CN216535790U

CN216535790U - Absorbent article manufacturing apparatus

Info

Publication number: CN216535790U
Application number: CN202122037598.XU
Authority: CN
Inventors: 木村笙子; 田代和泉; 吉田英聪; 丹下雄贵
Original assignee: Oji Holdings Corp
Current assignee: Oji Holdings Corp
Priority date: 2020-08-31
Filing date: 2021-08-27
Publication date: 2022-05-17
Anticipated expiration: 2031-08-27
Also published as: CN114099144A; CN114099144B

Abstract

The present invention relates to an apparatus for manufacturing an absorbent article. An absorbent article (1) comprises: an absorber (6C); and a1 st sheet which is laminated on the skin-facing surface side of the absorbent body (6C) and is composed of a nonwoven fabric comprising fibers of a thermoplastic resin. The manufacturing device is provided with a recess forming part, the recess forming part is configured to press the absorbent body (6C) and the 1 st sheet from the 1 st sheet side by using a pressing roller (R1) in a state that the absorbent body (6C) and the 1 st sheet are laminated, a recess (20) is formed on the absorbent body (6C) and the 1 st sheet, the recess forming part (M) is configured that the temperature of the pressing roller (R1) is set to be higher than the heat-resistant temperature of the thermoplastic resin, the thickness of the 1 st sheet after passing through the recess forming part (M) is more than 2.1mm, and the gram weight is 20g/M²The thickness of the fiber is 2.0dtex or more.

Description

Absorbent article manufacturing apparatus

Technical Field

The present invention relates to an apparatus for manufacturing an absorbent article.

Background

As an absorbent article that absorbs liquid such as urine and body fluid, an absorbent article is known in which a compressed groove is provided in an absorber and a top sheet covering the skin-facing surface side of the absorber (for example, japanese patent application laid-open No. 2019-103782).

SUMMERY OF THE UTILITY MODEL

In an absorbent article, the top sheet is formed to have a high basis weight (weight per unit area) and a large volume, so that the feel of the skin to the wearer can be improved. However, if the top sheet is formed to be high in cost and large in volume, the fixing property of the concave portions such as the compressed grooves formed in the absorbent body and the top sheet is lowered.

The present invention provides a technique for improving the fixing property of a concave portion formed in an absorbent article.

In order to solve the above problem, the present invention provides a concave portion forming step of setting the temperature of the press roll to be higher than the heat-resistant temperature of the thermoplastic resin contained in the 1 st sheet.

The utility model according to claim 1 is a method for manufacturing an absorbent article. The absorbent article includes: an absorbent body; and a1 st sheet which is laminated on the skin-facing surface side of the absorbent body and is composed of a nonwoven fabric comprising fibers of a thermoplastic resin. The manufacturing method comprises the following steps: in the recess forming step, the absorbent body and the 1 st sheet are pressed from the 1 st sheet side with a pressing roll in a state where the absorbent body and the 1 st sheet are laminated, and recesses are formed in the absorbent body and the 1 st sheet. In the recess forming step, the temperature of the press roller is set to be higher than the heat-resistant temperature of the thermoplastic resin. The thickness of the 1 st sheet after the recess forming step is 2.1mm or more, and the grammage is 20g/m²Of the above, the fibersThe thickness is more than 2.0 dtex.

In the method of manufacturing the absorbent article, the depth of the concave portion may be 1.3mm or more and the width may be 2.0mm or less.

In the method of manufacturing the absorbent article, in the concave portion forming step, the temperature of the press roller may be set to be lower than the melting point of the thermoplastic resin.

In the method of manufacturing the absorbent article, in the depressed portion forming step, the depressed portion may be formed by the absorbent body and the 1 st sheet passing between the press roll and an anvil roll provided at a position facing the press roll.

In the method of manufacturing the absorbent article, a temperature of the anvil roll may be set to a temperature lower than the temperature of the press roll.

In the method for producing the absorbent article, the 1 st sheet may be at least one of a top sheet covering the skin-facing surface side of the absorbent body and a core wrap sheet covering the absorbent body on the skin-facing surface side.

In the method of manufacturing the absorbent article, the concave portion may have a component in a longitudinal direction of the absorbent body.

In the method of manufacturing the absorbent article, the 1 st sheet may be formed to contain 2 types of fibers of the thermoplastic resin. In the concave portion forming step, the temperature of the press roll may be set to be higher than the lower heat-resistant temperature of the 2 kinds of thermoplastic resins and lower than the higher heat-resistant temperature of the 2 kinds of thermoplastic resins.

The utility model according to claim 2 is an absorbent article manufacturing apparatus. The absorbent article includes: an absorbent body; and a1 st sheet which is laminated on the skin-facing surface side of the absorbent body and is composed of a nonwoven fabric comprising fibers of a thermoplastic resin. The manufacturing apparatus includes a concave portion forming portion configured to form a concave portion from the 1 st sheet in a state where the absorbent body and the 1 st sheet are stackedThe absorbent body and the 1 st sheet are pressed by a press roll, and a concave portion is formed in the absorbent body and the 1 st sheet. The concave portion forming portion is configured such that the temperature of the press roller is set higher than the heat-resistant temperature of the thermoplastic resin. The thickness of the 1 st sheet after passing through the recess-forming part is 2.1mm or more, and the grammage is 20g/m²The thickness of the fiber is 2.0dtex or more.

