Rotational Manufacturing Process Explained

In the case of rotational molding, the vessel, or substrate, acts as a mold for the final part. After preparing the interior surface of the substrate, the substrate is mounted to a multi-axis machine.  Rotational grade polymer, which is in a granular form, is placed inside the metal mold and then heated while being rotated about two perpendicular axes simultaneously.  During the heating cycle, the polymer particles melt and adhere to the metal substrate forming a thin, uniform layer of thermoplastic.  After a predetermined time at a specific temperature, all plastic is distributed over the interior surface of the part; the mold is then cooled by a combination of forced air and/or water mist. The part is removed from the machine, producing a seamless, hollow freestanding thermoplastic part.   The resulting product can then be machined to tight tolerances, painted or otherwise finished, and assembled with other molded products to create a finished part.