There are no high pressures or forces involved in the rotational moulding process, which simplifies the construction of the moulds and enables large or complex parts to be produced with low-cost moulds and relatively short lead times.

The fact that there are no pressures also means that the moulded parts are relatively stress free, compared to other high pressure processes. This advantage is especially important when considering large, load-bearing parts in applications which must provide corrosion or stress-crack resistance.

Relative to their size rotationally moulded parts can therefore be made with thinner walls than comparable parts made by other processes. Rotational moulding also tends to produce thicker wall sections as outside corners, which gives the process a distinct advantage over blow moulding and thermo-forming which tend to produce the opposite effect.

The surface finish, texture and colour of rotationally moulded parts can be tailored to suit the products requirements. Metal inserts or integrally moulded in threads are also possible with this process.

Re-entrant parts with closely spaced double walls are common. Many parts are moulded with little or no draft angle and with some materials it is even possible to produce parts with undercuts.
When designing a new part or converting an existing product review the advantages rotational moulding has to offer – before deciding on the manufacturing process. These advantages include:

• Economical tooling costs
• One-piece construction
• Virtually stress free
• Hollow parts with no seams
• Weight reduction possibilities
• Relatively uniform wall thickness
• No thinning in the extremities
• Variety of surface textures, finishes and colours
• The ability to produce parts with different wall thickness from the same mould
• Design flexibility, from small and intricate to large and complex
• Metal inserts as integral parts
• Economical for prototypes, short production runs as well as volume production
• Minor undercuts are possible, with no draft angles required
• Short lead time
• Resistance to stress cracking and corrosion
• Excellent load-bearing properties