Composite material sleeper, preparation device and preparation method

Abstract

The invention belongs to the technical field of composite material preparation, and particularly relates to a composite material sleeper, a preparation device and a preparation method.The composite material sleeper comprises a core material and a skin wrapping the core material, the space between the core material and the skin is filled with foam, and the foam is obtained after foaming of foaming resin; the inner side of the skin is provided with a lug boss towards the core material; the preparation device of the composite material sleeper comprises a skin preparation device and a plugging device, and the plugging device is located at the end of a core material and the end of the skin so as to seal the end of the core material and the end of the skin. The device for preparing the skin comprises a roller, a gum dipping box, a feeding device for pouring materials into the gum dipping box and a mold, further comprises a traction clamping mechanism and a transmission platform which are sequentially arranged in the moving direction of the skin and are used for dragging the skin, and further comprises a cutting device for cutting off the skin. The device effectively improves the product quality uniformity, improves the transverse strength of the product, improves the product performance, and is high in automation degree.

Description

Technical Field

[0001] The present invention belongs to the technical field of composite material preparation, and in particular relates to a composite material sleeper, a preparation device and a preparation method. Background Art

[0002] Traditional polyurethane foam synthetic sleepers are composite materials made from continuous fibers as reinforcement, polyurethane as a matrix material, and additives, produced through a foaming and pultrusion process. While the continuous fibers reinforce the longitudinal direction, resulting in superior performance, the cross-sectional area lacks fiber reinforcement, relying primarily on the strength of the polyurethane foam resin itself for support. This results in extremely poor transverse performance, and weak transverse strength can easily lead to application risks such as low pullout resistance of screw spikes, delamination, and transverse cracking.

[0003] In order to solve the problem of low lateral strength of products, many domestic units have conducted relevant research in this regard.

[0004] Patent application CN106349446A has developed a reinforced fiber with a content of more than 60% and a density of more than 840g / cm 3 High-fiber content, high-density polyurethane foam synthetic sleepers are made by increasing product density and glass fiber content to improve the overall lateral strength of the product. Although this method is effective, as the density increases, the product cost will also increase significantly. At the same time, the glass fiber content and product density are too high, and the product rigidity is too large, which is inconsistent with the product's shock absorption and lightweight requirements.

[0005] Patent application CN118418322A proposes adding chopped fibers to the product body to improve the transverse strength of the product. However, if the chopped fibers are too short, the transverse reinforcement effect on the product is limited. If the chopped fibers are too long, the fluidity of the resin is affected, making the process very difficult to implement.

[0006] Authorized patent CN108504085B and patent application CN119800780A propose wrapping a polyurethane-impregnated continuous glass fiber with a glass fiber fabric during the main body molding process. The polyurethane-impregnated continuous fiber and glass fiber fabric are then simultaneously fed into a laminating machine for foaming and curing. This wrapping of fiber fabric (glass cloth / reinforcement mat, etc.) improves the product's lateral strength. While this technical approach is theoretically effective and economical, it faces a significant practical challenge. After the sleeper blank is matured and removed from the mold, each surface must be sanded to a depth of 2-4 mm to remove burrs and then painted for weather resistance. However, the thickness of this wrapping fiber fabric, typically no more than 2 mm after curing, is almost completely removed during the main body molding process, resulting in no lateral reinforcement in the actual product. CN108504085B deliberately avoids this problem; CN119800780A proposes adding release paper to avoid surface grinding and spraying, but the feasibility of this technical statement is questionable. First of all, the use of release agent / release paper in production is a routine operation, and its effect is to facilitate product demoulding, but it cannot eliminate flash and subsequent grinding and sanding. In the industry, there has been no real product with reinforced cloth / felt wrapped on the product surface. Therefore, how to improve the lateral strength of the product has become an industry difficulty. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a composite material sleeper, a preparation device and a preparation method, which can effectively improve the uniformity of product quality, increase the lateral strength of the product, improve product performance, and have a high degree of automation.

[0008] An embodiment of the present invention provides a composite material sleeper, comprising a core material and a skin wrapped around the core material, wherein the space between the core material and the skin is filled with foam, the foam being obtained by foaming a foaming resin; a protrusion facing the core material is provided on the inner side of the skin; The manufacturing device of the composite material sleeper includes a device for preparing the skin and a sealing device, wherein the sealing device is located at the ends of the core material and the skin to seal the ends of the core material and the skin; The device for preparing the skin includes a roller, a dipping box, a feeding device for filling the dipping box with material, and a mold. The roller is provided with a fiber fabric, and the fiber fabric passes through the dipping box and the mold in sequence. The dipping box dips the fiber fabric, and the mold solidifies and shapes the dipped fiber fabric to obtain the skin. It also includes a traction clamping mechanism and a transmission platform which are sequentially arranged along the moving direction of the skin and are used to pull the skin, and a cutting device which is used to cut the skin.

[0009] An embodiment of the present invention provides a device for preparing the composite material sleeper, comprising a device for preparing a skin and a sealing device, wherein the sealing device is located at the ends of the core material and the skin to seal the ends of the core material and the skin; The device for preparing the skin includes a roller, a dipping box, a feeding device for filling the dipping box with material, and a mold. The roller is provided with a fiber fabric, and the fiber fabric passes through the dipping box and the mold in sequence. The dipping box dips the fiber fabric, and the mold solidifies and shapes the dipped fiber fabric to obtain the skin. It also includes a traction clamping mechanism and a transmission platform which are sequentially arranged along the moving direction of the skin and are used to pull the skin, and a cutting device which is used to cut the skin.

[0010] Preferably, the number of the rollers and the number of the fiber fabrics are 2 respectively.

[0011] Preferably, a preforming tool is also included, which preforms the surface of the fiber fabric into an L shape, and two L-shaped fiber fabrics are enclosed to form the shape of the skin, and then enter the dipping box.

