JP6851910B2 - Sheet folding device and manufacturing method of absorber using it - Google Patents

Description

The present invention relates to a sheet folding device that folds both sides of a sheet that is continuously conveyed, and a method for manufacturing an absorber using the device.

In the production line of products such as disposable diapers and sanitary napkins, a folding device for folding a sheet such as a continuously conveyed non-woven fabric or a resin film to the sheet side is used. For example, Patent Document 1 describes a transport conveyor on which a sheet is placed on a transport surface and transports the sheet, and a folding guide that folds a side edge of the sheet transported by the transport conveyor in a direction orthogonal to the transport direction. A sheet folding device comprising the above is described. The folding guides in this folding device are arranged along the side edges along the transport direction of the transport conveyor, and have a side wall portion having a portion located above the same plane as the transport surface, and the transport conveyor from the side wall portion. It is provided with an extension portion that extends inward in a direction orthogonal to the transport direction.

Further, in Patent Document 2, as a method for producing an absorber capable of producing an absorbent core including an absorbent core and a core wrap sheet covering the absorbent core, the absorbent core is placed on the core wrap sheet and then the absorbent core is arranged. The side portions extending laterally from each side edge of the absorbent core are sequentially folded back so as to cover the upper surface of the absorbent core using a pair of folding guides, and one of the folding guides is folded back. We have proposed an absorber capable of producing an absorber having a overlapping portion between the side portion and the other side portion folded back by the other folded guide.

Japanese Unexamined Patent Publication No. 2010-131111 Japanese Unexamined Patent Publication No. 2016-97172

The transport conveyor in the folding device of Patent Document 1 has an upstream portion located on the upstream side and a downstream portion located on the downstream side in the transport direction of the transport conveyor, and has a transport surface of a transport belt in the upstream portion and the downstream portion. The transport surface of the transport conveyor in the portion is connected with a predetermined inclination angle, and a pair of the folded guides are arranged on both sides of the transport surface of the transport belt in the downstream portion, and the transport conveyor in the upstream portion is transported. A pair of side plates (side support plates) are arranged on both sides of the surface. By having such a configuration, it becomes easy to bend both side portions of the sheet while transporting the sheet.
However, in the production of an absorber in which the folded width of both sides of the sheet is increased and the folded both sides are overlapped and bonded to each other, or the absorbent core is coated with a core wrap sheet, the absorbent core is used. When an adhesive is applied to the sheet before folding back for the purpose of overlapping and joining both sides of the core wrap sheet arranged on one side to both sides of the core wrap sheet arranged on the other side, the adhesive is applied. , It may break through from the sheet and adhere to the side plate (side support plate), and the adhesive may irregularly adhere to the side portion of the sheet, resulting in wrinkles on the sheet.
Also, when manufacturing an absorber in which the absorbent core is coated with a core wrap sheet, the material for forming the absorbent core such as a highly absorbent polymer or paper powder is scattered on the side plate (side support plate). The deposits may adhere to the sheet, which may reduce the adhesive strength of the adhesive when the sheet is coated with the adhesive, and the deposits are absorbed at irregular timings. It may be taken into the body and partially deteriorate the performance and feel of the absorber.

Therefore, an object of the present invention is to provide a sheet folding device and a method for manufacturing an absorber that can solve the problems of the prior art.

The present invention is a pair of a conveyor that carries a long sheet on a transport surface and a pair of both sides of the sheet that are conveyed by the conveyor and folded back in a direction orthogonal to the transport direction. The folding guides are provided, and the pair of folding guides are arranged along the transport direction of the conveyor and have an upper portion located above the same plane as the transport surface, and the side wall. A sheet folding device having an inward extending portion extending inward in a direction orthogonal to the conveying direction of the sheet from the upper portion of the portion.
The pair of folded guides has an inner edge of each of the inward extending portions that is inclined so as to approach the opposite side in the direction orthogonal to the transport direction as it goes downstream in the transport direction of the conveyor. Have and
It has an upstream portion located on the upstream side and a downstream portion located on the downstream side in the transport direction of the transport conveyor, and the transport surface of the transport conveyor in the upstream portion and the transport surface of the transport conveyor in the downstream portion are predetermined. The pair of folded guides are arranged on both sides of the conveyor surface of the conveyor in the downstream portion, and the pair of side support plates are arranged on both sides of the conveyor surface of the conveyor in the upstream portion. Is arranged,
Each of the pair of side support plates has an outer edge that is inclined from the outside to the inside in a direction orthogonal to the transport direction toward the downstream of the transport direction of the conveyor. Provided is a sheet folding device that is tilted downward toward the outside in a direction orthogonal to the transport direction of the conveyor.

The present invention comprises a step of arranging an absorbent core in a central region in the width direction of a long core wrap sheet transported in one direction, and a core wrap sheet in which the absorbent core is arranged. The side portions of the core wrap sheet extending laterally from each side edge of the core wrap sheet by the sheet folding device while being conveyed are defined as one surface of the absorbent core facing the central region. A folding step of folding back to the other side of the opposite side and covering both sides of the absorbent core with the core wrap sheet, and the absorption in one or both of both side portions of the core wrap sheet folded by the folding step. The present invention provides a method for producing an absorber, which comprises an adhesive coating step of preliminarily applying an adhesive to a surface facing the sex core side before folding back.

According to the sheet folding device of the present invention, the side portion of the sheet being conveyed can be satisfactorily folded back, and the adhesive adheres to the side support plate and deposits are deposited on the side support plate. It is also possible to effectively suppress the inconvenience caused by.

According to the method for producing an absorber of the present invention, it is possible to prevent the adhesive strength of the adhesive applied before the folding process from being lowered by the deposits deposited on the side support plate, and the adhesive retains the shape. It is possible to stably produce an absorber having improved properties.

