A novel lightweight sound-insulating floor for rail vehicles and its preparation method

Abstract

This invention belongs to the field of rail vehicle technology, specifically relating to a novel lightweight sound-insulating floor for rail vehicles and its preparation method. The novel lightweight sound-insulating floor for rail vehicles provided by this invention includes a resin matrix, sound-absorbing layer units, and reinforcing layer units, with the sound-absorbing layer units and reinforcing layer units alternately arranged, and the resin matrix penetrating through the sound-absorbing layer units and reinforcing layer units. The preparation method of the novel lightweight sound-insulating floor for rail vehicles provided by this invention includes the following steps: Step 1: preparing a composite layer; Step 2: impregnation with resin; Step 3: drying; Step 4: pressing and molding. The novel lightweight sound-insulating floor for rail vehicles provided by this invention is lightweight, sound-insulating, and has a simple structure and preparation method. The preparation method provided by this invention does not require complex ingredient mixing and adopts an integrated molding technology, avoiding defects such as delamination and bubbling, thus ensuring the stability of the floor quality.

Description

Technical Field

[0001] This invention belongs to the field of rail vehicle technology, specifically relating to a novel lightweight sound-insulating floor for rail vehicles and its preparation method. Background Technology

[0002] To reduce the density of rail vehicles, lightweight materials commonly used for rail vehicle floors include aluminum alloy profiles, composite resins, and fibers. However, aluminum alloy profiles have poor sound insulation properties. To improve sound insulation, various sound insulation panels are available in existing technologies.

[0003] Chinese invention patent application No. 201910386565.0 discloses a rail vehicle floor structure, including a body side beam, a chassis crossbeam, an interior floor, and a body floor. The lower surfaces of the body side beam and chassis crossbeam are connected to the body floor, the upper surface of the body floor is connected to an insulating material, and a thermal insulation material is connected on top of the insulating material. Shock-absorbing pads are laid on the upper surfaces of the body side beam and chassis crossbeam, and the interior floor is connected to the upper surfaces of the body side beam and chassis crossbeam. The interior floor is composed of a fiberglass outer skin, a foam core, an artificial marble layer, and fluorescent strips embedded in the marble layer from bottom to top. The fluorescent strips are standard parts made of HPPL material; the fiberglass outer skin is 1.5mm thick phenolic fiberglass; the foam core is 7mm thick fireproof lightweight thermosetting foam core; the artificial marble layer is 4.5mm thick; and the fluorescent strips are made of high-performance photoluminescent material with a thickness of 4.5mm. The insulation material used is made of glass fiber cotton, pre-oxidized fiber cotton, or polyester fiber cotton, with a thickness between 20mm and 50mm, and the surface is covered with aluminum foil or black fiberglass cloth. This technology improves sound and heat insulation performance compared to existing technologies, and features high mechanical properties, impact resistance, resistance to deformation, flame retardancy, low smoke and low toxicity, chemical corrosion resistance, water and moisture resistance, low thermal conductivity, non-slip surface, strong surface decoration, resistance to roller indentations, and easy cleaning. However, based on the principle that greater thickness leads to better sound and heat insulation, this technology sets the total thickness of the floor interlayer to more than four times that of traditional structures; the function of the glass fiber cotton, pre-oxidized fiber cotton, or polyester fiber cotton is for heat insulation.

[0004] Chinese utility model patent No. 201020292928.9 discloses a structure for the internal filling material of a rail vehicle door. This structure involves bonding a three-dimensional hollow glass fiber reinforced phenolic resin board with phenolic foam in the middle to an asphalt board, and then bonding the asphalt board to another three-dimensional hollow glass fiber reinforced phenolic resin board with phenolic foam in the middle. This technology offers advantages such as high load-bearing capacity, increased compressive strength, and improved rigidity; good sound insulation, heat insulation, and safety performance; and relatively light weight. However, the asphalt board plays a role in heat and sound insulation in this technology, which significantly increases the density of the board structure, hindering the achievement of lightweight design.

[0005] It is evident that the greater the thickness of the floor and the harder the material used, the better the sound insulation effect. However, this will greatly increase the weight or density of the floor, which cannot meet the requirements for weight reduction of vehicle components in the field of rail vehicles.