[0012] Preferably, the feeding device includes a storage barrel I, a storage barrel II and a mixing gun head. The materials in the storage barrel I and the storage barrel II enter the mixing gun head through a pipeline for mixing, and the mixed materials enter the dipping box through a pipeline to impregnate the fiber fabric.

[0013] Preferably, a metering device is further included, and the metering device is used to measure the supply amount of the material.

[0014] Preferably, the sealing device includes a mounting frame located at the end and both sides of the skin and a seal and a clamping member arranged on the mounting frame, the seal including a sealing pressure plate and a sealing driving member for driving the sealing pressure plate to move; the clamping member includes two clamping members respectively located at both ends of the skin for clamping the skin, including an upper clamping member and a lower clamping member, the upper clamping member includes an upper clamping pressure plate and an upper clamping driving member for driving the upper clamping pressure plate to move; the lower clamping member includes a lower clamping pressure plate and a lower clamping driving member for driving the lower clamping pressure plate to move.

[0015] An embodiment of the present invention provides a method for preparing a composite material sleeper, which is performed using the aforementioned preparation device and includes the following steps: preparing a core material; The skin is prepared in the following steps: Put the fiber fabric into the drum and put the material into the feeding device; The unwinding roller is started, and the fiber fabric enters the dipping box. The feeding device feeds the material. After entering the dipping box, the material fully impregnates the fiber fabric. The impregnated fiber fabric enters the mold, and the mold solidifies and shapes the impregnated fiber fabric to obtain the skin; The skin moves under the action of the traction and clamping mechanism, and the skin enters the transmission platform, and the cutting device cuts the skin to obtain the cut skin; Place the sealing device at the end of the skin to seal it, lift the other end of the skin to a certain angle (10°-45°) with the ground, and then inject foaming resin into the skin, and let the foaming resin flow to the bottom of the sealing end; The core material is placed in the skin. The cross-sectional dimensions of the core material are 0-2mm smaller than the inner cavity dimensions of the skin cross-sectional dimensions, so that the core material can be smoothly placed in the skin. The inner side of the skin is preferably provided with a protrusion facing the core material. The protrusions are located in four directions of the skin. In one direction, the sum of the distances between the core material and the two protrusions is equal to the width of the skin. Therefore, the protrusions of the skin can automatically position the core material in the center of the skin. Seal the other end of the skin with a sealing device, then lay the product flat and put it into the drying room to wait for the foaming resin to solidify and fill the gap between the skin and the core material; After the foaming resin is completely solidified, the sealing devices at both ends are removed to obtain the composite material sleeper.

[0016] Preferably, the preparation device also includes a preforming tooling, and the number of the rollers and fiber fabrics is 2 respectively; before entering the dipping box, the fiber fabric is preformed into an L-shape by the preforming tooling, and the two L-shaped fiber fabrics are enclosed to form the shape of the skin, and then enter the dipping box.

[0017] The beneficial effect of the present invention is that the present invention adopts a multi-layer composite structure design, which can greatly improve the lateral strength of traditional polyurethane foam synthetic sleepers, and also has the advantages of lower cost and lighter weight.

[0018] The present invention utilizes a pure fiberglass extrusion skin, significantly improving the product's transverse strength, preventing transverse cracking and enhancing shear resistance. The core material utilizes conventional polyurethane foam synthetic sleepers, providing excellent bending resistance. The rigid polyurethane foam filling in the center securely connects the skin and core, while also providing cushioning and shock absorption. This invention offers superior performance, convenient process implementation, high production efficiency, and stable and controllable product quality.

[0019] Due to process constraints, the corners of traditional polyurethane foam synthetic sleepers are all right angles, which are easily bumped and split during transportation and construction; the skin corners of the present invention can be designed and manufactured with arcs, solving the problem of bumping corners that has long plagued traditional polyurethane foam synthetic sleepers.

[0020] Traditional polyurethane foam composite sleepers use continuous fiber reinforced polyurethane foam synthetic sleepers, and their transverse strength perpendicular to the continuous fiber direction is less than 1 / 20 of the longitudinal strength, and the performance is seriously uneven. During the use of the product, low transverse strength can easily lead to application risks such as low pull-out resistance of threaded spikes, product delamination and transverse cracking. The present invention adopts a composite structure of skin + core material + foam filling, which greatly improves the transverse strength of the product and improves the safety of product use. In actual application, it can improve the buffering and shock absorption effect on train tracks and improve the comfort of train operation. The product performance is better than that of traditional polyurethane foam synthetic sleepers. The cost of the product can be reduced by reducing the density of the core material, and it has significant prospects for promotion and application.

[0021] The present invention has strong designability, and the skin can be designed into any uniform cross-sectional structure suitable for the pultrusion process. At the same time, different fiber cloth layers can be used for pultrusion in the process manufacturing, such as 0° fiber, 0° / 90° biaxial cloth, ±45° biaxial cloth, etc., and targeted selection and design can be carried out according to the product usage scenario, performance requirements, etc.

[0022] Traditional polyurethane foam synthetic sleepers are made of continuous fiber reinforced polyurethane foam with a cellular structure on the surface, which is prone to defects such as holes and has poor appearance quality. They generally need to be leveled with putty, which increases production costs. At the same time, the adhesion between putty and paint is poor, and the sprayed paint is easy to fall off. The skin of the present invention adopts pure cloth polyurethane pultrusion, which has a smooth surface, better appearance quality, and stronger adhesion to paint. In addition, the traditional polyurethane foam synthetic sleeper is made into the core material. Due to the secondary foam filling, defects such as holes on the surface of the core material can be foamed and filled, and the core material does not need to be surface treated such as putty.

