A paper diaper with an ultra-thin core

Abstract

The present application relates to the field of disposable sanitary products, and particularly relates to a paper diaper with an ultra-thin core, which has the characteristics of good air permeability and high water absorption efficiency, and the paper diaper body comprises a liquid-permeable surface layer, an absorption core layer and a liquid-impermeable bottom layer, the absorption core layer comprises a first non-woven fabric, a second non-woven fabric, a third non-woven fabric, a fourth non-woven fabric and a bulky non-woven fabric, a plurality of hot-pressing areas are hot-pressed on the bulky non-woven fabric, the hot-pressing areas are distributed in the transverse direction at intervals, an absorption area is formed between the two adjacent hot-pressing areas, the grammage of the bulky non-woven fabric is 20-50 g / m2, the longitudinal tensile strength of the bulky non-woven fabric is greater than or equal to 18 N / 5 cm, the first high-molecular water-absorbing resin particles are arranged on the bulky non-woven fabric and located in the absorption area, and the first high-molecular water-absorbing resin particles are partially embedded in the pores of the bulky non-woven fabric; the first non-woven fabric is covered on the upper surface of the bulky non-woven fabric and is hot-pressed and compounded with the bulky non-woven fabric in the hot-pressing area.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of disposable sanitary products, in particular to a paper diaper with an ultra-thin core. BACKGROUND

[0002] The structure of a paper diaper generally includes, from top to bottom, a liquid-permeable surface layer, an absorbent core layer, and a liquid-impermeable bottom layer arranged in layers. The absorbent core layer is composed of an absorbent core, which is usually formed by mixing high-molecular water-absorbing resin particles and wood pulp fibers and wrapping them with non-woven fabric to form a block structure for absorbing and retaining body excretions; the liquid-permeable surface layer is composed of hydrophilic non-woven fabric and hydrophobic non-woven fabric fixed on both sides of the hydrophilic non-woven fabric, respectively, for providing comfort and dryness when in contact with the body, while allowing liquid to pass freely into the underlying absorbent core layer; the liquid-impermeable bottom layer is composed of a breathable, water-impermeable film and hydrophobic non-woven fabric, for retaining absorbed liquid in the absorbent core layer, thereby preventing the absorbed liquid from soiling the wearer's pants.

[0003] Traditional absorbent cores not only have the problem of lumping and breaking during use, but also have a large thickness and poor air permeability, reducing the comfort of the user. The absorbent core widely used in the market is composed of a double-layer non-woven fabric with a high-molecular water-absorbing resin material sandwiched in the middle, the high-molecular water-absorbing resin material is spread on the upper surface of one of the non-woven fabrics, and the other non-woven fabric is combined by spraying glue. This kind of absorbent core has a relatively thin thickness, but the high-molecular water-absorbing resin material is not easy to fix, which can easily cause the high-molecular water-absorbing resin material to deviate or leak, seriously affecting the water absorption efficiency. SUMMARY

[0004] Therefore, in view of the above problems, the present application provides a paper diaper with an ultra-thin core that has good air permeability and high water absorption efficiency.

[0005] To achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0006] A paper diaper with an ultra-thin core, comprising a paper diaper body, the longitudinal direction is defined as the length direction of the paper diaper body, and the transverse direction is defined as the width direction of the paper diaper body, the paper diaper body has a front waist region, a crotch region, and a back waist region arranged in sequence along the longitudinal direction;

[0007] The paper diaper body comprises a liquid-permeable surface layer, an absorbent core layer and a liquid-impermeable bottom layer arranged in sequence from top to bottom, the absorbent core layer comprises a first non-woven fabric, a second non-woven fabric, a third non-woven fabric, a fourth non-woven fabric and a bulky non-woven fabric, a plurality of hot-pressing zones distributed along the longitudinal direction are hot-pressed on the bulky non-woven fabric, the hot-pressing zones are distributed along the transverse direction, and an absorption zone is formed between adjacent hot-pressing zones, the grammage of the bulky non-woven fabric is 20-50 g / m2, the longitudinal tensile strength of the bulky non-woven fabric is greater than or equal to 18 N / 5 cm, and first high-molecular water-absorbing resin particles are arranged on the bulky non-woven fabric and located in the absorption zone, and the first high-molecular water-absorbing resin particles are partially embedded in the pores of the bulky non-woven fabric.

