A nonwoven composite material, a method for producing and using the same, and an apparatus for producing a nonwoven composite material

Abstract

The application provides a non-woven composite material and a preparation method and application thereof, and a production device of the non-woven composite material, and relates to the technical field of layered composite materials. In the non-woven composite material, the intermediate water absorption layer is a cross fiber net formed by raw materials of a core layer including chemical fibers and short fibers, the area of the cross fiber net accounts for more than 50% of the area of the intermediate water absorption layer, and the fibers of the intermediate water absorption layer are not arranged in a single orientation, so that the strength of the non-woven composite material is improved. Moreover, the first chemical fiber net layer and the second chemical net layer prepared by using thermoplastic polymers and functional master batches as raw materials form covering and protection for the intermediate water absorption layer, so that the falling of the short fibers of the intermediate water absorption layer is significantly reduced, and the cross fiber net of the intermediate water absorption layer also significantly reduces the falling of the flock pulp fibers.

Description

Technical Field

[0001] This invention relates to the field of layered composite material technology, specifically to a nonwoven composite material, its preparation method and application, and a production apparatus for nonwoven composite materials. Background Technology

[0002] Nonwoven fabrics are ubiquitous in daily life and industrial production, especially with the increasing demand for disposable hygiene products. Currently, nonwoven fabrics are mainly produced using a multi-fiber co-spray dry web forming process. This process involves co-spraying meltblown fibers and fluff pulp fibers. Meltblown fibers have smaller fiber diameters, larger specific surface areas, and stronger cleaning capabilities; fluff pulp fibers have better skin-friendliness and water absorption and retention. This multi-fiber co-spray dry web forming technology allows for the preparation of composite materials with strong water absorption. However, existing nonwoven fabrics clearly have low strength. Summary of the Invention

[0003] In view of this, the purpose of the present invention is to provide a nonwoven composite material and its preparation method, apparatus and application, wherein the nonwoven composite material provided by the present invention has high strength.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] This invention provides a nonwoven composite material comprising a first chemical fiber web layer, an intermediate absorbent layer, and a second chemical fiber web layer stacked sequentially.

[0006] The first chemical fiber mesh layer is a layered mesh structure formed from the raw materials for preparing the first surface layer; the raw materials for preparing the first surface layer include a first thermoplastic polymer and a first functional masterbatch;

[0007] The second chemical fiber network layer is a layered network structure formed from the raw materials used to prepare the second surface layer; the raw materials used to prepare the second surface layer include a second thermoplastic polymer and a second functional masterbatch;

[0008] The intermediate absorbent layer is a cross-fiber web structure formed from the core layer preparation raw materials, which include chemical filaments and short fibers; the area of ​​the cross-fiber web accounts for more than 50% of the area of ​​the intermediate absorbent layer.

[0009] Preferably, the average fiber diameter of the first chemical fiber web layer and the second chemical fiber web layer are independently 0.5 to 10 μm, and the basis weight is independently 0.1 to 10 gsm;

[0010] The mass fraction of the first thermoplastic polymer in the raw material for preparing the first surface layer is 89.5% to 95%.

[0011] The mass fraction of the second thermoplastic polymer in the raw material for preparing the second surface layer is 89.5%–95%.

[0012] The mass of the first chemical fiber web layer and the second chemical fiber web layer independently accounts for 3 to 20% of the mass of the nonwoven composite material;

[0013] The raw materials for preparing the first and second surface layers also include functional additives, which include one or more of water-absorbing agents, softeners, and antibacterial agents; the mass of the functional additives accounts for 0.2% to 8% of the mass of the nonwoven composite material.

[0014] The raw materials for preparing the first and second surface layers also include antioxidants.

[0015] Preferably, the chemical filaments include one or more of the following: polypropylene-based fibers, polyethylene-based fibers, polyethylene terephthalate-based fibers, styrene-butadiene-styrene triblock copolymer-based fibers, and ethylene-vinyl acetate copolymer-based fibers.

[0016] The short fibers include one or more of cellulose short fibers, synthetic short fibers, and superabsorbent short fibers;

[0017] The core layer preparation materials also include functional fillers, which include superabsorbent fibers, low-melting-point fibers and superabsorbent resins; the melting point of the low-melting-point fibers is ≤150℃;

[0018] In the nonwoven composite material, the mass fraction of chemical filaments is 6.5-23.2%, and the mass fraction of short fibers is 20-69.6%.

[0019] The intermediate absorbent layer has several layers.

[0020] Preferably, the first thermoplastic polymer and the second thermoplastic polymer independently include one or more of polypropylene, modified polypropylene, polyethylene, modified polyethylene, polyethylene terephthalate, styrene-butadiene-styrene triblock copolymer and ethylene-vinyl acetate copolymer;

[0021] The first functional masterbatch and the second functional masterbatch independently include one or more of hydrophilic masterbatch, biodegradable masterbatch, soft masterbatch and antibacterial masterbatch.

[0022] The present invention also provides a method for preparing the nonwoven composite material described in the above technical solution, comprising the following steps:

[0023] The raw material for the first surface layer is heated to melt and then spun into a first chemical fiber web layer; a first cooling process is performed during the first spinning process.

[0024] The raw materials for core layer preparation are cross-mixed and laid on the surface of the first chemical fiber web layer to form an intermediate absorbent layer with cross-fiber web, thus obtaining a chemical fiber web layer-intermediate absorbent layer.

[0025] The raw material for the second surface layer is heated to melt, and a second chemical fiber web layer is formed by second spinning on the surface of the intermediate absorbent layer of the chemical fiber web layer-intermediate absorbent layer-chemical fiber web layer; a second cooling is performed during the second spinning process.

[0026] The nonwoven composite material is obtained by hot rolling the chemical fiber web layer, the intermediate absorbent layer, and the chemical fiber web layer together.

[0027] Preferably, the first cooling and the second cooling independently include atomized spray cooling or cold air cooling using a cooling liquid; the cooling liquid includes pure water or a functional additive solution; the spray rate of the cooling liquid is 0-200 L / h;

[0028] When the core layer preparation raw materials also include functional fillers, chemical filaments, short fibers and functional fillers are cross-mixed;

[0029] The hot-rolled composite temperature is 90–160°C.

[0030] This invention provides the application of the nonwoven composite material described in the above technical solution or the nonwoven composite material prepared by the above technical solution in disposable hygiene products or wipes.

[0031] The present invention also provides a production apparatus for the preparation method of the nonwoven composite material described in the above technical solution or the preparation method of the nonwoven composite material described in the above technical solution, including a first surface layer preparation unit 1, a core layer preparation unit 2, a second surface layer preparation unit 3, a web forming curtain 4, and a hot rolling mill 6;

[0032] The first surface layer preparation unit 1 is provided with a first spinning assembly 11 and a first spraying system 12; the first spinning assembly 11 includes a coaxial melt-blown spinning assembly or an air knife drawing spinning assembly; the first spinning assembly 11 includes at least one melt chamber, and each melt chamber is connected to a spinneret.

[0033] The core layer preparation unit 2 is provided with a molding box 21, and the molding box 21 is provided with a raw material inlet 23 and a raw material inlet pipe 25;

[0034] The second surface layer preparation unit 3 includes a third spinning assembly 31 and a second spraying system 32; the third spinning assembly 31 includes a coaxial meltblown spinning assembly or an air knife drawing spinning assembly; the third spinning assembly 31 includes at least one melt chamber, and each melt chamber is connected to a spinneret.

[0035] The mesh material outlets of the first surface layer preparation unit 1, the core layer preparation unit 2, and the second surface layer preparation unit 3 are respectively connected to the mesh curtain 4;

[0036] The net curtain 4 is equipped with a bottom air suction system 41.

[0037] Preferably, the core layer preparation unit 2 is further provided with a second spinning assembly 22, a raw material addition system 24, and a fiber unwinding system 26. The fiber outlet of the second spinning assembly 22 is connected to the forming box 21. The second spinning assembly 22 includes a coaxial meltblown spinning assembly or an air knife drawing spinning assembly. The second spinning assembly 22 includes at least one melt chamber, and each melt chamber is connected to a spinneret. The fiber unwinding system 26 is provided on the raw material inlet pipe 25. The forming box 21 is connected to the raw material addition system 24.

[0038] The number of core layer preparation units 2 is several.

[0039] Preferably, the production apparatus further includes a heating device 5, a quality inspection unit 7, and a winding and slitting unit 8.

[0040] In the nonwoven composite material provided by this invention, the intermediate absorbent layer is a cross-fiber web formed from core layer preparation materials including chemical filaments and short fibers. The area of ​​the cross-fiber web accounts for more than 50% of the area of ​​the intermediate absorbent layer. The fibers in the intermediate absorbent layer are not arranged in a single orientation, which improves the strength of the nonwoven composite material. Moreover, the first chemical fiber web layer and the second chemical web layer, prepared using thermoplastic polymers and functional masterbatches as raw materials, coat and protect the intermediate absorbent layer, significantly reducing the shedding of short fibers in the intermediate absorbent layer. At the same time, the cross-fiber web of the intermediate absorbent layer also significantly reduces the shedding of fluff pulp fibers.

