Preparation method of leakproof baby paper diaper

Abstract

The invention relates to the field of disposable hygienic products, in particular to a preparation method of a leakage-proof baby paper diaper, mainly solves the problem of poor side leakage prevention effect of existing paper diapers, is used for preparing paper diapers with the characteristics of good side leakage prevention effect and adaptability to dynamic activity requirements of users with different body types, and comprises a paper diaper body, the preparation method of the paper diaper body comprises the following steps: 1) preparing the liquid-tight bottom layer, and defining a plurality of continuous absorption units in the conveying direction of the liquid-tight bottom layer; 2) preparing an absorption core layer; the method comprises the steps of (1) preparing an absorption core layer, (2) preparing an absorption unit of a liquid-tight bottom layer, (3) slitting the absorption core layer in the step (2) to form single absorbers, sequentially transferring the absorbers to the absorption unit of the liquid-tight bottom layer in the step (1) to be compounded, and sequentially distributing the absorbers at intervals in the conveying direction of the liquid-tight bottom layer, (4) preparing a liquid-tight surface layer, and (5) slitting the product along the boundary of the absorption unit to form a single paper diaper body.

Description

Technical Field

[0001] The present invention relates to the field of disposable sanitary products, and in particular to a method for preparing leak-proof baby diapers. Background Art

[0002] The structure of diapers is generally as follows: from top to bottom, it includes a liquid-permeable surface layer, an absorbent core layer, and a liquid-impermeable bottom layer stacked in sequence. The absorbent core layer is composed of a fluffy non-woven fabric combined with a high-molecular water-absorbent resin or a mixture of wood pulp fiber and a high-molecular water-absorbent resin and wrapped by a non-woven fabric to form a block structure for absorbing and retaining human excretions. The liquid-permeable surface layer is composed of a hydrophilic non-woven fabric and a hydrophobic non-woven fabric fixed on both sides of the hydrophilic non-woven fabric, which is used to provide a comfortable and dry feeling when in contact with the body, while allowing liquid to pass freely into the absorbent core layer below. The liquid-impermeable bottom layer is composed of a breathable and water-impermeable film and a hydrophobic non-woven fabric, which is used to keep the absorbed liquid in the absorbent core layer, thereby preventing the absorbed liquid from soiling the wearer's pants.

[0003] According to the structure of existing diapers, the leakage prevention part mainly relies on the three-dimensional guards on both sides of the liquid-permeable surface layer. After the elastic rubber band absorbs the liquid, uneven pressure distribution may cause gaps, and liquid may easily seep out from the sides. In addition, the contact surface between the three-dimensional guards and the legs is a single-layer structure, which cannot adapt to the dynamic activity needs of users of different body shapes. Summary of the Invention

[0004] Therefore, in order to solve the above problems, the present invention provides a method for preparing a leak-proof baby diaper which has good side leakage prevention effect and can adapt to the dynamic activity needs of users of different body shapes.

