Frequently Asked Questions
Rotomolding is a 4 step process which involves, mold loading, heating, cooling and mold unloading. The process occurs at atmospheric pressure using gravitational forces.
A mold charged with plastic polymer powder is loaded onto an arm of the machine which rotates in a biaxial rotation on two perpendicular axis. The biaxial rotation creates a centrifugal force which pushes the powder to inside surface of the mold cavity. As the mold reaches peak temperature the plastic powder begins to melt and uniformly coat the inside surface of the mold cavity creating a uniform layer of plastic. Once the mold has completed the heat cycle, the cooling cycle begins where the plastic cures and solidifies. Once the cooling cycle is complete, the molded part is unloaded from the mold cavity.
- Tooling cost is inexpensive compared to Injection molding, Blow molding and Thermoforming. The process is performed in a low pressure environment, which allows for more economical molds to be produced.
- Mold/ Tooling lead times are short compared to other plastic manufacturing processes. On average a medium sized aluminum CNC machined tool be produced in 5-6 weeks and a cast aluminum mold in 8 weeks.
- Low to high volume orders are feasible ranging from 1 to 20 000 units per year.
- Manufacturing capabilities allows for small to very large hollow plastic shapes with complex geometry to be molded. Parts can range in size from a 4 inch cube to a 25 000 gallon holding tank.
- Rotomolded parts have very good resin distribution which facilitates uniform wall thickness in most areas. Outside corners also tend to form thicker which provides a significant strength advantage over blow molded and thermoformed parts.
- Various metal inserts, colored graphics, raised/recessed logos and textures can be molded into the part. Thereby eliminating secondary processes.
- Part colors can be switched easily and require a quick one step clean processing. This is more efficient than other processes which require a purging process to be carried out.
- Double walled parts can be molded and filled with structural foam as a post process. Depending on the density of the foam this can provide buoyancy, rigidity or insulation properties.
Rotomolding is another term for rotational molding; it is an abbreviated form. For more information about the rotomolding process, click on rotational molding under the services tab.
Many terms are used to reference the rotational molding process. Rotomolded is a verb describing the rotational molding process.