This question is based on the assumption that most materials expand when heated. Why does shrink wrap do the opposite?
In: 52
The polymers are fabricated into an elongated state and when heat is applied, they return to their preferred coiled up state, which causes them to shrink.
Imagine a bunch of strips of paper, all in parallel to each other, and all of the same length, let’s say 12 inches. If you crumple them all up, the result would be a much shorter length. That’s what the heat is doing to the material the plastic is made of.
Latest Answers