Absorption core body and preparation device of absorption core body

Abstract

The embodiment of the invention provides an absorption core body which comprises a body, the body comprises a porous network-shaped structural body composed of absorption fibers, and the absorption core body is characterized in that the absorption fibers comprise first absorption fibers and second absorption fibers, the length of the second absorption fibers is smaller than that of the first absorption fibers, and the length of the second absorption fibers is smaller than that of the first absorption fibers. The body comprises a middle area and a peripheral area surrounding the periphery of the middle area, the thickness and the density of the peripheral area are larger than those of the middle area, pores formed by interweaving the first absorptive fibers are filled with the second absorptive fibers in the peripheral area, a good barrier effect can be achieved, manufacturing is easy, use is comfortable, and the structure is simple. The invention further provides a preparation device for preparing the absorption core.

Description

Technical Field

[0001] The invention relates to an absorbent core and a device for preparing the absorbent core. Background Art

[0002] Absorbent products such as sanitary napkins, panty liners, and diapers are widely used in people's daily lives. Typically, these absorbent products include a liquid-permeable top sheet, a liquid-impermeable bottom sheet, and an absorbent core sandwiched between the top sheet and the bottom sheet, and body fluids are absorbed and retained by the absorbent core.

[0003] In order to prevent the body fluid from leaking sideways, leakproof edges are usually set on the side. In the prior art, there are usually two forms of leakproof edges: one is to set a "cushion layer" formed by laying a water-repellent material on both sides of the top sheet, and the "cushion layer" forms a barrier effect. In this form, since the "cushion layer" is directly laid on the top sheet, its height is very limited. On the one hand, it cannot fit well with the skin. On the other hand, due to the low height, it is still easy to leak sideways. At the same time, if the thickness of the "cushion layer" is increased, the comfort of use will be reduced; the second is to fold the water-repellent material and set an elastic material, such as a rubber band, at the fold line. When in use, under the elastic force of the elastic material, the water-repellent material stands up to form a enclosure, thereby greatly increasing the enclosure effect, such as the structures shown in documents such as CN114007565A and CN116056674A. However, in this form, due to the elastic force of the elastic material, the fold line will contact the skin, which is easy to cause skin wear or discomfort in use.

[0004] In order to increase the height of the leak-proof partition and achieve excellent comfort at the same time, some improved technologies have been developed, such as patent document number CN101686880A, entitled: Absorbent Article, which discloses that the leak-proof partition is folded and wrapped to form a pleated portion with a cavity, and a plurality of elastic components are arranged in the pleated portion, so that a three-dimensional effect and excellent comfort are formed by the elastic components and the cavity, but this structural form is complex and inconvenient to produce.

[0005] In other improvements, such as CN215994505U, it is proposed to set protrusions around the absorbent core to form a blocking effect. However, it is found in practice that only setting protrusions on the edges cannot actually achieve a good blocking effect. Body fluids can easily pass through these protrusions and diffuse outward. Therefore, a new technical solution is needed to solve the above technical problems. Summary of the invention

[0006] To this end, the present invention provides an absorbent core to solve the above technical problems.

[0007] An absorbent core comprises a main body, wherein the main body comprises a porous network structure composed of absorbent fibers, characterized in that the absorbent fibers comprise first absorbent fibers and second absorbent fibers, and the length of the second absorbent fibers is shorter than that of the first absorbent fibers, the main body comprises a central region and a peripheral region surrounding the central region, the thickness and density of the peripheral region are greater than those of the central region, and the second absorbent fibers in the peripheral region are filled in pores formed by the interweaving of the first absorbent fibers.

[0008] The peripheral area includes an adjacent area adjacent to the central area and an outer area away from the central area, the density of the adjacent area is greater than that of the outer area or the density of the peripheral area gradually decreases from the side toward the central area to the side away from the central area.

[0009] The proportion of the second absorbent fibers in the main body is greater than 10%, and the proportion of the second absorbent fibers in the peripheral area is greater than or equal to 20%.

