Alginate fiber paper diaper and preparation method thereof

Abstract

The invention provides an alginate fiber paper diaper and a preparation method thereof, and belongs to the technical field of nursing materials. The core function layer of the paper diaper is widely made of renewable natural materials such as alginate fibers, the degradable breathable PE bottom film is combined, dependence of a traditional paper diaper on petroleum-based raw materials is reduced, the paper diaper has excellent environment friendliness and sustainability, and the paper diaper can be widely applied to paper diapers. The invention provides a new paper diaper choice with high protection performance, natural health property and eco-friendly property for the market, and accurately meets the consumption requirements of modern child-rearing families on high-end, safe and environment-friendly products. The natural antibacterial property of the alginate fiber material is effectively utilized, efficient control over peculiar smell is achieved, the skin irritation and allergy risk possibly caused by addition of a chemical bacteriostatic agent are avoided, the biological safety and health of the product are remarkably improved, and the alginate fiber composite material is especially suitable for infant groups with delicate skin.

Description

Technical Field

[0001] This invention relates to the field of nursing care products technology, and in particular to an algae fiber diaper and its preparation method. Background Technology

[0002] As a disposable hygiene product, disposable diapers are designed to quickly absorb and retain urine, keeping the wearer's skin dry and comfortable while effectively preventing leakage. Traditional disposable diapers typically employ a multi-layered composite structure, including a skin-friendly top layer, a distribution layer, an absorbent core, a leak-proof bottom layer, and elastic leak-proof features around the legs and waist. The top layer, in direct contact with the skin, must be soft, skin-friendly, and allow for rapid absorption. The absorbent core is the core functional layer, primarily relying on a mixture of fluff pulp and superabsorbent polymer (SAP) to absorb and store liquids. The bottom layer is usually a PE film used to prevent leakage.

[0003] Despite continuous technological advancements, traditional disposable diapers still face a series of ongoing technical challenges. The primary issue is backflow, where absorbed liquid seeps back to the skin under external pressure, creating a damp environment that can easily lead to rashes and discomfort over time. This is often related to insufficient anti-backflow layer design or poor core water-locking structure. Secondly, there's the problem of side leakage, especially during infant activity or nighttime sleep, when urine easily leaks through gaps in the waistband and leg openings. Current solutions often address this by increasing elasticity or side panel height, but this frequently comes at the cost of breathability and wearing comfort. Furthermore, to combat odor and skin health risks caused by bacteria growth in a damp environment, many products add chemical antibacterial agents, which may cause skin allergies or raise potential biosafety controversies. Regarding material sustainability, the widespread use of petroleum-based nonwoven fabrics in the top layer and the consumption of wood pulp resources in the core also contradict growing environmental protection demands.

[0004] In recent years, the industry has attempted to adopt natural fiber materials (such as cotton and bamboo fiber) to seek healthier and more environmentally friendly solutions. However, these attempts often face new technological challenges: the processing performance of natural materials is poorly compatible with existing high-speed production lines, and their functionality lags behind that of synthetic materials. For example, natural antibacterial components are easily deactivated under high-temperature processing conditions, and the uniformity of fiber mixing is difficult to control, leading to unstable product performance. Therefore, the market urgently needs an innovative design and manufacturing solution for diapers that can systematically solve the problems of leak prevention, antibacterial properties, backflow prevention, and material environmental friendliness, while also ensuring excellent wearing comfort. Summary of the Invention

[0005] The purpose of this invention is to provide a seaweed fiber diaper and its preparation method, using environmentally friendly raw materials with excellent performance.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides a diaper with a ring-shaped closed structure, comprising, from top to bottom, a top layer, an upper anti-reverse osmosis functional layer, an absorbent core layer, a lower anti-reverse osmosis functional layer, and a bottom film; it also includes a ring-shaped waistband system, side leakage barriers, and leg leakage barriers; the layers are tightly connected by heat-pressing composite, and the side leakage barriers and leg leakage barriers form a surrounding leakage barrier; The surface layer is a seaweed fiber nonwoven fabric, which is woven from seaweed fiber and cotton fiber mixed at a mass ratio of 0.1 to 100:1, and has air pores. Both the upper and lower anti-reverse osmosis functional layers are non-woven fabrics made of a mixture of seaweed fiber and cotton fiber, and both are coated with a water-repellent finishing agent on one side to form a water-repellent and hydrophilic side. The water-repellent side of the upper anti-reverse osmosis functional layer faces upward and the hydrophilic side faces downward, while the water-repellent side of the lower anti-reverse osmosis functional layer faces downward and the hydrophilic side faces upward. The absorbent core layer contains seaweed fiber absorbers; The bottom film is a breathable PE film; The ring-shaped waist system is composed of an elastic non-woven fabric and the bottom film; The anti-leakage partition is a three-dimensional non-woven fabric structure, which is set on both sides and connected by ultrasonic welding. The leak-proof edge of the leg is made of elastic Lycra.

[0007] Preferably, the basis weight of the surface layer is 10~90g / m². 2 The diameter of the vent holes is 0.6~0.7mm, and the pore density is 30~40 pores / cm³. 2 .

