Simulation of the stretch blow molding process of PET bottles

Author(s):  
J. P. McEvoy ◽  
C. G. Armstrong ◽  
R. J. Crawford
Author(s):  
Syed Ayesha Yasmeen

Blow Molding is one of the most versatile and economical process available for molding hollow materials. When polyethylene is stretched, it exhibits strain-hardening properties, which are temperature, pressure, velocity and strain-rate dependent. In this paper, preform is made by extrusion and forced between two halves by pressurization. This process includes isothermal and transient flow of Newtonian fluid in complex geometries simultaneous with structuring and solidification. A time dependent problem is defined and setting material properties and boundaries condition for bottle blow molding. Numerical data available in POLYDATA for a time dependent problem using ANSYS POLYFLOW were applied. Results display in form contours associated with different variables at different time steps and good agreement with the bottle thickness profile is observed. In this paper, the analysis of the stretch-blow molding (SBM) process of polyethylene terephthalate (PET), parison plastic bottles is studied by the finite element method (FEM). A hyper elastic constitutive behavior was calibrated using material data available in literature in variant high temperatures and strain rates and was used in the numerical simulation. Hydrostatic pressure with convention heat transfer has been used instead of a blowing process. Comparisons of numerical results with experimental observations demonstrate that the model can predict an overall trend of thickness distribution. Through the study, it becomes clear that the proposed model is applicable for simulating the stretch-blow molding process of PET bottles, and is capable of offering helpful knowledge in the production of bottles and the design of an optimum preform.


2009 ◽  
Vol 413-414 ◽  
pp. 691-698 ◽  
Author(s):  
Ya Yue Pan ◽  
Shui Ying Zheng ◽  
Xiao Hong Pan

Nowadays, polyethylene terephthalate (PET) bottles have been increasingly used as drink containers. They are usually manufactured by a stretch-blow molding process. The improper parameters set in the stretch blow molding process may lead to many defects in the stretch-blow bottle. Finite Element (FE) simulations of the forming process were performed in this paper. The influences of the technological parameters, such as the balance between stretching and blowing rate, the movement of the stretch rod and the inflation pressure, were studied. As a result, the defects, such as over-thin area, cracking and deformation, can be predicted by this method. Especially, it is shown that the cracking in the bottom of products may result from the improper values of the dwell time and the stretch rate. The trends shown by the simulation results are in good agreement with the experimental results. The method can be applied to predict the probable defects, assess the structural properties, and optimize the processing parameters of the stretch blow molding process.


2014 ◽  
Vol 488-489 ◽  
pp. 121-124
Author(s):  
Lu Yong Sun ◽  
Jin Long Zou ◽  
Kai Chen

The researched PET beverage bottle molding process was analyzed with the combination of stretch blow molding technological process of the manufacturing enterprise. The molding results would be influenced by some technological parameters. In order to study the effect of these factors on the forming properties and thickness distribution of molding bottle, the article builds the physical model and finite element model of PET bottles stretch blow molding process, and simulates stretch blow molding process by using POLYFLOW software for analyzing the thickness distribution of molding bottle. Comparing different thickness distribution under the different condition of stretch speed, pre-blowing pressure, and blowing pressure, the technological parameters were optimized, so as to achieve the goal of optimization of molding bottle.


KREATOR ◽  
2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Tommy Prasetya Kana ◽  
Handika Dany Rahmayanti ◽  
HM Didik

The type of plastic packaging that is popular in the community is bottle packaging. The plastic material that is generally used to make plastic bottles is High Density Polyethylene (HDPE). The plastic bottle industry in Indonesia usually uses a blow molding process in its production process, where the blow molding process consists of injection blow molding, extrusion blow molding and stretch blow molding. The SMC B11 machine is one of the extrusion blow molding machines used to produce plastic bottle packaging. In producing workpieces, this machine still produces several products that are not in accordance with company standards, including in terms of production cycle times and product defects. Defects or defects that are often encountered include the appearance of spots, bent parison which causes the bottle to bend (the bottle body is thin one side) and blow pin which causes the thread to not fit.Keywords— Bottle, Plastic, Defect, Extrussion Blow Molding


2014 ◽  
Vol 2014 ◽  
pp. 1-6
Author(s):  
Afef Bougharriou ◽  
Mohieddine Jeridi ◽  
Mohamed Hdiji ◽  
Anoir Boughrira ◽  
Kacem Saï

The electric bubbles are a useful product made of PMMA material. They are produced by the stretch blow molding process. Thickness, which reflects the quality of the electric bubble, is a crucial parameter that deserves special attention for the molding process. In this work, finite element simulations of the stretch blow molding process are performed aiming at the determination of the preform geometry to ensure homogeneous thickness of the finished product. The geometrical parameters of the preform are optimized allowing a better homogeneity thickness compared to existing data. The predicted parameters allow the improvement of the thickness distribution. The standard deviation of the thickness is reduced to about 95% compared to the existing bubble.


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