WO2015093303A1

WO2015093303A1 - Absorbent body fabrication method

Info

Publication number: WO2015093303A1
Application number: PCT/JP2014/082120
Authority: WO
Inventors: 浩志丸山; 康泰木崎
Original assignee: 花王株式会社
Priority date: 2013-12-18
Filing date: 2014-12-04
Publication date: 2015-06-25
Also published as: CN105792784B; CN105792784A; JP2015116338A; TWI634877B; JP5946817B2; TW201526882A

Abstract

Provided is a method for fabrication of an absorbent body which is formed when an absorbent core whereon depression parts are disposed in at least a longitudinal direction of a product is enveloped with a covering sheet, said method comprising an adhesive coating step of coating the covering sheet inner face which envelopes the absorbent core with an adhesive, and an encapsulation step of folding both lateral parts of the covering sheet so as to overlap and envelope the absorbent core, and overlapping and bonding the lateral parts upon the side of the face of the absorbent core whereupon the depression parts are positioned. In the adhesive coating step, in order that upon the lateral part the edge whereof contacts the absorbent core, the width of a dry edge region from the said edge to the outer side end of the adhesive coating region is kept constant, the adhesive is coated while detecting the location of the edge and computing the width of the dry edge region.

Description

Absorber manufacturing method

The present invention relates to a method for producing an absorbent for use in absorbent articles such as disposable diapers, sanitary napkins, and incontinence pads.

As an absorber used for an absorbent article such as a disposable diaper, there is one in which an absorbent core made of a fiber material such as pulp fiber or a water-absorbing polymer is wrapped with a covering sheet. Several proposals have heretofore been made as methods for producing such an absorber.
For example, in Patent Document 1, as a rotating drum that forms an absorber, a concave portion on the outer peripheral surface thereof has a suction part and a non-suction part, and the depth of the non-suction part is made shallower than the depth of the suction part. It is listed. When the fiber material is deposited in the concave portion, a deposit having a thick portion and a thin portion is obtained, and by pressing this, an absorbent body having a uniform apparent thickness and having a high density portion and a low density portion is obtained. It is done.
Patent Document 2 describes a technique in which a hot melt adhesive is interposed between thin paper and an absorbent mat in which fibrous materials are accumulated to heat-treat the absorbent mat.

JP 2012-16684 A JP-A-6-311998

The present invention relates to a method for producing an absorbent body in which an absorbent core having grooves at least in the product longitudinal direction is wrapped with a covering sheet, wherein an adhesive is applied to the inner surface of the covering sheet surrounding the absorbent core. Wrapping the adhesive core to overlap the both sides of the covering sheet and wrap the absorbent core, and the both sides are overlapped and joined on the surface side of the absorbent core where the grooves are arranged A packaging step, and in the adhesive coating step, an outer edge of the adhesive coating region from the edge on the side of the both sides where the edge is in contact with the absorbent core A manufacturing method of an absorbent body, wherein the adhesive is applied while detecting the position of the edge and calculating the width of the non-coating region so that the width of the non-coating region is kept constant. provide.

The above and other features and advantages of the present invention will become more apparent from the following description with reference to the accompanying drawings as appropriate.

It is the figure which showed an example of the absorptive core obtained with the manufacturing method of the absorber of this invention, (A) is the top view seen from the 1st surface side, (B) was seen from the 2nd surface side. It is a plan view, and (C) is an enlarged cross-sectional view showing a cross-section taken along the line CC of (A). (A) is the expanded sectional view of the absorber which wraps the absorptive core of FIG. 1 with a covering sheet, (B) is the top view which showed the packaging process which wraps an absorptive core with a covering sheet. It is the schematic which showed an example of the manufacturing apparatus of an absorber preferable for enforcing the manufacturing method of the absorber of this invention. (A) is explanatory drawing which showed typically the coating process of the hot-melt-type adhesive agent to the both sides in FIG. 3, (B) is an enlarged plan view of a sensor area | region, (C) is a coating sheet. It is a figure which shows the state in which the edge of is in the center position (appropriate reference position) of a sensor area, (D) is the inner side of the width direction rather than the center position (appropriate reference position) of a sensor sheet It is a figure which shows the state which exists in the side, (E) is a figure which shows the state which the edge of a coating sheet exists in the width direction outer side rather than the center position (appropriate reference position) of a sensor area | region. It is sectional drawing which showed the cross section of the recessed part in the rotating drum outer peripheral surface used for the manufacturing apparatus of FIG. It is the flowchart which showed the process of test | inspecting the edge position of the cover sheet side part in this embodiment.

Detailed Description of the Invention

Some absorbent bodies use an absorbent core having grooves at least in the longitudinal direction from the viewpoint of air permeability and softness when incorporated in absorbent articles such as diapers. The groove portion serves as an air passage for the absorber and serves as a flexible portion of the absorber.
The absorbent core having a groove portion is excellent in flexibility, but the integrity is weakened during liquid absorption and may be partially separated. If the absorbent core breaks, liquid leakage may occur from it. Therefore, it is necessary that the absorbent core is firmly fixed to the covering sheet while maintaining flexibility.

As a form of fixing the absorbent core with the covering sheet, an adhesive is applied to the covering sheet to wrap the absorbent core, and both sides of the covering sheet are overlapped and joined on the surface side having the groove portion of the absorbent core There is. However, non-coating regions (dry edges) are provided on both sides of the covering sheet in order to prevent the adhesive from sticking out, which can hinder continuous production. If this non-coating region overlaps the periphery of the groove, the absorbent core is not fixed to the covering sheet at that portion.
If the width of the non-coating region is too wide, the absorbing portion between the grooves cannot be fixed, and it may be partially separated during liquid absorption. On the other hand, if the width of the non-coating region is too narrow, the adhesive protrudes during coating, which may hinder continuous production.
Thus, it is desired from the viewpoint of improving the performance of the absorber that the absorber is stably continuously manufactured with a suitable width of the non-coating region. Conventionally, the position of the covering sheet has been adjusted using a meandering correction machine that keeps the conveyance of the long covering sheet at a fixed position. However, this is position adjustment on the upstream side of the adhesive coating process. Therefore, more reliable management of the non-coating region is desired in the adhesive coating process on the downstream side.

