overlapped, an adhesive for bonding an elastic member is applied to a predetermined portion of one or both of the sheets 120 and 130 facing each other. In a state where the elastic members 61a, 61b, 51 are sandwiched in an extended state, the two sheets 120, 130 are narrowed by a pair of sandwiching rolls 154a, 154b to join the elastic members 61a, 61b, 51 and both sheets. 120 and 130 are joined. The adhesive is preferably applied at least in the vicinity of the top of the ridge in the non-shrinkable sheet 130.

  The leg elastic members 61a and 61b are introduced between the sheets 120 and 130 while being swung by a known swing guide in a direction perpendicular to the conveying direction of the sheets 120 and 130. In the stretchable sheet joining step S <b> 2, by joining the two sheets 120 and 130, the outer packaging material continuous body 110 with a limited degree of extension in the longitudinal direction is obtained.

  The outer packaging material continuous body 110 formed in the stretchable sheet joining step S2 is transported in the longitudinal direction without being substantially expanded in the composite sheet transporting step S3. The means for conveying the outer packaging material continuous body 110 without substantially extending in the composite sheet conveying step S3 is not particularly limited, but the elastic sheet 120 is conveyed without substantially expanding in the elastic sheet conveying step S1. For example, an outer packaging material continuous body suction conveyance conveyor (not shown) that conveys the outer packaging material continuous body 110 while sucking it is used.

  The outer packaging material continuous body suction conveyance conveyor is disposed so as to contact only the non-shrinkable sheet 130 side or the elastic sheet 120 side of the outer packaging material continuous body 110 or sandwich both sides. It is preferable that the outer packaging material continuum suction conveyance conveyor sucks the outer packaging material continuum 110 entirely. However, the outer packaging material continuum suction conveyance conveyor can be expanded and contracted at a place where it is difficult to suck the entire packaging material 110 such as a place where the trim 111 is removed. Partial suction may be performed after securing the non-stretched state of the adhesive sheet 120.

The pants-type disposable diaper 1 shown in FIG. 1 can be manufactured in the same manner as a conventional so-called cross-flow type pants-type disposable diaper, except that the outer packaging material continuum 110 obtained as described above is used. it can.
For example, as shown in FIG. 5, the trim 111 for leg opening formation is removed by a rotary cutter, laser cutter, water jet cutter or the like in the composite sheet conveying step S3, and the outer packaging material in the diaper continuous body forming step S4. On the continuous body 110, the absorptive main body 10 is intermittently joined, and the diaper continuous body 100 is obtained.

The absorbent main body 10 is joined to the outer packaging material continuous body 110 while maintaining the non-stretched state of the stretchable sheet 120. In other words, the absorbent main body 10 is joined to the outer packaging material continuous body 110 while maintaining the wrinkles of the non-shrinkable sheet 130. In addition, after extending | stretching the elastic sheet 120, the absorptive main body 10 can also be joined to the outer packaging material continuous body 110. FIG.
The adhesive 15 that joins the absorbent main body 10 to the outer packaging material continuous body 110 can be applied to either or both of the absorbent main body 10 and the outer packaging material continuous body 110. Further, the trim 111 can be removed after the absorbent main body 10 is joined to the outer packaging material continuous body 110.

  Next, in the diaper separation step S5, the outer packaging material continuous body 110 in the diaper continuous body 100 is folded in the width direction so that both side portions 112a and 112b of the outer packaging material continuous body 110 cover both ends of the absorbent main body 10. The both side portions 112a and 112b that are folded back are joined. Next, after the side seal portions S, S are formed on the outer packaging material continuous body 110 by heat sealing, ultrasonic sealing, high frequency sealing, or the like, the diaper continuous body 100 is cut at the side seal portion S individually. The pants-type disposable diaper 1 is obtained.

  According to the manufacturing method of the absorbent article of this embodiment, in the elastic sheet conveying step S1, the belt-shaped elastic sheet 120 having elasticity in the longitudinal direction is conveyed in the longitudinal direction without substantially extending. In the stretchable sheet joining step S2, the stretchable sheet 120 is stretched by joining the belt-like non-shrinkable sheet 130 that does not substantially shrink in the longitudinal direction so that the longitudinal directions of both the sheets 120 and 130 coincide with each other. A composite sheet (outer packaging material continuous body) 110 composed of the adhesive sheet 120 and the non-shrinkable sheet 130 is formed. Therefore, since it is possible to prevent a reduction in width caused by applying tension in the longitudinal direction of the elastic sheet 120 during conveyance, the elastic sheet 120 is expected to be reduced during conveyance and widened after removal of tension. There is no need to transport. Therefore, the elastic sheet 120 can be stably conveyed, and the absorbent article can be manufactured with high accuracy.