[0005] To achieve the above object, the present invention adopts the following technical solutions: A method for preparing a leak-proof baby diaper, comprising a diaper body, the method comprising the following steps: 1) preparing a liquid-impermeable bottom layer, defining a plurality of continuous absorbent units along the transport direction of the liquid-impermeable bottom layer; 2) preparing an absorbent core layer; 3) cutting the absorbent core layer from step 2) into individual absorbent bodies, and sequentially transferring the absorbent bodies to the absorbent units of the liquid-impermeable bottom layer from step 1 for lamination, with the absorbent bodies being sequentially spaced apart along the conveying direction of the liquid-impermeable bottom layer; 4) Preparation of liquid-permeable surface layer: a. Unwinding the rolled hydrophobic fabric and cutting the hydrophobic fabric along its transverse central axis to form two axially symmetrically distributed hydrophobic nonwoven fabrics; b. Compounding the first leak-proof elastic bands on the lateral inner sides of the hydrophobic non-woven fabrics, and folding the lateral inner ends of the hydrophobic non-woven fabrics downward to cover the first leak-proof elastic bands to form a first three-dimensional protective enclosure; c. Compounding the second leak-proof elastic bands on the lateral outer sides of the hydrophobic non-woven fabric; d. unrolling the rolled first leak-proof pad for transport, and cutting it into individual first leak-proof pad layers, and then transferring and laminating the first leak-proof pad layers onto the hydrophobic non-woven fabric, and locating them laterally inside the second leak-proof elastic band; e. Folding the outer lateral ends of the hydrophobic non-woven fabric upward and wrapping them over the second leak-proof elastic and the first leak-proof cushion layer to form a second three-dimensional protective enclosure; f. unwinding and conveying the rolled hydrophilic nonwoven fabric; g. Laminating the middle portion of the hydrophobic non-woven fabric of step e to both sides of the hydrophilic non-woven fabric of step f through a first glue layer; h. Compounding the product of step g) on ​​the product of step 3); i. Prepare a front leak-proof sheet, and laminate the front leak-proof sheet onto the product prepared in step h, with the left and right edges of the front leak-proof sheet being laminated and connected to the first three-dimensional guardrails distributed on both sides thereof via a second glue layer and a third glue layer, respectively. The upper edge of the front leak-proof sheet is laminated and connected to the upper edge of the hydrophilic non-woven fabric located in the absorbent unit via a fourth glue layer, so that a front pocket having a first opening is formed between the front leak-proof sheet, the two first three-dimensional guardrails, and the liquid-permeable surface layer; j. Prepare a rear leak-proof sheet, and composite-connect the left and right edges of the rear leak-proof sheet to the second three-dimensional guard panels located on both sides thereof via a fifth and sixth glue layers, respectively. Composite-connect the lower edge of the rear leak-proof sheet to the lower edge of the hydrophilic non-woven fabric located within the absorbent unit via a seventh glue layer, thereby forming a rear pocket having a second opening between the rear leak-proof sheet, the two second three-dimensional guard panels, and the liquid-permeable surface layer. 5) Cutting the product of step j along the boundaries of the absorbent unit to form individual diaper bodies.

[0006] Furthermore, an eighth glue layer for compounding with the first three-dimensional guard and the hydrophilic non-woven fabric is provided in the middle of the two lateral sides of the rear leakage-proof sheet.

[0007] Furthermore, the rear leak-proof sheet includes an upper layer, a lower layer, at least one first elastic band and at least three second elastic bands, the first elastic band is compounded between the upper layer and the lower layer and distributed on the upper edge of the rear leak-proof sheet, the second elastic bands are compounded between the upper layer and the lower layer and distributed between the seventh glue layer and the eighth glue layer, and the second elastic bands are distributed in the transverse direction.

[0008] Furthermore, the stretching ratio of the second elastic band is greater than the stretching ratio of the first elastic band.

[0009] Furthermore, the front leak-proof sheet includes a first sheet layer and at least one third elastic band, wherein the third elastic band is compounded to the longitudinal lower side of the first sheet layer and is folded and wrapped around the lower edge of the first sheet layer.

[0010] Furthermore, the longitudinal length of the absorbent core layer is smaller than the longitudinal length 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, so that an expansion cavity is formed between the lower edge of the absorbent core layer and the lower edge of the liquid-permeable surface layer.

[0011] Furthermore, the longitudinal middle portion of the first three-dimensional guard is compositely connected to the upper surface of the hydrophilic non-woven fabric through a ninth glue layer, and the ninth glue layer does not cover the first leak-proof elastic band.

[0012] Furthermore, a second leak-proof cushion layer is provided in the longitudinal middle portion of the upper surface of the liquid-impermeable bottom layer and on the lower side of the second three-dimensional protective enclosure.

[0013] Furthermore, the first anti-leakage cushion layer and the second anti-leakage cushion layer both include bulky non-woven fabrics and polymer water-absorbing resin particles spread on the bulky non-woven fabrics, or a mixture of fluff pulp and polymer water-absorbing resin particles.

