zwickiLine for Flexible Low-Force Testing
In the food industry, yogurts, sauces, mustard, tomato paste, and oils are among frequently tested products. Medicinal gels, colors, emulsions, creams, and oils are examples from other industries.
Zwick's back extrusion fixture offers an alternative solution to rotation viscometers. The principle of the back extrusion fixture is based on the displacement of the test material through an annular gap between piston and back extrusion cell. The cell is filled with the test substance and the piston is lowered into the container, pressing the material up through the annular gap. When the piston is raised, the material flows back through the annular gap into the cell.
The force is measured in the down and up cycle at a defined position. The dynamic viscosity is evaluated from the measured force difference and the flow rate of the liquid in the annular gap.
The Zwick system can repeat this cycle as often as desired with freely adjustable shear rates. The test can be optimally adapted to the test material, and the viscosity can be measured across the entire shear range with one single test.
The icing on the cake: testXpert II test program especially developed for viscosity testing:
This special test program includes numerous extras especially for viscosity testing. Examples: automatic preconditioning, determination of cycle numbers and speed, selection of results, etc. The test software is clearly arranged and enables comprehensive evaluation and presentation of data as well as graphical evaluation and reporting.
Viscosity test on yogurt
zwickiLine materials testing machine, food industry