[0008] Preferably, in the upper and lower anti-reverse osmosis functional layers, the mass ratio of seaweed fiber to cotton fiber is 1:2~5; and the basis weight of the nonwoven fabric is 10~90g / m². 2 .

[0009] Preferably, the water-repellent finishing agent comprises the following components in parts by weight: 10-15 parts of waterborne polyurethane, 5-8 parts of waterborne carnauba wax emulsion, 3-5 parts of polydimethylsiloxane PEG-10-15 crosslinked polymer, and the balance being deionized water.

[0010] Preferably, the elastic nonwoven fabric of the circular waistband system contains spandex fibers; the circumference of the circular waistband system is adjustable in the range of 40~60cm, and the tensile resilience is ≥90%.

[0011] The present invention also provides a method for preparing the above-mentioned diaper, comprising the following steps: (a) Raw material pretreatment; (b) Fabrication of the anti-reverse osmosis functional layer; (c) Fabrication of the absorbent core layer; (d) Topcoat and basecoat treatment; (e) Multilayer composites and ring molding; (f) Post-processing and quality inspection; The raw material pretreatment in step (a) includes washing, crushing, alkaline extraction, bleaching and drying of seaweed raw materials to obtain seaweed fiber; The water temperature for cleaning is 30~35℃, and the cleaning time is 5~8 minutes; The crushing speed is 1400~1600 r / min, and the particles are crushed to a size ≤5 mm; The alkaline extraction method uses a 2-3% NaOH solution and is carried out at a constant temperature of 80-85℃ for 1.5-2.5 hours. The bleaching process uses a hydrogen peroxide solution with a mass fraction of 1-2%, and is performed at a pH of 9-10 and a temperature of 55-65℃ for 25-35 minutes. The temperature of the drying hot air is 60~70℃, so that the moisture content is controlled at 8~10%.

[0012] Preferably, step (a) further includes: opening the cotton fibers using a fiber opener, and then mixing them with the seaweed fibers obtained in step (a) in a cotton blender, with a mixing uniformity of ≥95%; Step (b) involves fabricating the anti-reverse osmosis functional layer, which includes: The mixed fibers are combed into a single fiber web, and after being laid in layers, they are bonded together with hot air to form a non-woven fabric base. A water-repellent finishing agent is sprayed onto one side of the nonwoven fabric substrate; After drying and curing, a water-repellent and hydrophilic anti-reverse osmosis functional layer is formed.

[0013] Preferably, the combing speed is 15~20m / min, and the thickness of the formed single fiber web is 0.3~0.5mm; The layers are laid in 3 to 5 layers, with a total thickness of 1.0 to 1.2 mm; The hot air bonding temperature is 125~135℃, the wind speed is 11~14m / s, and the bonding time is 30~40s; The basis weight of the nonwoven fabric substrate is 40~50 g / m². 2 ; The application rate of the water-repellent finishing agent is 8~10 g / m². 2 The spraying pressure is 0.3~0.4MPa; The drying and curing temperature is 80~90℃, and the time is 2~3 minutes.

[0014] Preferably, the absorbent core layer fabrication in step (c) includes: using sodium alginate as raw material to form a web through airflow and hot-press curing into a cotton-like paper; The wind speed at which the airflow forms a network is 12~15m / s; The hot-press curing temperature is 110~120℃, and the pressure is 0.2~0.3MPa; The basis weight of the cotton-like paper is 30~40 g / m³. 2 The thickness is 0.2~0.3mm.

[0015] Preferably, step (e) of the multilayer composite and ring forming includes: The layers are stacked and hot-pressed in the following order: surface layer → upper anti-reverse osmosis functional layer → absorbent core layer → lower anti-reverse osmosis functional layer → bottom membrane. The hot-pressing composite temperature is 70~80℃, the pressure is 0.3~0.5MPa, and the composite speed is 13~17m / min; After hot-pressing, the anti-leakage barrier is added to both sides of the composite layer by ultrasonic sealing, and the anti-leakage barrier for the legs is also added. The frequency of the ultrasonic sealing is 21~24kHz; An adjustable adhesive area for the ring-shaped waistband system is formed by hot-pressing bonding. A die-cutting machine is used to cut the composite roll material into ring-shaped diapers.

[0016] The beneficial effects of this invention are: This invention utilizes renewable natural materials such as seaweed fiber in its core functional layer, combined with a biodegradable and breathable PE bottom film. This reduces the reliance of traditional diapers on petroleum-based raw materials, giving the product excellent environmental friendliness and sustainability. This invention provides the market with a new diaper option that simultaneously offers superior protection, natural health benefits, and eco-friendly characteristics, precisely meeting the consumption needs of modern families with young children for high-end, safe, and environmentally friendly products. Through the synergistic effect of a ring-shaped closed structure and a double-sided anti-reverse osmosis functional layer, combined with a 360-degree three-dimensional leak-proof side panel and elastic leg leak-proof side panels, this invention significantly improves the reliability of preventing side and back leaks, effectively reducing the risk of liquid leakage in various usage scenarios. Simultaneously, by utilizing the inherent natural antibacterial properties of seaweed fiber, it achieves efficient odor control, avoiding the skin irritation and allergy risks that may arise from adding chemical antibacterial agents. This significantly improves the product's biosafety and health benefits, making it particularly suitable for infants with delicate skin.