[0041] Furthermore, this invention introduces superabsorbent fibers into the intermediate absorbent layer. These fibers are evenly distributed and cross-laminated within the intermediate absorbent layer, significantly improving the water absorption performance of the nonwoven composite material. The introduction of low-melting-point chemical fibers into the intermediate absorbent layer, followed by thermal activation during the hot-rolling composite process, strengthens the binding force of the short fibers in the nonwoven composite material, resulting in a significant improvement in its anti-linting performance.

[0042] Furthermore, the present invention introduces a water-absorbing agent into the first chemical fiber web layer and / or the second chemical web layer, which can improve the water absorption performance of the nonwoven composite material; introduces the softener, which can improve the softness performance of the nonwoven composite material; and introduces an antibacterial agent, which can improve the antibacterial and antifungal performance of the nonwoven composite material.

[0043] As shown in the test results of the examples, the nonwoven composite material provided by the present invention has a longitudinal strength of 12.56-48.3N, a longitudinal elongation of 30.8-58.3%, a transverse strength of 6.43-40.2N, a longitudinal elongation of 50.1-78.4%, a water absorption time of less than 16-36s, a water absorption ratio of 969-8532%, and a lint shedding coefficient of 3.73-4.5. This indicates that the nonwoven composite material provided by the present invention has high strength, good anti-lint shedding performance, and strong water absorption.

[0044] This invention provides a method for preparing the nonwoven composite material described in the above-mentioned technical solution. In the preparation of the first and second chemical fiber web layers, cooling is performed during the spinning process, resulting in superior fiber strength and significantly improving the strength of the nonwoven composite material. The intermediate absorbent layer prepared by this invention is a cross-fiber web formed from core layer raw materials including chemical filaments and short fibers. The area of ​​the cross-fiber web accounts for more than 50% of the area of ​​the intermediate absorbent layer, and the fibers in the intermediate absorbent layer are not arranged in a single orientation, thus improving the strength of the nonwoven composite material. The first and second chemical fiber web layers coat and protect the intermediate absorbent layer, significantly reducing lint from the fluff pulp fibers (short fibers) in the intermediate absorbent layer. Simultaneously, the cross-fiber web of the intermediate absorbent layer also significantly reduces lint from the fluff pulp fibers. This invention uses hot rolling to composite the chemical fiber web layer-intermediate absorbent layer-chemical fiber web layer, bonding the relatively separated fiber layers together at the rolling points, improving the bonding strength between the fibers in each layer. Moreover, the preparation method provided by this invention is simple in process, easy to operate, and has low production costs, making it suitable for industrial production.

[0045] Each spinning component in the production device used in this invention is equipped with an independent raw material supply device, which is independent of each other and does not interfere with each other. It has a special configuration with multiple raw material inlets and a special structure of spinning components. In the production process, a variety of raw materials can be used, and the special spatial structure makes the prepared nonwoven composite material have better bulkiness, strength, water absorption and good anti-linting performance. Attached Figure Description

[0046] Figure 1 This is a schematic diagram of the production apparatus used to prepare nonwoven composite materials according to the present invention. In the diagram, 1 is the first surface layer preparation unit, 11 is the first spinning assembly, 12 is the first spraying system, 2 is the core layer preparation unit, 21 is the molding box, 22 is the second spinning assembly, 23 is the raw material inlet, 24 is the raw material addition system, 25 is the raw material inlet pipe, 26 is the fiber unwinding system, 3 is the second surface layer preparation unit, 31 is the third spinning assembly, 32 is the second spraying system, 4 is the web forming curtain, 5 is the heating device, 6 is the hot rolling mill, 7 is the quality inspection unit, and 8 is the winding and slitting unit.

[0047] Figure 2 This is a schematic diagram of the No. 1 spinning assembly.

[0048] Figure 3 This is a schematic diagram of the No. 2 spinning assembly.

[0049] Figure 4 This is a schematic diagram of the No. 3 spinning assembly.

[0050] Figure 5 This is a schematic diagram of the No. 4 spinning assembly.

[0051] Figure 6 This is a schematic diagram of the No. 5 spinning assembly.

[0052] Figure 7 This is a schematic diagram of the No. 6 spinning assembly.

[0053] Figure 8 This is a schematic diagram of the thermal device structure;

[0054] Figure 9 This is a schematic diagram of the structure of the nonwoven composite material (2 layers with an intermediate water-absorbing layer) prepared according to the present invention;

[0055] Figure 10 This is a schematic diagram of the structure of the nonwoven composite material (1-layer intermediate water-absorbing layer) prepared according to the present invention. Detailed Implementation

[0056] This invention provides a nonwoven composite material comprising a first chemical fiber web layer, an intermediate absorbent layer, and a second chemical fiber web layer stacked sequentially.

[0057] The first chemical fiber mesh layer is a layered mesh structure formed from the raw materials for preparing the first surface layer; the raw materials for preparing the first surface layer include a first thermoplastic polymer and a first functional masterbatch;

[0058] The second chemical fiber network layer is a layered network structure formed from the raw materials used to prepare the second surface layer; the raw materials used to prepare the second surface layer include a second thermoplastic polymer and a second functional masterbatch;

[0059] The intermediate absorbent layer is a cross-fiber web structure formed from the core layer preparation raw materials, which include chemical filaments and short fibers; the area of ​​the cross-fiber web accounts for more than 50% of the area of ​​the intermediate absorbent layer; the short fibers include cellulose short fibers.

[0060] In this invention, a schematic diagram of the structure of the nonwoven composite material is shown below. Figure 9 The following is combined with Figure 9 A detailed description of nonwoven composite materials is provided.

[0061] The nonwoven composite material provided by this invention includes a first chemical fiber web layer. In this invention, the first chemical fiber web layer is a layered network structure formed from the raw materials used to prepare the first surface layer. In this invention, the function of the first chemical fiber web layer is to cover and protect the intermediate absorbent layer.

[0062] In this invention, the raw materials for preparing the first surface layer include a first thermoplastic polymer and a first functional masterbatch. Preferably, the first thermoplastic polymer comprises one or more of polypropylene (PP), modified polypropylene, polyethylene (PE), polyethylene terephthalate (PET), styrene-butadiene-styrene triblock copolymer (SBS), and ethylene-vinyl acetate copolymer (EVA). This invention does not specifically limit the type of modified polypropylene; any modified polypropylene well-known to those skilled in the art can be used. In this invention, the melt index of the first thermoplastic polymer is preferably 30 to 1800 g / 10 min, and in specific embodiments it can be 30 g / 10 min, 50 g / 10 min, 100 g / 10 min, 200 g / 10 min, 300 g / 10 min, 400 g / 10 min, 500 g / 10 min, 600 g / 10 min, 700 g / 10 min, 800 g / 10 min, 900 g / 10 min, 1000 g / 10 min, 1100 g / 10 min, 1200 g / 10 min, 1300 g / 10 min, 1400 g / 10 min, 1500 g / 10 min, 1600 g / 10 min, 1700 g / 10 min or 1800 g / 10 min.

[0063] In this invention, the mass fraction of the first thermoplastic polymer in the raw material for preparing the first surface layer is preferably 89.5% to 95%, and in specific embodiments it can be 89.5%, 90%, 90.5%, 91%, 91.5%, 92%, 92.5%, 93%, 93.5%, 94%, 94.5% or 95%.

[0064] In this invention, the first functional masterbatch preferably comprises one or more of hydrophilic masterbatch, biodegradable masterbatch, softening masterbatch, and antibacterial masterbatch. In this invention, the hydrophilic masterbatch preferably comprises one or more of polyether-based hydrophilic masterbatch, polyamide-based hydrophilic masterbatch, and fatty acid ester-based hydrophilic masterbatch. In this invention, the biodegradable masterbatch preferably comprises aerobic biodegradable masterbatch and / or anaerobic biodegradable masterbatch. In this invention, the softening masterbatch preferably comprises amide-based softener masterbatch. In this invention, the antibacterial masterbatch preferably comprises one or more of nano-cuprous oxide, nano-zinc oxide, and silver ion antibacterial agents.

[0065] In this invention, the raw materials for preparing the first surface layer preferably further include functional additives, which preferably include one or more of water-absorbing agents, softeners, and antibacterial agents. In this invention, the mass of the functional additives (commercially available products) preferably accounts for 0.2% to 8% of the mass of the nonwoven composite material, and in specific embodiments, it can be 0.2%, 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, or 8%. In this invention, the addition of the water-absorbing agent can improve the water absorption performance of the nonwoven composite material; the addition of the softener can improve the softness performance of the nonwoven composite material; and the addition of the antibacterial agent can improve the antibacterial and antifungal properties of the nonwoven composite material.

[0066] In this invention, the antibacterial agent preferably includes an organic antibacterial agent, more preferably one or more of a quaternary ammonium salt compound, polyhexamethylene biguanide hydrochloride, and polyhexamethylene guanidine hydrochloride; the antibacterial agent is used in the form of an antibacterial agent solution, which is preferably obtained by diluting a commercially available antibacterial agent stock solution; the concentration of the antibacterial agent solution is preferably 50-300 g / L, and in specific embodiments it can be 50 g / L, 100 g / L, 150 g / L, 200 g / L, 250 g / L, or 300 g / L; the diluent used for dilution preferably includes water.