According to the present invention, the fixability of the concave portion formed in the absorbent article can be improved.

Drawings

Features, advantages and technical and industrial significance of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings, in which like reference numerals represent like elements.

Fig. 1 is a perspective view of a diaper of an embodiment.

Fig. 2 is an exploded perspective view of the diaper of the embodiment.

Fig. 3 is a plan view of the extended diaper of the embodiment as viewed from the skin surface side.

Fig. 4 is a cross-sectional view of the diaper in the non-worn state of the embodiment taken along the width direction.

Fig. 5 is a flowchart associated with a method of manufacturing a diaper of an embodiment.

Fig. 6 is a perspective view of a recess forming device used in the method of manufacturing a diaper according to the embodiment.

Fig. 7 is a graph (1) showing the air flow resistance of the diaper manufactured by the method for manufacturing a diaper according to the embodiment.

Fig. 8 is a graph (2) showing the air flow resistance of the diaper manufactured by the method for manufacturing a diaper according to the embodiment.

Fig. 9 is a table showing the results of evaluating the liquid permeability of the topsheet of the diaper.

Fig. 10 is a table showing sensory test results of diapers.

Fig. 11 is a table showing the relationship between the depth and width of the recess of the diaper and the ventilation resistance.

Fig. 12 is a table showing the results of evaluating the liquid permeability of the topsheet of the diaper after absorption of urine.

Fig. 13 is a table showing sensory test results of diapers after urine absorption.

Fig. 14 is a table showing the relationship between the depth and width of the recess of the diaper and the ventilation resistance after urine absorption.

Fig. 15 is a cross-sectional view of a diaper in a non-worn state of a modification cut along the width direction.

Detailed Description

Hereinafter, an absorbent article according to an embodiment of the present invention will be described with reference to the drawings. The configurations of the following embodiments are examples, and the present invention is not limited to the configurations of these embodiments.

< embodiment >

In the present embodiment, a tape-type disposable diaper (which is an example of an "absorbent article" referred to in the present application and will be hereinafter simply referred to as "diaper") has a longitudinal direction defined as a direction connecting a front body disposed to face an abdomen of a wearer and a back body disposed to face a back of the wearer. The crotch portion disposed in the crotch (disposed opposite to the crotch) of the wearer is located 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). In a state where the diaper is worn on a wearer (hereinafter simply referred to as a "worn state"), one side facing the skin of the wearer (the inner side in the worn state) is referred to as a skin surface side, and the opposite side to the skin surface side (the outer side in the worn state) is referred to as a non-skin surface side. The direction connecting the skin surface side and the non-skin surface side is defined as the thickness direction, and the direction perpendicular to both the longitudinal direction and the thickness direction is defined as the width direction. In addition, the thickness direction is referred to as a plan view.

Fig. 1 is a perspective view of a diaper of the present embodiment. The diaper 1 has a crotch region 1B which is a portion corresponding to the crotch of a wearer and covers the pudendum of the wearer in a worn state, a front body region 1F which is a portion corresponding to the front body of the wearer and located on the front side of the crotch region 1B, and a rear body region 1R which is a portion corresponding to the rear body of the wearer and located on the rear side of the crotch region 1B. The left and right edges of the back region 1R are provided with

tapes

2L, 2R that can be applied (stuck) to the front patch 2F provided on the non-wearer side surface of the front region 1F. When the

tapes

2L and 2R are attached to the front patch 2F in a state where the front body region 1F is disposed on the abdominal side of the wearer and the rear body region 1R is disposed on the back side of the wearer, the diaper 1 is fixed to the body of the wearer in a state of surrounding the abdominal circumference and the thighs of the wearer. Since the diaper 1 is fixed to the body of the wearer in this manner, the wearer can walk while standing with the diaper 1.

In the diaper 1, an absorber capable of absorbing and retaining liquid is disposed mainly around the crotch region 1B. In the diaper 1, in order to suppress formation of a gap which becomes an outflow path of liquid between the diaper 1 and the skin of the wearer, the leg gathers 3AL, 3AR are provided at a portion surrounding the leg hole (thigh) of the wearer, the three-dimensional gathers 3BL, 3BR are provided at the inner side in the width direction of the diaper 1 than the leg gathers 3AL, 3AR, and the waist gather 3R is provided at a portion surrounding the abdominal hole of the wearer. The leg gathers 3AL, 3AR, the three-dimensional gathers 3BL, 3BR, and the waist gather 3R are brought into close contact with the skin of the wearer by the elastic force of the elastic member. Thus, the liquid discharged from the pudendal region of the wearer is absorbed by the absorbent body of the diaper 1 without leaking from the diaper 1. Further, as the elastic member, linear or belt-like rubber can be appropriately selected.

Fig. 2 is an exploded perspective view of the diaper 1. The diaper 1 has a cover sheet 4 which forms an outer surface in a worn state. The cover sheet 4 is a sheet-like member having a substantially rectangular appearance and provided with narrowed portions 4KL and 4KR at positions corresponding to the long sides, and forms the exterior surface of the diaper 1. The narrowed portions 4KL and 4KR are provided at the positions of the thighs of the wearer. The cover sheet 4 is provided for reinforcement of the back sheet 5 described later and/or improvement of texture, and for example, a liquid impermeable nonwoven fabric made of a thermoplastic resin can be used as a material thereof in order to suppress leakage of excrement. Examples of the thermoplastic resin include Polyethylene (PE), polypropylene (PP), and the like. The cover sheet 4 is not limited to a single-layer structure, and may have a multilayer structure including an inner cover sheet and an outer cover sheet.

