Collaboration between SIPA and Italian cap & closure production technology specialist SACMI is yielding positive results. The two companies have been working together since 2012 on the S.U.P.E.R. project, which aims to deliver new combinations of lightweight screw caps and PET bottle necks for the latest generation of bottles for still and sparkling waters. Their target is a new combination of PET preforms and closures that provides advantages for processors and end-users alike. S.U.P.E.R. stands for Sustainable, Unique, Productive, Easy, and Reliable.
The two companies set themselves various objectives, apart from weight reduction. The first objective was to use the same combination of neck/cap both for still and carbonated water eliminating the time for line changes and therefore saving money. Then, they wanted to create a closure system that was as easy as possible to use while still offering the safety and security features of current systems, for example. The development was aimed at bottles up to 3.5vol of CO2 and 1,5L in volume, and was intended to be compatible with 26-mm CETIE GME 30.28 necks.
The new SUPER 26/22 system is distinguished by a very low height and weight—the neck is just 12.0 mm high in its standard version and weighs just 1.86 grams (1.82 g in a version with SACMI’s Multi-Lock system, which breaks all the links on the security ring as soon as the user begins to unscrew the cap). A CETIE 26/22 for still water is the same height as the SUPER 26/22 neck, but weighs 1.90 g.
A special “high” version suitable also for CSD till 4,2 CO2 weights 2.3 g. This contrasts with a PCO1881 cap that is 17.0 mm high and weighs 3.8g, almost twice as much—and which takes caps that can be up to 0.6g heavier.
The two companies have in recent months been carrying out various validation tests, in the laboratory and on production lines, on the functionality and ease of use of the SUPER 26/22 system. In a nutshell: the system passed all the tests.
A joint development team checked, in particular, to make sure that the threads on the new neck are sufficient to keep the cap in place, and to ensure that there is minimal risk of ‘blow-off’ when the cap is first unscrewed from the bottle (this is obviously more important for carbonated products). In the Opening Performance Test, the cap & neck combination was assessed to make sure that any excess pressure that builds up in a half-empty bottle is released during opening while the cap is still attached to the thread, and that no blow-off occurs—this is when the internal pressure is sufficient to force the cap explosively off the thread).
The two companies have additionally carried out tests to make sure that the closure system is easy to use by the consumer, also due to the multi-lock system. They looked at how much force is needed to open a still-sealed bottle, for example. This is a particularly important test, not only because there is nothing worse than a closure that won’t open, but also because the new SUPER 26/22 cap, being smaller than any other, is a little less easy to grip. Once again, the SUPER 26/22 came through with flying colours.
Converting current preform injection molds to the SUPER 26/22 requires few hardware changes. No significant modifications are needed in the blowing machine and in the filling line changing from CETIE26-22 to Super. Whatever the costs involved in such modifications, these can quickly be recouped through savings in raw materials and in energy. A company producing 150 million preforms a year (in this case, 90 million for still water bottles, 60 million for sparkling water) stands to save close to €250,000 on their PET bill at current prices, and some €25,000 in electricity (in Europe). That works out to a return on investment inside four months.