Question

Which of the following moulds or moulding is also known as sodium silicate process.

(a) Shell moulding

(b) Permanent moulding

(c) Slush moulding

(d) Co2 moulding

This question was addressed to me in an online quiz.

I need to ask this question from CO2 Process topic in chapter Special Casting Techniques of Casting-Forming-Welding I

Answer 1

Right choice is (d) Co2 moulding

For explanation I would say: Carbon dioxide moulding is also known as sodium silicate process is one of the widely used processes for preparing of moulds and cores. Basically, sodium silicate is used as a binder, but it binds the sand particles only in the presence of Co2. Co2 is passed through the mould to tighten it, as shown in below figure.