[0017] This invention possesses excellent process adaptability and scalability: the Velcro design of the ring waistband system allows for adjustment of the adhesive area and strength to accommodate different waist sizes and activity levels; the anti-backflow functional layer's durability can be further enhanced by optimizing the formulation of the water-repellent finishing agent and the spraying process; the absorbency and thickness of the absorbent core can be balanced by adjusting the quantity and distribution of the seaweed fiber absorbent. In summary, this invention systematically solves industry challenges such as diaper leakage, backflow, chemical irritation, and non-degradable materials. Through material innovation and structural design, it successfully achieves a balance between protective performance, wearing comfort, health and safety, and environmental friendliness, providing a reliable and scalable technical solution for developing high-performance, environmentally friendly diapers. Attached Figure Description

[0018] Figure 1 Photograph of the core layer before it absorbs water; Figure 2 Photograph of the core layer after it has absorbed water; Figure 3 Test report 1 for the seaweed fiber material used in this invention; Figure 4 Test report 2 for the seaweed fiber material used in this invention; Figure 5 Test report 3 for the seaweed fiber material used in this invention. Detailed Implementation

[0019] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0020] Example 1 The diaper has a closed, ring-shaped structure, consisting of the following components from top to bottom: Surface layer (using 22.5g / m²) 2 The seaweed fiber nonwoven fabric has a certain degree of antibacterial properties and features a diameter of 0.65mm and a pore density of 35 pores / cm². 2 (vent holes) The upper anti-reverse osmosis functional layer (a non-woven fabric made of seaweed fiber and cotton fiber in a mass ratio of 3:7, with a basis weight of 45g / m²) 2 Apply a water-repellent finishing agent to one side (mass fraction: 12.5% ​​waterborne polyurethane, 6.5% waterborne carnauba wax emulsion, 4% polydimethylsiloxane PEG-10-15 crosslinked polymer, balance deionized water), with the water-repellent side facing up and the hydrophilic side facing down, and a contact angle ≥130°. Absorbent core layer (comprising cotton-like paper (0.25mm thick) and seaweed fiber absorbent (sodium alginate copolymer), antibacterial rate: ≥90% against Escherichia coli and Staphylococcus aureus, with a sustained antibacterial time of ≥8h) The lower anti-reverse osmosis functional layer (a non-woven fabric made of seaweed fiber and cotton fiber in a mass ratio of 3:7, with a basis weight of 45g / m²) 2 A single-sided spray coating of water-repellent finishing agent (mass fraction: 12.5% ​​waterborne polyurethane, 6.5% waterborne carnauba wax emulsion, 4% polydimethylsiloxane PEG-10-15 crosslinked polymer, balance deionized water) is applied with the water-repellent side facing down and the hydrophilic side facing up, with a contact angle ≥130°. Bottom film (breathable PE film, thickness 0.015mm, transverse tensile strength ≥150%) And a circular waistband system (composed of elastic nonwoven fabric (containing 2% spandex fiber) and a base film, with an adjustable circumference range of 40-60cm and a tensile resilience of ≥90%). The anti-leakage structure includes 360° anti-leakage barriers on both sides (non-woven fabric three-dimensional structure, 11mm wide and 5mm high, connected to the surface / bottom film by ultrasonic welding) and anti-leakage barriers on the legs (elastic Lycra edge, 8mm wide, with an elongation rate of ≥200%).

[0021] Each layer is tightly connected by hot-pressing composite, forming a surrounding leak-proof barrier.

[0022] The absorbent layer material used in this invention, as shown in the photograph before water absorption, is as follows. Figure 1 As shown, after absorbing water, it is like Figure 2 As shown.

[0023] The test report for the seaweed fiber material used in this invention is as follows: Figures 3-5 As shown.

[0024] The production process includes raw material pretreatment, fabrication of the anti-reverse osmosis functional layer, fabrication of the absorbent core layer, treatment of the surface and bottom membranes, multi-layer composite and ring molding, post-treatment and quality inspection.

[0025] In the raw material pretreatment stage, the core raw materials include seaweed fiber with a length of 4mm and a fineness of 1.35dtex, cotton fiber with a length of 3mm and a fineness of 1.1dtex, cotton-like paper, seaweed fiber absorbent, water-repellent finishing agent, breathable PE bottom film, and seaweed fiber nonwoven fabric surface layer.

[0026] The seaweed raw materials (brown algae / red algae) were washed (water temperature 32.5℃, washing time 6.5min), crushed (speed 1500r / min, crushed to particle size ≤5mm), extracted by alkaline method (NaOH solution mass fraction 2.5%, constant temperature extraction at 82.5℃ for 2h, seaweed fiber was separated), bleached (hydrogen peroxide mass fraction 1.5%, pH value 9.5, treatment at 60℃ for 30min) and dried (hot air temperature 65℃, moisture content controlled at 9%).

