ASTM D1434-82(2003)
(Test Method)Standard Test Method for Determining Gas Permeability Characteristics of Plastic Film and Sheeting
Standard Test Method for Determining Gas Permeability Characteristics of Plastic Film and Sheeting
SIGNIFICANCE AND USE
These measurements give semiquantitative estimates for the gas transmission of single pure gases through film and sheeting. Correlation of measured values with any given use, such as packaged contents protection, must be determined by experience. The gas transmission rate is affected by conditions not specifically provided for in these tests, such as moisture content (Note 2), plasticizer content, and nonhomogeneities. These tests do not include any provision for testing seals that may be involved in packaging applications.
Note 2—The tests are run using gas with 0 % moisture changes.
Interlaboratory testing has revealed that permeances measured by these procedures exhibit a strong dependence on the procedure being used, as well as on the laboratory performing the testing. Agreement with other methods is sometimes poor and may be material-dependent. The materials being tested often affect the between-laboratory precision. The causes of these variations are not known at this time. It is suggested that this method not be used for referee purposes unless purchaser and seller can both establish that they are measuring the same quantity to a mutually agreed upon level of precision.
Use of the permeability coefficient (involving conversion of the gas transmission rate to a unit thickness basis) is not recommended unless the thickness-to-transmission rate relationship is known from previous studies. Even in essentially homogeneous structures, variations in morphology (as indicated, for example, by density) and thermal history may influence permeability.
SCOPE
1.1 This test method covers the estimation of the steady-state rate of transmission of a gas through plastics in the form of film, sheeting, laminates, and plastic-coated papers or fabrics. This test method provides for the determination of (1) gas transmission rate (GTR), (2) permeance, and, in the case of homogeneous materials, (3) permeability.
1.2 Two procedures are provided:
1.2.1 Procedure M Manometric.
1.2.2 Procedure V Volumetric.
1.3 The values stated in SI units are to be regarded as the standard.
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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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation:D1434–82 (Reapproved 2003)
Standard Test Method for
Determining Gas Permeability Characteristics of Plastic Film
and Sheeting
This standard is issued under the fixed designation D1434; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope used unit of GTR, is 1 mL (STP)/(m ·d) at a pressure
differential of one atmosphere.
1.1 This test method covers the estimation of the steady-
3.1.2 permeance, P—the ratio of the gas transmission rate
state rate of transmission of a gas through plastics in the form
to the difference in partial pressure of the gas on the two sides
of film, sheeting, laminates, and plastic-coated papers or
of the film. The SI unit of permeance is 1 mol/ (m ·s·Pa). The
fabrics. This test method provides for the determination of (1)
test conditions (see 5.1) must be stated.
gastransmissionrate(GTR),(2)permeance,and,inthecaseof
3.1.3 permeability,P—theproductofthepermeanceandthe
homogeneous materials, (3) permeability.
thickness of a film. The permeability is meaningful only for
1.2 Two procedures are provided:
homogeneous materials, in which it is a property characteristic
1.2.1 Procedure M— Manometric.
of the bulk material. This quantity should not be used unless
1.2.2 Procedure V— Volumetric.
the constancy of the permeability has been verified using
1.3 The values stated in SI units are to be regarded as the
severaldifferentthicknessesofthematerial.TheSIunitofPis
standard.
1 mol/(m·s·Pa). The test conditions (see 3.1) must be stated.
1.4 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
NOTE 1—One millilitre (STP) is 44.62 µmol, one atmosphere is 0.1013
responsibility of the user of this standard to establish appro- MPa, and one day is 86.4 310 s. GTR in SI units is obtained by
−10
multiplying the value in inch-pound units by 5.160 310 . Additional
priate safety and health practices and determine the applica-
units and conversions are shown in Appendix X1.
bility of regulatory limitations prior to use.
3.1.4 steady state—the state attained when the amount of
2. Referenced Documents
gas absorbed in the film is in equilibrium with the flux of gas
2.1 ASTM Standards:
through the film. For MethodVthis is obtained when the GTR
D618 Practice for Conditioning Plastics for Testing
is constant.