The diaper 1 further includes a back sheet 5, an absorbent body 6C, and a top sheet 7 (an example of "1 st sheet" in the present application) laminated in this order on the wearer-side surface of the cover sheet 4. The back sheet 5, the absorber 6C, and the top sheet 7 are sheet-like members each having a substantially rectangular appearance, and are sequentially stacked on the cover sheet 4 in a state where the longitudinal direction coincides with the longitudinal direction of the cover sheet 4. The back sheet 5 is a sheet made of a liquid impermeable thermoplastic resin for suppressing leakage of excrement, similarly to the cover sheet 4. The back sheet 5 is preferably made of a material having moisture permeability in order to suppress the damp feeling in the worn state. The top sheet 7 is made of a breathable nonwoven fabric formed of fibers made of a thermoplastic resin and arranged on the skin surface side of the wearer so as to cover the water absorption surface of the absorbent body 6C. The topsheet 7 has liquid permeability in a part or all thereof. Therefore, in the state where the diaper 1 is worn, the liquid excreted from the wearer passes through the top sheet 7 contactable with the skin of the wearer, enters the absorber 6C, and is absorbed therein. Further, the top sheet 7 may have hydrophilicity. The longitudinal direction of the diaper 1 is the same as the longitudinal direction of the absorbent body 6C and the top sheet 7.

The backsheet 5, the absorbent body 6C, and the topsheet 7 extend from the front body region 1F to the back body region 1R. Thus, when the private parts of the wearer are covered with the cover sheet 4 in which the back sheet 5, the absorbent body 6C, and the top sheet 7 are laminated, both longitudinal ends of the back sheet 5, the absorbent body 6C, and the top sheet 7 are positioned on the ventral side and the dorsal side of the wearer. That is, the wearer's pudendal region is covered with the absorbent body 6C from the abdomen side to the back side of the wearer. Therefore, regardless of which posture the wearer discharges the liquid to the outside of the body, the wearer has the abdomen facing downward or the back facing downward, the discharged liquid contacts the absorbent body 6C via the top sheet 7.

In the diaper 1, the elastic members 4SL and 4SR for forming the above-described leg gathers 3AL and 3AR are provided between the cover sheet 4 and the back sheet 5 so as to stretch and contract in the longitudinal direction of the diaper 1. The elastic members 4SL and 4SR are provided in an appropriate number (3 in the present embodiment) determined in accordance with the elastic force (contractive force) required for the design of the diaper 1 and the like.

The diaper 1 further includes elongated belt-

like side panels

8L and 8R. The

side sheets

8L and 8R are liquid-impermeable sheets provided on the long side portions of the top sheet 7. In the

side sheets

8L and 8R, similarly to the cover sheet 4, narrowed portions 8KL and 8KR are provided at the portions where the thighs of the wearer are located. Elastic members 8EL and 8ER for forming the three-dimensional gathers 3BL and 3BR are woven into the

side sheets

8L and 8R along the longitudinal direction. When the diaper 1 is in a worn state, that is, when the diaper 1 is in a U-shape in side view, the

side sheets

8L and 8R are pulled up in the longitudinal direction by the contraction force of the elastic members 8EL and 8ER and rise from the top sheet 7, and become the three-dimensional gathers 3BL and 3BR which prevent the liquid from flowing out.

In addition, in the cover sheet 4, the elastic member 4C that prevents a gap from being formed between the diaper 1 and the abdominal circumference of the wearer is provided along the longitudinal direction of the diaper 1 on the inner side in the width direction of the diaper 1 than the elastic members 4SL, 4 SR. The elastic member 4C is provided in accordance with an elastic force (contractive force) or the like required in design in the diaper 1.

Further, an elastic member 9ER for forming the waist gather 3R described above is provided between the backsheet 5 and the top sheet 7 at a position on the back side of the end of the absorbent body 6C. The elastic member 9ER is provided between the back sheet 5 and the top sheet 7 in such a direction that the longitudinal direction in the stretching direction is the lateral direction of the diaper 1. Thus, when the

belts

2L, 2R provided on both the left and right sides of the elastic member 9ER are attached to the front patch 2F on the abdominal side of the wearer, the elastic member 9ER exerts a contractive force to bring the diaper 1 into close contact with the wearer, thereby preventing a gap from being formed between the diaper 1 and the abdominal circumference of the wearer.

The Absorbent body 6C has a structure in which a particulate Absorbent resin such as SAP (Super Absorbent Polymer) which is a hydrophilic Polymer having a crosslinked structure and is capable of absorbing and retaining water is retained in gaps between short fibers of cellulose-based fibers such as pulp fibers, rayon fibers, or cotton fibers, or short fibers obtained by hydrophilization treatment of synthetic fibers such as polyethylene, polypropylene, or polyethylene terephthalate. Thus, in the absorbent body 6C, the volume change of the absorbent resin before and after the absorption of the liquid is basically performed in the short fibers holding the absorbent resin in the gaps. Therefore, if the entire absorbent body 6C is viewed in overhead, the thickness of the absorbent body 6C that has absorbed liquid does not have a higher expansion rate than the expansion rate of the absorbent resin itself.

