About Rotational Molding
Roto-Moulding or Rotational Molding is a modern technology in plastic process, which is accepted world widely. It has many advantages for user and manufacturer; roto-molding has useful applications in conventional and inventive product lines.
With roto-molding process it is possible to create one piece, seamless and stress free plastic products with superior surface finish of any size gigantic or small, in every possible shape and even exotic nature. Roto-moulding offers a definite production and cost advantage over other processes.
Rotational molding, or rotomoulding, is a highly versatile manufacturing option that allows for unlimited design possibilities with the additional benefit of low production costs. Roto molding is a cost-effective way to produce large parts.
Plastic resins are loaded into a mold that is heated as it is rotated slowly on both the vertical and the horizontal axis. This simultaneous heating and rotation distributes the material on the inner surfaces of the mold and fuses it.
There are four stages of Rotomolding process:
The pre-measured plastic resin is loaded into the mold in the first stage. In rotomolding resins most common used materials are Polyethylene and plastisol. At the same time several molds may be loaded on a given machine. The charged molds are then closed and moved into the oven, where they slowly rotate on two axes.
As the mold penetrate by the heat, the melting resin adheres to the mold’s inner surface until it is thoroughly fused, evenly coating the entire surface.
In the cooling stage, the mold continues to be rotate to maintain even walls as air, water spray, or a combination of the two gradually cools the mold. The mold is then opened, the finished part removed, and the mold is ready for its next cycle.
Benefits of Rotomolding
The ease of the roto-molding concept offers various unbelievable advantages compared to other processes.
- Unlike other plastic molding processes, roto-molding results in seamless parts with uniform wall thickness and more material in corners, to absorb shocks and stresses where they occur most.
- The finished part is stronger as in thermoforming or pressure forming, the material is not stressed. Plus the molds don’t need to be designed to withstand the high pressures of injection molding.
- Tooling costs are lower in that regard and minor changes can be easily made to existing molds as the mold has no internal core to manufacture, Roto-molding also offers superb flexibility and precision. Complex contours, metal inserts, flanges, and molded-in threads can be designed into the walls – requiring fewer steps to get to your finished product. And the color can never crack or chip off, because it’s molded-in, all the way through. Of course, this means no painting is required.
- Roto-molded plastic products are easy to handle and less expensive to ship due to lighter weight than metal or fiberglass.
- Roto-molded plastic products are tough, long lasting, and corrosion-proof.
Rotomoulding applications cover extensive markets which are indicative of the numerous industrial opportunities for rotomoulded products.
- General Industry
- Water or Liquid Storage
- Wasted Water Treatment
- Custom Molding
- Commercial & Safety
- Marine Applications
- Materials Handling
- Three Arm Fixed Turret Fixed Oven
- High Speed Mixer
- Scrap Grinder
- Vibro Screen
- Shuttle Machine
- Rock N Roll