[0023] Conventional split molding solutions generally use hand lay-up technology for reinforcement: that is, after sanding the rough surface, brush epoxy resin / vinyl resin / unsaturated resin, etc. on the surface, and then lay fiber fabrics layer by layer for reinforcement. The skin production of the present invention has high production efficiency and can be continuously produced by foaming pultrusion of polyurethane foam synthetic sleepers, but the two are completely different (the core material is made of polyurethane foam pultrusion, and the skin is made of polyurethane pultrusion. The two are very different, and the resin systems and molding equipment used are completely different, and they belong to two completely different processes). In addition, the use of biaxial pultrusion is also different from conventional pultrusion. Conventional pultrusion processes generally use continuous fiber pultrusion, while the use of pure glass fiber pultrusion is a special pultrusion process in the pultrusion process. Finally, the conventional method for connecting the separately molded skin and core material is also to directly bond them with adhesive resins such as epoxy resin and acrylic acid, while the present invention uses filling foam. On the one hand, it can connect the skin and the core material, and on the other hand, the filling foam in the middle can also increase the shock absorption and noise reduction performance of the product. Moreover, the use of polyurethane resin foam filling can also save the puttying process on the surface of the core material.

[0024] This invention features a composite rail sleeper with a three-layer structure consisting of a skin and a foam core. This structural design is well-suited for rail sleeper applications, significantly improving the product's lateral strength. Furthermore, the product eliminates the need for spraying on the surface and applying putty to the core, resulting in a higher compressive strength, improved collision resistance, cost reduction, and vibration and noise reduction. Furthermore, the product boasts a highly efficient production process, stable and reliable product quality, and significant application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the cross-sectional structure of the composite material sleeper of the present invention.

[0026] Figure 2 It is a structural schematic diagram of the device for preparing the skin of the composite material sleeper of the present invention.

[0027] Figure 3 Schematic diagram of the installation structure of the blocking device of the present invention.

[0028] Figure 4 Schematic diagram of the structure of the blocking device.

[0029] Figure 5 It is a structural schematic diagram of the preforming tooling of the present invention. Figure 5 (a) is a schematic structural diagram of the first preformed plate, Figure 5 (b) is a schematic structural diagram of the second preformed plate, Figure 5 (c) is a schematic structural diagram of the third preformed plate.

[0030] In the figure, 1 core material, 2 foam, 3 skin, 31 raised part; 4 roller, 5 fiber fabric, 6 preform tooling, 7 dipping box, 8 mold, 9 storage barrel I, 10 storage barrel II, 11 metering device, 12 mixing gun head, 13 traction clamping mechanism, 14 transmission platform, 15 cutting device, 16 blocking device, 17 mounting frame, 181 sealing handwheel, 182 sealing screw, 183 sealing pressure plate, 191 upper clamping handwheel, 192 upper clamping screw, 193 upper clamping pressure plate, 201 lower clamping handwheel, 202 lower clamping screw, 203 lower clamping pressure plate. DETAILED DESCRIPTION Example 1

[0031] A composite material sleeper comprises a core material 1 and a skin 3 wrapped around the core material 1, wherein foam 2 is filled between the core material 1 and the skin 3.

[0032] The core material 1 of this embodiment is a traditional polyurethane foam synthetic sleeper. Different density models can be selected according to different usage scenarios of the product. Generally, the core material density range is 0.4-1.3g / cm 3 .

[0033] The core material 1 may be rectangular, preferably square. It may also have other shapes, such as a recessed portion provided on the surface of the core material 1. For example, the recessed portion may be provided in the middle of each of the four sides of the rectangle, with the cross-sectional shape of the recessed portion being rectangular. Alternatively, the recessed portion may be provided in each of the four corners of the rectangle, with the cross-sectional shape of the recessed portion being rectangular.

[0034] The foam 2 is obtained by foaming a foaming material, preferably a foaming resin. The foaming resin can be polyurethane foaming resin, phenolic foaming resin, vinyl foaming resin, etc., preferably polyurethane foaming resin. The thickness of the foam 2 is 3-30 mm.

[0035] The skin 3 is formed by a composite material pultrusion process. The skin 3 is obtained by impregnating a resin material with reinforcing fibers and then curing it at high temperature. The reinforcing fibers are a mixture of any one or more of glass fibers, carbon fibers, and aramid fibers, preferably glass fibers. The fiber structure can be a mixture of one or more of continuous fibers, chopped strands, continuous mats, stitched mats, composite mats, biaxial cloth, triaxial cloth, and uniaxial cloth, preferably biaxial cloth. The resin material can be polyurethane resin, vinyl resin, unsaturated resin, or epoxy resin, preferably polyurethane resin.

[0036] The wall thickness of the skin 3 is 0.5-15mm. It can be designed with constant wall thickness or variable wall thickness, preferably constant wall thickness. The shape of the skin 3 is preferably rectangular, such as Figure 1 As shown, the corners of the skin 3 can be rounded or right-angled, with the rounded corner design being preferred. The rounded corner design facilitates pultrusion molding and, compared with the right-angle design of traditional polyurethane foam synthetic sleepers, can prevent the product from being easily damaged by bumps during transportation and construction.

[0037] The inner side of the skin 3 is provided with a protrusion 31 in the direction of the core material 1. Figure 1 As described above, multiple ( Figure 1 Two arcuate protrusions 31 are shown, pointing toward the core material 1. Alternatively, a rectangular protrusion pointing toward the core material 1 may be provided in the center of each of the four sides of the skin 3. Alternatively, a curved protrusion pointing toward the core material 1 may be provided in the center of each of the four sides of the skin 3. The protrusions 31 on the four sidewalls of the skin 3 precisely support and enclose the core material 1, allowing the core material 1 to be positioned precisely in the center of the skin 3. This means that the protrusions 31 serve a positioning function.

[0038] The raised portion 31 and / or the recessed portion of this embodiment can increase the connection area between the foam 2 and the core material 1 and the skin 3, thereby enhancing interlayer bonding and improving mechanical properties.

