Sound absorption needling non-woven composite material and preparation method thereof

Abstract

The invention discloses a sound-absorbing needling non-woven composite material and a preparation method thereof, and relates to the technical field of sound-absorbing materials, the sound-absorbing needling non-woven composite material sequentially comprises a sound-absorbing layer, a resonance layer and a damping layer from top to bottom; the sound absorption layer is a needle-punched non-woven fabric made of basalt fibers and hollow polyester fibers; the resonance layer is prepared from the following raw materials in parts by weight: 100 parts of sulfonyl grafted ultra-high molecular weight polyethylene, 10-15 parts of expanded perlite particles, 5-8 parts of nano titanium dioxide, 0.8-1 part of a catalyst, 1-3 parts of a coupling agent, 1-3 parts of a lubricant and 0.8-1.2 parts of an antioxidant; and the damping layer is made of a fluorosilicone type thermoplastic polyurethane elastomer. The composite material is excellent in mechanical property, remarkable in sound absorption effect and simple in preparation process.

Description

Technical Field

[0001] The present invention relates to the technical field of sound-absorbing materials, and particularly to a sound-absorbing needle-punched nonwoven composite material and a preparation method thereof. Background Art

[0002] With the rapid development of modern industry and transportation, the problem of noise pollution has become increasingly serious, having many adverse effects on people's life, work and health. As an important means of controlling noise propagation, sound-absorbing materials have a wide range of application requirements in the fields of architecture, transportation, aerospace, etc.

[0003] Traditional sound-absorbing materials mostly adopt high-density sound insulation materials or micro-perforated plate structures. The former has the risk of secondary pollution and high costs, while the latter can improve the low-frequency sound absorption performance, but has a complex design and a narrow frequency band. Other sound-absorbing materials on the market also more or less have technical defects such as poor mechanical properties, being prone to cause potential hazards to human health and the environment during use, the sound absorption effect needs to be further improved, and it is difficult to meet the sound absorption requirements in complex noise environments. It is in this situation that needle-punched nonwoven composite materials emerge as the times require. Due to their excellent sound absorption and noise reduction performance, low processing costs, high output, and little environmental pollution during processing, etc., these materials have become relatively ideal substrates for sound absorption and noise reduction applications and have received extensive attention in recent years.

[0004] Existing sound-absorbing needle-punched nonwoven composite materials still have some deficiencies in terms of sound absorption performance, mechanical properties, and preparation processes. For example, the structural design of some composite materials is unreasonable, resulting in the inability to achieve a good balance between sound absorption performance and mechanical properties; the binder used in the preparation process may affect the sound absorption performance of the material and there are environmental protection problems; the preparation process is complex and the cost is high, which is not conducive to large-scale industrial production.

[0005] To solve the above problems, the Chinese invention patent document with the authorization publication number CN103106898B discloses a low-frequency sound-absorbing needle-punched nonwoven composite material, its preparation method and application. The composite material includes kapok fiber / hollow polyester nonwoven fabric and polyethylene film. The preparation method includes: mixing, opening, carding, and forming a web with 60% - 90% kapok fiber and 40% - 10% hollow polyester fiber by mass percentage; inputting the fiber web into a needle-punching machine for needle-punching reinforcement, winding, and cutting to obtain kapok / hollow polyester needle-punched nonwoven fabric; placing a 0.06mm - 0.10mm polyethylene film flat on one side of the above-mentioned needle-punched nonwoven fiber web, laminating, taking out, and cooling to obtain the product. This composite material can be applied to fields such as automotive interiors, buildings, and high-speed rails; this sound-absorbing material is lightweight and the preparation method is simple to operate. However, the strength of kapok fiber is relatively low, about one-third of that of polyester fiber, and the price of kapok fiber is relatively high, which is not conducive to large-scale application of this sound-absorbing material. In addition, the mechanical properties and sound-absorbing effect of this composite material still need to be further improved.

[0006] It can be seen that developing a sound-absorbing needle-punched nonwoven composite material with excellent mechanical properties, significant sound-absorbing effect, and simple preparation process meets the market demand, has broad market value and application prospects, and is of great significance for promoting the development of the sound-absorbing material field. Summary of the Invention

[0007] In view of this, the purpose of the present invention is to provide a sound-absorbing needle-punched nonwoven composite material with excellent mechanical properties, significant sound-absorbing effect, and simple preparation process, and its preparation method.

[0008] To achieve the above purpose, the present invention provides the following technical solutions:

[0009] A sound-absorbing needle-punched nonwoven composite material, which sequentially includes a sound-absorbing layer, a resonance layer, and a damping layer from top to bottom; the sound-absorbing layer is a needle-punched nonwoven fabric made of basalt fiber and hollow polyester fiber; the resonance layer is made of the following raw materials by weight: 100 parts of sulfonic acid group-grafted ultra-high molecular weight polyethylene, 10 - 15 parts of expanded perlite particles, 5 - 8 parts of nano-titanium dioxide, 0.8 - 1 part of catalyst, 1 - 3 parts of coupling agent, 1 - 3 parts of lubricant, 0.8 - 1.2 parts of antioxidant; the damping layer is made of fluorosilicon-based thermoplastic polyurethane elastomer.

