About > Processes
Rotational moulding (often referred to as Rotamoulding or Rotomoulding) is a process used for producing hollow plastic products. It differs from other processing methods in that the heating, melting, shaping, and cooling stages all occur after the polymer is placed in the mould, therefore no external pressure is applied during forming.
The process involves charging the hollow tool with a carefully predetermined quantity of resin powder and placing this into an oven which is then rotated slowly about two axes.
The resin heats up to the required temperature, fuses and adheres to the inner wall of the moulding tool, thereby taking its shape. Following a brief curing period, cold air (and sometimes water) is aimed at the mould which releases the plastic from the metal tool prior to demould.
Production cycle times vary depending on product size and wall thickness but can be as little as 10 minutes for a small, lightweight moulding.
Mouldings can be produced in a wide variety of colours with 'moulded in' inserts to accommodate fixings.
Whilst a range of plastic materials can be rotationally moulded, the most commonly used is polyethylene. Other plastics include;
- Polypropylene
- Nylon
- Polycarbonate
- Crosslink
- Fire retardant MDPE (UL94 U2 Standard)
Key benefits
Lower cost tooling
Shorter lead times
Smaller runs possible at lower cost
Greater flexibility in batch quantity size
A more cost-effective alternative to metal or glass fibre laminated products.
