JP7484595B2 - Liquid application method, method for manufacturing absorbent articles using the same, and device for manufacturing absorbent articles - Google Patents

Description

The present invention relates to a liquid application method, a method for manufacturing absorbent articles using the same, and an apparatus for manufacturing absorbent articles.

Conventionally, absorbent articles such as disposable diapers, incontinence pads, and sanitary products are known. In general, absorbent articles are formed into a thin sheet-like or mat-like shape and include an absorbent body that absorbs bodily fluids discharged by the wearer. Patent Document 1 describes a method for manufacturing an absorbent article that includes an absorbent body.

JP 2019-213855 A

In the manufacturing process of absorbent articles, materials used in the absorbent body are transported by a transport device. The manufacturing process of absorbent articles may include a step of applying liquid to the materials while they are being transported by the transport device. In order to achieve the functions required for the absorbent article, it is necessary to apply liquid to the materials at a specified application width. However, no specific proposal has been made regarding the method of applying liquid.

The present invention aims to provide a technology that can apply liquid to materials at a specified application width.

In order to solve the above problem, the present invention adjusts the liquid adhesion width according to the liquid spray pressure.

In detail, the present invention is a liquid application method for applying liquid to a material made of a fibrous material that is transported in a fixed direction by a transport device by spraying the liquid from a liquid spraying device, the liquid spraying device having a nozzle for spraying the liquid, adjusting the spray pressure of the nozzle according to the transport speed of the transport device, and adjusting the application width of the liquid according to the spray pressure.

In the above liquid deposition method, the deposition width may be adjusted by the relative distance between the material and the nozzle.

In the above liquid deposition method, the deposition width may be adjusted by changing the angle of the nozzle relative to the vertical direction.

In the above liquid deposition method, the deposition width may be adjusted by the angle between the transport direction of the transport device and the horizontal direction.

In the above liquid application method, the application width may be adjusted by tilting the widthwise end of the material inward or outward of the material.

In the above liquid deposition method, the deposition width may be adjusted by spraying compressed air toward the liquid discharged from the nozzle.

In the above liquid deposition method, the deposition width may be adjusted using a control device having a spray pressure adjustment unit that adjusts the spray pressure of the nozzle according to the conveying speed of the conveying device, and a deposition width adjustment unit that adjusts the deposition width of the liquid according to the spray pressure.

The present invention can also be seen as a method for manufacturing an absorbent article. For example, the present invention may be a method for manufacturing an absorbent article, which includes a liquid application step in which liquid is applied to the material used in the absorbent article using the liquid application method described above.

The present invention can also be seen from the perspective of an absorbent article manufacturing apparatus. For example, the present invention may be an absorbent article manufacturing apparatus that includes a conveying device that conveys a material made of a fibrous material in a fixed direction, a liquid spraying device having a nozzle that sprays a liquid and sprays the liquid toward the material on the conveying device, a spray pressure adjustment unit that adjusts the spray pressure of the nozzle according to the conveying speed of the conveying device, and a deposition width adjustment unit that adjusts the deposition width of the liquid according to the spray pressure.

According to the present invention, liquid can be applied to materials at a predetermined application width.

FIG. 1 is a flow chart outlining a liquid deposition method. FIG. 2 is a diagram showing an example of an apparatus for manufacturing absorbent articles. FIG. 3 is a block diagram showing the functional parts of the control device. FIG. 4 is a diagram showing a second specific example of a liquid application method using an absorbent article manufacturing apparatus. FIG. 5A is a diagram (part 1) showing a specific example 3 of a liquid application method using an absorbent article manufacturing apparatus. FIG. 5B is a diagram (part 2) showing specific example 3 of a liquid application method using an absorbent article manufacturing apparatus. FIG. 6A is a diagram (part 1) showing a specific example 4 of a liquid application method using an absorbent article manufacturing apparatus. FIG. 6B is a diagram (part 2) showing specific example 4 of a liquid application method using an absorbent article manufacturing apparatus. FIG. 7A is a diagram (part 1) showing a specific example 5 of a liquid application method using an absorbent article manufacturing apparatus. FIG. 7B is a diagram (part 2) showing specific example 5 of a liquid application method using an absorbent article manufacturing apparatus. FIG. 8 is a perspective view of a tape-type disposable diaper. FIG. 9 is an exploded perspective view of the diaper. FIG. 10 is a cross-sectional view of the crotch region cut in the width direction.

