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CN-121976356-A - Multifunctional non-woven material and preparation method thereof

CN121976356ACN 121976356 ACN121976356 ACN 121976356ACN-121976356-A

Abstract

The invention relates to a multifunctional non-woven material and a preparation method thereof, belonging to the technical field of non-woven materials. The multifunctional nonwoven material is formed by sequentially compounding a bottom fiber web, a transition layer fiber web and a surface fiber web, wherein the bottom fiber web is used as a mechanical supporting, insulating and flame-retardant layer, high-proportion aramid fiber is used as a main body, good physical entanglement with the transition layer fiber web is realized by matching with a small amount of lyocell fiber, interlayer binding force is obviously improved, the transition layer fiber web is a structure and performance buffer transition layer, the lyocell fiber and the aramid fiber are compounded in a nearly equal proportion, the surface fiber web is an electromagnetic shielding and heat conducting functional layer, the supported catalytic lyocell fiber generated by in-situ catalytic graphitization is used as a functional main body, a small amount of aramid fiber is used as a framework, brittle fracture and slag drop of the carbonized lyocell layer are effectively prevented, and the obtained product has excellent electromagnetic shielding efficiency, good in-plane heat conductivity, high mechanical strength, intrinsic flame retardance and flexibility.

Inventors

  • YANG XUHONG
  • WANG YINA
  • LIU YUQING
  • GAN JINPENG
  • WANG YUEHAN
  • YANG YIFAN

Assignees

  • 苏州大学

Dates

Publication Date
20260505
Application Date
20260407

Claims (10)

  1. 1. A method for preparing a multifunctional nonwoven material, comprising the steps of: S1, mixing lyocell fibers and aramid fibers according to a mass ratio of (10-30) (70-90), and carrying out air-laying to obtain a bottom fiber web; S2, mixing lyocell fibers and aramid fibers according to a mass ratio of (45-55), and forming a transition layer fiber net on the surface of the bottom layer fiber net in S1 through air-laying; S3, mixing the supported catalytic lyocell fibers with the aramid fibers according to the mass ratio of (70-90) (10-30), forming a surface layer fiber web on the transition layer fiber web surface in S2 through air-laying to obtain a multi-layer fiber web preform, wherein the supported catalytic lyocell fibers are prepared by sequentially carrying out pretreatment on the lyocell fibers by an organic carboxylate solution and impregnation reaction by an iron salt solution; s4, carrying out hydroentanglement reinforcement and dehydration on the multilayer fiber net preform in the S3, and carrying out hot air treatment to obtain a non-woven material; and S5, embossing and creasing the non-woven material in the step S4, and performing heat treatment to obtain the multifunctional non-woven material.
  2. 2. The method for producing a multifunctional nonwoven material according to claim 1, wherein in S1-S3, the air-laid process parameters are independently 20 ℃ to 25 ℃ temperature, 58% to 62% humidity, 18m/S to 22m/S main air duct air flow speed, 9m/min to 11m/min web curtain speed, and-0.7 kPa to-0.9 kPa.
  3. 3. The method of producing a multifunctional nonwoven material according to claim 1, wherein in S3, the concentration of the organic carboxylate solution is 0.05mol/L to 0.2mol/L; And/or the pretreatment is carried out at a temperature of 45-55 ℃ for 55-65 min.
  4. 4. The method of producing a multifunctional nonwoven material according to claim 1, characterized in that in S3, the concentration of the iron salt solution is 0.05mol/L to 0.2mol/L; the ferric salt is selected from one or more of ferric nitrate, ferric chloride and ferric sulfate; and/or the time of the dipping reaction is 55min-65min, and the pH value of the system is 7.5-8.5.
  5. 5. The method of producing a multifunctional nonwoven according to claim 1, wherein in S4, the hydroentangling is performed sequentially with 14bar-16bar prewetting, 68bar-72bar front hydroentangling, 88bar-92bar back hydroentangling, and 48bar-52bar surface finishing; And/or the aperture of the water needle for the water jet reinforcement is 0.1mm-0.15mm, and the conveying speed of the fiber web is 9m/min-11m/min.
  6. 6. The method of producing a multifunctional nonwoven according to claim 1, characterized in that in S4 the dewatering is performed at a negative pressure of-0.4 bar to-0.6 bar.
  7. 7. The method of producing a multifunctional nonwoven according to claim 1, wherein in S4, the temperature of the hot air treatment is 105 ℃ to 115 ℃ for 18min to 22min.
  8. 8. The method of producing a multifunctional nonwoven according to claim 1, wherein in S5, the embossing crimp treatment is performed at a temperature of 75 ℃ to 85 ℃ and a line pressure of 48N/mm to 52N/mm.
  9. 9. The method of producing a multifunctional nonwoven according to claim 1, wherein in S5, the heat treatment is to heat up to 280 to 320 ℃ and hold the temperature for 55 to 65 minutes at a rate of 1.8 to 2.2 ℃ per minute under an air atmosphere, then heat up to 760 to 840 ℃ and hold the temperature for 28 to 32 minutes at a rate of 4.8 to 5.2 ℃ per minute under a nitrogen atmosphere, and then heat up to 1100 to 1300 ℃ and hold the temperature for 55 to 65 minutes at a rate of 7.5 to 8.5 ℃ per minute.
  10. 10. A multifunctional nonwoven prepared by the method of any one of claims 1-9.

