Question

seventy years ago, almost all electrical appliances were completly made out of metal. now , most appliances are plastic on the outside. why do you think this is?

Answer 1

Plastic material comparatively to metal is:
• Inexpensive;
• Light;
• Corrosion resistant;
• Durable;
• Chemically inert;
• Of low thermal expansion;
• Has good thermal and electrical insulating property;
• Recyclable;
• Versatile;
• Odourless;
• Does not decompose;
• Not signal blocking (as a metal).