Large Flat Panels Need Shape and Support
ARM warns that broad flat areas on rotomolded parts can bow. Case lids and fold-out work surfaces benefit from early geometry review.
The ARM guide explains that large flat surfaces in hollow molded parts can bow as the material cools. It discusses options including surface features, slight outward contours, reinforcing ribs and cooling fixtures. These are design strategies rather than guarantees for a specific case size.
Design the working surface, not just the outline
A field table or broad case lid may need to remain usable and visually even under load. An apparently simple flat panel can therefore drive mold design, support geometry and inspection criteria. Early prototypes can reveal whether the chosen thickness and shape work together.
- Identify surfaces that must mate, seal or support equipment.
- Discuss ribs or contours before freezing the tool design.
- Check the panel after cooling and under its intended working load.
The cover is a CASEROVA product illustration showing a fold-out work surface; it is not an ARM test specimen.
Source: Association of Rotational Molders — Flatness Considerations
