Filamentary extrusion of microcellular polymers using a rapid decompressive element

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Park, Chul B.¹; Suh, Nam P.²

Filamentary extrusion of microcellular polymers using a rapid decompressive element

Polym Eng Sci. January 1996;36(1):34-48

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

An extrusion process for manufacturing microcellular plastics is presented. In the past, microcellular structures have been produced in batch processes by using a thermodynamic instability of a polymer/gas system. In order to utilize such a thermodynamic instability in a continuous extrusion process, a large amount of gas must be dissolved quickly in a molten plastic flowing in the machine, and a rapid drop in the gas solubility must be induced in the flowing polymer/gas solution. Since the solubility of a gas in a polymer is a sensitive function of pressure, a thermodynamic instability for producing a microcellular structure can be induced by rapidly lowering the pressure. This paper presents a means for continuously forming the polymer/gas solution at an industrial processing rate and a means of nucleating microcells in the polymer/gas solution using a nozzle. Finally, a process model for controlling the cell morphology is presented by identifying the key parameters that control microcellular foaming in a continuous process. The experimental results agree with theoretical analyses, confirming the fact that the processing pressure strongly affects the microcellular foaming process through its effects on the amount of gas dissolved in the polymer and the magnitude of the pressure drop in the nucleation device.
Links

DOI: 10.1002/pen.10382

WoS: A1996TQ61100005

Cited By (39)

Year	Entry
2011	Diaz-Acosta CA. Continuous Microcellular Foaming of Polylactic Acid/natural Fiber Composites [PhD thesis]. East Lansing, MI: Michigan State University; 2011.
1998	Behravesh AH. Extrusion Processing of Low-Density Microcellular Foams [PhD thesis]. University of Toronto; 1998.
1998	Rizvi GM. Extrusion Foaming of Plastic/wood-Fiber Composites Using a Chemical Blowing Agent [Master's thesis]. University of Toronto; 1998.
1998	Yeung AK-F. Development of Microcellular Foam Sheet Extrusion Systems [Master's thesis]. University of Toronto; 1998.
1999	Park SS. On-Line Measurement of the PVT Properties of Polymer/CO₂ Solutions Using a Gear Pump [Master's thesis]. University of Toronto; 1999.
2000	Zhang H. Extrusion of Fine-Celled Plastic/wood-Fiber Composite Foams Using CO₂ as a Blowing Agent [Master's thesis]. University of Toronto; 2000.
2001	Guo G. Manufacture of Fine-Celled Plastic/wood-Fiber Composite Foams Using CO₂ as a Blowing Agent [Master's thesis]. University of Toronto; 2001.
2001	Lee PC. Manufacture of Microcellular Open-Celled Polyolefin Foams [Master's thesis]. University of Toronto; 2001.
2001	Lin WSL. Effect of Moisture and Other Volatiles on the Cellular Structure of Plastic/wood-Fiber Composite Foams [Master's thesis]. University of Toronto; 2001.
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.
2002	Xu X. Design of an Injection-Molding System for Manufacture of Microcellular Foams [PhD thesis]. University of Toronto; 2002.
2003	Rizvi GM. Development of Extrusion Processing Technology for Manufacture of Fine-Celled Plastic/wood-Fiber Composite Foams [PhD thesis]. University of Toronto; 2003.
2005	Xu D. The Role of Die Shape for Promoting Large Volume Expansion Ratios of the Extruded Foams [PhD thesis]. University of Toronto; 2005.
2006	Lee C-DP. Extrusion Processing of Low-Bulk Density, Microcellular, Open-Cell Thermoplastic Foams [PhD thesis]. University of Toronto; 2006.
2007	Wong H-FS. Mechanical Characterization of Thermoplastic Polyolefin (TPO) Foams [Master's thesis]. University of Toronto; 2007.
2007	Zhu Z. Modeling of Expansion and Collapse of Extruded Filamentary Foam Through Cell-to-Cell Diffusion [PhD thesis]. University of Toronto; 2007.
2008	Ahmed MYSE-S. Design and Manufacturing of Novel Microcellular Acoustical Foams [PhD thesis]. University of Toronto; 2008.
2008	Kim S-G. A Study on the Foaming Behavior of Thermoplastic Polyolefin (TPO) Blends [PhD thesis]. University of Toronto; 2008.
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	Lee JWS. Investigation of Foaming Behaviors in Injection Molding Using Mold Pressure Profile [PhD thesis]. University of Toronto; 2009.
2009	Leung SNS. Mechanisms of Cell Nucleation, Growth, and Coarsening in Plastic Foaming: Theory, Simulation, and Experiment [PhD thesis]. University of Toronto; 2009.
2009	Wang J. Rheology of Foaming Polymers and Its Influence on Microcellular Processing [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	Price AD. Fabrication, Modelling and Application of Conductive Polymer Composites [PhD 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.
2013	Hasan MM. A Systematic Study of Solubility of Physical Blowing Agents and Their Blends in Polymers and Their Nanocomposites [PhD thesis]. University of Toronto; 2013.
2013	Jung PU. Development of Innovative Gas-Assisted Foam Injection Molding Technology [PhD thesis]. University of Toronto; 2013.
2013	Xu M. Development of Lightweight, Biodegradable Plastic Foam Fibres With Poly (lactic) Acid-Clay Nanocomposites [Master's thesis]. University of Toronto; 2013.
2014	Chu RKM. Open-Cell Foaming With Injection Molding [PhD thesis]. University of Toronto; 2014.
2015	Andalib KMZ. Increasing Void Fraction of the Polypropylene Foams Blown With Chemical Blowing Agents in High Temperature Extrusion [Master's thesis]. University of Toronto; November 2015.
2017	Mahmood SH. Thermodynamic Investigation of the Interaction Between Polymer and Gases [PhD thesis]. University of Toronto; 2017.
2017	Tabatabaei Naeini A. In-Situ Visualization and Quantification of Polymer Crystallization Under Complex Flows During Foam Extrusion Processing [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	Mendoza-Cedeno SL. Effects of Long-Chain Branching and Molecular Weight on the Foamability of Polypropylene in Foam Injection Molding [Master's thesis]. University of Toronto; 2022.
2022	Wang C. Bubble Dynamics in High-Pressure Foam Injection Molding [PhD thesis]. University of Toronto; 2022.