ASTM F2338-03
(Test Method)Standard Test Method for Nondestructive Detection of Leaks in Packages by Vacuum Decay Method
Standard Test Method for Nondestructive Detection of Leaks in Packages by Vacuum Decay Method
SCOPE
1.1 Test PackagesPackages that can be nondestructively evaluated by this test method include:
1.1.1 Rigid and semi-rigid non-lidded trays.
1.1.2 Trays or cups sealed with porous barrier lidding material.
1.2 Leaks DetectedThis test method is capable of detecting package leaks using an absolute or differential pressure transducer leak detector. The sensitivity of a test is a function of the sensitivity of the transducer, the package design, the design of the package test fixture, and critical test parameters of time and pressure. Types and sizes of leaks that may be detected for various package systems, as well as test sensitivities are described below. These data are based on precision and bias confirmation studies.
1.2.1 Trays or Cups (Non-lidded)Hole or crack defects in the wall of the tray/cup of at least 50 m in diameter can be detected at a Target Vacuum of 4104 Pa (400 mbar) using an absolute pressure transducer test instrument.
1.2.2 Trays Sealed with Porous Barrier Lidding MaterialHole or crack defects in the wall of the tray/cup of at least 100 m in diameter can be detected. Channel defects in the seal area (made using wires of 125 m in diameter) can be detected. Severe seal bonding defects in both continuous adhesive and dot matrix adhesive package systems can be detected. Slightly incomplete dot matrix adhesive bonding defects can also be detected. All porous barrier lidding material packages were tested at a Target Vacuum of 4104 Pa (400 mbar) using an absolute pressure transducer test instrument. Using a calibrated volumetric airflow meter, the sensitivity of the test for porous lidded packages is shown to be approximately 10-2 Pam3s-1.
1.3 Test ResultsThe test results are qualitative (Accept/Reject). Acceptance criteria for test results are established from quantitative baseline vacuum decay measurements obtained from control, non-leaking packages.
1.4 Standard Value UnitsThe values used in this test method are stated in SI units and are to be regarded as standard units. Values 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.
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Designation: F 2338 – 03
Standard Test Method for
Nondestructive Detection of Leaks in Packages by Vacuum
Decay Method
This standard is issued under the fixed designation F 2338; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope 1.5 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
1.1 Test Packages—Packages that can be nondestructively
responsibility of the user of this standard to establish appro-
evaluated by this test method include:
priate safety and health practices and determine the applica-
1.1.1 Rigid and semi-rigid non-lidded trays.
bility of regulatory limitations prior to use.
1.1.2 Trays or cups sealed with porous barrier lidding
material.
2. Referenced Documents
1.2 Leaks Detected—This test method is capable of detect-
2.1 ASTM Standards:
ing package leaks using an absolute or differential pressure
D 996 Terminology of Packaging and Distribution
transducer leak detector. The sensitivity of a test is a function
E 691 Practice for Conducting an Interlaboratory Study to
of the sensitivity of the transducer, the package design, the
Determine the Precision of a Test Method
design of the package test fixture, and critical test parameters
F 17 Terminology Relating to Flexible Barrier Materials
of time and pressure. Types and sizes of leaks that may be
F 1327 Terminology Relating to Barrier Materials for Medi-
detected for various package systems, as well as test sensitivi-
cal Packaging
ties are described below. These data are based on precision and
bias confirmation studies.
3. Terminology
1.2.1 Trays or Cups (Non-lidded)—Hole or crack defects in
3.1 Definitions—For definitions used in this test method,
the wall of the tray/cup of at least 50 μm in diameter can be
4 see Terminologies D 996, F 17, and F 1327.
detected at a Target Vacuum of 4·10 Pa (400 mbar) using an
3.2 Definitions of Terms Specific to This Standard:
absolute pressure transducer test instrument.
3.2.1 baseline vacuum decay, n—the extent of vacuum
1.2.2 Trays Sealed with Porous Barrier Lidding Material—
change within the test chamber over time demonstrated by a
Hole or crack defects in the wall of the tray/cup of at least 100
control, non-leaking package.
μm in diameter can be detected. Channel defects in the seal
3.2.2 control, non-leaking packages, n—packages without
area (made using wires of 125 μm in diameter) can be detected.
defects and properly sealed according to manufacturer’s speci-
Severe seal bonding defects in both continuous adhesive and
fications with non-defective lidding materials.
dot matrix adhesive package systems can be detected. Slightly
3.2.3 semi-rigid trays or cups, n—trays made of material
incomplete dot matrix adhesive bonding defects can also be
that retain shape upon deflection. For example, thermoformed
detected. All porous barrier lidding material packages were
4 PETE or PETG trays are considered semi-rigid trays.
tested at a Target Vacuum of 4·10 Pa (400 mbar) using an
3.2.4 spotty or mottled seals, n—an incomplete adhesive
absolute pressure transducer test instrument. Using a calibrated
bond made between a package tray or cup and porous lidding
volumetric airflow meter, the sensitivity of the test for porous
-2 3 -1 material that can be visibly identified by a distinctive pattern of
lidded packages is shown to be approximately 10 Pa·m ·s .
dots, spotting or mottling on the tray sealing surface after the
1.3 Test Results—The test results are qualitative (Accept/
lid is removed.