[0006] Meanwhile, when the floor is used in rail vehicles, a flooring fabric is laid on the surface. In existing technologies, aluminum alloy profile floors or other multi-layered flooring with internal perforations and external reinforcement require the removal of all material at the dent site if dents occur due to external forces. This necessitates applying adhesive, covering with a surface cover, sanding the surface, and then bonding the flooring fabric with adhesive. Because the structure is porous, dents caused by external forces can lead to compression and deformation of the perforations, requiring repairs such as applying adhesive or even additional material, covering with a cover, and then bonding the flooring fabric with adhesive. This process is complex, time-consuming, and uses a lot of material, making on-site repairs in vehicles in use inconvenient.

[0007] Chinese invention patent application No. 201810335181.1 discloses a lightweight automobile cover and its preparation method. The lightweight automobile cover includes an inner core and a coating on the surface of the inner core. The inner core is made of raw materials, based on 100 parts by weight of raw material phenol. The raw material composition includes: 100 parts by weight of raw material phenol, 30-120 parts by weight of raw material aldehyde, 10-48 parts by weight of short fibers, 10-30 parts by weight of long fibers, 12-40 parts by weight of modified silica, 6-20 parts by weight of foaming agent, 2-10 parts by weight of surfactant, 10-30 parts by weight of catalyst, and 200-360 parts by weight of organic solvent. The short fibers have a length of 0.3-2 micrometers and the long fibers have a length of 5-20 micrometers. The preparation method includes the following steps: (1) After uniformly mixing raw material phenol, first part raw material aldehyde, catalyst, long fiber with a length of 5-20 micrometers, modified silica, foaming agent and surfactant in an organic solvent, the mixture is refluxed at 80-120℃ for 3-5 hours to obtain a prepolymer; short fiber with a length of 0.3-2 micrometers and second part raw material aldehyde are added to the prepolymer, ultrasonically dispersed for 30-60 minutes, and then refluxed at 90-110℃ for 1-2 hours to form a gel; (2) Gel heat treatment: the gel is placed in steam at a pressure of 150-500 kPa and a temperature of 130-200℃ for 1-2 hours. (3) After 3 hours, the mixture is cooled to room temperature to obtain flame-retardant high-strength lightweight phenolic resin; (4) The flame-retardant high-strength lightweight phenolic resin is hot-stamped into an integral shape to obtain the inner core; (5) Coating spraying: Modified epoxy resin, butyl methacrylate, reduced graphene oxide, leveling agent, wetting agent, and curing agent are mixed evenly in an organic solvent to form a coating emulsion. The coating emulsion is then sprayed onto the surface of the core material and cured to form a coating. This technology features lightweight car cover plates with high strength and has the function of shock absorption and sound insulation, which improves the stability and comfort of the car during driving.

[0008] However, the shortcomings of this existing technology are: (1) It uses a mixture of phenolic resin and foaming agent to produce phenolic resin foam, thereby reducing the mass of the system and playing a role in buffering external forces and sound insulation; it uses long and short fibers to enhance strength, so its internal structure has defects such as instability and differentiation, and its sound insulation effect and strength are also limited, making it unsuitable for use in rail vehicles. (2) It has a large variety of raw materials, complex formulation, and time-consuming process, making it unsuitable for widespread use. Summary of the Invention

[0009] To overcome the above-mentioned defects, the present invention aims to provide a novel lightweight sound insulation floor for rail vehicles, which is lightweight, sound-insulating, simple in structure, and easy to manufacture; another objective of the present invention is to provide a method for manufacturing the novel lightweight sound insulation floor.

[0010] To achieve the above objectives, the technical solution provided by the present invention is as follows: a novel lightweight sound insulation floor for rail vehicles, comprising a resin matrix, a sound-absorbing layer unit, and a reinforcing layer unit, wherein the sound-absorbing layer unit and the reinforcing layer unit are alternately arranged, and the resin matrix penetrates through the sound-absorbing layer unit and the reinforcing layer unit.

[0011] The optimized sound-absorbing layer unit includes 1-5 sound-absorbing layers, and the reinforcing layer unit includes 1-5 reinforcing layers; the resin matrix is ​​made of phenolic foam resin, the sound-absorbing layer is made of microporous composite fiber material, and the reinforcing layer is made of glass fiber.

[0012] The optimized arrangement involves setting up reinforcement layer units, sound absorption layer units, reinforcement layer units, and sound absorption layer units sequentially from bottom to top, until the total number of reinforcement layers and sound absorption layers is 36-90.

