Experimental observation and numerical simulation of transient “stress fangs” within flowing molten polyethylene
K Lee, MR Mackley, TCB McLeish, TM Nicholson… - Journal of …, 2001 - pubs.aip.org
We report experimental observations and matching numerical simulation for the time-
dependent start-up flow of two molten polyethylenes (PEs) within a slit entry and exit
geometry. For the case of a low density polyethylene (LDPE), an unexpected transient,
birefringence “stress fang” was observed downstream of the slit exit. The stress fang
consisted of a localized region of stress concentration. The stress fang, however, was not
observed for a linear low density polyethylene (LLDPE) sample subjected to the same …
dependent start-up flow of two molten polyethylenes (PEs) within a slit entry and exit
geometry. For the case of a low density polyethylene (LDPE), an unexpected transient,
birefringence “stress fang” was observed downstream of the slit exit. The stress fang
consisted of a localized region of stress concentration. The stress fang, however, was not
observed for a linear low density polyethylene (LLDPE) sample subjected to the same …