ASTM D6701-16

Standard Test Method for Determining Water Vapor Transmission Rates Through Nonwoven and Plastic Barriers

SIGNIFICANCE AND USE
5.1 The purpose of this test method is to obtain values for the water vapor transmission rate of barrier materials.  
5.2 Water vapor transmission rate is an important property of materials and can be related to shelf life; product stability, breath-ability, and wearing comfort.  
5.3 Data from this test method is suitable as a referee method of testing, provided that the purchaser and seller have agreed on sampling procedures, test conditions, and acceptance criteria.
SCOPE
1.1 This test method covers a procedure for determining the rate of water vapor transmission ranging between 500 to 100,000 g/m2day through nonwoven and plastic barrier materials. The method is applicable to films, barriers consisting of single or multilayer synthetic or natural polymers, nonwoven fabric, and nonwoven fabrics coated with films up to 3 mm (0.1 in.) in thickness.  
1.2 This test method provides for the determination of (1) water vapor transmission rate (WVTR), and (2) the permeance to water vapor.  
1.3 The values stated in metric units are to be regarded as the standard. The acceptable units for water vapor transmission rate are usually g/m2day.  
1.4 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

• Status: Historical
• Publication Date: 31-Jul-2016
• ICS: 59.080.30 - Textile fabrics
• ICS: 83.080.01 - Plastics in general
• Technical Committee: F02 - Primary Barrier Packaging
• Drafting Committee: F02.10 - Permeation

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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: D6701 − 16
Standard Test Method for
Determining Water Vapor Transmission Rates Through
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Nonwoven and Plastic Barriers
This standard is issued under the fixed designation D6701; 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.
1. Scope F1249 Test Method for Water Vapor Transmission Rate
Through Plastic Film and Sheeting Using a Modulated
1.1 This test method covers a procedure for determining the
Infrared Sensor
rate of water vapor transmission ranging between 500 to
2
100,000 g/m day through nonwoven and plastic barrier mate-
3. Terminology
rials. The method is applicable to films, barriers consisting of
single or multilayer synthetic or natural polymers, nonwoven
3.1 Definitions:
fabric,andnonwovenfabricscoatedwithfilmsupto3mm(0.1
3.1.1 water vapor permeability coeffıcient, n—the ratio of
in.) in thickness.
the permeance and the thickness.
1.2 This test method provides for the determination of (1)
3.1.1.1 Discussion—This quantity should not be used unless
water vapor transmission rate (WVTR), and (2) the permeance
the relationship between thickness and permeance has been
to water vapor.
verified in tests using several thickness’ of the material. The
water vapor permeability is meaningful only for homogeneous
1.3 The values stated in metric units are to be regarded as
materials, in which case it is a property characteristic of bulk
the standard.The acceptable units for water vapor transmission
2
material. An accepted unit of water vapor permeability is the
rate are usually g/m day.
2
metric perm centimeter, or 1g per m per day per mm Hg-cm of
1.4 This standard does not purport to address all of the
2
thickness. The SI unit is the mol/m -s-Pa-mm.
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
3.1.2 water vapor permeance, n—the ratio of a barrier’s
priate safety and health practices and determine the applica-
water vapor transmission rate to the vapor pressure difference
bility of regulatory limitations prior to use.
between the two surfaces.
3.1.2.1 Discussion—An accepted unit of water vapor per-
2. Referenced Documents
2
meance is the metric perm, or 1 g/m per day per mm Hg. The
2
2
2.1 ASTM Standards:
SI unit is the mol/m -s-Pa. Since the water vapor permeance of
D123 Terminology Relating to Textiles
a specimen is generally a function of relative humidity and
3
D1898 Practice for Sampling of Plastics (Withdrawn 1998)
temperature, therefore those conditions must be stated.
D4204 Practice for Preparing Plastic Film Specimens for a
3.1.3 water vapor transmission rate (WVTR), n—thesteady-
Round-Robin Study
state time rate of water vapor flow through unit area of a
D5729 Test Method for Thickness of Nonwoven Fabrics
specimen, normal to the surfaces under specific conditions of
3
(Withdrawn 2008)
temperature and humidity at each surface.
E691 Practice for Conducting an Interlaboratory Study to
3.1.3.1 Discussion—A common practice accepted unit of
Determine the Precision of a Test Method
2
water vapor transmission rate is metric g/m per day. The test
conditions of relative humidity and temperature where the
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This test method is under the jurisdiction ofASTM Committee F02 on Flexible driving force is the difference in relative humidity across the
Barrier Packaging and is the direct responsibility of Subcommittee F02.10 on
specimen must be stated.
Permeation.
Current edition approved Aug. 1, 2016. Published September 2016. Originally
4. Summary of Test Method
approved in 2001. Last previous edition approved in 2001 as D6701–01, which was
withdrawn in October 2008 and reinstated in August 2016.
2
4.1 Adry chamber, guard film, and a wet chamber make up
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
a diffusion cell in which the test film is sealed. A first test is
Standards volume information, refer to the standard’s Document Summary page on
madeofthewatervaportransmissionrateoftheguardfilmand
the ASTM website.
3
air gap between an evaporator assembly that generates 100 %
The last approved version of this historical standard is referenced on
www.astm.org. relative humidity. A sensor produces an electrical signal, the
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D6701 − 16
FIG. 1 Typical Cell Cross Section
amplitude of which is proportional to water vapor concentra- 6. Apparatus
tion. The electrical sig
...