The SAP particles of the present embodiment are obtained by granulating a resin composition containing SAP. The "resin composition containing SAP" as used herein is a concept including both a composition composed of SAP alone and a composition containing SAP as a main component and other substances therein to such an extent that the water absorption is not adversely affected. Examples of the "other substances" include additives (such as a surface modifier added for the purpose of hydrophobizing the particle surface), unreacted monomers remaining during synthesis of the SAP, and the like.

Fig. 3 is a plan view of the diaper 1 in an extended state as viewed from the skin surface side. Fig. 4 is a cross-sectional view of the diaper 1 taken along the line AA of fig. 3 in the width direction. In fig. 3 and 4, the front patch 2F, the elastic members 4C, 4SR, 4SL, 8EL, 8ER, 9ER, and the

side sheets

8L and 8R are not shown.

The diaper 1 of the present embodiment includes the concave portions 20 formed in a diagonal lattice shape with respect to the rectangular absorbent body 6C. The concave portion 20 is formed by pressing the absorbent body 6C and the top sheet 7 from the side of the top sheet 7 in a state where the top sheet 7 is laminated on the skin-facing surface side of the absorbent body 6C. Since the recesses 20 formed in a lattice shape have a component in the longitudinal direction of the absorbent body 6C, the liquid can be diffused in the longitudinal direction of the absorbent body 6C through the recesses 20. This allows the diaper 1 to diffuse a liquid such as urine discharged by the wearer into the entire absorbent body 6C along the concave portions 20, and to efficiently absorb the liquid in the entire absorbent body 6C. In the diaper 1, the absorbent body 6C can be easily folded by providing the concave portion 20 in the absorbent body 6C, and therefore, the fit feeling to the wearer can be improved.

In the diaper 1, the concave portion 20 is provided on the skin-facing surface side of the top sheet 7, whereby the air flow resistance on the surface of the top sheet 7 can be reduced. This makes it possible to facilitate the flow of air from the inside to the outside of the diaper 1, and to suppress the diaper from becoming damp when worn. The ventilation resistance of the surface of the top sheet 7 will be described in detail later.

Next, a method for manufacturing a diaper according to the present embodiment will be described. The method of manufacturing the diaper of the present embodiment is characterized in the recess forming step of forming the recesses 20 in the absorbent body 6C and the top sheet 7, and therefore the recess forming step will be described in detail below. Fig. 5 is a flowchart showing an outline of the method for manufacturing a diaper according to the present embodiment. In the method of manufacturing a diaper of the present embodiment, first, the top sheet 7 is laminated on the skin-facing surface side of the absorber 6C (step S101). The top sheet 7 is an air-permeable nonwoven fabric formed of fibers containing a thermoplastic resin. The thickness of the absorbent body 6C and the top sheet 7 before compression is, for example, 7.75 mm.

Next, the absorbent body 6C and the top sheet 7 are formed with the concave portions 20 (step S102, an example of the "concave portion forming step" in the present application). In the step of forming the concave portion 20 (step S102), the absorbent body 6C and the top sheet 7 are pressed from the side of the top sheet 7 in a state where the absorbent body 6C and the top sheet 7 are laminated. The top sheet 7 after the step of forming the recessed portion 20 has a thickness of 2.1mm or more and a grammage of 20g/m²The thickness of the fiber is 2.0dtex or more.

Fig. 6 is a perspective view of a concave portion forming device M (an example of a "concave portion forming portion" in the present application) used in the method for manufacturing a diaper according to the present embodiment. The concave portion forming device M includes a press roller R1 and an anvil roller R2 provided at a position facing the press roller R1. A gap of about 0.35mm to 0.45mm is provided between the press roll R1 and the anvil roll R2. The pressure roller R1 includes a convex portion RC that presses the absorbent body 6C and the top sheet 7. The convex portions RC are formed in a diagonal lattice shape with respect to the absorber 6C. The press roll R1 and the anvil roll R2 are made of metal such as iron. In fig. 6, the MD direction corresponds to the longitudinal direction of the absorbent body 6C and the top sheet 7, and the CD direction corresponds to the width direction of the absorbent body 6C and the top sheet 7.

The concave portion forming device M presses the continuous absorbent body 6C and the top sheet 7, which have flowed from the upstream side in the MD direction to the direction of arrow B1, from the side of the top sheet 7 by the convex portions RC by passing between the press roll R1 rotating in the direction of arrow B2 and the anvil roll R2 rotating in the direction of arrow B3. Thereby, the absorbent body 6C and the top sheet 7 are formed with the concave portions 20. The transport speed of the absorbent body 6C and the top sheet 7 to the arrow B1 is 3.5 to 4.0 m/s. The continuous absorbent body 6C and top sheet 7 are cut into lengths corresponding to1 diaper after the formation of the concave portions 20.

Here, in the step of forming the concave portion 20, the temperature of the press roll R1 is set to be higher than the heat-resistant temperature (normal heat-resistant temperature) of the thermoplastic resin used for the air-permeable nonwoven fabric of the top sheet 7. The press roller R1 is heated by a heater not shown and set to a temperature higher than the heat-resistant temperature. In the present embodiment, the nonwoven fabric of the top sheet 7 contains at least polyethylene as a thermoplastic resin. The heat-resistant temperature of the polyethylene is, for example, 70 ℃. When the top sheet 7 is heated at a temperature higher than the heat-resistant temperature of polyethylene, the fibers of polyethylene are deformed to form a half-film of the top sheet 7, so that the shape of the top sheet 7 is easily conformed to the concave portion 20 formed in the absorbent body 6C, and the fixing property of the concave portion 20 is improved.

