ASTM E398-03(2009)e1
(Test Method)Standard Test Method for Water Vapor Transmission Rate of Sheet Materials Using Dynamic Relative Humidity Measurement
Standard Test Method for Water Vapor Transmission Rate of Sheet Materials Using Dynamic Relative Humidity Measurement
SIGNIFICANCE AND USE
No single set of test conditions can represent all climatic and use conditions, so this WVTR test method serves more to compare different materials at a stated set of conditions than to predict their actual performance in the field under any conditions.
The water vapor transmission rate, under known and carefully controlled conditions, may be used to evaluate the vapor barrier qualities of a sheet. Direct correlation of values obtained under different conditions of test temperature and relative humidity will be valid provided the barrier material under test does not undergo changes in solid state (such as a crystalline transition or melting point) at or between the conditions of test.
SCOPE
1.1 This test method covers dynamic evaluation of the rate of transfer of water vapor through a flexible barrier material and allows conversion to the generally recognized units of water vapor transmission (WVT) as obtained by various other test methods including the gravimetric method described in Test Methods E 96/E 96M.
1.2 Limitations—This test method is limited to flexible barrier sheet materials composed of either completely hydrophobic materials, or combinations of hydrophobic and hydrophilic materials having at least one surface that is hydrophobic.
1.3 The minimum test value obtained by this test method is limited by the leakage of water vapor past the clamping seals of the test instrument. A reasonable value may be approximately 0.01 g/24 h·m2 for any WVTR method including the desiccant procedure of Test Methods E 96/E 96M at 37.8°C, and 90 % relative humidity. This limit can be checked for each instrument with an impervious specimen such as aluminum foil. Calibration procedures can compensate for the leakage rate if so stated.
1.4 This test method is not suitable for referee testing at this time, but is suitable for control testing and material comparison.
1.5 Several other ASTM test methods are available to test a similar property. This test method is unique in that it closely duplicates typical product storage where a transfer of moisture from a package into the environment is allowed to proceed without constantly sweeping the environmental side with dry gas. Methods with constantly swept dry sides include Test Methods F 1249, F 372, and F 1770.
1.6 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.7 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.
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´1
Designation: E398 − 03(Reapproved 2009)
Standard Test Method for
Water Vapor Transmission Rate of Sheet Materials Using
Dynamic Relative Humidity Measurement
This standard is issued under the fixed designation E398; 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.
´ NOTE—Units information was revised editorially in May 2009.
1. Scope 1.6 The values stated in SI units are to be regarded as
standard. No other units of measurement are included in this
1.1 This test method covers dynamic evaluation of the rate
standard.
of transfer of water vapor through a flexible barrier material
1.7 This standard does not purport to address all of the
and allows conversion to the generally recognized units of
safety concerns, if any, associated with its use. It is the
water vapor transmission (WVT) as obtained by various other
responsibility of the user of this standard to establish appro-
test methods including the gravimetric method described in
priate safety and health practices and determine the applica-
Test Methods E96/E96M.
bility of regulatory limitations prior to use.
1.2 Limitations—This test method is limited to flexible
2. Referenced Documents
barrier sheet materials composed of either completely hydro-
phobic materials, or combinations of hydrophobic and hydro-
2.1 ASTM Standards:
philic materials having at least one surface that is hydrophobic.
C168 Terminology Relating to Thermal Insulation
E96/E96M Test Methods for Water Vapor Transmission of
1.3 The minimum test value obtained by this test method is
Materials
limited by the leakage of water vapor past the clamping seals
F17 Terminology Relating to Flexible Barrier Packaging
of the test instrument. A reasonable value may be approxi-
2 F372 Test Method for Water Vapor Transmission Rate of
mately 0.01 g/24 h·m for any WVTR method including the
Flexible Barrier Materials Using an Infrared Detection
desiccant procedure ofTest MethodsE96/E96Mat 37.8°C, and
Technique (Withdrawn 2009)
90 % relative humidity. This limit can be checked for each
F1249 Test Method for Water Vapor Transmission Rate
instrument with an impervious specimen such as aluminum
Through Plastic Film and Sheeting Using a Modulated
foil. Calibration procedures can compensate for the leakage
Infrared Sensor
rate if so stated.
F1770 Test Method for Evaluation of Solubility, Diffusivity,
1.4 This test method is not suitable for referee testing at this and Permeability of Flexible Barrier Materials to Water
Vapor (Withdrawn 2004)
time, but is suitable for control testing and material compari-
son.
