Question

A designer has to make a permanently pleated skirt. What type of fabric will he select?

• A. \( \text{Silk} \)
• B. \( \text{Polyester} \)
• C. \( \text{Silk-Cotton blend} \)
• D. \( \text{Cotton-Wool blend} \)

Hint:

If a garment is labeled "Permanent Press" or "Permanently Pleated," it almost always contains a high percentage of synthetic fibers like polyester.

Answer 1

The Correct Option is B

Concept: Thermoplasticity is a property of synthetic fibers that allows them to be softened by heat and then "set" into a new shape (like pleats or creases) that becomes permanent once cooled.

Step 1: Identify the fiber with heat-setting properties.
Polyester is a synthetic, thermoplastic fiber. When subjected to high-temperature steam or heat during the pleating process, the molecular structure of the polyester shifts. Once it cools, the pleats are "locked" in place. These pleats will survive washing and wearing without disappearing.

Step 2: Evaluate natural fibers.
Natural fibers like silk, cotton, and wool are not thermoplastic. While they can be ironed into pleats, these pleats are temporary and will wash out or flatten over time unless treated with heavy chemical resins.