Polyurethane material for industrial AGV truckles and preparation method thereof

Abstract

The invention relates to the technical field of AGV caster material processing, in particular to a polyurethane material for industrial AGV casters and a preparation method thereof.The polyurethane material is prepared from, by weight, 50-60 parts of polyurethane elastomer, 15-20 parts of ultra-high molecular weight polyethylene, 6-10 parts of polyether block polyamide, 2-3 parts of compatilizer and 10-20 parts of inorganic filler; the polyurethane material for the industrial AGV caster prepared by adopting the formula can keep excellent flexibility, elasticity, impact resistance, wear resistance and friction force in a low-temperature environment, can be used in an environment of-50 DEG C, and does not have an embrittlement phenomenon. Meanwhile, good friction force is kept under the low-temperature condition, so that the risk of slipping of the trundle under the low-temperature condition can be reduced, and it is ensured that the trundle can stably operate in the extremely low-temperature environment.

Description

Technical Field

[0001] This application relates to the field of AGV caster material processing technology, and more specifically, to a polyurethane material for industrial AGV casters and its preparation method. Background Technology

[0002] AGV casters are wheels installed at the bottom of Automated Guided Vehicles (AGVs), and commonly used materials include polyurethane, rubber, and nylon. Among these, polyurethane has become the preferred material for AGV caster manufacturing due to its high wear resistance, high load-bearing capacity, shock absorption, and long service life.

[0003] However, during use, it was found that polyurethane AGV casters become brittle in low-temperature environments, leading to a decrease in their elasticity and flexibility. This affects the shock absorption performance and friction with the ground, increasing the risk of slippage. At the same time, low temperatures reduce the flexibility of polyurethane AGV casters, making them less smooth to rotate and increasing resistance during startup and operation. This affects the AGV's movement efficiency and accuracy, especially in winter in cold regions where this problem is more pronounced. Summary of the Invention

[0004] To improve the low-temperature resistance of polyurethane AGV casters, this application provides a polyurethane material for industrial AGV casters and its preparation method.

[0005] In a first aspect, this application provides a polyurethane material for industrial AGV casters, employing the following technical solution: A polyurethane material for industrial AGV casters is prepared from the following raw materials in parts by weight: 50-60 parts of polyurethane elastomer 15-20 parts of ultra-high molecular weight polyethylene 6-10 parts of polyether block polyamide 2-3 parts compatibilizer 10-20 parts of inorganic filler.

[0006] By adopting the above technical solution, a polyurethane material for industrial AGV casters is prepared. This material maintains excellent flexibility, elasticity, impact resistance, wear resistance, and friction in low-temperature environments, and can be used in environments down to -50℃ without cracking. Simultaneously, it maintains good friction under low-temperature conditions, reducing the risk of slippage and ensuring stable operation in extreme low-temperature environments.

[0007] This application overcomes the defect of polyurethane becoming brittle at low temperatures by using polyurethane elastomer, ultra-high molecular weight polyethylene, and polyether block polyamide in specific proportions, thus improving the low-temperature resistance of polyurethane materials used in industrial AGV casters. This allows them to maintain flexibility and impact resistance even in extreme low-temperature environments. Ultra-high molecular weight polyethylene significantly improves the material's wear resistance and self-lubrication, reducing the coefficient of friction and ensuring smooth caster rotation even at low temperatures, reducing starting and running resistance. The introduction of polyether block polyamide effectively enhances the material's flexibility and resilience, working synergistically with polyurethane to optimize the caster's shock absorption and ground friction under low-temperature conditions, preventing slippage. The addition of a compatibilizer ensures that all components are tightly integrated, forming a uniform and stable material system, fully utilizing the advantages of each raw material. Inorganic fillers further improve the material's strength and broaden the applicable temperature range of the casters.

