Blow molding process analysis

Erchiqui, F. (2006) A new hybrid approach using the explicit dynamic finite element method and thermodynamic law for the analysis of the fhermoforming and blow molding processes for polymer materials. Polym. Eng. Sci., 46, 1554-1564. 

Draw resonance occurs in processes where the extrudate is exposed to a free surface stretching flow, such as blown film extrusion, fiber spinning, and blow molding. It manifests itself in a regular cyclic variation of the dimensions of the extrudate. An extensive review [169] and an analysis [170] of draw resonance were done by Petrie and Denn. Draw resonance occurs above a certain critical draw ratio while the polymer is still in the molten state when it is taken up and rapidly quenched after take-up. 

PITA (Polymer Inflation Thinning Analysis, GE Plastics, Pittsfield, MA). Blow-molding FEA design model that accounts for both performance part design and the processing characteristics that influence part design. Modeled as a nonlinear elastic with the material properties dependent on temperature and strain rate. Accurately predicts wall thicknesses for complicated parts from small to large shapes. 

In this section we first review some of the more salient technological features of blow molding. We then consider the parts of the process which can be subjected to quantitative analysis and design. 

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