Standard Test Methods for Evaporation Rates of Volatile Liquids by Shell Thin-Film Evaporometer

SIGNIFICANCE AND USE
The rate of evaporation of volatile liquids from a solution or dispersion is important because it affects the rate of deposition of a film and flow during deposition, and thereby controls the structure and appearance of the film. In the formulation of paints and related products, solvents are chosen based on the evaporation characteristics appropriate to the application technique and the curing temperature.
SCOPE
1.1 These test methods cover the determination of the rate of evaporation of volatile liquids of low viscosity using the Shell thin-film evaporometer. These test methods have been applied to a wide range of volatile liquids, including paint, varnish, and lacquer solvents and thinners to various hydrocarbons and to insecticide spray-base oils.
1.2 The test methods for the determination of evaporation rate using the thin-film evaporometer are: SectionsTest Method A2,3—Manual Recording5-11Test Method B—Automatic Recording12-17
1.3 These test methods are limited only by the viscosity of the volatile liquid which must be sufficiently low to permit the dispensing of an accurately measured specimen from a syringe.
1.4 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.5 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. Specific hazard statements are given in 5.2 and 5.6.

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ASTM D3539-87(2004) - Standard Test Methods for Evaporation Rates of Volatile Liquids by Shell Thin-Film Evaporometer
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: D3539 – 87 (Reapproved 2004)
Standard Test Methods for
Evaporation Rates of Volatile Liquids by Shell Thin-Film
Evaporometer
This standard is issued under the fixed designation D3539; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope
1.1 These test methods cover the determination of the rate
of evaporation of volatile liquids of low viscosity using the
Shell thin-film evaporometer. These test methods have been
applied to a wide range of volatile liquids, including paint,
varnish, and lacquer solvents and thinners to various hydrocar-
bons and to insecticide spray-base oils.
1.2 The test methods for the determination of evaporation
rate using the thin-film evaporometer are:
Sections
2,3
Test Method A —Manual Recording 5-11
Test Method B—Automatic Recording 12-17
1.3 These test methods are limited only by the viscosity of
the volatile liquid which must be sufficiently low to permit the
dispensingofanaccuratelymeasuredspecimenfromasyringe.
1.4 The values stated in SI units are to be regarded as the
standard. The values given in parentheses are for information
FIG. 1 Details of the Thin-Film Evaporometer
only.
1.5 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
D891 Test Methods for Specific Gravity, Apparent, of
responsibility of the user of this standard to establish appro-
Liquid Industrial Chemicals
priate safety and health practices and determine the applica-
E1 Specification for ASTM Liquid-in-Glass Thermometers
bility of regulatory limitations prior to use. Specific hazard
statements are given in 5.2 and 5.6. 3. Summary of Test Methods
3.1 Aknown volume of liquid is spread on a known area of
2. Referenced Documents
filter paper that is suspended from a sensitive balance in a
2.1 ASTM Standards:
cabinet. Dried air or nitrogen at 25°C is passed through the
cabinet at a known rate. The loss of weight of the filter
paper/liquid is determined and plotted against time.
These test methods are under the jurisdiction of ASTM Committee D01 on
Paint and Related Coatings, Materials, and Applications and are the direct
responsibility of Subcommittee D01.24 on Physical Properties of Liquid Paints & 4. Significance and Use
Paint Materials.
4.1 The rate of evaporation of volatile liquids from a
CurrenteditionapprovedJuly1,2004.PublishedJuly2004.Originallyapproved
solution or dispersion is important because it affects the rate of
in 1976. Last previous edition approved in 1996 as D3539–76(1996). DOI:
10.1520/D3539-87R04.
deposition of a film and flow during deposition, and thereby
These test methods are essentially the same as the one developed by the New
controls the structure and appearance of the film. In the
York Society for Paint Technology. The Precision section was added by ASTM
formulation of paints and related products, solvents are chosen
SubcommitteeD01.24andisbaseduponthedataoftheNewYorkSocietyforPaint
Technology. based on the evaporation characteristics appropriate to the
See “Comparative Evaporation Rates of Solvents: II,” New York Club,
application technique and the curing temperature.
Technical Subcommittee No. 66, Offıcial Digest, 28, No. 382, 1956, p. 1060.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D3539 – 87 (2004)
NOTE 1—One-litre flasks should be used throughout.
FIG. 2 Diagram of Dehumidification Apparatus
TEST METHOD A—EVAPORATION RATE USING 5.7 Hygrometer (or other humidity-sensing device), capable
THE MANUAL THIN-FILM EVAPOROMETER of indicating low humidities.
5.8 Thermometers, of suitable accuracy such as ASTM
5. Apparatus
BombCalorimeterthermometer56Chavingarangefrom19to
5.1 Evaporometer, thin-film evaporometer as shown in
35°C, subdivisions 0.02°C or Thermometer 56F (66 to 95°F
Fig. 1 (see Annex A1).
with 0.05°F subdivisions), and conforming to the requirements
5.2 Constant-Temperature Cabinet for evaporometer.
of Specification E1.