After the pressing, the thickness of the absorbent body 6C is 2.1mm, and the thickness/gram weight of the top sheet 7 is 0.1 mm/22-40 gsm. Here, samples of diapers were prepared in which the press roll R1 was set to 60 ℃, 75 ℃, 90 ℃, 105 ℃ during pressing and the thickness/gram weight of the topsheet 7 was set to 0.1mm/25gsm, 0.1mm/28gsm, 0.1mm/30gsm, 0.1mm/35gsm, 0.1mm/40gsm, and the air flow resistance of the surface of the topsheet 7 was measured. Fig. 7 and 8 are graphs showing the air flow resistance of the surface of the top sheet 7 of each sample. The horizontal axis of fig. 7 and 8 indicates the temperature (° c) of the pressure roller R1 in the step of forming the concave portion 20, and the vertical axis of fig. 7 and 8 indicates the air flow resistance (Pa) of the surface of the top sheet 7 of each sample diaper. Fig. 7 is a graph showing the air flow resistance before the artificial urine is injected into the diaper of each sample, and fig. 8 is a graph showing the air flow resistance after the artificial urine is injected into the diaper of each sample. For artificial urine, 20g of urea, 8g of sodium chloride, 0.8g of magnesium sulfate, 7 g of water and substance, and 0.3g of calcium chloride, 2g of water and substance were dissolved in 1000mL of distilled water and prepared. In the present embodiment, a diaper for babies (size L (having the same configuration as Whito12 manufactured by prince beauve corporation except for the top sheet)) was produced as a sample. In a state where the diaper of each sample was worn on the infant dummy, 50ml of artificial urine, which is an average urine output of 1 time of the infant, was injected into the diaper at a speed of 7ml/s from the back side of the diaper at a position of 190 mm. In addition, the dummy at the time of injection faces upward. In each sample, the depth of the concave portion 20 was set to 1.3mm, and the width of the concave portion 20 was set to 2.0 mm.

Here, a method for measuring the air flow resistance on the surface of the top sheet 7 in the diaper will be described. For measurement of the ventilation resistance, a ventilation measuring device, a low-capacity compressor, a drawing board, a marker, and scissors were prepared. First, a diaper was attached to a drawing board in an extended state, and the three-dimensional gathers were cut with scissors. Next, the groove of the lattice of the diaper from which the three-dimensional gathers were cut was lightly traced with a marker. Then, marks are marked at the measurement positions in the back region 1R, the crotch region 1B, and the front region 1F of the top sheet 7 with a marker. The measurement preparation operation is completed in the above manner. The average value of the measurement results at 3 points marked with a marker is used as the measurement value of the air flow resistance.

Next, the ventilation resistance was measured by the following method. First, a low-capacity compressor and a measuring device are connected by a pipe. Next, the plug of the measuring apparatus was inserted into the socket, the power of the low-power compressor was turned on, and the air supply valve was opened. Here, the flow rate of the flow meter displayed in the low power compressor was adjusted to 8.0L/min. In addition, it was confirmed that the value of the measuring apparatus was 0.4MPa or more. Next, the center of the hole of the measuring device and the center of the measurement position marked on the diaper were aligned, and the measuring device was placed on the top sheet 7, and the pressure (Pa) indicated by the measuring device was recorded as the ventilation resistance.

The line a1 in the graph of FIG. 7 and the line b1 in the graph of FIG. 8 are obtained by connecting points showing the air flow resistance of the surface of the topsheet 7 with respect to the temperatures (60 ℃, 75 ℃, 90 ℃, 105 ℃) in the step of forming the concave portion 20 in a diaper having a thickness/gram weight of the topsheet 7 of 0.1mm/25 gsm. The line a2 in the graph of fig. 7 and the line b2 in the graph of fig. 8 are obtained by connecting points indicating the air flow resistance of the surface of the top sheet 7 with respect to each temperature in the step of forming the concave sections 20 in a diaper having the thickness/grammage of the top sheet 7 of 0.1mm/28 gsm. The line a3 in the graph of fig. 7 and the line b3 in the graph of fig. 8 are obtained by connecting points showing the air flow resistance of the surface of the top sheet 7 with respect to each temperature in the step of forming the concave portion 20 in a diaper having a thickness/grammage of 0.1mm/30gsm of the top sheet 7. The line a4 in the graph of fig. 7 and the line b4 in the graph of fig. 8 are obtained by connecting points indicating the air flow resistance of the surface of the top sheet 7 with respect to each temperature in the step of forming the concave sections 20 in a diaper having the thickness/grammage of the top sheet 7 of 0.1mm/35 gsm. The line a5 in the graph of fig. 7 and the line b5 in the graph of fig. 8 are obtained by connecting points showing the air flow resistance of the surface of the top sheet 7 with respect to each temperature in the step of forming the concave portion 20 in a diaper having a thickness/grammage of 0.1mm/40gsm of the top sheet 7. Further, point c1 in FIG. 7 and point c2 in FIG. 8 are points showing the air flow resistance of the surface of the top sheet 7 with respect to the temperature (60 ℃) in the step of forming the concave portion 20 in the diaper of the comparative example (conventional example) in which the thickness/grammage of the top sheet 7 is set to 0.1mm/22 gsm.

