One-way liquid conducting nonwoven fabric and its manufacturing apparatus

Abstract

This invention relates to the field of nonwoven materials technology, and discloses a unidirectional liquid-guiding nonwoven fabric and its preparation apparatus. The unidirectional liquid-guiding nonwoven fabric comprises, from top to bottom, a liquid-guiding layer, a barrier layer, and a liquid-retaining layer that are stacked and connected together; both the liquid-guiding layer and the barrier layer are hydrophobic; the surface of the liquid-guiding layer has several raised areas and several non-raised areas; the liquid-retaining layer includes a hydrophilic fiber web; some of the hydrophilic fibers in the liquid-retaining layer pass through the barrier layer and are in contact with the lower surface of the liquid-guiding layer. The nonwoven fabric of this invention can achieve unidirectional liquid guidance, allowing liquid to quickly permeate from the surface of the liquid-guiding layer to the liquid-retaining layer, while effectively preventing liquid backflow in the liquid-retaining layer, thus helping to keep the surface of the liquid-guiding layer dry.

Description

Technical Field

[0001] This invention relates to the field of nonwoven materials technology, and in particular to a unidirectional liquid-guided nonwoven fabric and its preparation apparatus. Background Technology

[0002] Disposable personal hygiene products typically consist of a top layer, an inner absorbent layer, and a waterproof bottom layer, with each layer bonded together using hot melt adhesive. The top layer, which comes into direct contact with the skin, is made of materials that are breathable, soft, quickly absorbent, and comfortable against the skin.

[0003] Based on the surface material, disposable hygiene products can be broadly categorized into hot-air nonwoven fabric and pure cotton nonwoven fabric. Hot-air nonwoven fabric is characterized by its rapid liquid absorption and soft feel, but it is less breathable and more prone to causing allergies compared to pure cotton nonwoven fabric. Pure cotton nonwoven fabric is generally spunlace nonwoven fabric. These types of hygiene products are fluffy and soft, made from natural fibers, and are more skin-friendly and safer, making them popular with consumers.

[0004] However, the two existing disposable hygiene product surface materials do not have a one-way liquid guiding function, which poses a risk of backflow during use. This reduces the dryness of the disposable hygiene product surface, affecting the comfort during use. At the same time, the moist surface creates a humid environment between the product and the human body, which is more conducive to bacterial growth. Summary of the Invention

[0005] To address the technical problem that existing disposable hygiene product surface materials cannot achieve unidirectional liquid guidance, this invention provides a unidirectional liquid-guided nonwoven fabric and its preparation apparatus. This nonwoven fabric enables unidirectional liquid guidance, allowing liquid to quickly permeate from the surface of the liquid-guiding layer to the liquid-retaining layer while effectively preventing backflow of liquid from the liquid-retaining layer, thus helping to keep the surface of the liquid-guiding layer dry.

[0006] The specific technical solution of this invention is as follows:

[0007] In a first aspect, the present invention provides a unidirectional liquid-guiding nonwoven fabric, comprising, from top to bottom, a liquid-guiding layer, a permeation-blocking layer, and a liquid-retaining layer that are stacked and connected to each other; both the liquid-guiding layer and the permeation-blocking layer are hydrophobic; the surface of the liquid-guiding layer is provided with a plurality of raised areas and a plurality of non-raised areas; the liquid-retaining layer includes a hydrophilic fiber web; some of the hydrophilic fibers in the liquid-retaining layer pass through the permeation-blocking layer and are in contact with the lower surface of the liquid-guiding layer.

[0008] This invention utilizes a three-layer structure design with specific hydrophilic and hydrophobic properties, and includes raised and non-raised areas on the surface of the liquid-conducting layer. Furthermore, it allows some hydrophilic fibers in the liquid storage layer to pass through the barrier layer and connect with the lower surface of the liquid-conducting layer, thereby achieving unidirectional liquid conduction in the nonwoven fabric. Specifically:

[0009] By utilizing a hydrophobic liquid-conducting layer and a barrier layer, backflow of liquid within the storage layer can be prevented. However, this also hinders liquid from permeating from the surface of the liquid-conducting layer to the storage layer. Therefore, this invention employs a design with raised and non-raised regions on the surface of the liquid-conducting layer. Some hydrophilic fibers in the storage layer pass through the barrier layer and connect with the lower surface of the liquid-conducting layer. When used in nonwoven fabric, liquid on the surface of the liquid-conducting layer easily flows to the lower, non-raised region and, guided by the hydrophilic fibers within the barrier layer, enters and is stored in the storage layer. In this configuration, the barrier layer between the liquid-conducting layer and the storage layer provides a one-way barrier to the liquid flow between them. Liquid can pass from the liquid-conducting layer through the barrier layer into the storage layer, but the liquid in the storage layer is locked and cannot return to the surface of the liquid-conducting layer, achieving excellent anti-backflow performance. Through the above methods, the present invention can regulate the position of liquid entering the storage layer, accelerate the liquid inflow rate, and prevent liquid backflow through the locking effect of the hydrophobic liquid guiding layer, the seepage barrier layer and the storage layer, so that the surface of the liquid guiding layer can remain dry.

[0010] Preferably, the mass per unit area of ​​the raised region in the liquid guiding layer is greater than the mass per unit area of ​​the non-raised region.

[0011] Compared to the similar mass per unit area between raised and non-raised areas, a design where the mass per unit area of ​​raised areas is greater than that of non-raised areas is beneficial for accelerating the permeation of liquid from the surface of the liquid guiding layer into the liquid storage layer. This is because, as mentioned above, some hydrophilic fibers in the liquid storage layer pass through the barrier layer and come into contact with the lower surface of the liquid guiding layer. Therefore, with a design where the mass per unit area of ​​raised areas is greater than that of non-raised areas, the proportion of hydrophilic fibers in non-raised areas is higher than that in raised areas, making it easier for liquid to penetrate into the liquid storage layer through non-raised areas.

[0012] Furthermore, the raised and non-raised areas are formed by jacquard weaving.

[0013] The raised and non-raised areas formed by embossing have similar mass per unit area, while jacquard can make the mass per unit area of ​​the raised area greater than that of the non-raised area, thus accelerating the penetration of liquid from the surface of the liquid guiding layer into the liquid storage layer to a greater extent.

[0014] Preferably, the unit area mass of the raised region and the non-raised region are 10-18 g / m², respectively. 2 and 2~10g / m 2 .

[0015] Preferably, the raised and non-raised regions in the liquid guiding layer are arranged alternately; the total area of ​​all non-raised regions in the liquid guiding layer accounts for 15-50% of the total area of ​​the liquid guiding layer; and the minimum projected size of the non-raised regions on the surface of the liquid guiding layer is not less than 1 mm.

[0016] The proportion of non-protruding areas in the liquid-conducting layer affects the liquid's infiltration and backflow performance. When its proportion is too small, it will affect the liquid's infiltration; when it is too large, it will reduce the anti-backflow performance.

[0017] In addition, because the liquid is not easily wetted on the raised parts of the liquid guiding layer, it will form liquid droplets due to its own surface tension. When the minimum projected size of the non-raised area on the surface of the liquid guiding layer is too small, these liquid droplets cannot quickly seep through the non-raised area, causing the one-way liquid guiding function to fail.

[0018] Furthermore, the minimum projected size of the non-protruding area on the surface of the liquid guiding layer is 1 to 2.5 mm.

[0019] Preferably, the fiber packing density in the liquid-conducting layer, the impermeable layer, and the liquid-storing layer is in the following relationship: fiber packing density in the liquid-conducting layer < fiber packing density in the impermeable layer < fiber packing density in the liquid-storing layer.

[0020] The packing density of fiber materials affects the capillary diameter inside the material; the higher the packing density, the smaller the capillary diameter. Capillary action and capillary diameter are inversely proportional, meaning that the smaller the capillary diameter, the more pronounced the capillary action.

[0021] After in-depth research, our R&D team discovered that setting the fiber packing density of the liquid-conducting layer < the fiber packing density of the barrier layer < the fiber packing density of the liquid-storage layer can make the capillary phenomenon of the liquid-storage layer, barrier layer, and liquid-conducting layer show a decreasing trend. This is beneficial for storing liquid in the liquid-storage layer. At the same time, because the capillary effect of the barrier layer and the liquid-conducting layer is weak, the liquid in the liquid-storage layer will not seep back to the surface of the liquid-conducting layer, which helps to keep the surface of the liquid-conducting layer dry.