Below, an embodiment of the present invention will be described with reference to the drawings. Note that the configurations of the following embodiments are examples, and the present invention is not limited to the configurations of these embodiments.

<Summary of liquid application method>
A material made of a fiber material is used for the absorbent body of the absorbent article. Examples of the fiber material include short fibers of cellulosic fibers such as pulp fibers, rayon fibers, or cotton fibers, and short fibers of synthetic fibers such as polyethylene, polypropylene, or polyethylene terephthalate that have been hydrophilized. The material is formed in a sheet shape and cut to a predetermined size to be used as an absorbent body. A liquid is attached to the material during transportation by a transport device before being cut. The liquid is, for example, water or a chemical solution. For example, when particles of super absorbent polymer (SAP) are spread on the material, a liquid such as water or a chemical solution is attached to the material in a step before the process of spreading the SAP particles in order to hold the SAP particles on the material. The SAP particle group is held on the material by the water attached to the material, so that the SAP particles can be arranged in an appropriate position. Furthermore, in order to improve the comfort of the absorbent article when worn, liquid medicines such as skin care agents and antibacterial agents may be attached to the material.

To achieve the required functionality in an absorbent article, liquid must be applied to the material at a specified application width. Note that the application width is the width of liquid application in the width direction perpendicular to the longitudinal direction of the material.

The liquid attachment method according to this embodiment is a method of attaching liquid to materials conveyed in a fixed direction by a conveying device by spraying the liquid from a liquid spraying device. The liquid spraying device has a nozzle that sprays liquid toward the materials being conveyed. For example, the amount of liquid attached can be adjusted by the spray pressure of the liquid from the nozzle. Specifically, the amount of attached liquid can be increased by increasing the spray pressure, and decreased by decreasing the spray pressure. However, the amount of attached liquid also changes depending on the conveying speed of the conveying device that conveys the materials. For example, when the spray pressure is constant, the amount of attached liquid per unit area decreases as the conveying speed increases, and the amount of attached liquid per unit area increases as the conveying speed decreases. For this reason, in order to keep the amount of attached liquid per unit area constant, it is necessary to adjust the spray pressure according to the conveying speed. In general, the higher the spray pressure of a nozzle, the wider the spray width of the liquid, and the lower the spray pressure, the narrower the spray width of the liquid. Therefore, adjusting the spray pressure will change the width of the attached liquid on the materials.

In addition, when the conveying speed is increased to increase the production speed of absorbent articles, the amount of liquid adhering per unit area decreases, so it is possible to increase the spray pressure to keep the amount of liquid adhering constant. However, increasing the spray pressure increases the width over which the liquid is sprayed, which increases the width over which the liquid adheres to the material. Furthermore, if the width over which the liquid is sprayed becomes too wide, there is a risk that the liquid will be sprayed outside the widthwise ends of the material.

In addition, when the conveying speed is reduced to reduce the production speed of absorbent articles, the amount of liquid attached per unit area decreases, so it is possible to increase the spray pressure to keep the amount of liquid attached constant, but when the spray pressure is reduced, the width of the liquid sprayed becomes narrower, and the width of the liquid attached to the material becomes narrower. When liquid is attached to a material to hold SAP particles on the material, if the width of the liquid attachment becomes narrower than the arrangement width of the SAP particles, the SAP particles cannot be held on the material. In addition, when a medicinal liquid such as a skin care agent or antibacterial agent is attached to the material, the medicinal liquid cannot be attached to the required area, so the effect of the medicinal liquid cannot be fully obtained. In addition, it is possible to replace the nozzle with one that can spray liquid at an appropriate attachment width depending on the conveying speed, but since the manufacturing equipment needs to be temporarily stopped when replacing the nozzle, replacing the nozzle depending on the conveying speed reduces the productivity of absorbent articles.

Therefore, in the liquid application method according to the present embodiment, the spray pressure of the nozzle is adjusted according to the conveying speed of the conveying device, and the liquid application width is adjusted according to this spray pressure. With the liquid application method according to the present embodiment, it is possible to apply liquid to the material in a predetermined application width without the need to replace the nozzle.

