KR100675848B1 - Ultra-thin absorbing Core of diaper and manufacturing method thereof - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultra-thin absorbent core for use in a disposable diaper, wherein the disposable diaper absorbs body fluid between a liquid permeable topsheet that is in direct contact with a user's skin when in use and a liquid impermeable backsheet that forms an exterior surface during use. An absorbent core of the present invention, comprising: a form-maintaining region formed by high pressure bonding of downy pulp and superabsorbent resin and synthetic fibers; And an absorption / diffusion region formed by low compression, thereby providing an ultra-thin absorbent core of a disposable diaper which is remarkably thin in thickness, light in weight, and does not interfere with the external force without disturbing the absorption ability of the absorbent resin.

Diaper, Absorption Core, Absorption Diffusion, Form Maintenance, Unevenness

Description

Ultra-thin absorbing core of diaper and manufacturing method thereof

1 is a plan view showing an unfolded state of a general ultra-thin disposable diaper,

2 is a partial cross-sectional view taken along the line A-A of FIG.

Figure 3 is a cross-sectional view in the width direction of the ultra-thin absorbent core according to an embodiment of the present invention,

4 is a longitudinal plan view of an ultra-thin absorbent core according to an embodiment of the present invention;

5 is a cross-sectional view showing an upper heating roller and a lower heating roller for manufacturing an absorbent core according to the present invention;

6 is a schematic view showing an embodiment of a manufacturing process of an ultra-thin absorbent core according to the present invention.

<Explanation of symbols for the main parts of the drawings>

A: transverse centerline

C: Ultra-thin absorbent core D: Disposable diaper

1: anterior waist region 2: crotch region

3: rear waist area 4: back seat

5: Absorbent Core 6: Top Sheet

7: absorption diffusion layer 8: inner solidification band

9: outer curd band 10: tissue

11: coagulation band flap 12: coagulation band flap

13: coagulation band end portion 14: coagulation band end adhesion portion

15: solid state band elastic body 16: solid side band flap

17: Coagulation band outer side flap 18: Reattachment fastening means fixing portion

19: Reattachment fastening means 20: Front fastening means

21: waistband 22: plastic film on the back sheet

23: Nonwoven fabric of back sheet 24: Absorption / diffusion area

25: shape holding area 26: heating roller

27: sedimentation part 28: ridge

29: fluff pulp 30: low melting point synthetic fiber

31: drum former 32: super absorbent polymer

33: heating chamber

The present invention relates to an ultra-thin absorbent core for use in disposable diapers, which is composed of a low compression absorbing / diffusion region and a high pressure bonding shape holding region, which is remarkably thin in thickness, light, and does not impair absorption of the absorbent resin. It relates to an ultra-thin absorbent core of a disposable diaper which is free of distractions of form by external force without being.

Disposable diapers absorb the body fluids such as blood, urine and menstrual blood so that the user can use them hygienically and conveniently. In general, disposable diapers are products that absorb secretions (e.g., urine, blood, menstrual blood, etc.) excreted by various physiological actions of the wearer, that is, products that absorb urine, feces, menstrual discharge and vaginal discharge. Examples include disposable diapers used by infants or incontinents, women's sanitary napkins, panty liners, and the like.

Such disposable diapers typically have a liquid permeable top sheet that is in direct contact with the wearer's skin when worn, and a liquid impermeable back sheet that forms an outer surface when worn, disposed between the top sheet and the back sheet. It comprises an absorbent core (absorbent core), a leg flap (lap) consisting of an elastic body and the fastening means as a basic component.

Among the above components, the top sheet is generally composed of soft to the touch and does not irritate the skin of the wearer, in particular the top sheet should have a physical property that can quickly pass the liquid body secretion to the absorbent core . Top sheets suitable as having these properties are made and used from a wide range of materials such as porous plastic films, natural fibers, synthetic fibers or mixtures of natural and synthetic fibers.

The absorbent core is a means capable of absorbing and retaining liquid secretions. Therefore, the absorbent core is typically made of fluff pulp and super absorbent polymer as a liquid absorbent material, and tissues for wrapping them, and passes through a liquid permeable top sheet. To absorb the body fluid at high speed and to prevent the absorbed body fluid from contacting the skin again. The size, shape (e.g., rectangular, hourglass, etc.), structure, and absorbent capacity of the absorbent core are adapted to fit the wearer from infant to adult, and the absorbent core is a known attachment such as adhesive on the back sheet. It is attached and fixed by means.

