Preparation process of embedded absorption core body

Abstract

The invention relates to the field of disposable hygienic products, in particular to a preparation process of an embedded absorption core, which comprises the following steps: step S1, forming a lower-layer core on a first forming die wheel, outputting the lower-layer core to a supporting layer, and conveying the lower-layer core forwards; and S2, the middle core body is output to a lower-layer core body on the bearing layer, a lower-layer pit is formed in the middle of the lower-layer core body, and the middle core body is embedded into the lower-layer pit, or the middle core body is pressed on the lower-layer core body. The technical problems that an existing common wood pulp core body is insufficient in bonding strength, and a composite core body is low in absorption speed are solved.

Description

Technical Field

[0001] The present invention relates to the field of disposable sanitary products, in particular to a preparation process of an embedded absorbent core. Background Art

[0002] Currently, existing technologies for preparing absorbent cores often utilize a single layer structure or a simple composite structure. These structures present limitations in terms of absorption performance, product strength, and comfort. Specifically, absorbent cores with a single layer structure often struggle to simultaneously achieve high absorption rates and good distribution uniformity, leading to potential localized leakage or insufficient absorption during use. While simple composite structures improve absorption performance to a certain extent, the lack of interlayer bonding strength makes them prone to delamination during use, impacting the overall performance and user experience of the product. For example, Chinese patent publication number: CN221357439U discloses an antibacterial composite absorption core, the core body includes a first absorption layer and a second absorption layer arranged in sequence from top to bottom, the outer layer of the core body is provided with a covering layer, a first antibacterial layer is sandwiched between the first absorption layer and the covering layer, a second antibacterial layer is sandwiched between the second absorption layer and the covering layer, water-absorbing resin particles are sandwiched between the first absorption layer and the second absorption layer, the first antibacterial layer has an antibacterial protective effect on the upper end surface of the core body, and the second antibacterial layer has an antibacterial protective effect on the lower end surface of the core body, a number of bamboo fibers are laid between the first absorption layer and the second absorption layer, the bamboo fibers have an antibacterial effect, and effectively inhibit the growth of bacteria inside the core body, the first antibacterial layer and the second antibacterial layer are both composed of bamboo fibers, have a rapid absorption effect on liquid, and do not affect the infiltration rate of liquid in the core.

[0003] In addition, the traditional absorbent core preparation process often finds it difficult to achieve precise matching and tight integration between layers during the core molding and assembly process, resulting in unstable product performance and low production efficiency.

[0004] Therefore, how to develop a new absorbent core preparation process that can ensure high absorption performance while improving the overall strength and comfort of the product and achieving precise matching and close integration between layers has become a technical problem that needs to be urgently solved in the current absorbent core manufacturing field. Summary of the Invention

[0005] Therefore, in response to the above problems, the present invention proposes a preparation process for an embedded absorbent core, which solves the technical problems of insufficient bonding strength of conventional wood pulp cores and slow absorption speed of composite cores.

[0006] To achieve the above object, the present invention adopts the following technical solution: a preparation process of an embedded absorbent core, comprising the following steps:

[0007] Step S1, forming a lower core body on a first forming die wheel, outputting the lower core body to a supporting layer, and conveying it forward;

[0008] Step S2: output the intermediate core to the lower core on the supporting layer. The lower core has a lower recess in the middle, and the intermediate core is embedded in the lower recess, or the intermediate core is pressed onto the lower core.

[0009] Furthermore, after step S2, step S3 is also included: outputting the upper core body to the lower core body embedded in the middle core body on the supporting layer, so that the upper core body covers the lower core body and covers the middle core body.

[0010] Furthermore, the upper core body is formed by the second forming die wheel and output to the lower core body embedded in the middle core body on the supporting layer. The second forming die wheel matches the conveying speed of the supporting layer to ensure that the upper core body is accurately covered on the lower core body and the middle core body.

[0011] Furthermore, the intermediate core body is a core body structure that is composited off-line, and the composite process has been completed before being output to the lower core body on the supporting layer; or, the intermediate core body is a core body structure that is composited online, and the composite process is carried out simultaneously during the process of being output to the lower core body on the supporting layer.

[0012] Furthermore, the middle core has a three-layer structure, which includes a first non-woven fabric layer, a SAP layer and a second non-woven fabric layer from bottom to top. The SAP layer is formed by SAP fixed-point spreading, forming multi-region and multi-density SAP partitions on the SAP layer.

