Infant paper diaper preparation process based on expanded non-woven fabric core body

Abstract

The invention relates to the technical field of disposable hygienic products, in particular to a preparation process of a baby diaper based on a puffed non-woven fabric core, which has the characteristics of high processing efficiency and stable structure, high diffusion speed and high absorption efficiency of the prepared core, and comprises the following steps: preparing an absorption core layer: a, unwinding and conveying a fluffy non-woven fabric through a first unwinding mechanism; b, guiding the fluffy non-woven fabric into a preheating area of a bulking mechanism, and controlling a spraying system to uniformly spray water mist to the surface of the fluffy non-woven fabric through a control system to wet the fluffy non-woven fabric; c, the fluffy non-woven fabric is guided into a heating area of a puffing mechanism, the surface of the non-woven fabric is impacted through bidirectional high-pressure airflow, the airflow temperature is progressively increased in the forward direction and then progressively decreased in the reverse direction, a dynamic temperature gradient is formed, adhesion fibers are physically separated, and the pore size is enlarged; and d, guiding the fluffy non-woven fabric into a balance area of a bulking mechanism, and transversely stretching the fluffy non-woven fabric by adopting a differential roller group at the temperature of 100-110 DEG C to increase gaps among fibers.

Description

Technical Field

[0001] The present invention relates to the technical field of disposable sanitary products, and in particular to a process for preparing baby diapers based on an expanded non-woven fabric core. Background Art

[0002] In the absence of grooving, the online absorbent paper core of diapers has the problem of insufficient fluffiness of the non-woven fabric, which affects the penetration of the polymer absorbent resin particles (SAP particles), resulting in poor absorption and diffusion, and concentrated absorption in the middle, resulting in poor dryness in the middle of the product; and when the absorbent paper core adopts a single-layer guide groove or a simple composite structure, the direction of liquid flow is restricted, which can easily lead to local saturation, slow absorption speed, and high re-infiltration rate; if the core partition grooving process is adopted, there is a problem of material deviation during the production process, the upper and lower polymer layers cannot be aligned, and the grooving presses on the polymer, which can easily cause damage to the polymer morphology and affect the product's absorption performance.

[0003] In addition, the current production process of diaper core fluffy cloth mainly adopts unidirectional airflow or static hot air treatment, which has significant technical defects: on the one hand, unidirectional airflow can easily cause uneven heating of fibers, resulting in local overheating or insufficient expansion, resulting in significant differences in pore distribution (CV coefficient of variation value > 15%), and at the same time, unilateral expansion causes stress imbalance between layers, making the product prone to deformation or stratification, and the unidirectional heat loss is serious, resulting in excessive energy consumption; on the other hand, during long-term storage, the fluffy cloth is compressed, resulting in a decrease in fluffiness, which directly affects the penetration depth of SAP particles and the bonding strength between the upper and lower layers of materials, and ultimately leads to reduced core absorption efficiency and the risk of structural stratification.

[0004] At the same time, the traditional spreading process lacks negative pressure adsorption and material conveying and positioning devices, which leads to poor pressing of the polymer grooves, loose fixation of the polymer, and accumulation problems when the finished product is used. Summary of the Invention

[0005] Therefore, in response to the above problems, the present invention provides a process for preparing baby diapers based on an expanded non-woven fabric core, which has the characteristics of high processing efficiency, stable core structure, fast diffusion speed and high absorption efficiency.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A process for preparing baby diapers based on an expanded non-woven fabric core comprises the following steps:

[0008] 1) preparing a liquid-permeable surface layer;

[0009] 2) Preparation of absorbent core layer:

[0010] a. The fluffy non-woven fabric is unwound and conveyed by a first unwinding mechanism, wherein the direction extending along the conveying direction of the fluffy non-woven fabric is defined as the longitudinal direction, and the direction extending along the width direction of the fluffy non-woven fabric is defined as the transverse direction;

