Integrally-formed composite sleeper, preparation process and preparation device

Abstract

The invention provides an integrally-formed synthetic sleeper, a preparation process and a preparation device.The integrally-formed synthetic sleeper comprises a polyurethane resin matrix, continuous glass fibers are longitudinally arranged in the polyurethane resin matrix and used for longitudinal reinforcement of the synthetic sleeper, and a reinforcement layer composed of glass fiber fabric and polyurethane resin is arranged on the surface of the polyurethane resin matrix. The thickness of the reinforcing layer is 1 to 10 mm; the overall density of the synthetic sleeper is 0.64-1.4 g / cm < 3 >, and the polyurethane resin accounts for 35-50% of the total weight of the synthetic sleeper; the continuous glass fiber accounts for 35-60% of the total weight of the synthetic sleeper, and the glass fiber fabric accounts for 3-10% of the total weight of the synthetic sleeper; the overall strength of the composite sleeper can be remarkably improved, and transverse cracking is avoided; vOC generated in the production process of the synthetic sleeper and solid waste pollution caused by polishing are reduced.

Description

Technical Field

[0001] The present invention relates to the field of rail transit technology, and in particular to an integrally formed synthetic sleeper, a preparation process and a preparation device. Background Art

[0002] Sleepers are important parts in the field of rail transit. They can evenly transfer the load transmitted by the train to the roadbed, and play an important role in the stable and safe operation of rail transit. At present, the most widely used sleepers in the world are wooden sleepers and reinforced concrete sleepers. However, wooden sleepers are prone to decay and aging, uneven strength, and high water absorption. Reinforced concrete sleepers have high maintenance costs, short life, poor toughness, heavy weight, difficult installation, and difficult on-site drilling. Therefore, in recent years, new synthetic sleepers have been widely studied by countries around the world.

[0003] Polyurethane foam synthetic sleepers are a composite material synthetic sleeper formed by glass fiber reinforced polyurethane foam, also known as synthetic sleepers. They are widely used due to their advantages such as light weight, high strength, corrosion resistance, insulation, good weather resistance, and high production and installation efficiency. However, synthetic sleepers in the prior art also use unidirectional continuous glass fiber reinforcement and no lateral fiber reinforcement, which poses a risk of lateral cracking during use. During the production of synthetic sleepers, a release agent needs to be sprayed on the mold surface to allow the sleeper to be demolded smoothly. After demolding, the product surface needs to be polished and painted. The production process is complicated and generates more VOC and dust pollution. Summary of the invention

[0004] In view of this, the present invention aims to propose an one-piece synthetic sleeper, a preparation process and a preparation device. One of the problems to be solved is that the synthetic sleepers in the prior art use unidirectional continuous glass fiber reinforcement and no lateral fiber reinforcement, which poses a risk of lateral cracking during use; the second problem to be solved is that during production, a release agent needs to be sprayed on the mold surface to allow the sleeper to be demolded smoothly. After demolding, the product surface needs to be polished and painted, which complicates the production process and generates more VOC and dust pollution.

[0005] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0006] An integrally formed synthetic sleeper comprises a polyurethane resin matrix, continuous glass fibers are longitudinally arranged in the polyurethane resin matrix for longitudinal reinforcement of the synthetic sleeper, a reinforcing layer composed of a glass fiber fabric and polyurethane resin is arranged on the surface of the polyurethane resin matrix, and the thickness of the reinforcing layer is 1 to 10 mm; the overall density of the synthetic sleeper is 0.64 to 1.4 g / cm 3 , among which polyurethane resin accounts for 35-50% of the total weight of the synthetic sleeper; continuous glass fiber accounts for 35-60% of the total weight of the synthetic sleeper, and glass fiber fabric accounts for 3-10% of the total weight of the synthetic sleeper.

[0007] Providing a reinforcement layer on the surface of a synthetic sleeper can significantly increase the overall strength of the synthetic sleeper and avoid lateral cracking; the reinforcement layer is prepared from glass fiber fabric reinforced polyurethane resin, and the glass fiber fabric is selected from a composite felt of a set color and is used to produce synthetic sleepers of a desired color, thereby reducing the painting process and alleviating pollution to the environment. The color of the synthetic sleeper can be customized according to demand to meet the personalized needs of different customers, and the color of the synthetic sleeper can be ensured to remain consistent throughout the entire production process, which helps to improve the appearance quality of the product and increase the beauty and consistency of the product.

[0008] Furthermore, the polyurethane resin is compounded by component A and component B in a weight ratio of 100:100-150; wherein component A is a polyol combination material, and component B is isocyanate.

[0009] This setting can ensure the performance and quality of the polyurethane resin and improve the overall strength and stability of the synthetic sleeper.

[0010] Furthermore, the average hydroxyl value of component A is 300-500 mgKOH / g, the viscosity at 25°C is 500-2000 mPa·s, and the functionality is 3-6; the isocyanate content of component B is 30-32%, the viscosity at 25°C is 200-600 mPa·s, and the functionality is 2-3.

[0011] The polyurethane resin obtained by mixing component A and component B has moderate reactivity and viscosity, which is conducive to the impregnation of continuous glass fibers and glass fiber fabrics. The polyurethane foaming and curing process is stable, and the obtained composite material synthetic sleeper has high strength.

[0012] Furthermore, the surface density of the glass fiber fabric is 300 to 1500 g / m 2 .

[0013] This arrangement makes it easy to adjust the surface density of the glass fiber fabric according to actual application conditions, and can produce synthetic sleepers with different surface reinforcement layer thicknesses to meet the use requirements of different working conditions.

