Question

Which of the following is a discontinuous polymer processing operation?

• A. Calendering
• B. Extrusion
• C. Film blowing
• D. Thermoforming

Hint:

Discontinuous operations typically involve a cycle where the material is processed and then stopped for the next batch, like thermoforming and injection molding.

Answer 1

The Correct Option is D

Discontinuous polymer processing operations involve periodic steps in the processing cycle. Among the listed options: - (A) Calendering is a continuous operation where the polymer is passed through rollers to form sheets. - (B) Extrusion is also continuous, where the polymer is forced through a mold to form a continuous shape. - (C) Film blowing is a continuous process for making plastic films by blowing air into the extruded plastic. - (D) Thermoforming, however, is a discontinuous process where a sheet of plastic is heated and formed into a specific shape, typically done in cycles. Thus, the correct answer is (D) Thermoforming.