Rotational molding, also known as rotocasting or rotomolding, is used to create hollow parts that can be of large volumes.
Rotomolding is an alternative to represent a blow molded part. With a short lead time and low-cost, rotomolded parts are a cost-saving solution that allows flexibility in size, geometry and material. It is ideal for creating large parts and capturing undercuts that are difficult to replicate in traditional silicone mold making.
As in typical mold making, the process begins with a master part that is used to create a mold with a void in the shape of the master. The mold is mounted on an automated rotational casting machine and filled with a particular weight of urethane then closed. The machine continually spins the mold in two perpendicular axes while the urethane disperses and sticks to the inner wall of the mold. After time, the urethane cures a hollow part that can be removed, trimmed and finished.