Patent Publication Number: US-2011049758-A1

Title: Apparatus and method for manufacturing absorbent body

Description:
TECHNICAL FIELD 
     The present invention relates to an apparatus and a method for manufacturing an absorbent body of an absorbent article such as a disposable diaper. 
     BACKGROUND ART 
     As examples of an absorbent article that absorbs fluid, disposable diapers, sanitary napkins, and the like are used. These absorbent articles include an absorbent body that is produced by forming pulp fibers, as an example of fluid absorbent fibers, into a predetermined shape. 
     This absorbent body  1  is shaped by a fiber stacking apparatus  10  in a production line (see  FIG. 1 , for example), and then placed on top of a sheet-like member  3  such as a nonwoven fabric continuously carried on a conveyor  81 . 
     The fiber stacking apparatus  10  includes as the main body a rotating drum  20  that rotates in a clockwise direction, and has recessed form dies  21  formed on the outer circumferential surface of the rotating drum  20 . Moreover, a distribution opening  31   a  of a fiber distributing duct  31  that distributes pulp fibers  2  is provided so as to face the outer circumferential surface. Thus, when a form die  21  passes the position of the distribution opening  31   a  as the rotating drum  20  rotates, the pulp fibers  2  released in the fiber distributing duct  31  accumulate in the form die  21  and are formed into an absorbent body  1 . Thereafter, when the form die  21  reaches a position that faces the conveyor  81 , the absorbent body  1  is released from the form die  21  and transferred onto the sheet-like member  3  on the conveyor  81 . 
     Note that a polymer charging member  41  for charging a superabsorbent polymer  5  into the form die  21  is also disposed in the fiber distributing duct  31  (see JP-A-2-107250, for example). 
     DISCLOSURE OF INVENTION 
     Problem to be Solved by the Invention 
     In order to charge the superabsorbent polymer  5  uniformly in a width direction (a direction perpendicular to the plane of the paper in  FIG. 1 ), the polymer charging member  41  is formed wide in the width direction. Moreover, since the polymer charging member  41  is set in the fiber distributing duct  31  as described above, the polymer charging member  41  is disposed to intersect at least a part of a distribution path of the pulp fibers  2 . 
     However, with this configuration, a range A 3  that is under the polymer charging member  41  is created in the distribution path of the pulp fibers  2 , and when the form die  21  passes through the range A 3 , the accumulation of the pulp fibers  2  is restrained. As a result, there is a risk that the pulp fibers  2  cannot be accumulated as intended. 
     For example, in order to prevent gel blocking (a phenomenon that may occur in the case where the mixture ratio of the superabsorbent polymer  5  to the pulp fibers  2  is high in an upper layer (the user&#39;s skin side) of the absorbent body  1 , which is a phenomenon, during absorption of fluid by the absorbent body  1 , particles of the superabsorbent polymer  5  in the upper layer swell and join together, and act like a wall so as to inhibit penetration of fluid into a lower layer) of the absorbent body  1 , it is preferable that the mixture ratio of the superabsorbent polymer  5  in the upper layer of the absorbent body  1  is low. However, as shown in  FIG. 1 , in the case where the polymer charging member  41  in the fiber distributing duct  31  extends from a downstream end to the center in a rotating direction Dc (a moving direction of the form die  21 ) of the rotating drum  20 , the position A 3  in which pulp fibers  21  of the upper layer of the absorbent body  1  should be accumulated is in the shadow of the polymer charging member  41 , and thus the pulp fibers  2  are restrained from reaching the form die  21 . As a result, it is difficult to increase the mixture ratio of the pulp fibers  2  in the upper layer. 
     The present invention was made in light of conventional problems as those described above, and it is an object thereof to provide an apparatus and a method for manufacturing an absorbent body that, even in the case where the polymer charging member for charging the superabsorbent polymer is disposed to intersect at least a part of the distribution path of the fluid absorbent fibers, enable the fluid absorbent fibers to be accumulated in the form die without being interfered by the polymer charging member. 
