Melt-blown heat-shrinkable fiber paper and preparation method thereof

Abstract

The invention discloses melt-blown heat-shrinkable fiber paper and a preparation method thereof.According to the method, a superfine fiber heat-shrinkable material is prepared through a melt-blown technology, and the material is fine and smooth in fiber, has filtering and low-resistance performance which cannot be achieved by conventional fiber, and meanwhile has strength and toughness which cannot be achieved by common melt-blown fiber; the polypropylene melt-blown fiber is not easy to fluff like common polypropylene melt-blown fiber in use. The thermal shrinkage materials with different styles are prepared by researching different raw materials and production processes. The materials can be made into filtering, packaging and joining materials through different post-treatment processes. In the product application process, gluing and compounding of other materials are not needed, the environment-friendly performance in the preparation process and the repeated recycling performance are achieved, and the cyclic low-carbon development direction is met.

Description

Technical Field

[0001] The invention belongs to the technical field of high-performance fiber materials and manufacturing, and relates to a method for preparing melt-blown heat-shrinkable fiber paper. Background Art

[0002] At present, heat shrink technology is mainly used in products such as heat shrink film, heat shrink tube, heat shrink belt and heat shrink fiber leather base cloth. Among them, heat shrink film is mainly used in product packaging and other fields due to its good transparency and fit; heat shrink tube and heat shrink belt are mainly used for connection, insulation or product protection; leather base cloth products mainly use the texture and waterproof and breathable properties of ultra-fine high shrinkage fibers to make imitation leather products. Existing filter materials are mainly formed into filter products with certain filtration efficiency and low resistance through processes such as fiber dispersion, bonding enhancement and compounding. Some of them are compounded by fibers through needle punching, weaving, etc., with large fiber diameter and poor filtration performance; melt-blown cloth is also produced by melt-blown method for filtration. This method has better filtration performance, but it also has disadvantages such as low tensile strength and easy to fluff; ultra-fine filtration uses thin films or nano-scale fibers with fibril structure to make more efficient filtration products, but it needs to be compounded with strong supporting materials, which brings the problem of using adhesives in the compounding process, increases the resistance of the product, and is not conducive to recycling. Summary of the invention

[0003] The present invention provides a method for preparing melt-blown heat-shrinkable fiber paper. Specifically, based on the research on heat-shrinkable materials and improved melt-blowing technology, the method breaks the original multi-step preparation process of heat-shrinkable fiber products, directly adopts the melt-blowing method to produce ultrafine fibers into a web, and forms a fiber paper structure after heat treatment; the purpose is to make the fiber paper have the high efficiency, low resistance and high barrier properties of melt-blown fibers, and have higher strength, stronger toughness and less prone to pilling than ordinary melt-blown non-woven fabrics, and can be used to prepare filter materials, packaging materials, connecting materials, etc.

[0004] The purpose of the present invention can be achieved through the following technical solutions:

[0005] A melt-blown heat-shrinkable fiber paper having a unit area mass of 75 to 85 g / m 2 The particle filtration efficiency is 78-82%, the ventilation resistance is 28-32Pa, the longitudinal pulling force is 38-42N, and the transverse pulling force is 40-50N.

[0006] In the technical solution of the present invention: the base material of the fiber paper is polyethylene terephthalate (PET) resin.

[0007] In the technical solution of the present invention: the preparation method is to use a high-shrinkage melt-blown base material for melt-blowing to form a high-shrinkage ultra-fine melt-blown cloth net, which is then set by a heat setting machine to form a fiber paper product.

[0008] In the technical solution of the present invention: the high shrinkage melt-blown base material is polyethylene terephthalate (PET) resin.

[0009] In the technical solution of the present invention: the melt-blowing method is to dry the melt-blown base material and send it into a screw extruder through a slice conveying system, and extrude and melt it into a high-temperature melt; then the melt is metered by a metering pump and sent into a spinning system, and under the action of pressure, it is extruded from the spinneret hole, and the melt fine flow is stretched and thinned under the clamping of high-temperature stretching airflow on both sides of the spinneret hole to make it into ultrafine fibers; the obtained fibers are collected on a negative pressure mesh curtain or a negative pressure porous roller, and are bonded into cloth by self-heating and negative pressure.

[0010] In the technical solution of the present invention: the heat setting machine is a tension heat setting machine, an oven heat setting machine or a hot air setting machine; the setting temperature is 50 to 130° C., and the setting time is 3 to 150 seconds.

