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download astm f1249 pdfWHITE PAPER
ASTM E96 VS. F1249
Modern barriers require more sensitive and accurate
test methods. Does E96 stand up to the test?
May 16, 2017
Abstract and Introduction
Water Vapor Permeation, ASTM E96
ASTM E96 and ASTM F1249
ASTM F1249 continued
Key Benefits of F1249, Conclusion
CONTROLLING MOISTURE IS KEY
TO PRODUCT QUALITY
ASTM International (formerly known as the American Society
for Testing Materials) is recognized as a global leader in the
development of international voluntary consensus standards.
ASTM has approved two test methods to track water vapor
transmission from materials: ASTM E96 – Water Vapor
Transmission of Materials Using Gravimetric Method (adopted in
1941), and ASTM 1249 – Water Vapor Transmission Rate Through
Plastic Film Sheeting Using a Modulated Infrared Sensor
(adopted in 1990). This white paper explores these methods to
determine which provides better water vapor transmission rate
(WVTR) test results to meet today’s packaging needs.
Product packaging plays an important role in protecting product
quality for the duration of its desired shelf life and provides
packaged product stability. Controlling moisture into and out of
packaging is key to ensuring products meet increasingly longer
shelf lives, and prevents products from drying out or becoming
soggy before they are consumed.
Packaging plays an important role in
protecting product quality.
At the same time, manufacturers seek to avoid the expense of
over-packaging their products by finding a material that meets
their needs without employing overly expensive packaging
solutions. In today’s global economy where products are
often manufactured and shipped to different regions that can
have widely varying environmental conditions, selecting the
right packaging material often involves weighing economic,
technical and geographic factors.
Package engineers need precise, repeatable and sensitive WVTR
test results that prevent both over-packaging expenses and
costly product shelf life failures. They also need testing methods
that can produce accurate results quickly, without adversely
affecting product development or time-to-market schedules.
Manufacturers seek to avoid the expense of over-packaging
their products by finding a material that meets their needs
without being overly expensive.
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BOTH TEMPERATURE AND RH
Water Vapor Permeation
When considering packaging materials, it’s important to
remember that all materials permeate. Measuring permeation
in various packaging materials is useful because a number of
factors can affect shelf life, resulting in spoilage and/or a bad
brand experience by consumers.
In some materials, RH can also affect the permeation rate of
gases. Proper RH generation and measurement are necessary
to obtain accurate permeation results. To ensure proper testing
conditions, RH must always be measured at the film.
Effects of Humidity on O₂ Transmission Rate of Materials
(10 x 10 ^11 ml x cm/cm2 x sec x cmHg ) analyzed at 25°C Source: K. Cooksey, Important factors
for selecting food packaging materials based on permeability.
The following equation describes units of permeation:
Known as the gravimetric or cup test method, ASTM E96 (E96) is
used to determine WVTR through a barrier film or sheet. The two
test procedures associated with this method are the desiccant
method and the water method.
Permeation is affected by temperature and relative humidity
(RH). Typically, permeation rates change 5% to 7% per degree
C. Consequently, precise control of both factors is critical for
During the gravimetric test, a cup or dish is filled with desiccant
or water, placed in a temperature and humidity controlled
chamber, and weighed periodically. Depending on the barrier
properties and sample thickness, the gravimetric method could
require a test time of one day to two to three weeks (or longer).
Enough data points should be collected until weight gain (or
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F1249 AUTOMATES THE EXACT
CONDITIONS REQUIRED FOR TESTING