3. Terminology
1.5 Several otherASTM test methods are available to test a
3.1 Definitions—For definitions of terms concerning the
similar property. This test method is unique in that it closely
transmission of water vapor refer to Terminologies C168 and
duplicates typical product storage where a transfer of moisture
F17.
from a package into the environment is allowed to proceed
without constantly sweeping the environmental side with dry
4. Summary of Test Method
gas. Methods with constantly swept dry sides include Test
4.1 Thespecimenismountedbetweentwochambers,oneof
Methods F1249, F372, and F1770.
relatively high relative humidity and the other of relatively low
relative humidity. After conditioning and isolation of
This test method is under the jurisdiction ofASTM Committee F02 on Flexible
Barrier Packaging and is the direct responsibility of Subcommittee F02.10 on For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Permeation. A previous version was under the jurisdiction of ASTM Committee contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
C16. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved May 1, 2009. Published June 2009. Originally the ASTM website.
approved in 1970. Last previous edition approved in 2003 as E398 – 03. DOI: The last approved version of this historical standard is referenced on
10.1520/E0398-03R09E01. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
´1
E398 − 03 (2009)
FIG. 1 Sectional Diagram of a Typical Test Chamber Using Relative Humidity Sensing
chambers, the rate at which the moisture increases within the spacing 8 mm or less, between the water source and the
relatively low relative humidity chamber over a predetermined specimen and yet no direct contact. Other levels of relative
range of interest is measured. This rate is compared to the rate humidity may be obtained with saturated salt solutions or a
for a calibration sample (calibrated gravimetrically) and the stream of controlled humidified air.
WVTR is determined. 6.1.4 Air Source—Air dried below the operating humidity
range of the instrument (5 % relative humidity or less) shall be
5. Significance and Use
used as a purge for the sensor-side chamber.Various desiccants
5.1 Nosinglesetoftestconditionscanrepresentallclimatic have been found satisfactory as drying agents.
6.1.5 Sensor, with rapid response and sensitivity capable of
and use conditions, so this WVTR test method serves more to
compare different materials at a stated set of conditions than to detecting changes in the moisture content of the gas within the
dry chamber of 0.05 % relative humidity or less. This sensor
predict their actual performance in the field under any condi-
may take any of a number of forms. For this purpose, the
tions.
following have been described in the literature: an electrical
5.2 The water vapor transmission rate, under known and
4 5
resistance element, an electrolytic cell, and a beam of
carefully controlled conditions, may be used to evaluate the
infrared radiation.
vapor barrier qualities of a sheet. Direct correlation of values
6.1.6 Data Collection, a means to convert the sensor’s
obtained under different conditions of test temperature and
moisture-change response into a signal that can be used to
relative humidity will be valid provided the barrier material
calculate the passage of moisture through the material under
under test does not undergo changes in solid state (such as a
test.This may take the form of registering the time required for
crystalline transition or melting point) at or between the
the signal to pass between two selected levels of relative
conditions of test.
humidity, or the change in signal over a given interval of time.
6.1.7 Temperature Control, a means of maintaining the
6. Apparatus
test-cell purge air and the test specimen at a constant known
6.1 The apparatus employed should have the following
temperature within 60.1°C is provided.
elements:
6.1.8 Standard Films, which have been calibration by gra-
6.1.1 Test Cell, designed to clamp a defined sample area
vimetric means. Various films have been found satisfactory
sufficiently large to be representative of the sample (an area of
with various thicknesses of PET most commonly used.
50 cm has been shown to be satisfactory) between two
chambers, one to contain an atmosphere of low relative
7. Test Specimens or Sample
humidity (sensor-side chamber), and the other an atmosphere
7.1 Test specimens shall be representative of the sample.
of higher relative humidity (humidified chamber) (see Fig. 1).
7.2 Where the test specimen is completely hydrophobic, no
6.1.2 Clamping Arrangement, to allow rapid insertion and
special conditioning procedure is required except that the
removal of the test specimen equipped
...
This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
´1
Designation:E398–03 Designation:E398–03 (Reapproved 2009)
Standard Test Method for
Water Vapor Transmission Rate of Sheet Materials Using
Dynamic Relative Humidity Measurement
This standard is issued under the fixed designation E 398; 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.
´ NOTE—Units information was revised editorially in May 2009.
1. Scope
1.1 This test method covers dynamic evaluation of the rate of transfer of water vapor through a flexible barrier material and
allows conversion to the generally recognized units of water vapor transmission (WVT) as obtained by various other test methods
including the gravimetric method described in Test Methods E 96/E 96M.
1.2 Limitations—This test method is limited to flexible barrier sheet materials composed of either completely hydrophobic
materials, or combinations of hydrophobic and hydrophilic materials having at least one surface that is hydrophobic.
1.3 The minimum test value obtained by this test method is limited by the leakage of water vapor past the clamping seals of
the test instrument. A reasonable value may be approximately 0.01 g/24 h·m for any WVTR method including the desiccant
procedure of Test Methods E 96/E 96M at 37.8°C (100°F),37.8°C, and 90 % relative humidity. This limit can be checked for each
instrument with an impervious specimen such as aluminum foil. Calibration procedures can compensate for the leakage rate if so
stated.