[0022] Preferably, the barrier layer comprises a solidified hot-melt fiber web.

[0023] The hot-melt fiber mesh has increased strength and can provide a certain skeletal support for the raised and non-raised areas on the surface of the liquid guiding layer. This is beneficial for fixing and strengthening the raised areas on the surface of the liquid guiding layer, and thus better achieving the beneficial effects of the present invention.

[0024] Preferably, the barrier layer has thermal shrinkage properties, with a thermal shrinkage temperature of 130–150°C.

[0025] By thermally shrinking the barrier layer through heat treatment, the raised effect on the surface of the liquid-conducting layer can be made more obvious, thereby improving the anti-backflow performance of the nonwoven fabric.

[0026] Preferably, the barrier layer has a number of through holes that penetrate the barrier layer; some of the hydrophilic fibers in the liquid storage layer pass through the through holes and are in contact with the lower surface of the liquid guiding layer.

[0027] By setting through holes in the barrier layer, some hydrophilic fibers in the liquid storage layer can more easily penetrate into the liquid guiding layer, forming a more stable liquid absorption channel. At the same time, the through holes can be arranged according to design requirements to meet the absorption needs when the liquid volume is large.

[0028] Preferably, the total area of ​​all through holes in the barrier layer accounts for 5-10% of the total area of ​​the barrier layer; the diameter of the through holes is 0.5-2 mm.

[0029] Preferably, the mass per unit area of ​​the barrier layer is 6–10 g / m². 2 .

[0030] Preferably, the liquid-conducting layer comprises a hydrophobic fiber web.

[0031] Furthermore, the liquid-conducting layer comprises a hydrophobic fiber web containing three-dimensional crimped fibers.

[0032] Three-dimensional crimped fibers are more likely to form a fluffy structure during hydroentangling, which is more conducive to the formation of raised and non-raised areas in jacquard weaving.

[0033] Furthermore, the mass of the three-dimensional crimped fiber accounts for 10% to 20% of the total mass of the hydrophobic fiber web.

[0034] Furthermore, the fibers in the hydrophobic fiber web are one or more of polylactic acid fibers, hydrophobic lyocell fibers, hydrophobic viscose fibers, and undegreased cotton fibers.

[0035] Furthermore, the fiber linear density in the hydrophobic fiber web is 0.5 to 1.7 dtex.

[0036] Smaller fiber fineness (linear density) in the liquid-conducting layer contributes to a more skin-friendly feel.

[0037] Preferably, the average mass per unit area of ​​the liquid-conducting layer is 8–15 g / m². 2 .

[0038] Preferably, the mass per unit area of ​​the liquid storage layer is 6–10 g / m². 2 .

[0039] Secondly, the present invention provides an apparatus for preparing the unidirectional liquid-guided nonwoven fabric, comprising:

[0040] A first hydroentangling mechanism for hydroentangling from the outside of the liquid storage sheet;

[0041] A second hydroentangling mechanism is used for hydroentangling from the outside of the liquid-conducting layer sheet and for jacquard on the outer surface of the liquid-conducting layer sheet; the second hydroentangling mechanism is located downstream of the first hydroentangling mechanism;

[0042] A dewatering mechanism located downstream of the second hydroentangling mechanism;

[0043] A drying unit located downstream of the dehydration unit;

[0044] A stacking mechanism; the stacking mechanism is located upstream of the first hydroentangling mechanism and is used to stack the liquid-conducting layer sheet, the barrier layer sheet, and the liquid-storage layer sheet together sequentially from top to bottom; or, the stacking mechanism includes a first stacking mechanism located upstream of the first hydroentangling mechanism and used to stack the barrier layer sheet and the liquid-storage layer sheet together, and a second stacking mechanism located between the first hydroentangling mechanism and the second hydroentangling mechanism and used to stack the liquid-conducting layer sheet onto the surface of the barrier layer sheet.

[0045] The above-mentioned device operates in the following two ways:

[0046] Method 1: In the lamination mechanism, the liquid-conducting layer sheet, the barrier layer sheet, and the liquid-storage layer sheet are sequentially laminated from top to bottom. The resulting three-layer laminated material enters the first hydroentangling mechanism. By hydroentangling from the outside of the liquid-storage layer sheet, some hydrophilic fibers in the liquid-storage layer sheet can penetrate the barrier layer sheet, thus strengthening the connection between the liquid-storage layer sheet and the barrier layer sheet. The laminated material is then fed into the second hydroentangling mechanism, where hydroentangling from the outside of the liquid-conducting layer sheet strengthens the connection between the liquid-conducting layer sheet and the barrier layer sheet. Jacquard weaving on the outer surface of the liquid-conducting layer sheet creates raised and non-raised areas on the surface of the liquid-conducting layer. Finally, the dehydration and drying mechanisms remove moisture from the laminated material.

[0047] Method 2: In the first lamination mechanism, the barrier layer sheet and the liquid storage layer sheet are laminated together to form a double-layer laminated material. This material enters the first hydroentangling mechanism, where hydroentangling from the outside of the liquid storage layer sheet allows some hydrophilic fibers in the liquid storage layer sheet to penetrate the barrier layer sheet, strengthening the connection between the two layers. The double-layer laminated material is then fed into the second lamination mechanism, forming a three-layer laminated material consisting of a liquid-conducting layer sheet, a barrier layer sheet, and a liquid storage layer sheet stacked sequentially. This material is then fed into the second hydroentangling mechanism, where hydroentangling from the outside of the liquid-conducting layer sheet strengthens the connection between the liquid-conducting layer sheet and the barrier layer sheet. Jacquard weaving on the outer surface of the liquid-conducting layer sheet creates raised and non-raised areas. Finally, the material passes through a dehydration mechanism and a drying mechanism to remove moisture.

[0048] Preferably, the second hydroentangling mechanism includes a hydroentangling drum B, a hydroentangling drum C located downstream of the hydroentangling drum B, and at least one hydroentangling head B and at least one hydroentangling head C facing the hydroentangling drum B and the hydroentangling drum C respectively; the surface of the hydroentangling drum C is provided with a jacquard template.

[0049] Preferably, the first hydroentangling mechanism includes a hydroentangling drum A and at least one hydroentangling head A facing the hydroentangling drum A.

[0050] Furthermore, the first hydroentangling mechanism also includes a support screen A located below the hydroentangling drum A and a plurality of guide rollers for conveying the support screen A; a pre-wet hydroentangling head corresponding to the hydroentangling drum A in the vertical direction is provided below the support screen A.

[0051] Preferably, the dewatering mechanism includes a support screen B and a plurality of guide rollers for conveying the support screen B; a vacuum suction device is provided below the support screen B.

[0052] Preferably, the drying mechanism includes a housing; the housing is equipped with heating equipment, a mesh belt, and several mesh belt rollers for conveying the mesh belt.

[0053] Preferably, a rolling mechanism is provided downstream of the drying mechanism.

[0054] Thirdly, the present invention provides a method for preparing the unidirectional liquid-guided nonwoven fabric, comprising the following steps:

[0055] (1) Hydrophobic fibers are made into a hydrophobic fiber mesh to obtain a liquid-conducting layer sheet;

[0056] (2) The hydrophilic fibers are made into a hydrophilic fiber web to obtain a liquid storage layer sheet;

[0057] (3) The liquid-conducting layer sheet, the seepage-blocking layer sheet and the liquid-storage layer sheet are stacked and reinforced, and raised and non-raised areas are formed on the outer surface of the liquid-conducting layer sheet by jacquard to obtain the stacked sheet;

[0058] (4) Remove the moisture from the laminated sheets to obtain a unidirectional liquid-guided nonwoven fabric.

[0059] Preferably, step (3) includes the following steps: after stacking the liquid-conducting layer sheet, the barrier layer sheet, and the liquid-storage layer sheet from top to bottom, perform hydroentangling from the outside of the liquid-storage layer sheet so that some of the hydrophilic fibers in the liquid-storage layer sheet pass through the barrier layer sheet; then perform hydroentangling from the outside of the liquid-conducting layer sheet; finally, perform hydroentangling from the outside of the liquid-storage layer sheet on the jacquard template surface so that raised and non-raised areas are formed on the outer surface of the liquid-conducting layer sheet.

