Dry-method composite spunlace material preparation system and method

Abstract

The invention discloses a dry method composite spunlace material preparation system and method, and belongs to the field of composite spunlace non-woven fabrics. The system comprises a composite low-negative-pressure compression roller exhaust device, a double-web-curtain clamping device and a low-pressure water jet infiltration device which are sequentially arranged along the technological process. The method comprises the following steps: carding fibers into a web, compounding the web with a base material, performing multi-stage extrusion and negative pressure suction through a composite low-negative pressure compression roller to efficiently discharge air in a fiber layer, and performing low-pressure water jet pre-infiltration in a double-web-curtain clamping state to further discharge residual gas and wet the fibers, and finally, performing high-pressure spunlace, dewatering and drying to obtain a finished product. According to the invention, the problem of sliver defect caused by air retention when the fiber net and the low-permeability base material are compounded is solved from the process source, the porosity of the product is obviously reduced, the compactness and quality stability of the material are improved, and meanwhile, the material waste is reduced.

Description

Technical Field

[0001] This invention belongs to the field of composite spunlace nonwoven fabrics, and mainly relates to a dry composite spunlace material preparation system and method. Background Technology

[0002] When using hydroentangling composite technology to produce two-layer fiber-paper composites and three-layer fiber-paper-fiber composites, the "cotton sliver" problem is prone to occur. After investigation and analysis, it was found that the formation of the "cotton sliver" is related to the tightness of adhesion between the fiber layers and the paper. The carded fiber web is relatively loose, often containing numerous voids with a large amount of air. The paper has poor air permeability, and the large amount of air in the fiber layers cannot be expelled in time during the first hydroentangling process. This causes "bubbling" in some areas of the paper due to the inability to expel air, resulting in unevenly distributed strips—"cotton slivers"—on the fabric surface during subsequent hydroentangling processes. Statistics show that this occurs when producing a fabric with a basis weight of 70 g / m². 2 When producing two-layer composite materials with a width of 3.2 meters, an average of 20-40 "slivers" are generated per 100 meters, unevenly distributed along the width direction; the production weight is 80g / m². 2 When using a three-layer composite material with a width of 3.2 meters, an average of 30-60 "strips" are generated per 100 meters, unevenly distributed along the width direction. These "strips" have a significant impact on the quality of the finished product and result in considerable material waste.

[0003] Traditional pressure rollers have low air venting efficiency, and air easily remains between the fiber layer and the paper during use, forming a "bubble isolation layer." After pre-wetting, the fibers and paper cannot be fully wetted. Furthermore, the porosity of the fiber mesh in existing processes is generally greater than 50%, affecting the density of the final product.

[0004] CN116356508A discloses a pre-wetting and degassing treatment device and method for spunlace nonwoven fabric. The device and method include a worktable with five sets of supports arranged symmetrically from left to right; a limiting mechanism on the supports arranged in a front-to-back configuration; a spraying mechanism on the supports arranged in a front-to-back configuration; two sets of pre-wetting and extrusion mechanisms; and a tapping and degassing mechanism on a connecting plate between the fourth and fifth sets of supports. Pre-wetting and degassing are performed by tilting the formed fiber web in the pre-wetting zone. However, this method of pre-wetting and degassing the fiber web can easily lead to problems such as excessive moisture absorption causing the web to fall off and deformation. Summary of the Invention

[0005] To address the "sliver" problem and high fiber mesh porosity issues in the production of fiber-paper composite materials using the spunlace composite process, this invention provides a dry composite spunlace material preparation system and method.

[0006] The objective of this invention is achieved through the following technical solution.

[0007] On one hand, the present invention provides a dry composite hydroentangled material preparation system, comprising: A composite low negative pressure roller exhaust device is used for preliminary and main exhaust of fiber web composite structures; The double-net curtain clamping device is located behind the composite low negative pressure roller exhaust device and is used to clamp and convey the fiber web composite structure after exhaust treatment. The low-pressure water jet impregnation device includes a low-pressure water jet impregnation water jet head, which is disposed in the double mesh curtain clamping device and is used to pre-impregnate the fiber mesh composite structure in the clamping state with water jet and further degas it.

[0008] Furthermore, the composite low negative pressure roller exhaust device includes: frame; The initial venting roller is set on the frame and has evenly distributed holes A on its surface, which are used for initial venting when the fiber web composite structure is squeezed. A low negative pressure main pressure roller is set after the initial exhaust pressure roller. The surface of the low negative pressure main pressure roller is provided with uniformly distributed circular holes of the same size, which are used to absorb the air discharged from the fiber web composite structure when pressure is applied to the fiber web composite structure by utilizing the low negative pressure effect. The low negative pressure auxiliary pressure roller has the same structure as the low negative pressure main pressure roller and is used for further exhaust. Each pressure roller is provided with a support roller below it, and the surface of the support roller is provided with holes B; Each pressure roller is equipped with a pneumatic device at its end for adjusting the pressure of the pressure roller; Each pressure roller is equipped with a brush on its upper side to clean residual fibers from the roller surface.

[0009] Furthermore, a pneumatic device is provided on the end face of the preliminary exhaust pressure roller to adjust the height and pressure of the preliminary exhaust pressure roller; a support roller is provided directly below the preliminary exhaust pressure roller to generate positive pressure with the preliminary exhaust pressure roller, and the positive pressure of the preliminary exhaust pressure roller is controlled at 0.1-1 MPa.

