PETpla.net Insider 04/ 2013

CAPPING / CLOSURES 35 PET planet insider Vol. 14 No. 04/13 www.petpla.net latter is a degraded organoleptic per- formance and may also lead to a need to eliminate pockets, dead volumes or similar traps for deployed chemi- cals. Radiation can be an obstacle as well, since, depending on energy and intensity, electro-magnetic radiation can lead to changes to the inherent material properties, for example by cross-linking of polymer chains. An overview of potential hazards per type of treatment can be found in Table 3. The main difference between the effects of pre-treatments and the effect of filling methods on the packaging is that the former risks are merely carried over from the pre- treatment whereas the latter risks are applied directly to the package. For example, beverages treated by a UHT process are usually cooled down sig- nificantly from the initial temperature of up to 150°C (1) once packaged, whereas the heat applied from tunnel pasteurisation acts directly on the package. Neck standardisation and its limits Beverage packaging is a high volume business which is one reason why standardisation is a very help- ful tool within the industry. There is no doubt that standardisation allowed for fast development cycles and lead times since one could rely on an 1881 neck always being an 1881 neck for instance. But the idea of standardisa- tion has its limits. In the early days of PET necks, it seemed like a good idea to take neck designs used for glass bottles and use them unchanged for the plastic bottles. These neck designs have proved to work well for many years. But obviously plastic and glass are significantly different materials. Bearing in mind the dif- ferent types of treatment described above, it becomes immediately clear that resistivity against high tempera- tures, for example, has never been a problem with glass bottles while for plastic bottles the very opposite might be the case. Let us take a 38mm neck finish for aseptic cold fill (ACF) applica- tions as an example of issues when adopting unchanged the glass necks. Bottles with 38mm ACF necks and closures are usually used as pack- ages for sensitive beverages. The SINGLE STAGE ISBM MACHINES FOR PET BOTTLES & JARS MORE CAVITIES LESS INVESTMENT PATENTED TECHNOLOGY www.cypet.eu 10 & 12.5 Ltr bottles 2 Cavities Machine Model K 28 100ml Bottles 16 Cavities Model K 28 5 Ltr Bottle 80mm Jar 2 Cavities Model K 16