JP5965979B2 - Absorber manufacturing equipment - Google Patents

Description

  The present invention relates to an absorber manufacturing apparatus.

  As an apparatus for manufacturing absorbent articles for absorbent articles such as disposable diapers, sanitary napkins, and incontinence pads, a rotating drum having a concave portion for accumulation is provided on the outer peripheral surface, and the outer peripheral surface absorbs pulp and the like while rotating the rotating drum The body material is supplied in a scattered state, and the absorber material is deposited in the accumulation recess by suction from the bottom surface of the accumulation recess composed of a porous member in which a large number of suction holes are formed. 2. Description of the Related Art Absorber manufacturing apparatuses are known in which a deposit formed into a predetermined shape is released from the inside to obtain an absorber. The absorbent body is used as an absorbent body of an absorbent article as it is or after being coated with a cover sheet such as paper or a breathable nonwoven fabric.

  Further, as such an absorber manufacturing apparatus, a first suction region having a high opening area ratio and a second suction region having a lower opening area ratio than the first suction area are provided on the bottom surface of the concave portion for accumulation, thereby absorbing capacity. An apparatus for manufacturing an absorbent body having a portion designed to be partially high has also been proposed (see Patent Document 1).

JP 2004-65930 A

  The absorber manufacturing apparatus described in Patent Document 1 is capable of partially adjusting the accumulation amount of the absorber material in the concave portion for accumulation and manufacturing an absorber in which the basis weight of the absorber material is partially different. However, when changing the specifications such as the area ratio of the areas having different basis weights, it was necessary to modify the accumulation recesses themselves, which required a lot of labor.

  The present invention relates to providing an absorber manufacturing apparatus that can solve the problems of the prior art.

  The present invention includes a rotating drum having a plurality of accumulation recesses formed on the outer peripheral surface at predetermined intervals, and a duct for supplying fiber material as an absorbent material in a scattered state toward the outer peripheral surface of the rotating drum. A fiber material supply unit for supplying the fiber material into the duct, and a release means for releasing the deposit generated by the deposition of the fiber material in the accumulation recess as an absorber from the accumulation recess. And by changing the supply amount of the fiber material per unit time to the duct, a portion having a relatively large basis weight of the fiber material and a relatively small basis weight of the fiber material in each absorbent body An absorbent body manufacturing apparatus that manufactures an absorbent body having a portion, measuring the uneven distribution state of the fiber material in the absorber or the deposit, and based on the measured uneven distribution state, to the duct by the fiber material supply unit Changing the supply of fiber material That comprises a supply amount controller, there is provided an apparatus for manufacturing the absorbent body.

  According to the absorber manufacturing apparatus of the present invention, it is possible to manufacture an absorber in which a large amount of absorber material is unevenly distributed at a desired site, and it is possible to stably produce the absorber continuously.

FIG. 1 is a schematic view showing an embodiment of an absorbent body manufacturing apparatus according to the present invention. FIG. 2 is an exploded perspective view showing the structure of the concave portion for accumulation in the manufacturing apparatus shown in FIG. FIG. 3 (a) is a graph showing how to change the supply amount of the fiber material in the preferred embodiment, and FIG. 3 (b) is a graph showing the period of the concave portion for accumulation corresponding to FIG. 3 (a). FIG. 3C is an explanatory diagram of the length of the duct opening in the drum circumferential direction and the like. FIG. 4 is a perspective view showing an example of an absorbent body obtained by the present invention. Fig.5 (a)-FIG.5 (c) are graphs which show the displacement of the height position of the upper surface of an absorber used for discrimination | determination of the appropriateness of the uneven distribution state of a fiber material. FIG. 6 is a diagram corresponding to FIG. 3A illustrating an example in which the phase of the supply amount is changed according to the pattern of the uneven distribution state of the absorber. Fig.7 (a) and FIG.7 (b) are side views which show the other example of the absorber obtained by this invention. FIG. 8 is an explanatory diagram of a method for measuring the basis weight of the portion with the lowest basis weight of the fiber material and the portion with the highest basis weight of the fiber material. Fig.9 (a)-FIG.9 (c) are side views which show the duct of the other shape used in the Example.

Hereinafter, the present invention will be described based on preferred embodiments thereof.
As shown in FIG. 1, an absorbent body manufacturing apparatus 1 according to an embodiment of the present invention includes a rotating drum 2 having a plurality of accumulation recesses 22 formed on an outer peripheral surface at predetermined intervals, and an outer periphery of the rotating drum 2. The duct 4 that supplies the fiber material 31 as the absorber material in a scattered state toward the surface 2f, the fiber material supply unit 5 that supplies the fiber material 31 into the duct 4, and the accumulation recess 22 A release air blow device 6 is provided as a release means for releasing the deposit formed by the deposition of the material 31 and the water-absorbing polymer 32 from the accumulation recess 22 as the absorbent body 3, and the rotating drum 2. A vacuum conveyor 7 serving as a conveying means disposed below and a supply amount control unit 8 for controlling the amount of the fiber material 31 supplied from the fiber material supply unit 5 into the duct 4.

