Rotational Molding
Rotational molding is also a thermoplastic molding method, and the vast majority of products are hollow. Unlike thermoforming, the raw material used in rotomolding is a powder, and the color of the powder is usually changed when a product requires a color. It is worth mentioning that the raw material powder is loaded directly into the mold. Next, the mold is closed, and the mold is heated while rotating at high speed in the machine room so that the raw materials are covered on the surface of the mold cavity layer by layer under the action of gravity and heat, and then finally cooled, demolded and shaped to obtain a product made by the rotomolding process.
Next are two videos, some machine photos, some mold photos, and some product photos. Kindly check for reference:)
Rotational machines
The following two videos have documented the process in more detail.