With rotational moulding companies facing tightening margins and reduced order intake, higher productivity through faster cycle times and reduced energy consumption takes on an ever more important role.
Italian machinery builder Persico, for instance, believes cost-effective production with more advanced equipment can cut cost and improve part quality. Its fully automated Leonardo machine offers up to 35% faster cycle times and up to 25% lower energy consumption compared with earlier designs, claims the firm. The Leonardo also saves energy by using direct oil mould heating applied selectively at appropriate levels throughout the moulding.
Persico has now installed more than 40 of its latest fully-automated Leonardo series, including 15 in Italy, seven in France, six in the UK, four in the US, and two in Australia. The two Australian Leonardo machines are installed at Precision Poly, where they are used to produce vertical 2,000 and 3,000-litre rainwater tanks.
Precision Poly founder Malcolm Baird says that the company has seen a 61% reduction in carbon dioxide emissions since installing the Leonardo. Total plant energy costs have been reduced by 38%; together with 20% lower raw material consumption per tank.
Aside from rotomoulding machinery, Persico also makes and supplies aluminium rotomoulding tools. While these were made entirely by casting as recently as 2000, the company says the balance has steadily shifted towards CNC milled aluminium tooling. Persico uses 20 CNC milling machines for tool production in-house, supplemented by production on a further 60 machines at partner companies.
Rotomachinery Group, which comprises Polivinil in Italy and STP in the USA, has introduced a new CRM series of rotational moulding machinery, which it claims is the "answer to the terrible recession that is ravaging the economies of countries all around the world".
CRM series machines are designed to be commercially attractive to rotational moulders on a limited budget. New CRM machine features include a pinion and crown design for minor axis rotation, improved oven air flow oven and a modified door mechanism.
Polivinil has also introduced the Intel Rec system for automatic mould recognition. The system has a microchip on each mould to transmit data to monitoring software for analysis. Visual and audible alarms are set off in the event of incompatibility and real time correction and alternatives proposed. Intel Rec is said to help moulders to cut production times and reduce moulding errors.
Control specialist 493K claims its systems, which include the K-Kontrol control system and K-Paq portable temperature monitor, can improve cost efficiency and end product quality.
UK-based tank producer Clarehill Plastics installed a K-Kontrol system last year. Marketing manager John Switzer says the system means Clarehill has better control over the process. "It builds upon our existing systems and provides us with real time analytical and decision making tools, which assists in producing high quality products more efficiently and effectively, enhancing quality levels and profitability," he says.
New Zealand-based LaPlastecnica has launched a new 19mm version of its Techno-Vent device, which allows moulders to heat and cool parts while pressurising the mould.
Tests carried out by LaPlastecnica on a single arm shuttle rotomoulding machine at Ico Polymers in Auckland in New Zealand have shown an average 34% cooling rate improvement. The cooling rate improvement on multi-arm machines is expected to be even faster.
LaPlastecnica managing director Rory Jones says that product consistency also improved and that there was a 10% improvement in the heating rate. Peak internal air temp (PIAT) was also higher and deformation was down by 18%.
Jones says some rotational moulders have reported an additional benefit of using the TechnoVent system; several German moulders located in residential areas have found them useful in controlling odours.