JP2013099429A - Method for producing water-absorbent article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a water-absorbent article which can prevent highly water-absorbent polymer particles from getting locally lopsided.SOLUTION: The water-absorbent article includes: a first section which intercalates a highly water-absorbent polymer particles 4 between two overlapped sheet pieces; and a second section surrounding the first section. The method for manufacturing the water-absorbent article includes a process for manufacturing a composite web 137 which is a continuum in the water-absorbent article, wherein, among guide rolls for driving the composite web 137 to run toward the machine direction MD, the angle between a first guide roll 161 positioned upstream of the machine direction MD and a second guide roll 162 adjacent to the first guide roll 161 downstream of the machine direction MD is changed within a range of 30-180° to the orientation of the running direction of the composite web 137, the orientation of the running direction of the composite web 137 being directed toward the first guide roll 161.

Description

  The present invention relates to a method for producing a water-absorbent article suitable for use as an absorbent body or disposable wipes in a body fluid-absorbing wearing article such as a disposable diaper.

  A water-absorbing pad in which superabsorbent polymer particles are interposed between sheet pieces in which at least one of the two sheet pieces is water-permeable is known.

  For example, an absorbent sheet described in Japanese Patent Application Laid-Open No. 2009-131510 (Patent Document 1) is one in which highly water-absorbing polymer particles are contained between an upper sheet and a lower sheet, and the upper sheet and the lower sheet In the non-joined part surrounded by the joined part, the pocket is formed by the upper sheet and the lower sheet, and the superabsorbent polymer particles are accommodated in the pocket. The superabsorbent polymer particles are movable within the pockets.

JP 2009-131510 A

  In the absorbent sheet described in Patent Document 1, since the superabsorbent polymer particles before water absorption can move relatively freely, for example, when this absorbent sheet is used in a disposable diaper, depending on the posture of the diaper wearer, A deviation occurs in the distribution of the superabsorbent polymer particles. Such a case may occur when the wearing feeling of the diaper is deteriorated or the superabsorbent polymer particles are not present at a site where the body fluid such as urine should be absorbed.

  An object of the present invention is to provide a method for producing a water-absorbent article that can solve such problems.

  In order to solve the above-mentioned problems, the present invention is intended to provide highly water-absorbing polymer particles between opposing surfaces of the two sheet pieces in which at least one of the two overlapping sheet pieces is water permeable. It is a manufacturing method of a water-absorbing article having a first zone interposed and a second zone in which the opposing surfaces are joined to each other and surround the first zone.

  In this manufacturing method, the present invention is characterized as follows. That is, the first web and the second web, which are continuous bodies of the two sheet pieces, are continuously run in the machine direction. In the first web, the superabsorbent polymer particles are supplied to the facing surface of the portion corresponding to the first section, while the portion of the second web corresponding to the first section and the second section is supplied. A hot melt adhesive is applied to the opposite surface. By superposing the first web and the second web, a composite web having the first section and the second section is formed, and the composite web is run in the machine direction. The composite web is sequentially brought into contact with a plurality of guide rolls that rotate so as to cause the composite web to travel in the machine direction, and the first guide roll located on the upstream side in the machine direction among the plurality of guide rolls; The direction of the travel direction of the composite web between the second guide roll adjacent to the first guide roll on the downstream side in the machine direction is set to the direction of the travel direction of the composite web toward the first guide roll. The angle is changed in the range of 30-180 degrees.

  In one embodiment of the invention, the range of the angles is less than 90 degrees.

  In another embodiment of the present invention, the composite web is sequentially brought into contact with the first guide roll, the second guide roll, and a third guide roll adjacent to the second guide roll on the downstream side. The range of the angle is less than 90 degrees between the first roll and the second roll, and the composite web is caused to run downhill or uphill, and the second roll and the third roll Between the rolls, the composite web is caused to run so as to have an upward slope or a downward slope.

In one embodiment of the present invention, the first zone contains the superabsorbent polymer particles in a mass ratio of 30 to 300 g / m ² .

  In one embodiment of the present invention, the application amount of the hot melt adhesive per unit area in the second area is the same as the application amount of the hot melt adhesive per unit area in the first area. is there.

  In one embodiment of the present invention, the application amount of the hot melt adhesive per unit area in the second area is larger than the application amount of the hot melt adhesive per unit area in the first area.

