A method for producing a continuous filament nonwoven fabric

Abstract

The application discloses a preparation method of continuous filament non-woven fabric, comprising the following steps: (1) spinning solution is extruded through a spinneret, passes through a gas gap layer, enters an accelerating slit of a coagulation bath device, and is solidified and drafted through an accelerating fluid to obtain a cellulose filament bundle; (2) the cellulose filament bundle is formed into a fiber web with mutual overlapping between the filament bundles on a laying device; and (3) the fiber web is subjected to a post-processing procedure to prepare the continuous filament non-woven fabric. The application adds the accelerating slit in the coagulation bath device, solidifies and drafts the spinning solution through the accelerating fluid, and prepares the fiber filament bundle with good mechanical properties and high fineness uniformity; meanwhile, the spinning speed is adjusted through the relationship between the outlet width of the accelerating slit and the spinning speed, and the spinning effect is further improved; then, the laying device is used to form the uniform and consistent fiber web, and the water jet and washing integrated process is used for the post-processing, so that the preparation method has a short process flow and low energy consumption.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of non-woven material preparation, and particularly relates to a preparation method of continuous filament non-woven fabric. BACKGROUND

[0002] Non-woven fabric is a kind of fabric formed without spinning and weaving, which is formed by arranging textile short fibers or filaments in a certain direction or randomly to form a web structure, and then being reinforced by mechanical, thermal bonding or chemical methods.

[0003] Non-woven fabric breaks through the traditional textile principle, and has the characteristics of short process, fast production speed, high yield and wide application. With the development of society and the improvement of people's life, the demand for non-woven fabric is increasing, the development of the entire non-woven fabric industry is extremely rapid, and the application is also more and more widely, how to prepare non-woven fabric with good tow forming effect and excellent quality is a problem to be solved at present.

[0004] Most of the existing preparation of lyocell filament non-woven fabric adopts the method of air drafting and mist coagulation, the mechanical properties of the product prepared by this method are poor, resulting in a large number of broken ends, high chipping rate, poor uniformity in the length direction of the fiber, and complex process flow and high energy consumption.

[0005] Therefore, the present application is proposed. SUMMARY

[0006] The technical problem solved by the present application is to overcome the shortcomings of the prior art, and to provide a preparation method of continuous filament non-woven fabric. By changing the internal structure of the coagulation bath device, an acceleration slit is added to the coagulation bath device, so that the spinning solution is solidified and drawn by the acceleration fluid, and a fiber filament bundle with good drawing effect and high fineness uniformity is prepared. At the same time, the spinning speed is adjusted through the relationship between the outlet width of the acceleration slit and the spinning speed, and the spinning effect is further improved. Then, a uniform and consistent web is formed by the laying device, and a continuous filament non-woven fabric with good combination and overall uniformity is prepared by the post-processing procedure.

[0007] To solve the above technical problems, the basic idea of the technical scheme adopted by the present application is:

[0008] A preparation method of continuous filament non-woven fabric, comprising:

[0009] (1) the spinning solution is extruded through the spinneret, passes through the air gap layer, and enters the acceleration slit of the coagulation bath device, and is solidified and drawn by the acceleration fluid to obtain a cellulose filament bundle;

[0010] (2) the cellulose filament bundle forms a web structure in which the filaments overlap each other on the laying device;

[0011] (3) the web is subjected to a post-treatment process to produce a continuous filament nonwoven fabric;

[0012] the relationship between the exit width D of the acceleration slit and the spinning speed V satisfies:

[0013] V = a x D 2 -b x D + c;

[0014] wherein 5 ≤ a ≤ 60, 30 ≤ b ≤ 400, 20 ≤ c ≤ 600, 4ac - b 2 > 0.

[0015] Preferably, 10 ≤ a ≤ 50, 30 ≤ b ≤ 200, 20 ≤ c ≤ 300;

[0016] More preferably, 15 ≤ a ≤ 50, 30 ≤ b ≤ 100, 20 ≤ c ≤ 200.

[0017] In the above scheme, the method for producing a continuous filament nonwoven fabric uses dry-jet wet spinning technology, and is mainly used to produce a lyocell continuous filament nonwoven fabric.

[0018] The spinning speed of the filament bundle is adjusted by the width of the acceleration slit in the coagulation bath device, further improving the spinning effect, wherein the unit of the width of the acceleration slit D is mm, and the unit of the spinning speed is m / min.