[0013] In the optimized design, the number of reinforcement layers in the reinforcement layer unit is 1, and the number of sound-absorbing layers in the sound-absorbing layer unit is 1.

[0014] The optimized glass fiber density is 1.5-2 g / cm³. 3 The microporous composite fiber material is made of nylon or polyester composite fiber, with a micropore diameter of 0.1-0.3 mm; the density of the phenolic foaming resin is 450-800 kg / m³. 3 .

[0015] The optimized design has a weight of ≤13kg per square meter and a sound insulation performance of ≥28dB.

[0016] The method for preparing the novel lightweight sound-insulating floor for rail vehicles provided by the present invention includes the following steps:

[0017] Step 1: Configure the composite layer: Stack the 1-5 sound-absorbing layers and the 1-5 reinforcement layers to form a composite layer;

[0018] Step 2: Impregnation; Prepare the resin matrix and immerse the composite layer into the resin matrix; the resin matrix includes phenolic resin and foaming agent;

[0019] Step 3: Drying: Dry the impregnated composite layer;

[0020] Step 4: Cutting: Cut the composite layer to the required length and width;

[0021] Step 5: Arrange the semi-finished products: Stack the composite layers into semi-finished products according to the thickness requirements;

[0022] Step 6: Pressing and shaping: Use a hot press to press the semi-finished product into shape.

[0023] In the optimized step one, when configuring the composite layer, layers 1-5 of the sound-absorbing layer and layer 1-5 of the reinforcement layer are drawn out from the sound-absorbing layer roll and the reinforcement layer roll respectively, and stacked to form a composite layer; the composite layer is automatically cut after passing through the impregnation and drying steps in sequence under the traction of the power.

[0024] In the optimized version, the thickness of the reinforcing layer in step one is 0.2-0.5mm, and the thickness of the sound-absorbing layer is 0.1-0.25mm; in step four, the length of the composite layer after cutting is 2-3.5m, and the width is 1-1.5m.

[0025] The optimized method involves the following steps: Step 2 uses hydrofluoroolefin as the foaming agent, and the weight ratio of phenolic resin to foaming agent is (5-10):1; the amount of resin matrix should submerge the composite layer and extend it by at least 0.1 mm; the impregnation time is 0.5-1 minute, and the temperature is room temperature; Step 3 drying time is 0.5-1 minute, and the temperature is 60-80℃; Step 6 pressing pressure is 4-10MPa, the temperature is 120-150℃, and the time is 20-60 minutes.

[0026] In this invention, the glass fiber used is commercially available edge-stitched felt, which is woven from continuous glass fibers, improving the mechanical properties and other indicators of the flooring. The microporous composite fiber material uses commercially available microporous nylon or polyester fibers. All raw materials used in this invention are commercially available, simple to obtain, and do not require complex formulation and manufacturing processes. After the product is manufactured, each sound-absorbing layer and reinforcing layer forms an integrated board structure, possessing both sound absorption and reinforcement functions, while also giving the entire product integrity and strength, facilitating the processing of finished products.

[0027] The novel lightweight sound-insulating flooring provided by this invention comprises a resin matrix, sound-absorbing layer units, and reinforcing layer units. The raw materials themselves have high strength and durability. The reinforcing layer enhances the flooring's strength, while the sound-absorbing layer provides sound insulation. The resin matrix integrates the sound-absorbing layer units and the reinforcing layer units, thereby improving the overall strength of the flooring and giving it lightweight sound-insulating characteristics.

[0028] The alternating arrangement of sound-absorbing and reinforcing layer units not only achieves a gradual sound insulation effect but also provides layer-by-layer reinforcement.

[0029] The alternating arrangement involves sequentially layering 1-5 reinforcing layers, 1-5 sound-absorbing layers, 1-5 reinforcing layers, and 1-5 sound-absorbing layers from bottom to top, until the total number of reinforcing layers and sound-absorbing layers reaches 36-90. When each reinforcing layer unit consists of a single reinforcing layer and a single sound-absorbing layer unit, the arrangement is repeated from bottom to top: reinforcing layer, sound-absorbing layer, reinforcing layer, sound-absorbing layer, until the total number of reinforcing layers and sound-absorbing layers reaches 36-90. This arrangement provides the best gradual sound insulation and layer-by-layer reinforcement performance. Furthermore, because the composite unit consists of one sound-absorbing layer and one reinforcing layer, the steps of configuring the composite layers, impregnating, drying, and cutting are easier to perform, facilitating production.