[0011] b. Introduce the fluffy non-woven fabric into the preheating area of ​​the puffing mechanism, and control the spray system through the control system to evenly spray water mist on the surface of the fluffy non-woven fabric to moisten and soften the fiber surface, and preheat the fluffy non-woven fabric for 5 to 10 seconds in an environment with a temperature of 50°C to 70°C and a wind speed of 0.5m / s to 1.0m / s;

[0012] c. The fluffy non-woven fabric is introduced into the heating zone of the puffing mechanism. The bidirectional high-pressure airflow impacts the surface of the non-woven fabric. The airflow temperature increases in the positive direction, raising the temperature from 120°C to 150°C at a speed of 1.5m / s, and then decreases in the reverse direction, lowering the temperature from 150°C to 120°C at a speed of 1.0m / s, forming a dynamic temperature gradient, physically separating the adhered fibers and expanding the pore size.

[0013] d. The fluffy non-woven fabric is introduced into the equilibrium zone of the puffing mechanism. At a temperature of 100℃ to 110℃, a differential speed roller group is used to stretch the fluffy non-woven fabric transversely to increase the gap between fibers. The roller temperature is controlled at 60℃ to 80℃ to assist in fiber shaping, and the lower surface of the fluffy non-woven fabric is sprayed with glue.

[0014] e. The bottom material is unrolled and conveyed through the second unwinding mechanism, and the upper surface of the bottom material is sprayed with glue;

[0015] f. applying a lower layer of high molecular weight water-absorbing resin particles to the upper surface of the base material by a first high molecular weight water-absorbing resin discharging mechanism to form a lower absorbent layer, wherein the lower absorbent layer has at least one first channel distributed longitudinally and to which no lower layer of high molecular weight water-absorbing resin particles are applied;

[0016] g. Compounding the product of step f with a fluffy nonwoven fabric;

[0017] h. Pass the product of step g through a negative pressure adsorption plate to stabilize the pore structure and prevent shrinkage, wherein the pressure of the negative pressure adsorption plate is -0.03MPa to -0.05MPa;

[0018] i. applying an upper layer of polymer water-absorbing resin particles to the upper surface of the fluffy non-woven fabric by a second polymer water-absorbing resin feeding mechanism to form an upper absorbent layer, wherein the upper absorbent layer has at least one second channel distributed longitudinally and to which no upper layer of polymer water-absorbing resin particles are applied;

[0019] j. The top layer material is unrolled and conveyed through the third unwinding mechanism, and the lower surface of the top layer material is sprayed with glue;

[0020] k. Compounding the top layer material with the product of step i;

[0021] 1. Pressing the top layer material, fluffy non-woven fabric and bottom layer material along the first channel and the second channel area by a pressing mechanism to form a guide channel;

[0022] m. cutting the product of step 1 to form a single absorbent core layer;

[0023] 3) preparing a liquid-impermeable bottom layer;

[0024] 4) laminating the liquid-permeable surface layer, the absorbent core layer and the liquid-impermeable bottom layer;

[0025] 5) Cut the product from step 4 into individual baby diaper bodies.

[0026] Furthermore, in the above step b, the atomization pressure of the spray system is 2.0Bar~4.0Bar, the particle size is 50μm~150μm, and the spraying amount is 0.5g / m 2 ~2.0g / m 2 .

[0027] Furthermore, in the above step c, the airflow is blown obliquely at an angle of 45° to enhance the three-dimensional arrangement of the fibers and perform a secondary puffing treatment.

[0028] Furthermore, in the above step d, the transverse stretching ratio of the fluffy non-woven fabric is 5 to 8%.

[0029] Furthermore, in the above step d, the differential roller group has at least two rollers, and the speed difference between two adjacent rollers is 10-15%.

[0030] Furthermore, in the above step 1, the pressing mechanism includes a pressing roller, the pressing roller has a raised pressure point, and the cross section of the raised pressure point is trapezoidal.

[0031] Furthermore, the temperature of the pressing roller is 60° C. to 80° C., and the linear pressure is 50 N / cm to 80 N / cm.

