ASTM F2622-08(2013)
(Test Method)Standard Test Method for Oxygen Gas Transmission Rate Through Plastic Film and Sheeting Using Various Sensors
Standard Test Method for Oxygen Gas Transmission Rate Through Plastic Film and Sheeting Using Various Sensors
SIGNIFICANCE AND USE
5.1 The O2GTR is an important determinant of the packaging protection afforded by barrier materials. It is not, however, the sole determinant, and additional tests, based on experience, must be used to correlate packaging performance with O2GTR. It is suitable as a referee method of testing, provided that the purchaser and the seller have agreed on sampling procedures, standardization procedures, test conditions, and acceptance criteria.
5.2 Testing which has compared select instruments with other sensors to the instruments specifically described in Test Method D3985 is shown in Section 16, Precision and Bias, of this method.
5.3 The Precision and Bias section of this method shows results using several instruments with non-coulometric and coulometric sensors.
SCOPE
1.1 This test method covers a procedure for determination of the steady-state rate of transmission of oxygen gas through plastics in the form of film, sheeting, laminates, coextrusions, or plastic-coated papers or fabrics. It provides for the determination of (1) oxygen gas transmission rate (O2GTR), (2) the permeance of the film to oxygen gas (PO2), and (3) oxygen permeability coefficient (P'O2) in the case of homogeneous materials.
1.2 This test method does not purport to be the only method for measurement of O2GTR. There may be other methods of O2GTR determination that use other oxygen sensors and procedures.
1.3 This test method has intentionally been prepared to allow for the use of various sensors, devices, and procedures. The precision and bias of each design needs to be individually established to determine the applicability of that instrument or method to meet the needs of the user.
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
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.
General Information
Relations
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: F2622 − 08 (Reapproved 2013)
Standard Test Method for
Oxygen Gas Transmission Rate Through Plastic Film and
Sheeting Using Various Sensors
This standard is issued under the fixed designation F2622; 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.
1. Scope D3985Test Method for Oxygen Gas Transmission Rate
Through Plastic Film and Sheeting Using a Coulometric
1.1 This test method covers a procedure for determination
Sensor
of the steady-state rate of transmission of oxygen gas through
plastics in the form of film, sheeting, laminates, coextrusions,
3. Terminology
or plastic-coated papers or fabrics. It provides for the determi-
3.1 Definitions:
nation of (1) oxygen gas transmission rate (O GTR), (2) the
3.1.1 oxygen permeability coeffıcient (P'O )—theproductof
permeance of the film to oxygen gas (PO ), and (3) oxygen
the permeance and the thickness of film. The permeability is
permeability coefficient (P’O ) in the case of homogeneous
meaningfulonlyforhomogeneousmaterials,inwhichcaseitis
materials.
a property characteristic of the bulk material. The oxygen
1.2 Thistestmethoddoesnotpurporttobetheonlymethod
permeabilitycoefficientshouldnotbeused,unlesstherelation-
for measurement of O GTR. There may be other methods of
ship between thickness and permeance has been verified on
O GTR determination that use other oxygen sensors and
tests using several different thicknesses of the material. The SI
procedures.
unit of oxygen permeability is the mol/(m·s·Pa). The test
1.3 This test method has intentionally been prepared to conditions (see 3.1.3) must be stated.
allow for the use of various sensors, devices, and procedures.
3.1.2 oxygen permeance (PO )—the ratio of the O GTR to
2 2
The precision and bias of each design needs to be individually
the difference between the partial pressure of O on the two
established to determine the applicability of that instrument or
sidesofthefilm.TheSIunitofpermeanceisthemol/(m ·s·Pa).
method to meet the needs of the user.
The test conditions (see 15.1) must be stated.
1.4 The values stated in SI units are to be regarded as
3.1.3 oxygen transmission rate (O GTR)—the quantity of
standard. No other units of measurement are included in this
oxygen gas passing through a unit area of the parallel surfaces
standard.
of a plastic film per unit time under the conditions of test. The
SI unit of transmission rate is the mol/(m ·s). The test
1.5 This standard does not purport to address all of the
conditions, including temperature and oxygen partial pressure
safety concerns, if any, associated with its use. It is the
on both sides of the film must be stated.
responsibility of the user of this standard to establish appro-
3.1.3.1 Discussion—AcommonlyusedunitofO GTRisthe
priate safety and health practices and determine the applica-
3 2
cm (STP)⁄m ·d) at one atmosphere pressure difference where
bility of regulatory limitations prior to use.
1cm (STP) is 44.62 µmol, 1 atm is 0.1013 MPa, and one day
2. Referenced Documents
is 86.4 × 10 s. The O GTR in SI units is obtained by
-10
multiplying the value in inch-pound units by 5.160 × 10 .
2.1 ASTM Standards:
D1898Practice for Sampling of Plastics (Withdrawn 1998)
4. Summary of Test Method
4.1 Theoxygengastransmissionrateisdeterminedafterthe
ThistestmethodisunderthejurisdictionofASTMCommitteeF02onFlexible
sample has equilibrated in a controlled test environment.