[0010] Furthermore, the diameter of the hole A is 5-10mm, the density of hole A is 10,000-40,000 holes / square meter, and the initial exhaust pressure roller is not connected to an external fan; the surface of the support roller is provided with uniformly arranged holes B of the same size, the diameter of hole B is 5-10mm, and the density of hole B is 10,000-40,000 holes / square meter.

[0011] Furthermore, the low-negative-pressure main pressure roller is connected to an external fan to generate negative pressure, and the basis weight of the fiber web composite structure is 15-120 g / m². 2The positive pressure applied by the low negative pressure exhaust main pressure roller is 0.5-2MPa, and the negative pressure corresponding to the low negative pressure main pressure roller is 0.15-1.2Pa; the diameter of the circular holes is 1-5mm, and the distribution of the circular holes is 40,000-1,000,000 per square meter.

[0012] Furthermore, the low negative pressure main pressure roller and the low negative pressure auxiliary pressure roller are equipped with fixed air ducts with openings at a certain angle. The fixed air ducts are connected to the negative pressure pipeline to ensure uniform negative pressure in the width direction.

[0013] Furthermore, an independent transmission device is provided below the composite low negative pressure roller exhaust device, which includes several transmission rollers and a support net curtain covering them.

[0014] Furthermore, the double-net curtain clamping device includes a clamping net curtain A located above the fiber web composite structure and a clamping net curtain B located below the fiber web composite structure; the spacing between the clamping net curtain A and the clamping net curtain B is adjustable, used to apply clamping pressure to the composite structure, and the surface linear velocity of the two is consistent.

[0015] Furthermore, the low-pressure water jet wetting device includes: dual-mode spraying technology, supporting pulsed and continuous spraying; a water needle plate with an orifice diameter of 0.1-0.2mm and a spraying pressure of 0.8-1.5MPa; a wetting depth control module to ensure that the water permeability reaches 85-92%; and a vacuum suction device located directly below to absorb excess water.

[0016] On the other hand, the present invention provides a method for preparing a dry composite hydroentangled material, comprising the following steps: Step S1: The fibers are opened and combed to form a fiber web; Step S2: Use an unwinding device to lay paper or other substrates flat above, below, or between multiple layers of fiber web to form a fiber web composite structure. Step S3: The fiber web composite structure is fed into the composite low negative pressure roller exhaust device for exhaust. Step S4: The vented fiber web composite structure is fed into the double-net curtain clamping device and subjected to low-pressure water jet impregnation. Step S5: The impregnated fiber web composite structure is fed into a hydroentangling system for hydroentangling processing. Step S6 involves dehydration, drying, and winding.

[0017] The beneficial effects of this invention are as follows: (1) By setting up a composite low negative pressure roller, a double mesh curtain clamping device, and a low pressure water jet wetting device in the dry composite spunlace material preparation process, the present invention effectively solves the "cotton strip" problem in the production of spunlace composite process and reduces material waste.

[0018] (2) The fiber web can be vented by the composite low negative pressure roller venting scheme provided by the present invention, which can effectively solve the problem of fiber web "bubbling".

[0019] (3) When the fiber web is produced using the method provided by the present invention, the porosity of the fiber web can be less than 50%, which improves the density of the product.

[0020] (4) This invention provides a variety of dry-process composite hydroentangled materials preparation processes, providing some directions for thinking about the diversity of hydroentangled composite materials.

[0021] Compared to conventional dry-process composite hydroentangled materials that do not pre-vent the fiber web, this invention creatively employs a composite low-negative-pressure roller venting device to pre-vent the fiber web, removing a large amount of air from it. Then, low-pressure water jet impregnation is applied, spraying a uniform water jet onto the fiber web held by the double-layer curtain, fully impregnating the fiber web and expelling air from the gaps between the fibers, allowing the fiber web to adhere tightly to the paper. Simultaneously, the fiber's flexural modulus and elastic recovery rate decrease, while the fiber surface friction coefficient increases, allowing for more effective absorption of water jet energy during subsequent high-pressure hydroentangling, strengthening fiber entanglement, and improving the product's density.

[0022] Furthermore, because this invention greatly reduces the air in the fiber web before hydroentangling, it can significantly reduce the problem of "cotton slivers" formed due to the poor air permeability of the paper during hydroentangling, thereby improving the fabric quality and reducing material waste.

[0023] Compared with the technology using traditional pressure rollers, the composite low negative pressure pressure roller exhaust device and the double-net curtain clamping low-pressure water jet pre-impregnation technology used in this invention have high exhaust efficiency. While exhausting, the low negative pressure pressure roller will also absorb the air discharged from the fiber web. During use, very little air will remain between the fiber layer and the paper, reducing the probability of the formation of "bubble isolation layer". During pre-impregnation, the fibers and paper can be fully wetted, reducing the formation of "cotton slivers".

