Preparation method of a leak-proof baby diaper

Abstract

The present application relates to the field of disposable sanitary products, and particularly relates to a preparation method of a leakage-proof baby diaper, mainly solving the problem of poor side leakage prevention effect of the existing diaper, and being used for preparing a diaper with good side leakage prevention effect and the characteristics of adapting to the dynamic activity requirements of users with different body types, comprising a diaper body, and the preparation method of the diaper body comprises the following steps: 1) preparing a liquid-impermeable bottom layer, defining a plurality of continuous absorption units along the conveying direction of the liquid-impermeable bottom layer; 2) preparing an absorption core layer; 3) cutting the absorption core layer of step 2) to form single absorption bodies, and transferring the absorption bodies to the absorption units of the liquid-impermeable bottom layer of step 1) in sequence for compounding, and the absorption bodies are distributed in sequence and at intervals along the conveying direction of the liquid-impermeable bottom layer; 4) preparing a liquid-permeable surface layer; 5) cutting the above product along the boundary of the absorption unit to form a single diaper body.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of disposable sanitary products, in particular to a preparation method of a leakage-proof baby diaper. BACKGROUND

[0002] The structure of the diaper generally comprises, 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 formed by combining fluffy non-woven fabric with high molecular water-absorbing resin or mixing wood pulp fibers and high molecular water-absorbing resin and wrapping them with non-woven fabric to form a block structure for absorbing and retaining body excretion. 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, which is used to retain the absorbed liquid in the absorbent core layer, thereby preventing the absorbed liquid from soiling the wearer's pants.

[0003] According to the existing structure of the diaper, the leakage-proof part mainly relies on the three-dimensional containment on both sides of the liquid-permeable surface layer. However, due to uneven pressure distribution after the elastic rubber absorbs liquid, gaps are easily generated, and liquid can easily seep out from the side. Moreover, the contact surface between the three-dimensional containment and the leg is a single-layer structure, which cannot adapt to the dynamic activity needs of users of different body types. SUMMARY

[0004] Therefore, to solve the above problems, the present application provides a preparation method of a leakage-proof baby diaper with good side leakage prevention effect and adaptability to the dynamic activity needs of users of different body types.

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

[0006] A preparation method of a leakage-proof baby diaper, comprising a diaper body, the preparation method of the diaper body comprising the following steps:

[0007] 1) preparing a liquid-impermeable bottom layer, defined as having a plurality of continuous absorption units along the conveying direction of the liquid-impermeable bottom layer;

[0008] 2) preparing an absorbent core layer;

[0009] 3) cutting the absorbent core layer of step 2) to form individual absorption bodies, and transferring the absorption bodies to the absorption units of the liquid-impermeable bottom layer of step 1) in sequence for compounding, with each absorption body being spaced apart along the conveying direction of the liquid-impermeable bottom layer;

[0010] 4) preparing a liquid-permeable surface layer:

[0011] a. Unwind and convey the rolled hydrophobic fabric, and cut the hydrophobic fabric along its transverse central axis to form two hydrophobic nonwoven fabrics that are symmetrically distributed.

[0012] b. The first leak-proof elastic bands are respectively bonded to the transverse inner side of the hydrophobic nonwoven fabric, and the transverse inner end of the hydrophobic nonwoven fabric is folded down to cover the first leak-proof elastic bands to form the first three-dimensional protective enclosure.

[0013] c. The second leak-proof elastic band is respectively bonded to the transverse outer side of the hydrophobic nonwoven fabric;

[0014] d. The first leak-proof pad, which is in the form of a roll, is unwound and conveyed, and then cut into individual first leak-proof pad layers. The first leak-proof pad layers are then transferred and laminated onto the hydrophobic nonwoven fabric, and are located on the transverse inner side of the second leak-proof elastic band.

[0015] e. Fold the outer horizontal end of the hydrophobic nonwoven fabric upwards and wrap it over the second leak-proof elastic band and the first leak-proof padding layer to form a second three-dimensional protective enclosure.

[0016] f. Unwind and convey the rolled hydrophilic nonwoven fabric;

[0017] g. The transverse middle part of the hydrophobic nonwoven fabric from step e is bonded to both transverse sides of the hydrophilic nonwoven fabric from step f through the first adhesive layer.

