Abstract
A microscope and high speed motion analysis equipment were used to image the flow field occurring in die flow of concentrated suspensions following twin screw extrusion processing. The motion analysis revealed the development of a particle-free wall slip layer adjacent to the die wall. The nature of the slip layer is affected by the air content of the suspension. Air bubbles which are spherical away from the wall become ellipsoidal as they approach the wall and completely flatten into a thin film at the wall. The films of air momentarily stick to the die surface and then are dragged back into the bulk of the flowing suspension. The mechanism of slip layer formation and the role played by the entrained air have significant ramifications on the wall slip and rheological behavior of concentrated suspensions.
Original language | English |
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Pages | 1130-1134 |
Number of pages | 5 |
State | Published - 1995 |
Event | Proceedings of the 53rd Annual Technical Conference. Part 1 (of 3) - Boston, MA, USA Duration: 7 May 1995 → 11 Oct 1995 |
Conference
Conference | Proceedings of the 53rd Annual Technical Conference. Part 1 (of 3) |
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City | Boston, MA, USA |
Period | 7/05/95 → 11/10/95 |