Modelling of poly(ethylene terephthalate) in injection stretch-blow moulding

Simulations of the injection stretch-blow moulding process have been develo ped for the manufacture of poly(ethylene terephthalate) bottles using the c ommercial finite element package ABAQUS/standard. Initially a simulation of the manufacture of a 330 mt bottle was developed with three different mate rial models (hyperelastic, creep, and a non-linear viscoelastic model (Buck ley model)) to ascertain their suitability For modelling poly(ethylene tere phthalate). The Buckley model was found to give results for the sidewall th ickness that matched best with those measured from bottles off the producti on line. Following the investigation of the material models, the Buckley mo del was chosen to conduct a three-dimensional simulation of the manufacture of a 2 L bottle. It was found that the model was also capable of predictin g the wall thickness distribution accurately for this bottle. In the develo pment of the three-dimensional simulation a novel approach, which uses an a xisymmetric model until the material reaches the petaloid base, was develop ed. This resulted in substantial savings in computing time.