At Rotoplas we believe in innovation. Using state of the art rotational moulding technology we specialise in the design, manufacture and supply of a range of products. Our product development team has extensive industry experience and is constantly working to turn great concepts into reality.
All of our rainwater tanks and trolleys begin their life through the rotational moulding process.
We also manufacture a range of contract items for industries and applications such as construction, automotive, marine, electrical, agriculture and waste management.
What is Rotational Moulding?
Rotational moulding is a thermoplastic manufacturing process used for producing hollow plastic products. This is achieved through the use of powdered resin in a hollow mould, which is heated until the resin melts and forms a solid wall inside the mould.
Click here to read a quick Introduction to Rotational Moulding, written by Roy Crawford, a Professor of Mechanical Engnineering who conducted significant research into rotational moulding.
The Rotational Moulding Process
We use tools like Computer Aided Drawing and Finite Element Analysis testing to perfect our product concepts. We engage our highly skilled mould makers to produce a quality mould ready for production.
Powdered polyethylene resin is placed inside the mould. The amount, or shot weight, varies depending on the product, and the thickness required. The mould is placed in a heated environment to allow the resin to melt, and rotated to ensure even distribution of the material within. The mould enters the cooling cycle. Whilst still rotating, fans blow cool air onto the hot mould. The resin inside solidifies as the mould is cooled. Once cooled, the mould is opened and the part is released. The product is now ready for post mould work if required.
Benefits of Rotational Moulding
Rotational moulding has many benefits over other moulding processes including:
- Ability to mould one-piece hollow parts
- Comparatively cheap tooling cost
- Faster tooling manufacture
- Ability to produce short runs
- Ability to vary wall thickness at any time
- Ability to mould in metal threads
- Large colour range and ability to change colour each cycle
- Range of materials including Diesel grade, Anti-static and Flame retardant