[0067] In this invention, the softener preferably comprises a hydrophilic softener, more preferably a fatty alcohol polyoxyethylene ether and / or polyether-modified dimethyl silicone oil. In this invention, the absorbent preferably comprises one or more of polyether absorbents, polyamide absorbents, fatty acid ester absorbents, and quaternary ammonium salt absorbents; the polyether absorbent preferably includes Transfar Chemicals' hydrophilic softener TF-4511, Transfar Chemicals' hydrophilic high-feel silicone oil TF-405, etc.; the polyamide absorbent preferably includes Transfar Chemicals' hydrophilic softening oil TF-440A, etc.; the fatty acid ester absorbent preferably includes Lupert from Luda Technology. TM W312, Raysoft CS-N (non-silicone softener from Lurui Fine Chemicals), etc.; the preferred quaternary ammonium salt absorbents include TF-4514 (high-concentration, soft, hydrophilic softener from Chuanhua Chemicals) and Raysoft CS-N (non-silicone softener from Lurui Fine Chemicals).

[0068] In this invention, the raw materials for preparing the first surface layer preferably further include an antioxidant, which preferably includes one or more of 2,6-di-tert-butyl-4-methylphenol (BHT), hindered phenolic antioxidants, and phosphite antioxidants; the antioxidant preferably accounts for 0.1% to 2% of the mass of the raw materials for preparing the first surface layer, and in specific embodiments, it can be 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, or 2%.

[0069] In this invention, the raw materials for preparing the first surface layer preferably include one or more of mixture 1, mixture 2, mixture 3, and mixture 4. In specific embodiments, they can be one, two, or three of mixture 1, mixture 2, mixture 3, and mixture 4. When the raw materials for preparing the first surface layer are two or more of mixture 1, mixture 2, mixture 3, and mixture 4, the first chemical fiber web layer is a mixed fiber web layer formed by fibers of different compositions, which further improves the surface strength of the nonwoven composite material. The mass ratio of any two mixtures in the raw materials for preparing the first surface layer is preferably 1:0.5 to 2. In specific embodiments, it can be 1:0.5, 1:0.6, 1:0.7, 1:0.8, or 1:2. The mass ratio of any three mixtures in the raw materials for preparing the first surface layer is preferably 1:0.5 to 2:0.5 to 2. In specific embodiments, it can be 1:0.5:0.5, 1:0.5:1, 1:0.5:1.5, 1:0.5:2, 1:1:0.5, 1:1:1, 1:1:1.5, 1:1:2, 1:1.5:0.5, 1:1.5:1.5, 1:1.5:2, 1:1:0.5, 1:1:1, 1:1:1.5, 1:1:2, 1:1.5:0.5, 1:1.5:1, 1:1.5:1.5, 1:1.5:2, 1:2:0.5, 1:2:1, 1:2:1.5, or 1:2:2.

[0070] In this invention, the mixture 1 preferably includes polypropylene particles, hydrophilic masterbatch and biodegradable masterbatch, and the mass ratio of polypropylene particles, hydrophilic masterbatch and biodegradable masterbatch in the mixture 1 is preferably 94-96:3-5:1, more preferably 94:5:1, 95:4:1 or 96:3:1.

[0071] In this invention, the mixture 2 preferably includes polypropylene particles and hydrophilic masterbatch, and the mass ratio of polypropylene particles to hydrophilic masterbatch in the mixture 2 is preferably 95-97:3-5, and in specific embodiments it can be 95:5, 96:4 or 97:3.

[0072] In this invention, the mixture 3 preferably includes modified polyethylene particles, hydrophilic masterbatch, and styrene-butadiene-styrene triblock copolymer. The mass ratio of the modified polyethylene particles, hydrophilic masterbatch, and styrene-butadiene-styrene triblock copolymer in the mixture 3 is preferably 30-89:1-10:10-60, and more preferably 75:5:20.

[0073] In this invention, the mixture 4 preferably includes EVA resin and antioxidant, and the mass ratio of EVA resin to antioxidant in the mixture 4 is preferably 99.9-98.5:0.1-1.5, more preferably 99:1.

[0074] In this invention, the average diameter of the fibers in the first chemical fiber web layer is preferably 0.5 to 10 μm, and in specific embodiments it can be 0.5 μm, 1 μm, 1.9 μm, 2 μm, 2.3 μm, 2.4 μm, 2.6 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm or 10 μm; the basis weight of the first chemical fiber web layer is preferably 0.1 to 10 gsm, and in specific embodiments it can be 0.1 gsm, 0.5 gsm, 1 gsm, 2 gsm, 3 gsm, 4 gsm, 5 gsm, 6 gsm, 7 gsm, 8 gsm, 9 gsm or 10 gsm.

[0075] The nonwoven composite material provided by the present invention includes an intermediate absorbent layer, wherein the intermediate absorbent layer is a cross-fiber web structure formed from the raw materials for preparing the core layer.

[0076] In this invention, the number of layers of the intermediate absorbent layer is preferably several, more preferably 1 to 8 layers. In specific embodiments, it can be 1, 2, 3, 4, 5, 6, 7 or 8 layers; the raw materials for preparing the core layer of each intermediate absorbent layer are preferably the same or different.

[0077] In this invention, the core layer preparation materials include chemical filaments and short fibers; the chemical filaments preferably include one or more of polypropylene-based fibers, polyethylene-based fibers, polyethylene terephthalate-based fibers, styrene-butadiene-styrene triblock copolymer-based fibers, and ethylene-vinyl acetate copolymer-based fibers; the raw materials for preparing the chemical filaments are preferably the same as those selected for the first surface layer preparation materials, and will not be repeated here. In this invention, the diameter of the chemical filaments is preferably 0.1–5 μm, and in specific embodiments can be 0.1 μm, 0.5 μm, 1 μm, 2 μm, 3 μm, 4 μm, or 5 μm; this invention does not have a special limitation on the length of the chemical filaments, and continuous chemical filaments well known to those skilled in the art can be used.

[0078] In this invention, the short fibers preferably include one or more of cellulose short fibers, synthetic short fibers, and superabsorbent short fibers; the short fibers play a role in water absorption and conduction in the material; the length of the short fibers is preferably 1-8 mm, and in specific embodiments can be 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, or 8 mm; the diameter of the short fibers is preferably 2-5 mm, and in specific embodiments can be 2 mm, 3 mm, 4 mm, or 5 mm.

[0079] In this invention, the core layer preparation raw materials preferably further include functional fillers, which preferably include one or more of superabsorbent fiber (SAF), low-melting-point fiber, and superabsorbent polymer resin (SAP, granular). The superabsorbent fiber and superabsorbent polymer resin mainly function to absorb water, which can significantly improve the water absorption performance of the nonwoven composite material. In this invention, the melting point of the low-melting-point fiber is preferably ≤150℃, more preferably 110~150℃, and in specific embodiments it can be 110℃, 115℃, 120℃, 125℃, 130℃, 135℃, 140℃, 145℃, or 150℃; the low-melting-point fiber preferably includes low-melting-point PE fiber, and the melting point of the low-melting-point PE fiber is preferably 110℃; the low-melting-point fiber can play an adhesive binding role for the short cellulose fibers.

[0080] In this invention, the mass fraction of chemical filaments in the nonwoven composite material is preferably 6.5% to 23.2%, and in specific embodiments it can be 6.5%, 7%, 8%, 9%, 10%, 10.85%, 11%, 12%, 13%, 13.3%, 14%, 15%, 16%, 17.7%, 18%, 19%, 20%, 21%, 22%, 23%, or 23.2%; the mass fraction of short fibers in the nonwoven composite material is preferably 20% to 69.6%, and in specific embodiments it can be 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, or 69.6%.

[0081] In this invention, the area of ​​the cross-fiber web accounts for more than 50% of the area of ​​the intermediate absorbent layer, preferably 50% to 100%, and in specific embodiments, it can be >50%, >55%, >60%, >65%, >70%, >75%, >80%, >85%, >90%, >95%, or 100%. In this invention, the crossing angle of each fiber in the cross-fiber web is random.

[0082] In this invention, the mass of the first chemical fiber web layer preferably accounts for 3-20% of the mass of the nonwoven composite material. In specific embodiments, it can be 3%, 3.5%, 3.6%, 4%, 4.5%, 5%, 5.45%, 5.5%, 6%, 6.5%, 6.65%, 7%, 7.5%, 8%, 8.35%, 8.5%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, or 20%.

[0083] In this invention, the second chemical fiber web layer is a layered network structure formed from the raw materials for preparing the second surface layer; the raw materials for preparing the second surface layer include a second thermoplastic polymer and a second functional masterbatch. In this invention, the optional types of the raw materials for preparing the second surface layer of the second chemical fiber web layer, the fiber diameter of the second chemical fiber web layer, and the basis weight are preferably the same as those of the aforementioned first chemical fiber web layer, and will not be repeated here.

[0084] The present invention also provides a method for preparing the nonwoven composite material described in the above technical solution, comprising the following steps:

[0085] The raw material for the first surface layer is heated to melt and then spun into a first chemical fiber web layer; a first cooling process is performed during the first spinning process.

[0086] The raw materials for core layer preparation are cross-mixed and laid on the surface of the first chemical fiber web layer to form an intermediate absorbent layer with cross-fiber web, thus obtaining a chemical fiber web layer-intermediate absorbent layer.

[0087] The raw material for the second surface layer is heated to melt, and a second chemical fiber web layer is formed by second spinning on the surface of the intermediate absorbent layer of the chemical fiber web layer-intermediate absorbent layer-chemical fiber web layer; a second cooling is performed during the second spinning process.

