ASTM E2408-04(2009)
(Test Method)Standard Test Method for Relative Extensional Viscosity of Agricultural Spray Tank Mixes
Standard Test Method for Relative Extensional Viscosity of Agricultural Spray Tank Mixes
SIGNIFICANCE AND USE
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:
To compare the potential for drift control of different polymers.
To compare the relative extensional viscosity component of different spray tank mixtures.
To determine the extent of breakdown of polymer solutions used as drift control additives during the recirculation of the solutions through pumps and screens.
To use as a parameter in the Spray Drift Task Force Models for droplet size prediction.
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.
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.
SCOPE
1.1 This test method covers the determination of the relative extensional viscosity or Screen Factor (SF) of dilute agricultural spray mixes.
1.2 The test can be used for tank mixes containing dissolved, emulsified or dispersed materials, or mixtures.
1.3 Results may be affected by the quality of the water used. Make-up water quality should therefore be specified in the presentation of results.
1.4 Proper safety and hygiene precautions must be taken when working with pesticide formulations to prevent skin or eye contact, vapor inhalation, and environmental contamination. Read and follow all handling instructions for the specific formulation and conduct the test in accordance with good laboratory practice.
Note 1—References to the development of extensional viscosity from dissolved polymers, extensional viscosity effects on the droplet size distribution of sprays, and measurements of screen factor on recirculated spray mixes containing polymers are available. ,
1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
General Information
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: E2408 − 04(Reapproved 2009)
Standard Test Method for
Relative Extensional Viscosity of Agricultural Spray Tank
Mixes
This standard is issued under the fixed designation E2408; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 2. Referenced Documents
2.1 ASTM Standards:
1.1 Thistestmethodcoversthedeterminationoftherelative
D1193 Specification for Reagent Water
extensional viscosity or Screen Factor (SF) of dilute agricul-
E609 Terminology Relating to Pesticides
tural spray mixes.
E1116 Test Method for Emulsification Characteristics of
1.2 The test can be used for tank mixes containing
Pesticide Emulsifiable Concentrates
dissolved, emulsified or dispersed materials, or mixtures.
2.2 CIPAC Documents:
CIPAC Monograph 1 (Instructions for the preparation of
1.3 Resultsmaybeaffectedbythequalityofthewaterused.
hard water)
Make-up water quality should therefore be specified in the
CIPAC Method MT 18.1.1 to 18.1.7 (Instructions for the
presentation of results.
preparation of standard waters)
1.4 Proper safety and hygiene precautions must be taken
3. Terminology
when working with pesticide formulations to prevent skin or
eye contact, vapor inhalation, and environmental contamina-
3.1 Definitions:
tion. Read and follow all handling instructions for the specific
3.1.1 screen factor, (SF)—the ratio of the flow time of a test
formulation and conduct the test in accordance with good
fluid (t ) to the flow time of water (t ) through the screen
p w
laboratory practice. viscometer apparatus.
3.1.2 extensional viscosity, (E)—a measure of the resistance
NOTE 1—References to the development of extensional viscosity from
of a fluid to distortion by a stretching force.
dissolved polymers, extensional viscosity effects on the droplet size
distribution of sprays, and measurements of screen factor on recirculated
2,3
4. Significance and Use
spray mixes containing polymers are available.
4.1 Extensional viscosity is a measure of the resistance of a
1.5 The values stated in SI units are to be regarded as
liquid to stretching forces, such as those occurring during the
standard. No other units of measurement are included in this
disruption of liquid films and the formation of sprays used in
standard.
agriculture and other purposes including painting operations or
1.6 This standard does not purport to address all of the
metal working. This method for measurement of a Screen
safety concerns, if any, associated with its use. It is the
Factor, gives a relative value for extensional viscosity, which
responsibility of the user of this standard to establish appro-
may be used:
priate safety and health practices and determine the applica- 4.1.1 To compare the potential for drift control of different
bility of regulatory limitations prior to use. polymers.
4.1.2 To compare the relative extensional viscosity compo-
nent of different spray tank mixtures.
4.1.3 To determine the extent of breakdown of polymer
This test method is under the jurisdiction of ASTM Committee E35 on
solutionsusedasdriftcontroladditivesduringtherecirculation
Pesticides, Antimicrobials, and Alternative Control Agentsand is the direct respon-
sibility of Subcommittee E35.22 on Pesticide Formulations and Delivery Systems.
of the solutions through pumps and screens.