The backsheet is impermeable to the liquid so that the body secretions absorbed and absorbed by the absorbent core do not contaminate or wet products that are in direct contact with the diaper, such as the wearer's clothing or bed sheet. The back sheet is preferably impermeable to liquids and permeable to gases. As a film having such physical properties, a plastic film has been generally used, and in recent years, a material obtained by adhering a nonwoven fabric to a polyethylene film has been widely used.

The leg flaps are positioned adjacent each longitudinal edge to allow the diaper to be worn and secured to the wearer's leg. The preferred configuration of the leg flaps consists of side flaps and flap elastomers as specifically described in US Pat. No. 3,860,003. When the back sheet is formed by adhering a nonwoven fabric to a polyethylene film, an elastic body may be bonded in a stretchable state between the outer polyethylene film and the nonwoven fabric.

The fastening means performs a function of wearing a disposable diaper on the body and maintaining its wearing state. Fastening means are widely used fastening members such as adhesive tape tabs or hooks and loops.

The coagulation band is usually formed adjacent to the absorbent core of a disposable diaper to prevent leakage of urine or feces that cannot be absorbed from the absorbent core, and is composed of a liquid permeable or liquid impermeable material.

The various members of each of the components of the diaper are adhesively fixed by hot melt adhesive, heat fusion, or other bonding method which is well known in the diaper field to form the diaper.

The technical level of disposable diaper products, including adult diapers such as infants and incontinents, has been rapidly developed and the basic performance in terms of the amount of absorption to absorb and store the body fluids excreted by physiological action is inconvenient for the user. It was possible to adjust so that.

In addition, in order to quickly absorb excretion (e.g., urine, blood, menstrual blood, etc.) excreted by the wearer and to provide comfort in use, it has been developed into an ultra-thin form that increases the absorption capacity of the absorbent core and makes the thickness thinner. .

Conventional absorbent cores are prepared using fluff pulp, starch graft copolymers, cross-linked carboxymethylcellulose derivatives, modified hydrophilic acrylates, etc., made by grinding wood pulp on a fibrous web. The absorbent resin has been produced by uniformly or intentionally distributing it uniformly, and then adding water to it and then compressing it in order to improve the strength (Integrity) of the absorbent core.

Recent diapers tend to become lighter and lighter as they are more ergonomically developed. This improves breathability due to lightness and thinness when worn, improves freshness, and prevents side effects such as itching and rashes when worn for a long time with excellent breathability, and consumers prefer thin and light diapers due to the advantages of being easy to carry. to be.

Ultra-thin absorbent core distributes fluff pulp and low melting point synthetic fiber uniformly or non-uniformly, inhales through core molding drum and injects super absorbent resin to form core shape and maintains a certain temperature range. By applying a predetermined pressure with a heating roller while heating for a predetermined time through a heating chamber, a low melting point synthetic fiber is melted to prepare absorbent cores in which dispersed fluff pulp is bonded to each other.

However, because the ultra-thin absorbent core presses the entire absorbent core with a heating roller, the superabsorbent polymer is compressed and unable to swell, thereby rapidly discharging secretions (for example, urine, blood, menstrual blood, etc.) compared to the conventional absorbent core. The suction property is drastically reduced, and the surface wettability of the absorbent core is poor, and thus it is difficult to use in actual diapers.

The principle that suction (e.g., urine, blood, menstrual blood, etc.) is sucked into the absorbent core is made by capillary phenomenon, so that the suction is performed smoothly when the absorbent core is low density, but the ultra-absorbent thinner absorbs the entire absorbent core. The core has a problem that the suction force of the body fluid, the surface drying properties are greatly reduced.

An object of the present invention is to form an absorption / diffusion region and a shape maintaining region integrally to solve the problems of the ultra-thin absorbent core, which can quickly absorb, diffuse and keep the form secreted repeatedly, the shape can be safely maintained An improved ultra-thin absorbent core is provided to provide a disposable diaper which is remarkably thin in thickness, light in weight and excellent in shape retention, without aggregation.