1 (a) and 1 (b) are cross-sectional views taken along the width direction of an example of an absorber produced by the method for producing an absorber of the present invention. FIG. 2 is an overall schematic view showing an example of an apparatus preferably used in the method for producing an absorber of the present invention. FIG. 3 is a schematic perspective view showing a sheet folding device used in the device shown in FIG. FIG. 4 is a schematic plan view showing how the sheet folding device shown in FIG. 3 is used to fold both side portions of the core wrap sheet in which the absorbent core is arranged in the central region. FIG. 5 is a schematic cross-sectional view taken along line VV of the device shown in FIG. FIG. 6 is a schematic sectional view taken along line VI-VI of the device shown in FIG. FIG. 7 is a schematic view showing a state in which the transport direction of the core wrap sheet changes in the apparatus shown in FIG. FIG. 8 is a cross-sectional view showing another example of a side support plate that is inclined downward toward the outside in a direction orthogonal to the transport direction of the conveyor. 9 (a) to 9 (c) are schematic cross-sectional views showing another example of the absorber produced in the present invention.

Hereinafter, the present invention will be described based on the preferred embodiment with reference to the drawings.
1 (a) and 1 (b) are cross-sectional views taken along the width direction of an example of an absorber 5 manufactured by the method for producing an absorber of the present invention.
The absorber 5 includes at least an absorbent core 50 made of a fiber material or a highly absorbent polymer as a forming material, and a core wrap sheet 51 covering the absorbent core 50. The absorbent core 50 in the absorber 5 has a constricted portion having a narrow width direction in the central portion in the longitudinal direction, and the absorber 5 manufactured in the present invention has such a shape. Not limited.

The core wrap sheet 51 of the absorber 5 shown in FIGS. 1 (a) and 1 (b) has a central region 51 m facing one surface of the absorbent core 50 and an absorbent core 50 facing the central region 51 m. It has both side portions 51a and 51b that are folded back to the other surface side opposite to one surface, and one side portion 51a and the other side portion 51b are located at the central portion in the width direction of the absorber 5. It has a superposed portion 53 in which one side portion 51a and the other side portion 51b overlap.

One side portion 51a is folded back before the other side portion 51b in the method for producing the absorber 5 described later, and one side edge portion 50a and the polymerization portion 53 of the polymerization portion 53 and the absorbent core 50 At both sites between and, the surface on the absorbent core 50 side is bonded to the absorbent core 50 by an adhesive. The other side portion 51b is folded back after the one side portion 51a in the method for producing the absorber 5 described later, and in the polymerization portion 53, the surface on the absorbent core 50 side is folded back on one side. At the site between the other side edge portion 50b of the absorbent core 50 and the polymerization portion 53, which is bonded to the side portion 51a with an adhesive, the surface on the absorbent core 50 side is bonded to the absorbent core 50 by the adhesive. It is joined to.
In this way, in the polymerization section 53, the one side portion 51a and the other side portion 51b are joined by an adhesive, so that the shape retention of the absorber 5 is enhanced, and the absorbable core 50 Leakage of forming material is prevented.

The method for producing an absorbent body of the present invention includes a step of arranging an absorbent core in a central region in the width direction of a long core wrap sheet transported in one direction, and a step of arranging the absorbent core, and the absorbent core is arranged. While transporting the core wrap sheet, the sheet folding device described later allows both side portions of the core wrap sheet extending laterally from each side edge of the absorbent core to absorb the absorption so as to face the central region. Of the folding step of folding back to the other side opposite to one side of the sex core and covering both sides of the absorbent core with the core wrap sheet, and both side portions of the core wrap sheet folded by the folding step. An adhesive coating step is provided in which an adhesive is previously applied to one or both of the surfaces facing the absorbent core side before folding back.
FIG. 2 shows an outline of an absorber manufacturing apparatus 1 preferably used in a method for manufacturing an absorber having these steps. The manufacturing apparatus 1 shown in the figure is roughly divided into a fiber stacking portion 2, a transfer portion 3, a folding portion 4, an adhesive coating portion 6, and a cutting apparatus 7.

The fiber stacking portion 2 in the manufacturing apparatus 1 includes a fiber stacking drum 20 in which a plurality of accumulation recesses 21 are formed at predetermined intervals on the outer peripheral surface, and a material for forming an absorbent core (hereinafter, also referred to as an absorbent core forming material). The fiber material and the highly absorbent polymer (absorbent particles) are provided with a duct 22 that accompanies the air flow and supplies the fiber material to the outer peripheral surface of the fiber stacking drum 20. The duct 22 has one end portion 22a that covers a part of the outer peripheral surface of the fiber stacking drum 20, and the other end portion 22b that is connected to the fiber material introduction device 23 that introduces a fiber material such as pulp fiber. An introduction device 24 for a highly absorbent polymer is provided between them. The fiber material introduction device 23 includes, for example, a crusher 23b that crushes sheet-shaped wood pulp 23a into defibrated pulp and feeds the defibrated pulp as pulp fibers into a duct. As shown in FIG. 2, instead of using the fiber material and the highly absorbent polymer as the absorbent particles as the absorbent core forming material, only the fiber material can be used, or the high absorption as the absorbent particles can be used. It is also possible to use only the sex polymer.

The stacking fiber drum 20 has a cylindrical shape and is rotationally driven in the direction of arrow R1 in FIG. On the outer peripheral surface of the stacking fiber drum 20, an accumulation recess 21 having a shape corresponding to the shape to be imparted to the absorbent core 50 to be manufactured is formed. An intake fan (not shown) is connected to the fiber stack drum 20, and the partitioned space 20A in the fiber stack drum can be maintained at a negative pressure by driving the intake fan. A large number of pores (not shown) are formed on the bottom surface of the individual accumulation recesses 21, and the accumulation is performed while the individual accumulation recesses 21 pass through the space 20A maintained at a negative pressure. The pores on the bottom surface of the recess 21 function as suction holes. As a result, the fiber material and the highly absorbent polymer are sucked and deposited in the accumulation recess 21, and formed into the absorbent core 50 having a shape corresponding to the accumulation recess 21. In the present embodiment, the space 20B is not connected to the intake fan and is non-suctioned, that is, has zero pressure, but may be maintained at a negative pressure like the space 20A.