[0032] Furthermore, the number of the first channels and the number of the second channels are both three.

[0033] Furthermore, a first temperature sensor, a first heating component and a first air pump are provided in the preheating zone of the puffing mechanism; a second temperature sensor, a third temperature sensor, a second heating component, a third heating component, a second air pump and a third air pump are provided in the heating zone of the puffing mechanism; and a fourth temperature sensor and a fourth air pump are provided in the balancing zone of the puffing mechanism.

[0034] Furthermore, a fifth temperature sensor is provided on the negative pressure adsorption plate, and the first temperature sensor, the second temperature sensor, the third temperature sensor, the fourth temperature sensor, and the fifth temperature sensor are electrically connected to the input end of the control system, respectively, and the first heating component, the second heating component, the third heating component, the first air pump, the second air pump, the third air pump, the fourth air pump, and the spray system are electrically connected to the output end of the control system, respectively.

[0035] By adopting the above-mentioned technical scheme, the beneficial effects of the present invention are: a preparation process for baby diapers based on an expanded non-woven fabric core, which realizes three-dimensional reconstruction of the fiber structure through multi-segment expansion treatment combined with dynamic temperature gradient control, thereby improving the uniformity and stability of the core pores; adopts the synergistic effect of differential roller group transverse stretching and surface spraying, taking into account both fiber gap expansion and structural shaping, and the double polymer layer channel design is combined with the guide groove pressing technology to establish a three-dimensional guide network to improve the longitudinal diffusion speed, which can improve the composite strength between the layers of materials, the longitudinal diffusion of liquid, the slow absorption speed, and the high re-infiltration rate. The negative pressure adsorption shaping process effectively prevents fiber shrinkage and maintains the integrity of the expanded structure; the industrialized production process design has a high degree of automation, realizes continuous and stable production, and improves production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic structural diagram of the preparation process of an embodiment of the present invention;

[0037] Figure 2 is a schematic cross-sectional view of the puffing mechanism in an embodiment of the present invention;

[0038] Figure 3 2 is a schematic top view of a single absorbent core layer in an embodiment of the present invention;

[0039] Figure 4 is a schematic cross-sectional view of a single absorbent core layer in an embodiment of the present invention;

[0040] Figure 5 It is a circuit module diagram of an embodiment of the present invention. DETAILED DESCRIPTION

[0041] The present invention will now be further described with reference to the accompanying drawings and specific embodiments.

[0042] The embodiments of the present invention are:

[0043] refer to Figures 1 to 5 As shown, a process for preparing baby diapers based on an expanded non-woven fabric core comprises the following steps:

[0044] 1) preparing a liquid-permeable surface layer;

[0045] 2) Preparation of absorbent core layer:

[0046] a. The fluffy nonwoven fabric 1 is unwound and conveyed by a first unwinding mechanism, wherein the direction extending along the conveying direction of the fluffy nonwoven fabric 1 is defined as the longitudinal direction, and the direction extending along the width direction of the fluffy nonwoven fabric 1 is defined as the transverse direction;

[0047] b. The fluffy non-woven fabric 1 is introduced into the preheating zone 101 of the puffing mechanism 10. The control system 11 controls the spray system 12 to evenly spray water mist onto the surface of the fluffy non-woven fabric 1 to moisten it, soften the fiber surface, prevent electrostatic adsorption, and enhance the thermoplasticity of the fiber. The fluffy non-woven fabric is preheated for 5 to 10 seconds in an environment with a temperature of 50° C. to 70° C. and a wind speed of 0.5 m / s to 1.0 m / s to activate the thermal shrinkage potential of the fiber and avoid direct high temperature impact.

[0048] c. The fluffy non-woven fabric 1 is introduced into the heating zone 102 of the puffing mechanism 10. The surface of the non-woven fabric is impacted by a bidirectional high-pressure airflow. The airflow temperature increases in the positive direction from 120°C to 150°C at a speed of 1.5 m / s, and then decreases in the reverse direction from 150°C to 120°C at a speed of 1.0 m / s, thereby forming a dynamic temperature gradient, physically separating the adhered fibers, and expanding the pore size.

