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Predicting Polyolefin Foamability Using Melt Rheology. Associated Polymer Labs Presented by Jim Zwynenburg. Agenda. Define Rheology Test Resulting Data Converting Data Plots Interpretations Examples Remember to Remember. Definitions. Rheology Rheo means Flow
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Predicting Polyolefin Foamability Using Melt Rheology Associated Polymer Labs Presented by Jim Zwynenburg
Agenda • Define • Rheology Test • Resulting Data • Converting Data • Plots • Interpretations • Examples • Remember to Remember Associated Polymer Labs www.testplastic.com
Definitions • Rheology • Rheo means Flow • Ology means the study of • The Study of Flow • Melt Strength • Is a property of the polymer melt which indicates its ability to withstand drawing without breaking. Associated Polymer Labs www.testplastic.com
ASTM D-4440Standard Test Method for Plastics: Dynamic Mechanical Properties Melt Rheology • Frequency Sweep at 190C • Temperature Ramp from 140C-230C for Polyethylene • Temperature Ramp from 180C-260C for Polypropylene Associated Polymer Labs www.testplastic.com
Rheology Test Sensitivity Increases with Decreasing Frequency Associated Polymer Labs www.testplastic.com
Rheology Lab for Solids and Melts Associated Polymer Labs www.testplastic.com
Typical Data from Temperature Ramp Associated Polymer Labs www.testplastic.com
Rheology Plot 1 Associated Polymer Labs www.testplastic.com
Converted Data Associated Polymer Labs www.testplastic.com
Plotting Data • Tan-Delta (G”/G’) Converted into log. • Fractions (less than one, become negative numbers) • Plot on Linear Scale • Eta* (Complex Viscosity) converted into log. • Decimal place becomes the first number, example 4000Pa-sec is 4.0 • Plot on Linear Scale Associated Polymer Labs www.testplastic.com
Rheology Plot 2 Associated Polymer Labs www.testplastic.com
Rheology Plot 3 Associated Polymer Labs www.testplastic.com
Rheology Plot 4 • Every Polyolefin has a Unique Curve • Fingerprint The Resin • Know the response of the polymer • Imagine The Possibilities Associated Polymer Labs www.testplastic.com
Example 1, Using Recycled Resin • Recycled content appears to separate at higher temperatures Associated Polymer Labs www.testplastic.com
Example 2, Blending Vertically • To blend Polyolefins, • Use the WZ Theorem: geometric averaging of the viscosities produces the new blended viscosity. Associated Polymer Labs www.testplastic.com
Example 3; Blending is as easy as 1,2,3 Associated Polymer Labs www.testplastic.com
Remember to Remember • Polyolefins viscosity is 1+2=3 • Testing takes one hour • Measure and Know the Resin Properties • Applies to recycled, fractional melts, additives, rheology modifiers, crosslinking agents, etc • New Models are available for all thermoplastic materials • Cost Savings Associated Polymer Labs www.testplastic.com
The End I’m Grateful to share my experience and knowledge Extra Special Thanks to Gary Wilkes Special Thanks to Stephen Driscolle, University of Massachusetts Jay Patel, Patel Scientific Members of the Foams Committee for accepting my paper Everyone present for listening Associated Polymer Labs www.testplastic.com