[0008] Preferably, the polyurethane elastomer is prepared by the following method: 1) Heat polytetrahydrofuran ether and polyester polyol to 100-105℃, dehydrate for 1-2 hours, then add antioxidant and catalyst, adjust the temperature in the reactor to 120-150℃ and the pressure to -0.08--0.1MPa, react for 3-5 hours to form component A; The weight ratio of polytetrahydrofuran ether, polyester polyol, antioxidant and catalyst is 10:(4-6):(1-3):(0.05-0.1); 2) Heat the chain extender and diisocyanate to 100-120℃ to form component B; The weight ratio of chain extender to diisocyanate is 1:(15-20); 3) Add components A and B to a twin-screw extruder at the same time. The weight ratio of components A to B is 1:(2-5). Control the reaction temperature of the extruder at 100-120℃ to carry out the polymerization reaction and form thermoplastic polyurethane elastic. 4) The thermoplastic polyurethane elastomer is dried and aged at a temperature of 110℃-125℃ and a pressure of -0.08-0.1MPa for 4-10 hours to obtain the polyurethane elastomer.

[0009] By adopting the above technical solution, polyurethane elastomers are prepared according to specific methods and weight ratios. These polyurethane materials are used to prepare industrial AGV casters, which can effectively improve the problems of existing polyurethane material AGV casters becoming brittle in low-temperature environments, resulting in decreased elasticity and flexibility, poor shock absorption performance, reduced friction with the ground, decreased flexibility, and uneven rotation. This avoids increasing the risk of slippage and the resistance to starting and running, thereby improving the movement efficiency and accuracy of AGVs.

[0010] Components A and B are simultaneously added to a twin-screw extruder and polymerized at a reaction temperature of 100-120°C. This crucial step ensures thorough mixing and reaction of components A and B, forming a thermoplastic polyurethane elastomer with a three-dimensional network structure. The efficient mixing and shearing action of the twin-screw extruder results in a more uniform and complete reaction, improving the molecular weight distribution uniformity and mechanical properties of the polyurethane elastomer. By controlling the weight ratio of components A and B, the hardness, flexibility, and low-temperature resistance of the polyurethane elastomer can be precisely adjusted, enabling it to meet the requirements of AGV casters while possessing excellent overall performance.

[0011] Preferably, the number average molecular weight of the polytetrahydrofuran ether is 2000-8000.

[0012] By adopting the above technical solution, polytetrahydrofuran ether within this molecular weight range has a low glass transition temperature. As a soft segment in polyurethane elastomers, it can effectively reduce the glass transition temperature of polyurethane. This allows the polyurethane elastomer to maintain good flexibility and elasticity in low-temperature environments, preventing it from becoming brittle. This significantly improves the low-temperature resistance of polyurethane AGV casters, reducing problems such as decreased elasticity and flexibility and slippage caused by low temperatures, ensuring stable operation of AGVs in cold regions.

[0013] Simultaneously, when combined with other raw materials such as polyester polyols, the polyurethane elastomer achieves a good balance between flexibility and strength. The flexible segments of polytetrahydrofuran provide flexibility and resilience, while the rigid segments such as polyester polyols provide the material with a certain degree of strength and rigidity. This balance allows AGV casters to withstand a certain load while maintaining good shock absorption performance, reducing vibration and impact during operation, and improving the stability and comfort of AGV operation.

[0014] Preferably, the polyester polyol is composed of polyethylene glycol ester polyol with a functionality of 2-3 and a number average molecular weight of 1000-3000 and polycaprolactone diol with a functionality of 1-5 and a number average molecular weight of 2000-5000 in a weight ratio of 1:(3-6).

[0015] By adopting the above technical solution and optimizing the type and amount of polyester polyol, the combination of the two allows the polyurethane elastomer to balance flexibility and strength. It can withstand certain loads while maintaining good shock absorption performance, reducing vibration and impact during AGV operation and improving its operational stability and comfort. The synergistic effect of polyethylene glycol ester polyol and polycaprolactone diol effectively lowers the glass transition temperature of the polyurethane elastomer, enabling it to maintain good flexibility and elasticity even at low temperatures.

[0016] Furthermore, the network structure formed by polyethylene glycol polyol can disperse stress, reducing local deformation and wear of the material during friction. Meanwhile, polycaprolactone diol acts as a lubricant in the polyurethane molecular chain, reducing the coefficient of friction between molecular chains, further reducing material wear during friction, extending the service life of AGV casters, and lowering replacement frequency.