Description

Multifunctional non-woven material and preparation method thereof Technical Field The invention belongs to the technical field of non-woven materials, and particularly relates to a multifunctional non-woven material and a preparation method thereof. Background Along with the rapid iteration of the new energy automobile industry, the power battery is used as a whole automobile core energy unit, the operation safety, the signal stability and the thermal management efficiency of the power battery become key bottlenecks for restricting the performance upgrading of the whole automobile, and the performance of functional materials in the battery pack directly determines the comprehensive performance of the power battery system. In order to respond to urgent demands of new energy automobile industry for high-performance and high-integration materials, an integrated functional material integrating flexible adaptation, efficient electromagnetic shielding, rapid heat conduction, intrinsic flame retardance and light weight characteristics is needed in a battery pack, so that the integrated functional material is used for replacing a traditional multi-component stacking scheme, and the integration level, the operation safety and the long-term reliability of a battery system are fundamentally improved. The main stream solutions aiming at the internal functional requirements of the battery pack in the current market still have a plurality of remarkable technical bottlenecks, and the requirements of industrial development are difficult to meet, and the main stream solutions are embodied in the following aspects: The method has the advantages that the method increases the weight and the structural complexity of a battery system, and further causes the problem of mismatch of interface impedance between layers due to the difference of thermal expansion coefficients and electromagnetic characteristics among different materials, so that the overall heat dissipation efficiency and the electromagnetic shielding effect of the system are weakened, even if part of advanced materials try to integrate the electromagnetic shielding function in a heat conducting matrix, the technical route of the method also depends on metal coatings such as silver, nickel and the like, the preparation cost of the materials is greatly increased, oxidation corrosion of the metal coatings is easy to occur under complex vehicle environments such as high humidity and salt fog, and the stability of the battery system is influenced. Secondly, the problems of low utilization rate of raw material resources and outstanding environmental protection pressure are also more serious, and the preparation cost of the existing high-performance heat conduction shielding filler such as primary carbon fiber, graphene and the like is high, so that the large-scale industrialized application of the high-performance heat conduction shielding filler is limited. The waste lyocell fibers and industrial waste aramid fibers generated in the textile industry are huge in stock, and the estimated waste aramid fiber protective equipment, industrial leftover materials and the like generated in the world each year can reach tens of thousands of tons, and the current treatment mode of the high-value polymer materials is mainly landfill, incineration or degradation processing, so that the high-value recycling of resources is not realized, and the environmental burden is further increased. Thirdly, the existing carbonized material technology has obvious performance and process short plates, the traditional carbonized fiber material with a single homogeneous structure is difficult to realize multifunctional synergy, the uncatalyzed high-temperature graphitization process generally needs a processing temperature exceeding 2000 ℃, the energy consumption is extremely high, and the product obtained by directly carbonizing the waste fiber has low graphitization degree, the heat conductivity coefficient is generally poor, and the electromagnetic shielding efficiency is difficult to break through the bottleneck of 30 dB. For example, chinese patent CN115850787a discloses a recyclable aramid nanofiber aerogel, a preparation method and application thereof, the prepared heat insulation material with ultra-low thermal conductivity is not matched with the application scene of the cooperative requirement of the interior of a power battery pack on efficient heat dissipation and electromagnetic shielding, and cannot adapt to the actual use requirement of the battery pack, and patent CN107057338a discloses an electromagnetic shielding high-heat conductivity nylon composite material for a new energy automobile battery box body, wherein although the performance of a material part is improved by adding metal indium or graphene, the core requirement of the automobile industry on low-cost and large-scale manufacturing is difficult to meet due to excessive dependence on expensive fillers. Based on this, the pres