PETpla.net Insider 09 / 2014

BOTTLE MAKING 28 PET planet insider Vol. 15 No. 09/14 www.petpla.net Liquiform, one step bottle forming and filling by Alexander Büchler The 50/50 Joint Venture between Amcor and Sidel Liquiform has seen the development of a bottle forming and filling technology which makes forming and filling bottles possible in a single step. This means that the energy-intensive compressed air conditioning process can be dispensed with, along with some of the transfer and/or logistics steps in the process. We spoke with Ann O’Hara, President, LiquiForm. In the classic process, the preform is initially heated in a furnace before being placed in the mould and then the actual liquid or whatever product is to be bottled is forced at pressure into the preform, moulding it into the bottle shape. This results in a filled bottle, ready for capping and labelling. PETplanet: Hello Ann, is it your aim, with your new Liquiform hydro- forming technology, to revolutionise the stretch blow moulding and filling sector? Ms Ann O’Hara: We think it makes sense to mould the preform into a bottle by means of the end product instead of using compressed air. In this way we not only save on the filling machine but primarily also on the air compressor and hence any amount of energy. Beyond the primary benefits, there are secondary opportunities to leverage the “non- air” process for its additional benefits – smaller clean rooms for aseptic filling, more ambitious designs given the more precise forming, potential elimination of the stretch rod, reduc- tion of waste given the increased accuracy of filling volume, etc. And in the end, the step change in effi- ciency, combined with the additional benefits, will revolutionise the con- tainer forming market. PETplanet: If I understand the system correctly, the preform is tra- ditionally heated in an oven, goes into a normal stretch blow moulding machine and your process involves initial stretching and then moulding the walls with the product liquid. Does the liquid not immediately cool the inner wall of the heated preform and at least make it difficult to shape the bottle correctly? Ms Ann O’Hara: Our trials have shown that this is not the case. On the contrary. The liquid is so fast that the cooling of the bottle wall only happens at the wall of the mould. In a similar way to blow moulding, we go into the cavity at a pressure of 14bar. And in fact, after the bottle is formed, there is a benefit of the liquid cooling in that the newly formed container does not need to be held in the mould very long and much less than in air blow- ing where there is a designed in “hold time” to allow for that cooling. To take advantage of that speed improvement we are working on offtake processes and technologies. PETplanet: Is the process slower? In the case of traditional stretch blow moulding / filler lines there are around six filler valves serving one stretch blow moulding cavity. Do you only mould at a stretch blow moulding speed of 1/6? Ms Ann O’Hara: No, the speed of the stretch blow moulding cavity stays the same.The filler process is con- siderably. The LF process can form and fill a 2l container in less than 0.3s compared to over 10s on conventional filling systems. PETplanet: Up to now we have only had one empty bottle, perhaps with 30g, in one cavity. Now, with the high rotational speeds of the blow Ann O’Hara President at LiquiForm