[0013] Furthermore, the middle core is made of non-woven fabric, the gram weight of the non-woven fabric is 10-50g / ㎡, and it is used solely to enhance the core strength of the product.

[0014] Furthermore, part or all of the intermediate core is made of fluffy non-woven fabric, and the fluffy non-woven fabric is crushed or in sheet form. By adding the fluffy non-woven fabric, the core strength, softness and resilience of the product are enhanced.

[0015] Furthermore, a pressing device is used to press the middle core into the lower recess of the lower core, during the process of the middle core being embedded in the lower recess.

[0016] Furthermore, the pressing device includes a first rolling mechanism and a second rolling mechanism, the first rolling mechanism is used to achieve preliminary pressing of the intermediate core body, and the second rolling mechanism is used to achieve secondary pressing of the intermediate core body, the first rolling mechanism includes a first upper roller and a first lower roller, the second rolling mechanism includes a second upper roller and a second lower roller, the conveying speed of the first rolling mechanism is greater than the conveying speed of the second rolling mechanism, and the speed difference is 5% to 15% of the conveying speed of the first rolling mechanism, the gap between the first upper roller and the first lower roller is greater than the gap between the second upper roller and the second lower roller, and the gap difference is 1-5mm.

[0017] Furthermore, in step S2, a corresponding positioning sensor is set on the conveying mechanism of the intermediate core body, and a positioning mark of each lower core body is set on the conveyed supporting layer. The positioning sensor detects the positioning mark and feeds back the signal to the control system. The control system adjusts the conveying speed of the supporting layer and the conveying mechanism according to the signal to ensure the precise matching of the intermediate core body and the lower depression.

[0018] Furthermore, the positioning sensor is an image sensor that collects images of the surface of the supporting layer in real time and identifies the shape and position of the positioning mark through an image processing algorithm. The image processing algorithm includes:

[0019] Step S211, image acquisition: the image sensor acquires image data of the surface of the supporting layer at a certain frame rate;

[0020] Step S212, image preprocessing: grayscale the collected image to convert the color image into a grayscale image to reduce the image data volume; then filter the image to remove noise interference. Common filtering algorithms include Gaussian filtering and median filtering.

[0021] Step S213, positioning marker identification: using an edge detection algorithm to extract edge information from the image, and then using a shape matching algorithm to search for an area in the edge image that matches the shape of the preset positioning marker to determine the position of the positioning marker;

[0022] Step S214, position information extraction: calculate the center coordinates of the positioning marker as the position information of the positioning marker, and send the position information to the control system.

[0023] Furthermore, the control system adjusts the conveying speed of the supporting layer and the conveying mechanism according to the signal fed back by the positioning sensor, and adopts the following control algorithm:

[0024] S221, position error calculation: The control system presets a target position for the middle core to match the lower recess. When the positioning sensor detects the positioning mark, the control system calculates the position error Δx based on the current position of the positioning mark and the target position.

[0025] S222, speed adjustment calculation: Based on the position error Δx, the conveying speed adjustment Δv of the support layer and the conveying mechanism is calculated using a proportional-integral-differential (PID) control algorithm. The formula of the PID control algorithm is:

[0026]

[0027] Among them, K P is the proportionality coefficient, K i is the integral coefficient, K d is the differential coefficient, and t is the time.

[0028] S223, speed adjustment: The control system adjusts the speed of the driving motors of the supporting layer and the conveying mechanism according to the calculated speed adjustment amount Δv, thereby changing the conveying speed and gradually reducing the position error between the middle core and the lower layer depression to achieve precise matching.

[0029] By adopting the above technical solution, the beneficial effects of the present invention are:

[0030] 1. By forming a lower core with a lower depression on the first forming die wheel and embedding the middle core into this depression, a multi-layer composite structure of the absorbent core is achieved. This structure not only improves the overall absorption capacity of the absorbent core, but also strengthens the bonding strength between the cores through the depression design, preventing delamination during use, and improving product durability and user experience.

[0031] 2. The addition of the upper core covering step makes the absorbent core form a more complete multi-layer structure. The addition of the upper core not only further enhances the absorption performance, but also plays a role in protecting the middle and lower cores, improving the overall quality and stability of the product.

[0032] 3. The upper core is formed by the second forming die wheel, and its conveying speed is matched with that of the supporting layer, achieving accurate coverage of the upper core. This ensures a close connection between the upper core, the lower core, and the middle core, further improving the product's absorption performance and overall quality.

