A multi-layer composite nonwoven material and methods and systems for making the same

Abstract

The present application belongs to the technical field of non-woven composite materials, and particularly relates to a multi-layer composite non-woven material and a preparation method and system thereof. The first web layer and the second web layer of the composite material are prepared by melt-blowing or spun-bonding, serving as the outermost two surface layers of the composite material; meanwhile, the short fibers with cardability are carded into a carded web by a carding method, and the carded web obtained by carding the short fibers is mixed with the filaments obtained by melt-blowing to form a mixed web, and the carded web and / or the mixed web are used as the intermediate water-absorbing layer web of the composite material, and after heat rolling, pre-water jetting, water jetting and drying, the composite non-woven material is obtained. The multi-layer composite non-woven material prepared by the method has high strength, good water-absorbing performance, less fabric surface fluff, high surface compactness and clear pattern appearance.

Description

Technical Field

[0001] This invention belongs to the field of nonwoven composite materials technology, specifically relating to a multilayer composite nonwoven material and its preparation method and system. Background Technology

[0002] The demand for disposable hygiene products in my country has increased significantly, leading to the booming development of the nonwoven industry. Fibers produced through the spunbond process have finer fibers and stronger wiping and cleaning abilities compared to cellulose fibers, but their water absorption is relatively poor. Currently, nonwoven materials with good water absorption are generally prepared using carding and hydroentangling reinforcement methods. In the reinforcement process, the entanglement of the carded fibers mainly plays a reinforcing role.

[0003] However, conventional carding and hydroentangling reinforcement methods currently require relatively long fibers; otherwise, they cannot achieve good carding and reinforcement effects. The shorter the fiber, the worse the entanglement effect during reinforcement, resulting in poorer reinforcement and reduced product strength. This is especially true when using recycled fibers or waste cotton fibers with shorter fiber lengths as raw materials for nonwoven materials, which can lead to lower nonwoven material strength and more fuzz on the fabric surface. Summary of the Invention

[0004] The purpose of this invention is to provide a multilayer composite nonwoven material and its preparation method and system. The multilayer composite nonwoven material prepared by the method provided by this invention has high strength and low surface fuzz.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] This invention provides a method for preparing a multilayer composite nonwoven material, comprising the following steps:

[0007] The first raw material is subjected to a first meltblown or first spunbond process to obtain a first fiber web layer, wherein the first raw material includes a first thermoplastic polymer;

[0008] An intermediate fiber web layer is prepared on the surface of the first fiber web layer, the intermediate fiber web layer comprising a plurality of stacked mixed fiber webs and / or a plurality of carded fiber webs; the preparation method of the mixed fiber web includes the following steps: firstly carding a first absorbent short fiber into a web to obtain a first carded fiber web; secondly meltblowing a second raw material, and mixing the obtained meltblown filaments onto the first carded fiber web to obtain a mixed fiber web; the second raw material comprises a second thermoplastic polymer; the preparation method of the carded fiber web includes the following steps: secondly carding a second absorbent short fiber into a web;

[0009] On the surface of the intermediate fiber web layer, a third raw material is subjected to a third melt-blowing or a second spunbonding process to form a second fiber web layer, thereby obtaining a multilayer fiber web; the third raw material includes a third thermoplastic polymer;

[0010] The multi-layer fiber web is hot-rolled using hot rolling rollers to obtain a hot-rolled fiber web. The first fiber web layer of the multi-layer fiber web forms the lower surface of the hot-rolled fiber web, and the second fiber web layer of the multi-layer fiber web forms the upper surface of the hot-rolled fiber web. The hot rolling is performed using hot rolling rollers, and the roller surface of the hot rolling rollers is provided with a pattern.

[0011] The hot-rolled fiber web is pre-hydroentangled and then hydroentangled to obtain a hydroentangled fiber web; the hydroentangling includes sequentially performing a first drum-type reverse entangling, a drum-type forward entangling, a second drum-type reverse entangling, and a flat-web-type forward entangling; the first drum-type reverse entangling is performed on the lower surface of the hot-rolled fiber web on the rotating circumference of the drum, the drum-type forward entangling is performed on the upper surface of the hot-rolled fiber web on the rotating circumference of the drum, the second drum-type reverse entangling is performed on the lower surface of the hot-rolled fiber web on the rotating circumference of the drum, and the flat-web-type forward entangling is performed on the upper surface of the hot-rolled fiber web on a suction screen, while a vacuum is drawn on the lower surface of the hot-rolled fiber web;

[0012] The hydroentangled fiber web is dried to obtain the multilayer composite nonwoven material.

[0013] Preferably, the diameters of the meltblown filaments obtained from the first meltblown, second meltblown, and third meltblown processes, as well as the spunbond filaments obtained from the first and second spunbond processes, are independently 2–20 μm; the basis weights of the first and second web layers are independently 1–25 gsm; and the total mass of the first and second web layers accounts for 5–60% of the mass of the multilayer composite nonwoven material, more preferably 10–60%.

[0014] The weight of the intermediate fiber web layer is 10-80 gsm; the mass of the intermediate fiber web layer accounts for 40-95% of the mass of the multilayer composite nonwoven material, more preferably 40-90%.

[0015] Preferably, the first, second, and third thermoplastic polymers independently comprise one or more of polypropylene, polyethylene, polyester, nylon, polyurethane, polylactic acid, and thermoplastic biodegradable plastics. The thermoplastic biodegradable plastic preferably comprises polybutylene terephthalate (PET) and / or polybutylene succinate (PSS); the first, second, and third thermoplastic polymers are independently monocomponent or multicomponent fibers.

[0016] Preferably, the first raw material further includes a first functional masterbatch, wherein the mass ratio of the first thermoplastic polymer to the first functional masterbatch is (80-100):(0-20), and the first functional masterbatch is not 0;

[0017] The second raw material also includes a second functional masterbatch, wherein the mass ratio of the second thermoplastic polymer to the second functional masterbatch is (80-100):(0-20), and the second functional masterbatch is not 0;

[0018] The third raw material also includes a third functional masterbatch, wherein the mass ratio of the third thermoplastic polymer to the third functional masterbatch is (80-100):(0-20), and the third functional masterbatch is not 0;

[0019] The first functional masterbatch, the second functional masterbatch, and the third functional masterbatch independently include one or more of elastomer masterbatch, hydrophilic masterbatch, soft masterbatch, and biodegradable masterbatch.

[0020] Preferably, the first and second absorbent staple fibers independently comprise one or more of cotton fibers, cashmere fibers, linen fibers, viscose fibers, and lyocell fibers;

[0021] The first and second absorbent short fibers are independently monocomponent short fibers or bicomponent short fibers, wherein the bicomponent short fibers include one or more of the following: core-sheath type, parallel type, trifoliate type, and orange segment type.

[0022] The lengths of the first and second absorbent short fibers are greater than 10 mm.

[0023] Preferably, the hot rolling roll includes an upper heating roll and a lower heating roll, the hot rolling temperature is 80-120°C, and the inter-roll pressure of the upper heating roll and the lower heating roll is 25-100 bar;

[0024] The patterns include dot patterns, line patterns, or combinations of patterns.

[0025] Preferably, the water pressure of the pre-hydroentangled head is 0.5 to 60 Bar; the water pressure of the first drum-type reverse entanglement, the drum-type forward entanglement, the second drum-type reverse entanglement, and the flat net-type forward entanglement heads is independently 20 to 120 Bar.

[0026] The drying process is called baking, and the baking temperature is 90-130℃.

[0027] The present invention provides a composite multilayer nonwoven material prepared by the preparation method described in the above technical solution, comprising a first layer structure, an intermediate layer structure and a second layer structure stacked sequentially; the first layer structure is formed by a first meltblown fiber web or a second spunbond fiber web; the intermediate layer structure is formed by a plurality of mixed-blown fiber webs and / or a plurality of carded fiber webs; and the second layer structure is formed by a second meltblown fiber web or a second spunbond fiber web.

[0028] The present invention provides a preparation system for the preparation method described in the above technical solution, including a web forming curtain, a web forming system disposed above the web forming curtain, the web forming system including a first polymer meltblown molding system and / or a polymer spunbond molding system, and further including a plurality of mixed-blown systems and / or a plurality of second carding systems; the mixed-blown system includes at least one second polymer meltblown molding system, one first carding system and one molding box;

[0029] A hot rolling device is located downstream of the forming curtain, a first drum is located downstream of the hot rolling device, the first drum rotates counterclockwise, a pre-wetted water-piercing head is located below the first drum, and a first water-piercing head is located on the right side of the first drum.

[0030] A second drum is positioned above the first drum; the second drum rotates clockwise, and a second water jetting head is positioned to the left and / or above the second drum;

[0031] A third drum is located downstream of the first drum; the third drum rotates counterclockwise, and a third water jet is located to the left and / or below the third drum;

[0032] A suction screen is located downstream of the third drum; a fourth water jet is located above the suction screen; and a suction device is located below the suction screen.

[0033] A drying device is located downstream of the suction screen, and a winding device is located downstream of the drying device.

[0034] Preferably, the spinnerets of the first polymer meltblown forming system and the second polymer meltblown forming system include a first spinneret, a second spinneret, or a third spinneret.

[0035] The first spinneret is provided with a single row of first spinneret holes. The first spinneret holes are inverted conical holes. The outer conical surface of the first spinneret holes is fitted with a first airflow stretching hole. The first airflow stretching hole is an inverted conical hole and coaxial with the first spinneret holes. The long fiber ejected from the first spinneret holes and the stretching gas ejected from the first airflow stretching hole converge at the top of the cone. The angle between the stretching gas and the long fiber is 30 to 70°.