[0019] In the process of step (1), the formation of the filament bundle completely relies on the coagulation bath, which can simultaneously function as coagulation and drafting. After passing through the coagulation bath, the internal structure of the filament bundle no longer changes.

[0020] The drafting of the filament bundle by the coagulation bath does not rely on mechanical external force, the forming process is simple, and the energy consumption is low.

[0021] Further, the ratio H / D of the inlet width H of the acceleration slit to the exit width D of the acceleration slit is 1-8;

[0022] Preferably, the ratio H / D is 1-6.

[0023] Further, the pressure at the exit of the acceleration slit is 0.1-3 MPa;

[0024] Preferably, the pressure at the exit of the acceleration slit is 0.5-2 MPa.

[0025] In the above scheme, when the ratio of the inlet width of the acceleration slit to the exit width of the acceleration slit and the pressure at the exit of the acceleration slit are within the above-mentioned limited ranges, the spinning effect can be effectively improved.

[0026] Further, the ratio of the flow rate of the coagulation bath to the spinning speed is 1-10;

[0027] Preferably, the ratio of the flow rate of the coagulation bath to the spinning speed is 1-6.

[0028] In the above scheme, when the ratio of the flow rate of the coagulation bath to the spinning speed is within the above defined range, the effect of forming the fiber bundle can be effectively improved.

[0029] It should be noted that the coagulation bath device has a coagulation bath acceleration zone due to the addition of the acceleration slit. The flow rate of the accelerated fluid in the acceleration zone is the flow rate of the coagulation bath, and the spinning speed is the speed of the fiber falling on the laying machine. The influence on the spinning speed mainly includes the following aspects:

[0030] The influence of the accelerated draft of the accelerated fluid in the coagulation bath device; the influence of the acceleration of the fiber due to gravity in the height difference between the coagulation bath device and the laying machine; and the flow rate of the spinning fluid caused by the extrusion force when the spinneret extrudes the spinning fluid; since the height difference between the spinneret, the coagulation bath device and the laying machine is constant, the influence on the spinning speed is mainly caused by the structure of the acceleration slit in the coagulation bath device.

[0031] Further, the spinning position of the continuous filament nonwoven fabric is at least 1, preferably 2-4.

[0032] Further, the distance between adjacent spinning positions is 500-3000 mm, preferably 1000-2000 mm.

[0033] Further, the grammage of the nonwoven material of the continuous filament nonwoven fabric is 5-60 g / m 2 2 ;

[0034] Preferably, the grammage of the nonwoven material is 20-40 g / m 2 2 .

[0035] In the above scheme, the continuous filament nonwoven fabric can be single-layered or multi-layered, and has self-bonding property between layers.

[0036] Further, the post-processing procedure of the web includes at least one hydroentanglement process, and the hydroentanglement process adopts a double-sided forming processing mode of the front and back surfaces of the web.

[0037] In the above scheme, the continuous filament nonwoven fabric is entangled and reinforced by the hydroentanglement process, and the front and back surfaces are reinforced by the front and back hydroentanglement process, which can ensure the uniform consistency of the double surfaces.

[0038] Further, the number of hydroentanglement heads in the hydroentanglement process is 3-7.

[0039] ​​In the above scheme, the equipment in the water jet process adopts a roller arrangement or a combination of a platform and a roller.

[0040] Further, the water jet process adopts a water jet washing integrated process, and a low-pressure water jet washing processing mode is adopted in the last water jet.

[0041] In the above scheme, the water jet washing integrated process is adopted, which fully utilizes the characteristics of high water jet flow speed and high exchange efficiency, and under the condition of ensuring that the fiber web formed by the fiber bundle does not need to be bonded by an adhesive, the fiber web can be combined stably under the water jet condition to form a continuous filament non-woven fabric with excellent mechanical properties, and the water is washed step by step in the water jet stage, and the water is washed in the last stage by using clean water in a low-pressure water jet washing mode.

[0042] Compared with the conventional short fiber non-woven fabric, the long fiber bundle is first washed and cut, then laid and water jetted, and the melt-blown process needs a special water washing technology, and in the present application, a water jet washing integrated process is adopted, that is, water jetting and water washing are carried out simultaneously, which not only shortens the process flow, but also simplifies the equipment, reduces energy consumption and cost.