[0027] Cotton fibers are opened using a fiber opener (800 rpm) to remove knots and impurities. Then, they are thoroughly mixed with seaweed fibers in a blender at a 3:7 mass ratio (mixing time 12.5 min, uniformity ≥95%). For the anti-reverse osmosis functional layer, the mixed fibers are carded into a single-fiber web (carding speed 17.5 m / min, web thickness 0.4 mm). After being layered by a web-laying machine (4 layers, web-laying speed 17.5 m / min, total thickness 1.1 mm), they are bonded using a hot air bonding machine (hot air temperature 130℃, air velocity 12.5 m / s, bonding time 35 s) to form a nonwoven fabric base (45 g / m²). 2 Subsequently, a single-sided spraying machine was used to evenly spray the water-repellent finishing agent onto one side of the nonwoven fabric (spraying amount 9g / m²). 2 The coating is applied at a pressure of 0.35 MPa and then dried in an oven at 85°C for 2.5 minutes to form a functional layer with a water-repellent surface contact angle of ≥130° and a hydrophilic surface on one side.

[0028] The absorbent core layer is manufactured using a dust-free paper machine with sodium alginate as the raw material (pulp concentration 4%). The paper is formed into a cotton-like paper (35 g / m²) through airflow forming (wind speed 13.5 m / s) and hot-press curing (temperature 115℃, pressure 0.25 MPa). 2 (0.25mm thick) as the absorbent (dosage 17.5g / m³) 2 A preliminary absorption layer is formed by particles with a diameter of 0.2 mm.

[0029] The surface layer uses seaweed fiber nonwoven fabric, with perforations to enhance liquid permeation speed (permeation time ≤ 2s). The bottom membrane uses a breathable PE membrane, unwound using an unwinding machine to maintain stable tension (6.5N). In the multi-layer lamination and ring-forming stage, the following sequence is used: surface layer → upper anti-reverse osmosis functional layer (water-repellent side up, hydrophilic side down) → absorbent core layer → lower anti-reverse osmosis functional layer (water-repellent side down, hydrophilic side up) → bottom membrane. This is achieved through hot-press lamination using a five-roll laminator (with added arc-shaped guide rollers, curvature radius 50mm) (temperature 75℃, pressure 0.4MPa, lamination speed 15m / min, ensuring interlayer peel strength ≥ 3.5N / 15mm). On both sides of the composite roll material, non-woven fabric leak-proof barriers are added using an ultrasonic sealing machine (ultrasonic frequency 22.5kHz), with a sealing strength ≥2N / 15mm. Simultaneously, Lycra leak-proof barriers are added to the leg openings, forming a three-dimensional leak-proof barrier (side leakage test: placed at a 30° angle, 80mL of simulated urine is injected; no side leakage). The waistband closure is achieved by heat-pressing (temperature 80℃, pressure 0.3MPa, time 1.5s) to form an adjustable Velcro fastening area (length 10cm, adhesive strength ≥1.5N / 25mm). A circular die-cutting machine is used to cut the composite roll material into circular diapers (die-cutting diameter range 120-180mm, cutting accuracy ±0.8mm). In the post-processing and quality inspection stages, the integrity of each composite layer, the sealing performance of the leak-proof structure, the thickness uniformity (deviation ≤0.1mm), the annular flatness (circumference deviation ≤1mm, curvature uniformity ≥95%), the water absorption performance (3 injections of 30mL simulated urine each time, 15min interval, total water absorption rate ≥1000%, reverse osmosis amount ≤0.15g, reverse osmosis rate ≤5%), and the production qualification rate (≥98%) are tested. This technical solution prevents liquid from seeping back through the single-sided water-repellent properties of the anti-reverse osmosis functional layer, and physically blocks side leakage through the three-dimensional leak-proof partition and elastic Lycra edge; natural antibacterial properties are achieved through the natural antibacterial components (such as seaweed polysaccharides) contained in the seaweed fiber itself, eliminating the need for added chemical antibacterial agents and ensuring higher safety. Each process step is controlled by dedicated equipment to ensure stable and repeatable functions.

[0030] Example 2 The diaper has a closed, ring-shaped structure, consisting of the following components from top to bottom: Surface layer (using 23g / m²) 2 The seaweed fiber nonwoven fabric has inherent antibacterial properties and features a diameter of 0.7mm and a pore density of 38 pores / cm². 2 (vent holes) The upper anti-reverse osmosis functional layer (a non-woven fabric made of seaweed fiber and cotton fiber, with a basis weight of 45g / m²) 2Apply a water-repellent finishing agent to one side (mass fraction: 12.5% ​​waterborne polyurethane, 6.5% waterborne carnauba wax emulsion, 4% polydimethylsiloxane PEG-10-15 crosslinked polymer, balance deionized water), with the water-repellent side facing up and the hydrophilic side facing down, and a contact angle ≥130°. Absorbent core layer (comprising cotton-like paper (0.25mm thick) and seaweed fiber absorbent (sodium alginate copolymer), antibacterial rate: ≥90% against Escherichia coli and Staphylococcus aureus, with a sustained antibacterial time of ≥8h) The lower anti-reverse osmosis functional layer (a non-woven fabric made of a blend of seaweed fiber and cotton fiber, with a basis weight of 45 g / m²) 2 A single-sided spray coating of water-repellent finishing agent (mass fraction: 12.5% ​​waterborne polyurethane, 6.5% waterborne carnauba wax emulsion, 4% polydimethylsiloxane PEG-10-15 crosslinked polymer, balance deionized water) is applied with the water-repellent side facing down and the hydrophilic side facing up, with a contact angle ≥130°. Bottom film (breathable PE film, thickness 0.015mm, transverse tensile strength ≥150%) And a circular waistband system (composed of elastic nonwoven fabric (containing 2% spandex fiber) and a base film, with an adjustable circumference range of 40-60cm and a tensile resilience of ≥90%). The anti-leakage structure includes 360° anti-leakage barriers on both sides (non-woven fabric three-dimensional structure, 11mm wide and 5mm high, connected to the surface / bottom film by ultrasonic welding) and anti-leakage barriers on the legs (elastic Lycra edge, 8mm wide, with an elongation rate of ≥200%).