[0011] In the technical solution of the present invention: the melt flow index (MFI) of the high shrinkage meltblown base material is 150-800g / 10min, and the melting point ranges from 150 to 250°C; the drying temperature of the base material is 110 to 130°C, and the drying time is 4 to 8 hours.

[0012] In the technical solution of the present invention: the screw extruder is a single screw extruder, the screw aspect ratio is 22-30, the screw temperature is controlled at 200-290°C; the melt temperature is 290-320°C; the high-temperature air flow pressure is 0.07-0.12MPa, and the air flow temperature is 290-320°C.

[0013] In the technical solution of the present invention: the metering pump has a rotation speed of 5 to 12 revolutions per minute, and a spinning system pressure of 0.5 to 3.5 MPa; the spinneret hole diameter is 0.2 to 0.4 mm, and the aspect ratio is 5 to 15:1.

[0014] In the technical solution of the present invention: the melt fine flow stretching area is 5 to 20 cm from the spinneret hole; the negative pressure air volume is 1000 to 3500 m 3 / h; the adhesive cloth structure is a multi-layer disordered structure.

[0015] The mechanism of the present invention is as follows: the present invention utilizes the relatively slow crystallization speed of PET polyester material, spins the high-shrinkage PET base material by melt-blowing production method, and instantly stretches and thins the fibers under the drawing of high-temperature hot air flow to obtain a low-crystallization, high-oriented supramolecular structure, which is bonded into a non-woven fabric under rapid cooling; when the non-woven fabric is heated at a certain temperature, the original macromolecules are deoriented, causing high shrinkage, and the entanglement force between fibers is enhanced, thereby improving the density and strength of the product; different styles of products can be made under different external tension control during the shrinkage process.

[0016] In the technical solution of the present invention, unless otherwise specified, the pressure referred to is gauge pressure.

[0017] Beneficial effects of the present invention:

[0018] 1. The fiber diameter of the product produced by the present invention ranges from 0.5 to 6 microns, which is 3 to 10 times thinner than the fiber spun by conventional spinning methods. The fiber mesh structure has good air permeability and hydrophobicity; the product weight is 20 to 150 g / m 2 When using a flow rate of 32L / min for salt particle filtration, the filtration efficiency for particles ≥0.3μm is between 65% and 99%, and the product resistance in the range is 10 to 100Pa. Under the same filtration efficiency, the thinner the product, the lower the filtration resistance.

[0019] 2. The product weight of the present invention is 40-60g / m 2 The longitudinal breaking strength of the product is 40-60N, and the transverse breaking strength is 40-60N. The product strength is 3-4 times higher than that of ordinary melt-blown products, which solves the problem of low strength of melt-blown products. After shaping, the product has high width, good foldability, no linting, similar to paper, and better folding resistance than paper.

[0020] 3. The shrinkage temperature of the nonwoven fabric prepared by the present invention is 50-90°C, the transverse shrinkage rate (CD) of the product is 35-55%, and the longitudinal shrinkage rate (MD) is 40-55%. It has good bidirectional shrinkage ability and can be well attached to the surface of the product when used as a packaging shrink material. The product has a fine texture and a soft feel. After proper shaping and curing, the surface is smooth and can be written and printed, and has good ornamental properties.

[0021] 4. The product produced by the present invention does not require glue coating or compounding with other materials during production, and has environmental protection and recyclable performance during the preparation process, which is in line with the development direction of circular low-carbon. At the same time, the raw materials used can be domestically produced and can be mass-produced, the product cost is low, and it has a competitive advantage. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is an electron microscope picture of the fiber product of Example 1.

[0023] Figure 2 This is the effect diagram of the product of Example 1.

[0024] Figure 3 This is the filter element product after winding and shaping in Example 2. DETAILED DESCRIPTION

[0025] The present invention is further described below in conjunction with embodiments, but the protection scope of the present invention is not limited thereto:

[0026] Example 1

[0027] A preparation method of melt-blown heat-shrinkable fiber paper, the steps of which are: melt-blown base material polyethylene terephthalate (PET) is dried and sent to a screw extruder through a slice conveying system, extruded and melted into a high-temperature melt; then the melt is metered by a metering pump and sent to a spinning system, extruded from a spinneret under pressure, and the melt is stretched and thinned under the clamping of high-temperature drafting airflows on both sides of the spinneret to form ultrafine fibers; the obtained fibers are collected on a negative pressure mesh curtain or a negative pressure porous roller, and are bonded into cloth by self-heating and negative pressure. The cloth net is introduced into a five-roller heat setting machine for setting to form a fiber paper product.