The rotary drum 2 includes a cylindrical drum main body 20 made of a metal rigid body, and an outer peripheral member 21 that is arranged on the outer peripheral portion of the drum main body 20 and forms the outer peripheral surface 2 f of the rotary drum 2. Has been. The outer peripheral member 21 receives power from a motor (not shown) such as a motor and rotates around the horizontal axis in the direction of arrow R, while the drum body 20 is fixed and does not rotate.
As shown in FIG. 2, the outer peripheral member 21 has a porous plate 27 (porous member) and a pattern forming plate 28 that is fixed on the outer surface 27 a side of the porous plate 27, as shown in FIG. 2. . The bottom surface of the accumulation recess 22 is formed from a porous plate 27.

  The pattern forming plate 28 has an outer surface 28a that forms the outer peripheral surface 2f of the rotating drum 2 and an inner surface 28b that faces the rotating shaft side of the rotating drum 2, and an accumulation recess is provided between the outer surface 28a and the inner surface 28b. 22 has a space portion 280 having a shape corresponding to the three-dimensional shape in 22. The outline 22L of the space 280 coincides with the outline of the accumulation recess 22. As the pattern forming plate 28, for example, a plate formed by machining a metal or resin plate such as stainless steel or aluminum to form an opening (a space portion 280 having a shape corresponding to the three-dimensional shape in the accumulation recess 22), Alternatively, a plate in which the opening is integrally formed using a mold, a punched or etched plate, a superposition of these plates, or the like can be used.

The porous plate 27 transmits the air flow generated by the suction from the drum body 20 side to the outside of the rotating drum 2, holds the absorber material carried on the air flow without passing it, and the air It is a breathable plate that only allows it to pass through. The porous plate 27 is formed with a plurality of (multiple) suction holes (pores) penetrating the plate 27 in the thickness direction with a uniform distribution over the entire plate 27, and the accumulation recess 22 is a rotating drum. While passing through a space maintained at a negative pressure in 2, the suction hole functions as an airflow vent. The porous plate 27 in the present manufacturing apparatus 1 has a constant aperture ratio over the entire region, and no suction force control plate or the like that partially varies the suction force is disposed below the porous plate 27. . That is, the accumulation recess 22 in the manufacturing apparatus 1 generates a uniform suction force on the entire bottom surface.
As the porous plate 27, for example, a metal or resin mesh plate, or a metal or resin plate formed with a plurality of (many) pores by etching or punching can be used.

  As shown in FIG. 1, the drum body 20 includes a plurality of mutually independent spaces A, B, C, partitioned by a partition plate 20p provided from the central axis side of the rotary drum 2 toward the outer peripheral surface 2f. D. An intake fan (not shown) is connected to the central shaft portion 222 of the drum body 20, and a shutter valve or the like whose opening area can be adjusted is installed between the central shaft portion 222 and each space. Thus, the pressure in the partitioned spaces A to D in the rotary drum 2 can be adjusted by increasing or decreasing the opening area of the shutter. In the manufacturing apparatus 1, the suction force in the region of the space A located in the region where the outer peripheral surface 2 f is covered with the duct 4 is stronger than the suction force in the regions of the spaces B to D. Since the spaces C and D are regions including the transfer position of the absorber 3 in the accumulation recess 22 and the front and back thereof, zero pressure or positive pressure is preferable.

As shown in FIG. 1, the duct 4 extends from the fiber material supply unit 5 to the rotary drum 2, and an opening on the downstream side of the duct 4 is above the space A of the rotary drum 2 maintained at a negative pressure. 2f is covered. The fiber material supply unit 5 includes a pulverizer 51 as a defibrator. A raw material sheet 31A of a fiber material such as a wood pulp sheet is introduced into the pulverizer 51 by raw material supply rollers 52 and 52, and the pulverizer 51 The fiber material 31 generated by the fiber is configured to be supplied into the duct 4.
Between the rotating drum 2 and the fiber material supply unit 5 in the duct 4, a spray pipe 55 that supplies the duct 4 with a water-absorbing polymer 32, which is another kind of absorber material, is provided. By the operation of the intake fan (not shown) of the rotating drum 2, the absorber material (the fiber material 31 and the water-absorbing polymer 32) is sucked into the space in the duct 4 toward the outer peripheral surface 2 f of the rotating drum 2. Such an air flow is generated.

  The holding belt 24 is an endless breathable or non-breathable belt, and is stretched over the roll 25, the roll 26, and other rolls (not shown), and is rotated along with the rotation of the rotary drum 2. When the pressing belt 24 is a breathable belt, it is preferable that the absorbent material (the fiber material 31 and the water-absorbing polymer 32) in the accumulation concave portion 22 is not allowed to pass therethrough. Even if the pressure in the space B is set to atmospheric pressure, the presser belt 24 can hold the deposit in the stacking recess 22 in the stacking recess 22 until it is transferred onto the vacuum conveyor 7.

  The vacuum conveyor 7 (conveying means) is disposed below the rotary drum 2 and is close to the outer peripheral surface 2f located in the space C where the rotary drum 2 is set to have a weak positive pressure or zero pressure (atmospheric pressure). Are arranged. The vacuum conveyor 7 includes an endless breathable belt 73 and a vacuum box 74 disposed at a position facing the outer peripheral surface 2f of the rotary drum 2 with the breathable belt 73 interposed therebetween. On the vacuum conveyor 7, a covering sheet 35 made of tissue paper or a liquid-permeable nonwoven fabric is introduced.