[0060] Preferably, step (3) includes the following steps: after stacking the barrier layer sheet and the liquid storage layer sheet, hydroentanglement is performed from the outside of the liquid storage layer sheet so that some of the hydrophilic fibers in the liquid storage layer sheet pass through the barrier layer sheet; then the liquid guiding layer sheet is stacked on the surface of the barrier layer sheet, and hydroentanglement is performed from the outside of the liquid guiding layer sheet; finally, hydroentanglement is performed from the outside of the liquid storage layer sheet on the surface of the jacquard template so that raised areas and non-raised areas are formed on the outer surface of the liquid guiding layer sheet.

[0061] Furthermore, in step (3), pre-wetting is performed before hydroentangling from the outside of the liquid storage sheet.

[0062] As a preferred option, the specific process of step (4) includes the following steps: first, dehydration is carried out by vacuum suction, and then drying is carried out.

[0063] Furthermore, the drying temperature is higher than the heat shrinkage temperature of the barrier layer.

[0064] When the barrier layer has thermal shrinkage properties, the above-mentioned drying temperature setting can cause the barrier layer to thermally shrink during the drying process, thereby reinforcing and shaping the raised areas on the liquid-conducting layer.

[0065] Compared with the prior art, the present invention has the following advantages:

[0066] (1) The present invention uses a three-layer structure design with specific hydrophilic and hydrophobic properties, and sets raised and non-raised areas on the surface of the liquid guiding layer, and allows some hydrophilic fibers in the liquid storage layer to pass through the barrier layer and connect with the lower surface of the liquid guiding layer. This enables the non-woven fabric to guide liquid in one direction. While allowing the liquid to quickly penetrate from the surface of the liquid guiding layer to the liquid storage layer, it can also give it good anti-backflow performance, thereby keeping the surface of the liquid guiding layer dry.

[0067] (2) The present invention adopts a design in which the fiber packing density of the liquid guiding layer, the seepage barrier layer and the liquid storage layer increases step by step. By utilizing the gradually enhanced capillary effect, it is beneficial to lock the liquid in the liquid storage layer and prevent it from seeping back to the surface of the liquid guiding layer, which can further improve the dryness of the surface of the liquid guiding layer.

[0068] (3) By controlling the area ratio and minimum projection size of the non-protruding area on the surface of the liquid guiding layer, the liquid guiding layer uses three-dimensional crimped fibers, and the barrier layer uses hot melt fiber mesh with heat shrinkage, the present invention can better play the role of the protruding and non-protruding areas, further improve the one-way liquid guiding performance of the non-woven fabric, so that the liquid on the surface of the liquid guiding layer can quickly seep down, and the liquid in the storage layer is not easy to seep back. Attached Figure Description

[0069] Figure 1 These are schematic diagrams of the cross-sectional structure of the unidirectional liquid-guiding nonwoven fabrics in Embodiments 1-5 of the present invention;

[0070] Figure 2 This is a schematic diagram of the surface structure of the liquid-conducting layer in Embodiments 1-3 and Embodiment 5 of the present invention;

[0071] Figure 3 This is a schematic diagram of the surface structure of the liquid-conducting layer in Embodiment 4 of the present invention;

[0072] Figure 4 This is a schematic diagram of the connection of the unidirectional liquid-guided nonwoven fabric preparation device in Embodiments 1-4 of the present invention;

[0073] Figure 5 This is a schematic diagram of the connection of the unidirectional liquid-guided nonwoven fabric preparation device in Embodiment 5 of the present invention.

[0074] The attached diagram is labeled as follows: liquid guiding layer 1, permeation barrier layer 2, liquid storage layer 3, raised area 101, non-raised area 102, through hole 201, overlapping guide roller A401, overlapping guide roller B402, spunlace drum A501, spunlace head A502, support screen curtain A503, support screen curtain A guide roller 504, pre-wetted spunlace head 505, spunlace drum B601, spunlace drum C602, spunlace head B603, spunlace head C604, support screen curtain B701, support screen curtain B guide roller 702, vacuum suction device 703, box body 801, heating equipment 802, mesh belt 803, mesh belt roller 804, winding mechanism 9, guide cloth roller 10, liquid guiding layer sheet 11, permeation barrier layer sheet 12, liquid storage layer sheet 13, unidirectional liquid guiding nonwoven fabric 14. Detailed Implementation

[0075] The present invention will be further described below with reference to embodiments.

[0076] General Implementation Examples

[0077] A type of unidirectional liquid-guided nonwoven fabric, such as Figures 1-3 As shown, from top to bottom, it includes a liquid-conducting layer 1, a permeation-blocking layer 2, and a liquid-storing layer 3 that are stacked and connected to each other; both the liquid-conducting layer 1 and the permeation-blocking layer 2 are hydrophobic; the surface of the liquid-conducting layer 1 is provided with a number of raised areas 101 and a number of non-raised areas 102; the liquid-storing layer 3 includes a hydrophilic fiber web; some of the hydrophilic fibers in the liquid-storing layer 3 pass through the permeation-blocking layer 2 and are in contact with the lower surface of the liquid-conducting layer 1.

[0078] In one specific embodiment, the raised regions 101 and non-raised regions 102 in the liquid guiding layer 1 are arranged alternately; the total area of ​​all non-raised regions 102 in the liquid guiding layer 1 accounts for 15-50% of the total area of ​​the liquid guiding layer 1; the minimum projected size of the non-raised regions 102 on the surface of the liquid guiding layer 1 is 1-2.5 mm; the unit area mass of the raised regions 101 is greater than the unit area mass of the non-raised regions 102.

[0079] In one specific embodiment, the fiber packing density in the liquid-conducting layer 1, the seepage-blocking layer 2, and the liquid-storing layer 3 is in the following relationship: fiber packing density of liquid-conducting layer 1 < fiber packing density of seepage-blocking layer 2 < fiber packing density of liquid-storing layer 3.

[0080] In one specific embodiment, the barrier layer 2 includes a solidified hot-melt fiber web and has thermal shrinkage properties, with a thermal shrinkage temperature of 130–150°C.

[0081] In one specific embodiment, the barrier layer 2 is provided with a plurality of through holes 201 penetrating the barrier layer 2; some of the hydrophilic fibers in the liquid storage layer 3 pass through the through holes 201 through the barrier layer 2 and are in contact with the lower surface of the liquid guiding layer 1; the total area of ​​all the through holes 201 in the barrier layer accounts for 5 to 10% of the total area of ​​the barrier layer 2; the diameter of the through holes 201 is 0.5 to 2 mm.

[0082] In one specific embodiment, the liquid-conducting layer 1 comprises a hydrophobic fiber web. Optionally, the hydrophobic fiber web contains 10% to 20% (by mass) of three-dimensional crimped fibers. Optionally, the fibers in the hydrophobic fiber web are one or more of polylactic acid fibers, hydrophobic lyocell fibers, hydrophobic viscose fibers, and undegreased cotton fibers, with a fiber linear density of 0.5 to 1.7 dtex.

[0083] In one specific embodiment, the average mass per unit area of ​​the liquid-conducting layer 1 is 8–15 g / m². 2 The unit area mass of the raised region 101 and the non-raised region 102 in the liquid guiding layer 1 are 10-18 g / m², respectively. 2 and 2~10g / m 2 The mass per unit area of ​​the barrier layer 2 is 6-10 g / m². 2 The mass per unit area of ​​the liquid storage layer 3 is 6-10 g / m³. 2 .

[0084] An apparatus for preparing the unidirectional liquid-guided nonwoven fabric, such as Figure 4 and Figure 5 As shown, it includes:

[0085] A first hydroentangling mechanism for hydroentangling from the outside of the liquid storage sheet;

[0086] A second hydroentangling mechanism is used for hydroentangling from the outside of the liquid-conducting layer sheet and for jacquard on the outer surface of the liquid-conducting layer sheet; the second hydroentangling mechanism is located downstream of the first hydroentangling mechanism;

[0087] A dewatering mechanism located downstream of the second hydroentangling mechanism;

[0088] A drying unit located downstream of the dehydration unit;

[0089] A stacking mechanism; the stacking mechanism is located upstream of the first hydroentangling mechanism and is used to stack the liquid-conducting layer sheet, the barrier layer sheet, and the liquid-storage layer sheet together sequentially from top to bottom; or, the stacking mechanism includes a first stacking mechanism located upstream of the first hydroentangling mechanism and used to stack the barrier layer sheet and the liquid-storage layer sheet together, and a second stacking mechanism located between the first hydroentangling mechanism and the second hydroentangling mechanism and used to stack the liquid-conducting layer sheet onto the surface of the barrier layer sheet.