[0036] The second spinneret is provided with a single row or multiple rows of second spinnerets. The second spinnerets are cylindrical holes. A second airflow stretching hole is sleeved on the outer circumferential surface of the second spinnerets. The second airflow stretching hole is an annular hole and coaxial with the second spinnerets.

[0037] The third spinneret is provided with a single row or multiple rows of third airflow stretching holes. The third airflow stretching holes are cylindrical holes. The outer circumferential surface of the third airflow stretching holes is fitted with third spinnerets. The third spinnerets are annular holes and coaxial with the third airflow stretching holes.

[0038] This invention provides a method for preparing a multilayer composite nonwoven material. The method involves preparing a first and second fiber web layer of the composite material via meltblowing or spunbonding, serving as the outermost two surface layers. Simultaneously, short fibers with combable properties are combed into a web to obtain a combed fiber web. This combed fiber web is then mixed with meltblown filaments to form a hybrid fiber web. The combed fiber web can be used alone as the intermediate fiber web of the composite material, serving as the intermediate absorbent layer, or the combed fiber web combined with the hybrid fiber web can be used together as the intermediate fiber web of the composite material, serving as the absorbent layer. This results in a multilayer fiber web with a "sandwich" structure. Subsequently, the present invention obtains a composite nonwoven material after hot rolling, pre-hydroentangling, hydroentangling, and drying. In the process of hot rolling to composite the three-layer fiber web, the present invention simultaneously applies patterns by hot rolling roller embossing, using hot rolling rollers to impart patterns to the product. Since the filaments obtained from the thermoplastic polymer melt during hot rolling, the clarity of the pattern effect imparted during the hot rolling composite molding process is better. Then, the hydroentangling method is used to make the filaments and water-absorbing short fibers in the product more tightly wrapped and mixed. The resulting multi-layer composite nonwoven material has high strength, good water absorption, and low surface fuzz and high surface density.

[0039] Meanwhile, the preparation method provided by this invention completes the process from raw materials to finished fabric in one step, which can reduce a large number of intermediate steps, save a lot of electricity, manpower and equipment, and significantly reduce processing costs. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the device structure used in Embodiment 1 of the present invention;

[0041] Figure 2 This is a schematic diagram of the structure of the multilayer composite nonwoven material prepared in Example 1 of the present invention;

[0042] Figure 3 This is a schematic diagram of the device structure used in Embodiment 2 of the present invention;

[0043] Figure 4 This is a schematic diagram of the structure of the multilayer composite nonwoven material prepared in Example 2 of the present invention;

[0044] Figure 5 This is a schematic diagram of the device structure used in Embodiment 3 of the present invention;

[0045] Figure 6 This is a schematic diagram of the structure of the multilayer composite nonwoven material prepared in Example 3 of the present invention;

[0046] Figure 7 This is a schematic diagram of the device structure used in Embodiment 4 of the present invention;

[0047] Figure 8 This is a schematic diagram of the structure of the multilayer composite nonwoven material prepared in Example 4 of the present invention;

[0048] Figure 9 This is a schematic diagram of the device structure used in Embodiment 5 of the present invention;

[0049] Figure 10 This is a schematic diagram of the structure of the multilayer composite nonwoven material prepared in Example 5 of the present invention;

[0050] Figure 11 This is a schematic diagram of the device structure used in Embodiment 6 of the present invention;

[0051] Figure 12 This is a schematic diagram of the structure of the multilayer composite nonwoven material prepared in Example 6 of the present invention;

[0052] Figure 13 This is a schematic diagram of the device structure used in Embodiment 7 of the present invention;

[0053] Figure 14 This is a schematic diagram of the structure of the multilayer composite nonwoven material prepared in Example 7 of the present invention;

[0054] Figure 15 This is a schematic diagram of the device structure used in Embodiment 8 of the present invention;

[0055] Figure 16 This is a schematic diagram of the structure of the multilayer composite nonwoven material prepared in Example 8 of the present invention;

[0056] Figure 17 This is a schematic diagram of the device structure used in Embodiment 9 of the present invention;

[0057] Figure 18 This is a schematic diagram of the structure of the multilayer composite nonwoven material prepared in Example 9 of the present invention;

[0058] Figure 19 This is a pattern rendering of the multilayer composite nonwoven material prepared in Example 1 of the present invention;

[0059] Figure 20 This is a pattern effect diagram of the multilayer composite nonwoven material prepared in Comparative Example 1 of the present invention;

[0060] Figure 21 This is a pattern rendering of the commercially available nonwoven material used in this invention;

[0061] In the diagram: 1 is the first structural layer, 2 is the intermediate structural layer, 3 is the second structural layer, 4 is the first polymer meltblown molding system, 5 is the second polymer meltblown molding system, 6 is the first carding system, 7 is the first conveyor screen, 8 is the forming screen, 9 is the hot rolling system, 10 is the pre-wetted water-jet head, 11 is the first water-jet head, 12 is the first drum, 13 is the second water-jet head, 14 is the second drum, 15 is the third water-jet head, 16 is the third drum, 17 is the fourth water-jet head, 18 is the suction screen, 19 is the drying device, 20 is the winding device, 21 is the third polymer meltblown molding system, 22 is the fourth polymer meltblown molding system, 23 is the second carding system, 24 is the first polymer spunbond molding system, 25 is the second polymer spunbond molding system, 26 is the first forming box, 27 is the second forming box, and 28 is the second conveyor screen. Detailed Implementation

[0062] This invention provides a method for preparing a multilayer composite nonwoven material, comprising the following steps:

[0063] The first raw material is subjected to a first meltblown or first spunbond process to obtain a first fiber web layer, wherein the first raw material includes a first thermoplastic polymer;

[0064] An intermediate fiber web layer is prepared on the surface of the first fiber web layer, the intermediate fiber web layer comprising a plurality of stacked mixed fiber webs and / or a plurality of carded fiber webs; the preparation method of the mixed fiber web includes the following steps: firstly carding a first absorbent short fiber into a web to obtain a first carded fiber web; secondly meltblowing a second raw material, and mixing the obtained meltblown filaments onto the first carded fiber web to obtain a mixed fiber web; the second raw material comprises a second thermoplastic polymer; the preparation method of the carded fiber web includes the following steps: secondly carding a second absorbent short fiber into a web;

[0065] On the surface of the intermediate fiber web layer, a third raw material is subjected to a third melt-blowing or a second spunbonding process to form a second fiber web layer, thereby obtaining a multilayer fiber web; the third raw material includes a third thermoplastic polymer;

[0066] The multi-layer fiber web is hot-rolled using hot rolling rollers to obtain a hot-rolled fiber web. The first fiber web layer of the multi-layer fiber web forms the lower surface of the hot-rolled fiber web, and the second fiber web layer of the multi-layer fiber web forms the upper surface of the hot-rolled fiber web. The hot rolling is performed using hot rolling rollers, and the roller surface of the hot rolling rollers is provided with a pattern.

[0067] The hot-rolled fiber web is pre-hydroentangled and then hydroentangled to obtain a hydroentangled fiber web; the hydroentangling includes sequentially performing a first drum-type reverse entangling, a drum-type forward entangling, a second drum-type reverse entangling, and a flat-web-type forward entangling; the first drum-type reverse entangling is performed on the lower surface of the hot-rolled fiber web on the rotating circumference of the drum, the drum-type forward entangling is performed on the upper surface of the hot-rolled fiber web on the rotating circumference of the drum, the second drum-type reverse entangling is performed on the lower surface of the hot-rolled fiber web on the rotating circumference of the drum, and the flat-web-type forward entangling is performed on the upper surface of the hot-rolled fiber web on a suction screen, while a vacuum is drawn on the lower surface of the hot-rolled fiber web;

[0068] The hydroentangled fiber web is dried to obtain the multilayer composite nonwoven material.

[0069] In this invention, unless otherwise specified, all raw materials / components used in the preparation are commercially available products well known to those skilled in the art.

[0070] This invention involves subjecting a first raw material to a first meltblown or first spunbond process to obtain a first fiber web layer. The first raw material comprises a first thermoplastic polymer. In this invention, the first thermoplastic polymer preferably comprises one or more of polypropylene, polyethylene, polyester, nylon, polyurethane, polylactic acid, and thermoplastic biodegradable plastics. The thermoplastic biodegradable plastic preferably comprises polybutylene terephthalate (PBAT) and / or polybutylene succinate (PBS). The first thermoplastic polymer is preferably a single-component fiber or a multi-component fiber, more preferably a single-component fiber, a two-component fiber, or a multi-component fiber. The first raw material preferably also includes a first functional masterbatch. The first functional masterbatch preferably comprises one or more of elastomer masterbatch, hydrophilic masterbatch, flexible masterbatch, and biodegradable masterbatch, more preferably one, two, or three of elastomer masterbatch, hydrophilic masterbatch, flexible masterbatch, and biodegradable masterbatch. When the first functional masterbatch preferably includes any two of elastomer masterbatch, hydrophilic masterbatch, soft masterbatch, and biodegradable masterbatch, the mass ratio of any two first functional masterbatches is preferably (5-6):(1-5), specifically preferably 6:1 or 5:5. In this invention, when the first raw material preferably also includes the first functional masterbatch, the mass ratio of the first thermoplastic polymer to the first functional masterbatch is preferably (80-100):(0-20), and the first functional masterbatch is not 0, more preferably (85-95):(5-15), specifically preferably 95:5, 93:7, 90:10, or 92:8. This invention does not have special requirements for the specific implementation process of the first meltblown or first spunbond. The diameter of the meltblown filament obtained by the first meltblown is preferably 2-20 μm, more preferably 5-15 μm. The diameter of the spunbond filament obtained by the first spunbond is preferably 2-20 μm, more preferably 5-15 μm. The basis weight of the first fiber web layer is preferably 1-25 gsm, more preferably 2-20 gsm, and specifically preferably 17.5 gsm, 2 gsm, 2.5 gsm, or 10 gsm. The percentage of the mass of the first fiber web layer to the mass of the multilayer composite nonwoven material is preferably 2.5-30%, and specifically preferably 25%, 3.335%, 4.4%, 13.9%, 13.15%, 16.65%, 14.3%, 11.1%, or 12.5%.