     Means for Solving the Problem 
     In order to solve the problems as described above, a main aspect of the present invention is an apparatus for manufacturing an absorbent body in which while a form die is moved in one direction along a predetermined moving path, fluid absorbent fibers are distributed toward the form die and accumulated in the form die, whereby the absorbent body is formed, wherein a polymer charging member for charging a superabsorbent polymer into the form die is disposed to intersect at least a part of a distribution path of the fluid absorbent fibers; and a space through which the fluid absorbent fibers are allowed to pass along the distribution path is formed in the polymer charging member. 
     Another main aspect of the present invention is a method for manufacturing an absorbent body in which while a form die is moved in one direction along a predetermined moving path, fluid absorbent fibers are distributed toward the form die and accumulated in the form die, whereby the absorbent body is formed, wherein a polymer charging member for charging a superabsorbent polymer into the form die is disposed to intersect at least a part of a distribution path of the fluid absorbent fibers; and the fluid absorbent fibers are let through a space formed in the polymer charging member along the distribution path to reach the form die. 
     Other features of the present invention will become apparent from the description of the present specification with reference to the accompanying drawings. 
     EFFECTS OF THE INVENTION 
     According to the present invention, even in a case where the polymer charging member for charging the superabsorbent polymer is disposed to intersect at least a part of the distribution path of fluid absorbent fibers, the fluid absorbent fibers can be accumulated in the form die without being interfered by the polymer charging member. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a side view of an apparatus  10  for manufacturing an absorbent body  1  according to the present embodiment of the invention. 
         FIG. 2  is an enlarged cross-sectional view of a fiber distributing duct  31 . 
         FIG. 3A  is a side view of a polymer charging member  41 , and  FIG. 3B  is a plan view seen from line B-B in  FIG. 3A . 
         FIG. 4  is an explanatory diagram of another method for shifting discharge openings  41   a  of the polymer charging member  41  in a circumferential direction Dc. 
         FIG. 5  is an explanatory diagram of an external shape of pipes  41   b  of the polymer charging member  41  and are cross-sectional views taken along line V-V in  FIG. 3A . 
         FIGS. 6A to 6D  are explanatory diagrams of preferred examples of the external shape. 
         FIG. 7A  is a side view of another embodiment of the polymer charging member  41 , and  FIG. 7B  is a plan view seen from line B-B in  FIG. 7A . 
     
    
    
     LIST OF REFERENCE NUMERALS 
     
         
         
           
               1  absorbent body,  2  pulp fiber (fluid absorbent fiber),  2   a  upper layer,  2   b  lower layer, 
               3  sheet-like member,  5  superabsorbent polymer,  5   a  intermediate layer, 
               10  fiber stacking apparatus (apparatus for manufacturing an absorbent body),  20  rotating drum,  21  form die, 
               31  fiber distributing duct,  31   a  distribution opening,  31   b  opening, 
               41  polymer charging member,  41   a  discharge opening,  41   b  pipe,  41   c  single pipe, 
               41   d  single pipe,  81  belt conveyor,  83  suction box, 
             S gap (space), H through-hole (space), 
             A 1  first area, A 2  second area, A 3  third area, 
             Rs predetermined range, C 20  rotation axis, Dc circumferential direction (rotating direction) 
           
         
       
    
     BEST MODE FOR CARRYING OUT THE INVENTION 
     At least the following matters will be made clear from the description of the present specification with reference to the accompanying drawings. 
     An apparatus for manufacturing an absorbent body in which while a form die is moved in one direction along a predetermined moving path, fluid absorbent fibers are distributed toward the form die and accumulated in the form die, whereby the absorbent body is formed, 
     wherein a polymer charging member for charging a superabsorbent polymer into the form die is disposed to intersect at least a part of a distribution path of the fluid absorbent fibers; and
         a space through which the fluid absorbent fibers are allowed to pass along the distribution path is formed in the polymer charging member.       

