What do liquid storage tanks have in common with kayaks, bins, toys, outdoor furniture and an incredible number of other products? Many of them are created through the process of rotational moulding. When buying a storage tanks such as for water, fuel or waste, those made in this fashion are stronger, versatile and yet also more economical.
Why is this the case? Why does rotational moulding make better water tanks than other methods?
What is Rotational moulding?
Products created through rotational moulding are made from a polymer powder or resin, most often Polyethylene. Additives can be added to alter features such as UV protection and different colours.
The polymer is placed in a mould, preheated to between 260 and 370 degrees celsius, which melts the material. The mould is then rotated on two axis, allowing the polymer to coat the inside of the mould. This is done at relative slows speeds – 20 rotations a minute – to ensure an even and eloquent distribution of the polymer.
Once the process is complete, the mould is cooled. The object shrinks slightly and is easily removed from the mould.
Why is rotational moulding superior?
It would be a mistake to assume that all storage tanks will perform the same. Tanks made through rotational moulding techniques last far longer, yet cost much less. There are several reasons for this.
The first is that rotational moulding does not use pressure to create the tank. Instead the polymer coats all the surfaces equally, resulting in an even finish, This makes the final product considerably more reliable, not the least because objects made this way are virtually stress free.
The process is also much easier to control. Even though rotational moulding is by no means simple, it has far fewer chances for complications than other techniques.
Moulds can be made from cast aluminium or sheet metal. As the wide variety of products made from rotational moulding prove, there are few limits to what kind of object can be fashioned. From a small water buoy to a tank that can hold 50,000 litres of water, rotational moulding offers a lot of choice.
Are all rotational mould processes the same?
Rotational moulding is considerably simpler when compared to other methods. But it still requires expert skills and knowledge. The right mixes of polymer, good temperature control, proper mould manufacturing and timing all are factors that can make or break a good tank.
Calcamite specialises in rotational moulding, using in-house ovens and moulds to create our products. As leaders in the field, we have crafted everything from small tanks for households to interconnected underground systems used at stadiums and industrial parks.