In view of the above points, the present invention grasps the width of the non-coated region of the covering sheet in a timely and accurate manner in the continuous production of the absorbent body, ensures the fixing property of the absorbent core to the covering sheet, and maintains the shape. The present invention relates to a method for producing an absorbent body, which can stably produce an absorbent body having excellent properties.

According to the method for producing an absorbent body of the present invention, in continuous production of the absorbent body, the width of the non-coated area of the covering sheet is accurately grasped in a timely manner, and the fixing property of the absorbent core to the covering sheet is ensured. An absorber excellent in shape retention can be stably produced.

A preferred embodiment of the method for producing an absorbent body of the present invention will be described below with reference to the drawings. The absorbent body obtained by the production method of the present invention has a function of being incorporated in an absorbent article and absorbing and retaining excretory fluids. The absorbent article widely includes various forms that are worn along the wearer's crotch along the abdomen and dorsal side to absorb excretory fluids, such as disposable diapers, sanitary napkins, incontinence pads, Includes panty liners.

First, the basic structure of the absorber 10 obtained by the manufacturing method of the absorber of this embodiment will be described. The absorbent body 10 is formed by wrapping a liquid-retaining absorbent core in a hydrophilic covering sheet. The absorptive core is a fiber assembly obtained by stacking fiber materials as described later. FIG. 1 shows an example of an absorbent core. The absorptive core 1 shown in FIG. 1 has a vertically long planar shape, and its outer shape is constricted at the central portion in the longitudinal direction, and the width expands toward both front and rear ends.
As shown in FIG. 1A, the absorbent core 1 has a first surface 1A and a second surface 1B, and a plurality of grooves (vertical grooves) 11 are formed in the first surface 1A in the longitudinal direction. ing. Further, a plurality of groove portions (lateral groove portions) 12 are formed in the width direction orthogonal to the longitudinal direction. These

groove portions

11 and 12 are concave portions that are recessed in the thickness direction from the surface of the first surface 1A of the absorbent core 1, and are opposite to the first surface 1A as shown in FIGS. 1 (B) and (C). It does not penetrate the second surface 1B side of the surface. A portion of the absorbent core 1 that is surrounded by the

grooves

11 and 12 and protrudes toward the first surface 1A is called a protruding absorption portion 15 and is located on the second surface 1B side where the

grooves

11 and 12 remain without penetrating. This portion is referred to as a thin skin absorbing portion 16. The first surface 1A of the absorbent core 1 is an uneven surface, and the second surface 1B is a flat surface.

The

groove portions

11 and 12 in the absorbent core 1 serve as ventilation paths in the absorbent body, and have an effect of reducing stuffiness when the absorbent core 1 is incorporated and attached to the absorbent article. In particular, the groove 11 is effective in preventing stuffiness because moisture that tends to stay in the crotch is moved along the longitudinal direction and discharged to the outside. The

grooves

11 and 12 serve as a liquid diffusion path. In particular, the groove 11 diffuses the liquid in the longitudinal direction and enables liquid absorption in a wide area of the absorbent core 1, which is effective in preventing side leakage of the liquid.
Further, the absorbent core 1 can be softly deformed with the

grooves

11 and 12 as flexible shafts. The groove 11 in the longitudinal direction enables deformation that can cope with pressure from the outside in the width direction in the crotch. The groove 12 in the width direction enables deformation that can fit complex undulations of the body when the absorbent core 1 is incorporated into an absorbent article and is stretched from the crotch toward the abdomen and back.

The groove part which the absorptive core 1 has is not limited to the thing of this embodiment mentioned above, What is necessary is just to have a groove part of a longitudinal direction at least. The number and length of the grooves can be arbitrarily set. Further, the groove is not limited to a linear shape as shown in FIG. 1, and may be a curved shape as long as it extends in the longitudinal direction. The arrangement of the grooves may not be parallel to the center axis in the width direction connecting both ends of the absorbent core 1 in the longitudinal direction. For example, there may be one formed so as to have an inclination angle left and right from the central portion toward both front and rear end portions with respect to the central axis. Further, the groove portion is not limited to the non-penetrating one as in the present embodiment, and may be one that penetrates in the thickness direction from the first surface 1A to the second surface 1B without leaving the thin skin absorbing portion 16. Moreover, the external shape of the absorptive core 1 is not limited to the shape shown in FIG. 1, A rectangular shape, an ellipse shape, etc. may be sufficient.

As shown in FIGS. 2A and 2B, the absorbent core 1 is wrapped and wrapped by a single cover sheet 2 so that both

side portions

21 and 22 of the cover sheet 2 overlap each other. Specifically, the second surface 1B side of the absorbent core 1 is covered with the central portion 28 in the width direction (X direction) of the covering sheet 2, and both

side portions

21 and 22 extending outward in the width direction are wound up to It is folded back alternately on the first surface 1A side. Both

side portions

21 and 22 are overlapped and joined on the first surface (uneven surface) 1A side where the groove portion of the absorbent core 1 is arranged. Thereby, the laminated part 29 of the both

side parts

21 and 22 of the coating sheet 2 is arrange | positioned by the 1st surface 1A side where the groove part of the absorptive core 1 was distribute | arranged. In the laminated portion 29, one side portion 21 of the covering sheet 2 is folded inward from the other side portion 22, and an edge thereof is in contact with the first surface 1 </ b> A having the groove portion of the absorbent core 1. Since the covering sheet 2 covers the entire area of the first surface, the second surface, and the side surfaces of the absorbent core 1 as described above, the covering sheet 2 has a width that is at least twice the length of the absorbent core 1 in the width direction (X direction). Have. The

side portions

21 and 22 of the covering sheet 2 are portions that are folded back from the second surface side 1B of the absorbent core 1 toward the first surface side 1A in this packaging form. The center part 28 is a part which covers the 2nd surface side 1B of the absorptive core 1, and is a part except the

side parts

21 and 22 in the width direction of a coating sheet. Note that in the cross-sectional view of FIG. 2A, the constituent members are shown with an interval in order to easily identify the constituent members. Therefore, in practice, each component is in contact or bonded.