[0031] Each layer is tightly connected by hot-pressing composite, forming a surrounding leak-proof barrier.

[0032] The production process includes raw material pretreatment, fabrication of the anti-reverse osmosis functional layer, fabrication of the absorbent core layer, treatment of the surface and bottom membranes, multi-layer composite and ring molding, post-treatment and quality inspection.

[0033] In the raw material pretreatment stage, the core raw materials include seaweed fiber with a length of 4mm and a fineness of 1.35dtex, cotton fiber with a length of 3mm and a fineness of 1.1dtex, cotton-like paper, seaweed fiber absorbent, water-repellent finishing agent, breathable PE bottom film, and seaweed fiber nonwoven fabric surface layer.

[0034] The seaweed raw materials (brown algae / red algae) were washed (water temperature 32.5℃, washing time 6.5min), crushed (speed 1500r / min, crushed to particle size ≤5mm), extracted by alkaline method (NaOH solution mass fraction 2.5%, constant temperature extraction at 82.5℃ for 2h, seaweed fiber was separated), bleached (hydrogen peroxide mass fraction 1.5%, pH value 9.5, treatment at 60℃ for 30min) and dried (hot air temperature 65℃, moisture content controlled at 9%).

[0035] Cotton fibers are opened using a fiber opener (800 rpm) to remove knots and impurities. Then, they are thoroughly mixed with seaweed fibers in a blender at a 2:8 mass ratio (mixing time 12 min, uniformity ≥95%). For the anti-reverse osmosis functional layer, the mixed fibers are carded into a single-fiber web (carding speed 17.5 m / min, web thickness 0.4 mm). After being layered by a web-laying machine (4 layers, web-laying speed 17.5 m / min, total thickness 1.1 mm), they are bonded using a hot air bonding machine (hot air temperature 130℃, air velocity 12.5 m / s, bonding time 35 s) to form a nonwoven fabric base (45 g / m²). 2 Subsequently, a single-sided spraying machine was used to evenly spray the water-repellent finishing agent onto one side of the nonwoven fabric (spraying amount 9g / m²). 2 The coating is applied at a pressure of 0.35 MPa and then dried in an oven at 85°C for 2.5 minutes to form a functional layer with a water-repellent surface contact angle of ≥130° and a hydrophilic surface on one side.

[0036] The absorbent core layer is manufactured using a dust-free paper machine with sodium alginate as the raw material (pulp concentration 4%). The paper is formed into a cotton-like paper (35 g / m²) through airflow forming (wind speed 13.5 m / s) and hot-press curing (temperature 115℃, pressure 0.25 MPa). 2 A preliminary absorption layer is formed by using a material with a thickness of 0.25 mm as the absorber (dosage 17.5 g / m2, particle size 0.2 mm).

[0037] The surface layer uses seaweed fiber nonwoven fabric, with perforations to enhance liquid permeation speed (permeation time ≤ 2s). The bottom membrane uses a breathable PE membrane, unwound using an unwinding machine to maintain stable tension (6.5N). In the multi-layer lamination and ring-forming stage, the following sequence is used: surface layer → upper anti-reverse osmosis functional layer (water-repellent side up, hydrophilic side down) → absorbent core layer → lower anti-reverse osmosis functional layer (water-repellent side down, hydrophilic side up) → bottom membrane. This is achieved through hot-press lamination using a five-roll laminator (with added arc-shaped guide rollers, curvature radius 50mm) (temperature 75℃, pressure 0.4MPa, lamination speed 15m / min, ensuring interlayer peel strength ≥ 3.5N / 15mm). On both sides of the composite roll material, non-woven fabric leak-proof barriers are added using an ultrasonic sealing machine (ultrasonic frequency 22.5kHz), with a sealing strength ≥2N / 15mm. Simultaneously, Lycra leak-proof barriers are added to the leg openings, forming a three-dimensional leak-proof barrier (side leakage test: placed at a 30° angle, 80mL of simulated urine is injected; no side leakage). The waistband closure is achieved by heat-pressing (temperature 80℃, pressure 0.3MPa, time 1.5s) to form an adjustable Velcro fastening area (length 10cm, adhesive strength ≥1.5N / 25mm). A circular die-cutting machine is used to cut the composite roll material into circular diapers (die-cutting diameter range 120-180mm, cutting accuracy ±0.8mm). In the post-processing and quality inspection stages, the integrity of each composite layer, the sealing performance of the leak-proof structure, the thickness uniformity (deviation ≤0.1mm), the annular flatness (circumference deviation ≤1mm, curvature uniformity ≥95%), the water absorption performance (3 injections of 30mL simulated urine each time, 15min interval, total water absorption rate ≥1000%, reverse osmosis amount ≤0.15g, reverse osmosis rate ≤5%), and the production qualification rate (≥98%) are tested. This technical solution prevents liquid from seeping back through the single-sided water-repellent properties of the anti-reverse osmosis functional layer, and physically blocks side leakage through the three-dimensional leak-proof partition and elastic Lycra edge; natural antibacterial properties are achieved through the natural antibacterial components (such as seaweed polysaccharides) contained in the seaweed fiber itself, eliminating the need for added chemical antibacterial agents and ensuring higher safety. Each process step is controlled by dedicated equipment to ensure stable and repeatable functions.