[0010] The present invention also provides a preparation device for preparing the above-mentioned absorbent core, comprising: A molding assembly, comprising a molding cylinder fixed on a central axis and rotating around the central axis, the molding cylinder comprising a cylinder wall, a plurality of molds being arranged on the cylinder wall, the molds comprising a side wall, a bottom net and a receiving cavity formed by the side wall and the bottom net, the bottom net comprising a first area corresponding to a central area and a second area corresponding to a peripheral area, wherein the second area is recessed toward the central axis; A spreading assembly, comprising a first spreading device arranged around the forming cylinder for spreading the first absorbent fibers, the first spreading device comprising a box having a first spreading cavity, the first spreading cavity comprising a first spreading opening facing the cylinder wall, and the spreading assembly further comprising a second spreading device arranged in the first spreading cavity for spreading the second absorbent fibers; The adsorption component is arranged in the forming tube, and comprises a first suction channel corresponding to the first zone and in a negative pressure state, and a second suction channel corresponding to the second zone and in a negative pressure state.

[0011] The mesh aperture of the second zone is smaller than the mesh aperture of the first zone.

[0012] The wind pressure in the first dispersing cavity is defined as P1, the wind pressure in the first air suction channel is defined as p1, and the wind pressure in the second air suction channel is defined as p2, and P1-p2>P1-p1.

[0013] Among them, the difference between P1-p2 and P1-p1 is greater than 3kPa.

[0014] Wherein, the second diffusion device comprises a second diffusion port. If the distance between the second diffusion port and the central axis is defined as L2, and the distance between the first diffusion port and the central axis is defined as L1, then L2-L1=5-20cm.

[0015] Wherein, the first suction channel and the second suction channel are configured to rotate synchronously with the corresponding molds.

[0016] Wherein, the preparation device also includes a transfer roller, the transfer roller includes a roller surface that contacts the cylinder wall and is in a negative pressure state, the cylinder wall also includes an adsorption area opposite to the first spreading port and a separation area corresponding to the transfer roller, the adsorption component includes a movable control valve for opening or closing the first suction channel and the second suction channel, and the control valve is configured such that when the first suction channel and the second suction channel rotate to correspond to the adsorption area, the control valve opens, and when the first suction channel and the second suction channel rotate to correspond to the separation area, the control valve closes.

[0017] Beneficial effects: An embodiment of the present invention provides an absorbent core, including a main body, wherein the main body includes a porous network structure composed of absorbent fibers, characterized in that the absorbent fibers include first absorbent fibers and second absorbent fibers, and the length of the second absorbent fibers is shorter than the first absorbent fibers, and the main body includes a central area and a peripheral area surrounding the central area, the thickness and density of the peripheral area are greater than those of the central area, and the second absorbent fibers in the peripheral area are filled in the pores formed by the interweaving of the first absorbent fibers, which can form a good barrier effect, and is easy to manufacture and comfortable to use. The present invention also provides a preparation device for preparing the above-mentioned absorbent core. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A three-dimensional schematic diagram of an absorbent core according to an embodiment of the present invention; Figure 2 for Figure 1 Schematic diagram of the cross section at AA; Figure 3 To form Figure 1 Schematic diagram of a device for preparing an absorbent core; Figure 4 for Figure 3 Schematic diagram of the cross section at BB; Figure 5 for Figure 4 Enlarged schematic diagram at point C in the middle.

[0019] Component Description: Main body 10; first absorbent fiber 101; second absorbent fiber 102; middle area 11; peripheral area 12; adjacent area 121; forming component 20; side plate 21; cylinder wall 22; adsorption area 221; separation area 222; central axis 23; mold 24; accommodating chamber 240; middle part 2401; peripheral part 2402; side wall 241; bottom net 242; first area 2421; second area 2422; adsorption component 25; first suction channel 251; second suction channel 252; spreading component 30; first spreading device 31; front section 311; middle section 312; rear section 313; first spreading chamber 310; first spreading port 3101; second spreading device 32; second spreading port 3201; transfer roller 41; conveying device 42. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and effect of the present application clearer and more specific, the following will describe the embodiments of the technical solution of the present application in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0021] Please refer to the attached Figure 1-2 An embodiment of the present invention provides an absorbent core, which includes a main body 10. The main body 10 includes a porous network structure composed of absorbent fibers. The absorbent fibers are preferably cellulose fibers, specifically wood pulp fibers, and more specifically mechanical or chemical-mechanical sulfite pulp. In addition, the wood pulp can be coniferous wood pulp or broadleaf wood pulp.