[0028] The melt flow index (MFI) of the meltblown base material is 170 g / 10 min and the melting point is 195°C.

[0029] The base material drying temperature is 120°C and the drying time is 6 hours.

[0030] The screw aspect ratio is 30, and the screw temperature is controlled at 200-290°C.

[0031] The melt temperature is 290-310°C.

[0032] The metering pump speed is 6 rpm, and the spinning system pressure is 3.2 MPa.

[0033] The spinneret hole diameter is 0.32 mm and the aspect ratio is 10:1.

[0034] The high-temperature air flow pressure is 0.08MPa and the air flow temperature is 310℃.

[0035] The melt stream stretching area is 12 cm from the spinneret hole.

[0036] Negative pressure porous roller air volume is 3000m 3 / h.

[0037] Five-roller setting machine, tension setting temperature 85℃, setting time 15 seconds.

[0038] The product weight is 80.6g / m 2 After testing, the product resistance is 30Pa and the filtration efficiency is 80%.

[0039] It has high stiffness and tight fibers, with a longitudinal breaking strength of 40N and a transverse breaking strength of 45N.

[0040] The product has good foldability and shape retention performance, and can be made into pleated filter paper for use as filtering material.

[0041] Comparative Example 1

[0042] A method for preparing a melt-blown nonwoven fabric comprises the following steps: feeding a prepared PP base material into a screw extruder through a slice conveying system, and after extrusion and melting, feeding a polymer melt with a stable flow rate and pressure into a spinning system through a metering pump. Under the action of pressure, the melt is ejected from a spinneret with a diameter of 0.25 mm to form a filament. The melt fine flow is stretched and thinned under the tension of the drafting airflow on both sides of the spinneret to form ultrafine fibers. The fibers are collected on a suction porous roller and bonded into a fabric by self-heating and negative pressure.

[0043] The melt flow index (MFI) of the PP base material is 1500g / 10min, and the melting point is 165℃;

[0044] The screw temperature is controlled at 180-265°C.

[0045] The melt temperature is 265-270°C.

[0046] The metering pump speed is 10 rpm, and the spinning system pressure is 0.6 MPa.

[0047] The aspect ratio of the spinneret hole is 12:1.

[0048] The high-temperature air flow pressure is 0.07MPa and the air flow temperature is 275℃.

[0049] The melt stream stretching area is 19 cm from the spinneret hole.

[0050] Negative pressure porous roller air volume is 2700m 3 / h.

[0051] The product weight is 79.6g / m 2 After testing, the product resistance is 29Pa and the filtration efficiency is 82%.

[0052] The product is relatively soft, with a slightly raised surface, a longitudinal breaking strength of 14N, and a transverse breaking strength of 16N.

[0053] It is not foldable, cannot maintain its shape, and does not meet the conditions for product manufacture.

[0054] Comparative Example 2

[0055] A method for preparing a meltblown heat-shrinkable nonwoven fabric, wherein the preliminary steps are substantially the same as those of Example 1, except that the meltblown product is directly subjected to a performance test without undergoing heat setting.

[0056] The product weight is 79.8g / m 2 , after testing, the resistance is 28Pa and the filtration efficiency is 81%.

[0057] The product surface is slightly fuzzy, the longitudinal breaking strength is 18N, and the transverse breaking strength is 21N.

[0058] It has certain foldability, but poor shape retention after folding and does not meet the conditions for finished products.

[0059] Comparative Example 3

[0060] A method for preparing meltblown heat shrinkable fiber paper, wherein the preliminary steps are basically the same as those in Example 1. During heat setting, the tension setting temperature is 85° C. and the setting time is 15 seconds. The difference is that each roller is controlled by a single frequency conversion and the speed difference is 0.

[0061] The product weight is 79.8g / m 2 , after testing, the resistance is 35Pa and the filtration efficiency is 80%.

[0062] It has high stiffness and tight fibers, with a longitudinal breaking strength of 32N and a transverse breaking strength of 39N.

[0063] The product has good foldability and shape retention, but the breaking strength is average and it does not have any performance advantages.