[0008] The first non-woven fabric is arranged on the upper surface of the bulky non-woven fabric and is hot-pressed and combined with the bulky non-woven fabric in the hot-pressing zone, the second non-woven fabric is bonded to the lower surface of the bulky non-woven fabric, wood pulp fibers are filled between the second non-woven fabric and the bulky non-woven fabric and located in the hot-pressing zone, the second non-woven fabric forms a downward protruding protruding part in the hot-pressing zone through the wood pulp fibers, a plurality of strip-shaped grooves are pressed downward on the fourth non-woven fabric, the strip-shaped grooves are distributed along the vertical direction and are distributed in the absorption zone, a connecting zone is formed between adjacent strip-shaped grooves, second high-molecular water-absorbing resin particles are filled in the strip-shaped grooves, the third non-woven fabric is arranged on the fourth non-woven fabric and is bonded and connected in the connecting zone, the transverse width dimension of the fourth non-woven fabric is greater than that of the bulky non-woven fabric by 5-15 mm, the transverse two sides of the fourth non-woven fabric are folded upward and inward to the upper surface of the first non-woven fabric, and the protruding part abuts against part of the connecting zone, and the upper surface of the third non-woven fabric is combined with the lower surface of the second non-woven fabric.

[0009] Further, the total grammage of the absorbent core layer is 120-160 g / m2, and the liquid diffusion length measured 30 seconds after 50 ml of saline is injected under a pressure of 3.2 KPa is greater than or equal to 12 cm, and the back penetration amount is less than or equal to 0.8 g.

[0010] Further, the longitudinal fiber density of the bulky non-woven fabric is lower than the transverse fiber density by 10-30%, and the surface is distributed with embossed grooves.

[0011] Further, the volume ratio of the second high-molecular water-absorbing resin particles to the volume of the strip-shaped grooves is 3-5:10.

[0012] Further, a suture line is hot-pressed in the transverse middle part of the connecting zone, the suture line is distributed along the longitudinal direction, and the transverse width dimension of the suture line to the transverse width dimension of the connecting zone is 1-2:5.

[0013] Further, the absorbent core layer has upper and lower edges distributed at the longitudinal ends, and has left and right edges distributed at the transverse ends, and the longitudinal ends of the heat-pressing area are not connected to the upper and lower edges.

[0014] Further, the basis weight of the first high-molecular water-absorbing resin particles in the bulky nonwoven fabric gradually decreases from the middle of the longitudinal direction to the longitudinal ends.

[0015] Further, the strip-shaped grooves are distributed in the crotch region.

[0016] Further, the first high-molecular water-absorbing resin particles have a particle size of 100-500 μm, the second high-molecular water-absorbing resin particles have a particle size of 80-400 μm, and the particle sizes of the first and second high-molecular water-absorbing resin particles are different.

[0017] Further, the width of the heat-pressing area is 1-8 cm, the interval distance between adjacent two heat-pressing areas is 5-15 cm, the width of the strip-shaped grooves is 1-5 cm, and the width of the connecting area between adjacent two strip-shaped grooves is 3-10 cm.