  The mold release air blow device 6 is a mold release means for releasing the deposit obtained by depositing the absorbent material (the fiber material 31 and the water-absorbing polymer 32) in the stacking recess 22 from the stacking recess 22. Function as. The release air blow device 6 is disposed inside the outer peripheral member 21 in the space C, and the inner surface of the porous plate (porous member) that forms the bottom surface of the accumulation recess 22 on which the absorbent material is deposited. Air can be blown from the side toward the outer surface 27a side, and the release of the deposited product from the accumulation recess 22 is promoted by the air.

  The manufacturing apparatus 1 includes a supply amount control unit 8 that controls the amount of the fiber material 31 supplied from the fiber material supply unit 5 into the duct 4. Although not shown in detail, the supply amount control unit 8 includes a computer having a display unit and an input unit, an interface for electrically connecting the computer and other devices, and a predetermined program incorporated in the computer. It is configured. Moreover, this manufacturing apparatus 1 is provided with the surface displacement measuring device 82, The signal from the surface displacement measuring device 82 is input into the computer of supply amount control part 8, and the absorber conveyed on the conveyance means 7A The change in the height position of the upper surface of the absorber 3 along the flow direction X of 3 is recorded in a storage device such as an HDD, RAM, SSD, and displayed on the display unit. Further, the computer outputs a control signal to the drive motor 53 to control the rotation of the drive motor 53, thereby controlling the supply amount of the raw material sheet 31A to the pulverizer 51 and the fiber material into the duct 4. The supply amount of 31 can be controlled. Instead of a computer, a programmable logic controller (PLC) can also be used.

  The drive motor 53 rotates the pair of supply rollers 52 and 52 that feed the raw material sheet 31 </ b> A of the fiber material 31 to the pulverizer 51. By increasing the rotation speed of the drive motor 53, the supply amount of the raw material sheet 31A to the pulverizer 51 increases, and the supply amount of pulp (fiber material) per unit time to the duct 4 increases. On the other hand, by reducing the rotational speed of the drive motor 53, the supply amount of the raw material sheet 31A to the pulverizer 51 is reduced, and the supply amount of pulp (fiber material) per unit time to the duct 4 is reduced.

  The supply rollers 52 and 52 in the manufacturing apparatus 1 are connected and interlocked via, for example, gears and the like, and are rotated in the opposite directions at the same peripheral speed by one drive motor 53. As the drive motor 53, a servo motor is preferably used. A known device such as an input / output interface or a servo amplifier is provided between the drive motor 53 and the supply amount control unit 8 according to the type of rotation control signal output from the supply amount control unit 8 or the type of motor. Be placed.

In addition, the manufacturing apparatus 1 includes a mechanism for covering the upper and lower surfaces of the absorber 3 released from the accumulation recess 22 with the covering sheets 35 and 36 to obtain the absorber continuous body 30A. The covering sheet 36 covering the surface opposite to the covering sheet 35 supplied on the vacuum conveyor 7 in the absorbent body 3 is placed after the absorbent body 3 is placed at the center in the width direction on one side of the covering sheet 35. Further, both sides of the covering sheet 35 folded back to the other side may be used, or a covering sheet 36 different from the covering sheet 35 supplied onto the vacuum conveyor 7 may be used. As the covering sheets 35 and 36, thin paper (tissue paper), liquid-permeable nonwoven fabric, or the like can be used.
Further, the manufacturing apparatus 1 cuts the absorbent continuous body 30A into the absorbent body 30 having a length (hereinafter also referred to as a length of one absorbent article) used for each absorbent article. A device 9 is provided. As the cutting device 9, various known cutting means used for manufacturing absorbent articles and absorbent bodies can be used. For example, as shown in FIG. 1, a cutter roll 91 having a cutting blade 92 and its blade are received. It has the anvil roll 93, and what cuts the absorber continuous body 30A sequentially by a fixed period by rotation of both rolls can be used.

A method for continuously manufacturing the absorber 3 using the above-described absorber manufacturing apparatus 1 will be described.
In order to manufacture the absorber 3 using the manufacturing apparatus 1 described above, the rotary drum 2 is rotated and the intake fan is operated to make the space A have a negative pressure. Further, the release air blow device 6, the vacuum conveyor 7, the belt conveyor 7 </ b> A disposed adjacent to the vacuum conveyor 7, and the cutting device 9 are operated.
By the operation of the intake fan, a uniform suction force is generated over the entire bottom surface of the accumulation recess 22 located on the space A, and the air flowing in the duct 4 toward the outer peripheral surface of the rotary drum 2. A flow is generated.

  When the supply rollers 52 and 52 of the fiber material supply unit 5 are operated to introduce the raw material sheet 31 </ b> A of the fiber material 31 into the pulverizer 51, the fiber material 31 generated by defibration by the pulverizer 51 is in the duct 4. To be supplied. The fiber material 31 supplied into the duct 4 is in a scattered state, is carried on the air flow flowing through the duct 4, and is supplied toward the outer peripheral surface of the rotary drum 2.

