Elongational rheometer and on-line process controller

摘要

Elongational viscosity may be easily and accurately measured by observing the flow characteristics of a high viscosity fluid through a hyperbolic or semi-hyperbolic die, without lubrication of the fluid flowing through the die. The effects of developing orientation in the fluid during converging elongational flow are so strong that the shearing contribution becomes negligible in comparison, eliminating the need for lubrication during measurements.