Absorbent core of the ultra-thin disposable diaper of the present invention for achieving the above object is located between the liquid permeable topsheet in direct contact with the user's skin when in use, and the liquid impermeable backsheet that forms the outer surface in use to absorb body fluids An absorbent core of a disposable diaper, comprising: a shape maintaining region formed by pressing high-pressure pulp, superabsorbent resin, and synthetic fibers; And an absorption / diffusion region formed by low compression.

The absorption / diffusion region and the shape maintaining region are configured in a ratio of 90:10 to 99: 1 of the total width of the absorbent core in the transverse direction, and the shape maintaining regions are formed in at least two of the shape maintaining regions in the transverse total width of the absorbent core. It is desirable to.

In addition, the length of the shape holding area is at least 20% or more of the total length of the absorbent core, and the spacing between the shape holding areas formed in the length direction of the absorbent core is preferably formed within 60% of the length of one shape holding area.

The two shape-retaining regions adjacent in the lateral direction of the absorbent core are formed to overlap at least 10% in the longitudinal direction of the absorbent core at the same time, and are continuous straight lines, continuous sine curves, or discontinuous straight lines and discontinuous sine. It is preferable to form one or two or more shapes selected from curves or discontinuous cells.

On the other hand, the absorbent core manufacturing method for achieving the other object of the present invention comprises the steps of: sucking the pulverized fluff pulp and low melting point-containing fibers in the drum former and the superabsorbent resin to form an absorbent core appearance; Melting the low melting synthetic fiber while passing the molded absorbent core through a heating chamber maintaining a temperature in a predetermined range; And passing under constant pressure between the upper heating roller in which the unevenness is formed and the cylindrical lower heating roller without the unevenness. It characterized in that to perform sequentially.

In the heating roller passing step, a high pressure-bonded shape maintaining area is formed while passing through the uneven portion of the upper heating roller, and a low compression absorption / diffusion area is formed through the non-uneven portion.

The present invention provides an absorbent core which is formed by pressing by a heating roller having raised unevenness and formed of a low compression absorption / diffusion area and a high pressure shape maintenance area.

Significantly thin and light, providing an improved ultra-thin absorbent core that forms the absorption / diffusion area and the shape-keeping area integrally to quickly absorb and diffuse repeated discharges and maintain their shape safely. It is excellent in shape maintenance, and it is possible to manufacture disposable diapers without aggregation.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

The present invention is preferably applied to disposable absorbent products such as disposable diapers for baby or urinary incontinence, women's menstrual products, panty liners.

1 is a plan view showing the unfolded state of the ultra-thin disposable diaper (D) to which the present invention is applied, Figure 2 is a partial cross-sectional view of the disposable diaper of Figure 1 taken along line A-A. 3 is a cross-sectional view of the ultra-thin absorbent core according to the present invention, Figure 4 is a plan view. 5 is a cross-sectional view of the heating roller, Figure 6 is a schematic diagram showing a manufacturing process of the ultra-thin absorbent core.

1 and 2 will be described the configuration of one embodiment of a disposable diaper. As shown, the disposable diaper D has an hourglass-like appearance divided into the front waist region 1, the crotch region 2, and the rear waist region 3. The outer shape of the disposable diaper (D) does not necessarily have to be symmetrical in right and left and front and rear, but preferably has a symmetrical structure.

The upper sheet 6 of the components of the disposable diaper D is located on the upper part (the direction in contact with the skin of the wearer) that absorbs the body fluid, and is absorbed by hot melt adhesive, heat or ultrasonic waves. It is adhered to the core 5 and the back sheet 4.

The topsheet 6 is soft to the touch and should not irritate the wearer's skin, and the topsheet 6 may also be fabric, nonwoven material or having a liquid permeability that easily passes liquid (eg, urine). It may be made of a thermoplastic film with holes formed. Suitable woven and nonwoven materials may consist of natural fibers, synthetic fibers or a mixture of natural and synthetic fibers.

An absorption diffusion layer 7 is positioned between the absorbent core 5 and the upper sheet 6. Absorption diffusion layer 7 has a liquid permeability to easily pass through the liquid (for example, urine), and to adhere the respective materials by hot melt adhesive, heat or ultrasonic waves.

