The rise of rotational moulding
Post-recession recovery is not the only reason the UK’s rotational moulding industry is on the up, says Karen Drinkwater, Head of the BPF's Rotational Moulders Group. Here she writes for BP&R on the reasons behind the optimism and why the future looks bright.
It’s 2014 and there seems to be a sense of growth within the UK rotational moulding sector. This is more than just economic recovery following a period of recession – it is an increase in activity, an improvement of processes, and an enhanced profile within manufacturing – in short, a build-up of confidence.
There are a great many reasons as to why this is so. There have always been great benefits when using rotational moulding to produce components and these remain the same. The process produces highly durable, robust, hollow items ideal for the toughest of environments. There is also a great deal of freedom when designing for rotational moulding, enabling the achievement of complex and organic shapes – a real bonus for product designers who now find that it is possible to produce one part encompassing many features that would otherwise require multiple components at a higher cost in labour, materials and production time.
Rotational moulding has also experienced increased popularity due to the continued conversion of existing products from other materials such as steel or wood to plastic. The reasons are numerous and include weight reduction, cleanliness and timeliness of production. Rotational moulding has always been popular in the environmental arena with its products being re-usable, recycled and recyclable and this is set to continue with the introduction of biomaterials to the sector.
This goes some way to explain the recent confidence in the sector, but there is something else to consider. Rotational moulders have always been entrepreneurial by nature, many still being owner-managed. This hands-on approach has resulted in a progressive attitude, which has pushed technical knowledge and ability forward. This progression has has been supported by the sector’s material suppliers. Well-established companies have responded to some of the industry’s requirements with new materials such as V0-rated polyethylene, the bioresin already mentioned and other new grades. Others are new suppliers who are emerging to develop improved polypropylenes, flow promoters and decorating techniques. There is still a long way to go – rotational moulding has always lagged behind the major sectors of the polymer industry due to lack of critical mass – but progress is definitely happening.
Five years ago there was a clear divide between products that could be produced from steel tools and those that were produced from an aluminium tool, determined by complexity and surface detail. Improvements in steel tool technology have led to more of an overlap between the two. Projects that were once unviable in aluminium are now competitive in steel. Aluminium tool making continues to progress with advances in coating and cooling technologies.
Machinery innovations have also led to increased cycle times and efficiencies in production. Some UK moulders have invested in the revolutionary Leonardo semi-automatic moulding machine, which has rapid cycle times and all-electric machines are also now available. Not every moulder has such equipment, and rotational moulding is still by comparison a slow, labour intensive process, but not to the extent as it was. Moulders continue to look for ways to improve efficiency on their existing machinery.
Growth within the sector is of course also dependent on new projects. Organic growth from existing products is fine, but these contracts don’t push the boundaries of the industry. It is the new, challenging work that enthuses a moulder and the sector as a whole. The challenge for rotational moulders has been to identify and attract these projects.
Rotational moulding makes up only a small percentage of the polymer industry. Most within the industry will have heard of the process, but few have any depth of knowledge, or awareness of what can be achieved – and the same can be said for the wider manufacturing community. In the past, little has been done to rectify this and perhaps this is where the significant change has been. Rotational moulders from across the country have been joining together to promote their industry to the wider manufacturing community. This has not been easy, as rotational moulding serves so many industry sectors – how do you reach as many as possible? A long-term view has resulted in the decision to target young designers whilst they are gaining their qualifications. Numerous presentations have been given in leading universities across the country, highlighting the design benefits of rotational moulding. At Manchester Metropolitan University the BPF Rotational Moulding Group was invited to work with students on their second year ‘live’ project, where more in-depth discussions occurred and students actually designed products for the process. As this work continues, more and more students will qualify with some knowledge of rotational moulding and graduate into the workplace.
Working together within the sector has not proved as difficult as some may have thought. We are now looking to the future and at what else can be achieved to improve the UK rotational moulding industry. Discussions are underway concerning a possible apprenticeship programme and further research projects and a materials seminar and an International Conference are also scheduled. Further progress and confidence is ahead.