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:

In extrusion, the feed zone does not involve significant heating, while the compression zone involves shear heating, and the metering zone controls the melt flow rate.

Answer 1

The Correct Option is A, B

In an industrial extruder, the polymer is processed through different zones, each with a specific function related to the flow and heating of the material. Let's match each zone with its corresponding function.
- Feed zone (P): In this zone, the material is introduced into the extruder, and there is no significant heating. The main role of this zone is to prepare the material for the compression zone. Hence, P-2 is correct, as no heating occurs in the feed zone.
- Compression zone (Q): This zone is where the polymer undergoes compression, and shear forces begin to act on it. These forces, combined with the heat from the surrounding areas, help to melt the polymer. Hence, Q-5 is correct, as polymer melts due to shear forces imparted by the screw.
- Metering zone (R): In this zone, the material is uniformly melted and the flow rate is controlled. The helical flight of the screw imparts a constant flow of the melt, ensuring smooth processing. Therefore, R-4 is correct, as the helical flight of the screw imparts constant flow to the melt. Thus, the correct options are (A) P-2; Q-5; R-1 and (B) P-2; Q-3; R-4.