The backsheet 4 is located on the opposite side of the top sheet with the absorbent core 5 interposed therebetween and in contact with the user's clothing side in use. The backsheet 4 is attached to the absorbent core 5 and the top sheet 6 by a solid adhesive or heat. The backsheet 4 is also liquid (e.g., urine) impermeable and prevents body fluids absorbed by the absorbent core 5 from leaving the disposable diaper D and contaminating the wearer's clothing and surrounding environment. Perform the function.

The back sheet 4 is made of a thin plastic film, and is formed so that fine pores are formed in the film by molding (extrusion or injection) by adding an inorganic material such as calcium carbonate to the garment surface (the skin of the wearer) of the absorbent core 5. Allow vapor to escape in the opposite direction of contact). Suitable materials for the backsheet 4 are thermoplastic films having a weight of 10 g / m ² to 30 g / m ² , preferably comprising a polyethylene film or a polypropylene film.

The back sheet 4 adds a nonwoven fabric 23 to the plastic film 22 to provide a soft feel to the user in order to provide a soft fit to the user. The nonwoven fabric 23 may be attached to the plastic film 22 in the same width as the transverse width, preferably, the plastic film 22 is reduced to the same size as the transverse width of the absorbent core, and the nonwoven fabric 23 To make and attach the same size as the overall width of the disposable diaper (D).

Absorption diffusion layer (7) is located between the upper sheet (6) and the absorbent core (5) is a liquid permeable to easily pass through the liquid (for example, urine), and to adhere the respective materials with hot melt adhesive, heat or ultrasonic waves, etc. .

The absorbent core 5 is located between the top sheet 6 and the back sheet 4, and absorbs the body fluid passing through the top sheet 6 at a high speed, and prevents the absorbed body fluid from contacting the skin again. To retain fluids.

The absorbent core 5 is composed of a fluff pulp, a super absorbent polymer, and a tissue (10, Tissue), and has a wide variety of sizes and shapes (eg, rectangular, hourglass, ' T'-shaped, asymmetrical, etc.).

Coagulation bands 8 and 9 are formed on the left and right sides of the absorbent core 5 to form pockets to prevent leakage of body fluid from the absorbent core. The coagulation band includes the coagulation band flap attachment portion 12, the coagulation band end portion 13, the coagulation band end adhesion portion 14, the coagulation band elastic body 15, the coagulation band flap 11, and the coagulation band side flaps 16 and 17. The stiffening band flap 11 is formed at least in the crotch portion by a portion other than the spooling band end adhesive portion 14 to stand by the spooling band elastic body 15 to form an absorbent pocket outside the absorbent core 5. The body fluid which escapes from the absorbent core 5 is trapped and prevented from leaking.

The coagulation bands 8 and 9 are made of a hydrophobic nonwoven fabric or a waterproof nonwoven film, and the hydrophobic nonwoven material forms a coagulation band flap 11 in two layers to enhance the hydrophobic effect, and the coagulation band flap 11 ) Can be bonded with a solid adhesive. Hydrophobic nonwovens generally have a weight of 13 to 28 g / m 2.

In addition, the coagulation band forms at least one elastic body on the coagulation band flap 11 between the coagulation band flap adhesion portion 12 and the coagulation band end portion 13 so that the coagulation band end portion 13 closely adheres to the baby skin. The elastic modulus of the solidifying band elastic body 15 is set in the range of 150 to 230%, but preferably 180 to 200%. The elastic band elastic body 15 is mainly used for the elastic yarn, the elastic yarn is used polyurethane spandex (Polyurethane Spandex) or natural rubber.

The rotatable band end portion 13 is a portion where the rotatable band flap 11 contacts the user's skin, and the rotatable band flap adhesion portion 12 has the rotatable band flap 11 outside the absorbent core 5 of the disposable diaper D. The side flap (16, 17) is the portion that is bonded in the longitudinal direction of the disposable diaper (D).

The rotatable band end adhesive portion 14 is formed at the waist of the longitudinal outer both edges of the disposable diaper D such that the rotatable band flap 11 forms an absorbent pocket by the rotatable band flap adhesion portion 12 and the rotatable band elastic body 15. The adhesive part which fixes the coagulation band flap 11 to the inside or the outer side of the coagulation band flap adhesion part 12 is said.

