Standard Test Method for Relative Extensional Viscosity of Agricultural Spray Tank Mixes

Importancia y uso:

4.1 Extensional viscosity is a measure of the resistance of a liquid to stretching forces, such as those occurring during the disruption of liquid films and the formation of sprays used in agriculture and other purposes including painting operations or metal working. This method for measurement of a Screen Factor, gives a relative value for extensional viscosity, which may be used:

4.1.1 To compare the potential for drift control of different polymers.

4.1.2 To compare the relative extensional viscosity component of different spray tank mixtures.

4.1.3 To determine the extent of breakdown of polymer solutions used as drift control additives during the recirculation of the solutions through pumps and screens.

4.1.4 To use as a parameter in the Spray Drift Task Force Models for droplet size prediction.

4.2 It should also be noted that many drift control polymers are irreversibly destroyed during the recirculation of spray mixes by pumping with high shear pumps such as gear or centrifugal pumps. It is advisable to subject the test mixture to similar pumping regimes to simulate practical conditions before carrying out the extensional viscosity test. Measurements of extensional viscosity are the only presently known method of determining the extent of this breakdown properties of dilute polymer solutions.

4.3 This method is intended to produce a relative value for extensional viscosity. The purpose of the method is to compare the extensional viscosity produced by different polymer types or concentrations of polymer in spray tank mixes.

Subcomité:

E35.22

Referida por:

E2798-19

Volúmen:

11.08

Número ICS:

17.060 (Measurement of volume, mass, density, viscosity)