[0071] After obtaining the first fiber web layer, the present invention prepares an intermediate fiber web layer on the surface of the first fiber web layer. The intermediate fiber web layer includes a plurality of stacked mixed fiber webs and / or a plurality of carded fiber webs. The preparation method of the mixed fiber web includes the following steps: performing a second meltblown process on a second raw material, the second raw material including a second thermoplastic polymer; performing a first carding process on a first water-absorbing short fiber to obtain a first carded fiber web; mixing the meltblown filaments obtained from the second meltblown process onto the first carded fiber web to obtain a mixed fiber web; the preparation method of the carded fiber web includes the following steps: performing a second carding process on a second water-absorbing short fiber.

[0072] In this invention, the number of layers in the hybrid fiber web is preferably one or two. The preparation method of the hybrid fiber web includes the following steps: secondly melt-blowing a second raw material, the second raw material comprising a second thermoplastic polymer; firstly carding a first absorbent short fiber to obtain a first carded fiber web; and mixing the meltblown filaments obtained from the second meltblowing onto the first carded fiber web to obtain the hybrid fiber web. The second thermoplastic polymer preferably includes one or more of polypropylene, polyethylene, polyester, nylon, polyurethane, polylactic acid, and thermoplastic biodegradable plastics. The thermoplastic biodegradable plastic preferably includes polybutylene terephthalate (PBAT) and / or polybutylene succinate (PBS). The second thermoplastic polymer is preferably a single-component fiber or a multi-component fiber, more preferably a single-component fiber, a two-component fiber, or a multi-component fiber. The second raw material preferably also includes a second functional masterbatch. The second functional masterbatch preferably includes one or more of elastomer masterbatch, hydrophilic masterbatch, soft masterbatch, and biodegradable masterbatch, more preferably including one, two, or three of elastomer masterbatch, hydrophilic masterbatch, soft masterbatch, and biodegradable masterbatch. When the second functional masterbatch preferably includes any two of elastomer masterbatch, hydrophilic masterbatch, soft masterbatch, and biodegradable masterbatch, the mass ratio of any two first functional masterbatches is preferably (5-6):(1-5), specifically preferably 6:1 or 5:5. In this invention, when the first raw material preferably also includes the first functional masterbatch, the mass ratio of the first thermoplastic polymer to the first functional masterbatch is preferably (80-100):(0-20), and the first functional masterbatch is not 0, more preferably (85-95):(5-15), specifically preferably 98:2, 93:7, or 95:5. This invention does not have special requirements for the specific implementation process of the second meltblown or first spunbond. The diameter of the meltblown filament obtained by the second meltblown process is preferably 2-20 μm, more preferably 5-15 μm. The diameter of the spunbond filament obtained by the first spunbond process is preferably 2-20 μm, more preferably 5-15 μm. The first absorbent short fiber preferably includes one or more of cotton fiber, cashmere fiber, linen fiber, viscose fiber, and lyocell fiber, more preferably one or two of cotton fiber, cashmere fiber, linen fiber, viscose fiber, and lyocell fiber. The first absorbent short fiber is preferably a new fiber used for the first time or a recycled fiber, such as waste cotton from textile processing, recycled cotton, or recycled fibers from other synthetic fibers. The first absorbent short fiber is preferably a single-component short fiber or a two-component short fiber, wherein the two-component short fiber preferably includes one or more of core-sheath type, parallel type, trefoil type, and orange segment type. The length of the first absorbent short fiber is preferably 10-65 mm, and not 10 mm. The present invention does not have special requirements for the specific implementation process of the first carding and web forming.In this invention, the mixing of the meltblown filaments obtained by the second meltblown process with the first carded fiber web is preferably carried out in a forming box, and the mixed fiber web is obtained on a forming curtain after mixing in the forming box. In this invention, the meltblown filaments obtained by the second meltblown process are mixed on any one surface of the first carded fiber web, or on both surfaces of the first carded fiber web. When the meltblown filaments obtained by the second meltblown process are mixed on both surfaces of the first carded fiber web, the compositions of the two meltblown surface layers formed on the two surfaces of the first carded fiber web are preferably the same or different; the basis weights of the two meltblown surface layers formed on the two surfaces of the first carded fiber web are preferably equal or unequal. In this invention, the basis weight of the fiber web layer formed by the meltblown filaments obtained by the second meltblown process in the mixed fiber web is preferably 16 gsm, 7.5 gsm, 8 gsm, 15 gsm, or 30 gsm. The basis weight of the first carded fiber web formed by the first carding is 40 gsm, 18.5 gsm, 20 gsm, 45 gsm, or 65 gsm.

[0073] In this invention, the second carded fiber web obtained by the second carding process preferably has one layer. The method for preparing the carded fiber web includes the following steps: carding the second absorbent short fiber into a second web. In this invention, the second absorbent short fiber preferably includes one or more of cotton fiber, cashmere fiber, hemp fiber, viscose fiber, and lyocell fiber, more preferably one or two of cotton fiber, cashmere fiber, hemp fiber, viscose fiber, and lyocell fiber. The second absorbent short fiber is preferably a new fiber used for the first time or a recycled fiber, such as waste cotton from textile processing, recycled cotton, or recycled fibers from other synthetic fibers. The second absorbent short fiber is preferably a single-component short fiber or a two-component short fiber, wherein the two-component short fiber preferably includes one or more of core-sheath type, side-by-side type, trefoil type, and orange segment type. The length of the second absorbent short fiber is preferably 10-65 mm, and not 10 mm. This invention does not have special requirements for the specific implementation process of the second carding process. The second combed fiber web has a thickness of 35 gsm, 40 gsm, or 45 gsm.

[0074] As one or more embodiments of the present invention, the intermediate fiber web layer consists of a second carded fiber web obtained by a second carding process. The basis weight of the second carded fiber web is preferably 35 gsm, and the mass of the second carded fiber web as a percentage of the mass of the multilayer composite nonwoven material is preferably 50%.

[0075] As one or more embodiments of the present invention, the intermediate fiber web layer consists of a single layer of mixed fiber web. In the single layer of mixed fiber web, the meltblown filaments obtained from the second meltblown process are mixed on both surfaces of the first carded fiber web. The basis weight of the fiber web formed by the meltblown filaments on the two surfaces of the single layer of mixed fiber web is preferably 8 gsm, 7.5 gsm, or 15 gsm, respectively. The basis weight of the first carded fiber web obtained from the first carding process is preferably 40 gsm, 45 gsm, or 65 gsm. The mass percentage of the mixed fiber web to the mass of the multilayer composite nonwoven material is preferably 93.3%.

[0076] As one or more embodiments of the present invention, the intermediate fiber web layer consists of two layers of mixed fiber web. In each layer of mixed fiber web, the meltblown filaments obtained by the second meltblown process are mixed on one surface of the first carded fiber web, and the surface layers formed by the meltblown filaments obtained by the second meltblown process in the two layers of mixed fiber web are in contact with each other. The basis weight of the fiber web formed by the meltblown filaments obtained by the second meltblown process in the two layers of mixed fiber web is preferably 7.5 gsm or 8 gsm, and the basis weight of the first carded fiber web formed by the first carded fiber web in the two layers of mixed fiber web is preferably 18.5 gsm or 20 gsm.

[0077] In this invention, the basis weight of the intermediate fiber web layer is 10-80 gsm, more preferably 20-70 gsm, even more preferably 25-65 gsm, and specifically preferably 56 gsm, 26 gsm, 28 gsm, 60 gsm or 65 gsm.

[0078] In this invention, the mass percentage of the intermediate fiber web layer to the mass of the multilayer composite nonwoven material is preferably 40-95%, more preferably 40-90%, and specifically preferably 50%, 93.33%, 91.2%, 72.2%, 73.7%, 66.7%, 75%, or 64.3%.