[0014] The present application also provides a process for preparing an integrally formed synthetic sleeper, which is used to prepare the above-mentioned integrally formed synthetic sleeper, comprising the steps of:

[0015] Step S1: Calculating the number of continuous glass fibers according to the density and glass fiber content of the synthetic sleeper;

[0016] Step S2: layering the continuous glass fibers according to the calculation results;

[0017] Step S3: uniformly impregnating the layered continuous glass fibers with polyurethane resin;

[0018] Step S4: sequentially wrapping the continuous glass fiber impregnated with the polyurethane resin with glass fiber fabric and release paper;

[0019] Step S5: heating the continuous glass fiber coated with the glass fiber fabric and the release paper and the polyurethane resin, and curing the polyurethane resin to form a fiber-reinforced polyurethane synthetic sleeper;

[0020] Step S6: cutting and segmenting the cured fiber-reinforced polyurethane synthetic sleeper according to size requirements to obtain a finished synthetic sleeper.

[0021] By calculating the number of continuous glass fibers, the appropriate number of fibers can be determined according to the density and glass fiber content of the synthetic sleeper, thereby achieving control over the density and performance of the synthetic sleeper. The layered continuous glass fibers can better combine with the polyurethane resin to improve the overall strength and stability of the synthetic sleeper. The overall surface coating of the glass fiber fabric can not only increase the surface strength of the synthetic sleeper and avoid lateral cracking, but also form a reinforcement layer on the surface to form a sandwich structure, which can improve the overall mechanical properties of the product. In addition, coating the release paper on the outside of the glass fiber fabric facilitates the demoulding of the product, without the need to spray a release agent or polish the surface, reducing VOC and dust pollution in the production process.

[0022] The present application also provides a preparation device for an integrally formed synthetic sleeper, which is used to prepare the integrally formed synthetic sleeper described above, and includes a yarn frame, a closed glue dipping box, a glue injection machine, a felt guide, a felt frame, a crawler machine and a sawing machine arranged in sequence, the felt guide including a first felt guide and a second felt guide, the felt frame including a first felt frame and a second felt frame, the yarn frame is used to place continuous glass fibers, the closed glue dipping box is used to uniformly impregnate the continuous glass fibers with polyurethane resin, the glue injection machine is used to transport polyurethane resin into the closed glue dipping box, the first felt frame is used to place glass fiber fabric, the first felt guide is used to guide the glass fiber fabric to be coated on the surface of the continuous glass fibers, the second felt frame is used to place release paper, the second felt guide is used to guide the release paper to be coated on the surface of the glass fiber fabric, the crawler machine is provided with a mold, the mold is used to heat and pressurize the glass fibers impregnated with polyurethane resin, so that the polyurethane resin is cured to form a fiber-reinforced polyurethane synthetic sleeper, and the sawing machine is used to cut the fiber-reinforced polyurethane synthetic sleeper.

[0023] This setting can reduce the production process of composite sleepers, greatly improve production efficiency, and ensure the quality and consistency of composite sleepers.

[0024] Furthermore, the crawler machine includes a lower crawler machine and an upper crawler machine, and baffles are arranged on the left and right sides of the crawler machine. The baffles cooperate with the upper crawler machine and the lower crawler machine to form a mold cavity. The synthetic sleeper is solidified and formed in the mold cavity, and automatically separated from the mold cavity as the crawler machine rotates.

[0025] This setting can not only accurately control the shape and size of the composite sleepers, ensure the consistency and quality of the products, but also improve production efficiency and operational convenience.

[0026] Furthermore, the glue injection machine includes a component A tank, a component B tank, a mixing gun head and a diverter. The component A tank and the component B tank are connected to the mixing gun head through pipelines, respectively. The mixing gun head is connected to the diverter through the pipeline. The diverter is connected to the closed dipping box through the diversion glue injection tube. The component A tank is used to store polyurethane resin A, the component B tank is used to store polyurethane resin B, the mixing gun head is used to mix polyurethane resin A and polyurethane resin B, and the diverter is used to evenly divide the mixed polyurethane resin output by the mixing gun head and input it into the closed dipping box.

[0027] This arrangement can ensure that the polyurethane resin A and the polyurethane resin B are fully mixed to form a uniform mixed polyurethane resin, which is evenly distributed on the surface of the continuous glass fiber to ensure uniform impregnation of the glass fiber.

[0028] Furthermore, the pulling speed of the mold is 0.3-1.0 m / min, the mold temperature is 40-90° C., and the curing time of the synthetic sleeper in the mold is 40-60 min.

[0029] This setting can make the composite sleeper fully solidify in the mold, improving product quality and production efficiency.

[0030] Compared with the prior art, the one-piece synthetic sleeper, preparation process and preparation device described in the present invention have the following advantages:

[0031] 1) It can significantly increase the overall strength of the synthetic sleeper, including but not limited to the finished product's bending strength, spike pull-out strength, lateral compression strength, etc., and can avoid lateral cracking;

[0032] 2) It reduces the steps of spraying release agent, surface grinding and painting, reduces VOC and dust pollution in the production process, and reduces pollution to the environment.