(Warning—In instances with the solvents and other volatile
materials normally tested using this apparatus and under the
6. Preparation of Evaporometer
conditions specified in this test method, the concentration of
6.1 Placethefilterpaperdiskonthewiresupport,threading
solvent or other flammable material being exhausted into the
thehookthroughasmallholeinthecenterofthepaper.Attach
laboratory atmosphere will be significantly below any concen-
the hook to the steel spring below the sighting disk and allow
tration that could be hazardous, that is, a lower flammable
the paper and the paper support to hang therefrom.
limit.However,itmaybedesirabletolocatetheinstrumentand
6.2 Close the evaporometer and cabinet doors and allow the
cabinet in a laboratory exhaust hood if the routine handling of
temperatureinbothchambersandthehumiditytoequilibrateat
certain materials may present a hazard due to toxicity, extreme
the following test conditions:
volatility, or flammability.)
Cabinet and evaporation temperature: 25 6 0.25°C (77 6 0.5°F)
5.3 Interval Timer: Stopwatch or Electric Timer—A timer
Evaporometer humidity: 0 to 5 % relative humidity
that gives an audible signal at 10 or 20-s intervals and that
gives a warning signal approximately 3 s before the end of the
Approximately 2 h are required for the humidity to drop to
interval is preferred.
less than 5%.
5.4 Filter Paper Disk—Fast, open-textured filter paper, 90
6.3 Adjust the air flow to 21 L/min (center of ball float
mm in diameter, with a circle approximately 60 mm in
opposite correct mark on the rotometer scale).
diameter (and concentric with the edge) lightly drawn on the
paper with a pencil.
7. Conditioning
5.5 Syringe—A1.00-mLhypodermicsyringeequippedwith
7.1 Bring the sample or a portion of it to an equilibrium
a 225-mm needle of 1.3-mm outside diameter stainless steel
temperature of 25 6 0.5°C (77 6 1.0°F) in a constant-
tubing. Duetomanufacturingvariations,thesyringeshouldbe
temperature bath. Determine the specific gravity of the sample
calibrated before use.
at this temperature in accordance with Test Methods D891.
5.6 Dehumidification Equipment—A suggested setup is
given in a schematic diagram, Fig. 2.(Warning—Use of this
dehumidification apparatus requires the safety practices rela- 8. Procedure
tive to the handling, use, and disposal of hazardous acids and
8.1 Record the position of the filter paper as indicated by
caustics be observed. When handling these materials, protec-
alignmentofthesightingdiskwithitsmirrorimage.Thisisthe
tive eye or face shields, or both, and protective clothing are
no-load position.
recommended.)
8.2 Raise the wire mesh bracket until the bottom of the disk
support rests lightly on it.
The manual Shell thin-film evaporometer is no longer available.
8.3 Withdraw into the syringe 0.70 mLof the solvent which
Syringe: Becton, Dickinson and Co., No. 1YT available from Fisher Scientific
isat25 60.5°C(77 61.0°F).Makecertainthatallairbubbles
Co.Needle:SpecialSyringeNeedleTypeLNR,18-gage,9-in.longbluntroundend,
areexpelledfromthesyringeandtheneedlebeforeapplication
no bevel available on special order from Becton, Dickinson and Co. through Fisher
Scientific Co., 711 Forbes Ave., Pittsburgh, PA 15239. of the specimen to the filter paper.
D3539 – 87 (2004)
was delivered. If it passes to the left of the origin, then the aliquot was
8.4 Insert the hypodermic needle into the small opening on
smaller than specified.
theright-handsideoftheinstrumentandpositiontheneedletip
so that it almost touches the disk and is just over the line that
10. Report
was drawn.
10.1 Report the elapsed time in seconds at 10 weight %
8.5 Start applying the solvent to the disk. As the first drop
intervals through 90% and for 95 and 100% evaporation, and
hits the disk, start the timer.The solvent should be applied at a
the relative evaporation rate (n-butyl acetate=1.0). Relative
uniformratein 62sandasevenlyaspossiblealongthedrawn
evaporationrateiscalculatedfromthe90weight%evaporated
line. To ensure consistent specimen size, touch the tip of the
times for the test solvent and for n-butyl acetate (99% ester).
hypodermic needle to the filter paper to dispense the last drop
of solvent.
11. Precision
8.6 Immediatelylowerthewiremeshbracketawayfromthe
11.1 On the basis of an interlaboratory study of the test
disk support. Obtain the first reading of the position of the
method in which operators in six laboratories determined the
sighting disk at 40 s and then every 20 s. Record the time and
90% evaporation point of six solvents covering a broad range
the scale reading on the report form. A sample report form is
in evaporation rate, the between-laboratories coefficient of
shown in Annex A2.
variation was found to be 6.3% relative at 24 df after
discarding two divergent values. On the basis of the results
NOTE 1—With very slow evaporating solvents, it is not necessary to
obtained by three laboratories on three of the solvents having
takereadingsasoftenasevery20s.Theoperatorcandetermineasuitable
time interval after the first 200 s.
90% evaporated times of 200 to 600 s, the within-laboratory
coefficientofvariationwasfoundtobe0.83%relativeat18df.