[0043] Different from the previous single water jet clean water storage tank, the water jet process adopts a plurality of liquid storage tanks, which are arranged from high to low according to the water amount of the water jet head and the concentration of the coagulation bath, and adjacent liquid storage tanks are connected by circulating water pumps to realize efficient utilization of water jet water or water washing water and reduce energy consumption.

[0044] Further, the hole diameter and the number of the spinneret holes can be the same or different, which can be adjusted according to actual process needs.

[0045] After adopting the above technical scheme, the present application has the following beneficial effects compared with the prior art:

[0046] The present application provides a preparation method of a continuous filament non-woven fabric, which changes the internal structure of the coagulation bath device, adds an acceleration slit in the coagulation bath device, and makes the spinning solution solidify and draw by the accelerated fluid to prepare a fiber filament bundle with good drawing effect and high fineness uniformity.

[0047] The spinning speed is adjusted by the relationship between the outlet width of the acceleration slit and the spinning speed, and the spinning effect is further improved.

[0048] Then a uniform and consistent fiber web is formed by a laying device, and a water jet washing integrated process is adopted for post-processing, which has a short process flow, simple equipment, low energy consumption and small occupied area.

[0049] The continuous filament non-woven fabric prepared by the present application has the advantages of green environmental protection, easy natural degradation, good uniformity of cloth surface, good mechanical properties, less broken ends, no shedding, and wider application range.

[0050] The application provides a preparation method of continuous filament nonwoven fabric, which has the characteristics of simple method, simple operation, low requirement for equipment, low cost and wide application prospect.

[0051] The specific embodiments of the application will be further described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0052] The accompanying drawings, which are part of this application, serve to further understand the application, the illustrative embodiments of the application and the description thereof serve to explain the application, but do not constitute undue limitation on the application. Obviously, the drawings described below are only some embodiments, and other drawings can be obtained by those skilled in the art without creative labor. In the drawings:

[0053] Figure 1 is a structural diagram of the accelerating slit in the coagulation bath device in the application;

[0054] Figure 2 is a process flow diagram of the dry-jet wet spinning method for preparing lyocell continuous filament nonwoven fabric in the application;

[0055] In the figure, 1 is an upper funnel, 2 is a lower funnel, 3 is a gasket, 4 is an accelerating slit, wherein H is the inlet of the accelerating slit, and D is the outlet of the accelerating slit.

[0056] It should be noted that these drawings and written descriptions are not intended to limit the scope of the concept of the application in any way, but to illustrate the concept of the application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0057] In order to make the purpose, technical scheme and advantages of the application more clear, the technical scheme of the application will be described clearly and completely below in combination with some embodiments, and those skilled in the art can understand that the following embodiments are only used to explain the technical principles of the application, and are not intended to limit the protection scope of the application. For example, although the application describes the steps of the method of the application in a specific order, these orders are not limiting, and those skilled in the art can perform the steps in different orders without deviating from the basic principles of the application.

[0058] In the application, the structure of the accelerating slit 4 in the coagulation bath device is as shown in Figure 1 The axial direction of the coagulation bath device is the draft direction of the filament bundle, and the coagulation bath device comprises an upper funnel 1 and a lower funnel 2 arranged in an upper-lower manner, the lower part of the upper funnel 1 extends into the inside of the lower funnel 2, thus forming the accelerating slit 4 between the outer side surface of the upper funnel 1 and the inner side surface of the lower funnel 2, and the width of the accelerating slit 4 gradually decreases from the inlet to the outlet.

[0059] The lower part of the coagulation bath device is provided with a gasket 3, the thickness of the gasket 3 can be adjusted; when the position of the upper funnel 1 is fixed, the adjustment of the width of the acceleration slit 4 can be completed by changing the thickness of the gasket 3, and then the spinning speed is affected.

[0060] In the application, the working principle of the coagulation bath device is as follows: part of the coagulation bath liquid flows out from the acceleration slit 4 between the upper funnel 1 and the lower funnel 2 quickly, drives the air in the intersection area of the upper funnel 1 and the lower funnel 2 to flow downward together, and thus a vacuum zone is formed in the intersection area, the coagulation bath liquid above the upper funnel 1 is gradually accelerated to flow downward under the action of the vacuum, and the rapid downward flow of the whole coagulation bath is realized, that is, the acceleration zone.

[0061] In the application, the spinning solution starts to solidify after entering the coagulation bath, and is stretched by the entrainment of the liquid accelerated downward by the coagulation bath, so as to improve the crystallinity and orientation degree of the fiber.