[0064] Comparative Example 4

[0065] A method for preparing meltblown heat shrinkable fiber paper, wherein the preliminary steps are basically the same as those in Example 1. During heat setting, the tension setting temperature is 85°C and the setting time is 15 seconds. The difference is that each roller is controlled by a single frequency conversion and the speed difference is 3‰.

[0066] The product weight is 79.8g / m 2 , after testing, the resistance is 28Pa and the filtration efficiency is 76%.

[0067] It has high stiffness and tight fibers, with a longitudinal breaking strength of 30N and a transverse breaking strength of 39N.

[0068] The product has good foldability and shape retention, but the breaking strength is average and it does not have any performance advantages.

[0069] Comparative Example 5

[0070] A method for preparing meltblown fiber paper, wherein the preliminary steps are substantially the same as those of comparative example 1, except that the product of comparative example 1 is subsequently subjected to heat setting treatment.

[0071] The tensile setting temperature is 85°C and the setting time is 15 seconds.

[0072] Each roller is controlled by single frequency conversion, and the speed difference is 0.

[0073] The product weight is 79.6g / m 2 After testing, the product resistance is 25Pa and the filtration efficiency is 82%.

[0074] The product is relatively soft, with a fluffy surface, a longitudinal breaking strength of 14N, and a transverse breaking strength of 15N.

[0075] It is not foldable, cannot maintain its shape, and does not meet the conditions for product manufacture.

[0076] Comparative Example 6

[0077] A method for preparing melt-blown heat-shrinkable fiber paper, wherein the melt-blown base material is the same as that in Example 1 and is dried, and the metering pump has a rotation speed of 6 rpm. The difference is that the production conditions are the production process parameters and equipment of conventional PP melt-blown in Comparative Example 1.

[0078] The screw temperature is controlled at 180-265°C, the melt temperature is 265-270°C, the spinneret aspect ratio is 12:1, the high-temperature airflow pressure is 0.07MPa, and the airflow temperature is 275°C. The melt flow stretching area is 19cm from the spinneret hole. The negative pressure porous roller air volume is 2700m 3 / h.

[0079] The production status is: the spinneret can spray out filament bundles, the die head detection pressure is 5.9MPa, which exceeds the normal operating pressure of <3.5MPa, and does not meet the production conditions of meltblown equipment.

[0080] The ejected filaments are in a cotton-like state and cannot be bonded together, so they do not meet the molding conditions.

[0081] The cotton tow was tested and its diameter was >10 μm, indicating that the fiber diameter was relatively large.

[0082] Comparative Example 7

[0083] A method for preparing meltblown heat-shrinkable fiber paper, wherein the meltblown base material is the same as that in comparative example 1, except that the production conditions are the production process parameters and equipment of the high-shrinkage meltblown base material in embodiment 1.

[0084] The screw temperature is controlled at 200-290℃. The melt temperature is 290-310℃. The metering pump speed is 6 rpm. The spinneret hole diameter is 0.32mm, and the spinneret hole aspect ratio is 10:1. The high-temperature air flow pressure is 0.08MPa, and the air flow temperature is 310℃. The melt flow stretching area is 12cm from the spinneret hole. The negative pressure porous roller air volume is 3000m 3 / h.

[0085] The production situation is: when the melt is ejected from the spinneret, fine broken fibers are produced, which cannot become a tow. Under the action of hot air, flying fibers are formed around the equipment, and production cannot be carried out.

[0086] Table 1 Comparison of main indicators of different implementation methods

[0087]

[0088]

[0089] By comparing Comparative Example 1 with Comparative Example 2, it can be seen that the filtration efficiency of Comparative Example 2 is slightly lower than that of Comparative Example 1, and the difference in ventilation resistance is not large, but the tension and elongation indicators have very obvious advantages, which can solve the problem of low strength of ordinary melt-blown products.

[0090] Further comparison of Example 1 with Comparative Example 2 shows that the tensile force of the product is significantly improved after the shaping treatment, and the feel and surface state of the product also change significantly, indicating that the shaping treatment plays an important role in improving material properties.

[0091] Comparing Comparative Examples 3 and 4 with Example 1, it can be seen that controlling the speed difference of each shaping roller has a significant impact on the shaping effect, and a certain negative speed difference has a positive contribution to the self-improvement and strength improvement of the product during the heating process. When the speed difference is positive, it has a certain stretching effect on the fabric surface, which is not conducive to the contraction and improvement of the fiber, and at the same time it will affect the filtration efficiency. Different process parameters have a great influence on the performance difference of the manufactured products, which determines the function of the product.

