Deformation Behaviour of Filled and Capped PET Bottles in the High-Speed Labeling Machine

The increasing use of PET bottles has been and continues to be a dramatic growth story in the packaging industry. The adaption of PET bottles for soft drinks, juice drinks, water, food and other products continues to provide exciting packaging opportunities. Increasing use meant increase in demand and the need for saving time in the process chain of the packaging industry. One area where a high speed process is possible is labeling. In higher output ranges in the labeling technology, PET bottles are subjected to undesirable deformations which in turn might result in bottle losses in the machine carrousel or to a bad placement of the label. Information on this deformation should be available in the earliest possible stage of machine planning, such that the desire to simulate comes into play. Before simulating such a high speed labeling process, it is necessary to have a reliable filled PET bottle model which is justified to be used in the simulation of the real process. The first step in this approach is to simulate the top load performance of an empty PET bottle and validate the simulation results with experimental results by comparing load and buckling deformation. Sensitivity studies are carried out with respect to material, geometry and Finite Element parameters to obtain an optimized parameter set which ensures a reliable model of the empty PET bottle. This model is then the basis to simulate the top load performance of liquid filled PET bottle. For the filled PET bottle the right modeling approach to account for the presence of liquid, i.e. water and its associated physics (inertia, compressibility and hydrostatic pressure), must be determined. Control Volume, Smoothed Particle Hydrodynamics and Arbitrary Lagrangian Eulerian approaches are discussed to highlight the benefits and drawbacks of each approach for accurately simulating the top load performance of filled PET bottle. Load-deformation curves and bucking shapes of the top load test are compared with simulation results to justify the usage of a reliable filled PET bottle. The third and final step is to simulate the high speed labeling process by identifying the right approach to account for the machine kinematics and the inertia effects of the liquid. Added element mass or SPH approach for accounting inertia of the liquid in combination with machine kinematics is investigated in order to identify the most accurate combination for bottle deformation in the labeling process.