Question

The permeability of core sand is generally kept higher as compared to that of moulding sand in core making operation.

(a) True

(b) False

The question was posed to me during an internship interview.

Origin of the question is Core Making Machines topic in chapter Foundry Mechanizations of Casting-Forming-Welding I

Answer 1

Correct option is (a) True

Easiest explanation: In the core making process, the permeability of the core sand should be sufficiently high as compared to that of the moulding sand. So the core gases easily escape through the area of the core recesses which is generated by the core prints. And the core sand should also be of highly refractoriness in nature to sustain high temperature of molten metal.