And it may include a fastening means (19, 20) to maintain the disposable diaper (D) is configured to wear on the body, the fastening means (19, 20) is a re-adhesive tape or hook-loop system (Hook & Loop System) Mechanical fastening means such as are used. Each material is also adhesively fixed by hot melt adhesive, heat fusion or other bonding method.

The fastening means is a re-adhesive consisting mainly of a fixing part of the re-adhesive fastening means 19 fixed to the corners of the corresponding band side flaps 16 and 17 of the rear waist portion 3 of the disposable diaper D and the free end portion which is not fixed. It is formed in the transverse direction on the fastening means 19 and the front waist portion, it is composed of a front fastening means 20 to provide a target (Target) region to which the re-adhesive fastening means 19 can be bonded.

The waist band 21 is formed by bonding an elastic body to the waist of the disposable diaper (D). Waistband elastomer is mainly used polyurethane foam (Polyurethane Foam), polyurethane film (Polyurethane Film), polyurethane nonwoven elastomer and elastic yarn, the elastic yarn is used polyurethane Spandex (polyurethane Spandex) or natural rubber. The waistband 21 may be formed over the entire width of the disposable diaper D in the transverse direction between the longitudinal end portion of the disposable diaper D and the outer side of the absorbent core 5, or may be formed to be short.

As shown in FIG. 3, the cross section of the absorbent core according to the present invention included in the disposable diaper configured as described above is composed of an absorbent / diffusion region 24 and a shape maintaining region 25.

Absorption / diffusion region 24 serves to rapidly absorb secretions that are repeatedly introduced and to spread the secretions far away from the secretion point. The shape maintaining region 25 serves to maintain the shape of the absorbent core by compressing the low melting synthetic fibers melted by heat to increase the bonding force between the fluff pulp.

In the ultra-thin absorbent core C of the present invention, the absorption / diffusion region 24 and the shape maintaining region 25 are formed at a predetermined ratio. The absorption / diffusion region 24 and the shape maintaining region 25 of the ultra-thin absorbent core C are generally composed of 90:10 ratio of the total width of the ultra-thin absorbent core C transversely, preferably 95: 5, more preferably. Preferably 99: 1.

The absorption / diffusion region 24 is made up of 90% or more of the total width of the ultra-thin absorption core C in the transverse direction. If the absorption / diffusion region 24 is less than 90%, the absorbent and storage role of the secretion is insufficient, and thus, the original purpose of the absorbent core may not be properly performed. Therefore, other additional efforts are required to improve the absorption function of the secretion.

If the composition is less than 1%, the absorbent core is easily distracted by external force such as secretion or the load of the wearer, and the shape thereof cannot be maintained. If the amount is more than 50%, the ultra-thin absorbent core (C) has a high density, so that the absorption of secretion is increased. Since there is a problem in that it is not easy, the shape maintenance area | region 25 is comprised in less than 50% at least 1% or more of the ultra-wide absorption core C transverse width.

The shape maintaining area 25 is preferably formed in at least two or more and five or less in the transverse direction of the ultra-thin absorbent core C, and more preferably in three.

In addition, the length of the shape maintaining region 25 may be the entire length of the ultra-thin absorbent core C, and is formed at least 20% of the length of the absorbent core. When the length of the shape holding area 25 is formed to be shorter than the length of the absorbent core, a plurality of shape holding areas 25 having the same length may be formed in the length direction of the absorbent core, and the shape holding area 25 adjacent to the length direction is formed. The spacing between) is within 10% to 60% of the length of one shape-retaining area 25. In addition, the ultra-thin absorbent core (C) in the lateral direction adjacent to the shape holding area 25 is located in the longitudinal direction at the same time within 60% or more of 10% or more of the length of the two adjacent shape holding area 25 and the shape holding area (25) It is made to overlap.

FIG. 4 is a front view showing the upper surface of the absorbent core C composed of the absorption / diffusion regions 24 and the shape maintaining regions 25a, b, and c. As shown in FIG. It may be a straight line 25a and a continuous sine curve, or may be in various forms such as a discontinuous straight line 25b and a discontinuous sine curve 25c or a discontinuous cell.

