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A New High Sensitivity System to Detect Instabilities During the Extrusion of Polymer Melts
Author(s) -
Naue Ingo F. C.,
Kádár Roland,
Wilhelm Manfred
Publication year - 2015
Publication title -
macromolecular materials and engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.913
H-Index - 96
eISSN - 1439-2054
pISSN - 1438-7492
DOI - 10.1002/mame.201500148
Subject(s) - materials science , bar (unit) , instability , sensitivity (control systems) , extrusion , fourier transform , plastics extrusion , polymer , pressure sensor , in situ , analytical chemistry (journal) , composite material , optics , mechanics , thermodynamics , chromatography , physics , chemistry , quantum mechanics , electronic engineering , meteorology , engineering
This publication is concerned with the development of a novel high sensitivity instability detection die for a laboratory size extruder. The high sensitivity system consists of piezoelectric transducers placed along the die length to monitor local pressure fluctuations, having temporal and pressure resolution of up to Δ t ≈ 10 −3 s and Δ p ≈ 10 −5 bar, at a nominal pressure of 500 bar. The system is tested on short chain branched polyethylenes, namely on the detection and characterization of the sharkskin instability. It is shown that the determined instabilities are related to characteristic peaks in the corresponding in situ pressure Fourier‐transform spectra and that other peaks are caused by different, but defined, sources. The in situ results obtained are validated through optical image analysis of the instabilities.