[0024] Compared to CN116356508A, a pre-wetting and degassing treatment device and method for spunlace nonwoven fabric, the former involves variable fiber web movement directions and spraying and beating during movement. This can cause the fiber web to absorb excessive moisture or become stretched or deformed due to the beating, leading to poor product uniformity. In contrast, the composite low-negative-pressure roller degassing device used in this invention degassing the fiber web in a horizontal direction. Furthermore, the pressure applied to the fiber web is parallel to its weight, preventing stretching and deformation due to the horizontal component of the force. Attached Figure Description

[0025] Figure 1This is a schematic diagram of a composite low negative pressure roller device; Figure 2 This is a schematic diagram of the structure of the low negative pressure main pressure roller and the low negative pressure auxiliary pressure roller; Figure 3 This is a schematic diagram of the support roller structure; Figure 4 This is a schematic diagram of the assembly of the various components of the system.

[0026] Explanation of reference numerals in the attached drawings: 1. Frame; 2. Brush; 3. Initial exhaust pressure roller; 4. Pneumatic device; 5. Support roller; 6. Low negative pressure main pressure roller; 7. Low negative pressure auxiliary pressure roller; 8. Drive roller; 9. Drag net curtain; 10. Circular small hole; 11. Fixed air duct; 12. Negative pressure pipe; 13. Fan; 14. Low pressure water jet wetting water jet head; 15. Double net curtain clamping device. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0028] like Figure 1 , 4 As shown, this invention provides a dry composite hydroentangled material preparation system, including a composite low-negative-pressure roller exhaust device, a double-net curtain clamping device 15, and a low-pressure water jet wetting device. A composite low-negative-pressure roller exhaust device is added above the combed fiber web composite structure before it enters the hydroentangled section, along its width direction. This device applies uniform pressure to the fiber web composite structure, expelling most of the air. Following the composite low-negative-pressure roller exhaust device, a double-net curtain clamping device 15 is installed. This device clamps the fiber web composite structure, keeping it under pressure and reducing secondary air intake caused by fiber rebound. A low-pressure water jet wetting hydroentangling head 14 is installed in the double-web curtain clamping device. The hydroentangling head applies a uniform water jet to the fiber web composite structure, fully wetting the fibers and filling the small gaps in the fiber web. At the same time, it can cause partial entanglement between the fibers, reducing fiber rebound and re-absorption of air, while ensuring that the fiber web adheres tightly to the paper. After the fiber web has been fully wetted by the low-pressure water jet and most of the air has been expelled, it is then subjected to high-pressure hydroentangling. This reduces the problem of bubbling caused by the inability of some paper to expel a large amount of air in time, greatly reducing the generation of "cotton slivers" during subsequent hydroentangling processing and reducing material waste.

[0029] Preferably, the composite low negative pressure roller exhaust device is arranged in the width direction and perpendicular to the conveying direction of the fiber web.

[0030] Furthermore, the composite low negative pressure roller exhaust device includes a frame 1, a preliminary exhaust roller 3, a low negative pressure main roller 6, a low negative pressure auxiliary roller 7, a fan 13 for generating negative pressure, a pneumatic device 4 for controlling the pressure of the roller, a brush 2 for cleaning the fibers adhering to the surface of the roller, and a transmission device independently set below the roller.

[0031] Preferably, the frame 1 is used to support the composite low negative pressure roller (initial exhaust roller 3, low negative pressure main roller 6, and low negative pressure auxiliary roller 7), with some of the rollers of the composite low negative pressure roller mounted on the frame.

[0032] Preferably, the surface of the initial venting roller 3 is provided with uniformly arranged circular holes A of the same size, which are used for initial venting when the fiber web composite structure is squeezed.

[0033] Furthermore, the diameter of the circular holes A on the surface of the initial exhaust roller 3 is 5-10 mm. If the hole diameter is too small, "bubbling" is likely to occur; if the hole diameter is too large, protrusions and indentations are likely to occur on the surface of the fiber web.

[0034] Furthermore, the holes A on the surface of the initial exhaust roller 3 are distributed at 10,000-40,000 per square meter. To ensure a uniform distribution of holes for good exhaust effect, the relationship between hole diameter and hole distribution is as follows: the smaller the hole diameter, the denser the hole distribution should be. There is only one uniform hole distribution value on the same roller.

[0035] Preferably, the initial exhaust roller is not connected to an external fan.

[0036] Preferably, a brush is provided on the entire width of the roller surface above the initial exhaust roller to clean the small amount of fiber remaining on the roller.

[0037] Preferably, the end face of the preliminary exhaust roller is provided with a pneumatic device to adjust the height and pressure of the preliminary exhaust roller.

[0038] Furthermore, the positive pressure of the initial exhaust roller is controlled at 0.1-1 MPa.

[0039] Preferably, a support roller 5 is provided directly below the initial venting roller to generate positive pressure with the initial venting roller.

[0040] Preferably, the surface of the support roller 5 is provided with uniformly arranged holes B of the same size, which are used to expel air when the fiber web is squeezed.

[0041] Furthermore, the diameter of the hole B on the surface of the support roller is 5-10 mm.

[0042] Furthermore, the holes B on the surface of the support roller are distributed at 10,000-40,000 per square meter. To ensure a uniform distribution of holes for good air venting, the relationship between hole diameter and hole distribution is as follows: the smaller the hole diameter, the denser the hole distribution should be. Only one uniform hole distribution value exists on the same roller.

[0043] Preferably, a low negative pressure main pressure roller 6 is provided after the initial exhaust pressure roller 3.