[0033] 3) The entire surface is wrapped with glass fiber cloth reinforcement material, which has many beneficial effects: ① Improve the lateral strength of the synthetic sleeper and prevent lateral cracking; ② There is a reinforcement layer on the upper, lower, left and right surfaces of the synthetic sleeper, so that the synthetic sleeper forms a sandwich-like structure, which can effectively improve the stress safety of the synthetic sleeper; ③ Release film is used as release paper during the production process, and there is no release agent on the surface of the product, and the surface is wrapped with glass fiber cloth as a whole. The appearance of the sleeper is regular and no post-polishing is required, which reduces the pollution caused by release agents and polishing dust and the waste of raw materials. If colored surface felt is used, the painting process can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic diagram of the overall structure of the device for preparing an integrally formed synthetic sleeper according to an embodiment of the present invention;

[0035] Figure 2 for Figure 1 Schematic diagram of the structure of the middle guide felt;

[0036] Figure 3 It is a schematic diagram of the structure of the composite sleeper according to an embodiment of the present invention;

[0037] Description of reference numerals:

[0038] 1. Yarn frame; 11. Continuous glass fiber; 2. Closed dipping box; 3. Glue injection machine; 31. Component A tank; 32. First component B tank; 33. First mixing gun head; 34. Diverter; 35. Diverter injection hose; 36. Component C tank; 37. Second component B tank; 38. Second mixing gun head; 39. Second injection hose; 4. Felt guide; 41. First felt guide; 42. Second felt guide; 5. Felt frame; 51. First felt frame; 511. Glass fiber fabric; 52. Second felt frame; 521. Release paper; 6. Track machine; 61. Lower track machine; 62. Upper track machine; 7. Sawing machine; 100. Synthetic sleeper; 101. Polyurethane resin matrix; 102. Reinforcement layer. DETAILED DESCRIPTION

[0039] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0040] like Figure 1-3 As shown, an integrally formed synthetic sleeper comprises a polyurethane resin matrix 101, continuous glass fibers 11 are longitudinally arranged in the polyurethane resin matrix 101, and are used for longitudinal reinforcement of the synthetic sleeper 100. A reinforcing layer 102 composed of a glass fiber fabric 511 and a polyurethane resin is arranged on the surface of the polyurethane resin matrix 101, and the thickness of the reinforcing layer 102 is 1 to 10 mm; the overall density of the synthetic sleeper is 0.64 to 1.4 g / cm 3 , wherein the polyurethane resin accounts for 35-50% of the total weight of the synthetic sleeper 100; the continuous glass fiber 11 accounts for 35-60% of the total weight of the synthetic sleeper 100, and the glass fiber fabric 511 accounts for 3-10% of the total weight of the synthetic sleeper 100.

[0041] Specifically, the continuous glass fibers 11 are longitudinally arranged in the polyurethane resin matrix 101, which can increase the longitudinal strength and stability of the synthetic sleeper 100. The fiber fabric reinforcement layer 102 is arranged on the surface of the synthetic sleeper 100, which can significantly increase the transverse strength of the synthetic sleeper 100 and avoid transverse cracking. The synthetic sleeper with a reinforcement layer added to the surface forms a sandwich structure with higher overall strength. The thickness of the reinforcement layer 102 ranges from 1 to 10 mm, and the appropriate thickness can be flexibly selected according to the specific application scenario, thereby expanding the scope of application. The material ratio in the present application can further improve the performance and quality of the synthetic sleeper 100.

[0042] Preferably, the continuous glass fiber 11 is configured as alkali-free glass fiber direct yarn or twisted yarn, and the linear density is 4800-19200 tex.

[0043] Preferably, the glass fiber fabric 511 is made of composite felt of a set color and is used to produce synthetic sleepers 100 of the required color, which reduces the painting process and reduces pollution to the environment. The color of the synthetic sleeper 100 can be customized according to demand to meet the personalized needs of different customers. It can ensure that the color of the synthetic sleeper 100 remains consistent throughout the entire production process, which helps to improve the appearance quality of the product and increase the beauty and consistency of the product.

[0044] Preferably, the glass fiber fabric 511 is one or more combinations of continuous mat, stitched mat, chopped mat, knitted mat, mesh cloth, biaxial cloth made of glass fiber, carbon fiber, basalt fiber, nylon fiber, polyester fiber.

[0045] As a preferred example of the present invention, the polyurethane resin is compounded by component A and component B in a weight ratio of 100:100-150; wherein component A is a polyol combination material, and component B is isocyanate.

[0046] Specifically, polyol has good elasticity and flexibility, can increase the durability and impact resistance of the synthetic sleeper 100, and can also provide suitable viscosity and fluidity; isocyanate can control the hardness, strength and durability of the polyurethane resin, so that the synthetic sleeper 100 has appropriate rigidity and strength. This setting can ensure the performance and quality of the polyurethane resin, and ensure the uniform impregnation of the polyurethane mixed resin and the glass fiber reinforcement material, thereby improving the overall strength and stability of the synthetic sleeper 100.

[0047] As a preferred example of the present invention, the average hydroxyl value of component A is 300-500 mgKOH / g, the viscosity at 25°C is 500-2000 mPa·s, and the functionality is 3-6; the isocyanate content of component B is 30-32%, the viscosity at 25°C is 200-600 mPa·s, and the functionality is 2-3.

[0048] Specifically, the average hydroxyl value ranges from 300 to 500 mgKOH / g, which can provide sufficient reactivity and is conducive to the reaction with the isocyanate of component B to form a polyurethane resin. The moderate viscosity is conducive to the mixing of the polyurethane components A and B, and the uniform impregnation of the glass fiber reinforced material. The higher the functionality, the higher the degree of cross-linking of the polyurethane resin, and the hardness and strength will also increase, which helps to improve the hardness and strength of the synthetic sleeper. This setting can provide sufficient reactivity and viscosity, which is conducive to the reaction of component A with component B to form a polyurethane resin, and can improve the hardness and strength of the synthetic sleeper.