[0033] 4. The intermediate core can be either an off-line composite core structure or an online composite core structure. The off-line composite core structure can be prepared in advance to reduce online production time; while the online composite core structure can be adjusted according to real-time needs, improving production flexibility and efficiency.

[0034] 5. The central core adopts a three-layer structure, comprising a first non-woven fabric layer, an SAP layer, and a second non-woven fabric layer. SAP is distributed in multiple zones and densities through targeted SAP spreading. This design not only improves SAP utilization and absorption efficiency, but also ensures more uniform absorption across different areas of the absorbent core, reducing the risk of localized leakage and enhancing the overall performance of the product. Of course, a five-layer structure is also possible, such as three layers of non-woven fabric sandwiching two SAP layers.

[0035] 6. The middle core is made of non-woven fabric with a grammage of 10-50g / ㎡. This design enhances the core strength of the product. The non-woven fabric has good air permeability and moisture absorption. At the same time, the control of grammage also ensures the flexibility and durability of the core, so that the absorbent core maintains high absorption performance while also having better physical properties.

[0036] 7. The middle core is partially or entirely made of fluffy non-woven fabric. This design not only enhances the core strength of the product, but also improves the softness and resilience of the product. The addition of fluffy non-woven fabric makes the absorbent core more comfortable during use, reduces the discomfort caused by the hard core, and improves the user experience.

[0037] 8. The middle core is pressed into the lower depression of the lower core using a pressing device, achieving a tight bond between the cores. This pressing method not only improves the bonding strength between the cores, but also prevents delamination during use, ensuring the overall performance and stability of the absorbent core.

[0038] 9. The lamination device includes a first roller and a second roller, which achieve precise insertion of the intermediate core through two laminations. The speed and gap difference between the first and second rollers ensures a more uniform and efficient lamination process, improving the bond between the intermediate core and the lower core, and further enhancing the overall performance of the product. Furthermore, the speed difference creates a rubbing effect between the second and first rollers, further enhancing the lamination effect.

[0039] 10. By installing positioning sensors on the intermediate core's conveying mechanism and setting positioning markers on the support layer, the intermediate core is precisely aligned with the lower recess. This precise positioning technology not only improves production efficiency but also ensures product quality stability, reducing performance degradation or product scrap caused by positional deviation.

[0040] 11. Positioning sensors use image sensors and image processing algorithms to identify the shape and position of positioning markers. This technology not only improves positioning accuracy but also automates and intelligentizes the production process, reducing human intervention and errors, and improving production efficiency and product quality.

[0041] 12. The control system adjusts the conveying speed of the support layer and conveyor mechanism based on feedback from the positioning sensor, using a PID control algorithm to achieve precise matching. This intelligent speed adjustment method not only improves the flexibility and adaptability of the production process, but also ensures the precise connection between the middle core and the lower depression, further improving the overall performance and stability of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is a first structural diagram of the first embodiment of the present invention.

[0043] Figure 2 This is a second structural diagram of the first embodiment of the present invention.

[0044] Figure 3 It is a structural diagram of the intermediate core during online compounding.

[0045] Figure 4 It is a structural diagram when the middle core line is in compliance.

[0046] Figure 5 This is a first structural diagram of the second embodiment of the present invention.

[0047] Figure 6 This is a second structural diagram of the second embodiment of the present invention.

[0048] Reference numerals:

[0049] 1. First forming die wheel; 2. Second forming die wheel; 3. Adsorption conveying device; 4. First rolling mechanism; 41. First upper roller; 42. First lower roller; 5. Second rolling mechanism; 51. Second upper roller; 52. Second lower roller; 61. Input conveyor belt; 62. Adsorption conveyor belt; 63. Adsorption transfer device; 621. Negative pressure bellows; 622. Positive pressure bellows; 7. Support layer; 91. Lower core; 92. Middle core; 93. Upper core. DETAILED DESCRIPTION

[0050] The present invention will now be further described with reference to the accompanying drawings and specific embodiments.

[0051] This embodiment provides a preparation process of an embedded absorbent core, comprising the following steps:

[0052] Step S1: forming a lower core body 91 on a first forming die wheel 1, wherein the middle portion of the lower core body 91 has a lower recess, and outputting the lower core body 91 to the supporting layer 7 and conveying it forward;

[0053] Step S2: The intermediate core 92 is output to the lower core 91 on the supporting layer 7, and the intermediate core 92 is embedded into the lower recess.