[0088] The nonwoven composite material is obtained by hot rolling the chemical fiber web layer, the intermediate absorbent layer, and the chemical fiber web layer together.

[0089] In this invention, the raw material for preparing the first surface layer is heated to melt and then spun to obtain a first chemical fiber web layer; a first cooling process is performed during the first spinning process.

[0090] In this invention, the heating to melt is preferably carried out by heating and melting through a single-screw extrusion, twin-screw extrusion or multi-screw extrusion equipment, which can spray out chemical fibers of the same or different compositions at the same time. When chemical fibers of different compositions are sprayed out at the same time, a first chemical fiber web is formed in the form of mixed fibers, thereby further improving the surface strength of the nonwoven composite material.

[0091] In this invention, the first cooling preferably includes atomized spray cooling or cold air cooling using a cooling liquid; the cooling liquid preferably includes pure water or a functional additive solution. In this invention, the functional additives and their concentrations in the functional additive solution are the same as those described above, and will not be repeated here. In this invention, the spray rate of the cooling liquid is preferably 0-200 L / h, and in specific embodiments it can be 10 L / h, 20 L / h, 30 L / h, 40 L / h, 50 L / h, 60 L / h, 70 L / h, 80 L / h, 90 L / h, 100 L / h, 110 L / h, 120 L / h, 130 L / h, 140 L / h, 150 L / h, 160 L / h, 170 L / h, 180 L / h, 190 L / h, or 200 L / h. In this invention, the angle between the cooling liquid sprayed by the atomized spray and the direction of fiber ejection is preferably 90° to 180°, and in specific embodiments, it can be 90°, 100°, 110°, 120°, 130°, 140°, 150°, 160°, 170°, or 180°. In this invention, the temperature of the cooling air is preferably 5°C to 30°C. This invention performs a first cooling process during the first spinning stage, giving the fiber superior strength properties, thereby significantly improving the strength of the nonwoven composite material. In this invention, the temperature of the fiber after the first cooling is preferably ≤150°C, more preferably ≤100°C.

[0092] After the first spinning is completed, the present invention preferably further includes performing a first drawing on the obtained fibers; the drawing air volume of each spinneret during the first drawing process is preferably 0.1 to 1 m³ / s. 3 / h, in a specific embodiment, can be 0.1m. 3 / h, 0.2m 3 / h, 0.3m 3 / h, 0.4m 3 / h, 0.5m 3 / h, 0.6m 3 / h, 0.7m 3 / h, 0.8m 3 / h, 0.9m 3 / h or 1m 3 / h; the first stretching preferably includes enclosed air outlet stretching, middle air outlet duct stretching, or side slit stretching.

[0093] After obtaining the first chemical fiber web layer, the present invention cross-mixes the core layer preparation raw materials and lays them on the surface of the first chemical fiber web layer to form an intermediate absorbent layer with cross-fiber web, thus obtaining the chemical fiber web layer-intermediate absorbent layer.

[0094] In this invention, the chemical filament is preferably obtained by a third thermoplastic polymer and a third functional masterbatch through a third spinning process. In this invention, no cooling is performed during the third spinning process. In this invention, the optional types of the third thermoplastic polymer, the optional types of the third functional masterbatch, and the mass fractions of the third thermoplastic polymer and the third functional masterbatch in the chemical filament are preferably the same as the corresponding preparation conditions of the chemical fiber web, and will not be repeated here. In this invention, the third spinning preferably includes meltblowing.

[0095] After the third spinning is completed, the present invention preferably further includes a second drawing of the obtained fibers to obtain chemical filaments. In the present invention, the method of the second drawing is preferably the same as that of the first drawing, and will not be described again here.

[0096] In this invention, when the raw materials for preparing the core layer also include functional fillers, it is preferable to cross-mix chemical filaments, short fibers and functional fillers.

[0097] In this invention, the net laying is preferably carried out on the netting curtain. The bottom of the net can be used to adjust the suction size at the corresponding position by setting baffles with different mesh sizes separately. That is, the degree of mixing and cross-mixing of raw materials in the forming box can be controlled according to the combination of baffles with different mesh sizes. At the same time, the outer chemical fibers can be finely adjusted in the forming area of ​​the netting curtain.

[0098] In this invention, the intermediate absorbent layer is preferably prepared once or twice. When the intermediate absorbent layer is prepared twice, it is preferable to prepare a second intermediate absorbent layer on the surface of the intermediate absorbent layer prepared in the first preparation.

[0099] After obtaining the chemical fiber web layer-intermediate absorbent layer, the raw material for the second surface layer is heated to melt, and a second chemical fiber web layer is formed on the surface of the intermediate absorbent layer of the chemical fiber web layer-intermediate absorbent layer through a second spinning process, resulting in a chemical fiber web layer-intermediate absorbent layer-chemical fiber web layer; a second cooling process is performed during the second spinning process. In this invention, the preparation method of the second chemical fiber web layer is preferably the same as the preparation method of the first chemical fiber web layer, and will not be described again here.

[0100] After obtaining the chemical fiber web layer-intermediate absorbent layer-chemical fiber web layer, the present invention performs hot rolling composite of the chemical fiber web layer-intermediate absorbent layer-chemical fiber web layer to obtain the nonwoven composite material.

[0101] In this invention, the hot-rolled composite is preferably not heat-treated or is heat-treated. When the core layer preparation raw material contains low-melting-point chemical fibers, heat treatment is preferred. In this invention, the heat treatment temperature is preferably 90–180°C, and in specific embodiments, it can be 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, or 180°C. The drying treatment is preferably performed using an oven. In this invention, the purpose of the heat treatment is to remove moisture from the material and to activate the low-melting-point chemical fibers. Under the action of heat (e.g., hot air), the low-melting-point chemical fibers partially melt, causing them to act as an adhesive to the short cellulose fibers. Simultaneously, due to the effects of heat and moisture in the material, the hydrogen bonds between the cellulose fibers within the material are opened, forming a more porous nonwoven composite material. This invention can impart permanent patterns to the nonwoven composite material through the patterns on the hot-rolled rollers, and the pattern shapes are diverse.

[0102] In this invention, the preferred temperature for hot rolling composite is 90–160°C, and in specific embodiments, it can be 90°C, 100°C, 110°C, 115°C, 120°C, 125°C, 130°C, 140°C, 150°C, or 160°C; the preferred pressure for hot rolling composite is 25–85 bar, and in specific embodiments, it can be 20 bar, 30 bar, 40 bar, 50 bar, 60 bar, 65 bar, 70 bar, 75 bar, 80 bar, or 85 bar; the hot rolling composite is preferably performed using a circular roll embossing machine. This invention does not impose any special limitations on the pattern on the circular roll used for hot rolling composite; it can be determined according to actual needs.

[0103] After the hot-rolled composite is completed, the present invention preferably further includes the obtaining hot-rolled composite material being inspected for metal content, weight, and appearance defects by an automatic quality inspection unit, and then being slit and rolled to obtain a nonwoven composite material product.

[0104] This invention provides the application of the nonwoven composite material described in the above technical solution or the nonwoven composite material prepared by the above technical solution in disposable hygiene products or wipes.

[0105] The present invention also provides a production apparatus for the preparation method of the nonwoven composite material described in the above technical solution or the preparation method of the nonwoven composite material described in the above technical solution, including a first surface layer preparation unit 1, a core layer preparation unit 2, a second surface layer preparation unit 3, a web forming curtain 4, and a hot rolling mill 6;

[0106] The first surface layer preparation unit 1 is provided with a first spinning assembly 11 and a first spraying system 12; the first spinning assembly 11 includes a coaxial melt-blown spinning assembly or an air knife drawing spinning assembly; the first spinning assembly 11 includes at least one melt chamber, and each melt chamber is connected to a spinneret.

[0107] The core layer preparation unit 2 is provided with a molding box 21, and the molding box 21 is provided with a raw material inlet 23 and a raw material inlet pipe 25;

[0108] The second surface layer preparation unit 3 includes a third spinning assembly 31 and a second spraying system 32; the third spinning assembly 31 includes a coaxial meltblown spinning assembly or an air knife drawing spinning assembly; the third spinning assembly 31 includes at least one melt chamber, and each melt chamber is connected to a spinneret.

[0109] The mesh material outlets of the first surface layer preparation unit 1, the core layer preparation unit 2, and the second surface layer preparation unit 3 are respectively connected to the mesh forming curtain 4; the mesh forming curtain 4 is provided with a mesh bottom suction system 41.

[0110] In this invention, the structural schematic diagram of the production device is as follows: Figure 1 As shown below, in conjunction with Figure 1 The production equipment is described in detail.

[0111] The production apparatus provided by the present invention includes a first surface layer preparation unit 1, the first surface layer preparation unit 1 being provided with a first spinning assembly 11 and a first spraying system 12; the first spinning assembly 11 includes a coaxial melt-blown spinning assembly or an air knife drawing spinning assembly; the first spinning assembly 11 includes at least one melt chamber, each melt chamber being connected to a spinneret.

[0112] In this invention, the coaxial meltblown spinning assembly preferably includes a spinneret, a melt cavity, a melt channel, a hot air channel, a hot air chamber, an outer air plate, and an inner air plate; the spinneret preferably includes a plate body and spinnerets; each melt cavity is connected to a spinneret; the number of melt cavities is preferably 1 to 5, and in specific embodiments it can be 1, 2, 3, 4 or 5.