[0014] By adopting the above-mentioned technical solution, the beneficial effects of the present invention are as follows: the preparation method of the leak-proof baby diaper is provided with a double-layer three-dimensional guard structure on the liquid-permeable surface layer, namely the first three-dimensional guard, and the second three-dimensional guard, and the first three-dimensional guard is formed by a hydrophobic non-woven fabric covering a first leak-proof elastic, which can effectively prevent liquid from rapidly seeping out from the side; the second three-dimensional guard is further coated with the second leak-proof elastic and the first leak-proof pad on the basis of the first three-dimensional guard, thereby enhancing the leak-proof ability of the side. Compared with the traditional single-layer three-dimensional guard, this double-layer three-dimensional guard structure greatly improves the sealing of the diaper side, reduces the possibility of liquid leakage from the side due to uneven pressure distribution or baby movement, and provides more reliable protection against side leakage for the baby. The front and back leak-proof sheets respectively form a front pocket and a back pocket with the first three-dimensional guard, the second three-dimensional guard, and the liquid-permeable surface layer. The front pocket and the back pocket have a certain amount of storage space. When the baby is moving, such as crawling, turning over, kicking, etc., these dynamic activities may cause liquid to flow and surge in the diaper. The front and back pockets can hold some liquid that flows during activity, preventing it from spilling outside the diaper. They can also better adapt to the shape of the legs and buttocks of babies of different body shapes, allowing the diaper to fit more closely to the baby's body, further improving the leak-proof effect and meeting the leak-proof needs of babies during various dynamic activities. The absorbent core layer is cut into individual absorbent bodies and spaced apart on the liquid-impermeable backsheet. This design allows the absorbent bodies to more precisely correspond to the baby's excretion sites, improving liquid absorption efficiency. Furthermore, combined with the double-layer three-dimensional guard of the liquid-permeable topsheet and the front and back leak-proof flaps, the diaper quickly absorbs liquid while effectively preventing leakage, achieving synergistic optimization of absorption and leak-proof functions, providing babies with a dry and comfortable wearing experience. The preparation method has clear steps, and the preparation and compounding processes of each component are operational and controllable. Through reasonable process design, such as cutting, transferring, and compounding, the accurate formation and stable connection of the various structural components of the diaper can be ensured, facilitating large-scale industrial production and improving production efficiency and product quality stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Schematic diagram of the preparation process structure of an embodiment of the present invention; Figure 2 is a schematic diagram of the three-dimensional structure of an embodiment of the present invention; Figure 3 is a schematic diagram of a top view of the structure of an embodiment of the present invention; Figure 4 yes Figure 3 Schematic diagram of the cross-sectional structure at AA in the middle; Figure 5 yes Figure 3 Schematic diagram of the cross-sectional structure at the middle BB; Figure 6 yes Figure 3Schematic diagram of the cross-sectional structure at CC in the middle; Figure 7 yes Figure 3 Schematic diagram of the cross-sectional structure at DD in the middle.

[0016] Description of reference numerals: 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 surface layer; 12. Absorbent core layer; 13. Liquid-impermeable bottom layer; 20. Expansion cavity; 21. Hydrophilic non-woven fabric; 22. Hydrophobic non-woven fabric; 23. First leak-proof elastic band; 24. Second leak-proof elastic band; 25. First leak-proof cushion layer; 26. Front leak-proof flap; 27. Back leak-proof flap; 28. First three-dimensional protective skirt; 29. ​​Second three-dimensional protective skirt; 30. Second leak-proof cushion layer; 31. First opening; 32. Front pocket; 33. Second opening; 34. Back pocket; 40. Elastic fiber mesh layer; 101, front waist area; 102, crotch area; 103, back waist area; 201, upper edge; 202, lower edge; 203, left edge; 204, right edge; 131. Breathable and waterproof film; 132. Bottom nonwoven fabric; 261. First layer; 262. Third elastic band; 271. Upper layer; 272. Lower layer; 273. First elastic band; 274. Second elastic band; 300. Hydrophobic fabric. DETAILED DESCRIPTION

[0017] The present invention will now be further described with reference to the accompanying drawings and specific embodiments.

