摘要 |
In a method for the manufacture of sand cores for metal casting processes by the urethane Cold Box Process gaseous trimethylamine is conducted through parts of a metering device (3) and then, in a concentration of from 0.01 to 0.12 wt.% based on the quantity of sand used per core into a core shooting machine (4) where it is brought into contact with the sand, and prior to the introduction of the gaseous trimethylamine into the core shooting machine (4) a purging gas is introduced, the relationship between the trimethylamine and the purging gas being such that for a quantity T of trimethylamine the quantity L of purging gas used is in the ratio of T:L of from 1:1000 to 1:10000. |