[0079] After obtaining the intermediate fiber web layer, the present invention further applies a third raw material to the surface of the intermediate fiber web layer through a third melt-blowing or second spunbonding process to obtain a second fiber web layer, resulting in a multilayer fiber web. The third raw material comprises a third thermoplastic polymer. In the present invention, the third thermoplastic polymer preferably comprises one or more of polypropylene, polyethylene, polyester, nylon, polyurethane, polylactic acid, and thermoplastic biodegradable plastics. The thermoplastic biodegradable plastic preferably comprises polybutylene terephthalate (PBAT) and / or polybutylene succinate (PBS). The third thermoplastic polymer is preferably a single-component fiber or a multi-component fiber, more preferably a single-component fiber, a two-component fiber, or a multi-component fiber. The first raw material preferably also includes a third functional masterbatch. The third functional masterbatch preferably comprises one or more of elastomer masterbatch, hydrophilic masterbatch, flexible masterbatch, and biodegradable masterbatch, more preferably one, two, or three of elastomer masterbatch, hydrophilic masterbatch, flexible masterbatch, and biodegradable masterbatch. When the third functional masterbatch preferably includes any two of elastomer masterbatch, hydrophilic masterbatch, soft masterbatch, and biodegradable masterbatch, the mass ratio of any two third functional masterbatches is preferably (5-6):(1-5), specifically preferably 6:1 or 5:5. In this invention, when the third raw material preferably also includes the third functional masterbatch, the mass ratio of the third thermoplastic polymer to the third functional masterbatch is preferably (80-100):(0-20), and the third functional masterbatch is not 0, more preferably (85-95):(5-15), specifically preferably 95:5, 93:7, 90:10, or 92:8. This invention does not have special requirements for the specific implementation process of the third meltblown or second spunbond. The diameter of the meltblown filament obtained by the third meltblown is preferably 2-20 μm, more preferably 5-15 μm. The diameter of the spunbond filament obtained by the second spunbond is preferably 2-20 μm, more preferably 5-15 μm. The basis weight of the second fiber web layer is preferably 1–25 gsm, more preferably 2–20 gsm, and specifically preferably 17.5 gsm, 2 gsm, 2.5 gsm, 15 gsm, or 10 gsm. The percentage of the mass of the third fiber web layer to the mass of the multilayer composite nonwoven material is preferably 2.5–30%, and specifically preferably 25%, 3.335%, 4.4%, 13.9%, 13.15%, 16.65%, 21.4%, 16.7%, or 12.5%.

[0080] In this invention, the first and third fiber web layers have the same basis weight and the same percentage of mass in the multilayer composite nonwoven material.

[0081] After obtaining the multi-layered fiber web, the present invention hot-rolls the multi-layered fiber web to obtain a hot-rolled fiber web. The first fiber layer of the multi-layered fiber web forms the lower surface of the hot-rolled fiber web, and the second fiber layer of the multi-layered fiber web forms the upper surface of the hot-rolled fiber web. The hot rolling is performed using hot rolling rolls, and the surface of the hot rolling rolls is provided with a pattern. In the present invention, the hot rolling rolls preferably include an upper heating roll and a lower heating roll, and the hot rolling temperature is preferably 80-120°C, more preferably 90-110°C. In a specific embodiment of the present invention, the temperature of the upper heating roll is preferably 115°C, 110°C, or 120°C, and the temperature of the lower heating roll is preferably 110°C, 105°C, or 115°C. The inter-roll pressure of the upper heating roll and the lower heating roll is preferably 25-100 bar, more preferably 50 bar, 58 bar, or 48 bar. The pattern includes dotted patterns, line patterns, or combined patterns. In a specific embodiment of the present invention, the pattern preferably includes a regular hexagonal geometric pattern, a leaf line pattern, a cartoon character line pattern, a dotted pattern, or a "sesame dot" pattern.

[0082] After obtaining the hot-rolled fiber web, the present invention pre-hydroentangles the hot-rolled fiber web and then hydroentangles it to obtain a hydroentangled fiber web. The hydroentanglement includes sequentially performing a first drum-type reverse entanglement, a drum-type forward entanglement, a second drum-type reverse entanglement, and a flat-web forward entanglement. The first drum-type reverse entanglement involves performing a first hydroentanglement on the lower surface of the hot-rolled fiber web on the rotating circumference of the drum. The drum-type forward entanglement involves performing a second hydroentanglement on the upper surface of the hot-rolled fiber web on the rotating circumference of the drum. The second drum-type reverse entanglement involves performing a third hydroentanglement on the lower surface of the hot-rolled fiber web on the rotating circumference of the drum. The flat-web forward entanglement involves performing a fourth hydroentanglement on the upper surface of the hot-rolled fiber web on a suction screen, while simultaneously drawing a vacuum on the lower surface of the hot-rolled fiber web. In the present invention, the water pressure of the pre-hydroentangled hydroentanglement head is preferably 0.5 to 60 Bar, specifically preferably 10 Bar or 5 Bar. The water pressure of the first rotary drum-type reverse bar is preferably 20-120 Bar, specifically preferably 90 Bar, 80 Bar, 85 Bar, or 60 Bar. The water pressure of the rotary drum-type forward bar is preferably 20-120 Bar, specifically preferably 90 Bar, 80 Bar, 85 Bar, or 60 Bar. The water pressure of the second rotary drum-type reverse bar is preferably 20-120 Bar, specifically preferably 90 Bar, 80 Bar, 85 Bar, or 60 Bar. The water pressure of the flat mesh-type forward bar is preferably 20-120 Bar, specifically preferably 90 Bar, 80 Bar, 85 Bar, or 60 Bar.

[0083] This invention performs pre-hydraulic treatment on the pre-formed composite material; the first and third spunlace heads, respectively, work with the first and third rotating drums to reinforce the reverse side of the composite material with hydroentangling; the second spunlace head, working with the second rotating drum, and the fourth spunlace head, working with the suction screen, reinforce the front side of the composite material with hydroentangling; the fourth spunlace head, working with the suction screen, can perforate the product to make it easier for water molecules to contact the cellulose fibers inside the composite material, thereby further improving the water absorption performance of the product.

[0084] After obtaining the spunlace fiber web, the present invention dries and winds the spunlace fiber web to obtain the multilayer composite nonwoven material. In the present invention, the drying is oven drying, and the oven drying temperature is preferably 90-130℃, specifically preferably 120℃, 110℃, 105℃, or 125℃.

[0085] The present invention provides a composite multilayer nonwoven material prepared by the preparation method described in the above technical solution, comprising a first layer structure, an intermediate layer structure and a second layer structure stacked sequentially; the first layer structure is formed by a first meltblown fiber web or a second spunbond fiber web; the intermediate layer structure is formed by a plurality of mixed-blown fiber webs and / or a plurality of carded fiber webs; and the second layer structure is formed by a second meltblown fiber web or a second spunbond fiber web.

[0086] The present invention provides a preparation system for the preparation method described in the above technical solution, including a web forming curtain, a web forming system disposed above the web forming curtain, the web forming system including a first polymer meltblown molding system and / or a polymer spunbond molding system, and further including a plurality of mixed-blown systems and / or a plurality of second carding systems; the mixed-blown system includes at least one second polymer meltblown molding system, one first carding system and one molding box;

[0087] A hot rolling device is located downstream of the forming curtain, a first drum is located downstream of the hot rolling device, the first drum rotates counterclockwise, a pre-wetted water-piercing head is located below the first drum, and a first water-piercing head is located on the right side of the first drum.

[0088] A second drum is positioned above the first drum; the second drum rotates clockwise, and a second water jetting head is positioned to the left and / or above the second drum;

[0089] A third drum is located downstream of the first drum; the third drum rotates counterclockwise, and a third water jet is located to the left and / or below the third drum;

[0090] A suction screen is located downstream of the third drum; a fourth water jet is located above the suction screen; and a suction device is located below the suction screen.

[0091] A drying device is located downstream of the suction screen, and a winding device is located downstream of the drying device.

[0092] In this invention, the web-forming system above the web-forming curtain is configured according to the layer structure of the composite multilayer nonwoven material, including the quantity and arrangement order of the first polymer meltblown molding system, the polymer spunbond molding system, the mixing and spraying system, and the second carding system. Preferably, the web-forming system above the web-forming curtain is selectively operated or shut down, thereby altering the structure of the composite material.

[0093] As one or more embodiments of the present invention, the web forming system above the web forming curtain is provided with one or two first polymer meltblown forming systems according to the layer structure of the composite multilayer nonwoven material.

[0094] As one or more embodiments of the present invention, the web forming system above the web forming curtain is provided with one or two polymer spunbond molding systems according to the layer structure of the composite multilayer nonwoven material.

[0095] As one or more embodiments of the present invention, the web forming system above the web forming curtain is provided with one or two mixing spraying systems according to the layer structure of the composite multilayer nonwoven material.

[0096] As one or more embodiments of the present invention, the web forming system above the web forming curtain is provided with a second combing system according to the layer structure of the composite multilayer nonwoven material.

[0097] In this invention, the spinnerets of the first polymer meltblown forming system and the second polymer meltblown forming system preferably include a first spinneret, a second spinneret, or a third spinneret.

[0098] The first spinneret is provided with a single row of first spinneret holes. The first spinneret holes are inverted conical holes. The outer conical surface of the first spinneret holes is fitted with a first airflow stretching hole. The first airflow stretching hole is an inverted conical hole and coaxial with the first spinneret holes. The long fiber ejected from the first spinneret holes and the stretching gas ejected from the first airflow stretching hole converge at the top of the cone. The angle between the stretching gas and the long fiber is 30 to 70°.

[0099] The second spinneret has one or more rows of second spinneret holes, each of which is cylindrical. A second airflow stretching hole, which is annular and coaxial with the second spinneret hole, is fitted onto the outer circumferential surface of each second spinneret hole. The angle between the second airflow ejected from the second airflow stretching hole and the filament flow ejected from the second spinneret hole is preferably less than 10°.

[0100] The third spinneret has one or more rows of third airflow drawing holes, each of which is cylindrical. A third spinneret hole is fitted onto the outer circumference of each third airflow drawing hole. The third spinneret hole is annular and coaxial with the third airflow drawing hole. Preferably, the angle between the third airflow ejected from the third airflow drawing hole and the filament flow ejected from the third spinneret hole is less than 10°.