The absorbent body 10 of the present embodiment includes an absorbent core 1 having a first surface 1A that is an uneven surface and a second surface 1B that is a flat surface. The absorbent body 10 is a surface where the both

side portions

21 and 22 of the covering sheet 2 do not overlap, and the surface on which the second surface 1B of the absorbent core 1 is disposed is incorporated into the absorbent article as a skin contact surface. Thereby, the joint of the covering sheet 2 becomes the non-skin contact surface side and does not hinder the permeation of the liquid. Further, when the thin skin absorbing portion 16 is on the skin contact surface side, the liquid can be diffused in the groove portion on the first surface side 1A away from the skin while receiving the liquid widely on the flat second surface 1B of the absorbent core 1. Thereby, the liquid return to the skin side is suppressed, and the liquid absorption performance is excellent. In addition, as arrangement | positioning to the absorbent article of the absorber 10, it is not limited to the said form. Depending on the application or the like of the absorbent article, the surface where the

side portions

21 and 22 do not overlap may be the non-skin contact surface, and the surface where the

side portions

21 and 22 overlap may be the skin contact surface. The skin contact surface is a surface directed toward the wearer's skin when the absorbent article is worn, and the non-skin contact surface is a surface directed toward the opposite clothing side.

The cover sheet 2 is coated with an adhesive for fixing the absorbent core 1 to the inner surface 2 </ b> A enclosing the absorbent core 1. In this embodiment, a hot melt type adhesive is used, and the

side portions

21 and 22 and the central portion 28 are separately applied. In the central portion 28, an adhesive is applied in a spiral coating pattern with a low coating density so as not to impede liquid permeability on the second surface 1B side of the absorbent core 1 serving as a liquid receiving surface. (Hereinafter, the adhesive of the central portion 28 is also referred to as an adhesive 28S.) On the other hand, in order to secure the fixing property on both

side portions

21 and 22, the adhesive is applied in a stripe-like coating pattern having a dense coating density (hereinafter, the adhesives on both

side portions

21 and 22 are applied). Also referred to as

adhesives

21S and 22S, respectively).
The both

sides

21 and 22 are provided with adhesive non-coating regions (dry edge regions) 25 and 26 with a predetermined width H1 from the respective end edges 23 and 24 from the viewpoint of preventing the adhesive from protruding. These

non-coating regions

25 and 26 constitute a part of the above-described laminated portion 29. In the laminated portion 29, the non-coating region 25 of the side portion 21 entering the inside is not bonded to the absorbent core 1 while being in contact with the first surface (uneven surface) 1 </ b> A side where the groove portion of the absorbent core 1 is arranged. is there.

In the laminated portion 29, the width H1 of the inner non-coating region 25 is preferably a moderately suppressed length for fixing the protruding absorbing portion 15 between the groove portions. That is, the width H <b> 1 is preferably within a distance from the vertical groove portion 11 to another adjacent vertical groove portion 11. Specifically, it is preferable that the length H2 in the width direction of the longitudinal groove portion 11 of the absorbent core 1 and the length H3 in the width direction of the protruding absorption portion 15 (H2 + H3) be shorter (H1 <H2 + H3), and the protrusion. It is more preferable that the absorption portion 15 is shorter than the length H3 in the width direction (H1 <H3). In particular, the width H1 of the non-coating region 25 is shorter than the length H3 in the width direction of the protrusion absorbing portion 15 (H1 <H3), so that even if the shape and arrangement of the longitudinal groove portion 11 are various modes, the protrusion absorption The part 15 and the covering sheet 2 can be joined. That is, by appropriately suppressing the width H <b> 1 of the non-coating region 25, the protruding absorbing portion 15 that overlaps the laminated portion 29 can be fixed with the adhesives 21 </ b> S and 22 </ b> S of the side portion 21 and the side portion 22.
A preferable numerical value of the width H1 of the non-coating region 25 is determined by the lengths of the longitudinal groove portion 11 and the protruding absorbent portion 15, and varies depending on the size and use of the absorbent body and the absorbent article to be incorporated. For example, as an absorbent body used for a disposable diaper for infants, when the length H2 of the longitudinal groove 11 is 2 mm and the length H3 of the protruding absorber 15 is 10 mm, it is preferably 11 mm or less, more preferably 10 mm or less, and further 8 mm or less. preferable. Thereby, a protrusion part can be fixed reliably. The lower limit is preferably 1 mm or more, more preferably 3 mm or more, and still more preferably 5 mm or more. Thereby, it can process stably, without protruding at the time of adhesive agent 22S coating.

In addition, the coating pattern of the adhesive in the central portion 28 is not limited to the spiral shape of the present embodiment, and various patterns having a low coating density that does not impair liquid permeability can be employed. For example, there are dot shape, omega (Ω) character shape, and meander shape. Further, the adhesive coating pattern on both

side portions

21 and 22 is not limited to the stripe shape of the present embodiment, and various coating patterns having a dense coating density can be employed. For example, there is a surface shape.

Next, an example of the manufacturing apparatus 100 used for the manufacturing method of the absorber of the present invention will be described with reference to FIGS.
As shown in FIG. 3, a coating part 50 for applying a hot-melt adhesive to the covering sheet 2, and a stacking part 60 for stacking pulp fibers and a water-absorbing polymer to form the absorbent core 1. The absorbent core 1 is placed on the covering sheet 2 and has a packaging portion 70 that wraps the covering sheet 2 by folding both sides. Furthermore, it has the cutting part 80 cut | disconnected to the magnitude | size of the absorber 10. FIG. In addition, a pressurizing part and other components may be optionally included.

The coating unit 50 includes the side coating device 51 that applies the adhesive to the both

side portions

21 and 22 in the width direction of the covering sheet 2 and the central coating device that applies the adhesive to the central portion 28. 58. For example, a hot melt gun can be used as each coating apparatus. By these coating apparatuses, the adhesive coating is continuously applied to the

side portions

21 and 22 and the central portion 28 with respect to the long strip-shaped covering sheet 2 continuously drawn out from the raw roll (not shown). Do. The central coating device 58 has a coating head 59 that performs pattern control by an air flow and applies an adhesive in a non-contact state. Thereby, as above-mentioned, an adhesive agent can be apply | coated to the center part 28 of the coating sheet 2 with a sparse pattern of coating density. The side coating apparatus 51 includes coating heads 53 and 54 that are brought into contact with both sides of the covering sheet 2 and coat the adhesive closely.
Further, an edge detection sensor is provided on the coating head 53 disposed on the side portion 21 disposed on the inner side when folded back in a subsequent process, on both

sides

21 and 22 of the covering sheet 2 via a support portion 55. The part 31 is joined and integrated. In this embodiment, from the viewpoint of shape retention of the absorbent core, the edge detection sensor 31 is installed only on the side portion 21 that is folded inward. The edge detection sensor unit 31 is a width sensor that detects a region having a predetermined width. The edge detection sensor part 31 is installed in the coating head 53 so as to detect the edge 23 of the side part 21. With this installation, the hot melt application position and the center position of the edge detection sensor unit 31 are determined, and accurate non-coating area (dry edge) management that cannot be realized by a conventional meandering correction device can be performed. This point will be described in detail below.

