A Design-of-Experiment Study on the Microcellular Extrusion of Sub-critical CO2 Saturated PLA Pellets
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D. Miller
and V. Kumar
Abstract
In this study we explore the use of solid-state nucleation in pellets as a means to decouple cell nucleation from cell growth in extrusion. This is achieved by feeding the extruder with gas-saturated PLA pellets. Cell nucleation occurs, similar to that of the well-studied solid-state batch foaming process, when gas-saturated pellets are crushed and heated in the feed section of the extruder. The polymer melt consequently contains the nucleated cells. Further, the gas content in the pellets provides a means to deliver a controlled amount of blowing agent for cell growth at the die exit. It was found that gas concentrations in partially desorbed pellets offers greater control of part density and foam morphology compared to that of fully saturated pellets at 2 MPa. Using Design-of-Experiment statistical methods it was found that gas concentration in the polymer was the most significant variable influencing foam density, whereas the extrudate cooling method was found to control cell size.
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© 2011, Carl Hanser Verlag, Munich
Articles in the same Issue
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- Applicability of the Impact Response Analysis Method for Reinforced Concrete Beams Mixed with Polyvinyl Alcohol Short Fibers
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- Model and Numerical Simulation for the Second Penetration in Water-assisted Injection Molding
- Influence of Extrusion Conditions on the Rheological Behavior of Nuclear Bituminized Waste Products
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- PPS-News
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Articles in the same Issue
- Contents
- Contents
- Regular Contributed Articles
- Applicability of the Impact Response Analysis Method for Reinforced Concrete Beams Mixed with Polyvinyl Alcohol Short Fibers
- Epoxy-Montmorillonite Nanocomposites Applied to Powder Coatings
- Direct Imprinting Using Magnetic Nickel Mold and Electromagnetism Assisted Pressure for Replication of Microstructures
- Automated Mold Heating System Using High Frequency Induction with Feedback Temperature Control
- The Prediction of Bowing Distortion of Film after Transverse Stretching with Consideration of Heated Air Flow in a Tenter
- The Influence of Injection Molding and Injection Compression Molding on Ultra-high Molecular Weight Polyethylene Polymer Microfabrication
- A Design-of-Experiment Study on the Microcellular Extrusion of Sub-critical CO2 Saturated PLA Pellets
- Optimization of Injection Molding Process for SGF and PTFE Reinforced PC Composites Using Response Surface Methodology and Simulated Annealing Approach
- Flow Visualisation in Co-rotating Twin Screw Extruders: Positron Emission Particle Tracking and Numerical Particle Trajectories
- The Influence of Melt and Process Parameters on the Quality and Occurrence of Part Defects in Water-assisted Injection Molded Tubes
- Model and Numerical Simulation for the Second Penetration in Water-assisted Injection Molding
- Influence of Extrusion Conditions on the Rheological Behavior of Nuclear Bituminized Waste Products
- Influence of Dicumyl Peroxide Content on Thermal and Mechanical Properties of Polylactide
- Rapid Communications
- Calculation of Average Residence Time in a Ko-kneader
- PPS-News
- PPS News