Mainly using ordinary alkaline silica sol

With the increasing requirements for the quality and accuracy of precision castings, the manufacturing process using water glass or ethyl silicate as binders has seriously hindered the development of China's casting industry due to the drawbacks of "poor precision casting" and environmental pollution. Therefore, in order to improve the quality of castings and narrow the gap with the international precision casting industry, it is imperative to replace water glass and ethyl silicate with silica sol. At the same time, the use of silica sol water glass composite shell making process can improve the smoothness of castings without the need to increase significant financial and material resources or change the main process.