[0092] Comparing Comparative Example 5 with Comparative Example 1, it can be seen that conventional PP melt-blown does not have the fiber self-shrinkage and strengthening process under heat setting conditions, and the filtration efficiency decreases to a certain extent after treatment, which shows that the performance of conventional melt-blown materials is essentially different from that of the materials of this method.

[0093] By comparing Comparative Example 6 with Example 1, it can be seen that when using the same new melt-blown raw material and conventional melt-blown production process parameters and equipment, the equipment working pressure exceeds the use range, the prepared product has a large fineness and cannot be bonded, and does not meet the molding and production conditions.

[0094] By comparing Comparative Example 7 with Example 1, it can be seen that when using the same conventional meltblown raw materials, if a new product production process is adopted, the fiberization and receiving cloth of the product cannot be achieved, and the production conditions are quite different.

[0095] Example 2

[0096] A preparation method of melt-blown heat-shrinkable fiber paper, the steps of which are: melt-blown base material polyethylene terephthalate (PET) is dried and sent to a screw extruder through a slice conveying system, extruded and melted into a high-temperature melt; then the melt is metered by a metering pump and sent to a spinning system, extruded from a spinneret under pressure, and the melt is stretched and thinned under the high-temperature drafting airflow on both sides of the spinneret to form ultrafine fibers; the obtained fibers are collected on a negative pressure mesh curtain or a negative pressure porous roller, and bonded into cloth by self-heating and negative pressure. The cloth is wound according to demand to form a wound filter element, and after being heat-set in an oven, a filter element paper product is made.

[0097] The melt flow index (MFI) of the meltblown base material is 170 g / 10 min and the melting point is 195°C.

[0098] The base material drying temperature is 120°C and the drying time is 6 hours.

[0099] The screw aspect ratio is 30, and the screw temperature is controlled at 200-290°C.

[0100] The melt temperature is 300-310°C.

[0101] The metering pump speed was 6 rpm, and the spinning system pressure was 3.1 MPa.

[0102] The spinneret hole diameter is 0.32 mm and the aspect ratio is 10:1.

[0103] The high-temperature air flow pressure is 0.08MPa and the air flow temperature is 310℃.

[0104] The melt stream stretching area is 12 cm from the spinneret hole.

[0105] Negative pressure porous roller air volume is 3000m 3 / h.

[0106] The number of winding layers is 10 and the winding diameter is 4cm.

[0107] Oven heat setting, setting temperature 85℃, setting time 15 seconds.

[0108] The product weight is 210g / m 2 After testing, the product resistance is 110Pa and the filtration efficiency is 95%.

[0109] It has high stiffness and tight fit, with a longitudinal breaking strength of 170N and a transverse breaking strength of 163N.

[0110] The product has good shape retention and can work well with filter element accessories.

[0111] Example 3

[0112] A method for preparing a meltblown heat shrinkable cloth, wherein the cloth-making process is the same as that of Example 2. After the cloth is made, the cloth is cut into rolls according to demand, and after the product covers the product to be packaged, it is cut and heat-set and shrunk to form a packaged product.

[0113] The melt flow index (MFI) of the meltblown base material is 235 g / 10 min and the melting point is 205°C.

[0114] The base material drying temperature is 120°C and the drying time is 6 hours.

[0115] The screw aspect ratio is 30, and the screw temperature is controlled at 200-290°C.

[0116] The melt temperature is 305-310°C.

[0117] The metering pump speed is 6 rpm, and the spinning system pressure is 2.8 MPa.

[0118] The spinneret hole diameter is 0.32 mm and the aspect ratio is 10:1.

[0119] The high-temperature air flow pressure is 0.08MPa and the air flow temperature is 315℃.

[0120] The melt stream stretching area is 12 cm from the spinneret hole.

[0121] Negative pressure porous roller air volume is 3000m 3 / h.

[0122] The test roll had a transverse shrinkage (CD) of 41% and a longitudinal shrinkage (MD) of 46%.

[0123] Heat setting in oven, setting temperature 85℃, setting time 10 seconds.

[0124] The product weight is 30g / m 2 After testing, the longitudinal breaking strength is 21N and the transverse breaking strength is 23N.

[0125] It has high shrinkage, fits tightly to the product, has good packaging texture, and is waterproof and breathable.

