The cold box casting refers to a resin sand forming process that is instantaneously formed at room temperature by means of gas or aerosol catalysis/hardening.
The most common method of cold box casting is the triethylamine method, which uses phenolic-urethane resin and is hardened by blowing triethylamine gas.
The characteristics of this process are: the core making sand can be used for a long time, the drawing time is short, the production efficiency is high, and the energy consumption is low. It is suitable for the mass production of cores and is widely used in the automotive diesel engine industry.
Diesel engine castings, such as cylinder blocks, cylinder heads, intake and exhaust pipes, etc., have complex core shapes and small partial cross-sectional areas, which are prone to false shots, fractures, etc., or veins appear in the castings due to the large expansion by using quartz sand. The probability of defects such as sticking sand and pores is relatively high. Using ceramic sand or a mixture of ceramic sand and quartz sand in a proper proportion, the amount of resin added is reduced by 20-30%, and the above defects have been significantly improved. At the same time, the collapsibility of the sand core is very good, which reduces the cleaning workload. Therefore, in recent years, almost all large-scale diesel engine casting foundries have adopted the ceramic sand cold core box process.
Ceramic sand (Ceramsite sand) is a spherical modeling sand made of selected high-quality alumina bauxite through processes including electrofusing, ball making, and sieving. It has high refractoriness (>1820℃), small-angle coefficient (<1.06, approximately spherical), low acid consumption value (neutral material), a small amount of binder (reduce the amount of binder by 30%), and strength High, non-breaking, non-toxic and other characteristics, suitable for sand casting (molding sand, core sand), coated sand, V method casting, lost foam casting (filled sand), paint (ceramic sand powder), 3D printing and other casting processes, It is widely used in automobile engines and auto parts, large steel castings, iron castings and other fields, and is called green environmentally friendly foundry sand.