  In one embodiment of the present invention, a plurality of the first areas are formed in the water absorbent article.

  In one embodiment of the present invention, each of the two sheet pieces is water permeable.

  In one embodiment of the present invention, the sheet piece that is water permeable is a hydrophilic nonwoven fabric formed of thermoplastic synthetic fibers.

  In one embodiment of the present invention, one of the two sheet pieces is water permeable, the other is either impermeable or hardly permeable, and the superabsorbent polymer particles are It is joined to the sheet piece which is either impermeable or hardly permeable.

  According to the method for manufacturing a water-absorbent article according to the present invention, the angle between the composite web that travels toward the first guide roll and the composite web that travels from the first guide roll toward the second guide roll is 30. By setting it to -180 degrees, the composite web can be brought into close contact with the first guide roll. The superabsorbent polymer particles that are not bonded to the first web or the second web in the first section of the composite web and are accumulated locally in the first section are such that the composite web is on the peripheral surface of the first guide roll. When the contact starts, the accumulated state collapses and is subjected to the action of spreading inside the first area. As a result, the superabsorbent polymer particles can be uniformly distributed in the first zone of the composite web, in other words the first zone of the water-absorbent article.

The partially broken top view of a water absorbing article. The figure which shows the II-II line | wire cut surface of FIG. The figure which shows an example of the manufacturing process of a water absorptive article. The elements on larger scale of FIG. The figure similar to FIG. 3 which shows an example of an embodiment.

  The details of the method for producing a water-absorbent article according to the present invention will be described below with reference to the accompanying drawings.

  1 and 2, double-headed arrows A, B, and C indicate a vertical direction, a horizontal direction, and a thickness direction that are orthogonal to each other in the water-absorbent article 1. In these drawings, the article 1 includes an upper layer sheet 2 that is water permeable, a lower layer sheet 3 that is either water permeable, poorly water permeable, or water impermeable, and superabsorbent polymer particles 4. As the superabsorbent polymer 4, various known polymers can be mentioned as will be apparent to those skilled in the art. For example, a polymer such as a sodium polyacrylate-based one or a starch acrylonitrile-based one, which is water-insoluble and has a water absorbing power 10 times or more of its own weight can be mentioned. The article 1 also includes a plurality of first areas 6 in which the upper sheet 2 and the lower sheet 3 are separated from each other and the superabsorbent polymer particles 4 are joined to the lower sheet 3, and the upper sheet 2 and the lower sheet 3 A second region 7 that is joined. That the lower layer sheet 3 is water permeable means that the lower layer sheet 3 can easily pass water in the same manner as the upper layer sheet 2, and that the lower layer sheet 3 is hardly water permeable means that the upper layer sheet 2 and Means that the lower layer sheet 3 is in a state of not allowing water to permeate as much as the upper layer sheet 2. The lower layer sheet layer 3 is impermeable to water in comparison with the upper layer sheet 2. Is in a state of substantially not transmitting. Depending on the application, use state, manufacturing method, and the like of the article 1, any one of a water-permeable material, a hardly water-permeable material, and a water-impermeable material is adopted for the lower layer sheet 3. In FIG. 2, the diameter of the superabsorbent polymer particle 4 is exaggerated in order to clearly show the presence of the superabsorbent polymer particle 4 described later.

The first zone 6 is surrounded by the second zone 7 and forms a water absorbing zone by including the superabsorbent polymer particles 4 as the water absorbing material. The first zone 6 is a superabsorbent polymer. the particles 4 preferably at a rate of 30~300g / ^{m 2,} more preferably contains a ratio of 40~280g / ^{m 2.} Moreover, in the preferable 1st area | region 6, it has joined to the lower layer sheet 3 via the hot melt adhesive 11 for polymer particle fixation uniformly apply | coated to the whole lower layer sheet 3. FIG. However, the first area 6 is an area that may contain superabsorbent polymer particles that are not bonded to the lower layer sheet 3, and the first area 6 may be included between the lower layer sheet 3 and the upper layer sheet 2. The upper limit of the total amount of superabsorbent polymer particles that can be produced is 400 g / m ² . In the first area 6, it is preferable that the lower layer sheet 3 and the upper layer sheet 2 are not joined, but in the manufacturing process of the article 1 (see FIGS. 3 and 4), it is extremely unintended. The upper layer sheet 2 may be bonded to the lower layer sheet 3 with a small area.