[0113] In this invention, the coaxial meltblown spinning assembly preferably includes Figure 2 The No. 1 spinning assembly shown has a melt chamber and multiple rows of spinnerets.

[0114] In this invention, the coaxial meltblown spinning assembly preferably includes Figure 3 The No. 2 spinning assembly shown has two melt chambers with multiple rows of spinnerets. The two melt chambers are melt chamber 1 and melt chamber 2.

[0115] In this invention, the coaxial meltblown spinning assembly preferably includes Figure 4The No. 3 spinning assembly shown has three melt chambers and multiple rows of spinnerets. The three melt chambers are melt chamber 1, melt chamber 2 and melt chamber 3.

[0116] In this invention, the coaxial meltblown spinning assembly preferably includes Figure 5 The No. 4 spinning assembly shown has two melt chambers with multiple rows of spinnerets. The two melt chambers are melt chamber 1 and melt chamber 2, which are distributed vertically.

[0117] In this invention, the air-knife drafting spinning assembly preferably includes a melt chamber 1, a melt chamber 2, a spinneret, a spinneret orifice, a melt channel, a hot air channel, and an air knife; each melt chamber is connected to a spinneret orifice; the number of melt chambers is preferably 1 to 2, and in specific embodiments, it can be 1 or 2. In this invention, the air-knife drafting spinning assembly preferably includes... Figure 6 The No. 5 spinning assembly with the structure shown is or Figure 7 The No. 6 spinning assembly with the structure shown.

[0118] In this invention, the drawing of the first spinning assembly 11 preferably includes encircling air outlet drawing, intermediate air outlet drawing, or side slit drawing; the encircling air outlet drawing is preferably: each spinneret corresponds to an encircling air outlet, and a drawing airflow with process temperature is sprayed around the spinneret to draw the sprayed melt, and the encircling air outlet drawing component has no special requirements on the number of rows of spinnerets; the intermediate air outlet drawing is preferably: the melt spraying channel is located around the air outlet, and when the melt is sprayed, the intermediate air outlet sprays a drawing airflow to draw it, and the intermediate air outlet drawing has no special requirements on the number of rows of spinnerets; the side slit drawing is preferably: the drawing airflow is sprayed in the side slits of the spinneret to draw the melt; when the side slit drawing component is used, the number of rows of spinnerets is 1 to 2. In this invention, the first spinning assembly 11 preferably uses a single-cavity parallel double-row spinneret, a single-cavity staggered double-row spinneret, or a double-cavity single-row spinneret. Preferably, this invention allows for easy switching between different spinning assemblies by simply assembling and disassembling the fixing bolt wedge.

[0119] In this invention, the first spray system 12 preferably includes a water tank, a pressurized water pump, a flow control valve, a transmission pipe, and an atomizing spray head. The first spray system 12 is preferably located in the range of 5 to 50 cm below the spinneret. In specific embodiments, it can be located in the range of 5 cm, 10 cm, 15 cm, 20 cm, 25 cm, 30 cm, 35 cm, 40 cm, 45 cm, or 50 cm below the spinneret. The angle between the first spray system 12 and the direction of movement of the chemical fiber is preferably 90 to 180°. In specific embodiments, it can be 90°, 100°, 110°, 120°, 130°, 140°, 150°, 160°, 170°, or 180°.

[0120] The production apparatus provided by the present invention includes a core layer preparation unit 2; the core layer preparation unit 2 is provided with a molding box 21, and the molding box 21 is provided with a raw material inlet 23 and a raw material inlet pipe 25.

[0121] In this invention, fibrous raw materials are preferably transported to the molding box 21 through the raw material inlet pipe 25, and granular raw materials are preferably transported to the molding box 21 through the raw material adding system 24.

[0122] In this invention, the material of the molding box 21 preferably includes one or more of metal, rigid polymer, and glass; the metal preferably includes steel; the rigid polymer preferably includes polycarbonate. In this invention, during the preparation of the intermediate absorbent layer, chemical fibers and short fibers (or chemical fibers, short fibers, and superabsorbent fibers) are mixed and cross-linked within the molding box 21.

[0123] In this invention, the core layer preparation unit 2 preferably further comprises a second spinning assembly 22, a raw material addition system 24, and a fiber unwinding system 26. The fiber outlet of the second spinning assembly 22 is connected to the forming box 21. The second spinning assembly 22 includes a coaxial melt-blown spinning assembly or an air-knife drawing spinning assembly. The second spinning assembly 22 includes at least one melt chamber, and each melt chamber is connected to a spinneret. The fiber unwinding system 26 is disposed on the raw material inlet pipe 25. The forming box 21 is connected to the raw material addition system 24. The number of the second spinning assemblies 22 is one or two. The two spinning assemblies can be opened simultaneously, either one can be opened, or both can be closed simultaneously without interfering with or affecting each other. The structural composition of the second spinning assembly 22 is preferably the same as that of the first spinning assembly 11, and will not be described again here.

[0124] In this invention, the raw material addition system 24 is preferably provided with a raw material transfer pipe. The inner wall of the raw material transfer pipe is smooth and has no sharp edges, so that superabsorbent fibers will not remain. The superabsorbent fibers are evenly distributed in the CD direction by the raw material addition system 24 and transported to the molding box 21 through the transfer pipe.

[0125] In this invention, the number of core layer preparation units 2 is preferably several, and the number of core layer preparation units 2 is preferably the same as the number of layers of the intermediate absorbent layer.

[0126] The production apparatus provided by the present invention further includes a second surface layer preparation unit 3, which includes a third spinning assembly 31 and a second spraying system 32. In the present invention, the structural composition of the second surface layer preparation unit 3 is preferably the same as that of the first surface layer preparation unit 1, and will not be described in detail here.

[0127] The production apparatus provided by this invention also includes a web forming curtain 4, which is equipped with a bottom suction system 41. The web material outlets of the first surface layer preparation unit 1, the core layer preparation unit 2, and the second surface layer preparation unit 3 are respectively connected to the web forming curtain 4. In this invention, under the action of the bottom suction system 41, each fiber web is laid on the web forming curtain 4. The bottom suction system 41 can adjust the suction size at the corresponding position by separately setting baffles with different mesh sizes. That is, the degree of mixing, overlapping, and crossing of raw materials in the forming box 21 can be controlled according to the combination of baffles with different mesh sizes. At the same time, the first chemical fiber web layer and the second chemical fiber web layer can be finely adjusted in the forming area of ​​the web forming curtain 4.

[0128] The production apparatus provided by the present invention preferably further includes a heating device 5, which preferably adopts a hot air penetration drying method. It is equipped with two motor-driven active rollers at the top and bottom, which can better match the high-speed movement of the material and avoid fabric breakage as much as possible. Two tension adjusting rollers that can move laterally are arranged in the middle to adjust the tightness of the material.

[0129] In this invention, the heating device 5 preferably includes a drying chamber, and the drying chamber is preferably equipped with a perforated distribution plate. The perforated distribution plate preferably includes a distribution plate 1 and a distribution plate 2, both of which are equipped with guide rollers. A tension adjusting roller is provided on the connecting line between the guide rollers on the distribution plate 1 and the guide rollers on the distribution plate 2. The drying chamber is preferably equipped with a hot air inlet and an air outlet. In this invention, the distribution plate 1 is used to evenly disperse the hot air blown in by the hot air fan into the drying chamber. The hot air penetrates the material distributed along the M-shape in the drying chamber and is extracted by the exhaust fan after passing through the distribution plate 2. The main function of the distribution plate 1 and the distribution plate 2 is to disperse the hot air flow, ensuring that the airflow entering the drying chamber is uniform, preventing damage to local parts of the fabric or uneven stress on the fabric surface due to uneven airflow distribution.

[0130] The production apparatus provided by this invention includes a hot rolling mill 6. Preferably, the hot rolling mill 6 is equipped with working patterned rolls and spare patterned rolls. The spare patterned rolls can be disassembled, repaired, and maintained without stopping the machine, minimizing the impact on product production. The hot rolling mill 6 used in this invention can achieve rapid switching of patterned rolls and can be used for "Y"-type automatic roll changing.

[0131] The production apparatus provided by the present invention preferably also includes a quality inspection unit 7 and a winding and slitting unit 8.

[0132] The following is combined Figure 1 The preparation of nonwoven composite materials is described in detail.

[0133] The raw material for the first surface layer is heated to a melt and then spun by the first spinning assembly 11. After being first drawn onto the forming curtain 4, a first chemical fiber web layer is obtained. During the first spinning process, the first spray system 12 is used for the first cooling.

[0134] The core layer preparation raw materials are cross-mixed in the molding box 21 and laid on the surface of the first chemical fiber web layer through the web forming curtain 4 to form an intermediate absorbent layer with cross-fiber web, thus obtaining a chemical fiber web layer - intermediate absorbent layer; the area of ​​the cross-fiber web is controlled to be more than 50% of the area of ​​the intermediate absorbent layer by the bottom suction system 41; the chemical fibers in the core layer preparation raw materials are preferably obtained by third spinning of a third thermoplastic polymer and a third functional masterbatch through a second spinning assembly 22;

[0135] The raw material for the second surface layer is heated to melt, and then spun a second time on the surface of the intermediate absorbent layer of the chemical fiber web layer-intermediate absorbent layer by the third spinning assembly 31 to form a second chemical fiber web layer. After being drawn a second time onto the surface of the intermediate absorbent layer on the web forming curtain 4, a chemical fiber web layer-intermediate absorbent layer-chemical fiber web layer is obtained. During the second spinning process, a second cooling process is carried out by the second spray system 32.