[0018] By adopting the foregoing technical scheme, the paper diaper with the ultra-thin core body has the following beneficial effects: the paper diaper with the ultra-thin core body is provided with the absorption core layer comprising the first non-woven fabric, the second non-woven fabric, the third non-woven fabric, the fourth non-woven fabric and the bulky non-woven fabric, the bulky non-woven fabric is hot-pressed with a plurality of longitudinal distribution and transverse interval hot-pressing areas, adjacent hot-pressing areas form absorption areas and are provided with the first high-molecular water-absorbing resin particles partially embedded in the pores of the bulky non-woven fabric, the problems of the traditional absorption core body, such as lumping, fracture, large thickness and poor air permeability, are solved, meanwhile, the deviation or leakage of the high-molecular water-absorbing resin material is avoided, the water-absorbing efficiency is improved, and the overall structure makes the paper diaper have the ultra-thin characteristics, good air permeability and improved user comfort; and the first non-woven fabric and the bulky non-woven fabric are hot-pressed and compounded in the hot-pressing area, the second non-woven fabric is bonded to the lower surface of the bulky non-woven fabric and is filled with wood pulp fibers in the hot-pressing area to form a downward protruding protruding part, the fourth non-woven fabric is pressed to fill the second high-molecular water-absorbing resin particles in the strip-shaped groove, the third non-woven fabric is covered on the fourth non-woven fabric and is bonded and connected in the connecting area, and the fourth non-woven fabric is folded and attached on the upper surface of the first non-woven fabric on the two sides in the transverse direction and the protruding part abuts against part of the connecting area, which further optimizes the performance of the absorption core layer, enhances the ability of absorbing and fixing liquid, and ensures the stability of the structure; in particular, in use, part of the liquid passes through the first non-woven fabric into the absorption area and is absorbed by the first high-molecular water-absorbing resin particles, the space provided by the pores of the bulky non-woven fabric can provide sufficient space for the expansion of the first high-molecular water-absorbing resin particles, the absorption efficiency is ensured, part of the liquid is guided by the flow guiding effect of the hot-pressing area, and the wood pulp fibers in the protruding part quickly infiltrate into the strip-shaped groove at the bottom to be absorbed by the second high-molecular water-absorbing resin particles, the absorption amount is ensured, and the liquid is absorbed by the two parts, thereby forming rapid absorption and high water-absorbing efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a top view structural schematic diagram of the embodiment of the present application;

[0020] Figure 2 is a sectional view structural schematic diagram of A-A in Figure 1

[0021] Figure 3 is a sectional view structural schematic diagram of B in Figure 2

[0022] Figure 4 is a top view structural schematic diagram of the absorption core layer in the embodiment of the present application;

[0023] Figure 5 is a top view structural schematic diagram of the third non-woven fabric and the fourth non-woven fabric in the compound state in the embodiment of the present application;

[0024] Figure 6 is a structural schematic diagram of the liquid diffusion length test in the embodiment of the present application; ​​

[0025] Figure 7 Figure 1 is a structural diagram of a re-wet amount test in the embodiment of the present application.

[0026] Legend of reference signs:

[0027] 1, diaper body; 2, hot-pressing area; 3, absorption area; 4, protruding part; 5, strip-shaped groove; 6, connecting area; 7, embossed groove; 8, suture line;

[0028] 101, front waist area; 102, crotch area; 103, back waist area; 201, pressure device; 202, test table; 203, pipette; 204, filter paper; 301, upper edge; 302, lower edge; 303, left edge; 304, right edge;

[0029] 121, first non-woven fabric; 122, second non-woven fabric; 123, third non-woven fabric; 124, fourth non-woven fabric; 125, bulky non-woven fabric; 126, first high-molecular water-absorbing resin particle; 127, second high-molecular water-absorbing resin particle; 128, wood pulp fiber. DETAILED DESCRIPTION

[0030] The present application will be further described in conjunction with the drawings and specific embodiments.

[0031] The embodiment of the present application is:

[0032] Reference Figures 1 to 5 As shown in the drawings, a diaper with an ultra-thin core includes a diaper body 1, with the longitudinal direction defined as the length direction of the diaper body 1 and the transverse direction defined as the width direction of the diaper body 1. The diaper body 1 has a front waist area 101, a crotch area 102, and a back waist area 103 distributed in sequence along the longitudinal direction.