[0101] In this invention, the spinnerets of the first and second polymer meltblown forming systems can be configured as either a "slit-knife" meltblown type or a "coaxial" meltblown type. The "slit-knife" meltblown type involves two converging gas streams to form a single airflow, with the drawing gas forming an angle of approximately 30-70° with the filament flow direction. When the polymer filament leaves the spinneret in the meltblown mold, it is cooled and drawn by the air knife, ultimately adhering and falling onto the mesh screen. The "coaxial" meltblown type has annular fluid release holes around each spinneret, and the drawing gas can form an angle of less than 10° with the filament flow direction, allowing the essentially parallel airflow to coaxially draw the polymer melt. When the meltblown device is configured as a "slit-knife" meltblown type, the spinneret has a single row of holes; when the meltblown device is configured as a "coaxial" meltblown type, the spinneret can have a single row of holes or multiple rows of holes, with multi-row spinnerets including 2, 3, 4, or more rows.

[0102] In this invention, the drying device is preferably an oven, including tunnel type, rotary screen type, and infrared heating type. Finally, the wiping material is finished by a post-processing device to impart certain functionalities.

[0103] To further illustrate the present invention, the technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0104] Example 1

[0105] This embodiment follows Figure 1 The device structure diagram shown is used to prepare multilayer composite nonwoven materials. A schematic diagram of the structure of the prepared multilayer composite nonwoven material is shown below. Figure 2 As shown, the multilayer composite nonwoven material prepared in this embodiment consists of a first meltblown layer, an intermediate water-absorbing layer, and a second meltblown layer from top to bottom.

[0106] The first and second meltblown layers are made of thermoplastic polypropylene and hydrophilic masterbatch (purchased from Argus, model: HYL1047). They are formed into a polypropylene meltblown fiber web by melting, extrusion, stretching, and cooling through the first and second polymer meltblown molding systems, respectively. The first and second polymer meltblown molding systems adopt a "coaxial meltblowing" method, and the spinnerets have eight rows. The raw materials used in the first and second polymer meltblown molding systems have a mass ratio of polypropylene to hydrophilic masterbatch of 95%:5%.

[0107] The intermediate absorbent layer is composed of recycled cotton and orange-petal bicomponent fibers (Lutai Textile Co., Ltd., bicomponent chemical fiber), wherein the recycled cotton fiber accounts for 70% of the total mass of the intermediate absorbent layer, and the orange-petal bicomponent fibers account for 30% of the total mass of the intermediate absorbent layer. After passing through the first carding system, the mixed fibers are carded into a relatively parallel fiber web, which is laid flat between the first and second meltblown layers, adsorbed by the web forming curtain, and transported to the hot rolling process along with the first and second meltblown layers for hot rolling.

[0108] The first and second meltblown fiber webs have a basis weight of 17.5 gsm, and the total mass of the first and second meltblown fiber webs accounts for 50% of the entire composite fiber material by mass percentage; the intermediate absorbent layer fiber web has a basis weight of 35 gsm, and accounts for 50% of the entire composite fiber material by mass percentage.

[0109] The hot rolling process has an upper roll temperature of 115°C, a lower roll temperature of 110°C, and an inter-roll pressure of 50 bar; the hot rolling roll has a pattern composed of regular hexagonal geometric patterns.

[0110] The resulting composite fiber web material is reinforced by a downstream hydroentanglement system and then dried by a drying device. During the hydroentanglement process, the orange-petal bicomponent fibers are opened and de-fibered into ultrafine fibers with a diameter of about 2 micrometers after being impacted by high-pressure water jets. These fibers then entangle with the cotton fibers, thereby significantly improving the strength of the product.

[0111] The water pressure of the pre-hydroentangled head is 10 Bar; the water pressure of the first to fourth hydroentangled heads is 90 Bar; the drying device is a tunnel-type (flat mesh type) hot air penetration drying device; the drying temperature is 120℃; the final product is wound and formed by a winding device to form a multi-layer composite nonwoven material. Figure 19 The image shows the pattern effect of the multilayer composite nonwoven material prepared in Example 1 of this invention.

[0112] Example 2

[0113] This embodiment follows Figure 3The device structure diagram shown is used to prepare multilayer composite nonwoven materials. A schematic diagram of the structure of the prepared multilayer composite nonwoven material is shown below. Figure 4 As shown, the multilayer composite nonwoven material prepared in this embodiment consists of a first meltblown layer, a mixed-blown water-absorbing layer, and a second meltblown layer from top to bottom.

[0114] The first and second meltblown layers are made of thermoplastic polypropylene and hydrophilic masterbatch (purchased from Argus, model: HYL1047). They are formed into a polypropylene meltblown fiber web by melting, extrusion, stretching, and cooling through the first and second polymer meltblown molding systems, respectively. The first and second polymer meltblown molding systems adopt a "coaxial meltblown" form, and the spinnerets have eight rows. The mass ratio of polypropylene to hydrophilic masterbatch used in the first and second polymer meltblown molding systems is 95%:5%.

[0115] The mixed-blown absorbent layer is composed of a third meltblown layer, a fourth meltblown layer, and a cotton fiber web combed by the first carding system, all mixed-blown in a forming box. The third and fourth meltblown layers are made of thermoplastic polypropylene and hydrophilic masterbatch, which are melted, extruded, stretched, and cooled by the third and fourth polymer meltblown forming systems to form polypropylene meltblown fibers. The third and fourth polymer meltblown forming systems adopt a "coaxial meltblowing" method, and the spinnerets have fourteen rows. The mass ratio of polypropylene to hydrophilic masterbatch (purchased from Argus, model: HYL1047) used in the third and fourth polymer meltblown forming systems is 98%:2%, which is combined with the cotton fiber web combed by the carding system in the forming box.

[0116] The mixed-blown absorbent layer is formed in the forming box, laid flat on the web forming curtain between the first and second meltblown layers, and then fed into the hot rolling process by the web forming curtain for hot rolling; the basis weight of the first and second meltblown fiber webs is 2 gsm; the basis weight of the fiber web formed by the third and fourth meltblown fibers in the mixed-blown absorbent layer is 8 gsm, and the weight of the cotton fiber web after being combed by the first carding system is 40 gsm; the outer fiber web of the composite material (total mass of the first and second meltblown layers) accounts for 6.67% of the entire composite fiber material by mass percentage, and the middle mixed-blown absorbent layer accounts for 93.33% of the entire composite material.

[0117] The hot rolling process has an upper roll temperature of 110°C, a lower roll temperature of 105°C, and an inter-roll pressure of 58 bar; the hot rolling roll has a leaf-shaped pattern.

[0118] The resulting composite fiber web material is reinforced by a subsequent hydroentangling reinforcement system and then dried by a drying device. The water pressure of the pre-hydroentangling head is 5 Bar, and the water pressure of the first to fourth hydroentangling heads is 80 Bar. The drying device is a circular mesh hot air penetration drying device with a set temperature of 110°C for drying. The final product is wound and formed by a winding device to form a multi-layer composite nonwoven material.

[0119] Example 3

[0120] This embodiment follows Figure 5 The device structure diagram shown is used to prepare multilayer composite nonwoven materials. A schematic diagram of the structure of the prepared multilayer composite nonwoven material is shown below. Figure 6 As shown, the multilayer composite nonwoven material prepared in this embodiment consists of, from top to bottom, a first meltblown layer, a first mixed-blown water-absorbing layer, a second mixed-blown water-absorbing layer, and a second meltblown layer.

[0121] The first and second meltblown layers are thermoplastic polypropylene, hydrophilic masterbatch (purchased from Argus, model: HYL1047), and biodegradable masterbatch (Hubei Jinlong Nonwoven Fabric Co., Ltd., PLM v3.2.14a). These materials are melted, extruded, stretched, and cooled through the first and second polymer meltblown molding systems to form a polypropylene meltblown fiber web. The first and second polymer meltblown molding systems employ a coaxial meltblowing method, using eight rows of spinnerets. The mass ratio of the raw materials used in the first and second polymer meltblown molding systems—polypropylene:hydrophilic masterbatch (purchased from Argus, model: HYL1047):biodegradable masterbatch (Hubei Jinlong Nonwoven Fabric Co., Ltd., PLM v3.2.14a)—is 93%:6%:1%.

[0122] The first mixed-blown absorbent layer is formed by mixing and spraying the third meltblown layer and the cotton fiber web combed by the first carding system in the first forming box. The second mixed-blown absorbent layer is formed by mixing and spraying the fourth meltblown layer and the cotton fiber web combed by the second carding system in the second forming box. The third and fourth meltblown layers are thermoplastic polypropylene, hydrophilic masterbatch (purchased from Argus, model: HYL1047), and biodegradable masterbatch (Hubei Jinlong Nonwoven Fabric Co., Ltd., PLM v3.2.14a). They are formed into polypropylene meltblown fibers through melting, extrusion, stretching, and cooling by the third and fourth polymer meltblown forming systems. The third and fourth polymer meltblown forming systems adopt a "coaxial meltblown" form, and the spinneret has fourteen rows. The polypropylene, hydrophilic masterbatch (purchased from Argus, model: HYL1047), and biodegradable masterbatch (Hubei Jinlong Nonwoven Fabric Co., Ltd., PLM) used in the third and fourth polymer meltblown forming systems are: The mass ratio of v3.2.14a) is 93%:6%:1%. The first and second cotton fiber webs, combed together by the first and second carding systems, are formed in the first and second forming boxes. The first and second mixed-blown absorbent layers emerge from the first and second forming boxes, are laid flat on the forming curtain between the first and second meltblown layers, and are fed into the hot rolling process for hot rolling. The basis weights of the first and second meltblown fiber webs are 2.5 gsm each. The basis weights of the third and fourth meltblown fiber webs are 7.5 gsm each, and the basis weights of the intermediate short fiber webs (first and second cotton fiber webs) are 18.5 gsm each. The outer layer fiber webs (first and second meltblown fiber webs) account for 8.8% of the total composite fiber material by mass percentage, and the intermediate mixed-blown absorbent layers (first and second mixed-blown absorbent layers) account for 91.2% of the total composite material.