     According to such an apparatus for manufacturing an absorbent body, the fluid absorbent fibers reach the form die along the distribution path by passing through the space formed in the polymer charging member. Thus, even when the form die moves to a position under the polymer charging member, the fluid absorbent fibers can be accumulated in the form die without being interfered by the polymer charging member. 
     In the apparatus for manufacturing an absorbent body, it is desirable that the polymer charging member is a branch pipe in which a discharge opening from which the superabsorbent polymer is discharged is branched into a plurality of pipes; and
         the plurality of pipes are aligned in a width direction intersecting both the moving path and the distribution path, and the plurality of pipes are arranged so that adjacent pipes are spaced apart by a gap.       

     According to such an apparatus for manufacturing an absorbent body, the fluid absorbent fibers reach the position in the shadow of the polymer charging member through the gap between the pipes. In other words, the gap corresponds to the space through which the fluid absorbent fibers are allowed to pass along the distribution path. Thus, even when the form die moves to a position under the polymer charging member, the fluid absorbent fibers can be accumulated in the form die without being interfered by the polymer charging member. 
     Moreover, since the plurality of pipes are aligned in the width direction, the superabsorbent polymer can also be charged uniformly in the width direction. 
     In the apparatus for manufacturing an absorbent body, it is desirable that the positions of discharge openings of the plurality of pipes are shifted in a direction along the moving path relative to a discharge opening of a respective adjacent pipe in the width direction. 
     According to such an apparatus for manufacturing an absorbent body, the positions of adjacent discharge openings in the width direction are shifted from each other in the direction along the moving path, and so the timing at which the superabsorbent polymer is discharged can be staggered between the adjacent discharge openings. As a result, the positions of the superabsorbent polymer that is charged into adjacent positions in the width direction can be shifted in the thickness direction of the absorbent body, and thus gel blocking during absorption of fluid by the absorbent body can thus be effectively prevented. 
     In the apparatus for manufacturing an absorbent body, it is desirable that the positions of the discharge openings of the plurality of pipes in the direction along the moving path are staggered according to the positions thereof in the width direction. 
     According to such an apparatus for manufacturing an absorbent body, the positions at which the superabsorbent polymer is charged in the thickness direction of the absorbent body can be evenly arranged without deviation with respect to the width direction. 
     In the apparatus for manufacturing an absorbent body, it is desirable that an external shape of the plurality of pipes in which a width of an end portion on an upstream side in the distribution path is narrower than a portion on a downstream side from the end portion. 
     According to such an apparatus for manufacturing an absorbent body, the fluid absorbent fibers can be effectively prevented from collecting at the end portion because the pipes have the above-described external shape, and so the gap through which the fluid absorbent fibers should pass can be reliably secured without clogging. 
     In the apparatus for manufacturing an absorbent body, it is desirable that the form die is formed on an outer circumferential surface of a rotating drum that rotates in a circumferential direction, and the rotation in the circumferential direction causes the form die to move along a path, as the moving path, in the circumferential direction; 
     a distribution opening of a fiber distribution duct for distributing the fluid absorbent fibers toward the form die is provided at a predetermined position in the circumferential direction so as to face the outer circumferential surface of the rotating drum; and
         the polymer charging member, in the fiber distribution duct, extends from an upstream end toward a downstream side or from a downstream end toward an upstream side in the circumferential direction.       

     According to such an apparatus for manufacturing an absorbent body, effects of the invention of the present application can be achieved in an effective manner. 
     A method for manufacturing an absorbent body in which while a form die is moved in one direction along a predetermined moving path, fluid absorbent fibers are distributed toward the form die and accumulated in the form die, whereby the absorbent body is formed, 
     wherein a polymer charging member for charging a superabsorbent polymer into the form die is disposed to intersect at least a part of a distribution path of the fluid absorbent fibers; and
         the fluid absorbent fibers are let through a space formed in the polymer charging member along the distribution path to reach the form die.       

