Why is packing tape nearly impossible to tear when intact, but easily shreds if you cut the slightest nick into it?

Question

Why is packing tape nearly impossible to tear when intact, but easily shreds if you cut the slightest nick into it?

In: 6079

Answer 1

It’s because when you nick it, there’s a breaking point it can follow. That breaking point is where it splits, and since there isn’t any guide on an uncut piece of tape, it’s trying to evenly distribute that breaking point across the whole material because there’s nothing to show it where to break.