Thread Content
Coating wear of equipment during production is a very real issue. When providing protection, it can be divided into protection using rigid wear-resistant materials and protection using elastic wear-resistant materials. In the protection of elastomeric wear-resistant materials, elastomeric polyurethanes have clear advantages. Polyurethane elastomers are elastic materials that lie between ordinary rubbers and plastics; they possess the elasticity of rubber as well as the strength of plastics. It has a high elongation rate and a wide range of hardness levels; it boasts excellent wear resistance, biocompatibility, and blood compatibility. At the same time, it also possesses excellent properties such as oil resistance, impact resistance, low-temperature resistance, radiation resistance, load-bearing capacity, and thermal insulation. Sprayed polyurethane possesses excellent properties such as wear resistance, water and oil resistance, vibration absorption and noise reduction, high strength, and strong adhesion to metal frames. It produces low levels of noise, offers good self-cleaning capabilities, reduces the load on screening machines, saves energy consumption, extends the lifespan of these machines, and ensures high-quality screening results. This polyurethane elastomer material is a non-metallic material that meets the requirements of mining industries. Various vibrating screens, slurry pumps, magnetic separation drums, and thickeners used in mines can all be utilized. It was learned from the mine site that the wear on the conveyor belt is more severe on the non-load-bearing surface, which seems to contradict theory. After careful analysis, it is concluded that during the operation of the conveyor belt, as the conveyor speed increases, there is not only theoretical pure rolling friction between the non-loading surface of the belt and the idlers, but also sliding friction. When individual idlers stop rotating due to certain reasons (such as poor bearing lubrication), the sliding friction becomes more pronounced, while the frictional wear on the bearing surface is mainly caused by interaction with the material (coal). Throughout the entire transportation process, except for the brief sliding friction and impact friction (during loading) at the times of loading and unloading, the conveyor belt surface and the material remain relatively stationary for most of the time. Therefore, in existing conveyor belts that operate at high speeds, it is the non-loading surface that suffers more severe wear; often, the steel wires become exposed on the non-loading surface even when the loading surface is still in relatively good condition. Furthermore, as the speed of the conveyor belt increases, the frictional heat between the belt and the idlers and rollers also increases, which accelerates the wear of the non-load-bearing surface of the conveyor belt. At present, standard flame-retardant conveyor belts are used in coal mines in our country, with a coal handling volume of generally 6 to 8 million tons, sometimes reaching 10 million tons; it is estimated that the annual cost associated with these conveyor belts ranges between 100 million and 200 million yuan. To increase the service life of the conveyor belt, it is first necessary to find ways to minimize friction on the belt, specifically sliding friction ； Secondly, when selecting the material for the conveyor belt, it is necessary to choose a material with low friction and high wear resistance. However, during mechanical operation, frictional wear of the conveyor belt is inevitable. The cost of replacing the conveyor belt is high; therefore, to save costs, the worn conveyor belt can be repaired. By using repair materials with excellent adhesive properties, it is possible to restore the conveyor belt, reduce friction between the original belt material and the idlers, and extend its service life. Two-component, solid-based, shrink-resistant polyurethane repair materials are available in the form of paste and are packaged in cans or other formats suitable for use on site. This repair material is highly effective for repairing damages in products with elastic properties such as rubber, polyurethane linings, conveyor belts, pulleys, etc. Polyurethane repair materials are room-temperature curing, solvent-free polyether adhesive types ； It features fast curing speed, simple operation, ease of use, good filling properties, resistance to media, aging resistance, high bonding strength, and high strength ； After curing, it exhibits excellent toughness, wear resistance, corrosion resistance, as well as resistance to impact wear and cavitation. The polyurethane adhesive repair material series features strong adhesion properties; different primers and adhesives are used depending on the substrate, and suitable primers and adhesives can be found for both metal and non-metal substrates. After being mixed in the proper proportions, polyurethane repair material can be applied to form a thick coating; since the material contains no volatile components, the coating does not shrink. The cured surface can be machined or polished to achieve a relatively smooth surface. These features make it easier to achieve a smooth repair surface that matches that of the original substrate when using polyurethane repair materials for surface repairs.