[0039] As an example, the cross-sectional dimensions of the skin 3 are 200 mm x 140 mm, the wall thickness is 3 mm, and the corners are rounded R3. The cross-sectional dimensions of the core material 1 are 164 mm x 104 mm; the middle is filled with a rigid polyurethane foam material with a thickness of 15 mm.

[0040] The skin 3 is pultruded using a [90° / 0°]s layer. The resin used is a non-foamed polyurethane resin with a resin content of 25%. The core material 1 is a traditional polyurethane foamed synthetic sleeper with a density of 0.74g / cm 3 ;Filling foam density is 0.45g / cm 3 The dimensions of the composite sleeper are as follows: the skin (3) has a cross-sectional dimension of 200 mm x 140 mm, a wall thickness of 3 mm, and rounded corners. The core (1) has a cross-sectional dimension of 164 mm x 104 mm; the center is filled with rigid polyurethane foam with a thickness of 15 mm.

[0041] The comparative example uses a traditional polyurethane foam synthetic sleeper, i.e., a core material, with a size of 200 mm × 140 mm.

[0042] The product performance comparison is shown in Table 1 and Table 2.

[0043] Table 1 Comparison of test results of finished products of composite sleepers and traditional polyurethane foam synthetic sleepers

[0044] Table 2 Comparison of product skin and core material performance test results

[0045] The skin 3 is a rectangular structure with a cross-section of 240mm x 240mm, a wall thickness of 5mm, and corners with a radius of R5. The core 1 has a cross-section of 210mm x 210mm and is filled with rigid polyurethane foam with a thickness of 10mm.

[0046] The skin is pultruded using [±45° / 0°]s ply, and the resin is non-foamed polyurethane resin with a resin content of 20%. The core material 1 is a traditional polyurethane foamed synthetic sleeper with a density of 0.74g / cm 3 ;Filling foam density is 0.70g / cm 3 .

[0047] The core material of the traditional polyurethane foam synthetic sleeper is 240mm×240mm in cross-section.

[0048] The product performance comparison of the prepared composite material sleeper and the traditional polyurethane foam synthetic sleeper is shown in Table 3 and Table 4.

[0049] Table 3 Comparison of test results of composite sleepers and traditional polyurethane foam synthetic sleepers

[0050] Table 4 Comparison of product skin and core material performance test results Example 2

[0051] A device for preparing the composite material sleeper as described in Example 1, comprising a device for preparing the skin 3 and a sealing device 16, wherein the sealing device 16 is located at the ends of the core material 1 and the skin 3 to seal the ends of the core material 1 and the skin 3; The device for preparing the skin 3 includes a roller 4, a dipping box 7, a feeding device for filling the dipping box 7 with material, and a mold 8. A fiber fabric 5 is provided on the roller 4, and the fiber fabric 5 passes through the dipping box 7 and the mold 8 in sequence. The dipping box 7 dips the fiber fabric 5 in glue, and the mold 8 solidifies and shapes the dipped fiber fabric 5 to obtain the skin 3. It also includes a traction clamping mechanism 13 and a transmission platform 14 that are sequentially arranged along the moving direction of the skin 3 for traction of the skin 3 , and a cutting device 15 for cutting the skin 3 .

[0052] The number of the rollers 4 and the number of the fiber fabrics 5 are two respectively, and a preforming tooling 6 is also included. The preforming tooling 6 preforms the surface of the fiber fabric 5 into an L shape. The two L-shaped fiber fabrics 5 are enclosed to form the shape of the skin 3 and then enter the dipping box 7.

[0053] The feeding device includes a storage barrel I9, a storage barrel II10 and a mixing gun head 12. The materials in the storage barrel I9 and the storage barrel II10 enter the mixing gun head 12 through a pipeline for mixing, and the mixed materials enter the dipping box 7 through a pipeline to impregnate the fiber fabric 5.

[0054] The device further comprises a metering device 11, which is used to measure the supply amount of the material.

[0055] The structure of the blocking device 16 is as follows Figure 4 As shown, it includes a mounting frame 17 located at the end and both sides of the skin 3 and a seal and a clamping member arranged on the mounting frame 17, the seal including a sealing pressure plate 183 and a sealing drive for driving the sealing pressure plate 183 to move; the clamping member includes two clamping members respectively located at both ends of the skin 3 for clamping the skin 3, including an upper clamping member and a lower clamping member, the upper clamping member includes an upper clamping pressure plate 193 and an upper clamping drive for driving the upper clamping pressure plate 193 to move; the lower clamping member includes a lower clamping pressure plate 203 and a lower clamping drive for driving the lower clamping pressure plate 203 to move.

[0056] The sealing drive member includes a sealing hand wheel 181 connected to each other and a sealing screw 182 threadedly connected to the mounting frame 17 .

[0057] The upper clamping drive member includes an upper clamping hand wheel 191 connected to each other and an upper clamping screw 192 threadedly connected to the mounting frame 17.

[0058] The lower clamping drive member includes a lower clamping hand wheel 201 connected to each other and a lower clamping screw 202 threadedly connected to the mounting frame 17 .

[0059] The shape of the mounting frame 17 matches that of the skin 3 and comprises three perpendicular mounting plates, each with an overall rectangular cross-section that is open at one end. The seal is mounted on the middle mounting plate, which has a through-hole through which the sealing screw 182 passes and is threadedly connected to the mounting plate. The upper clamping member is mounted on the upper mounting plate, which has a through-hole through which the upper clamping screw 192 passes and is threadedly connected to the upper mounting plate. The lower clamping member is mounted on the lower mounting plate, which has a through-hole through which the lower clamping screw 202 passes and is threadedly connected to the lower mounting plate.

[0060] It also includes a sealing elastic pad arranged between the sealing pressure plate 183 and the skin 3.

[0061] The handwheel is fixedly connected to the screw; the screw engages the mounting frame via a threaded pair. The screw and pressure plate can be fixed or separate, but the preferred solution is to separate them. This allows the pressure plate to remain independent of the handwheel's rotation, facilitating process execution. Clockwise rotation of the handwheel pushes the screw inward, while counterclockwise rotation pushes the screw outward.