[0010] Preferably, the mass ratio of the basalt fiber to the hollow polyester fiber is (1 - 3):(3 - 5).

[0011] Preferably, the length of the basalt fiber is 30 - 50mm, and the linear density is 1.0 - 2.0dtex.

[0012] Preferably, the hollowness of the hollow polyester fiber is 4-13%, the fineness is 0.7-2.0 dtex, and the length is 45-65 mm.

[0013] Preferably, the preparation method of the sulfonic acid group grafted ultra-high molecular weight polyethylene comprises the following steps: taking 2-acrylamido-2-methylpropanesulfonic acid and ammonium persulfate, adding them into water, dissolving to obtain an initiating solution, taking ultra-high molecular weight polyethylene powder, adding the initiating solution thereto and stirring, the stirring speed is 60-100 rpm, under nitrogen protection, the temperature is 70-80 °C, reacting for 4-6 h, washing with water and drying to obtain the sulfonic acid group grafted ultra-high molecular weight polyethylene.

[0014] Preferably, the mass ratio of the 2-acrylamido-2-methylpropanesulfonic acid, ammonium persulfate, water, and ultra-high molecular weight polyethylene powder is 1:(0.03-0.05):(3-5):(10-20).

[0015] Preferably, the grade of the ultra-high molecular weight polyethylene powder is UH060P, provided by PetroChina Daqing Petrochemical.

[0016] Preferably, the particle size of the expanded perlite particles is 0.5-1 mm.

[0017] Preferably, the particle size of the nano-titanium dioxide is 10-80 nm.

[0018] Preferably, the mass ratio of the catalyst phosphorus pentoxide to polyphosphoric acid is (3-5):1.

[0019] Preferably, the lubricant is zinc stearate.

[0020] Preferably, the coupling agent is at least one of silane coupling agent KH550, silane coupling agent KH560, and silane coupling agent KH570.

[0021] Preferably, the antioxidant is at least one of antioxidant 1010 and antioxidant 168.

[0022] Furthermore, there is no special requirement for the source of the fluorosilicone thermoplastic polyurethane elastomer. In an embodiment of the present invention, the fluorosilicone thermoplastic polyurethane elastomer is prepared by the method of Example 6 of the Chinese invention patent with the authorized publication number CN111154064B.

[0023] Another object of the present invention is to provide a preparation method of the sound-absorbing needle-punched nonwoven composite material, comprising the following steps:

[0024] Step S1: Mix basalt fiber and hollow polyester fiber evenly according to the mass ratio, and then make a needle-punched nonwoven fabric through opening, carding, web-forming, needle punching reinforcement, winding, and cutting to form a sound-absorbing layer;

[0025] Step S2: After uniformly mixing each raw material of the resonance layer by weight, put it into a twin-screw extruder, melt and extrude to obtain a cast sheet; then perform biaxial stretching on the cast sheet at 110 - 120 °C to obtain the resonance layer;

[0026] Step S3: Knead the fluorosilicon thermoplastic polyurethane elastomer into a film to obtain the damping layer;

[0027] Step S4: Put the sound-absorbing layer, resonance layer, and damping layer into a plasma chamber, perform corona treatment at a power of 100 - 200 W for 12 - 30 min, then stack them from top to bottom in sequence and hot press them into shape to obtain the sound-absorbing needle-punched nonwoven composite material.

[0028] Preferably, the thickness of the needle-punched nonwoven fabric in Step S1 is 3 - 10 mm.

[0029] Preferably, the speed of the needling in Step S1 is 7 - 15 m / min, the frequency is 800 - 1000 needles / min, and the needle implantation density is 3000 - 4000 needles / m.

[0030] Preferably, the extrusion temperature of the twin-screw extruder in Step S2 is 180 - 230 °C, and the screw rotation speed is 190 - 250 rpm.

[0031] Preferably, the draw ratio of the biaxial stretching in Step S2 is 2 - 4 times.

[0032] Preferably, the thickness of the resonance layer in Step S2 is 3 - 8 mm.

[0033] Preferably, the thickness of the damping layer in Step S3 is 5 - 12 mm.

[0034] Preferably, the temperature of the hot pressing in Step S4 is 170 - 180 °C, the pressure is 2 - 5 MPa, and the time is 5 - 10 min.

[0035] The beneficial effects produced by adopting the above technical solution are as follows:

[0036] (1) The preparation method of the sound-absorbing needle-punched nonwoven composite material provided by the present invention is simple, easy to implement, has low dependence on equipment, high preparation efficiency and high finished product qualification rate, and is suitable for large-scale industrial production.

