Historical notes on flow visualization in polymer melt processing

Abstract

Flow visualization is commonly used technique in fluid mechanics to get qualitative or quantitative information about flow patterns. Many different visualization techniques have been until now developed. Due to high temperatures and pressures inside processing tools, only four of them, namely dye adding, particle tracking velocimetry, laser-Doppler velocimetry and flow induced birefringence can be used in polymer melt extrusion. In this paper, some interesting historical notes of these methods are presented and their first applications in polymer melt extrusion are shortly introduced. © 2019 Author(s).