The second region 7 is a super absorbent polymer particle 4 when the super absorbent polymer particle 4 contained in the first region 6 is not joined to the polymer particle fixing hot melt adhesive 11 and can move freely. An area for preventing the particles 4 from escaping from the first area 6, that is, an area for sealing the periphery of the first area 6, which does not include or is formed of the water-absorbing material. Including the superabsorbent polymer particles 4 up to a mass of up to 20 g / m ² , which is not intended in the manufacturing process of the upper layer sheet 2 and article 1, except for the superabsorbent polymer particles 4. It is also a region that forms a substantially non-water-absorbing region. That is, even if the second area 7 may contain the superabsorbent polymer particles 4, the mass (g / m ² ) of the superabsorbent polymer particles 4 is the first per unit area of the lower layer sheet 3. The area 6 is less than the mass (g / m ² ) of the superabsorbent polymer particles 4 included in one area 6. In the second area 7, the upper layer sheet 2 and the lower layer sheet 3 are joined via the hot melt adhesive 12 for sealing. In the article 1, the peel strength of both sheets 2 and 3 can be improved by further welding the upper layer sheet 2 and the lower layer sheet 3 that are joined as described above. In any embodiment, the upper layer sheet 2 and the lower layer sheet 3 in the second area 7 are not peeled even during use of the article 1. In the article 1 illustrated in FIG. 2, the polymer particle fixing hot melt adhesive 11 applied so as to overlap in the second area 7 and the second hot melt adhesive 102 (see FIGS. 3 and 4) described later. Forms a hot-melt adhesive 12 for sealing, and the upper-layer sheet 2 and the lower-layer sheet 3 are joined via the hot-melt adhesive 12 for sealing. As the hot melt adhesive in the article 1, a conventional one in this kind of article can be used.

  The article 1 in the illustrated example is made to be long in the longitudinal direction A. In the longitudinal direction A, eight first sections 6 indicated by reference numerals 6a to 6h, that is, water absorption areas are arranged. Each of the first areas 6a to 6h has a periphery 61 that defines its planar shape. The periphery 61 of the first areas 6 adjacent in the vertical direction A includes opposite side portions 62 that face each other in the vertical direction A and extend in the horizontal direction B. For example, in the periphery 61 of the adjacent first areas 6a and 6b in FIG. 1, opposite side portions 62 facing each other in the longitudinal direction A and extending in the lateral direction B are indicated by reference numerals 62a and 62b.

  In the article 1, the second area 7 is on both sides of the article 1 and extends in the longitudinal direction A. The side edges 7 a extend in the longitudinal direction A. An intermediate portion 7c extending between the adjacent first areas 6 and extending in the lateral direction B is provided.

  When such an article 1 is used as, for example, an absorbent body of a disposable diaper or a urine absorbing pad of an incontinence patient pant, the longitudinal direction A of the article 1 is made to coincide with the front-rear direction of the diaper, and the central portion of the longitudinal direction A is a diaper. To come to the inseam area. The upper layer sheet 2 is formed of a water-permeable sheet piece and is directed to the skin of the diaper wearer.

  In the diaper, the possibility of obtaining various functions and effects is improved by using the article 1. For example, urine excreted by the wearer passes through the upper layer sheet 2 in the first section 6 and is absorbed by the superabsorbent polymer particles 4 so that it does not flow. In the diaper, by fixing the superabsorbent polymer particles 4 to the lower layer sheet 3 formed of the hardly water-permeable or water-impermeable sheet piece, the wearer's crotch can be changed even if the posture of the wearer changes variously. The distribution state of the highly water-absorbing polymer particles 4 in the part is always constant, and no bias occurs in the first area 6. Therefore, in the article 1, urine can be permeated in a wide area of the upper layer sheet 2 and absorbed in a wide area of the first area 6. In addition, the distribution of the superabsorbent polymer particles 4 is biased inside the first section 6. In other words, the superabsorbent polymer particles 4 are unevenly distributed locally in the first section 6, and the article 1 has a uniform thickness. By not becoming anything, the article 1 does not press the wearer's skin locally. Incidentally, the state that the article 1 is not uniform in thickness becomes prominent when the superabsorbent polymer particles 4 swell after absorbing urine. In the first zone 6, the polymer particle fixing hot melt adhesive 11 is applied to the lower layer sheet 3 and not applied to the upper layer sheet 2, so that the polymer particle fixing hot melt adhesive 11 is applied to the upper layer sheet 2. There is no impediment to water permeability. The superabsorbent polymer particles 4 fixed to the lower layer sheet 3 prevent the upper layer sheet 2 from approaching and joining to the lower layer sheet 3 to which the hot melt adhesive 11 for fixing polymer particles is applied, This prevents the article 1 from being poorly flexible by bonding the upper sheet 2 to the lower sheet 3. In the article 1 when placed in the crotch region of the diaper, a plurality of intermediate portions 7c that are parallel to each other as shown in the drawing act so that the article 1 can be easily bent in the longitudinal direction A. The width W of the intermediate part 7c acting in this way is preferably 2 to 15 mm.