[0030] The resin matrix is ​​made of phenolic foam resin, the sound-absorbing layer is made of microporous composite fiber material, and the reinforcing layer is made of glass fiber. The composite fiber and glass fiber can be bonded together by phenolic resin and have sufficient strength. The foam of phenolic foam resin can also reduce the weight of the floor and have the effect of sound insulation.

[0031] This invention employs preferred sound-absorbing layers, reinforcing layers, and types and parameters of phenolic foaming resin, as well as a preferred setting method, to produce flooring with higher sound insulation performance and lower weight per square meter without increasing thickness, thus exhibiting lightweight sound insulation characteristics.

[0032] The novel lightweight, high-sound-insulating flooring provided by this invention offers excellent maintainability. If unforeseen external forces cause dents or other defects, these can be directly repaired with adhesive. Furthermore, due to the excellent bonding between phenolic resin and polyurethane adhesive, simply cleaning the surface is sufficient before bonding the flooring to a vehicle; surface sanding is unnecessary, thus facilitating immediate maintenance.

[0033] The present invention provides a novel method for preparing lightweight, high-sound-insulating flooring, employing an assembly line operation and simplifying the process. First, 1-5 layers of sound-absorbing material and 1-5 layers of reinforcing material are drawn from a roll and stacked to form a composite layer. This is followed by impregnation with adhesive, drying (actually semi-drying), and cutting. Then, the semi-finished products are arranged according to the required specifications and finally pressed into shape. The steps are scientifically designed, easy to operate, and highly efficient. Firstly, by configuring a composite layer consisting of individual sound-absorbing and reinforcing layer units, the processes of impregnation, drying, and cutting are facilitated. Furthermore, the impregnation and drying can be performed on a unit basis, allowing for preliminary bonding of the composite layer before the production of semi-finished and finished products. Secondly, the product preparation method provided by this invention eliminates the need for impregnation after all reinforcing and sound-absorbing layers are stacked. Impregnation of the composite unit alone is sufficient to produce a product with excellent sound insulation, lightweight, and strength properties through pressing. This simplifies the impregnation, drying, and cutting operations, thereby improving production efficiency. Third, the semi-finished product, which is formed by stacking and arranging the composite layers according to the thickness requirements, is not completely dry after drying, but in a semi-dry state. This facilitates subsequent stacking and pressing operations, and finally allows the product to be made with the required sound insulation, lightweight and strength properties through pressing molding.

[0034] In step one, when configuring the composite layer, layers 1-5 of the sound-absorbing layer and layer 1-5 of the reinforcing layer are drawn out from the sound-absorbing layer roll and the reinforcing layer roll respectively, and stacked to form the composite layer. Under the traction of the power, the composite layer goes through the impregnation and drying steps in sequence and is then automatically cut. That is, the impregnation and drying operations are carried out in the production line, which improves production efficiency.

[0035] This invention produces a product with excellent sound insulation, lightweight, and strength properties by setting scientifically appropriate reinforcement layer thickness, sound absorption layer thickness, type of foaming agent, weight ratio of phenolic resin and foaming agent, pressing pressure, pressing temperature, and time.

[0036] The amount of resin matrix should submerge the single-layer sound-absorbing layer and reinforcing layer in step one by at least 0.1 mm, with an impregnation time of 0.5-1 minute at room temperature. This setting saves energy, simplifies the process, and meets the resin impregnation requirements for producing a qualified finished product. The drying time is 0.5-1 minute at 60-80 degrees Celsius; this is essentially a semi-drying operation, facilitating subsequent cutting, arrangement, and final pressing. The length and width of the sound-absorbing layer and reinforcing layer can be adjusted to meet the environmental requirements of the flooring's application.

[0037] The beneficial effects of this invention are as follows:

[0038] 1. The novel lightweight high sound insulation floor provided by this invention has the characteristics of being lightweight and having excellent sound insulation performance compared with the prior art. It does not require increasing the product thickness or the weight per square meter, and the sound insulation effect is improved by at least 3dB. That is, the product weight per square meter is as low as less than 13kg while the sound insulation performance reaches more than 28dB, which greatly improves the comfort of the vehicle.

