Question

Choose the option(s) that correctly match(es) the Zones with their typical Functions in an industrial extruder.

• A. P-2; Q-5; R-1
• B. P-2; Q-3; R-4
• C. P-5; Q-1; R-2
• D. P-2; Q-1; R-3

Hint:

Extruder zones: Feed zone → conveys granules; Compression zone → melts the polymer; Metering zone → ensures constant flow rate.

Answer 1

The Correct Option is A, B

Step 1: Feed Zone (P).
- In this zone, solid polymer granules are simply conveyed forward. - No melting occurs here. - Therefore, the correct function is No heating takes place (2). \(\Rightarrow P-2\).

Step 2: Compression Zone (Q).
- Here, polymer starts to melt. - Melting occurs due to external heating elements and shear. - Given choices: “Polymer melts due to heat transferred from heating element” is most appropriate. \(\Rightarrow Q-3\).

Step 3: Metering Zone (R).
- The role of this zone is to homogenize the melt and deliver it at a uniform flow rate. - Hence, function is: “The helical flight of the screw imparts constant flow of the melt.” \(\Rightarrow R-4\).

Step 4: Combine.
Thus, the correct mapping is: \[ P-2,\; Q-3,\; R-4 \] Final Answer: \[ \boxed{\text{(B) P-2; Q-3; R-4}} \]