[0018] h. Composite the product from step g onto the product from step 3);

[0019] i. Prepare a front leak-proof sheet, and laminate the front leak-proof sheet onto the product of step h. The left and right edges of the front leak-proof sheet are laminated and connected to the first three-dimensional protective walls distributed on both sides of the lateral direction through the second and third adhesive layers, respectively. The upper edge of the front leak-proof sheet is laminated and connected to the upper edge of the hydrophilic nonwoven fabric located in the absorbent unit through the fourth adhesive layer, so that a front bag with a first opening is formed between the front leak-proof sheet, the two first three-dimensional protective walls and the liquid-permeable surface layer.

[0020] j. Prepare a rear leak-proof sheet. Connect the left and right edges of the rear leak-proof sheet to the second three-dimensional protective barriers distributed on both sides of the lateral direction through the fifth and sixth adhesive layers, respectively. Connect the lower edge of the rear leak-proof sheet to the lower edge of the hydrophilic nonwoven fabric located in the absorbent unit through the seventh adhesive layer, so that a rear bag with a second opening is formed between the rear leak-proof sheet, the two second three-dimensional protective barriers and the liquid-permeable surface layer.

[0021] 5) Cut the product from step j along the boundary of the absorbent unit to form a single diaper body.

[0022] Furthermore, the middle of the lateral sides of the rear leak-proof sheet is provided with an eighth adhesive layer for bonding with the first three-dimensional protective barrier and the hydrophilic non-woven fabric.

[0023] Furthermore, the rear leak-proof sheet includes an upper sheet, a lower sheet, at least one first elastic band, and at least three second elastic bands. The first elastic band is bonded between the upper sheet and the lower sheet and is distributed at the upper edge of the rear leak-proof sheet. Each of the second elastic bands is bonded between the upper sheet and the lower sheet and is distributed between the seventh adhesive layer and the eighth adhesive layer. Each of the second elastic bands is distributed in the transverse direction.

[0024] Furthermore, the stretch ratio of the second elastic band is greater than that of the first elastic band.

[0025] Furthermore, the front leak-proof sheet includes a first sheet layer and at least one third elastic band, the third elastic band being bonded to the longitudinal lower side of the first sheet layer and folded over the lower edge of the first sheet layer.

[0026] Furthermore, the longitudinal length of the absorbent core layer is smaller than that of the liquid-permeable surface layer, and the upper edge of the absorbent core layer is aligned with the upper edge of the liquid-permeable surface layer, thereby forming an expansion cavity between the lower edge of the absorbent core layer and the lower edge of the liquid-permeable surface layer.

[0027] Furthermore, the longitudinal center of the first three-dimensional enclosure is compositely connected to the upper surface of the hydrophilic nonwoven fabric through a ninth adhesive layer, and the ninth adhesive layer does not cover the first leak-proof elastic band.

[0028] Furthermore, a second leak-proof pad is provided at the longitudinal center of the upper surface of the impermeable bottom layer and on the lower side of the second three-dimensional enclosure.

[0029] Furthermore, both the first and second leak-proof padding layers include bulky nonwoven fabric and superabsorbent polymer particles or fluff pulp mixed with superabsorbent polymer particles sprinkled on the bulky nonwoven fabric.

[0030] By adopting the aforementioned technical solution, the beneficial effects of this invention are as follows: The method for preparing this leak-proof baby diaper involves setting a double-layer three-dimensional protective structure on the liquid-permeable surface layer, namely a first three-dimensional protective structure and a second three-dimensional protective structure. The first three-dimensional protective structure is formed by covering the first leak-proof elastic band with hydrophobic non-woven fabric, which can effectively prevent liquid from rapidly seeping out from the side. The second three-dimensional protective structure, based on the first three-dimensional protective structure, further enhances the leak-proof capability of the side by covering the second leak-proof elastic band and the first leak-proof padding layer. Compared with the traditional single-layer three-dimensional protective structure, this double-layer three-dimensional protective structure greatly improves the sealing performance of the diaper side and reduces the possibility of liquid leakage from the side due to uneven pressure distribution or baby activity, providing more reliable side leakage protection for the baby. Furthermore, the front leak-proof sheet and the back leak-proof sheet form a front pocket and a back pocket with the first three-dimensional protective structure, the second three-dimensional protective structure, and the liquid-permeable surface layer, respectively. The front pocket and the back pocket have a certain amount of space. When the baby is active, such as crawling, rolling over, kicking, etc., these dynamic activities may cause liquid to flow and surge inside the diaper. The front and back pockets can hold some of the liquid that flows during activity, preventing leakage outside the diaper. They also better adapt to the leg and buttock shapes of babies of different sizes, ensuring a closer fit and further improving leak-proof performance. This meets the leak-proof needs of babies during various dynamic activities. The absorbent core layer is cut into individual absorbent elements and spaced apart on the impermeable bottom layer. This design allows the absorbent elements to more precisely target the baby's excretion sites, improving absorption efficiency. Combined with the double-layer three-dimensional protective barrier of the permeable surface layer and the front and back leak-proof panels, it effectively prevents leakage while quickly absorbing liquid, achieving synergistic optimization of absorption and leak-proof functions. This provides babies with a dry and comfortable wearing experience. The manufacturing method has clear steps, and the preparation and lamination processes of each component are operable and controllable. Through reasonable process design, such as cutting, transfer, and lamination operations, the accurate forming and stable connection of each part of the diaper structure can be guaranteed, which is conducive to large-scale industrial production, improving production efficiency and product quality stability. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the preparation process structure according to an embodiment of the present invention;