[0017] Preferably, the inorganic filler is pretreated by the following method: S1, the inorganic filler is placed in sulfuric acid solution, heated for 2-3 hours, removed, and rinsed to obtain acidified inorganic filler; S2, the acidified inorganic filler, ethanol and aminosilane coupling agent are mixed, ultrasonicated, filtered, and dried to obtain pretreated inorganic filler. The weight ratio of inorganic filler, ethanol and aminosilane coupling agent is 1:(4-6):(0.2-0.5).

[0018] The inorganic filler includes silicon dioxide, silicon nitride, quartz, and mica powder. By adopting the above technical solution, the dispersibility of the pretreated inorganic filler is improved, enabling it to be uniformly dispersed in the polyurethane matrix and more tightly bonded to the polyurethane elastomer. When subjected to external forces, stress can be transferred more effectively between the filler and the matrix, thereby improving the tensile strength, flexural strength and other mechanical properties of the polyurethane elastomer, enhancing the load-bearing capacity and wear resistance of the AGV casters, and extending their service life.

[0019] Preferably, the polyether block polyamide is Elastomers.

[0020] By adopting the above technical solution, the selected As a polyether block polyamide, the elastomer helps to improve the problem of the polyurethane material becoming brittle at low temperatures, enhances the material's elasticity and flexibility, thereby improving the shock absorption performance and friction with the ground of the casters, reducing the risk of slippage, and also improving the casters' flexibility, making rotation smoother, reducing the resistance to starting and running, and improving the movement efficiency and accuracy of the AGV.

[0021] Preferably, the compatibilizer comprises at least one of maleic anhydride-grafted styrene-ethylene-butadiene-styrene block copolymer elastomer, maleic anhydride-grafted ethylene-octene copolymer, and ethylene-methyl acrylate-glycidyl methacrylate terpolymer.

[0022] By adopting the above technical solutions and optimizing the types of compatibilizers, polyurethane elastomers, ultra-high molecular weight polyethylene and polyether block polyamides can be better mixed and combined with each other, reducing phase separation and forming a more uniform and stable microstructure, thereby improving the material's comprehensive properties such as impact strength, low-temperature resistance and wear resistance.

[0023] Preferably, the molecular weight of the ultra-high molecular weight polyethylene is 4 million to 7.5 million.

[0024] By adopting the above technical solutions, the molecular weight of ultra-high molecular weight polyethylene is optimized, further improving the overall performance of polyurethane materials, such as low-temperature resistance, impact resistance, and abrasion resistance.

[0025] Secondly, this application provides a method for preparing polyurethane material for industrial AGV casters, employing the following technical solution: A method for preparing a polyurethane material for industrial AGV casters includes the following preparation steps: Polyurethane elastomer, ultra-high molecular weight polyethylene, polyether block polyamide, compatibilizer and inorganic filler are mixed and extruded to granulate, thus obtaining a polyurethane material for industrial AGV casters.

[0026] By adopting the above technical solution, polyurethane elastomer, ultra-high molecular weight polyethylene, polyether block polyamide, compatibilizer and inorganic filler are used as raw materials, and polyurethane material for industrial AGV casters is made by mixing, extrusion and granulation. This can effectively avoid the problems of existing polyurethane material AGV casters becoming brittle, losing elasticity and flexibility, deteriorating shock absorption and friction, and reducing flexibility in low temperature environments. It ensures that the casters can be used normally at low temperatures and improves the movement efficiency and accuracy of AGVs.

[0027] In summary, this application has the following beneficial effects: 1. This application uses polyurethane elastomer, ultra-high molecular weight polyethylene, polyether block polyamide, compatibilizer and inorganic filler in combination, so that the polyurethane material used for industrial AGV casters can maintain flexibility, elasticity, impact resistance, wear resistance and friction in a low temperature environment of -50℃, without cracking, reducing the risk of slippage and ensuring stable operation of the casters. Detailed Implementation Example

[0028] The polyurethane elastomer was purchased from Dongguan Yingxiang Plastic Raw Materials Co., Ltd., model number UD-98AU10, brand name Bayer UDE.

[0029] Maleic anhydride-grafted styrene-ethylene-butadiene-styrene block copolymer elastomer is a product of LG Chem in South Korea, model number LH4001.