[0033] The diaper body 1 includes a liquid-permeable surface layer 11, an absorption core layer 12, and a liquid-impermeable bottom layer 13 stacked in sequence from top to bottom. The absorption core layer 12 includes a first non-woven fabric 121, a second non-woven fabric 122, a third non-woven fabric 123, a fourth non-woven fabric 124, and a bulky non-woven fabric 125. The bulky non-woven fabric 125 has five hot-pressing areas 2 distributed along the longitudinal direction. Each hot-pressing area 2 is distributed along the transverse direction, and an absorption area 3 is formed between two adjacent hot-pressing areas 2. The grammage of the bulky non-woven fabric 125 is 20-50 g / m², preferably 45 g / m². The longitudinal tensile strength of the bulky non-woven fabric 125 is ≥18 N / 5 cm. The first high-molecular water-absorbing resin particles 126 are provided on the bulky non-woven fabric 125 and located in the absorption area 3, and part of the first high-molecular water-absorbing resin particles 126 are embedded in the pores of the bulky non-woven fabric 125.

[0034] The first non-woven fabric 121 is covered on the upper surface of the bulky non-woven fabric 125, and is heat-pressed and combined with the bulky non-woven fabric 125 at the heat-pressing area 2, the second non-woven fabric 122 is adhered to the lower surface of the bulky non-woven fabric 125, the second non-woven fabric 122 and the bulky non-woven fabric 125 are filled with wood pulp fibers 128 at the heat-pressing area 2, the second non-woven fabric 122 forms the protruding part 4 protruding downward at the heat-pressing area 2 by the wood pulp fibers 128, the fourth non-woven fabric 124 is pressed downward with a plurality of strip-shaped grooves 5, each of the strip-shaped grooves 5 is distributed in the vertical direction and is distributed in the absorbing area 3, the connecting area 6 is formed between two adjacent strip-shaped grooves 5, the second high molecular water-absorbing resin particles 127 are filled in each of the strip-shaped grooves 5, the third non-woven fabric 123 is covered on the fourth non-woven fabric 124 and is adhered and connected at the connecting area 6, the transverse width size of the fourth non-woven fabric 124 is 5-15mm larger than the transverse width size of the bulky non-woven fabric 125, preferably 12mm, the transverse two sides of the fourth non-woven fabric 124 are folded upward and inward and are attached to the upper surface of the first non-woven fabric 121, and the protruding part 4 abuts against part of the connecting area 6, and the upper surface of the third non-woven fabric 123 is combined on the lower surface of the second non-woven fabric 122.

[0035] The paper diaper with an ultra-thin core has the following advantages: the absorption core layer 12 is provided with a first non-woven fabric 121, a second non-woven fabric 122, a third non-woven fabric 123, a fourth non-woven fabric 124 and a bulky non-woven fabric 125, the bulky non-woven fabric 125 is hot-pressed with a plurality of longitudinal distribution and transverse interval hot-pressing areas 2, adjacent hot-pressing areas 2 form absorption areas 3 and are provided with first high-molecular water-absorbing resin particles 126 partially embedded in the pores of the bulky non-woven fabric, the problems of lumping, breaking, large thickness and poor air permeability of the conventional absorption core are solved, the deviation or leakage of the high-molecular water-absorbing resin material is avoided, the water-absorbing efficiency is improved, the overall structure makes the paper diaper have the characteristics of ultra-thin and good air permeability, and the comfort of the user is improved; and the first non-woven fabric 121 and the bulky non-woven fabric 125 are hot-pressed and compounded in the hot-pressing areas 2, the second non-woven fabric 122 is bonded to the lower surface of the bulky non-woven fabric 125 and is filled with wood pulp fibers 128 in the hot-pressing areas 2 to form downward protruding protrusions 4, the fourth non-woven fabric 124 is pressed to form a strip-shaped groove 5 filled with second high-molecular water-absorbing resin particles 127, the third non-woven fabric 123 covers the fourth non-woven fabric 124 and is bonded and connected in the connecting areas 6, the fourth non-woven fabric 124 is folded and attached to the upper surface of the first non-woven fabric 121 on the transverse two sides and the protrusions 4 abut against part of the connecting areas 6, this structure further optimizes the performance of the absorption core layer 12, enhances the ability to absorb and fix liquid, and at the same time guarantees the stability of the structure; in specific use, part of the liquid passes through the first non-woven fabric 121 into the absorption areas 3 and is absorbed by the first high-molecular water-absorbing resin particles 126, and the space in the bulky non-woven fabric 125 can provide sufficient space for the expansion of the first high-molecular water-absorbing resin particles 126, guaranteeing the absorption efficiency, at the same time, part of the liquid is guided by the flow guiding effect of the hot-pressing areas 2 and quickly infiltrates into the strip-shaped groove 5 at the bottom through the wood pulp fibers 128 in the protrusions 4 and is absorbed by the second high-molecular water-absorbing resin particles 127, guaranteeing the absorption amount, and through the respective absorption effects of the two parts, rapid absorption and high water-absorbing efficiency are formed.