[0044] Preferably, the low negative pressure main pressure roller 6 can apply uniform pressure to the fiber web composite structure and uniformly discharge most of the air in the fiber web composite structure.

[0045] Preferably, the surface of the low negative pressure main pressure roller is provided with uniformly distributed circular holes 10 of the same size, which are used to absorb the air discharged from the fiber web composite structure when pressure is applied to the fiber web composite structure by utilizing the low negative pressure effect.

[0046] Furthermore, the diameter of the circular holes on the surface of the low negative pressure main pressure roller is 1-5mm. If the hole diameter is too small, "bubbling" is likely to occur; if the hole diameter is too large, the fibers are easily sucked into the low negative pressure main pressure roller.

[0047] Furthermore, the distribution of circular holes on the surface of the low-negative-pressure main roller is 40,000-1,000,000 per square meter. To ensure a uniform distribution of holes for good exhaust effect, the relationship between hole diameter and hole distribution is: the smaller the hole diameter, the denser the hole distribution should be. Only one uniform hole distribution value exists on the same roller.

[0048] Furthermore, the external fan 13 connected to the low negative pressure main pressure roller is used to generate negative pressure.

[0049] Preferably, the basis weight of the fiber web is 15-120 g / m². 2 The negative pressure corresponding to the low negative pressure main pressure roller is 0.15-1.2 Pa. If the negative pressure is too high, the fiber web will easily be attracted to the pressure roller.

[0050] As a preferred option, such as Figure 2 As shown, the low negative pressure main pressure roller 6 has a fixed air duct 11 with a certain angle opening inside, and the fixed air duct 11 is connected to the negative pressure pipe 12.

[0051] Furthermore, the fixed air duct inside the low negative pressure main pressure roller 6 is inverted "U" shape and will not rotate with the pressure roller.

[0052] Furthermore, the fixed air duct inside the low negative pressure main pressure roller 6 has a pressure stabilizing function, ensuring that the negative pressure in the width direction of the part in contact with the fiber web is uniform and the same.

[0053] Preferably, the low negative pressure main pressure roller is connected to the fan in the form of a flexible hose for easy lifting and lowering.

[0054] In this design, the low-negative-pressure main pressure roller only has negative pressure in a short area where it applies pressure to the fiber web, and the negative pressure is very low. It is only used to draw air from the fiber web to prevent bubbling from occurring in the fiber web in front of or behind the low-negative-pressure main pressure roller. At the same time, the low negative pressure of the main pressure roller can prevent the fiber web from sticking to the pressure roller due to the negative pressure.

[0055] Preferably, a brush is provided on the entire width of the roller surface above the low negative pressure main roller to clean the small amount of fiber remaining on the roller.

[0056] Preferably, the end face of the low negative pressure main pressure roller is provided with a pneumatic device to adjust the height and pressure of the low negative pressure main pressure roller.

[0057] Preferably, a support roller is provided directly below the low negative pressure main roller to generate positive pressure with the low negative pressure main roller.

[0058] Furthermore, the positive pressure of the low negative pressure main pressure roller is controlled at 0.5-2 MPa.

[0059] As a preferred option, such as Figure 3 As shown, the surface of the support roller 5 is provided with uniformly arranged holes of the same size, which are used to expel air when the fiber web is squeezed.

[0060] Furthermore, the diameter of the holes on the surface of the support roller is 5-10 mm.

[0061] Furthermore, the surface of the support roller has 10,000-40,000 holes per square meter. To ensure a uniform distribution of holes for good air venting, the relationship between hole diameter and hole distribution is as follows: the smaller the hole diameter, the denser the hole distribution should be. Only one uniform hole distribution value exists on the same roller.

[0062] Preferably, a low negative pressure auxiliary pressure roller is provided behind the low negative pressure main pressure roller.

[0063] Preferably, the function of the low negative pressure auxiliary pressure roller is to further expel air from the fiber web.

[0064] Preferably, the surface of the low negative pressure auxiliary pressure roller is provided with uniformly distributed circular holes of the same size, which are used to further absorb the air discharged from the fiber web when pressure is applied to the fiber web by utilizing the low negative pressure effect.

[0065] Furthermore, the diameter of the circular holes on the surface of the low negative pressure auxiliary pressure roller is 1-5mm. If the hole diameter is too small, "bubbling" is likely to occur; if the hole diameter is too large, the fibers are easily sucked into the low negative pressure main pressure roller.

[0066] Furthermore, the distribution of circular holes on the surface of the low-negative-pressure auxiliary roller is 40,000-1,000,000 per square meter. To ensure a uniform distribution of holes for good air exhaust, the relationship between hole diameter and hole distribution is as follows: the smaller the hole diameter, the denser the hole distribution should be. Only one uniform hole distribution value exists on the same roller.

[0067] As a preferred option, such as Figure 2 As shown, the low negative pressure auxiliary pressure roller and the low negative pressure main pressure roller are connected to the same fan.

[0068] Preferably, the basis weight of the fiber web is 15-120 g / m². 2 The negative pressure corresponding to the low negative pressure auxiliary pressure roller is 0.15-1.2 Pa. If the negative pressure is too high, the fiber web will easily be attracted to the pressure roller.