As shown in FIG. 5, the ultra-thin absorbent core C is formed by the upper heating roller 26a and the cylindrical lower heating roller 26b having the raised and unevenness formed thereon. The raised uneven portion is called the raised portion 28, and the uneven portion without the uneven portion is called the settled portion 27. The shape maintaining region 25 is formed by the high pressure 28 by the ridge 28, and the absorption / diffusion region 24 is formed by the relatively low compression by the settling portion 27.

6 is a schematic view schematically showing an absorbent core manufacturing process according to the present invention. As shown in the drawing, the ground pulp pulp 29 and the low melting synthetic fiber 30 are sucked into the drum former 31, and the superabsorbent resin 32 is introduced to form an absorbent core.

The low melting point soluble fiber 30 is melted while the molded absorbent core is passed through the heating chamber 33 maintaining a temperature in a predetermined range. Absorbent core passing through the heating chamber 33 is pressed at a constant pressure while passing through the unevenly formed heating roller 26, the low melting point synthetic fiber 30 is absorbed by causing mutual bonding between the fluff pulp (29) The core is formed to maintain a proper shape.

At this time, the upper roller 26a of the heating roller 26 is designed to have the settling portion 27 and the ridge 26b, and the lower roller 26b is designed to be flat so that the absorption / diffusion region 24 of the present invention is achieved. And the shape maintaining area 25 is designed to be formed.

In the above, specific preferred embodiments of the present invention have been illustrated and described. However, the present invention is not limited to the above-described embodiments, and various modifications can be made by those skilled in the art without departing from the gist of the present invention attached to the claims. will be.

According to the present invention, the absorption / diffusion region and the shape maintaining region are integrally formed in the absorbent core constituting the disposable diaper, so that the discharged substances can be rapidly absorbed and diffused and the shape can be safely maintained. Significantly thin, light, and excellent in shape maintenance, it is possible to manufacture disposable diapers without aggregation.

Claims (10)

In the absorbent core of a disposable diaper that absorbs body fluid between the liquid permeable topsheet that is in direct contact with the user's skin when in use and the liquid impermeable backsheet that forms the exterior surface during use, A morphology maintenance region formed by high pressure bonding of downy pulp, superabsorbent resin, and synthetic fibers; And an absorption / diffusion region formed by low compression. The absorbent / diffusion area and the shape maintaining area are absorbent cores for disposable diapers, characterized in that the ratio of 90:10 to 99: 1 of the total width of the absorbent core in the transverse direction. delete The method of claim 1, Absorption core of the disposable diaper, characterized in that the shape maintaining area is formed in 2 to 5 in the transverse overall width of the absorbent core. The method of claim 1, The length of the shape maintaining region is 20% to 100% of the total length of the absorbent core absorbent core of the disposable diaper, The method of claim 1, An interval between the shape holding regions formed in the longitudinal direction of the absorbent core is 10% to 60% of the length of one shape holding region, the absorbent core of the disposable diaper. The method of claim 1, Absorption core of the disposable diaper, characterized in that the two shape-retention areas adjacent in the transverse direction of the absorbent core to overlap at the same time in the longitudinal direction of the absorbent core 10% to 60%. The method of claim 1, The shape maintaining area is formed of any one or a combination of continuous straight lines, continuous sine curves, or discontinuous straight lines, discontinuous sine curves or discontinuous cells, or a combination thereof. Sucking the pulverized fluff pulp and low melting point-containing fiber into a drum former and introducing a super absorbent polymer to form an absorbent core shape; Melting the low melting synthetic fiber while passing the molded absorbent core through the heating chamber; And Passing under constant pressure between the uneven upper heating roller and the uneven cylindrical lower heating roller is formed; Absorbent core manufacturing method of a disposable diaper, characterized in that to perform sequentially. The method of claim 8, The irregularities formed on the upper heating roller is absorbent core manufacturing method of the disposable diaper, characterized in that formed in the transverse direction. The method of claim 8, Absorbent core is an absorbent core manufacturing of the disposable diaper, characterized in that through the concave-convex portion of the upper heating roller is formed a high pressure-bonded shape maintaining area, passing through a portion that is not concave-convex, low-compression absorption / diffusion area is formed Way.

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