[0136] The chemical fiber web layer, the intermediate absorbent layer, and the chemical fiber web layer are hot-rolled together in a hot rolling mill 6 to obtain the nonwoven composite material.

[0137] In this invention, taking a two-layer intermediate absorbent layer as an example, after forming an intermediate absorbent layer with a cross-fiber web, the invention preferably further includes preparing a second intermediate absorbent layer on the area of ​​the intermediate absorbent layer. Specifically, when preparing the second intermediate absorbent layer, the core layer preparation raw material is used to prepare the second intermediate absorbent layer in the second core layer preparation unit to obtain a chemical fiber web layer - intermediate absorbent layer; the area of ​​the cross-fiber web is controlled to be more than 50% of the area of ​​the intermediate absorbent layer by the bottom air suction system 41; the chemical fiber in the core layer preparation raw material is preferably obtained by a third thermoplastic polymer and a third functional masterbatch through a fourth spinning process using a third spinning assembly 31.

[0138] To further illustrate the present invention, the following detailed description of the invention's solutions, in conjunction with the accompanying drawings and embodiments, is provided, but should not be construed as limiting the scope of protection of the present invention.

[0139] In the following embodiments, the hydrophilic masterbatch was purchased from Changzhou Wangyi New Material Technology Co., Ltd., and the biodegradable masterbatch was purchased from Transfar Chemical Group. The short fibers have a length of 1–8 mm. Except for the short fibers and superabsorbent resin, the other fibers in the first chemical fiber web layer, the intermediate absorbent layer, and the second chemical fiber web layer are all continuous long fibers.

[0140] Example 1

[0141] The nonwoven composite material consists of, from bottom to top, a first chemical fiber web layer, a middle absorbent layer (2 layers), and a second chemical fiber web layer.

[0142] (1) Polypropylene granules, hydrophilic masterbatch, and biodegradable masterbatch are mixed at a mass ratio of 94:5:1 and extruded through the first spinning assembly 11 (spinning assembly No. 1) using a single-screw extruder. The airflow is then drawn onto the forming curtain 4 using an enclosed air outlet. ， A first chemical fiber web layer is obtained. During the spraying process, a first spray system 12, located 20 cm below the spinneret, sprays pure water mist for cooling, with a spray rate of 150 L / h; the average fiber diameter of the first chemical fiber web layer is 2–3 μm, and the basis weight is 2 gsm.

[0143] (2) Polypropylene granules, hydrophilic masterbatch and biodegradable masterbatch are mixed in a mass ratio of 96:3:1. The resulting mixture is melt-blown through the second spinning assembly 22 (spinning assembly No. 1) and drawn by an external ring-type airflow through the spinneret to obtain chemical filaments. The chemical filaments are cross-mixed with cellulose short fibers in a metal forming box 21. The area of ​​the cross-fiber web is controlled to be greater than 75% of the area of ​​the intermediate water-absorbing layer by the bottom suction system 41. The intermediate water-absorbing layer is formed on the net curtain 4 below the forming box 21.

[0144] (3) Repeat step (2) on the surface of the intermediate absorbent layer using the second core layer preparation unit to obtain the chemical fiber web layer-intermediate absorbent layer.

[0145] (4) Repeat step (1) on the surface of the chemical fiber web layer-intermediate absorbent layer using the second surface layer preparation unit 3 to obtain the chemical fiber web layer-intermediate absorbent layer-chemical fiber web layer.

[0146] (5) The composite material is transported from the forming screen 4 to the hot rolling mill 6 for hot rolling (temperature 125℃, pressure 75 bar). The pattern design features animal cartoon elements. After passing through an automatic quality inspection unit to detect metal content, weight, and appearance defects, it is slit and rolled to obtain the nonwoven composite material. The nonwoven composite material has a weight of 55 gsm, a total content of 7.2 wt% for the two chemical fiber web layers, a chemical filament content of 23.2 wt%, and a cellulose short fiber content of 69.6 wt%.

[0147] Example 2

[0148] The nonwoven composite material consists of, from bottom to top, a first chemical fiber web layer, a middle absorbent layer (2 layers), and a second chemical fiber web layer.

[0149] (1) Polypropylene granules with a melt index of 35 g / 10 min and hydrophilic masterbatch are mixed at a mass ratio of 95:5 and extruded through the first spinning assembly 11 using a single-screw extruder. The filaments are then adsorbed onto the web forming curtain 4 via a slit-drawing method to obtain the first chemical fiber web layer. Cooling is achieved during the extrusion process using cold air (5-30℃). The average fiber diameter of the first chemical fiber web layer is 7.8 μm, and the basis weight is 10 gsm.

[0150] (2) Polypropylene granules with a melt index of 1200 g / 10 min are mixed with hydrophilic masterbatch at a mass ratio of 97:3 and sprayed out through the melt chamber 1 of the second spinning assembly 22 (spinning assembly No. 2). The mixture is then drawn using an outer ring drawing airflow through the spinneret orifice to obtain chemical filament 1. At the same time, polypropylene granules with a melt index of 500 g / 10 min are mixed with hydrophilic masterbatch at a mass ratio of 97:3 and sprayed out through the melt chamber 2 of the second spinning assembly 22 (spinning assembly No. 2). The mixture is then drawn using an outer ring drawing airflow through the spinneret orifice to obtain chemical filament 2. The chemical filament 1 and chemical filament 2 are cross-mixed with cellulose short fibers and superabsorbent polymer (SAP) in a metal molding box 21. The area of ​​the cross-fiber web is controlled to be greater than 75% of the area of ​​the intermediate absorbent layer by the bottom suction system 41. The mixture is then formed on the net curtain 4 below the molding box 21 to form the intermediate absorbent layer. The chemical fiber web formed uses low melt index polypropylene particles near the middle layer, resulting in higher fiber strength, stronger adhesion, and a more porous spatial structure, which allows the fluff pulp fibers and SAF to be better bound. In addition, the part near the surface layer uses polypropylene particles with a higher melt index, resulting in finer fibers, smaller pores, and a denser fiber web, which can better encapsulate the fluff pulp and SAF.

[0151] (3) Repeat step (2) on the surface of the intermediate absorbent layer using the second core layer preparation unit to obtain the chemical fiber web layer-intermediate absorbent layer.

[0152] (4) Repeat step (1) on the surface of the chemical fiber web layer-intermediate absorbent layer using the second surface layer preparation unit 3 to obtain the chemical fiber web layer-intermediate absorbent layer-chemical fiber web layer.

[0153] (5) The composite material is transported from the forming screen 4 to the hot rolling mill 6 for hot rolling (temperature 125℃, pressure 75 bar). To avoid the impact of hot rolling on the SAP effect, the pattern is designed as a sesame dot pattern. After passing through the automatic quality inspection unit for metal content, weight, and appearance defects, it is slit and rolled to obtain the nonwoven composite material. The nonwoven composite material has a weight of 120 gsm, a total content of 16.7 wt% for the two chemical fiber web layers, a SAP content of 50 wt%, a cellulose short fiber content of 20 wt%, and a content of 6.65 wt% for both chemical filament 1 and chemical filament 2.

[0154] Example 3

[0155] The nonwoven composite material consists of, from bottom to top, a first chemical fiber web layer, a middle absorbent layer (2 layers), and a second chemical fiber web layer.

[0156] (1) Modified PE particles, hydrophilic masterbatch, and styrene-butadiene-styrene triblock copolymer elastomer are mixed in a mass ratio of 75:5:20 to form a first mixed raw material; polypropylene particles and hydrophilic masterbatch are mixed in a mass ratio of 95:5 to form a second mixed raw material; EVA resin and antioxidant BHT are mixed in a mass ratio of 99:1 to form a third mixed raw material; the three mixed raw materials are melted in a mass ratio of 1:1:1 by separate screw extrusion equipment and conveyed to three adjacent melt chambers in the first spinning assembly 11 (spinning assembly No. 3), and extruded through corresponding spinnerets. The spinnerets are drawn onto the web forming curtain 4 by an outer ring-type drawing airflow, and the three fibers interweave to form a fiber web, thus obtaining the first chemical fiber web layer. Among them, the first mixed raw material is extruded through the outermost spinneret, the second mixed raw material is extruded through the middle spinneret, and the third mixed raw material is extruded through the innermost spinneret. During the spraying process, a first spraying system 12, located 20cm below the spinneret, sprays pure water to cool the fibers, with a spraying rate of 120L / h. The average fiber diameter of the first chemical fiber web layer is 2.3μm, and the basis weight is 9gsm.

[0157] (2) EVA is ejected through the second spinning assembly 22 (spinning assembly No. 1) and drawn by the outer ring of the spinneret to obtain chemical filaments. The chemical filaments are cross-mixed with cellulose short fibers and superabsorbent polymer (SAP) in the metal forming box 21. The area of ​​the cross-fiber web is controlled by the bottom suction system 41 to be greater than 75% of the area of ​​the intermediate absorbent layer. The intermediate absorbent layer is formed on the net curtain 4 below the forming box 21.