[0062] The skin 3 is placed between the upper clamping plate 193 and the lower clamping plate 203. By rotating the upper clamping handwheel 191 and the lower clamping handwheel 201, the clamping handwheel drives the clamping screw to move inward and press against the clamping plate, thereby holding the upper and lower surfaces of the skin 3. Then, the sealing handwheel 181 is rotated clockwise to push the sealing screw 182 against the sealing plate 183. The sealing plate 183 then seals the end of the skin 3 together with the sealing elastic gasket. The sealing elastic gasket can ensure good sealing of the entire end surface and prevent glue leakage.

[0063] When in use, the steps are as follows: seal one end of the skin 3 with the sealing device 16, and then tilt the skin 3 upward at a certain angle as a whole to prevent the resin from flowing out from the other end after the subsequent injection of foamed resin; inject a certain amount of foamed polyurethane resin into the skin 3 according to the designed foam density and the volume between the skin 3 and the core material 1; then directly insert the core material 1 into the skin 3 (the size of the core material 1 is designed to be 0-2mm smaller than the size surrounded by the four raised parts of the skin 3, which allows the core material 1 to be smoothly placed in the skin 3 and avoids interference caused by fluctuations in the sanding size of the core material 1). Since the four sides of the skin 3 have raised positioning devices, the core material 1 is directly in the center of the skin 3; after inserting the core material 1, use the sealing device 16 to seal the glue injection end of the skin 3; then place the product flat in the drying room and wait for the polyurethane foam to solidify.

[0064] The cutting device 15 is a conventional cutting device, which is used to cut the skin 3 after solidification.

[0065] The fiber fabric 5 rolled up in a ball is placed on the drum 4. The fiber fabric is a mixture of one or more of continuous fiber, chopped strand mat, continuous mat, stitched mat, composite mat, biaxial fabric, triaxial fabric, and uniaxial fabric, preferably biaxial fabric.

[0066] The number of the rollers 4 and the corresponding fiber fabrics 5 can be set to 4, and the 4 fiber fabrics 5 just enclose the shape of the skin 3. Preferably, the number of the rollers 4 and the corresponding fiber fabrics 5 are set to 2 respectively, such as Figure 2 The figure shows two upper and lower rollers 4 and corresponding fiber fabrics 5. First, one fiber fabric 5 is preformed into an L shape by a preforming tool 6. The two L-shaped fiber fabrics 5 are enclosed to form the shape of the skin 3. Figure 2 As shown, the preforming tooling 6 preforms the fiber fabric 5 at the lower end into an L-shaped cross-section, i.e., two vertical surfaces; the preforming tooling 6 preforms the fiber fabric 5 at the lower end into an L-shaped cross-section, i.e., two vertical surfaces, and the two L-shaped fiber fabrics 5 are enclosed to form the shape of the skin 3.

[0067] The preforming tool 6 comprises two forming plates with L-shaped cross sections, so that the two fiber fabrics 5 are formed into L-shapes. Figure 5 As shown, the preforming tool 6 includes three preforming plates arranged in sequence along the forward direction of the fiber fabric 5, namely the first preforming plate (such as Figure 5 (a)), the second preformed plate (as shown Figure 5 (b)) and the third preformed plate (as shown Figure 5(c) shows), the preformed plate includes two straight plates at a certain angle, the angle of the two straight plates of the first preformed plate is 140-160° (preferably 150°), the angle of the two straight plates of the second preformed plate is 130-140° (preferably 135°), and the angle of the two straight plates of the third preformed plate is 90°. Finally, under the action of the third preformed plate, one fiber fabric 5 is L-shaped, the two fiber fabrics 5 are rectangular as a whole, and the two L-shaped fiber fabrics are overlapped and enter the next process.

[0068] The feeding device includes a storage barrel I9, a storage barrel II10 and a mixing gun head 12. The materials in the storage barrel I9 and the storage barrel II10 enter the mixing gun head 12 through a pipeline for mixing. The mixed materials enter the dipping box 7 through a pipeline to wet the fiber fabric 5. A hole is provided at the upper end of the dipping box 7. The mixed materials enter the dipping box 7 from the hole through a pipeline. A metering device 11 is provided on the pipeline to measure the amount of material.

[0069] Along the moving direction of the fiber fabric 5, the mold 8 is divided into 3 sections for high-temperature curing and molding. Depending on the pultruded product, the length of the mold 8 is generally 0.8m-3.5m, and the length of the dipping box 7 is generally 0.2m-0.6m. The longer the mold 8, the better the curing effect, but the greater the traction resistance. The length of the mold 8 of the present invention is 1.1m, and the length of the dipping box 7 is 0.4m. After the surface of the core material 1 is wrapped with fiber fabric, it is continuously pultruded and injected with glue while pultruding. The flow rate of the injected glue is controlled to ensure that the fiber fabric is fully impregnated. The pultrusion speed of the present invention is 0.4m / min.

[0070] The mold 8 is wrapped with upper and lower L-shaped heating plates, with a total of three groups at the front, middle and back, so as to achieve three-stage temperature control heating, and the heating plates are heated by resistance wires.

[0071] The traction and clamping mechanism 13 is also included. It is used to pull the cured fiber fabric 5, i.e., the skin 3. Due to the high friction between the cured skin 3 and the mold 8, the traction and clamping mechanism 13 can effectively pull the cured skin 3 out of the mold 8 and into the subsequent process. The traction and clamping mechanism 13 is a conventional structure, using two clamping mechanisms for cross-traction to achieve continuous pultrusion. Each clamping mechanism contains two sets of cylinders: one set of cylinders is used to drive the clamping plate up and down, and the other set of cylinders is used to drive the clamping device forward and backward.