In the fiber stacking portion 2, the fiber material and the highly absorbent polymer are supplied into the duct 22 while being sucked from the bottom surface of the accumulation recess 21, so that they are deposited in the accumulation recess 21 in a predetermined shape. It is molded into an absorbent core 50. When the fibrous material and the highly absorbent polymer are deposited in the accumulation recess 21, the holding belt 25 covers the fibrous material and the highly absorbent polymer to prevent the fibrous material and the highly absorbent polymer from falling off. Then, the molded absorbent core 50 is conveyed to the lower part by the rotation of the fiber stacking drum 20, and after the holding by the holding belt 25 is released, it is transferred by the air discharge from the air discharge device 26. In the part 3, the mold is released from the accumulation recess 21 and moved onto the conveyor belt 31.

The transfer unit 3 includes an endless conveyor belt 31 orbiting in the direction of arrow R2 in FIG. 2, and a suction box 32 installed in the orbit of the conveyor belt 31. The conveyor belt 31 is breathable. The conveyor belt 31 is composed of, for example, a mesh belt. The suction box 32 is installed at a position facing the air discharge device 26 with the conveyor belt 31 interposed therebetween, and can suck the air blown out from the air discharge device 26. A core wrap sheet 51 is supplied to the conveyor belt 31 in advance before the transfer of the absorbent core 50, and the absorbent core 50 released from the accumulation recess is placed on the core wrap sheet 51. In this state, it is conveyed to the folded-back portion 4 located on the downstream side of the transfer portion 3.
As shown in FIGS. 3 and 4, the absorbent core 50 is placed in the central region 51 m in the width direction of the core wrap sheet 51. The absorbent core 50 is preferably placed so that the position of the widthwise center line extending in the longitudinal direction coincides with the position of the widthwise centerline extending in the longitudinal direction on the core wrap sheet 51. In that case, the extending portion of the core wrap sheet 51 extending laterally from the side edge of the absorbent core 50 has the same extending width. However, the absorbent core 50 is placed so that the position of the width direction center line on the absorbent core 50 deviates from the position of the width direction center line on the core wrap sheet 51, and the extension width of the left and right extension portions is provided. May be different.

The sheet folding device 41 shown in FIG. 3 is arranged in the folding unit 4. In FIG. 3, the absorbent core 50 and the core wrap sheet 51 are not shown except that the arrangement position of the absorbent core 50 is indicated by a chain line. Further, in FIG. 3, the absorbent core 50 and the core wrap sheet 51 are conveyed from the upper right to the lower left in the figure.

The folding device 41 includes a conveyor 42 for transporting a long core wrap sheet 51 on the transport surface 42a. As shown in FIG. 2, the conveyor 42 includes an endless conveyor belt 42b orbiting in the direction of arrow R3 and a suction box (not shown) installed in the orbit of the conveyor belt 42b. .. One surface of the conveyor belt 42b forms the transport surface 42a of the conveyor 42. FIG. 3 shows only a part of the conveyor belt 42b in the longitudinal direction. The conveyor belt 42b is made of a breathable material. For example, it is composed of a mesh belt. The suction box is used to suck and hold the absorbent core 50 and the core wrap sheet 51 on which the absorbent core 50 is placed via the conveyor belt 42b.

Further, as shown in FIG. 3, the folding device 41 includes a pair of folding guides 43a and 43b. As shown in FIG. 4, the pair of folding guides 43a and 43b fold both side portions 51a and 51b of the core wrap sheet 51 transported by the transport conveyor along the transport direction MD into a direction CD orthogonal to the transport direction MD. It is a thing.
As shown in FIGS. 3 and 5, the folded guides 43a and 43b are side walls having an upper portion arranged along the transport direction MD of the conveyor 42 and located above the same plane as the transport surface 42a, respectively. It has a portion 44 and an inward extending portion 45 extending inward of the direction CD orthogonal to the transport direction MD of the core wrap sheet 51 from the upper portion of the side wall portion 44. The side wall portion 44 is composed of a flat plate-shaped member and extends in a direction orthogonal to the transport surface 42a. The upper end of the side wall portion 44 is connected to the outer edge of the inward extending portion 45, and is arranged substantially parallel to the vertical direction. The inward extending portion 45 preferably extends from the upper end portion of the side wall portion 44 toward the inside of the direction CD orthogonal to the transport direction MD. In the folded-back guides 43a and 43b, the lower portion of the side wall portion 44 is fixed to the device housing 46 by a known fixing means such as a bolt.

As shown in FIG. 3, each of the inward extending portions 45 of the folding guides 43a and 43b is composed of a flat plate-shaped member including a triangular portion in a plan view, with respect to the conveying surface 42a of the conveying conveyor 42. They are arranged almost in parallel. The folding guides 43a and 43b are linearly inclined so as to approach the opposite side of the direction CD orthogonal to the transporting direction MD toward the downstream of the transporting direction MD of the transporting conveyor at the respective inward extending portions 45. It has inner edges 45a and 45b of the above. That is, the inner edge portion 45a of one folding guide 43a is inclined so as to approach the other folding guide 43b toward the downstream side of the transport direction MD of the conveyor, and the inner edge portion of the other folding guide 43b. The portion 45b is inclined so as to approach one of the folding guides 43a toward the downstream side of the transport direction MD of the transport conveyor. On the other hand, the outer edges 46a and 46b of the inward extending portions 45 of the folding guides 43a and 43b have a linear shape parallel to the transport direction MD. Therefore, in the inward extending portion 45 of the folding guide 43b, the overhang width W toward the opposite side of the direction CD orthogonal to the transport direction MD gradually increases along the transport direction MD.