[0039] 2. This invention utilizes microporous composite fiber materials and glass fibers, layered alternately to progressively insulate and reinforce the sound, and is bonded together with phenolic resin. The phenolic foam resin further reduces the weight of the flooring and improves sound insulation. This invention is easy to manufacture and features lightweight, sound insulation, and high strength.

[0040] 3. The novel lightweight and high-sound-insulating floor provided by this invention has good heat insulation performance, which can offset the energy consumption caused by the temperature difference between the inside and outside of the vehicle, thus achieving the effect of energy saving and emission reduction. At the same time, it has high strength, excellent pressure resistance and impact resistance, which effectively improves the reliability of the floor. It also has excellent resistance to acid and alkali corrosion and aging, avoiding the need for repair and replacement due to corrosion and aging of the floor, thereby reducing the total life cycle cost.

[0041] 4. The preparation method provided by this invention does not require complicated ingredients and adopts one-piece molding technology, which will not have defects such as delamination or bubbling, thus ensuring the stability of the flooring quality.

[0042] 5. The preparation method provided by this invention creatively introduces the roll assembly line process into the field of flooring manufacturing. It cleverly utilizes the process of first configuring a single composite layer, impregnating and drying (semi-drying), then cutting and arranging, and finally pressing and molding. Starting from the sound-absorbing layer and the reinforcing layer roll, the process is carried out through assembly line operation. Moreover, the impregnation is only for the composite layer, which simplifies the operation difficulty and improves the operation efficiency. Attached Figure Description

[0043] Figure 1 This is a schematic diagram of the novel lightweight sound-insulating floor provided by the present invention.

[0044] 1. Resin matrix; 2. Reinforcing layer; 3. Sound-absorbing layer. Detailed Implementation

[0045] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0046] The testing standards used in the examples and comparative examples were as follows: compressive strength was tested according to GB / T 8813; sound insulation performance was tested according to GB / T19889.3; impact strength: with a 2.5mm rubber flooring cloth attached to the floor, a 500g Ф50 steel ball was dropped from a height of 2m, and the collapse amount including the flooring cloth was measured; thermal conductivity was tested according to GB / T 10295.

[0047] The technical solution adopted in this embodiment of the invention is as follows: a novel lightweight sound insulation floor for rail vehicles, comprising a resin matrix, a sound-absorbing layer unit, and a reinforcing layer unit, wherein the sound-absorbing layer unit and the reinforcing layer unit are alternately arranged, and the resin matrix penetrates through the sound-absorbing layer unit and the reinforcing layer unit.

[0048] The sound-absorbing layer unit includes 1-5 sound-absorbing layers, and the reinforcing layer unit includes 1-5 reinforcing layers; the resin matrix is ​​made of phenolic foam resin, the sound-absorbing layer is made of microporous composite fiber material, and the reinforcing layer is made of glass fiber.

[0049] The structure consists of reinforcement layer units, sound absorption layer units, reinforcement layer units, and sound absorption layer units arranged sequentially from bottom to top, until the total number of reinforcement layers and sound absorption layers is 36-90.

[0050] The number of reinforcing layers in the reinforcing layer unit is 1, and the number of sound-absorbing layers in the sound-absorbing layer unit is 1.

[0051] The density of the glass fiber is 1.5-2 g / cm³. 3 The microporous composite fiber material is made of nylon or polyester composite fiber, with a micropore diameter of 0.1-0.3 mm; the density of the phenolic foaming resin is 450-800 kg / m³. 3 .

[0052] Among them, the weight per square meter is ≤13kg, and the sound insulation performance is ≥28dB.

[0053] The method for preparing a novel lightweight sound-insulating floor for rail vehicles provided in this embodiment of the invention includes the following steps:

[0054] Step 1: Configure the composite layer: Stack the 1-5 sound-absorbing layers and the 1-5 reinforcement layers to form a composite layer;

[0055] Step 2: Impregnation; Prepare the resin matrix and immerse the composite layer into the resin matrix; the resin matrix includes phenolic resin and foaming agent;

[0056] Step 3: Drying: Dry the impregnated composite layer;

[0057] Step 4: Cutting: Cut the composite layer to the required length and width;

[0058] Step 5: Arrange the semi-finished products: Stack the composite layers into semi-finished products according to the thickness requirements;

[0059] Step 6: Pressing and shaping: Use a hot press to press the semi-finished product into shape.

