PETpla.net Insider 07 / 2017

BOTTLE MAKING 14 PET planet Insider Vol. 18 No. 07/17 www.petpla.net PETplanet: Mr Saxena, can you briefly describe the differences between the LiquiForm process and the classical 2-stage process? Saxena: In the classic 2-stage process, heated PET preforms are moulded into shape using com- pressed air and subsequently filled with a liquid. LiquiForm eliminates the compressed air and forms the bottle using the actual product. The output is a filled bottle ready to be capped, produced using less equipment, energy, labour and space. Beyond the energy and cost reduction, we are discovering that the bottle has superior definition and more uniform material distribution. Most importantly, whilst current technologies are resin- specific, LiquiForm has the flexibility to process different resins and sizes more easily on a single machine. This offers packaged goods companies an opportunity to simplify their supply chains and move packaging produc- tion closer to the market. PETplanet: Do the preforms have to be specially modified in order to be used with LiquiForm, or is any stand- ard preform suitable for this purpose? Saxena: Standard preforms can be used in most instances. In fact, the vast majority of our work has been with standard preforms. But of course, as LiquiForm is a different process, there are opportunities for optimising the preforms to further improve the results. PETplanet: Clearly, the moulding process must also be carried out very quickly to avoid the liquid cooling the heated preforms? Saxena: You are right. One of the challenges using liquid instead of compressed air is that liquids have a much higher thermal conductivity and thus creates a cooling effect. So the forming process has to be carried out very, very quickly – our cycle time is a fraction of the time required for the compressed air process. Roughly 1-2/10 of a second (0.1-0.2s) for a standard 0.5l water bottle. PETplanet: To what extent does the viscosity of different liquids have to be considered? Saxena: We have been able to process a range of liquid products so far. Even very thick products such as a shampoo or conditioner which have a viscosity of up to 10,000 Centipoise, we have been able to do – and this, by the way, is an ongoing develop- ment. As we go along we add more and more products. The process is slightly adapted to suit each liquid’s condition. But the LiquiForm process is very versatile in handling not only various types of liquids but also differ- ent filling conditions. So for example you can have temperatures ranging from 10°C up to 87°C. PETplanet: Due to possible changes in a liquid’s volume, bottles are never fully filled. But if you are using the liquid to form the bottle, how do you form the neck area and below? Do you have to remove the liquid again after formfilling? Saxena: You are right, you don’t want the liquid all the way up to the neck and we have a number of tech- niques to have the liquid at the cor- rect level at the head space. In some cases, the liquid may be removed, in some cases not. PETplanet: Does the additional weight of the liquid affect the cavities? Saxena: Indeed it does. A filled bottle is much heavier than an empty bottle and impacts the mechanism for taking the bottle out of the form- ing cavity. The equipment makers will have to design the outtake mecha- nism accordingly and ensure that the product doesn’t spill if the bottle is not already capped. So far we have successfully developed in our lab in Michigan anything from 200ml to 2l - simply because we designed the equipment that way. We are cur- rently in the process of upgrading that equipment. We hope to be able to go as high as 4 or 5l in the future. PETplanet: You are claiming that LiquiForm could be used even without moulds in a low-budget so-called free blow approach. What is the reaction to that? Saxena: We are still continuing to work in this area. People in both developed and undeveloped markets find this free-blow process very inter- LiquiForm commercial debut expected with a bottle from the HPC sector by Gabriele Kosmehl The first bottle to be made using the LiquiForm process is expected to be launched soon on the market. PETplanet spoke with Ashish Saxena, Vice President and General Manager of the LiquiForm Group, about this and on-going projects and developments. Ashish Saxena, Vice President and Gen- eral Manager of the LiquiForm Group bottle making