Then, in the folding device 41 of the present embodiment, as shown in FIG. 4, one of the core wrap sheets 51 is provided by the first folding guide 43a, which is one of the pair of folding guides 43a and 43b. The side portion 51a is folded back, and the other side portion 51b of the core wrap sheet 51 is folded back so as to partially overlap the folded side portion 51a by the second folding guide 43b which is the other folding guide. It has been done. In other words, the first folding guide 43a is a folding guide that folds back the side that is folded first among both side portions along the longitudinal direction of the core wrap sheet 51, and the second folding guide 43b is the core wrap sheet 51. It is a folding guide that folds back the side that is folded back later from both sides along the longitudinal direction of.
Then, in the folding device 41 of the present embodiment, as shown in FIG. 3, the conveyor 42 of the inner edge portion 45a of the first folding guide 43a that folds the one side portion 51a that folds back at the tip of the core wrap sheet 51. The inclination angle θ1 with respect to the transport direction MD is made larger than the tilt angle θ2 of the inner edge portion 45b of the second folding guide 43b that folds back the other side portion 51b to be folded back with respect to the transport direction MD of the conveyor 42.

As shown in FIG. 3, the conveyor 42 in the sheet folding device 41 has an upstream portion 41U located on the upstream side of the transport direction MD of the transport conveyor 42 and a downstream portion 41D located on the downstream side. .. The transport surface 42u of the upstream portion 41U is connected to the transport surface 42d of the downstream portion 41D at a predetermined inclination angle. The first folding guide 43a and the second folding guide 43b described above are arranged on both sides of the transport surface 42d of the downstream portion 41D, and a pair of sides on both sides of the transport surface 42u of the upstream portion 41U. Part support plates 47a and 47b are arranged.

The side support plates 47a and 47b support the extending portions of the core wrap sheet 51 during transportation from the side edges Sa and Sb (side edges of the conveyor belt 42b) of the transfer surface 42a of the transfer conveyor 42 from below. , It has a triangular shape when viewed in a plan view. The side support plates 47a and 47b have outer edge portions 48a inclined so as to approach the CD in the direction orthogonal to the transport direction MD toward the downstream side of the transport direction MD of the conveyor 42, respectively. , 48b.
Further, as shown in FIGS. 3 and 6, each of the pair of side support plates 47a and 47b is inclined downward toward the outside of the direction CD orthogonal to the transport direction MD of the conveyor 42.
Further, the side support plates 47a and 47b each have inner edge portions 49a and 49b extending along both side edges of the transport surface 42u of the transport conveyor 42 in the upstream portion 41U, and the inner edge portions 49a and 49b respectively. Is arranged at a height equal to or lower than the transport surface 42u in the height direction H defined as a direction perpendicular to the transport surface 42u.

At least one of the inner edge 49a of the side support plate 47a and the inner edge 49b of the side support plate 47b, preferably both, are located at the same height as the transport surface 42u or slightly lower than the transport surface 42u. However, since there is substantially no step between the transport surface 42u and the sheet to be folded, it is possible to prevent the sheet to be folded from being wrinkled and the accuracy of folding the sheet from being lowered. The occurrence of wrinkles on the sheet tends to lead to inconveniences such as deterioration of the shape retention and appearance of the absorber when the absorber coated with the sheet is manufactured. Further, when wrinkles occur, the overlapping width W1 (see FIG. 1) of the overlapping portion 53 becomes shorter than the desired width, so that there is a concern that the adhesive strength may be lowered and the material for forming the absorbent core 50 may leak out.
The expression that the inner edge of the side support plate is arranged at the same height as the transport surface includes the case where the height positions of the inner edge and the transport surface are the same, and the expression thereof. The case where the step d between the inner edge portion and the transport surface is 1 mm or less is also included. The step referred to here includes both a step generated when the inner edge portion is higher than the transport surface and a step generated when the inner edge portion is lower than the transport surface.
On the other hand, when the inner edge of the side support plate is lower than the transport surface and the step d is more than 1 mm, the inner edge is arranged at a position lower than the transport surface. The step d between the two is preferably small, for example, 5 mm or less. The height positions of the inner edges of the pair of side support plates 47a and 47b are all aligned with the height position of the transport surface or arranged at a position lower than the transport surface. More preferred.

Further, the distance d2 (see FIG. 6) between the inner edges 49a, 49b of the side support plates 47a, 47b and the transport surface 42u in the direction CD orthogonal to the transport direction of the transport belt shall be 5 mm or less. Is preferable, and more preferably 0 mm.

The adhesive coating unit 6 comprises a central coating device 6 m for applying an adhesive on the central region 51 m of the core wrap sheet 51 before the absorbent core 50 is placed in the transfer unit 3, and a central region 51 m. Side coating devices 6a and 6b for applying an adhesive are provided on both side portions 51a and 51b of the core wrap sheet which are located on both sides of the core wrap sheet and which are later folded back at the folded portion. Instead of arranging the side coating devices 6a and 6b on the upstream side of the transfer unit 3, the side coating devices 6a and 6b may be arranged between the transfer unit 3 or the transfer unit 3 and the folded-back unit 4. After applying the adhesive to the core wrap sheet 51 by the central coating device 6 m, the absorbent core 50 is arranged, and the core wrap sheet 51 and the absorbent core 50 are joined to absorb the core wrap sheet 51 and the core wrap sheet 51. It becomes difficult for a gap to be formed between the sex core 50 and the absorber 5, which has excellent liquid absorbency and an absorber 5 which has excellent shape retention. As the adhesive to be coated by the adhesive coating unit 6, various known adhesives such as a hot melt adhesive can be used. Further, the adhesive may be continuously applied to the entire surface, but a pattern coating in which a coated portion and a non-coated portion are mixed is preferable. Examples of the coating pattern for pattern coating include a spiral pattern, a stripe pattern, and a dot pattern.