[0032] Figure 2 This is a three-dimensional structural schematic diagram of an embodiment of the present invention;

[0033] Figure 3 This is a top view of the structure according to an embodiment of the present invention;

[0034] Figure 4 yes Figure 3 Schematic diagram of the cross-sectional structure at point AA;

[0035] Figure 5 yes Figure 3Schematic diagram of the cross-sectional structure at point BB;

[0036] Figure 6 yes Figure 3 A schematic diagram of the cross-sectional structure at the CC section;

[0037] Figure 7 yes Figure 3 A schematic diagram of the cross-sectional structure at point DD.

[0038] Explanation of reference numerals in the attached figures:

[0039] 1. Diaper body; 2. First adhesive layer; 3. Second adhesive layer; 4. Third adhesive layer; 5. Fourth adhesive layer; 6. Fifth adhesive layer; 7. Sixth adhesive layer; 8. Seventh adhesive layer; 9. Eighth adhesive layer; 10. Ninth adhesive layer; 11. Liquid-permeable top layer; 12. Absorbent core layer; 13. Liquid-impermeable bottom layer;

[0040] 20. Expansion cavity; 21. Hydrophilic nonwoven fabric; 22. Hydrophobic nonwoven fabric; 23. First leak-proof elastic band; 24. Second leak-proof elastic band; 25. First leak-proof padding layer; 26. Front leak-proof sheet; 27. Rear leak-proof sheet; 28. First three-dimensional protective barrier; 29. ​​Second three-dimensional protective barrier; 30. Second leak-proof padding layer; 31. First opening; 32. Front pocket; 33. Second opening; 34. Rear pocket; 40. Elastic fiber mesh layer;

[0041] 101. Front waist area; 102. Groin area; 103. Rear waist area; 201. Upper edge; 202. Lower edge; 203. Left edge; 204. Right edge;

[0042] 131. Breathable but waterproof membrane; 132. Bottom nonwoven fabric; 261. First layer; 262. Third elastic band; 271. Top layer; 272. Bottom layer; 273. First elastic band; 274. Second elastic band; 300. Hydrophobic fabric. Detailed Implementation

[0043] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments.

[0044] The embodiments of the present invention are as follows:

[0045] refer to Figure 1 , Figure 2 and Figure 3 As shown, a method for preparing a leak-proof baby diaper includes a diaper body 1, and the method for preparing the diaper body 1 includes the following steps:

[0046] 1) Prepare an impermeable bottom layer 13, defining a plurality of continuous absorption units along the transport direction of the impermeable bottom layer 13;

[0047] 2) Preparation of absorber core layer 12;

[0048] 3) Cut the absorbent core layer 12 of step 2) into individual absorbers, and transfer the absorbers sequentially to the absorbent unit of the impermeable bottom layer 13 of step 1 for composite. The absorbers are distributed sequentially at intervals along the conveying direction of the impermeable bottom layer.

[0049] 4) Preparation of liquid-permeable surface layer 11:

[0050] a. Unwind and convey the hydrophobic fabric 300 in roll form, and cut the hydrophobic fabric 300 along its transverse central axis to form two hydrophobic nonwoven fabrics 22 that are symmetrically distributed.

[0051] b. The first leak-proof elastic band 23 is respectively bonded to the transverse inner side of the hydrophobic nonwoven fabric 22, and the transverse inner end of the hydrophobic nonwoven fabric 22 is folded down to cover the first leak-proof elastic band 23 to form the first three-dimensional protective enclosure 28.

