Luggage trolleys are often in complex and changing environments, and their surface coatings must have good wear resistance and rust resistance to extend the service life of the trolleys and ensure the integrity of their appearance and functions.
Luggage trolleys are frequently used in airports, stations and other places, often rub and collide with various objects, and may be exposed to humid environments. Therefore, the wear resistance and rust resistance of their surface coatings are crucial. By rationally selecting coating materials and optimizing coating processes, the comprehensive performance of the coating can be effectively improved to meet the use requirements of luggage trolleys.
Ceramic coating materials such as tungsten carbide and aluminum oxide can be used. These ceramic materials have the characteristics of high hardness and high wear resistance, can withstand large friction stress, and are not easily worn. For example, the hardness of tungsten carbide coatings can reach 20003000HV, which can effectively resist the friction between luggage and trolleys.
In order to achieve the anti-rust function, zinc-rich primer can be selected as the base coating. Zinc has good electrochemical protection and can form a dense protective film on the metal surface. Even if the coating is partially damaged, zinc will be corroded first, thereby protecting the base metal from corrosion. In addition, anti-rust pigments such as zinc phosphate and zinc molybdate can be added to the topcoat to further enhance the anti-rust performance of the coating.
Before applying the coating, the surface of the trolley needs to be pretreated. First, the rust, oil and impurities on the surface are removed by sandblasting or shot blasting to form a certain degree of roughness on the surface and increase the adhesion of the coating to the substrate. Then, chemical treatment such as phosphating or passivation is performed. Phosphating can form a phosphate conversion film on the metal surface to improve the adhesion and corrosion resistance of the coating; passivation can form a passivation film on the metal surface to enhance the corrosion resistance of the metal and provide a good foundation for the subsequent coating.
Generally speaking, it is difficult for a single-layer coating to meet the requirements of wear resistance and rust prevention at the same time. Therefore, a multi-layer coating structure can be adopted, such as a combination of primer, intermediate paint and topcoat. The primer mainly plays the role of rust prevention and adhesion increase, the intermediate paint can increase the thickness and toughness of the coating, improve the wear resistance of the coating, and the topcoat provides good surface hardness and gloss, while further enhancing the anti-rust performance.
The thickness of the coating has an important influence on its performance. A coating that is too thin is easily worn or penetrated and cannot effectively protect the substrate; a coating that is too thick may cause problems such as cracking and peeling. According to the use environment and requirements of the luggage trolley, the general primer thickness is controlled at 50-100μm, the intermediate paint thickness is 100-150μm, the topcoat thickness is 50-80μm, and the total coating thickness is about 200-300μm.
The curing process of the coating also has a great influence on its performance. During the curing process, parameters such as temperature, time and humidity need to be strictly controlled. Generally speaking, high-temperature curing can fully cross-link the resin molecules in the coating and improve the hardness and wear resistance of the coating, but too high a temperature may cause the coating to discolor or generate stress. Therefore, the appropriate curing temperature and time should be selected according to the characteristics of the coating material. For example, for some epoxy resin coatings, it can be cured at 150-200℃ for 24 hours to obtain good performance. At the same time, the ambient humidity should be controlled to avoid curing in a high humidity environment to avoid affecting the quality of the coating.
In order to ensure that the wear resistance and rust prevention performance of the coating meet the requirements, the coating needs to be quality tested and evaluated. The wear resistance of the coating is tested using a wear tester, and its wear resistance is evaluated by measuring the amount of wear of the coating after a certain number of frictions. For rust prevention performance, a salt spray test can be carried out. The trolley sample coated with the coating is placed in a salt spray test chamber to simulate a humid, salty environment and observe the rust of the coating within a certain period of time. In addition, the comprehensive performance of the coating can be evaluated by adhesion testing, hardness testing and other methods, and problems with the coating can be discovered and improved in a timely manner.
By selecting suitable coating materials, optimizing surface pretreatment processes, adopting reasonable coating processes and curing processes, and conducting strict quality testing and evaluation, the wear resistance and rust prevention effects of the luggage trolley surface coating can be effectively achieved. This can increase the service life of the luggage trolley, reduce maintenance costs, and provide users with a better user experience.