     According to such a method for manufacturing an absorbent body, the fluid absorbent fibers reach the form die along the distribution path by passing through the space formed in the polymer charging member. Thus, even when the form die moves to the position under the polymer charging member, the fluid absorbent fibers can be accumulated in the form die without being interfered by the polymer charging member. 
     EMBODIMENT OF THE INVENTION 
       FIGS. 1 and 2  are explanatory diagrams of an apparatus  10  and a method for manufacturing an absorbent body  1  according to an embodiment of the invention.  FIG. 1  is a side view of the manufacturing apparatus  10 , and  FIG. 2  is an enlarged cross-sectional view of a fiber distributing duct  31 . 
     As shown in  FIG. 1 , the apparatus  10  for manufacturing the absorbent body  1  according to the present embodiment is a so-called fiber stacking apparatus  10 , and includes a rotating drum  20  that has recessed form dies  21  formed on an outer circumferential surface thereof and rotates in a circumferential direction Dc, a fiber distributing duct  31  that distributes pulp fibers  2  toward the outer circumferential surface of the rotating drum  20 , thereby stacking pulp fibers  2  into the form dies  21  and thus forming absorbent bodies  1 , and a belt conveyor  81  that is disposed downstream of the position where the fiber distributing duct  31  is located in the circumferential direction Dc and carries the released absorbent bodies  1  released from the form dies  21 . 
     Note that in the following, the circumferential direction Dc of the rotating drum  20  will be simply referred to as the “circumferential direction Dc”, and a width direction of the rotating drum  20  will be simply referred to as the “width direction”. 
     The main body of the rotating drum  20  is, for example, a cylinder body that is driven to rotate in one direction, e.g., the clockwise direction, about a horizontal rotation axis C 20 . The form dies  21  are formed on the outer circumferential surface thereof at a predetermined pitch in the circumferential direction Dc, and many air suction holes (not shown) are formed at the bottom face of each form die  21 . Thus, the pulp fibers  2  in the fiber distributing duct  31  are distributed by riding on an air current produced in the fiber distributing duct  31  by suction of air through the air suction holes and then accumulate in the form dies  21 . 
     Note that the air suction is ceased in a predetermined range Rs at which the form dies  21  face the belt conveyor  81 , and in this predetermined range Rs, the absorbent bodies  1  in the form dies  21  are successively released from the form dies  21  by suction of air from a suction box  83  in the carrying conveyor  81  and are transferred onto the belt conveyor  81 . Thereafter, the absorbent bodies  1  are carried by the belt conveyor  81 . 
     Incidentally, as shown in  FIG. 1 , a sheet-like member  3 , such as nonwoven fabric, tissue paper, or the like, may be placed on top of the belt conveyor  81  in advance and the absorbent bodies  1  may be transferred onto the sheet-like member  3 . In such case, the sheet-like member  3  serves as, for example, a surface sheet (a sheet that is brought into contact with the user&#39;s skin) of a disposable diaper or a sanitary napkin. 
     As shown in  FIG. 2 , the fiber distributing duct  31  is, for example, a tubular member with a rectangular cross section and is disposed above the rotating drum  20 , and a distribution opening  31   a  at the bottom end thereof covers an upper portion of the outer circumferential surface of the rotating drum  20  over a predetermined range in the circumferential direction Dc. Moreover, the pulp fibers  2  that have been ground by a grinder, which is not shown, or the like are supplied from an opening  31   b  at the upper end, which is an end on the opposite side of the distribution opening  31   a , and thus a path along which the pulp fibers  2  are distributed from above and downward is formed in the fiber distribution duct  31 . Thus, when the form dies  21 , with the rotation of the rotating drum  20 , pass through the position of the distribution opening  31   a , the pulp fibers  2  accumulate in the form dies  21  and are formed into absorbent bodies  1 . 