In this example of the article 1 when used for a diaper, the upper layer sheet 2 includes a sheet piece of a water-permeable nonwoven fabric formed of thermoplastic synthetic fibers and subjected to a hydrophilic treatment, for example, an SMS formed of polypropylene fibers. The sheet piece of a nonwoven fabric (spunbond-meltblown-spunbond nonwoven fabric) can be used in a state of being subjected to a hydrophilic treatment. Spunbonded nonwoven fabric to each other the mass of 10-12 g / ^{m 2,} which is interposed meltblown nonwoven fabric having a weight of 0.5 to 2 g / ^{m 2} between having a mass of 4-5 g / ^{m 2} is one example of the SMS nonwoven fabric There is a sheet piece with

The lower layer sheet 3 may be a non-woven sheet piece made of hydrophobic thermoplastic synthetic fiber and hardly or water-impermeable. For example, the 10~13g / ^{m 2} which is interposed meltblown nonwoven fabric having a weight of 0.5 to 2 g / ^{m 2} between the spunbonded nonwoven fabric to each other with a mass of 4-6 g / ^{m 2} formed of polypropylene fibers A sheet piece of SMS nonwoven fabric having a mass and poor water permeability can be used. The lower layer sheet 3 was also formed of a water-impermeable sheet piece formed of a plastic film such as a polyethylene film having a thickness of 0.01 to 0.03 mm, or a water-impermeable plastic film and a thermoplastic synthetic fiber. It is possible to use a water-impermeable sheet piece that is a laminate with a water-permeable or hardly water-permeable nonwoven fabric. In the laminated body, the superabsorbent polymer particles 4 are bonded to the nonwoven fabric so that the nonwoven fabric is inside the article 1 and the water-impermeable plastic film is outside the article 1, and from the fiber gap in the nonwoven fabric. It is preferable to stop leakage of body fluid with a plastic film.

Some of the highly water-absorbing polymer particles 4 have various water absorption speeds, and those having a constant water absorption speed can be used alone, or those having different water absorption speeds can be mixed and used. However, as an example, a water absorption rate of about 30 seconds according to the VORTEX method defined in JIS K 7224 can be used with the upper limit of 400 g / m ² for the first zone 6. However, the amount of the superabsorbent polymer particles 4 used is preferably adjusted in consideration of the size of the section of the first section 6 and the usage pattern of the article 1. It is preferable to use the superabsorbent polymer particles 4 having a small amount of components eluted with respect to urine. This is because components that elute from the superabsorbent polymer particles 4 when they are in contact with urine may increase the viscosity of the urine and increase discomfort when the urine touches the skin.

The polymer particle fixing hot melt adhesive 11 is applied to the lower layer sheet 3 in the first area 6 in order to fix the superabsorbent polymer particles 4 to the lower layer sheet 3. It may be applied also to the lower layer sheet 3. For example, in FIG. 2, the polymer particle fixing hot melt adhesive 11 is applied at a mass ratio of 1-12 g / m ² so as to be uniformly distributed over the entire upper surface 3 a of the lower layer sheet 3. The superabsorbent polymer particles 4 fixed to the lower layer sheet 3 in the first area 6 are not covered with the polymer particle fixing hot melt adhesive 11 so that the entire surface thereof is covered with the hot melt adhesive for fixing polymer particles. It is preferable that the agent 11 reduces the coating amount per unit area as much as possible. The hot melt adhesive 11 for fixing polymer particles can also be applied to the lower layer sheet 3 so as to be intermittently distributed like dots or beads, or continuously covers the entire first area 6. It can also be applied. However, in any case, the surface of the superabsorbent polymer particle 4 is bonded to the upper surface 3a while the portion facing the upper surface 3a of the lower layer sheet 3 is covered with the hot melt adhesive 11 for fixing the polymer particles. It is preferable that the portion facing the lower surface 2b (see FIG. 2) is in a state in which urine can be rapidly absorbed without being covered with the polymer particle fixing hot melt adhesive 11.

