These are the two different moulding processes used to produce the majority of plastic food contact approved storage containers.
Injection moulding is when preheated polymer is injected under pressure into moulds, which then open to release the formed article. This process is commonly used for trays and crates. It is quick and efficient, resulting in lower costs per unit, however it is not as robust as roto-moulded items – particularly when comparing larger items such as trucks and tanks.
In contrast, roto moulding involves placing polymer granules inside a heated mould tool. This mould is rotated, and as the granules melt they are evenly distributed on the inside surface of the mould, becoming smooth and solid when cooled. The production process is slow – hence unit costs are higher – but the final product is extremely durable and makes for a much longer life. For the rigours of production, storage and waste disposal, roto-moulded plastic items soon show excellent returns on initial outlay due to their inherent strength.