     Incidentally, a polymer charging member  41  for charging a superabsorbent polymer  5  into the form dies  21  is disposed in the fiber distributing duct  31  in close proximity to the outer circumferential surface of the rotating drum  20 . A discharge opening  41   a  of the polymer charging member  41  is positioned approximately at the center of the distribution opening  31   a  relative to the circumferential direction Dc. 
     The purpose of employing such an arrangement is, in light of preventing gel blocking during absorption of fluid by the absorbent body  1  and so on, to form an absorbent body  1  into a three-layer structure (see the bottom right accumulated state diagram in  FIG. 2 ) by forming an intermediate layer  5   a  with a high mixture ratio of superabsorbent polymer  5  in the middle of absorbent body  1  in the thickness direction and forming the upper layer  2   a  and the lower layer  2   b  sandwiching the intermediate layer  5   a  with high mixture ratios of pulp fibers  2 . 
     In other words, first, in a first area A 1  in  FIG. 2 , mainly pulp fibers  2  are accumulated in the form dies  21 , and a lower layer  2   b  mainly composed of the pulp fibers is formed (see bottom left accumulated state diagram in  FIG. 2 ). In a subsequent second area A 2 , mainly superabsorbent polymer  5  is charged onto the lower layer  2   b  by the polymer charging member  41 , and an intermediate layer  5   a  with abundant superabsorbent polymer  5  is formed (see bottom center accumulated state diagram in  FIG. 2 ). Then, in a last third area A 3 , mainly pulp fibers  2  accumulate on the intermediate layer  5   a , and the upper layer  2   a  mainly composed of pulp fibers is formed (see bottom right accumulated state diagram in  FIG. 2 ). Thus, the absorbent body  1  having a three-layered structure is formed. 
     However, in the case where the discharge opening  41   a  of the polymer charging member  41  is positioned at the center of the distribution opening  31   a  in the circumferential direction Dc, either the third area A 3  between the center and the downstream end in the circumferential direction Dc of the distribution opening  31   a , as shown in  FIG. 2 , or the first area A 1  between the upstream end and the center in the circumferential direction Dc is inevitably located under the polymer charging member  41 , and consequently, in either the upper layer  2   a  or the lower layer  2   b , a layer mainly composed of pulp fibers cannot be formed, and the absorbent body  1  would not have the intended three-layer structure. 
     To address this problem, in the present embodiment, a space along the distribution path of the pulp fibers  2  is formed in the polymer charging member  41 , and the pulp fibers  2  are allowed to pass through this space, thereby ensuring pulp fibers  2  to accumulate in the form dies  21  at any position in the third area A 3  and the first area A 1 , which may be located under the polymer charging member  41 . 
     Hereinafter, the polymer charging member  41  according to the present embodiment will be described in detail. 
       FIG. 3A  is a side view of the polymer charging member  41 , and  FIG. 3B  is a plan view seen from line B-B in  FIG. 3A . 
     As can be seen with from  FIGS. 3A and 3B , in this example, the polymer charging member  41  is disposed horizontally across the above-described third area A 3 . Thus, in this example, the polymer charging member  41  may inhibit the pulp fibers  2  from accumulating into the upper layer  2   a.    
     In this regard, in this example, the polymer charging member  41  is configured as a branch pipe in which a portion on the discharge opening  41   a  side from which the superabsorbent polymer  5  is discharged is branched into a plurality of (seven in the example shown) pipes  41   b , and each of the plurality of pipes  41   b  aligned in the width direction are arranged so that adjacent pipes  41   b  are spaced apart by a gap S. 