[0049] As a preferred example of the present invention, the surface density of the glass fiber fabric 511 is 300 to 1500 g / m 2 , which can be 1 layer or multiple layers.

[0050] Specifically, the greater the surface density of the glass fiber fabric and the more layers, the thicker the reinforcement layer formed, and the higher the lateral strength of the synthetic sleeper. The surface density of the glass fiber fabric 511 can be adjusted according to actual application conditions to produce synthetic sleepers with different surface reinforcement layer thicknesses.

[0051] Furthermore, the surface fiber fabric reinforcement layer is formed by glass fiber cloth and reinforced polyurethane resin. The reinforced polyurethane resin contains a mixture of component C and component B in a weight fraction ratio of 100:100-180, wherein component B is polyisocyanate, and component C is a mixture of the above component A (polyurethane composite material) and polyether amine resin. After the components B and C are mixed and reacted, a polyurea-urethane block polymer is formed. The block polymer has good strength and toughness, and significantly improves the strength and wear resistance of the surface reinforcement layer.

[0052] Furthermore, the water content of the component C is ≤0.2%, and after reacting with the component B, the foam density is relatively high, and the density of the formed reinforcement layer is relatively high, which can reach 1.0~1.6g / cm 3 , so the surface strength is higher.

[0053] Furthermore, the polyether amine resin is an aliphatic amino-terminated polyether, with a molecular weight of 400-2000, a functionality of 2-3, and a proportion of 10%-30% in component C. The polyether amine resin has a high reactivity with isocyanate, and the reaction is an exothermic reaction, which can accelerate the reaction speed of the polyol resin and component B and accelerate the curing speed of the surface reinforcement layer. The use of catalysts can be reduced, the temperature of the mold can be lowered, and the production energy consumption can be reduced.

[0054] In the actual use of synthetic sleepers, the stress on the sleepers is different under different use conditions, or the degree of damage to the sleepers in different sections of the same line is also very different, resulting in different strength requirements for the sleepers. For example, for the same line, sleepers are more likely to crack horizontally on bridges and in areas with a small radius, while the core materials of the same batch of sleepers are basically the same. Therefore, it is necessary to adjust the lateral strength and overall strength of the sleepers by adjusting the thickness of the fiber fabric reinforcement layer on the sleeper surface. The thickness of the fiber fabric reinforcement layer on the sleeper surface should be determined in the following ways:

[0055] (1) Calculation of sleeper bending moment

[0056]

[0057] M——positive bending moment of the sleeper, KN·m;

[0058] P d ——Dynamic load on sleeper, KN;

[0059] e——the length of the support under the rail, m;

[0060] a1——the distance from the center of the sleeper bearing rail groove to the sleeper end, m;

[0061] b q ——Sleeper pressure distribution width, m.

[0062] (2) Detect the stress σ on the top surface of the sleeper under different lines or different train axle load conditions

[0063]

[0064] Where σ is the lateral pressure dynamic stress of the sleeper

[0065] F is the contact area between the rail bottom or pad and the sleeper;

[0066] R d is the dynamic pressure of the rail.

[0067] (3) The surface strength of the sleeper must be at least three times the stress on the top of the sleeper to ensure that the sleeper will not break. However, if the surface strength of the sleeper is too high, it will cause unnecessary waste and cause the track to be too rigid, which will have an adverse effect on the track foundation and train running comfort. Therefore, the surface strength of the sleeper has a certain range, the minimum value ensures that it will not break, and the maximum value ensures that the surface strength is not too high. The minimum value is three times the stress on the top of the sleeper, that is, 3σ, and the maximum value is 3σ (1+β), where β is the eccentric load coefficient, generally 0.15~0.2.

[0068] The distances from different stress points to the neutral axis are calculated based on the stress borne by the sleeper and the bending moment of the sleeper.

[0069]

[0070] Among them, σ g is the maximum or minimum value in the above step (2), M is the bending moment of the sleeper in the above step (1), I is the moment of inertia of the sleeper section, and y is the distance from different force points to the neutral axis.

[0071] According to the maximum and minimum values ​​of the surface strength, the corresponding y value is calculated, which is the distance between the inner and outer sides of the corresponding reinforcement layer and the neutral axis, and the difference between the two is the thickness of the reinforcement layer. In this way, the thickness of the fiber fabric reinforcement layer on the surface of the sleeper can be adaptively set to fully ensure the strength of the sleeper under different conditions, while not causing an increase in the pressure and vibration acceleration on the roadbed, thereby ensuring the safety of train operation and the service life of the sleeper.

[0072] The present application also provides a process for preparing an integrally formed synthetic sleeper, which is used to prepare the above-mentioned integrally formed synthetic sleeper, comprising the steps of:

[0073] Step S1: Calculating the number of continuous glass fibers 11 according to the density and glass fiber content of the synthetic sleeper 100;

[0074] Step S2: layering the continuous glass fiber 11 according to the calculation results;

[0075] Step S3: uniformly impregnating the layered continuous glass fibers 11 with polyurethane resin;

[0076] Step S4: coating the continuous glass fiber 11 impregnated with polyurethane resin with a surface glass fiber fabric reinforcement layer 511; wherein the surface glass fiber fabric reinforcement layer is made of glass fiber impregnated with a reinforced polyurethane resin mixed with component C and component B; after coating the surface glass fiber fabric reinforcement layer 511, it is then coated with release paper 521;

[0077] Step S5: heating the continuous glass fiber 11 coated with the glass fiber fabric 511 and the release paper 521 and the polyurethane resin, and curing the polyurethane resin to form a fiber-reinforced polyurethane synthetic sleeper 100;

[0078] Step S6: cutting and segmenting the cured fiber-reinforced polyurethane synthetic sleeper 100 according to size requirements to obtain a finished synthetic sleeper 100.

