The How It’s Made of rotomolding is very simple. Imagine a
Kinder Surprise with the chocolaty goodness inside all gone! That leaves
an empty, hollow, egg shaped plastic shell. As sad as that may be, you can
guess what will happen if we place a few chocolate chips inside, close it, and
put it in our pants pocket. The chips will melt and coat the inside of the
shell. If you cool the coated shell, solidifying the chocolate inside, and open it,
you will once again be surprised by the hollow egg shaped chocolate before
you. Exchange the chocolate for plastic, your pants pocket for a hot oven,
and the plastic shell for a steel mold. Add a little biaxial motion and we’re
home.