[0036] In addition, referring to Table 1, the total gram weight of the absorption core layer 12 is 120-160 g / m², preferably 150 g / m², the liquid diffusion length measured 30 seconds after 50 ml of saline is injected under a pressure of 3.2 KPa is ≥12 cm, and the back leakage amount is ≤0.8 g, while guaranteeing ultra-thin, the liquid absorption and diffusion capacity are good, the back leakage is effectively reduced, the skin of the user is kept dry, and the use comfort is improved.

[0037] The test method includes the following steps:

[0038] I. Prepare test equipment:

[0039] Pressure device 201: a pressure plate capable of applying a constant pressure of 3.2 kPa, with an area ≥100 cm² and a flat bottom;

[0040] Test bench 202: A rigid platform placed horizontally with a flat surface and no water absorption;

[0041] Standard saline solution: 0.9% sodium chloride solution;

[0042] Pipette 203: Accuracy ±0.5ml, used to measure 50ml of saline solution;

[0043] Stopwatch: Accuracy ±0.1 seconds;

[0044] Ruler: Accuracy ±1mm, used to measure the diffusion length;

[0045] Filter paper 204: Quantitative ≥80g / m², used to absorb reabsorbed liquid;

[0046] Electronic balance: Accuracy ±0.001g, used to weigh the reabsorption amount;

[0047] Marking tool: Waterproof marker or template, used to mark the injection point.

[0048] II. Sample preparation:

[0049] Cut the absorbent core layer 12 sample to a size of ≥20cm x 20cm, ensuring that the diffusion area is not affected by the edges, and the sample needs to be equilibrated in an environment with a temperature of 23±2℃ and a humidity of 50±5% for 24 hours before testing.

[0050] III. Test steps:

[0051] 5.1. Liquid diffusion length test (refer to Figure 6 shown)

[0052] 1. Sample placement: Place the sample flat on the test bench 202, ensuring that the surface is flat and wrinkle-free;

[0053] 2. Mark the injection point: Mark a 1cm diameter circular area in the center of the sample with a marker as the injection point;

[0054] 3. Apply pressure: Place the pressure plate above the sample, ensuring uniform distribution of pressure, adjust to 3.2kPa, which can be achieved through pressure calibration device;

[0055] 4. Inject liquid: Use pipette 203 to uniformly inject 50ml of saline solution into the injection point within 5 seconds;

[0056] 5. Timing and observation: Start the stopwatch and remove the pressure plate after 30 seconds;

[0057] 6. Measure the diffusion length: Measure the length of the liquid on the surface of the sample along the longest transverse diffusion direction from the edge of the injection point to the farthest diffusion point, record it as the diffusion length (unit: cm).