[0054] The intermediate core body 92 is a core structure that has been composited off-line, and the composite process has been completed before it is output to the lower core body 91 on the supporting layer 7; or, the intermediate core body 92 is a core structure that has been composited on-line, and the composite process is carried out simultaneously during the process of being output to the lower core body 91 on the supporting layer 7.

[0055] Alternatively, the intermediate core 92 may be a three-layer structure, comprising, from bottom to top, a first non-woven fabric layer, a SAP layer, and a second non-woven fabric layer. The SAP layer is formed by spot-spreading SAP, creating multiple SAP zones with varying densities. Of course, other hierarchical structures are also possible, such as a five-layer structure or a seven-layer structure.

[0056] Alternatively, the intermediate core 92 is made of non-woven fabric, the weight of which is 10-50 g / m2, and is solely used to enhance the core strength of the product.

[0057] Alternatively, part or all of the intermediate core 92 is made of fluffy non-woven fabric, which is crushed or in sheet form. By adding the fluffy non-woven fabric, the core strength, softness and resilience of the product are enhanced.

[0058] Specifically, the middle core 92 is selected according to actual needs. Of course, the middle core 92 can be semi-embedded, such as Figure 1 As shown; it can also be fully embedded, such as Figure 2 The lower core 91 can be made of wood pulp, wood pulp mixed with SAP particles, or a mixture of wood pulp and other materials. The specific mixing method and mixing ratio can be selected according to actual needs. In addition, the support layer 7 can be bonded to the lower core 91 by spraying glue.

[0059] In step S2, the intermediate core 92 is pressed into the lower recess of the lower core 91 by a pressing device. When the intermediate core 92 is formed online, refer to Figure 3 As shown, along the conveying direction (indicated by the arrow), it includes a first forming die wheel 1, a second forming die wheel 2, an adsorption conveying device 3 located below the first forming die wheel 1 and the second forming die wheel 2, and a pressing device located at the output end of the adsorption conveying device 3. When the intermediate core 92 is a core structure that has been composited outside the line, please refer to the specific Figure 4As shown, it can be input through the input conveyor belt 61, then transferred by adsorption using the adsorption conveyor belt 62, and finally input from outside the line to the lower core body 91 using the adsorption transfer device 63. The first forming die wheel 1, the second forming die wheel 2, the adsorption conveyor device 3, the input conveyor belt 61, the adsorption conveyor belt 62 and the adsorption transfer device 63 are all conventional equipment in the art. For example, the adsorption conveyor belt 62 is a conveyor belt with mesh, which is provided with a negative pressure bellows 621 for adsorption and a positive pressure bellows 622 for blowing away to achieve transfer.

[0060] The pressing device includes a first rolling mechanism 4 and a second rolling mechanism 5. The first rolling mechanism 4 is used to achieve preliminary pressing of the intermediate core 92, and the second rolling mechanism 5 is used to achieve secondary pressing of the intermediate core 92. The first rolling mechanism 4 includes a first upper roller 41 and a first lower roller 42, and the second rolling mechanism 5 includes a second upper roller 51 and a second lower roller 52. The conveying speed of the first rolling mechanism 4 is greater than the conveying speed of the second rolling mechanism 5, and the speed difference is 5% to 15% of the conveying speed of the first rolling mechanism 4. The gap between the first upper roller 41 and the first lower roller 42 is greater than the gap between the second upper roller 51 and the second lower roller 52, and the gap difference is 1-5mm.

[0061] Furthermore, the conveying speed of the second rolling mechanism 5 varies periodically during the conveying process, and the period can be limited to 0.1 seconds, 0.2 seconds or other values. The variation of the conveying speed can fluctuate by ±3% of the initial speed.

[0062] The two-step lamination process achieves precise insertion of the intermediate core 92. The design of the conveying speed and gap difference between the first and second roller pressing mechanisms 4 and 5 makes the lamination process more uniform and efficient, improving the bond quality between the intermediate core 92 and the lower core 91 and further enhancing the overall performance of the product. Furthermore, the speed difference creates a rubbing effect between the second roller pressing mechanism 5 and the first roller pressing mechanism 4, further enhancing the lamination effect.

[0063] Of course, the pressing device can also adopt a conventional structure, such as a single roller mechanism. The support layer can be a non-woven fabric, toilet paper, or other conventional materials suitable for the absorbent core. The lower core can also be provided with no lower recess, with the intermediate core being laid directly on the upper surface of the lower core.