[0090] In one specific embodiment, the second hydroentangling mechanism includes a hydroentangling drum B 601, a hydroentangling drum C 602 located downstream of the hydroentangling drum B 601, and at least one hydroentangling head B 603 and at least one hydroentangling head C 604 facing the hydroentangling drum B 601 and the hydroentangling drum C 602 respectively; the surface of the hydroentangling drum C 602 is provided with a jacquard template.

[0091] In one specific embodiment, the first hydroentangling mechanism includes a hydroentangling drum A501, at least one hydroentangling head A502 facing the hydroentangling drum A501, a support curtain A503 disposed below the hydroentangling drum A501, and a plurality of support curtain A guide rollers 504 for conveying the support curtain A503; a pre-wetted hydroentangling head 505 corresponding to the hydroentangling drum A501 in the vertical direction is provided below the support curtain A503.

[0092] In one specific embodiment, the dehydration mechanism includes a support screen B 701 and a plurality of support screen B guide rollers 702 for conveying the support screen B 701; a vacuum suction device 703 is provided below the support screen B 701.

[0093] In one specific embodiment, the drying mechanism includes a housing 801; the housing 801 is provided with a heating device 802, a mesh belt 803, and a plurality of mesh belt rollers 804 for conveying the mesh belt 803.

[0094] In one specific implementation, a rolling mechanism 9 is provided downstream of the drying mechanism.

[0095] A method for preparing the unidirectional liquid-guided nonwoven fabric includes the following steps:

[0096] (1) Hydrophobic fibers are made into a hydrophobic fiber mesh to obtain a liquid-conducting layer sheet;

[0097] (2) The hydrophilic fibers are made into a hydrophilic fiber web to obtain a liquid storage layer sheet;

[0098] (3) The liquid-conducting layer sheet, the seepage-blocking layer sheet and the liquid-storage layer sheet are stacked and reinforced, and raised and non-raised areas are formed on the outer surface of the liquid-conducting layer sheet by jacquard to obtain the stacked sheet;

[0099] (4) Remove the moisture from the laminated sheets to obtain a unidirectional liquid-guided nonwoven fabric.

[0100] As a specific implementation method, the specific process of step (3) includes the following steps: stacking the liquid-conducting layer sheet, the barrier layer sheet and the liquid-storing layer sheet from top to bottom, pre-wetting them and then performing hydroentangling from the outside of the liquid-storing layer sheet so that some of the hydrophilic fibers in the liquid-storing layer sheet can pass through the barrier layer sheet; then performing hydroentangling from the outside of the liquid-conducting layer sheet; finally, performing hydroentangling from the outside of the liquid-storing layer sheet on the jacquard template surface so that raised areas and non-raised areas are formed on the outer surface of the liquid-conducting layer sheet.

[0101] As a specific implementation method, the specific process of step (3) includes the following steps: stacking the barrier layer sheet and the liquid storage layer sheet, pre-wetting them, and then performing hydroentangling from the outside of the liquid storage layer sheet to allow some of the hydrophilic fibers in the liquid storage layer sheet to pass through the barrier layer sheet; then stacking the liquid guiding layer sheet onto the surface of the barrier layer sheet, and then performing hydroentangling from the outside of the liquid guiding layer sheet; finally, performing hydroentangling from the outside of the liquid storage layer sheet on the surface of the jacquard template to form raised and non-raised areas on the outer surface of the liquid guiding layer sheet.

[0102] As a specific implementation method, the specific process of step (4) includes the following steps: first, dehydration is carried out by vacuum suction, and then drying is carried out, wherein the drying temperature is higher than the heat shrinkage temperature of the barrier layer.

[0103] Example 1

[0104] A unidirectional liquid-guided nonwoven fabric with a unit area mass of 28 g / m² 2 Its structure is as follows Figure 1 As shown, from top to bottom, it consists of a liquid-conducting layer 1, a seepage-blocking layer 2, and a liquid-reservoir layer 3, which are stacked and connected to each other. Wherein:

[0105] The average mass per unit area of ​​the liquid-conducting layer 1 is 12 g / m². 2 The main body is a hydrophobic fiber network composed of polylactic acid fibers with a fiber linear density of 1.1 dtex, containing some hydrophilic fibers that penetrate from the liquid storage layer 3; the surface of the liquid guiding layer 1 consists of raised regions 101 and non-raised regions 102, wherein: as Figure 2 As shown, raised regions 101 and non-raised regions 102 are arranged alternately. The projection of the raised regions 101 onto the surface of the liquid-conducting layer 1 is a square. The minimum spacing between adjacent raised regions 101 (non-raised regions) is 1.2 mm. The mass per unit area of ​​the raised regions 101 is 14 g / m². 2 The mass per unit area of ​​the non-protruding region 102 is 6 g / m². 2 The total area of ​​all non-protruding regions 102 in the liquid guiding layer 1 accounts for 25% of the area of ​​the liquid guiding layer 1.

[0106] The mass per unit area of ​​barrier layer 2 is 8 g / m² 2 The main body is polyester (PET) spunbond nonwoven fabric, containing some hydrophilic fibers that penetrate through the liquid storage layer 3.

[0107] The mass per unit area of ​​liquid storage layer 3 is 8 g / m³. 2 It is a hydrophilic fiber web composed of viscose fibers with a fiber linear density of 2.4 dtex.

[0108] The fiber packing density in the raised and non-raised regions of the liquid-conducting layer 1 is 0.058 g / cm³. 3 and 0.063 g / cm 3 The fiber packing density of the barrier layer 2 is 0.067 g / cm³. 3 The fiber packing density of the liquid storage layer 3 is 0.071 g / cm³. 3 .

[0109] An apparatus for preparing the above-mentioned unidirectional liquid-guided nonwoven fabric has the following structure: Figure 4 As shown, in the processing sequence, it includes: a stacking mechanism, a first hydroentangling mechanism, a second hydroentangling mechanism, a dehydration mechanism, a drying mechanism, and a winding mechanism. Among them:

[0110] The stacking mechanism consists of a set of stacking guide rollers A 401 arranged vertically opposite each other, used to stack the liquid guiding layer sheet (hydrophobic fiber web), the permeation barrier layer sheet (polyester spunbond nonwoven fabric) and the liquid storage layer sheet (hydrophilic fiber web) together from top to bottom.

[0111] The first hydroentangling mechanism consists of a hydroentangling drum A501, two hydroentangling heads A502, a circulating support curtain A503, three support curtain guide rollers A504 for conveying the support curtain A503, and a pre-wetted hydroentangling head 505. The hydroentangling head A502 faces the hydroentangling drum A501 and is used for hydroentangling from the outside of the liquid storage layer sheet; the support curtain A503 is located below the hydroentangling drum A501 and is used to introduce the laminated fiber web onto the hydroentangling drum A501; the pre-wetted hydroentangling head 505 is located below the support curtain A503 and corresponds to the hydroentangling drum A501 in the vertical direction.

[0112] The second hydroentangling mechanism consists of a hydroentangling drum B 601, two hydroentangling heads B 603, a hydroentangling drum C 602, and two hydroentangling heads C 604. Hydroentangling heads B 603 face the hydroentangling drum B 601 and are used for hydroentangling from the outside of the liquid-conducting layer sheet. The surface of the hydroentangling drum C 602 is provided with a jacquard die, and the hydroentangling heads C 604 face the hydroentangling drum C 602 and are used for hydroentangling from the outside of the liquid-conducting layer sheet, thereby forming raised areas 101 and non-raised areas 102 on the surface of the liquid-conducting layer 1. A guide roller 10 is provided between the hydroentangling drum A 501 and the hydroentangling drum B 601.

[0113] The dewatering mechanism consists of a circulating support screen B 701, three guide rollers 702 for conveying the support screen B 701, and a vacuum suction device 703 located below the support screen B 701. A guide roller 10 is provided between the hydroentangled drum C 602 and the dewatering mechanism.

[0114] The drying mechanism is a loose-type dryer, consisting of a housing 801, a heating device 802, a circulating mesh belt 803, and three mesh belt rollers 804 for conveying the mesh belt 803. The heating device 802, the mesh belt 803, and the mesh belt rollers 804 are all located inside the housing 801.