[0049] d. The fluffy non-woven fabric 1 is introduced into the balancing zone 103 of the puffing mechanism 10. The fluffy non-woven fabric 1 is transversely stretched by a differential roller group 13 at a temperature of 100°C to 110°C to increase the inter-fiber gaps. The roller temperature is controlled at 60°C to 80°C to assist in fiber shaping. The lower surface of the fluffy non-woven fabric 1 is sprayed with glue.

[0050] e. The bottom material 2 is unwound and conveyed by the second unwinding mechanism, and the upper surface of the bottom material is sprayed with glue;

[0051] f. A lower layer of high molecular water-absorbing resin particles is applied to the upper surface of the base material 2 by a first high molecular water-absorbing resin discharging mechanism 14 to form a lower absorbent layer 3. The lower absorbent layer 3 has four first channels 4 distributed longitudinally and not applied with the lower layer of high molecular water-absorbing resin particles;

[0052] g. Compounding the product of step f with the fluffy nonwoven fabric 1;

[0053] h. Pass the product of step g through a negative pressure adsorption plate 15 to stabilize the pore structure and prevent shrinkage. The pressure of the negative pressure adsorption plate 15 is -0.03 MPa to -0.05 MPa, preferably -0.04 MPa;

[0054] i. The upper layer of polymer water-absorbing resin particles is applied to the upper surface of the fluffy non-woven fabric 1 by the second polymer water-absorbing resin unloading mechanism 16 to form an upper absorbent layer 5. The upper absorbent layer 5 has four second channels 6 distributed in the longitudinal direction and not applied with the upper layer of polymer water-absorbing resin particles;

[0055] j. The top layer material 7 is unwound and conveyed by the third unwinding mechanism, and the lower surface of the top layer material 7 is sprayed with glue;

[0056] k. Compounding the top layer material 7 with the product of step i;

[0057] 1. Press the top material 7, the fluffy non-woven fabric 1 and the bottom material 2 along the first channel 4 and the second channel 6 by means of a pressing mechanism 17 to form a guide channel;

[0058] m. cutting the product of step 1 to form a single absorbent core layer;

[0059] 3) preparing a liquid-impermeable bottom layer;

[0060] 4) laminating the liquid-permeable surface layer, the absorbent core layer and the liquid-impermeable bottom layer;

[0061] 5) Cut the product from step 4 into individual baby diaper bodies.

[0062] This baby diaper preparation process based on an expanded non-woven fabric core achieves three-dimensional reconstruction of the fiber structure through multi-segment expansion treatment combined with dynamic temperature gradient control, thereby improving the uniformity and stability of the core pores. It adopts the synergistic effect of differential roller group transverse stretching and surface spraying, taking into account both fiber gap expansion and structural shaping. The double polymer layer channel design is combined with the guide groove pressing technology to establish a three-dimensional guide network to increase the longitudinal diffusion speed. It can improve the composite strength between the layers of materials, the longitudinal diffusion of liquids, the slow absorption speed, and the high re-infiltration rate. The negative pressure adsorption shaping process effectively prevents fiber shrinkage and maintains the integrity of the expanded structure. The industrialized production process design has a high degree of automation, realizes continuous and stable production, and improves production efficiency.

[0063] In this embodiment, in the above step b, the atomization pressure of the spray system 12 is 2.0Bar~4.0Bar, preferably 2.8Bar, the particle size is 50μm~150μm, preferably 80μm, and the spraying amount is 0.5g / m 2 ~2.0g / m 2 , preferably 1.2g / m 2 , finely control the atomization parameters to ensure uniform wetting of the fibers and avoid local over-wetting that affects the puffing effect. Water mist in a specific particle size range can penetrate into the fiber gaps to soften the gelatin layer without damaging the fiber strength. The preset spraying amount accurately controls the degree of fiber softening, providing a basis for subsequent step-by-step puffing.