[0052] c. The second leak-proof elastic band 24 is respectively bonded to the transverse outer side of the hydrophobic nonwoven fabric 22;

[0053] d. The first leak-proof pad, which is in the form of a roll, is unwound and conveyed, and then cut into individual first leak-proof pad layers 25. The first leak-proof pad layers 25 are then transferred and laminated onto the hydrophobic nonwoven fabric 22, and are located on the transverse inner side of the second leak-proof elastic band 24.

[0054] e. Fold the outer horizontal end of the hydrophobic nonwoven fabric 22 upward and wrap it over the second leak-proof elastic band 24 and the first leak-proof padding layer 25 to form the second three-dimensional protective enclosure 29.

[0055] f. Unwind and convey the hydrophilic nonwoven fabric 21 in roll form;

[0056] g. The transverse middle part of the hydrophobic nonwoven fabric 22 from step e is bonded to both transverse sides of the hydrophilic nonwoven fabric 21 from step f through the first adhesive layer 2.

[0057] h. Composite the product from step g onto the product from step 3);

[0058] i. Prepare a front leak-proof sheet 26, and laminate the front leak-proof sheet 26 onto the product of step h. The left and right edges of the front leak-proof sheet 26 are laminated and connected to the first three-dimensional protective walls 28 distributed on both sides of the lateral direction through the second adhesive layer 3 and the third adhesive layer 4, respectively. The upper edge of the front leak-proof sheet 26 is laminated and connected to the upper edge of the hydrophilic non-woven fabric 21 located in the absorption unit through the fourth adhesive layer 5, so that a front bag 32 with a first opening 31 is formed between the front leak-proof sheet 26, the two first three-dimensional protective walls 28 and the liquid-permeable surface layer 11.

[0059] j. Prepare a rear leak-proof sheet 27. The left and right edges of the rear leak-proof sheet 27 are respectively bonded to the second three-dimensional protective walls 29 distributed on both sides of the lateral direction through the fifth adhesive layer 6 and the sixth adhesive layer 7. The lower edge of the rear leak-proof sheet 27 is bonded to the lower edge of the hydrophilic non-woven fabric 21 located in the absorption unit through the seventh adhesive layer 8, so that a rear bag 34 with a second opening 33 is formed between the rear leak-proof sheet 27, the two second three-dimensional protective walls 29 and the liquid-permeable surface layer 11.

[0060] 5) Cut the product from step j along the boundary of the absorbent unit to form a single diaper body 1.

[0061] The manufacturing method of this leak-proof baby diaper involves setting a double-layer three-dimensional protective structure on the liquid-permeable surface layer 11, namely a first three-dimensional protective barrier 28 and a second three-dimensional protective barrier 29. The first three-dimensional protective barrier 28 is formed by covering the first leak-proof elastic band 23 with a hydrophobic non-woven fabric 22, which can effectively prevent liquid from seeping out quickly from the side. The second three-dimensional protective barrier 29, based on the first three-dimensional protective barrier 28, further enhances the leak-proof capability of the side by covering the second leak-proof elastic band 24 and the first leak-proof padding layer 25. This double-layer three-dimensional protective structure is superior to the traditional single-layer three-dimensional protective barrier. This greatly improves the sealing of the diaper's sides, reducing the possibility of liquid leakage from the sides due to uneven pressure distribution or baby's activity, providing more reliable side leakage protection for the baby. Furthermore, the front leak-proof sheet 26 and the rear leak-proof sheet 27, together with the first three-dimensional guard 28, the second three-dimensional guard 29, and the liquid-permeable surface layer 11, form the front pocket 32 ​​and the rear pocket 34, respectively. The front pocket 32 ​​and the rear pocket 34 have a certain amount of space. When the baby is active, such as crawling, rolling over, kicking, etc., these dynamic activities may cause liquid to flow and surge inside the diaper. The front pocket 32 ​​and back pocket 34 can accommodate some of the liquid that flows due to activity, preventing liquid from overflowing onto the outside of the diaper. They also better adapt to the leg and buttock shapes of babies of different sizes, making the diaper fit the baby's body more closely and further improving the leak-proof effect. This meets the leak-proof needs of babies during various dynamic activities. Meanwhile, the absorbent core layer 12 is cut into individual absorbents and distributed at intervals on the liquid-impermeable bottom layer 13. This design allows the absorbents to more accurately correspond to the baby's excretion site, improving the absorption efficiency of liquid. At the same time, in conjunction with the double-layer three-dimensional protective barrier of the liquid-permeable surface layer 11 and the front leak-proof sheet 26 and back leak-proof sheet 27, liquid is quickly absorbed while effectively preventing leakage. This achieves synergistic optimization of absorption and leak-proof functions, providing babies with a dry and comfortable wearing experience. The manufacturing method has clear steps, and the preparation and composite process of each component is operable and controllable. Through reasonable process design, the accurate molding and stable connection of each part of the diaper structure can be guaranteed, which is conducive to large-scale industrial production and improving production efficiency and product quality stability.