     Therefore, pulp fibers  2  are made to reach even the form dies  21  moving in the third area A 3  in  FIG. 3A  through the gaps S (corresponding to the aforementioned space). As a result, obstruction of the accumulation of pulp fibers  2  in the upper layer  2   a  can be effectively minimized. Moreover, since the plurality of pipes  41   b  are aligned in the width direction, the superabsorbent polymer  5  may be charged uniformly in the width direction. 
     Here, at least three pipes  41   b  are disposed in the width direction at a predetermined pitch, and furthermore, the width of the gap S between the pipes  41   b  is set to 1 mm or more. When three or more pipes  41   b  are disposed, the distribution of the charged superabsorbent polymer  5  in the width direction can be made further uniform, and the distribution of the accumulated pulp fibers  2  in the width direction can be made uniform. Moreover, when the width dimension of the gap S is set to 1 mm or more, clogging with pulp fibers  2  in the gap S can be minimized. The inner width and the inner height of the discharge opening  41   a  of each pipe  41   b  are set within a range of 2 to 50 mm. When the inner width and the inner height are set within such range, the number of pipes  41   b  can be increased while minimizing clogging with the superabsorbent polymer  5  in each pipe  41   b.    
     Moreover, as shown in  FIG. 3B , the positions of the discharge openings  41   a  of the pipes  41   b  are shifted in the circumferential direction Dc relative to the discharge opening  41   a  of a respective adjacent pipe  41   b  in the width direction. More specifically, the positions of the discharge openings  41   a  in the circumferential direction Dc are staggered according to the positions thereof in the width direction. The purpose of this is to stagger the timing at which the superabsorbent polymer  5  is charged, between the adjacent discharge openings  41   a . In this manner, the positions of the superabsorbent polymer  5  that is charged into adjacent areas in the width direction can be arranged in a vertical zigzag pattern in the thickness direction of the absorbent body  1 , and as a result, the joining of particles of the superabsorbent polymer  5 , which swell when the absorbent body  1  absorbs fluid, in the width direction can be minimized and gel blocking can thus be effectively prevented. 
     Examples of methods for shifting the positions of the discharge openings  41   a  in the circumferential direction Dc include a method of setting the angle of inclination from the horizontal line of a portion of each pipe  41   b  in the vicinity of the discharge opening  41   a  so that adjacent pipes  41   b  have mutually different angles of inclination, as shown in  FIG. 3A , and a method of directing the portions in the vicinity of the discharge openings  41   a  of all of the pipes  41   b  vertically downward and setting the length of each pipe  41   b  so that adjacent pipes  41   b  have mutually different lengths, as shown in a side view of  FIG. 4 . 
     Note that as shown in  FIG. 3B , in the case where the positions of the discharge openings  41   a  in the circumferential direction Dc are staggered according to the positions thereof in the width direction, it is advantageous to set the number of pipes  41   b  to an odd number. In this manner, the pipes  41   b  are arranged in perfect line symmetry with respect to a center line CL in the width direction, and thus, the distribution of accumulated pulp fibers in the width direction can be made further uniform. 
       FIG. 5  is an explanatory diagram showing external shapes of the pipes  41   b  and is a cross-sectional view taken along line V-V in  FIG. 3A . In this example, the cross-sectional shape of each pipe  41   b  when cut in the width direction is rectangular. Preferably, however, it is advantageous that an end portion on the upstream side in the above-described distribution path is narrower than that on the downstream side. Specific examples of such a cross-sectional shape include a streamline shape whose upstream end is tapered as shown in  FIG. 6A , a triangular shape whose vertex angle is positioned at the upstream end as shown in  FIG. 6B , a trapezoidal shape with the shorter side of the parallel opposite sides of which is positioned upstream as shown in  FIG. 6C , and an elliptical shape whose major axis extends along the above-described distribution path as shown in  FIG. 6D . With such external shapes, the pulp fibers  2  can be effectively prevented from accumulating on the end portion on the upstream side in the distribution path (see  FIG. 5 ), and induction of clogging of the gap S can be minimized. 