[0058] 5.2 Infiltration amount test (refer to Figure 7

[0059] 1. Place filter paper: immediately after removing the pressure plate, place 5 layers of dry filter paper 204 in alignment over the injection point;

[0060] 2. Apply standard pressure: apply uniform pressure to the filter paper with a pressure plate (or 1 kg weight), remove after 15 seconds;

[0061] 3. Weigh the infiltration amount: weigh the total mass of the filter paper after absorbing the liquid, subtract the initial mass of the filter paper, and obtain the infiltration amount (unit: g).

[0062] IV. Result determination:

[0063] Diffusion length: if the measured value is ≥ 12 cm, it is determined to be qualified; otherwise, it is unqualified;

[0064] Infiltration amount: if the measured value is ≤ 0.8 g, it is determined to be qualified; otherwise, it is unqualified.

[0065] Table 1: Test data of liquid diffusion length and infiltration amount of 50 ml of physiological saline injected under a pressure of 3.2 KPa after 30 seconds:

[0066]

[0067] At the same time, the longitudinal fiber density of the bulky non-woven fabric 125 is 10% to 30% lower than the transverse fiber density, preferably 25%, and the surface is distributed with embossed grooves 7, so that the bulky non-woven fabric 125 has different mechanical properties in the longitudinal and transverse directions, the embossed grooves 7 increase the surface area, which is beneficial to the rapid absorption and diffusion of liquid, further improves the air permeability and water absorption performance of the absorption core layer 12, and can provide certain storage capacity to accommodate part of the first high molecular water-absorbing resin particles.

[0068] Further, referring to Table 2, the volume ratio of the second high molecular water-absorbing resin particles 127 to the volume of the strip-shaped groove 5 is 3 to 5:10, preferably 4:10, so that the second high molecular water-absorbing resin particles 127 can fully fill the strip-shaped groove 5, while ensuring the water absorption capacity, avoiding affecting the overall performance of the absorption core layer 12 due to excessive or insufficient filling, and improving the water absorption efficiency and structural stability.

[0069] Table 2: Structural stability test data of the volume ratio of the second high molecular water-absorbing resin particles to the volume of the strip-shaped groove:

[0070]

[0071] ​In this embodiment, the connecting area 6 has a suture line 8 in the middle of the transverse direction, which is distributed in the longitudinal direction, and the ratio of the transverse width of the suture line 8 to the transverse width of the connecting area 6 is 1-2:5, preferably 1.2:5. The suture line enhances the bonding strength of the third non-woven fabric 123 and the fourth non-woven fabric 124 in the connecting area 6, prevents delamination during use, ensures the integrity of the structure of the absorbent core layer 12, improves the durability of the diaper, and the bonding connection of the connecting area 6 cooperates with the suture line 8 to separate the bonding area on the connecting area 6 under the condition of water absorption and expansion of the second high-molecular water-absorbing resin particles 127, providing more expansion space and fully ensuring the water absorption performance of the second high-molecular water-absorbing resin particles 127, further improving the water absorption capacity.

[0072] Furthermore, the absorbent core layer 12 has upper edges 301 and lower edges 302 distributed at both ends of the longitudinal direction, and the left edges 303 and right edges 304 distributed at both ends of the transverse direction, and the longitudinal ends of the heat-pressing area 2 are not connected to the upper edges 301 and lower edges 302, so that the absorbent core layer 12 has a certain flexibility at both ends of the longitudinal direction, reducing the edge stiffness caused by the connection of the heat-pressing area 2, improving the fit of the diaper with the body, enhancing the comfort of the user, and reducing the risk of front and rear leakage.

[0073] Further, the grammage of the first high-molecular water-absorbing resin particles 126 in the bulky non-woven fabric 125 gradually decreases from the middle of the longitudinal direction to both ends of the longitudinal direction, which conforms to the distribution characteristics of human excretion on the diaper, and the excretion is relatively more in the middle of the longitudinal direction, and more grammage of high-molecular water-absorbing resin particles can be effectively absorbed, while the excretion is less at both ends of the longitudinal direction, and reducing the particle grammage can reduce the cost while ensuring the overall absorption performance.