[0037] (2) The sound-absorbing needle-punched nonwoven composite material provided by the present invention sequentially includes a sound-absorbing layer, a resonance layer, and a damping layer from top to bottom; the sound-absorbing layer is a needle-punched nonwoven fabric made of basalt fibers and hollow polyester fibers; the resonance layer is made of the following raw materials by weight: 100 parts of sulfonic acid group-grafted ultra-high molecular weight polyethylene, 10-15 parts of expanded perlite particles, 5-8 parts of nano-titanium dioxide, 0.8-1 part of catalyst, 1-3 parts of lubricant, 1-3 parts of coupling agent, 0.8-1.2 parts of antioxidant; the damping layer is made of fluorosilicone thermoplastic polyurethane elastomer. Through the design of the above structure, the limitation of the sound-absorbing frequency band of a single material can be broken through, and the synergistic improvement of sound-absorbing performance and physical strength is realized; the combination of porous sound absorption, resonance sound absorption, and damping sound absorption has a synergistic effect and can effectively improve the sound-absorbing effect. Through the reasonable selection of the composition of each layer of materials and the corona treatment before hot pressing, the bonding ability between each layer can be enhanced, delamination during use can be avoided, and the structural stability and performance stability can be improved.

[0038] (3) The sound-absorbing needle-punched nonwoven composite material provided by the present invention, the resonance layer is made of the following raw materials by weight: 100 parts of sulfonic acid group-grafted ultra-high molecular weight polyethylene, 10-15 parts of expanded perlite particles, 5-8 parts of nano-titanium dioxide, 0.8-1 part of catalyst, 1-3 parts of lubricant, 0.8-1.2 parts of antioxidant; on the one hand, using sulfonic acid group-grafted ultra-high molecular weight polyethylene can improve the processing performance of ultra-high molecular weight polyethylene, and on the other hand, the introduced sulfonic acid group will chemically react with the benzene ring-containing structures in the sound-absorbing layer and the damping layer under the action of the catalyst, so that each layer is connected together in the form of chemical bonds, further improving the adhesion between each layer, thereby improving the structural and performance stability. The addition of expanded perlite particles and nano-titanium dioxide can further improve the sound energy conversion efficiency, and then improve the sound-absorbing effect.

[0039] (4) The sound-absorbing needle-punched nonwoven composite material provided by the present invention, the damping layer is made of fluorosilicone thermoplastic polyurethane elastomer; for the first time, the fluorosilicone thermoplastic polyurethane elastomer is applied to the sound-absorbing needle-punched nonwoven composite material, which can not only provide a support structure for the composite material and improve the mechanical properties of the material, but also, through the damping effect, when the sound causes the material to vibrate, friction will occur between the internal polymer chain segments, thereby converting the sound energy into heat energy and dissipating it, playing a sound-absorbing role.

[0040] (5) The sound-absorbing needle-punched nonwoven composite material provided by the present invention, through the reasonable selection of the preparation process parameters, has high product preparation efficiency and qualified rate, excellent mechanical properties, and remarkable sound-absorbing effect. Detailed implementation mode

[0041] To enable those skilled in the art to better understand the technical solution of the present invention and make the above features, objectives, and advantages of the present invention clearer and easier to understand, the present invention will be further described below in conjunction with embodiments. The embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0042] Example 1

[0043] A sound-absorbing needle-punched nonwoven composite material, which sequentially includes a sound-absorbing layer, a resonance layer, and a damping layer from top to bottom; the sound-absorbing layer is a needle-punched nonwoven fabric made of basalt fibers and hollow polyester fibers; the resonance layer is made of the following raw materials in parts by weight: 100 parts of sulfonic acid group-grafted ultra-high molecular weight polyethylene, 10 parts of expanded perlite particles, 5 parts of nano-titanium dioxide, 0.8 part of catalyst, 1 part of lubricant, 1 part of coupling agent, 0.8 part of antioxidant; the damping layer is made of a fluorosilicone thermoplastic polyurethane elastomer.

[0044] The mass ratio of the basalt fibers to the hollow polyester fibers is 1:3; the length of the basalt fibers is 30 mm, and the linear density is 1.0 dtex; the hollowness of the hollow polyester fibers is 4%, the fineness is 0.7 dtex, and the length is 45 mm.

[0045] The preparation method of the sulfonic acid group-grafted ultra-high molecular weight polyethylene includes the following steps: Take 2-acrylamido-2-methylpropanesulfonic acid and ammonium persulfate and add them to water to dissolve and prepare an initiation solution. Take ultra-high molecular weight polyethylene powder, add the initiation solution thereto and stir, the stirring speed is 60 rpm, under nitrogen protection, the temperature is 70 °C, react for 4 h, wash and dry to obtain sulfonic acid group-grafted ultra-high molecular weight polyethylene; the mass ratio of 2-acrylamido-2-methylpropanesulfonic acid, ammonium persulfate, water, and ultra-high molecular weight polyethylene powder is 1:0.03:3:10; the grade of the ultra-high molecular weight polyethylene powder is UH060P, provided by PetroChina Daqing Petrochemical; through elemental analysis and calculation of the weight change before and after grafting, the grafting rate of the sulfonic acid group-grafted ultra-high molecular weight polyethylene is 9.2%; the grafting rate = (dry weight of sulfonic acid group-grafted ultra-high molecular weight polyethylene - dry weight of ultra-high molecular weight polyethylene before grafting) / (dry weight of ultra-high molecular weight polyethylene before grafting) × 100%.