[0115] The preparation process of the unidirectional liquid-guided nonwoven fabric in this embodiment is as follows:

[0116] (1) Polylactic acid fibers are opened and combed to form a hydrophobic fiber web, which is used as a liquid-conducting layer sheet;

[0117] (2) Viscose fibers are opened and combed to form a hydrophilic fiber web, which is used as a liquid storage layer sheet;

[0118] (3) The liquid-guiding layer sheet 11, the barrier layer sheet 12 and the liquid storage layer sheet 13 are fed into the unidirectional liquid-guiding nonwoven fabric preparation device of this embodiment. After being stacked from top to bottom by the stacking guide roller A401, they enter the first hydroentangling mechanism and are sent to the support screen A503 for pre-wetting with water sprayed from the pre-wetting hydroentangling head 505. Then, they are transferred to the hydroentangling drum A501. High-pressure water is sprayed from the outside of the liquid storage layer sheet through the hydroentangling head A502, so that the fibers in the liquid storage layer sheet are entangled with each other and some of the hydrophilic fibers in the liquid storage layer sheet pass through the barrier layer sheet, so that the two are bonded and fixed.

[0119] (4) The composite material is fed into the hydroentangled drum B 601 through the guide roller 10, so that one side of the liquid-conducting layer sheet 11 faces outward; high-pressure water jet is sprayed from the outside of the liquid-conducting layer sheet through the hydroentangled head B 603, so that the fibers in the liquid-conducting layer sheet are entangled with each other and solidified with the barrier layer sheet.

[0120] (5) The solidified material is fed into the hydroentangled drum C 602, so that the liquid-conducting layer sheet is attached to the jacquard die. High-pressure water is sprayed from the outside of the liquid-conducting layer sheet through the hydroentangled head C 604, so that raised areas 101 and non-raised areas 102 are formed on the surface of the liquid-conducting layer sheet 11.

[0121] (6) The hydroentangled material is fed onto the support screen B 701, and excess moisture is removed under the action of the vacuum suction device 703; then the material is fed onto the mesh belt 803 of the drying mechanism, so that the liquid guiding layer sheet 11 faces upward; then it is rolled into a unidirectional liquid guiding nonwoven fabric 14 by the rolling mechanism 9.

[0122] Example 2

[0123] A unidirectional liquid-guided nonwoven fabric with a unit area mass of 28 g / m² 2 Its structure is as follows Figure 1 As shown, from top to bottom, it consists of a liquid-conducting layer 1, a seepage-blocking layer 2, and a liquid-reservoir layer 3, which are stacked and connected to each other. Wherein:

[0124] The average mass per unit area of ​​the liquid-conducting layer 1 is 12 g / m². 2 The main body is a hydrophobic fiber network composed of polylactic acid fibers with a fiber linear density of 1.1 dtex, containing some hydrophilic fibers that penetrate from the liquid storage layer 3; the surface of the liquid guiding layer 1 consists of raised regions 101 and non-raised regions 102, wherein: as Figure 2 As shown, raised regions 101 and non-raised regions 102 are arranged alternately. The projection of the raised regions 101 onto the surface of the liquid-conducting layer 1 is a square. The minimum spacing between adjacent raised regions 101 (non-raised regions) is 1.2 mm. The mass per unit area of ​​the raised regions is 14 g / m². 2 The mass per unit area of ​​the non-protruding region is 6 g / m². 2 The total area of ​​all non-protruding regions 102 in the liquid guiding layer 1 accounts for 25% of the area of ​​the liquid guiding layer 1.

[0125] The mass per unit area of ​​barrier layer 2 is 8 g / m² 2 The main body is a polypropylene (PP) heat-shrinkable nonwoven fabric with a heat shrinkage temperature of 130℃, containing some hydrophilic fibers that penetrate through the liquid storage layer 3.

[0126] The mass per unit area of ​​liquid storage layer 3 is 8 g / m³. 2 It is a hydrophilic fiber web composed of 100% viscose fiber with a fiber linear density of 2.4 dtex.

[0127] The fiber packing density in the raised and non-raised regions of the liquid-conducting layer 1 is 0.064 g / cm³. 3 and 0.069 g / cm 3 The fiber packing density of the barrier layer 2 is 0.073 g / cm³. 3 The fiber packing density of liquid storage layer 3 is 0.078 g / cm³. 3 .

[0128] An apparatus for preparing the above-mentioned unidirectional liquid-guided nonwoven fabric has the same structure as in Example 1.

[0129] The preparation process of the unidirectional liquid-guided nonwoven fabric in this embodiment is as follows:

[0130] (1) Same as steps (1) to (5) in Example 1;

[0131] (2) The hydroentangled material is fed onto the support screen B 701, and excess moisture is removed under the action of the vacuum suction device 703; then the material is fed onto the mesh belt 803 of the drying mechanism, with the liquid-guiding layer sheet 11 facing upwards, and the drying temperature in the drying mechanism is set to 165℃, so that the barrier layer sheet (polypropylene heat shrink nonwoven fabric) shrinks due to heat; then it is rolled into a unidirectional liquid-guiding nonwoven fabric 14 by the rolling mechanism 9.

[0132] Example 3

[0133] A unidirectional liquid-guided nonwoven fabric with a unit area mass of 32 g / m² 2 Its structure is as follows Figure 1 As shown, from top to bottom, it consists of a liquid-conducting layer 1, a seepage-blocking layer 2, and a liquid-reservoir layer 3, which are stacked and connected to each other. Wherein:

[0134] The average mass per unit area of ​​the liquid-conducting layer 1 is 14 g / m². 2 The main body is a hydrophobic fiber web composed of polyester fibers with a fiber linear density of 0.9 dtex, and also includes some hydrophilic fibers that penetrate from the liquid storage layer 3; the surface of the liquid guiding layer 1 consists of raised regions 101 and non-raised regions 102, wherein: as Figure 2 As shown, raised regions 101 and non-raised regions 102 are arranged alternately. The projection of the raised regions 101 onto the surface of the liquid-conducting layer 1 is a square. The minimum interval between adjacent raised regions 101 (non-raised regions) is 1.3 mm. The mass per unit area of ​​the raised regions is 16.5 g / m². 2 The mass per unit area of ​​the non-protruding region is 8 g / m². 2 The total area of ​​all non-protruding regions 102 in the liquid guiding layer 1 accounts for 30% of the area of ​​the liquid guiding layer 1.

[0135] The mass of the barrier layer 2 is 8 g / m². 2 The main body is a PET / PTT composite short fiber heat-shrinkable nonwoven fabric, containing some hydrophilic fibers that penetrate through the liquid storage layer 3; the barrier layer 2 is provided with several through holes 201 that penetrate through the barrier layer 2, and some of the hydrophilic fibers in the liquid storage layer 3 penetrate through the through holes 201 to the liquid guiding layer 1; the diameter of the through holes 201 is 1 mm, and the total area of ​​the through holes 201 accounts for 8% of the total area of ​​the barrier layer 2.

[0136] The mass per unit area of ​​liquid storage layer 3 is 10 g / m³. 2 It is a hydrophilic fiber web composed of viscose fibers with a fiber linear density of 1.64 dtex.

[0137] The fiber packing density in the raised and non-raised regions of the liquid-conducting layer 1 is 0.06 g / cm³. 3 and 0.071 g / cm 3 The fiber packing density of the barrier layer 2 is 0.067 g / cm³. 3The fiber packing density of liquid storage layer 3 is 0.07 g / cm³. 3 .

[0138] An apparatus for preparing the above-mentioned unidirectional liquid-guided nonwoven fabric has the same structure as in Example 1.

[0139] The preparation process of the unidirectional liquid-guided nonwoven fabric in this embodiment is as follows:

[0140] (1) Same as steps (1) to (2) in Example 1;

[0141] (2) Perforation is made in PET / PTT composite short fiber heat shrink nonwoven fabric to form through holes, which serve as a barrier layer sheet;

[0142] (3) Same as steps (3) to (5) in Example 1;

[0143] (4) The hydroentangled material is fed onto the support screen B 701, and excess moisture is removed under the action of the vacuum suction device 703; then the material is fed onto the mesh belt 803 of the drying mechanism, with the liquid guiding layer sheet 11 facing upwards, and the drying temperature in the drying mechanism is set to 170℃, so that the barrier layer sheet (PET / PTT composite short fiber heat shrink nonwoven fabric) shrinks due to heat; then it is rolled into a unidirectional liquid guiding nonwoven fabric 14 by the rolling mechanism 9.