  In the manufacturing apparatus 1 of the present embodiment, the supply amount control unit 8 periodically changes the supply amount per unit time of the fiber material supplied in a scattered state to the rotating drum 2. Specifically, the supply amount per unit time of the fiber material 31 supplied into the duct 4 is periodically changed. More specifically, the raw material sheet 31A of the fiber material is pulverized as a defibrating machine by periodically changing the rotational speed of the supply rollers 52, 52 for supplying the raw material by a computer included in the supply amount control unit 8. The speed supplied to the machine 51 is periodically changed, whereby the supply amount per unit time of the fiber material 31 supplied into the duct 4 is periodically changed. A program for causing such a change is installed in the computer of the supply amount control unit 8. The rotation speed of the supply rollers 52 and 52 may be periodically changed using a programmable logic controller.

For example, the supply amount control unit 8 periodically changes the rotation speed of the supply rollers 52 and 52 for supplying raw materials in the pattern shown in FIG. Thus, the mass a of the fiber material 31 supplied to the duct 4 is periodically changed in the same pattern.
The pattern shown in FIG. 3A is a pattern in which the step of supplying a relatively small amount of fiber material 31 to the duct 4 and the step of supplying a relatively large amount of fiber material 31 to the duct 4 are repeated alternately. The fiber material 31 is continuously supplied by changing the supply amount. Instead of this, the fiber material 31 may be supplied to the duct 4 in a pattern in which the step of not supplying the fiber material 31 to the duct 4 and the step of supplying the fiber material 31 to the duct 4 are alternately repeated.

The vertical axis in the graph of FIG. 3A is the speed at which the raw material sheet 31A of the fiber material 31 is introduced into the crusher 51 by the supply rollers 52, 52, and per unit time of the fiber material 31 supplied to the duct 4. The supply amount (mass a) also changes. The graph of FIG. 3B shows the period of the concave part 22 for accumulation that passes through the portion covered with the duct 4, and one period is for one accumulation as shown in FIG. 3C, for example. After the specific position P1 of the concave portion 22a, for example, the front end in the rotational direction R passes through the specific position P2 in the direction along the circumferential direction of the rotary drum 2 of the duct 4, the specific position P1 common to the subsequent concave portion 22b for accumulation is , Corresponding to the time until passing through the specific position P2.
When the manufacturing apparatus 1 is in operation, the supply amount control unit 8 changes the speed at which the raw material sheet 3A of the fiber material is supplied to the pulverizer 51 as shown in FIGS. 3 (a) and 3 (b), and The period when the accumulation recess 22 passes through the portion covered with the duct 4 is matched.

Then, the supply amount control unit 8 periodically changes the supply amount per unit time of the fiber material 31 supplied into the duct 4, thereby depositing the fiber material 31 on the deposit to be accumulated in the accumulation recess 22. A portion with a small amount of accumulation and a portion with a large amount of accumulation of the fiber material 31 can be formed, and the basis weight of the fiber material is relatively in each absorber obtained by releasing from the concave portion 22 for accumulation. A large portion and a portion having a relatively small basis weight of the fiber material are formed. FIG. 4 is a perspective view showing an example of the absorber 3 manufactured by the apparatus 1 of the present embodiment.
In the absorbent body 3 shown in FIG. 4, a high basis weight portion 33 having a relatively large basis weight of the fiber material is formed on one end 3 a side corresponding to the rotation direction front end f of the accumulation recess 22, and the accumulation recess 22. A low basis weight portion 34 having a relatively small basis weight of the fiber material is formed on the other end 3b side corresponding to the rear end r in the rotation direction. The absorber 3 has a longitudinal direction 3X corresponding to the circumferential direction of the rotary drum 2 and a width direction 3Y orthogonal to the longitudinal direction. When the absorbent body 3 is transported by a vacuum conveyor 7 or a belt conveyor 7A as a transport means, as shown in FIG. 1, the longitudinal direction 3X is along the transport direction X, and one end 3a having a high basis weight portion 33. The side is directed downstream in the transport direction.
As shown in FIG. 1, the absorbent body 3 thus obtained is coated with the covering sheets 35 and 36 to form an absorbent body continuous body 30 </ b> A, and then cut into a predetermined length by the cutting device 9. The absorbent body 30 covered with the covering sheet is incorporated into an absorbent article such as a disposable diaper.

The supply amount control unit 8 records the displacement of the height of the upper surface of the absorber 3 being transported by the transport means, based on the signal input from the surface displacement measuring device 82. FIG. 5A is a graph showing the displacement of the height position of the upper surface of the absorber 3 recorded in the storage unit of the supply amount control unit 8. 5 to 360 on the horizontal axis of FIG. 5A shows the time length for one cycle of the cutting cycle by the cutter roll 91 or one cycle of the above-described concave portion for accumulation divided into 360 equal parts, Each 0 point on the horizontal axis is a point in time when a detection signal is input from a detector that detects a reference position provided on the cutter roll or the rotary drum. Instead, the rotary encoder 83 is attached to the shaft portion of the cutter roll 91 of the cutting device, and the length of the pulse corresponding to one rotation of the cutter roll 91 output from the rotary encoder 83 is set to 0 to 360 on the horizontal axis. It can also be the length.
In the storage unit of the supply amount control unit 8, a preferable range of the height position of the upper surface at a plurality of positions in the length from 0 to 360 on the horizontal axis is recorded in advance according to the target absorber to be manufactured. Depending on whether or not each value of the absorber actually measured at the time of manufacturing the absorber 3 satisfies these values, the manufactured absorber 3 has the form of the target absorber 3. Can be determined. As the surface displacement meter 82, a laser displacement meter or the like can be used.
For example, although the absorber 3 to be manufactured has the form shown in FIG. 5A, the form of the absorber 3 determined by the input value from the surface displacement measuring device 82 is the same as that shown in FIG. ), The phase of the supply amount is changed in accordance with the unevenly distributed pattern of the absorber as shown in FIG. The phase moving direction is a direction in which the uneven distribution state of the fiber material in the manufactured absorbent body approaches the uneven distribution state of the target absorbent body.