[0046] The particle size of the expanded perlite particles is 0.5 mm; the particle size of the nano-titanium dioxide is 10 nm; the catalyst is a mass ratio of phosphorus pentoxide to polyphosphoric acid of 3:1; the lubricant is zinc stearate; the coupling agent is silane coupling agent KH550; the antioxidant is antioxidant 1010; the fluorosilicone thermoplastic polyurethane elastomer is made according to the method of Example 6 of the Chinese invention patent with the authorization publication number CN111154064B.

[0047] A preparation method of the sound-absorbing needled nonwoven composite material comprises the following steps:

[0048] Step S1: After mixing basalt fibers and hollow polyester fibers evenly according to the mass ratio, they are subjected to opening, carding, web-forming, needle punching reinforcement, winding, and cutting to make a needled nonwoven fabric, forming a sound-absorbing layer;

[0049] Step S2: After mixing the raw materials of the resonance layer evenly by weight, they are put into a twin-screw extruder and melt-extruded to obtain a cast sheet; then the cast sheet is subjected to biaxial stretching at 110°C to obtain the resonance layer;

[0050] Step S3: The fluorosilicon-based thermoplastic polyurethane elastomer is kneaded into a film to obtain a damping layer;

[0051] Step S4: The sound-absorbing layer, resonance layer, and damping layer are put into a plasma chamber, corona-treated at a power of 100 W for 12 min, then stacked from top to bottom in sequence and hot-pressed to form a sound-absorbing needled nonwoven composite material.

[0052] In step S1, the thickness of the needled nonwoven fabric is 5 mm; in step S1, the speed of the needle punching is 7 m / min, the frequency is 800 punches / min, and the needle implantation density is 3000 needles / m; in step S2, the extrusion temperature of the twin-screw extruder is 180°C, and the screw speed is 190 rpm; in step S2, the stretching ratio of the biaxial stretching is 3 times; in step S2, the thickness of the resonance layer is 4 mm; in step S3, the thickness of the damping layer is 6 mm; in step S4, the temperature of the hot pressing is 170°C, the pressure is 2 MPa, and the time is 5 min.

[0053] Example 2

[0054] A sound-absorbing needled nonwoven composite material comprises a sound-absorbing layer, a resonance layer, and a damping layer from top to bottom in sequence; the sound-absorbing layer is made of a needled nonwoven fabric composed of basalt fibers and hollow polyester fibers; the resonance layer is made of the following raw materials by weight: 100 parts of sulfonic acid group-grafted ultra-high molecular weight polyethylene, 11 parts of expanded perlite particles, 6 parts of nano-titanium dioxide, 0.85 part of catalyst, 1.5 parts of lubricant, 1.5 parts of coupling agent, and 0.9 part of antioxidant; the damping layer is made of a fluorosilicon-based thermoplastic polyurethane elastomer.

[0055] The mass ratio of the basalt fibers to the hollow polyester fibers is 1.5:3.5; the length of the basalt fibers is 35 mm, and the linear density is 1.2 dtex; the hollowness of the hollow polyester fibers is 6%, the fineness is 1.0 dtex, and the length is 50 mm.

[0056] The preparation method of the sulfonic acid group-grafted ultra-high molecular weight polyethylene comprises the following steps: Take 2-acrylamido-2-methylpropanesulfonic acid and ammonium persulfate, add them into water, and dissolve to prepare an initiating solution. Take ultra-high molecular weight polyethylene powder, add the initiating solution thereto and stir, with the stirring speed being 70 rpm, under nitrogen protection, at a temperature of 73 °C, react for 4.5 h, wash with water and dry to obtain the sulfonic acid group-grafted ultra-high molecular weight polyethylene; the mass ratio of 2-acrylamido-2-methylpropanesulfonic acid, ammonium persulfate, water, and ultra-high molecular weight polyethylene powder is 1:0.035:3.5:13; the grade of the ultra-high molecular weight polyethylene powder is UH060P, provided by PetroChina Daqing Petrochemical; the particle size of the expanded perlite particles is 0.7 mm; the particle size of the nano-titanium dioxide is 30 nm.

[0057] The mass ratio of the catalyst phosphorus pentoxide to polyphosphoric acid is 3.5:1; the lubricant is zinc stearate; the coupling agent is silane coupling agent KH560; the antioxidant is antioxidant 168; the fluorosilicone thermoplastic polyurethane elastomer is prepared by the method of Example 6 of the Chinese invention patent with the authorization publication number CN111154064B.