[0062] In step 1) above, during the preparation of the liquid-impermeable bottom layer 13, an elastic fiber web layer 40 is added between the breathable and water-impermeable film 131 and the bottom non-woven fabric 132 during the lamination process. The fibers of the elastic fiber web layer 40 are irregularly interwoven. This added elastic fiber web layer 40 provides the liquid-impermeable bottom layer 13 with better elasticity and flexibility. During infant activity, diapers are subjected to stretching and bending in various directions. The elastic fiber web layer 40 allows the liquid-impermeable bottom layer 13 to better adapt to these deformations, reducing wrinkles and tears caused by stretching. This enhances the liquid-impermeable bottom layer's ability to retain absorbed liquid, further preventing leakage and improving the overall leak-proof performance and comfort of the diaper.

[0063] In step b) above, after folding the inner lateral end of the hydrophobic nonwoven fabric 22 downwards to wrap around the first leak-proof elastic band 23 to form the first three-dimensional protective barrier 28, several evenly distributed wavy raised textures are formed on the outer surface of the first three-dimensional protective barrier 28 through a hot-pressing process. The wavy raised textures on the outer surface of the first three-dimensional protective barrier 28 can increase the friction with the baby's leg skin, effectively reducing the relative sliding between the first three-dimensional protective barrier 28 and the leg when the baby is active, allowing the first three-dimensional protective barrier 28 to better fit the leg and reducing the risk of liquid seepage from the side. At the same time, the wavy raised textures can also create a certain gap between the first three-dimensional protective barrier 28 and the leg, enhancing breathability, reducing stuffiness, and improving the baby's wearing comfort.

[0064] In step i) above, when preparing the front leak-proof sheet 26, a layer of antibacterial nano-silver coating is coated on the side of the front leak-proof sheet 26 facing the baby's skin. The thickness of the nano-silver coating is 0.1-0.5 μm. The coated nano-silver coating has excellent antibacterial properties and can effectively inhibit the growth and reproduction of bacteria inside the diaper. Infant excrement contains a large number of bacteria, which, if not inhibited in time, can easily lead to skin infections and other problems. The nano-silver coating can continuously release silver ions, destroying the cell walls and cell membranes of bacteria, thereby achieving sterilization, providing a healthier and more hygienic wearing environment for the baby, reducing the risk of skin diseases caused by bacterial infection, and protecting the baby's health.

[0065] refer to Figures 2 to 7As shown, a leak-proof baby diaper includes a diaper body 1, defined as extending along the length direction of the diaper body 1 as the longitudinal direction and extending along the width direction of the diaper body 1 as the transverse direction. The diaper body 1 has a front waist area 101, a crotch area 102 and a back waist area 103 distributed sequentially along the longitudinal direction. The diaper body 1 includes a liquid-permeable surface layer 11, an absorbent core layer 12 and a liquid-impermeable bottom layer 13 stacked sequentially from top to bottom. The liquid-permeable surface layer 11, the absorbent core layer 12 and the liquid-impermeable bottom layer 13 each have an upper edge 201 and a lower edge 202 distributed at both ends of the longitudinal direction and a left edge 203 and a right edge 204 distributed at both ends of the transverse direction.

[0066] The liquid-permeable surface layer 11 includes a hydrophilic nonwoven fabric 21, two hydrophobic nonwoven fabrics 22, a first leak-proof elastic band 23, a second leak-proof elastic band 24, a first leak-proof padding layer 25, a front leak-proof sheet 26, and a rear leak-proof sheet 27. The hydrophilic nonwoven fabric 21 covers the upper surface of the absorbent core layer 12, and the two lateral sides of the hydrophilic nonwoven fabric 21 wrap downwards around the two lateral sides of the absorbent core layer 12. The two hydrophobic nonwoven fabrics 22 are distributed on the lateral sides of the hydrophilic nonwoven fabric 21, and the lateral middle of the hydrophobic nonwoven fabric 22 is bonded to the absorbent core layer 12 by a first adhesive layer 2. The hydrophilic nonwoven fabric 21 is compositely connected to the two transverse sides and the liquid-impermeable bottom layer 13. The first leak-proof elastic band 23 is located on the transverse inner side of the hydrophobic nonwoven fabric 22 and is folded and covered by the transverse inner end of the hydrophobic nonwoven fabric 22 to form a first three-dimensional protective barrier 28. The second leak-proof elastic band 24 and the first leak-proof pad 25 are located on the transverse outer side of the hydrophobic nonwoven fabric 22 and are folded and covered by the transverse outer end of the hydrophobic nonwoven fabric 22 to form a second three-dimensional protective barrier 29. The second leak-proof elastic band 24 is distributed on the transverse outer side of the first leak-proof pad layer 25.