  In this way, according to the manufacturing apparatus 1 of the present embodiment, the absorption in which a large amount of the absorber material is unevenly distributed at a desired site in one absorber simply by changing the supply amount of the fiber material per unit time. A body can be manufactured, and the uneven distribution state of the manufactured absorber 3 is monitored using the surface displacement meter 82 and the like, and the fiber material supply unit supplies the fiber material to the duct based on the uneven distribution state. By changing the amount, the absorbent body in which the fiber material is unevenly distributed in a desired state can be stably produced continuously.

  The absorbent body 30 or the absorbent body 30 having the core portion made of the absorbent body 3 is preferably used as an absorbent body of an absorbent article. The absorbent article is mainly used to absorb and retain body fluids excreted from the body such as urine and menstrual blood. Absorbent articles include, for example, disposable diapers, sanitary napkins, incontinence pads, panty liners, etc., but are not limited to these, and widely include articles used to absorb liquid discharged from the human body. To do.

Moreover, the absorber 3 in which the absorbent body 3 or the core portion is composed of the absorbent body 3 is composed of the high basis weight portion 33 having a relatively high basis weight and the low basis weight portion 34 having a relatively low basis weight. And the deposit amount of the absorber material is partially different. Therefore, in particular, as an absorbent body used for a disposable diaper, it is incorporated into an absorbent article so that the high basis weight portion 33 is on the ventral side (front side) and the low basis weight portion 34 is on the back side (rear side). It is preferable that the performance of the absorber is maximized.
Moreover, having the high basic weight part and low basic weight part from which the basic weight of a fiber material differs in the absorber 3 is easy to ensure a high absorption capacity | capacitance in a required part, for example, However, Absorption of the part inferior to necessity It is also preferable from the viewpoint of reducing the capacity and reducing the amount of the raw material used as a whole. In addition, the absorber 3 can also be used as an absorber of an absorbent article, without coat | covering with the coating sheets 35 and 36. FIG.

The absorber 3 to be manufactured may have the form shown in FIG. 5B or 5C. Moreover, the thing of the form shown to Fig.7 (a) or FIG.7 (b) may be sufficient.
The absorbent body shown in FIG. 5B has a high basis weight portion 33 having the largest basis weight of the fiber material at the center portion in the longitudinal direction 3X corresponding to the circumferential direction of the rotating drum 2, and has a high height in the longitudinal direction 3X. The basis weight portion 33 has a low basis weight portion 34 with the smallest basis weight of the fiber material.
The absorbent body shown in FIG. 7A has a high basis weight portion 33 having the largest basis weight of the fiber material at the center portion in the longitudinal direction 3X corresponding to the circumferential direction of the rotary drum 2, and has one end in the longitudinal direction 3X. It has a low basis weight part 34 with the smallest basis weight of the fiber material on the side, and the basis weight of the fiber material is less than the high basis weight part 33 and more than the low basis weight part 34 on the other end side in the longitudinal direction 3X. An intermediate basis weight portion 38 is provided.
In the absorbent body shown in FIG. 7B, a plurality of high basis weight portions 33 are formed in a state of being separated from each other in the longitudinal direction 3X corresponding to the circumferential direction of the rotary drum 2. In the absorbent body shown in FIG. 7 (b), the three portions other than the two high basis weight portions 33 are all the low basis weight portions 34 having the smallest basis weight of the fiber material. Or two places can also be made into the intermediate | middle basic weight part 38 in which the basic weight of a fiber material is less than the high basic weight part 33, and is larger than the low basic weight part 34.

From the viewpoint of connecting the change in the supply amount of the fiber material 31 to the difference in basis weight of the fiber material in the absorbent body 3, the length of the duct opening in the drum circumferential direction is relative to the length of the accumulation recess 22 in the drum circumferential direction. The ratio is preferably 2.0 or less, more preferably 1.5 or less. Further, from the viewpoint of the magnitude relationship between the deposition rate of the fiber material and the pneumatic transport rate of the same material in the duct 4, the ratio is preferably more than 0, and more preferably 0.1 or more.
As shown in FIG. 3C, the length of the duct opening in the drum circumferential direction is the length between both ends 4f and 4r of the opening 4e on the rotating drum side of the duct 4 in the direction along the circumferential direction of the rotating drum. It is measured along the outer peripheral surface of the rotating drum. The length of the accumulation recess 22 in the drum circumferential direction is the length between both ends f and r of the accumulation recess 22 in the direction along the circumferential direction of the rotating drum, and is measured along the outer peripheral surface of the rotation drum.

