Effect of the pressure drop rate on cell nucleation in continuous processing of microcellular polymers

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Park, Chul B.¹; Baldwin, Daniel F.²; Suh, Nam P.²

Effect of the pressure drop rate on cell nucleation in continuous processing of microcellular polymers

Polym Eng Sci. March 1995;35(5):432-440

Affiliations

¹Department of Mechanical Engineering, University of Toronto, Toronto, Ontario M5S 1A4, Canada

²Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
Abstract

Microllular plastics are cellular polymers characterized by cell densities greater than 10⁹ cells/cm³ and cells smaller than 10 μm. One of the critical steps in the continuous production of microcellular plastics is the promotion of high cell nucleation rates in a flowing polymer matrix. These high nucleation rates can be achieved by first forming a polymer/gas solution followed by rapidly decreasing the solubility of gas in the polymer. Since, in the processing range of interest, the gas solubility in the polymer decreases as the pressure decreases, a rapid pressure drop element, consisting of a nozzle, has been employed as a continuous microcellular nucleation device. In this paper, the effects of the pressure drop rate on the nucleation of cells and the cell density are discussed. The experimental results indicate that both the magnitude and the cell density are discussed. The experimental results indicate that both the magnitude and the rate of pressure drop play a strong role in microcellular processing. The pressure phenomenon affects the thermodynamic instability induced in the polymer/gas solution and the competition between cell nucleation and growth.
Links

DOI: 10.1002/pen.760350509

WoS: A1995QM85600008

Cited By (24)

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1998	Behravesh AH. Extrusion Processing of Low-Density Microcellular Foams [PhD thesis]. University of Toronto; 1998.
2001	Naguib HE. Extrusion Processing for Manufacture of Low-Density, Fine-Celled Polypropylene Foams [PhD thesis]. University of Toronto; 2001.
2001	Richards EV. Design of an Apparatus to Measure Gas Solubilities in Polymers [Master's thesis]. University of Toronto; 2001.
2003	Rizvi GM. Development of Extrusion Processing Technology for Manufacture of Fine-Celled Plastic/wood-Fiber Composite Foams [PhD thesis]. University of Toronto; 2003.
2006	Lee C-DP. Extrusion Processing of Low-Bulk Density, Microcellular, Open-Cell Thermoplastic Foams [PhD thesis]. University of Toronto; 2006.
2008	Li YGG. Development of a Novel Visualization and Measurement Apparatus for the PVT Behaviours of Polymer/gas Solutions [PhD thesis]. University of Toronto; 2008.
2009	Leung SNS. Mechanisms of Cell Nucleation, Growth, and Coarsening in Plastic Foaming: Theory, Simulation, and Experiment [PhD thesis]. University of Toronto; 2009.
2010	Lin K. Development of High Strength Microcellular Foams Using Polyether Block Amide [Master's thesis]. University of Toronto; 2010.
2010	Zhang H. Scale-Up of Extrusion Foaming Process for Manufacture of Polystyrene Foams Using Carbon Dioxide [Master's thesis]. University of Toronto; 2010.
2012	Chen N. The Effects of Crosslinking on Foaming of EVA [PhD thesis]. University of Toronto; 2012.
2012	Mahmood S. A Thermodynamic Investigation of the PVT, Solubility and Surface Tension of Polylactic Acid (PLA)/CO₂ Mixtures [Master's thesis]. University of Toronto; 2012.
2012	Wong AT. In Situ Observation of Plastic Foaming Under Static Condition, Extensional Flow and Shear Flow [PhD thesis]. University of Toronto; 2012.
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2013	Xu M. Development of Lightweight, Biodegradable Plastic Foam Fibres With Poly (lactic) Acid-Clay Nanocomposites [Master's thesis]. University of Toronto; 2013.
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2016	Ding W. Development of Polylactic Acid/cellulose Nanofiber Biocomposite Foams [PhD thesis]. University of Toronto; 2016.
2016	Shaayegan V. Investigation of Cell Nucleation and Growth in Foam Injection Molding Through Visualization [PhD thesis]. University of Toronto; November 2016.
2017	Mahmood SH. Thermodynamic Investigation of the Interaction Between Polymer and Gases [PhD thesis]. University of Toronto; 2017.
2017	Wang C. Simulation Ofh Cell Growth in High-Pressure Foam Injection Molding [Master's thesis]. University of Toronto; March 2017.
2022	Wang C. Bubble Dynamics in High-Pressure Foam Injection Molding [PhD thesis]. University of Toronto; 2022.
2015	Ding H. Development and Fabrication of Thermally Conductive Polymer Matrix Composite Foams [Master's thesis]. York University; December 2015.
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