[0126] Example 4

[0127] A method for preparing a meltblown heat shrinkable cloth, wherein the cloth-making process is the same as that of Example 2. After the cloth is made, the cloth is cut into rolls according to demand, and the product is wrapped around an object to be connected and then shaped and shrunk, thereby wrapping the object and completing the connection.

[0128] The melt flow index (MFI) of the meltblown base material is 165 g / 10 min and the melting point is 205°C.

[0129] The base material drying temperature is 120°C and the drying time is 6 hours.

[0130] The screw aspect ratio is 30, and the screw temperature is controlled at 200-290°C.

[0131] The melt temperature is 300-310°C.

[0132] The metering pump speed is 6 rpm, and the spinning system pressure is 3.2 MPa.

[0133] The spinneret hole diameter is 0.32 mm and the aspect ratio is 10:1.

[0134] The high-temperature air flow pressure is 0.08MPa and the air flow temperature is 315℃.

[0135] The melt stream stretching area is 11 cm from the spinneret hole.

[0136] Negative pressure porous roller air volume is 3000m 3 / h.

[0137] The test roll has a transverse shrinkage (CD) of 37% and a longitudinal shrinkage (MD) of 42%.

[0138] The number of winding layers is 60.

[0139] Hot air heat setting, setting temperature 87℃, setting time 20 seconds.

[0140] The product weight is 1270g / m 2 , thickness 10mm, high fit and tight connection.

Claims

1. A melt-blown heat-shrinkable fiber paper, characterized in that: The fiber paper has a unit area mass of 75 to 85 g / m 2 The particle filtration efficiency is 78-82%, the ventilation resistance is 28-32Pa, the longitudinal pulling force is 38-42N, and the transverse pulling force is 40-50N.

2. The melt-blown heat-shrinkable fiber paper according to claim 1, characterized in that: The base material of the fiber paper is polyethylene terephthalate (PET) resin.

3. A method for preparing the melt-blown heat-shrinkable fiber paper according to claim 1, characterized in that: The preparation method comprises the following steps: using a high-shrinkage melt-blown base material for melt-blowing to form a high-shrinkage ultra-fine melt-blown cloth net, and then shaping the net through a heat-setting machine to produce a fiber paper product.

4. The method for preparing meltblown heat shrinkable fiber paper according to claim 3, characterized in that: The high shrinkage melt-blown base material is polyethylene terephthalate (PET) resin.

5. The method for preparing melt-blown heat-shrinkable fiber paper according to claim 3, characterized in that: The melt-blowing method comprises the following steps: drying the melt-blown base material and sending it to a screw extruder through a slice conveying system, where it is extruded and melted to form a high-temperature melt; then the melt is metered by a metering pump and sent to a spinning system, where it is extruded from a spinneret under pressure, and the melt stream is stretched and thinned by high-temperature stretching airflows on both sides of the spinneret to form ultrafine fibers; the obtained fibers are collected on a negative pressure mesh curtain or a negative pressure porous roller, and are bonded into a cloth by self-heating and negative pressure.

6. The method for preparing meltblown heat shrinkable fiber paper according to claim 3, characterized in that: The heat setting machine is a tension heat setting machine, an oven heat setting machine or a hot air setting machine; the setting temperature is 50 to 130° C., and the setting time is 3 to 150 seconds.

7. According to claim 5, it is characterized in that: The high shrinkage melt-blown base material has a melt flow index (MFI) of 150 to 800 g / 10 min and a melting point range of 150 to 250° C. The base material drying temperature is 110 to 130° C. and the drying time is 4 to 8 hours.

8. The method according to claim 5, characterized in that: The screw extruder is a single screw extruder, the screw aspect ratio is 22-30, the screw temperature is controlled at 200-290°C; the melt temperature is 290-320°C; the high temperature air flow pressure is 0.07-0.12MPa, and the air flow temperature is 290-320°C.

9. The method according to claim 5, characterized in that: The metering pump has a rotation speed of 5 to 12 revolutions per minute, and a spinning system pressure of 0.5 to 3.5 MPa; the spinneret hole diameter is 0.2 to 0.4 mm, and the aspect ratio is 5 to 15:

1.

10. The method according to claim 5, characterized in that: The melt fine flow stretching area is 5 to 20 cm from the spinneret hole; the negative pressure air volume is 1000 to 3500 m 3 / h; the adhesive cloth structure is a multi-layer disordered structure.

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