PETpla.net Insider 04 / 2012

CAPPING / CLOSURES 18 PET planet insider Vol. 13 No. 04/12 www.petpla.net Mold Hot Runner Solutions claim 30% savings for injection moulded plastic closures production Stack, mould, save How can plastic closure manufacturers increase output without investing in additional or larger injection moulding machines? Mold Hotrunner Solutions (MHS), a global sup- plier of hotrunner systems and engineering services, offers a new stack mould technology that can double production of valve-gated parts. Harald Schmidt, President of MHS, explains the new technology. World demand for caps and clo- sures is projected to grow by 4.6% annually, to in excess of US$40 billion in 2014 . While beverages will remain the main consumers of caps and closures, rapid gains are expected in other markets, such as food and phar- maceuticals. Technological advances that address this growing market potential have been significantly led by manu- facturers of all-electric and hybrid injection moulding machines and control equipment. Mould-makers and hotrunner manufacturers have been slower to produce substantial contri- butions to improved energy savings and cycle time reductions. However, new hotrunner technology is aimed at precisely these issues, while lowering production costs and improving part quality. Small, compact stack-mould systems with internal valve-gate com- ponents offer a number of advantages compared with their large, single face predecessors. For example, they can produce parts with much more efficiency, inside significantly smaller injection moulding machines. A rising number of moulders are expected to employ back-to-back valve-gate stack moulds, in order to gain a competitive advantage in the marketplace. How to break the cycle time barrier In order to lower the production cost of injection moulded caps and closures, moulders must increase productivity. Without investing in addi- tional equipment, greater production output can only be achieved by reduc- ing cycle times – but it is impossible to cut cycle times in half on a single face mould, given the high degree of efficiency already in place. However, doubling the number of parts pro- duced by implementing a stack mould solution makes a step-change in pro- ductivity possible. The cost of purchasing and operating additional or larger injec- tion moulding machines, moulds and controllers is substantial. An end user in the packaging business, relying on plastic closures for its product, will pay that additional cost through higher prices for each part; moulders will simply become less competitive. Three ways to injection mould 96 closures per shot: A small stack mould shows better performance than a bigger single face mould Annual production of plastic closures (million of parts)