Extrusion capillary rheometer

description

Overview

Polymer melt is a pseudoplastic fluid with shear thinning flow characteristics, and the relationship between viscosity and shear rate constitutes the viscosity spectrum. The viscosity spectrum can comprehensively characterize the flow behavior of polymer melts, and the processing characteristics of polymers depend on their flow behavior

The viscosity spectrum of polymer melt can be measured using an extrusion capillary rheometer. The basic principle is to use an appropriate method to stabilize the flow of polymer melt from a capillary tube. During this process, the pressure drop generated when the melt flows through the capillary tube and the outflow rate per unit time are measured simultaneously. By performing appropriate calculations on these measurements, the viscosity spectrum can be obtained

There are two ways to make polymer melt flow through capillaries, one is to use piston propulsion, and the other is to use screw extrusion. Screw extrusion measurement is closer to the extrusion processing environment, especially suitable for materials that must undergo strong shear to form a uniform melt (such as mixtures of several materials)

Product performance

The use of capillary mouth molds can test the apparent viscosity curve of materials

Selecting capillary die with different aspect ratios to test the true viscosity curve of materials

Optional narrow slit die for testing the rheological curve of materials under special flow fields

An optional laser caliper can be used to record the diameter of the extruded material in real time and study its extrusion swelling behavior

Scope of application

epigenetic/Real viscosity curve test

Measurement and analysis of extrusion swelling behavior

Research and development of new products and formulas

Optimization of production process parameters