Question

The resin mainly used in shell moulding is

• A. Phenol formaldehyde
• B. Ethanol formaldehyde
• C. Phenol
• D. Ethanol

Hint:

Shell moulding always uses a {thermosetting resin}, most commonly phenol formaldehyde.

Answer 1

The Correct Option is A

Step 1: Understanding shell moulding process.
Shell moulding is an advanced sand casting process in which a thin shell is formed around a heated metal pattern using sand mixed with a thermosetting resin. The resin binds the sand grains together to form a strong shell.
Step 2: Role of resin in shell moulding.
The resin used must have good bonding strength, thermal stability, and should harden quickly when heated. Phenol formaldehyde resin fulfills all these requirements and is therefore widely used.
Step 3: Analysis of other options.
(B) Ethanol formaldehyde: Not used as a binding resin in shell moulding.
(C) Phenol: Phenol alone is not a resin and cannot act as a binder.
(D) Ethanol: Ethanol is a solvent, not a resin.
Step 4: Conclusion.
Hence, phenol formaldehyde resin is mainly used in shell moulding.