[0074] At the same time, the strip-shaped grooves 5 are distributed in the crotch area 102, which is an area where human excretion is concentrated and frequent activities occur. By arranging the strip-shaped grooves 5 in this area, the second high-molecular water-absorbing resin particles 127 can better play a role in quickly absorbing and fixing excretion, preventing side leakage, and improving the leakage prevention performance of the diaper.

[0075] In this embodiment, the particle size of the first high-molecular water-absorbing resin particles 126 is 100-500 μm, preferably 320-400 μm, and the particle size of the second high-molecular water-absorbing resin particles 127 is 80-400 μm, preferably 80-120 μm, and the particle sizes of the first and second high-molecular water-absorbing resin particles 126 and 127 are different. Different particle sizes of high-molecular water-absorbing resin particles cooperate with each other, large-particle-size particles can quickly absorb a large amount of liquid, and small-particle-size particles can fill the gaps between large-particle-size particles, improving the density and water absorption uniformity of the absorbent core layer 12, and further improving the water absorption efficiency.

[0076] At the same time, the width of the hot-pressing area 2 is 1-8 cm, preferably 2 cm, the interval distance between two adjacent hot-pressing areas 2 is 5-15 cm, preferably 6 cm, the width of the strip-shaped groove 5 is 1-5 cm, preferably 1 cm, and the width of the connecting area 6 between two adjacent strip-shaped grooves 5 is 3-10 cm, preferably 3 cm, so that the absorbent core layer 12 has sufficient absorption area 3 and connecting area 6 while ensuring structural stability, which is conducive to the absorption, diffusion and fixation of liquid, optimizes the performance of the absorbent core layer 12 and improves the overall quality of the paper diaper.

[0077] In the embodiment, the filling amount of the wood pulp fiber 128 is 10-30 g per square meter of the hot-pressing area, preferably 16 g, and the length of the wood pulp fiber 128 is 2-10 mm, preferably 7 mm, and the appropriate filling amount can ensure that the second non-woven fabric 122 forms a good raised portion 4 structure in the hot-pressing area 2, thereby ensuring good liquid infiltration effect, and the appropriate fiber length can affect the distribution and filling effect of the wood pulp fiber 128 in the hot-pressing area 2, thereby affecting the absorption and air permeability of the paper diaper.

[0078] In addition, the terms "first", "second", "third" and the like are used only for descriptive purposes and are not to be construed as indicating or implying relative importance or an indicated number of technical features. Therefore, the features defined as "first", "second" and "third" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise specifically defined and limited.

[0079] In the present application, unless otherwise specifically defined and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrated; it can be directly connected or indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0080] In the present application, unless otherwise specifically defined and limited, the first feature "on" or "under" the second feature can be that the first and second features are in direct contact or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature "above", "over" and "on" the second feature can be that the first feature is directly above or obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "under" and "under" the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0081] While this application has been particularly shown and described with references to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details can be made therein without departing from the spirit and scope of the application as defined by the appended claims.

