Why is plastic used for bottles?
Show answer & explanation
Answer: Lightweight durable and moldable
Plastic is cheapest material ever — Wrong. Plastic is inexpensive, but it's chosen for bottles because it's lightweight (reducing shipping costs), durable (doesn't break like glass), doesn't rust (unlike metal), and easily moldable into any shape. Cost is one factor among several engineering advantages.
Lightweight durable and moldable ✓ — Correct! Plastic (especially PET and HDPE) is ideal for bottles because it's: lightweight (reducing shipping costs), durable and shatter-resistant (safer than glass), chemically inert (doesn't react with most liquids), waterproof, easily molded into any shape, and inexpensive to produce. These combined properties make plastic superior to glass or metal for many beverage applications.
Plastic keeps liquids fresher — Wrong. Plastic is permeable to some gases over time (carbonation can escape from soda, oxygen can enter). It's used because it's lightweight, durable, shatterproof, cheap, and easily moldable—not superior preservation. Glass actually preserves better but is heavier and breakable.
More Materials & Engineering questions
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