[0022] It is understandable that the network structure can also be filled with super absorbent polymers (SAP), which are usually distributed in the network structure in the form of particles, and can absorb and retain at least about 10 times its weight of body fluid under a pressure of 0.5 psi. The super absorbent polymer particles can be inorganic or organic cross-linked hydrophilic polymers, such as polyvinyl alcohol, polyethylene oxide, cross-linked starch, guar gum, xanthan gum, etc. The particles can be in the form of powder, granules, fine particles or fibers. In the present embodiment, the super absorbent polymer is cross-linked sodium polyacrylate.

[0023] The main body 10 includes a central area 11 and a peripheral area 12 surrounding the central area 11. The thickness and density of the peripheral area 12 are greater than those of the central area 11, so that the entire main body 10 presents a shape of a middle depression and surrounding bulges. At the same time, since the density of the raised peripheral area 12 is greater than that of the central area 11, body fluids can be confined by the peripheral area 12 to form a barrier.

[0024] In this embodiment, the absorbent fibers include first absorbent fibers 101 and second absorbent fibers 102, and the length of the second absorbent fibers 102 is shorter than that of the first absorbent fibers 101. In addition, in the peripheral area 12, the second absorbent fibers 102 are filled in the pores formed by the interweaving of the first absorbent fibers 101, so that the density of the peripheral area 12 is greater than that of the middle area 11. The fiber length refers to the average length of the fiber.

[0025] In addition, the density of the peripheral zone 12 being greater than the density of the middle zone 11 means that the density of the peripheral zone 12 is more than 10% higher than the density of the peripheral zone 12, and the thickness of the peripheral zone 12 being greater than the thickness of the middle zone 11 means that the thickness of the peripheral zone 12 should be more than 1 mm greater than the thickness of the middle zone 11, and the thickness is the natural thickness, which refers to the thickness of the area to be measured when it is in a natural form without applying pressure to the area to be measured or applying a pressure plate to the area to be measured during thickness measurement.

[0026] In addition, the length of the first absorbent fibers 101 should be at least 120% of the length of the second absorbent fibers 102 .

[0027] In a specific embodiment, the first absorbent fibers 101 are made of softwood pulp and generally have an average length greater than 2.5 mm, and the second absorbent fibers 102 are made of hardwood pulp and generally have an average length of 0.7-1.1 mm.

[0028] Furthermore, the proportion of the second absorbent fibers 102 in the main body 10 is greater than 10%, and the proportion of the second absorbent fibers 102 in the peripheral area 12 is greater than or equal to 20%.

[0029] Furthermore, the peripheral area 12 includes an adjacent area 121 adjacent to the central area 11 and an outer area away from the central area 11. The density of the adjacent area 121 is greater than that of the outer area, or the density of the peripheral area 12 gradually decreases from the side toward the central area 11 to the side away from the central area 11. In this case, on the one hand, body fluids can be blocked by the peripheral area 12. On the other hand, due to the high density on the inner side, the pores between the inner fibers are small, while the pores between the outer fibers are large. According to the principle of capillary action, the side with small pores will have a stronger capillary action, that is, the body fluid will not easily penetrate from the inside to the outside, thereby forming a stronger barrier effect. Thirdly, due to the low density on the outside, the outer edge area can be softer, so that the edge position can have a more comfortable feeling when it fits the skin.

[0030] Please refer to Figure 3-5 , this embodiment will be further described below in conjunction with the preparation device for forming the above-mentioned absorbent core.

[0031] The preparation device includes a spreading component 30 , a forming component 20 and an adsorption component 25 .

[0032] The molding assembly 20 includes a molding cylinder fixed on a central axis 23 and driven by the central axis 23 to rotate around the axis of the central axis 23. The molding cylinder includes a pair of circular side plates 21 arranged at intervals and a cylinder wall 22 connecting the pair of side plates 21. A plurality of molds 24 are arranged on the cylinder wall 22.