[0064] Example 2 discloses a preparation process of an embedded absorbent core of the same inventive concept, which differs from Example 1 in that:

[0065] After step S2 , step S3 is also included: outputting the upper core 93 to the lower core 91 on the supporting layer 7 , which has been embedded with the intermediate core 92 , so that the upper core 93 covers the lower core 91 and the intermediate core 92 .

[0066] The upper core body 93 is formed by the second forming die wheel 2 and output to the lower core body 91 on the supporting layer 7 which has been embedded with the intermediate core body 92. The second forming die wheel 2 matches the conveying speed of the supporting layer 7 to ensure that the upper core body 93 is accurately covered on the lower core body 91 and the intermediate core body 92.

[0067] The addition of the covering step of the upper core 93 allows the absorbent core to form a more complete multi-layer structure. The addition of the upper core 93 not only further enhances the absorption performance, but also protects the middle core 92 and the lower core 91, thereby improving the overall quality and stability of the product. The upper core 93 is formed by the second molding die wheel 2, and its conveying speed is matched with the supporting layer 7, thereby achieving accurate covering of the upper core 93. The close connection between the upper core 93 and the lower core 91 and the middle core 92 is ensured, further improving the absorption performance and overall quality of the product. Among them, the upper core 93 can be wood pulp or wood pulp mixed with SAP particles. The specific mixing ratio can be selected according to actual needs.

[0068] like Figure 5 As shown, it is the state of the upper core 93 when the middle core 92 is half embedded in the lower core 91; Figure 6 As shown, it is the state of the upper core 93 when the middle core 92 is embedded in the lower core 91. The composite method of the upper core 93 is similar to that of the middle core 92, and the process and equipment when the middle core 92 and the lower core 91 are composited can be referred to.

[0069] Referring to Example 3, a preparation process of an embedded absorbent core of the same inventive concept is disclosed, which differs from Example 1 in that:

[0070] In step S2, a corresponding positioning sensor is set on the conveying mechanism of the intermediate core body, and a positioning mark of each lower core body is set on the conveyed supporting layer. The positioning sensor detects the positioning mark and feeds back the signal to the control system. The control system adjusts the conveying speed of the supporting layer and the conveying mechanism according to the signal to ensure the precise matching of the intermediate core body and the lower depression.

[0071] Furthermore, the positioning sensor is an image sensor that collects images of the surface of the supporting layer in real time and identifies the shape and position of the positioning mark through an image processing algorithm. The image processing algorithm includes:

[0072] Step S211, image acquisition: the image sensor acquires image data of the surface of the supporting layer at a certain frame rate;

[0073] Step S212, image preprocessing: grayscale the collected image to convert the color image into a grayscale image to reduce the image data volume; then filter the image to remove noise interference. Common filtering algorithms include Gaussian filtering and median filtering.

[0074] Step S213, positioning marker identification: using an edge detection algorithm to extract edge information from the image, and then using a shape matching algorithm to search for an area in the edge image that matches the shape of the preset positioning marker to determine the position of the positioning marker;

[0075] Step S214, position information extraction: calculate the center coordinates of the positioning marker as the position information of the positioning marker, and send the position information to the control system.

[0076] Furthermore, the control system adjusts the conveying speed of the supporting layer and the conveying mechanism according to the signal fed back by the positioning sensor, and adopts the following control algorithm:

[0077] S221, position error calculation: The control system presets a target position for the middle core to match the lower recess. When the positioning sensor detects the positioning mark, the control system calculates the position error Δx based on the current position of the positioning mark and the target position.

[0078] S222, speed adjustment calculation: Based on the position error Δx, the conveying speed adjustment Δv of the support layer and the conveying mechanism is calculated using a proportional-integral-differential (PID) control algorithm. The formula of the PID control algorithm is:

[0079]

[0080] Among them, K P is the proportionality coefficient, K i is the integral coefficient, K d is the differential coefficient, and t is the time.

[0081] S223, speed adjustment: The control system adjusts the speed of the driving motors of the supporting layer and the conveying mechanism according to the calculated speed adjustment amount Δv, thereby changing the conveying speed and gradually reducing the position error between the middle core and the lower layer depression to achieve precise matching.