[0069] Preferably, the low negative pressure auxiliary pressure roller is provided with a fixed air duct with an opening at a certain angle, and the fixed air duct is connected to the negative pressure pipeline.

[0070] Furthermore, the fixed air duct inside the low negative pressure auxiliary pressure roller is inverted "U" shape and will not rotate with the pressure roller.

[0071] Furthermore, the fixed air duct inside the low negative pressure auxiliary pressure roller has a pressure stabilizing function, ensuring that the negative pressure in the width direction of the part in contact with the fiber web is uniform and the same.

[0072] Preferably, the low negative pressure auxiliary roller is connected to the fan in the form of a flexible hose.

[0073] Preferably, a brush is provided on the entire width of the roller surface above the low negative pressure auxiliary roller to clean the small amount of fiber remaining on the roller.

[0074] Preferably, the end face of the low negative pressure auxiliary pressure roller is provided with a pneumatic device to adjust the height and pressure of the low negative pressure auxiliary pressure roller.

[0075] Furthermore, the positive pressure of the low negative pressure auxiliary pressure roller is controlled at 0.5-2 MPa.

[0076] Preferably, a support roller is provided directly below the low negative pressure auxiliary roller to generate positive pressure with the low negative pressure auxiliary roller.

[0077] Preferably, the surface of the support roller is provided with uniformly arranged holes of the same size to expel air when the fiber web is squeezed.

[0078] Furthermore, the diameter of the holes on the surface of the support roller is 5-10 mm.

[0079] Furthermore, the surface of the support roller has 10,000-40,000 holes per square meter. To ensure a uniform distribution of holes for good air venting, the relationship between hole diameter and hole distribution is as follows: the smaller the hole diameter, the denser the hole distribution should be. Only one uniform hole distribution value exists on the same roller.

[0080] Preferably, the composite low negative pressure roller is equipped with a transmission device, which is located below the composite low negative pressure roller.

[0081] Preferably, the transmission device has several support rollers 5 and transmission rollers 8, and the roller surface is covered with a support net curtain 9.

[0082] Preferably, the support net curtain has good air permeability.

[0083] Preferably, each pressure roller has a corresponding support roller below it.

[0084] Preferably, the diameter of the pressure roller is the same as the diameter of the support roller.

[0085] Preferably, each pressure roller and a support roller are referred to as a set.

[0086] As a preferred option, multiple sets of low negative pressure auxiliary pressure rollers can be set according to actual exhaust requirements.

[0087] A double-net curtain clamping device is installed after the composite low negative pressure roller exhaust device.

[0088] Preferably, the double mesh curtain clamping device comprises a frame, a clamping mesh curtain A located above the fiber mesh composite structure, and a clamping mesh curtain B located below the fiber mesh composite structure.

[0089] Preferably, the frame mainly serves to support the double-net curtain clamping device, which is mounted on the frame.

[0090] Preferably, the clamping net curtain A and clamping net curtain B consist of a transmission device, guide rollers and net curtains.

[0091] In this solution, the double-screen clamping device applies a clamping effect to the fiber web by adjusting the distance between clamping screen A and clamping screen B. This clamping effect applies pressure to the fiber web, keeping the fiber web and paper in close contact.

[0092] Preferably, the mesh curtain has good air permeability, which can promptly discharge the air that is discharged from the fiber mesh due to the clamping effect.

[0093] Preferably, the operating speed of the transmission device of the double-net curtain clamping device can be adjusted to match the operating speed of the fiber web.

[0094] Preferably, to ensure that the fibers do not wrinkle or slip significantly between the fibers and the paper, the surface linear velocity of clamping screen A and clamping screen B should be kept consistent.

[0095] The low-pressure water jet wetting device is installed in the double-wire curtain clamping device. It can spray a uniform water jet onto the fiber web clamped by the double-wire curtain, fully wetting the fiber web and expelling air from the gaps between the fibers, allowing the fiber web to adhere tightly to the paper. At the same time, the fiber's bending modulus and elastic recovery rate decrease, and the fiber surface friction coefficient increases, which allows for more effective absorption of water jet energy during subsequent high-pressure hydroentangling, enhancing the fiber entanglement effect.

[0096] Preferably, the low-pressure water jet wetting device is equipped with dual-mode spraying technology, namely pulsed and continuous spraying. One or a combination of the two can be used depending on the actual needs.

[0097] Preferably, the low-pressure water jet wetting device is connected to an external water pump for supplying water and controlling the water supply pressure.

[0098] Furthermore, the pressure range of the low-pressure water jet wetting device is 0.8MPa-1.5MPa.

[0099] Preferably, the low-pressure water jet wetting device is equipped with a water needle plate.

[0100] Furthermore, the aperture of the water needle plate of the low-pressure water jet wetting device is 0.1-0.2 mm.

[0101] Furthermore, the water jets sprayed by the low-pressure water jet wetting device are cylindrical in shape.

[0102] Preferably, the water jet of the low-pressure water jet wetting device passes through the clamping mesh curtain A.

[0103] Furthermore, the water jets of the low-pressure water jet wetting device disperse after passing through the clamping mesh curtain A, resulting in a more uniform water flow distribution and a good wetting effect on the fiber mesh.

[0104] Preferably, the low-pressure water jet wetting device is equipped with a wetting depth control module to ensure that the water permeability reaches 85-92% and fully wets the fiber web.

