Question

Why the air already present inside the corebox is necessary to be evacuated before pressurised air is blown into it?

(a) The air has comparatively low pressure hence, distortion occurs

(b) Hot tears will occur on the surface

(c) It will cause poor sand distribution and poor compaction

(d) Nothing will happen as the pressure of incoming air neutralises inside air pressure

I got this question in semester exam.

I want to ask this question from Finishing of Cores topic in section Core and Core Making of Casting-Forming-Welding I

Answer 1

Correct choice is (c) It will cause poor sand distribution and poor compaction

For explanation I would say: The air inside the corebox does not get enough time to escape hence sand distribution and compaction is poor.