[0058] A preparation method of the sound-absorbing needle-punched nonwoven composite material comprises the following steps:

[0059] Step S1: Mix basalt fibers and hollow polyester fibers evenly according to the mass ratio, and then make a needle-punched nonwoven fabric through opening, carding, web-forming, needle punching reinforcement, winding, and cutting to form a sound-absorbing layer;

[0060] Step S2: Mix the raw materials of the resonance layer evenly according to the weight parts, put them into a twin-screw extruder, melt and extrude to obtain a cast sheet; then perform biaxial stretching on the cast sheet at 113 °C to obtain the resonance layer;

[0061] Step S3: Knead the fluorosilicone thermoplastic polyurethane elastomer into a film to obtain a damping layer;

[0062] Step S4: Put the sound-absorbing layer, resonance layer, and damping layer into a plasma cavity, perform corona treatment at a power of 130 W for 15 min, then stack them in order from top to bottom and hot press them into shape to obtain the sound-absorbing needle-punched nonwoven composite material.

[0063] The thickness of the needle-punched nonwoven fabric described in step S1 is 5 mm; the needle-punching speed in step S1 is 9 m / min, the frequency is 850 punches / min, and the needle implantation density is 3,300 needles / m; the extrusion temperature of the twin-screw extruder described in step S2 is 190 °C, and the screw rotation speed is 210 rpm; the draw ratio of the biaxial stretching in step S2 is 3 times; the thickness of the resonance layer described in step S2 is 4 mm; the thickness of the damping layer described in step S3 is 6 mm; the temperature of the hot pressing and forming in step S4 is 173 °C, the pressure is 3 MPa, and the time is 6 min.

[0064] Example 3

[0065] A sound-absorbing needle-punched nonwoven composite material, which sequentially includes a sound-absorbing layer, a resonance layer and a damping layer from top to bottom; the sound-absorbing layer is a needle-punched nonwoven fabric made of basalt fibers and hollow polyester fibers; the resonance layer is made of the following raw materials by weight: 100 parts of sulfonic acid group-grafted ultra-high molecular weight polyethylene, 13 parts of expanded perlite particles, 6.5 parts of nano-titanium dioxide, 0.9 part of catalyst, 2 parts of lubricant, 2 parts of coupling agent, 1 part of antioxidant; the damping layer is made of fluorosilicone thermoplastic polyurethane elastomer.

[0066] The mass ratio of the basalt fibers to the hollow polyester fibers is 2:4; the length of the basalt fibers is 40 mm, and the linear density is 1.5 dtex; the hollowness of the hollow polyester fibers is 9%, the fineness is 1.4 dtex, and the length is 55 mm.

[0067] The preparation method of the sulfonic acid group-grafted ultra-high molecular weight polyethylene includes the following steps: Take 2-acrylamido-2-methylpropanesulfonic acid and ammonium persulfate and add them to water to dissolve and prepare an initiation solution. Take ultra-high molecular weight polyethylene powder, add the initiation solution thereto and stir, the stirring speed is 80 rpm, under nitrogen protection, the temperature is 75 °C, react for 5 h, wash with water and dry to obtain sulfonic acid group-grafted ultra-high molecular weight polyethylene; the mass ratio of 2-acrylamido-2-methylpropanesulfonic acid, ammonium persulfate, water, and ultra-high molecular weight polyethylene powder is 1:0.04:4:15; the grade of the ultra-high molecular weight polyethylene powder is UH060P, provided by PetroChina Daqing Petrochemical; the particle size of the expanded perlite particles is 0.8 mm; the particle size of the nano-titanium dioxide is 60 nm.

[0068] The catalyst is a mass ratio of phosphorus pentoxide to polyphosphoric acid of 4:1; the lubricant is zinc stearate; the coupling agent is silane coupling agent KH570; the antioxidant is antioxidant 1010; the fluorosilicone thermoplastic polyurethane elastomer is prepared by the method of Example 6 of the Chinese invention patent with the authorized publication number CN111154064B.

[0069] A preparation method of the sound-absorbing needled nonwoven composite material comprises the following steps:

[0070] Step S1: After uniformly mixing basalt fibers and hollow polyester fibers according to a mass ratio, they are subjected to opening, carding, web forming, needle punching reinforcement, winding, and cutting to make a needled nonwoven fabric, forming a sound-absorbing layer;

[0071] Step S2: After uniformly mixing the raw materials of the resonance layer according to parts by weight, they are put into a twin-screw extruder and melt-extruded to obtain a cast sheet; then the cast sheet is subjected to biaxial stretching at 115°C to obtain the resonance layer;

[0072] Step S3: Knead the fluorosilicon-based thermoplastic polyurethane elastomer into a film to obtain a damping layer;

[0073] Step S4: Put the sound-absorbing layer, resonance layer, and damping layer into a plasma chamber, corona-treat for 22 min at a power of 150 W, then stack them from top to bottom in sequence and hot-press to form the sound-absorbing needled nonwoven composite material.

[0074] In step S1, the thickness of the needled nonwoven fabric is 5 mm; in step S1, the speed of the needle punching is 12 m / min, the frequency is 900 punches / min, and the needle implantation density is 3500 needles / m; in step S2, the extrusion temperature of the twin-screw extruder is 210°C, and the screw rotation speed is 230 rpm; in step S2, the biaxial stretching ratio is 3 times; in step S2, the thickness of the resonance layer is 4 mm; in step S3, the thickness of the damping layer is 6 mm; in step S4, the temperature of the hot-pressing is 175°C, the pressure is 3.5 MPa, and the time is 7 min.