[0018] The embodiments of the present invention are: 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. The method for preparing the diaper body 1 includes the following steps: 1) preparing a liquid-impermeable bottom layer 13, and defining a plurality of continuous absorbent units along the transport direction of the liquid-impermeable bottom layer 13; 2) preparing an absorbent core layer 12; 3) Cutting the absorbent core layer 12 from step 2) into individual absorbent bodies, and transferring the absorbent bodies sequentially to the absorbent units of the liquid-impermeable bottom layer 13 from step 1 for lamination, with the absorbent bodies sequentially spaced apart along the conveying direction of the liquid-impermeable bottom layer; 4) Preparation of liquid-permeable surface layer 11: a. Unwinding and conveying the rolled hydrophobic fabric 300, and cutting the hydrophobic fabric 300 along its transverse central axis to form two axially symmetrical hydrophobic non-woven fabrics 22; b. Compounding the first leak-proof elastic bands 23 on the lateral inner sides of the hydrophobic non-woven fabric 22, and folding the lateral inner ends of the hydrophobic non-woven fabric 22 downward to cover the first leak-proof elastic bands 23 to form a first three-dimensional protective enclosure 28; c. Compounding the second leak-proof elastic bands 24 on the lateral outer sides of the hydrophobic non-woven fabric 22; d. unwinding the rolled first leak-proof pad and cutting it into individual first leak-proof pad layers 25 , then transferring and laminating the first leak-proof pad layers 25 onto the hydrophobic non-woven fabric 22 and locating them laterally inside the second leak-proof elastic band 24 ; e. Fold the outer lateral ends of the hydrophobic non-woven fabric 22 upward and wrap them around the second leak-proof elastic 24 and the first leak-proof cushion layer 25 to form a second three-dimensional protective enclosure 29; f. unwinding and conveying the rolled hydrophilic nonwoven fabric 21; g. Laminating the middle of the hydrophobic non-woven fabric 22 of step e to both sides of the hydrophilic non-woven fabric 21 of step f through the first glue layer 2; h. Compounding the product of step g) on ​​the product of step 3); i. Prepare a front leak-proof sheet 26 and laminate the front leak-proof sheet 26 onto the product prepared in step h. The left and right edges of the front leak-proof sheet 26 are laminated and connected to the first three-dimensional protective panels 28 disposed on both sides thereof via the second glue layer 3 and the third glue 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 within the absorbent unit via the fourth glue layer 5, so that a front pocket 32 ​​having a first opening 31 is formed between the front leak-proof sheet 26, the two first three-dimensional protective panels 28, and the liquid-permeable surface layer 11. j. Prepare a rear leak-proof sheet 27, and bond the left and right edges of the rear leak-proof sheet 27 to the second three-dimensional protective panels 29 located on both sides thereof via a fifth glue layer 6 and a sixth glue layer 7, respectively. Bond the lower edge of the rear leak-proof sheet 27 to the lower edge of the hydrophilic non-woven fabric 21 located within the absorbent unit via a seventh glue layer 8, thereby forming a rear pocket 34 having a second opening 33 between the rear leak-proof sheet 27, the two second three-dimensional protective panels 29, and the liquid-permeable surface layer 11. 5) Cutting the product of step j along the boundaries of the absorbent units to form individual diaper bodies 1 .

[0019] The preparation method of the leak-proof baby diaper is to set a double-layer three-dimensional guard structure on the liquid-permeable surface layer 11, namely the first three-dimensional guard 28 and the second three-dimensional guard 29, and the first three-dimensional guard 28 is formed by a hydrophobic non-woven fabric 22 covering a first leak-proof elastic 23, which can effectively prevent liquid from quickly seeping out from the side; the second three-dimensional guard 29 is based on the first three-dimensional guard 28 and further covers the second leak-proof elastic 24 and the first leak-proof pad 25 to enhance the leak-proof ability of the side. This double-layer three-dimensional guard structure is better than the traditional single-layer three-dimensional guard , which greatly improves the sealing of the side of the diaper, reduces the possibility of liquid leakage from the side due to uneven pressure distribution or baby activities, and provides more reliable protection against side leakage for the baby. The front leak-proof sheet 26 and the back leak-proof sheet 27 respectively form a front pocket 32 ​​and a back pocket 34 with the first three-dimensional guard 28, the second three-dimensional guard 29 and the liquid-permeable surface layer 11. The front pocket 32 ​​and the back pocket 34 have a certain amount of accommodation space. When the baby is active, such as crawling, turning over, kicking, etc., these dynamic activities may cause the liquid to flow and surge in the diaper. The front pocket 32 ​​and the back pocket 34 can hold some of the liquid that flows due to activity, preventing the liquid from overflowing onto the outside of the diaper. At the same time, they can better adapt to the shape of the legs and buttocks of babies of different body shapes, making the diaper fit more closely to the baby's body, further improving the leak-proof effect, and meeting the leak-proof effect of the baby under various dynamic activities. At the same time, the absorbent core layer 12 is cut into individual absorbent bodies and distributed at intervals on the liquid-impermeable bottom layer 13. This design allows the absorbent bodies to more accurately correspond to the baby's excretion site, improving the efficiency of liquid absorption. At the same time, combined with the double-layer three-dimensional guard of the liquid-permeable surface layer 11 and the front leak-proof flap 26 and the back leak-proof flap 27 structure, while quickly absorbing liquid, it effectively prevents liquid leakage, achieving synergistic optimization of absorption and leak-proof functions, providing a dry and comfortable wearing experience for babies. The preparation method has clear steps, and the preparation and compounding process of each component is operable and controllable. Through reasonable process design, it can ensure the accurate molding and stable connection of the various structural parts of the diaper, which is conducive to large-scale industrial production, improving production efficiency and product quality stability.

