PETpla.net Insider 09 / 2010

BOTTLING / FILLING 40 PET planet insider Vol. 11 No. 09/10 www.petpla.net The results of this global analysis are being integrated by PETplanet Insider (in close collaboration with the Technical University of Ilmenau) into a brand new database - PET- planet Zoom - which is now freely available to be viewed and/or downloaded. Based on 60 different criteria the wide variety in the PET container business will be highlighted and compared to provide useful factual details, concisely assembled in a clear and comprehensible format . Table 2: Comparison bottle weights and weight/volume ratio (branded drinks vs. private label) If, for example, the most widely used bottles with vol- umes of 0.5, 1.0 and 1.5l are compared with each other the comparison of branded drinks and private label drinks alone shows that for branded drinks heavier bottles are generally used for all volumes. The reasons are a more appealing feel in the hand and the inclusion of different design ele- ments into the bottle shape. This applies to a less significant degree in the 1 litre market segment, where the smaller difference can be partly explained by a high proportion of juices and mixed drinks. In the 0.5l segment the weight disadvantage of branded product bottles, at an average of 10g/l, is twice that of, for example, the 1.5l segment with an average of 5g/l. The leaders in the lightweighting field are the private label bottles in the 1.5l segment, which, in direct comparison with branded drinks, exhibit a high potential for lightweighting and in terms of weight technology are even better than the 1l bottles. The lighter weight of the private label bottles does however impact on the material proper- ties, where the level of induced orientation (“LIO”) can be used as a benchmark. Table 3: Comparison of crystallinity The most noticeable difference is the almost universal lower LIO in bottles for branded drinks. The reason for this can be traced back to a lower degree of stretching from preform to bottle during the stretch blow moulding proc- ess. One point to note here, among others, is the correla- tion with the specific weight (grams/litre) in table 2 where the differences between the individual categories follow the findings from table 3. Table 4: “Orange peel” defect comparison Part of our research is also concerned with identifying defects in the bottles in order to be able to compare their quality against various criteria. As an example, the surface defect known as “orange peel” is illustrated. A surprising discovery was the fact that with branded drinks bottles, across all classes, there is a high level of orange peel, and whilst less attention may be paid to the poor quality in the base of the bottle the poor quality of visible areas around the bottle neck is quite noticeable. As a further important characteristic of a PET bottle the closure has also been included in our research. In addition to dimensions and weight the neck finish/thread type is also examined. Table 5: Average cap weight, including ring (grams). Level of carbonation: (n) = none, (m) = medium, h = high. Depending on the volume and level of carbonation an interesting picture emerges with regard to cap weight within the different classes. Whereas the cap weight falls with increasing levels of carbonation in 0.5l bottles a contrary trend can be seen with 1.5l bottles. The higher weights with non-carbonated drinks are, with private label 0.5l bottles, generally due to the use of special caps and with 1.5l branded product bottles due to a tendency to adopt