[0079] Specifically, the appropriate fiber quantity can be determined according to the density and glass fiber content of the synthetic sleeper 100, and the layering control can be performed. The layered continuous glass fiber 11 can be better combined with the polyurethane resin to improve the overall strength and stability of the synthetic sleeper 100. The coated glass fiber fabric 511 can increase the surface lateral strength of the synthetic sleeper and avoid lateral cracking. The release paper 521 coated on the outside of the glass fiber fabric 511 facilitates the demoulding of the product, without the need for spraying a release agent and surface polishing, thereby reducing VOC and dust pollution in the production process.

[0080] The present application also provides a preparation device for an integrally formed synthetic sleeper, which is used to prepare the above-mentioned integrally formed synthetic sleeper, including a creel 1, a closed glue dipping box 2, a glue injection machine 3, a felt guide 4, a felt frame 5, a crawler machine 6 and a sawing machine 7 arranged in sequence, the felt guide 4 includes a first felt guide 41 and a second felt guide 42, the felt frame 5 includes a first felt frame 51 and a second felt frame 52, the creel 1 is used to place continuous glass fiber 11, the closed glue dipping box 2 is used to coat the surface of the continuous glass fiber 11 with polyurethane resin, the glue injection machine 3 is used to transport polyurethane resin into the closed glue dipping box 2, and the first .... The felt frame 51 is used to place the glass fiber fabric 511, the first felt guide 41 is used to guide the glass fiber fabric 511 to be coated on the surface of the continuous glass fiber 11, the second felt frame 52 is used to place the release paper 521, the second felt guide 42 is used to guide the release paper 521 to be coated on the surface of the glass fiber fabric 511, the crawler machine 6 is provided with a mold, the mold is used to heat and pressurize the continuous glass fiber 11 coated with polyurethane resin, so that the polyurethane resin is cured to form a fiber-reinforced polyurethane synthetic sleeper 100, and the sawing machine 7 is used to cut the fiber-reinforced polyurethane synthetic sleeper 100.

[0081] Specifically, the creel 1 is provided with a yarn dividing plate for stratifying the continuous glass fiber 11. The continuous glass fiber 11 is led out from the creel 1, passes through the yarn dividing plate, the closed dipping box 2, the first felt guide 41, and the second felt guide 42 from front to back, and then enters the crawler conveyor 6. The continuous glass fiber 11 moves backward under the extrusion and traction of the crawler conveyor 6. This arrangement can reduce the production process of synthetic sleepers, greatly improve production efficiency, and ensure the quality and consistency of the synthetic sleepers 100.

[0082] Preferably, a release cloth may also be used, wherein the release paper / cloth comprises at least one of a polyethylene release film, a polypropylene release film, a polytetrafluoroethylene release film, a polyester release film, a laminated release paper, and a non-woven fabric.

[0083] As a preferred example of the present invention, the crawler machine 6 includes a lower crawler machine 61 and an upper crawler machine 62, and baffles are arranged on the left and right sides of the crawler machine 6. The baffles cooperate with the upper crawler machine 62 and the lower crawler machine 61 to form a mold cavity. The synthetic sleeper 100 is cured and formed in the mold cavity, and automatically separated from the mold cavity as the crawler machine 6 rotates.

[0084] Specifically, this arrangement can not only accurately control the shape and size of the composite sleeper 100, ensuring the consistency and quality of the product, but also improve production efficiency and operational convenience.

[0085] As a preferred example of the present invention, the glue injection machine 3 includes a component A tank 31, a component B tank 32, a mixing gun head 33 and a diverter 34. The component A tank 31 and the component B tank 32 are respectively connected to the mixing gun head 33 through pipelines, the mixing gun head 33 is connected to the diverter 34 through a pipeline, and the diverter 34 is connected to the closed dipping box 2 through a diversion glue injection tube 35. The component A tank 31 is used to store polyurethane resin A, the component B tank 32 is used to store polyurethane resin B, the mixing gun head 33 is used to mix polyurethane resin A and polyurethane resin B, and the diverter 34 is used to evenly divide the mixed polyurethane resin output by the mixing gun head 33 and input it into the closed dipping box 2.

[0086] The glue injection machine 3 also includes a component C material tank 36, a second component B material tank 37, a second mixing gun head 38 and a second glue injection pipe 39 arranged downstream of the closed dipping box 2. The component C material tank 36 and the second component B material tank 37 are connected to the second mixing gun head 38 through a pipeline, and the second mixing gun head 38 introduces the reinforced polyurethane resin into the surface glass fiber cloth through the second glue injection pipe 39.

[0087] Specifically, through the mixing of the mixing gun head 33, it can be ensured that the polyurethane resin A and the polyurethane resin B are fully mixed to form a uniform mixed polyurethane resin, which has better fluidity and wettability, thereby improving the consistency and quality of the synthetic sleeper 100. The mixed polyurethane resin output by the mixing gun head 33 is evenly divided and input into the closed dipping box 2 through the diverter 34, thereby ensuring that the mixed polyurethane resin is evenly distributed on the surface of the continuous glass fiber 11 during the injection process, thereby improving the quality and strength of the synthetic sleeper 100. This arrangement can ensure that the polyurethane resin A and the polyurethane resin B are fully mixed to form a uniform mixed polyurethane resin, which is evenly distributed on the surface of the continuous glass fiber 11, thereby improving the quality and strength of the synthetic sleeper 100.