[0020] During the preparation of the liquid-impermeable backsheet 13 in step 1), during the lamination process between the breathable and water-impermeable film 131 and the backsheet nonwoven fabric 132, an elastic fiber mesh layer 40 is added between the two. The fibers of this elastic fiber mesh layer 40 are randomly interlaced. This added elastic fiber mesh layer 40 imparts greater elasticity and flexibility to the liquid-impermeable backsheet 13. During infant activity, diapers are subject to various stretching and bending. The elastic fiber mesh layer 40 allows the liquid-impermeable backsheet 13 to better adapt to these deformations, reducing wrinkles and damage caused by stretching. This enhances the backsheet's ability to retain absorbed liquid, further preventing leakage and improving the diaper's overall leak-proof performance and comfort.

[0021] In step b), after the lateral inner end of the hydrophobic non-woven fabric 22 is folded downward and wrapped around the first leak-proof elastic band 23 to form the first three-dimensional protective girdle 28, a plurality of evenly distributed wavy raised textures are formed on the outer surface of the first three-dimensional protective girdle 28 through a heat pressing process. The wavy raised texture on the outer surface of the first three-dimensional protective girdle 28 increases friction with the skin of the infant's legs, effectively reducing relative sliding between the first three-dimensional protective girdle 28 and the legs when the infant is moving, allowing the first three-dimensional protective girdle 28 to better fit the legs and reduce the risk of liquid leakage from the sides. At the same time, the wavy raised texture also creates a certain gap between the first three-dimensional protective girdle 28 and the legs, enhancing breathability, reducing stuffiness, and improving the comfort of the infant. When preparing the front leak-proof sheet 26 in step i) above, a nanosilver coating with antibacterial properties is applied to the side of the front leak-proof sheet 26 facing the infant's skin. The nanosilver coating has a thickness of 0.1-0.5 μm. The applied nanosilver coating has excellent antibacterial properties and can effectively inhibit the growth and reproduction of bacteria within the diaper. Infant excrement contains a large number of bacteria, which, if not promptly suppressed, can easily cause skin infections and other problems. The nanosilver coating continuously releases silver ions, destroying bacterial cell walls and membranes, thereby achieving the purpose of sterilization. This provides a healthier and more hygienic wearing environment for infants, reduces the risk of skin diseases caused by bacterial infections, and protects the baby's health.