  In the composite sheet transporting step S3, the composite sheet (outer packaging material continuous body) 110 formed in the composite sheet forming step (stretchable sheet joining step S2) is transported in the longitudinal direction without substantially extending. Therefore, the absorptive main body 10 can be joined to the outer packaging material continuous body 110 in a state where the outer packaging material continuous body 110 is maintained in a non-expanded state.

  Next, another embodiment of the method for producing an absorbent article of the present invention will be described. Another embodiment will be described with a focus on differences from the first embodiment, and the description of the same points will be omitted. Therefore, the description regarding the first embodiment is also applied to other embodiments as appropriate.

  In the first embodiment, after the ridges are formed on the non-shrinkable sheet 130 so that the unevenness is repeated along the longitudinal direction, the non-shrinkable sheet 130 is joined to the stretchable sheet 120 with the folds formed. In this way, the non-shrinkable sheet 130 is joined to the stretchable sheet 120 in a stretchable state. However, in the method for manufacturing an absorbent article of the present invention, the non-shrinkage has a stretchability in the longitudinal direction. By using the stretchable sheet 130, the non-shrinkable sheet 130 can be joined to the stretchable sheet 120 in a stretchable state without forming wrinkles.

Specifically, as shown in FIG. 6, the method for manufacturing an absorbent article according to the second embodiment includes a non-shrinkable sheet extension enabling step S <b> 21 as compared with the first embodiment shown in FIG. 5. Not.
Further, in the second embodiment, the non-shrinkable sheet 130 having extensibility in the longitudinal direction is not directly manufactured, and has extensibility in the width direction and substantially no shrinkage in the width direction. After forming the belt-like sheet 130 ′, the belt-like sheet 130 ′ is cut into short objects 131, the short objects 131 are rotated by 90 degrees, and then connected to form a non-shrinkable sheet 130 having extensibility in the longitudinal direction. It has gained.

  More specifically, the belt-like sheet 130 ′ having extensibility in the width direction is intermittently cut by a known cutting means (not shown) such as a roller cutter, a laser cutter, a water jet cutter, etc., and sequentially by the intermittent cutting. After the resulting short object 131 is rotated 90 degrees, the pitch is reduced, and the end portions in the flow direction of the adjacent short objects 131 are overlapped and connected to each other so as to be non-extensible in the longitudinal direction (machine direction). A shrinkable sheet 130 is obtained. The short objects 131 are connected to each other by arranging the adjacent short objects 131 so that the end portions in the flow direction overlap each other, and processing such as heat sealing, ultrasonic sealing, and high frequency sealing is performed on the overlapping portions. Do by applying.

As a method (or mechanism) for rotating the short object 131 by 90 degrees, a known method (or mechanism) can be used. For example, Japanese Patent Laid-Open No. 63-252824, Japanese Patent Laid-Open No. 3-226411, and Japanese Patent No. 3145371. The method described in the gazette and the like can be used.
In addition, as a method of filling the pitch of the short object 131 after being rotated by 90 degrees and overlapping the ends in the flow direction of the adjacent short objects 131, for example, the short object 131 after being rotated by 90 degrees is used. The first short object conveyed by two different conveying paths alternately every other one, and arranged on a continuous conveying means such as a belt conveyor with an interval, is arranged on the other conveying path. It is possible to use a method in which the second short object conveyed by the path is arranged on the same continuous conveying means so that both end portions thereof overlap with the ends of the first short object before and after the second short object.

In addition, one conveyance path and the other conveyance path rotate, for example, adsorbing the short object 131 on the peripheral surface, and receiving the short object on the peripheral surface at a predetermined position by controlling the adsorption, It can be constituted by a combination of a suction roll that can be detached from the peripheral surface and a known conveying means such as a belt conveyor. The peripheral surface of the suction roll may be composed of a suction head divided into a plurality of parts.
According to the second embodiment, the same effect as the first embodiment is achieved.

As mentioned above, although the manufacturing method of the composite sheet of this invention and the manufacturing method of an absorbent article were demonstrated based on the preferable embodiment, this invention is not restrict | limited to each embodiment mentioned above, It can change suitably.
The manufacturing method of the composite sheet of this invention is not restricted to the process of forming the composite sheet in the manufacturing method of an absorbent article, It can apply suitably to the process of forming the composite sheet in other various manufacturing methods.