D1898 Practice for Sampling of Plastics
4. Summary of Test Method
3. Terminology
4.1 The sample is mounted in a gas transmission cell so as
3.1 Definitions of Terms Specific to This Standard:
to form a sealed semibarrier between two chambers. One
3.1.1 gas transmission rate, GTR— the quantity of a given
chamber contains the test gas at a specific high pressure, and
gas passing through a unit of the parallel surfaces of a plastic
theotherchamber,atalowerpressure,receivesthepermeating
film in unit time under the conditions of test. The SI unit of
gas. Either of the following procedures is used:
GTR is 1 mol/(m ·s). The test conditions, including tempera-
4.1.1 Procedure M— In Procedure M the lower pressure
ture and partial pressure of the gas on both sides of the film,
chamber is initially evacuated and the transmission of the gas
must be stated. Other factors, such as relative humidity and
through the test specimen is indicated by an increase in
hydrostatic pressure, that influence the transport of the gas
pressure.
must also be stated.The inch-pound unit of GTR, a commonly
4.1.2 Procedure V— In Procedure V the lower pressure
chamber is maintained near atmospheric pressure and the
transmission of the gas through the test specimen is indicated
ThistestmethodisunderthejurisdictionofASTMCommitteeF02onFlexible
by a change in volume.
Barrier Materials and is the direct responsibility of Subcommittee F02.10 on
Permeation.
Current edition approved July 30, 1982. Published November 1982. Originally 5. Significance and Use
published as D1434–56T. Last previous edition D1434–75.
5.1 Thesemeasurementsgivesemiquantitativeestimatesfor
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
the gas transmission of single pure gases through film and
contactASTM Customer Service at service@astm.org. ForAnnual Book ofASTM
Standards volume information, refer to the standard’s Document Summary page on
sheeting. Correlation of measured values with any given use,
the ASTM website.
such as packaged contents protection, must be determined by
Withdrawn.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D1434–82 (2003)
experience. The gas transmission rate is affected by conditions
not specifically provided for in these tests, such as moisture
content (Note 2), plasticizer content, and nonhomogeneities.
These tests do not include any provision for testing seals that
may be involved in packaging applications.
NOTE 2—The tests are run using gas with 0% moisture changes.
5.2 Interlaboratory testing has revealed that permeances
measured by these procedures exhibit a strong dependence on
the procedure being used, as well as on the laboratory
performing the testing. Agreement with other methods is
sometimes poor and may be material-dependent.The materials
being tested often affect the between-laboratory precision. The
causes of these variations are not known at this time. It is
suggested that this method not be used for referee purposes
unless purchaser and seller can both establish that they are
measuringthesamequantitytoamutuallyagreeduponlevelof
FIG. 1 Manometric Gas Transmission Cell
precision.
5.3 Use of the permeability coefficient (involving conver-
sionofthegastransmissionratetoaunitthicknessbasis)isnot
material. Enough specimens must be tested to ensure that the
recommended unless the thickness-to-transmission rate rela-
information obtained is representative of the batch or other lot
tionship is known from previous studies. Even in essentially
size being tested.
homogeneous structures, variations in morphology (as indi-
PROCEDURE M
cated, for example, by density) and thermal history may
influence permeability.
(Pressurechangesinthemanometriccellmaybedetermined
by either visual or automatic recording.)
