PETpla.net Insider 09 / 2019

EDITOUR 23 PET planet Insider Vol. 19 No. 09/19 www.petpla.net BOTTLE MAKING 23 Until now, it has been the injection and cooling times of preforms at the first sta- tion of the process that have determined the cycle time for single-stage machines. To reduce cycle time, past practise within the industry has been to make the preform as thin as possible resulting in an elongated design necessary to incorporate the PET mass for the bottle. This, in turn, led to low stretch ratios at stretch-blow mould resulting in less orientation. Using this new mould- ing method, preforms are designed much thicker and therefore shorter while cooling is virtually eliminated from the first station and now occurs at the second station in combi- nation with preform conditioning. With the Zero Cooling system, there is ample time to cool the thicker walls of the shorter preforms, and the revised geometry provides improved stretch ratios, resulting in bottles with better orientation. Blow moulding at the third station is already shorter than the required injection time so has no influence on cycle time. The final result is an average reduction of 30% on overall cycle time. The end result: signifi- cantly shorter cycles combined with a greatly improved product. Machine testing area at ASB Thane