[0075] Example 4

[0076] A sound-absorbing needled nonwoven composite material comprises a sound-absorbing layer, a resonance layer, and a damping layer from top to bottom in sequence; the sound-absorbing layer is made of a needled nonwoven fabric of basalt fibers and hollow polyester fibers; the resonance layer is made of the following raw materials according to parts by weight: 100 parts of sulfonic acid group-grafted ultra-high molecular weight polyethylene, 14 parts of expanded perlite particles, 7.5 parts of nano-titanium dioxide, 0.95 part of catalyst, 2.5 parts of lubricant, 2.5 parts of coupling agent, and 1.1 parts of antioxidant; the damping layer is made of a fluorosilicon-based thermoplastic polyurethane elastomer.

[0077] The mass ratio of the basalt fibers to the hollow polyester fibers is 2.5:4.5; the length of the basalt fibers is 45 mm, and the linear density is 1.8 dtex; the hollowness of the hollow polyester fibers is 12%, the fineness is 1.8 dtex, and the length is 60 mm.

[0078] The preparation method of the sulfonic acid group grafted ultra-high molecular weight polyethylene comprises the following steps: Take 2-acrylamido-2-methylpropanesulfonic acid and ammonium persulfate, add them into water, and dissolve to prepare an initiating solution. Take ultra-high molecular weight polyethylene powder, add the initiating solution thereto and stir, with the stirring speed being 95 rpm, under nitrogen protection, at a temperature of 78 °C, react for 5.5 h, after washing with water and drying, sulfonic acid group grafted ultra-high molecular weight polyethylene is obtained; the mass ratio of 2-acrylamido-2-methylpropanesulfonic acid, ammonium persulfate, water, and ultra-high molecular weight polyethylene powder is 1:0.045:4.5:18; the grade of the ultra-high molecular weight polyethylene powder is UH060P, provided by PetroChina Daqing Petrochemical Company.

[0079] The particle size of the expanded perlite particles is 0.9 mm; the particle size of the nano-titanium dioxide is 70 nm; the catalyst is phosphorus pentoxide and polyphosphoric acid with a mass ratio of 4.5:1; the lubricant is zinc stearate; the coupling agent is a mixture of silane coupling agent KH550, silane coupling agent KH560, and silane coupling agent KH570 in a mass ratio of 1:3:5; the antioxidant is a mixture of antioxidant 1010 and antioxidant 168 in a mass ratio of 3:5; the fluorosilicon thermoplastic polyurethane elastomer is prepared by the method of Example 6 of the Chinese invention patent with the authorized publication number CN111154064B.

[0080] A preparation method of the sound-absorbing needle-punched nonwoven composite material comprises the following steps:

[0081] Step S1: Mix basalt fibers and hollow polyester fibers evenly according to the mass ratio, and then through opening, carding, web-forming, needle punching reinforcement, winding, and cutting, a needle-punched nonwoven fabric is made to form a sound-absorbing layer;

[0082] Step S2: Mix the raw materials of the resonance layer evenly according to the weight parts, put them into a twin-screw extruder, melt and extrude to obtain a cast sheet; then perform biaxial stretching on the cast sheet at 118 °C to obtain the resonance layer;

[0083] Step S3: Knead the fluorosilicon thermoplastic polyurethane elastomer into a film to obtain a damping layer;

[0084] Step S4: Put the sound-absorbing layer, resonance layer, and damping layer into a plasma chamber, perform corona treatment at a power of 190 W for 28 min, then stack them from top to bottom in sequence and hot press them into shape to obtain the sound-absorbing needle-punched nonwoven composite material.

[0085] The thickness of the needled nonwoven fabric described in step S1 is 5 mm; the needling speed in step S1 is 13 m / min, the frequency is 950 stabs / min, and the needle implantation density is 3,800 needles / m; the extrusion temperature of the twin-screw extruder described in step S2 is 220 °C, and the screw speed is 240 rpm; the draw ratio of the biaxial drawing in step S2 is 3 times; the thickness of the resonance layer in step S2 is 4 mm; the thickness of the damping layer in step S3 is 6 mm; the temperature of the hot pressing in step S4 is 178 °C, the pressure is 4.5 MPa, and the time is 9 min.

[0086] Example 5

[0087] A sound-absorbing needled nonwoven composite material, which sequentially includes a sound-absorbing layer, a resonance layer, and a damping layer from top to bottom; the sound-absorbing layer is a needled nonwoven fabric made of basalt fibers and hollow polyester fibers; the resonance layer is made of the following raw materials by weight: 100 parts of sulfonic acid group-grafted ultra-high molecular weight polyethylene, 15 parts of expanded perlite particles, 8 parts of nano-titanium dioxide, 1 part of catalyst, 3 parts of lubricant, 3 parts of coupling agent, and 1.2 parts of antioxidant; the damping layer is made of a fluorosilicone thermoplastic polyurethane elastomer.

