Q. Sometimes over-gassing can cause the sticking of pattern to the mould in Co2 moulding.

 in co2 moulding, over-gassing and under-gassing can affects the properties of cured sand adversely. when the continuous passing of co2 is done for long time, this may results into sticking of pattern with the mould which cannot be removed easily, so proper care should be taken while passing of co2 gas.