[0064] In this embodiment, in the above step c, the airflow angle is 45° oblique blowing, which enhances the three-dimensional arrangement of the fibers and performs a secondary puffing treatment to increase the bulkiness and porosity of the fluffy non-woven fabric 1. The 45° oblique airflow produces a vortex effect, breaking the planar arrangement of the fibers and increasing the vertical interweaving; the three-dimensional arrangement forms a connected pore structure, thereby improving the core body's back-seepage barrier ability.

[0065] In this embodiment, in the above step d, the transverse stretching of the fluffy non-woven fabric 1 is 5 to 8%, preferably 6%, and the stretching rate accurately balances the relationship between fiber ductility and structural stability; the transverse stretching cooperates with the longitudinal transport to form a biaxially oriented structure, enhances the isotropic absorption capacity, and quantitative stretching avoids fiber breakage, thereby maintaining the overall mechanical properties of the non-woven fabric.

[0066] In this embodiment, in the above step d, the differential roller group 13 has four rollers, and the speed difference between two adjacent rollers is 10-15%. The specific speed difference generates controllable shear stress and evenly releases the stress in the fiber; the progressive stretching process prevents stress concentration and ensures uniform expansion of the fiber network; the dynamic variable speed stretching promotes the staggered arrangement of fibers to form a multi-level pore structure.

[0067] In this embodiment, in the above step 1, the pressing mechanism 17 includes a pressing roller, which has a raised pressure point. The cross-section of the raised pressure point is trapezoidal, and the trapezoidal pressure point design realizes stress gradient distribution to avoid collapse of the fiber structure; selective pressing maintains the structural integrity of the diversion channel and the absorption capacity of the surrounding area; the geometric embossing design enhances the deformation resistance of the diversion groove and extends the service retention rate.

[0068] In this embodiment, the temperature of the pressing roller is 60°C to 80°C, preferably 70°C, and the line pressure is 50N / cm to 80N / cm, preferably 75N / cm, to ensure the consistency of the groove forming depth (deviation ≤±0.1mm).

[0069] In this embodiment, the number of the first channels 4 and the second channels 6 are both three, and the three channels form a centrally symmetrical guide system to improve the radial diffusion efficiency of the liquid; the multi-channel design establishes redundant guide paths to enhance absorption reliability, and the symmetrical layout balances the stress distribution of the core to prevent structural distortion during use.

[0070] In addition, the preheating zone 101 of the puffing mechanism 10 is provided with a first temperature sensor 21, a first heating component 31 and a first air pump 41; the heating zone 102 of the puffing mechanism 10 is provided with a second temperature sensor 22, a third temperature sensor 23, a second heating component 32, a third heating component 33, a second air pump 42 and a third air pump 43; the balancing zone 103 of the puffing mechanism 10 is provided with a fourth temperature sensor 24 and a fourth air pump 44. The multi-sensor array realizes closed-loop control of all parameters of the puffing process; independent regulation of each section ensures parameter stability in each process stage; and a dynamic feedback mechanism compensates for environmental disturbances to ensure batch consistency.

[0071] Furthermore, a fifth temperature sensor 25 is provided on the negative pressure adsorption plate 15, and the first temperature sensor 21, the second temperature sensor 22, the third temperature sensor 23, the fourth temperature sensor 24, and the fifth temperature sensor 25 are electrically connected to the input end of the control system 11, respectively, and the first heating component 31, the second heating component 32, the third heating component 33, the first air pump 41, the second air pump 42, the third air pump 43, the fourth air pump 44, and the spray system 12 are electrically connected to the output end of the control system 11, respectively. The five-dimensional temperature monitoring network accurately captures the process thermal field distribution; the actuator linkage control realizes real-time optimization of process parameters; and the intelligent control system improves process stability and energy utilization efficiency.