The hot melt adhesive 12 for sealing is added at a rate of 5-30 g / m ² with respect to the hot melt adhesive 11 for fixing polymer particles applied to the lower layer sheet 3 located in the second area 7 and the lower layer sheet 3. The second hot melt adhesive 102 shown in FIG. By adjusting the application amount of the hot melt adhesive between the first area 6 and the second area 7 in this way, the hot melt adhesive 11 for fixing polymer particles is highly absorbent in the first area 6. While the surface of each of the polymer particles 4 is widely covered to avoid affecting the water absorption amount and the water absorption speed of the highly water-absorbing polymer particles 4, in the second area 7, only the hot melt adhesive 11 for fixing the polymer particles is used. When the amount of adhesive applied is small and peeling between the upper layer sheet 2 and the lower layer sheet 3 cannot be reliably prevented, the additional use of the second hot melt adhesive 102 can prevent the peeling. In the second zone 7, when the superabsorbent polymer particles 4 that are not fixed to the lower sheet 3 are present in the first zone 6, the superabsorbent polymer particles 4 are moved from the first zone 6 to the second zone 6. The upper sheet through the hot-melt adhesive 12 for sealing that is continuous or substantially continuous along the periphery of the first area 6 so that it can be prevented from moving to 7 2 and the lower layer sheet 3 are preferably joined. The polymer particle fixing hot melt adhesive 11 and the second hot melt adhesive 102 used in this way can be the same or those that adhere well to each other. Further, when the function as the sealing hot-melt adhesive 12 can be achieved only by the polymer particle fixing adhesive 11 applied to the second area 7, the second hot-melt adhesive 102 in FIG. 4 is unnecessary. Become. In this case, the application amount per unit area of the polymer particle fixing hot melt adhesive 11 may be the same in the first area 6 and the second area 7.

  Each dimension of the first area 6 in the longitudinal direction A and the lateral direction B in the article 1 when used for a diaper, that is, each dimension of the longitudinal direction A and the lateral direction B in FIG. 1 is a diaper. An appropriate value can be set in accordance with the size of. As an example, the dimension in the vertical direction A and the dimension in the horizontal direction B can be set in a range of 25 to 250 mm. It is preferable that the number of divisions of the 1st area 6 when it is such a dimension is 5-15. The width of the side edge 7a and the end edge 7b of the second area 7 is preferably 5-40 mm. It is preferable that the dimension in the vertical direction A of the intermediate part 7c is 3-30 mm.

  3 and 4 are an example of a process diagram when the article 1 is continuously manufactured, and a partial enlarged view of the suction drum 130 in the process diagram. In FIG. 3, the first web 131 which is a continuous body of the upper layer sheet 2 is supplied toward the peripheral surface 135 of the suction drum 130 from the right side of the drawing. The first web 131 that is in close contact with the peripheral surface 135 by the pressing action by the guide roll 141 and the suction action that works from the peripheral surface 135 toward the inside of the suction drum 130 is a polymer set above the suction drum 130. Superabsorbent polymer particles 4 are supplied from the particle supply device 136. From the left side of the figure, the second web 132 which is a continuous body of the lower layer sheet 3 is continuously supplied to the peripheral surface 135 of the suction drum 130 via the guide roll 142. The first hot melt adhesive 101 is applied to one surface of the second web 132 by a first coater 121 provided on the upstream side of the suction drum 130. Subsequently, the second hot melt adhesive 102 is applied onto a part of the first hot melt adhesive 101 already applied by the second coater 122 provided on the downstream side of the first coater 121. The first web 131 to which the superabsorbent polymer particles 4 are supplied and the second web 132 to which the first and second hot melt adhesives 101 and 102 are applied are on the peripheral surface 135 of the suction drum 130. The composite web 137 is formed by joining and joining via the first hot melt adhesive 101 and the second hot melt adhesive 102. The composite web 137 advances in the machine direction MD and is separated from the suction drum 130, and is then pressed by a pair of first guide rolls 161 that also serve as a press roll, and is at least a part of the superabsorbent polymer particles 4. And the first hot melt adhesive 101 come into contact with each other, and the superabsorbent polymer particles 4 are fixed to the second web 132 through the first hot melt adhesive 101. In FIG. 3, the composite web 137 separated from the first press roll 143 enters between the pair of first guide rolls 161 in a substantially horizontal state, and the superabsorbent polymer particles 4 are bonded to the first hot melt adhesive. It is fixed to the second web 132 via the agent 101. The first hot melt adhesive 101 is the polymer particle fixing hot melt adhesive 11 in the article 1, but the one that overlaps the second hot melt adhesive 102 is integrated with the second hot melt adhesive 102. Thus, the sealing hot melt adhesive 12 in the article 1 is formed.