As shown by lines a 1-a 5 of the graph of fig. 7, it was found that: when the temperature of the pressure roller R1 in the step of forming the concave portion 20 is set to 75 ℃ or higher, the air flow resistance decreases. This is because setting the temperature of the pressure roll R1 to 75 ℃ or higher deforms the fibers of the polyethylene contained in the top sheet 7, thereby making the top sheet 7 into a semi-film and improving the fixing property of the concave portions 20. The higher the fixability of the concave portion 20, the more the compressed air delivered from the low-capacity compressor passes through the concave portion 20, so that the pressure indicated by the measuring device, that is, the ventilation resistance of the surface of the top sheet 7 can be made smaller.

As shown by lines b1 to b5 in the graph of fig. 8, the following were found: by setting the temperature of the pressure roller R1 at 75 ℃ or higher in the step of forming the concave portion 20, the ventilation resistance decreases even after the diaper absorbs 1 time of urine. This is because a part of the concave portion 20 is maintained even after the absorbent body 6C absorbs urine and swells. More specifically, this is because: even if the bottom of the concave portion 20 is lifted up by the expansion of the absorbent body 6C, the concave portion 20 of the top sheet 7 is partially formed into a half film and deformed, so that the concave portion 20 can be maintained in the top sheet 7. Since the concave portion 20 is maintained in the top sheet 7 even after the absorbent body 6C absorbs urine, compressed air sent from a low-capacity compressor can be passed through the concave portion 20, and the air flow resistance on the surface of the top sheet 7 can be reduced.

As described above, in the method of manufacturing a diaper according to the present embodiment, by setting the temperature of the pressure roller R1 to be higher than the heat-resistant temperature of the thermoplastic resin contained in the top sheet 7 in the step of forming the concave portion 20, the top sheet 7 can be made into a semi-film, and the fixability of the concave portion 20 can be improved. The top sheet 7 has a thickness of 2.1mm or more and a grammage of 20g/m²The thickness of the fiber is 2.0dtex or more. According to the diaper manufactured by the method of manufacturing a diaper of the present embodiment, even when a bulky nonwoven fabric having a large size is used for the top sheet 7, the air flow resistance on the surface of the top sheet 7 can be reduced as compared with the conventional example. The diaper manufactured by the method for manufacturing a diaper according to the present embodiment can reduce the air flow resistance on the surface of the top sheet 7 and suppress the feeling of stuffiness in the worn state.

In the step of forming the concave portion 20, the temperature of the pressure roll R1 is set to be lower than the melting point of the polyethylene contained in the top sheet 7. If the temperature of the pressure roll R1 is set to be higher than the melting point of polyethylene, the depressed portion 20 forming portion of the top sheet 7 becomes a film, and it becomes difficult for liquid to pass through from the depressed portion 20 to the absorbent body 6C. Therefore, in order to allow the liquid to pass in the direction of the absorbent body 6C and to absorb the liquid into the absorbent body 6C also at the formation portion of the concave portion 20 of the top sheet 7, it is desirable that the formation portion of the concave portion 20 of the top sheet 7 is not formed into a film. The melting point of the low-density polyethylene is 95 to 130 ℃ and the melting point of the high-density polyethylene is 120 to 140 ℃. In the present embodiment, the temperature of the press roll R1 is preferably set to 130 ℃.

Here, the spreading of urine in the case where the top sheet 7 at the formation portion of the concave portion 20 was made into a non-film, semi-film, or film was examined. In the step of forming the concave portion 20, the top sheet 7 is not made into a film by setting the temperature of the pressure roller R1 to be lower than the heat-resistant temperature of the thermoplastic resin contained in the top sheet 7, is made into a semi-film by setting the temperature of the pressure roller R1 to be equal to or higher than the heat-resistant temperature of the thermoplastic resin and lower than the melting point of the thermoplastic resin, and is made into a film by setting the temperature of the pressure roller R1 to be equal to or higher than the melting point of the thermoplastic resin. In addition, a breathable nonwoven fabric including fibers of polyethylene having a heat-resistant temperature of 70 ℃ and a melting point of 130 ℃ was used for the top sheet of the diaper of the sample produced in this verification. In the step of forming the concave portion 20 in the sample preparation of this test, the temperature of the pressure roller R1 was set to 60 ℃, 90 ℃, and 140 ℃.

In this test, a diaper for infants (for example, size L (the same as described above)) was also produced as a sample. In a state where the diaper of each sample was worn on the infant dummy, 50ml of artificial urine, which is an average urine output of 1 time of the infant, was injected into the diaper at a speed of 7ml/s from the back side of the diaper at a position of 190 mm. The artificial urine is the same as the above-described artificial urine. In addition, the dummy at the time of injection faces upward. In each sample, the depth of the concave portion 20 was set to 1.3mm, and the width of the concave portion 20 was set to 2.0 mm.