6. Test Specimen
MANOMETRIC VISUAL DETERMINATION
6.1 Thetestspecimenshallberepresentativeofthematerial,
free of wrinkles, creases, pinholes, and other imperfections,
9. Apparatus
and shall be of uniform thickness. The test specimen shall be
9.1 The apparatus shown in Fig. 1 and Fig. 2 consists of the
cuttoanappropriatesize(generallycircular)tofitthetestcell.
following items:
6.2 The thickness of the specimen shall be measured to the
9.1.1 Cell Manometer System—The calibrated cell manom-
nearest 2.5 µm (0.1 mil) with a calibrated dial gage (or
eter leg, which indicates the pressure of transmitted gas, shall
equivalent) at a minimum of five points distributed over the
consist of precision-bore glass capillary tubing at least 65 mm
entire test area. Maximum, minimum, and average values
long with an inside diameter of 1.5 mm.
should be recorded. An alternative measure of thickness
9.1.2 Cell Reservoir System, consisting of a glass reservoir
involving the weighing of a known area of specimens having a
of sufficient size to contain all the mercury required in the cell.
known density is also suitable for homogeneous materials.
9.1.3 Adapters—Solid and hollow adapters for measure-
ment of widely varying gas transmission rates. The solid
7. Conditioning
adapter provides a minimum void volume for slow transmis-
7.1 Standard Conditioning—Condition all test specimens at
sion rates. The hollow adapter increases the void volume by
23 6 2°C (73.4 6 3.6°F) in a desiccator over calcium chloride
about a factor of eight for faster transmission rates.
or other suitable desiccant for not less than 48 h prior to test in
9.1.4 Cell Vacuum Valve, capable of maintaining a vacuum-
accordance with Practice D618, for those tests where condi-
tight seal.
tioning is required. In cases of disagreement, the tolerances
9.1.5 Plate Surfaces, that contact the specimen and filter
shall be 6 1°C (6 1.8°F).
paper shall be smooth and flat.
7.2 Alternative Conditioning—Alternatives to 7.1 may be 9.1.6 O-Ring, for sealing the upper and lower plates.
9.1.7 Pressure Gage, mechanical or electrical type with a
used for conditioning the specimens provided that these
conditions are described in the report. range from 0 to 333 kPa absolute. Used for measuring
upstream gas pressure.
8. Sampling 9.1.8 Barometer, suitable for measuring the pressure of the
atmosphere to the nearest 133 Pa.
8.1 The techniques used in sampling a batch of material to
be tested by these procedures must depend upon the kind of
information that is sought. Care should be taken to ensure that
TheDowgastransmissioncellsuppliedbyCustomScientificInstruments,Inc.,
samples represent conditions across the width and along the
Whippany, NJ, has been found satisfactory for this purpose.
length of rolls of film. Practice D1898 provides guidelines for 1
The Demi-G Valve ( ⁄4-in. IPS) manufactured by G. W. Dahl Co., Inc., Bristol,
deciding what procedures to use in sampling a batch of RI, or a precision-ground glass stopcock, meets this requirement.
D1434–82 (2003)
A—Supporting Legs
FIG. 3 Cell Manometer with Test Specimen in Place
B—Lower Plate
C—Upper Plate
D—Adapter suchdiscontinuitiesoccur,themercuryshouldberemovedand
E—Vacuum Valve
the cell cleaned as follows:
FIG. 2 Schematic View of Gas Transmission Cell
(1) Wash with toluene (to remove greases and oils).
(2) Wash with acetone (to remove toluene).
(3) Wash with distilled water (to remove acetone).
9.1.9 Vacuum Gage, to register the pressure during evacua-
(4) Wash with a 1+1 mixture of nitric acid and distilled
tion of the system to the nearest 13 Pa.
water (to remove any mercury salts that may be present). This
9.1.10 Vacuum Pump, capable of reducing the pressure in
operation may be repeated if necessary in order to ensure
the system to 26 Pa or less.
complete cleaning of glassware.
9.1.11 Needle Valve, for slowly admitting and adjusting the
(5) Wash with distilled water (to remove nitric acid).
pressure of the test gas.
(6) Wash with acetone (to remove water).
9.1.12 Cathetometer, to measure the height of mercury in
(7) Dry the cell at room temperature or by blowing a small
the cell manometer leg accurately. This instrument should be
amount of clean dry air through it.
capable of measuring changes to the nearest 0.5 mm.
9.1.13 Micrometer, to measure specimen thickness, gradu-
11. Calibration
ated to 2.5 µm (0.1 mil) or better.