  In addition, in order to manufacture an absorbent body in which the fiber material is unevenly distributed by changing the supply amount of the fiber material 31 into the duct 4, a portion having a high fiber material concentration and a concentration are present on the outer peripheral surface of the rotary drum 2. It is preferable that the lower portion reaches in a wavy manner.

In the absorbent body produced in the present invention, the ratio of the basis weight of the portion with the largest basis weight of the fiber material to the basis weight of the portion with the lowest basis weight of the fiber material is preferably 1.5 or more, more preferably 2 or more, preferably 30 or less. Moreover, the basis weight of the lowest basis weight of the fiber material is preferably 100 g / m ² or more and 3000 g / m ² or less from the viewpoint of the absorber strength.
The basis weight of the portion having the largest basis weight of the fiber material and the portion having the lowest basis weight of the fiber material is obtained as follows. That is, as shown in FIG. 8, a straight line C along the width direction 3Y is drawn from one end 3a of the absorbent body 3 in the longitudinal direction 3X at intervals of 30 mm, and the absorbent body 3 is divided into a plurality of portions 3A to 3F with the straight line C as a boundary. And the area and the mass of the fiber material contained are determined for each of the divided portions. Then, the basis weight is calculated from the calculated mass and area, the basis weight of the divided portion with the highest calculated basis weight is set as the basis weight of the portion with the largest basis weight of the fiber material, and the calculated basis weight is the smallest division. The basis weight of the portion is the basis weight of the portion with the smallest basis weight of the fiber material. In addition, as shown with a dotted line in FIG. 8, when the absorber 3 has a portion 3G extending from the last drawn straight line Ce with a length of less than 30 mm, the portion 3G is not divided by the straight line Ce. As a part of the previous part 3F, the basis weight of the part 3F is calculated. The one end 3a in the longitudinal direction 3X of the absorbent body 3 is the one end closer to the abdomen side (front side) of the wearer in the front-rear direction when the absorbent article is an absorbent body. When the relationship between the wearer's front and rear is unknown, the end corresponding to the rotational direction front end f of the concave portion 22 for accumulation is defined as one end, and when the relationship is unknown, any one end in the longitudinal direction is defined as one end.

In the method of the present embodiment, in addition to supplying the fiber material 31 to the duct 4, it is also preferable to continuously supply the water-absorbing polymer 32 at a constant supply amount. The water-absorbing polymer 32 is supplied from, for example, the spray tube 55 described above, and supplied into the air stream that conveys the fiber material 31.
Even if the water-absorbing polymer 32 is continuously supplied, the water-absorbing polymer 32 has a larger amount of the water-absorbing polymer 32 in the air flow conveying the fiber material 31 than in the portion having a low concentration in the portion having a high concentration of the fiber material. Since 32 is entangled, a relatively large amount is included. Therefore, as the absorbent body 3, an absorbent body having more water-absorbing polymer in a portion where the basis weight of the fiber material is relatively large than in a portion where the basis weight of the fiber material is relatively small is obtained.
Thus, according to the method of the present embodiment, an absorbent body in which water-absorbing polymers are unevenly distributed can be obtained without providing means for changing the supply amount in the water-absorbing polymer 32 supply device.

  The absorbent article typically includes a top sheet, a back sheet, and a liquid-retaining absorbent body disposed between both sheets. The upper and lower surfaces of the absorber may be covered with one or a plurality of covering sheets. The back sheet may or may not have water vapor permeability. The absorbent article may further include various members according to specific uses of the absorbent article. Such members are known to those skilled in the art. For example, when the absorbent article is applied to a disposable diaper or a sanitary napkin, a pair or two or more pairs of three-dimensional guards can be arranged on the outer side of both sides of the absorbent body.

  As the fiber material and the water-absorbing polymer used in the present invention, various materials conventionally used for absorbent bodies of absorbent articles such as sanitary napkins, panty liners, and disposable diapers can be used without particular limitation. For example, short fibers of cellulosic fibers such as pulp fibers, rayon fibers, and cotton fibers, and short fibers of synthetic fibers such as polyethylene are used. These fibers can be used alone or in combination of two or more. Moreover, it is preferable that the fiber material is entirely or partly pulp fiber, and the ratio of the pulp fiber in the fiber material is preferably 50 to 100% by mass, more preferably 80 to 100% by mass, More preferably, it is 100 mass%. In addition to the fiber material, a deodorant or an antibacterial agent may be supplied into the duct as necessary. The water-absorbing polymer may or may not be supplied.

  Examples of water-absorbing polymers include sodium polyacrylate, (acrylic acid-vinyl alcohol) copolymer, cross-linked sodium polyacrylate, (starch-acrylic acid) graft copolymer, and (isobutylene-maleic anhydride) copolymer. Examples thereof include a polymer and a saponified product thereof, and polyaspartic acid. A fiber and a water absorbing polymer can be used individually by 1 type or in combination of 2 or more types.