[0072] Specifically, the puffing mechanism 10 includes a box body 104, and an inlet 105 and an outlet 106 are respectively provided on both longitudinal sides of the box body 104. The box body 104 has a chamber, and two partitions 20 are provided in the chamber, and the chamber is divided into a preheating zone 101, a heating zone 102 and a balancing zone 103 by the partition 20. A channel 107 for the fluffy non-woven fabric 1 to pass through the inlet 105 and the outlet 106 is provided in the box body 104. A first air inlet 111 is provided on the lower side of the preheating zone 101, and the first heating component 31 and the first fan 41 are provided at the first air inlet 111. The spray system 12 is provided on the upper part of the preheating zone 101, and a second air inlet 112 and a second air outlet 113 are respectively provided on the upper side of the heating zone 102. The second heating component 32 and the second air pump 42 are provided at the second air inlet 112. The lower side is provided with a third air inlet 114 and a third air outlet 115, the third heating component 33 and the third air pump 43 are provided at the third air inlet 114, the upper hot air flow channel 108 and the lower hot air flow channel 109 are provided in the heating zone 102 and on the upper and lower sides of the channel 107, respectively, the upper hot air flow channel 108 is connected to the second air inlet 112 and the second air outlet 113, the middle part of the upper hot air flow channel 108 is connected to the flow channel 1 07, the lower hot air flow channel 109 is connected to the third air inlet 114 and the third air outlet 115, the lower hot air flow channel 109 is connected to the front area of ​​the flow channel 107, the upper hot air flow channel 108 and the lower hot air flow channel 109 are rotationally symmetrically distributed, the balancing area 103 is provided with a fourth air inlet 116, the fourth air pump 44 is provided at the fourth air inlet 116, and the differential roller group 13 is provided in the balancing area 103.

[0073] The puffing mechanism 10 realizes bidirectional reflux puffing treatment of the fluffy nonwoven fabric 1 to improve the pore uniformity of the fluffy nonwoven fabric 1, which can help polymers better enter the pores of the fluffy fabric, improve the penetration depth and bonding strength of SAP particles, and reduce energy consumption.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] 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 baby diapers based on an expanded nonwoven fabric core, characterized in that: The following steps are involved: 1) preparing a liquid-permeable surface layer; 2) Preparation of absorbent core layer: a. The fluffy non-woven fabric is unwound and conveyed by a first unwinding mechanism, wherein the direction extending along the conveying direction of the fluffy non-woven fabric is defined as the longitudinal direction, and the direction extending along the width direction of the fluffy non-woven fabric is defined as the transverse direction; b. Introduce the fluffy non-woven fabric into the preheating area of ​​the puffing mechanism, and control the spray system through the control system to evenly spray water mist on the surface of the fluffy non-woven fabric to moisten and soften the fiber surface, and preheat the fluffy non-woven fabric for 5 to 10 seconds in an environment with a temperature of 50°C to 70°C and a wind speed of 0.5m / s to 1.0m / s; c. The fluffy non-woven fabric is introduced into the heating zone of the puffing mechanism. The bidirectional high-pressure airflow impacts the surface of the non-woven fabric. The airflow temperature increases in the positive direction, raising the temperature from 120°C to 150°C at a speed of 1.5m / s, and then decreases in the reverse direction, lowering the temperature from 150°C to 120°C at a speed of 1.0m / s, forming a dynamic temperature gradient, physically separating the adhered fibers and expanding the pore size. d. The fluffy non-woven fabric is introduced into the equilibrium zone of the puffing mechanism. At a temperature of 100℃ to 110℃, a differential speed roller group is used to stretch the fluffy non-woven fabric transversely to increase the gap between fibers. The roller temperature is controlled at 60℃ to 80℃ to assist in fiber shaping, and the lower surface of the fluffy non-woven fabric is sprayed with glue. e. The bottom material is unrolled and conveyed through the second unwinding mechanism, and the upper surface of the bottom material is sprayed with glue; f. applying a lower layer of high molecular weight water-absorbing resin particles to the upper surface of the base material by a first high molecular weight water-absorbing resin discharging mechanism to form a lower absorbent layer, wherein the lower absorbent layer has at least one first channel distributed longitudinally and to which no lower layer of high molecular weight water-absorbing resin particles are applied; g. Compounding the product of step f with a fluffy nonwoven fabric; h. Pass the product of step g through a negative pressure adsorption plate to stabilize the pore structure and prevent shrinkage, wherein the pressure of the negative pressure adsorption plate is -0.03MPa to -0.05MPa; i. applying an upper layer of polymer water-absorbing resin particles to the upper surface of the fluffy non-woven fabric by a second polymer water-absorbing resin feeding mechanism to form an upper absorbent layer, wherein the upper absorbent layer has at least one second channel distributed longitudinally and to which no upper layer of polymer water-absorbing resin particles are applied; j. The top layer material is unrolled and conveyed through the third unwinding mechanism, and the lower surface of the top layer material is sprayed with glue; k. Compounding the top layer material with the product of step i; 1. Pressing the top layer material, fluffy non-woven fabric and bottom layer material along the first channel and the second channel area by a pressing mechanism to form a guide channel; m. cutting the product of step 1 to form a single absorbent core layer; 3) preparing a liquid-impermeable bottom layer; 4) laminating the liquid-permeable surface layer, the absorbent core layer and the liquid-impermeable bottom layer; 5) Cut the product from step 4 into individual baby diaper bodies.

