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Experimental study and numerical simulation of the injection stretch/blow molding process
Author(s) -
Schmidt F. M.,
Agassant J. F.,
Bellet M.
Publication year - 1998
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.10310
Subject(s) - materials science , discretization , molding (decorative) , crank , blow molding , mechanics , constitutive equation , process (computing) , work (physics) , transfer molding , finite element method , mechanical engineering , mathematics , composite material , computer science , mold , mathematical analysis , thermodynamics , physics , engineering , cylinder , operating system
The injection stretch/blow molding process of PET bottles is a complex process, in which the performance of the bottles depends on various processing parameters. Experimental work has been conducted on a properly instrumented stretch/blow molding machine in order to characterize these processing parameters. The objective being a better understanding of the pressure evolution, preform free inflation has been processed and compared with a simple thermodynamic model. In addition, a numerical model for the thermomechanical simulation of the stretch/blow molding process has been developed. At each time step, mechanical and temperature balance equations are solved separately on the current deformed configuration. Then, the geometry is updated. The dynamic equilibrium and the Oldroyd B constitutive equations are solved separately using an iterative procedure based on a fixed‐point method. The heat transfer equation is discretized using the Galerkin method and approximated by a Crank‐Nicholson's scheme over the time increment. Successful free blowing simulations as well as stretch/blow molding simulations have been performed and compared with experiments.