[0088] Preferably, the mixing gun head 33 is connected to the diverter 34 and is connected to multiple injection holes of the closed dipping box 2 through multiple diverter injection tubes 35 to ensure uniform injection of the polyurethane resin and uniform impregnation of the continuous glass fiber 11.

[0089] As a preferred example of the present invention, the pulling speed of the mold is 0.3-1.0 m / min, the mold temperature is 40-90° C., and the curing time of the synthetic sleeper 100 in the mold is 40-60 min.

[0090] Specifically, by controlling the pulling speed, mold temperature and curing time, the synthetic sleeper 100 can be fully cured in the mold, thereby improving product quality and production efficiency.

[0091] Example 1

[0092] The hydroxyl value of component A of the polyurethane composite material is 320±20mgKOH / g, the viscosity is 1200mPas, and component B uses polymeric MDI with an isocyanate index of 31.2%. The mass ratio of component A to component B is set to 100:100, and components A and B are pumped into the glue injection machine in advance for standby use;

[0093] By changing the position of the baffle plate and the distance between the lower crawler machine 61 and the upper crawler machine 62, the mold cavity size of the crawler machine 6 is adjusted to 200mm (width) × 140mm (height), and the product density is 0.70±0.04g / cm 3 , calculated based on a glass fiber content of 50%, the reinforcement material uses 9600tex continuous glass fiber 11 direct yarn, the number of which is 1030 bundles. The continuous glass fiber 11 passes through the closed dipping box 2 into the mold, and enters the crawler machine mold cavity under the extrusion and traction of the crawler machine 6. The glass fiber fabric 511 uses a width of 700mm and a surface density of 600g / m 2 The continuous felt has two layers, and the felt guide 4 uses a layer of PET release paper as the release paper 521, with a width of 720 mm and a surface density of 90 g / m 2 , the glass fiber fabric 511 and the release paper 521 wrap the continuous glass fiber in sequence and enter the mold together.

[0094] When the mold temperature of the crawler machine 6 is preheated to 50°C, the glue injection machine 3 is turned on for glue injection. The glass fiber fabric 511 and the demoulding paper 521 are sequentially coated on the outside of the continuous glass fiber 11 impregnated with the polyurethane resin. The resin flow of the glue injection machine 3 is adjusted in time to ensure that the polyurethane resin evenly impregnates the continuous glass fiber 11 and the fiber fabric 511. The production speed is controlled at 0.75m / min. The product is demoulded after being cured in the mold for 40 minutes. After the product is demoulded, it is sawed according to the set length. After sawing, the demoulding paper 521 is cleaned to obtain the finished synthetic sleeper 100. The thickness of the glass fiber fabric reinforcement layer 102 on the surface of the finished synthetic sleeper 100 is 1.5mm.

[0095] Example 2

[0096] The hydroxyl value of component A of the polyurethane composite material is 400±20mgKOH / g, the viscosity is 800mPas, and component B is polymerized MDI with an isocyanate index of 31.2%. The mass ratio of component A to component B is set to 100:120, and components A and B are pumped into the glue injection machine in advance for standby use;

[0097] By changing the position of the baffle plate and the distance between the lower crawler machine 61 and the upper crawler machine 62, the mold cavity size of the crawler machine 6 is adjusted to 230 mm (width) × 140 mm (height), and the product density is 0.80 ± 0.04 g / cm 3 , calculated based on a glass fiber content of 50%, the reinforcement material uses 13800tex continuous glass fiber plied yarn, the number of which is 840 bundles, the continuous glass fiber 11 passes through the closed dipping box 2 into the mold, and enters the crawler machine cavity under the extrusion and traction of the crawler machine 6, the glass fiber fabric 511 is 750mm wide, and the 3-layer surface density is 600g / m 2 The density of fiberglass mesh + 1 layer is 450g / m 2 The polyester stitched composite felt is black, and the felt guide 4 uses a layer of PE release film as the release paper 521, with a width of 770 mm and a surface density of 120 g / m 2 , the glass fiber fabric 511 and the release paper 521 wrap the continuous glass fiber in sequence and enter the mold together.

[0098] When the mold temperature of the crawler machine 6 is preheated to 60°C, the glue injection machine 3 is turned on for glue injection. The glass fiber fabric 511 and the demoulding paper 521 are sequentially coated on the outside of the continuous glass fiber 11 impregnated with the polyurethane resin. The resin flow of the glue injection machine 3 is adjusted in time to ensure that the polyurethane resin evenly impregnates the continuous glass fiber 11 and the fiber fabric 511. The production speed is controlled to be 0.6m / min. The product is demoulded after being cured in the mold for 50 minutes. After the product is demoulded, it is sawed according to the set length. After sawing, the demoulding paper 521 is cleaned to obtain a black synthetic sleeper 100 finished product. The thickness of the glass fiber fabric reinforcement layer 102 on the surface of the synthetic sleeper 100 finished product is 3mm.