Figure 1 is a flow chart showing an overview of the liquid attachment method according to this embodiment. In the liquid attachment process according to this embodiment, first, the spray pressure of the nozzle is adjusted according to the conveying speed of the conveying device (step S101). Next, the liquid attachment width is adjusted according to the nozzle spray pressure (step S102). The amount of liquid sprayed from the nozzle per unit time is increased by increasing the nozzle spray pressure as the conveying speed increases, and the amount of liquid sprayed from the nozzle per unit time is decreased by decreasing the nozzle spray pressure as the conveying speed decreases, thereby keeping the amount of liquid sprayed per unit area of the material constant. In addition, increasing the nozzle spray pressure increases the liquid spray width, and decreasing the nozzle spray pressure decreases the liquid spray width. The liquid attachment method according to this embodiment can maintain the liquid attachment width on the material almost constant even if the liquid spray width changes depending on the nozzle spray pressure.

Next, the liquid attachment method according to the present embodiment will be described in more detail with reference to FIG. 2. FIG. 2 is a diagram showing an example of an absorbent article manufacturing apparatus used in the absorbent article manufacturing method using the liquid attachment method according to the present embodiment. The present manufacturing apparatus M used for manufacturing absorbent articles includes a conveying line M1 (an example of the "conveying device" in the present application), a liquid spraying device M2, and a control device M3. The conveying line M1 is a conveyor that conveys material A, which is a so-called continuous sheet, in a certain direction (the direction indicated by the arrow in the figure). The material A is made of a fibrous material, and is used as an absorbent body of an absorbent article by cutting it to a predetermined size. The liquid spraying device M2 has a nozzle 200 that sprays liquid L toward the material A, and sprays liquid L on the material A on the conveying line M1. The liquid L is attached to the material A by spraying it toward the material A. The spray pressure of the nozzle 200 is adjusted to 0.01 MPa to 0.5 MPa so that a predetermined amount of liquid is attached depending on the conveying speed.

The control device M3 is composed of a microcomputer, and realizes each function by having a CPU (Central Processing Unit) (not shown) execute programs stored in a storage means (such as a ROM (Read Only Memory), not shown). FIG. 3 is a block diagram showing the functional parts of the control device M3. The control device M3 has, as its functional parts, a spray pressure adjustment part 301 and a deposition width adjustment part 302. The spray pressure adjustment part 301 is a functional part that adjusts the spray pressure of the nozzle 200 in accordance with the conveying speed of the conveying line so that a predetermined amount of liquid is deposited on the material A. The deposition width adjustment part 302 is a functional part that adjusts the deposition width of the liquid in accordance with the spray pressure of the nozzle 200.

Next, specific examples of adjusting the adhesion width of liquid L will be described. In this embodiment, the adhesion width of liquid L is adjusted using five methods, specific examples 1 to 5.

<Specific example 1>
Specific example 1 is a method of adjusting the adhesion width by adjusting the relative distance between the material A and the nozzle 200. The liquid L is sprayed from the nozzle opening of the nozzle 200 toward the material A in a cone shape with the nozzle opening as the apex. The liquid L may be sprayed from the nozzle opening in a flat shape. Therefore, the adhesion width can be adjusted by the diameter of the bottom surface of the cone. The adhesion width of the liquid L on the material A becomes narrower as the relative distance between the material A and the nozzle 200 becomes closer, and becomes wider as the relative distance between the material A and the nozzle 200 becomes farther. Therefore, the adhesion width can be adjusted by the relative distance between the material A and the nozzle 200. The control device M3 stores the adhesion width of the liquid L based on the spray pressure of the nozzle 200 and the relative distance between the material A and the nozzle 200, and the adhesion width adjustment unit 302 adjusts this relative distance to adhere the liquid with a predetermined adhesion width. Specifically, the adhesion width adjustment unit 302 adjusts this relative distance by operating a drive mechanism that moves either the liquid spraying device M2 or the conveying line M1 in the vertical direction. The relative distance between the material A and the nozzle 200 may be adjusted by vertically moving the liquid spraying device M2 including the nozzle 200, or by vertically moving the conveying line M1. A known driving mechanism may be used.