The edge detection sensor unit 31 includes a sensor region 32 having a predetermined length S1 extending in the width direction of the cover sheet 2 as shown in FIG. The sensor region 32 is disposed so as to overlap the edge 23 of the side portion 21 of the cover sheet 2 and detects the position of the edge 23. Thereby, the position fluctuation | variation of the edge 23 of the covering sheet 2 conveyed continuously can be grasped | ascertained in the range of length S1 of the sensor area | region 32 (refer FIG.4 (B)). In the present embodiment, the center position 321 of the length S1 of the sensor region 32 is set as the appropriate reference position ST of the edge 23 (see FIG. 4B). Position information in which the edge 23 is shifted from the center position 321 to the inner side (the inner side in the width direction of the covering sheet 2) and the outer side (the outer side in the width direction of the covering sheet 2) of the sensor region 32. By detecting, it is possible to grasp the presence / absence of the position fluctuation of the edge 23. The width direction here is a direction (CD; Cross Direction) orthogonal to the machine flow direction (MD; Machine Direction). This coincides with the width direction (X direction) orthogonal to the longitudinal direction (Y direction) when the absorbent body 10 is formed.

The coating head 53 integrated with the edge detection sensor unit 31 is disposed inward in the width direction of the covering sheet 2 with respect to the edge detection center unit 31. Thereby, the application position of the adhesive to the side part 21 is determined. In the present embodiment, when the edge 23 of the covering sheet 2 overlaps the center position 321 of the sensor region 32 of the edge detection sensor unit 31 (see FIG. 4C), the adhesive coating head 53 is appropriate. The arrangement position is determined. In this state, the length in the width direction (CD) between the edge 23 of the coating sheet 2 and the coating outer edge 53A in the width direction of the coating head 53 is set as an appropriate setting width HT of the non-coating region 25. The setting is made (see FIG. 4C).

A control unit 40 is connected to the edge detection sensor unit 31. The control unit 40 receives the detected position information of the edge 23 together with the detection time information 23T, and calculates the width H1 of the non-coating area as needed. The calculated value is stored in time series in the control unit 40 together with the detection time information.
For example, when position information SN of the edge 23 of the cover sheet 2 is detected on the inner side of the center position 321 of the sensor region 32 included in the edge detection sensor unit 31 (see FIG. 4D), the position information SN Is received by the control unit 40 together with the detection time information 23T. The control unit 40 determines the position information SN as a numerical value of the minus coordinate axis from the appropriate reference position ST (= 0 (zero) value), and calculates the deviation width as a minus difference “−SN”. That is, it is determined that the edge 23 is close to the coating outer edge 53A of the coating head 53 by the difference “−SN”. This minus difference “−SN” is added to the appropriate setting width HT of the non-coating area (HT + (− SN)), and is calculated and stored as the width H1 (= HT−SN) of the non-coating area at the time of detection. .
On the contrary, when the position information SW of the edge 23 of the covering sheet 2 is detected on the outer side of the center position 321 of the sensor region 32 of the edge detection sensor unit 31 (see FIG. 4E), the control unit 40 is detected. Then, it determines as follows. When the position information SW is received together with the detection time information 23T, the control unit 40 determines the position information SW as a numerical value of the plus coordinate axis from the appropriate reference position ST (= 0 (zero) value). Then, the deviation width is calculated as a plus difference “+ SW”. That is, it is determined that the edge 23 is away from the coating outer edge 53 </ b> A of the coating head 53. This plus difference “+ SW” is added to the appropriate setting width HT of the non-coating area (HT + (+ SW)), and is calculated and stored as the non-coating area width H1 (= HT + SW) at the time of the inspection.
When the detected position information is the proper reference position ST, the width H1 of the non-coating area is kept at the proper set width HT (H1 = HT).
Based on the width H1 of the non-coating area calculated from these detection values, whether or not the width H1 of the non-coating area is appropriate can be determined in a timely manner in the manufacturing method of the absorber described later.

The stacking unit 60 is a component that forms the absorbent core 1, and includes a defibrating device 61 that defibrates a pulp sheet fed from a pulp raw roll (not shown) to obtain pulp fibers, and a defibrating device 61. It has a duct 62 serving as a path for carrying the drawn pulp fiber in an air stream, a water-absorbing polymer supply unit 63 provided in the duct, and a rotating drum 64 as a fiber stacker.
The rotating drum 64 has a plurality of recesses 641 for depositing raw materials (fiber materials) of the absorbent core 1 such as pulp fibers and water-absorbing polymers on the outer peripheral surface thereof (see FIG. 5). As shown in FIG. 5, the concave portion 641 is formed by laminating and fixing a porous plate 643 and a pattern forming plate 644 in a through-hole of a cylindrical frame body 642 made of a metal rigid body. On the pattern forming plate 644, crosspieces 645 for forming grooves are arranged in a pattern. The crosspiece 645 has a height shorter than the depth of the concave portion 641 and is arranged close to the frame body 642 side. Inside the rotating drum 64, spaces B, C, D, and E that are partitioned from each other are formed. An intake fan (not shown) is connected to the space B, and the space B is maintained at a negative pressure by driving the intake fan. Thereby, an air flow is generated in the duct 62. The space D is maintained at a positive pressure by a pressurizing means (not shown). The space C may be maintained at a negative pressure in order to convey the absorbent core 1 in which the fiber material is deposited while being stably held. In that case, the space C is preferably maintained at a lower level of negative pressure than the space B. In the space E, the bottom of the recess may be cleaned by maintaining the pressure equal to the atmospheric pressure or by air blowing (not shown) from the inside of the drum.