1.4 This test method is not suitable for referee testing at this time, but is suitable for control testing and material comparison.
1.5The values stated in SI units are to be regarded as standard. The values gives in parentheses are provided for information
purposes only.
1.6Several 1.5 Several other ASTM test methods are available to test a similar property. This test method is unique in that it
closely duplicates typical product storage where a transfer of moisture from a package into the environment is allowed to proceed
without constantly sweeping the environmental side with dry gas. Methods with constantly swept dry sides include Test Methods
F 1249, ASTM F 372, and ASTM F 1770.
1.6 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.7 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.
2. Referenced Documents
2.1 ASTM Standards:
C 168 Terminology Relating to Thermal Insulation
C677 Practice for Use of a Polyethylene Terephthalate Reference Film for the Measurement of the Time-Averaged Vapor
Pressure in a Controlled Humidity Space
E 96/E 96M Test Methods for Water Vapor Transmission of Materials
F17 Terminology Relating to Flexible Barrier Packaging
F 372 Test Method for Water Vapor Transmission Rate of Flexible Barrier Materials Using an Infrared Detection Technique
F 1249 Test Method forWaterVaporTransmission RateThrough Plastic Film and Sheeting Using a Modulated Infrared Sensor
F 1770 Test Method for Evaluation of Solubility, Diffusivity, and Permeability of Flexible Barrier Materials to Water Vapor
3. Terminology
3.1 Definitions—For definitions of terms concerning the transmission of water vapor refer to Terminologies C 168 and F 17.
This test method is under the jurisdiction of ASTM Committee F02 on Flexible Barrier MaterialsPackaging and is the direct responsibility of Subcommittee F02.10 on
Permeation. A previous version was under the jurisdiction of ASTM Committee C16.
Current edition approved May 10, 2003. Published July 2003. Originally approved in 1970. Discontinued in 1994 and reinstated as E 398–03.
Current edition approved May 1, 2009. Published May 2009. Originally approved in 1970. Last previous edition approved in 2003 as E 398 – 03.
For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM 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.
´1
E398–03 (2009)
4. Summary of Test Method
4.1 The specimen is mounted between two chambers, one of relatively high relative humidity and the other of relatively low
relative humidity.After conditioning and isolation of chambers, the rate at which the moisture increases within the relatively low
relative humidity chamber over a predetermined range of interest is measured. This rate is compared to the rate for a calibration
sample (calibrated gravimetrically) and the WVTR is determined.
5. Significance and Use
5.1 No single set of test conditions can represent all climatic and use conditions, so this WVTR test method serves more to
compare different materials at a stated set of conditions than to predict their actual performance in the field under any conditions.
5.2 The water vapor transmission rate, under known and carefully controlled conditions, may be used to evaluate the vapor
barrierqualitiesofasheet.Directcorrelationofvaluesobtainedunderdifferentconditionsoftesttemperatureandrelativehumidity
will be valid provided the barrier material under test does not undergo changes in solid state (such as a crystalline transition or
melting point) at or between the conditions of test.
6. Apparatus
6.1 The apparatus employed should have the following elements:
6.1.1 Test Cell, designed to clamp a defined sample area sufficiently large to be representative of the sample (an area of 50 cm
has been shown to be satisfactory) between two chambers, one to contain an atmosphere of low relative humidity (sensor-side
chamber), and the other an atmosphere of higher relative humidity (humidified chamber) (see Fig. 1).
6.1.2 Clamping Arrangement, to allow rapid insertion and removal of the test specimen equipped with gaskets against which
the specimen is held to the dry chamber by a clamping force sufficient to resist leakage.
6.1.3 Humidification Provision, for maintaining humidity in the wet cell at the desired level. Where an atmosphere close to
saturation is required, this may be achieved by means of a reservoir of water or a saturated sponge provided there is a spacing 8
mm (0.31 in.) or less, between the water source and the specimen and yet no direct contact. Other levels of relative humidity may
be obtained with saturated salt solutions or a stream of controlled humidified air.
6.1.4 Air Source—Air dried below the operating humidity range of the instrument (5 % relative humidity or less) shall be used
as a purge for the sensor-side chamber. Various desiccants have been found satisfactory as drying agents.
6.1.5 Sensor, with rapid response and sensitivity capable of detecting changes in the moisture content of the gas within the dry
chamber of 0.05 % relative humidity or less. This sensor may take any of a number of forms. For this purpose, the following have
3 4
been described in the literature: an electrical resistance element, an electrolytic cell, an electrolytic cell and a beam of infrared
radiation.
6.1.6 Data Collection, a means to convert the sensor’s moisture-change response into a signal that can be used to calculate the
passage of moisture through the material under test. This may take the form of registering the time required for the signal to pass
Ranger, H. O., and Gluckman, M. J., Modern Packagi
...
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