[0123] The hot rolling process has an upper roll temperature of 120°C, a lower roll temperature of 115°C, and an inter-roll pressure of 48 bar; the hot rolling roll has a pattern composed of cartoon character lines.

[0124] The resulting composite fiber web material is reinforced by a subsequent hydroentangling reinforcement system and then dried by a drying device. The water pressure of the pre-hydroentangling head is 10 Bar, and the water pressure of the first to fourth hydroentangling heads is 85 Bar. The drying device is a circular mesh hot air penetration drying device with a set temperature of 105°C for drying. The final product is wound and formed by a winding device to form a multi-layer composite nonwoven material.

[0125] Example 4

[0126] This embodiment follows Figure 7 The device structure diagram shown is used to prepare multilayer composite nonwoven materials. A schematic diagram of the structure of the prepared multilayer composite nonwoven material is shown below. Figure 8 As shown, the multilayer composite nonwoven material prepared in this embodiment consists of, from top to bottom, a first spunbond layer, a first mixed-spray water-absorbing layer, a second mixed-spray water-absorbing layer, and a second spunbond layer.

[0127] The first and second spunbond layers are thermoplastic polypropylene, hydrophilic masterbatch (purchased from Argus, model: HYL1047), and biodegradable masterbatch (Hubei Jinlong Nonwoven Fabric Co., Ltd., PLM v3.2.14a). These layers are formed by melting, extrusion, cooling, and stretching through a first polymer spunbond molding system and a second polymer spunbond molding system, thereby creating a first polypropylene spunbond fiber web and a second polypropylene spunbond fiber web. The mass ratio of polypropylene:hydrophilic masterbatch (purchased from Argus, model: HYL1047):biodegradable masterbatch (Hubei Jinlong Nonwoven Fabric Co., Ltd., PLM v3.2.14a) in the first and second polymer spunbond molding systems is 93%:6%:1%.

[0128] The first mixed-blown absorbent layer is formed by mixing and spraying the third meltblown layer and the cotton fiber web combed by the first carding system in the first forming box. The second mixed-blown absorbent layer is formed by mixing and spraying the fourth meltblown layer and the cotton fiber web combed by the second carding system in the second forming box. The third and fourth meltblown layers are thermoplastic polypropylene, hydrophilic masterbatch (purchased from Argus, model: HYL1047), and biodegradable masterbatch (Hubei Jinlong Nonwoven Fabric Co., Ltd., PLM v3.2.14a). They are formed into polypropylene meltblown fibers through melting, extrusion, stretching, and cooling by the third and fourth polymer meltblown forming systems. The third and fourth polymer meltblown forming systems adopt a "coaxial meltblown" form, and the spinneret has fourteen rows. In the third polymer meltblown forming system, the components are: polypropylene, hydrophilic masterbatch (purchased from Argus, model: HYL1047), and biodegradable masterbatch (Hubei Jinlong Nonwoven Fabric Co., Ltd., PLM). The mass ratio of v3.2.14a) is 93%:6%:1%. The first cotton fiber web formed by the first carding system and the second cotton fiber web formed by the second carding system are combined within the first and second forming boxes. The first and second mixed-spray absorbent layers emerge from the first and second forming boxes, are laid flat between the bottom and top spunbond layers, and are conveyed by a conveyor screen to the hot rolling process for hot rolling treatment. The bottom spunbond fiber web has a basis weight of 10 gsm, and the top spunbond fiber web has a basis weight of 10 gsm. The first and second melt... The basis weight of the spun fiber web is 7.5 gsm, and the basis weight of the two intermediate short fiber webs (first cotton fiber web and second cotton fiber web) is 18.5 gsm. The outer fiber web of the composite material (first spunbond layer and second spunbond layer) accounts for 27.8% of the total composite fiber material by mass percentage, and the intermediate mixed-spun water-absorbing layer (first mixed-spun water-absorbing layer and second mixed-spun water-absorbing layer) accounts for 72.2% of the total composite material. The hot rolling process has an upper roller temperature of 120°C, a lower roller temperature of 115°C, and an inter-roller pressure of 48 bar. The pattern of the hot rolling roller is composed of a dotted pattern.

[0129] The resulting composite fiber web material is reinforced by a subsequent hydroentangling reinforcement system and then dried by a drying device. The water pressure of the pre-hydroentangling head is 10 Bar, and the water pressure of the first to fourth hydroentangling heads is 85 Bar. The drying device is a circular mesh hot air penetration drying device with a set temperature of 105°C for drying. The final product is wound and formed by a winding device to form a multi-layer composite nonwoven material.

[0130] Example 5

[0131] This embodiment follows Figure 9 The device structure diagram shown is used to prepare multilayer composite nonwoven materials. A schematic diagram of the structure of the prepared multilayer composite nonwoven material is shown below. Figure 10 As shown, the multilayer composite nonwoven material prepared in this embodiment consists of, from top to bottom, a first spunbond layer, a first mixed-spray water-absorbing layer, a second mixed-spray water-absorbing layer, and a second meltblown layer.

[0132] The first spunbond layer is composed of thermoplastic polypropylene, hydrophilic masterbatch (purchased from Argus, model: HYL1047), and flexible masterbatch (Zhejiang Jinchun Polymer Materials Co., Ltd., 5068M). These components are melted, extruded, cooled, and stretched through a first polymer spunbond molding system to form a polypropylene spunbond fiber web. The mass ratio of polypropylene, hydrophilic masterbatch, and flexible masterbatch in the first polymer spunbond molding system is 90%:5%:5%.

[0133] The second meltblown layer is a thermoplastic polypropylene and a hydrophilic masterbatch (purchased from Argus, model: HYL1047). Through a second polymer meltblown molding system, the polypropylene meltblown fiber web is formed by melting, extrusion, stretching, and cooling. The mass ratio of polypropylene to hydrophilic masterbatch is 95%:5%. The second polymer meltblown molding system adopts a "coaxial meltblown" form, and the spinneret has eight rows.

[0134] The first mixed-blown absorbent layer is composed of a third meltblown layer and a cotton fiber web combed by the first carding system, which are mixed and sprayed together in the first forming box. The second mixed-blown absorbent layer is composed of a fourth meltblown layer and a cotton fiber web combed by the second carding system, which are mixed and sprayed together in the second forming box. The third and fourth meltblown layers are thermoplastic polypropylene, hydrophilic masterbatch (purchased from Argus, model: HYL1047), and biodegradable masterbatch (Hubei Jinlong Nonwoven Fabric Co., Ltd., PLM). v3.2.14a) Polypropylene meltblown fibers are formed through melting, extrusion, stretching, and cooling using a third and fourth polymer meltblown molding system. The third and fourth polymer meltblown molding systems employ a "coaxial meltblowing" method, using fourteen rows of spinnerets. The mass ratio of polypropylene to hydrophilic masterbatch (purchased from Argus, model: HYL1047) in both systems is 95%:5%. The fibers are combined with the first cotton fiber web formed by the first carding system and the second cotton fiber web formed by the second carding system within the first and second molding boxes. The first and second mixed-blown absorbent layers are formed within the first and second molding boxes. The fibers are laid flat between the bottom spunbond layer and the top meltblown layer, and conveyed to the hot rolling process by a conveyor screen for hot rolling treatment. The bottom spunbond layer has a fiber web basis weight of 10 gsm, the top meltblown layer has a fiber web basis weight of 10 gsm, the third and fourth meltblown fiber webs have a basis weight of 8 gsm each, and the intermediate short fiber webs have a basis weight of 20 gsm each. The outer fiber web of the composite material (the first spunbond layer and the second meltblown layer) accounts for 26.3% of the entire composite fiber material by mass percentage, and the intermediate mixed-blown water-absorbing layers (the first mixed-blown water-absorbing layer and the second mixed-blown water-absorbing layer) account for 73.7% of the entire composite material. The hot rolling process has an upper roller temperature of 120°C, a lower roller temperature of 115°C, and an inter-roller pressure of 48 bar. The hot rolling rollers have a dotted pattern.

[0135] The resulting composite fiber web material is reinforced by a subsequent hydroentangling reinforcement system and then dried by a drying device. The water pressure of the pre-hydroentangling head is 10 Bar, and the water pressure of the first to fourth hydroentangling heads is 85 Bar. The drying device is a circular mesh hot air penetration drying device with a set temperature of 105°C for drying. The final product is wound and formed by a winding device to form a multi-layer composite nonwoven material.

[0136] Example 6

[0137] This embodiment follows Figure 11 The device structure diagram shown is used to prepare multilayer composite nonwoven materials. A schematic diagram of the structure of the prepared multilayer composite nonwoven material is shown below. Figure 12 As shown, the multilayer composite nonwoven material prepared in this embodiment consists of a first spunbond layer, an intermediate absorbent layer, and a second spunbond layer from top to bottom.

[0138] The first and second spunbond layers are thermoplastic polypropylene and hydrophilic masterbatch (purchased from Argus, model: HYL1047). They are formed by melting, extrusion, cooling, and stretching through a first polymer spunbond molding system and a second polymer spunbond molding system, respectively, to form a first polypropylene spunbond fiber web and a second polypropylene spunbond fiber web. The mass ratio of polypropylene to hydrophilic masterbatch (purchased from Argus, model: HYL1047) in the first and second polymer spunbond molding systems is 95%:5%.