[0030] Maleic anhydride-grafted ethylene-octene copolymer is a product of Dow Chemical Company, USA, model AMPLIFY GR216.

[0031] The ethylene-methyl acrylate-glycidyl methacrylate terpolymer is a product of DuPont, USA, model number [model number missing]. PTW.

[0032] Example 1 A polyurethane material for industrial AGV casters is prepared by the following method: 500g of polyurethane elastomer, 150g of ultra-high molecular weight polyethylene, 60g of polyether block polyamide, 20g of compatibilizer (maleic anhydride-grafted styrene-ethylene-butadiene-styrene block copolymer elastomer) and 100g of inorganic filler (silica) were mixed and extruded to obtain polyurethane material for industrial AGV casters.

[0033] Ultra-high molecular weight polyethylene has a molecular weight of 4 million.

[0034] The difference between Examples 2-3 and Example 1 lies in the types, amounts, and parameters of the raw materials used to prepare the polyurethane materials for industrial AGV casters. Specific differences are shown in Table 1. Table 1. Raw material types, dosages, and parameters for preparing polyurethane materials for industrial AGV casters in Examples 1-3. Example 4 A polyurethane material for industrial AGV casters, the difference between this embodiment and Embodiment 1 is that the polyurethane elastomer is prepared by the following method: 1. Heat 500g of polytetrahydrofuran ether and 200g of polyester polyol to 100℃ and dehydrate for 1 hour. Then add 50g of antioxidant and 2.5g of catalyst (zinc isooctanoate). Adjust the temperature in the reactor to 120℃ and the pressure to -0.08MPa. React for 3 hours to form component A. The polyester polyol is composed of polyethylene glycol ester polyol with a functionality of 2 and a number average molecular weight of 1000 and polycaprolactone diol with a functionality of 1 and a number average molecular weight of 2000, in a weight ratio of 1:3.

[0035] The number average molecular weight of polytetrahydrofuran ethers is 2000.

[0036] The weight ratio of polytetrahydrofuran ether, polyester polyol, antioxidant and catalyst is 10:4:1:0.5; 2) Heat 50g of chain extender (ethylene glycol) and 750g of diisocyanate (terephthalic diisocyanate) to 100℃ to form component B; The weight ratio of chain extender to diisocyanate is 1:15; 3) Add 300g of component A and 600g of component B to a twin-screw extruder at the same time. The weight ratio of component A to component B is 1:2. Control the reaction temperature of the extruder at 100℃ to carry out the polymerization reaction and form thermoplastic polyurethane elastic. 4) The thermoplastic polyurethane elastomer was dried and aged for 4 hours at a temperature of 110℃ and a pressure of -0.08MPa to obtain the polyurethane elastomer.

[0037] The difference between Examples 5-6 and Example 4 lies in the types and amounts of raw materials used to prepare the polyurethane elastomers, as well as the experimental parameters. Specific differences are shown in Table 2. Example 5: The polyester polyol is composed of polyethylene glycol ester polyol with a functionality of 2 and a number average molecular weight of 2000 and polycaprolactone diol with a functionality of 3 and a number average molecular weight of 4000, in a weight ratio of 1:5.

[0038] Example 6: The polyester polyol is composed of polyethylene glycol ester polyol with a functionality of 3 and a number average molecular weight of 3000 and polycaprolactone diol with a functionality of 6 and a number average molecular weight of 5000, in a weight ratio of 1:6.

[0039] Example 7 A polyurethane material for industrial AGV casters. The difference between this embodiment and Embodiment 4 is that the polyester polyol is polyethylene glycol ester polyol with a functionality of 2 and a number average molecular weight of 1000.

[0040] Example 8 A polyurethane material for industrial AGV casters, the difference between this embodiment and Embodiment 1 is that the inorganic filler is pretreated by the following method: S1. Place 100g of inorganic filler in a 50% sulfuric acid solution, heat for 2 hours, remove and rinse to obtain acidified inorganic filler; S2. Mix acidified inorganic filler, 400g of ethanol and 20g of aminosilane coupling agent (3-aminopropyltrimethoxysilane), sonicate, filter and dry to obtain pretreated inorganic filler; The weight ratio of inorganic filler, ethanol and aminosilane coupling agent is 1:4:0.2.

