Some of the advantages of rotational moulding over other plastic moulding processes are:

• Economic tooling costs in either fabricated steel, cast aluminium or
  CNC machined aluminium.
• Mouldings are a one piece construction, virtually stress free and can
  be totally enclosed or with openings.
• Due to the low stress in the moulding it is stronger and therefore can
  be made lighter.
• Wall thickness of the product is even and can be varied via shot weight.
• Rotational mouldings can be produced with a variety of surface finishes and
  practically any colour.
• Wide variety of available materials to suit many applications where
  strength, rigidity, chemical resistance, UV resistance, temperature
  resistance and impact resistance are important.
• The ability to produce multi walled mouldings.
• Design flexibility, from small and intricate to large and complex.
• Structural and load bearing components can be moulded and given
  immense strength through foam filling.
• Economical for low, medium and high volume production runs.
• Metal inserts can be moulded in as integral parts.
• Short lead times for tooling and production.
• Excellent resistance to environmental stress cracking and corrosion.
• Most materials can be easily recycled.
• Recycled materials can be used to make new products without
  significant reduction in performance.