<Specific example 2>
Specific example 2 is a method of adjusting the deposition width by the angle of the nozzle 200 with respect to the vertical direction. FIG. 4 is a diagram showing the manufacturing device M with the nozzle 200 tilted with respect to the vertical direction. Note that the control device M3 is omitted in FIG. 4. As shown in FIG. 2, when the nozzle 200 is facing vertically, the liquid L is sprayed from the nozzle mouth toward the material A in a cone shape with the nozzle mouth as the apex. When the nozzle 200 is tilted with respect to the vertical direction, the liquid L is sprayed from the nozzle mouth toward the material A in an oblique cone shape with the nozzle mouth as the apex. The larger the angle of the nozzle 200 with respect to the vertical direction, the wider the deposition width of the liquid on the material A becomes. Therefore, the deposition width can be adjusted by the angle of the nozzle 200 with respect to the vertical direction. The control device M3 stores the spray pressure of the nozzle 200 and the deposition width of the liquid L based on the angle of the nozzle 200 with respect to the vertical direction, and the deposition width adjustment unit 302 adjusts this angle in order to deposit the liquid with a predetermined deposition width. Specifically, the deposition width adjustment unit 302 adjusts this angle by operating a drive mechanism that tilts the liquid spraying device M2 including the nozzle 200 in the conveying direction shown in the drawing, or in the width direction of the material A perpendicular to the conveying direction and the vertical direction. Note that a known drive mechanism can be used.

<Specific example 3>
Specific example 3 is a method of adjusting the adhesion width by the angle between the conveying direction of the conveying line M1 and the horizontal direction. FIG. 5A is a diagram showing the manufacturing device M in a state in which the conveying direction is tilted with respect to the horizontal direction so that the downstream side in the conveying direction is higher than the upstream side in the conveying direction. FIG. 5B is a diagram showing the manufacturing device M in a state in which the conveying direction is tilted with respect to the horizontal direction so that the downstream side in the conveying direction is lower than the upstream side in the conveying direction. Note that the control device M3 is omitted in FIGS. 5A and 5B. As shown in FIG. 5A, the conveying direction is tilted with respect to the horizontal direction so that the downstream side in the conveying direction is higher than the upstream side in the conveying direction, thereby narrowing the adhesion width. On the other hand, as shown in FIG. 5B, the conveying direction is tilted with respect to the horizontal direction so that the downstream side in the conveying direction is lower than the upstream side in the conveying direction, thereby widening the adhesion width. Therefore, the adhesion width can be adjusted by the angle between the conveying direction of the conveying line M1 and the horizontal direction. The control device M3 stores the spray pressure of the nozzle 200 and the deposition width of the liquid L based on the angle between the transport direction of the transport line M1 and the horizontal direction, and the deposition width adjustment unit 302 adjusts this angle to deposit the liquid at a predetermined deposition width. Specifically, the deposition width adjustment unit 302 adjusts this angle by operating a drive mechanism that tilts the transport line M1 so that the transport direction is inclined with respect to the horizontal direction. Note that a known drive mechanism can be used.

<Specific Example 4>
Specific example 4 is a method of adjusting the attachment width by tilting the width direction end of the material A to the inside or outside of the material A. FIG. 6A is a diagram showing the manufacturing apparatus M in a state in which the width direction end of the material A is tilted to the inside of the material A when the manufacturing apparatus M is viewed from the downstream side to the upstream side. FIG. 6B is a diagram showing the manufacturing apparatus M in a state in which the width direction end of the material A is tilted to the outside of the material A when the manufacturing apparatus M is viewed from the downstream side to the upstream side. In this example, two nozzles 200 are arranged in the liquid spraying apparatus M2 so as to be aligned in the width direction of the material A. In this way, the liquid spraying apparatus M2 may have two or more nozzles 200. Note that the control device M3 is omitted in FIGS. 6A and 6B. As shown in FIG. 6A, the attachment width can be narrowed by tilting the width direction end of the material A to the inside of the material A. Also, as shown in FIG. 6B, the attachment width can be widened by tilting the width direction end of the material A to the outside of the material A. The deposition width adjustment unit 302 tilts the material A by controlling the advancement onto the conveying line M1 of guide G1, which tilts the widthwise end of material A toward the inside of material A, or guide G2, which tilts the widthwise end of material A toward the outside of material A, to adjust the deposition width of the liquid. The deposition width adjustment unit 302 adjusts the deposition width of the liquid by controlling a drive mechanism that advances guides G1 and G2 onto the conveying line M1. Note that a known drive mechanism can be used as the drive mechanism.