In the fiber stacking unit 60, when the fiber material is supplied to the rotating drum 64 while riding in the air current in the duct 62, the fiber material is deposited in the rotating recess 641 so as to avoid the crosspiece 645. Thereby, the absorptive core 1 which consists of a groove part, the protrusion absorption part 15, and the thin skin absorption part 16 is formed. As shown in FIG. 5, the part of the crosspiece 645 of the concave portion 641 becomes a groove, and the fiber material is deposited in a space without the crosspiece 645 to form the protruding absorption section 15. 16
The formed absorbent core 1 is released at the position of the space D and transferred to the cover sheet 2 that is conveyed. This mold release and transfer are performed by positive pressure in the space D and suction from the vacuum conveyor 71 side described later.

The packaging unit 70 includes a vacuum conveyor 71 corresponding to the space D in the rotary drum 64 of the stacking unit 60, and a folding means 72 that folds the

side portions

21 and 22 of the covering sheet 2 in order. Thereby, both sides are folded and folded as shown in FIG. 2B, and the entire circumference in the width direction of the absorbent core 1 is covered with the covering sheet 2 and packaged. At this time, the 2nd surface 1B of the absorptive core 1 is joined and fixed with the center part 28 of the coating sheet 2 with the rough | crude adhesive agent 28S. 1 A of 1st surfaces of the absorptive core 1 are joined and fixed with the both

sides

21 and 22 of the coating sheet 2 with the

dense adhesives

21S and 22S. At that time, both

side portions

21 and 22 overlap on the first surface 1A of the absorbent core 1 to form a laminated portion 29. In the laminated portion 29, the adhesive 21 </ b> S and the adhesive 22 </ b> S are overlapped in the thickness direction and the both

side portions

21 and 22 are joined, thereby sealing the absorbent core 1.

After the packaging, the cutting unit 80 cuts the covering sheet 2 with a cutting means (not shown) such as a cutter roll at a portion where the absorbent core 1 is not provided, and has a length corresponding to one absorbent body 10.

Next, an embodiment of the method for producing an absorbent body according to the present invention will be described. In the present embodiment, the manufacturing apparatus 100 described above is used.
As shown in FIG. 3, the manufacturing method includes an adhesive coating process 201 (side coating process 202 and a central coating process 203) in the coating part 50, a stacking process 204 in the stacking part 60, and a packaging part. 70 has a packaging step 205. Furthermore, the absorber of predetermined length is obtained by the cutting process 206 in the cutting part 80 after that.

In the adhesive coating process 201, as shown in FIG. 3, the rolls 101A to 101E are rotated to continuously feed the long strip-shaped covering sheet 2 from an upstream raw roll (not shown). The coating of the adhesive described above in the coating unit 50 is continuously performed on the covered cover sheet 2. In this embodiment, the side coating process 202 and the central coating process 203 are performed in this order. The order of both coating processes is not necessarily limited to this, For example, the order of the center coating process 203 and the side part coating process 202 may be sufficient.

First, in the side part coating process 202, the coating heads 53 and 54 of the coating part 51 are brought into contact with both

side parts

21 and 22 in the width direction of the covering sheet 2 to perform dense coating. In this embodiment, coating is performed with a stripe pattern. At that time, the edge detection sensor part 31 integrated with one coating head 53 via the support part 55 continues to detect the position of the edge 23 of the one side part 21 of the covering sheet 2. That is, in the side part coating process 202, the application of the adhesive to the both

side parts

21 and 22 of the covering sheet 2 and the detection of the position of the edge 23 of the side part 21 are continued simultaneously. From the position of the edge 23, the control unit 40 connected to the edge detection sensor unit 31 continues to calculate the width H1 of the non-coating region 25 in the side part 21. The calculated width H1 and detection time information 23T at which the position of the edge 23 is detected are stored in time series. This point will be described in more detail with reference to FIG.

First, in the control unit 40, the center position 321 in the width direction in the sensor region 32 of the edge detection sensor unit 31 is set in advance as the appropriate reference position ST of the edge 23 of the cover sheet 2 (step S1). Further, an appropriate setting width HT of the non-coating region 25 is set from the appropriate reference position ST (Step S1). If necessary, an upper limit value α and a lower limit value β of an allowable range of the deviation width from the appropriate setting width HT are set (step S1). Further, in the manufacturing apparatus 100, the conveyance speed SP of the cover sheet 2 and the distance SK from the edge detection sensor unit 31 to the position of the absorbent body discharge sorting process (not shown) taken as a unit after cutting are set. (Step S1). This distance SK is basic information for setting how many sheets after the defect is detected should be discharged.
The appropriate setting width HT is determined from the viewpoints of securing the fixing force of the absorbent core 1 and preventing the adhesive from protruding. As described above, it is preferable to set the distance within a distance from the vertical groove portion 11 of the absorbent core 1 to another adjacent vertical groove portion 11. Specifically, it is preferable to set the width (H1 <H2 + H3) shorter than the sum of the length H2 in the width direction of the longitudinal groove portion 11 of the absorbent core 1 and the length H3 in the width direction of the protruding absorption portion 15. It is more preferable to set the width (H1 <H3) shorter than the length H3 in the width direction of the protrusion absorbing portion 15. In addition, when the width | variety of the protrusion absorption part 15 is not uniform by arrangement | positioning etc. of the vertical groove part 11, the coating in the width direction of the appropriate setting width | variety HT and the coating head 53 on the basis of the place where the width | variety of the protrusion absorption part 15 is the shortest. The position of the outer edge 53A is set. In accordance with the appropriate setting width HT, the width from the center position 321 of the sensor region 321 (that is, the appropriate reference position ST of the edge) to the coating outer edge 53A in the width direction of the coating head 53 is set.

Next, when the edge detection sensor unit 31 detects the position of the edge 23 of the side portion 21 of the covering sheet 2 in the sensor region 32, the position information is transmitted to the control unit 40 together with the detection time information 23T. This information is received and stored by the control unit 40 (step S2).
When the received position information is the position information SN inside the appropriate reference position ST, the control unit 40 adds (−SN) to the appropriate setting width HT, and the width H1 (= HT + (−) of the non-coating area. SN)). When the received position information is position information SW outside the appropriate reference position ST, (+ SW) is added to the appropriate setting width HT, and the width H1 (= HT + (+ SW)) of the non-coating area is calculated. When the received position information is the proper reference position ST, the width H1 of the non-coating area is kept at the proper set width HT (H1 = HT). The width H1 of the non-coating area calculated in this way is stored in time series together with the detection time information 23T (step S3).