8.7 Stopthetimerwhenthesightingdiskhasreturnedtothe
Based on these coefficients, the following criteria should be
original unloaded position.
used for judging the acceptability of results at the 95%
NOTE 2—Thefilterpapermaybereusedprovidedthesolventleavesno
confidence level:
appreciable residue in evaporating.
11.1.1 Repeatability—For solvents with 90% evaporation
times of 200 to 600 s, two results, each the mean of two
9. Calculation
determinations, obtained by the same operator on different
9.1 Calculate the evaporation rate as follows: days should be considered suspect if they differ by more than
2.5%.
C
ER 5 3100~B 2 Z! (1)
11.1.2 Reproducibility—Two results, each the mean of two
S
determinations, obtained by operators in different laboratories
should be considered suspect if they differ by more than
where:
18.2%.
S = V 3 D and Z= N−(S/C)
TEST METHOD B—EVAPORATION RATE USING
ER = evaporation rate, wt %,
C = spring constant, cm/g elongation, THIN-FILM EVAPOROMETER, AUTOMATIC
S = specimen weight,
RECORDING
V = 0.70-mLaliquot volatile liquid at 25 6 0.5°C (77 6
12. Apparatus
1.0°F),
D = densityofvolatileliquidat25 60.5°C(77 61.0°F) 12.1 Evaporometer, automatic thin-film evaporometer, as
(Taken as equivalent to specific gravity but with shown in Fig. 3.
units of mL/g) 12.2 Filter Paper Disk—See 5.4.
B = scale reading taken during evaporation of aliquot,
12.3 Syringe—See 5.5.
Z = zero percent evaporated, scale reading= N−(S/C).
12.4 Dehumidification Equipment—See 5.6.
and
12.5 Strip Chart Recorder—Any strip chart recorder ca-
N = no-load scale reading (100% evaporated reading).
pable of recording the output signal (0 to 15 mA) from the
9.2 Plot the percent evaporated against elapsed time in electronic optical weight-sensing device. The recorder should
secondsanddrawasmoothcurvethroughthepoints.Fromthe
provide a range of chart speeds including 6.3 to 50 mm ( ⁄4 to
curve,determineat10weight%incrementsto90%andfor95 2 in.)/min. It is also desirable for the recorder to accommodate
and100%evaporationthetimeinsecondstothenearestvalue
2 or more mA ranges in order to regulate the sensitivity of
as follows:
measurement.
Approximate Elapsed
13. Preparation of Evaporometer
Time to 100 % Report to Nearest
Evaporated Point, s Indicated Value, s
13.1 Place the filter paper disk on the wire frame threading
Less than 300 1
thehookthroughasmallholeinthecenterofthepaper.Attach
300 to 600 5
600 to 1800 10 the wire frame to the support hook in the evaporometer.
1800 to 3600 30
3600 to 7200 60
More than 7200 nearest 2 % of indicated value Supporting data have been filed atASTM International Headquarters and may
be obtained by requesting Research Report RR: D01-1003.
NOTE 3—The curve drawn through the various points should pass
The automatic Shell thin-film evaporometer, Apparatus Catalog No. F1522 is
through zero or the origin. If it passes to the right of the origin, the
available from the Falex Corporation, Inc., 2055 Comprehensive Drive,Aurora, IL
delivery time was in excess of 12 s or an aliquot larger than that specified 60505.
D3539 – 87 (2004)
FIG. 3 Automatic Thin-Film Evaporometer
13.2 Close the evaporometer and cabinet doors and equili- specimen onto the filter paper. The complete specimen should
brate both chambers as in 6.2. bedispenseduniformlyin10 62salongtheline.Therecorder
13.3 Adjust the air flow to 21 min/L.
pen will “advance” immediately to an “apex” position equiva-
lent to the total weight of the specimen, less that portion that
14. Conditioning of Sample
evaporated during the application period. The pen will gradu-
14.1 See 7.1.
ally return to its original position as the solvent evaporates and
the chart advances. The evaporation is complete when the
15. Procedure
recording pen has returned to its original “no-load” position.
15.1 When all components (including the filter paper in
NOTE 6—It is common for the final portion of the curve to exhibit a
place) are at equilibrium, adjust the recording pen to a
“tailing-off.” This is due to artifacts of the method such as (1) hydrogen
prominent “zero” position near the edge of the chart on the
bonding of the last traces of solvent with the cellulose fibers of the filter
recorder; then turn the switch for the chart motor to the OFF
paper and (2) a gradual diminution of the area of the filter paper wet by
position. This constitutes the “zero” load and time position for
solvent (that is, in the final stage of evaporation, drying of the paper
the test.
progresses from the outer edge toward the center of the disk). Thus, it is
common practice for the evaporation cycle to be considered “complete”
NOTE 4—The milliampere range and chart speed should be selected, if
when the recording pen returns to 99.5% of the original displacement.
possible, so that the dimensions of the weight and time axes of the plotted
curve are approximately the same length.
16. Calculations and Reporting
15.2 Measure 0.70 mL of test sample into the hypodermic
...

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