<Specific Example 5>
Specific example 5 is a method of adjusting the adhesion width by injecting compressed air toward the liquid L discharged from the nozzle 200. FIG. 7A is a diagram showing the manufacturing apparatus M in a state in which compressed air is injected toward the lower end of the width direction end of the liquid L so that the adhesion width of the liquid L becomes narrower when the manufacturing apparatus M is viewed from the downstream side toward the upstream side. FIG. 7B is a diagram showing the manufacturing apparatus M in a state in which compressed air is injected toward the upper end of the width direction end of the liquid L so that the adhesion width of the liquid L becomes wider when the manufacturing apparatus M is viewed from the downstream side toward the upstream side. The manufacturing apparatus M in this example is equipped with an air injection device M4 that injects compressed air. In this example, two nozzles 200 are arranged in the liquid spraying device M2 so as to be aligned in the width direction of the material A. In FIGS. 7A and 7B, the white arrows represent the flow of compressed air. As shown in FIG. 7A, the adhesion width of the liquid L can be narrowed by injecting compressed air toward the lower end of the width direction end of the liquid L. On the other hand, as shown in FIG. 7B, by injecting compressed air toward the upper end of the width direction end of the liquid L, the compressed air bounces off the liquid L and flows outward in the width direction. The rebounded compressed air causes the liquid L to flow outward in the width direction, thereby widening the adhesion width of the liquid L. The adhesion width adjustment unit 302 controls the operation of the air injection device M4 to inject compressed air toward the liquid L as shown in Figures 7A and 7B, thereby adjusting the adhesion width of the liquid L. The control device M3 stores the spray pressure of the nozzle 200 and the adhesion width of the liquid L based on the injection pressure and injection direction of the compressed air, and the adhesion width adjustment unit 302 adjusts the injection pressure and injection direction in order to adhere the liquid to a predetermined adhesion width.

By employing any one of specific examples 1 to 5, the liquid adhesion method according to this embodiment can adjust the liquid adhesion width according to the spray pressure of the liquid L, so that the liquid can be adhered to the material in a predetermined amount and width. Furthermore, the liquid adhesion method according to this embodiment can be used in a liquid adhesion process in which liquid is adhered to materials used in absorbent articles. Therefore, the liquid adhesion method according to this embodiment can be used in a method for manufacturing absorbent articles.

As an example of an absorbent article using the above manufacturing method, a tape-type disposable diaper will be described. FIG. 8 is a perspective view of a tape-type disposable diaper (hereinafter simply referred to as a "diaper") 1. In this embodiment, the direction connecting the front body arranged opposite the wearer's abdomen and the rear body arranged opposite the back of the diaper 1 is the longitudinal direction. Between the front body (one side in the longitudinal direction) and the rear body (the other side in the longitudinal direction) (the center in the longitudinal direction), the crotch part arranged under the wearer's crotch (opposed to the crotch). In addition, when the paper diaper is worn by a wearer (hereinafter abbreviated as "worn state"), the side facing the wearer's skin (the inner side when worn) is the skin-facing side, and the opposite side to the skin-facing side (the outer side when worn) is the non-skin-facing side. Furthermore, the direction connecting the skin-facing side and the non-skin-facing side is the thickness direction, and the direction perpendicular to both the longitudinal direction and the thickness direction is the width direction. In addition, the view from the thickness direction is the planar view.

The diaper 1 has a crotch region 1B that covers the wearer's genitals when worn, a front body region 1F located in front of the crotch region 1B, and a back body region 1R located behind the crotch region 1B. Tapes 2L, 2R that can be attached to a front patch 2F provided on the non-wearer side surface of the front body region 1F are provided on both the left and right edges of the back body region 1R. Thus, when the tapes 2L, 2R are attached to the front patch 2F with the front body region 1F positioned on the wearer's abdomen and the back body region 1R positioned on the wearer's back, the diaper 1 is fixed to the wearer's body in a state that surrounds the wearer's waist and thighs.

The diaper 1 has an absorbent body capable of absorbing and retaining liquid, which is mainly disposed near the crotch region 1B. The absorbent body is applied with liquid by the liquid application method described above. The diaper 1 also has three-dimensional gathers 3BL, 3BR in areas surrounding the wearer's thighs and a waist gather 3R in areas surrounding the wearer's abdominal circumference, in order to prevent the formation of gaps between the diaper 1 and the wearer's skin that can serve as a liquid outflow path. The three-dimensional gathers 3BL, 3BR and the waist gather 3R are in close contact with the wearer's skin by the elasticity of the rubber thread. Thus, liquid discharged from the wearer's pubic area is absorbed by the absorbent body of the diaper 1 without leaking out of the diaper 1.