[0072] The transmission platform 14 is composed of a plurality of rollers, which may be self-powered or unpowered. Example 3

[0073] A method for preparing a composite material sleeper, using the preparation device described in Example 2, comprises the following steps: A core material 1 is prepared; The skin 3 is prepared by the following specific steps: Place the fiber fabric 5 into the drum 4 and the material into the feeding device; The unwinding roller 4 is started, and the fiber fabric 5 enters the dipping box 7. The feeding device feeds the material. After entering the dipping box 7, the material fully impregnates the fiber fabric 5. The impregnated fiber fabric 5 enters the mold 8. The mold 8 solidifies and shapes the impregnated fiber fabric 5 to obtain the skin 3. Place the sealing device 16 on the end of the skin 3 to seal it, lift the other end of the skin to form a certain angle (10°-45°) with the ground, and then inject foaming resin into the skin 3, and the foaming resin flows to the bottom of the sealing end.

[0074] Then place the core material 1 inside the skin 3. The cross-sectional size of the core material is 0-2mm smaller than the inner cavity size of the skin cross-sectional area, so that the core material can be smoothly placed into the skin. The inner convex structure of the skin can also automatically position the core material in the center of the skin. The other end of the skin is sealed with a sealing device 16, and the product is then laid flat and placed in a drying room to wait for the resin to foam and solidify, filling the gap between the skin and the core material.

[0075] After the foaming resin is completely solidified, the blocking devices 16 at both ends are removed to obtain a composite material sleeper consisting of skin + core material + foam filling.

[0076] The preparation device also includes a preforming tooling 6, and the number of the rollers 4 and the fiber fabrics 5 are two respectively; before entering the dipping box 7, the fiber fabrics 5 are preformed into an L shape by the preforming tooling 6, and the two L-shaped fiber fabrics 5 are enclosed to form the shape of the skin 3, and then enter the dipping box 7.

[0077] The specific steps are as follows: Step 1: Product core material production The core material 1 of the product is a traditional polyurethane foam synthetic sleeper, which is prepared by conventional operations.

[0078] Step 2: Product skinning The product skin 3 is made of ordinary polyurethane pultrusion. The resin used, the molding method, the molding equipment and the core material are completely different. The details are as follows: (1) Fiber fabric design: The fiber fabric 5 is rolled into a ball and placed on the roller 4. The fiber fabric 5 is a mixture of one or more of continuous fiber, chopped strand mat, continuous mat, stitched mat, composite mat, biaxial fabric, triaxial fabric, and uniaxial fabric, preferably biaxial fabric. It contains two groups, the upper group is responsible for the upper wall thickness and left wall thickness of the molded skin 3, and the lower group is responsible for the lower wall thickness and right wall thickness of the molded skin 3. The width of the fiber fabric 5 is determined according to the width of the molded product cross-section cavity. For example, if the cross-section of the molded product is 240 240mm, the width of the upper cavity + the width of the left cavity is 480mm. Similarly, the width of the lower cavity + the width of the right cavity is also 480mm. The width of the fiber fabric is generally the required cavity width plus 5% margin, so the width of the upper and lower fabrics is 480. 1.05 = 504 mm. The excess is mainly due to the need for overlap transition of the upper and lower fabrics at the corners. The surface density of the fiber fabric is 100-1500 g / m 2 One or more layers of fiber fabric can be stacked, and different types of fiber fabrics can be stacked, such as using a [90° / 0°]s symmetrical layer or a [±45° / 0°]s counter-layer. In addition to using two pieces of fiber fabric for wrapping, a cavity wrapping design with four pieces each can also be used.

[0079] (2) Positioning of preforming tooling 6: Since the fiber fabric 5 is initially unfolded in a flat state, the upper fiber fabric is responsible for forming the upper wall thickness and the left wall thickness. Therefore, before the fiber fabric enters the mold cavity, a preforming device 6 is required for transition. The main purpose is to gradually transition the flat fiber fabric into a 90-degree bent fiber fabric and smoothly enter the mold cavity. The preforming device 6 includes three devices, front, middle, and back, for gradual transition.

[0080] (3) Resin injection: The resin used for impregnation can be polyurethane resin, vinyl resin, unsaturated resin, or epoxy resin, with polyurethane resin being preferred. If vinyl resin, unsaturated resin, or epoxy resin is used, the impregnation method can be closed or open impregnation tanks (equivalent to the impregnation box 7), that is, the fiber fabric is impregnated after passing through a pool filled with resin, and then the fiber fabric impregnated with resin is directly placed in a mold for curing and molding.

[0081] The present invention prefers polyurethane resin, preferably using a sealed dipping box. This is primarily because polyurethane resin is particularly sensitive to ambient temperature and humidity. Using an open dipping box, the resin readily absorbs moisture from the air, which can affect molding. The polyurethane resin comprises an isocyanate, primarily diphenylmethane diisocyanate, and a polyol blend, wherein the polyol blend does not contain a foaming agent. The two groups are metered separately by a metering device 11 and then mixed in a mixing gun 12. The mixed resin is then injected into the dipping box 7 via a glue injection hose. The injected resin continuously impregnates the fiber fabric 5 drawn into the dipping box 7.

[0082] (4) Dipping box 7 for impregnation and high-temperature curing of mold: The fiber fabric 5 first enters the dipping box 7. The dipping box 7 and the mold 8 are connected in a split manner, mainly for the convenience of disassembly and cleaning. The dipping box 7 and the mold 8 can also be connected as a whole (it also has a dipping box 7 and a mold 8). The function of the dipping box 7 is to seal the fiber fabric 5 entering the dipping box with resin. After the fiber fabric 5 is impregnated with resin, it is quickly cured and formed in the mold 8 at high temperature. The length of the mold 8 is generally 1-2m. The mold 8 is generally temperature-controlled in three stages. The front stage is the preheating stage, the temperature is generally 40-80℃, the middle stage is 120-180℃, and the rear stage is 160-200℃.