[0060] In step one, when configuring the composite layer, layers 1-5 of the sound-absorbing layer and layer 1-5 of the reinforcing layer are drawn out from the sound-absorbing layer roll and the reinforcing layer roll respectively, and stacked to form a composite layer; under the traction of power, the composite layer goes through the impregnation and drying steps in sequence and is then automatically cut.

[0061] In step one, the thickness of the reinforcing layer is 0.2-0.5mm, and the thickness of the sound-absorbing layer is 0.1-0.25mm; in step four, the length of the composite layer after cutting is 2-3.5m, and the width is 1-1.5m.

[0062] In step two, the foaming agent is hydrofluoroolefin, and the weight ratio of phenolic resin to foaming agent is (5-10):1; the amount of resin matrix should submerge the composite layer and be at least 0.1 mm above it; the impregnation time is 0.5-1 minutes, and the temperature is room temperature; in step three, the drying time is 0.5-1 minutes, and the temperature is 60-80℃; in step six, the pressing pressure is 4-10MPa, the temperature is 120-150℃, and the time is 20-60 minutes. Example 1

[0063] The technical solution adopted in this embodiment is that the number of reinforcing layers in the reinforcing layer unit is 1, and the number of sound-absorbing layers in the sound-absorbing layer unit is 1.

[0064] The density of the glass fiber is 1.7 g / cm³. 3 The microporous composite fiber material is a polyester composite fiber with a micropore diameter of 0.2 mm.

[0065] In the preparation method of a novel lightweight sound insulation floor for rail vehicles used in this embodiment, step one involves stacking a sound-absorbing layer and a reinforcing layer to form a composite layer.

[0066] In step four, the composite layer is cut to a length of 2.5m and a width of 1.5m.

[0067] Step 2: The weight ratio of phenolic resin to foaming agent is 7:1; the pressing pressure is 7 MPa, the temperature is 130℃, and the time is 40 minutes. Example 2

[0068] The difference between this embodiment and Embodiment 1 is that the weight ratio of phenolic resin and foaming agent is different, and products of different thicknesses are selected for testing. Specifically, it is divided into two examples: Embodiment 2-1 and Embodiment 2-2.

[0069] Comparative Example 1

[0070] This comparative example uses existing technology. Comparative example 1-1 is an aluminum alloy profile floor, which structurally includes upper and lower panels and a central aluminum profile. Comparative example 1-2 uses a fiberglass surface-bonded floor, which is formed by surface bonding, curing, and then cutting into strips that are vertically installed along the length of the floor surface.

[0071] Comparative Example 2

[0072] The difference between this comparative example and Example 1 is that the weight ratio of phenolic resin and foaming agent is different, and products with different thicknesses are selected for testing. Specifically, it is divided into two examples: Comparative Example 2-1 and 2-2.

[0073] Examples 1 and 2, along with Comparative Examples 1 and 2, were tested for areal density, sound insulation performance, compressive strength, impact strength, and thermal conductivity. Comparative Example 1 used products of various thicknesses for comparison. The parameter comparison results are recorded in the table below.

[0074] Table 1

[0075]

[0076] From the comparison in the table above, it can be seen that (1) from the comparison between the examples and comparative examples 2-1 and 2-2, the performance of the examples provided by the present invention, with a weight ratio of phenolic resin to foaming agent of (5-10):1, is better than that of comparative examples 2-1 and 2-2. Its weight per square meter is as low as less than 13 kg, its sound insulation performance reaches more than 28 dB, and its compressive strength and impact strength are excellent. (2) from the comparison between examples 1, 2-1 and 2-2, it can be seen that the thickness of the product in the examples is 18-25 mm. The thickness is not proportional to the weight per square meter and the sound insulation performance. It can be seen that its thickness does not affect its performance. That is, the examples of the present invention do not need to improve the performance by increasing the product thickness. (3) Compared with other products of similar thickness in the prior art (Comparative Example 1), this embodiment has a lower weight per square meter and excellent sound insulation performance. For example, the product in the prior art that meets the requirements of weight per square meter and thickness, such as the first example in Comparative Example 1-1 (weight per square meter 13kg), has a sound insulation performance of 25dB. To achieve a sound insulation performance equivalent to that of this embodiment, which is 28dB, its thickness or weight per square meter would need to be significantly increased (e.g., the second example in Comparative Example 1-1 has a 50% increase in weight per square meter), which would seriously fail to meet the requirements for use in rail vehicles. In summary, the embodiment provided by this invention is superior to the comparative example. Example 3

[0077] The difference between this embodiment and Embodiment 1 is that in this embodiment, the number of reinforcing layers in the reinforcing layer unit is 5, and the number of sound-absorbing layers in the sound-absorbing layer unit is 3.