In the folded-back portion 4, the absorbent core 50 and the core wrap sheet 51 conveyed by the circulation of the conveyor belt 42b are conveyed in only one direction in the plan view of the folded-back portion 4, but the folded-back portion 4 In the side view of, there are two directions D1 and D2. Specifically, the folded-back portion 4 has a different transport direction in the side view of the folded-back portion 4 between the upstream portion 41U located on the upstream side in the transport direction and the downstream portion 41D located on the downstream side in the transport direction. .. The upstream portion 41U includes a pair of side support plates 47a and 47b in addition to a part of the conveyor belt 42b and a part of the suction box (not shown). On the other hand, the downstream portion 41D includes a pair of folding guides 43a and 43b in addition to a part of the conveyor belt 42b and a part of the suction box (not shown).

In the upstream portion 41U, the absorbent core 50 and the core wrap sheet 51 are conveyed in the substantially horizontal direction. On the other hand, in the downstream portion 41D, the transport direction D2 changes so as to incline vertically downward with respect to the transport direction D1. However, in the upstream portion 41U, the absorbent core 50 and the core wrap sheet 51 may be conveyed vertically upward, and in the downstream portion 41D, they may be conveyed in a substantially horizontal direction. That is, the transport direction of the core wrap sheet 51 in the downstream portion 41D changes so as to be inclined toward the vertically downward side with respect to the transport direction of the core wrap sheet 51 in the upstream portion 41U. As shown in FIG. 7, the inclination referred to here is a position where the X1-Y1 plane of the core wrap sheet 51 before the change of the transport direction and the X2-Y2 plane of the core wrap sheet 51 after the change of the transport direction intersect. It is an angular relationship in which these planes intersect so that the straight line L is orthogonal to the transport direction D1. The inclination angle θ (see FIG. 7) due to the change in the transport direction is preferably in the range of 135 degrees or more and 175 degrees or less, and more preferably in the range of 140 degrees or more and 170 degrees or less.

In order to manufacture the above-mentioned absorber 5 by using the absorber manufacturing apparatus 1 having the above configuration, as shown in FIG. 4, in the adhesive coating portion 6, the central region 51 m of the core wrap sheet 51 is used. After applying adhesives to both side portions 51a and 5b of the core wrap sheet 51 sandwiching the central region 51 m, in the transfer portion 3, the fiber stacking portion 2 is placed on the central region 51 m of the core wrap sheet 51. The formed absorbent core 50 is placed. Then, the core wrap sheet 51 on which the absorbent core 50 is arranged is introduced into the folded-back portion 4, one side portion 51a of the core wrap sheet 51 is folded back by the first folded-back guide 43a, and the other side portion 51b is folded back. Is folded back by the second folding guide 43b so that a part of the folded portion overlaps the one side portion 51a that has been folded. As a result, a long absorber 5 in which both sides of the absorbent core 50 are covered with the core wrap sheet 51 is obtained. The absorber 5 has a polymerization portion 53 in which one side portion 51a and the other side portion 51b overlap at the central portion in the width direction. The elongated absorber 5 is cut as it is or by a known cutting device 7 to the length of one absorbent article, and then sent to a production line for an absorbent article such as a disposable diaper.

According to the method for manufacturing the absorber and the sheet folding device 41 of the present embodiment, as shown in FIGS. 3 and 6, each of the pair of side support plates 47a and 47b is in the transport direction MD of the transport conveyor 42. Since it is inclined downward toward the outside of the orthogonal direction CD, at least a part of each of the pair of side support plates 47a and 47b comes into contact with both sides of the core wrap sheet 51, and is performed thereafter. The folding of both sides by the folding guide can proceed smoothly, and a part of the adhesive coated on both sides of the core wrap sheet 51 before folding by the side coating devices 6a, 6b, etc. Even if it reaches the back side of the sheet, it is difficult to adhere to the sheet 51 because the contact area between the sheet 51 and the side support plates 47a and 47b is small. Therefore, both side portions of the core wrap sheet 51 can be satisfactorily folded back while being conveyed, and the adhesive adhering to the side support plates 47a and 47b irregularly adheres to the side portions of the core wrap sheet 51. It is possible to suppress the occurrence of inconveniences such as wrinkles.

Further, according to the method for manufacturing the absorber and the sheet folding device 41 of the present embodiment, as shown in FIGS. 3 and 6, each of the pair of side support plates 47a and 47b has a transport direction of the transport conveyor 42. Direction perpendicular to MD Since the CD is inclined downward toward the outside, the material for forming the absorbent core such as the highly absorbent polymer and the fiber material scattered during the transportation is placed on the side support plates 47a and 47b. It is also possible to suppress the accumulation and the adhesion of the deposit to the core wrap sheet 51 to reduce the adhesive force of the adhesive applied to the sheet 51. In addition, it is also possible to prevent the deposits from randomly adhering to the core wrap sheet 51 and being taken into the absorber 5 at irregular timings. Therefore, the expected performance and feel of the absorber will not be partially deteriorated due to the inclusion of the sediment in an unintended site.
As described above, according to the method for producing an absorber of the present embodiment, it is possible to prevent the adhesive strength of the adhesive applied before the folding process from being lowered by the deposits deposited on the side support plate. The absorber 5 whose shape retention is improved by the adhesive can be stably produced.

From the viewpoint of ensuring that such an effect is exhibited more reliably, the side support plates 47a and 47b have inclination angles θa and θb (see FIG. 6) with respect to the surface Lh parallel to the transport surface 42u, preferably 1 degree. As described above, it is more preferably 5 degrees or more, preferably 45 degrees or less, more preferably 30 degrees or less, and preferably 1 degree or more and 45 degrees or less, more preferably 5 degrees or more and 30 degrees or less.
The inclination angle θa of one side support plate 47a and the inclination angle θb of the other side support plate 47b (see FIG. 6) may be the same or different.

Further, in the absorber manufacturing device and the sheet folding device 41 of the present embodiment, as shown in FIG. 3, the transport surface 42u of the conveyor 42 in the upstream portion 41U is further upstream than the upstream portion 41U of the folding device 41. A conveyor belt 31 which is wider than (conveyor belt 42b) and has a uniform transport surface including portions on which both side portions of the core wrap sheet 51 are arranged is arranged.