  FIG. 4 shows a state where the first web 131 and the second web 132 merge to form a composite web 137, and the suction drum 130 is shown in a partial cross-sectional view. A plurality of recesses 145 are formed in the circumferential surface 135 of the suction drum 130 so as to be arranged in the circumferential direction. The planar shape of each of the recesses 145 corresponds to the planar shape of each of the first areas 6 arranged in the longitudinal direction A in FIG. The depth of the recess 145 is set to such an extent that a single supply amount of the superabsorbent polymer particles 4 supplied intermittently from the polymer supply device 136 can be accommodated. In the recess 145, suction toward the inside of the suction drum 130 acts, and the first web 131 placed on the peripheral surface 135 is deformed so as to follow the recess 145. In the deformed portion of the first web 131, the superabsorbent polymer particles 4 supplied from the polymer particle supply device 136 toward the concave portion 145 are accommodated. In the peripheral surface portion 135a located as a raised portion between the adjacent concave portions 145 and 145 in the peripheral surface 135, the first web 131 and the second web 132 merge, and the two webs 131 and 132 are combined. When passing the first press roll 143 (see FIG. 3), the peripheral surface portion 135a and the first press roll 143 are pressed and joined to form a composite web 137.

  In FIG. 3 again, the composite web 137 that has passed through the first guide roll 161 proceeds in the machine direction MD, reaches the cutter 138 through the second guide roll 162, and is intermittently cut by the cutter 138, and the individual articles 1 and Become. Both the first guide roll 161 and the second guide roll 162 are driven and rotated so that the composite web 137 travels in the machine direction MD, or are freely rotatable. An angle (intersection angle) α between the composite web 137 passing through the first guide roll 161 toward the second guide roll 162 and traveling in a horizontal direction so as to enter the first guide roll 161. Is changed so that the traveling direction is in a range of 30 to 180 degrees, and in the illustrated example, the traveling direction is inclined so as to have a downward slope in the machine direction MD. That is, the second roll 162 indicated by the solid line is at a position where the intersection angle α is about 30 degrees. For reference, the second roll 162 indicated by an imaginary line is in a position when the intersection angle α is about 120 degrees.

  In the process of FIG. 3, by only using the suction drum 130 and the polymer particle supply device 136, the superabsorbent polymer particles 4 to be supplied to the recesses 145 of the suction drum 130 are first positioned on the bottom surface 146 of the recesses 145. It is difficult to uniformly distribute the web 131. Also in the first zone 6 (see FIG. 1) formed when the first web 131 and the second web 132 merge and pass through the first press roll 143, the superabsorbent polymer particles 4 are uniformly distributed. It is difficult to distribute it. In the first zone 6, the superabsorbent polymer particles 4 are unevenly distributed downstream in the machine direction MD, and the superabsorbent polymer particles 4 are present on the first hot melt adhesive 101 applied to the second web 132. There may be many parts that have not yet been joined. In the first zone 6, the unevenly distributed portion of the superabsorbent polymer particles 4 may be thicker than the other portions.

  However, in the process of FIG. 3, when the direction in which the composite web 137 travels on the first guide roll 161 is changed by the angle α, the composite web 137 is in close contact with the peripheral surface of at least one of the pair of first guide rolls 161. By the action between the peripheral surfaces, the highly water-absorbing polymer particles 4 that are unevenly distributed are pushed to the upstream side in the machine direction MD in the first section 6 and are widely and uniformly distributed in the first section 6. It becomes possible. In the illustrated example, when the composite web 137 is brought into close contact with the lower guide roll 161a of the pair of first guide rolls 161, the upper guide roll 161 can be omitted.