[0105] Preferably, a vacuum suction device is installed directly below the low-pressure water jet wetting device to absorb excess water.

[0106] In this solution, the porosity of the fiber web, after most of the air has been expelled, is less than 50%, which effectively improves the density of the product.

[0107] Secondly, this invention provides a method for preparing a dry-process composite hydroentangled material, comprising the following steps: Step 1: The fibers are opened and combed to form a fiber web; Step 2: Use an unwinding device to lay paper or other substrates flat above, below, or between multiple layers of fiber web to form a fiber web composite structure; Step 3: Feed the fiber web composite structure into the composite low negative pressure roller exhaust device for exhaust; Step 4: The vented fiber mesh composite structure is fed into the double mesh curtain clamping device and then impregnated with low-pressure water jet. Step 5: The impregnated fiber web composite structure is fed into the hydroentangling system for hydroentangling processing; Step 6: Dehydrate, dry, and wind the product.

[0108] Preferably, in step 1, the fibers in the fiber web can be viscose fiber, polyester fiber, bamboo fiber, lyocell fiber, polylactic acid fiber, PP fiber, polyvinyl alcohol fiber, aramid fiber, and other fibers, as well as combinations of them in different proportions.

[0109] Preferably, in step 1, the fiber web can be a multi-layer fiber web that has been individually carded by multiple carding machines.

[0110] Preferably, in step 2, the unwinding device can unwind the paper so that it is located on the upper side of the fiber web, on the lower side of the fiber web, or between multiple layers of fiber web.

[0111] Preferably, in step 2, the unwinding device can unwind paper rolls, PP spunbond fabric, meltblown fabric, spunlace fabric, mesh material, and other materials that can be used in spunlace composite production.

[0112] Preferably, step 2 may include multiple unwinding devices.

[0113] Preferably, in step 3, after the fiber web and paper form a simple upper and lower layer structure, they enter the composite low negative pressure roller device.

[0114] Preferably, in step 3, the negative pressure of the air duct inside the composite low negative pressure roller and the positive pressure generated by the composite low negative pressure roller on the fiber web can be adjusted accordingly based on the specific weight, thickness and production line speed of the fiber web.

[0115] Preferably, in step 4, the vented fiber composite structure is subjected to low-pressure water jet impregnation under the clamping of a double mesh curtain.

[0116] Preferably, in step 4, the low-pressure water jet wetting can be selected as pulse wetting, continuous wetting, or a combination of both, depending on the actual situation.

[0117] Preferably, in step 4, the pressure of the low-pressure water jet wetting can be adjusted according to the degree of wetting of the fiber web.

[0118] Preferably, in step 5, the hydroentangling system can be a flatbed hydroentangling system, a circular hydroentangling system, or a combination thereof.

[0119] Preferably, in step 5, the hydroentangling pressure of the hydroentangling system can be adjusted.

[0120] Preferably, in step 6, the dehydration method can be suction dehydration, roll dehydration, or a combination thereof.

[0121] Preferably, in step 6, the drying method can be drum drying, hot air penetration drying, or a combination thereof.

[0122] Example 1 Polyester fibers of 1.33 dtex * 38 mm were selected, opened using an opening machine, and then sent to a carding machine for carding to obtain fiber web A. The basis weight of fiber web A was set to 120 g / m². 2 The paper roll is unwound using an unwinding device. The selected paper is wood pulp paper with a basis weight of 30 g / m². 2After unwinding, the wood pulp paper is stacked on top of fiber web A, with the wood pulp paper positioned below fiber web A. The stacked wood pulp paper and fiber web A are then fed into a composite low-negative-pressure roller degassing device for degassing. The initial degassing roller has a positive pressure of 1 MPa, an orifice diameter of 10 mm, and 10,000 holes per square meter. The support roller surface has an orifice diameter of 10 mm and 10,000 holes per square meter. The low-negative-pressure main roller has a positive pressure of 2 MPa, an orifice diameter of 5 mm, 40,000 holes per square meter, and a negative pressure of 1.2 Pa. The support roller surface below the low-negative-pressure main roller has an orifice diameter of 5 mm and 40,000 holes per square meter. The low-negative-pressure auxiliary roller has a positive pressure of 2 MPa, an orifice diameter of 5 mm, 40,000 holes per square meter, and a negative pressure of 1.2 Pa. The support roller surface below the low-negative-pressure auxiliary roller has a 5mm aperture and 40,000 holes per square meter. The fiber web and paper, after passing through the composite low-negative-pressure roller exhaust device, are then fed into a double-web curtain clamping device. A low-pressure water jet impregnation device is used for wetting and further exhaust, employing continuous jet technology with a needle plate aperture of 0.2mm and an impregnation pressure of 1.5MPa. The porosity of the resulting fiber web after exhaust is 45-50%. The exhausted fiber web and paper are then fed into a flat-web hydroentangling system for hydroentangling, with 5-8 hydroentangling passes at a pressure of 6-10MPa. Afterward, they undergo suction dewatering, roll drying, and a combination of drum drying and hot air penetration drying before being wound up to obtain the finished product. Using this production method, 10-20 "slivers" are produced per 100 meters.