Further, in the method of manufacturing the absorber and the sheet folding device 41 of the present embodiment, as shown in FIG. 3, the inclination angle of the first folding guide 43a that folds the one side portion 51a that folds back at the tip of the core wrap sheet 51. θ1 is made larger than the inclination angle θ2 of the second folding guide 43b to be folded back on the other side portion 51b to be folded back later. Therefore, as shown in FIGS. 1A and 1B, even when the absorber 5 having a large overlapping width W1 between one side portion 51a and the other side portion 51b of the core wrap sheet 51 is manufactured. , The portion where the first folding guide 43a and the second folding guide 43b overlap can be eliminated or significantly reduced, and the surface of the side portion 51b that is folded after the core wrap sheet 51 on the absorbent core 50 side can be used. Even when the adhesive is applied, the side portion 51b is firmly attached by the second folding guide 43b while preventing the adhesive on the side portion 51b from adhering to the first folding guide 43a. It can be folded back, and the side edge of the core wrap sheet 51 being conveyed can be folded back at a desired position with high accuracy.
When the adhesive applied to the side portion 51b to be folded back by the second folding guide 43b comes into contact with the first folding guide 43a, the first folding guide 43a is contaminated by the adhesive, and it takes time to maintain the manufacturing apparatus. Inconveniences such as this will occur.

The absorber produced by the method for producing an absorber of the present invention has an overlapping width W1 of one side portion 51a and the other side portion 51b of the core wrap sheet 51 [see FIG. 1 (a)], that is, the polymerization portion 53. The width is preferably 10 mm or more, more preferably 15 mm or more, more preferably 50 mm or less, further preferably 45 mm or less, and preferably 10 mm or more and 50 mm or less. It is more preferably 15 mm or more and 45 mm or less. When the width W1 of the polymerization portion 53 is within this range, the shape-retaining property of the absorber 5 is further enhanced, and leakage of the material forming the absorbent core 50 is prevented.
Further, in the absorber produced by the method for producing an absorber of the present invention, the overlap width W1 [see FIG. 1 (a)] between one side portion 51a and the other side portion 51b of the core wrap sheet 51 is the absorption. The maximum length W2 of the body 5 in the direction orthogonal to the transport direction MD of the conveyor [see FIG. 1 (a)] is preferably 6.9% or more and 45.5% or less, preferably 13.8%. It is more preferably 36.4% or less.

From the viewpoint of preventing the adhesive from adhering to the first folding guide 43a and the like, the inclination angle θ1 of the first folding guide 43a is preferably different from the inclination angle θ2 of the second folding guide 43b. It is 1 ° or more, more preferably 2 ° or more, preferably 12 ° or less, more preferably 11 ° or less, preferably 1 ° or more and 12 ° or less, and more preferably 2 ° or more and 11 ° or less. ..
From the same viewpoint, the inclination angle θ1 of the first folding guide 43a is preferably 5 ° or more, more preferably 6 ° or more, and preferably 15 ° or less, more preferably 12 ° or less. It is preferably 5 ° or more and 15 ° or less, and more preferably 6 ° or more and 12 ° or less. From the same viewpoint, the inclination angle θ2 of the second folding guide 43b is preferably 3 ° or more, more preferably 4 ° or more, provided that it is smaller than the inclination angle θ1 of the first folding guide 43a. It is preferably 12 ° or less, more preferably 10 ° or less, preferably 3 ° or more and 12 ° or less, and more preferably 4 ° or more and 10 ° or less.

When the inclination angle θ1 of the first folding guide 43a is increased as in the present embodiment, a high tension is likely to be applied to the portion of the core wrap sheet 51 located outside the side edge of the transport surface of the transport conveyor 42. As a result, the side portion 51a of the core wrap sheet 51 before folding back tends to curl in a cross-sectional arc shape toward the coated surface side of the adhesive in the vicinity indicated by the reference numeral P1 in FIG. When the side portion 51a of the core wrap sheet 51 is greatly curled, the adhesive-coated surfaces of the side portion 51a come into contact with each other, the side portion 51a of the core wrap sheet is folded back while being folded, and the width W1 of the overlapping portion 53 is formed. Inconveniences such as insufficient

From the viewpoint of suppressing curling of the side portion 51a of the core wrap sheet 51, the side support plate 47a located on the same side as the first folding guide 43a with the center line CL along the transport direction MD of the conveyor 42 as a boundary. The outer edge portion 48a of the conveyor belt 42 has an inclination angle θ3 with respect to the side edge Sa (side edge of the conveyor belt 42b) of the conveyor surface 42a on the same side as the second folding guide 43b with the center line CL as a boundary. It is preferable that the inclination angle θ4 of the outer edge portion 48b of the side portion support plate 47b located with respect to the side edge Sb (the side edge of the conveyor belt 42b) of the transport surface of the conveyor 42 is larger than that.

From the same viewpoint, the difference between the inclination angle θ4 and the inclination angle θ3 is preferably 1 ° or more, more preferably 2 ° or more, and preferably 15 ° or less, more preferably 12 ° or less. It is preferably 1 ° or more and 15 ° or less, and more preferably 2 ° or more and 12 ° or less.
Further, the inclination angle θ3 of the outer edge portion 48a of the side support plate 47a located on the same side as the first folding guide 43a is preferably 0 ° or more, more preferably 1 ° or more, and more preferably. Is 7 ° or less, more preferably 6 ° or less, preferably 0 ° or more and 7 ° or less, and more preferably 1 ° or more and 6 ° or less.
Further, the inclination angle θ4 of the outer edge portion 48b of the side support plate 47b located on the same side as the second folding guide 43b is preferably 0 ° or more, more preferably 1 ° or more, and more preferably. Is 15 ° or less, more preferably 12 ° or less, preferably 0 ° or more and 15 ° or less, and more preferably 1 ° or more and 12 ° or less.