[0062] Example 1

[0063] One spinning position is used for spinning, after the lyocell spinning solution is extruded from the spinneret, the lyocell spinning solution is cooled by blowing, enters the coagulation bath device, and the relationship between the outlet width D of the acceleration slit and the spinning speed V satisfies:

[0064] V=15xD 2 -30xD+29.6 (Formula I);

[0065] The row number of the spinning hole is 15 rows, the hole diameter of the spinneret is 0.1 mm, the inlet width of the acceleration slit is 0.4 mm, the outlet width of the acceleration slit is 0.4 mm, the slit pressure is 0.1 MPa, the flow rate of the coagulation bath is 80 m / min, the spinning speed of the yarn is 20 m / min, and the yarn falls on the screen curtain of the laying machine to form a single-layer web after coming out of the coagulation bath. Five heads of the hydroentangling equipment are used to perform front and back hydroentanglement and washing processing on the web, and then the continuous filament nonwoven fabric is formed through drying and winding, and the gram weight of the sample is 38 g / m 2 .

[0066] Example 2

[0067] Two spinning positions are used for spinning, the distance between the spinning positions is 1500 mm, the row number of the spinning hole is 20 rows, the hole diameter of the spinneret is 0.09 mm, after the lyocell spinning solution is extruded from the spinneret, the lyocell spinning solution is cooled by blowing, enters the coagulation bath device, and the relationship between the outlet width D of the acceleration slit and the spinning speed V satisfies:

[0068] V=30xD 2 -83xD+72 (Formula II);

[0069] V=30xD2 - 83xD + 67 (Formula III);

[0070] The corresponding accelerating slit inlet width of the coagulation bath device of Formula II and Formula III is 1.1 mm and 2.5 mm respectively, the accelerating slit outlet width is 0.5 mm and 0.6 mm respectively, the slit pressure is 0.7 MPa and 0.4 MPa respectively, the flow rate of the coagulation bath is 120 m / min and 110 m / min respectively, the filament spinning speed is 38 m / min and 33 m / min respectively, and the lyocell filament bundle forms a double-layer web on the laying machine. The web is processed by front and back hydroentanglement using a hydroentanglement device with 6 heads, and then dried and wound to form a continuous filament nonwoven fabric, and the sample has a grammage of 38 g / m 2 .

[0071] Example 3

[0072] Spinning is performed using three spinning positions, the distance between adjacent spinning positions is 1200 mm, the number of rows of spinneret holes is 25 rows, and the spinneret hole diameters are 1.0 mm, 0.09 mm and 0.08 mm respectively. After the lyocell spinning solution is extruded from the spinneret, it is cooled by air blowing, enters the coagulation bath device, and the relationship between the outlet width D of the accelerating slit and the spinning speed V satisfies:

[0073] V = 25xD 2 - 40xD + 51.75 (Formula IV);

[0074] V = 25xD 2 - 40xD + 45.75 (Formula V);

[0075] V = 25xD 2 - 40xD + 41.75 (Formula VI);

[0076] The corresponding accelerating slit inlet width of the coagulation bath device of Formula IV, Formula V and Formula VI is 3.0 mm, the accelerating slit outlet width is 0.5 mm, the slit pressure is 1.5 MPa, 1.2 MPa and 1.4 MPa respectively, the flow rate of the coagulation bath is 160 m / min, 130 m / min and 110 m / min respectively, the filament spinning speed is 38 m / min, 32 m / min and 28 m / min respectively, and the lyocell filament bundle forms a three-layer web on the laying machine. The web is processed by front and back hydroentanglement using a hydroentanglement device with 7 heads, and then dried and wound to form a continuous filament nonwoven fabric, and the sample has a grammage of 38 g / m 2 .

[0077] Example 4

[0078] The spinning is performed using one spinning position, the jet row number is 25 rows, the jet plate hole diameter is 0.08 mm, after the lyocell spinning solution is extruded from the jet plate, it is cooled by blowing, enters the solidification bath device, and the relationship between the outlet width D of the acceleration slit and the spinning speed V satisfies:

[0079] V = 20 x D 2 - 30 x D + 53.8 (Formula VII) ;

[0080] The inlet width of the acceleration slit of the solidification bath device is 2.4 mm, the outlet width of the acceleration slit is changed to 0.4 mm, the slit pressure is 1.57 MPa, the flow rate of the solidification bath is 215 m / min, the spinning speed of the filament is 45 m / min, the lyocell filament bundle forms a single layer web on the lapper, the web is processed by the water jet equipment with 4 heads for front and back water jet processing, and then is dried and wound to form the continuous filament nonwoven fabric, the sample has a grammage of 37 g / m 2 .