  Further, when the composite web 137 passing through the first guide roll 161 toward the second guide roll 162 is inclined as shown in the illustrated example, the superabsorbent polymer particles 4 that are unevenly distributed in the first section 6 are provided. However, it may move down the slope to promote uniform distribution of the superabsorbent polymer particles 4. It is also possible for the composite web 137 to travel in a manner of an upward slope between the first guide roll 161 and the second guide roll 162.

  In the embodiment illustrated in FIG. 5, a third guide roll 163 is provided on the downstream side of the second guide roll 162. The composite web 137 that has left the suction drum 130 (see FIG. 3) travels in the machine direction MD. However, the composite web 137 travels horizontally between the first guide roll 161 and the second guide roll 162. The crossing angle α is less than 90 degrees and the traveling direction is a downward slope. Between the 2nd guide roll 162 and the 3rd guide roll 162, it exists in the aspect from which the direction to drive | works becomes an upward slope. When the composite web 137 is run in this way, the superabsorbent polymer particles 4 that are inside the first section 6 and are not bonded to the first hot melt adhesive 101 and are movable are combined with each other. When 137 is in a downward gradient manner, it can move from the upstream side to the downstream side in the machine direction MD and can be widely distributed in the first section 6. When the composite web 137 is in an ascending mode, the superabsorbent polymer particles 4 in a movable state move inside the first section 6 from the downstream side in the machine direction MD toward the upstream side, It becomes possible to widely distribute in one area 6. Therefore, traveling in the machine direction MD while repeating the aspect in which the composite web 137 has a downward slope and the aspect in which the composite web 137 has an upward slope an appropriate number of times causes the superabsorbent polymer particles 4 to spread widely in the first section 6. It is preferable to distribute the same.

  In the article 1 thus formed, the first hot melt adhesive 101 is uniformly distributed in both the longitudinal direction A and the lateral direction B with respect to each of the first area 6 and the second area 7. Although it can be in the state of being applied intermittently, it can also be in the state of being applied continuously in at least one of the vertical direction A and the horizontal direction B. Therefore, there is no special rule in selecting the model of the first coater 121 for applying the first hot melt adhesive 101, and the same applies to the second coater 122 for applying the second hot melt adhesive 102. It is. However, in the article 1, the hot melt adhesives 11 and 12 are continuous between the polymer particle fixing hot melt adhesive 11 in the first section 6 and the sealing hot melt adhesive 12 in the second section 7. It is preferable to be in an aspect or an aspect close to each other so that the distance between them does not exceed 5 mm even if it is not a continuous aspect. When the polymer particle fixing hot-melt adhesive 11 is applied in such a manner so as to reach every corner of the first area 6, the superabsorbent polymer particles 4 also reach every corner of the first area 6. Become. For example, the superabsorbent polymer particles 4 can be distributed along the opposite side portion 62 immediately inside the opposite side portion 62 of the first area 6. The superabsorbent polymer particles 4 are preferably distributed so as to cover almost the entire upper surface 3a (see FIG. 2) of the lower layer sheet 3 in the first section 6, and the superabsorbent polymer particles 4 thus distributed are In the first zone 6, it is possible to prevent the upper layer sheet 2 and the lower layer sheet 3 from being bonded via the polymer particle fixing hot melt adhesive 11. When the article 1 requires the hot melt adhesive to be applied also to the upper layer 2, the hot melt adhesive can be applied to a necessary portion of the upper layer sheet 2 in the steps of FIGS. .

  In the present invention, there is no special provision for the shape of the article 1, the shape of the first section 6, and the number of sections formed by the first section 6, and appropriate changes can be made to these shapes and numbers in the illustrated example. It is. For example, the shape of the second area 7 can be changed so that the article 1 in FIG. 1 can be divided into two or three in the lateral direction B of the first area 6. 3 and 5, the composite web 137 when it is separated from the suction drum 130 can be run in a state intersecting with the horizontal, in addition to running horizontally as in the illustrated example. There is no special rule for the number of guide rolls that are positioned downstream of the suction drum 130 and used to change the direction in which the composite web 137 travels. The guide roll may be connected to the drive device and may be rotated, or may be a free roll that is not connected to the drive device and can be freely rotated. The ordering in the first, second, and third guide rolls 161, 162, and 163 means the order of the guide rolls arranged in the machine direction, and does not mean the order that is adjacent to the suction drum 130. That is, in the manufacturing method according to the present invention, an appropriate roll can be interposed between the suction drum 130 and the first guide roll 161 if necessary in assembling the manufacturing process.