[0041] Example 9 A polyurethane material for industrial AGV casters, the difference between this embodiment and Embodiment 4 is that the inorganic filler is pretreated by the following method: S1. Place 100g of inorganic filler in a 50% sulfuric acid solution, heat for 3 hours, remove and rinse to obtain acidified inorganic filler; S2. Mix acidified inorganic filler, 600g of ethanol and 50g of aminosilane coupling agent (3-aminopropyltriethoxysilane), sonicate, filter and dry to obtain pretreated inorganic filler; The weight ratio of inorganic filler, ethanol and aminosilane coupling agent is 1:6:0.5.

[0042] Comparative Example Comparative Example 1 A polyurethane material for industrial AGV casters. The difference between this comparative example and Example 1 is that ultra-high molecular weight polyethylene is replaced with polyethylene with a molecular weight of 40,000.

[0043] Comparative Example 2 A polyurethane material for industrial AGV casters. The difference between this comparative example and Example 1 is that the polyether block polyamide is replaced with pure polyamide resin.

[0044] The polyamide resin was purchased from Suzhou Deyi Polyplastics Co., Ltd., model PA66, brand name DuPont.

[0045] Detection methods / test methods Flexibility Test: Standard specimens with dimensions of 80mm × 10mm × 4mm (length × width × height) were prepared from the polyurethane materials used in Examples 1-9 and Comparative Examples 1-2 for industrial AGV casters. The specimens were placed on two supports of a bending testing machine with a support spacing of 60mm. A bending load was applied to the specimens at a rate of 10mm / min, and the bending angles of the specimens under different loads were recorded. If no cracks appeared in the specimen when it reached the specified bending angle of 90°, and it could essentially return to its original shape without significant permanent deformation after the load was removed, then the polyurethane material could be determined to have good flexibility at low temperatures.

[0046] Resilience Test: A flat, circular polyurethane sample is made and fixed on the sample stage of a falling ball rebound tester. A steel ball is placed at a height of 500 mm and allowed to fall freely onto the sample surface. The height of the rebound is recorded. This test is repeated 10 times, and the average value is used to calculate the resilience. The formula for calculating resilience is: Resilience (%) = (Steel ball rebound height / Steel ball drop height) × 100%. If the material's resilience is greater than 60%, it indicates that the material has good elasticity.

[0047] Abrasion resistance: Standard-sized cylindrical specimens of polyurethane material were prepared and mounted on the specimen fixture of a rotary abrasion testing machine. The grinding wheel speed of the testing machine was set to 60 r / min, the test pressure to 1 MPa, and the test time to 1 hour. After the test, the wear depth of the specimen was measured.

[0048] Static friction coefficient test: A flat polyurethane sample is prepared and placed on the test platform of a coefficient of friction meter along with a standard mating material. The instrument pressure is set to 10N, and the horizontal thrust is gradually increased. The thrust value is recorded when the sample begins to slide. The static friction coefficient is calculated as: Static friction coefficient = Thrust / Pressure. A static friction coefficient greater than 0.5 indicates that the material has good friction at low temperatures, reducing the risk of slippage.

[0049] Low-temperature resistance test: Various samples of the polyurethane materials used for industrial AGV casters in Examples 1-9 and Comparative Examples 1-2 were prepared and then placed at an ambient temperature of -50°C for 48 hours. The flexibility, resilience, abrasion resistance, and static friction coefficient were then tested. The experimental data are shown in Table 3. Table 3. Experimental data of Examples 1-8 and Comparative Examples 1-2 As can be seen from the experimental data of Example 1 and Comparative Examples 1-2, the polyurethane material for industrial AGV casters prepared by mixing polyurethane elastomer, ultra-high molecular weight polyethylene, polyether block polyamide, compatibilizer and inorganic filler in this application can greatly improve its flexibility, resilience, wear resistance, static friction coefficient and low temperature resistance, so that it can be used in a low temperature environment of -50℃ and adapt to low temperature weather.

[0050] As can be seen from the experimental data of Examples 1 and 4-6, the polyurethane elastomer prepared by the specific method in this application can further improve the flexibility, resilience, wear resistance, static friction coefficient and low temperature resistance of the polyurethane material used for industrial AGV casters, ensuring that the industrial AGV casters can operate stably in extreme low temperature environments.