[0067] The left edge 203 and right edge 204 of the front leak-proof sheet 26 are respectively bonded to the first three-dimensional protective barriers 28 distributed on both sides of the lateral direction through the second adhesive layer 3 and the third adhesive layer 4. The upper edge 201 of the front leak-proof sheet 26 is bonded to the upper edge 201 of the hydrophilic nonwoven fabric 21 through the fourth adhesive layer 5, so that a front bag 32 with a first opening 31 is formed between the front leak-proof sheet 26, the two first three-dimensional protective barriers 28 and the liquid-permeable surface layer 11. The left edge 203 and right edge 204 of the rear leak-proof sheet 27 are connected to the first three-dimensional protective barriers 28 distributed on both sides of the lateral direction through the second adhesive layer 3 and the third adhesive layer 4. The fifth adhesive layer 6 and the sixth adhesive layer 7 are respectively bonded to the second three-dimensional protective barrier 29 distributed on both sides of the lateral direction. The lower edge 202 of the rear leak-proof sheet 27 is bonded to the lower edge 202 of the hydrophilic nonwoven fabric 21 through the seventh adhesive layer 8, so that a rear bag 34 with a second opening 33 is formed between the rear leak-proof sheet 27, the two second three-dimensional protective barriers 29 and the liquid-permeable surface layer 11. The middle part of the lateral sides of the rear leak-proof sheet 27 is provided with an eighth adhesive layer 9 for bonding with the first three-dimensional protective barrier 28 and the hydrophilic nonwoven fabric 21.

[0068] This leak-proof baby diaper utilizes hydrophilic nonwoven fabric 21, hydrophobic nonwoven fabric 22, first leak-proof elastic band 23, and second leak-proof elastic band 24 to form a first three-dimensional protective barrier 28 and a second three-dimensional protective barrier 29, respectively. This enhances the leak-proof performance of the sides and effectively solves the problem in the prior art where uneven pressure distribution of the elastic bands in the three-dimensional protective barrier leads to gaps and easy leakage of liquid from the sides. At the same time, a front leak-proof sheet 26 and a rear leak-proof sheet 27 are provided, which, together with the first three-dimensional protective barrier 28, the second three-dimensional protective barrier 29, and the liquid-permeable surface layer 11, form a front pocket 32 ​​and a rear pocket 34, respectively, further improving the side leakage prevention effect. Moreover, this structure can better adapt to the dynamic activity needs of users of different body types and reduce the risk of liquid leakage.

[0069] Specifically, the rear leak-proof sheet 27 includes an upper layer 271, a lower layer 272, two first elastic bands 273, and five second elastic bands 274. The first elastic bands 273 are bonded between the upper layer 271 and the lower layer 272 and are distributed at the upper edge 201 of the rear leak-proof sheet 27. Each of the second elastic bands 274 is bonded between the upper layer 271 and the lower layer 272 and is distributed between the seventh adhesive layer 8 and the eighth adhesive layer 9. Each of the second elastic bands 274 is distributed in the transverse direction. The rear leak-proof sheet 27 utilizes the upper layer... 271, lower layer 272 and elastic band structure with different distributions, the first elastic band 273 is distributed on the upper edge 201 of the back leak-proof piece 27, and five second elastic bands 274 are distributed between the seventh glue layer 8 and the eighth glue layer 9 and are distributed in the transverse direction. This structure makes the back leak-proof piece 27 have better elasticity and fit, and can better adjust its shape according to the user's leg movements, further enhancing the leak-proof effect, while improving the user's wearing comfort, and keeping the second opening 33 of the back pocket 34 open, so as to accommodate feces and other excrement.

[0070] Furthermore, the stretch ratio of the second elastic band 274 is greater than that of the first elastic band 273. This design allows the back anti-leakage patch 27 to have different elastic properties in different parts. The second elastic band 274 between the seventh adhesive layer 8 and the eighth adhesive layer 9 has a large stretch ratio, which can better adapt to the large range of leg movements and provide a tighter fit. Meanwhile, the stretch ratio of the first elastic band 273 at the upper edge is relatively small, which ensures a certain fit without causing excessive restraint to the user, thus improving the overall user experience.