[0139] The intermediate absorbent layer is a mixture of recycled cotton and ES fiber. After being combed by a carding system, the mixed fibers are combed into a relatively parallel fiber web, which is laid flat between the first spunbond layer and the second spunbond layer. It is adsorbed by the web forming curtain and transported with the first and second spunbond layers to the subsequent hot rolling process.

[0140] The first and second spunbond fiber webs each have a basis weight of 10 gsm, accounting for 33.3% of the entire composite fiber material by mass percentage; the intermediate absorbent layer fiber web has a basis weight of 40 gsm, accounting for 66.7% of the entire composite fiber material by mass percentage.

[0141] The hot rolling process has an upper roll temperature of 115°C, a lower roll temperature of 110°C, and an inter-roll pressure of 50 bar; the hot rolling roll has a pattern composed of regular hexagonal geometric patterns.

[0142] The resulting composite fiber web material is reinforced by a subsequent hydroentangling reinforcement system and perforated by a fourth hydroentangling head, then dried by a drying device. Simultaneously, the ES fibers pass through a hot air drying system, where they bond with surrounding short fibers to form a curled spatial shape. The water pressure of the pre-hydroentangling head is 10 Bar; the water pressure of the first to third hydroentangling heads is 70 Bar; and the water pressure of the fourth hydroentangling head is 85 Bar. The drying device is a tunnel-type (flat-net type) hot air penetration drying device; the drying temperature is 120℃. The final product is wound and formed by a winding device to create a multi-layer composite nonwoven material.

[0143] Example 7

[0144] This embodiment follows Figure 13 The device structure diagram shown is used to prepare multilayer composite nonwoven materials. A schematic diagram of the structure of the prepared multilayer composite nonwoven material is shown below. Figure 14 As shown, the multilayer composite nonwoven material prepared in this embodiment consists of a first spunbond layer, a mixed-spray absorbent layer, and a second spunbond layer from top to bottom.

[0145] The first and second spunbond layers are thermoplastic polypropylene, hydrophilic masterbatch (purchased from Argus, model: HYL1047), and elastomer masterbatch (Zhejiang Jinchun Polymer Materials Co., Ltd., high molecular weight EVA wax). They are formed into a polypropylene spunbond fiber web through a first polymer spunbond molding system and a second polymer spunbond molding system, respectively, by melting, extrusion, cooling, and stretching. The mass ratio of polypropylene:hydrophilic masterbatch:elastomer masterbatch in the first and second polymer spunbond molding systems is 90%:5%:5%.

[0146] The mixed-blown absorbent layer consists of a third meltblown layer, a fourth meltblown layer, and a carded cotton fiber web, which are mixed and sprayed in a forming box. The third and fourth meltblown layers are thermoplastic polypropylene and hydrophilic masterbatch (purchased from Argus, model: HYL1047). Through the third and fourth polymer meltblown forming systems, polypropylene meltblown fibers are formed by melting, extrusion, stretching, and cooling. The third and fourth polymer meltblown forming systems adopt a "coaxial meltblowing" form, and the spinnerets have eight rows. The mass ratio of polypropylene to hydrophilic masterbatch (purchased from Argus, model: HYL1047) in the third and fourth polymer meltblown forming systems is 98%:2%. They are combined with the cotton fiber web formed by the carding system in the first forming box.

[0147] The mixed-spray absorbent layer emerges from the first forming box, is laid flat on the web forming curtain between the first and second spunbond layers, and is then fed into the hot rolling process by the web forming curtain for hot rolling; the basis weight of the first and second spunbond layers is 10 gsm; the basis weight of the third and fourth meltblown layers is 7.5 gsm; the basis weight of the intermediate short fiber web is 45 gsm; and the total weight of the composite material is 80 gsm.

[0148] The hot rolling process has an upper roll temperature of 110°C, a lower roll temperature of 105°C, and an inter-roll pressure of 58 bar; the hot rolling roll has a leaf-shaped pattern.

[0149] The resulting composite fiber web material is reinforced by a subsequent hydroentangling reinforcement system and then dried by a drying device. The water pressure of the pre-hydroentangling head is 10 Bar, and the water pressure of the first to fourth hydroentangling heads is 85 Bar. The drying device is a circular mesh hot air penetration drying device with a set temperature of 110°C for drying. The final product is wound and formed by a winding device to form a multi-layer composite nonwoven material.

[0150] Example 8

[0151] This embodiment follows Figure 15 The device structure diagram shown is used to prepare multilayer composite nonwoven materials. A schematic diagram of the structure of the prepared multilayer composite nonwoven material is shown below. Figure 16 As shown, the multilayer composite nonwoven material prepared in this embodiment consists of a first spunbond layer, an intermediate absorbent layer, and a second meltblown layer from top to bottom.

[0152] The spunbond layer is a thermoplastic polypropylene and a hydrophilic masterbatch (purchased from Argus, model: HYL1047). Through a first polymer spunbond molding system, the polypropylene is melted, extruded, cooled, and stretched to form a polypropylene spunbond fiber web; wherein the mass ratio of polypropylene to hydrophilic masterbatch in the first polymer spunbond molding system is 92%:8%.

[0153] The meltblown layer is a thermoplastic polypropylene and a hydrophilic masterbatch (purchased from Argus, model: HYL1047). Through a second polymer meltblown molding system, the polypropylene meltblown fiber web is formed by melting, extrusion, stretching, and cooling. The mass ratio of polypropylene to hydrophilic masterbatch in the second polymer meltblown molding system is 95%:5%.

[0154] The intermediate absorbent layer is a mixture of recycled cotton and ES fiber. After passing through the first carding system, the mixed fibers are carded into a relatively parallel fiber web, which is laid flat between the spunbond layer and the meltblown layer. It is adsorbed by the web forming curtain and then sent to the hot rolling process along with the spunbond layer and the meltblown layer.

[0155] The first spunbond layer has a basis weight of 10 gsm, which accounts for 14.3% of the entire composite fiber material by mass percentage; the second meltblown layer has a basis weight of 15 gsm, which accounts for 21.4% of the entire composite material by mass percentage; and the intermediate absorbent fiber web has a basis weight of 45 gsm, which accounts for 64.3% of the entire composite fiber material by mass percentage.

[0156] The hot rolling process has an upper roll temperature of 120°C, a lower roll temperature of 110°C, and an inter-roll pressure of 48 bar; the hot rolling roll has a "sesame seed" pattern.

[0157] The resulting composite fiber web material is reinforced by a subsequent hydroentangling reinforcement system and dried by a drying device. Simultaneously, the ES fibers are bonded to the surrounding short fibers and form a curled spatial shape after passing through a hot air drying system. The water pressure of the pre-hydroentangling head is 10 Bar, and the water pressure of the first to fourth hydroentangling heads is 60 Bar. The drying device is a tunnel-type (flat mesh type) hot air penetration drying device. The drying temperature is 125℃. The final product is wound and formed by a winding device to form a multi-layer composite nonwoven material.

[0158] Example 9

[0159] This embodiment follows Figure 17 The device structure diagram shown is used to prepare multilayer composite nonwoven materials. A schematic diagram of the structure of the prepared multilayer composite nonwoven material is shown below. Figure 18 As shown, the multilayer composite nonwoven material prepared in this embodiment consists of a first spunbond layer, a mixed-spray water-absorbing layer, and a second meltblown layer from top to bottom.

[0160] The first spunbond layer is composed of thermoplastic polypropylene, hydrophilic masterbatch (purchased from Argus, model: HYL1047), and elastomer masterbatch (Zhejiang Jinchun Polymer Materials Co., Ltd., high molecular weight EVA wax). These components are melted, extruded, cooled, and stretched through a first polymer spunbond molding system to form a polypropylene spunbond fiber web. The mass ratio of polypropylene:hydrophilic masterbatch:elastomer masterbatch in the first polymer spunbond molding system is 90%:5%:5%.

[0161] The second meltblown layer is a thermoplastic polypropylene and a hydrophilic masterbatch (purchased from Argus, model: HYL1047). The two materials are melted, extruded, stretched, and cooled by a second polymer meltblown molding system to form a polypropylene meltblown fiber web. The mass ratio of polypropylene to hydrophilic masterbatch (purchased from Argus, model: HYL1047) in the second polymer meltblown molding system is 95%:5%.

[0162] The mixed-blown absorbent layer is composed of a third meltblown layer, a fourth meltblown layer, and a carded cotton fiber web, which are mixed-blown in the first forming box. The third and fourth meltblown layers are thermoplastic polypropylene and hydrophilic masterbatch formed by melting, extrusion, stretching, and cooling through the third and fourth polymer meltblown forming systems to form polypropylene meltblown fibers. The third and fourth polymer meltblown forming systems adopt a "coaxial meltblowing" form, and the spinnerets have eight rows. The mass ratio of polypropylene to hydrophilic masterbatch (purchased from Argus, model: HYL1047) in the third and fourth polymer meltblown forming systems is 98%:2%. It is combined with the cotton fiber web formed by the carding system in the first forming box. The mixed-blown absorbent layer comes out of the first forming box, is laid flat on the web forming curtain between the first spunbond layer and the second meltblown layer, and is sent to the hot rolling process by the web forming curtain for hot rolling.