[0088] The mass ratio of the basalt fibers to the hollow polyester fibers is 3:5; the length of the basalt fibers is 50 mm, and the linear density is 2.0 dtex; the hollowness of the hollow polyester fibers is 13%, the fineness is 2.0 dtex, and the length is 65 mm.

[0089] The preparation method of the sulfonic acid group-grafted ultra-high molecular weight polyethylene includes the following steps: Take 2-acrylamido-2-methylpropanesulfonic acid and ammonium persulfate and add them to water to dissolve to obtain an initiation solution. Take ultra-high molecular weight polyethylene powder, add the initiation solution thereto and stir, the stirring speed is 100 rpm, under nitrogen protection, the temperature is 80 °C, react for 6 h, wash and dry to obtain sulfonic acid group-grafted ultra-high molecular weight polyethylene; the mass ratio of 2-acrylamido-2-methylpropanesulfonic acid, ammonium persulfate, water, and ultra-high molecular weight polyethylene powder is 1:0.05:5:20; the grade of the ultra-high molecular weight polyethylene powder is UH060P, provided by PetroChina Daqing Petrochemical.

[0090] The particle size of the expanded perlite particles is 1 mm; the particle size of the nano-titanium dioxide is 80 nm; the catalyst is a mass ratio of phosphorus pentoxide to polyphosphoric acid of 5:1; the lubricant is zinc stearate; the coupling agent is silane coupling agent KH550; the antioxidant is antioxidant 1010; the fluorosilicone thermoplastic polyurethane elastomer is made by the method of Example 6 of the Chinese invention patent with the authorization publication number CN111154064B.

[0091] A preparation method of the sound-absorbing needle-punched nonwoven composite material comprises the following steps:

[0092] Step S1: After uniformly mixing basalt fibers and hollow polyester fibers according to a mass ratio, they are subjected to opening, carding, web-forming, needle punching reinforcement, winding, and cutting to make a needle-punched nonwoven fabric, forming a sound-absorbing layer;

[0093] Step S2: After uniformly mixing the raw materials of the resonance layer according to parts by weight, they are put into a twin-screw extruder for melt extrusion to obtain a cast sheet; then the cast sheet is subjected to biaxial stretching at 120°C to obtain the resonance layer;

[0094] Step S3: The fluorosilicon-based thermoplastic polyurethane elastomer is kneaded into a film to obtain a damping layer;

[0095] Step S4: The sound-absorbing layer, resonance layer, and damping layer are placed in a plasma cavity, corona-treated at a power of 200 W for 30 min, then laminated from top to bottom in sequence and hot-pressed to form the sound-absorbing needle-punched nonwoven composite material.

[0096] In step S1, the thickness of the needle-punched nonwoven fabric is 5 mm; in step S1, the speed of the needle punching is 15 m / min, the frequency is 1000 punches / min, and the needle implantation density is 4000 needles / m; in step S2, the extrusion temperature of the twin-screw extruder is 230°C, and the screw rotation speed is 250 rpm; in step S2, the stretching ratio of the biaxial stretching is 3 times; in step S2, the thickness of the resonance layer is 4 mm; in step S3, the thickness of the damping layer is 6 mm; in step S4, the temperature of the hot-pressing is 180°C, the pressure is 5 MPa, and the time is 10 min.

[0097] Comparative Example 1

[0098] A sound-absorbing needle-punched nonwoven composite material and its preparation method are basically the same as those in Example 1, except that there is no sound-absorbing layer.

[0099] Comparative Example 2

[0100] A sound-absorbing needle-punched nonwoven composite material and its preparation method are basically the same as those in Example 1, except that there is no damping layer, and an equal amount of ultra-high molecular weight polyethylene is used to replace the sulfonic acid group-grafted ultra-high molecular weight polyethylene.

[0101] The sound-absorbing needle-punched nonwoven composite materials prepared in Examples 1-5 and Comparative Examples 1-2 are respectively subjected to relevant performance tests, and the test results are shown in Table 1. The test methods are as follows:

[0102] (1) Sound absorption coefficient: The sound absorption performance of the composite materials prepared in each example was tested by the impedance tube method. The test frequency range was 100 - 5000 Hz, and the test was based on "Measurement of Sound Absorption Coefficient and Acoustic Impedance in Acoustic Impedance Tube - Part 1: Standing - Wave Ratio Method" (GB / T 18696.1 - 2004).

[0103] (2) Tensile strength: The tensile strength test was carried out in accordance with GB / T 1040.1 - 2018.

[0104] Table 1 Test results of the sound - absorbing needle - punched non - woven composite material

[0105] Test items Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 1 Comparative Example 2 Average sound absorption coefficient 0.83 0.85 0.88 0.89 0.92 0.68 0.75 Tensile strength (MPa) 332 336 338 343 345 321 310

[0106] As can be seen from Table 1, compared with the comparative example, the sound - absorbing needle - punched non - woven composite material disclosed in the embodiments of the present invention has better sound absorption effect and mechanical properties; the use of sulfonic acid - group - grafted ultra - high - molecular - weight polyethylene and the setting of the damping layer and the sound - absorbing layer are beneficial to improving the above - mentioned properties.