Current edition approved Oct. 1, 2009. Published November 2009. Originally
4.1.4 To use as a parameter in the Spray Drift Task Force
approved in 2004. Last previous edition approved in 2004 as E2408 – 04. DOI:
Models for droplet size prediction.
10.1520/E2408-04R09.
Dexter, R. W., “Measurements of Extensional Viscosity of Polymer Solutions
and its Effect on Atomization from a Spray Nozzle,” Atomization and Sprays,Vol
6, 1996, pp. 167–191 For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Zhu, H., Dexter, R. W., Fox, R. D., Reichard, D. L., Brazee, R. D., and Okzan, contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
H.E.,“DropletSizeandViscosityEffectsinRecirculatedPolymerSpraySolutions,” Standards volume information, refer to the standard’s Document Summary page on
J. Agric. Engr. Res., Vol 67, 1997, pp. 35–45 the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E2408 − 04 (2009)
NOTE2—Appropriatesafetyprecautionsshouldbetakenwhenusingan
4.2 It should also be noted that many drift control polymers
open flame for rounding the ends of the glass tubes.
are irreversibly destroyed during the recirculation of spray
mixes by pumping with high shear pumps such as gear or
5.2 Assembly of Screen Viscometer—Refer to Fig. 1, which
centrifugal pumps. It is advisable to subject the test mixture to
shows the arrangement of the separate items of equipment, and
similar pumping regimes to simulate practical conditions
Fig. 2, which shows the placement of the screen pack in the
before carrying out the extensional viscosity test. Measure-
plastic union.
ments of extensional viscosity are the only presently known
5.2.1 Push the five stainless screen discs, one at a time, into
method of determining the extent of this breakdown properties
the ⁄4 in. (0.635 cm) plastic union. Push each screen down to
of dilute polymer solutions. 1
the central lug in the union, using a piece of ⁄4 in. glass tubing.
Ensure that the last of the 5 screens fits tightly into the plastic
4.3 This method is intended to produce a relative value for
tube to keep the pack of screens well compacted and fixed in
extensional viscosity.The purpose of the method is to compare
place.
the extensional viscosity produced by different polymer types
or concentrations of polymer in spray tank mixes. 5.2.2 Push the silicone rubber sleeve (Item 4) on to the
lowerendofthepipettetube(Item3).Leaveapproximately0.8
5. Apparatus
cm of the silicone tube projecting beyond the glass.
5.2.3 Pushtheshortglasstube(Item5)intotheplasticunion
5.1 List of Materials for Construction of Screen Viscometer:
firmlyandpressdownonthepackofscreens.Screwontheend
5.1.1 Item 1—Fluorinated plastic ⁄4 in. (0.635 cm) straight
cap of the union to retain the position of the screen pack.
union, reference SKU-II4, P#D1O77019. Norton Performance
Ensure that the Teflon cone supplied with the union is fitted
Plastics, 150 Dey Road, Wayne, New Jersey, 07470, USA.
properly, to provide a leak tight seal.About 0.6 cm of the glass
5.1.2 Item 2—Cut five (5) ⁄4 in. diameter discs (see 5.2)
tube should protrude from the end cap of the union.
from100mesh(150µmaperture)USAStandardTestingSieve,
ASTM E11 specification, stainless steel plain weave screen, so 5.2.4 Push together the glass tube protruding from the end
as to fit tightly into the ⁄4 in. plastic union. cap, into the silicone rubber sleeve attached to the pipette.
5.1.3 Item 3—Glass 25 mL pipette, {VWR catalog #7102 Check the alignment of the pipette and screen pack for
(1999)} or equivalent. External diameter of the tube below the straightness.
bulb of the pipette = 0.82 cm. Cut off the lower part of the
5.3 Other Accessories Required:
pipette at a point 2.5 cm below the bulb. Round off the sharp
5.3.1 Two 500 mL beakers.
edges of the tube with a flame.
5.3.2 A stand and clamp to hold the pipette firmly in a
5.1.4 Item 4—Silicone rubber tubing, flexible, for use as a
vertical position.
sleeve to join a glass tube (Item 5) to the lower end of the
5.3.3 A stopwatch, reading to 0.01 s.
pipette (Item 3).
5.3.4 A 200 mesh USA Standard Testi
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