PETpla.net Insider 06 / 2011

CAPPING / CLOSURES 25 PET planet insider Vol. 12 No. 03/11 conventional and short threads, each in the order of around 45%. In a further consideration of the various thread standards, the weights and dimensions of the caps have also been recorded. In the following the various lid weights and heights are compared with one another on a country by country basis within the volume clusters <0.3l, 0.3l to 0.5l and 0.5l to 1.5l. Fig. 2 illustrates cap weights in Austria, France, Egypt, Kenya, USA and the UK for bottles with a volume of up to 0.3L. One interesting factor is the relatively small height of the cap in Austria, Egypt, the USA and the UK (less than 11.5mm). These, with the exception of the USA and despite their lack of height, feature the heaviest caps at more than 3g. The USA, with a very small average cap height of 11.5mm and weigh- ing in at 2g, exhibits the light- est caps in this comparison. The highest caps in use, at almost 15mm, are to be found in Kenya and Thailand; how- ever, at approx. 2.7g, these are considerably lighter than caps from Austria and Egypt. In our study, caps with drink- ing mouthpieces have been excluded from the evaluation to avoid distorting the results. By contrast to the cap comparisons illustrated in Figl 2, the category extending from 0.3l to 0.5l demonstrates an almost proportional rela- tionship between the height of the cap and its weight (cf: Fig 3.) Here too special caps were excluded from the study so as to avoid any distor- tion of the result. The cap weights here lie in a signifi- cantly narrower band between 2.5g and 3.3g, whilst the cap heights are between 13.3mm and 15.4mm. The caps used in Germany are the excep- tion in the analysis. Despite having the smallest average cap height in the compari- son (13.3mm), their weight was found to be only aver- age. By contrast, in Thailand Performance Filling & Capping Labelling Blowing Fig. 3: Cap weight and height by countries – bottles 0.3l to 0.5l