     Incidentally, the polymer charging member  41  does not necessarily have to be a branch pipe over the entire length thereof, and for example, as shown in  FIG. 3B , it is sufficient as long as a portion accommodated in the fiber distributing duct  31  is a branch pipe. Accordingly, a portion located outside the fiber distributing duct  31  may be a single pipe  41   c  whose pipe path is not partitioned and is continuous as a single communicating hole and the cross-sectional shape of which is wide in the width direction. However, at a branching point, it is advantageous that there is no wall perpendicular to the flow direction of the superabsorbent polymer  5  shown in  FIG. 3B . For example, it is desirable that the gap S gradually decreases from the end of the pipes  41   b  toward the branching point, and finally, all of the pipes  41   b  are in communication with one another to form a wide single pipe  41   c . With such a configuration, accumulation of the superabsorbent polymer  5  on the aforementioned perpendicular wall portion can be avoided, and clogging with the superabsorbent polymer  5  can be effectively prevented. 
     Other Embodiments 
     In the foregoing, an embodiment of the present invention has been described. However, the present invention is not limited to this embodiment, and modifications such as those described below are possible. 
     In the foregoing embodiment, as an example, a configuration of a branch pipe as the polymer charging member  41  in which space that allows pulp fibers  2  to pass is formed was described. And as shown in  FIG. 3B , each pipe  41   b  had its own discharge opening  41   a . However, the polymer charging member  41  is not limited to such. For example, as shown in  FIGS. 7A and 7B , the pipes  41   b  that have been branched may again be in communication with one another at the position of the discharge openings  41   a  and form a single pipe  41   d  that is wide in the width direction. Note that in this case, the polymer charging member  41  has such an appearance that a plurality of through-holes H are formed in a direction along the distribution path of the pulp fibers  2 . 
     In the foregoing embodiment, as an example, a configuration in which the form dies  21  are formed in the outer circumferential surface of the rotating drum  20  where the form dies  21  move along a path in the circumferential direction Dc of the rotating drum  20  was described. However, the configuration is not limited to such, and any configuration can be adopted as long as the form dies  21  move in one direction along a predetermined moving path. For example, it is also possible that the form dies  21  are moved along a predetermined circular path by a chain conveyor or the like, with the fiber distributing duct  31  and the belt conveyor  81  disposed at predetermined positions in the circular path. 
     In the foregoing embodiment, a fiber distributing duct  31  that is continuous in a vertical direction was disposed above the rotating drum  20 , with the distribution opening  31   a  of the duct covering the outer circumferential surface of the rotating drum  20  from above, thereby forming the distribution path of the pulp fibers  2  that extends in the vertical direction. However, the fiber distributing duct  31  is not limited to such. For example, it is also possible that the fiber distributing duct  31  that is continuous in the horizontal direction or a slanting direction, is disposed lateral to the rotating drum  20  with the distribution opening  31   a  of the duct laterally covering the outer circumferential surface of the rotating drum  20 , thereby forming the distribution path of the pulp fibers  2  that extends in the horizontal direction or the slanting direction. 
     In the foregoing embodiment, the orientation of the longitudinal direction of the absorbent bodies  1  on the rotating drum  20  was not described in particular. However, this longitudinal direction may be a so-called “machine direction” wherein the longitudinal direction of the absorbent bodies  1  are oriented in the circumferential direction Dc of the rotating drum  20 , or a so-called “cross direction” wherein the longitudinal direction of the absorbent bodies  1  are oriented in the width direction of the rotating drum  20 . 
     In the foregoing embodiment, the pulp fibers  2  (pulp that has been ground into fibers) were described as an example of the fluid absorbent fibers. However, cellulose such as cotton, regenerated cellulose such as rayon and fibrillated rayon, semi-synthetic cellulose such as acetate and triacetate, fibrous polymers, and thermoplastic fibers may also be used, or may also be used in combination.