Rotational molding is one of the fastest growing plastic making processes in the world today. As the name suggests, rotational molding machines are responsible for making these plastics. The machine consists of a heated hollow mold which is usually filled with a charge or shot of the material. The machine is then slowly rotated. This causes the soft material inside to disperse and stick to the walls of the machine uniformly.
In order to ensure even thickness, the molding machine is kept rotating at all times while heated and cooled. This ensures that there is no sagging or deformation during the cooling process.