[0022] refer to Figures 2 to 7 As shown, a leak-proof baby diaper includes a diaper body 1, wherein the longitudinal direction is defined as the length direction of the diaper body 1, and the transverse direction is defined as the width direction of the diaper body 1. The diaper body 1 has a front waist region 101, a crotch region 102, and a back waist region 103 distributed in sequence 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 in sequence 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 longitudinal ends, and a left edge 203 and a right edge 204 distributed at both transverse ends. The liquid-permeable surface layer 11 includes a hydrophilic non-woven fabric 21, two hydrophobic non-woven fabrics 22, a first leak-proof elastic band 23, a second leak-proof elastic band 24, a first leak-proof pad layer 25, a front leak-proof sheet 26 and a back leak-proof sheet 27. The hydrophilic non-woven fabric 21 covers the upper surface of the absorbent core layer 12, and the lateral sides of the hydrophilic non-woven fabric 21 are downwardly covered on the lateral sides of the absorbent core layer 12. The two hydrophobic non-woven fabrics 22 are distributed on the lateral sides of the hydrophilic non-woven fabric 21, and the lateral middle part of the hydrophobic non-woven fabric 22 is connected to the first glue layer 2 and the back glue layer 2. The hydrophilic non-woven fabric 21 is compositely connected to the liquid-impermeable bottom layer 13 on both lateral sides. The first leak-proof elastic band 23 is arranged on the lateral inner side of the hydrophobic non-woven fabric 22 and is folded and wrapped around the lateral inner end of the hydrophobic non-woven fabric 22 to form a first three-dimensional protective enclosure 28. The second leak-proof elastic band 24 and the first leak-proof pad 25 are arranged on the lateral outer side of the hydrophobic non-woven fabric 22 and are folded and wrapped around the lateral outer end of the hydrophobic non-woven fabric 22 to form a second three-dimensional protective enclosure 29. The second leak-proof elastic band 24 is distributed on the lateral outer side of the first leak-proof pad layer 25. The left edge 203 and the right edge 204 of the front leak-proof sheet 26 are respectively connected to the first three-dimensional guards 28 distributed on both sides of the transverse direction through the second glue layer 3 and the third glue layer 4. The upper edge 201 of the front leak-proof sheet 26 is connected to the upper edge 201 of the hydrophilic non-woven fabric 21 through the fourth glue layer 5, so that a front pocket 32 ​​with a first opening 31 is formed between the front leak-proof sheet 26, the two first three-dimensional guards 28 and the liquid-permeable surface layer 11. The left edge 203 and the right edge 204 of the rear leak-proof sheet 27 are connected to the first three-dimensional guards 28 distributed on both sides of the transverse direction. The fifth glue layer 6 and the sixth glue layer 7 are respectively compounded and connected with the second three-dimensional guardrails 29 distributed on both sides in the horizontal direction. The lower edge 202 of the rear leak-proof sheet 27 is compounded and connected with the lower edge 202 of the hydrophilic non-woven fabric 21 through the seventh glue layer 8, so that a rear pocket 34 with a second opening 33 is formed between the rear leak-proof sheet 27, the two second three-dimensional guardrails 29 and the liquid-permeable surface layer 11. The middle part of the two sides in the horizontal direction of the rear leak-proof sheet 27 is provided with an eighth glue layer 9 for compounding with the first three-dimensional guardrail 28 and the hydrophilic non-woven fabric 21.

[0023] The leak-proof baby diaper utilizes a hydrophilic non-woven fabric 21, a hydrophobic non-woven fabric 22, a first leak-proof elastic band 23 and a second leak-proof elastic band 24 to form a first three-dimensional guard 28 and a second three-dimensional guard 29 respectively, thereby enhancing the leak-proof performance of the side edges and effectively solving the problem in the prior art that gaps are generated in the three-dimensional guards due to uneven pressure distribution of the elastic elastic bands, and liquid is easily seeped out from the sides. At the same time, a front leak-proof sheet 26 and a rear leak-proof sheet 27 are provided to form a front pocket 32 ​​and a rear pocket 34 with the first three-dimensional guard 28, the second three-dimensional guard 29 and the liquid-permeable surface layer 11 respectively, thereby further improving the side leakage prevention effect. In addition, this structure can better adapt to the dynamic activity needs of users of different body shapes and reduce the risk of liquid leakage.

[0024] Specifically, the rear leak-proof sheet 27 includes an upper sheet 271, a lower sheet 272, two first elastic bands 273 and five second elastic bands 274. The first elastic bands 273 are compounded between the upper sheet 271 and the lower sheet 272 and are distributed on the upper edge 201 of the rear leak-proof sheet 27. Each of the second elastic bands 274 is compounded between the upper sheet 271 and the lower sheet 272 and is distributed between the seventh glue layer 8 and the eighth glue layer 9. Each of the second elastic bands 274 is distributed in the transverse direction. 271, the lower sheet layer 272 and the differently distributed elastic structures, the first elastic band 273 is distributed on the upper edge 201 of the rear leak-proof sheet 27, and the five second elastic bands 274 are distributed between the seventh glue layer 8 and the eighth glue layer 9 and are distributed laterally. This structure makes the rear leak-proof sheet 27 have better elasticity and fit, and can better adjust its shape according to the user's leg movements, further enhance the leak-proof effect, and at the same time improve the user's wearing comfort, and keep the second opening 33 of the rear pocket 34 open to facilitate the accommodation of feces and other excrement.