[0123] Example 2 Polylactic acid (PLA) fibers (1.67*38mm) and lyocell fibers (1.33dtex*38mm) were uniformly mixed in a 3:7 ratio, opened by an opening machine, and then carded by a carding machine to obtain fiber web B. The basis weight of fiber web B was set to 60 g / m². 2 The meltblown fabric was unwound using an unwinding device. The selected meltblown fabric was PBAT biodegradable meltblown fabric with a basis weight of 20 g / m². 2After unwinding, the meltblown fabric is stacked with fiber web B, with fiber web B positioned above the meltblown fabric. Then, the stacked fiber web B and meltblown fabric are fed into a composite low-negative-pressure roller exhaust device for exhaust treatment. The initial exhaust roller has a positive pressure of 1 MPa, an orifice diameter of 10 mm, and 10,000 holes per square meter. The support roller surface has an orifice diameter of 10 mm and 10,000 holes per square meter. The low-negative-pressure main roller has a positive pressure of 1 MPa, an orifice diameter of 5 mm, 40,000 holes per square meter, and a negative pressure of 0.6 Pa. The support roller below the low-negative-pressure main roller has an orifice diameter of 5 mm and 40,000 holes per square meter. The low-negative-pressure auxiliary roller has a positive pressure of 2 MPa, an orifice diameter of 1 mm, 1,000,000 holes per square meter, and a negative pressure of 0.6 Pa. The support roller surface below the low-negative-pressure auxiliary roller has a 5mm aperture and 40,000 holes per square meter. The fiber web and meltblown fabric, after passing through the composite low-negative-pressure roller exhaust device, are then fed into a double-curtain clamping device. A low-pressure water jet wetting device is used for wetting and further exhaust, employing pulse jet technology with a needle plate aperture of 0.15mm and an impregnation pressure of 1.2MPa. The porosity of the resulting fiber web after exhaust is 40-45%. The exhausted fiber web and paper are then fed into a hydroentangling system combining cylindrical and flat wires for hydroentangling, with 4-6 hydroentangling passes at a pressure of 5-8MPa. Afterward, it undergoes dewatering and hot air penetration drying before being wound up to obtain the finished product. Using this method, 3-9 "slivers" are produced per 100 meters.

[0124] Example 3 Polyester fibers of 1.56 dtex*38 mm and viscose fibers of 1.70 dtex*40 mm were uniformly mixed in a 5:5 ratio, opened by an opening machine, and then fed into a carding machine for carding to obtain fiber web C and fiber web D. The basis weight of fiber web C was set to 15 g / m². 2 The basis weight of fiber web D is set to 15 g / m². 2 The paper roll is unwound using an unwinding device. The selected paper is wood pulp paper with a basis weight of 30 g / m². 2After unwinding, the wood pulp paper is stacked with fiber webs C and D, with fiber web C on top, the wood pulp paper between fiber webs C and D, and fiber web D at the bottom of the stack. Then, the stacked fiber webs C, wood pulp paper, and fiber web D are fed into a composite low-negative-pressure roller degassing device for degassing. The initial degassing roller has a positive pressure of 0.1 MPa, an orifice diameter of 5 mm, and 40,000 holes per square meter. The support roller surface has an orifice diameter of 5 mm and 40,000 holes per square meter. The low-negative-pressure main roller has a positive pressure of 0.5 MPa, an orifice diameter of 1 mm, 1,000,000 holes per square meter, and a negative pressure of 0.15 Pa. The support roller surface below the low-negative-pressure main roller has an orifice diameter of 5 mm and 40,000 holes per square meter. The positive pressure of the low-negative-pressure auxiliary pressure roller is set to 0.5 MPa, the aperture is 1 mm, and the number of holes is 1,000,000 per square meter; the negative pressure is set to 0.15 Pa. The aperture of the support roller surface below the low-negative-pressure auxiliary pressure roller is 5 mm, and the number of holes is 40,000 per square meter. The fiber web and paper, after passing through the composite low-negative-pressure roller degassing device, are then fed into a double-wire curtain clamping device. A low-pressure water jet wetting device is used for wetting and further degassing, employing a combination of continuous and pulsed jetting technology. The needle plate aperture is 0.1 mm, and the wetting pressure is 0.8 MPa. The porosity of the fiber web obtained after degassing is 35-40%. The degassed fiber web and paper are then fed into a rotary wire hydroentangling system for hydroentangling, with 3-5 hydroentangling passes and a hydroentangling pressure of 4-6 MPa. After dewatering by suction and drying in a drying cylinder, the finished product is obtained by winding. Using this production method, 1-5 tampons are produced per 100 meters.

[0125] Comparative Example 1 Compared with Example 1, if the negative pressure of the low negative pressure main pressure roller and the low negative pressure auxiliary pressure roller is set to 1.5 Pa and other conditions are not changed, the fiber web is likely to be adsorbed on the low negative pressure roller, resulting in the fiber web wrapping around the roller.

[0126] Comparative Example 2 Compared with Example 2, if the positive pressure of the initial venting roller is set to 2 MPa and other conditions are not changed, the fiber web before entering the initial venting roller is prone to "bubbling" due to poor venting. If this situation continues, the fiber web entering the low negative pressure main roller and low negative pressure auxiliary roller will be deformed or overlapped due to the presence of "bubbling", which will further lead to the generation of more "cotton strips".

