Rotational molding is a process that begins with a powdered (pulverized) form of thermoplastic (such as Polyethylene) being placed into a mold which is mounted on a machine that rotates the mold on both the vertical and the horizontal axis. The rotating mold is heated to melt the resin which is continuously and evenly distributed over the mold surfaces. After the appropriate cycle time, the mold is cooled and yields a rigid, cured part. At this point, any trimming or finishing takes place.

Rotational molding offers many design advantages over other molding processes such as injection molding. Rotational molding allows parts to be molded as a single piece whereas other modes of production might require several parts to be molded seperately and then later combined to form a complete assembly. This benefit can greatly reduce machine and tooling costs, as well as eliminate labor related to fabrication and finishing.

Rotational molding also allows inserts, threads, handles, minor undercuts and even molded in color graphics to be incorporated in a single step. There is also a great variety of materials available that address specific needs such as flame retardancy, UV stabalization and static elimination.

Probably one of the most pronounced benefits of rotational molding is the abilty to produce extremely large parts. Our machines are capable of molding a finished part (such as a cylindrical tank) with a diameter of 6 feet and length of 8 feet. Parts of a much smaller scale can also be good candidates for rotational molding and several can be run simultaneously if there are multiple molds.