[0082] By installing a positioning sensor on the conveying mechanism of the intermediate core and setting a positioning mark on the supporting layer, precise matching of the intermediate core and the lower depression is achieved. This precise positioning technology not only improves production efficiency, but also ensures the stability of product quality and reduces performance degradation or product scrap due to positional offset. The positioning sensor uses an image sensor and uses an image processing algorithm to identify the shape and position of the positioning mark. This technology not only improves positioning accuracy, but also realizes the automation and intelligence of the production process, reduces human intervention and errors, and improves production efficiency and product quality. The control system adjusts the conveying speed of the supporting layer and conveying mechanism based on the feedback signal from the positioning sensor, and uses a PID control algorithm to achieve precise matching. This intelligent speed adjustment method not only improves the flexibility and adaptability of the production process, but also ensures the precise docking of the intermediate core and the lower depression, further improving the overall performance and stability of the product.

[0083] 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 process for preparing an embedded absorbent core, characterized in that: The following steps are involved: Step S1, forming a lower core body on a first forming die wheel, outputting the lower core body to a supporting layer, and conveying it forward; Step S2: output the intermediate core to the lower core on the supporting layer. The lower core has a lower recess in the middle, and the intermediate core is embedded in the lower recess, or the intermediate core is pressed onto the lower core.

2. The preparation process of the embedded absorbent core according to claim 1, characterized in that: After step S2, step S3 is also included: outputting the upper core body to the lower core body embedded in the middle core body on the supporting layer, so that the upper core body covers the lower core body and covers the middle core body.

3. The preparation process of the embedded absorbent core according to claim 2, characterized in that: The upper core body is formed by the second forming die wheel and output to the lower core body embedded in the middle core body on the supporting layer. The second forming die wheel matches the conveying speed of the supporting layer to ensure that the upper core body is accurately covered on the lower core body and the middle core body.

4. The process for preparing the embedded absorbent core according to any one of claims 1 to 3, characterized in that: The intermediate core body is a core body structure that has been composited off-line, and the composite process has been completed before it is output to the lower core body on the supporting layer; or, the intermediate core body is a core body structure that has been composited on-line, and the composite process is carried out simultaneously during the process of being output to the lower core body on the supporting layer.

5. The process for preparing the embedded absorbent core according to claim 4, characterized in that: The middle core has a three-layer structure, which includes a first non-woven fabric layer, a SAP layer and a second non-woven fabric layer from bottom to top. The SAP layer is formed by SAP fixed-point spreading, forming multi-region and multi-density SAP partitions on the SAP layer.

6. The process for preparing the embedded absorbent core according to any one of claims 1 to 3, characterized in that: The middle core is made of non-woven fabric, the weight of the non-woven fabric is 10-50g / ㎡, and it is used solely to enhance the core strength of the product.

7. The process for preparing the embedded absorbent core according to any one of claims 1 to 3, characterized in that: Part or all of the middle core is made of fluffy non-woven fabric, which is crushed or in sheet form. By adding the fluffy non-woven fabric, the core strength, softness and resilience of the product are enhanced.

8. The process for preparing the embedded absorbent core according to claim 1, characterized in that: The middle core body is pressed into the lower recess of the lower core body by using a pressing device, during the process of the middle core body being embedded in the lower recess.

9. The process for preparing the embedded absorbent core according to claim 8, characterized in that: The pressing device includes a first rolling mechanism and a second rolling mechanism. The first rolling mechanism is used to achieve preliminary pressing of the intermediate core body, and the second rolling mechanism is used to achieve secondary pressing of the intermediate core body. The first rolling mechanism includes a first upper roller and a first lower roller, and the second rolling mechanism includes a second upper roller and a second lower roller. The conveying speed of the first rolling mechanism is greater than the conveying speed of the second rolling mechanism, and the speed difference is 5% to 15% of the conveying speed of the first rolling mechanism. The gap between the first upper roller and the first lower roller is greater than the gap between the second upper roller and the second lower roller, and the gap difference is 1-5mm.

10. The process for preparing the embedded absorbent core according to any one of claims 1 to 3, characterized in that: In step S2, a corresponding positioning sensor is set on the conveying mechanism of the intermediate core body, and a positioning mark of each lower core body is set on the conveyed supporting layer. The positioning sensor detects the positioning mark and feeds back the signal to the control system. The control system adjusts the conveying speed of the supporting layer and the conveying mechanism according to the signal to ensure the precise matching of the intermediate core body and the lower depression.

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