[0083] (5) Traction pultrusion: The fiber fabric 5 impregnated with resin is passed through the mold 8 and cured at high temperature. After exiting the mold, it is already solidified and is pulled back and forth by two alternately running traction clamping mechanisms 13, thereby forming continuous and stable traction.

[0084] (6) Cutting: Finally, the cutting device 15 is used to cut the product to a fixed length according to the actual length required by the product, thereby obtaining the skin 3 required by the present invention.

[0085] Step 3: Foam Filling like Figure 1 As shown, one end of the skin 3 is blocked with a blocking device 16, and the other end of the skin is lifted up to form a certain inclination angle (10°-45°) with the ground. Then, a foaming resin is injected into the skin 3, and then the product core material 1 is suspended in the center of the skin 3. Then, the injection end is also sealed with a blocking device 16. The foaming resin can be polyurethane foam resin, phenolic foam resin, vinyl foam resin, etc., preferably polyurethane foam resin, and the foam thickness is 3-30 mm. After curing and molding, the composite material sleeper of the present invention is obtained.

[0086] The present invention adopts split molding, which includes three main process molding methods. The first is the core material production, which adopts traditional polyurethane pultrusion foaming molding; the second is the skin production, which adopts polyurethane biaxial pultrusion molding; and the third is pure foam filling process.

[0087] The split molding lateral reinforcement effect of the present invention is much better than that of one-piece molding. First, since there will be flash on the surface of the composite material sleeper after molding, and in order to facilitate surface spraying, each surface generally needs to be polished 2-4mm, and the thickness of the fiber fabric wrapped on the surface generally does not exceed 2mm after curing, the surface reinforcement fabric will be sanded off, and it is actually difficult to have a significant lateral reinforcement effect. Secondly, the resin material used in the present invention is different from that of one-piece molding. Since the conventional sleeper surface is molded in one piece with felt / cloth added, the resin system for impregnating the continuous fiber and the resin system for impregnating the glass fiber fabric must be consistent. The reactions and curing of resins of different systems are completely different and cannot be mixed. Patent authorization document CN108504085B and patent application CN119800780A adopt one-piece molding, and the continuous fiber needs to be impregnated with polyurethane foam resin, and the polyol mixture therein needs to contain a foaming agent water component. During molding, after mixing the isocyanate and polyol mixture, the -NCO group in the isocyanate reacts with water to produce CO2 gas. Simultaneously, the -NCO group reacts with the hydroxyl group in the polyol to produce carbamate. The reaction in polyurethane foam resin is primarily a balance between gelation and foaming reactions. Therefore, the polyurethane resin used to impregnate fiber fabrics must be the same polyurethane foam resin used to impregnate continuous fibers. The product formed by polyurethane foam resin has a closed-cell porous structure, and the structure formed by the foam resin and surface-reinforced fiber fabric has limited lateral reinforcement.

[0088] Because the skin of the present invention is manufactured in separate parts, the preferred polyurethane resin can be a non-foaming resin. The polyol mixture contains no water as a blowing agent, resulting in no foaming reaction. The polyurethane is formed through a polycondensation reaction between the isocyanate and the polyol. The cured product is continuous and dense, free of pores, and possesses high strength and high molecular chain density. The performance of the skin structure formed by this and fiber fabric is far superior to that of surface-reinforced structures formed by foamed resin and fiber fabric.

[0089] Table 5 lists a performance comparison table of the polyurethane foam resin used in the polyurethane foam synthetic sleeper and the polyurethane resin used in the skin. Table 6 lists a performance comparison table of the polyurethane foam resin and the polyurethane resin used in the skin using the same fabric reinforcement. It can be seen that the performance of the polyurethane resin used in the skin is much higher than that of the polyurethane foam resin used in the traditional polyurethane foam synthetic sleeper, and the performance of the material structure composited with the fiber fabric is also much higher than that of the material structure composited with the foamed polyurethane resin and the fiber fabric.

[0090] Table 5 Comparison of properties of polyurethane foam resin and non-foam resin

[0091] Table 6 Performance comparison of the same fiber fabric reinforced polyurethane foam resin / non-foamed resin

[0092] In addition to greatly improving the transverse strength of the product, the present invention also has the following advantages: (1) Due to the limitations of traditional polyurethane foam synthetic sleeper laminating machines, the cross-section of the formed product is rectangular, and the straight corners are easily damaged during transportation and installation. If the corners are rounded through a secondary process, the cost is too high. Since the skin of the present invention is made of ordinary polyurethane pultrusion, its mold can be designed to round the straight corners, so that the straight corners of the formed skin product can be turned into rounded corners, thus solving the problem of the product being easily damaged.

[0093] (2) Due to the pure foam filling between the skin and the core material, the shock absorption and noise reduction capabilities of the product can be greatly improved.

[0094] (3) Since the surface of traditional polyurethane foam synthetic sleepers has a cellular structure, it is generally necessary to scrape putty before painting after sanding. This can make the paint more beautiful on the one hand and reduce the amount of paint on the other hand (the surface of the sleeper has a cellular structure, and the paint sprayed without putty is easily absorbed by the pores). The skin of the present invention adopts non-foaming polyurethane pultrusion, the product is continuous and dense, and it has no pores. The skin surface does not need to be polished or puttyed, and can be directly sprayed with paint.

[0095] (4) In addition to being able to be directly sprayed with paint, the surface of the skin can also be made paint-free. The polyurethane pultrusion of the skin generally uses aromatic polyurethane, which contains benzene rings, has strong molecular chain rigidity, and has high mechanical strength, but has poor yellowing resistance, and generally requires surface spraying with paint for protection. In the present invention, the polyurethane resin for the skin can use not only aromatic polyurethane but also aliphatic polyurethane, which contains linear or cyclic aliphatic hydrocarbons, has high molecular chain flexibility, and is excellent in ultraviolet resistance. Therefore, if aliphatic polyurethane is used for pultrusion, the skin does not need to be further sprayed with paint.