Fig. 9 is a table showing the present verification result. The longer the artificial urine arrival position (mm) from the injection position toward the front body region side/the back body region side, the lower the liquid permeability of the top sheet 7. As shown in fig. 9, it was confirmed that: when the concave portion 20 of the top sheet 7 is partially formed into a film, the liquid permeability of the top sheet 7 is lowered. In the diaper manufactured by the method for manufacturing a diaper according to the present embodiment, the concave portion 20 forming portion of the top sheet 7 is formed into a half film. This diaper can ensure the required liquid permeability of the top sheet 7 while improving the fixing property of the concave portions 20.

Next, the feeling of the skin of the top sheet 7 when the top sheet 7 was formed into a non-film, semi-film, or film at the formation portion of the concave portion 20 was confirmed by a sensory test (the subject 18). Fig. 10 is a table showing the results of the sensory test. In the sample used in the sensory test results, the depth of the concave portion 20 was set to 1.3mm, and the width of the concave portion 20 was set to 2.0 mm. In the table of fig. 10, "n is the number of people who answer that the skin feel is bad. The diaper of the sample in which the concave portion 20 of the top sheet 7 was partially semifilmed was provided with good wearing feeling by the sensory test. The diaper manufactured by the method for manufacturing a diaper of the present embodiment can provide a good wearing feeling.

Next, 9 kinds of diaper samples were produced in which the depth of the concave portion 20 was 1.2mm, 1.3mm, and 1.4mm, and the width of the concave portion was 1.9mm, 2.0mm, and 2.1mm, and the air flow resistance of the top sheet surface of each sample was measured. Fig. 11 is a table showing the measurement results. From the measurement results, it was found that: the recess 20 is preferably formed to have a depth of 1.3mm or more and a width of 2.0mm or less. This can reduce the ventilation resistance to 250Pa or less. The concave portion 20 having such a depth and width can maintain its shape even after the absorbent body 6C absorbs urine by sufficiently deforming the top sheet 7.

Next, the diaper after absorbing urine was verified in the same manner as in fig. 9 to 11, and the urine diffusibility, sensory test, and ventilation resistance were verified. The conditions and methods other than using the diaper after absorbing urine are the same as those for verifying the results shown in fig. 9 to 11.

First, the diaper of each sample was previously filled with 50ml of artificial urine, which is an average urine output of 1 time of the infant. The artificial urine used in this verification was the same as the artificial urine described above. The diaper of each sample was set in a state of being inclined by 60 degrees in the longitudinal direction so that the front body region 1F was upward and the back body region 1R was downward. Then, 50ml of artificial urine was injected from a burette at a rate of 15ml/sec to the urination position of the diaper in a worn state.

Fig. 12 is a table showing the present verification result. The longer the artificial urine arrival position (mm) from the injection position toward the front body region side/the back body region side, the lower the liquid permeability of the top sheet 7. As shown in fig. 12, it was confirmed that: when the concave portion 20 of the top sheet 7 is partially formed into a film, the liquid permeability of the top sheet 7 is lowered. In the diaper manufactured by the method for manufacturing a diaper according to the present embodiment, the concave portion 20 forming portion of the top sheet 7 is formed into a half film. This diaper can ensure the liquid permeability of the top sheet 7 as required even after the 1 st urine absorption while improving the fixability of the concave portion 20.

Next, the feeling of the skin of the top sheet 7 when the top sheet 7 was formed into a non-film, semi-film, or film at the formation portion of the concave portion 20 was confirmed by a sensory test (the subject 18). Fig. 13 is a table showing the results of the sensory test. In the sample used in the sensory test results, the depth of the concave portion 20 before urine absorption was set to 1.3mm, and the width of the concave portion 20 was set to 2.0 mm. In the table of fig. 13, "n is the number of people who answer that the skin feel is bad. The diaper of the sample in which the concave portion 20 of the top sheet 7 was partially semifilmed was provided with good wearing feeling by the sensory test. The diaper manufactured by the method for manufacturing a diaper according to the present embodiment can provide a good wearing feeling even after the 1 st urine absorption.

Next, 9 kinds of diaper samples were produced in which the depth of the concave portion 20 before urine absorption was 1.2mm, 1.3mm, and 1.4mm, and the width of the concave portion was 1.9mm, 2.0mm, and 2.1mm, and the air flow resistance of the top sheet surface of each sample was measured. Fig. 14 is a table showing the measurement results. From the measurement results, it was found that: the recess 20 is preferably formed to have a depth of 1.3mm or more and a width of 2.0mm or less. This makes it possible to reduce the ventilation resistance of the top sheet surface to 240Pa or less even after the 1 st urine absorption.

As described above, according to the diaper 1 of the present embodiment, the top sheet 7 is formed into a half-film, so that the nonwoven fabric of the top sheet 7 is shaped, and the wearing feeling and the air permeability are good even after urine absorption.

Further, the absorbent body 6C and the top sheet 7 pass between the press roll R1 and the anvil roll R2, thereby forming the concave portions 20. Further, the anvil roll R2 is set to a lower temperature than the press roll R1. The anvil roll R2 may or may not be heated. Thus, the temperature setting of the anvil roll R2 is suitable for half-filming only the topsheet. In the case of extrusion processing of a sheet not in contact with the press roll R1 (for example, a core wrap sheet, a second sheet of a lower layer in the case where the top sheet 7 is doubled), the temperature of the anvil roll R2 is preferably set to be higher than the heat-resistant temperature of a thermoplastic resin (for example, polyethylene) contained in the sheet and lower than the melting point of the thermoplastic resin in order to deform the sheet at a heat-resistant temperature or higher. Thus, the top sheet 7 can be heated to a temperature higher than the heat-resistant temperature of polyethylene and lower than the melting point of polyethylene by the anvil roll R2.