9 is an exploded perspective view of the diaper 1. FIG. 10 is a cross-sectional view of the crotch region 1B cut in the width direction. The diaper 1 has a cover sheet 4 that forms the outer surface when worn. The cover sheet 4 is a sheet-like member having a generally rectangular appearance with constrictions 4KL and 4KR at the portions corresponding to the long sides. The constrictions 4KL and 4KR are provided at the locations where the wearer's thighs are located. The cover sheet 4 is provided to reinforce the back sheet 5 and to improve the feel. For example, a nonwoven fabric made of a liquid-impermeable thermoplastic resin can be used as the material for the cover sheet 4 in order to prevent leakage of excrement. Examples of liquid-impermeable thermoplastic resins include polyethylene (PE) and polypropylene (PP).

The diaper 1 has a back sheet 5, an absorbent 6C, and a top sheet 7, which are laminated in order on the wearer's side of the cover sheet 4. The back sheet 5, the absorbent 6C, and the top sheet 7 are all sheet-like members having a rectangular appearance, and are laminated in order on the cover sheet 4 with their longitudinal direction coinciding with the longitudinal direction of the cover sheet 4. The back sheet 5, like the cover sheet 4, is a sheet formed of a liquid-impermeable thermoplastic resin material to suppress leakage of excrement. The top sheet 7 is a sheet-like member that is placed on the wearer's skin side so as to cover the water-absorbing surface of the absorbent 6C. This top sheet 7 is liquid-permeable in part or in its entirety. Therefore, when the diaper 1 is worn, liquid excreted from the wearer passes through the top sheet 7, which may come into contact with the wearer's skin, and enters the absorbent 6C, where it is absorbed. For example, woven fabric, nonwoven fabric, and porous film can be used as the material for the top sheet 7. Furthermore, the top sheet 7 may also be hydrophilic.

When the wearer's genitals are covered with the cover sheet 4, which is made up of the back sheet 5, absorbent body 6C, and top sheet 7 laminated together, the longitudinal ends of the back sheet 5, absorbent body 6C, and top sheet 7 are positioned on the wearer's ventral and dorsal sides. In other words, the wearer's genitals are covered by the absorbent body 6C from the wearer's ventral to dorsal sides. Therefore, whether the wearer is in a ventral or dorsal position when excreting liquid, the excreted liquid comes into contact with the absorbent body 6C via the top sheet 7.

The diaper 1 also has long, strip-like side sheets 8L, 8R for forming the above-mentioned three-dimensional gathers 3BL, 3BR. The side sheets 8L, 8R are provided on the long sides of the top sheet 7. The side sheets 8L, 8R have constrictions 8KL, 8KR at the locations where the wearer's thighs are located, similar to the three-dimensional gathers 3BL, 3BR of the diaper 1. The constrictions 8KL, 8KR have rubber threads 8EL, 8ER arranged along the longitudinal direction. Therefore, when the diaper 1 is worn, i.e., when the diaper 1 is U-shaped in side view, the constrictions 8KL, 8KR are pulled in the longitudinal direction by the contraction force of the rubber threads 8EL, 8ER and rise from the top sheet 7, forming three-dimensional gathers that prevent liquid from leaking out.

The rubber thread 9ER for forming the waist gather 3R is provided between the back sheet 5 and the top sheet 7 at a position further back than the end of the absorbent body 6C. The rubber thread 9ER is provided between the back sheet 5 and the top sheet 7 with its longitudinal direction, which is the stretch direction, oriented in the left-right direction of the diaper 1. Thus, when the tapes 2L, 2R provided on both sides of the rubber thread 9ER are attached to the front patch 2F on the wearer's abdominal side, the rubber thread 9ER exerts a contractile force to bring the diaper 1 into close contact with the wearer and prevent the formation of a gap between the diaper 1 and the wearer's abdominal circumference. Rubber threads 9SL, 9SR for preventing the formation of a gap between the diaper 1 and the wearer's abdominal circumference are also provided on both sides of the absorbent body 6C.

The absorbent 6C has a structure in which granular absorbent resin such as SAP, a hydrophilic polymer with a cross-linked structure capable of absorbing and retaining water, is held in the gaps between short fibers of cellulosic fibers such as pulp fibers, rayon fibers, or cotton fibers, or short fibers that have been hydrophilically treated synthetic fibers such as polyethylene, polypropylene, or polyethylene terephthalate.