[0025] In addition, the stretching ratio of the second elastic band 274 is greater than the stretching ratio of the first elastic band 273. The stretching ratio of the second elastic band 274 is greater than the stretching ratio of the first elastic band 273. This design enables the rear anti-leakage sheet 27 to have different elastic properties in different parts. The second elastic band 274 between the seventh glue layer 8 and the eighth glue layer 9 has a large stretching ratio, which can better adapt to the large-scale movement of the legs and provide a tighter fit; while the stretching ratio of the first elastic band 273 at the upper edge is relatively small. While ensuring a certain fit, it will not cause excessive restraint to the user, thereby improving the overall user experience.

[0026] Furthermore, the front leak-proof sheet 26 includes a first sheet layer 261 and two third elastic bands 262. The third elastic bands 262 are compounded on the longitudinal lower side of the first sheet layer 261 and are folded and wrapped through the lower edge 202 of the first sheet layer 261. This structure enables the front leak-proof sheet 26 to have a certain elasticity, so that it can better fit the user's body, form an effective leak-proof barrier at the front, and prevent liquid from leaking from the front. At the same time, it improves the structural stability and durability of the front leak-proof sheet 26 and keeps the first opening 31 of the front pocket 32 ​​open.

[0027] At the same time, the longitudinal length of the absorbent core layer 12 is smaller than the longitudinal length 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 the liquid from overflowing due to the saturation of the absorbent core layer 12, further enhancing the leakage-proof performance of the diaper without affecting the overall wearing comfort.

[0028] Furthermore, the longitudinal middle part of the first three-dimensional protective girder 28 is compositely connected to the upper surface of the hydrophilic non-woven fabric 21 through the ninth glue layer 10, and the ninth glue layer 10 does not cover the first leakage-proof elastic band 23. This connection method not only ensures the stable connection between the first three-dimensional protective girder 28 and the hydrophilic non-woven fabric 21, but also does not affect the elasticity of the first leakage-proof elastic band 23, so that the first three-dimensional protective girder 28 can better play its leakage-proof role while maintaining its good fit and adaptability.

[0029] In this embodiment, a second leak-proof pad layer 30 is provided in the longitudinal middle part of the upper surface of the liquid-impermeable bottom layer 13 and on the lower side of the second three-dimensional protective enclosure 29, thereby increasing the leak-proof ability of the liquid-impermeable bottom layer 13. When a small amount of liquid passes through the second three-dimensional protective enclosure 29, the second leak-proof pad layer 30 can absorb the liquid to 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 layer 30 can increase the tension of the crotch area 102, so that the area is in an expanded state, avoiding excessive fit to the skin, and improving the comfort of use and absorption efficiency.

[0030] Furthermore, the first leak-proof pad layer 25 and the second leak-proof pad layer 30 both include fluffy non-woven fabrics and polymer water-absorbent resin particles spread on the fluffy non-woven fabrics. The fluffy non-woven fabrics have good air permeability and liquid conductivity, and can quickly disperse liquid to the polymer water-absorbent resin particles; the polymer water-absorbent resin particles have strong water absorption and water retention capabilities, and can absorb and lock a large amount of liquid to prevent liquid backseepage, thereby effectively improving the leak-proof and liquid absorption performance of the leak-proof pad layer. Of course, the fluff pulp and the polymer water-absorbent resin particles can also be mixed and wrapped by non-woven fabrics.

[0031] 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 the technical features being referred to. Thus, a feature identified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0032] In the present invention, unless otherwise expressly specified or limited, terms such as "mounted," "connected," "connect," and "fixed" should be understood broadly. For example, they may refer to fixed connection, detachable connection, or integration; they may refer to direct connection or indirect connection through an intermediate medium; they may refer to internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0033] In the present invention, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0034] Although the present invention has been particularly shown and described in conjunction with preferred embodiments, it will be understood by those skilled in the art that various changes in form and details may be made to the present invention without departing from the spirit and scope of the invention as defined in the appended claims, and all such changes are within the scope of protection of the present invention.

