Rotomoulding

Rotational moulding is a versatile niche  method  of manufacturing plastic products which has seen steady growth during recent years.

A heated mold causes the material within to melt and form a puddle at the bottom of the mold cavity. The mold is then slowly rotated (usually around two perpendicular axes) causing the melted material to flow and stick to the walls of the mold. In order to maintain even thickness throughout the part, the mold continues to rotate during the cooling phase.

Rotational molding offers design advantages over other molding processes. With proper design, parts that are assembled from several pieces can be molded as one part, eliminating expensive fabrication costs.

The process also has a number of inherent design strengths, such as consistent wall thickness and strong outside corners that are virtually stress free. If additional strength is required, reinforcing ribs can be designed into the part.

Rotational molding delivers the product the designer envisions. Designers can select the best material for their application, additives to help make the part weather resistant, flame retardant, or static free can be specified.

Inserts, threads, handles, minor undercuts, flat surfaces that eliminate draft angles or fine surface detail can all be part of the design. Designers also have the option of multi-wall molding that can be either hollow or foam filled.

For more information please turn to the following Wikipedia entry:
en.wikipedia.org/wiki/Rotational_molding
or visit www.rotomolding.org.