The inclination angle θ3 of the outer edge portion 48a of the side support plate 47a located on the same side as the first folding guide 43a is located on the same side as the second folding guide 43b with the center line CL as a boundary. When the inclination angle θ4 of the outer edge portion 48b of the side support plate 47b is larger than the inclination angle θ4, the curl described above is less likely to occur, while the curl is less likely to occur from both side edges of the conveyor near the boundary between the upstream portion 41U and the downstream portion 41D. Wrinkles may occur on the extension. From the viewpoint of preventing such wrinkles, as shown in FIG. 3, in the transport direction MD of the conveyor 42, on the upstream side of the upstream end of the inward extending portion 45 of the first folding guide 43a. It is preferable to have a tack contact plate portion 55 provided on the side portion of the transport surface 42a and projecting upward from the transport surface 42a of the conveyor, particularly the transport surface 42a of the conveyor in the upstream portion 41U. In the present embodiment, the tack contact plate portion 55 is provided on the first folding guide 43a. That is, the first folding guide 43a and the tack contact plate portion 55 are integrated members, and the tack contact plate portion 55 is on the upstream side of the inward extending portion 45 of the first folding guide 43a. It extends upstream from the end 45c and protrudes upward from the conveyor surface 42a of the conveyor, particularly the conveyor surface 42a at the upstream 41U.

The tack contact plate portion 55 abuts from the lower surface of the core wrap sheet 51 near the position of the side edge of the conveyor, and is aligned with the height of the wrinkles generated or more so as to follow from the lower surface of the core wrap sheet 51. The width W1 of the desired polymerization portion 53 is maintained by preventing the side edge portion 50a of the absorber from being folded back with wrinkles.
The tack contact plate portion 55 shown in FIG. 3 has the same thickness as the side wall portion 44 of the first folding guide 43a, and the height of the upper edge portion of the tack contact plate portion 55 from the transport surface is 1 mm or more. Is preferable, and 2 mm or more is more preferable.
Further, in the tack contact plate portion 55, it is preferable that the upper end portion of the end portion on the upstream side in the transport direction, which is a portion in contact with the core wrap sheet 51, is formed in an arc shape in a side view. The radius of curvature of the portion is preferably 0.5 mm or more, more preferably 1 mm or more.

The absorber 5 produced in the present invention is preferably used as an absorber for an absorbent article. Absorbent articles are mainly used for absorbing and retaining body fluids excreted from the body such as urine and menstrual blood. Absorbent articles include, but are not limited to, disposable diapers, sanitary napkins, incontinence pads, panty liners, etc., and broadly include articles used for absorbing liquid discharged from the human body. To do.

The absorbent article typically comprises a front sheet, a back sheet and a liquid-retaining absorber interspersed between the sheets. The back sheet may or may not have water vapor permeability. The absorbent article may further include various members according to the specific use of the absorbent article. Such members are known to those of skill in the art. For example, when an absorbent article is applied to a disposable diaper or a sanitary napkin, one or more pairs of three-dimensional guards can be arranged on both sides in the longitudinal direction corresponding to the front-back direction of the wearer.

As the fiber material and the highly absorbent polymer which are the materials for forming the absorbent body, various materials conventionally used for the absorbent body of absorbent articles such as sanitary napkins, panty liners, and disposable diapers should be used without particular limitation. Can be done. For example, short fibers of cellulosic fibers such as pulp fibers, rayon fibers and cotton fibers, short fibers of synthetic fibers such as polyethylene and the like are used. These fibers may be used alone or in combination of two or more. Further, in addition to the fiber material, a deodorant, an antibacterial agent, or the like may be supplied into the duct as needed. Also, the highly absorbent polymer may or may not be supplied.

Examples of the highly absorbent polymer include sodium polyacrylate, (acrylic acid-vinyl alcohol) copolymer, sodium polyacrylate crosslinked polymer, (dempun-acrylic acid) graft copolymer, and (isobutylene-maleic anhydride). Examples thereof include copolymers and saponified products thereof, polyasparaginic acid and the like. The fibers and the highly absorbent polymer may be used alone or in combination of two or more.
As the core wrap sheet 51, tissue paper (thin paper), a liquid-permeable non-woven fabric, or the like can be used.

Although one embodiment of the sheet folding device and the method for producing an absorber of the present invention has been described above, the present invention is not limited to the above-described embodiment and can be appropriately modified.
For example, one or both of the pair of side support plates 47a and 47b gradually increase the inclination angle with respect to the transport surface 42u toward the outside of the direction CD orthogonal to the transport direction of the transport conveyor 42. For example, the cross-sectional shape of the transport conveyor 42 in a plane orthogonal to the transport direction MD and parallel to the height direction H may be arcuate as shown in FIG. In this case, the inclination angle θ of the side support plates 47a and 47b with respect to the plane Lh parallel to the transport surface 42u of the upstream portion 41U is the inclination angle of the tangent line at the inner edge portion 49a with respect to the plane Lh parallel to the transport surface 42u. To do.
Further, although not shown, one or both of the pair of side support plates 47a and 47b gradually increase or have an inclination angle θ with respect to the transport surface 42u from the upstream side to the downstream side of the transport direction MD of the conveyor. It may be a gradual decrease.

In the rotary drum of the absorber manufacturing apparatus shown in FIG. 2, a plurality of accumulation recesses forming the absorber for one absorbent article were formed at intervals in the circumferential direction of the rotary drum. Alternatively, a rotating drum provided with a recess for accumulation that is continuous in the circumferential direction may be used to manufacture a strip-shaped absorber having a structure in which absorbent cores for a plurality of absorbent articles are connected.
Further, in the above-described embodiment, an absorbent core using defibrated pulp as a fiber material is used, but the present invention is not limited to this, and a polymer sheet in which a highly absorbent polymer is supported on a fibrous sheet such as a non-woven fabric is used. Is also good.

Further, in the above-described embodiment, before the folding step, the absorption of the core wrap sheet 51 in both the side portion 51a folded by the first folding guide and the side portion 51b folded by the second folding guide. The adhesive was applied to the surface facing the sex core side, but the adhesive was applied to only one of the side portion 51a folded back by the first folding guide and the side portion 51b folded back by the second folding guide. You may. Further, although the adhesive is also applied to the central region 51 m of the core wrap sheet 51, the adhesive can be omitted.