[0033] The mold 24 includes a side wall 241 and a bottom net 242, and the side wall 241 and the bottom net 242 are arranged to form an open accommodating cavity 240, and the absorbent fibers are filled into the accommodating cavity 240 to form the main body 10. In the present embodiment, the bottom net 242 includes a first area 2421 corresponding to the middle area 11 and a second area 2422 corresponding to the peripheral area 12, wherein the second area 2422 is recessed toward the central axis 23 so that the thickness of the peripheral area 12 formed after demolding is greater than the thickness of the middle area 11. It can be understood that the bottom net 242 includes a plurality of mesh holes so that airflow can pass through the mesh holes and the absorbent fibers carried by the airflow can be intercepted by the bottom net 242 and stacked in the accommodating cavity 240.

[0034] The spreading assembly 30 includes a first spreading device 31 arranged around the forming cylinder. The first spreading device 31 is mainly used to spread the first absorbent fibers 101. The first spreading device 31 includes a box body with a first spreading chamber 310. The first spreading chamber 310 includes a first spreading port 3101 facing the cylinder wall 22, so that the absorbent fibers in the first spreading chamber 310 are filled into the accommodating chamber 240 of the mold 24 through the first spreading port 3101. It can be understood that a feed port is also arranged upstream of the first spreading device 31. The feed port is configured to be connected to a fiber spreading device for receiving the absorbent fibers dispersed by the fiber spreading device. The fiber spreading device can be a crusher. At the same time, the first spreading device 31 is configured to be connected to an air supply device for forming a positive pressure in the first spreading chamber 310 and making the absorbent fibers in the first spreading chamber 310 uniformly dispersed under the action of wind.

[0035] It can be understood that the mold 24 is evenly distributed on the cylinder wall 22 along the circumference of the cylinder wall 22 at equal intervals, so that the mold 24 can pass through the first distribution port 3101 in sequence during the rotation of the forming cylinder, so that the first absorbent fiber can be filled into the mold 24 from the first distribution port 3101. Specifically, the first distribution port 3101 includes a front section 311, a middle section 312 and a rear section 313. The mold 24 passes through the front section 311, the middle section 312 and the rear section 313 in sequence, and the absorbent fiber is filled into the accommodating cavity 240 to form the main body 10 during the process of passing through the front section 311, the middle section 312 and the rear section 313.

[0036] The adsorption component 25 is arranged in the forming cylinder, including a first suction channel 251 corresponding to the first area 2421 and a second suction channel 252 corresponding to the second area 2422, and the first suction channel 251 is configured to be connected to the first negative pressure device so that a negative pressure is formed in the first suction channel 251, and the second suction channel 252 is configured to be connected to the second negative pressure device so that a negative pressure is also formed in the second suction channel 252. If the wind pressure in the first dispersing chamber 310 is defined as P1, the wind pressure in the first suction channel 251 is defined as p1, and the wind pressure in the second suction channel 252 is defined as p2. 252 is p2, then P1-p2>P1-p1, that is, the accommodating chamber 240 includes the middle part 2401 corresponding to the first area 2421 and the peripheral part 2402 corresponding to the second area 2422, then the wind pressure on the peripheral part 2402 formed by the first distributing chamber 310 and the second air suction channel 252 should be greater than the wind pressure on the middle part 2401 formed by the first distributing chamber 310 and the first air suction channel 251. In this case, more absorbent fibers can be accumulated in the peripheral area 12 so that the density of the peripheral area 12 is greater than that of the middle area 11.

[0037] It can be understood that the first suction channel 251 and the second suction channel 252 are configured to rotate synchronously with the corresponding mold 24, that is, the first suction channel 251 remains corresponding to the first zone 2421 and the second suction channel 252 remains corresponding to the second zone 2422, thereby maintaining P1-p2>P1-p1 during the rotation of the mold 24.