Barrier Packaging and is the direct responsibility of Subcommittee F02.10 on
Control of carrier gas flow rate (for concentration detectors),
Permeation.
relative humidity, temperature, and oxygen concentration in
Current edition approved Oct. 1, 2013. Published November 2013. Originally
approved in 2008. Last previous edition approved in 2008 as F2622 – 08. DOI:
both the carrier gas and permeant (test) gas chambers is
10.1520/F2622-08R13.
critical.
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
4.2 The specimen is mounted as a sealed semi-barrier
Standards volume information, refer to the standard’s Document Summary page on
between two chambers at ambient atmospheric pressure. A
the ASTM website.
stream of nitrogen slowly purges one chamber and the other
The last approved version of this historical standard is referenced on
www.astm.org. chamber contains oxygen. As oxygen gas permeates through
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F2622 − 08 (2013)
the film into the nitrogen carrier gas, it is transported to the Valves connect the carrier gas side of each individual diffusion
detector where it produces a signal representing the oxygen cell to the sensor in a predetermined pattern. Carrier gas is
transmission rate. continually purging the carrier gas sides of those cells that are
not connected to the sensor. Either test gas or carrier gas, as is
5. Significance and Use
appropriate, purges the test gas chamber of any individual cell.
5.1 The O GTR is an important determinant of the pack- 7.1.2 Flow Controller—A flow controller will control the
flow of carrier and test gases with sufficient precision to allow
aging protection afforded by barrier materials. It is not,
however, the sole determinant, and additional tests, based on determinationoftheoxygenpermeabilityininstrumentswhich
calculate the oxygen permeability based on the oxygen con-
experience, must be used to correlate packaging performance
with O GTR. It is suitable as a referee method of testing, centration change in the carrier gas stream. In some instru-
ments(suchastheCoulometric),theflowratedoesnotneedto
provided that the purchaser and the seller have agreed on
sampling procedures, standardization procedures, test be controlled as precisely.
7.1.3 Flow Switching Valves—Valves for the switching of
conditions, and acceptance criteria.
the nitrogen and test gas flow streams.
5.2 Testing which has compared select instruments with
7.1.4 Sensor—An oxygen-sensitive sensor with sufficient
other sensors to the instruments specifically described in Test
sensitivity and precision to yield meaningful results can use
Method D3985 is shown in Section 16, Precision and Bias, of
various operating principles including coulometric, electro-
this method.
chemical and zirconium oxide. Different sensors may have
5.3 The Precision and Bias section of this method shows
different levels of sensitivity. The user should select the
results using several instruments with non-coulometric and
instrument/sensor system which will adequately cover the
coulometric sensors.
oxygen permeation range and degree of precision of interest.
7.1.5 Data Recording System—An appropriate data record-
6. Interferences
ing system shall record all pertinent information. Various
6.1 The presence of certain interfering substances in the
integrated and external computer systems have been found
carrier gas stream may give rise to unwanted electrical outputs
effective.
and error factors. Interfering substances include carbon
monoxide, hydrocarbons, free chlorine, and some strong oxi-
8. Reagents and Materials
dizing agents. Exposure to carbon dioxide should also be
8.1 Nitrogen Carrier Gas shall consist of nitrogen. The
minimized to avoid damage to the sensor through reaction in
carrier gas shall be dry and contain not more than 5 ppm of
some sensor types.
oxygen. If catalysts or other oxygen absorbers are employed, a
higher oxygen level may be found to be acceptable. If other
7. Apparatus
gases are needed to be included in this nitrogen to allow
7.1 Oxygen Gas Transmission Apparatus, with the follow-
catalysts to function they may be incorporated up to 5%.
ing:
8.2 Oxygen Test Gas shall be dry and contain not less than
7.1.1 Diffusion Cell shall consist of two metal halves,
99% oxygen (except as provided in 13.8).
which, when closed upon the test specimen, will accurately
define a circular area. The volume enclosed by each cell half,
8.3 Sealing Grease—For some instrument types, a vacuum
when clamped, is not critical; it should be small enough to
or stopcock grease may be required to seal the specimen film
allow for rapid gas exchange, but not so small that an in the diffusion cell.
unsupported film which happens to sag or bulge will contact
8.4 Water for Humidification—For humidification of the
the top or bottom of the cell. The diffusion cell shall be
carrier and permeant gas streams, ultra-high purity water is
provided with a thermometer well for measuring temperature.
required for some instrument types to prevent plugging of the
7.1.1.1 O-Ring—Various designs may be included in the
humidification system. This water should have a resistivity of
diffusion cell design. Some systems may require vacuum
at least 18 MΩ.An example of a suitable type is high-pressure
greasetoformaproperseal.Thedesignwilldefinethetestarea
liquid chromatography (HPLC) water.
of the film as it is tested.
