PA 11 Nylon 11 Polyamide 11 powder for Butterfly valve plate

Material composite technology often takes advantage of the strengths and weaknesses of various materials in terms of performance, and may have more cost advantages. Before the introduction of nylon coating technology for disc valve plates to China, stainless steel was the most commonly used material for inner valve plates, which had high material costs and processing difficulties. Nylon valve door technology was generally coated with nylon powder after the formation of relatively inexpensive cast iron plates, with higher edge wear resistance than metal and a certain degree of plastic resilience, which can ensure sealing and better service life than stainless steel. Its anti-corrosion effect on weak acid and alkali was also better than stainless steel, and its overall cost was significantly reduced compared to pure stainless steel. Therefore, in the past decade, this technology has developed rapidly after being introduced to China, especially in seawater valves, which have advantages. Obvious.

This technology is usually achieved by thermal spraying for valve plates with a diameter of over 400mm. Depending on the size of the valve plate, the valve plate is heated to around 250 ℃ to remove air from the pores of the cast iron. Then, an electrostatic spray gun is used to spray and flatten the film, which is then cooled in water. For valve plates with a diameter of less than 400mm, they are light in weight and easy to move. They are usually processed by fluidized bed immersion coating. The valve plate is heated to a range of about 240-300 and directly immersed in fluidized powder for 3-8 seconds. After being removed from the flow, it is water-cooled and formed.

Due to the thick valve plate and large heat capacity, it is not easy to cool down. When applying nylon, the temperature should not be too high, otherwise it is prone to yellowing and becoming brittle. If the temperature is too low, it may not level well. Therefore, based on the specific size of the valve plate and temperature conditions, it is necessary to explore the optimal heating temperature conditions.