The top sheet 7 may be formed of 2 kinds of fibers of thermoplastic resin. In this case, in the step of forming the concave portion 20, the temperature of the pressure roller R1 is preferably set to be higher than the lower heat-resistant temperature of the 2 kinds of thermoplastic resins and lower than the higher heat-resistant temperature of the 2 kinds of thermoplastic resins. This makes it possible to prevent the recessed portion 20-formed portion of the top sheet 7 from becoming too hard and to maintain the liquid permeability at the recessed portion 20-formed portion by forming the fibers of at least one thermoplastic resin contained in the top sheet 7 into a half film and not forming the fibers of another thermoplastic resin contained in the top sheet 7 into a half film. For example, the top sheet 7 may contain polyethylene and polyethylene terephthalate (PET) as fibers of a thermoplastic resin. The heat-resistant temperature of PET is higher than that of polyethylene, and is about 200 ℃. In addition, short fibers are easier to bend than long fibers (more distinct folds appear when the fibers are bent at the bending position between the fibers than when the fibers are bent halfway).

< modification example >

Next, a method for manufacturing a diaper according to a modification of the present embodiment will be described. Fig. 15 is a cross-sectional view in the width direction similar to fig. 4 of a diaper 1 produced by the method for producing a diaper according to the present modification. In the present modification, the step of forming the concave portions 20 is performed in a state where the core-covering sheet 10 (an example of the "1 st sheet" referred to in the present application) is laminated between the absorbent body 6C and the top sheet 7. In the present modification, a breathable nonwoven fabric formed of fibers containing a thermoplastic resin is used for the core-covering sheet 10. As the thermoplastic resin, polyethylene, PET, or the like is used as in the top sheet 7. Further, the basis weight of the core wrap sheet was 8 gsm.

The core wrap sheet 10 is a sheet that wraps the entire absorbent body 6C, and a portion disposed on the skin-facing surface side of the absorbent body 6C is laminated on the absorbent body 6C. In the present modification, the step of forming the concave portion 20 is performed in a state where the core wrap sheet 10 is laminated on the skin-facing surface side of the absorber 6C and the top sheet 7 is disposed so as to cover the skin-facing surface side of the core wrap sheet 10. This partially forms a half-film of the recess 20 of the core-wrapping sheet 10, and deforms along the recess 20, thereby improving the fixing property of the recess 20. Thus, the diaper manufactured by the method of manufacturing a diaper according to the present modification can reduce the air flow resistance on the skin-facing surface side of the absorber 6C, that is, on the top sheet 7 surface side, and suppress the feeling of stuffiness in the worn state. The core wrap sheet has a thickness of 2.1mm or more and a grammage of 20g/m²The thickness of the fiber is 2.0dtex or more.

< other embodiment >

Next, other embodiments will be described. The diaper 1 of the above embodiment is a belt-type diaper, but the method and apparatus for manufacturing an absorbent article of the present invention can be applied to the manufacture of a pants-type diaper.

In the above embodiment, the top sheet may be formed of 2 sheets of nonwoven fabric, and 1 sheet of the nonwoven fabric may be a breathable nonwoven fabric formed of fibers containing a thermoplastic resin. According to this configuration, the air-permeable nonwoven fabric formed of fibers containing a thermoplastic resin is formed into a half-film in the step of forming the recessed portion 20, and the fixing property of the recessed portion 20 can be improved.

Claims

1. An apparatus for manufacturing an absorbent article (1), the absorbent article (1) comprising: an absorber (6C); and a1 st sheet laminated on the skin-facing surface side of the absorbent body (6C) and composed of a nonwoven fabric comprising fibers of a thermoplastic resin, the manufacturing apparatus being characterized in that,

a recessed part forming part configured to form a recessed part (20) in the absorbent body (6C) and the 1 st sheet by pressing the absorbent body (6C) and the 1 st sheet from the 1 st sheet side using a pressing roll (R1) in a state where the absorbent body (6C) and the 1 st sheet are laminated,

the thickness of the 1 st sheet after passing through the recess forming part (M) is 2.1mm or more, and the grammage is 20g/M²The thickness of the fiber is 2.0dtex or more.

2. The manufacturing apparatus of an absorbent article (1) according to claim 1,

the depth of the recess (20) is 1.3mm or more and the width is 2.0mm or less.

3. The manufacturing apparatus of an absorbent article (1) according to claim 1 or 2,

the recess-forming section is configured such that the recesses (20) are formed by the absorbent body (6C) and the 1 st sheet passing between the press roll (R1) and an anvil roll (R2) provided at a position facing the press roll (R1).

4. The manufacturing apparatus of an absorbent article (1) according to claim 1 or 2,

the first sheet (1) is at least one of a top sheet covering the skin-facing surface side of the absorbent body (6C) and a core wrap sheet covering the absorbent body (6C).

5. The manufacturing apparatus of an absorbent article (1) according to claim 1 or 2,

the recessed portion (20) has a component in the longitudinal direction of the absorbent body (6C).

6. The manufacturing apparatus of an absorbent article (1) according to claim 1 or 2,

the 1 st sheet is formed by containing 2 kinds of fibers of the thermoplastic resin.