[0096] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of protection of the present application is limited to these examples. In line with the present application, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of different aspects of one or more embodiments of the present application as described above, which are not provided in detail for the sake of simplicity.

[0097] The one or more embodiments of this application are intended to encompass all such substitutions, modifications, and variations that fall within the broad scope of this application. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of one or more embodiments of this application should be included in the scope of protection of this application.

Claims

1. A composite material sleeper, characterized in that: The invention comprises a core material (1) and a skin (3) wrapped around the core material (1), wherein foam (2) is filled between the core material (1) and the skin (3), and the foam (2) is obtained by foaming a foaming resin; a protrusion (31) is provided on the inner side of the skin (3) in the direction of the core material (1); The composite material sleeper preparation device comprises a device for preparing a skin (3) and a sealing device (16), wherein the sealing device (16) is located at the ends of the core material (1) and the skin (3) to seal the ends of the core material (1) and the skin (3); The device for preparing the skin (3) comprises a roller (4), a dipping box (7), a feeding device for pouring material into the dipping box (7), and a mold (8); a fiber fabric (5) is provided on the roller (4); the fiber fabric (5) passes through the dipping box (7) and the mold (8) in sequence; the dipping box (7) dips the fiber fabric (5) in glue, and the mold (8) solidifies and shapes the dipped fiber fabric (5) to obtain the skin (3); It also includes a traction clamping mechanism (13) and a transmission platform (14) for traction of the skin (3) which are sequentially arranged along the moving direction of the skin (3), and a cutting device (15) for cutting the skin (3).

2. A device for preparing a composite material sleeper according to claim 1, characterized in that: It comprises a device for preparing a skin (3) and a sealing device (16), wherein the sealing device (16) is located at the ends of the core material (1) and the skin (3) to seal the ends of the core material (1) and the skin (3); The device for preparing the skin (3) comprises a roller (4), a dipping box (7), a feeding device for pouring material into the dipping box (7), and a mold (8); a fiber fabric (5) is provided on the roller (4); the fiber fabric (5) passes through the dipping box (7) and the mold (8) in sequence; the dipping box (7) dips the fiber fabric (5) in glue, and the mold (8) solidifies and shapes the dipped fiber fabric (5) to obtain the skin (3); It also includes a traction clamping mechanism (13) and a transmission platform (14) for traction of the skin (3) which are sequentially arranged along the moving direction of the skin (3), and a cutting device (15) for cutting the skin (3).

3. The preparation device according to claim 2, characterized in that: The number of the rollers (4) and the number of the fiber fabrics (5) are respectively 2.

4. The preparation device according to claim 2, characterized in that: It also includes a preforming tool (6), which preforms the surface of the fiber fabric (5) into an L-shape. Two L-shaped fiber fabrics (5) are enclosed to form the shape of the skin (3), and then enter the dipping box (7).

5. The preparation device according to claim 2, characterized in that: The feeding device comprises a storage barrel I (9), a storage barrel II (10) and a mixing gun head (12). The materials in the storage barrel I (9) and the storage barrel II (10) enter the mixing gun head (12) through a pipeline for mixing, and the mixed materials enter the dipping box (7) through a pipeline to impregnate the fiber fabric (5).

6. The preparation device according to claim 5, characterized in that: It also includes a metering device (11), which is used to measure the supply amount of the material.

7. The preparation device according to claim 2, characterized in that: The sealing device (16) includes a mounting frame (17) located at the end and both sides of the skin (3) and a sealing member and a clamping member arranged on the mounting frame (17), wherein the sealing member includes a sealing pressure plate (183) and a sealing driving member for driving the sealing pressure plate (183) to move; the clamping member includes two clamping members respectively located at both ends of the skin (3) for clamping the skin (3), including an upper clamping member and a lower clamping member, wherein the upper clamping member includes an upper clamping pressure plate (193) and an upper clamping driving member for driving the upper clamping pressure plate (193) to move; and the lower clamping member includes a lower clamping pressure plate (203) and a lower clamping driving member for driving the lower clamping pressure plate (203) to move.

8. A method for preparing a composite material sleeper, characterized in that: The method is carried out using the preparation device according to any one of claims 2 to 7, comprising the following steps: A core material (1) is prepared; The skin (3) is prepared by the following specific steps: Put the fiber fabric (5) into the drum (4), and put the material into the feeding device; The roller (4) is started to unwind, and the fiber fabric (5) enters the dipping box (7). The feeding device feeds the material. After the material enters the dipping box (7), the fiber fabric (5) is fully impregnated. The impregnated fiber fabric (5) enters the mold (8). The mold (8) solidifies and shapes the impregnated fiber fabric (5) to obtain the skin (3). The skin (3) moves under the action of the traction clamping mechanism (13), and the skin (3) enters the transmission platform (14). The cutting device (15) cuts the skin (3) to obtain the cut skin (3); The sealing device (16) is placed at the end of the skin (3) for sealing, the other end of the skin is lifted up to form a certain inclination angle with the ground, and then a foaming resin is injected into the skin (3), and the foaming resin flows to the bottom of the sealing end; Placing the core material (1) inside the skin (3); The other end of the skin is sealed with a sealing device (16), and then the product is laid flat and placed in a drying room to wait for the foaming resin to solidify and fill the gap between the skin (3) and the core material (1); After the foaming resin is completely solidified, the blocking devices (16) at both ends are removed to obtain a composite material sleeper.

9. The preparation method according to claim 8, characterized in that: The preparation device further includes a preforming tool (6), and the number of the rollers (4) and the fiber fabrics (5) are respectively two; before entering the dipping box (7), the fiber fabrics (5) are preformed into an L-shape by the preforming tool (6), and the two L-shaped fiber fabrics (5) are enclosed to form the shape of the skin (3), and then enter the dipping box (7).

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