As mentioned above, although one Embodiment of the manufacturing apparatus of the absorber of this invention was described, this invention is not restrict | limited to embodiment mentioned above, Each can be changed suitably.
For example, in the above-described embodiment, the surface displacement measuring instrument is used to measure the uneven distribution state of the fiber material in the absorbent body. However, instead of this, image processing or a capacitance sensor can be used.
In the image processing, for example, the basis weight amount of the fiber material can be determined based on the density of the absorber in the image captured by the imaging unit. The electrostatic capacity sensor is preferable because it is suitable for measuring insulators such as cellulose fibers such as pulp fibers, rayon fibers, and cotton fibers used as a material for absorbent articles, and synthetic fibers such as polyethylene.

This invention discloses the following absorbent articles further regarding embodiment mentioned above.
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A rotating drum having a plurality of accumulation recesses formed at predetermined intervals on the outer peripheral surface; a duct for supplying fiber material as an absorbent material in a scattered state toward the outer peripheral surface of the rotating drum; The duct includes a fiber material supply section for supplying the fiber material to the stack, and mold release means for releasing the deposit generated by depositing the fiber material in the stacking recess as an absorber from the stacking recess. By changing the supply amount per unit time of the fiber material to each of the absorbent bodies, each absorbent body has a portion having a relatively high basis weight of the fiber material and a portion having a relatively low basis weight of the fiber material. An absorber manufacturing apparatus for manufacturing an absorber,
An absorbent body comprising a supply amount control unit that measures the uneven distribution state of the fiber material in the absorber or the deposit and changes the supply amount of the fiber material to the duct by the fiber material supply unit based on the measured uneven distribution state. manufacturing device.

<2>
Manufacture of the absorbent body according to <1>, wherein a ratio of a length of the duct opening in the circumferential direction of the duct opening to the rotating drum side to a length in the drum circumferential direction of the accumulation recess is 2.0 or less apparatus.
<3>
The supply amount control unit changes the supply amount of the fiber material so as to manufacture an absorbent body in an unevenly distributed state that matches the unevenly distributed state of the fiber material registered in the storage unit in advance. <1> or <2 The manufacturing apparatus of the absorber as described in>.
<4>
The absorber according to any one of <1> to <3>, wherein a surface displacement measuring instrument, an image processing, or a capacitance sensor is used for measuring the uneven distribution state of the fiber material in the absorber or the deposit. Manufacturing equipment.
<5>
The rotating drum includes a cylindrical drum main body and an outer peripheral member that is arranged on the outer peripheral portion of the drum main body and forms an outer peripheral surface of the rotating drum. A porous plate and a pattern forming plate fixed to be overlapped on the outer surface side of the porous plate, and the bottom surface of the concave portion for accumulation is formed from the porous plate. The manufacturing apparatus of the absorber as described in any one of>-<4>.

<6>
The porous plate transmits an air flow generated by suction from the drum body side to the outside of the rotating drum, holds the absorber material carried on the air flow without passing through, and only air The apparatus for producing an absorbent body according to the above <5>, which is a gas permeable plate that allows gas to pass therethrough.
<7>
The duct extends from the fiber material supply unit to the rotating drum,
The fiber material supply unit includes a pulverizer as a defibrator, a fiber material raw material sheet is introduced into the pulverizer by a raw material supply roller, and the fiber material generated by defibration by the pulverizer is placed in the duct. The absorber manufacturing apparatus according to any one of <1> to <6>, which is supplied.
<8>
The said fiber material supply part is a manufacturing apparatus of the absorber as described in said <7> provided with a pair of supply roller which sends the said raw material sheet | seat to the said grinder, and the drive motor which rotationally drives this supply roller.
<9>
By increasing the rotation speed of the drive motor, the supply amount of the fiber material per unit time to the duct is increased, and by decreasing the rotation speed of the drive motor, the supply amount of the fiber material per unit time to the duct is increased. The manufacturing apparatus of the absorber as described in <8> in which decreases.
<10>
The supply amount control unit includes a computer having a display unit and an input unit, an interface for electrically connecting the computer and other devices, and a predetermined program incorporated in the computer. The manufacturing apparatus of the absorber as described in any one of <1> to <6>.

<11>
A computer that outputs a control signal to the drive motor to control the rotation of the drive motor, thereby controlling the supply amount of the raw material sheet to the pulverizer and into the duct; The manufacturing apparatus of the absorbent body according to any one of <7> to <10>, wherein the supply amount of the fiber material is controlled.
<12>
A mechanism for obtaining a continuous absorbent body by coating the upper and lower surfaces of the absorbent body released from the accumulation recess with a covering sheet, and absorbing the length of the absorbent continuous body used for individual absorbent articles. The manufacturing apparatus for an absorbent body according to any one of <1> to <11>, comprising a cutting device for cutting the body.
<13>
<7> in which the cycle of changing the speed at which the raw material sheet is supplied to the pulverizer by the supply amount control unit and the cycle in which the concave portions for accumulation pass through the portion covered by the duct are matched. The manufacturing apparatus of the absorber as described in any one of ~ <12>.
<14>
Between the rotating drum and the fiber material supply unit in the duct, a spray pipe for supplying a water-absorbing polymer, which is another kind of absorbent material, to the duct is provided <1> to <13> The manufacturing apparatus of the absorber of any one of.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the scope of the present invention is not limited to such examples.