[0078] Comparative Example 3

[0079] The difference between this comparative example and Example 1 lies in the different methods of setting the sound-absorbing layer and the reinforcing layer. In Comparative Example 3-1, the floor only uses a sound insulation layer and does not use a reinforcing layer; in Comparative Example 3-2, the floor only uses a reinforcing layer and does not use a sound insulation layer; in Comparative Example 3-3, the sound-absorbing layer is entirely placed on top of the reinforcing layer; in Comparative Example 3-4, the sound insulation layer is placed in the middle, and the reinforcing layer is divided into two equal parts, with one half placed on top of the sound insulation layer and the other half placed below it.

[0080] Examples 1 and 3, and Comparative Example 3 were tested for areal density, sound insulation performance, compressive strength, and impact strength, as detailed in Table 2.

[0081] Table 2

[0082]

[0083] As can be seen from the comparison in the table above, the embodiment provided by the present invention uses an alternating arrangement of reinforcing layer units, sound-absorbing layer units, reinforcing layer units, and sound-absorbing layer units from bottom to top, achieving a sound insulation performance of over 28dB, and superior compressive strength and impact resistance compared to the comparative example. Specifically, in Comparative Example 3-1, the floor only uses a sound insulation layer without a reinforcing layer, resulting in insufficient mechanical strength; in Comparative Example 3-2, the floor only uses a reinforcing layer without a sound insulation layer, reducing its sound insulation; in Comparative Example 3-3, the sound-absorbing layer is entirely placed on top of the reinforcing layer, affecting both sound insulation and mechanical strength; in Comparative Example 3-4, the sound insulation layer is placed in the middle, and the reinforcing layer is divided into two equal parts, with one half placed on top of the sound insulation layer and the other half placed below, affecting sound insulation. Therefore, the embodiment provided by the present invention is superior to the comparative example. Example 4

[0084] The difference between this embodiment and Embodiment 1 lies in the density of the glass fiber and the diameter of the micropores in the microporous composite fiber material layer. Specifically, it is divided into four examples: Embodiment 4-1, 4-2, 4-3, and 4-4.

[0085] Comparative Example 4

[0086] The difference between this comparative example and Example 1 lies in the density of the glass fiber and the diameter of the micropores in the microporous composite fiber material layer. Specifically, it is divided into four examples: Comparative Examples 4-1, 4-2, 4-3, and 4-4.

[0087] The sound insulation performance, compressive strength, and impact strength of Examples 1 and 4 and Comparative Example 4 were tested, as detailed in Table 3.

[0088] Table 3

[0089]

[0090] As can be seen from the comparison in the table above, the embodiments provided by this invention utilize a scientifically controlled density of glass fiber and a micropore diameter of the microporous composite fiber material, resulting in lightweight sound insulation characteristics. Furthermore, their compressive strength, impact strength, and thermal conductivity are superior to the comparative example. Excessive glass fiber density leads to an increase in the product's weight per square meter, while insufficient density reduces its mechanical properties. Similarly, excessively large or small micropore diameters in the microporous composite fiber material negatively impact its sound insulation performance. In conclusion, the embodiments provided by this invention are superior to the comparative example. Example 5

[0091] The difference between this embodiment and Embodiment 1 lies in the pressing pressure, temperature, and time. Specifically, it is divided into four examples: Embodiments 5-1, 5-2, 5-3, and 5-4.

[0092] Comparative Example 5

[0093] The difference between this comparative example and Example 1 lies in the pressing pressure, temperature, and time. Specifically, it is divided into four examples: Comparative Examples 5-1, 5-2, 5-3, and 5-4.

[0094] The compressive strength and impact strength of Examples 1 and 5 and Comparative Example 5 were tested, as detailed in Table 4.

