Understanding Composite Structures in Rotational Moulding
The race to find a new alternative to produce renewable energy has begun a long time ago, but limitations in the way we manufacture products affects the development of new prototypes. Rotational moulding is the forgotten manufacturing technology that has the potential to produce large structures, like those needed in renewable energy generation. The principle of rotational moulding is simple; the process consists of introducing an amount of plastic powder into a hollow mould, the mould is then rotated and heated at relatively low speeds. After a specific processing time, the plastic enclosed in the mould adheres to the mould surface to form a part. In summary, this process has the potential to produce a hollow part that can be made in one piece with no weld lines or joints. The fact that the moulds are relatively inexpensive, and there is no material waste in the process, makes rotational moulding an attractive technology for use in parts manufacturing for the renewable energy sector.
Based on this approach, a Renewable Engine Research Group, composed of three PhD students, was formed in 2017 at Queen’s University Belfast. This research group focused on exploiting the advantages of rotational moulding to produce an impact on the current renewable energy manufacturing technology. One of these PhD projects, led by David Castellanos (in collaboration with Platinum Tanks Ltd), is focused on the mechanisms of part formation to expand the number of material combinations that could be used in the process. Consequently, an interaction test called Fibre-Particle Interactions Test (FPIT) was developed to study the way two different materials can stick together to form a part.
The conclusions from these lab-scale tests have the potential to improve the strength and mechanical performance of the final part. In order to expand the understanding between what is happening between the lab scale and the full-scale process, a visual imaging system has been developed to monitor composite structures formation in real-time. Developing new material combinations in rotational moulding can reduce production costs of lightweight aircraft structures, reinforced boat hulls or renewable wind turbine blades, making them more accessible for industries and people.