[0038] The spreading component 30 further includes a second spreading device 32 disposed in the first spreading chamber 310, for spreading the second absorbent fibers 102, wherein the length of the second absorbent fibers 102 is shorter than that of the first absorbent fibers 101. In a specific embodiment, the second spreading device 32 includes a second spreading opening 3201, wherein the second spreading opening 3201 is spaced apart from the first spreading opening 3101, and the second spreading opening 3201 is located in the middle section 312 of the first spreading opening 3101. Usually, only one second spreading device 32 is provided, and is only provided in the middle section 312 of the second spreading opening 3201, so that when the second absorbent fibers 102 are spread, the second absorbent fibers 102 are mainly filled in the middle position of the network structure formed by the first absorbent fibers 101.

[0039] It can be understood that since the wind pressure of the peripheral part 2402 is greater than the wind pressure of the middle part 2401, the air flow rate of the peripheral part 2402 is greater than the air flow rate of the middle part 2401, and the second absorbent fibers 102 dispersed from the second distributing port 3201 will flow more toward the peripheral part 2402 and be filled in the network structure formed by the first absorbent fibers 101. In addition, since the first absorbent fibers 101 are longer, the pores between the formed network structures are larger, which can provide space for the filling of the second absorbent fibers 102. At the same time, the density of the peripheral area 12 is greater than the density of the middle area through the above-mentioned arrangement. In addition, since the second distributing port 3201 is arranged in the middle section 312, when the second absorbent fibers 102 are dispersed, the air flow direction thereof is to flow toward the surrounding peripheral areas, forming a form in which the density of the adjacent area 121 is greater than the density of the outer area or the density of the peripheral area 12 gradually decreases from the side toward the middle area 11 to the side away from the middle area 11.

[0040] Further, the study found that the spacing distance between the second diffusion opening 3201 and the first diffusion opening 3101 should be at an appropriate distance. More specifically, there should be a relatively short spacing distance so that the second absorbent fibers 102 can enter the network structure formed by the first absorbent fibers 101 along with the rapid airflow after diffusion. However, when the spacing distance is too long, the second absorbent fibers 102 and the first absorbent fibers 101 will form a uniform mixture or a nearly uniform mixture in the first diffusion chamber 310, resulting in the inability to enter the network structure alone. Therefore, if the distance between the second diffusion opening 3201 and the axis of the central axis 23 is defined as L2, and the distance between the first diffusion opening 3101 and the axis of the central axis 23 is defined as L1, then L2-L1=5-20 cm. It can be understood that L2-L1 is the spacing distance between the second diffusion opening 3201 and the first diffusion opening 3101. More preferably, L2-L1 is 6-12 cm.

[0041] Furthermore, the mesh aperture of the second zone 2422 should be smaller than that of the first zone 2421 so that the second absorbent fibers 102 with shorter fiber length can be retained in the peripheral portion 2402. However, the mesh aperture of the second zone 2422 cannot be too small. When the mesh aperture of the second zone 2422 is too small, on the one hand, the mesh is prone to clogging, and on the other hand, the flow resistance of the airflow in the second portion is too large, resulting in uneven stacking or missing of the first absorbent fibers 101 and the second absorbent fibers 102 in the second portion. In a preferred embodiment, the mesh aperture of the second zone 2422 cannot be less than 100 mesh.

[0042] Furthermore, the difference between P1-p2 and P1-p1 should be greater than 3 kPa, so that when the mesh aperture of the second zone 2422 is smaller, the air flow rate through the second zone 2422 can still be faster than the air flow rate in the first zone 2421. In a preferred embodiment, the difference between P1-p2 and P1-p1 should be greater than 8 kPa.

[0043] Furthermore, the preparation device also includes a transfer roller 41 located downstream of the forming component 20, the transfer roller 41 includes a roller surface that contacts the drum wall 22, the roller surface includes a plurality of adsorption holes, the adsorption holes are connected to the negative pressure device so that negative pressure is formed on the roller surface, the drum wall 22 also includes an adsorption area 221 opposite to the first dispersing port 3101 and a separation area 222 corresponding to the transfer roller 41, and the adsorption component 25 includes a control valve that can be moved to open or close the first suction channel 251 and the second suction channel 252 , and the control valve is configured so that when the first suction channel 251 and the second suction channel 252 rotate to correspond to the adsorption area 221, the control valve is opened, and when the first suction channel 251 and the second suction channel 252 rotate to correspond to the separation area 222, the control valve is closed. It can be understood that when the control valve is closed, the first suction channel 251 and the second suction channel 252 will not be able to maintain a negative pressure state, so that the body 10 located in the accommodating cavity 240 is transferred to the roller surface of the transfer roller 41 under the action of the negative pressure at the roller surface, thereby forming demolding.