[0071] Furthermore, the front leak-proof flap 26 includes a first layer 261 and two third elastic bands 262. The third elastic bands 262 are bonded to the lower longitudinal side of the first layer 261 and are folded and covered by the lower edge 202 of the first layer 261. This structure gives the front leak-proof flap 26 a certain degree of elasticity, allowing it to better fit the user's body and form an effective leak-proof barrier at the front to prevent liquid from leaking from the front. At the same time, it improves the structural stability and durability of the front leak-proof flap 26 and keeps the first opening 31 of the front pocket 32 ​​open.

[0072] Meanwhile, the longitudinal length of the absorbent core layer 12 is smaller than that of the liquid-permeable surface layer 11, and the upper edge 201 of the absorbent core layer 12 is aligned with the upper edge 201 of the liquid-permeable surface layer 11, so that an expansion cavity 20 is formed between the lower edge 202 of the absorbent core layer 12 and the lower edge 202 of the liquid-permeable surface layer 11. The expansion cavity 20 can provide a larger storage space for excess feces and other excrement after the absorbent core layer 12 absorbs a certain amount of liquid, while preventing liquid from overflowing due to saturation of the absorbent core layer 12, further enhancing the leak-proof performance of the diaper, without affecting the overall wearing comfort.

[0073] Furthermore, the longitudinal center of the first three-dimensional protective enclosure 28 is compositely connected to the upper surface of the hydrophilic nonwoven fabric 21 through the ninth adhesive layer 10, and the ninth adhesive layer 10 does not cover the first leak-proof elastic band 23. This connection method not only ensures the stable connection between the first three-dimensional protective enclosure 28 and the hydrophilic nonwoven fabric 21, but also does not affect the elasticity of the first leak-proof elastic band 23, so that the first three-dimensional protective enclosure 28 can better play its leak-proof role, while maintaining its good fit and adaptability.

[0074] In this embodiment, a second leak-proof pad 30 is provided at the longitudinal center of the upper surface of the liquid-impermeable bottom layer 13 and below the second three-dimensional guard 29, which increases the leak-proof capability of the liquid-impermeable bottom layer 13. When a small amount of liquid permeates through the second three-dimensional guard 29, the second leak-proof pad 30 can absorb the liquid and prevent it from further penetrating into the wearer's pants, thereby further improving the overall leak-proof performance of the diaper. In addition, the second leak-proof pad 30 can increase the tension of the crotch area 102, so that the area is in an expanded state, avoiding excessive contact with the skin, and improving the comfort and absorption efficiency.

[0075] Furthermore, both the first leak-proof pad 25 and the second leak-proof pad 30 include bulky nonwoven fabric and superabsorbent polymer particles sprinkled on the bulky nonwoven fabric. The bulky nonwoven fabric has good air permeability and liquid conductivity, which can quickly disperse liquid onto the superabsorbent polymer particles. The superabsorbent polymer particles have strong water absorption and retention capabilities, which can absorb and lock in a large amount of liquid, preventing liquid backflow, thereby effectively improving the leak-proof and liquid absorption performance of the leak-proof pad. Alternatively, the pad can be a mixture of fluff pulp and superabsorbent polymer particles wrapped in nonwoven fabric.

[0076] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0077] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0078] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0079] Although the invention has been specifically shown and described in conjunction with preferred embodiments, those skilled in the art should understand that various changes in form and detail may be made to the invention without departing from the spirit and scope of the invention as defined in the appended claims, all of which shall be within the scope of protection of the invention.