2. The process for preparing baby diapers based on an expanded non-woven fabric core according to claim 1, characterized in that: In the above step b, the atomization pressure of the spray system is 2.0Bar~4.0Bar, the particle size is 50μm~150μm, and the spraying amount is 0.5g / m 2 ~2.0g / m 2 .

3. The process for preparing baby diapers based on an expanded nonwoven fabric core according to claim 1, characterized in that: In the above step c, the airflow is blown obliquely at an angle of 45° to enhance the three-dimensional arrangement of the fibers and perform a secondary puffing treatment.

4. The process for preparing baby diapers based on an expanded nonwoven fabric core according to claim 1, characterized in that: In the above step d, the transverse stretching ratio of the fluffy non-woven fabric is 5-8%.

5. The process for preparing baby diapers based on an expanded non-woven fabric core according to claim 1, characterized in that: In the above step d, the differential roller set has at least two rollers, and the speed difference between two adjacent rollers is 10-15%.

6. The process for preparing baby diapers based on an expanded nonwoven fabric core according to claim 1, characterized in that: In the above step 1, the pressing mechanism includes a pressing roller, the pressing roller has a raised pressure point, and the cross section of the raised pressure point is trapezoidal.

7. The process for preparing baby diapers based on an expanded nonwoven fabric core according to claim 6, characterized in that: The temperature of the pressing roller is 60° C. to 80° C., and the linear pressure is 50 N / cm to 80 N / cm.

8. The process for preparing baby diapers based on an expanded nonwoven fabric core according to claim 1, characterized in that: There are three first channels and three second channels.

9. The process for preparing baby diapers based on an expanded non-woven fabric core according to any one of claims 1 to 8, characterized in that: The preheating zone of the puffing mechanism is provided with a first temperature sensor, a first heating component and a first air pump; the heating zone of the puffing mechanism is provided with a second temperature sensor, a third temperature sensor, a second heating component, a third heating component, a second air pump and a third air pump; the equalization zone of the puffing mechanism is provided with a fourth temperature sensor and a fourth air pump.

10. The process for preparing baby diapers based on an expanded non-woven fabric core according to claim 9, characterized in that: A fifth temperature sensor is provided on the negative pressure adsorption plate, and the first temperature sensor, the second temperature sensor, the third temperature sensor, the fourth temperature sensor, and the fifth temperature sensor are electrically connected to the input end of the control system, respectively, and the first heating component, the second heating component, the third heating component, the first air pump, the second air pump, the third air pump, the fourth air pump, and the spray system are electrically connected to the output end of the control system, respectively.

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