[0144] Example 4

[0145] A unidirectional liquid-guided nonwoven fabric with a unit area mass of 30 g / m 2 Its structure is as follows Figure 1 As shown, from top to bottom, it consists of a liquid-conducting layer 1, a seepage-blocking layer 2, and a liquid-reservoir layer 3, which are stacked and connected to each other. Wherein:

[0146] The average mass per unit area of ​​the liquid-conducting layer 1 is 12 g / m². 2 The main body is a hydrophobic fiber web composed of water-repellent treated Lyocell fibers with a fiber linear density of 1.33 dtex, and also includes some hydrophilic fibers penetrating from the liquid storage layer 3; the surface of the liquid guiding layer 1 consists of raised regions 101 and non-raised regions 102, wherein: the surface structure of the liquid guiding layer 1 is as follows Figure 3 As shown, raised regions 101 and non-raised regions 102 are arranged alternately. The non-raised regions 102 are elongated strips with a projected width of 1.2 mm on the surface of the liquid-conducting layer 1. The mass per unit area of ​​the raised regions is 14 g / m². 2 The mass per unit area of ​​the non-protruding region is 6 g / m². 2 The total area of ​​all non-protruding regions 102 in the liquid guiding layer 1 accounts for 25% of the area of ​​the liquid guiding layer 1.

[0147] The mass per unit area of ​​the barrier layer 2 is 10 g / m² 2The main body is 100% polylactic acid spunbond nonwoven fabric, containing some hydrophilic fibers that penetrate through the liquid storage layer 3.

[0148] The mass per unit area of ​​liquid storage layer 3 is 8 g / m³. 2 It is a hydrophilic fiber web composed of 100% Lyocell fiber with a fiber linear density of 1.7 dtex.

[0149] The fiber packing density in the raised and non-raised regions of the liquid-conducting layer 1 is 0.04 g / cm³. 3 and 0.06 g / cm 3 The fiber packing density of the barrier layer 2 is 0.067 g / cm³. 3 The fiber packing density of liquid storage layer 3 is 0.08 g / cm³. 3 .

[0150] An apparatus for preparing the above-mentioned unidirectional liquid-guided nonwoven fabric has the same structure as in Example 1.

[0151] The preparation process of the unidirectional liquid-guided nonwoven fabric in this embodiment is the same as in Embodiment 1.

[0152] Example 5

[0153] A unidirectional liquid-guiding nonwoven fabric, with the same structure as in Example 1.

[0154] An apparatus for preparing the above-mentioned unidirectional liquid-guided nonwoven fabric has the following structure: Figure 5 As shown, in the processing sequence, it includes: a first stacking mechanism, a first hydroentangling mechanism, a second stacking mechanism, a second hydroentangling mechanism, a dehydration mechanism, a drying mechanism, and a winding mechanism 9. Wherein:

[0155] The first lamination mechanism consists of a lamination guide roller A 401, used to lamination the barrier layer sheet (polyester spunbond nonwoven fabric) and the liquid storage layer sheet (hydrophilic fiber web) together.

[0156] The first hydroentangling mechanism consists of a hydroentangling drum A 501, two hydroentangling heads A 502, a circulating support curtain A 503, three support curtain A guide rollers 504 for conveying the support curtain A 503, and a pre-wet hydroentangling head 505. The hydroentangling head A 502 faces the hydroentangling drum A 501 and is used for hydroentangling from the outside of the liquid storage layer sheet; the support curtain A 503 is located below the hydroentangling drum A 501 and is used to introduce the laminated fiber web onto the hydroentangling drum A 501; the pre-wet hydroentangling head 505 is located below the support curtain A 503 and corresponds to the hydroentangling drum A 501 in the vertical direction.

[0157] The second lamination mechanism consists of a set of lamination guide rollers B 402 arranged vertically opposite each other, used to lamination the liquid-conducting layer sheet (hydrophobic fiber web) onto the surface of the barrier layer sheet.

[0158] The second hydroentangling mechanism consists of a hydroentangling drum B 601, two hydroentangling heads B 603, a hydroentangling drum C 602, and two hydroentangling heads C 604. Hydroentangling heads B 603 face the hydroentangling drum B 601 and are used for hydroentangling from the outside of the liquid-conducting layer sheet. The surface of the hydroentangling drum C 602 is provided with a jacquard template, and the hydroentangling heads C 604 face the hydroentangling drum C 602 and are used for hydroentangling from the outside of the liquid-conducting layer sheet, thereby forming raised areas 101 and non-raised areas 102 on the surface of the liquid-conducting layer 1.

[0159] The dewatering mechanism consists of a circulating support screen B 701, three guide rollers 702 for conveying the support screen B 701, and a vacuum suction device 703 located below the support screen B 701. A guide roller 10 is provided between the hydroentangled drum C 602 and the dewatering mechanism.

[0160] The drying mechanism is a loose-type dryer, consisting of a housing 801, a heating device 802, a circulating mesh belt 803, and three mesh belt rollers 804 for conveying the mesh belt 803. The heating device 802, the mesh belt 803, and the mesh belt rollers 804 are all located inside the housing 801.

[0161] The preparation process of the unidirectional liquid-guided nonwoven fabric in this embodiment is as follows:

[0162] (1) Polylactic acid fibers are opened and combed to form a hydrophobic fiber web, which is used as a liquid-conducting layer sheet;

[0163] (2) Viscose fibers are opened and combed to form a hydrophilic fiber web, which is used as a liquid storage layer sheet;

[0164] (3) The barrier layer sheet 12 and the liquid storage layer sheet 13 are fed into the one-way liquid-guiding nonwoven fabric preparation device of this embodiment. After being stacked by the stacking guide roller A401, they enter the first hydroentangling mechanism and are sent to the support screen A503 for pre-wetting with water sprayed from the pre-wetting hydroentangling head 505. Then, they are transferred to the hydroentangling drum A501. High-pressure water is sprayed from the outside of the liquid storage layer sheet through the hydroentangling head A502, so that the fibers in the liquid storage layer sheet are entangled with each other and some of the hydrophilic fibers in the liquid storage layer sheet pass through the barrier layer sheet, so that the two are bonded and fixed to obtain a double-layer composite material.

[0165] (4) The liquid guiding layer sheet 11 is stacked onto the surface of the barrier layer sheet in the double-layer composite material by the stacking guide roller B 402, forming a three-layer composite material consisting of liquid guiding layer sheet 11, barrier layer sheet 12 and liquid storage layer sheet 13 from top to bottom.

[0166] (5) The three-layer composite material is fed into the hydroentangled drum B 601, so that the liquid-conducting layer sheet 11 faces outward; high-pressure water jet is sprayed from the outside of the liquid-conducting layer sheet through the hydroentangled head B 603, so that the fibers in the liquid-conducting layer sheet are entangled with each other and solidified with the barrier layer sheet.

[0167] (6) The solidified material is fed into the hydroentangled drum C 602, so that the liquid-conducting layer sheet is attached to the jacquard die. High-pressure water is sprayed from the outside of the liquid-conducting layer sheet through the hydroentangled head C 604, so that raised areas 101 and non-raised areas 102 are formed on the surface of the liquid-conducting layer sheet 11.

[0168] (7) The hydroentangled material is fed onto the support screen B 701, and excess moisture is removed under the action of the vacuum suction device 703; then the material is fed onto the mesh belt 803 of the drying mechanism, so that the liquid guiding layer sheet 11 faces upward; then it is rolled into a unidirectional liquid guiding nonwoven fabric 14 by the rolling mechanism 9.

[0169] Example 6

[0170] A unidirectional liquid-guiding nonwoven fabric differs from Example 1 only in that the total area of ​​all non-protruding regions 102 in the liquid-guiding layer 1 accounts for 15% of the area of ​​the liquid-guiding layer 1.

[0171] An apparatus for preparing the above-mentioned unidirectional liquid-guided nonwoven fabric has the same structure as in Example 1.

[0172] The preparation process of the unidirectional liquid-guided nonwoven fabric in this embodiment is the same as in Embodiment 1.

[0173] Example 7

[0174] A unidirectional liquid-guiding nonwoven fabric differs from Example 1 only in that the total area of ​​all non-protruding regions 102 in the liquid-guiding layer 1 accounts for 50% of the area of ​​the liquid-guiding layer 1.

[0175] An apparatus for preparing the above-mentioned unidirectional liquid-guided nonwoven fabric has the same structure as in Example 1.

[0176] The preparation process of the unidirectional liquid-guided nonwoven fabric in this embodiment is the same as in Embodiment 1.

[0177] Example 8

[0178] A unidirectional liquid-guiding nonwoven fabric differs from Example 1 only in that the main body of the liquid-guiding layer 1 is a hydrophobic fiber web composed of 15% (by mass percentage in the hydrophobic fiber web) three-dimensional crimped polylactic acid fibers mixed into ordinary polylactic acid fibers.