[0095] Table 4

[0096]

[0097] The weight per square meter of the above-mentioned embodiments and comparative examples in this comparison group all ranged from 11.2 to 11.4 kg, and their sound insulation performance all reached above 28 dB. However, as can be seen from the comparison table above, the embodiments provided by this invention employ scientific pressing pressure, temperature, and time, resulting in product compressive strength and impact resistance superior to the comparative examples. Insufficient or excessive pressing pressure, temperature, and time both lead to a decrease in the mechanical properties of the product; therefore, the embodiments provided by this invention are superior to the comparative examples.

[0098] As can be seen from the comparison of the above embodiments and comparative examples, the novel lightweight high sound insulation floor provided by the present invention has the characteristics of being lightweight and having excellent sound insulation performance compared with the prior art. It does not require increasing the product thickness or the weight per square meter, and the sound insulation effect is improved by at least 3dB. The product weighs less than 13kg per square meter while achieving a sound insulation performance of more than 28dB, which greatly improves the comfort inside the vehicle.

Claims

1. A method for preparing a novel lightweight sound-insulating floor for rail vehicles, characterized in that: It includes a resin matrix, a sound-absorbing layer unit, and a reinforcing layer unit, with the sound-absorbing layer unit and the reinforcing layer unit arranged alternately, and the resin matrix penetrating through the sound-absorbing layer unit and the reinforcing layer unit; The sound-absorbing layer unit includes 1-5 sound-absorbing layers, and the reinforcing layer unit includes 1-5 reinforcing layers; the resin matrix is ​​made of phenolic foam resin, the sound-absorbing layer is made of microporous composite fiber material, and the reinforcing layer is made of glass fiber. The density of the glass fiber is 1.5-2 g / cm 3 ; the microporous composite fiber material is nylon or polyester composite fiber, the micropore diameter is 0.1-0.3 mm; the density of the phenolic foaming resin is 450-800 kg / m 3 ; Weight per square meter ≤13kg, sound insulation performance ≥28dB; Its preparation method includes the following steps: Step 1: Configure the composite layer: Stack the 1-5 sound-absorbing layers and the 1-5 reinforcement layers to form a composite layer; Step 2: Impregnation; Prepare the resin matrix and immerse the composite layer into the resin matrix; the resin matrix includes phenolic resin and foaming agent; Step 3: Drying: Dry the impregnated composite layer; Step 4: Cutting: Cut the composite layer to the required length and width; Step 5: Arrange the semi-finished products: Stack the composite layers into semi-finished products according to the thickness requirements; Step Six: Pressing and Shaping: Press the semi-finished product into shape using a hot press; In step one, when configuring the composite layer, layers 1-5 of the sound-absorbing layer and layer 1-5 of the reinforcing layer are drawn out from the sound-absorbing layer roll and the reinforcing layer roll respectively, and stacked to form a composite layer; under the traction of the power, the composite layer goes through the impregnation and drying steps in sequence and is then automatically cut. Step 2: The foaming agent is hydrofluoroolefin, and the weight ratio of phenolic resin to foaming agent is (5-10):1; the amount of resin matrix should submerge the composite layer and be at least 0.1 mm above it; the impregnation time is 0.5-1 minute, and the temperature is room temperature; Step 3: The drying time is 0.5-1 minute, and the temperature is 60-80℃; Step 6: The pressing pressure is 4-10MPa, the temperature is 120-150℃, and the time is 20-60 minutes.

2. The method for preparing a novel lightweight sound-insulating floor for rail vehicles according to claim 1, characterized in that: The reinforcement layer unit, sound absorption layer unit, reinforcement layer unit, and sound absorption layer unit are arranged sequentially from bottom to top until the total number of reinforcement layers is 36-90 and the total number of sound absorption layers is 36-90.

3. The method for preparing a novel lightweight sound-insulating floor for rail vehicles according to claim 2, characterized in that: The number of reinforcing layers in the reinforcing layer unit is 1, and the number of sound-absorbing layers in the sound-absorbing layer unit is 1.

4. A method for preparing a novel lightweight sound-insulating floor for rail vehicles according to any one of claims 1-3, characterized in that: In step one, the thickness of the reinforcing layer is 0.2-0.5mm, and the thickness of the sound-absorbing layer is 0.1-0.25mm; in step four, the length of the composite layer after cutting is 2-3.5m, and the width is 1-1.5m.

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