Based on the calculated width H1 of the non-coating region, the quality is judged (step S4). For example, the control unit 40 determines a deviation (H1 <HT or H1> HT) from the appropriate setting width, and determines that the width H1 of the non-coating region where the deviation has occurred is defective. Alternatively, an allowable range of deviation width (α ≦ SN (= HT−H1), β ≧ SW (= H1−HT)) is set in advance by the control unit 40, and the deviation width is within the allowable range. When it deviates (when it falls below the lower limit α or above the upper limit β), the width H1 of the non-coating area is determined to be defective. The upper limit β is preferably set within a distance from the vertical groove 11 of the absorbent core 1 to another adjacent vertical groove 11.
Further, the control unit detects the detection time information 23T corresponding to the width H1 of the non-coating area determined to be defective, the conveying speed SP of the covering sheet 2 set in advance, and the discharge detection sorting step of the absorber from the edge detection sensor unit 31 ( Based on the distance SK up to (not shown), it is possible to determine how many sheets should be discharged after detecting a defect and to identify the defective absorber 10.

In the manufacturing method of the absorbent body in the present embodiment, the width H1 of the non-coating region 23 can be inspected simultaneously with the application of the adhesive from the detected and calculated numerical values, and the suitability can be monitored timely. For example, the width H1 of the non-coating area calculated by the control unit 40 can be displayed on another monitor and confirmed. Thereby, it is useful for quality control in manufacture of an absorber and an absorbent article incorporating the same. Further, when it is determined that the width H1 of the non-coating area is defective, the defect signal (alarm) 40X may be displayed on the monitor or an alarm sound may be generated. Further, as described above, a display for specifying the absorber 10 determined to be defective may be displayed on the monitor. Or you may make it exclude the absorber 10 specified as inferior goods with the actuator etc. of a downstream process.
Further, the position of the cover sheet 2 may be returned to the proper position by the adjusting means by feedback control from the deviation width (−SN, + SW). For example, the position adjusting means (not shown) of the covering sheet 2 installed in the previous process of the HM coating process controls the position of the covering sheet 2 according to the detection value of the end detection sensor unit 31 by feedback control. By doing so, the width of the dry edge can always be controlled within the standard.

In this way, the

adhesives

21S and 22S are continuously applied to the both

side portions

21 and 22 of the covering sheet 2 while the width H1 of the non-coating region 23 of the side portion 21 is constantly monitored. Next, in the central part coating step 203, the coating head 59 of the coating part 58 is brought into a non-contact state with respect to the central part 28 of the covering sheet 2, and the adhesive 28S is applied in a sparse pattern. In the present embodiment, coating is performed with a spiral pattern. Thereafter, the covering sheet 2 reaches the position of the vacuum conveyor 71 of the packaging unit 70. At that position, the fiber stacking process 204 in the fiber stacking section 60 described above is performed separately. That is, the absorptive core 1 which has the groove part, the protrusion absorption part, and the thin skin absorption part by which the predetermined pattern arrangement was carried out is produced continuously.

Next, a packaging process 205 in the packaging unit 70 is executed. At the position of the vacuum conveyor 71, the absorbent core 1 created in the fiber stacking process 204 is transferred to the central portion 28 of the covering sheet 2. Thereby, the 2nd surface 1B of the absorptive core 1 is joined and fixed to the center part 28 of the coating sheet 2 with the adhesive agent 28S. Thereafter, the folding means 72 is continuously folded and joined so that both side portions of the covering sheet 2 overlap the first surface 1A side where the groove portion of the absorbent core 1 is located, thereby forming the laminated portion 29 of the both

side portions

21 and 22. Is done. In the laminated portion 29, the

adhesives

21S and 22S on the both

side portions

21 and 22 are joined to each other in the thickness direction, and the absorbent core 1 is thereby sealed. Further, the first surface 1 </ b> A of the absorbent core 1 is bonded and fixed to the

entire side portions

21 and 22 including the laminated portion 29 by the

adhesives

21 and 22.
In this state, it is conveyed to the position of the cutting part 80 by the belt conveyor 81, and the cutting process 206 is performed. That is, what wrapped the absorptive core 1 with the coating sheet 2 is cut | disconnected by cutting means (not shown), such as a cutter roll, and the absorber 10 of predetermined length is obtained.

The absorber obtained by the method for producing an absorbent body of the present invention is preferably used as an absorbent body of an absorbent article as described above. The absorbent article typically includes a basic structure in which the absorbent body is disposed and bonded between a liquid-permeable top sheet and a liquid-impermeable back sheet. Further, another member may be combined.

As materials for the absorbent core 1 and the covering sheet 2 constituting the absorbent body 10, those used for this type of article can be used without particular limitation.
For example, as the fiber material constituting the absorbent core 1, pulp fibers such as defibrated pulp, short fibers of cellulosic fibers such as 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. Further, as described above, a water-absorbing polymer may be introduced into the duct 4 as a raw material for the absorber 3. Further, as the fiber material, a fibrous water-absorbing polymer can be used alone or in combination with the fiber material. Furthermore, a deodorant, an antibacterial agent, etc. can be supplied with a fiber material etc. as needed.
Examples of the material of the covering sheet 2 include thin paper (tissue paper) and hydrophilic nonwoven fabric.

The present invention further discloses the following method for producing an absorbent body, an absorbent body obtained by this production method, and an absorbent article using the absorbent body with respect to the above-described embodiments and embodiments.

<1> A method for producing an absorbent body, in which an absorbent core in which grooves are disposed at least in a product longitudinal direction is wrapped with a covering sheet,
An adhesive coating step of applying an adhesive to the inner surface of the covering sheet that wraps the absorbent core, and folding the covering sheet so as to overlap both sides of the covering sheet, wrapping the absorbent core, and absorbing the both sides And a packaging step of overlapping and bonding on the surface side where the groove portion of the conductive core is arranged,
In the adhesive coating step, the non-coating region from the edge to the outer end of the adhesive coating region at the side of the both sides where the edge abuts the absorbent core. The manufacturing method of the absorber which coats the adhesive while detecting the position of the edge and calculating the width of the non-coating region so that the width is kept constant.