Reject). Acceptance criteria for test results are established from
3.2.5 volumetric airflow meter, n—a calibration tool that
quantitative baseline vacuum decay measurements obtained
can be used to provide an artificial leak of known volumetric
from control, non-leaking packages.
airflow rate into the test chamber for verification of instrument
1.4 Standard Value Units—The values used in this test
sensitivity. Airflow meters should be calibrated to NIST
method are stated in SI units and are to be regarded as standard
standards. The operational range of the meter should reflect the
units. Values in parentheses are for information only.
desired limit of sensitivity for the intended leak test.
1 2
This test method is under the jurisdiction of ASTM Committee F02 on Flexible For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Barrier Materials and is the direct responsibility of Subcommittee F02.60 on contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Medical Device Packaging. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved Nov. 1, 2003. Published January 2004. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
F2338–03
3.3 Definitions of Test Cycle and Critical Parameters block off any porous barrier surface of the package during the
Terms—For terms and abbreviations relating to the test cycle test to prevent a rapid loss of chamber vacuum resulting
and the critical parameters for establishing accept/reject limits, primarily from gas migration through the porous surface. Leak
see Annex A1. detection is based solely on the ability to detect the change in
pressure inside the test chamber as a result of air egress from
4. Summary of Test Method
the properly masked package when challenged with vacuum
4.1 The test package is placed in a test chamber to which
conditions.
vacuum is applied. The chamber is then isolated from the
5.3 This test is a useful research tool for optimization of
vacuum source and an absolute or differential vacuum trans-
package sealing parameters and for comparative evaluation of
ducer is used to monitor the test chamber for both the level of
various package and materials. This test method is also
vacuum, as well as the change in vacuum over time. Vacuum
applicable to production settings as it is rapid, non-invasive
decay, or rise in chamber pressure, is a result of package
and non-destructive, making it useful for either 100 % on-line
headspace gas being drawn out of the package through any
testing or to perform tests on a statistical sampling from the
leaks present, plus background noise. Leak detection requires
production operation.
vacuum decay in excess of the background noise level.
5.4 Leak test results that exceed the permissible limits for
Background noise vacuum decay may result from package
the vacuum decay test are indicated by audible or visual signal
expansion when exposed to vacuum, or from residual gases
responses, or both.
inherent in the test chamber or test system lines.
4.2 Porous barrier lidded tray or cup packages are tested for
6. Apparatus
leaks located in the tray or cup, and at the lidding material/tray
6.1 Vacuum Decay Leak Detection Apparatus—All vacuum
seal junction. Leaks in the porous lidding material itself cannot
decay test systems include a test chamber with a lower
be detected. When testing such packages, steps are taken to
compartment (lower tooling) designed to nest the test package,
physically mask or block the porous barrier surface to prevent
and an upper lid (top tooling) for closing the test chamber. Fig.
the migration of package gas through the porous lid. These
1 illustrates a test chamber designed for testing packages with
steps may require some sample preparation, depending on the
porous barrier lidding material. The test fixture upper lid
masking approach required, but must be nondestructive and
consists of a flexible bladder to mask the package’s porous
noninvasive. Vacuum decay from porous barrier lidded pack-
barrier during the test cycle. The test chamber is connected to
ages may potentially include background noise from gas
the vacuum decay test system. This system includes a vacuum
trapped between the lidding material and the masking surface,
source for establishing vacuum within the chamber at the
or from transverse gas flow through the porous barrier material
beginning of the test cycle, and an absolute or differential
itself at the lid/tray seal junction.
pressure transducer for monitoring the level of vacuum as well
4.3 The sensitivity of a vacuum decay leak test is a function
as the pressure change as a function of time during the test
of several factors. Smaller leaks can be detected with more
cycle. A calibrated volumetric airflow meter may be placed
sensitive pressure transducers, and with longer test times. Also,
in-line with the test system for verifying the sensitivity of a
pressure changes can be more readily detected with smaller
leak test.
void volumes between the test package and the test chamber,
6.2 Tray Nest or Lower Tooling—The bottom half of the test
and with smaller test system line volumes. Steps to reduce
chamber is dimensionally designed to closely nest the test
background noise can also improve sensitivity. For example,
package, while still allowing for easy gas flow around the test
for porous barrier lidded packages, more effective masking
package. Without ready gas flow around the package, leakage
techniques will minimize background noise.
sites can be blocked. Conversely, the larger the gap between
NOTE 1—Further information on the “Leak Test Theory” may be found
the test chamber and the test package, the less sensitive the leak
in Annex A1.
test, as vacuum decay from package leakage will be minimized
in a larger net test chamber volume.