[0099] Example 3

[0100] The hydroxyl value of component A of the polyurethane composite material is 480±20mgKOH / g, the viscosity is 700mPas, and component B uses polymeric MDI with an isocyanate index of 31.2%. The mass ratio of component A to component B is set to 100:140. Component A and component B are pumped into the glue injection machine in advance for standby use;

[0101] By changing the position of the baffle plate and the distance between the lower crawler machine 61 and the upper crawler machine 62, the mold cavity size of the crawler machine 6 is adjusted to 240 mm (width) × 240 mm (height), and the product density is 1.20 ± 0.06 g / cm 3 , calculated with a glass fiber content of 55%, the reinforcement material uses 19200tex continuous glass fiber plied yarn, the number is 1990 bundles, the continuous glass fiber 11 passes through the closed dipping box 2 into the mold, and enters the crawler machine mold cavity under the extrusion and traction of the crawler machine 6. The glass fiber fabric 511 uses a width of 980mm and a 6-layer density of 600g / m 2 0° / 90° glass fiber biaxial fabric + 1 layer density 450g / m 2 The continuous felt, the felt guide 4 uses a layer of PET release paper as the release paper 521, the width is 1000mm, the surface density is 120g / m 2 , the glass fiber fabric 511 and the release paper 521 wrap the continuous glass fiber in sequence and enter the mold together.

[0102] When the mold temperature of the crawler machine 6 is preheated to 60°C, the glue injection machine 3 is turned on for glue injection. The glass fiber fabric 511 and the demoulding paper 521 are sequentially coated on the outside of the continuous glass fiber 11 impregnated with the polyurethane resin. The resin flow of the glue injection machine 3 is adjusted in time to ensure that the polyurethane resin is evenly impregnated into the continuous glass fiber 11 fiber fabric 511. The production speed is controlled at 0.55m / min. The product is demoulded after being cured in the mold for 50 minutes. After the product is demoulded, it is sawed according to the set length. After sawing, the demoulding paper 521 is cleaned to obtain the finished synthetic sleeper 100. The thickness of the glass fiber fabric reinforcement layer 102 on the surface of the finished synthetic sleeper 100 is 6mm.

[0103] Example 4

[0104] When the continuous glass fiber 11 impregnated with polyurethane resin is coated with the surface glass fiber fabric reinforcement layer 511, the surface glass fiber fabric reinforcement layer adopts a reinforced polyurethane resin mixed and compounded by impregnating the glass fiber with component C and component B; after coating the surface glass fiber fabric reinforcement layer 511, it is coated with release paper 521. The mass ratio of component B to component C is 140:100, the water content of component C is 0.18%, the content of polyether amine resin is 20wt%, and the molecular weight is 1000-1200. Other parameters and conditions in this embodiment are the same as those in Example 3.

[0105] Comparative Example 1

[0106] All reinforcement materials are 9600tex continuous glass fiber direct yarn, with 1120 bundles arranged, and no glass fiber fabric reinforcement on the surface;

[0107] Other molding process parameters are the same as those in “Example 1”.

[0108] Comparative Example 2

[0109] All reinforcement materials are made of 13800tex continuous glass fiber yarn, with 900 bundles arranged, and no glass fiber fabric reinforcement on the surface;

[0110] Other molding process parameters are the same as those in “Example 2”.

[0111] Comparative Example 3

[0112] All reinforcement materials are 9600tex continuous glass fiber direct yarn, with 2180 bundles arranged, and no glass fiber fabric reinforcement on the surface;

[0113] Other molding process parameters are the same as those in “Example 3”.

[0114] Performance measurement

[0115] In the above embodiments and comparative examples, the density is determined in accordance with GB / T1463-2005 "Test method for density and relative density of fiber reinforced plastics"; the mechanical properties of Examples 1, 2 and Comparative Examples 1, 2 are tested with reference to CJ / T3992012 "Polyurethane foam synthetic sleepers" standard; the mechanical properties of Example 3 and Comparative Example 3 are tested with reference to TJ / GW161-2018 "HFFP composite material sleepers for railway steel beams" interim technical conditions.

[0116] The fiber-reinforced polyurethane composite synthetic sleepers obtained in Examples 1 to 3 and Comparative Examples 1 to 3 were tested, and the specific results are shown in Table 1.

[0117] Table 1. Comparison of performance of synthetic sleeper products in the examples and comparative examples

[0118]

[0119] Note: 1. The compression strength is sampled from the product surface;

[0120] 2. The direction along the fibers is vertical; the direction perpendicular to the fibers is horizontal.

[0121] It can be seen from the test results in Table 1 that for the example and comparative examples with similar density, except for the vertical compressive strength, the lateral compressive strength, the pull-out strength of the threaded spikes and the load in the bending zone of the finished product of the example products are all greater than those of the corresponding comparative products, which proves that the surface reinforcement layer of the present invention can significantly increase the overall strength of the synthetic sleeper, and has obvious advantages in performance compared with the existing unidirectional fiber reinforced synthetic sleepers.

[0122] In summary, the one-piece molded synthetic sleeper, preparation process and preparation device described in the present application have the following advantages: 1. It can significantly increase the overall strength of the synthetic sleeper 100, avoid lateral cracking, and increase the service life of the synthetic sleeper; 2. It reduces the painting process and reduces pollution to the environment. The color of the synthetic sleeper 100 can be customized according to needs to meet the personalized needs of different customers. It can ensure that the color of the synthetic sleeper 100 remains consistent throughout the production process, which helps to improve the appearance quality of the product. It has good durability and anti-aging properties, and can ensure that the color of the synthetic sleeper 100 remains bright and stable after long-term use; 3. It is easy to demold the product without spraying a release agent and surface polishing, which reduces VOC and dust pollution in the production process.