Claims

1. A method for preparing leak-proof baby diapers, characterized in that: The diaper body is provided, and the preparation method of the diaper body comprises the following steps: 1) preparing a liquid-impermeable bottom layer, defining a plurality of continuous absorbent units along the transport direction of the liquid-impermeable bottom layer; 2) preparing an absorbent core layer; 3) cutting the absorbent core layer from step 2) into individual absorbent bodies, and sequentially transferring the absorbent bodies to the absorbent units of the liquid-impermeable bottom layer from step 1 for lamination, with the absorbent bodies being sequentially spaced apart along the conveying direction of the liquid-impermeable bottom layer; 4) Preparation of liquid-permeable surface layer: a. Unwinding the rolled hydrophobic fabric and cutting the hydrophobic fabric along its transverse central axis to form two axially symmetrically distributed hydrophobic nonwoven fabrics; b. Compounding the first leak-proof elastic bands on the lateral inner sides of the hydrophobic non-woven fabrics, and folding the lateral inner ends of the hydrophobic non-woven fabrics downward to cover the first leak-proof elastic bands to form a first three-dimensional protective enclosure; c. Compounding the second leak-proof elastic bands on the lateral outer sides of the hydrophobic non-woven fabric; d. unrolling the rolled first leak-proof pad for transport, and cutting it into individual first leak-proof pad layers, and then transferring and laminating the first leak-proof pad layers onto the hydrophobic non-woven fabric, and locating them laterally inside the second leak-proof elastic band; e. Folding the outer lateral ends of the hydrophobic non-woven fabric upward and wrapping them over the second leak-proof elastic and the first leak-proof cushion layer to form a second three-dimensional protective enclosure; f. unwinding and conveying the rolled hydrophilic nonwoven fabric; g. Laminating the middle portion of the hydrophobic non-woven fabric of step e to both sides of the hydrophilic non-woven fabric of step f through a first glue layer; h. Compounding the product of step g) on ​​the product of step 3); i. Prepare a front leak-proof sheet, and laminate the front leak-proof sheet onto the product prepared in step h, with the left and right edges of the front leak-proof sheet being laminated and connected to the first three-dimensional guardrails distributed on both sides thereof via a second glue layer and a third glue layer, respectively. The upper edge of the front leak-proof sheet is laminated and connected to the upper edge of the hydrophilic non-woven fabric located in the absorbent unit via a fourth glue layer, so that a front pocket having a first opening is formed between the front leak-proof sheet, the two first three-dimensional guardrails, and the liquid-permeable surface layer; j. Prepare a rear leak-proof sheet, and composite-connect the left and right edges of the rear leak-proof sheet to the second three-dimensional guard panels located on both sides thereof via a fifth and sixth glue layers, respectively. Composite-connect the lower edge of the rear leak-proof sheet to the lower edge of the hydrophilic non-woven fabric located within the absorbent unit via a seventh glue layer, thereby forming a rear pocket having a second opening between the rear leak-proof sheet, the two second three-dimensional guard panels, and the liquid-permeable surface layer. 5) Cutting the product of step j along the boundaries of the absorbent unit to form individual diaper bodies.

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

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 layer, a lower sheet layer, at least one first elastic band and at least three second elastic bands. The first elastic band is compounded between the upper sheet layer and the lower sheet layer and distributed at the upper edge of the rear leak-proof sheet. The second elastic bands are compounded between the upper sheet layer and the lower sheet layer and distributed between the seventh glue layer and the eighth glue layer. The second elastic bands are distributed in the transverse direction.

4. The method for preparing leak-proof baby diapers according to claim 3, characterized in that: The stretching ratio of the second elastic band is greater than the stretching ratio 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 layer and at least one third elastic band. The third elastic band is compounded on the longitudinal lower side of the first sheet layer and is folded and wrapped around the lower edge of the first sheet layer.

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, so that an expansion cavity is formed 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 middle portion of the first three-dimensional guard is compositely connected to the upper surface of the hydrophilic non-woven fabric through a ninth glue layer, and the ninth glue layer does not cover the first leak-proof elastic band.

8. The method for preparing leak-proof baby diapers according to claim 7, characterized in that: A second leak-proof cushion layer is provided in the longitudinal middle portion of the upper surface of the liquid-impermeable bottom layer and on the lower side of the second three-dimensional protective enclosure.

9. The method for preparing leak-proof baby diapers according to claim 8, characterized in that: The first anti-leakage cushion layer and the second anti-leakage cushion layer both include bulky non-woven fabrics and polymer water-absorbing resin particles spread on the bulky non-woven fabrics, or a mixture of fluff pulp and polymer water-absorbing resin particles.

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