With the increasing requirements for environmental protection and the development of valve surface coating technology, plastic powder coating (spraying) technology has been widely used in valves, especially in tap water, food, medical and health industries. Plastic spraying on the surface is an important protection method to prevent secondary pollution of the medium. At the same time, many valve manufacturers also use plastic spraying on the surface of the valve as one of the means to improve the product quality.
The surface of the valve is sprayed with thermosetting organic polymer plastics such as epoxy resin, polyester resin, polyurethane resin, etc., using spraying, melt spraying, electrostatic powder spraying, etc., through heat melting, leveling, and Chemical and other technological processes, forming a continuous tough and firm plastic coating film on the surface of the valve. Compared with the traditional spray painting process, the valve surface spraying has the advantages of no environmental pollution, non-toxic to the human body, good coating adhesion and mechanical strength, and excellent appearance quality. It also has excellent cathodic disbondment resistance and chemical resistance. Stable performance. It is resistant to water, oil, acid, alkali, and salt; its cost is lower than the spray paint process. It has high work efficiency and is suitable for assembly line operation.
At present, there are no technical standards or general quality requirements for plastic spraying on the surface of valves in China or outside the country. This has caused valve manufacturers and valve users to feel blindly and confused during production and inspection. This article is based on several domestic valve factories. Many years of practice in the production of plastic spraying on the surface of the valve and through the tracking and comparison of the use of plastic sprayed valves in different geographical environments, different use media and different operating conditions, combined with tests, tests and tests on the quality of the sprayed valves Domestic and foreign related industry standards have determined the technical requirements, inspection items and inspection methods for the surface quality of plastic-sprayed valves.
