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Some comments on post extrusion swelling phenomena: Die entrance or die passage
Author(s) -
Chapoy L. L.,
Pedersen S.
Publication year - 1977
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.760171005
Subject(s) - die (integrated circuit) , extrusion , swelling , capillary action , materials science , viscoelasticity , mechanics , flow (mathematics) , composite material , physics , nanotechnology
The mechanistic origins of the post extrusion swelling phenomenon have been the subject of considerable debate. Conflicting theories have postulated that it is caused either by (1) deformations at the die entrance which are recovered upon die exit as a consequence of viscoelastic memory or (2) elastic enorgy, which is stored during capillary flow by the action of normal stress, and subsequently released upon die exit or by both (1) and (2). We have described these situations by mathematical models and show that the resulting equations are similar despite different origins. The difficulties in interpreting the results mechanistically are discussed. Empirically, the results can be described as being exponential in capillary residence irrespective of cause.