With decades of experience and expertise that have seen us lead the world in the manufacture of caps with this technology, Sacmi has developed a completely new system that allows preform production to be synchronised with stretch-blow moulding of the preform using a rotary blow moulder. This result was achieved thanks to the flexibility of the process which, in the event of stretch-blow moulder stoppage, allows production and handling of cold preforms within an automated ultra-clean storage environment.
The core advantage - compared to injection technology - is the heightened efficiency that stems from single-stage technology (i.e. synchronised production of preforms and their subsequent stretch-blowing). Minimum levels of potential preform contamination (thanks to high machine outlet temperatures and immediate transition to subsequent blow-moulding and bottling) make it ideal for the dairy industry and other fields where even low-level preform and container contamination can affect product integrity; in addition to considerable savings on the preform cleaning and decontamination fronts, producers can also enjoy huge energy savings as there is no need to cool, store and subsequently reheat preforms prior to blowing.
Elimination of the preform storage unit (now transformed into the dynamic Sacmi CPB Link buffer which intervenes, only as necessary, to make up for the different "average efficiency" of the two processes and, in any case, acts in a controlled ultra-clean environment) eradicates preform cleaning and heating-cooling costs, allowing manufacturers to cut average bottle costs by 5 - 15% while keeping energy consumption (including all preform production and blow moulding) below 1 kWh per kg of processed PET. This result is also achieved thanks to net savings on the use of raw material (preform weight is reduced by 0.2 - 0.4 g, about 4%, container characteristics remaining equal, thanks to absence of the gate; this technology also allows flat-bottomed preforms to be produced).
Last but not least comes container quality and healthiness: acetaldehyde formation is directly proportional to PET processing temperature and pressure and is thus minimised thanks to compression, a process which acts at lower temperatures and pressures, providing manufacturers with considerable savings vis-à-vis the additives needed to prevent the formation of this harmful substance; because high-viscosity PET can be used (not possible in the injection process, as it needs to transit very narrow channels) it is possible to obtain stronger, longer-lasting containers. Moreover, the moisture absorption that typically affects traditional PET manufacturing processes is virtually eliminated thanks to synchronization of preform production and blow-moulding. Then, of course, there is an evident boost to logistical efficiency (no internal preform transport and storage facilities required).
“Sacmi heroPET 4.0”, explains Iacopo Bianconcini, Marketing Manager of the Sacmi Group Beverage and Closures&Containers Division, “represents the culmination of that PET revolution which began in 1973 when plastic bottles first started replacing glass ones. For years, neither traditional preform and container production methods nor the subsequent bottling stage underwent any major changes: even after the launch, in 1997, of the first stretch-blow moulding machines integrated with the bottling line, the three phases remained largely distinct. With heroPET4.0, we’ve overcome all the problems that previously hindered full integration of these processes, doing so by making full use of compression technology, a field in which Sacmi has world-beating skills that stem from decades of experience and thousands of systems installed all over the world".