Extrusion Visualization Facility |
| An instrumented slit die located at the exit of a twin screw extruder allows in-situ optical measurements of blend morphology and critical processing parameters. The combination of in-line optical microscopy and light scattering probes a size range from 0.1 microns to 100 microns. The facility has been used for the study of polymer blends, reactive blends, in-situ fiber formation and slippage. |
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| The properties of a polymeric material can frequently be enhanced by blending it with a second immiscible polymer containing synergistic properties. An example is the blending of rubber into nylon, in which a significant increase in impact strength can be acheived. The final properties depend strongly on the morphology of the dispersed phase. |
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| The shear stress in the channel has a profound effect on the morphology as seen in these three light scattering (upper panel) / optical microscopy (panel) pairs. At low shear (left side) , the disperesed phases is shperical. At intermediate shear, long fibers of the dispersed phase form, parallel to the shear direction. At higher shear (right side), the fibers break up into ellipsoidal droplets. |
Contact Information |
| Dr. Kalman Migler Polymers Division National Institute of Standards and Technology Tel: 301 975 4876 |
| NIST Materials Science & Engineering Laboratory - Polymers Division |
