Talking about the research and optimization status of rust removal and sandblasting process parameters
- 2020-09-23-

Talking about the research and optimization status of rust removal and sandblasting process parameters

The sandblasting and rust removal process is the most important surface treatment method before spraying on ships, and the rust removal sandblasting machine is the construction equipment of this process. It has important applications in shipbuilding and ship repairing processes. It is the surface treatment process of domestic shipbuilding enterprises. One of the most widely used devices in China.Rust removal sandblasting machineThe working principle is: the high-speed airflow in the air inlet is used as the jet stream, and the low-speed airflow containing a large amount of abrasives is used as the jet stream. The two air streams are mixed through the sandblasting nozzle and ejected from the nozzle at high speed. In the gun body, the jet airflow exchanges momentum and energy with abrasive particles and low-speed airflow (the jet airflow). Under the shearing action of the jet airflow and the abrasive material, they are entrained into the sandblasting nozzle, and continue to exchange momentum and energy with the jet airflow, forming a mixed fluid of airflow and abrasive material. Finally, the abrasive particles are accelerated and ejected, forming a circular free jet at the outlet of the blast nozzle of the rust removing sandblasting machine.

One of the main evaluation criteria of the rust removal sandblasting machine is the roughness obtained after the sandblasting is completed. A good roughness can improve the adhesion of the coating, but also ensure the thickness of the coating, save the amount of paint, and reduce the construction cost. Therefore, how to obtain the ideal roughness is the primary goal of optimizing the sandblasting process of the rust removing sandblasting machine. In the quality evaluation of ship coating, for the evaluation of roughness, according to GB/T 13288 "Assessment of surface roughness of steel before painting", visual comparison with standard samples, or direct measurement of surface roughness with instruments, The Sa2.5 grade requires the roughness Rz to be 70~85μm, 75~80μm is the best; to obtain the ideal roughness, it is necessary to optimize the combination of various parameters in the rust removal sandblasting machine.

At present, the domestic research on the blasting process of the rust removal sandblasting machine is still mainly in the state of experience summary. Through the accumulation of years of work experience of the older generation of painters, plus the long-term construction experience of major domestic shipping companies, the Mainly operating habits, after being integrated as the guiding norm for the production of current shipping companies, it lacks theoretical basis. The parameter setting of various factors is mainly subjective, and the inheritance of experience is emphasized. As a result, domestic shipbuilding and repairing companies still follow the traditional operating methods and procedures for decades without analyzing and summarizing them at the theoretical level.

The research on the blasting process of rust-removing sandblasting machine is abroad, especially in European and American countries. The research direction is mainly focused on the cold working direction of sandblasting/peening strengthening, and this research direction has reached a very high level. At present, MIC, A few companies such as Boeing of the United States and Rosler Co. of Germany have monopolized advanced sandblasting/shot forming technologies. However, the research on the surface treatment direction of sandblasting and rust removal has stagnated. Compared with the 1950s, the research status has no substantial breakthrough and development.

In summary, at this stage, there is no plan for optimizing various construction parameters of the rust removal and sandblasting machine based on the actual situation of the production site and after actual verification.