Page 57 - Plastics News May 2026
P. 57
TECHNOLOGY NEWS
REAL-TIME MELT MONITORING IN EXTRUSION
AND INJECTION MOLDING
can push the process outside its validated win-
dow. The result may include dimensional varia-
tion, surface defects, color shifts, or changes in
mechanical performance. Many of these prob-
lems begin upstream, but processors often de-
tect them only during offline inspection or down-
stream testing.
This gap has increased interest in inline melt
monitoring. Two methods stand out: inline rheol-
ogy and near-infrared or infrared spectroscopy.
Rheological indicators track changes in flow be-
nline rheology and spectroscopy enable real- havior. Spectroscopic methods detect changes
time melt monitoring, improving quality con- in composition and molecular structure. Used
Itrol in extrusion and injection molding. together, these tools give processors a broader
view of melt quality during production and help
In extrusion and molding, product quality de- identify deviations before defects spread.
pends on the condition of the polymer melt dur-
In extrusion and molding, product quality de-
ing shaping. Changes in viscosity, composition, pends on the condition of the polymer melt dur-
temperature history, moisture, or contamination ing shaping. Changes in viscosity, composition,
A dedicated inline viscometer is installed perpendicular to the extruder barrel, enabling direct,
real-time measurement of polymer melt viscosity between the screw and the die. Courtesy of
Rheonics.
May 2026 PLASTICS NEWS 59