[0123] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. An integrally formed synthetic sleeper, characterized in that: The invention comprises a polyurethane resin matrix (101), continuous glass fibers (11) are longitudinally arranged in the polyurethane resin matrix (101) and are used for longitudinal reinforcement of a synthetic sleeper (100); a reinforcing layer (102) composed of glass fiber fabric (511) and polyurethane resin is arranged on the surface of the polyurethane resin matrix (101), and the thickness of the reinforcing layer (102) is 1 to 10 mm; the overall density of the synthetic sleeper is 0.64 to 1.4 g / cm 3 , wherein the polyurethane resin accounts for 35 to 50% of the total weight of the synthetic sleeper (100); the continuous glass fiber (11) accounts for 35 to 60% of the total weight of the synthetic sleeper (100); and the glass fiber fabric (511) accounts for 3 to 10% of the total weight of the synthetic sleeper (100).

2. The one-piece synthetic sleeper according to claim 1, characterized in that: The polyurethane resin is compounded by component A and component B in a weight ratio of 100:100-150; wherein component A is a polyol combination material, and component B is isocyanate.

3. The one-piece synthetic sleeper according to claim 2, characterized in that: The average hydroxyl value of the component A is 300-500 mgKOH / g, the viscosity at 25°C is 500-2000 mPa·s, and the functionality is 3-6; the isocyanate content of the component B is 30-32%, the viscosity at 25°C is 200-600 mPa·s, and the functionality is 2-3.

4. The one-piece synthetic sleeper according to claim 1, characterized in that: The surface density of the glass fiber fabric (511) is 300 to 1500 g / m 2 .

5. A process for preparing an integrally formed synthetic sleeper, used for preparing the integrally formed synthetic sleeper according to any one of claims 1 to 4, characterized in that: Includes steps: Step S1: Calculating the number of continuous glass fibers (11) according to the density and glass fiber content of the synthetic sleeper (100); Step S2: layering the continuous glass fibers (11) according to the calculation results; Step S3: uniformly impregnating the layered continuous glass fibers (11) with polyurethane resin; Step S4: sequentially wrapping the glass fiber fabric (511) and the release paper (521) on the outside of the continuous glass fiber (11) impregnated with the polyurethane resin; Step S5: heating the continuous glass fiber (11) coated with the glass fiber fabric (511) and the release paper (521) and the polyurethane resin, and curing the polyurethane resin to form a fiber-reinforced polyurethane synthetic sleeper (100); Step S6: cutting and segmenting the cured fiber-reinforced polyurethane synthetic sleeper (100) according to size requirements to obtain a finished synthetic sleeper (100).

6. A device for preparing an integrally formed synthetic sleeper, used for preparing the integrally formed synthetic sleeper according to any one of claims 1 to 4, characterized in that: The invention comprises a creel (1), a closed glue dipping box (2), a glue injector (3), a felt guide (4), a felt frame (5), a crawler machine (6) and a sawing machine (7) which are arranged in sequence. The felt guide (4) comprises a first felt guide (41) and a second felt guide (42). The felt frame (5) comprises a first felt frame (51) and a second felt frame (52). The creel (1) is used to place continuous glass fibers (11). The closed glue dipping box (2) is used to uniformly impregnate the continuous glass fibers (11) with polyurethane resin. The glue injector (3) is used to transport polyurethane resin into the closed glue dipping box (2). The first felt frame (51) is used to place glass fiber fabrics ( 511), the first felt guide (41) is used to guide the glass fiber fabric (511) to be wrapped around the surface of the continuous glass fiber (11), the second felt frame (52) is used to place the release paper (521), the second felt guide (42) is used to guide the release paper (521) to be wrapped around the surface of the glass fiber fabric (511), the crawler (6) is provided with a mold, the mold is used to heat and pressurize the continuous glass fiber (11) impregnated with polyurethane resin, so that the polyurethane resin is cured to form a fiber-reinforced polyurethane synthetic sleeper (100), and the sawing machine (7) is used to cut the fiber-reinforced polyurethane synthetic sleeper (100).

7. The manufacturing device of the integrally formed synthetic sleeper according to claim 6, characterized in that: The crawler machine (6) comprises a lower crawler machine (61) and an upper crawler machine (62). Baffles are arranged on the left and right sides of the crawler machine (6). The baffles cooperate with the upper crawler machine (62) and the lower crawler machine (61) to form a mold cavity. The synthetic sleeper (100) is solidified and formed in the mold cavity and is automatically separated from the mold cavity as the crawler machine (6) rotates.

8. The manufacturing device of the integrally formed synthetic sleeper according to claim 6, characterized in that: The glue injection machine (3) comprises a component A material tank (31), a component B material tank (32), a mixing gun head (33) and a flow divider (34). The component A material tank (31) and the component B material tank (32) are respectively connected to the mixing gun head (33) through pipelines. The mixing gun head (33) is connected to the flow divider (34) through a pipeline. The flow divider (34) is connected to the closed glue dipping box (2) through a flow diversion glue injection pipe (35). The component A material tank (31) is used to store polyurethane resin A, the component B material tank (32) is used to store polyurethane resin B, the mixing gun head (33) is used to mix polyurethane resin A and polyurethane resin B, and the flow divider (34) is used to evenly divide the mixed polyurethane resin output by the mixing gun head (33) and input it into the closed glue dipping box (2).

9. The manufacturing device of the integrally formed synthetic sleeper according to claim 6, characterized in that: The pulling speed of the mold is 0.3-1.0 m / min, the mold temperature is 40-90° C., and the curing time of the synthetic sleeper (100) in the mold is 40-60 min.

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