Abstract
The extensional flow has considerable influence on the pressure loss in converging flows, which are present in both extrusion and injection moulding. Both plane- and axi-symmetric converging flows have been studied with LDPE, HDPE and PS. The transient extensional viscosities are determined in all cases. The extensional viscous description used is the one proposed by Cogswell (3).
The extensional viscosities in the two now different flow fields ate compared. The plane-symmetric extensional viscosity is found to be larger than the axi-symmetric for the HDPE melt. The two viscosities are comparable for the LDPE and the PS melts.
Further more, the pressure losses are characterised with the Deborah number in which the characteristic time of the material is shear rate dependent and the characteristic rime of the now is Hencky strain rate dependent.
The extensional viscosities in the two now different flow fields ate compared. The plane-symmetric extensional viscosity is found to be larger than the axi-symmetric for the HDPE melt. The two viscosities are comparable for the LDPE and the PS melts.
Further more, the pressure losses are characterised with the Deborah number in which the characteristic time of the material is shear rate dependent and the characteristic rime of the now is Hencky strain rate dependent.
| Original language | English |
|---|---|
| Title of host publication | ANTEC '97 Plastics Saving Planet Earth, Conference Proceedings |
| Volume | 1-3 |
| Place of Publication | Toronto, Canada |
| Publisher | The Society of Plastic Engineers |
| Publication date | 1997 |
| Pages | 1022-1026 |
| ISBN (Print) | 1-56676-553-6 |
| Publication status | Published - 1997 |
| Event | ANTEC 97 - Toronto, Canada Duration: 27 Apr 1997 → 2 May 1997 Conference number: 55 |
Conference
| Conference | ANTEC 97 |
|---|---|
| Number | 55 |
| Country/Territory | Canada |
| City | Toronto |
| Period | 27/04/1997 → 02/05/1997 |