Which plastic softens when heated and hardens when cooled, allowing it to be reshaped and recycled?

• A. Ferrous metal
• B. Thermoplastic
• C. Non-ferrous metal
• D. Design for recycling

Answer: (B)

The material described is a thermoplastic. Thermoplastics soften when heated and harden when cooled, which means they can be melted, reshaped, and then solidified again. This property makes them easy to recycle and reuse because the same material can be melted and remolded multiple times without permanent chemical changes. In contrast, metals—whether ferrous or non-ferrous—don’t rely on reversible softening to be reshaped in the same simple melt-and-solid cycle, and the option about “design for recycling” refers to a practice, not a material's behavior. Thermosetting plastics, once cured, do not melt and can’t be reshaped by heating, so they aren’t readily recycled in the same way.