[0038] Example 3 The diaper has a closed, ring-shaped structure, consisting of the following components from top to bottom: Surface layer (using 21g / m²) 2 The seaweed fiber nonwoven fabric has a certain degree of antibacterial properties and features a diameter of 0.55mm and a pore density of 32 pores / cm². 2 (vent holes) The upper anti-reverse osmosis functional layer (a non-woven fabric made of seaweed fiber and cotton fiber, with a basis weight of 45g / m²) 2Apply a water-repellent finishing agent to one side (mass fraction: 12.5% ​​waterborne polyurethane, 6.5% waterborne carnauba wax emulsion, 4% polydimethylsiloxane PEG-10-15 crosslinked polymer, balance deionized water), with the water-repellent side facing up and the hydrophilic side facing down, and a contact angle ≥130°. Absorbent core layer (comprising cotton-like paper (0.25mm thick) and seaweed fiber absorbent (sodium alginate copolymer), antibacterial rate: ≥90% against Escherichia coli and Staphylococcus aureus, with a sustained antibacterial time of ≥8h) The lower anti-reverse osmosis functional layer (a non-woven fabric made of a blend of seaweed fiber and cotton fiber, with a basis weight of 45 g / m²) 2 A single-sided spray coating of water-repellent finishing agent (mass fraction: 12.5% ​​waterborne polyurethane, 6.5% waterborne carnauba wax emulsion, 4% polydimethylsiloxane PEG-10-15 crosslinked polymer, balance deionized water) is applied with the water-repellent side facing down and the hydrophilic side facing up, with a contact angle ≥130°. Bottom film (breathable PE film, thickness 0.015mm, transverse tensile strength ≥150%) And a circular waistband system (composed of elastic nonwoven fabric (containing 2% spandex fiber) and a base film, with an adjustable circumference range of 40-60cm and a tensile resilience of ≥90%). The anti-leakage structure includes 360° anti-leakage barriers on both sides (non-woven fabric three-dimensional structure, 11mm wide and 5mm high, connected to the surface / bottom film by ultrasonic welding) and anti-leakage barriers on the legs (elastic Lycra edge, 8mm wide, with an elongation rate of ≥200%).

[0039] Each layer is tightly connected by hot-pressing composite, forming a surrounding leak-proof barrier.

[0040] The production process includes raw material pretreatment, fabrication of the anti-reverse osmosis functional layer, fabrication of the absorbent core layer, treatment of the surface and bottom membranes, multi-layer composite and ring molding, post-treatment and quality inspection.

[0041] In the raw material pretreatment stage, the core raw materials include seaweed fiber with a length of 4mm and a fineness of 1.35dtex, cotton fiber with a length of 3mm and a fineness of 1.1dtex, cotton-like paper, seaweed fiber absorbent, water-repellent finishing agent, breathable PE bottom film, and seaweed fiber nonwoven fabric surface layer.

[0042] The seaweed raw materials (brown algae / red algae) were washed (water temperature 32.5℃, washing time 6.5min), crushed (speed 1500r / min, crushed to particle size ≤5mm), extracted by alkaline method (NaOH solution mass fraction 2.5%, constant temperature extraction at 82.5℃ for 2h, seaweed fiber was separated), bleached (hydrogen peroxide mass fraction 1.5%, pH value 9.5, treatment at 60℃ for 30min) and dried (hot air temperature 65℃, moisture content controlled at 9%).

