This is a process used in the mass production, at relatively low cost, of mainly plastic products that are, as a rule, hollow. Rotational Moulding, or roto moulding, is used not only in creating items for the home and garden, but also in the manufacture of specialist engineering and industrial products. A metal moulding is made as a shell within which the plastic products are formed. There is an immense range of diverse products able to be made by rotational moulding. A plastic duck, bucket, pre-formed garden pond or even a kayak are all examples of items produced by this method. Products in commercial use include water or chemical containers. Small plastic components of more complex products can also be manufactured by rotational moulding.
How Rotational Moulding Works
A polymer powder is used in the making of the chosen product. The powder is poured into the slowly rotating metal shell/mould and as the mould warms the powder gradually turns to liquid which sticks to the sides of the mould. The mould rotates constantly on different axes so that the product has a uniform thickness throughout which will ensure the integrity of the item. The mould is then cooled slowly whilst still rotating and once cold the product shrinks slightly from the metal mould and can then be opened to reveal the finished item.
There is no waste in manufacturing items by rotational moulding. The amount of powder used determines the weight of the completed piece. Many different colours and finishes of plastic can also be used, so that only one process is required to manufacture the required product.
Summary
This isn't a new process in fact it has steadily evolved since the 1950s. What has changed is the ever increasing popularity in the manufacture of plastic goods which crossover from consumer bought items to products used for the harvesting of rainwater to containers for chemical storage. Rotational Moulding allows a wide variety of assorted products to be manufactured at a relatively low cost. The high demand for products made by roto moulding appears to be increasing year after year.
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