In the diaper 1 configured in this manner, when liquid is excreted from the wearer, the excreted liquid comes into contact with the absorbent body 6C via the top sheet 7. As a result, the absorbent body 6C absorbs the liquid excreted from the wearer and effectively prevents the liquid from leaking out of the diaper 1 to the outside.

In the manufacturing process of such a diaper 1, for example, the liquid application method described above can be used. For example, in the process of creating the absorbent body 6C, the liquid application method described above can be used on the material for the absorbent body 6C. According to the manufacturing method of the diaper 1 using the liquid application method described above, liquid can be applied to the material for the absorbent body 6C in a predetermined amount and width.

<Other embodiments>
Although the above-mentioned embodiments of the present invention have been described, the above-mentioned various embodiments can be combined as much as possible. In the above-mentioned embodiment, the control device M3 adjusts the spray pressure of the nozzle 200 according to the conveying speed of the conveying line, and adjusts the liquid adhesion width according to the spray pressure of the nozzle 200, but the present invention is not limited to this. For example, a factory worker may adjust the spray pressure of the nozzle 200 according to the conveying speed of the conveying line, and adjust the liquid adhesion width according to the spray pressure of the nozzle 200 by the methods of specific examples 1 to 5. In addition, the absorbent 6C of the diaper 1 manufactured using the above-mentioned manufacturing method may have a structure in which two absorbent cores made of a fiber material are laminated. In this case, SAP particles may be sprinkled on the lower absorbent core. By attaching a liquid such as water to the material for the lower absorbent core, the SAP particles can be held on the material.

1... Diaper 1B... Crotch region 1F... Front body region 1R... Back body region 2F... Front patch 2L, 2R... Tape 3BL, 3BR... Three-dimensional gathers 3R... Waist gathers 4... Cover sheet 4KL, 4KR... Constriction 5... Back sheet 6C... Absorbent body 7... Top sheet 8L, 8R... Side sheet 8KL, 8KR... Constriction 4C, 4SL, 4SR, 8EL, 8ER, 9ER... Elastic thread M... Manufacturing device M1... Conveyor line M2... Liquid spraying device M3... Control device M4... Air injection device 200... Nozzle 301... Spray pressure adjustment section 302... Adhesion width adjustment section A... Material L... Liquid

Claims (9)

1. A liquid application method for applying liquid to a material made of a fibrous material transported in a fixed direction by a transport device by spraying the liquid from a liquid spraying device, the method comprising:
The liquid spraying device has a nozzle for spraying the liquid,
adjusting the spray pressure of the nozzle in accordance with a conveying speed of the conveying device;
adjusting a deposition width of the liquid in response to the spray pressure;
A liquid deposition method comprising: The deposition width is adjusted by the relative distance between the material and the nozzle.
The liquid deposition method according to claim 1 . The deposition width is adjusted by adjusting the angle of the nozzle relative to the vertical direction.
The liquid deposition method according to claim 1 . The deposition width is adjusted by adjusting an angle between the conveying direction of the conveying device and the horizontal direction.
The liquid deposition method according to claim 1 . The attachment width is adjusted by tilting the width direction end of the material inward or outward.
The liquid deposition method according to claim 1 . adjusting the deposition width by jetting compressed air toward the liquid discharged from the nozzle;
The liquid deposition method according to claim 1 . adjusting the deposition width using a control device having a spray pressure adjusting unit that adjusts the spray pressure of the nozzle in accordance with the conveying speed of the conveying device, and a deposition width adjusting unit that adjusts the deposition width of the liquid in accordance with the spray pressure;
A liquid deposition method according to any one of claims 1 to 6. The method includes a liquid applying step of applying a liquid to the material to be used in the absorbent article by using the liquid applying method according to any one of claims 1 to 7.
A method for manufacturing an absorbent article. A conveying device that conveys a material made of a fibrous material in a fixed direction;
a liquid spraying device having a nozzle for spraying a liquid and spraying the liquid toward the material on the conveying device;
a spray pressure adjusting unit that adjusts the spray pressure of the nozzle in accordance with a conveying speed of the conveying device;
a deposition width adjustment unit that adjusts a deposition width of the liquid in response to the spray pressure;
An apparatus for manufacturing absorbent articles comprising:

Images