Novel high-speed elongation rheometer

Bier A, Arne W, Schubert DW (2023)

Publication Language: English

Publication Type: Conference contribution, Abstract of a poster

Publication year: 2023

Event location: Kopenhagen DK

Abstract

In many processes like film blowing, film
casting or fiber spinning elongational strain
occurs. For these processes, it is very impor-
tant to know and understand the occurring
elongational viscosities. However, for high
elongation rates the elongational viscosity
was and still is not accessible with existing
methods e.g. the extensional rheometer after
Sentmanat (SER), oil bath rheometer after
Meissner or tensile rheometer after Münstedt
(MTR) [1]. With the limitation of elongation
rates to a maximum of 10 s-1, those setups are
not suitable in the range up to 100 s-1, which
are typical in fiber spinning [2]. With the
“Rheotens”, slightly higher elongation rates of
up to 40 s-1 can be achieved, but in compar-
ison to the aerodynamic fiber stretching via
an aspirator, it is still by far insufficient for an
industrial relevant range.
Therefore, a novel method is developed to cal-
culate the elongational viscosity of polymers
during the fiber spinning process. To reduce
the complexity of the system two PMMAs (to
exclude crystallization effects) with different
molar masses are investigated using a capil-
lary rheometer. The diameter of the polymeric
strand is determined via a high-speed camera
from the die exit to the aspirator. In addition,
simulations are carried out to describe the
temperature profile of the polymeric strand
along the spinline. A two-way calibration
method was applied to calculate the force ap-
plied by the aspirator on the polymeric strand.
With this information, the temperature and
elongation rate dependent elongational
viscosity was determined. Furthermore, a
Carreau type function was applied to master
all measurements (as shown in Figure 1). With
strain rates up to 100 s-1 this work paves the
way to learn more about the elongational
viscosity in the high deformation range never
reached before [3].
F

Authors with CRIS profile

Alexander Bier Lehrstuhl für Werkstoffwissenschaften (Polymerwerkstoffe) Dirk Schubert Lehrstuhl für Werkstoffwissenschaften (Polymerwerkstoffe)

Involved external institutions

Fraunhofer-Institut für Techno- und Wirtschaftsmathematik (ITWM) / Fraunhofer Institute for Industrial Mathematics DE Germany (DE)

How to cite

APA:

Bier, A., Arne, W., & Schubert, D.W. (2023, May). Novel high-speed elongation rheometer. Poster presentation at Nordic Polymer Days 2023, Kopenhagen, DK.

MLA:

Bier, Alexander, Walter Arne, and Dirk W. Schubert. "Novel high-speed elongation rheometer." Presented at Nordic Polymer Days 2023, Kopenhagen 2023.

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