[0158] (3) Repeat step (2) on the surface of the intermediate absorbent layer using the second core layer preparation unit to obtain the chemical fiber web layer-intermediate absorbent layer.

[0159] (4) Repeat step (1) on the surface of the chemical fiber web layer-intermediate absorbent layer using the second surface layer preparation unit 3 to obtain the chemical fiber web layer-intermediate absorbent layer-chemical fiber web layer.

[0160] (5) The fibers are transported via the forming curtain 4 to the heating device 5 for heat treatment (drying temperature set at 130℃), and then further conveyed to the hot rolling mill 6 for hot rolling composite (temperature 125℃, pressure 75 bar). To avoid the influence of hot rolling on the SAP effect, the pattern is designed as a sesame dot pattern. After passing through the automatic quality inspection unit for metal content, weight, and appearance defects, the fibers are slit and rolled to obtain the nonwoven composite material. The nonwoven composite material has a weight of 120 gsm, a total content of 15 wt% for the two chemical fiber web layers, a SAP content of 50 wt%, a cellulose short fiber content of 20 wt%, and a chemical filament content of 15 wt%.

[0161] In this embodiment, the heat treatment by the heating device can stimulate the bonding effect of EVA fibers, reduce the shedding of fluff pulp and SAP in nonwoven composite materials, and can increase the strength of nonwoven composite materials to a certain extent.

[0162] Example 4

[0163] The nonwoven composite material consists of, from bottom to top, a first chemical fiber web layer, a middle absorbent layer (2 layers), and a second chemical fiber web layer.

[0164] (1) Modified PE particles, hydrophilic masterbatch, and styrene-butadiene-styrene triblock copolymer elastomer are mixed in a mass ratio of 75:5:20 to form a first mixed raw material. Polypropylene particles and hydrophilic masterbatch are mixed in a mass ratio of 95:5 to form a second mixed raw material. The two mixed raw materials are melted in a mass ratio of 1:1 by separate screw extrusion equipment and conveyed to two vertically distributed melt chambers in the first spinning assembly 11 (spinning assembly No. 4). They are then extruded through corresponding spinnerets onto the web forming curtain 4, where the two fibers interweave to form a fiber web, resulting in the first chemical fiber web layer. During the extrusion process, a first spraying system 12 located 20 cm below the spinnerets sprays pure water for cooling, with a spray rate of 180 L / h. The average fiber diameter of the first chemical fiber web layer is 2.6 μm, and the basis weight is 4 gsm. The drawing method is an external ring-type airflow drawing method outside the spinnerets.

[0165] (2) Polypropylene fibers are ejected through the second spinning assembly 22 (spinning assembly No. 1) and drawn by the outer ring of the spinneret to obtain chemical filaments. The chemical filaments are cross-mixed with cellulose short fibers and SAF in the metal forming box 21. The area of ​​the cross-fiber web is controlled to be greater than 75% of the area of ​​the intermediate water-absorbing layer by the bottom suction system 41. The intermediate water-absorbing layer is formed on the net curtain 4 below the forming box 21.

[0166] (3) Repeat step (2) on the surface of the intermediate absorbent layer using the second core layer preparation unit to obtain the chemical fiber web layer-intermediate absorbent layer.

[0167] (4) Repeat step (1) on the surface of the chemical fiber web layer-intermediate absorbent layer using the second surface layer preparation unit 3 to obtain the chemical fiber web layer-intermediate absorbent layer-chemical fiber web layer.

[0168] (5) The composite material is transported from the forming curtain 4 to the hot rolling mill 6 for hot rolling (temperature 115℃, pressure 65 bar). To avoid the influence of hot rolling on the SAF effect, the pattern is designed as a geometric pattern line. After passing through the automatic quality inspection unit for metal content, weight, and appearance defects, it enters the slitting and rolling process to obtain the nonwoven composite material. The nonwoven composite material has a weight of 60 gsm, a total content of 13.3 wt% for the two chemical fiber web layers, a SAF content of 10.85 wt%, a cellulose short fiber content of 65 wt%, and a chemical filament content of 10.85 wt%.

[0169] Example 5

[0170] The nonwoven composite material consists of, from bottom to top, a first chemical fiber web layer, a middle absorbent layer (2 layers), and a second chemical fiber web layer.

[0171] (1) Modified PE particles, hydrophilic masterbatch, and styrene-butadiene-styrene triblock copolymer elastomer are mixed in a mass ratio of 75:5:20 to form a first mixed raw material. Polypropylene particles and hydrophilic masterbatch are mixed in a mass ratio of 95:5 to form a second mixed raw material. The two mixed raw materials are melted in a mass ratio of 1:1 by separate screw extrusion equipment and conveyed to two adjacent melt chambers in the first spinning assembly 11 (spinning assembly No. 5). The fibers are extruded through corresponding spinnerets. The extruded fibers are drawn onto the web forming curtain 4 by hot air jets sprayed from the gaps between the air knives on both sides. The two types of fibers interweave to form a fiber web, resulting in the first chemical fiber web layer. During the extrusion process, pure water is sprayed for cooling by the first spraying system 12 located 20 cm below the spinneret, with a spraying rate of 150 L / h. The average fiber diameter of the first chemical fiber web layer is 2.4 μm, and the basis weight is 4 gsm.

[0172] (2) Polypropylene fibers are ejected from the second spinning assembly 22 (spinning assembly No. 1) and drawn using an external ring-type airflow drawing method to obtain chemical filaments. These chemical filaments are then cross-mixed with cellulose short fibers and low-melting-point PE short fibers (melting point 110℃) within a metal forming box 21. The area of ​​the cross-fiber web is controlled by the bottom suction system 41 to be greater than 75% of the area of ​​the intermediate absorbent layer. The mixture is then formed on the netting curtain 4 below the forming box 21 to form the intermediate absorbent layer. The drawing method is an external ring-type airflow drawing method using the spinning holes.

[0173] (3) Repeat step (2) on the surface of the intermediate absorbent layer using the second core layer preparation unit to obtain the chemical fiber web layer-intermediate absorbent layer.

[0174] (4) Repeat step (1) on the surface of the chemical fiber web layer-intermediate absorbent layer using the second surface layer preparation unit 3 to obtain the chemical fiber web layer-intermediate absorbent layer-chemical fiber web layer.

[0175] (5) The material is transported via the forming curtain 4 to the heating device 5 for heat treatment (drying temperature set at 120℃), and then further conveyed to the hot rolling mill 6 for hot rolling and compounding (temperature 115℃, pressure 65 bar). The pattern is designed as cartoon character lines. After passing through the automatic quality inspection unit for metal content, weight, and appearance defects, it enters the slitting and rolling process to obtain the nonwoven composite material. The nonwoven composite material has a weight of 60 gsm, a total content of 13.3 wt% for the two chemical fiber web layers, a low melting point PE short fiber content of 13.35 wt%, a cellulose short fiber content of 60 wt%, and a chemical filament content of 13.35 wt%.

[0176] In this embodiment, the heat treatment by the heating device can activate the bonding effect of low-melting-point PE fibers, reduce the shedding of nonwoven composite material fluff pulp, and increase the strength of nonwoven composite materials to a certain extent.

[0177] Example 6

[0178] The nonwoven composite material consists of, from bottom to top, a first chemical fiber web layer, a middle absorbent layer (2 layers), and a second chemical fiber web layer.

[0179] (1) Polypropylene granules and hydrophilic masterbatch are melted separately in a mass ratio of 95:5 using individual screw extrusion equipment and conveyed to the first spinning assembly 11 (spinning assembly No. 6) and extruded through the spinneret. The extruded fibers are drawn by hot air jets sprayed from the gaps between the air knives on both sides, and the two types of fibers are cross-mixed to form a first chemical fiber web layer on the web forming curtain 4. During the extrusion process, pure water is sprayed for cooling by the first spraying system 12 located 20 cm below the spinneret, with a spraying rate of 120 L / h. The average diameter of the fibers in the first chemical fiber web layer is 1.9 μm, and the basis weight is 3 gsm. Because the fiber web extruded by this type of spinning assembly has a higher density, it can better wrap the middle absorbent layer, preventing the material in the middle absorbent layer from falling off. On the other hand, it can increase the density of the fiber web and enhance the cleaning effect of the nonwoven material.

[0180] (2) Polypropylene granules, hydrophilic masterbatch and biodegradable masterbatch are mixed in a mass ratio of 96:3:1. The resulting mixture is melt-blown through the second spinning assembly 22 (spinning assembly No. 1) and drawn by an outer ring of the spinneret hole to obtain chemical filaments. The chemical filaments are cross-mixed with cellulose short fibers in a metal forming box 21. The area of ​​the cross-fiber web is controlled to be greater than 75% of the area of ​​the intermediate water-absorbing layer by the bottom suction system 41. The intermediate water-absorbing layer is formed on the net curtain 4 below the forming box 21.

[0181] (3) Repeat step (2) on the surface of the intermediate absorbent layer using the second core layer preparation unit to obtain the chemical fiber web layer-intermediate absorbent layer.

[0182] (4) Repeat step (1) on the surface of the chemical fiber web layer-intermediate absorbent layer using the second surface layer preparation unit 3 to obtain the chemical fiber web layer-intermediate absorbent layer-chemical fiber web layer.