  The method for producing an absorbent article of the present invention is not limited to the production of a pants-type disposable diaper having an absorbent main body and an outer packaging material, and can be applied to the production of pants-type or unfolded disposable diapers of other forms. it can. Moreover, it is not restrict | limited to manufacture of a disposable diaper, It can apply to manufacture of other absorbent articles, such as a sanitary napkin and a panty liner.

FIG. 1 is a perspective view showing an example of a pants-type disposable diaper manufactured by the method for manufacturing an absorbent article of the present invention. FIG. 2 is a plan view showing a developed state of the disposable diaper shown in FIG. 1. FIG. 3 is an exploded perspective view of the disposable diaper shown in FIG. 1. 4 is a cross-sectional view taken along line II-II shown in FIG. FIG. 5 is a perspective view schematically showing a first embodiment of the method for producing an absorbent article of the present invention. FIG. 6 is a perspective view schematically showing a second embodiment of the method for producing an absorbent article of the present invention.

Explanation of symbols

1 Pants-type disposable diaper (absorbent article)
2 Top sheet 3 Back sheet 4 Absorbent core 5 Waist opening 51 Waist elastic member 6 Leg openings 61a, 61b Leg elastic member 10 Absorbent body 11 Outer packaging material 12 Outer packaging sheet 13 Inner packaging sheet 100 Diaper continuous body 110 Outer packaging material Continuum (composite sheet)
120 Stretchable sheet 130 Non-shrinkable sheet S1 Stretchable sheet conveying process (first half of the composite sheet forming process)
S2 Elastic sheet joining process (the second half of the composite sheet forming process)
S3 Composite sheet conveyance process S4 Diaper continuous body formation process S5 Diaper separation process

Claims (4)

A method for producing an absorbent article comprising a stretchable composite sheet formed by joining a stretchable sheet having stretchability in the longitudinal direction and a non-shrinkable sheet that does not substantially shrink in the longitudinal direction,
A belt-like stretchable sheet having stretchability in the longitudinal direction is conveyed in the longitudinal direction without substantially stretching, and the longitudinal direction of both sheets is changed into a belt-like non-shrinkable sheet that does not substantially shrink in the longitudinal direction. By using a composite sheet manufacturing method for manufacturing a stretchable composite sheet composed of a stretchable sheet and a non-shrinkable sheet by matching and joining , the stretchable sheet and the non-shrinkable sheet are joined and combined. A composite sheet forming step for forming a sheet;
A composite sheet transporting step for transporting the composite sheet formed in the composite sheet forming step in the longitudinal direction without substantially extending;
The absorbent article is a pants-type disposable diaper provided with an absorbent body including an absorbent core and an outer packaging material joined to the non-skin contact surface side of the absorbent main body,
Using the composite sheet formed in the composite sheet forming step as an outer packaging material continuum,
In the middle of or after the composite sheet conveying step, the diaper continuous body forming step of intermittently joining the absorbent main body to the outer packaging material continuous body to form a diaper continuous body ,
In the composite sheet forming step, an elastic member is sandwiched between the belt-like stretchable sheet and the belt-like non-shrinkable sheet, and the joining of the stretchable sheet and the non-shrinkable sheet in the step is absorbed by the absorption Performed on both side edges of the abdominal side and back side as well as the peripheral edge of the waist opening and each peripheral edge of the pair of leg openings when it is made a property article, so that it is not joined at the other parts. ,
In the diaper continuum forming step, the outer wrapping material continuum and the absorbent main body are joined to each other except for the longitudinal end portions of the absorbent main body, and only the central portion in the width direction of the absorbent main body is The manufacturing method of the absorbent article performed so that it may join via an outer packaging material continuous body and an adhesive agent . The manufacturing method of the absorbent article of Claim 1 which conveys the said belt-shaped elastic sheet, without extending | stretching substantially, using the elastic sheet suction conveyance conveyor which conveys it, attracting | sucking. After two-fold the diaper continuum in the width direction of outer cover material continuum, definitive the enveloping member continuum, a position corresponding to the both side edge portions of the respective ventral and dorsal sides of when said absorbent article to form a side seal part, a manufacturing method of an absorbent article according to claim 1 or 2 by cutting the diaper continuum in the side seal portion includes a diaper separation step of separating the individual pants-type disposable diaper . Prior to the composite sheet forming step, the non-stretchable belt-like sheet is processed to obtain the stretchable sheet, or the low-stretchable belt-like sheet is processed to improve stretchability. The manufacturing method of the absorptive article given in any 1 paragraph of Claims 1-3 which comprise the elastic sheet formation process of obtaining said elastic sheet.

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