[0179] An apparatus for preparing the above-mentioned unidirectional liquid-guided nonwoven fabric has the same structure as in Example 1.

[0180] The preparation process of the unidirectional liquid-guided nonwoven fabric in this embodiment is the same as in Embodiment 1.

[0181] Comparative Example 1

[0182] A spunlace nonwoven material with a unit area mass of 38 g / m² 2It is composed of 50% bamboo fiber and 50% polyester fiber, with the bamboo fiber having a linear density of 1.33 dtex and the polyester fiber having a linear density of 1.56 dtex.

[0183] Comparative Example 2

[0184] A unidirectional liquid-guiding nonwoven fabric differs from Example 1 only in that the interval between adjacent raised areas 101 is 0.6 mm.

[0185] An apparatus for preparing the above-mentioned unidirectional liquid-guided nonwoven fabric has the same structure as in Example 1.

[0186] The preparation process of the unidirectional liquid-guided nonwoven fabric in this comparative example is the same as that in Example 1.

[0187] Comparative Example 3

[0188] A unidirectional liquid-guiding nonwoven fabric differs from Example 4 only in that the fiber packing density in the raised and non-raised areas of the liquid-guiding layer 1 is 0.082 g / cm³. 3 and 0.097 g / cm 3 The fiber packing density of the barrier layer 2 is 0.67 g / cm³. 3 The fiber packing density of liquid storage layer 3 is 0.08 g / cm³. 3 .

[0189] An apparatus for preparing the above-mentioned unidirectional liquid-guided nonwoven fabric has the same structure as in Example 1.

[0190] The preparation process of the unidirectional liquid-guided nonwoven fabric in this comparative example is the same as that in Example 1.

[0191] Comparative Example 4

[0192] A unidirectional liquid-guiding nonwoven fabric, with the same structure as in Example 1.

[0193] The apparatus for preparing the above-mentioned unidirectional liquid-guiding nonwoven fabric differs from that in Example 1 only in that: in the first hydroentangling mechanism, the hydroentangling head A 502 faces the hydroentangling drum A 501 and is used to perform hydroentangling from the outside of the liquid-guiding layer sheet; in the second hydroentangling mechanism, the hydroentangling head B 603 faces the hydroentangling drum B 601 and is used to perform hydroentangling from the outside of the liquid storage layer sheet.

[0194] The preparation process of the unidirectional liquid-guided nonwoven fabric in this comparative example is as follows:

[0195] (1) Same as steps (1) to (2) in Example 1;

[0196] (2) The liquid storage layer sheet 13, the barrier layer sheet 12 and the liquid guiding layer sheet 11 are fed into the one-way liquid guiding nonwoven fabric preparation device of this embodiment. After being stacked from top to bottom by the stacking guide roller A401, they enter the first hydroentangling mechanism and are sent to the support screen A503 for pre-wetting with water sprayed from the pre-wetting hydroentangling head 505. Then, they are transferred to the hydroentangling drum A501. High-pressure water is sprayed from the outside of the liquid guiding layer sheet through the hydroentangling head A502, so that the fibers in the liquid guiding layer sheet are entangled with each other and some of the hydrophobic fibers in the liquid guiding layer sheet pass through the barrier layer sheet, so that the two are bonded and fixed.

[0197] (3) The composite material is fed into the hydroentangled drum B 601 via the guide roller 10, so that one side of the liquid storage layer sheet 11 faces outward; high-pressure water jet is sprayed from the outside of the liquid storage layer sheet through the hydroentangled head B 603, so that the fibers in the liquid storage layer sheet are entangled with each other and solidified with the barrier layer sheet.

[0198] (4) Same as steps (5) to (6) in Example 1.

[0199] Comparative Example 5

[0200] A unidirectional liquid-guiding nonwoven fabric differs from Example 1 only in that the surface of the liquid-guiding layer 1 is flat and has no protruding areas 101.

[0201] The apparatus for preparing the above-mentioned unidirectional liquid-guided nonwoven fabric differs from that in Example 1 only in that the surface of the spunlace drum C 602 is not provided with a jacquard template.

[0202] The preparation process of the unidirectional liquid-guided nonwoven fabric in this comparative example is as follows:

[0203] (1) Same as steps (1) to (4) in Example 1;

[0204] (2) The solidified material is fed into the hydroentangled drum C602, so that the liquid-conducting layer sheet is attached to the hydroentangled drum C602, and high-pressure water is sprayed from the outside of the liquid storage layer sheet through the hydroentangled head B603.

[0205] (3) Same as step (6) in Example 1.

[0206] Comparative Example 6

[0207] A unidirectional liquid-guiding nonwoven fabric differs from Example 1 only in that the total area of ​​all non-protruding regions 102 in the liquid-guiding layer 1 accounts for 10% of the area of ​​the liquid-guiding layer 1.

[0208] An apparatus for preparing the above-mentioned unidirectional liquid-guided nonwoven fabric has the same structure as in Example 1.

[0209] The preparation process of the unidirectional liquid-guided nonwoven fabric in this comparative example is the same as that in Example 1.

[0210] Comparative Example 7

[0211] A unidirectional liquid-guiding nonwoven fabric differs from Example 1 only in that the total area of ​​all non-protruding regions 102 in the liquid-guiding layer 1 accounts for 75% of the area of ​​the liquid-guiding layer 1.

[0212] An apparatus for preparing the above-mentioned unidirectional liquid-guided nonwoven fabric has the same structure as in Example 1.

[0213] The preparation process of the unidirectional liquid-guided nonwoven fabric in this comparative example is the same as that in Example 1.

[0214] Comparative Example 8

[0215] A unidirectional liquid-guiding nonwoven fabric differs from Example 4 only in that the unit area mass of both the raised and non-raised areas in the liquid-guiding layer 1 is 12 g / m². 2 The fiber packing density in the raised area is 0.045 g / cm³. 3 The fiber packing density in the non-protruding area is 0.110 g / cm³. 3 .

[0216] The apparatus for preparing the above-mentioned unidirectional liquid-guided nonwoven fabric differs from that in Example 4 only in that the hydroentangled drum C602 and the two hydroentangled heads C604 are replaced with an embossing device for embossing the surface of the liquid-guided layer 1.

[0217] The preparation process of the unidirectional liquid-guided nonwoven fabric in this comparative example is as follows:

[0218] (1) Same as steps (1) to (4) in Example 1;

[0219] (2) The solidified material is fed into the embossing equipment, and the embossing process forms raised areas 101 and non-raised areas 102 on the surface of the liquid-conducting layer sheet.

[0220] (3) Same as step (6) in Example 1.

[0221] Test Example Test Objective: To characterize the absorption and backflow performance of a material by testing its liquid penetration time and backflow amount. A shorter penetration time and a smaller backflow amount indicate better performance.

[0222] Test method:

[0223] (1) Rewetting amount: The rewetting amount shall be determined in accordance with the GB / T 28004-2011 standard for diapers (pads, pads).

[0224] (2) Liquid penetration time: Performed in accordance with GB / T 24218.13-2010 "Textiles - Test methods for nonwoven fabrics - Part 13: Determination of liquid penetration time".

[0225] The test results are shown in Table 1.

[0226] Table 1. Comparison of nonwoven fabric performance test data in each embodiment and comparative example.

[0227]

[0228]

[0229] Test Result Analysis:

[0230] 1) As can be seen from the comparison between Example 1 and Example 2, since the barrier layer in Example 2 uses a material with heat shrinkage, it undergoes heat shrinkage during the drying process, which makes the protrusion effect on the surface of the liquid guiding layer more obvious, thus improving the anti-backflow performance of the nonwoven fabric.

[0231] 2) As can be seen from the comparison between Example 1 and Example 3, since Example 3 has through holes in the barrier layer, it accelerates the absorption rate of liquid by the storage layer, which increases the liquid penetration time of Example 3 by 25% compared with Example 1. However, due to the through holes, the amount of re-permeation in Example 3 increases by 26%.

[0232] 3) As can be seen from the comparison between Example 1 and Example 5, Example 5 changes the process of layering and hydroentangling in the preparation method. First, the hydroentangling barrier layer and the liquid storage layer are stacked and then the composite double-layer material is combined with the liquid guiding layer. This makes it impossible for the hydrophilic fibers to penetrate to the raised area of ​​the liquid guiding layer, and they only exist in the non-raised area. As a result, the amount of re-permeation in Example 5 is reduced by 43.4% compared with Example 1, while maintaining good absorption performance.

