Dr. Advait Bhat

September 18, 2019

Session 4B - Improving Dsign and Manufacturing

10:30 - 11:00 a.m.

The work presents a new methodology for preform design based on material characterization, material modelling and process simulation to evaluate the influence of processing conditions on bottle properties and thus enable optimized preform designs.  A case study is presented where a new preform was designed for an experimental PET material.  The experimental material was initially characterized using a combination of specialist biaxial stretching equipment and a unique state of the art free blow device alongside traditional testing techniques of DMTA and uniaxial tensile testing.  The combination of these test methods provided data that enabled an understanding of the how the natural draw ratio of the experimental material shifted with respect to processing history, how this differed to virgin PET and the influence of processing on final mechanical properties.  The key material data (i.e. the stress strain curves) at the different process conditions were used to calibrate a nonlinear viscoelastic model of the material behavior which was subsequently embedded within a simulation of the stretch blow molding process using the commercial FEA package Abaqus.   The simulation was initially validated against an existing prototype bottle.  Following validation, the simulation was used to redesign the preform to ensure that the material reached the critical areas of the container to prevent failure.  The new design not only met the in-service performance requirements of the container but also had a 10% reduction in weight.  The new lighter preform design was subsequently manufactured with the experimental PET and used to manufacture a container which passed all in-service performance requirements.  The work highlights the power and potential savings of using a simulation driven design approach to preform design in stretch blow molding.

Disclaimer: Any opinions or scientific interpretations expressed in this presentation are those of the author and do not necessarily reflect the position or policy of PepsiCo, Inc.

Dr. Bhat has been with PepsiCo as Modeling and Simulation Analyst for past three years working on new packaging innovations through the Discovery and Applications team. Dr. Bhat has a PhD in Mechanical and Aerospace Engineering from Oklahoma State University with technical interests in structural FE analysis and light-weighting strategies. During his tenure at PepsiCo, Dr. Bhat had the privilege to work on package development of many successful beverage brands such as Life WTR, Tropicana, Aquafina, Drinkfinity and Gatorade GX.