[0107] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above - mentioned embodiments. What is described in the above - mentioned embodiments and the specification is only the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A sound-absorbing needle-punched nonwoven composite material, characterized in that: The invention comprises a sound absorbing layer, a resonance layer and a damping layer from top to bottom; the sound absorbing layer is a needle-punched nonwoven fabric made of basalt fiber and hollow polyester fiber; the resonance layer is made of the following raw materials in parts by weight: 100 parts of sulfonic acid grafted ultra-high molecular weight polyethylene, 10-15 parts of expanded perlite particles, 5-8 parts of nano titanium dioxide, 0.8-1 parts of catalyst, 1-3 parts of coupling agent, 1-3 parts of lubricant and 0.8-1.2 parts of antioxidant; the damping layer is made of fluorosilicone thermoplastic polyurethane elastomer.

2. The sound-absorbing needle-punched nonwoven composite material according to claim 1, characterized in that: The mass ratio of the basalt fiber to the hollow polyester fiber is (1-3):(3-5).

3. The sound-absorbing needle-punched nonwoven composite material according to claim 1, characterized in that: The basalt fiber has a length of 30-50 mm and a linear density of 1.0-2.0 dtex; the hollow polyester fiber has a hollowness of 4-13%, a fineness of 0.7-2.0 dtex, and a length of 45-65 mm.

4. The sound-absorbing needle-punched nonwoven composite material according to claim 1, characterized in that: The preparation method of the sulfonic acid grafted ultra-high molecular weight polyethylene comprises the following steps: adding 2-acrylamide-2-methylpropanesulfonic acid and ammonium persulfate into water, dissolving to obtain an initiating solution, adding the initiating solution into ultra-high molecular weight polyethylene powder, stirring at a speed of 60-100 rpm, protecting with nitrogen, and keeping the temperature at 70-80°C, reacting for 4-6 hours, washing with water, and drying to obtain the sulfonic acid grafted ultra-high molecular weight polyethylene.

5. The sound-absorbing needle-punched nonwoven composite material according to claim 4, characterized in that: The mass ratio of the 2-acrylamido-2-methylpropanesulfonic acid, ammonium persulfate, water and ultra-high molecular weight polyethylene powder is 1:(0.03-0.05):(3-5):(10-20).

6. The sound-absorbing needle-punched nonwoven composite material according to claim 1, characterized in that: The grade of the ultra-high molecular weight polyethylene powder is UH060P; the particle size of the expanded perlite particles is 0.5-1 mm; and the particle size of the nano titanium dioxide is 10-80 nm.

7. The sound-absorbing needle-punched nonwoven composite material according to claim 1, characterized in that: The catalyst is phosphorus pentoxide and polyphosphoric acid in a mass ratio of (3-5):1; the lubricant is zinc stearate; the coupling agent is at least one of silane coupling agent KH550, silane coupling agent KH560, and silane coupling agent KH570; and the antioxidant is at least one of antioxidant 1010 and antioxidant 168.

8. A method for preparing the sound-absorbing needle-punched nonwoven composite material according to any one of claims 1 to 7, characterized in that: The steps include: Step S1, after the basalt fiber and the hollow polyester fiber are uniformly mixed according to the mass ratio, the fibers are opened, combed, webbed, needle-punched, wound, and cut to form a needle-punched nonwoven fabric to form a sound-absorbing layer; Step S2, after mixing the raw materials of the resonance layer uniformly by weight, putting them into a twin-screw extruder, and melting and extruding them to obtain a cast sheet; then biaxially stretching the cast sheet at 110-120° C. to obtain a resonance layer; Step S3, mixing the fluorosilicone type thermoplastic polyurethane elastomer into a film to obtain a damping layer; Step S4, placing the sound absorbing layer, the resonance layer and the damping layer into a plasma chamber, subjecting them to corona treatment for 12-30 minutes at a power of 100-200 W, stacking them in sequence from top to bottom, and hot pressing them to obtain a sound absorbing needle-punched nonwoven composite material.

9. The method for preparing the sound-absorbing needle-punched nonwoven composite material according to claim 8, characterized in that: The thickness of the needle-punched nonwoven fabric in step S1 is 3-10 mm; the speed of the needle punching in step S1 is 7-15 m / min, the frequency is 800-1000 punctures / min, and the needle density is 3000-4000 pieces / m; the extrusion temperature of the twin-screw extruder in step S2 is 180-230°C, and the screw speed is 190-250 rpm; the stretching ratio of the biaxial stretching in step S2 is 2-4 times.

10. The method for preparing the sound-absorbing needle-punched nonwoven composite material according to claim 8, characterized in that: The thickness of the resonance layer in step S2 is 3-8 mm; the thickness of the damping layer in step S3 is 5-12 mm; the temperature of the hot pressing molding in step S4 is 170-180° C., the pressure is 2-5 MPa, and the time is 5-10 min.