[0233] 4) As can be seen from the comparison between Example 1 and Example 8, Example 8, by adding three-dimensional crimped fibers to the liquid guiding layer, makes it easier to form a fluffy structure during the hydroentangling process, which is conducive to the formation of raised and non-raised areas in jacquard, thereby improving the anti-backflow performance of nonwoven fabric.

[0234] 5) As can be seen from the comparison between Example 4 and Comparative Example 8, compared with the embossing method in Comparative Example 8, Example 4, through jacquard weaving, can make the mass per unit area of ​​the formed raised area greater than that of the non-raised area. Since some of the hydrophilic fibers in the liquid storage layer pass through the barrier layer and are in contact with the lower surface of the liquid guiding layer, the smaller mass per unit area of ​​the non-raised area will result in a higher proportion of hydrophilic fibers in the non-raised area, allowing the liquid to penetrate through the non-raised area to the liquid storage layer.

[0235] 6) As can be seen from the comparison between Example 1 and Comparative Example 1, compared with the conventional product (Comparative Example 1), the amount of reabsorption in Example 1 is reduced by 72.6% compared with Comparative Example 1 by adopting the technical solution of the present invention, while maintaining good absorption performance.

[0236] 7) As can be seen from the comparison between Example 1 and Comparative Example 2, due to the small width of the non-protruding area in Comparative Example 2, the resistance is large during the transfer of liquid from the liquid guiding layer to the liquid storage layer, which results in the liquid penetration time of Comparative Example 2 being 5.9 seconds longer than that of Example 1. At the same time, some liquid is not absorbed by the liquid storage layer and remains on the surface of the liquid guiding layer, which results in the amount of backflow of Comparative Example 2 being 0.92g higher than that of Example 1.

[0237] 8) As can be seen from the comparison between Example 4 and Comparative Example 3, the packing density of the three-layer material affects the liquid absorption time and reabsorption performance. The gradually increasing packing density from the liquid-conducting layer to the liquid-storing layer can reduce the amount of material reabsorption and accelerate liquid absorption. Therefore, the amount of reabsorption in Example 4 was reduced by 53.4% ​​compared with Comparative Example 3.

[0238] 9) As can be seen from the comparison between Example 1 and Comparative Example 4, Comparative Example 4 changed the order of hydroentangling reinforcement, that is, hydroentangling was performed first from the hydrophobic fiber web side and then from the hydrophilic fiber web side. In this case, since the hydrophobic fiber web is reinforced first, and some hydrophobic fibers penetrate through the outer surface of the spunbond nonwoven fabric, the liquid on the liquid-conducting layer is less likely to penetrate through the barrier layer into the liquid storage layer, resulting in a sharp decrease in the liquid absorption performance of the material. Therefore, the liquid penetration time of Comparative Example 4 increased by 2.7 seconds compared with Example 1.

[0239] 10) As can be seen from the comparison between Example 1 and Comparative Example 5, the surface of the liquid-guiding layer in Example 1 adopts a design with raised and non-raised areas. As can be seen above, since some hydrophilic fibers in the liquid storage layer pass through the barrier layer and connect with the lower surface of the liquid-guiding layer, the smaller mass per unit area of ​​the non-raised areas results in a higher proportion of hydrophilic fibers in the non-raised areas. This allows liquid to penetrate through the non-raised areas to the liquid storage layer. Simultaneously, when the nonwoven fabric is used, the liquid on the surface of the liquid-guiding layer easily flows to the lower non-raised areas, which helps accelerate liquid infiltration. The raised areas, due to their higher mass per unit area and lower proportion of hydrophilic fibers, can effectively prevent liquid backflow.

[0240] 11) As can be seen from the comparison between Examples 1, 6, and 7 and Comparative Example 6, the area of ​​the non-protruding region on the surface of the liquid guiding layer in Comparative Example 6 is too small. Although it can still achieve unidirectional liquid guiding, the liquid seepage speed is relatively slow.

[0241] 12) As can be seen from the comparison between Examples 1, 6, and 7 and Comparative Example 7, the non-protruding area on the surface of the liquid guiding layer in Comparative Example 7 is too large, which will cause the nonwoven fabric to have poor anti-backflow performance, and the liquid in the storage layer is easy to backflow to the surface of the liquid guiding layer.

[0242] Unless otherwise specified, the raw materials and equipment used in this invention are all commonly used in the field; unless otherwise specified, the methods used in this invention are all conventional methods in the field.

[0243] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, alterations, and equivalent transformations made to the above embodiments based on the technical essence of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A unidirectional liquid-guiding nonwoven fabric, characterized in that, The structure, from top to bottom, comprises an interconnected liquid-conducting layer, a barrier layer, and a liquid-retaining layer, formed by hydroentangling the liquid-retaining layer sheet from the outside and then from the outside of the liquid-conducting layer sheet. Both the liquid-conducting layer and the barrier layer are hydrophobic. The surface of the liquid-conducting layer has several raised areas and several non-raised areas. The liquid-retaining layer includes a hydrophilic fiber web. Some of the hydrophilic fibers in the liquid-retaining layer pass through the barrier layer and are in contact with the lower surface of the liquid-conducting layer. The fiber packing density of the liquid-conducting layer is less than that of the barrier layer, which is less than that of the liquid-retaining layer. The raised and non-raised areas in the liquid-conducting layer are arranged alternately, with the total area of ​​the non-raised areas accounting for 15-50% of the total area of ​​the liquid-conducting layer. The unit area mass of the raised areas is greater than that of the non-raised areas, and the minimum projected size of the non-raised areas on the surface of the liquid-conducting layer is not less than 1 mm. The raised and non-raised areas are formed by jacquard weaving.

2. The unidirectional liquid-guiding nonwoven fabric as described in claim 1, characterized in that, The unit area mass of the raised region and the non-raised region are 10~18 g / m², respectively. 2 and 2~10g / m 2 .

3. The unidirectional liquid-guiding nonwoven fabric as described in claim 1 or 2, characterized in that, The minimum projected size of the non-protruding area on the surface of the liquid guiding layer is 1~2.5mm.

4. The unidirectional liquid-guiding nonwoven fabric as described in claim 1, characterized in that, The barrier layer comprises a solidified hot-melt fiber web.

5. The unidirectional liquid-guiding nonwoven fabric as described in claim 1 or 4, characterized in that, The barrier layer has thermal shrinkage properties, with a thermal shrinkage temperature of 130~150℃.

6. The unidirectional liquid-guiding nonwoven fabric as described in claim 1, characterized in that, The barrier layer has several through holes that penetrate the barrier layer; some of the hydrophilic fibers in the liquid storage layer pass through the through holes and are in contact with the lower surface of the liquid guiding layer.

7. The unidirectional liquid-guiding nonwoven fabric as described in claim 1, characterized in that, The liquid-conducting layer comprises a hydrophobic fiber web containing three-dimensional crimped fibers.

8. A process for preparing a unidirectional liquid-guided nonwoven fabric as described in any one of claims 1 to 7, characterized in that, The apparatus includes a preparation device for preparing the unidirectional liquid-guided nonwoven fabric; the preparation device includes: A first hydroentangling mechanism for hydroentangling from the outside of the liquid storage sheet; A second hydroentangling mechanism is used for hydroentangling from the outside of the liquid-conducting layer sheet and for jacquard on the outer surface of the liquid-conducting layer sheet; the second hydroentangling mechanism is located downstream of the first hydroentangling mechanism; A dewatering mechanism located downstream of the second hydroentangling mechanism; A drying unit located downstream of the dehydration unit; A stacking mechanism; the stacking mechanism is located upstream of the first hydroentangling mechanism and is used to stack the liquid-conducting layer sheet, the barrier layer sheet, and the liquid-storage layer sheet together sequentially from top to bottom; or, the stacking mechanism includes a first stacking mechanism located upstream of the first hydroentangling mechanism and used to stack the barrier layer sheet and the liquid-storage layer sheet together, and a second stacking mechanism located between the first hydroentangling mechanism and the second hydroentangling mechanism and used to stack the liquid-conducting layer sheet onto the surface of the barrier layer sheet.

9. The preparation process according to claim 8, characterized in that, The second hydroentangling mechanism includes a hydroentangling drum B, a hydroentangling drum C located downstream of the hydroentangling drum B, and at least one hydroentangling head B and at least one hydroentangling head C facing the hydroentangling drum B and the hydroentangling drum C respectively; the surface of the hydroentangling drum C is provided with a jacquard template.

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