[0051] The experimental data from Examples 4 and 7 show that using specific polyethylene glycol polyol and polycaprolactone diol in a specific ratio can improve the flexibility, resilience, wear resistance, static friction coefficient, and low-temperature resistance of polyurethane materials used in industrial AGV casters.

[0052] As can be seen from the experimental data of Examples 1 and 8, Examples 4 and 9, pretreatment of inorganic fillers by the method of this application can improve the flexibility, resilience, wear resistance, static friction coefficient and low temperature resistance of polyurethane materials used in industrial AGV casters.

[0053] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A polyurethane material for industrial AGV casters, characterized in that, It is prepared from the following raw materials in parts by weight: 50-60 parts of polyurethane elastomer 15-20 parts of ultra-high molecular weight polyethylene 6-10 parts of polyether block polyamide 2-3 parts compatibilizer 10-20 parts of inorganic filler.

2. The polyurethane material for industrial AGV casters according to claim 1, characterized in that, The polyurethane elastomer is prepared by the following method: 1) Heat polytetrahydrofuran ether and polyester polyol to 100-105℃, dehydrate for 1-2 hours, then add antioxidant and catalyst, adjust the temperature in the reactor to 120-150℃ and the pressure to -0.08--0.1MPa, react for 3-5 hours to form component A; The weight ratio of polytetrahydrofuran ether, polyester polyol, antioxidant and catalyst is 10:(4-6):(1-3):(0.05-0.1). The chain extender and diisocyanate are heated to 100-120℃ to form component B; The weight ratio of chain extender to diisocyanate is 1:(15-20); 3) Add components A and B to the twin-screw extruder at the same time. The weight ratio of components A to B is 1:(2-5). Control the reaction temperature of the extruder at 100-120℃ to carry out the polymerization reaction and form thermoplastic polyurethane elastic. 4) The thermoplastic polyurethane elastomer is dried and aged at a temperature of 110℃-125℃ and a pressure of -0.08-0.1MPa for 4-10 hours to obtain the polyurethane elastomer.

3. The polyurethane material for industrial AGV casters according to claim 2, characterized in that: The number average molecular weight of the polytetrahydrofuran ether is 2000-8000.

4. The polyurethane material for industrial AGV casters according to claim 2, characterized in that: The polyester polyol is composed of polyethylene glycol ester polyol with a functionality of 2-3 and a number average molecular weight of 1000-3000 and polycaprolactone diol with a functionality of 1-5 and a number average molecular weight of 2000-5000, in a weight ratio of 1:(3-6).

5. The polyurethane material for industrial AGV casters according to claim 4, characterized in that, The inorganic filler is pretreated by the following method: S1. Place the inorganic filler in a sulfuric acid solution, heat for 2-3 hours, remove and rinse to obtain acidified inorganic filler; S2. Mix the acidified inorganic filler, ethanol and aminosilane coupling agent, sonicate, filter and dry to obtain the pretreated inorganic filler; The weight ratio of inorganic filler, ethanol and aminosilane coupling agent is 1:(4-6):(0.2-0.5).

6. The polyurethane material for industrial AGV casters according to claim 1, characterized in that: The polyether block polyamide is a Pebax® elastomer.

7. The polyurethane material for industrial AGV casters according to claim 1, characterized in that: The compatibilizer includes at least one of maleic anhydride-grafted styrene-ethylene-butadiene-styrene block copolymer elastomer, maleic anhydride-grafted ethylene-octene copolymer, and ethylene-methyl acrylate-glycidyl methacrylate terpolymer.

8. The polyurethane material for industrial AGV casters according to claim 1, characterized in that: The ultra-high molecular weight polyethylene has a molecular weight of 4 million to 7.5 million.

9. A method for preparing a polyurethane material for industrial AGV casters as described in any one of claims 1-8, characterized in that, The preparation steps include the following: Polyurethane elastomer, ultra-high molecular weight polyethylene, polyether block polyamide, compatibilizer and inorganic filler are mixed and extruded to granulate, thus obtaining a polyurethane material for industrial AGV casters.

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