[0127] It should be noted that the above embodiments only illustrate some implementation methods, and those skilled in the art can make adjustments according to actual circumstances. The embodiments described above are merely preferred solutions of the present invention, but are not intended to limit the present invention. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention.

Claims

1. A dry-process composite hydroentangled material preparation system, characterized in that, include: A composite low negative pressure roller exhaust device is used for preliminary and main exhaust of fiber web composite structures; The double mesh curtain clamping device (15) is located behind the composite low negative pressure roller exhaust device and is used to clamp and convey the fiber mesh composite structure after exhaust treatment. The low-pressure water jet wetting device includes a low-pressure water jet wetting water jet head (14), which is disposed in the double mesh curtain clamping device (15) for water jet pre-wetting and further venting of the fiber mesh composite structure in the clamping state.

2. The dry composite hydroentangled material preparation system according to claim 1, characterized in that, The composite low negative pressure roller exhaust device includes: Rack (1); The initial venting roller (3) is set on the frame and has evenly distributed holes A on its surface for initial venting when the fiber web composite structure is squeezed. The low negative pressure main pressure roller (6) is set after the initial exhaust pressure roller. The surface of the low negative pressure main pressure roller is provided with uniformly distributed circular holes (10) of the same size, which are used to absorb the air discharged from the fiber web composite structure when pressure is applied to the fiber web composite structure by utilizing the low negative pressure effect. The low negative pressure auxiliary pressure roller (7) has the same structure as the low negative pressure main pressure roller (6) and is used for further exhaust. Each pressure roller is provided with a support roller (5) below it, and the surface of the support roller is provided with holes B; Each pressure roller end is equipped with a pneumatic device (4) for adjusting the pressure roller pressure; Each pressure roller is equipped with a brush (2) at an angle above it to clean residual fibers on the roller surface.

3. The dry composite hydroentangled material preparation system according to claim 2, characterized in that, The end face of the primary exhaust roller is provided with a pneumatic device to adjust the height and pressure of the primary exhaust roller; a support roller is provided directly below the primary exhaust roller to generate positive pressure with the primary exhaust roller, and the positive pressure of the primary exhaust roller is controlled at 0.1-1 MPa.

4. The dry composite hydroentangled material preparation system according to claim 2, characterized in that, The diameter of hole A is 5-10mm, and the density of hole A is 10,000-40,000 per square meter. The initial exhaust pressure roller is not connected to an external fan. The surface of the support roller is provided with holes B of the same size that are evenly arranged. The diameter of hole B is 5-10mm, and the density of hole B is 10,000-40,000 per square meter.

5. The dry composite hydroentangled material preparation system according to claim 2, characterized in that, The external fan (13) of the low negative pressure main pressure roller is used to generate negative pressure, and the basis weight of the fiber web composite structure is 15-120 g / m². 2 The positive pressure applied by the low negative pressure exhaust main pressure roller is 0.5-2MPa, and the negative pressure corresponding to the low negative pressure main pressure roller is 0.15-1.2Pa; the diameter of the circular holes is 1-5mm, and the distribution of the circular holes is 40,000-1,000,000 per square meter.

6. The dry composite hydroentangled material preparation system according to claim 2, characterized in that, The low negative pressure main pressure roller (6) and the low negative pressure auxiliary pressure roller (7) are provided with fixed air ducts (11) with a certain angle opening. The fixed air ducts (11) are connected to the negative pressure pipes (12) to ensure uniform negative pressure in the width direction.

7. The dry composite hydroentangled material preparation system according to claim 2, characterized in that, The composite low negative pressure roller exhaust device is provided with an independent transmission device below it. The transmission device includes several transmission rollers (8) and a support net curtain (9) covering them.

8. The dry composite hydroentangled material preparation system according to claim 1, characterized in that, The double mesh curtain clamping device (15) includes a clamping mesh curtain A located above the fiber mesh composite structure and a clamping mesh curtain B located below the fiber mesh composite structure; the spacing between the clamping mesh curtain A and the clamping mesh curtain B is adjustable and used to apply clamping pressure to the composite structure, and the surface linear velocity of the two is consistent.

9. The dry composite hydroentangled material preparation system according to claim 1, characterized in that, The low-pressure water jet wetting device includes: dual-mode spraying technology, supporting pulsed and continuous spraying; water needle plate orifice diameter of 0.1-0.2mm, spraying pressure of 0.8-1.5MPa; wetting depth control module to ensure water permeability of 85-92%; and a vacuum suction device located directly below to absorb excess water.

10. A method for preparing a dry-process composite hydroentangled material, characterized in that, The dry composite hydroentangled material preparation system according to any one of claims 1 to 9 includes the following steps: Step S1: The fibers are opened and combed to form a fiber web; Step S2: Use an unwinding device to lay paper or other substrates flat above, below, or between multiple layers of fiber web to form a fiber web composite structure. Step S3: The fiber web composite structure is fed into the composite low negative pressure roller exhaust device for exhaust. Step S4: The vented fiber mesh composite structure is fed into the double mesh curtain clamping device (15) and subjected to low-pressure water jet wetting. Step S5: The impregnated fiber web composite structure is fed into a hydroentangling system for hydroentangling processing. Step S6 involves dehydration, drying, and winding.

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