[0044] Furthermore, a conveying device 42 is provided downstream of the demoulding roller, and the body 10 located on the roller surface of the transfer roller 41 will be further transferred to the conveying device 42 and transported to the downstream direction by the conveying device 42.

[0045] The above description is only an implementation mode of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. An absorbent core, comprising a body, wherein the body comprises a porous network structure composed of absorbent fibers, characterized in that: The absorbent fibers include first absorbent fibers and second absorbent fibers, and the length of the second absorbent fibers is shorter than that of the first absorbent fibers. The body includes a central region and a peripheral region surrounding the central region. The thickness and density of the peripheral region are greater than those of the central region. In addition, the second absorbent fibers in the peripheral region are filled in pores formed by the interweaving of the first absorbent fibers.

2. The absorbent core according to claim 1, characterized in that The peripheral area includes an adjacent area adjacent to the central area and an outer area away from the central area. The density of the adjacent area is greater than that of the outer area, or the density of the peripheral area gradually decreases from the side toward the central area to the side away from the central area.

3. The absorbent core according to claim 1, characterized in that The proportion of the second absorbent fibers in the main body is greater than 10%, and at the same time, the proportion of the second absorbent fibers in the peripheral area is greater than or equal to 20%.

4. A device for preparing an absorbent core, used for preparing the absorbent core according to claim 1, characterized in that: The preparation device comprises: A molding assembly, comprising a molding cylinder fixed on a central axis and rotating around the central axis, the molding cylinder comprising a cylinder wall, a plurality of molds being arranged on the cylinder wall, the molds comprising a side wall, a bottom net and a receiving cavity formed by the side wall and the bottom net, the bottom net comprising a first area corresponding to a central area and a second area corresponding to a peripheral area, wherein the second area is recessed toward the central axis; A spreading assembly, comprising a first spreading device arranged around the forming cylinder for spreading the first absorbent fibers, the first spreading device comprising a box having a first spreading cavity, the first spreading cavity comprising a first spreading opening facing the cylinder wall, and the spreading assembly further comprising a second spreading device arranged in the first spreading cavity for spreading the second absorbent fibers; The adsorption component is arranged in the forming tube, and comprises a first suction channel corresponding to the first zone and in a negative pressure state, and a second suction channel corresponding to the second zone and in a negative pressure state.

5. The preparation device according to claim 4, characterized in that: The mesh aperture of the second zone is smaller than the mesh aperture of the first zone.

6. The preparation device according to claim 5, characterized in that: Define the wind pressure in the first dispersing cavity as P1, the wind pressure in the first air suction channel as p1, and the wind pressure in the second air suction channel as p2, then P1-p2>P1-p1.

7. The preparation device according to claim 6, characterized in that: The difference between P1-p2 and P1-p1 is greater than 3kPa.

8. The preparation device according to claim 6, characterized in that: The second diffusion device includes a second diffusion port. If the distance between the second diffusion port and the central axis is defined as L2, and the distance between the first diffusion port and the central axis is defined as L1, then L2-L1=5-20 cm.

9. The preparation device according to claim 5, characterized in that: The first suction channel and the second suction channel are configured to rotate synchronously with the corresponding molds.

10. The preparation device according to claim 9, characterized in that: The preparation device also includes a transfer roller, the transfer roller includes a roller surface that contacts the cylinder wall and is in a negative pressure state, the cylinder wall also includes an adsorption area opposite to the first spreading port and a separation area corresponding to the transfer roller, the adsorption component includes a control valve that can movably open or close the first suction channel and the second suction channel, and the control valve is configured such that when the first suction channel and the second suction channel rotate to correspond to the adsorption area, the control valve opens, and when the first suction channel and the second suction channel rotate to correspond to the separation area, the control valve closes.

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