7.1.1.2 Diffusion Cell Pneumatic Fittings—The diffusion
9. Precautions
cell shall incorporate suitable fittings for the introduction and
9.1 Temperature and relative humidity are critical param-
exhaust of gases without significant loss or leakage.
eters affecting the measurement of O GTR. Careful tempera-
7.1.1.3 It is desirable to thermostatically control the diffu-
ture and relative humidity control can help to minimize
sion cell.Asimple heating or heating/cooling system regulated
variations due to environmental fluctuations. During testing,
to 60.5°C, is adequate for this purpose. A thermistor sensor
thetemperatureshallbemonitoredtothenearest0.5°Candthe
andanappropriatecontrolcircuitwillservetoregulatethecell
relative humidity to the nearest 0.5 percent. The average
temperature unless measurements are being made close to
conditions and range of conditions experienced during the test
ambient temperature. In this case, it is desirable to provide
period shall both be reported.
cooling capability to remove some of the heat.
7.1.1.4 Experience has shown that arrangements using mul- 9.2 The sensor may require a relatively long time to
tiple diffusion cells are a practical way to increase the number stabilize to a low reading characteristic of a good barrier after
of measurements that can be obtained from a single sensor. it has been used to test a poor barrier such as low-density
F2622 − 08 (2013)
polyethylene. For this reason, materials of comparable gas 13.2.3 Specimen Preparation—The size of the specimen
transmission qualities should be tested together. obviously depends on the diffusion cell design. The sample is
placed carefully in the diffusion cell taking care to avoid
9.3 Back diffusion of air into the unit is undesirable. Care
wrinkles and creases. Clamp the halves of the cell together
should therefore be taken to ensure that there is a flow of
tightly.
nitrogen through the system at all times. This flow can be
13.2.4 Purging the System—Allow the gases to flow to
lowered when the instrument is not being used.
purge the system of ambient air before taking any measure-
9.4 Elevated temperatures can be used to hasten specimen
ments
outgassing, provided that the treatment does not alter the basic
13.3 Thefollowingthreeflowalternativeconfigurationsfor
structure of the specimen (crystallinity, density, and so forth).
thecarriergasaremadeusingvariousvalvesandcontrols.The
This can be accomplished by the use of the heaters in the
oxygen transmission rate in the carrier gas is measured in each
diffusion cells.
configuration. Typically, the background oxygen transmission
10. Sampling
rate levels are measured first, followed by the measured level
of oxygen transmission rate through the film.
10.1 The sampling units used for the determination of
13.3.1 Background Gas Cylinder Oxygen Transmission
O GTR shall be representative of the quantity of product for
Rate—The gas is flowed directly from the carrier gas source,
which the data are required, in accordance with Practice
through an oxygen reducing catalyst or other oxygen absorber,
D1898. Care shall be taken to ensure that samples are repre-
if desired, and then to the sensor.
sentativeofconditionsacrossthewidthandalongthelengthof
13.3.2 Background Diffusion Cell Oxygen Transmission
a roll of film.
Rate—A stream of carrier gas is directed through the upper
11. Test Specimens
(test gas) side of the diffusion cell) and another stream flows
through the lower (carrier gas) side of the diffusion cell
11.1 Test specimens shall be representative of the material
chambers. The oxygen transmission rate going through the
being tested and shall be free of defects, including wrinkles,
carrier side of the cell is measured.
creases, and pinholes, unless these are a characteristic of the
material being tested. 13.3.3 Measured Diffusion Cell Oxygen Transmission
Rate—The carrier gas is directed to flow through the carrier
11.2 Average thickness shall be determined to the nearest
side of the cell while oxygen (in whatever concentration is
2.5µm(0.0001in.),usingacalibrateddialgage(orequivalent)
desired) is directed through the oxygen (test gas) side of the
ataminimumoffivepointsdistributedovertheentiretestarea.
diffusion cell and then to the sensor.
Maximum, minimum, and average values shall be recorded. If
this measurement may damage the specimen, it can be done 13.4 Temperature shall be obtained by monitoring the tem-
after permeation has been tested.
perature as closely as possible to the specimen.
11.3 Ifthetestspecimenisofanasymmetricalconstruction,
13.5 Standby and Shutoff Procedures—Followthemanufac-
the two surfaces shall be marked by appropriate distinguishing
turer’s instructions in the instrument manual for putting the
marks and the orientation of the test specimen in the diffusion
instrumentintostandbymodewhenthesystemwillnotbeused
cell shall be reported (for example, “side II was mounted
for an extended period.
facing the oxygen (test gas) side of the diffusion cell”).
13.6 Tests in a Moist Environment—Thistestmethodcanbe
conducted with test and carrier gases at any controlled tem-
12. Conditioning
perature and relative humidity. Provision to control and moni-
12.1 After the sample has been mounted in the diffusion
tor environmental conditions must be made and validated.
cell, a sufficient length of time must be allowed for the film to
Designdetailstoaccomplishtemperatureandhumiditycontrol
reach equilibrium. No conditioning prior to mounting the film
are beyond t
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.