Effects of preform deformation behavior on the properties of the poly(ethylene terephthalate) bottles

Abstract

Plastics bottles made out of poly(ethylene terephthalate) (PET) are usually produced by injection stretch blow molding. Optimization of the process parameters is necessary to achieve bottles with adequate top load and burst strength. However, doing so experimentally is time‐consuming and costly. To overcome this difficulty, simulation packages based on finite element analysis methods have been developed. In this study, process optimization of a 350‐mL PET fruit juice bottle was carried out by means of BlowView and ANSYS simulation packages. BlowView was used for the ISBM process simulation and ANSYS for structural analysis of the bottles. The bottles were produced under different process conditions where the timing of the stretch rod movement was varied in relation to the activation of the blow pressure. The simulation results obtained through the both simulation packages were compared with experimental results. It was found that bottles of highest quality were produced if the sequencing of axial stretching and radial inflation results in simultaneous biaxial deformation of the preform. Truly biaxial orientation of PET molecules improved both top‐load and burst resistances of the bottles. The structural simulation studies performed by the ANYSYS simulation package validated most of our experimental findings. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Mechanical response of poly(lactic acid)‐based packaging under liquid exposure

“…Mechanical performance tests commonly conducted are the burst pressure test, top‐load analysis, and drop test. To evaluate the durability of the package during its life service, the strength of application is assessed by the measurement of the package's stress and deformation in response to various loads . Usually, this is followed by analysis of the critical load at the point of buckling, or the buckling load .…”

“…In this analysis, the performance of a liquid container made of a PLA‐based plastic containing a hydrocarbon liquid was evaluated by the simulation of the mechanical behavior under a top load by means of the FE model. The top‐load analysis aims to assess the durability of packages to withstand the axial load necessary to fill and stack the packages during manufacturing, storage, and distribution . The top‐load test is usually performed to identify the peak buckling load, which is the critical load that results in buckling.…”

“…The mechanical performance of a package can also be assessed through a burst strength analysis, which evaluates the stability of a package subjected to an internal pressure. This test is usually performed for bottles intended for carbonated beverages to ensure that the bottles do not blow up at the filling stage and that filled bottles do not expand excessively during storage and/or bottle warming for pasteurization purposes . When internal pressure analysis is done with the FE model, the top section of the bottle is clamped, and an internal pressure is applied to the inner surface.…”

“…To evaluate the durability of the package during its life service, the strength of application is assessed by the measurement of the package's stress and deformation in response to various loads. 36 Usually, this is followed by analysis of the critical load at the point of buckling, or the buckling load. 37 The FE method has been implemented in numerous studies to assess the structural performance of various package designs subjected to different loading conditions.…”

“…The top- load analysis aims to assess the durability of packages to withstand the axial load necessary to fill and stack the packages during manufacturing, storage, and distribution. 36,41 The top-load test is usually performed to identify the peak buckling load, which is the critical load that results in buckling. The response to the applied load is initially linear, but at a certain point, the compression force no longer increases linearly with applied deformation.…”