11.1 Eachcellshouldbecalibratedatthetesttemperatureas
9.1.14 Elevated-Temperature Fittings—Special cell fittings
follows (Fig. 3):
are required for high-temperature testing.
11.1.1 Determine the void volume of the filter paper from
the absolute density of its fiber content (Note 3), the weight of
10. Materials
the filter paper, and its apparent volume (Note 4). Express the
10.1 Test Gas—Thetestgasshallbedryandpure.Theratio
void volume determined in this way in microlitres and desig-
of the volume of gas available for transmission to the volume
nate as V .
CD
of gas transmitted at the completion of the test shall be at least
100:1.
NOTE 3—Any high-grade, medium-retention qualitative nonashing cel-
10.2 Mercury—Mercury used in the cell shall be triple lulosicfilterpaper,90mmindiameterwillbesatisfactoryforthispurpose.
Cellulose fiber has an approximate density of 1.45 g/mL.
distilled, checked regularly for purity, and replaced with clean
NOTE 4—The apparent volume may be calculated from the thickness
mercury when necessary.
and diameter of the filter paper.
10.2.1 Warning—Verylowconcentrationsofmercuryvapor
11.1.2 Determine the volume of the cell manometer leg
in the air are known to be hazardous. Guidelines for using
from B to C, Fig. 3, by mercury displacement. (Since the void
mercury in the laboratory have been published by Steere. Be
volume of the adapters is included in this part of the calibra-
sure to collect all spilled mercury in a closed container.
tion,thevolumefromBtoCshouldbedeterminedtwice,once
Transfers of mercury should be made over a large plastic tray.
withthesolidadapterinplace,andoncewiththehollow.)This
Under normal daily laboratory-use conditions, the cells should
volume is obtained by dividing the weight of the mercury
be cleaned about every 3 months. Dirty mercury is indicated
displaced by its density (Note 5). Determine this volume to
when the drop of the capillary becomes erratic or when
nearest 1 µL and designate as V .
mercury clings to the side of the capillary, or both. Whenever
BC
NOTE 5—The density of mercury at 23°C is 13.54 g/mL.
11.1.3 Determine the volume, in microlitres, of the cell
Steere, N. E. “Mercury Vapor Hazards and Control Measures” in Handbook of
Laboratory Safety, N. V. Steere, Ed., CRC Press Inc., Boca Raton, FL, 1979. manometer leg from A to B, Fig. 3, by mercury displacement.
D1434–82 (2003)
Determine the average cross-sectional area of the capillary by
dividingthisvolumebythelength(expressedtothenearest0.1
mm) from A to B. Determine this area to the nearest 0.01 mm
and designate as a .
c
11.1.4 Determine the area of the filter paper cavity to the
nearest 1 mm . Designate this area as A, the area of transmis-
sion.
11.1.5 Pourthemercuryfromthereservoirintothemanom-
eterofthecellbycarefullytippingthecell.Recordthedistance
from the datum plane to the upper calibration line B in the
capillary leg as h . Record the distance from the datum plane
B
to the top of the mercury meniscus in the reservoir leg as h .
L
Determine h and h to the nearest 0.5 mm.
B L
11.2 NBS Standard Reference Material 1470 is a polyester
film whose permeance to oxygen gas has been certified for a
range of experimental conditions. The calibration steps in 11.1
canbeverifiedbycomparingmeasurementsobtainedusingthis
methodoftestintheuser’slaboratorywiththevaluesprovided
on the certificate accompanying the SRM. FIG. 4 Component Arrangement of Gas Transmission Equipment
12. Procedure
entire procedure. (If a leak occurs on a second trial, this may indicate a
12.1 Transfer all the mercury into the reservoir of the cell
mechanical failure of the equipment.)
manometer system by carefully tipping the cell in such a way
12.12 Record the height of the mercury in the capillary leg,
that the mercury pours into the reservoir.
h , at the start of each test, that is, immediately before the test
o
12.2 Ins
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