Claims

1. A diaper with an ultra-thin core, characterized in that: Includes a diaper body, defined as extending along the length direction of the diaper body as the longitudinal direction and extending along the width direction of the diaper body as the transverse direction, the diaper body having a front waist area, a crotch area and a back waist area distributed sequentially along the longitudinal direction. The diaper body includes a liquid-permeable top layer, an absorbent core layer, and a liquid-impermeable bottom layer stacked sequentially from top to bottom. The absorbent core layer includes a first non-woven fabric, a second non-woven fabric, a third non-woven fabric, a fourth non-woven fabric, and a bulky non-woven fabric. The bulky non-woven fabric has multiple heat-pressed zones distributed longitudinally, and each heat-pressed zone is spaced apart in the transverse direction. An absorption zone is formed between two adjacent heat-pressed zones. The basis weight of the bulky non-woven fabric is 20-50 g / m². The bulky non-woven fabric has a longitudinal tensile strength ≥18 N / 5 cm. The bulky non-woven fabric has first superabsorbent polymer particles located in the absorption zone, and the first superabsorbent polymer particles are partially embedded in the pores of the bulky non-woven fabric. The first nonwoven fabric covers the upper surface of the bulky nonwoven fabric and is hot-pressed together with the bulky nonwoven fabric in the hot-pressing zone. The second nonwoven fabric is bonded to the lower surface of the bulky nonwoven fabric. Wood pulp fibers are filled between the second nonwoven fabric and the bulky nonwoven fabric in the hot-pressing zone. Through the wood pulp fibers, the second nonwoven fabric forms a downwardly convex protrusion in the hot-pressing zone. The fourth nonwoven fabric has several downwardly pressed strip-shaped grooves, each of which is distributed vertically and located in the absorption zone. Adjacent strips... A connecting area is formed between the grooves. Each of the grooves is filled with second superabsorbent polymer particles. The third nonwoven fabric covers the fourth nonwoven fabric and is bonded together at the connecting area. The transverse width of the fourth nonwoven fabric is 5-15 mm larger than that of the bulky nonwoven fabric. The transverse sides of the fourth nonwoven fabric are folded upward and inward and attached to the upper surface of the first nonwoven fabric, and the protrusions abut against part of the connecting area. The upper surface of the third nonwoven fabric is laminated to the lower surface of the second nonwoven fabric.

2. The diaper with an ultra-thin core according to claim 1, characterized in that: The total weight of the absorbent core is 120-160 g / m², and the liquid diffusion length measured 30 seconds after 50 ml of physiological saline is injected at a pressure of 3.2 kPa is ≥12 cm, and the reabsorption amount is ≤0.8 g.

3. The diaper with an ultra-thin core according to claim 2, characterized in that: The bulky nonwoven fabric has a longitudinal fiber density that is 10% to 30% lower than the transverse fiber density, and its surface is covered with embossed grooves.

4. The diaper with an ultra-thin core according to claim 3, characterized in that: The volume ratio of the second superabsorbent polymer particles to the volume of the strip groove is 3 to 5:

10.

5. The diaper with an ultra-thin core according to claim 4, characterized in that: A suture line is hot-pressed in the middle of the transverse direction of the connecting area. The suture line is distributed in the longitudinal direction, and the ratio of the transverse width of the suture line to the transverse width of the connecting area is 1 to 2:

5.

6. The diaper with an ultra-thin core according to any one of claims 1 to 5, characterized in that: The absorbent core layer has an upper edge and a lower edge distributed at both ends in the longitudinal direction, and a left edge and a right edge distributed at both ends in the transverse direction. The longitudinal ends of the hot-pressing zone are not connected to the upper edge and the lower edge.

7. The diaper with an ultra-thin core according to claim 6, characterized in that: The basis weight of the first superabsorbent polymer particles in the bulky nonwoven fabric gradually decreases from the middle of the longitudinal direction to both ends.

8. The diaper with an ultra-thin core according to claim 7, characterized in that: The strip-shaped grooves are distributed in the crotch area.

9. The diaper with an ultra-thin core according to claim 8, characterized in that: The particle size of the first superabsorbent polymer (SAP) particles is 100–500 μm, and the particle size of the second SAP particles is 80–400 μm, and the particle sizes of the first SAP particles and the second SAP particles are different.

10. The diaper with an ultra-thin core according to claim 9, characterized in that: The width of the hot-pressing zone is 1-8cm, the interval between two adjacent hot-pressing zones is 5-15cm, the width of the strip groove is 1-5cm, and the width of the connecting area between two adjacent strip grooves is 3-10cm.

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