[0081] Comparative Example 1

[0082] A cuprammonium filament nonwoven fabric is prepared by using the traditional wet spinning technology.

[0083] Cotton linters are dissolved in a cuprammonium solution to prepare a cuprammonium spinning solution, the spinning is performed by using the wet spinning mode, the spinning solution forms a filament bundle after coming out of the solidification bath, falls on the lapper to form a web, and then is post-processed to prepare a cuprammonium filament nonwoven fabric.

[0084] Experimental Example 1

[0085] The samples prepared in Example 1, Example 2, Example 3 and Comparative Example 1 are tested, and the test results are shown in Table 1:

[0086] Table 1

[0087]

[0088] As shown in Table 1, under the same grammage, the transverse strength and longitudinal strength of the continuous filament nonwoven fabric prepared by using the dry-jet wet spinning technology in the application in Example 1, Example 2 and Example 3 are obviously higher than those of the cuprammonium filament nonwoven fabric prepared by using the traditional wet spinning technology in Comparative Example 1, which is only because the fiber crystallinity and fiber strength of the continuous filament nonwoven fabric prepared by using the dry-jet wet spinning technology in the application are high, and thus the strength of the continuous filament nonwoven fabric is also high.

[0089] Experimental Example 2

[0090] The experimental example is based on Example 4, without changing the accelerating slit inlet width of the coagulation bath device, and changing the outlet width of the accelerating slit to obtain Comparative Example 2 to Comparative Example 9, and the same gram weight samples are tested, and the test results are shown in Table 2.

[0091] Table 2

[0092]

[0093] As can be seen from Table 2, according to the preparation method in the present application, when the ratio of the accelerating slit inlet width H and the accelerating slit outlet width D meets the limited range H / D of 1-8 in the present application, and the relationship between the outlet width D of the accelerating slit and the spinning speed V meets the requirements, such as Comparative Example 3 to Comparative Example 7 and Example 4, with the increase of the accelerating slit, the fiber spinning speed decreases, and the longitudinal and transverse strength of the continuous filament nonwoven fabric also decreases, which shows that the narrower the accelerating slit, the more obvious the accelerating effect of the coagulation bath on the fiber, the greater the drawing force of the coagulation bath on the fiber, the faster the fiber spinning speed, the higher the fiber crystallinity and orientation, and the higher the strength of the continuous filament nonwoven fabric.

[0094] However, when the ratio of the accelerating slit inlet width H and the accelerating slit outlet width D exceeds the limited range in the present application, such as Comparative Example 2 and Comparative Example 9, the transverse strength and longitudinal strength of the sample are obviously reduced, which shows that when the accelerating slit is too narrow, it is not conducive to the outflow of the spinning solution, which affects the spinning effect; when the accelerating slit is too large, the accelerating effect is not obvious, which also affects the spinning effect, and finally makes the performance of the continuous filament nonwoven fabric worse, especially when the relationship between the outlet width D of the accelerating slit and the spinning speed V does not meet the requirements in Comparative Example 2, the fiber performance is worse.

[0095] In Comparative Example 8, although the ratio of the accelerating slit inlet width H and the accelerating slit outlet width D meets the limited range H / D of 1-8 in the present application, because the relationship between the outlet width D of the accelerating slit and the spinning speed V does not meet the requirement of 4ac-b 2 >0, therefore, the fiber performance is poor.

[0096] Experimental Example 3

[0097] The same gram weight of continuous filament nonwoven fabric is prepared by using 1, 2, 3, 4, and 5 spinning positions, the jet aperture is 0.075 mm, the distance between adjacent spinning positions is 1500 mm, the jet hole row number is 25 rows, the accelerating slit inlet width of the coagulation bath device is adjusted to 0.8 mm, the accelerating slit outlet width is 0.7 mm, the slit pressure is 0.9 MPa, the flow rate of the coagulation bath is 135 m / min, the fiber spinning speed is 35 m / min, and the web is processed by water jet on both sides by using 6 heads of water jet equipment, and then dried and wound to form a nonwoven fabric, and the gram weight of the sample is 40 g / m2 .