5. Significance and Use
6.3 Upper Lid or Upper Tooling—The upper lid is designed
5.1 Leaks in medical device, pharmaceutical and food
to tightly seal the closed test chamber during the vacuum cycle.
packages may result in the ingress of unwanted gases (most
6.4 Mask or Block—The porous barrier lidding material of
commonly oxygen), harmful microbiological or particulate
packages must be masked or blocked during testing to mini-
contaminants. Package leaks may appear as imperfections in
mize egress of air from the package through the lidding.
the tray or cup, or in the lid materials themselves (holes or
Various masking techniques may be used, including a test
cracks), or they may be found at the juncture of the seal made
chamber designed with a flexible bladder in the upper tooling
between the tray and the lid material (channel defects, tears,
(refer to Fig. 1).
spotty or mottled seals). The ability to detect leaks is necessary
6.5 Volumetric Airflow Meter—An adjustable volumetric
to ensure consistency and integrity of packages.
airflow meter is placed in-line with the test chamber to
5.2 After initial set-up and calibration, the operations of
introduce an artificial leak of variable size. It is recommended
individual tests may be semi-automatic, automatic or manual.
that an airflow meter be used to verify the sensitivity of the leak
The test method permits the non-destructive detection of leaks
test parameters.
not visibly detectable. The test method does not require the
introduction of any extraneous materials or substances, such as
NOTE 2—Refer to Annex A2 for further information about the use of a
dyes or gases. However, it is important to physically mask or volumetric airflow meter for verifying leak test sensitivity.
F2338–03
FIG. 1 Schematic of Fixture and Test Package
7. Hazards eters. Control packages are to be made from the same materials
and according to the same design as the test units.
7.1 As the test chamber is closed, it may present pinch-point
hazards.
NOTE 4—Refer to Annex A2 for information on critical test parameter
selection.
8. Preparation of Apparatus
9.4 After critical test parameters have been selected, qualify
8.1 The test apparatus must be started, warmed-up, and
the ability of the test to reliably differentiate between known
made ready according to the manufacturer’s specifications.
non-leaking and defective packages.
Utilities required for instrument operation include electrical
9.5 Determine the sensitivity of the test using control
power and a supply of dry, non-lubricated compressed air,
non-leaking test packages and a calibrated volumetric airflow
according to manufacturer’s specifications.
meter.
NOTE 5—Refer to Annex A2 for information about test sensitivity
9. Calibration and Standardization
verification procedures.
9.1 Before test measurements are made, the apparatus must
9.6 Test qualification (see 9.4) and test sensitivity verifica-
be calibrated. The pressure transducers, the vacuum source
tion (see 9.5) are to be conducted frequently, typically at least
pressure gage, and the adjustable volumetric airflow meter
one or more times a day, preferably at the beginning of every
must all be calibrated according to the manufacturer’s recom-
shift.
mended procedures and maintenance schedule.
9.2 Critical test parameter settings must be established for
10. Procedure
each package/test fixture combination. Parameters will vary
10.1 Select and install the appropriately sized test chamber
based on the test package geometry and any porous barrier
for the package to be tested. Make any necessary adjustments
surface’s inherent porosity.
to the chamber to ensure a sufficiently tight seal of the chamber
NOTE 3—Refer to Section 4 and Annex A1 for a description of critical
lid (upper tooling) to the lower chamber tray nest (lower
test parameters.
tooling) when the test chamber is in the closed position.
9.3 A sample population of control non-leaking packages 10.2 Verify the pressure level available at the supply source.
must be used for selecting and optimizing critical test param- Check the functionality of the vacuum source.
F2338–03
10.3 Program the test instrument with all necessary test 12.1.1 As summarized in Table 1, two populations of
parameters and accept/reject criteria. non-lidded trays representing two tray sizes were tested.
10.4 Place the assembled package into the tray nest and Defective samples contained a single hole in the tray wall of
close the test chamber. Take appropriate steps to mask or block either 50 μm or 100 μm in diameter. Two of the five larger
any porous barrier surface of the package. trays, each with a 50 μm hole, repeatedly failed to be detected
at more than one test site, while the other three trays were
NOTE 6—Inspect and clean the masking or blocking surface according
consistently identified as leaking. At the completion of the
to a regularly established routine according to the instrument manufac-
study the two suspect trays were independently reexamin
...
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