How does rotomolding compare with injection molding and blow molding?

In comparison to injection and blow molding, rotational molding can easily produce both large, small precision and non-precision parts in a cost effective manner from a tiny medical bulb to a 16 foot kayak and up. Tooling for rotomolding is less expensive than injection molding because the process does not require any pressure to be held and rotomolding tooling is far less expensive than blow molding because there's no internal core to manufacture. Since there is no internal core, minor changes can be easily made to an existing mold, enabling product enhancements and line extensions to be considerably less expensive to develop and faster to bring to market.

In addition, Rotomolded parts are formed with heat and rotation, but not with pressure. Therefore, molds don't need to withstand the high pressure of injection molding.

Costs for product conversions from one material to another are reduced because rotomolding permits the replacement of heavier, often more costly materials with lighter, less expensive materials and does not require extreme or expensive tooling changes to switch materials. This advantage makes rotomolding as cost effective for one-of-a-kind prototypes as it does for large production runs.

Rotomolding also offers significant design advantages in comparison to injection molding and blow molding. With proper design and engineering, parts that are assembled from several injection or blow molded pieces can be molded as a single part, eliminating expensive fabrication costs and streamlining the manufacturing process.

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

Inserts, threads, handles, undercuts, flat surfaces that eliminate draft angles or fine surface detail are all designed in from the beginning. Designers also have the option of multi-wall molding that can be either hollow or foam filled. Sales and marketing teams always appreciates the range of colors, permanent, molded-in logos and graphics available.

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