<2> The method for producing an absorbent body according to <1>, wherein the grooves of the absorbent core are also disposed in the product width direction.
The manufacturing method of the absorber as described in said <1> or <2> which divides | segments a <3> above-mentioned covering sheet into a center part and both sides, and applies a hot-melt-type adhesive agent.
<4> The method for producing an absorbent body according to <3>, wherein the hot melt adhesive is applied in a planar or striped pattern on both side portions.
<5> The method according to <3> or <4>, wherein one side of the absorbent core is fixed with a hot-melt adhesive applied to the central portion, and the other surface is fixed with the hot-melt adhesive on both sides. Method for manufacturing the absorber.
<6> The method for producing an absorbent body according to any one of <1> to <5>, wherein the covering sheet is folded back so that the hot-melt adhesives coated on both side portions overlap each other.
<7> The width of the non-coating region from the edge of the covering sheet to the outer end of the adhesive coating region is extended from the longitudinal groove portion of the absorbent core to another adjacent longitudinal groove portion. <1> to <6> The manufacturing method of the absorber as described in any one of <6>.
<8> Any of the above <1> to <7>, which outputs a warning signal when the width of the non-coating area calculated by detecting the position of the edge of the covering sheet is outside the set range A method for producing the absorber according to claim 1.
<9><1> to <8> for controlling the traveling position of the covering sheet so that the width of the non-coating area calculated by detecting the position of the edge of the covering sheet is maintained within a set range. The manufacturing method of the absorber of any one of these.
<10> When the width of the non-coating region calculated by detecting the position of the edge of the covering sheet is outside the set range, the defective absorber is identified and excluded from <1> to <9 The manufacturing method of the absorber of any one of>.
<11> The position of the edge of the covering sheet is detected using an apparatus in which an edge detection sensor unit and an adhesive coating unit are integrated. Any one of <1> to <10> The manufacturing method of the absorber of description.

<12> The method for manufacturing an absorbent body according to <11>, wherein the edge detection sensor unit is a width sensor that detects a region having a predetermined width.
<13> In the above <11> or <12>, which determines an appropriate arrangement position of the coating head of the adhesive in a state where the edge of the covering sheet overlaps the center position of the sensor region of the edge detection sensor unit. The manufacturing method of the absorber of description.
<14> The method for manufacturing an absorbent body according to any one of <11> to <13>, wherein a control unit is connected to the edge detection sensor unit.
<15> The method for manufacturing an absorbent body according to <14>, wherein the control unit receives position information of the detected edge together with detection time information, and calculates the width of the non-coated region as needed.
<16> The method for manufacturing an absorbent body according to <15>, wherein the calculated value is stored in time series together with detection time information in the control unit.
<17> When the position information SN of the edge of the covering sheet is detected on the inner side of the center position of the sensor area of the edge detection sensor unit, the control unit receives the position information SN together with the detection time information. Then, the control unit determines the position information SN as a numerical value of the minus coordinate axis with respect to the appropriate reference position ST = 0 (zero) value, and calculates the deviation width as the minus difference “−SN” from <14> to <14> The manufacturing method of the absorber of any one of 16>.
<18> The negative difference “−SN” is added to the appropriate setting width HT of the non-coating region, and the non-coating region width H1 at the time of detection is calculated and stored as <17>. Method for manufacturing the absorber.
<19> When the position information SW of the edge of the cover sheet is detected on the outer side of the center position of the sensor area of the edge detection sensor unit, the control unit receives the position information SW together with the detection time information. Then, the position information SW is determined as a numerical value of the plus coordinate axis from the appropriate reference position ST = 0 (zero) value, and the deviation width is calculated as a plus difference “+ SW”. Any one of <14> to <16> The manufacturing method of the absorber as described in any one of.
<20> The absorbent according to <19>, wherein the plus difference “+ SW” is added to the appropriate setting width HT of the non-coating region, and is calculated and stored as the width H1 = HT + SW of the non-coating region at the time of the inspection Manufacturing method.

<21> The absorbent core according to any one of <1> to <20>, wherein the absorbent core has a first surface and a second surface, and a plurality of longitudinal grooves are formed in the first surface in a longitudinal direction. The manufacturing method of the absorber of description.
<22> The longitudinal groove portion is a recess recessed in the thickness direction from the surface of the first surface of the absorbent core 1, and does not penetrate the second surface 1B side opposite to the first surface 1A. The manufacturing method of the absorber as described in said <21>.
<23> The method for manufacturing an absorbent body according to <21> or <22>, wherein the first surface of the absorbent core is an uneven surface, and the second surface is a flat surface.
<24> The method for manufacturing an absorbent body according to <21>, wherein the longitudinal groove portion penetrates in the thickness direction from the first surface 1A to the second surface 1B.
<25> The absorbent core according to any one of <1> to <24>, wherein the absorbent core is wrapped and wrapped by a single cover sheet so that both side portions of the cover sheet overlap. Method.

<26> An absorbent body produced by the method for producing an absorbent body according to any one of <1> to <25>.
<27> An absorbent article using the absorbent body according to <26>.
<28> The absorbent body includes an absorbent core having a first surface that is an uneven surface and a second surface that is a flat surface, and the absorbent body overlaps both sides of the covering sheet. The absorbent article according to <27>, wherein the absorbent article is incorporated into the absorbent article with a surface on which the second surface of the absorbent core is disposed as a skin contact surface.
<29> The absorbent article according to <27> or <28>, wherein the absorbent article is any one of a disposable diaper, a sanitary napkin, an incontinence pad, and a panty liner.

While this invention has been described in conjunction with its embodiments, we do not intend to limit our invention in any detail of the description unless otherwise specified and are contrary to the spirit and scope of the invention as set forth in the appended claims. I think it should be interpreted widely.

This application claims priority based on Japanese Patent Application No. 2013-261863 filed in Japan on December 18, 2013, which is hereby incorporated herein by reference. Capture as part.

