Below is a list of Rotational Molding manufacturers from Ontario, California. Rotational moulding, also sometimes known as rotomoulding, is a thermoplastic fabrication process by which plastic goods are formed and manufactured using a revolving mold and high heat. Rotomolded products are hollow and have single piece construction, with uniform wall thickness and high tensile strength. They are often inexpensive to manufacture and require little further fabrication work.