[0098] In the present experimental example, the number of spinning positions is changed while other conditions are kept the same to prepare continuous filament nonwoven fabrics with the same grammage, and the experimental results are shown in Table 3.

[0099] Table 3

[0100]

[0101] As can be seen from the data in Table 3, with the increase of the number of spinning positions, the grammage unevenness of the continuous filament nonwoven fabric decreases.

[0102] For continuous filament nonwoven fabrics with the same grammage, the more the number of spinning positions, the more the number of layers of the continuous filament nonwoven fabric, and the better the overall uniformity, but the more the number of spinning positions, the more the equipment investment and energy consumption, and at the same time, the more the number of layers, the lower the single-layer grammage, and the higher the requirement for the cooperation of the suction net curtain and suction pressure, therefore, 2-4 spinning positions are preferred.

[0103] The above description is only the preferred embodiment of the present application, and does not limit the present application in any form, although the present application has been disclosed as above with the preferred embodiment, however, it is not intended to limit the present application, any person skilled in the art of the present patent can make some changes or modifications to the above-mentioned technical content with the prompt within the scope of the technical solution of the present application, but as long as it does not deviate from the content of the technical solution of the present application, any simple modification, equivalent change and modification of the above-mentioned embodiment according to the technical essence of the present application, all still belong to the scope of the present application.

Claims

1. A method for producing a continuous filament nonwoven fabric, characterized by, Comprise: (1) the spinning solution is extruded through the spinneret, passes through the air gap layer, enters the acceleration slit of the coagulation bath device, and is solidified and drawn by the accelerated fluid to obtain a cellulose filament bundle; (2) the cellulose filament bundle forms a web with mutual interlacing between the filaments on the laying device; (3) the web is prepared into a continuous filament nonwoven fabric through a post-treatment process; The relationship between the outlet width D of the acceleration slit and the spinning speed V satisfies: V = a x D 2 -b x D + c; wherein 15≤a≤50, 30≤b≤100, 20≤c≤200, 4ac-b 2 >0; The unit of outlet width D is mm, and the unit of spinning speed V is m / min; The ratio of the inlet width H of the acceleration slit to the outlet width D H / D is 1-8; The pressure at the outlet of the acceleration slit is 0.1-3 MPa; The ratio of the flow rate of the coagulation bath to the spinning speed is 1-10.

2. The method of claim 1, wherein The ratio of the inlet width H of the acceleration slit to the outlet width D H / D is 1-6.

3. The method of claim 1, wherein the continuous filament nonwoven fabric is prepared by the steps of: The pressure at the outlet of the acceleration slit is 0.5-2 MPa.

4. The method of claim 1, wherein the continuous filament nonwoven fabric is prepared by the steps of: The ratio of the flow rate of the coagulation bath to the spinning speed is 1-6.

5. The method of claim 1-4, wherein the method is characterized by, The spinning position of the continuous filament nonwoven fabric is at least 1.

6. The method of claim 5, wherein the continuous filament nonwoven fabric is prepared by the steps of: The spinning position is 2-4.

7. The method of claim 5, wherein the continuous filament nonwoven fabric is prepared by the steps of: The spacing between adjacent spinning positions is 500-3000 mm.

8. The method of claim 7, wherein the continuous filament nonwoven fabric is prepared by the steps of: The spacing between adjacent spinning positions is 1000-2000 mm.

9. The method of claim 1-4, wherein the method is characterized by, The nonwoven material of the continuous filament nonwoven cloth has a grammage of 5 g / m 2 60 g / m 2 .

10. The method of claim 9, wherein the continuous filament nonwoven fabric is prepared by the steps of: The nonwoven material of the continuous filament nonwoven cloth has a grammage of 20 g / m 2 40 g / m 2 .

11. The method of claim 1-4, wherein the method is characterized by, The post-treatment process of the web comprises at least one hydroentanglement process, and the hydroentanglement process adopts a double-sided forming processing mode of the front and back surfaces of the web.

12. The method of claim 11, wherein the continuous filament nonwoven fabric is prepared by a method comprising: The hydroentanglement process adopts a hydroentanglement and washing integrated process, and a low-pressure hydroentanglement and washing processing mode is adopted at the last hydroentanglement.

13. The method of claim 11, wherein the continuous filament nonwoven is prepared by a method comprising: The number of hydroentanglement heads in the hydroentanglement process is 3-7.

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