Claims

1. A method for preparing a leak-proof baby diaper, characterized in that: The diaper body is included, and the method for preparing the diaper body includes the following steps: 1) Prepare an impermeable substrate, defining a series of continuous absorption units along the transport direction of the impermeable substrate; 2) Preparation of the absorber core layer; 3) Cut the absorbent core layer of step 2) into individual absorbers, and transfer the absorbers sequentially to the absorbent unit of the impermeable bottom layer of step 1 for composite. The absorbers are distributed sequentially at intervals along the conveying direction of the impermeable bottom layer. 4) Preparation of a liquid-permeable surface layer: a. Unwind and convey the rolled hydrophobic fabric, and cut the hydrophobic fabric along its transverse central axis to form two hydrophobic nonwoven fabrics that are symmetrically distributed. b. The first leak-proof elastic bands are respectively bonded to the transverse inner side of the hydrophobic nonwoven fabric, and the transverse inner end of the hydrophobic nonwoven fabric is folded down to cover the first leak-proof elastic bands to form the first three-dimensional protective enclosure. c. The second leak-proof elastic band is respectively bonded to the transverse outer side of the hydrophobic nonwoven fabric; d. The first leak-proof pad, which is in the form of a roll, is unwound and conveyed, and then cut into individual first leak-proof pad layers. The first leak-proof pad layers are then transferred and laminated onto the hydrophobic nonwoven fabric, and are located on the transverse inner side of the second leak-proof elastic band. e. Fold the outer horizontal end of the hydrophobic nonwoven fabric upwards and wrap it over the second leak-proof elastic band and the first leak-proof padding layer to form a second three-dimensional protective enclosure. f. Unwind and convey the rolled hydrophilic nonwoven fabric; g. The transverse middle part of the hydrophobic nonwoven fabric from step e is bonded to both transverse sides of the hydrophilic nonwoven fabric from step f through the first adhesive layer. h. Composite the product from step g onto the product from step 3); i. Prepare a front leak-proof sheet, and laminate the front leak-proof sheet onto the product of step h. The left and right edges of the front leak-proof sheet are laminated and connected to the first three-dimensional protective walls distributed on both sides of the lateral direction through the second and third adhesive layers, respectively. The upper edge of the front leak-proof sheet is laminated and connected to the upper edge of the hydrophilic nonwoven fabric located in the absorbent unit through the fourth adhesive layer, so that a front bag with a first opening is formed between the front leak-proof sheet, the two first three-dimensional protective walls and the liquid-permeable surface layer. j. Prepare a rear leak-proof sheet. Connect the left and right edges of the rear leak-proof sheet to the second three-dimensional protective barriers distributed on both sides of the lateral direction through the fifth and sixth adhesive layers, respectively. Connect the lower edge of the rear leak-proof sheet to the lower edge of the hydrophilic nonwoven fabric located in the absorbent unit through the seventh adhesive layer, so that a rear bag with a second opening is formed between the rear leak-proof sheet, the two second three-dimensional protective barriers and the liquid-permeable surface layer. 5) The product from step j is cut along the boundary of the absorbent unit to form a single diaper body. A second leak-proof pad is provided in the longitudinal middle of the upper surface of the impermeable bottom layer and on the lower side of the second three-dimensional protective barrier. Both the first and second leak-proof pads include bulky nonwoven fabric and superabsorbent polymer particles or fluff pulp mixed with superabsorbent polymer particles sprinkled on the bulky nonwoven fabric.

2. The method for preparing leak-proof baby diapers according to claim 1, characterized in that: The middle of the two lateral sides of the rear leak-proof sheet is provided with an eighth adhesive layer for bonding with the first three-dimensional protective barrier and the hydrophilic non-woven fabric.

3. The method for preparing leak-proof baby diapers according to claim 2, characterized in that: The rear leak-proof sheet includes an upper sheet, a lower sheet, at least one first elastic band, and at least three second elastic bands. The first elastic band is bonded between the upper sheet and the lower sheet and is distributed at the upper edge of the rear leak-proof sheet. Each of the second elastic bands is bonded between the upper sheet and the lower sheet and is distributed between the seventh adhesive layer and the eighth adhesive layer. Each of the second elastic bands is distributed in the transverse direction.

4. The method for preparing leak-proof baby diapers according to claim 3, characterized in that: The stretch ratio of the second elastic band is greater than that of the first elastic band.

5. The method for preparing leak-proof baby diapers according to claim 1, characterized in that: The front leak-proof sheet includes a first sheet and at least one third elastic band, the third elastic band being bonded to the longitudinal lower side of the first sheet and folded over the lower edge of the first sheet.

6. The method for preparing the leak-proof baby diaper according to any one of claims 1 to 5, characterized in that: The longitudinal length of the absorbent core layer is smaller than that of the liquid-permeable surface layer, and the upper edge of the absorbent core layer is aligned with the upper edge of the liquid-permeable surface layer, thereby forming an expansion cavity between the lower edge of the absorbent core layer and the lower edge of the liquid-permeable surface layer.

7. The method for preparing leak-proof baby diapers according to claim 6, characterized in that: The longitudinal center of the first three-dimensional enclosure is compositely connected to the upper surface of the hydrophilic nonwoven fabric through the ninth adhesive layer, and the ninth adhesive layer does not cover the first leak-proof elastic band.

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