[0043] Cotton fibers are opened using a fiber opener (800 rpm) to remove knots and impurities. Then, they are thoroughly mixed with seaweed fibers in a blender at a 1:9 mass ratio (mixing time 15 min, uniformity ≥95%). For the anti-reverse osmosis functional layer, the mixed fibers are carded into a single-fiber web (carding speed 17.5 m / min, web thickness 0.4 mm). After being layered by a web-laying machine (4 layers, web-laying speed 17.5 m / min, total thickness 1.1 mm), they are bonded using a hot air bonding machine (hot air temperature 130℃, air velocity 12.5 m / s, bonding time 35 s) to form a nonwoven fabric base (45 g / m²). 2 Subsequently, a single-sided spraying machine was used to evenly spray the water-repellent finishing agent onto one side of the nonwoven fabric (spraying amount 9g / m²). 2 The coating is applied at a pressure of 0.35 MPa and then dried in an oven at 85°C for 2.5 minutes to form a functional layer with a water-repellent surface contact angle of ≥130° and a hydrophilic surface on one side.

[0044] The absorbent core layer is manufactured using a dust-free paper machine with sodium alginate as the raw material (pulp concentration 4%). The paper is formed into a cotton-like paper (35 g / m²) through airflow forming (wind speed 13.5 m / s) and hot-press curing (temperature 115℃, pressure 0.25 MPa). 2 A preliminary absorption layer is formed by using a material with a thickness of 0.25 mm as the absorber (dosage 17.5 g / m2, particle size 0.2 mm).

[0045] The surface layer uses seaweed fiber nonwoven fabric, with perforations to enhance liquid permeation speed (permeation time ≤ 2s). The bottom membrane uses a breathable PE membrane, unwound using an unwinding machine to maintain stable tension (6.5N). In the multi-layer lamination and ring-forming stage, the following sequence is used: surface layer → upper anti-reverse osmosis functional layer (water-repellent side up, hydrophilic side down) → absorbent core layer → lower anti-reverse osmosis functional layer (water-repellent side down, hydrophilic side up) → bottom membrane. This is achieved through hot-press lamination using a five-roll laminator (with added arc-shaped guide rollers, curvature radius 50mm) (temperature 75℃, pressure 0.4MPa, lamination speed 15m / min, ensuring interlayer peel strength ≥ 3.5N / 15mm). On both sides of the composite roll material, non-woven fabric leak-proof barriers are added using an ultrasonic sealing machine (ultrasonic frequency 22.5kHz), with a sealing strength ≥2N / 15mm. Simultaneously, Lycra leak-proof barriers are added to the leg openings, forming a three-dimensional leak-proof barrier (side leakage test: placed at a 30° angle, 80mL of simulated urine is injected; no side leakage). The waistband closure is achieved by heat-pressing (temperature 80℃, pressure 0.3MPa, time 1.5s) to form an adjustable Velcro fastening area (length 10cm, adhesive strength ≥1.5N / 25mm). A circular die-cutting machine is used to cut the composite roll material into circular diapers (die-cutting diameter range 120-180mm, cutting accuracy ±0.8mm). In the post-processing and quality inspection stages, the integrity of each composite layer, the sealing performance of the leak-proof structure, the thickness uniformity (deviation ≤0.1mm), the annular flatness (circumference deviation ≤1mm, curvature uniformity ≥95%), the water absorption performance (3 injections of 30mL simulated urine each time, 15min interval, total water absorption rate ≥1000%, reverse osmosis amount ≤0.15g, reverse osmosis rate ≤5%), and the production qualification rate (≥98%) are tested. This technical solution prevents liquid from seeping back through the single-sided water-repellent properties of the anti-reverse osmosis functional layer, and physically blocks side leakage through the three-dimensional leak-proof partition and elastic Lycra edge; natural antibacterial properties are achieved through the natural antibacterial components (such as seaweed polysaccharides) contained in the seaweed fiber itself, eliminating the need for added chemical antibacterial agents and ensuring higher safety. Each process step is controlled by dedicated equipment to ensure stable and repeatable functions.

[0046] As can be seen from the above embodiments, the present invention provides a new choice of diapers that simultaneously possesses superior protective performance, natural health attributes, and eco-friendly characteristics, precisely meeting the consumption needs of modern families with young children for high-end, safe, and environmentally friendly products. The present invention effectively utilizes the inherent natural antibacterial properties of seaweed fiber materials to achieve highly efficient odor control, avoiding the skin irritation and allergy risks that may arise from the addition of chemical antibacterial agents, significantly improving the product's biosafety and health benefits, and making it particularly suitable for infants and young children with delicate skin.

[0047] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A diaper, characterized in that, The diaper has a ring-shaped closed structure, and from top to bottom, it includes a top layer, an upper anti-reverse osmosis functional layer, an absorbent core layer, a lower anti-reverse osmosis functional layer, and a bottom film; it also includes a ring-shaped waistband system, anti-leakage side panels, and leg anti-leakage side panels; each layer is tightly connected by heat-pressing composite, and the anti-leakage side panels and leg anti-leakage side panels form a surrounding leak-proof barrier; The surface layer is a seaweed fiber nonwoven fabric, which is woven from seaweed fiber and cotton fiber mixed at a mass ratio of 0.1 to 100:1, and has air pores. Both the upper and lower anti-reverse osmosis functional layers are non-woven fabrics made of a mixture of seaweed fiber and cotton fiber, and both are coated with a water-repellent finishing agent on one side to form a water-repellent and hydrophilic side. The water-repellent side of the upper anti-reverse osmosis functional layer faces upward and the hydrophilic side faces downward, while the water-repellent side of the lower anti-reverse osmosis functional layer faces downward and the hydrophilic side faces upward. The absorbent core layer contains seaweed fiber absorbers; The bottom film is a breathable PE film; The ring-shaped waist system is composed of an elastic non-woven fabric and the bottom film; The anti-leakage partition is a three-dimensional non-woven fabric structure, which is set on both sides and connected by ultrasonic welding. The leak-proof edge of the leg is made of elastic Lycra.

