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Title: Simulation of the Two Stages Stretch-Blow Molding Process: Infrared Heating and Blowing Modeling

Abstract

In the Stretch-Blow Molding (SBM) process, the temperature distribution of the reheated perform affects drastically the blowing kinematic, the bottle thickness distribution, as well as the orientation induced by stretching. Consequently, mechanical and optical properties of the final bottle are closely related to heating conditions. In order to predict the 3D temperature distribution of a rotating preform, numerical software using control-volume method has been developed. Since PET behaves like a semi-transparent medium, the radiative flux absorption was computed using Beer Lambert law. In a second step, 2D axi-symmetric simulations of the SBM have been developed using the finite element package ABAQUS registered . Temperature profiles through the preform wall thickness and along its length were computed and applied as initial condition. Air pressure inside the preform was not considered as an input variable, but was automatically computed using a thermodynamic model. The heat transfer coefficient applied between the mold and the polymer was also measured. Finally, the G'sell law was used for modeling PET behavior. For both heating and blowing stage simulations, a good agreement has been observed with experimental measurements. This work is part of the European project ''APT{sub P}ACK'' (Advanced knowledge of Polymer deformation for Tomorrow's PACKaging)

Authors:
; ; ;  [1]
  1. CROMeP - Ecole des Mines d'Albi Carmaux - Campus Jarlard - 81013 Albi cedex 09 (France)
Publication Date:
OSTI Identifier:
21061722
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 908; Journal Issue: 1; Conference: NUMIFORM 2007: 9. international conference on numerical methods in industrial forming processes, Porto (Portugal), 17-21 Jun 2007; Other Information: DOI: 10.1063/1.2740863; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; A CODES; ABSORPTION; AIR; COMPUTERIZED SIMULATION; DEFORMATION; DISTRIBUTION; FINITE ELEMENT METHOD; HEAT TRANSFER; HEATING; LAMBERT LAW; MOLDING; OPTICAL PROPERTIES; ORIENTATION; POLYMERS; PROCESS CONTROL; TEMPERATURE DISTRIBUTION; THERMODYNAMICS

Citation Formats

Bordival, M., Schmidt, F. M., Le Maoult, Y., and Velay, V. Simulation of the Two Stages Stretch-Blow Molding Process: Infrared Heating and Blowing Modeling. United States: N. p., 2007. Web. doi:10.1063/1.2740863.
Bordival, M., Schmidt, F. M., Le Maoult, Y., & Velay, V. Simulation of the Two Stages Stretch-Blow Molding Process: Infrared Heating and Blowing Modeling. United States. doi:10.1063/1.2740863.
Bordival, M., Schmidt, F. M., Le Maoult, Y., and Velay, V. Thu . "Simulation of the Two Stages Stretch-Blow Molding Process: Infrared Heating and Blowing Modeling". United States. doi:10.1063/1.2740863.
@article{osti_21061722,
title = {Simulation of the Two Stages Stretch-Blow Molding Process: Infrared Heating and Blowing Modeling},
author = {Bordival, M. and Schmidt, F. M. and Le Maoult, Y. and Velay, V.},
abstractNote = {In the Stretch-Blow Molding (SBM) process, the temperature distribution of the reheated perform affects drastically the blowing kinematic, the bottle thickness distribution, as well as the orientation induced by stretching. Consequently, mechanical and optical properties of the final bottle are closely related to heating conditions. In order to predict the 3D temperature distribution of a rotating preform, numerical software using control-volume method has been developed. Since PET behaves like a semi-transparent medium, the radiative flux absorption was computed using Beer Lambert law. In a second step, 2D axi-symmetric simulations of the SBM have been developed using the finite element package ABAQUS registered . Temperature profiles through the preform wall thickness and along its length were computed and applied as initial condition. Air pressure inside the preform was not considered as an input variable, but was automatically computed using a thermodynamic model. The heat transfer coefficient applied between the mold and the polymer was also measured. Finally, the G'sell law was used for modeling PET behavior. For both heating and blowing stage simulations, a good agreement has been observed with experimental measurements. This work is part of the European project ''APT{sub P}ACK'' (Advanced knowledge of Polymer deformation for Tomorrow's PACKaging)},
doi = {10.1063/1.2740863},
journal = {AIP Conference Proceedings},
number = 1,
volume = 908,
place = {United States},
year = {Thu May 17 00:00:00 EDT 2007},
month = {Thu May 17 00:00:00 EDT 2007}
}
  • The total production costs of PET bottles are significantly affected by the costs of raw material. Approximately 70 % of the total costs are spent for the raw material. Therefore, stretch-blow molding industry intends to reduce the total production costs by an optimized material efficiency. However, there is often a trade-off between an optimized material efficiency and required product properties. Due to a multitude of complex boundary conditions, the design process of new stretch-blow molded products is still a challenging task and is often based on empirical knowledge. Application of current CAE-tools supports the design process by reducing development timemore » and costs. This paper describes an approach to determine optimized preform geometry and corresponding process parameters iteratively. The wall thickness distribution and the local stretch ratios of the blown bottle are calculated in a three-dimensional process simulation. Thereby, the wall thickness distribution is correlated with an objective function and preform geometry as well as process parameters are varied by an optimization algorithm. Taking into account the correlation between material usage, process history and resulting product properties, integrative coupled simulation steps, e.g. structural analyses or barrier simulations, are performed. The approach is applied on a 0.5 liter PET bottle of Krones AG, Neutraubling, Germany. The investigations point out that the design process can be supported by applying this simulative optimization approach. In an optimization study the total bottle weight is reduced from 18.5 g to 15.5 g. The validation of the computed results is in progress.« less
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