  The article 1 obtained by the manufacturing method according to the present invention is not limited to disposable diapers, but is used in combination with diapers and diaper covers, urine absorbing pads, incontinence patient pants. It can be used as a urine absorption pad for use together. The article 1 can also be used as a wipe for absorbing and treating water and other water-absorbing articles. In the article 1 when used as a wipe, a water-permeable sheet piece is used as the lower layer sheet 3. It can be used, or a sheet piece of poor water permeability or water impermeability can be used.

DESCRIPTION OF SYMBOLS 1 Water absorbent article 2 Upper layer sheet 3 Lower layer sheet 4 High water absorption polymer particle 6 1st area 7 2nd area 11 Hot melt adhesive (hot melt adhesive for polymer particle fixation)
12 Hot melt adhesive (hot melt adhesive for sealing)
131 1st web 132 2nd web 137 Composite web 161 Guide roll (1st guide roll)
162 Guide roll (second guide roll)
163 Guide Roll (Third Guide Roll)
MD Machine direction α angle (intersection angle)

Claims (10)

The first area where the superabsorbent polymer particles are interposed between the opposing surfaces of the two sheet pieces, wherein at least one of the two overlapping sheet pieces is water permeable, and the opposing surface are joined to each other. A method for producing a water-absorbent article having a second area surrounding the first area,
The first web and the second web, which are continuous bodies of the two sheet pieces, are continuously run in the machine direction,
In the first web, the superabsorbent polymer particles are supplied to the facing surface of the portion corresponding to the first section, while the portion of the second web corresponding to the first section and the second section is supplied. Apply hot melt adhesive to the opposite surface,
Overlapping the first web and the second web to form a composite web having the first section and the second section, and running the composite web in the machine direction;
The composite web is sequentially brought into contact with a plurality of guide rolls that rotate so as to cause the composite web to travel in the machine direction, and the first guide roll located on the upstream side in the machine direction among the plurality of guide rolls; The direction of the travel direction of the composite web between the second guide roll adjacent to the first guide roll on the downstream side in the machine direction is set to the direction of the travel direction of the composite web toward the first guide roll. The said manufacturing method characterized by changing an angle in the range of 30-180 degree | times.   The manufacturing method according to claim 1, wherein the range of the angle is less than 90 degrees.   The composite web is sequentially brought into contact with the first guide roll, the second guide roll, and a third guide roll adjacent to the second guide roll on the downstream side, and the first roll and the second roll In the meantime, the range of the angle is set to be less than 90 degrees, and the composite web is run so as to have a downward slope or an upward slope, and the composite web is inclined upward or downward between the second roll and the third roll. The manufacturing method of Claim 1 or 2 made to drive | work so that it may become a downward slope. The manufacturing method according to any one of claims 1 to 3, wherein the first water-absorbing polymer particles are contained in the first zone at a rate of 30 to 300 g / m ² in mass.   The amount of the hot melt adhesive applied per unit area in the second area is the same as the amount of the hot melt adhesive applied per unit area in the first area. The manufacturing method as described.   The application amount of the hot melt adhesive per unit area in the second area is larger than the application amount of the hot melt adhesive per unit area in the first area. Production method.   The manufacturing method according to claim 1, wherein a plurality of the first areas are formed in the water absorbent article.   Each of the said 2 sheet piece is water-permeable, The manufacturing method in any one of Claims 1-7.   The method according to any one of claims 1 to 8, wherein the sheet piece that is water permeable is a hydrophilic nonwoven fabric formed of thermoplastic synthetic fibers.   One of the two sheet pieces is water permeable, the other is either impermeable or hardly permeable, and the superabsorbent polymer particles are either impermeable or hardly permeable. The manufacturing method according to claim 1, wherein the sheet piece is bonded to the sheet piece.

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