[Example 1]
The absorber was manufactured using the apparatus shown in FIG. As the raw material sheet 31A, a wood pulp sheet is used, and the supply amount to the pulverizer 51 is changed as shown in FIG. The absorber 3 of the form shown was manufactured. During the manufacture of the absorber 3, a uniform suction force was generated over the entire area of the bottom surface of the concave portion for accumulation. Further, the water-absorbing polymer 32 was not supplied. Moreover, when the uneven distribution state of the fiber material of the absorber 3 was monitored using the surface displacement measuring device during manufacture, the uneven distribution state of the fiber material was always stable.
[Examples 2-5, Comparative Examples 1-3]
The shape of the duct 4 in the vicinity of the rotating drum 2 is changed to that shown in “Duct shape” in Table 1, and the length in the drum longitudinal direction of the accumulation recess is changed as shown in Table 1. The absorber was manufactured in the same manner as in Example 1. The length of the concave portion for accumulation in the longitudinal direction of the drum coincides with the length in the longitudinal direction of the manufactured absorbent body. About Comparative Examples 1-3, the wood pulp sheet was always supplied with respect to the grinder 51 at a fixed speed. “Present” in the column of “Pulp supply amount control” in Table 1 means that the supply amount of the wood pulp sheet was changed periodically.
Shapes 1 to 4 which are ducts shown in the column of “duct shape” in Table 1 are as follows.
Shape 1: Shape shown in FIG. 1, length of duct opening 940 mm
Shape 2: Shape shown in FIG. 9A, duct opening length 520 mm
Shape 3: shape shown in FIG. 9B, duct opening length 346 mm
Shape 4: Shape shown in FIG. 9C, duct opening length 173 mm

[Reference Examples 1-4]
The shape of the duct 4 in the vicinity of the rotating drum 2 is changed to that shown in “Duct shape” in Table 2, and the length in the drum longitudinal direction of the accumulation recess is changed as shown in Table 2. The absorber was manufactured in the same manner as in Example 1. About the reference examples 1-4, although the pulp supply amount was controlled, the length a of the drum circumferential direction of the duct opening part opened to the rotation drum side with respect to the length b of the drum circumferential direction of the said recessed part for accumulation | stacking The ratio was greater than 3.0.

(Evaluation)
About each absorber obtained in an Example and a comparative example, the basis weight ratio (henceforth uneven distribution magnification) of the part with the largest basis weight of fiber material, and the part with the lowest basis weight of fiber material was mentioned above. Table 1 and Table 2 show the values measured by the above.

  The absorbent bodies obtained in Examples 1 to 5, which are embodiments of the present invention, have an uneven magnification ratio of 1.5 or more, a portion with the largest basis weight of the fiber material, and a portion with the smallest basis weight of the fiber material, Is formed. On the other hand, the absorbent bodies obtained in Comparative Examples 1 to 3 have an uneven distribution ratio of 1.2 or less, and the basis weight is substantially constant.

DESCRIPTION OF SYMBOLS 1 Absorbent body manufacturing apparatus 2 Rotating drum 2f Outer peripheral surface 20 Drum body 21 Outer peripheral member 22 Concave portion for accumulation 3 Absorber 31 Fiber material 31A Raw material sheet 32 Water-absorbing polymer 33 High basis weight part 34 Low basis weight part 30 Having a covering sheet Absorber 4 Duct 4e Duct opening 5 Textile material supply unit 51 Crusher (defibrating machine)
52 Raw Material Supply Roller 53 Drive Motor 6 Release Air Blow Device 7 Vacuum Conveyor 7A Belt Conveyor 8 Supply Amount Control Unit 81 Surface Displacement Measuring Device 9 Cutting Device 91 Cutter Roll 92 Cutting Blade 93 Anvil Roll 55 Absorbing Polymer Dispersion Tube

Claims (4)

A rotating drum having a plurality of accumulation recesses formed at predetermined intervals on the outer peripheral surface; a duct for supplying fiber material as an absorbent material in a scattered state toward the outer peripheral surface of the rotating drum; The duct includes a fiber material supply section for supplying the fiber material to the stack, and mold release means for releasing the deposit generated by depositing the fiber material in the stacking recess as an absorber from the stacking recess. By changing the supply amount per unit time of the fiber material to each of the absorbent bodies, each absorbent body has a portion having a relatively high basis weight of the fiber material and a portion having a relatively low basis weight of the fiber material. An absorber manufacturing apparatus for manufacturing an absorber,
An absorbent body comprising a supply amount control unit that measures the uneven distribution state of the fiber material in the absorber or the deposit and changes the supply amount of the fiber material to the duct by the fiber material supply unit based on the measured uneven distribution state. manufacturing device.   2. The absorber manufacturing apparatus according to claim 1, wherein a ratio of a length in a circumferential direction of a duct opening portion opened to a rotating drum side to a length in a circumferential direction of the concave portion for accumulation is 2.0 or less. .   The said supply amount control part changes the supply amount of a fiber material so that the absorber of the uneven distribution state which matches the uneven distribution state of the fiber material previously registered into the memory | storage part may be manufactured. Absorber manufacturing equipment.   The manufacturing of the absorber according to any one of claims 1 to 3, wherein a surface displacement measuring instrument, an image processing, or a capacitance sensor is used for measuring the uneven distribution state of the fiber material in the absorber or the deposit. apparatus.

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