DESCRIPTION OF SYMBOLS 1 Absorbent core 1A 1st surface 1B 2nd surface 11 Groove part (vertical groove part)
12 Groove (Horizontal groove)
DESCRIPTION OF SYMBOLS 15 Protrusion absorption part 16 Thin skin absorption part 2

Cover sheet

21,22 Side part 23,24 (Side part)

Edge

25,26 Non-coating area | region 28 Center part 29 Lamination | stacking part 2A Inner surface 31 Edge detection sensor part 32 Sensor area | region 321 Center position 50 Coating part 60 Stacking part 70 Packaging part 80 Cutting part 201 Adhesive coating process 202 Side part coating process 203 Center part coating process 204 Stacking process 205 Packaging process 206 Cutting process ST (edge ) Appropriate reference position HT Appropriate setting width (for non-coating area)

Claims

A method for producing an absorbent body comprising at least a absorbent sheet in which grooves are arranged in the longitudinal direction of a product, which is wrapped with a covering sheet,
An adhesive application step of applying an adhesive to the inner surface of the covering sheet that encloses the absorbent core;
Wrapping the both sides of the covering sheet so as to overlap, wrapping the absorbent core, and having a packaging step of overlapping and joining the both side portions on the surface side where the groove portion of the absorbent core is disposed,
In the adhesive coating step, the non-coating region from the edge to the outer end of the adhesive coating region at the side of the both sides where the edge abuts the absorbent core. The manufacturing method of the absorber which coats the adhesive while detecting the position of the edge and calculating the width of the non-coating region so that the width is kept constant.
The method for manufacturing an absorbent body according to claim 1, wherein the groove portion of the absorbent core is also disposed in the product width direction.
The method for producing an absorbent body according to claim 1 or 2, wherein the cover sheet is coated with a hot melt adhesive in a central portion and both side portions.
The method for producing an absorbent body according to claim 3, wherein the hot melt adhesive is applied in a planar or striped pattern on both side portions.
The manufacturing method of the absorber of Claim 3 or 4 which fixes one side of an absorber core with the hot-melt-adhesive applied to the said center part, and fixes the other surface with the hot-melt-type adhesive of the said both sides. .
The method for producing an absorbent body according to any one of claims 1 to 5, wherein the covering sheet is folded back so that the hot melt adhesives coated on both sides overlap each other.
The width of the non-coating area from the edge of the covering sheet to the outer edge of the adhesive application area is within the distance from the longitudinal groove of the absorbent core to the adjacent longitudinal groove. The manufacturing method of the absorber of any one of Claim 1 to 6.
The warning signal is output according to any one of claims 1 to 7, wherein a warning signal is output when a width of the non-coating area calculated by detecting a position of the edge of the covering sheet is out of a setting range. Manufacturing method of absorber.
9. The travel position of the covering sheet is controlled so that the width of the non-coating area calculated by detecting the position of the edge of the covering sheet is maintained within a set range. The manufacturing method of the absorber of description.
The defective absorber is specified and excluded when the width of the non-coating region calculated by detecting the position of the edge of the covering sheet is outside the set range. The manufacturing method of the absorber as described in any one of.
The position of the said edge of the said coating sheet is detected using the apparatus which integrated the edge detection sensor part and the adhesive agent coating part, The absorber of any one of Claim 1 to 10 Production method.
The method for manufacturing an absorbent body according to claim 11, wherein the edge detection sensor unit is a width sensor that detects a region having a predetermined width.
The manufacture of the absorbent body according to claim 11 or 12, wherein an appropriate arrangement position of the coating head of the adhesive is determined in a state where an edge of the covering sheet overlaps a center position of a sensor region of the edge detection sensor unit. Method.
The manufacturing method of the absorber according to any one of claims 11 to 13, wherein a control unit is connected to the edge detection sensor unit.
The said control part is the manufacturing method of the absorber of Claim 14 which receives the positional information on the detected edge with detection time information, and calculates the width | variety of a non-coating area | region at any time.
The method of manufacturing an absorbent body according to claim 15, wherein the calculated value is stored in time series together with detection time information in the control unit.
When the position information SN of the edge of the covering sheet is detected on the inner side of the center position of the sensor area of the edge detection sensor unit, the control unit receives the position information SN together with detection time information, The control unit determines the position information SN as a numerical value of the minus coordinate axis from the value of the appropriate reference position ST = 0 (zero), and calculates the deviation width as a minus difference “−SN”. The manufacturing method of the absorber as described in a term.
The negative difference “−SN” is added to the appropriate setting width HT of the non-coating area, and is calculated and stored as the width H1 of the non-coating area at the time of detection = HT−SN. Production method.
When the position information SW of the edge of the covering sheet is detected on the outer side of the center position of the sensor area of the edge detection sensor unit, the control unit receives the position information SW together with the detection time information, The absorber according to any one of claims 14 to 16, wherein the information SW is determined as a numerical value of a plus coordinate axis from a value of an appropriate reference position ST = 0 (zero), and the deviation width is calculated as a plus difference "+ SW". Manufacturing method.
The method for manufacturing an absorbent body according to claim 19, wherein the plus difference "+ SW" is added to the appropriate setting width HT of the non-coating area, and is calculated and stored as the width H1 of the non-coating area at the time of the inspection = HT + SW.
The absorbent core according to any one of claims 1 to 20, wherein the absorbent core has a first surface and a second surface, and a plurality of longitudinal grooves are formed in the longitudinal direction on the first surface. Production method.
The method for manufacturing an absorbent body according to claim 21, wherein a plurality of lateral grooves are formed in the width direction on the first surface.
The said vertical groove part and the said horizontal groove part are the recessed parts depressed in the thickness direction from the surface of the 1st surface of the said absorptive core, and do not penetrate to the 2nd surface side of the surface opposite to a 1st surface. 23. A method for producing the absorber according to 22.
24. The method of manufacturing an absorbent body according to claim 23, wherein the absorbent core has a plurality of protruding absorbing portions that are surrounded by the vertical groove portion and the horizontal groove portion and protrude to the first surface side.
The method for manufacturing an absorbent body according to any one of claims 21 to 24, wherein the first surface of the absorbent core is an uneven surface and the second surface is a flat surface.
The method for manufacturing an absorbent body according to claim 21, wherein the longitudinal groove portion penetrates in the thickness direction from the first surface to the second surface.
27. The method for manufacturing an absorbent body according to any one of claims 1 to 26, wherein the absorbent core is wrapped and wrapped by a single cover sheet so that both side portions of the cover sheet overlap each other.
An absorber manufactured by the method for manufacturing an absorber according to any one of claims 1 to 27.
An absorbent article using the absorbent body according to claim 28.
The absorber includes an absorbent core having a first surface that is an uneven surface and a second surface that is a flat surface, and the absorber is a surface on which both sides of the covering sheet do not overlap. There,
The absorbent article according to claim 29, wherein the absorbent article is incorporated in the absorbent article with the surface on which the second surface of the absorbent core is disposed as a skin contact surface.
The absorbent article according to claim 29 or 30, wherein the absorbent article is any one of a disposable diaper, a sanitary napkin, an incontinence pad and a panty liner.