Further, in the above-described embodiment, as the absorbent core, a core having a constricted portion having a reduced width of the absorbent core at the central portion in the longitudinal direction of the absorbent core is manufactured, but the absorbent core has a total length in the longitudinal direction. The width may be uniform over the entire range. Further, it is also possible to form an accumulator having a strip-shaped accumulating recess continuous in the circumferential direction of the rotating drum and to manufacture an absorber including a long absorbent core continuous in the transport direction.

Further, as shown in FIG. 9A, the absorbent body 5 to be manufactured has the ends of the folded core wrap sheet 51 so that the both side portions 51a and 51b of the folded core wrap sheet 51 are not overlapped with each other so as to cover both side portions of the absorbent core 50. The portions may be in contact with each other, and as shown in FIG. 9B, the absorbent core 50 is folded back from one side to the other so as to cover both sides of the absorbent core 50. Both side portions 51a and 51b of the core wrap sheet 51 may be joined on the other side of the absorbent core 50 in a state of being overlapped on both side portions of the other core wrap sheet 56.
Further, as shown in FIG. 9C, the absorber 5 to be manufactured is a core wrap sheet 51 folded back from one side to the other side of the absorbent core 50 so as to cover both sides of the absorbent core 50. Both side portions 51a and 51b may have a superposed portion 53a joined in a palm-shaped manner. As shown in FIG. 9C, the palm-shaped overlapping portion 53a may be bonded to the core wrap sheet that directly covers the absorbent core 50 by a known bonding means such as an adhesive or a heat seal. It may be good or it may not be joined.

Further, the sheet folding device is applied to folding a sheet other than the core wrap sheet in an absorbent article such as a disposable diaper, a sanitary napkin, an incontinence pad, etc., instead of the core wrap sheet constituting the absorber of the absorbent article. You can also do it.

The reason why the folding start position cannot be significantly shifted between the first folding guide 43a and the second folding guide 43b is that the upstream portion 41U located on the upstream side in the transport direction and the upstream portion 41U located on the downstream side in the transport direction are located. The transport direction of the folded-back portion 4 in the side view is different from that of the downstream portion 41D, and the distance from the angle changing portion that changes the transport direction to the folded-back start portion is determined by the first folding guide 43a and the second folding guide 43a. This is because it cannot be significantly different from the folding guide 43b.

1 Absorbent manufacturing equipment 2 Fiber stacking part 3 Transfer part 4 Folded part 5 Absorber 50 Absorbent core 51 Core wrap sheet 53 Polymerizing part 6 Adhesive coating part 7 Cutting device 8 Air injection mechanism 83 Contact type guide 20 Fiber drum 21 Accumulation recess 22 Duct 23 Fiber material introduction device 41 Sheet folding device 41U Upstream part 41D Downstream part 42 Conveyor conveyor 42 Conveyor conveyor 42b Conveyor belt 42a Conveyor surface 42u Upstream part transfer surface 42d Downstream part transfer surface 43a No. 1 folding guide (folding guide)
43b Second folding guide (folding guide)
44 Side wall of the fold-back guide 45 Inward extension of the fold-back guide 45c Upstream ends of the inward extension 45a, 45b Inner edge of the inward extension 45a Inward extension of the first fold-back guide Inner edge of the part 45b Inner edge of the inner extension of the second folding guide 46 Device housing 46a, 46b Outer edge of the inner extension 47a, 47b Side support plate 48a, 48b Side support plate Outer edge 49a, 49b Inner edge of side support plate 55 Tuck contact plate

Claims (3)

A transport conveyor that carries a long sheet on a transport surface and a pair of folding guides that fold both sides of the sheet transported by the transport conveyor along the transport direction in a direction orthogonal to the transport direction. A side wall portion provided with an upper portion, each of which is provided along the transport direction of the transport conveyor and is located above the same plane as the transport surface, and a side wall portion above the side wall portion. A sheet folding device having an inward extending portion extending inward in a direction orthogonal to the conveying direction of the sheet from the portion.
The pair of folded guides has an inner edge of each of the inward extending portions that is inclined so as to approach the opposite side in the direction orthogonal to the transport direction as it goes downstream in the transport direction of the conveyor. Have and
It has an upstream portion located on the upstream side and a downstream portion located on the downstream side in the transport direction of the transport conveyor, and the transport surface of the transport conveyor in the upstream portion and the transport surface of the transport conveyor in the downstream portion are predetermined. The pair of folded guides are arranged on both sides of the conveyor surface of the conveyor in the downstream portion, and the pair of side support plates are arranged on both sides of the conveyor surface of the conveyor in the upstream portion. Is arranged,
Each of the pair of side support plates has an outer edge that is inclined from the outside to the inside in a direction orthogonal to the transport direction toward the downstream of the transport direction of the conveyor. A sheet folding device that is tilted downward toward the outside in a direction orthogonal to the transport direction of the conveyor. Each of the pair of the side support plates has an inner edge portion extending along both side edges of the transport surface of the transfer conveyor in the upstream portion, and the inner edge portion of the pair of the side support plates The sheet folding device according to claim 1, respectively, which is arranged at a height equal to or lower than the transport surface in a height direction defined as a direction perpendicular to the transport surface. .. The step of arranging the absorbent core in the central region in the width direction of the long core wrap sheet to be conveyed in one direction, and the core wrap sheet in which the absorbent core is arranged are conveyed while being conveyed. By the sheet folding device according to claim 1 or 2, both side portions of the core wrap sheet extending laterally from each side edge of the absorbent core are placed on one surface of the absorbent core facing the central region. In the folding step of folding back to the other side opposite to the other side and covering both sides of the absorbent core with the core wrap sheet, and in one or both of both side portions of the core wrap sheet folded by the folding step. A method for producing an absorber, comprising an adhesive coating step of applying an adhesive in advance to the surface facing the absorbent core side before folding back.

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