[0163] The first spunbond layer has a basis weight of 10 gsm, accounting for 11.1% of the entire composite fiber material by mass percentage; the second meltblown layer has a basis weight of 15 gsm, accounting for 16.7% of the entire composite material by mass percentage; the intermediate absorbent fiber web has a basis weight of 65 gsm, accounting for 72.2% of the entire composite fiber material by mass percentage; and the total basis weight of the composite material is 90 gsm.

[0164] The hot rolling process has an upper roll temperature of 115°C, a lower roll temperature of 105°C, and an inter-roll pressure of 58 bar; the hot rolling roll has a pattern of leaf lines.

[0165] The resulting composite fiber web material is reinforced by a subsequent hydroentangling reinforcement system and then dried by a drying device. The water pressure of the pre-hydroentangling head is 8 Bar, and the water pressure of the first to fourth hydroentangling heads is 80 Bar. The drying device is a circular mesh hot air penetration drying device with a set temperature of 115°C for drying. The final product is wound and formed by a winding device to form a multi-layer composite nonwoven material.

[0166] Comparative Example 1

[0167] Recycled cotton fibers are processed into a web by a carding device. The carded fiber web is then reinforced by a subsequent hydroentangling system and dried by a drying device. The water pressure of the pre-hydroentangling head is 10 Bar, and the water pressure of the first to fourth hydroentangling heads is 85 Bar. The drying device is a circular mesh hot air penetration drying device with a set temperature of 115°C for drying. The final product is wound into a pure cotton nonwoven material by a winding device.

[0168] Test case

[0169] The performance of the nonwoven materials prepared in Examples 1-9 and Comparative Example 1, as well as the commercially available nonwoven material (PurCotton - Baby Cotton Wipes), was tested. The test results are shown in Table 1.

[0170] Table 1. Performance test results comparing commercially available pure cotton spunlace fabric and nonwoven materials made from recycled cotton fibers via carding and spunlace fabric in Examples 1-9.

[0171]

[0172] As can be seen from the above embodiments, the method provided by the present invention prepares a first and second fiber web layer of the composite material by meltblowing or spunbonding, which serve as the outermost two surface layers of the composite material; simultaneously, short fibers with combable properties are combed into a web to obtain a combed fiber web, and the combed fiber web obtained by combing the short fibers is mixed with long filaments obtained by meltblowing to form a mixed fiber web. The combed fiber web is used alone as the middle fiber web of the composite material, serving as the middle absorbent layer of the composite material, or the combed fiber web and the mixed fiber web are used together as the middle fiber web of the composite material, serving as the absorbent layer of the composite material; thus, the composite material is obtained. After the multi-layer fiber web with a "sandwich" structure, the present invention obtains a composite nonwoven material through hot rolling, pre-hydroentangling, hydroentangling, and drying. In the process of hot rolling to composite the three-layer fiber web, the present invention simultaneously uses hot rolling rollers to impart patterns to the product. Since the filaments obtained from the thermoplastic polymer melt during hot rolling, the clarity of the pattern effect imparted during the hot rolling composite molding process is better. Then, the hydroentangling method is used to make the filaments and water-absorbing short fibers in the product more tightly wrapped and mixed. The resulting multi-layer composite nonwoven material has high strength, good water absorption, and low surface fuzz and high surface density.

[0173] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. Other embodiments can be obtained based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A method for preparing a multilayer composite nonwoven material, characterized in that, Includes the following steps: The first raw material is subjected to a first meltblown or first spunbond process to obtain a first fiber web layer. The first raw material includes a first thermoplastic polymer and a hydrophilic masterbatch, with a mass ratio of 95:5 between the first thermoplastic polymer and the hydrophilic masterbatch. The basis weight of the first fiber web layer is 17.5 gsm. An intermediate fiber web layer is prepared on the surface of the first fiber web layer, wherein the intermediate fiber web layer is a carded fiber web; the method for preparing the carded fiber web includes the following steps: a second water-absorbing short fiber is carded into a web; the second water-absorbing short fiber is a bicomponent fiber of recycled cotton and orange petal; the weight of the carded fiber web obtained by the second carding is 35 gsm; On the surface of the intermediate fiber web layer, a third raw material is subjected to a third melt-blowing or a second spunbonding process to form a second fiber web layer, resulting in a multilayer fiber web; the third raw material includes a third thermoplastic polymer and a hydrophilic masterbatch, with a mass ratio of the third thermoplastic polymer to the hydrophilic masterbatch of 95:5; the basis weight of the second fiber web layer is 17.5 gsm; The multi-layer fiber web is hot-rolled using hot rolling rollers to obtain a hot-rolled fiber web. The first fiber web layer of the multi-layer fiber web forms the lower surface of the hot-rolled fiber web, and the second fiber web layer of the multi-layer fiber web forms the upper surface of the hot-rolled fiber web. The hot rolling is performed using hot rolling rollers, and the roller surface of the hot rolling rollers is provided with a pattern. The hot-rolled fiber web is pre-hydroentangled and then hydroentangled to obtain a hydroentangled fiber web; the hydroentangling includes sequentially performing a first drum-type reverse entangling, a drum-type forward entangling, a second drum-type reverse entangling, and a flat-web-type forward entangling; the first drum-type reverse entangling is performed on the lower surface of the hot-rolled fiber web on the rotating circumference of the drum, the drum-type forward entangling is performed on the upper surface of the hot-rolled fiber web on the rotating circumference of the drum, the second drum-type reverse entangling is performed on the lower surface of the hot-rolled fiber web on the rotating circumference of the drum, and the flat-web-type forward entangling is performed on the upper surface of the hot-rolled fiber web on a suction screen, while a vacuum is drawn on the lower surface of the hot-rolled fiber web; The hydroentangled fiber web is dried to obtain the multilayer composite nonwoven material.

2. The preparation method according to claim 1, characterized in that, The diameters of the meltblown filaments obtained from the first and third meltblown processes, as well as the spunbond filaments obtained from the first and second spunbond processes, are independently 2 to 20 μm.

3. The preparation method according to claim 1 or 2, characterized in that, The first thermoplastic polymer and the third thermoplastic polymer independently include one or more of polypropylene, polyethylene, polyester, nylon, polyurethane and thermoplastic biodegradable plastics.

4. The preparation method according to claim 1 or 2, characterized in that, The length of the second absorbent short fiber is 10~65mm, but not 10mm.

5. The preparation method according to claim 1, characterized in that, The hot rolling roll includes an upper heating roll and a lower heating roll, the hot rolling temperature is 80~120℃, and the inter-roll pressure of the upper heating roll and the lower heating roll is 25~100 bar; The patterns include dot patterns, line patterns, or combinations of patterns.

6. The preparation method according to claim 1, characterized in that, The water pressure of the pre-hydroentangled head is 0.5~60 Bar; the water pressure of the first rotary drum reverse entanglement, rotary drum forward entanglement, second rotary drum reverse entanglement, and flat net forward entanglement heads is independently 20~120 Bar; The drying process is called baking, and the baking temperature is 90~130℃.

7. The composite multilayer nonwoven material prepared by the preparation method according to any one of claims 1 to 6, characterized in that, It includes a first layer structure, an intermediate layer structure, and a second layer structure stacked sequentially; the first layer structure is formed by a first meltblown fiber web or a first spunbond fiber web; the intermediate layer structure is formed by a carded fiber web; and the second layer structure is formed by a third meltblown fiber web or a second spunbond fiber web.

8. The preparation system used in the preparation method according to any one of claims 1 to 6, characterized in that, The system includes a forming curtain and a forming system disposed above the forming curtain. The forming system includes a first polymer meltblown forming system and / or a first polymer spunbond forming system, and further includes a plurality of mixed-blown systems and / or a plurality of second carding systems. Each mixed-blown system includes at least one second polymer meltblown forming system, one first carding system, and one forming box. A hot rolling device is located downstream of the forming curtain, a first drum is located downstream of the hot rolling device, the first drum can rotate counterclockwise, a pre-wetted water-piercing head is located below the first drum, and a first water-piercing head is located on the right side of the first drum. A second drum is positioned above the first drum; the second drum rotates clockwise, and a second water jetting head is positioned to the left and / or above the second drum; A third drum is located downstream of the first drum; the third drum rotates counterclockwise, and a third water jet is located to the left and / or below the third drum; A suction screen is located downstream of the third drum; a fourth water jet is located above the suction screen; and a suction device is located below the suction screen. A drying device is located downstream of the suction screen, and a winding device is located downstream of the drying device.

9. The preparation system according to claim 8, characterized in that, The spinnerets of the first polymer meltblown forming system and the second polymer meltblown forming system include a first spinneret, a second spinneret, or a third spinneret. The first spinneret is provided with a single row of first spinneret holes. The first spinneret holes are inverted conical holes. The outer conical surface of the first spinneret holes is fitted with a first airflow stretching hole. The first airflow stretching hole is an inverted conical hole and coaxial with the first spinneret holes. The long fiber ejected from the first spinneret holes and the stretching gas ejected from the first airflow stretching hole converge at the top of the cone. The angle between the stretching gas and the long fiber is 30~70°. The second spinneret is provided with a single row or multiple rows of second spinnerets. The second spinnerets are cylindrical holes. A second airflow stretching hole is sleeved on the outer circumferential surface of the second spinnerets. The second airflow stretching hole is an annular hole and coaxial with the second spinnerets. The third spinneret is provided with a single row or multiple rows of third airflow stretching holes. The third airflow stretching holes are cylindrical holes. The outer circumferential surface of the third airflow stretching holes is fitted with third spinnerets. The third spinnerets are annular holes and coaxial with the third airflow stretching holes.

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