Question

_________ is used for the pattern in the full mould process.

(a) Polythene

(b) Polysilicate foam

(c) Polyurethane foam

(d) Polystyrene foam

This question was addressed to me in an interview for internship.

My doubt is from Patterns and its Functions in division Casting Processes of Foundry and Forging

Answer 1

The correct choice is (d) Polystyrene foam

For explanation: In the full moulding process, the foam evaporates soon after the metal is poured. Hence Polystyrene foam is used as it is light and can easily be formed into any shape required. It can be used as light duty work for small castings.