[0183] (5) The composite material is transported from the forming screen 4 to the hot rolling mill 6 for hot rolling (temperature 125℃, pressure 75 bar). The pattern is a floral design containing animal cartoon elements. After passing through the automatic quality inspection unit for metal content, weight, and appearance defects, it is slit and rolled to obtain the nonwoven composite material. The nonwoven composite material has a weight of 55 gsm, a total content of 10.9 wt% for the two chemical fiber web layers, a cellulose short fiber content of 78.3 wt%, and a chemical filament content of 10.8 wt%.

[0184] Table 1. Performance test results of the nonwoven composite materials prepared in Examples 1-6 and similar commercially available products.

[0185]

[0186]

[0187] Among them, similar products sold in the market were purchased from wet toilet paper products manufactured by Fujian Yifa Nursing Products Co., Ltd.

[0188] As shown in Table 1, the nonwoven composite material provided by this invention has a longitudinal strength of 12.56–48.3 N, a longitudinal elongation of 30.8–58.3%, a transverse strength of 6.43–40.2 N, a longitudinal elongation of 50.1–78.4%, a water absorption time of less than 16–36 s, a water absorption ratio of 969–8532%, and a lint shedding coefficient of 3.73–4.5. This indicates that the nonwoven composite material provided by this invention has high strength, good anti-lint shedding performance, and strong water absorption.

[0189] The preparation method provided by this invention features a production apparatus with a special configuration of multiple raw material inlets and a special structure of the spinning assembly. This allows for the use of diverse raw materials and a unique spatial structure during production, resulting in nonwoven composite materials with improved bulkiness, strength, water absorption, and lint control. For example, in Examples 2 and 3, the addition of SAP to the intermediate absorbent layer increases the water absorption rate of the nonwoven composite material by 10 times compared to commercially available products. Furthermore, the use of a coaxial meltblown spinning assembly provides the nonwoven composite material with a superior spatial structure. Combined with the density of the surface chemical fiber layers (first and second chemical fiber web layers) and the variety of raw material types, the nonwoven composite material exhibits significantly improved strength and a marked reduction in lint.

[0190] Compared with commercially available products of the same weight, Examples 4 and 5 show that the thickness of the nonwoven composite material prepared by the present invention is increased by about 20%, and the change in raw materials results in a significant increase in both strength and elongation. In Example 4, the use of SAF increases the water absorption ratio of the nonwoven composite material by about 3 times. In addition, the dense structure of the first and second chemical fiber web layers reduces lint shedding to a certain extent. Furthermore, the use of low-melting-point fibers in Example 4 makes the nonwoven composite material more binding to the short cellulose fibers, resulting in a significant improvement in lint prevention performance.

[0191] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A nonwoven composite material, characterized in that, It includes a first chemical fiber web layer, an intermediate absorbent layer, and a second chemical fiber web layer stacked in sequence; The first chemical fiber mesh layer is a layered mesh structure formed from the raw materials for preparing the first surface layer; the raw materials for preparing the first surface layer include a first thermoplastic polymer and a first functional masterbatch; The second chemical fiber network layer is a layered network structure formed from the raw materials used to prepare the second surface layer; the raw materials used to prepare the second surface layer include a second thermoplastic polymer and a second functional masterbatch; The intermediate absorbent layer is a cross-fiber web structure formed from the core layer preparation raw materials, which include chemical filaments and short fibers; the area of ​​the cross-fiber web accounts for more than 50% of the area of ​​the intermediate absorbent layer; the diameter of the chemical filaments is 0.1~5μm; and the length of the short fibers is 1~8mm.

2. The nonwoven composite material according to claim 1, characterized in that, The average fiber diameter in the first chemical fiber web layer and the second chemical fiber web layer is independently 0.5~10μm, and the basis weight is independently 0.1~10gsm; The mass fraction of the first thermoplastic polymer in the raw material for preparing the first surface layer is 89.5% to 95%. The mass fraction of the second thermoplastic polymer in the raw material for preparing the second surface layer is 89.5% to 95%. The mass of the first chemical fiber web layer and the second chemical fiber web layer independently accounts for 3-20% of the mass of the nonwoven composite material; The raw materials for preparing the first and second surface layers also include functional additives, which include one or more of water-absorbing agents, softeners, and antibacterial agents; the mass of the functional additives accounts for 0.2% to 8% of the mass of the nonwoven composite material. The raw materials for preparing the first and second surface layers also include antioxidants.

3. The nonwoven composite material according to claim 1, characterized in that, The chemical filaments include one or more of the following: polypropylene-based fibers, polyethylene-based fibers, polyethylene terephthalate-based fibers, styrene-butadiene-styrene triblock copolymer-based fibers, and ethylene-vinyl acetate copolymer-based fibers. The short fibers include one or more of cellulose short fibers, synthetic short fibers, and superabsorbent short fibers; The core layer preparation raw materials also include functional fillers, which include one or more of superabsorbent fibers, low-melting-point fibers and superabsorbent resins; the melting point of the low-melting-point fibers is ≤150℃. In the nonwoven composite material, the mass fraction of chemical filaments is 6.5-23.2%, and the mass fraction of short fibers is 20-69.6%. The intermediate absorbent layer has several layers.

4. The nonwoven composite material according to claim 1 or 3, characterized in that, The first thermoplastic polymer and the second thermoplastic polymer independently include one or more of polypropylene, modified polypropylene, polyethylene, modified polyethylene, polyethylene terephthalate, styrene-butadiene-styrene triblock copolymer and ethylene-vinyl acetate copolymer; The first functional masterbatch and the second functional masterbatch independently include one or more of hydrophilic masterbatch, biodegradable masterbatch, soft masterbatch and antibacterial masterbatch.

5. The method for preparing the nonwoven composite material according to any one of claims 1 to 4, characterized in that, Includes the following steps: The raw material for the first surface layer is heated to melt and then spun into a first chemical fiber web layer. The first cooling process is carried out during the first spinning process; The raw materials for core layer preparation are cross-mixed and laid on the surface of the first chemical fiber web layer to form an intermediate absorbent layer with cross-fiber web, thus obtaining a chemical fiber web layer-intermediate absorbent layer. The raw material for the second surface layer is heated to melt, and a second chemical fiber web layer is formed by second spinning on the surface of the intermediate absorbent layer of the chemical fiber web layer-intermediate absorbent layer-chemical fiber web layer. A second cooling process is performed during the second spinning process; The nonwoven composite material is obtained by hot rolling the chemical fiber web layer, the intermediate absorbent layer, and the chemical fiber web layer together.

6. The preparation method according to claim 5, characterized in that, The first and second cooling independently include atomized spray cooling or cold air cooling using a cooling liquid; the cooling liquid includes pure water or a functional additive solution; the spray rate of the cooling liquid is 0~200L / h; When the core layer preparation raw materials also include functional fillers, chemical filaments, short fibers and functional fillers are cross-mixed; The hot-rolled composite temperature is 90~160℃.

7. The use of the nonwoven composite material according to any one of claims 1 to 4 or the nonwoven composite material prepared by the preparation method according to any one of claims 5 to 6 in disposable hygiene products or wipes.

8. A production apparatus for a method of preparing a nonwoven composite material according to any one of claims 1 to 4 or a nonwoven composite material according to any one of claims 5 to 6, comprising a first surface layer preparation unit (1), a core layer preparation unit (2), a second surface layer preparation unit (3), a web forming curtain (4), and a hot rolling mill (6). The first surface layer preparation unit (1) is provided with a first spinning assembly (11) and a first spraying system (12); the first spinning assembly (11) includes a coaxial melt-blown spinning assembly or an air knife drawing spinning assembly; the first spinning assembly (11) includes at least one melt chamber, and each melt chamber is connected to a spinneret. The core layer preparation unit (2) is provided with a molding box (21); the molding box (21) is provided with a raw material inlet (23) and a raw material inlet pipe (25); The second surface layer preparation unit (3) includes a third spinning assembly (31) and a second spraying system (32); the third spinning assembly (31) includes a coaxial meltblown spinning assembly or an air knife drawing spinning assembly; the third spinning assembly (31) includes at least one melt chamber, and each melt chamber is connected to a spinneret. The mesh material outlets of the first surface layer preparation unit (1), the core layer preparation unit (2), and the second surface layer preparation unit (3) are respectively connected to the mesh curtain (4); The net curtain (4) is equipped with a bottom air suction system (41).

9. The production apparatus according to claim 8, characterized in that, The core layer preparation unit (2) is further provided with a second spinning assembly (22), a raw material addition system (24), and a fiber unwinding system (26). The fiber outlet of the second spinning assembly (22) is connected to the forming box (21). The second spinning assembly (22) includes a coaxial meltblown spinning assembly or an air knife drawing spinning assembly. The second spinning assembly (22) includes at least one melt chamber, and each melt chamber is connected to a spinneret. The fiber unwinding system (26) is provided on the raw material inlet pipe (25). The forming box (21) is connected to the raw material addition system (24). The number of the second spinning assemblies (22) is one or two. The number of core layer preparation units (2) is several.

10. The production apparatus according to claim 8 or 9, characterized in that, The production apparatus also includes a heating device (5), a quality inspection unit (7), and a winding and slitting unit (8).

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