2. The diaper according to claim 1, characterized in that, The surface layer has a basis weight of 10~90g / m² 2 The diameter of the vent holes is 0.6~0.7mm, and the pore density is 30~40 pores / cm³. 2 .

3. The diaper according to claim 1, characterized in that, In the upper and lower anti-reverse osmosis functional layers, the mass ratio of seaweed fiber to cotton fiber is 1:2~5; the nonwoven fabric has a basis weight of 40~50g / m². 2 .

4. The diaper according to any one of claims 1 to 3, characterized in that, The water-repellent finishing agent comprises the following components in parts by weight: 10-15 parts of waterborne polyurethane, 5-8 parts of waterborne carnauba wax emulsion, 3-5 parts of polydimethylsiloxane PEG-10-15 crosslinked polymer, and the balance being deionized water.

5. The diaper according to claim 1, characterized in that, The elastic nonwoven fabric of the circular waistband system contains spandex fibers; the circumference of the circular waistband system is adjustable from 40 to 60 cm, and the tensile resilience is ≥90%.

6. The method for preparing the diaper according to any one of claims 1 to 5, characterized in that, Includes the following steps: (a) Raw material pretreatment; (b) Fabrication of the anti-reverse osmosis functional layer; (c) Fabrication of the absorbent core layer; (d) Topcoat and basecoat treatment; (e) Multilayer composites and ring molding; (f) Post-processing and quality inspection; The raw material pretreatment in step (a) includes washing, crushing, alkaline extraction, bleaching and drying of seaweed raw materials to obtain seaweed fiber; The water temperature for cleaning is 30~35℃, and the cleaning time is 5~8 minutes; The crushing speed is 1400~1600 r / min, and the particles are crushed to a size ≤5 mm; The alkaline extraction method uses a 2-3% NaOH solution and is carried out at a constant temperature of 80-85℃ for 1.5-2.5 hours. The bleaching process uses a hydrogen peroxide solution with a mass fraction of 1-2%, and is performed at a pH of 9-10 and a temperature of 55-65℃ for 25-35 minutes. The temperature of the drying hot air is 60~70℃, so that the moisture content is controlled at 8~10%.

7. The preparation method according to claim 6, characterized in that, Step (a) further includes: opening the cotton fibers using a fiber opener, and then mixing them with the seaweed fibers obtained in step (a) in a cotton blender, with a mixing uniformity of ≥95%; Step (b) involves fabricating the anti-reverse osmosis functional layer, which includes: The mixed fibers are combed into a single fiber web, and after being laid in layers, they are bonded together with hot air to form a non-woven fabric base. A water-repellent finishing agent is sprayed onto one side of the nonwoven fabric substrate; After drying and curing, a water-repellent and hydrophilic anti-reverse osmosis functional layer is formed.

8. The preparation method according to claim 7, characterized in that, The combing speed is 15~20m / min, and the thickness of the formed single fiber web is 0.3~0.5mm; The layers are laid in 3 to 5 layers, with a total thickness of 1.0 to 1.2 mm; The hot air bonding temperature is 125~135℃, the wind speed is 11~14m / s, and the bonding time is 30~40s; The basis weight of the nonwoven fabric substrate is 10~90 g / m². 2 ; The application rate of the water-repellent finishing agent is 8~10 g / m². 2 The spraying pressure is 0.3~0.4MPa; The drying and curing temperature is 80~90℃, and the time is 2~3 minutes.

9. The preparation method according to claim 6, characterized in that, The fabrication of the absorbent core layer in step (c) includes: using sodium alginate as raw material to form a web through airflow and hot-pressing to solidify it into a cotton-like paper; The wind speed at which the airflow forms a network is 12~15m / s; The hot-press curing temperature is 110~120℃, and the pressure is 0.2~0.3MPa; The basis weight of the cotton-like paper is 30~40 g / m³. 2 The thickness is 0.2~0.3mm.

10. The preparation method according to claim 6, characterized in that, Step (e) of the multilayer composite and ring forming includes: The layers are stacked and hot-pressed in the following order: surface layer → upper anti-reverse osmosis functional layer → absorbent core layer → lower anti-reverse osmosis functional layer → bottom membrane. The hot-pressing composite temperature is 70~80℃, the pressure is 0.3~0.5MPa, and the composite speed is 13~17m / min; After hot-pressing, the anti-leakage barrier is added to both sides of the composite layer by ultrasonic sealing, and the anti-leakage barrier for the legs is also added. The frequency of the ultrasonic sealing is 21~24kHz; An adjustable adhesive area for the ring-shaped waistband system is formed by hot-pressing bonding. A die-cutting machine is used to cut the composite roll material into ring-shaped diapers.

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